/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright 2020 Joyent, Inc.
 * Copyright 2015 Garrett D'Amore <garrett@damore.org>
 * Copyright 2020 RackTop Systems, Inc.
 * Copyright 2026 Oxide Computer Company
 */

/*
 * MAC Services Module
 *
 * The GLDv3 framework locking -  The MAC layer
 * --------------------------------------------
 *
 * The MAC layer is central to the GLD framework and can provide the locking
 * framework needed for itself and for the use of MAC clients. MAC end points
 * are fairly disjoint and don't share a lot of state. So a coarse grained
 * multi-threading scheme is to single thread all create/modify/delete or set
 * type of control operations on a per mac end point while allowing data threads
 * concurrently.
 *
 * Control operations (set) that modify a mac end point are always serialized on
 * a per mac end point basis, We have at most 1 such thread per mac end point
 * at a time.
 *
 * All other operations that are not serialized are essentially multi-threaded.
 * For example a control operation (get) like getting statistics which may not
 * care about reading values atomically or data threads sending or receiving
 * data. Mostly these type of operations don't modify the control state. Any
 * state these operations care about are protected using traditional locks.
 *
 * The perimeter only serializes serial operations. It does not imply there
 * aren't any other concurrent operations. However a serialized operation may
 * sometimes need to make sure it is the only thread. In this case it needs
 * to use reference counting mechanisms to cv_wait until any current data
 * threads are done.
 *
 * The mac layer itself does not hold any locks across a call to another layer.
 * The perimeter is however held across a down call to the driver to make the
 * whole control operation atomic with respect to other control operations.
 * Also the data path and get type control operations may proceed concurrently.
 * These operations synchronize with the single serial operation on a given mac
 * end point using regular locks. The perimeter ensures that conflicting
 * operations like say a mac_multicast_add and a mac_multicast_remove on the
 * same mac end point don't interfere with each other and also ensures that the
 * changes in the mac layer and the call to the underlying driver to say add a
 * multicast address are done atomically without interference from a thread
 * trying to delete the same address.
 *
 * For example, consider
 * mac_multicst_add()
 * {
 *      mac_perimeter_enter();  serialize all control operations
 *
 *      grab list lock          protect against access by data threads
 *      add to list
 *      drop list lock
 *
 *      call driver's mi_multicst
 *
 *      mac_perimeter_exit();
 * }
 *
 * To lessen the number of serialization locks and simplify the lock hierarchy,
 * we serialize all the control operations on a per mac end point by using a
 * single serialization lock called the perimeter. We allow recursive entry into
 * the perimeter to facilitate use of this mechanism by both the mac client and
 * the MAC layer itself.
 *
 * MAC client means an entity that does an operation on a mac handle
 * obtained from a mac_open/mac_client_open. Similarly MAC driver means
 * an entity that does an operation on a mac handle obtained from a
 * mac_register. An entity could be both client and driver but on different
 * handles eg. aggr. and should only make the corresponding mac interface calls
 * i.e. mac driver interface or mac client interface as appropriate for that
 * mac handle.
 *
 * General rules.
 * -------------
 *
 * R1. The lock order of upcall threads is natually opposite to downcall
 * threads. Hence upcalls must not hold any locks across layers for fear of
 * recursive lock enter and lock order violation. This applies to all layers.
 *
 * R2. The perimeter is just another lock. Since it is held in the down
 * direction, acquiring the perimeter in an upcall is prohibited as it would
 * cause a deadlock. This applies to all layers.
 *
 * Note that upcalls that need to grab the mac perimeter (for example
 * mac_notify upcalls) can still achieve that by posting the request to a
 * thread, which can then grab all the required perimeters and locks in the
 * right global order. Note that in the above example the mac layer iself
 * won't grab the mac perimeter in the mac_notify upcall, instead the upcall
 * to the client must do that. Please see the aggr code for an example.
 *
 * MAC client rules
 * ----------------
 *
 * R3. A MAC client may use the MAC provided perimeter facility to serialize
 * control operations on a per mac end point. It does this by by acquring
 * and holding the perimeter across a sequence of calls to the mac layer.
 * This ensures atomicity across the entire block of mac calls. In this
 * model the MAC client must not hold any client locks across the calls to
 * the mac layer. This model is the preferred solution.
 *
 * R4. However if a MAC client has a lot of global state across all mac end
 * points the per mac end point serialization may not be sufficient. In this
 * case the client may choose to use global locks or use its own serialization.
 * To avoid deadlocks, these client layer locks held across the mac calls
 * in the control path must never be acquired by the data path for the reason
 * mentioned below.
 *
 * (Assume that a control operation that holds a client lock blocks in the
 * mac layer waiting for upcall reference counts to drop to zero. If an upcall
 * data thread that holds this reference count, tries to acquire the same
 * client lock subsequently it will deadlock).
 *
 * A MAC client may follow either the R3 model or the R4 model, but can't
 * mix both. In the former, the hierarchy is Perim -> client locks, but in
 * the latter it is client locks -> Perim.
 *
 * R5. MAC clients must make MAC calls (excluding data calls) in a cv_wait'able
 * context since they may block while trying to acquire the perimeter.
 * In addition some calls may block waiting for upcall refcnts to come down to
 * zero.
 *
 * R6. MAC clients must make sure that they are single threaded and all threads
 * from the top (in particular data threads) have finished before calling
 * mac_client_close. The MAC framework does not track the number of client
 * threads using the mac client handle. Also mac clients must make sure
 * they have undone all the control operations before calling mac_client_close.
 * For example mac_unicast_remove/mac_multicast_remove to undo the corresponding
 * mac_unicast_add/mac_multicast_add.
 *
 * MAC framework rules
 * -------------------
 *
 * R7. The mac layer itself must not hold any mac layer locks (except the mac
 * perimeter) across a call to any other layer from the mac layer. The call to
 * any other layer could be via mi_* entry points, classifier entry points into
 * the driver or via upcall pointers into layers above. The mac perimeter may
 * be acquired or held only in the down direction, for e.g. when calling into
 * a mi_* driver enty point to provide atomicity of the operation.
 *
 * R8. Since it is not guaranteed (see R14) that drivers won't hold locks across
 * mac driver interfaces, the MAC layer must provide a cut out for control
 * interfaces like upcall notifications and start them in a separate thread.
 *
 * R9. Note that locking order also implies a plumbing order. For example
 * VNICs are allowed to be created over aggrs, but not vice-versa. An attempt
 * to plumb in any other order must be failed at mac_open time, otherwise it
 * could lead to deadlocks due to inverse locking order.
 *
 * R10. MAC driver interfaces must not block since the driver could call them
 * in interrupt context.
 *
 * R11. Walkers must preferably not hold any locks while calling walker
 * callbacks. Instead these can operate on reference counts. In simple
 * callbacks it may be ok to hold a lock and call the callbacks, but this is
 * harder to maintain in the general case of arbitrary callbacks.
 *
 * R12. The MAC layer must protect upcall notification callbacks using reference
 * counts rather than holding locks across the callbacks.
 *
 * R13. Given the variety of drivers, it is preferable if the MAC layer can make
 * sure that any pointers (such as mac ring pointers) it passes to the driver
 * remain valid until mac unregister time. Currently the mac layer achieves
 * this by using generation numbers for rings and freeing the mac rings only
 * at unregister time.  The MAC layer must provide a layer of indirection and
 * must not expose underlying driver rings or driver data structures/pointers
 * directly to MAC clients.
 *
 * MAC driver rules
 * ----------------
 *
 * R14. It would be preferable if MAC drivers don't hold any locks across any
 * mac call. However at a minimum they must not hold any locks across data
 * upcalls. They must also make sure that all references to mac data structures
 * are cleaned up and that it is single threaded at mac_unregister time.
 *
 * R15. MAC driver interfaces don't block and so the action may be done
 * asynchronously in a separate thread as for example handling notifications.
 * The driver must not assume that the action is complete when the call
 * returns.
 *
 * R16. Drivers must maintain a generation number per Rx ring, and pass it
 * back to mac_rx_ring(); They are expected to increment the generation
 * number whenever the ring's stop routine is invoked.
 * See comments in mac_rx_ring();
 *
 * R17 Similarly mi_stop is another synchronization point and the driver must
 * ensure that all upcalls are done and there won't be any future upcall
 * before returning from mi_stop.
 *
 * R18. The driver may assume that all set/modify control operations via
 * the mi_* entry points are single threaded on a per mac end point.
 *
 * Lock and Perimeter hierarchy scenarios
 * ---------------------------------------
 *
 * i_mac_impl_lock -> mi_rw_lock -> srs_lock -> s_ring_lock[i_mac_tx_srs_notify]
 *
 * ft_lock -> fe_lock [mac_flow_lookup]
 *
 * mi_rw_lock -> fe_lock [mac_bcast_send]
 *
 * srs_lock -> mac_bw_lock [mac_rx_srs_drain_bw]
 *
 * cpu_lock -> mac_srs_g_lock -> srs_lock -> s_ring_lock [mac_walk_srs_and_bind]
 *
 * i_dls_devnet_lock -> mac layer locks [dls_devnet_rename]
 *
 * Perimeters are ordered P1 -> P2 -> P3 from top to bottom in order of mac
 * client to driver. In the case of clients that explictly use the mac provided
 * perimeter mechanism for its serialization, the hierarchy is
 * Perimeter -> mac layer locks, since the client never holds any locks across
 * the mac calls. In the case of clients that use its own locks the hierarchy
 * is Client locks -> Mac Perim -> Mac layer locks. The client never explicitly
 * calls mac_perim_enter/exit in this case.
 *
 * Subflow creation rules
 * ---------------------------
 * o In case of a user specified cpulist present on underlying link and flows,
 * the flows cpulist must be a subset of the underlying link.
 * o In case of a user specified fanout mode present on link and flow, the
 * subflow fanout count has to be less than or equal to that of the
 * underlying link. The cpu-bindings for the subflows will be a subset of
 * the underlying link.
 * o In case if no cpulist specified on both underlying link and flow, the
 * underlying link relies on a  MAC tunable to provide out of box fanout.
 * The subflow will have no cpulist (the subflow will be unbound)
 * o In case if no cpulist is specified on the underlying link, a subflow can
 * carry  either a user-specified cpulist or fanout count. The cpu-bindings
 * for the subflow will not adhere to restriction that they need to be subset
 * of the underlying link.
 * o In case where the underlying link is carrying either a user specified
 * cpulist or fanout mode and for a unspecified subflow, the subflow will be
 * created unbound.
 * o While creating unbound subflows, bandwidth mode changes attempt to
 * figure a right fanout count. In such cases the fanout count will override
 * the unbound cpu-binding behavior.
 * o In addition to this, while cycling between flow and link properties, we
 * impose a restriction that if a link property has a subflow with
 * user-specified attributes, we will not allow changing the link property.
 * The administrator needs to reset all the user specified properties for the
 * subflows before attempting a link property change.
 * Some of the above rules can be overridden by specifying additional command
 * line options while creating or modifying link or subflow properties.
 *
 * Datapath
 * --------
 *
 * For information on the datapath, the world of soft rings, hardware rings, how
 * it is structured, and the path of an mblk_t between a driver and a mac
 * client, see mac_sched.c.
 */

#include <sys/types.h>
#include <sys/conf.h>
#include <sys/id_space.h>
#include <sys/esunddi.h>
#include <sys/stat.h>
#include <sys/mkdev.h>
#include <sys/stream.h>
#include <sys/strsun.h>
#include <sys/strsubr.h>
#include <sys/dlpi.h>
#include <sys/list.h>
#include <sys/modhash.h>
#include <sys/mac_provider.h>
#include <sys/mac_client_impl.h>
#include <sys/mac_soft_ring.h>
#include <sys/mac_stat.h>
#include <sys/mac_impl.h>
#include <sys/mac.h>
#include <sys/dls.h>
#include <sys/dld.h>
#include <sys/modctl.h>
#include <sys/fs/dv_node.h>
#include <sys/thread.h>
#include <sys/proc.h>
#include <sys/callb.h>
#include <sys/cpuvar.h>
#include <sys/atomic.h>
#include <sys/bitmap.h>
#include <sys/sdt.h>
#include <sys/mac_flow.h>
#include <sys/ddi_intr_impl.h>
#include <sys/disp.h>
#include <sys/sdt.h>
#include <sys/vnic.h>
#include <sys/vnic_impl.h>
#include <sys/vlan.h>
#include <inet/ip.h>
#include <inet/ip6.h>
#include <sys/exacct.h>
#include <sys/exacct_impl.h>
#include <inet/nd.h>
#include <sys/ethernet.h>
#include <sys/pool.h>
#include <sys/pool_pset.h>
#include <sys/cpupart.h>
#include <inet/wifi_ioctl.h>
#include <net/wpa.h>
#include <sys/mac_ether.h>

#define IMPL_HASHSZ     67      /* prime */

kmem_cache_t            *i_mac_impl_cachep;
mod_hash_t              *i_mac_impl_hash;
krwlock_t               i_mac_impl_lock;
uint_t                  i_mac_impl_count;
static kmem_cache_t     *mac_ring_cache;
static id_space_t       *minor_ids;
static uint32_t         minor_count;
static pool_event_cb_t  mac_pool_event_reg;

/*
 * Logging stuff. Perhaps mac_logging_interval could be broken into
 * mac_flow_log_interval and mac_link_log_interval if we want to be
 * able to schedule them differently.
 */
uint_t                  mac_logging_interval;
boolean_t               mac_flow_log_enable;
boolean_t               mac_link_log_enable;
timeout_id_t            mac_logging_timer;

#define MACTYPE_KMODDIR "mac"
#define MACTYPE_HASHSZ  67
static mod_hash_t       *i_mactype_hash;
/*
 * i_mactype_lock synchronizes threads that obtain references to mactype_t
 * structures through i_mactype_getplugin().
 */
static kmutex_t         i_mactype_lock;

/*
 * mac_tx_percpu_cnt
 *
 * Number of per cpu locks per mac_client_impl_t. Used by the transmit side
 * in mac_tx to reduce lock contention. This is sized at boot time in mac_init.
 * mac_tx_percpu_cnt_max is settable in /etc/system and must be a power of 2.
 * Per cpu locks may be disabled by setting mac_tx_percpu_cnt_max to 1.
 */
int mac_tx_percpu_cnt;
int mac_tx_percpu_cnt_max = 128;

/*
 * Call back functions for the bridge module.  These are guaranteed to be valid
 * when holding a reference on a link or when holding mip->mi_bridge_lock and
 * mi_bridge_link is non-NULL.
 */
mac_bridge_tx_t mac_bridge_tx_cb;
mac_bridge_rx_t mac_bridge_rx_cb;
mac_bridge_ref_t mac_bridge_ref_cb;
mac_bridge_ls_t mac_bridge_ls_cb;

static int i_mac_constructor(void *, void *, int);
static void i_mac_destructor(void *, void *);
static int i_mac_ring_ctor(void *, void *, int);
static void i_mac_ring_dtor(void *, void *);
static flow_entry_t *mac_rx_classify(mac_impl_t *, mac_resource_handle_t,
    mblk_t *);
void mac_tx_client_flush(mac_client_impl_t *);
void mac_tx_client_block(mac_client_impl_t *);
static void mac_rx_ring_quiesce(mac_ring_t *, uint_t);
static int mac_start_group_and_rings(mac_group_t *);
static void mac_stop_group_and_rings(mac_group_t *);
static void mac_pool_event_cb(pool_event_t, int, void *);

typedef struct netinfo_s {
        list_node_t     ni_link;
        void            *ni_record;
        int             ni_size;
        int             ni_type;
} netinfo_t;

/*
 * Module initialization functions.
 */

void
mac_init(void)
{
        mac_tx_percpu_cnt = ((boot_max_ncpus == -1) ? max_ncpus :
            boot_max_ncpus);

        /* Upper bound is mac_tx_percpu_cnt_max */
        if (mac_tx_percpu_cnt > mac_tx_percpu_cnt_max)
                mac_tx_percpu_cnt = mac_tx_percpu_cnt_max;

        if (mac_tx_percpu_cnt < 1) {
                /* Someone set max_tx_percpu_cnt_max to 0 or less */
                mac_tx_percpu_cnt = 1;
        }

        ASSERT(mac_tx_percpu_cnt >= 1);
        mac_tx_percpu_cnt = (1 << highbit(mac_tx_percpu_cnt - 1));
        /*
         * Make it of the form 2**N - 1 in the range
         * [0 .. mac_tx_percpu_cnt_max - 1]
         */
        mac_tx_percpu_cnt--;

        i_mac_impl_cachep = kmem_cache_create("mac_impl_cache",
            sizeof (mac_impl_t), 0, i_mac_constructor, i_mac_destructor,
            NULL, NULL, NULL, 0);
        ASSERT(i_mac_impl_cachep != NULL);

        mac_ring_cache = kmem_cache_create("mac_ring_cache",
            sizeof (mac_ring_t), 0, i_mac_ring_ctor, i_mac_ring_dtor, NULL,
            NULL, NULL, 0);
        ASSERT(mac_ring_cache != NULL);

        i_mac_impl_hash = mod_hash_create_extended("mac_impl_hash",
            IMPL_HASHSZ, mod_hash_null_keydtor, mod_hash_null_valdtor,
            mod_hash_bystr, NULL, mod_hash_strkey_cmp, KM_SLEEP);
        rw_init(&i_mac_impl_lock, NULL, RW_DEFAULT, NULL);

        mac_flow_init();
        mac_soft_ring_init();
        mac_bcast_init();
        mac_client_init();

        i_mac_impl_count = 0;

        i_mactype_hash = mod_hash_create_extended("mactype_hash",
            MACTYPE_HASHSZ,
            mod_hash_null_keydtor, mod_hash_null_valdtor,
            mod_hash_bystr, NULL, mod_hash_strkey_cmp, KM_SLEEP);

        /*
         * Allocate an id space to manage minor numbers. The range of the
         * space will be from MAC_MAX_MINOR+1 to MAC_PRIVATE_MINOR-1.  This
         * leaves half of the 32-bit minors available for driver private use.
         */
        minor_ids = id_space_create("mac_minor_ids", MAC_MAX_MINOR+1,
            MAC_PRIVATE_MINOR-1);
        ASSERT(minor_ids != NULL);
        minor_count = 0;

        /* Let's default to 20 seconds */
        mac_logging_interval = 20;
        mac_flow_log_enable = B_FALSE;
        mac_link_log_enable = B_FALSE;
        mac_logging_timer = NULL;

        /* Register to be notified of noteworthy pools events */
        mac_pool_event_reg.pec_func =  mac_pool_event_cb;
        mac_pool_event_reg.pec_arg = NULL;
        pool_event_cb_register(&mac_pool_event_reg);
}

int
mac_fini(void)
{

        if (i_mac_impl_count > 0 || minor_count > 0)
                return (EBUSY);

        pool_event_cb_unregister(&mac_pool_event_reg);

        id_space_destroy(minor_ids);
        mac_flow_fini();

        mod_hash_destroy_hash(i_mac_impl_hash);
        rw_destroy(&i_mac_impl_lock);

        mac_client_fini();
        kmem_cache_destroy(mac_ring_cache);

        mod_hash_destroy_hash(i_mactype_hash);
        mac_soft_ring_finish();


        return (0);
}

/*
 * Initialize a GLDv3 driver's device ops.  A driver that manages its own ops
 * (e.g. softmac) may pass in a NULL ops argument.
 */
void
mac_init_ops(struct dev_ops *ops, const char *name)
{
        major_t major = ddi_name_to_major((char *)name);

        /*
         * By returning on error below, we are not letting the driver continue
         * in an undefined context.  The mac_register() function will faill if
         * DN_GLDV3_DRIVER isn't set.
         */
        if (major == DDI_MAJOR_T_NONE)
                return;
        LOCK_DEV_OPS(&devnamesp[major].dn_lock);
        devnamesp[major].dn_flags |= (DN_GLDV3_DRIVER | DN_NETWORK_DRIVER);
        UNLOCK_DEV_OPS(&devnamesp[major].dn_lock);
        if (ops != NULL)
                dld_init_ops(ops, name);
}

void
mac_fini_ops(struct dev_ops *ops)
{
        dld_fini_ops(ops);
}

/*ARGSUSED*/
static int
i_mac_constructor(void *buf, void *arg, int kmflag)
{
        mac_impl_t      *mip = buf;

        bzero(buf, sizeof (mac_impl_t));

        mip->mi_linkstate = LINK_STATE_UNKNOWN;

        rw_init(&mip->mi_rw_lock, NULL, RW_DRIVER, NULL);
        mutex_init(&mip->mi_notify_lock, NULL, MUTEX_DRIVER, NULL);
        mutex_init(&mip->mi_promisc_lock, NULL, MUTEX_DRIVER, NULL);
        mutex_init(&mip->mi_ring_lock, NULL, MUTEX_DEFAULT, NULL);

        mip->mi_notify_cb_info.mcbi_lockp = &mip->mi_notify_lock;
        cv_init(&mip->mi_notify_cb_info.mcbi_cv, NULL, CV_DRIVER, NULL);
        mip->mi_promisc_cb_info.mcbi_lockp = &mip->mi_promisc_lock;
        cv_init(&mip->mi_promisc_cb_info.mcbi_cv, NULL, CV_DRIVER, NULL);

        mutex_init(&mip->mi_bridge_lock, NULL, MUTEX_DEFAULT, NULL);

        return (0);
}

/*ARGSUSED*/
static void
i_mac_destructor(void *buf, void *arg)
{
        mac_impl_t      *mip = buf;
        mac_cb_info_t   *mcbi;

        ASSERT(mip->mi_ref == 0);
        ASSERT(mip->mi_active == 0);
        ASSERT(mip->mi_linkstate == LINK_STATE_UNKNOWN);
        ASSERT(mip->mi_devpromisc == 0);
        ASSERT(mip->mi_ksp == NULL);
        ASSERT(mip->mi_kstat_count == 0);
        ASSERT(mip->mi_nclients == 0);
        ASSERT(mip->mi_nactiveclients == 0);
        ASSERT(mip->mi_single_active_client == NULL);
        ASSERT(mip->mi_state_flags == 0);
        ASSERT(mip->mi_factory_addr == NULL);
        ASSERT(mip->mi_factory_addr_num == 0);
        ASSERT(mip->mi_default_tx_ring == NULL);

        mcbi = &mip->mi_notify_cb_info;
        ASSERT(mcbi->mcbi_del_cnt == 0 && mcbi->mcbi_walker_cnt == 0);
        ASSERT(mip->mi_notify_bits == 0);
        ASSERT(mip->mi_notify_thread == NULL);
        ASSERT(mcbi->mcbi_lockp == &mip->mi_notify_lock);
        mcbi->mcbi_lockp = NULL;

        mcbi = &mip->mi_promisc_cb_info;
        ASSERT(mcbi->mcbi_del_cnt == 0 && mip->mi_promisc_list == NULL);
        ASSERT(mip->mi_promisc_list == NULL);
        ASSERT(mcbi->mcbi_lockp == &mip->mi_promisc_lock);
        mcbi->mcbi_lockp = NULL;

        ASSERT(mip->mi_bcast_ngrps == 0 && mip->mi_bcast_grp == NULL);
        ASSERT(mip->mi_perim_owner == NULL && mip->mi_perim_ocnt == 0);

        rw_destroy(&mip->mi_rw_lock);

        mutex_destroy(&mip->mi_promisc_lock);
        cv_destroy(&mip->mi_promisc_cb_info.mcbi_cv);
        mutex_destroy(&mip->mi_notify_lock);
        cv_destroy(&mip->mi_notify_cb_info.mcbi_cv);
        mutex_destroy(&mip->mi_ring_lock);

        ASSERT(mip->mi_bridge_link == NULL);
}

/* ARGSUSED */
static int
i_mac_ring_ctor(void *buf, void *arg, int kmflag)
{
        mac_ring_t *ring = (mac_ring_t *)buf;

        bzero(ring, sizeof (mac_ring_t));
        cv_init(&ring->mr_cv, NULL, CV_DEFAULT, NULL);
        mutex_init(&ring->mr_lock, NULL, MUTEX_DEFAULT, NULL);
        ring->mr_state = MR_FREE;
        return (0);
}

/* ARGSUSED */
static void
i_mac_ring_dtor(void *buf, void *arg)
{
        mac_ring_t *ring = (mac_ring_t *)buf;

        cv_destroy(&ring->mr_cv);
        mutex_destroy(&ring->mr_lock);
}

/*
 * Common functions to do mac callback addition and deletion. Currently this is
 * used by promisc callbacks and notify callbacks. List addition and deletion
 * need to take care of list walkers. List walkers in general, can't hold list
 * locks and make upcall callbacks due to potential lock order and recursive
 * reentry issues. Instead list walkers increment the list walker count to mark
 * the presence of a walker thread. Addition can be carefully done to ensure
 * that the list walker always sees either the old list or the new list.
 * However the deletion can't be done while the walker is active, instead the
 * deleting thread simply marks the entry as logically deleted. The last walker
 * physically deletes and frees up the logically deleted entries when the walk
 * is complete.
 */
void
mac_callback_add(mac_cb_info_t *mcbi, mac_cb_t **mcb_head,
    mac_cb_t *mcb_elem)
{
        mac_cb_t        *p;
        mac_cb_t        **pp;

        /* Verify it is not already in the list */
        for (pp = mcb_head; (p = *pp) != NULL; pp = &p->mcb_nextp) {
                if (p == mcb_elem)
                        break;
        }
        VERIFY(p == NULL);

        /*
         * Add it to the head of the callback list. The membar ensures that
         * the following list pointer manipulations reach global visibility
         * in exactly the program order below.
         */
        ASSERT(MUTEX_HELD(mcbi->mcbi_lockp));

        mcb_elem->mcb_nextp = *mcb_head;
        membar_producer();
        *mcb_head = mcb_elem;
}

/*
 * Mark the entry as logically deleted. If there aren't any walkers unlink
 * from the list. In either case return the corresponding status.
 */
boolean_t
mac_callback_remove(mac_cb_info_t *mcbi, mac_cb_t **mcb_head,
    mac_cb_t *mcb_elem)
{
        mac_cb_t        *p;
        mac_cb_t        **pp;

        ASSERT(MUTEX_HELD(mcbi->mcbi_lockp));
        /*
         * Search the callback list for the entry to be removed
         */
        for (pp = mcb_head; (p = *pp) != NULL; pp = &p->mcb_nextp) {
                if (p == mcb_elem)
                        break;
        }
        VERIFY(p != NULL);

        /*
         * If there are walkers just mark it as deleted and the last walker
         * will remove from the list and free it.
         */
        if (mcbi->mcbi_walker_cnt != 0) {
                p->mcb_flags |= MCB_CONDEMNED;
                mcbi->mcbi_del_cnt++;
                return (B_FALSE);
        }

        ASSERT(mcbi->mcbi_del_cnt == 0);
        *pp = p->mcb_nextp;
        p->mcb_nextp = NULL;
        return (B_TRUE);
}

/*
 * Wait for all pending callback removals to be completed
 */
void
mac_callback_remove_wait(mac_cb_info_t *mcbi)
{
        ASSERT(MUTEX_HELD(mcbi->mcbi_lockp));
        while (mcbi->mcbi_del_cnt != 0) {
                DTRACE_PROBE1(need_wait, mac_cb_info_t *, mcbi);
                cv_wait(&mcbi->mcbi_cv, mcbi->mcbi_lockp);
        }
}

void
mac_callback_barrier(mac_cb_info_t *mcbi)
{
        ASSERT(MUTEX_HELD(mcbi->mcbi_lockp));
        ASSERT3U(mcbi->mcbi_barrier_cnt, <, UINT_MAX);

        if (mcbi->mcbi_walker_cnt == 0) {
                return;
        }

        mcbi->mcbi_barrier_cnt++;
        do {
                cv_wait(&mcbi->mcbi_cv, mcbi->mcbi_lockp);
        } while (mcbi->mcbi_walker_cnt > 0);
        mcbi->mcbi_barrier_cnt--;
        cv_broadcast(&mcbi->mcbi_cv);
}

void
mac_callback_walker_enter(mac_cb_info_t *mcbi)
{
        mutex_enter(mcbi->mcbi_lockp);
        /*
         * Incoming walkers should give precedence to timely clean-up of
         * deleted callback entries and requested barriers.
         */
        while (mcbi->mcbi_del_cnt > 0 || mcbi->mcbi_barrier_cnt > 0) {
                cv_wait(&mcbi->mcbi_cv, mcbi->mcbi_lockp);
        }
        mcbi->mcbi_walker_cnt++;
        mutex_exit(mcbi->mcbi_lockp);
}

/*
 * The last mac callback walker does the cleanup. Walk the list and unlik
 * all the logically deleted entries and construct a temporary list of
 * removed entries. Return the list of removed entries to the caller.
 */
static mac_cb_t *
mac_callback_walker_cleanup(mac_cb_info_t *mcbi, mac_cb_t **mcb_head)
{
        mac_cb_t        *p;
        mac_cb_t        **pp;
        mac_cb_t        *rmlist = NULL;         /* List of removed elements */
        int     cnt = 0;

        ASSERT(MUTEX_HELD(mcbi->mcbi_lockp));
        ASSERT(mcbi->mcbi_del_cnt != 0 && mcbi->mcbi_walker_cnt == 0);

        pp = mcb_head;
        while (*pp != NULL) {
                if ((*pp)->mcb_flags & MCB_CONDEMNED) {
                        p = *pp;
                        *pp = p->mcb_nextp;
                        p->mcb_nextp = rmlist;
                        rmlist = p;
                        cnt++;
                        continue;
                }
                pp = &(*pp)->mcb_nextp;
        }

        ASSERT(mcbi->mcbi_del_cnt == cnt);
        mcbi->mcbi_del_cnt = 0;
        return (rmlist);
}

void
mac_callback_walker_exit(mac_cb_info_t *mcbi, mac_cb_t **headp,
    boolean_t is_promisc)
{
        boolean_t do_wake = B_FALSE;

        mutex_enter(mcbi->mcbi_lockp);

        /* If walkers remain, nothing more can be done for now */
        if (--mcbi->mcbi_walker_cnt != 0) {
                mutex_exit(mcbi->mcbi_lockp);
                return;
        }

        if (mcbi->mcbi_del_cnt != 0) {
                mac_cb_t *rmlist;

                rmlist = mac_callback_walker_cleanup(mcbi, headp);

                if (!is_promisc) {
                        /* The "normal" non-promisc callback clean-up */
                        mac_callback_free(rmlist);
                } else {
                        mac_cb_t *mcb, *mcb_next;

                        /*
                         * The promisc callbacks are in 2 lists, one off the
                         * 'mip' and another off the 'mcip' threaded by
                         * mpi_mi_link and mpi_mci_link respectively.  There
                         * is, however, only a single shared total walker
                         * count, and an entry cannot be physically unlinked if
                         * a walker is active on either list. The last walker
                         * does this cleanup of logically deleted entries.
                         *
                         * With a list of callbacks deleted from above from
                         * mi_promisc_list (headp), remove the corresponding
                         * entry from mci_promisc_list (headp_pair) and free
                         * the structure.
                         */
                        for (mcb = rmlist; mcb != NULL; mcb = mcb_next) {
                                mac_promisc_impl_t *mpip;
                                mac_client_impl_t *mcip;

                                mcb_next = mcb->mcb_nextp;
                                mpip = (mac_promisc_impl_t *)mcb->mcb_objp;
                                mcip = mpip->mpi_mcip;

                                ASSERT3P(&mcip->mci_mip->mi_promisc_cb_info,
                                    ==, mcbi);
                                ASSERT3P(&mcip->mci_mip->mi_promisc_list,
                                    ==, headp);

                                VERIFY(mac_callback_remove(mcbi,
                                    &mcip->mci_promisc_list,
                                    &mpip->mpi_mci_link));
                                mcb->mcb_flags = 0;
                                mcb->mcb_nextp = NULL;
                                kmem_cache_free(mac_promisc_impl_cache, mpip);
                        }
                }

                /*
                 * Wake any walker threads that could be waiting in
                 * mac_callback_walker_enter() until deleted items have been
                 * cleaned from the list.
                 */
                do_wake = B_TRUE;
        }

        if (mcbi->mcbi_barrier_cnt != 0) {
                /*
                 * One or more threads are waiting for all walkers to exit the
                 * callback list.  Notify them, now that the list is clear.
                 */
                do_wake = B_TRUE;
        }

        if (do_wake) {
                cv_broadcast(&mcbi->mcbi_cv);
        }
        mutex_exit(mcbi->mcbi_lockp);
}

static boolean_t
mac_callback_lookup(mac_cb_t **mcb_headp, mac_cb_t *mcb_elem)
{
        mac_cb_t        *mcb;

        /* Verify it is not already in the list */
        for (mcb = *mcb_headp; mcb != NULL; mcb = mcb->mcb_nextp) {
                if (mcb == mcb_elem)
                        return (B_TRUE);
        }

        return (B_FALSE);
}

static boolean_t
mac_callback_find(mac_cb_info_t *mcbi, mac_cb_t **mcb_headp, mac_cb_t *mcb_elem)
{
        boolean_t       found;

        mutex_enter(mcbi->mcbi_lockp);
        found = mac_callback_lookup(mcb_headp, mcb_elem);
        mutex_exit(mcbi->mcbi_lockp);

        return (found);
}

/* Free the list of removed callbacks */
void
mac_callback_free(mac_cb_t *rmlist)
{
        mac_cb_t        *mcb;
        mac_cb_t        *mcb_next;

        for (mcb = rmlist; mcb != NULL; mcb = mcb_next) {
                mcb_next = mcb->mcb_nextp;
                kmem_free(mcb->mcb_objp, mcb->mcb_objsize);
        }
}

void
i_mac_notify(mac_impl_t *mip, mac_notify_type_t type)
{
        mac_cb_info_t   *mcbi;

        /*
         * Signal the notify thread even after mi_ref has become zero and
         * mi_disabled is set. The synchronization with the notify thread
         * happens in mac_unregister and that implies the driver must make
         * sure it is single-threaded (with respect to mac calls) and that
         * all pending mac calls have returned before it calls mac_unregister
         */
        rw_enter(&i_mac_impl_lock, RW_READER);
        if (mip->mi_state_flags & MIS_DISABLED)
                goto exit;

        /*
         * Guard against incorrect notifications.  (Running a newer
         * mac client against an older implementation?)
         */
        if (type >= MAC_NNOTE)
                goto exit;

        mcbi = &mip->mi_notify_cb_info;
        mutex_enter(mcbi->mcbi_lockp);
        mip->mi_notify_bits |= (1 << type);
        cv_broadcast(&mcbi->mcbi_cv);
        mutex_exit(mcbi->mcbi_lockp);

exit:
        rw_exit(&i_mac_impl_lock);
}

/*
 * Mac serialization primitives. Please see the block comment at the
 * top of the file.
 */
void
i_mac_perim_enter(mac_impl_t *mip)
{
        mac_client_impl_t       *mcip;

        if (mip->mi_state_flags & MIS_IS_VNIC) {
                /*
                 * This is a VNIC. Return the lower mac since that is what
                 * we want to serialize on.
                 */
                mcip = mac_vnic_lower(mip);
                mip = mcip->mci_mip;
        }

        mutex_enter(&mip->mi_perim_lock);
        if (mip->mi_perim_owner == curthread) {
                mip->mi_perim_ocnt++;
                mutex_exit(&mip->mi_perim_lock);
                return;
        }

        while (mip->mi_perim_owner != NULL)
                cv_wait(&mip->mi_perim_cv, &mip->mi_perim_lock);

        mip->mi_perim_owner = curthread;
        ASSERT(mip->mi_perim_ocnt == 0);
        mip->mi_perim_ocnt++;
#ifdef DEBUG
        mip->mi_perim_stack_depth = getpcstack(mip->mi_perim_stack,
            MAC_PERIM_STACK_DEPTH);
#endif
        mutex_exit(&mip->mi_perim_lock);
}

int
i_mac_perim_enter_nowait(mac_impl_t *mip)
{
        /*
         * The vnic is a special case, since the serialization is done based
         * on the lower mac. If the lower mac is busy, it does not imply the
         * vnic can't be unregistered. But in the case of other drivers,
         * a busy perimeter or open mac handles implies that the mac is busy
         * and can't be unregistered.
         */
        if (mip->mi_state_flags & MIS_IS_VNIC) {
                i_mac_perim_enter(mip);
                return (0);
        }

        mutex_enter(&mip->mi_perim_lock);
        if (mip->mi_perim_owner != NULL) {
                mutex_exit(&mip->mi_perim_lock);
                return (EBUSY);
        }
        ASSERT(mip->mi_perim_ocnt == 0);
        mip->mi_perim_owner = curthread;
        mip->mi_perim_ocnt++;
        mutex_exit(&mip->mi_perim_lock);

        return (0);
}

void
i_mac_perim_exit(mac_impl_t *mip)
{
        mac_client_impl_t *mcip;

        if (mip->mi_state_flags & MIS_IS_VNIC) {
                /*
                 * This is a VNIC. Return the lower mac since that is what
                 * we want to serialize on.
                 */
                mcip = mac_vnic_lower(mip);
                mip = mcip->mci_mip;
        }

        ASSERT(mip->mi_perim_owner == curthread && mip->mi_perim_ocnt != 0);

        mutex_enter(&mip->mi_perim_lock);
        if (--mip->mi_perim_ocnt == 0) {
                mip->mi_perim_owner = NULL;
                cv_signal(&mip->mi_perim_cv);
        }
        mutex_exit(&mip->mi_perim_lock);
}

/*
 * Returns whether the current thread holds the mac perimeter. Used in making
 * assertions.
 */
boolean_t
mac_perim_held(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;
        mac_client_impl_t *mcip;

        if (mip->mi_state_flags & MIS_IS_VNIC) {
                /*
                 * This is a VNIC. Return the lower mac since that is what
                 * we want to serialize on.
                 */
                mcip = mac_vnic_lower(mip);
                mip = mcip->mci_mip;
        }
        return (mip->mi_perim_owner == curthread);
}

/*
 * mac client interfaces to enter the mac perimeter of a mac end point, given
 * its mac handle, or macname or linkid.
 */
void
mac_perim_enter_by_mh(mac_handle_t mh, mac_perim_handle_t *mphp)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        i_mac_perim_enter(mip);
        /*
         * The mac_perim_handle_t returned encodes the 'mip' and whether a
         * mac_open has been done internally while entering the perimeter.
         * This information is used in mac_perim_exit
         */
        MAC_ENCODE_MPH(*mphp, mip, 0);
}

int
mac_perim_enter_by_macname(const char *name, mac_perim_handle_t *mphp)
{
        int     err;
        mac_handle_t    mh;

        if ((err = mac_open(name, &mh)) != 0)
                return (err);

        mac_perim_enter_by_mh(mh, mphp);
        MAC_ENCODE_MPH(*mphp, mh, 1);
        return (0);
}

int
mac_perim_enter_by_linkid(datalink_id_t linkid, mac_perim_handle_t *mphp)
{
        int     err;
        mac_handle_t    mh;

        if ((err = mac_open_by_linkid(linkid, &mh)) != 0)
                return (err);

        mac_perim_enter_by_mh(mh, mphp);
        MAC_ENCODE_MPH(*mphp, mh, 1);
        return (0);
}

void
mac_perim_exit(mac_perim_handle_t mph)
{
        mac_impl_t      *mip;
        boolean_t       need_close;

        MAC_DECODE_MPH(mph, mip, need_close);
        i_mac_perim_exit(mip);
        if (need_close)
                mac_close((mac_handle_t)mip);
}

int
mac_hold(const char *macname, mac_impl_t **pmip)
{
        mac_impl_t      *mip;
        int             err;

        /*
         * Check the device name length to make sure it won't overflow our
         * buffer.
         */
        if (strlen(macname) >= MAXNAMELEN)
                return (EINVAL);

        /*
         * Look up its entry in the global hash table.
         */
        rw_enter(&i_mac_impl_lock, RW_WRITER);
        err = mod_hash_find(i_mac_impl_hash, (mod_hash_key_t)macname,
            (mod_hash_val_t *)&mip);

        if (err != 0) {
                rw_exit(&i_mac_impl_lock);
                return (ENOENT);
        }

        if (mip->mi_state_flags & MIS_DISABLED) {
                rw_exit(&i_mac_impl_lock);
                return (ENOENT);
        }

        if (mip->mi_state_flags & MIS_EXCLUSIVE_HELD) {
                rw_exit(&i_mac_impl_lock);
                return (EBUSY);
        }

        mip->mi_ref++;
        rw_exit(&i_mac_impl_lock);

        *pmip = mip;
        return (0);
}

void
mac_rele(mac_impl_t *mip)
{
        rw_enter(&i_mac_impl_lock, RW_WRITER);
        ASSERT(mip->mi_ref != 0);
        if (--mip->mi_ref == 0) {
                ASSERT(mip->mi_nactiveclients == 0 &&
                    !(mip->mi_state_flags & MIS_EXCLUSIVE));
        }
        rw_exit(&i_mac_impl_lock);
}

/*
 * Private GLDv3 function to start a MAC instance.
 */
int
mac_start(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;
        int             err = 0;
        mac_group_t     *defgrp;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
        ASSERT(mip->mi_start != NULL);

        /*
         * Check whether the device is already started.
         */
        if (mip->mi_active++ == 0) {
                mac_ring_t *ring = NULL;

                /*
                 * Start the device.
                 */
                err = mip->mi_start(mip->mi_driver);
                if (err != 0) {
                        mip->mi_active--;
                        return (err);
                }

                /*
                 * Start the default tx ring.
                 */
                if (mip->mi_default_tx_ring != NULL) {

                        ring = (mac_ring_t *)mip->mi_default_tx_ring;
                        if (ring->mr_state != MR_INUSE) {
                                err = mac_start_ring(ring);
                                if (err != 0) {
                                        mip->mi_active--;
                                        return (err);
                                }
                        }
                }

                if ((defgrp = MAC_DEFAULT_RX_GROUP(mip)) != NULL) {
                        /*
                         * Start the default group which is responsible
                         * for receiving broadcast and multicast
                         * traffic for both primary and non-primary
                         * MAC clients.
                         */
                        ASSERT(defgrp->mrg_state == MAC_GROUP_STATE_REGISTERED);
                        err = mac_start_group_and_rings(defgrp);
                        if (err != 0) {
                                mip->mi_active--;
                                if ((ring != NULL) &&
                                    (ring->mr_state == MR_INUSE))
                                        mac_stop_ring(ring);
                                return (err);
                        }
                        mac_set_group_state(defgrp, MAC_GROUP_STATE_SHARED);
                }
        }

        return (err);
}

/*
 * Private GLDv3 function to stop a MAC instance.
 */
void
mac_stop(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;
        mac_group_t     *grp;

        ASSERT(mip->mi_stop != NULL);
        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        /*
         * Check whether the device is still needed.
         */
        ASSERT(mip->mi_active != 0);
        if (--mip->mi_active == 0) {
                if ((grp = MAC_DEFAULT_RX_GROUP(mip)) != NULL) {
                        /*
                         * There should be no more active clients since the
                         * MAC is being stopped. Stop the default RX group
                         * and transition it back to registered state.
                         *
                         * When clients are torn down, the groups
                         * are release via mac_release_rx_group which
                         * knows the the default group is always in
                         * started mode since broadcast uses it. So
                         * we can assert that their are no clients
                         * (since mac_bcast_add doesn't register itself
                         * as a client) and group is in SHARED state.
                         */
                        ASSERT(grp->mrg_state == MAC_GROUP_STATE_SHARED);
                        ASSERT(MAC_GROUP_NO_CLIENT(grp) &&
                            mip->mi_nactiveclients == 0);
                        mac_stop_group_and_rings(grp);
                        mac_set_group_state(grp, MAC_GROUP_STATE_REGISTERED);
                }

                if (mip->mi_default_tx_ring != NULL) {
                        mac_ring_t *ring;

                        ring = (mac_ring_t *)mip->mi_default_tx_ring;
                        if (ring->mr_state == MR_INUSE) {
                                mac_stop_ring(ring);
                                ring->mr_flag = 0;
                        }
                }

                /*
                 * Stop the device.
                 */
                mip->mi_stop(mip->mi_driver);
        }
}

int
i_mac_promisc_set(mac_impl_t *mip, boolean_t on)
{
        int             err = 0;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
        ASSERT(mip->mi_setpromisc != NULL);

        if (on) {
                /*
                 * Enable promiscuous mode on the device if not yet enabled.
                 */
                if (mip->mi_devpromisc++ == 0) {
                        err = mip->mi_setpromisc(mip->mi_driver, B_TRUE);
                        if (err != 0) {
                                mip->mi_devpromisc--;
                                return (err);
                        }
                        i_mac_notify(mip, MAC_NOTE_DEVPROMISC);
                }
        } else {
                if (mip->mi_devpromisc == 0)
                        return (EPROTO);

                /*
                 * Disable promiscuous mode on the device if this is the last
                 * enabling.
                 */
                if (--mip->mi_devpromisc == 0) {
                        err = mip->mi_setpromisc(mip->mi_driver, B_FALSE);
                        if (err != 0) {
                                mip->mi_devpromisc++;
                                return (err);
                        }
                        i_mac_notify(mip, MAC_NOTE_DEVPROMISC);
                }
        }

        return (0);
}

/*
 * The promiscuity state can change any time. If the caller needs to take
 * actions that are atomic with the promiscuity state, then the caller needs
 * to bracket the entire sequence with mac_perim_enter/exit
 */
boolean_t
mac_promisc_get(mac_handle_t mh)
{
        mac_impl_t              *mip = (mac_impl_t *)mh;

        /*
         * Return the current promiscuity.
         */
        return (mip->mi_devpromisc != 0);
}

/*
 * Invoked at MAC instance attach time to initialize the list
 * of factory MAC addresses supported by a MAC instance. This function
 * builds a local cache in the mac_impl_t for the MAC addresses
 * supported by the underlying hardware. The MAC clients themselves
 * use the mac_addr_factory*() functions to query and reserve
 * factory MAC addresses.
 */
void
mac_addr_factory_init(mac_impl_t *mip)
{
        mac_capab_multifactaddr_t capab;
        uint8_t *addr;
        int i;

        /*
         * First round to see how many factory MAC addresses are available.
         */
        bzero(&capab, sizeof (capab));
        if (!i_mac_capab_get((mac_handle_t)mip, MAC_CAPAB_MULTIFACTADDR,
            &capab) || (capab.mcm_naddr == 0)) {
                /*
                 * The MAC instance doesn't support multiple factory
                 * MAC addresses, we're done here.
                 */
                return;
        }

        /*
         * Allocate the space and get all the factory addresses.
         */
        addr = kmem_alloc(capab.mcm_naddr * MAXMACADDRLEN, KM_SLEEP);
        capab.mcm_getaddr(mip->mi_driver, capab.mcm_naddr, addr);

        mip->mi_factory_addr_num = capab.mcm_naddr;
        mip->mi_factory_addr = kmem_zalloc(mip->mi_factory_addr_num *
            sizeof (mac_factory_addr_t), KM_SLEEP);

        for (i = 0; i < capab.mcm_naddr; i++) {
                bcopy(addr + i * MAXMACADDRLEN,
                    mip->mi_factory_addr[i].mfa_addr,
                    mip->mi_type->mt_addr_length);
                mip->mi_factory_addr[i].mfa_in_use = B_FALSE;
        }

        kmem_free(addr, capab.mcm_naddr * MAXMACADDRLEN);
}

void
mac_addr_factory_fini(mac_impl_t *mip)
{
        if (mip->mi_factory_addr == NULL) {
                ASSERT(mip->mi_factory_addr_num == 0);
                return;
        }

        kmem_free(mip->mi_factory_addr, mip->mi_factory_addr_num *
            sizeof (mac_factory_addr_t));

        mip->mi_factory_addr = NULL;
        mip->mi_factory_addr_num = 0;
}

/*
 * Reserve a factory MAC address. If *slot is set to -1, the function
 * attempts to reserve any of the available factory MAC addresses and
 * returns the reserved slot id. If no slots are available, the function
 * returns ENOSPC. If *slot is not set to -1, the function reserves
 * the specified slot if it is available, or returns EBUSY is the slot
 * is already used. Returns ENOTSUP if the underlying MAC does not
 * support multiple factory addresses. If the slot number is not -1 but
 * is invalid, returns EINVAL.
 */
int
mac_addr_factory_reserve(mac_client_handle_t mch, int *slot)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
        mac_impl_t *mip = mcip->mci_mip;
        int i, ret = 0;

        i_mac_perim_enter(mip);
        /*
         * Protect against concurrent readers that may need a self-consistent
         * view of the factory addresses
         */
        rw_enter(&mip->mi_rw_lock, RW_WRITER);

        if (mip->mi_factory_addr_num == 0) {
                ret = ENOTSUP;
                goto bail;
        }

        if (*slot != -1) {
                /* check the specified slot */
                if (*slot < 1 || *slot > mip->mi_factory_addr_num) {
                        ret = EINVAL;
                        goto bail;
                }
                if (mip->mi_factory_addr[*slot-1].mfa_in_use) {
                        ret = EBUSY;
                        goto bail;
                }
        } else {
                /* pick the next available slot */
                for (i = 0; i < mip->mi_factory_addr_num; i++) {
                        if (!mip->mi_factory_addr[i].mfa_in_use)
                                break;
                }

                if (i == mip->mi_factory_addr_num) {
                        ret = ENOSPC;
                        goto bail;
                }
                *slot = i+1;
        }

        mip->mi_factory_addr[*slot-1].mfa_in_use = B_TRUE;
        mip->mi_factory_addr[*slot-1].mfa_client = mcip;

bail:
        rw_exit(&mip->mi_rw_lock);
        i_mac_perim_exit(mip);
        return (ret);
}

/*
 * Release the specified factory MAC address slot.
 */
void
mac_addr_factory_release(mac_client_handle_t mch, uint_t slot)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
        mac_impl_t *mip = mcip->mci_mip;

        i_mac_perim_enter(mip);
        /*
         * Protect against concurrent readers that may need a self-consistent
         * view of the factory addresses
         */
        rw_enter(&mip->mi_rw_lock, RW_WRITER);

        ASSERT(slot > 0 && slot <= mip->mi_factory_addr_num);
        ASSERT(mip->mi_factory_addr[slot-1].mfa_in_use);

        mip->mi_factory_addr[slot-1].mfa_in_use = B_FALSE;

        rw_exit(&mip->mi_rw_lock);
        i_mac_perim_exit(mip);
}

/*
 * Stores in mac_addr the value of the specified MAC address. Returns
 * 0 on success, or EINVAL if the slot number is not valid for the MAC.
 * The caller must provide a string of at least MAXNAMELEN bytes.
 */
void
mac_addr_factory_value(mac_handle_t mh, int slot, uchar_t *mac_addr,
    uint_t *addr_len, char *client_name, boolean_t *in_use_arg)
{
        mac_impl_t *mip = (mac_impl_t *)mh;
        boolean_t in_use;

        ASSERT(slot > 0 && slot <= mip->mi_factory_addr_num);

        /*
         * Readers need to hold mi_rw_lock. Writers need to hold mac perimeter
         * and mi_rw_lock
         */
        rw_enter(&mip->mi_rw_lock, RW_READER);
        bcopy(mip->mi_factory_addr[slot-1].mfa_addr, mac_addr, MAXMACADDRLEN);
        *addr_len = mip->mi_type->mt_addr_length;
        in_use = mip->mi_factory_addr[slot-1].mfa_in_use;
        if (in_use && client_name != NULL) {
                bcopy(mip->mi_factory_addr[slot-1].mfa_client->mci_name,
                    client_name, MAXNAMELEN);
        }
        if (in_use_arg != NULL)
                *in_use_arg = in_use;
        rw_exit(&mip->mi_rw_lock);
}

/*
 * Returns the number of factory MAC addresses (in addition to the
 * primary MAC address), 0 if the underlying MAC doesn't support
 * that feature.
 */
uint_t
mac_addr_factory_num(mac_handle_t mh)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        return (mip->mi_factory_addr_num);
}


void
mac_rx_group_unmark(mac_group_t *grp, uint_t flag)
{
        mac_ring_t      *ring;

        for (ring = grp->mrg_rings; ring != NULL; ring = ring->mr_next)
                ring->mr_flag &= ~flag;
}

/*
 * The following mac_hwrings_xxx() functions are private mac client functions
 * used by the aggr driver to access and control the underlying HW Rx group
 * and rings. In this case, the aggr driver has exclusive control of the
 * underlying HW Rx group/rings, it calls the following functions to
 * start/stop the HW Rx rings, disable/enable polling, add/remove MAC
 * addresses, or set up the Rx callback.
 */
/* ARGSUSED */
static void
mac_hwrings_rx_process(void *arg, mac_resource_handle_t srs,
    mblk_t *mp_chain, boolean_t loopback)
{
        mac_soft_ring_set_t     *mac_srs = (mac_soft_ring_set_t *)srs;
        mac_srs_rx_t            *srs_rx = &mac_srs->srs_rx;
        mac_direct_rx_t         proc;
        void                    *arg1;
        mac_resource_handle_t   arg2;

        proc = srs_rx->sr_func;
        arg1 = srs_rx->sr_arg1;
        arg2 = mac_srs->srs_mrh;

        proc(arg1, arg2, mp_chain, NULL);
}

/*
 * This function is called to get the list of HW rings that are reserved by
 * an exclusive mac client.
 *
 * Return value: the number of HW rings.
 */
int
mac_hwrings_get(mac_client_handle_t mch, mac_group_handle_t *hwgh,
    mac_ring_handle_t *hwrh, mac_ring_type_t rtype)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        flow_entry_t            *flent = mcip->mci_flent;
        mac_group_t             *grp;
        mac_ring_t              *ring;
        int                     cnt = 0;

        if (rtype == MAC_RING_TYPE_RX) {
                grp = flent->fe_rx_ring_group;
        } else if (rtype == MAC_RING_TYPE_TX) {
                grp = flent->fe_tx_ring_group;
        } else {
                ASSERT(B_FALSE);
                return (-1);
        }

        /*
         * The MAC client did not reserve an Rx group, return directly.
         * This is probably because the underlying MAC does not support
         * any groups.
         */
        if (hwgh != NULL)
                *hwgh = NULL;
        if (grp == NULL)
                return (0);
        /*
         * This group must be reserved by this MAC client.
         */
        ASSERT((grp->mrg_state == MAC_GROUP_STATE_RESERVED) &&
            (mcip == MAC_GROUP_ONLY_CLIENT(grp)));

        for (ring = grp->mrg_rings; ring != NULL; ring = ring->mr_next, cnt++) {
                ASSERT(cnt < MAX_RINGS_PER_GROUP);
                hwrh[cnt] = (mac_ring_handle_t)ring;
        }
        if (hwgh != NULL)
                *hwgh = (mac_group_handle_t)grp;

        return (cnt);
}

/*
 * Get the HW ring handles of the given group index. If the MAC
 * doesn't have a group at this index, or any groups at all, then 0 is
 * returned and hwgh is set to NULL. This is a private client API. The
 * MAC perimeter must be held when calling this function.
 *
 * mh: A handle to the MAC that owns the group.
 *
 * idx: The index of the HW group to be read.
 *
 * hwgh: If non-NULL, contains a handle to the HW group on return.
 *
 * hwrh: An array of ring handles pointing to the HW rings in the
 * group. The array must be large enough to hold a handle to each ring
 * in the group. To be safe, this array should be of size MAX_RINGS_PER_GROUP.
 *
 * rtype: Used to determine if we are fetching Rx or Tx rings.
 *
 * Returns the number of rings in the group.
 */
uint_t
mac_hwrings_idx_get(mac_handle_t mh, uint_t idx, mac_group_handle_t *hwgh,
    mac_ring_handle_t *hwrh, mac_ring_type_t rtype)
{
        mac_impl_t              *mip = (mac_impl_t *)mh;
        mac_group_t             *grp;
        mac_ring_t              *ring;
        uint_t                  cnt = 0;

        /*
         * The MAC perimeter must be held when accessing the
         * mi_{rx,tx}_groups fields.
         */
        ASSERT(MAC_PERIM_HELD(mh));
        ASSERT(rtype == MAC_RING_TYPE_RX || rtype == MAC_RING_TYPE_TX);

        if (rtype == MAC_RING_TYPE_RX) {
                grp = mip->mi_rx_groups;
        } else {
                ASSERT(rtype == MAC_RING_TYPE_TX);
                grp = mip->mi_tx_groups;
        }

        while (grp != NULL && grp->mrg_index != idx)
                grp = grp->mrg_next;

        /*
         * If the MAC doesn't have a group at this index or doesn't
         * impelement RINGS capab, then set hwgh to NULL and return 0.
         */
        if (hwgh != NULL)
                *hwgh = NULL;

        if (grp == NULL)
                return (0);

        ASSERT3U(idx, ==, grp->mrg_index);

        for (ring = grp->mrg_rings; ring != NULL; ring = ring->mr_next, cnt++) {
                ASSERT3U(cnt, <, MAX_RINGS_PER_GROUP);
                hwrh[cnt] = (mac_ring_handle_t)ring;
        }

        /* A group should always have at least one ring. */
        ASSERT3U(cnt, >, 0);

        if (hwgh != NULL)
                *hwgh = (mac_group_handle_t)grp;

        return (cnt);
}

/*
 * This function is called to get info about Tx/Rx rings.
 *
 * Return value: returns uint_t which will have various bits set
 * that indicates different properties of the ring.
 */
uint_t
mac_hwring_getinfo(mac_ring_handle_t rh)
{
        mac_ring_t *ring = (mac_ring_t *)rh;
        mac_ring_info_t *info = &ring->mr_info;

        return (info->mri_flags);
}

/*
 * Set the passthru callback on the hardware ring.
 */
void
mac_hwring_set_passthru(mac_ring_handle_t hwrh, mac_rx_t fn, void *arg1,
    mac_resource_handle_t arg2)
{
        mac_ring_t *hwring = (mac_ring_t *)hwrh;

        ASSERT3S(hwring->mr_type, ==, MAC_RING_TYPE_RX);

        hwring->mr_classify_type = MAC_PASSTHRU_CLASSIFIER;

        hwring->mr_pt_fn = fn;
        hwring->mr_pt_arg1 = arg1;
        hwring->mr_pt_arg2 = arg2;
}

/*
 * Clear the passthru callback on the hardware ring.
 */
void
mac_hwring_clear_passthru(mac_ring_handle_t hwrh)
{
        mac_ring_t *hwring = (mac_ring_t *)hwrh;

        ASSERT3S(hwring->mr_type, ==, MAC_RING_TYPE_RX);

        hwring->mr_classify_type = MAC_NO_CLASSIFIER;

        hwring->mr_pt_fn = NULL;
        hwring->mr_pt_arg1 = NULL;
        hwring->mr_pt_arg2 = NULL;
}

void
mac_client_set_flow_cb(mac_client_handle_t mch, mac_rx_t func, void *arg1)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        flow_entry_t            *flent = mcip->mci_flent;

        mutex_enter(&flent->fe_lock);
        flent->fe_cb_fn = (flow_fn_t)func;
        flent->fe_cb_arg1 = arg1;
        flent->fe_cb_arg2 = NULL;
        flent->fe_flags &= ~FE_MC_NO_DATAPATH;
        mutex_exit(&flent->fe_lock);
}

void
mac_client_clear_flow_cb(mac_client_handle_t mch)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        flow_entry_t            *flent = mcip->mci_flent;

        mutex_enter(&flent->fe_lock);
        flent->fe_cb_fn = (flow_fn_t)mac_rx_def;
        flent->fe_cb_arg1 = NULL;
        flent->fe_cb_arg2 = NULL;
        flent->fe_flags |= FE_MC_NO_DATAPATH;
        mutex_exit(&flent->fe_lock);
}

/*
 * Export ddi interrupt handles from the HW ring to the pseudo ring and
 * setup the RX callback of the mac client which exclusively controls
 * HW ring.
 */
void
mac_hwring_setup(mac_ring_handle_t hwrh, mac_resource_handle_t prh,
    mac_ring_handle_t pseudo_rh)
{
        mac_ring_t              *hw_ring = (mac_ring_t *)hwrh;
        mac_ring_t              *pseudo_ring;
        mac_soft_ring_set_t     *mac_srs = hw_ring->mr_srs;

        if (pseudo_rh != NULL) {
                pseudo_ring = (mac_ring_t *)pseudo_rh;
                /* Export the ddi handles to pseudo ring */
                pseudo_ring->mr_info.mri_intr.mi_ddi_handle =
                    hw_ring->mr_info.mri_intr.mi_ddi_handle;
                pseudo_ring->mr_info.mri_intr.mi_ddi_shared =
                    hw_ring->mr_info.mri_intr.mi_ddi_shared;
                /*
                 * Save a pointer to pseudo ring in the hw ring. If
                 * interrupt handle changes, the hw ring will be
                 * notified of the change (see mac_ring_intr_set())
                 * and the appropriate change has to be made to
                 * the pseudo ring that has exported the ddi handle.
                 */
                hw_ring->mr_prh = pseudo_rh;
        }

        if (hw_ring->mr_type == MAC_RING_TYPE_RX) {
                ASSERT(!(mac_srs->srs_type & SRST_TX));
                mac_srs->srs_mrh = prh;
                mac_srs->srs_rx.sr_lower_proc = mac_hwrings_rx_process;
        }
}

void
mac_hwring_teardown(mac_ring_handle_t hwrh)
{
        mac_ring_t              *hw_ring = (mac_ring_t *)hwrh;
        mac_soft_ring_set_t     *mac_srs;

        if (hw_ring == NULL)
                return;
        hw_ring->mr_prh = NULL;
        if (hw_ring->mr_type == MAC_RING_TYPE_RX) {
                mac_srs = hw_ring->mr_srs;
                ASSERT(!(mac_srs->srs_type & SRST_TX));
                mac_srs->srs_rx.sr_lower_proc = mac_rx_srs_process;
                mac_srs->srs_mrh = NULL;
        }
}

int
mac_hwring_disable_intr(mac_ring_handle_t rh)
{
        mac_ring_t *rr_ring = (mac_ring_t *)rh;
        mac_intr_t *intr = &rr_ring->mr_info.mri_intr;

        return (intr->mi_disable(intr->mi_handle));
}

int
mac_hwring_enable_intr(mac_ring_handle_t rh)
{
        mac_ring_t *rr_ring = (mac_ring_t *)rh;
        mac_intr_t *intr = &rr_ring->mr_info.mri_intr;

        return (intr->mi_enable(intr->mi_handle));
}

/*
 * Start the HW ring pointed to by rh.
 *
 * This is used by special MAC clients that are MAC themselves and
 * need to exert control over the underlying HW rings of the NIC.
 */
int
mac_hwring_start(mac_ring_handle_t rh)
{
        mac_ring_t *rr_ring = (mac_ring_t *)rh;
        int rv = 0;

        if (rr_ring->mr_state != MR_INUSE)
                rv = mac_start_ring(rr_ring);

        return (rv);
}

/*
 * Stop the HW ring pointed to by rh. Also see mac_hwring_start().
 */
void
mac_hwring_stop(mac_ring_handle_t rh)
{
        mac_ring_t *rr_ring = (mac_ring_t *)rh;

        if (rr_ring->mr_state != MR_FREE)
                mac_stop_ring(rr_ring);
}

/*
 * Remove the quiesced flag from the HW ring pointed to by rh.
 *
 * This is used by special MAC clients that are MAC themselves and
 * need to exert control over the underlying HW rings of the NIC.
 */
int
mac_hwring_activate(mac_ring_handle_t rh)
{
        mac_ring_t *rr_ring = (mac_ring_t *)rh;

        MAC_RING_UNMARK(rr_ring, MR_QUIESCE);
        return (0);
}

/*
 * Quiesce the HW ring pointed to by rh. Also see mac_hwring_activate().
 */
void
mac_hwring_quiesce(mac_ring_handle_t rh)
{
        mac_ring_t *rr_ring = (mac_ring_t *)rh;

        mac_rx_ring_quiesce(rr_ring, MR_QUIESCE);
}

mblk_t *
mac_hwring_poll(mac_ring_handle_t rh, int bytes_to_pickup)
{
        mac_ring_t *rr_ring = (mac_ring_t *)rh;
        mac_ring_info_t *info = &rr_ring->mr_info;

        return (info->mri_poll(info->mri_driver, bytes_to_pickup));
}

/*
 * Send packets through a selected tx ring.
 */
mblk_t *
mac_hwring_tx(mac_ring_handle_t rh, mblk_t *mp)
{
        mac_ring_t *ring = (mac_ring_t *)rh;
        mac_ring_info_t *info = &ring->mr_info;

        ASSERT(ring->mr_type == MAC_RING_TYPE_TX &&
            ring->mr_state >= MR_INUSE);
        return (info->mri_tx(info->mri_driver, mp));
}

/*
 * Query stats for a particular rx/tx ring
 */
int
mac_hwring_getstat(mac_ring_handle_t rh, uint_t stat, uint64_t *val)
{
        mac_ring_t      *ring = (mac_ring_t *)rh;
        mac_ring_info_t *info = &ring->mr_info;

        return (info->mri_stat(info->mri_driver, stat, val));
}

/*
 * Private function that is only used by aggr to send packets through
 * a port/Tx ring. Since aggr exposes a pseudo Tx ring even for ports
 * that does not expose Tx rings, aggr_ring_tx() entry point needs
 * access to mac_impl_t to send packets through m_tx() entry point.
 * It accomplishes this by calling mac_hwring_send_priv() function.
 */
mblk_t *
mac_hwring_send_priv(mac_client_handle_t mch, mac_ring_handle_t rh, mblk_t *mp)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;
        mac_impl_t *mip = mcip->mci_mip;

        return (mac_provider_tx(mip, rh, mp, mcip));
}

/*
 * Private function that is only used by aggr to update the default transmission
 * ring. Because aggr exposes a pseudo Tx ring even for ports that may
 * temporarily be down, it may need to update the default ring that is used by
 * MAC such that it refers to a link that can actively be used to send traffic.
 * Note that this is different from the case where the port has been removed
 * from the group. In those cases, all of the rings will be torn down because
 * the ring will no longer exist. It's important to give aggr a case where the
 * rings can still exist such that it may be able to continue to send LACP PDUs
 * to potentially restore the link.
 */
void
mac_hwring_set_default(mac_handle_t mh, mac_ring_handle_t rh)
{
        mac_impl_t *mip = (mac_impl_t *)mh;
        mac_ring_t *ring = (mac_ring_t *)rh;

        ASSERT(MAC_PERIM_HELD(mh));
        VERIFY(mip->mi_state_flags & MIS_IS_AGGR);

        /*
         * We used to condition this assignment on the ring's
         * 'mr_state' being one of 'MR_INUSE'. However, there are
         * cases where this is called before the ring has any active
         * clients, and therefore is not marked as in use. Since the
         * sole purpose of this function is for aggr to make sure
         * 'mi_default_tx_ring' matches 'lg_tx_ports[0]', its
         * imperative that we update its value regardless of ring
         * state. Otherwise, we can end up in a state where
         * 'mi_default_tx_ring' points to a pseudo ring of a downed
         * port, even when 'lg_tx_ports[0]' points to a port that is
         * up.
         */
        mip->mi_default_tx_ring = rh;
}

int
mac_hwgroup_addmac(mac_group_handle_t gh, const uint8_t *addr)
{
        mac_group_t *group = (mac_group_t *)gh;

        return (mac_group_addmac(group, addr));
}

int
mac_hwgroup_remmac(mac_group_handle_t gh, const uint8_t *addr)
{
        mac_group_t *group = (mac_group_t *)gh;

        return (mac_group_remmac(group, addr));
}

/*
 * Program the group's HW VLAN filter if it has such support.
 * Otherwise, the group will implicitly accept tagged traffic and
 * there is nothing to do.
 */
int
mac_hwgroup_addvlan(mac_group_handle_t gh, uint16_t vid)
{
        mac_group_t *group = (mac_group_t *)gh;

        if (!MAC_GROUP_HW_VLAN(group))
                return (0);

        return (mac_group_addvlan(group, vid));
}

int
mac_hwgroup_remvlan(mac_group_handle_t gh, uint16_t vid)
{
        mac_group_t *group = (mac_group_t *)gh;

        if (!MAC_GROUP_HW_VLAN(group))
                return (0);

        return (mac_group_remvlan(group, vid));
}

/*
 * Determine if a MAC has HW VLAN support. This is a private API
 * consumed by aggr. In the future it might be nice to have a bitfield
 * in mac_capab_rings_t to track which forms of HW filtering are
 * supported by the MAC.
 */
boolean_t
mac_has_hw_vlan(mac_handle_t mh)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        return (MAC_GROUP_HW_VLAN(mip->mi_rx_groups));
}

/*
 * Get the number of Rx HW groups on this MAC.
 */
uint_t
mac_get_num_rx_groups(mac_handle_t mh)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        ASSERT(MAC_PERIM_HELD(mh));
        return (mip->mi_rx_group_count);
}

int
mac_set_promisc(mac_handle_t mh, boolean_t value)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        ASSERT(MAC_PERIM_HELD(mh));
        return (i_mac_promisc_set(mip, value));
}

/*
 * Set the RX group to be shared/reserved. Note that the group must be
 * started/stopped outside of this function.
 */
void
mac_set_group_state(mac_group_t *grp, mac_group_state_t state)
{
        /*
         * If there is no change in the group state, just return.
         */
        if (grp->mrg_state == state)
                return;

        switch (state) {
        case MAC_GROUP_STATE_RESERVED:
                /*
                 * Successfully reserved the group.
                 *
                 * Given that there is an exclusive client controlling this
                 * group, we enable the group level polling when available,
                 * so that SRSs get to turn on/off individual rings they's
                 * assigned to.
                 */
                ASSERT(MAC_PERIM_HELD(grp->mrg_mh));

                if (grp->mrg_type == MAC_RING_TYPE_RX &&
                    GROUP_INTR_DISABLE_FUNC(grp) != NULL) {
                        GROUP_INTR_DISABLE_FUNC(grp)(GROUP_INTR_HANDLE(grp));
                }
                break;

        case MAC_GROUP_STATE_SHARED:
                /*
                 * Set all rings of this group to software classified.
                 * If the group has an overriding interrupt, then re-enable it.
                 */
                ASSERT(MAC_PERIM_HELD(grp->mrg_mh));

                if (grp->mrg_type == MAC_RING_TYPE_RX &&
                    GROUP_INTR_ENABLE_FUNC(grp) != NULL) {
                        GROUP_INTR_ENABLE_FUNC(grp)(GROUP_INTR_HANDLE(grp));
                }
                /* The ring is not available for reservations any more */
                break;

        case MAC_GROUP_STATE_REGISTERED:
                /* Also callable from mac_register, perim is not held */
                break;

        default:
                ASSERT(B_FALSE);
                break;
        }

        grp->mrg_state = state;
}

/*
 * Quiesce future hardware classified packets for the specified Rx ring
 */
static void
mac_rx_ring_quiesce(mac_ring_t *rx_ring, uint_t ring_flag)
{
        ASSERT(rx_ring->mr_classify_type == MAC_HW_CLASSIFIER);
        ASSERT(ring_flag == MR_CONDEMNED || ring_flag  == MR_QUIESCE);

        mutex_enter(&rx_ring->mr_lock);
        rx_ring->mr_flag |= ring_flag;
        while (rx_ring->mr_refcnt != 0)
                cv_wait(&rx_ring->mr_cv, &rx_ring->mr_lock);
        mutex_exit(&rx_ring->mr_lock);
}

/*
 * Please see mac_tx for details about the per cpu locking scheme
 */
static void
mac_tx_lock_all(mac_client_impl_t *mcip)
{
        int     i;

        for (i = 0; i <= mac_tx_percpu_cnt; i++)
                mutex_enter(&mcip->mci_tx_pcpu[i].pcpu_tx_lock);
}

static void
mac_tx_unlock_all(mac_client_impl_t *mcip)
{
        int     i;

        for (i = mac_tx_percpu_cnt; i >= 0; i--)
                mutex_exit(&mcip->mci_tx_pcpu[i].pcpu_tx_lock);
}

static void
mac_tx_unlock_allbutzero(mac_client_impl_t *mcip)
{
        int     i;

        for (i = mac_tx_percpu_cnt; i > 0; i--)
                mutex_exit(&mcip->mci_tx_pcpu[i].pcpu_tx_lock);
}

static int
mac_tx_sum_refcnt(mac_client_impl_t *mcip)
{
        int     i;
        int     refcnt = 0;

        for (i = 0; i <= mac_tx_percpu_cnt; i++)
                refcnt += mcip->mci_tx_pcpu[i].pcpu_tx_refcnt;

        return (refcnt);
}

/*
 * Stop future Tx packets coming down from the client in preparation for
 * quiescing the Tx side. This is needed for dynamic reclaim and reassignment
 * of rings between clients
 */
void
mac_tx_client_block(mac_client_impl_t *mcip)
{
        mac_tx_lock_all(mcip);
        mcip->mci_tx_flag |= MCI_TX_QUIESCE;
        while (mac_tx_sum_refcnt(mcip) != 0) {
                mac_tx_unlock_allbutzero(mcip);
                cv_wait(&mcip->mci_tx_cv, &mcip->mci_tx_pcpu[0].pcpu_tx_lock);
                mutex_exit(&mcip->mci_tx_pcpu[0].pcpu_tx_lock);
                mac_tx_lock_all(mcip);
        }
        mac_tx_unlock_all(mcip);
}

void
mac_tx_client_unblock(mac_client_impl_t *mcip)
{
        mac_tx_lock_all(mcip);
        mcip->mci_tx_flag &= ~MCI_TX_QUIESCE;
        mac_tx_unlock_all(mcip);
        /*
         * We may fail to disable flow control for the last MAC_NOTE_TX
         * notification because the MAC client is quiesced. Send the
         * notification again.
         */
        i_mac_notify(mcip->mci_mip, MAC_NOTE_TX);
}

/*
 * Wait for an SRS to quiesce. The SRS worker will signal us when the
 * quiesce is done.
 */
static void
mac_srs_quiesce_wait(mac_soft_ring_set_t *srs,
    const mac_soft_ring_set_state_t srs_flag)
{
        mutex_enter(&srs->srs_lock);
        while (!(srs->srs_state & srs_flag))
                cv_wait(&srs->srs_quiesce_done_cv, &srs->srs_lock);
        mutex_exit(&srs->srs_lock);
}

/*
 * Quiescing an Rx SRS is achieved by the following sequence. The protocol
 * works bottom up by cutting off packet flow from the bottommost point in the
 * mac, then the SRS, and then the soft rings. There are 2 use cases of this
 * mechanism. One is a temporary quiesce of the SRS, such as say while changing
 * the Rx callbacks. Another use case is Rx SRS teardown. In the former case
 * the QUIESCE prefix/suffix is used and in the latter the CONDEMNED is used
 * for the SRS and MR flags. In the former case the threads pause waiting for
 * a restart, while in the latter case the threads exit. The Tx SRS teardown
 * is also mostly similar to the above.
 *
 * 1. Stop future hardware classified packets at the lowest level in the mac.
 *    Remove any hardware classification rule (CONDEMNED case) and mark the
 *    rings as CONDEMNED or QUIESCE as appropriate. This prevents the mr_refcnt
 *    from increasing. Upcalls from the driver that come through hardware
 *    classification will be dropped in mac_rx from now on. Then we wait for
 *    the mr_refcnt to drop to zero. When the mr_refcnt reaches zero we are
 *    sure there aren't any upcall threads from the driver through hardware
 *    classification. In the case of SRS teardown we also remove the
 *    classification rule in the driver.
 *
 * 2. Stop future software classified packets by marking the flow entry with
 *    FE_QUIESCE or FE_CONDEMNED as appropriate which prevents the refcnt from
 *    increasing. We also remove the flow entry from the table in the latter
 *    case. Then wait for the fe_refcnt to reach an appropriate quiescent value
 *    that indicates there aren't any active threads using that flow entry.
 *
 * 3. Quiesce the SRS and softrings by signaling the SRS. The SRS poll thread,
 *    SRS worker thread, and the soft ring threads are quiesced in sequence
 *    with the SRS worker thread serving as a master controller. This
 *    mechansim is explained in mac_srs_worker_quiesce().
 *
 * The restart mechanism to reactivate the SRS and softrings is explained
 * in mac_srs_worker_restart(). Here we just signal the SRS worker to start the
 * restart sequence.
 */
void
mac_rx_srs_quiesce(mac_soft_ring_set_t *srs,
    const mac_soft_ring_set_state_t srs_quiesce_flag)
{
        flow_entry_t *flent = srs->srs_flent;
        uint_t mr_flag;
        mac_soft_ring_set_state_t srs_done_flag;

        VERIFY(mac_perim_held((mac_handle_t)FLENT_TO_MIP(flent)));
        VERIFY0(srs->srs_type & SRST_TX);

        if (srs_quiesce_flag == SRS_CONDEMNED) {
                mr_flag = MR_CONDEMNED;
                srs_done_flag = SRS_CONDEMNED_DONE;

                if (srs->srs_type & SRST_CLIENT_POLL_V4) {
                        mac_srs_client_poll_disable(srs->srs_mcip, srs,
                            B_FALSE);
                }

                if (srs->srs_type & SRST_CLIENT_POLL_V6) {
                        mac_srs_client_poll_disable(srs->srs_mcip, srs,
                            B_TRUE);
                }
        } else {
                VERIFY3U(srs_quiesce_flag, ==, SRS_QUIESCE);
                mr_flag = MR_QUIESCE;
                srs_done_flag = SRS_QUIESCE_DONE;
                mac_srs_client_poll_quiesce(srs->srs_mcip, srs);
        }

        if (srs->srs_ring != NULL) {
                mac_rx_ring_quiesce(srs->srs_ring, mr_flag);
        } else {
                /*
                 * SRS is driven by software classification. In case
                 * of CONDEMNED, the top level teardown functions will
                 * deal with flow removal.
                 */
                if (srs_quiesce_flag != SRS_CONDEMNED) {
                        FLOW_MARK(flent, FE_QUIESCE);
                        mac_flow_wait(flent, FLOW_DRIVER_UPCALL);
                }
        }

        /*
         * Signal the SRS to quiesce itself, and then cv_wait for the
         * SRS quiesce to complete. The SRS worker thread will wake us
         * up when the quiesce is complete
         */
        mac_srs_signal(srs, srs_quiesce_flag);
        mac_srs_quiesce_wait(srs, srs_done_flag);
}

/*
 * Remove an SRS.
 */
void
mac_rx_srs_remove(mac_soft_ring_set_t *srs)
{
        flow_entry_t *flent = srs->srs_flent;
        int i;

        mac_rx_srs_quiesce(srs, SRS_CONDEMNED);
        /*
         * Locate and remove our entry in the fe_rx_srs[] array, and
         * adjust the fe_rx_srs array entries and array count by
         * moving the last entry into the vacated spot.
         */
        mutex_enter(&flent->fe_lock);
        for (i = 0; i < flent->fe_rx_srs_cnt; i++) {
                if (flent->fe_rx_srs[i] == srs)
                        break;
        }

        ASSERT(i != 0 && i < flent->fe_rx_srs_cnt);
        if (i != flent->fe_rx_srs_cnt - 1) {
                flent->fe_rx_srs[i] =
                    flent->fe_rx_srs[flent->fe_rx_srs_cnt - 1];
                i = flent->fe_rx_srs_cnt - 1;
        }

        flent->fe_rx_srs[i] = NULL;
        flent->fe_rx_srs_cnt--;
        mutex_exit(&flent->fe_lock);

        mac_srs_free(srs);
}

static void
mac_srs_clear_flag(mac_soft_ring_set_t *srs,
    const mac_soft_ring_set_state_t flag)
{
        mutex_enter(&srs->srs_lock);
        srs->srs_state &= ~flag;
        mutex_exit(&srs->srs_lock);
}

void
mac_rx_srs_restart(mac_soft_ring_set_t *srs)
{
        flow_entry_t    *flent = srs->srs_flent;
        mac_ring_t      *mr;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)FLENT_TO_MIP(flent)));
        ASSERT((srs->srs_type & SRST_TX) == 0);

        /*
         * This handles a change in the number of SRSs between the quiesce and
         * and restart operation of a flow.
         */
        if (!SRS_QUIESCED(srs))
                return;

        /*
         * Signal the SRS to restart itself. Wait for the restart to complete
         * Note that we only restart the SRS if it is not marked as
         * permanently quiesced.
         */
        if (!SRS_QUIESCED_PERMANENT(srs)) {
                mac_srs_signal(srs, SRS_RESTART);
                mac_srs_quiesce_wait(srs, SRS_RESTART_DONE);
                mac_srs_clear_flag(srs, SRS_RESTART_DONE);

                mac_srs_client_poll_restart(srs->srs_mcip, srs);
        }

        /* Finally clear the flags to let the packets in */
        mr = srs->srs_ring;
        if (mr != NULL) {
                MAC_RING_UNMARK(mr, MR_QUIESCE);
                /* In case the ring was stopped, safely restart it */
                if (mr->mr_state != MR_INUSE)
                        (void) mac_start_ring(mr);
        } else {
                FLOW_UNMARK(flent, FE_QUIESCE);
        }
}

/*
 * Temporary quiesce of a flow and associated Rx SRS.
 * Please see block comment above mac_rx_classify_flow_rem.
 */
/* ARGSUSED */
int
mac_rx_classify_flow_quiesce(flow_entry_t *flent, void *arg)
{
        int             i;

        for (i = 0; i < flent->fe_rx_srs_cnt; i++) {
                mac_rx_srs_quiesce((mac_soft_ring_set_t *)flent->fe_rx_srs[i],
                    SRS_QUIESCE);
        }
        return (0);
}

/*
 * Restart a flow and associated Rx SRS that has been quiesced temporarily
 * Please see block comment above mac_rx_classify_flow_rem
 */
/* ARGSUSED */
int
mac_rx_classify_flow_restart(flow_entry_t *flent, void *arg)
{
        int             i;

        for (i = 0; i < flent->fe_rx_srs_cnt; i++)
                mac_rx_srs_restart((mac_soft_ring_set_t *)flent->fe_rx_srs[i]);

        return (0);
}

void
mac_srs_perm_quiesce(mac_client_handle_t mch, boolean_t on)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        flow_entry_t            *flent = mcip->mci_flent;
        mac_impl_t              *mip = mcip->mci_mip;
        mac_soft_ring_set_t     *mac_srs;
        int                     i;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        if (flent == NULL)
                return;

        for (i = 0; i < flent->fe_rx_srs_cnt; i++) {
                mac_srs = flent->fe_rx_srs[i];
                mutex_enter(&mac_srs->srs_lock);
                if (on)
                        mac_srs->srs_state |= SRS_QUIESCE_PERM;
                else
                        mac_srs->srs_state &= ~SRS_QUIESCE_PERM;
                mutex_exit(&mac_srs->srs_lock);
        }
}

void
mac_rx_client_quiesce(mac_client_handle_t mch)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_impl_t              *mip = mcip->mci_mip;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        if (MCIP_DATAPATH_SETUP(mcip)) {
                (void) mac_rx_classify_flow_quiesce(mcip->mci_flent,
                    NULL);
                (void) mac_flow_walk_nolock(mcip->mci_subflow_tab,
                    mac_rx_classify_flow_quiesce, NULL);
        }
}

void
mac_rx_client_restart(mac_client_handle_t mch)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_impl_t              *mip = mcip->mci_mip;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        if (MCIP_DATAPATH_SETUP(mcip)) {
                (void) mac_rx_classify_flow_restart(mcip->mci_flent, NULL);
                (void) mac_flow_walk_nolock(mcip->mci_subflow_tab,
                    mac_rx_classify_flow_restart, NULL);
        }
}

/*
 * This function only quiesces the Tx SRS and softring worker threads. Callers
 * need to make sure that there aren't any mac client threads doing current or
 * future transmits in the mac before calling this function.
 */
void
mac_tx_srs_quiesce(mac_soft_ring_set_t *srs,
    const mac_soft_ring_set_state_t srs_quiesce_flag)
{
        mac_client_impl_t       *mcip = srs->srs_mcip;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mcip->mci_mip));

        ASSERT(srs->srs_type & SRST_TX);
        ASSERT(srs_quiesce_flag == SRS_CONDEMNED ||
            srs_quiesce_flag == SRS_QUIESCE);

        /*
         * Signal the SRS to quiesce itself, and then cv_wait for the
         * SRS quiesce to complete. The SRS worker thread will wake us
         * up when the quiesce is complete
         */
        mac_srs_signal(srs, srs_quiesce_flag);
        mac_srs_quiesce_wait(srs, srs_quiesce_flag == SRS_QUIESCE ?
            SRS_QUIESCE_DONE : SRS_CONDEMNED_DONE);
}

void
mac_tx_srs_restart(mac_soft_ring_set_t *srs)
{
        /*
         * Resizing the fanout could result in creation of new SRSs.
         * They may not necessarily be in the quiesced state in which
         * case it need be restarted
         */
        if (!SRS_QUIESCED(srs))
                return;

        mac_srs_signal(srs, SRS_RESTART);
        mac_srs_quiesce_wait(srs, SRS_RESTART_DONE);
        mac_srs_clear_flag(srs, SRS_RESTART_DONE);
}

/*
 * Temporary quiesce of a flow and associated Rx SRS.
 * Please see block comment above mac_rx_srs_quiesce
 */
/* ARGSUSED */
int
mac_tx_flow_quiesce(flow_entry_t *flent, void *arg)
{
        /*
         * The fe_tx_srs is null for a subflow on an interface that is
         * not plumbed
         */
        if (flent->fe_tx_srs != NULL)
                mac_tx_srs_quiesce(flent->fe_tx_srs, SRS_QUIESCE);
        return (0);
}

/* ARGSUSED */
int
mac_tx_flow_restart(flow_entry_t *flent, void *arg)
{
        /*
         * The fe_tx_srs is null for a subflow on an interface that is
         * not plumbed
         */
        if (flent->fe_tx_srs != NULL)
                mac_tx_srs_restart(flent->fe_tx_srs);
        return (0);
}

static void
i_mac_tx_client_quiesce(mac_client_handle_t mch,
    const mac_soft_ring_set_state_t srs_quiesce_flag)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mcip->mci_mip));

        mac_tx_client_block(mcip);
        if (MCIP_TX_SRS(mcip) != NULL) {
                mac_tx_srs_quiesce(MCIP_TX_SRS(mcip), srs_quiesce_flag);
                (void) mac_flow_walk_nolock(mcip->mci_subflow_tab,
                    mac_tx_flow_quiesce, NULL);
        }
}

void
mac_tx_client_quiesce(mac_client_handle_t mch)
{
        i_mac_tx_client_quiesce(mch, SRS_QUIESCE);
}

void
mac_tx_client_condemn(mac_client_handle_t mch)
{
        i_mac_tx_client_quiesce(mch, SRS_CONDEMNED);
}

void
mac_tx_client_restart(mac_client_handle_t mch)
{
        mac_client_impl_t *mcip = (mac_client_impl_t *)mch;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mcip->mci_mip));

        mac_tx_client_unblock(mcip);
        if (MCIP_TX_SRS(mcip) != NULL) {
                mac_tx_srs_restart(MCIP_TX_SRS(mcip));
                (void) mac_flow_walk_nolock(mcip->mci_subflow_tab,
                    mac_tx_flow_restart, NULL);
        }
}

void
mac_tx_client_flush(mac_client_impl_t *mcip)
{
        ASSERT(MAC_PERIM_HELD((mac_handle_t)mcip->mci_mip));

        mac_tx_client_quiesce((mac_client_handle_t)mcip);
        mac_tx_client_restart((mac_client_handle_t)mcip);
}

void
mac_client_quiesce(mac_client_impl_t *mcip)
{
        mac_rx_client_quiesce((mac_client_handle_t)mcip);
        mac_tx_client_quiesce((mac_client_handle_t)mcip);
}

void
mac_client_restart(mac_client_impl_t *mcip)
{
        mac_rx_client_restart((mac_client_handle_t)mcip);
        mac_tx_client_restart((mac_client_handle_t)mcip);
}

/*
 * Allocate a minor number.
 */
minor_t
mac_minor_hold(boolean_t sleep)
{
        id_t id;

        /*
         * Grab a value from the arena.
         */
        atomic_inc_32(&minor_count);

        if (sleep)
                return ((uint_t)id_alloc(minor_ids));

        if ((id = id_alloc_nosleep(minor_ids)) == -1) {
                atomic_dec_32(&minor_count);
                return (0);
        }

        return ((uint_t)id);
}

/*
 * Release a previously allocated minor number.
 */
void
mac_minor_rele(minor_t minor)
{
        /*
         * Return the value to the arena.
         */
        id_free(minor_ids, minor);
        atomic_dec_32(&minor_count);
}

uint32_t
mac_no_notification(mac_handle_t mh)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        return (((mip->mi_state_flags & MIS_LEGACY) != 0) ?
            mip->mi_capab_legacy.ml_unsup_note : 0);
}

/*
 * Prevent any new opens of this mac in preparation for unregister
 */
int
i_mac_disable(mac_impl_t *mip)
{
        mac_client_impl_t       *mcip;

        rw_enter(&i_mac_impl_lock, RW_WRITER);
        if (mip->mi_state_flags & MIS_DISABLED) {
                /* Already disabled, return success */
                rw_exit(&i_mac_impl_lock);
                return (0);
        }
        /*
         * See if there are any other references to this mac_t (e.g., VLAN's).
         * If so return failure. If all the other checks below pass, then
         * set mi_disabled atomically under the i_mac_impl_lock to prevent
         * any new VLAN's from being created or new mac client opens of this
         * mac end point.
         */
        if (mip->mi_ref > 0) {
                rw_exit(&i_mac_impl_lock);
                return (EBUSY);
        }

        /*
         * mac clients must delete all multicast groups they join before
         * closing. bcast groups are reference counted, the last client
         * to delete the group will wait till the group is physically
         * deleted. Since all clients have closed this mac end point
         * mi_bcast_ngrps must be zero at this point
         */
        ASSERT(mip->mi_bcast_ngrps == 0);

        /*
         * Don't let go of this if it has some flows.
         * All other code guarantees no flows are added to a disabled
         * mac, therefore it is sufficient to check for the flow table
         * only here.
         */
        mcip = mac_primary_client_handle(mip);
        if ((mcip != NULL) && mac_link_has_flows((mac_client_handle_t)mcip)) {
                rw_exit(&i_mac_impl_lock);
                return (ENOTEMPTY);
        }

        mip->mi_state_flags |= MIS_DISABLED;
        rw_exit(&i_mac_impl_lock);
        return (0);
}

int
mac_disable_nowait(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;
        int err;

        if ((err = i_mac_perim_enter_nowait(mip)) != 0)
                return (err);
        err = i_mac_disable(mip);
        i_mac_perim_exit(mip);
        return (err);
}

int
mac_disable(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;
        int err;

        i_mac_perim_enter(mip);
        err = i_mac_disable(mip);
        i_mac_perim_exit(mip);

        /*
         * Clean up notification thread and wait for it to exit.
         */
        if (err == 0)
                i_mac_notify_exit(mip);

        return (err);
}

/*
 * Called when the MAC instance has a non empty flow table, to de-multiplex
 * incoming packets to the right flow.
 */
/* ARGSUSED */
static flow_entry_t *
mac_rx_classify(mac_impl_t *mip, mac_resource_handle_t mrh, mblk_t *mp)
{
        flow_entry_t    *flent = NULL;
        uint_t          flags = FLOW_INBOUND;
        int             err;

        err = mac_flow_lookup(mip->mi_flow_tab, mp, flags, &flent);
        if (err == 0) {
                mac_client_impl_t       *mcip;

                /*
                 * This flent might just be an additional one on the MAC client,
                 * i.e. for classification purposes (different fdesc), however
                 * the resources, SRS et. al., are in the mci_flent, so if
                 * this isn't the mci_flent, we need to get it.
                 */
                if ((mcip = flent->fe_mcip) != NULL &&
                    mcip->mci_flent != flent) {
                        FLOW_REFRELE(flent);
                        flent = mcip->mci_flent;
                        FLOW_TRY_REFHOLD(flent, err);
                        if (err != 0)
                                return (NULL);
                }
        }

        /* flent will be NULL if mac_flow_lookup fails to find a match. */
        return (flent);
}

mblk_t *
mac_rx_flow(mac_handle_t mh, mac_resource_handle_t mrh, mblk_t *mp_chain)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;
        mblk_t          *mp_next, *tail, **unclass_nextp;
        mblk_t          *unclass_list = NULL;
        flow_entry_t    *prev_flent = NULL;

        /*
         * We walk the chain and attempt to classify each packet.
         * The packets that couldn't be classified will be returned
         * back to the caller.
         *
         * We want to batch together runs of matched packets bound
         * for the same flent into the same callback. Unmatched
         * packets should not break an ongoing chain.
         */
        mp_next = tail = mp_chain;
        unclass_nextp = &unclass_list;
        while (mp_next != NULL) {
                flow_entry_t    *flent;
                mblk_t          *mp = mp_next;
                mp_next = mp_next->b_next;
                mp->b_next = NULL;

                flent = mac_rx_classify(mip, mrh, mp);
                if (flent == NULL) {
                        /*
                         * Add the current mblk_t to the end of the
                         * unclassified packet chain at 'unclass_list'.
                         * Move the current head forward if we have not
                         * yet made any match.
                         */
                        if (prev_flent == NULL) {
                                mp_chain = mp_next;
                                tail = mp_next;
                        }
                        *unclass_nextp = mp;
                        unclass_nextp = &mp->b_next;
                        continue;
                }

                if (prev_flent == NULL || flent == prev_flent) {
                        /* Either the first valid match, or in the same chain */
                        if (prev_flent != NULL)
                                FLOW_REFRELE(prev_flent);
                        if (mp != tail)
                                tail->b_next = mp;
                } else {
                        ASSERT3P(prev_flent, !=, NULL);
                        (prev_flent->fe_cb_fn)(prev_flent->fe_cb_arg1,
                            prev_flent->fe_cb_arg2, mp_chain, B_FALSE);
                        FLOW_REFRELE(prev_flent);
                        mp_chain = mp;
                }

                prev_flent = flent;
                tail = mp;
        }
        /* Last chain */
        if (mp_chain != NULL) {
                ASSERT3P(prev_flent, !=, NULL);
                (prev_flent->fe_cb_fn)(prev_flent->fe_cb_arg1,
                    prev_flent->fe_cb_arg2, mp_chain, B_FALSE);
                FLOW_REFRELE(prev_flent);
        }
        return (unclass_list);
}

static int
mac_tx_flow_srs_wakeup(flow_entry_t *flent, void *arg)
{
        mac_ring_handle_t ring = arg;

        if (flent->fe_tx_srs)
                mac_tx_srs_wakeup(flent->fe_tx_srs, ring);
        return (0);
}

void
i_mac_tx_srs_notify(mac_impl_t *mip, mac_ring_handle_t ring)
{
        mac_client_impl_t       *cclient;
        mac_soft_ring_set_t     *mac_srs;

        /*
         * After grabbing the mi_rw_lock, the list of clients can't change.
         * If there are any clients mi_disabled must be B_FALSE and can't
         * get set since there are clients. If there aren't any clients we
         * don't do anything. In any case the mip has to be valid. The driver
         * must make sure that it goes single threaded (with respect to mac
         * calls) and wait for all pending mac calls to finish before calling
         * mac_unregister.
         */
        rw_enter(&i_mac_impl_lock, RW_READER);
        if (mip->mi_state_flags & MIS_DISABLED) {
                rw_exit(&i_mac_impl_lock);
                return;
        }

        /*
         * Get MAC tx srs from walking mac_client_handle list.
         */
        rw_enter(&mip->mi_rw_lock, RW_READER);
        for (cclient = mip->mi_clients_list; cclient != NULL;
            cclient = cclient->mci_client_next) {
                if ((mac_srs = MCIP_TX_SRS(cclient)) != NULL) {
                        mac_tx_srs_wakeup(mac_srs, ring);
                } else {
                        /*
                         * Aggr opens underlying ports in exclusive mode
                         * and registers flow control callbacks using
                         * mac_tx_client_notify(). When opened in
                         * exclusive mode, Tx SRS won't be created
                         * during mac_unicast_add().
                         */
                        if (cclient->mci_state_flags & MCIS_EXCLUSIVE) {
                                mac_tx_invoke_callbacks(cclient,
                                    (mac_tx_cookie_t)ring);
                        }
                }
                (void) mac_flow_walk(cclient->mci_subflow_tab,
                    mac_tx_flow_srs_wakeup, ring);
        }
        rw_exit(&mip->mi_rw_lock);
        rw_exit(&i_mac_impl_lock);
}

/* ARGSUSED */
void
mac_multicast_refresh(mac_handle_t mh, mac_multicst_t refresh, void *arg,
    boolean_t add)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        i_mac_perim_enter((mac_impl_t *)mh);
        /*
         * If no specific refresh function was given then default to the
         * driver's m_multicst entry point.
         */
        if (refresh == NULL) {
                refresh = mip->mi_multicst;
                arg = mip->mi_driver;
        }

        mac_bcast_refresh(mip, refresh, arg, add);
        i_mac_perim_exit((mac_impl_t *)mh);
}

void
mac_promisc_refresh(mac_handle_t mh, mac_setpromisc_t refresh, void *arg)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        /*
         * If no specific refresh function was given then default to the
         * driver's m_promisc entry point.
         */
        if (refresh == NULL) {
                refresh = mip->mi_setpromisc;
                arg = mip->mi_driver;
        }
        ASSERT(refresh != NULL);

        /*
         * Call the refresh function with the current promiscuity.
         */
        refresh(arg, (mip->mi_devpromisc != 0));
}

/*
 * The mac client requests that the mac not to change its margin size to
 * be less than the specified value.  If "current" is B_TRUE, then the client
 * requests the mac not to change its margin size to be smaller than the
 * current size. Further, return the current margin size value in this case.
 *
 * We keep every requested size in an ordered list from largest to smallest.
 */
int
mac_margin_add(mac_handle_t mh, uint32_t *marginp, boolean_t current)
{
        mac_impl_t              *mip = (mac_impl_t *)mh;
        mac_margin_req_t        **pp, *p;
        int                     err = 0;

        rw_enter(&(mip->mi_rw_lock), RW_WRITER);
        if (current)
                *marginp = mip->mi_margin;

        /*
         * If the current margin value cannot satisfy the margin requested,
         * return ENOTSUP directly.
         */
        if (*marginp > mip->mi_margin) {
                err = ENOTSUP;
                goto done;
        }

        /*
         * Check whether the given margin is already in the list. If so,
         * bump the reference count.
         */
        for (pp = &mip->mi_mmrp; (p = *pp) != NULL; pp = &p->mmr_nextp) {
                if (p->mmr_margin == *marginp) {
                        /*
                         * The margin requested is already in the list,
                         * so just bump the reference count.
                         */
                        p->mmr_ref++;
                        goto done;
                }
                if (p->mmr_margin < *marginp)
                        break;
        }


        p = kmem_zalloc(sizeof (mac_margin_req_t), KM_SLEEP);
        p->mmr_margin = *marginp;
        p->mmr_ref++;
        p->mmr_nextp = *pp;
        *pp = p;

done:
        rw_exit(&(mip->mi_rw_lock));
        return (err);
}

/*
 * The mac client requests to cancel its previous mac_margin_add() request.
 * We remove the requested margin size from the list.
 */
int
mac_margin_remove(mac_handle_t mh, uint32_t margin)
{
        mac_impl_t              *mip = (mac_impl_t *)mh;
        mac_margin_req_t        **pp, *p;
        int                     err = 0;

        rw_enter(&(mip->mi_rw_lock), RW_WRITER);
        /*
         * Find the entry in the list for the given margin.
         */
        for (pp = &(mip->mi_mmrp); (p = *pp) != NULL; pp = &(p->mmr_nextp)) {
                if (p->mmr_margin == margin) {
                        if (--p->mmr_ref == 0)
                                break;

                        /*
                         * There is still a reference to this address so
                         * there's nothing more to do.
                         */
                        goto done;
                }
        }

        /*
         * We did not find an entry for the given margin.
         */
        if (p == NULL) {
                err = ENOENT;
                goto done;
        }

        ASSERT(p->mmr_ref == 0);

        /*
         * Remove it from the list.
         */
        *pp = p->mmr_nextp;
        kmem_free(p, sizeof (mac_margin_req_t));
done:
        rw_exit(&(mip->mi_rw_lock));
        return (err);
}

boolean_t
mac_margin_update(mac_handle_t mh, uint32_t margin)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;
        uint32_t        margin_needed = 0;

        rw_enter(&(mip->mi_rw_lock), RW_WRITER);

        if (mip->mi_mmrp != NULL)
                margin_needed = mip->mi_mmrp->mmr_margin;

        if (margin_needed <= margin)
                mip->mi_margin = margin;

        rw_exit(&(mip->mi_rw_lock));

        if (margin_needed <= margin)
                i_mac_notify(mip, MAC_NOTE_MARGIN);

        return (margin_needed <= margin);
}

/*
 * MAC clients use this interface to request that a MAC device not change its
 * MTU below the specified amount. At this time, that amount must be within the
 * range of the device's current minimum and the device's current maximum. eg. a
 * client cannot request a 3000 byte MTU when the device's MTU is currently
 * 2000.
 *
 * If "current" is set to B_TRUE, then the request is to simply to reserve the
 * current underlying mac's maximum for this mac client and return it in mtup.
 */
int
mac_mtu_add(mac_handle_t mh, uint32_t *mtup, boolean_t current)
{
        mac_impl_t              *mip = (mac_impl_t *)mh;
        mac_mtu_req_t           *prev, *cur;
        mac_propval_range_t     mpr;
        int                     err;

        i_mac_perim_enter(mip);
        rw_enter(&mip->mi_rw_lock, RW_WRITER);

        if (current == B_TRUE)
                *mtup = mip->mi_sdu_max;
        mpr.mpr_count = 1;
        err = mac_prop_info(mh, MAC_PROP_MTU, "mtu", NULL, 0, &mpr, NULL);
        if (err != 0) {
                rw_exit(&mip->mi_rw_lock);
                i_mac_perim_exit(mip);
                return (err);
        }

        if (*mtup > mip->mi_sdu_max ||
            *mtup < mpr.mpr_range_uint32[0].mpur_min) {
                rw_exit(&mip->mi_rw_lock);
                i_mac_perim_exit(mip);
                return (ENOTSUP);
        }

        prev = NULL;
        for (cur = mip->mi_mtrp; cur != NULL; cur = cur->mtr_nextp) {
                if (*mtup == cur->mtr_mtu) {
                        cur->mtr_ref++;
                        rw_exit(&mip->mi_rw_lock);
                        i_mac_perim_exit(mip);
                        return (0);
                }

                if (*mtup > cur->mtr_mtu)
                        break;

                prev = cur;
        }

        cur = kmem_alloc(sizeof (mac_mtu_req_t), KM_SLEEP);
        cur->mtr_mtu = *mtup;
        cur->mtr_ref = 1;
        if (prev != NULL) {
                cur->mtr_nextp = prev->mtr_nextp;
                prev->mtr_nextp = cur;
        } else {
                cur->mtr_nextp = mip->mi_mtrp;
                mip->mi_mtrp = cur;
        }

        rw_exit(&mip->mi_rw_lock);
        i_mac_perim_exit(mip);
        return (0);
}

int
mac_mtu_remove(mac_handle_t mh, uint32_t mtu)
{
        mac_impl_t *mip = (mac_impl_t *)mh;
        mac_mtu_req_t *cur, *prev;

        i_mac_perim_enter(mip);
        rw_enter(&mip->mi_rw_lock, RW_WRITER);

        prev = NULL;
        for (cur = mip->mi_mtrp; cur != NULL; cur = cur->mtr_nextp) {
                if (cur->mtr_mtu == mtu) {
                        ASSERT(cur->mtr_ref > 0);
                        cur->mtr_ref--;
                        if (cur->mtr_ref == 0) {
                                if (prev == NULL) {
                                        mip->mi_mtrp = cur->mtr_nextp;
                                } else {
                                        prev->mtr_nextp = cur->mtr_nextp;
                                }
                                kmem_free(cur, sizeof (mac_mtu_req_t));
                        }
                        rw_exit(&mip->mi_rw_lock);
                        i_mac_perim_exit(mip);
                        return (0);
                }

                prev = cur;
        }

        rw_exit(&mip->mi_rw_lock);
        i_mac_perim_exit(mip);
        return (ENOENT);
}

/*
 * MAC Type Plugin functions.
 */

mactype_t *
mactype_getplugin(const char *pname)
{
        mactype_t       *mtype = NULL;
        boolean_t       tried_modload = B_FALSE;

        mutex_enter(&i_mactype_lock);

find_registered_mactype:
        if (mod_hash_find(i_mactype_hash, (mod_hash_key_t)pname,
            (mod_hash_val_t *)&mtype) != 0) {
                if (!tried_modload) {
                        /*
                         * If the plugin has not yet been loaded, then
                         * attempt to load it now.  If modload() succeeds,
                         * the plugin should have registered using
                         * mactype_register(), in which case we can go back
                         * and attempt to find it again.
                         */
                        if (modload(MACTYPE_KMODDIR, (char *)pname) != -1) {
                                tried_modload = B_TRUE;
                                goto find_registered_mactype;
                        }
                }
        } else {
                /*
                 * Note that there's no danger that the plugin we've loaded
                 * could be unloaded between the modload() step and the
                 * reference count bump here, as we're holding
                 * i_mactype_lock, which mactype_unregister() also holds.
                 */
                atomic_inc_32(&mtype->mt_ref);
        }

        mutex_exit(&i_mactype_lock);
        return (mtype);
}

mactype_register_t *
mactype_alloc(uint_t mactype_version)
{
        mactype_register_t *mtrp;

        /*
         * Make sure there isn't a version mismatch between the plugin and
         * the framework.  In the future, if multiple versions are
         * supported, this check could become more sophisticated.
         */
        if (mactype_version != MACTYPE_VERSION)
                return (NULL);

        mtrp = kmem_zalloc(sizeof (mactype_register_t), KM_SLEEP);
        mtrp->mtr_version = mactype_version;
        return (mtrp);
}

void
mactype_free(mactype_register_t *mtrp)
{
        kmem_free(mtrp, sizeof (mactype_register_t));
}

int
mactype_register(mactype_register_t *mtrp)
{
        mactype_t       *mtp;
        mactype_ops_t   *ops = mtrp->mtr_ops;

        /* Do some sanity checking before we register this MAC type. */
        if (mtrp->mtr_ident == NULL || ops == NULL)
                return (EINVAL);

        /*
         * Verify that all mandatory callbacks are set in the ops
         * vector.
         */
        if (ops->mtops_unicst_verify == NULL ||
            ops->mtops_multicst_verify == NULL ||
            ops->mtops_sap_verify == NULL ||
            ops->mtops_header == NULL ||
            ops->mtops_header_info == NULL) {
                return (EINVAL);
        }

        mtp = kmem_zalloc(sizeof (*mtp), KM_SLEEP);
        mtp->mt_ident = mtrp->mtr_ident;
        mtp->mt_ops = *ops;
        mtp->mt_type = mtrp->mtr_mactype;
        mtp->mt_nativetype = mtrp->mtr_nativetype;
        mtp->mt_addr_length = mtrp->mtr_addrlen;
        if (mtrp->mtr_brdcst_addr != NULL) {
                mtp->mt_brdcst_addr = kmem_alloc(mtrp->mtr_addrlen, KM_SLEEP);
                bcopy(mtrp->mtr_brdcst_addr, mtp->mt_brdcst_addr,
                    mtrp->mtr_addrlen);
        }

        mtp->mt_stats = mtrp->mtr_stats;
        mtp->mt_statcount = mtrp->mtr_statcount;

        mtp->mt_mapping = mtrp->mtr_mapping;
        mtp->mt_mappingcount = mtrp->mtr_mappingcount;

        if (mod_hash_insert(i_mactype_hash,
            (mod_hash_key_t)mtp->mt_ident, (mod_hash_val_t)mtp) != 0) {
                kmem_free(mtp->mt_brdcst_addr, mtp->mt_addr_length);
                kmem_free(mtp, sizeof (*mtp));
                return (EEXIST);
        }
        return (0);
}

int
mactype_unregister(const char *ident)
{
        mactype_t       *mtp;
        mod_hash_val_t  val;
        int             err;

        /*
         * Let's not allow MAC drivers to use this plugin while we're
         * trying to unregister it.  Holding i_mactype_lock also prevents a
         * plugin from unregistering while a MAC driver is attempting to
         * hold a reference to it in i_mactype_getplugin().
         */
        mutex_enter(&i_mactype_lock);

        if ((err = mod_hash_find(i_mactype_hash, (mod_hash_key_t)ident,
            (mod_hash_val_t *)&mtp)) != 0) {
                /* A plugin is trying to unregister, but it never registered. */
                err = ENXIO;
                goto done;
        }

        if (mtp->mt_ref != 0) {
                err = EBUSY;
                goto done;
        }

        err = mod_hash_remove(i_mactype_hash, (mod_hash_key_t)ident, &val);
        ASSERT(err == 0);
        if (err != 0) {
                /* This should never happen, thus the ASSERT() above. */
                err = EINVAL;
                goto done;
        }
        ASSERT(mtp == (mactype_t *)val);

        if (mtp->mt_brdcst_addr != NULL)
                kmem_free(mtp->mt_brdcst_addr, mtp->mt_addr_length);
        kmem_free(mtp, sizeof (mactype_t));
done:
        mutex_exit(&i_mactype_lock);
        return (err);
}

/*
 * Checks the size of the value size specified for a property as
 * part of a property operation. Returns B_TRUE if the size is
 * correct, B_FALSE otherwise.
 */
boolean_t
mac_prop_check_size(mac_prop_id_t id, uint_t valsize, boolean_t is_range)
{
        uint_t minsize = 0;

        if (is_range)
                return (valsize >= sizeof (mac_propval_range_t));

        switch (id) {
        case MAC_PROP_ZONE:
                minsize = sizeof (dld_ioc_zid_t);
                break;
        case MAC_PROP_AUTOPUSH:
                if (valsize != 0)
                        minsize = sizeof (struct dlautopush);
                break;
        case MAC_PROP_TAGMODE:
                minsize = sizeof (link_tagmode_t);
                break;
        case MAC_PROP_RESOURCE:
        case MAC_PROP_RESOURCE_EFF:
                minsize = sizeof (mac_resource_props_t);
                break;
        case MAC_PROP_DUPLEX:
                minsize = sizeof (link_duplex_t);
                break;
        case MAC_PROP_SPEED:
                minsize = sizeof (uint64_t);
                break;
        case MAC_PROP_STATUS:
                minsize = sizeof (link_state_t);
                break;
        case MAC_PROP_AUTONEG:
        case MAC_PROP_EN_AUTONEG:
                minsize = sizeof (uint8_t);
                break;
        case MAC_PROP_MTU:
        case MAC_PROP_LLIMIT:
        case MAC_PROP_LDECAY:
                minsize = sizeof (uint32_t);
                break;
        case MAC_PROP_FLOWCTRL:
                minsize = sizeof (link_flowctrl_t);
                break;
        case MAC_PROP_ADV_FEC_CAP:
        case MAC_PROP_EN_FEC_CAP:
                minsize = sizeof (link_fec_t);
                break;
        case MAC_PROP_ADV_400GFDX_CAP:
        case MAC_PROP_EN_400GFDX_CAP:
        case MAC_PROP_ADV_200GFDX_CAP:
        case MAC_PROP_EN_200GFDX_CAP:
        case MAC_PROP_ADV_100GFDX_CAP:
        case MAC_PROP_EN_100GFDX_CAP:
        case MAC_PROP_ADV_50GFDX_CAP:
        case MAC_PROP_EN_50GFDX_CAP:
        case MAC_PROP_ADV_40GFDX_CAP:
        case MAC_PROP_EN_40GFDX_CAP:
        case MAC_PROP_ADV_25GFDX_CAP:
        case MAC_PROP_EN_25GFDX_CAP:
        case MAC_PROP_ADV_10GFDX_CAP:
        case MAC_PROP_EN_10GFDX_CAP:
        case MAC_PROP_ADV_5000FDX_CAP:
        case MAC_PROP_EN_5000FDX_CAP:
        case MAC_PROP_ADV_2500FDX_CAP:
        case MAC_PROP_EN_2500FDX_CAP:
        case MAC_PROP_ADV_1000HDX_CAP:
        case MAC_PROP_EN_1000HDX_CAP:
        case MAC_PROP_ADV_100FDX_CAP:
        case MAC_PROP_EN_100FDX_CAP:
        case MAC_PROP_ADV_100T4_CAP:
        case MAC_PROP_EN_100T4_CAP:
        case MAC_PROP_ADV_100HDX_CAP:
        case MAC_PROP_EN_100HDX_CAP:
        case MAC_PROP_ADV_10FDX_CAP:
        case MAC_PROP_EN_10FDX_CAP:
        case MAC_PROP_ADV_10HDX_CAP:
        case MAC_PROP_EN_10HDX_CAP:
                minsize = sizeof (uint8_t);
                break;
        case MAC_PROP_PVID:
                minsize = sizeof (uint16_t);
                break;
        case MAC_PROP_IPTUN_HOPLIMIT:
                minsize = sizeof (uint32_t);
                break;
        case MAC_PROP_IPTUN_ENCAPLIMIT:
                minsize = sizeof (uint32_t);
                break;
        case MAC_PROP_MAX_TX_RINGS_AVAIL:
        case MAC_PROP_MAX_RX_RINGS_AVAIL:
        case MAC_PROP_MAX_RXHWCLNT_AVAIL:
        case MAC_PROP_MAX_TXHWCLNT_AVAIL:
                minsize = sizeof (uint_t);
                break;
        case MAC_PROP_WL_ESSID:
                minsize = sizeof (wl_linkstatus_t);
                break;
        case MAC_PROP_WL_BSSID:
                minsize = sizeof (wl_bssid_t);
                break;
        case MAC_PROP_WL_BSSTYPE:
                minsize = sizeof (wl_bss_type_t);
                break;
        case MAC_PROP_WL_LINKSTATUS:
                minsize = sizeof (wl_linkstatus_t);
                break;
        case MAC_PROP_WL_DESIRED_RATES:
                minsize = sizeof (wl_rates_t);
                break;
        case MAC_PROP_WL_SUPPORTED_RATES:
                minsize = sizeof (wl_rates_t);
                break;
        case MAC_PROP_WL_AUTH_MODE:
                minsize = sizeof (wl_authmode_t);
                break;
        case MAC_PROP_WL_ENCRYPTION:
                minsize = sizeof (wl_encryption_t);
                break;
        case MAC_PROP_WL_RSSI:
                minsize = sizeof (wl_rssi_t);
                break;
        case MAC_PROP_WL_PHY_CONFIG:
                minsize = sizeof (wl_phy_conf_t);
                break;
        case MAC_PROP_WL_CAPABILITY:
                minsize = sizeof (wl_capability_t);
                break;
        case MAC_PROP_WL_WPA:
                minsize = sizeof (wl_wpa_t);
                break;
        case MAC_PROP_WL_SCANRESULTS:
                minsize = sizeof (wl_wpa_ess_t);
                break;
        case MAC_PROP_WL_POWER_MODE:
                minsize = sizeof (wl_ps_mode_t);
                break;
        case MAC_PROP_WL_RADIO:
                minsize = sizeof (wl_radio_t);
                break;
        case MAC_PROP_WL_ESS_LIST:
                minsize = sizeof (wl_ess_list_t);
                break;
        case MAC_PROP_WL_KEY_TAB:
                minsize = sizeof (wl_wep_key_tab_t);
                break;
        case MAC_PROP_WL_CREATE_IBSS:
                minsize = sizeof (wl_create_ibss_t);
                break;
        case MAC_PROP_WL_SETOPTIE:
                minsize = sizeof (wl_wpa_ie_t);
                break;
        case MAC_PROP_WL_DELKEY:
                minsize = sizeof (wl_del_key_t);
                break;
        case MAC_PROP_WL_KEY:
                minsize = sizeof (wl_key_t);
                break;
        case MAC_PROP_WL_MLME:
                minsize = sizeof (wl_mlme_t);
                break;
        case MAC_PROP_VN_PROMISC_FILTERED:
                minsize = sizeof (boolean_t);
                break;
        case MAC_PROP_MEDIA:
                /*
                 * Our assumption is that each class of device uses an enum and
                 * that all enums will be the same size so it is OK to use a
                 * single one.
                 */
                minsize = sizeof (mac_ether_media_t);
                break;
        }

        return (valsize >= minsize);
}

/*
 * mac_set_prop() sets MAC or hardware driver properties:
 *
 * - MAC-managed properties such as resource properties include maxbw,
 *   priority, and cpu binding list, as well as the default port VID
 *   used by bridging. These properties are consumed by the MAC layer
 *   itself and not passed down to the driver. For resource control
 *   properties, this function invokes mac_set_resources() which will
 *   cache the property value in mac_impl_t and may call
 *   mac_client_set_resource() to update property value of the primary
 *   mac client, if it exists.
 *
 * - Properties which act on the hardware and must be passed to the
 *   driver, such as MTU, through the driver's mc_setprop() entry point.
 */
int
mac_set_prop(mac_handle_t mh, mac_prop_id_t id, char *name, void *val,
    uint_t valsize)
{
        int err = ENOTSUP;
        mac_impl_t *mip = (mac_impl_t *)mh;

        ASSERT(MAC_PERIM_HELD(mh));

        switch (id) {
        case MAC_PROP_RESOURCE: {
                mac_resource_props_t *mrp;

                /* call mac_set_resources() for MAC properties */
                ASSERT(valsize >= sizeof (mac_resource_props_t));
                mrp = kmem_zalloc(sizeof (*mrp), KM_SLEEP);
                bcopy(val, mrp, sizeof (*mrp));
                err = mac_set_resources(mh, mrp);
                kmem_free(mrp, sizeof (*mrp));
                break;
        }

        case MAC_PROP_PVID:
                ASSERT(valsize >= sizeof (uint16_t));
                if (mip->mi_state_flags & MIS_IS_VNIC)
                        return (EINVAL);
                err = mac_set_pvid(mh, *(uint16_t *)val);
                break;

        case MAC_PROP_MTU: {
                uint32_t mtu;

                ASSERT(valsize >= sizeof (uint32_t));
                bcopy(val, &mtu, sizeof (mtu));
                err = mac_set_mtu(mh, mtu, NULL);
                break;
        }

        case MAC_PROP_LLIMIT:
        case MAC_PROP_LDECAY: {
                uint32_t learnval;

                if (valsize < sizeof (learnval) ||
                    (mip->mi_state_flags & MIS_IS_VNIC))
                        return (EINVAL);
                bcopy(val, &learnval, sizeof (learnval));
                if (learnval == 0 && id == MAC_PROP_LDECAY)
                        return (EINVAL);
                if (id == MAC_PROP_LLIMIT)
                        mip->mi_llimit = learnval;
                else
                        mip->mi_ldecay = learnval;
                err = 0;
                break;
        }

        case MAC_PROP_ADV_FEC_CAP:
        case MAC_PROP_EN_FEC_CAP: {
                link_fec_t fec;

                ASSERT(valsize >= sizeof (link_fec_t));

                /*
                 * fec cannot be zero, and auto must be set exclusively.
                 */
                bcopy(val, &fec, sizeof (link_fec_t));
                if (fec == 0)
                        return (EINVAL);
                if ((fec & LINK_FEC_AUTO) != 0 && (fec & ~LINK_FEC_AUTO) != 0)
                        return (EINVAL);

                if (mip->mi_callbacks->mc_callbacks & MC_SETPROP) {
                        err = mip->mi_callbacks->mc_setprop(mip->mi_driver,
                            name, id, valsize, val);
                }
                break;
        }

        default:
                /* For other driver properties, call driver's callback */
                if (mip->mi_callbacks->mc_callbacks & MC_SETPROP) {
                        err = mip->mi_callbacks->mc_setprop(mip->mi_driver,
                            name, id, valsize, val);
                }
        }
        return (err);
}

/*
 * mac_get_prop() gets MAC or device driver properties.
 *
 * If the property is a driver property, mac_get_prop() calls driver's callback
 * entry point to get it.
 * If the property is a MAC property, mac_get_prop() invokes mac_get_resources()
 * which returns the cached value in mac_impl_t.
 */
int
mac_get_prop(mac_handle_t mh, mac_prop_id_t id, char *name, void *val,
    uint_t valsize)
{
        int err = ENOTSUP;
        mac_impl_t *mip = (mac_impl_t *)mh;
        uint_t  rings;
        uint_t  vlinks;

        bzero(val, valsize);

        switch (id) {
        case MAC_PROP_RESOURCE: {
                mac_resource_props_t *mrp;

                /* If mac property, read from cache */
                ASSERT(valsize >= sizeof (mac_resource_props_t));
                mrp = kmem_zalloc(sizeof (*mrp), KM_SLEEP);
                mac_get_resources(mh, mrp);
                bcopy(mrp, val, sizeof (*mrp));
                kmem_free(mrp, sizeof (*mrp));
                return (0);
        }
        case MAC_PROP_RESOURCE_EFF: {
                mac_resource_props_t *mrp;

                /* If mac effective property, read from client */
                ASSERT(valsize >= sizeof (mac_resource_props_t));
                mrp = kmem_zalloc(sizeof (*mrp), KM_SLEEP);
                mac_get_effective_resources(mh, mrp);
                bcopy(mrp, val, sizeof (*mrp));
                kmem_free(mrp, sizeof (*mrp));
                return (0);
        }

        case MAC_PROP_PVID:
                ASSERT(valsize >= sizeof (uint16_t));
                if (mip->mi_state_flags & MIS_IS_VNIC)
                        return (EINVAL);
                *(uint16_t *)val = mac_get_pvid(mh);
                return (0);

        case MAC_PROP_LLIMIT:
        case MAC_PROP_LDECAY:
                ASSERT(valsize >= sizeof (uint32_t));
                if (mip->mi_state_flags & MIS_IS_VNIC)
                        return (EINVAL);
                if (id == MAC_PROP_LLIMIT)
                        bcopy(&mip->mi_llimit, val, sizeof (mip->mi_llimit));
                else
                        bcopy(&mip->mi_ldecay, val, sizeof (mip->mi_ldecay));
                return (0);

        case MAC_PROP_MTU: {
                uint32_t sdu;

                ASSERT(valsize >= sizeof (uint32_t));
                mac_sdu_get2(mh, NULL, &sdu, NULL);
                bcopy(&sdu, val, sizeof (sdu));

                return (0);
        }
        case MAC_PROP_STATUS: {
                link_state_t link_state;

                if (valsize < sizeof (link_state))
                        return (EINVAL);
                link_state = mac_link_get(mh);
                bcopy(&link_state, val, sizeof (link_state));

                return (0);
        }

        case MAC_PROP_MAX_RX_RINGS_AVAIL:
        case MAC_PROP_MAX_TX_RINGS_AVAIL:
                ASSERT(valsize >= sizeof (uint_t));
                rings = id == MAC_PROP_MAX_RX_RINGS_AVAIL ?
                    mac_rxavail_get(mh) : mac_txavail_get(mh);
                bcopy(&rings, val, sizeof (uint_t));
                return (0);

        case MAC_PROP_MAX_RXHWCLNT_AVAIL:
        case MAC_PROP_MAX_TXHWCLNT_AVAIL:
                ASSERT(valsize >= sizeof (uint_t));
                vlinks = id == MAC_PROP_MAX_RXHWCLNT_AVAIL ?
                    mac_rxhwlnksavail_get(mh) : mac_txhwlnksavail_get(mh);
                bcopy(&vlinks, val, sizeof (uint_t));
                return (0);

        case MAC_PROP_RXRINGSRANGE:
        case MAC_PROP_TXRINGSRANGE:
                /*
                 * The value for these properties are returned through
                 * the MAC_PROP_RESOURCE property.
                 */
                return (0);

        default:
                break;

        }

        /* If driver property, request from driver */
        if (mip->mi_callbacks->mc_callbacks & MC_GETPROP) {
                err = mip->mi_callbacks->mc_getprop(mip->mi_driver, name, id,
                    valsize, val);
        }

        return (err);
}

/*
 * Helper function to initialize the range structure for use in
 * mac_get_prop. If the type can be other than uint32, we can
 * pass that as an arg.
 */
static void
_mac_set_range(mac_propval_range_t *range, uint32_t min, uint32_t max)
{
        range->mpr_count = 1;
        range->mpr_type = MAC_PROPVAL_UINT32;
        range->mpr_range_uint32[0].mpur_min = min;
        range->mpr_range_uint32[0].mpur_max = max;
}

/*
 * Returns information about the specified property, such as default
 * values or permissions.
 */
int
mac_prop_info(mac_handle_t mh, mac_prop_id_t id, char *name,
    void *default_val, uint_t default_size, mac_propval_range_t *range,
    uint_t *perm)
{
        mac_prop_info_state_t state;
        mac_impl_t *mip = (mac_impl_t *)mh;
        uint_t  max;

        /*
         * A property is read/write by default unless the driver says
         * otherwise.
         */
        if (perm != NULL)
                *perm = MAC_PROP_PERM_RW;

        if (default_val != NULL)
                bzero(default_val, default_size);

        /*
         * First, handle framework properties for which we don't need to
         * involve the driver.
         */
        switch (id) {
        case MAC_PROP_RESOURCE:
        case MAC_PROP_PVID:
        case MAC_PROP_LLIMIT:
        case MAC_PROP_LDECAY:
                return (0);

        case MAC_PROP_MAX_RX_RINGS_AVAIL:
        case MAC_PROP_MAX_TX_RINGS_AVAIL:
        case MAC_PROP_MAX_RXHWCLNT_AVAIL:
        case MAC_PROP_MAX_TXHWCLNT_AVAIL:
                if (perm != NULL)
                        *perm = MAC_PROP_PERM_READ;
                return (0);

        case MAC_PROP_RXRINGSRANGE:
        case MAC_PROP_TXRINGSRANGE:
                /*
                 * Currently, we support range for RX and TX rings properties.
                 * When we extend this support to maxbw, cpus and priority,
                 * we should move this to mac_get_resources.
                 * There is no default value for RX or TX rings.
                 */
                if ((mip->mi_state_flags & MIS_IS_VNIC) &&
                    mac_is_vnic_primary(mh)) {
                        /*
                         * We don't support setting rings for a VLAN
                         * data link because it shares its ring with the
                         * primary MAC client.
                         */
                        if (perm != NULL)
                                *perm = MAC_PROP_PERM_READ;
                        if (range != NULL)
                                range->mpr_count = 0;
                } else if (range != NULL) {
                        if (mip->mi_state_flags & MIS_IS_VNIC)
                                mh = mac_get_lower_mac_handle(mh);
                        mip = (mac_impl_t *)mh;
                        if ((id == MAC_PROP_RXRINGSRANGE &&
                            mip->mi_rx_group_type == MAC_GROUP_TYPE_STATIC) ||
                            (id == MAC_PROP_TXRINGSRANGE &&
                            mip->mi_tx_group_type == MAC_GROUP_TYPE_STATIC)) {
                                if (id == MAC_PROP_RXRINGSRANGE) {
                                        if ((mac_rxhwlnksavail_get(mh) +
                                            mac_rxhwlnksrsvd_get(mh)) <= 1) {
                                                /*
                                                 * doesn't support groups or
                                                 * rings
                                                 */
                                                range->mpr_count = 0;
                                        } else {
                                                /*
                                                 * supports specifying groups,
                                                 * but not rings
                                                 */
                                                _mac_set_range(range, 0, 0);
                                        }
                                } else {
                                        if ((mac_txhwlnksavail_get(mh) +
                                            mac_txhwlnksrsvd_get(mh)) <= 1) {
                                                /*
                                                 * doesn't support groups or
                                                 * rings
                                                 */
                                                range->mpr_count = 0;
                                        } else {
                                                /*
                                                 * supports specifying groups,
                                                 * but not rings
                                                 */
                                                _mac_set_range(range, 0, 0);
                                        }
                                }
                        } else {
                                max = id == MAC_PROP_RXRINGSRANGE ?
                                    mac_rxavail_get(mh) + mac_rxrsvd_get(mh) :
                                    mac_txavail_get(mh) + mac_txrsvd_get(mh);
                                if (max <= 1) {
                                        /*
                                         * doesn't support groups or
                                         * rings
                                         */
                                        range->mpr_count = 0;
                                } else  {
                                        /*
                                         * -1 because we have to leave out the
                                         * default ring.
                                         */
                                        _mac_set_range(range, 1, max - 1);
                                }
                        }
                }
                return (0);

        case MAC_PROP_STATUS:
        case MAC_PROP_MEDIA:
                if (perm != NULL)
                        *perm = MAC_PROP_PERM_READ;
                return (0);
        }

        /*
         * Get the property info from the driver if it implements the
         * property info entry point.
         */
        bzero(&state, sizeof (state));

        if (mip->mi_callbacks->mc_callbacks & MC_PROPINFO) {
                state.pr_default = default_val;
                state.pr_default_size = default_size;

                /*
                 * The caller specifies the maximum number of ranges
                 * it can accomodate using mpr_count. We don't touch
                 * this value until the driver returns from its
                 * mc_propinfo() callback, and ensure we don't exceed
                 * this number of range as the driver defines
                 * supported range from its mc_propinfo().
                 *
                 * pr_range_cur_count keeps track of how many ranges
                 * were defined by the driver from its mc_propinfo()
                 * entry point.
                 *
                 * On exit, the user-specified range mpr_count returns
                 * the number of ranges specified by the driver on
                 * success, or the number of ranges it wanted to
                 * define if that number of ranges could not be
                 * accomodated by the specified range structure.  In
                 * the latter case, the caller will be able to
                 * allocate a larger range structure, and query the
                 * property again.
                 */
                state.pr_range_cur_count = 0;
                state.pr_range = range;

                mip->mi_callbacks->mc_propinfo(mip->mi_driver, name, id,
                    (mac_prop_info_handle_t)&state);

                if (state.pr_flags & MAC_PROP_INFO_RANGE)
                        range->mpr_count = state.pr_range_cur_count;

                /*
                 * The operation could fail if the buffer supplied by
                 * the user was too small for the range or default
                 * value of the property.
                 */
                if (state.pr_errno != 0)
                        return (state.pr_errno);

                if (perm != NULL && state.pr_flags & MAC_PROP_INFO_PERM)
                        *perm = state.pr_perm;
        }

        /*
         * The MAC layer may want to provide default values or allowed
         * ranges for properties if the driver does not provide a
         * property info entry point, or that entry point exists, but
         * it did not provide a default value or allowed ranges for
         * that property.
         */
        switch (id) {
        case MAC_PROP_MTU: {
                uint32_t sdu;

                mac_sdu_get2(mh, NULL, &sdu, NULL);

                if (range != NULL && !(state.pr_flags &
                    MAC_PROP_INFO_RANGE)) {
                        /* MTU range */
                        _mac_set_range(range, sdu, sdu);
                }

                if (default_val != NULL && !(state.pr_flags &
                    MAC_PROP_INFO_DEFAULT)) {
                        if (mip->mi_info.mi_media == DL_ETHER)
                                sdu = ETHERMTU;
                        /* default MTU value */
                        bcopy(&sdu, default_val, sizeof (sdu));
                }
        }
        }

        return (0);
}

int
mac_fastpath_disable(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        if ((mip->mi_state_flags & MIS_LEGACY) == 0)
                return (0);

        return (mip->mi_capab_legacy.ml_fastpath_disable(mip->mi_driver));
}

void
mac_fastpath_enable(mac_handle_t mh)
{
        mac_impl_t      *mip = (mac_impl_t *)mh;

        if ((mip->mi_state_flags & MIS_LEGACY) == 0)
                return;

        mip->mi_capab_legacy.ml_fastpath_enable(mip->mi_driver);
}

void
mac_register_priv_prop(mac_impl_t *mip, char **priv_props)
{
        uint_t nprops, i;

        if (priv_props == NULL)
                return;

        nprops = 0;
        while (priv_props[nprops] != NULL)
                nprops++;
        if (nprops == 0)
                return;


        mip->mi_priv_prop = kmem_zalloc(nprops * sizeof (char *), KM_SLEEP);

        for (i = 0; i < nprops; i++) {
                mip->mi_priv_prop[i] = kmem_zalloc(MAXLINKPROPNAME, KM_SLEEP);
                (void) strlcpy(mip->mi_priv_prop[i], priv_props[i],
                    MAXLINKPROPNAME);
        }

        mip->mi_priv_prop_count = nprops;
}

void
mac_unregister_priv_prop(mac_impl_t *mip)
{
        uint_t i;

        if (mip->mi_priv_prop_count == 0) {
                ASSERT(mip->mi_priv_prop == NULL);
                return;
        }

        for (i = 0; i < mip->mi_priv_prop_count; i++)
                kmem_free(mip->mi_priv_prop[i], MAXLINKPROPNAME);
        kmem_free(mip->mi_priv_prop, mip->mi_priv_prop_count *
            sizeof (char *));

        mip->mi_priv_prop = NULL;
        mip->mi_priv_prop_count = 0;
}

/*
 * mac_ring_t 'mr' macros. Some rogue drivers may access ring structure
 * (by invoking mac_rx()) even after processing mac_stop_ring(). In such
 * cases if MAC free's the ring structure after mac_stop_ring(), any
 * illegal access to the ring structure coming from the driver will panic
 * the system. In order to protect the system from such inadverent access,
 * we maintain a cache of rings in the mac_impl_t after they get free'd up.
 * When packets are received on free'd up rings, MAC (through the generation
 * count mechanism) will drop such packets.
 */
static mac_ring_t *
mac_ring_alloc(mac_impl_t *mip)
{
        mac_ring_t *ring;

        mutex_enter(&mip->mi_ring_lock);
        if (mip->mi_ring_freelist != NULL) {
                ring = mip->mi_ring_freelist;
                mip->mi_ring_freelist = ring->mr_next;
                bzero(ring, sizeof (mac_ring_t));
                mutex_exit(&mip->mi_ring_lock);
        } else {
                mutex_exit(&mip->mi_ring_lock);
                ring = kmem_cache_alloc(mac_ring_cache, KM_SLEEP);
        }
        ASSERT((ring != NULL) && (ring->mr_state == MR_FREE));
        return (ring);
}

static void
mac_ring_free(mac_impl_t *mip, mac_ring_t *ring)
{
        ASSERT(ring->mr_state == MR_FREE);

        mutex_enter(&mip->mi_ring_lock);
        ring->mr_state = MR_FREE;
        ring->mr_flag = 0;
        ring->mr_next = mip->mi_ring_freelist;
        ring->mr_mip = NULL;
        mip->mi_ring_freelist = ring;
        mac_ring_stat_delete(ring);
        mutex_exit(&mip->mi_ring_lock);
}

static void
mac_ring_freeall(mac_impl_t *mip)
{
        mac_ring_t *ring_next;
        mutex_enter(&mip->mi_ring_lock);
        mac_ring_t *ring = mip->mi_ring_freelist;
        while (ring != NULL) {
                ring_next = ring->mr_next;
                kmem_cache_free(mac_ring_cache, ring);
                ring = ring_next;
        }
        mip->mi_ring_freelist = NULL;
        mutex_exit(&mip->mi_ring_lock);
}

int
mac_start_ring(mac_ring_t *ring)
{
        int rv = 0;

        ASSERT(ring->mr_state == MR_FREE);

        if (ring->mr_start != NULL) {
                rv = ring->mr_start(ring->mr_driver, ring->mr_gen_num);
                if (rv != 0)
                        return (rv);
        }

        ring->mr_state = MR_INUSE;
        return (rv);
}

void
mac_stop_ring(mac_ring_t *ring)
{
        ASSERT(ring->mr_state == MR_INUSE);

        if (ring->mr_stop != NULL)
                ring->mr_stop(ring->mr_driver);

        ring->mr_state = MR_FREE;

        /*
         * Increment the ring generation number for this ring.
         */
        ring->mr_gen_num++;
}

int
mac_start_group(mac_group_t *group)
{
        int rv = 0;

        if (group->mrg_start != NULL)
                rv = group->mrg_start(group->mrg_driver);

        return (rv);
}

void
mac_stop_group(mac_group_t *group)
{
        if (group->mrg_stop != NULL)
                group->mrg_stop(group->mrg_driver);
}

/*
 * Called from mac_start() on the default Rx group. Broadcast and multicast
 * packets are received only on the default group. Hence the default group
 * needs to be up even if the primary client is not up, for the other groups
 * to be functional. We do this by calling this function at mac_start time
 * itself. However the broadcast packets that are received can't make their
 * way beyond mac_rx until a mac client creates a broadcast flow.
 */
static int
mac_start_group_and_rings(mac_group_t *group)
{
        mac_ring_t      *ring;
        int             rv = 0;

        ASSERT(group->mrg_state == MAC_GROUP_STATE_REGISTERED);
        if ((rv = mac_start_group(group)) != 0)
                return (rv);

        for (ring = group->mrg_rings; ring != NULL; ring = ring->mr_next) {
                ASSERT(ring->mr_state == MR_FREE);

                if ((rv = mac_start_ring(ring)) != 0)
                        goto error;

                /*
                 * When aggr_set_port_sdu() is called, it will remove
                 * the port client's unicast address. This will cause
                 * MAC to stop the default group's rings on the port
                 * MAC. After it modifies the SDU, it will then re-add
                 * the unicast address. At which time, this function is
                 * called to start the default group's rings. Normally
                 * this function would set the classify type to
                 * MAC_SW_CLASSIFIER; but that will break aggr which
                 * relies on the passthru classify mode being set for
                 * correct delivery (see mac_rx_common()). To avoid
                 * that, we check for a passthru callback and set the
                 * classify type to MAC_PASSTHRU_CLASSIFIER; as it was
                 * before the rings were stopped.
                 */
                ring->mr_classify_type = (ring->mr_pt_fn != NULL) ?
                    MAC_PASSTHRU_CLASSIFIER : MAC_SW_CLASSIFIER;
        }
        return (0);

error:
        mac_stop_group_and_rings(group);
        return (rv);
}

/* Called from mac_stop on the default Rx group */
static void
mac_stop_group_and_rings(mac_group_t *group)
{
        mac_ring_t      *ring;

        for (ring = group->mrg_rings; ring != NULL; ring = ring->mr_next) {
                if (ring->mr_state != MR_FREE) {
                        mac_stop_ring(ring);
                        ring->mr_flag = 0;
                        ring->mr_classify_type = MAC_NO_CLASSIFIER;
                }
        }
        mac_stop_group(group);
}


static mac_ring_t *
mac_init_ring(mac_impl_t *mip, mac_group_t *group, int index,
    mac_capab_rings_t *cap_rings)
{
        mac_ring_t *ring, *rnext;
        mac_ring_info_t ring_info;
        ddi_intr_handle_t ddi_handle;

        ring = mac_ring_alloc(mip);

        /* Prepare basic information of ring */

        /*
         * Ring index is numbered to be unique across a particular device.
         * Ring index computation makes following assumptions:
         *      - For drivers with static grouping (e.g. ixgbe, bge),
         *      ring index exchanged with the driver (e.g. during mr_rget)
         *      is unique only across the group the ring belongs to.
         *      - Drivers with dynamic grouping (e.g. nxge), start
         *      with single group (mrg_index = 0).
         */
        ring->mr_index = group->mrg_index * group->mrg_info.mgi_count + index;
        ring->mr_type = group->mrg_type;
        ring->mr_gh = (mac_group_handle_t)group;

        /* Insert the new ring to the list. */
        ring->mr_next = group->mrg_rings;
        group->mrg_rings = ring;

        /* Zero to reuse the info data structure */
        bzero(&ring_info, sizeof (ring_info));

        /* Query ring information from driver */
        cap_rings->mr_rget(mip->mi_driver, group->mrg_type, group->mrg_index,
            index, &ring_info, (mac_ring_handle_t)ring);

        ring->mr_info = ring_info;

        /*
         * The interrupt handle could be shared among multiple rings.
         * Thus if there is a bunch of rings that are sharing an
         * interrupt, then only one ring among the bunch will be made
         * available for interrupt re-targeting; the rest will have
         * ddi_shared flag set to TRUE and would not be available for
         * be interrupt re-targeting.
         */
        if ((ddi_handle = ring_info.mri_intr.mi_ddi_handle) != NULL) {
                rnext = ring->mr_next;
                while (rnext != NULL) {
                        if (rnext->mr_info.mri_intr.mi_ddi_handle ==
                            ddi_handle) {
                                /*
                                 * If default ring (mr_index == 0) is part
                                 * of a group of rings sharing an
                                 * interrupt, then set ddi_shared flag for
                                 * the default ring and give another ring
                                 * the chance to be re-targeted.
                                 */
                                if (rnext->mr_index == 0 &&
                                    !rnext->mr_info.mri_intr.mi_ddi_shared) {
                                        rnext->mr_info.mri_intr.mi_ddi_shared =
                                            B_TRUE;
                                } else {
                                        ring->mr_info.mri_intr.mi_ddi_shared =
                                            B_TRUE;
                                }
                                break;
                        }
                        rnext = rnext->mr_next;
                }
                /*
                 * If rnext is NULL, then no matching ddi_handle was found.
                 * Rx rings get registered first. So if this is a Tx ring,
                 * then go through all the Rx rings and see if there is a
                 * matching ddi handle.
                 */
                if (rnext == NULL && ring->mr_type == MAC_RING_TYPE_TX) {
                        mac_compare_ddi_handle(mip->mi_rx_groups,
                            mip->mi_rx_group_count, ring);
                }
        }

        /* Update ring's status */
        ring->mr_state = MR_FREE;
        ring->mr_flag = 0;

        /* Update the ring count of the group */
        group->mrg_cur_count++;

        /* Create per ring kstats */
        if (ring->mr_stat != NULL) {
                ring->mr_mip = mip;
                mac_ring_stat_create(ring);
        }

        return (ring);
}

/*
 * Rings are chained together for easy regrouping.
 */
static void
mac_init_group(mac_impl_t *mip, mac_group_t *group, int size,
    mac_capab_rings_t *cap_rings)
{
        int index;

        /*
         * Initialize all ring members of this group. Size of zero will not
         * enter the loop, so it's safe for initializing an empty group.
         */
        for (index = size - 1; index >= 0; index--)
                (void) mac_init_ring(mip, group, index, cap_rings);
}

int
mac_init_rings(mac_impl_t *mip, mac_ring_type_t rtype)
{
        mac_capab_rings_t       *cap_rings;
        mac_group_t             *group;
        mac_group_t             *groups;
        mac_group_info_t        group_info;
        uint_t                  group_free = 0;
        uint_t                  ring_left;
        mac_ring_t              *ring;
        int                     g;
        int                     err = 0;
        uint_t                  grpcnt;
        boolean_t               pseudo_txgrp = B_FALSE;

        switch (rtype) {
        case MAC_RING_TYPE_RX:
                ASSERT(mip->mi_rx_groups == NULL);

                cap_rings = &mip->mi_rx_rings_cap;
                cap_rings->mr_type = MAC_RING_TYPE_RX;
                break;
        case MAC_RING_TYPE_TX:
                ASSERT(mip->mi_tx_groups == NULL);

                cap_rings = &mip->mi_tx_rings_cap;
                cap_rings->mr_type = MAC_RING_TYPE_TX;
                break;
        default:
                ASSERT(B_FALSE);
        }

        if (!i_mac_capab_get((mac_handle_t)mip, MAC_CAPAB_RINGS, cap_rings))
                return (0);
        grpcnt = cap_rings->mr_gnum;

        /*
         * If we have multiple TX rings, but only one TX group, we can
         * create pseudo TX groups (one per TX ring) in the MAC layer,
         * except for an aggr. For an aggr currently we maintain only
         * one group with all the rings (for all its ports), going
         * forwards we might change this.
         */
        if (rtype == MAC_RING_TYPE_TX &&
            cap_rings->mr_gnum == 0 && cap_rings->mr_rnum >  0 &&
            (mip->mi_state_flags & MIS_IS_AGGR) == 0) {
                /*
                 * The -1 here is because we create a default TX group
                 * with all the rings in it.
                 */
                grpcnt = cap_rings->mr_rnum - 1;
                pseudo_txgrp = B_TRUE;
        }

        /*
         * Allocate a contiguous buffer for all groups.
         */
        groups = kmem_zalloc(sizeof (mac_group_t) * (grpcnt+ 1), KM_SLEEP);

        ring_left = cap_rings->mr_rnum;

        /*
         * Get all ring groups if any, and get their ring members
         * if any.
         */
        for (g = 0; g < grpcnt; g++) {
                group = groups + g;

                /* Prepare basic information of the group */
                group->mrg_index = g;
                group->mrg_type = rtype;
                group->mrg_state = MAC_GROUP_STATE_UNINIT;
                group->mrg_mh = (mac_handle_t)mip;
                group->mrg_next = group + 1;

                /* Zero to reuse the info data structure */
                bzero(&group_info, sizeof (group_info));

                if (pseudo_txgrp) {
                        /*
                         * This is a pseudo group that we created, apart
                         * from setting the state there is nothing to be
                         * done.
                         */
                        group->mrg_state = MAC_GROUP_STATE_REGISTERED;
                        group_free++;
                        continue;
                }
                /* Query group information from driver */
                cap_rings->mr_gget(mip->mi_driver, rtype, g, &group_info,
                    (mac_group_handle_t)group);

                switch (cap_rings->mr_group_type) {
                case MAC_GROUP_TYPE_DYNAMIC:
                        if (cap_rings->mr_gaddring == NULL ||
                            cap_rings->mr_gremring == NULL) {
                                DTRACE_PROBE3(
                                    mac__init__rings_no_addremring,
                                    char *, mip->mi_name,
                                    mac_group_add_ring_t,
                                    cap_rings->mr_gaddring,
                                    mac_group_add_ring_t,
                                    cap_rings->mr_gremring);
                                err = EINVAL;
                                goto bail;
                        }

                        switch (rtype) {
                        case MAC_RING_TYPE_RX:
                                /*
                                 * The first RX group must have non-zero
                                 * rings, and the following groups must
                                 * have zero rings.
                                 */
                                if (g == 0 && group_info.mgi_count == 0) {
                                        DTRACE_PROBE1(
                                            mac__init__rings__rx__def__zero,
                                            char *, mip->mi_name);
                                        err = EINVAL;
                                        goto bail;
                                }
                                if (g > 0 && group_info.mgi_count != 0) {
                                        DTRACE_PROBE3(
                                            mac__init__rings__rx__nonzero,
                                            char *, mip->mi_name,
                                            int, g, int, group_info.mgi_count);
                                        err = EINVAL;
                                        goto bail;
                                }
                                break;
                        case MAC_RING_TYPE_TX:
                                /*
                                 * All TX ring groups must have zero rings.
                                 */
                                if (group_info.mgi_count != 0) {
                                        DTRACE_PROBE3(
                                            mac__init__rings__tx__nonzero,
                                            char *, mip->mi_name,
                                            int, g, int, group_info.mgi_count);
                                        err = EINVAL;
                                        goto bail;
                                }
                                break;
                        }
                        break;
                case MAC_GROUP_TYPE_STATIC:
                        /*
                         * Note that an empty group is allowed, e.g., an aggr
                         * would start with an empty group.
                         */
                        break;
                default:
                        /* unknown group type */
                        DTRACE_PROBE2(mac__init__rings__unknown__type,
                            char *, mip->mi_name,
                            int, cap_rings->mr_group_type);
                        err = EINVAL;
                        goto bail;
                }


                /*
                 * The driver must register some form of hardware MAC
                 * filter in order for Rx groups to support multiple
                 * MAC addresses.
                 */
                if (rtype == MAC_RING_TYPE_RX &&
                    (group_info.mgi_addmac == NULL ||
                    group_info.mgi_remmac == NULL)) {
                        DTRACE_PROBE1(mac__init__rings__no__mac__filter,
                            char *, mip->mi_name);
                        err = EINVAL;
                        goto bail;
                }

                /* Cache driver-supplied information */
                group->mrg_info = group_info;

                /* Update the group's status and group count. */
                mac_set_group_state(group, MAC_GROUP_STATE_REGISTERED);
                group_free++;

                group->mrg_rings = NULL;
                group->mrg_cur_count = 0;
                mac_init_group(mip, group, group_info.mgi_count, cap_rings);
                ring_left -= group_info.mgi_count;

                /* The current group size should be equal to default value */
                ASSERT(group->mrg_cur_count == group_info.mgi_count);
        }

        /* Build up a dummy group for free resources as a pool */
        group = groups + grpcnt;

        /* Prepare basic information of the group */
        group->mrg_index = -1;
        group->mrg_type = rtype;
        group->mrg_state = MAC_GROUP_STATE_UNINIT;
        group->mrg_mh = (mac_handle_t)mip;
        group->mrg_next = NULL;

        /*
         * If there are ungrouped rings, allocate a continuous buffer for
         * remaining resources.
         */
        if (ring_left != 0) {
                group->mrg_rings = NULL;
                group->mrg_cur_count = 0;
                mac_init_group(mip, group, ring_left, cap_rings);

                /* The current group size should be equal to ring_left */
                ASSERT(group->mrg_cur_count == ring_left);

                ring_left = 0;

                /* Update this group's status */
                mac_set_group_state(group, MAC_GROUP_STATE_REGISTERED);
        } else {
                group->mrg_rings = NULL;
        }

        ASSERT(ring_left == 0);

bail:

        /* Cache other important information to finalize the initialization */
        switch (rtype) {
        case MAC_RING_TYPE_RX:
                mip->mi_rx_group_type = cap_rings->mr_group_type;
                mip->mi_rx_group_count = cap_rings->mr_gnum;
                mip->mi_rx_groups = groups;
                mip->mi_rx_donor_grp = groups;
                if (mip->mi_rx_group_type == MAC_GROUP_TYPE_DYNAMIC) {
                        /*
                         * The default ring is reserved since it is
                         * used for sending the broadcast etc. packets.
                         */
                        mip->mi_rxrings_avail =
                            mip->mi_rx_groups->mrg_cur_count - 1;
                        mip->mi_rxrings_rsvd = 1;
                }
                /*
                 * The default group cannot be reserved. It is used by
                 * all the clients that do not have an exclusive group.
                 */
                mip->mi_rxhwclnt_avail = mip->mi_rx_group_count - 1;
                mip->mi_rxhwclnt_used = 1;
                break;
        case MAC_RING_TYPE_TX:
                mip->mi_tx_group_type = pseudo_txgrp ? MAC_GROUP_TYPE_DYNAMIC :
                    cap_rings->mr_group_type;
                mip->mi_tx_group_count = grpcnt;
                mip->mi_tx_group_free = group_free;
                mip->mi_tx_groups = groups;

                group = groups + grpcnt;
                ring = group->mrg_rings;
                /*
                 * The ring can be NULL in the case of aggr. Aggr will
                 * have an empty Tx group which will get populated
                 * later when pseudo Tx rings are added after
                 * mac_register() is done.
                 */
                if (ring == NULL) {
                        ASSERT(mip->mi_state_flags & MIS_IS_AGGR);
                        /*
                         * pass the group to aggr so it can add Tx
                         * rings to the group later.
                         */
                        cap_rings->mr_gget(mip->mi_driver, rtype, 0, NULL,
                            (mac_group_handle_t)group);
                        /*
                         * Even though there are no rings at this time
                         * (rings will come later), set the group
                         * state to registered.
                         */
                        group->mrg_state = MAC_GROUP_STATE_REGISTERED;
                } else {
                        /*
                         * Ring 0 is used as the default one and it could be
                         * assigned to a client as well.
                         */
                        while ((ring->mr_index != 0) && (ring->mr_next != NULL))
                                ring = ring->mr_next;
                        ASSERT(ring->mr_index == 0);
                        mip->mi_default_tx_ring = (mac_ring_handle_t)ring;
                }
                if (mip->mi_tx_group_type == MAC_GROUP_TYPE_DYNAMIC) {
                        mip->mi_txrings_avail = group->mrg_cur_count - 1;
                        /*
                         * The default ring cannot be reserved.
                         */
                        mip->mi_txrings_rsvd = 1;
                }
                /*
                 * The default group cannot be reserved. It will be shared
                 * by clients that do not have an exclusive group.
                 */
                mip->mi_txhwclnt_avail = mip->mi_tx_group_count;
                mip->mi_txhwclnt_used = 1;
                break;
        default:
                ASSERT(B_FALSE);
        }

        if (err != 0)
                mac_free_rings(mip, rtype);

        return (err);
}

/*
 * The ddi interrupt handle could be shared amoung rings. If so, compare
 * the new ring's ddi handle with the existing ones and set ddi_shared
 * flag.
 */
void
mac_compare_ddi_handle(mac_group_t *groups, uint_t grpcnt, mac_ring_t *cring)
{
        mac_group_t *group;
        mac_ring_t *ring;
        ddi_intr_handle_t ddi_handle;
        int g;

        ddi_handle = cring->mr_info.mri_intr.mi_ddi_handle;
        for (g = 0; g < grpcnt; g++) {
                group = groups + g;
                for (ring = group->mrg_rings; ring != NULL;
                    ring = ring->mr_next) {
                        if (ring == cring)
                                continue;
                        if (ring->mr_info.mri_intr.mi_ddi_handle ==
                            ddi_handle) {
                                if (cring->mr_type == MAC_RING_TYPE_RX &&
                                    ring->mr_index == 0 &&
                                    !ring->mr_info.mri_intr.mi_ddi_shared) {
                                        ring->mr_info.mri_intr.mi_ddi_shared =
                                            B_TRUE;
                                } else {
                                        cring->mr_info.mri_intr.mi_ddi_shared =
                                            B_TRUE;
                                }
                                return;
                        }
                }
        }
}

/*
 * Called to free all groups of particular type (RX or TX). It's assumed that
 * no clients are using these groups.
 */
void
mac_free_rings(mac_impl_t *mip, mac_ring_type_t rtype)
{
        mac_group_t *group, *groups;
        uint_t group_count;

        switch (rtype) {
        case MAC_RING_TYPE_RX:
                if (mip->mi_rx_groups == NULL)
                        return;

                groups = mip->mi_rx_groups;
                group_count = mip->mi_rx_group_count;

                mip->mi_rx_groups = NULL;
                mip->mi_rx_donor_grp = NULL;
                mip->mi_rx_group_count = 0;
                break;
        case MAC_RING_TYPE_TX:
                ASSERT(mip->mi_tx_group_count == mip->mi_tx_group_free);

                if (mip->mi_tx_groups == NULL)
                        return;

                groups = mip->mi_tx_groups;
                group_count = mip->mi_tx_group_count;

                mip->mi_tx_groups = NULL;
                mip->mi_tx_group_count = 0;
                mip->mi_tx_group_free = 0;
                mip->mi_default_tx_ring = NULL;
                break;
        default:
                ASSERT(B_FALSE);
        }

        for (group = groups; group != NULL; group = group->mrg_next) {
                mac_ring_t *ring;

                if (group->mrg_cur_count == 0)
                        continue;

                ASSERT(group->mrg_rings != NULL);

                while ((ring = group->mrg_rings) != NULL) {
                        group->mrg_rings = ring->mr_next;
                        mac_ring_free(mip, ring);
                }
        }

        /* Free all the cached rings */
        mac_ring_freeall(mip);
        /* Free the block of group data strutures */
        kmem_free(groups, sizeof (mac_group_t) * (group_count + 1));
}

/*
 * Associate the VLAN filter to the receive group.
 */
int
mac_group_addvlan(mac_group_t *group, uint16_t vlan)
{
        VERIFY3S(group->mrg_type, ==, MAC_RING_TYPE_RX);
        VERIFY3P(group->mrg_info.mgi_addvlan, !=, NULL);

        if (vlan > VLAN_ID_MAX)
                return (EINVAL);

        vlan = MAC_VLAN_UNTAGGED_VID(vlan);
        return (group->mrg_info.mgi_addvlan(group->mrg_info.mgi_driver, vlan));
}

/*
 * Dissociate the VLAN from the receive group.
 */
int
mac_group_remvlan(mac_group_t *group, uint16_t vlan)
{
        VERIFY3S(group->mrg_type, ==, MAC_RING_TYPE_RX);
        VERIFY3P(group->mrg_info.mgi_remvlan, !=, NULL);

        if (vlan > VLAN_ID_MAX)
                return (EINVAL);

        vlan = MAC_VLAN_UNTAGGED_VID(vlan);
        return (group->mrg_info.mgi_remvlan(group->mrg_info.mgi_driver, vlan));
}

/*
 * Associate a MAC address with a receive group.
 *
 * The return value of this function should always be checked properly, because
 * any type of failure could cause unexpected results. A group can be added
 * or removed with a MAC address only after it has been reserved. Ideally,
 * a successful reservation always leads to calling mac_group_addmac() to
 * steer desired traffic. Failure of adding an unicast MAC address doesn't
 * always imply that the group is functioning abnormally.
 *
 * Currently this function is called everywhere, and it reflects assumptions
 * about MAC addresses in the implementation. CR 6735196.
 */
int
mac_group_addmac(mac_group_t *group, const uint8_t *addr)
{
        VERIFY3S(group->mrg_type, ==, MAC_RING_TYPE_RX);
        VERIFY3P(group->mrg_info.mgi_addmac, !=, NULL);

        return (group->mrg_info.mgi_addmac(group->mrg_info.mgi_driver, addr));
}

/*
 * Remove the association between MAC address and receive group.
 */
int
mac_group_remmac(mac_group_t *group, const uint8_t *addr)
{
        VERIFY3S(group->mrg_type, ==, MAC_RING_TYPE_RX);
        VERIFY3P(group->mrg_info.mgi_remmac, !=, NULL);

        return (group->mrg_info.mgi_remmac(group->mrg_info.mgi_driver, addr));
}

/*
 * This is the entry point for packets transmitted through the bridge
 * code. If no bridge is in place, mac_ring_tx() transmits via the tx
 * ring. The 'rh' pointer may be NULL to select the default ring.
 */
mblk_t *
mac_bridge_tx(mac_impl_t *mip, mac_ring_handle_t rh, mblk_t *mp)
{
        mac_handle_t mh;

        /*
         * Once we take a reference on the bridge link, the bridge
         * module itself can't unload, so the callback pointers are
         * stable.
         */
        mutex_enter(&mip->mi_bridge_lock);
        if ((mh = mip->mi_bridge_link) != NULL)
                mac_bridge_ref_cb(mh, B_TRUE);
        mutex_exit(&mip->mi_bridge_lock);
        if (mh == NULL) {
                mp = mac_ring_tx((mac_handle_t)mip, rh, mp);
        } else {
                /*
                 * The bridge may place this mblk on a provider's Tx
                 * path, a mac's Rx path, or both. Since we don't have
                 * enough information at this point, we can't be sure
                 * that the destination(s) are capable of handling the
                 * hardware offloads requested by the mblk. We emulate
                 * them here as it is the safest choice. In the
                 * future, if bridge performance becomes a priority,
                 * we can elide the emulation here and leave the
                 * choice up to bridge.
                 *
                 * We don't clear the DB_CKSUMFLAGS here because
                 * HCK_IPV4_HDRCKSUM (Tx) and HCK_IPV4_HDRCKSUM_OK
                 * (Rx) still have the same value. If the bridge
                 * receives a packet from a HCKSUM_IPHDRCKSUM NIC then
                 * the mac(s) it is forwarded on may calculate the
                 * checksum again, but incorrectly (because the
                 * checksum field is not zero). Until the
                 * HCK_IPV4_HDRCKSUM/HCK_IPV4_HDRCKSUM_OK issue is
                 * resovled, we leave the flag clearing in bridge
                 * itself.
                 */
                if ((DB_CKSUMFLAGS(mp) & (HCK_TX_FLAGS | HW_LSO_FLAGS)) != 0) {
                        mac_hw_emul(&mp, NULL, NULL, MAC_ALL_EMULS);
                }

                mp = mac_bridge_tx_cb(mh, rh, mp);
                mac_bridge_ref_cb(mh, B_FALSE);
        }

        return (mp);
}

/*
 * Find a ring from its index.
 */
mac_ring_handle_t
mac_find_ring(mac_group_handle_t gh, int index)
{
        mac_group_t *group = (mac_group_t *)gh;
        mac_ring_t *ring = group->mrg_rings;

        for (ring = group->mrg_rings; ring != NULL; ring = ring->mr_next)
                if (ring->mr_index == index)
                        break;

        return ((mac_ring_handle_t)ring);
}
/*
 * Add a ring to an existing group.
 *
 * The ring must be either passed directly (for example if the ring
 * movement is initiated by the framework), or specified through a driver
 * index (for example when the ring is added by the driver.
 *
 * The caller needs to call mac_perim_enter() before calling this function.
 */
int
i_mac_group_add_ring(mac_group_t *group, mac_ring_t *ring, int index)
{
        mac_impl_t *mip = (mac_impl_t *)group->mrg_mh;
        mac_capab_rings_t *cap_rings;
        boolean_t driver_call = (ring == NULL);
        mac_group_type_t group_type;
        int ret = 0;
        flow_entry_t *flent;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        switch (group->mrg_type) {
        case MAC_RING_TYPE_RX:
                cap_rings = &mip->mi_rx_rings_cap;
                group_type = mip->mi_rx_group_type;
                break;
        case MAC_RING_TYPE_TX:
                cap_rings = &mip->mi_tx_rings_cap;
                group_type = mip->mi_tx_group_type;
                break;
        default:
                ASSERT(B_FALSE);
        }

        /*
         * There should be no ring with the same ring index in the target
         * group.
         */
        ASSERT(mac_find_ring((mac_group_handle_t)group,
            driver_call ? index : ring->mr_index) == NULL);

        if (driver_call) {
                /*
                 * The function is called as a result of a request from
                 * a driver to add a ring to an existing group, for example
                 * from the aggregation driver. Allocate a new mac_ring_t
                 * for that ring.
                 */
                ring = mac_init_ring(mip, group, index, cap_rings);
                ASSERT(group->mrg_state > MAC_GROUP_STATE_UNINIT);
        } else {
                /*
                 * The function is called as a result of a MAC layer request
                 * to add a ring to an existing group. In this case the
                 * ring is being moved between groups, which requires
                 * the underlying driver to support dynamic grouping,
                 * and the mac_ring_t already exists.
                 */
                ASSERT(group_type == MAC_GROUP_TYPE_DYNAMIC);
                ASSERT(group->mrg_driver == NULL ||
                    cap_rings->mr_gaddring != NULL);
                ASSERT(ring->mr_gh == NULL);
        }

        /*
         * At this point the ring should not be in use, and it should be
         * of the right for the target group.
         */
        ASSERT(ring->mr_state < MR_INUSE);
        ASSERT(ring->mr_srs == NULL);
        ASSERT(ring->mr_type == group->mrg_type);

        if (!driver_call) {
                /*
                 * Add the driver level hardware ring if the process was not
                 * initiated by the driver, and the target group is not the
                 * group.
                 */
                if (group->mrg_driver != NULL) {
                        cap_rings->mr_gaddring(group->mrg_driver,
                            ring->mr_driver, ring->mr_type);
                }

                /*
                 * Insert the ring ahead existing rings.
                 */
                ring->mr_next = group->mrg_rings;
                group->mrg_rings = ring;
                ring->mr_gh = (mac_group_handle_t)group;
                group->mrg_cur_count++;
        }

        /*
         * If the group has not been actively used, we're done.
         */
        if (group->mrg_index != -1 &&
            group->mrg_state < MAC_GROUP_STATE_RESERVED)
                return (0);

        /*
         * Start the ring if needed. Failure causes to undo the grouping action.
         */
        if (ring->mr_state != MR_INUSE) {
                if ((ret = mac_start_ring(ring)) != 0) {
                        if (!driver_call) {
                                cap_rings->mr_gremring(group->mrg_driver,
                                    ring->mr_driver, ring->mr_type);
                        }
                        group->mrg_cur_count--;
                        group->mrg_rings = ring->mr_next;

                        ring->mr_gh = NULL;

                        if (driver_call)
                                mac_ring_free(mip, ring);

                        return (ret);
                }
        }

        /*
         * Set up SRS/SR according to the ring type.
         */
        switch (ring->mr_type) {
        case MAC_RING_TYPE_RX:
                /*
                 * Setup an SRS on top of the new ring if the group is
                 * reserved for someone's exclusive use.
                 */
                if (group->mrg_state == MAC_GROUP_STATE_RESERVED) {
                        mac_client_impl_t *mcip =  MAC_GROUP_ONLY_CLIENT(group);

                        VERIFY3P(mcip, !=, NULL);
                        flent = mcip->mci_flent;
                        VERIFY3S(flent->fe_rx_srs_cnt, >, 0);
                        mac_rx_srs_group_setup(mcip, flent, SRST_LINK);
                        mac_fanout_setup(mcip, flent, MCIP_RESOURCE_PROPS(mcip),
                            mac_rx_deliver, mcip, NULL);
                } else {
                        ring->mr_classify_type = MAC_SW_CLASSIFIER;
                }
                break;
        case MAC_RING_TYPE_TX:
        {
                mac_grp_client_t        *mgcp = group->mrg_clients;
                mac_client_impl_t       *mcip;
                mac_soft_ring_set_t     *mac_srs;
                mac_srs_tx_t            *tx;

                if (MAC_GROUP_NO_CLIENT(group)) {
                        if (ring->mr_state == MR_INUSE)
                                mac_stop_ring(ring);
                        ring->mr_flag = 0;
                        break;
                }
                /*
                 * If the rings are being moved to a group that has
                 * clients using it, then add the new rings to the
                 * clients SRS.
                 */
                while (mgcp != NULL) {
                        boolean_t       is_aggr;

                        mcip = mgcp->mgc_client;
                        flent = mcip->mci_flent;
                        is_aggr = (mcip->mci_state_flags & MCIS_IS_AGGR_CLIENT);
                        mac_srs = MCIP_TX_SRS(mcip);
                        tx = &mac_srs->srs_tx;
                        mac_tx_client_quiesce((mac_client_handle_t)mcip);
                        /*
                         * If we are  growing from 1 to multiple rings.
                         */
                        if (tx->st_mode == SRS_TX_BW ||
                            tx->st_mode == SRS_TX_SERIALIZE ||
                            tx->st_mode == SRS_TX_DEFAULT) {
                                mac_ring_t      *tx_ring = tx->st_arg2;

                                tx->st_arg2 = NULL;
                                mac_tx_srs_stat_recreate(mac_srs, B_TRUE);
                                mac_tx_srs_add_ring(mac_srs, tx_ring);
                                if (mac_srs->srs_type & SRST_BW_CONTROL) {
                                        tx->st_mode = is_aggr ? SRS_TX_BW_AGGR :
                                            SRS_TX_BW_FANOUT;
                                } else {
                                        tx->st_mode = is_aggr ? SRS_TX_AGGR :
                                            SRS_TX_FANOUT;
                                }
                                tx->st_func = mac_tx_get_func(tx->st_mode);
                        }
                        mac_tx_srs_add_ring(mac_srs, ring);
                        mac_fanout_setup(mcip, flent, MCIP_RESOURCE_PROPS(mcip),
                            mac_rx_deliver, mcip, NULL);
                        mac_tx_client_restart((mac_client_handle_t)mcip);
                        mgcp = mgcp->mgc_next;
                }
                break;
        }
        default:
                ASSERT(B_FALSE);
        }
        /*
         * For aggr, the default ring will be NULL to begin with. If it
         * is NULL, then pick the first ring that gets added as the
         * default ring. Any ring in an aggregation can be removed at
         * any time (by the user action of removing a link) and if the
         * current default ring gets removed, then a new one gets
         * picked (see i_mac_group_rem_ring()).
         */
        if (mip->mi_state_flags & MIS_IS_AGGR &&
            mip->mi_default_tx_ring == NULL &&
            ring->mr_type == MAC_RING_TYPE_TX) {
                mip->mi_default_tx_ring = (mac_ring_handle_t)ring;
        }

        MAC_RING_UNMARK(ring, MR_INCIPIENT);
        return (0);
}

/*
 * Remove a ring from it's current group. MAC internal function for dynamic
 * grouping.
 *
 * The caller needs to call mac_perim_enter() before calling this function.
 */
void
i_mac_group_rem_ring(mac_group_t *group, mac_ring_t *ring,
    boolean_t driver_call)
{
        mac_impl_t *mip = (mac_impl_t *)group->mrg_mh;
        mac_capab_rings_t *cap_rings = NULL;
        mac_group_type_t group_type;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        ASSERT(mac_find_ring((mac_group_handle_t)group,
            ring->mr_index) == (mac_ring_handle_t)ring);
        ASSERT((mac_group_t *)ring->mr_gh == group);
        ASSERT(ring->mr_type == group->mrg_type);

        if (ring->mr_state == MR_INUSE)
                mac_stop_ring(ring);
        switch (ring->mr_type) {
        case MAC_RING_TYPE_RX:
                group_type = mip->mi_rx_group_type;
                cap_rings = &mip->mi_rx_rings_cap;

                /*
                 * Only hardware classified packets hold a reference to the
                 * ring all the way up the Rx path. mac_rx_srs_remove()
                 * will take care of quiescing the Rx path and removing the
                 * SRS. The software classified path neither holds a reference
                 * nor any association with the ring in mac_rx.
                 */
                if (ring->mr_srs != NULL) {
                        mac_rx_srs_remove(ring->mr_srs);
                        ring->mr_srs = NULL;
                }

                break;
        case MAC_RING_TYPE_TX:
        {
                mac_grp_client_t        *mgcp;
                mac_client_impl_t       *mcip;
                mac_soft_ring_set_t     *mac_srs;
                mac_srs_tx_t            *tx;
                mac_ring_t              *rem_ring;
                mac_group_t             *defgrp;
                uint_t                  ring_info = 0;

                /*
                 * For TX this function is invoked in three
                 * cases:
                 *
                 * 1) In the case of a failure during the
                 * initial creation of a group when a share is
                 * associated with a MAC client. So the SRS is not
                 * yet setup, and will be setup later after the
                 * group has been reserved and populated.
                 *
                 * 2) From mac_release_tx_group() when freeing
                 * a TX SRS.
                 *
                 * 3) In the case of aggr, when a port gets removed,
                 * the pseudo Tx rings that it exposed gets removed.
                 *
                 * In the first two cases the SRS and its soft
                 * rings are already quiesced.
                 */
                if (driver_call) {
                        mac_client_impl_t *mcip;
                        mac_soft_ring_set_t *mac_srs;
                        mac_soft_ring_t *sringp;
                        mac_srs_tx_t *srs_tx;

                        if (mip->mi_state_flags & MIS_IS_AGGR &&
                            mip->mi_default_tx_ring ==
                            (mac_ring_handle_t)ring) {
                                /* pick a new default Tx ring */
                                mip->mi_default_tx_ring =
                                    (group->mrg_rings != ring) ?
                                    (mac_ring_handle_t)group->mrg_rings :
                                    (mac_ring_handle_t)(ring->mr_next);
                        }
                        /* Presently only aggr case comes here */
                        if (group->mrg_state != MAC_GROUP_STATE_RESERVED)
                                break;

                        mcip = MAC_GROUP_ONLY_CLIENT(group);
                        ASSERT(mcip != NULL);
                        ASSERT(mcip->mci_state_flags & MCIS_IS_AGGR_CLIENT);
                        mac_srs = MCIP_TX_SRS(mcip);
                        ASSERT(mac_srs->srs_tx.st_mode == SRS_TX_AGGR ||
                            mac_srs->srs_tx.st_mode == SRS_TX_BW_AGGR);
                        srs_tx = &mac_srs->srs_tx;
                        /*
                         * Wakeup any callers blocked on this
                         * Tx ring due to flow control.
                         */
                        sringp = srs_tx->st_soft_rings[ring->mr_index];
                        ASSERT(sringp != NULL);
                        mac_tx_invoke_callbacks(mcip, (mac_tx_cookie_t)sringp);
                        mac_tx_client_quiesce((mac_client_handle_t)mcip);
                        mac_tx_srs_del_ring(mac_srs, ring);
                        mac_tx_client_restart((mac_client_handle_t)mcip);
                        break;
                }
                ASSERT(ring != (mac_ring_t *)mip->mi_default_tx_ring);
                group_type = mip->mi_tx_group_type;
                cap_rings = &mip->mi_tx_rings_cap;
                /*
                 * See if we need to take it out of the MAC clients using
                 * this group
                 */
                if (MAC_GROUP_NO_CLIENT(group))
                        break;
                mgcp = group->mrg_clients;
                defgrp = MAC_DEFAULT_TX_GROUP(mip);
                while (mgcp != NULL) {
                        mcip = mgcp->mgc_client;
                        mac_srs = MCIP_TX_SRS(mcip);
                        tx = &mac_srs->srs_tx;
                        mac_tx_client_quiesce((mac_client_handle_t)mcip);
                        /*
                         * If we are here when removing rings from the
                         * defgroup, mac_reserve_tx_ring would have
                         * already deleted the ring from the MAC
                         * clients in the group.
                         */
                        if (group != defgrp) {
                                mac_tx_invoke_callbacks(mcip,
                                    (mac_tx_cookie_t)
                                    mac_tx_srs_get_soft_ring(mac_srs, ring));
                                mac_tx_srs_del_ring(mac_srs, ring);
                        }
                        /*
                         * Additionally, if  we are left with only
                         * one ring in the group after this, we need
                         * to modify the mode etc. to. (We haven't
                         * yet taken the ring out, so we check with 2).
                         */
                        if (group->mrg_cur_count == 2) {
                                if (ring->mr_next == NULL)
                                        rem_ring = group->mrg_rings;
                                else
                                        rem_ring = ring->mr_next;
                                mac_tx_invoke_callbacks(mcip,
                                    (mac_tx_cookie_t)
                                    mac_tx_srs_get_soft_ring(mac_srs,
                                    rem_ring));
                                mac_tx_srs_del_ring(mac_srs, rem_ring);
                                if (rem_ring->mr_state != MR_INUSE) {
                                        (void) mac_start_ring(rem_ring);
                                }
                                tx->st_arg2 = (void *)rem_ring;
                                mac_tx_srs_stat_recreate(mac_srs, B_FALSE);
                                ring_info = mac_hwring_getinfo(
                                    (mac_ring_handle_t)rem_ring);
                                /*
                                 * We are  shrinking from multiple
                                 * to 1 ring.
                                 */
                                if (mac_srs->srs_type & SRST_BW_CONTROL) {
                                        tx->st_mode = SRS_TX_BW;
                                } else if (mac_tx_serialize ||
                                    (ring_info & MAC_RING_TX_SERIALIZE)) {
                                        tx->st_mode = SRS_TX_SERIALIZE;
                                } else {
                                        tx->st_mode = SRS_TX_DEFAULT;
                                }
                                tx->st_func = mac_tx_get_func(tx->st_mode);
                        }
                        mac_tx_client_restart((mac_client_handle_t)mcip);
                        mgcp = mgcp->mgc_next;
                }
                break;
        }
        default:
                ASSERT(B_FALSE);
        }

        /*
         * Remove the ring from the group.
         */
        if (ring == group->mrg_rings)
                group->mrg_rings = ring->mr_next;
        else {
                mac_ring_t *pre;

                pre = group->mrg_rings;
                while (pre->mr_next != ring)
                        pre = pre->mr_next;
                pre->mr_next = ring->mr_next;
        }
        group->mrg_cur_count--;

        if (!driver_call) {
                ASSERT(group_type == MAC_GROUP_TYPE_DYNAMIC);
                ASSERT(group->mrg_driver == NULL ||
                    cap_rings->mr_gremring != NULL);

                /*
                 * Remove the driver level hardware ring.
                 */
                if (group->mrg_driver != NULL) {
                        cap_rings->mr_gremring(group->mrg_driver,
                            ring->mr_driver, ring->mr_type);
                }
        }

        ring->mr_gh = NULL;
        if (driver_call)
                mac_ring_free(mip, ring);
        else
                ring->mr_flag = 0;
}

/*
 * Move a ring to the target group. If needed, remove the ring from the group
 * that it currently belongs to.
 *
 * The caller need to enter MAC's perimeter by calling mac_perim_enter().
 */
static int
mac_group_mov_ring(mac_impl_t *mip, mac_group_t *d_group, mac_ring_t *ring)
{
        mac_group_t *s_group = (mac_group_t *)ring->mr_gh;
        int rv;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
        ASSERT(d_group != NULL);
        ASSERT(s_group == NULL || s_group->mrg_mh == d_group->mrg_mh);

        if (s_group == d_group)
                return (0);

        /*
         * Remove it from current group first.
         */
        if (s_group != NULL)
                i_mac_group_rem_ring(s_group, ring, B_FALSE);

        /*
         * Add it to the new group.
         */
        rv = i_mac_group_add_ring(d_group, ring, 0);
        if (rv != 0) {
                /*
                 * Failed to add ring back to source group. If
                 * that fails, the ring is stuck in limbo, log message.
                 */
                if (i_mac_group_add_ring(s_group, ring, 0)) {
                        cmn_err(CE_WARN, "%s: failed to move ring %p\n",
                            mip->mi_name, (void *)ring);
                }
        }

        return (rv);
}

/*
 * Find a MAC address according to its value.
 */
mac_address_t *
mac_find_macaddr(mac_impl_t *mip, uint8_t *mac_addr)
{
        mac_address_t *map;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        for (map = mip->mi_addresses; map != NULL; map = map->ma_next) {
                if (bcmp(mac_addr, map->ma_addr, map->ma_len) == 0)
                        break;
        }

        return (map);
}

/*
 * Check whether the MAC address is shared by multiple clients.
 */
boolean_t
mac_check_macaddr_shared(mac_address_t *map)
{
        ASSERT(MAC_PERIM_HELD((mac_handle_t)map->ma_mip));

        return (map->ma_nusers > 1);
}

/*
 * Remove the specified MAC address from the MAC address list and free it.
 */
static void
mac_free_macaddr(mac_address_t *map)
{
        mac_impl_t *mip = map->ma_mip;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
        VERIFY3P(mip->mi_addresses, !=, NULL);

        VERIFY3P(map, ==, mac_find_macaddr(mip, map->ma_addr));
        VERIFY3P(map, !=, NULL);
        VERIFY3S(map->ma_nusers, ==, 0);
        VERIFY3P(map->ma_vlans, ==, NULL);

        if (map == mip->mi_addresses) {
                mip->mi_addresses = map->ma_next;
        } else {
                mac_address_t *pre;

                pre = mip->mi_addresses;
                while (pre->ma_next != map)
                        pre = pre->ma_next;
                pre->ma_next = map->ma_next;
        }

        kmem_free(map, sizeof (mac_address_t));
}

static mac_vlan_t *
mac_find_vlan(mac_address_t *map, uint16_t vid)
{
        mac_vlan_t *mvp;

        for (mvp = map->ma_vlans; mvp != NULL; mvp = mvp->mv_next) {
                if (mvp->mv_vid == vid)
                        return (mvp);
        }

        return (NULL);
}

static mac_vlan_t *
mac_add_vlan(mac_address_t *map, uint16_t vid)
{
        mac_vlan_t *mvp;

        /*
         * We should never add the same {addr, VID} tuple more
         * than once, but let's be sure.
         */
        for (mvp = map->ma_vlans; mvp != NULL; mvp = mvp->mv_next)
                VERIFY3U(mvp->mv_vid, !=, vid);

        /* Add the VLAN to the head of the VLAN list. */
        mvp = kmem_zalloc(sizeof (mac_vlan_t), KM_SLEEP);
        mvp->mv_vid = vid;
        mvp->mv_next = map->ma_vlans;
        map->ma_vlans = mvp;

        return (mvp);
}

static void
mac_rem_vlan(mac_address_t *map, mac_vlan_t *mvp)
{
        mac_vlan_t *pre;

        if (map->ma_vlans == mvp) {
                map->ma_vlans = mvp->mv_next;
        } else {
                pre = map->ma_vlans;
                while (pre->mv_next != mvp) {
                        pre = pre->mv_next;

                        /*
                         * We've reached the end of the list without
                         * finding mvp.
                         */
                        VERIFY3P(pre, !=, NULL);
                }
                pre->mv_next = mvp->mv_next;
        }

        kmem_free(mvp, sizeof (mac_vlan_t));
}

/*
 * Create a new mac_address_t if this is the first use of the address
 * or add a VID to an existing address. In either case, the
 * mac_address_t acts as a list of {addr, VID} tuples where each tuple
 * shares the same addr. If group is non-NULL then attempt to program
 * the MAC's HW filters for this group. Otherwise, if group is NULL,
 * then the MAC has no rings and there is nothing to program.
 */
int
mac_add_macaddr_vlan(mac_impl_t *mip, mac_group_t *group, uint8_t *addr,
    uint16_t vid, boolean_t use_hw)
{
        mac_address_t   *map;
        mac_vlan_t      *mvp;
        int             err = 0;
        boolean_t       allocated_map = B_FALSE;
        boolean_t       hw_mac = B_FALSE;
        boolean_t       hw_vlan = B_FALSE;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        map = mac_find_macaddr(mip, addr);

        /*
         * If this is the first use of this MAC address then allocate
         * and initialize a new structure.
         */
        if (map == NULL) {
                map = kmem_zalloc(sizeof (mac_address_t), KM_SLEEP);
                map->ma_len = mip->mi_type->mt_addr_length;
                bcopy(addr, map->ma_addr, map->ma_len);
                map->ma_nusers = 0;
                map->ma_group = group;
                map->ma_mip = mip;
                map->ma_untagged = B_FALSE;

                /* Add the new MAC address to the head of the address list. */
                map->ma_next = mip->mi_addresses;
                mip->mi_addresses = map;

                allocated_map = B_TRUE;
        }

        VERIFY(map->ma_group == NULL || map->ma_group == group);
        if (map->ma_group == NULL)
                map->ma_group = group;

        if (vid == VLAN_ID_NONE) {
                map->ma_untagged = B_TRUE;
                mvp = NULL;
        } else {
                mvp = mac_add_vlan(map, vid);
        }

        /*
         * Set the VLAN HW filter if:
         *
         * o the MAC's VLAN HW filtering is enabled, and
         * o the address does not currently rely on promisc mode.
         *
         * This is called even when the client specifies an untagged
         * address (VLAN_ID_NONE) because some MAC providers require
         * setting additional bits to accept untagged traffic when
         * VLAN HW filtering is enabled.
         */
        if (MAC_GROUP_HW_VLAN(group) &&
            map->ma_type != MAC_ADDRESS_TYPE_UNICAST_PROMISC) {
                if ((err = mac_group_addvlan(group, vid)) != 0)
                        goto bail;

                hw_vlan = B_TRUE;
        }

        VERIFY3S(map->ma_nusers, >=, 0);
        map->ma_nusers++;

        /*
         * If this MAC address already has a HW filter then simply
         * increment the counter.
         */
        if (map->ma_nusers > 1)
                return (0);

        /*
         * All logic from here on out is executed during initial
         * creation only.
         */
        VERIFY3S(map->ma_nusers, ==, 1);

        /*
         * Activate this MAC address by adding it to the reserved group.
         */
        if (group != NULL) {
                err = mac_group_addmac(group, (const uint8_t *)addr);

                /*
                 * If the driver is out of filters then we can
                 * continue and use promisc mode. For any other error,
                 * assume the driver is in a state where we can't
                 * program the filters or use promisc mode; so we must
                 * bail.
                 */
                if (err != 0 && err != ENOSPC) {
                        map->ma_nusers--;
                        goto bail;
                }

                hw_mac = (err == 0);
        }

        if (hw_mac) {
                map->ma_type = MAC_ADDRESS_TYPE_UNICAST_CLASSIFIED;
                return (0);
        }

        /*
         * The MAC address addition failed. If the client requires a
         * hardware classified MAC address, fail the operation. This
         * feature is only used by sun4v vsw.
         */
        if (use_hw && !hw_mac) {
                err = ENOSPC;
                map->ma_nusers--;
                goto bail;
        }

        /*
         * If we reach this point then either the MAC doesn't have
         * RINGS capability or we are out of MAC address HW filters.
         * In any case we must put the MAC into promiscuous mode.
         */
        VERIFY(group == NULL || !hw_mac);

        /*
         * The one exception is the primary address. A non-RINGS
         * driver filters the primary address by default; promisc mode
         * is not needed.
         */
        if ((group == NULL) &&
            (bcmp(map->ma_addr, mip->mi_addr, map->ma_len) == 0)) {
                map->ma_type = MAC_ADDRESS_TYPE_UNICAST_CLASSIFIED;
                return (0);
        }

        /*
         * Enable promiscuous mode in order to receive traffic to the
         * new MAC address. All existing HW filters still send their
         * traffic to their respective group/SRSes. But with promisc
         * enabled all unknown traffic is delivered to the default
         * group where it is SW classified via mac_rx_classify().
         */
        if ((err = i_mac_promisc_set(mip, B_TRUE)) == 0) {
                map->ma_type = MAC_ADDRESS_TYPE_UNICAST_PROMISC;
                return (0);
        }

        /*
         * We failed to set promisc mode and we are about to free 'map'.
         */
        map->ma_nusers = 0;

bail:
        if (hw_vlan) {
                int err2 = mac_group_remvlan(group, vid);

                if (err2 != 0) {
                        cmn_err(CE_WARN, "Failed to remove VLAN %u from group"
                            " %d on MAC %s: %d.", vid, group->mrg_index,
                            mip->mi_name, err2);
                }
        }

        if (mvp != NULL)
                mac_rem_vlan(map, mvp);

        if (allocated_map)
                mac_free_macaddr(map);

        return (err);
}

int
mac_remove_macaddr_vlan(mac_address_t *map, uint16_t vid)
{
        mac_vlan_t      *mvp;
        mac_impl_t      *mip = map->ma_mip;
        mac_group_t     *group = map->ma_group;
        int             err = 0;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
        VERIFY3P(map, ==, mac_find_macaddr(mip, map->ma_addr));

        if (vid == VLAN_ID_NONE) {
                map->ma_untagged = B_FALSE;
                mvp = NULL;
        } else {
                mvp = mac_find_vlan(map, vid);
                VERIFY3P(mvp, !=, NULL);
        }

        if (MAC_GROUP_HW_VLAN(group) &&
            map->ma_type == MAC_ADDRESS_TYPE_UNICAST_CLASSIFIED &&
            ((err = mac_group_remvlan(group, vid)) != 0))
                return (err);

        if (mvp != NULL)
                mac_rem_vlan(map, mvp);

        /*
         * If it's not the last client using this MAC address, only update
         * the MAC clients count.
         */
        map->ma_nusers--;
        if (map->ma_nusers > 0)
                return (0);

        VERIFY3S(map->ma_nusers, ==, 0);

        /*
         * The MAC address is no longer used by any MAC client, so
         * remove it from its associated group. Turn off promiscuous
         * mode if this is the last address relying on it.
         */
        switch (map->ma_type) {
        case MAC_ADDRESS_TYPE_UNICAST_CLASSIFIED:
                /*
                 * Don't free the preset primary address for drivers that
                 * don't advertise RINGS capability.
                 */
                if (group == NULL)
                        return (0);

                if ((err = mac_group_remmac(group, map->ma_addr)) != 0) {
                        if (vid == VLAN_ID_NONE)
                                map->ma_untagged = B_TRUE;
                        else
                                (void) mac_add_vlan(map, vid);

                        /*
                         * If we fail to remove the MAC address HW
                         * filter but then also fail to re-add the
                         * VLAN HW filter then we are in a busted
                         * state. We do our best by logging a warning
                         * and returning the original 'err' that got
                         * us here. At this point, traffic for this
                         * address + VLAN combination will be dropped
                         * until the user reboots the system. In the
                         * future, it would be nice to have a system
                         * that can compare the state of expected
                         * classification according to mac to the
                         * actual state of the provider, and report
                         * and fix any inconsistencies.
                         */
                        if (MAC_GROUP_HW_VLAN(group)) {
                                int err2;

                                err2 = mac_group_addvlan(group, vid);
                                if (err2 != 0) {
                                        cmn_err(CE_WARN, "Failed to readd VLAN"
                                            " %u to group %d on MAC %s: %d.",
                                            vid, group->mrg_index, mip->mi_name,
                                            err2);
                                }
                        }

                        map->ma_nusers = 1;
                        return (err);
                }

                map->ma_group = NULL;
                break;
        case MAC_ADDRESS_TYPE_UNICAST_PROMISC:
                err = i_mac_promisc_set(mip, B_FALSE);
                break;
        default:
                panic("Unexpected ma_type 0x%x, file: %s, line %d",
                    map->ma_type, __FILE__, __LINE__);
        }

        if (err != 0) {
                map->ma_nusers = 1;
                return (err);
        }

        /*
         * We created MAC address for the primary one at registration, so we
         * won't free it here. mac_fini_macaddr() will take care of it.
         */
        if (bcmp(map->ma_addr, mip->mi_addr, map->ma_len) != 0)
                mac_free_macaddr(map);

        return (0);
}

/*
 * Update an existing MAC address. The caller need to make sure that the new
 * value has not been used.
 */
int
mac_update_macaddr(mac_address_t *map, uint8_t *mac_addr)
{
        mac_impl_t *mip = map->ma_mip;
        int err = 0;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
        ASSERT(mac_find_macaddr(mip, mac_addr) == NULL);

        switch (map->ma_type) {
        case MAC_ADDRESS_TYPE_UNICAST_CLASSIFIED:
                /*
                 * Update the primary address for drivers that are not
                 * RINGS capable.
                 */
                if (mip->mi_rx_groups == NULL) {
                        err = mip->mi_unicst(mip->mi_driver, (const uint8_t *)
                            mac_addr);
                        if (err != 0)
                                return (err);
                        break;
                }

                /*
                 * If this MAC address is not currently in use,
                 * simply break out and update the value.
                 */
                if (map->ma_nusers == 0)
                        break;

                /*
                 * Need to replace the MAC address associated with a group.
                 */
                err = mac_group_remmac(map->ma_group, map->ma_addr);
                if (err != 0)
                        return (err);

                err = mac_group_addmac(map->ma_group, mac_addr);

                /*
                 * Failure hints hardware error. The MAC layer needs to
                 * have error notification facility to handle this.
                 * Now, simply try to restore the value.
                 */
                if (err != 0)
                        (void) mac_group_addmac(map->ma_group, map->ma_addr);

                break;
        case MAC_ADDRESS_TYPE_UNICAST_PROMISC:
                /*
                 * Need to do nothing more if in promiscuous mode.
                 */
                break;
        default:
                ASSERT(B_FALSE);
        }

        /*
         * Successfully replaced the MAC address.
         */
        if (err == 0)
                bcopy(mac_addr, map->ma_addr, map->ma_len);

        return (err);
}

/*
 * Freshen the MAC address with new value. Its caller must have updated the
 * hardware MAC address before calling this function.
 * This funcitons is supposed to be used to handle the MAC address change
 * notification from underlying drivers.
 */
void
mac_freshen_macaddr(mac_address_t *map, uint8_t *mac_addr)
{
        mac_impl_t *mip = map->ma_mip;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));
        ASSERT(mac_find_macaddr(mip, mac_addr) == NULL);

        /*
         * Freshen the MAC address with new value.
         */
        bcopy(mac_addr, map->ma_addr, map->ma_len);
        bcopy(mac_addr, mip->mi_addr, map->ma_len);

        /*
         * Update all MAC clients that share this MAC address.
         */
        mac_unicast_update_clients(mip, map);
}

/*
 * Set up the primary MAC address.
 */
void
mac_init_macaddr(mac_impl_t *mip)
{
        mac_address_t *map;

        /*
         * The reference count is initialized to zero, until it's really
         * activated.
         */
        map = kmem_zalloc(sizeof (mac_address_t), KM_SLEEP);
        map->ma_len = mip->mi_type->mt_addr_length;
        bcopy(mip->mi_addr, map->ma_addr, map->ma_len);

        /*
         * If driver advertises RINGS capability, it shouldn't have initialized
         * its primary MAC address. For other drivers, including VNIC, the
         * primary address must work after registration.
         */
        if (mip->mi_rx_groups == NULL)
                map->ma_type = MAC_ADDRESS_TYPE_UNICAST_CLASSIFIED;

        map->ma_mip = mip;

        mip->mi_addresses = map;
}

/*
 * Clean up the primary MAC address. Note, only one primary MAC address
 * is allowed. All other MAC addresses must have been freed appropriately.
 */
void
mac_fini_macaddr(mac_impl_t *mip)
{
        mac_address_t *map = mip->mi_addresses;

        if (map == NULL)
                return;

        /*
         * If mi_addresses is initialized, there should be exactly one
         * entry left on the list with no users.
         */
        VERIFY3S(map->ma_nusers, ==, 0);
        VERIFY3P(map->ma_next, ==, NULL);
        VERIFY3P(map->ma_vlans, ==, NULL);

        kmem_free(map, sizeof (mac_address_t));
        mip->mi_addresses = NULL;
}

/*
 * Logging related functions.
 *
 * Note that Kernel statistics have been extended to maintain fine
 * granularity of statistics viz. hardware lane, software lane, fanout
 * stats etc. However, extended accounting continues to support only
 * aggregate statistics like before.
 */

/* Write the flow description to a netinfo_t record */
static netinfo_t *
mac_write_flow_desc(flow_entry_t *flent, mac_client_impl_t *mcip)
{
        netinfo_t               *ninfo;
        net_desc_t              *ndesc;
        flow_desc_t             *fdesc;
        mac_resource_props_t    *mrp;

        ninfo = kmem_zalloc(sizeof (netinfo_t), KM_NOSLEEP);
        if (ninfo == NULL)
                return (NULL);
        ndesc = kmem_zalloc(sizeof (net_desc_t), KM_NOSLEEP);
        if (ndesc == NULL) {
                kmem_free(ninfo, sizeof (netinfo_t));
                return (NULL);
        }

        /*
         * Grab the fe_lock to see a self-consistent fe_flow_desc.
         * Updates to the fe_flow_desc are done under the fe_lock
         */
        mutex_enter(&flent->fe_lock);
        fdesc = &flent->fe_flow_desc;
        mrp = &flent->fe_resource_props;

        ndesc->nd_name = flent->fe_flow_name;
        ndesc->nd_devname = mcip->mci_name;
        bcopy(fdesc->fd_src_mac, ndesc->nd_ehost, ETHERADDRL);
        bcopy(fdesc->fd_dst_mac, ndesc->nd_edest, ETHERADDRL);
        ndesc->nd_sap = htonl(fdesc->fd_sap);
        ndesc->nd_isv4 = (uint8_t)fdesc->fd_ipversion == IPV4_VERSION;
        ndesc->nd_bw_limit = mrp->mrp_maxbw;
        if (ndesc->nd_isv4) {
                ndesc->nd_saddr[3] = htonl(fdesc->fd_local_addr.s6_addr32[3]);
                ndesc->nd_daddr[3] = htonl(fdesc->fd_remote_addr.s6_addr32[3]);
        } else {
                bcopy(&fdesc->fd_local_addr, ndesc->nd_saddr, IPV6_ADDR_LEN);
                bcopy(&fdesc->fd_remote_addr, ndesc->nd_daddr, IPV6_ADDR_LEN);
        }
        ndesc->nd_sport = htons(fdesc->fd_local_port);
        ndesc->nd_dport = htons(fdesc->fd_remote_port);
        ndesc->nd_protocol = (uint8_t)fdesc->fd_protocol;
        mutex_exit(&flent->fe_lock);

        ninfo->ni_record = ndesc;
        ninfo->ni_size = sizeof (net_desc_t);
        ninfo->ni_type = EX_NET_FLDESC_REC;

        return (ninfo);
}

/* Write the flow statistics to a netinfo_t record */
static netinfo_t *
mac_write_flow_stats(flow_entry_t *flent)
{
        netinfo_t               *ninfo;
        net_stat_t              *nstat;
        mac_soft_ring_set_t     *mac_srs;
        mac_rx_stats_t          *mac_rx_stat;
        mac_tx_stats_t          *mac_tx_stat;
        int                     i;

        ninfo = kmem_zalloc(sizeof (netinfo_t), KM_NOSLEEP);
        if (ninfo == NULL)
                return (NULL);
        nstat = kmem_zalloc(sizeof (net_stat_t), KM_NOSLEEP);
        if (nstat == NULL) {
                kmem_free(ninfo, sizeof (netinfo_t));
                return (NULL);
        }

        nstat->ns_name = flent->fe_flow_name;
        for (i = 0; i < flent->fe_rx_srs_cnt; i++) {
                mac_srs = (mac_soft_ring_set_t *)flent->fe_rx_srs[i];
                mac_rx_stat = &mac_srs->srs_rx.sr_stat;

                nstat->ns_ibytes += mac_rx_stat->mrs_intrbytes +
                    mac_rx_stat->mrs_pollbytes + mac_rx_stat->mrs_lclbytes;
                nstat->ns_ipackets += mac_rx_stat->mrs_intrcnt +
                    mac_rx_stat->mrs_pollcnt + mac_rx_stat->mrs_lclcnt;
                nstat->ns_oerrors += mac_rx_stat->mrs_ierrors;
        }

        mac_srs = (mac_soft_ring_set_t *)(flent->fe_tx_srs);
        if (mac_srs != NULL) {
                mac_tx_stat = &mac_srs->srs_tx.st_stat;

                nstat->ns_obytes = mac_tx_stat->mts_obytes;
                nstat->ns_opackets = mac_tx_stat->mts_opackets;
                nstat->ns_oerrors = mac_tx_stat->mts_oerrors;
        }

        ninfo->ni_record = nstat;
        ninfo->ni_size = sizeof (net_stat_t);
        ninfo->ni_type = EX_NET_FLSTAT_REC;

        return (ninfo);
}

/* Write the link description to a netinfo_t record */
static netinfo_t *
mac_write_link_desc(mac_client_impl_t *mcip)
{
        netinfo_t               *ninfo;
        net_desc_t              *ndesc;
        flow_entry_t            *flent = mcip->mci_flent;

        ninfo = kmem_zalloc(sizeof (netinfo_t), KM_NOSLEEP);
        if (ninfo == NULL)
                return (NULL);
        ndesc = kmem_zalloc(sizeof (net_desc_t), KM_NOSLEEP);
        if (ndesc == NULL) {
                kmem_free(ninfo, sizeof (netinfo_t));
                return (NULL);
        }

        ndesc->nd_name = mcip->mci_name;
        ndesc->nd_devname = mcip->mci_name;
        ndesc->nd_isv4 = B_TRUE;
        /*
         * Grab the fe_lock to see a self-consistent fe_flow_desc.
         * Updates to the fe_flow_desc are done under the fe_lock
         * after removing the flent from the flow table.
         */
        mutex_enter(&flent->fe_lock);
        bcopy(flent->fe_flow_desc.fd_src_mac, ndesc->nd_ehost, ETHERADDRL);
        mutex_exit(&flent->fe_lock);

        ninfo->ni_record = ndesc;
        ninfo->ni_size = sizeof (net_desc_t);
        ninfo->ni_type = EX_NET_LNDESC_REC;

        return (ninfo);
}

/* Write the link statistics to a netinfo_t record */
static netinfo_t *
mac_write_link_stats(mac_client_impl_t *mcip)
{
        netinfo_t               *ninfo;
        net_stat_t              *nstat;
        flow_entry_t            *flent;
        mac_soft_ring_set_t     *mac_srs;
        mac_rx_stats_t          *mac_rx_stat;
        mac_tx_stats_t          *mac_tx_stat;
        int                     i;

        ninfo = kmem_zalloc(sizeof (netinfo_t), KM_NOSLEEP);
        if (ninfo == NULL)
                return (NULL);
        nstat = kmem_zalloc(sizeof (net_stat_t), KM_NOSLEEP);
        if (nstat == NULL) {
                kmem_free(ninfo, sizeof (netinfo_t));
                return (NULL);
        }

        nstat->ns_name = mcip->mci_name;
        flent = mcip->mci_flent;
        if (flent != NULL)  {
                for (i = 0; i < flent->fe_rx_srs_cnt; i++) {
                        mac_srs = (mac_soft_ring_set_t *)flent->fe_rx_srs[i];
                        mac_rx_stat = &mac_srs->srs_rx.sr_stat;

                        nstat->ns_ibytes += mac_rx_stat->mrs_intrbytes +
                            mac_rx_stat->mrs_pollbytes +
                            mac_rx_stat->mrs_lclbytes;
                        nstat->ns_ipackets += mac_rx_stat->mrs_intrcnt +
                            mac_rx_stat->mrs_pollcnt + mac_rx_stat->mrs_lclcnt;
                        nstat->ns_oerrors += mac_rx_stat->mrs_ierrors;
                }
        }

        mac_srs = (mac_soft_ring_set_t *)(mcip->mci_flent->fe_tx_srs);
        if (mac_srs != NULL) {
                mac_tx_stat = &mac_srs->srs_tx.st_stat;

                nstat->ns_obytes = mac_tx_stat->mts_obytes;
                nstat->ns_opackets = mac_tx_stat->mts_opackets;
                nstat->ns_oerrors = mac_tx_stat->mts_oerrors;
        }

        ninfo->ni_record = nstat;
        ninfo->ni_size = sizeof (net_stat_t);
        ninfo->ni_type = EX_NET_LNSTAT_REC;

        return (ninfo);
}

typedef struct i_mac_log_state_s {
        boolean_t       mi_last;
        int             mi_fenable;
        int             mi_lenable;
        list_t          *mi_list;
} i_mac_log_state_t;

/*
 * For a given flow, if the description has not been logged before, do it now.
 * If it is a VNIC, then we have collected information about it from the MAC
 * table, so skip it.
 *
 * Called through mac_flow_walk_nolock()
 *
 * Return 0 if successful.
 */
static int
mac_log_flowinfo(flow_entry_t *flent, void *arg)
{
        mac_client_impl_t       *mcip = flent->fe_mcip;
        i_mac_log_state_t       *lstate = arg;
        netinfo_t               *ninfo;

        if (mcip == NULL)
                return (0);

        /*
         * If the name starts with "vnic", and fe_user_generated is true (to
         * exclude the mcast and active flow entries created implicitly for
         * a vnic, it is a VNIC flow.  i.e. vnic1 is a vnic flow,
         * vnic/bge1/mcast1 is not and neither is vnic/bge1/active.
         */
        if (strncasecmp(flent->fe_flow_name, "vnic", 4) == 0 &&
            (flent->fe_type & FLOW_USER) != 0) {
                return (0);
        }

        if (!flent->fe_desc_logged) {
                /*
                 * We don't return error because we want to continue the
                 * walk in case this is the last walk which means we
                 * need to reset fe_desc_logged in all the flows.
                 */
                if ((ninfo = mac_write_flow_desc(flent, mcip)) == NULL)
                        return (0);
                list_insert_tail(lstate->mi_list, ninfo);
                flent->fe_desc_logged = B_TRUE;
        }

        /*
         * Regardless of the error, we want to proceed in case we have to
         * reset fe_desc_logged.
         */
        ninfo = mac_write_flow_stats(flent);
        if (ninfo == NULL)
                return (-1);

        list_insert_tail(lstate->mi_list, ninfo);

        if (mcip != NULL && !(mcip->mci_state_flags & MCIS_DESC_LOGGED))
                flent->fe_desc_logged = B_FALSE;

        return (0);
}

/*
 * Log the description for each mac client of this mac_impl_t, if it
 * hasn't already been done. Additionally, log statistics for the link as
 * well. Walk the flow table and log information for each flow as well.
 * If it is the last walk (mci_last), then we turn off mci_desc_logged (and
 * also fe_desc_logged, if flow logging is on) since we want to log the
 * description if and when logging is restarted.
 *
 * Return 0 upon success or -1 upon failure
 */
static int
i_mac_impl_log(mac_impl_t *mip, i_mac_log_state_t *lstate)
{
        mac_client_impl_t       *mcip;
        netinfo_t               *ninfo;

        i_mac_perim_enter(mip);
        /*
         * Only walk the client list for NIC and etherstub
         */
        if ((mip->mi_state_flags & MIS_DISABLED) ||
            ((mip->mi_state_flags & MIS_IS_VNIC) &&
            (mac_get_lower_mac_handle((mac_handle_t)mip) != NULL))) {
                i_mac_perim_exit(mip);
                return (0);
        }

        for (mcip = mip->mi_clients_list; mcip != NULL;
            mcip = mcip->mci_client_next) {
                if (!MCIP_DATAPATH_SETUP(mcip))
                        continue;
                if (lstate->mi_lenable) {
                        if (!(mcip->mci_state_flags & MCIS_DESC_LOGGED)) {
                                ninfo = mac_write_link_desc(mcip);
                                if (ninfo == NULL) {
                                /*
                                 * We can't terminate it if this is the last
                                 * walk, else there might be some links with
                                 * mi_desc_logged set to true, which means
                                 * their description won't be logged the next
                                 * time logging is started (similarly for the
                                 * flows within such links). We can continue
                                 * without walking the flow table (i.e. to
                                 * set fe_desc_logged to false) because we
                                 * won't have written any flow stuff for this
                                 * link as we haven't logged the link itself.
                                 */
                                        i_mac_perim_exit(mip);
                                        if (lstate->mi_last)
                                                return (0);
                                        else
                                                return (-1);
                                }
                                mcip->mci_state_flags |= MCIS_DESC_LOGGED;
                                list_insert_tail(lstate->mi_list, ninfo);
                        }
                }

                ninfo = mac_write_link_stats(mcip);
                if (ninfo == NULL && !lstate->mi_last) {
                        i_mac_perim_exit(mip);
                        return (-1);
                }
                list_insert_tail(lstate->mi_list, ninfo);

                if (lstate->mi_last)
                        mcip->mci_state_flags &= ~MCIS_DESC_LOGGED;

                if (lstate->mi_fenable) {
                        if (mcip->mci_subflow_tab != NULL) {
                                (void) mac_flow_walk_nolock(
                                    mcip->mci_subflow_tab, mac_log_flowinfo,
                                    lstate);
                        }
                }
        }
        i_mac_perim_exit(mip);
        return (0);
}

/*
 * modhash walker function to add a mac_impl_t to a list
 */
/*ARGSUSED*/
static uint_t
i_mac_impl_list_walker(mod_hash_key_t key, mod_hash_val_t *val, void *arg)
{
        list_t                  *list = (list_t *)arg;
        mac_impl_t              *mip = (mac_impl_t *)val;

        if ((mip->mi_state_flags & MIS_DISABLED) == 0) {
                list_insert_tail(list, mip);
                mip->mi_ref++;
        }

        return (MH_WALK_CONTINUE);
}

void
i_mac_log_info(list_t *net_log_list, i_mac_log_state_t *lstate)
{
        list_t                  mac_impl_list;
        mac_impl_t              *mip;
        netinfo_t               *ninfo;

        /* Create list of mac_impls */
        ASSERT(RW_LOCK_HELD(&i_mac_impl_lock));
        list_create(&mac_impl_list, sizeof (mac_impl_t), offsetof(mac_impl_t,
            mi_node));
        mod_hash_walk(i_mac_impl_hash, i_mac_impl_list_walker, &mac_impl_list);
        rw_exit(&i_mac_impl_lock);

        /* Create log entries for each mac_impl */
        for (mip = list_head(&mac_impl_list); mip != NULL;
            mip = list_next(&mac_impl_list, mip)) {
                if (i_mac_impl_log(mip, lstate) != 0)
                        continue;
        }

        /* Remove elements and destroy list of mac_impls */
        rw_enter(&i_mac_impl_lock, RW_WRITER);
        while ((mip = list_remove_tail(&mac_impl_list)) != NULL) {
                mip->mi_ref--;
        }
        rw_exit(&i_mac_impl_lock);
        list_destroy(&mac_impl_list);

        /*
         * Write log entries to files outside of locks, free associated
         * structures, and remove entries from the list.
         */
        while ((ninfo = list_head(net_log_list)) != NULL) {
                (void) exacct_commit_netinfo(ninfo->ni_record, ninfo->ni_type);
                list_remove(net_log_list, ninfo);
                kmem_free(ninfo->ni_record, ninfo->ni_size);
                kmem_free(ninfo, sizeof (*ninfo));
        }
        list_destroy(net_log_list);
}

/*
 * The timer thread that runs every mac_logging_interval seconds and logs
 * link and/or flow information.
 */
/* ARGSUSED */
void
mac_log_linkinfo(void *arg)
{
        i_mac_log_state_t       lstate;
        list_t                  net_log_list;

        list_create(&net_log_list, sizeof (netinfo_t),
            offsetof(netinfo_t, ni_link));

        rw_enter(&i_mac_impl_lock, RW_READER);
        if (!mac_flow_log_enable && !mac_link_log_enable) {
                rw_exit(&i_mac_impl_lock);
                return;
        }
        lstate.mi_fenable = mac_flow_log_enable;
        lstate.mi_lenable = mac_link_log_enable;
        lstate.mi_last = B_FALSE;
        lstate.mi_list = &net_log_list;

        /* Write log entries for each mac_impl in the list */
        i_mac_log_info(&net_log_list, &lstate);

        if (mac_flow_log_enable || mac_link_log_enable) {
                mac_logging_timer = timeout(mac_log_linkinfo, NULL,
                    SEC_TO_TICK(mac_logging_interval));
        }
}

typedef struct i_mac_fastpath_state_s {
        boolean_t       mf_disable;
        int             mf_err;
} i_mac_fastpath_state_t;

/* modhash walker function to enable or disable fastpath */
/*ARGSUSED*/
static uint_t
i_mac_fastpath_walker(mod_hash_key_t key, mod_hash_val_t *val,
    void *arg)
{
        i_mac_fastpath_state_t  *state = arg;
        mac_handle_t            mh = (mac_handle_t)val;

        if (state->mf_disable)
                state->mf_err = mac_fastpath_disable(mh);
        else
                mac_fastpath_enable(mh);

        return (state->mf_err == 0 ? MH_WALK_CONTINUE : MH_WALK_TERMINATE);
}

/*
 * Start the logging timer.
 */
int
mac_start_logusage(mac_logtype_t type, uint_t interval)
{
        i_mac_fastpath_state_t  dstate = {B_TRUE, 0};
        i_mac_fastpath_state_t  estate = {B_FALSE, 0};
        int                     err;

        rw_enter(&i_mac_impl_lock, RW_WRITER);
        switch (type) {
        case MAC_LOGTYPE_FLOW:
                if (mac_flow_log_enable) {
                        rw_exit(&i_mac_impl_lock);
                        return (0);
                }
                /* FALLTHRU */
        case MAC_LOGTYPE_LINK:
                if (mac_link_log_enable) {
                        rw_exit(&i_mac_impl_lock);
                        return (0);
                }
                break;
        default:
                ASSERT(0);
        }

        /* Disable fastpath */
        mod_hash_walk(i_mac_impl_hash, i_mac_fastpath_walker, &dstate);
        if ((err = dstate.mf_err) != 0) {
                /* Reenable fastpath  */
                mod_hash_walk(i_mac_impl_hash, i_mac_fastpath_walker, &estate);
                rw_exit(&i_mac_impl_lock);
                return (err);
        }

        switch (type) {
        case MAC_LOGTYPE_FLOW:
                mac_flow_log_enable = B_TRUE;
                /* FALLTHRU */
        case MAC_LOGTYPE_LINK:
                mac_link_log_enable = B_TRUE;
                break;
        }

        mac_logging_interval = interval;
        rw_exit(&i_mac_impl_lock);
        mac_log_linkinfo(NULL);
        return (0);
}

/*
 * Stop the logging timer if both link and flow logging are turned off.
 */
void
mac_stop_logusage(mac_logtype_t type)
{
        i_mac_log_state_t       lstate;
        i_mac_fastpath_state_t  estate = {B_FALSE, 0};
        list_t                  net_log_list;

        list_create(&net_log_list, sizeof (netinfo_t),
            offsetof(netinfo_t, ni_link));

        rw_enter(&i_mac_impl_lock, RW_WRITER);

        lstate.mi_fenable = mac_flow_log_enable;
        lstate.mi_lenable = mac_link_log_enable;
        lstate.mi_list = &net_log_list;

        /* Last walk */
        lstate.mi_last = B_TRUE;

        switch (type) {
        case MAC_LOGTYPE_FLOW:
                if (lstate.mi_fenable) {
                        ASSERT(mac_link_log_enable);
                        mac_flow_log_enable = B_FALSE;
                        mac_link_log_enable = B_FALSE;
                        break;
                }
                /* FALLTHRU */
        case MAC_LOGTYPE_LINK:
                if (!lstate.mi_lenable || mac_flow_log_enable) {
                        rw_exit(&i_mac_impl_lock);
                        return;
                }
                mac_link_log_enable = B_FALSE;
                break;
        default:
                ASSERT(0);
        }

        /* Reenable fastpath */
        mod_hash_walk(i_mac_impl_hash, i_mac_fastpath_walker, &estate);

        (void) untimeout(mac_logging_timer);
        mac_logging_timer = NULL;

        /* Write log entries for each mac_impl in the list */
        i_mac_log_info(&net_log_list, &lstate);
}

/*
 * Walk the rx and tx SRS/SRs for a flow and update the priority value.
 */
void
mac_flow_update_priority(mac_client_impl_t *mcip, flow_entry_t *flent)
{
        pri_t                   pri;
        int                     count;
        mac_soft_ring_set_t     *mac_srs;

        if (flent->fe_rx_srs_cnt <= 0)
                return;

        if (((mac_soft_ring_set_t *)flent->fe_rx_srs[0])->srs_type ==
            SRST_FLOW) {
                pri = FLOW_PRIORITY(mcip->mci_min_pri,
                    mcip->mci_max_pri,
                    flent->fe_resource_props.mrp_priority);
        } else {
                pri = mcip->mci_max_pri;
        }

        for (count = 0; count < flent->fe_rx_srs_cnt; count++) {
                mac_srs = flent->fe_rx_srs[count];
                mac_update_srs_priority(mac_srs, pri);
        }
        /*
         * If we have a Tx SRS, we need to modify all the threads associated
         * with it.
         */
        if (flent->fe_tx_srs != NULL)
                mac_update_srs_priority(flent->fe_tx_srs, pri);
}

/*
 * RX and TX rings are reserved according to different semantics depending
 * on the requests from the MAC clients and type of rings:
 *
 * On the Tx side, by default we reserve individual rings, independently from
 * the groups.
 *
 * On the Rx side, the reservation is at the granularity of the group
 * of rings, and used for v12n level 1 only. It has a special case for the
 * primary client.
 *
 * If a share is allocated to a MAC client, we allocate a TX group and an
 * RX group to the client, and assign TX rings and RX rings to these
 * groups according to information gathered from the driver through
 * the share capability.
 *
 * The foreseable evolution of Rx rings will handle v12n level 2 and higher
 * to allocate individual rings out of a group and program the hw classifier
 * based on IP address or higher level criteria.
 */

/*
 * mac_reserve_tx_ring()
 * Reserve a unused ring by marking it with MR_INUSE state.
 * As reserved, the ring is ready to function.
 *
 * Notes for Hybrid I/O:
 *
 * If a specific ring is needed, it is specified through the desired_ring
 * argument. Otherwise that argument is set to NULL.
 * If the desired ring was previous allocated to another client, this
 * function swaps it with a new ring from the group of unassigned rings.
 */
mac_ring_t *
mac_reserve_tx_ring(mac_impl_t *mip, mac_ring_t *desired_ring)
{
        mac_group_t             *group;
        mac_grp_client_t        *mgcp;
        mac_client_impl_t       *mcip;
        mac_soft_ring_set_t     *srs;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        /*
         * Find an available ring and start it before changing its status.
         * The unassigned rings are at the end of the mi_tx_groups
         * array.
         */
        group = MAC_DEFAULT_TX_GROUP(mip);

        /* Can't take the default ring out of the default group */
        ASSERT(desired_ring != (mac_ring_t *)mip->mi_default_tx_ring);

        if (desired_ring->mr_state == MR_FREE) {
                ASSERT(MAC_GROUP_NO_CLIENT(group));
                if (mac_start_ring(desired_ring) != 0)
                        return (NULL);
                return (desired_ring);
        }
        /*
         * There are clients using this ring, so let's move the clients
         * away from using this ring.
         */
        for (mgcp = group->mrg_clients; mgcp != NULL; mgcp = mgcp->mgc_next) {
                mcip = mgcp->mgc_client;
                mac_tx_client_quiesce((mac_client_handle_t)mcip);
                srs = MCIP_TX_SRS(mcip);
                ASSERT(mac_tx_srs_ring_present(srs, desired_ring));
                mac_tx_invoke_callbacks(mcip,
                    (mac_tx_cookie_t)mac_tx_srs_get_soft_ring(srs,
                    desired_ring));
                mac_tx_srs_del_ring(srs, desired_ring);
                mac_tx_client_restart((mac_client_handle_t)mcip);
        }
        return (desired_ring);
}

/*
 * For a non-default group with multiple clients, return the primary client.
 */
static mac_client_impl_t *
mac_get_grp_primary(mac_group_t *grp)
{
        mac_grp_client_t        *mgcp = grp->mrg_clients;
        mac_client_impl_t       *mcip;

        while (mgcp != NULL) {
                mcip = mgcp->mgc_client;
                if (mcip->mci_flent->fe_type & FLOW_PRIMARY_MAC)
                        return (mcip);
                mgcp = mgcp->mgc_next;
        }
        return (NULL);
}

/*
 * Hybrid I/O specifies the ring that should be given to a share.
 * If the ring is already used by clients, then we need to release
 * the ring back to the default group so that we can give it to
 * the share. This means the clients using this ring now get a
 * replacement ring. If there aren't any replacement rings, this
 * function returns a failure.
 */
static int
mac_reclaim_ring_from_grp(mac_impl_t *mip, mac_ring_type_t ring_type,
    mac_ring_t *ring, mac_ring_t **rings, int nrings)
{
        mac_group_t             *group = (mac_group_t *)ring->mr_gh;
        mac_resource_props_t    *mrp;
        mac_client_impl_t       *mcip;
        mac_group_t             *defgrp;
        mac_ring_t              *tring;
        mac_group_t             *tgrp;
        int                     i;
        int                     j;

        mcip = MAC_GROUP_ONLY_CLIENT(group);
        if (mcip == NULL)
                mcip = mac_get_grp_primary(group);
        ASSERT(mcip != NULL);
        ASSERT(mcip->mci_share == 0);

        mrp = MCIP_RESOURCE_PROPS(mcip);
        if (ring_type == MAC_RING_TYPE_RX) {
                defgrp = mip->mi_rx_donor_grp;
                if ((mrp->mrp_mask & MRP_RX_RINGS) == 0) {
                        /* Need to put this mac client in the default group */
                        if (mac_rx_switch_group(mcip, group, defgrp) != 0)
                                return (ENOSPC);
                } else {
                        /*
                         * Switch this ring with some other ring from
                         * the default group.
                         */
                        for (tring = defgrp->mrg_rings; tring != NULL;
                            tring = tring->mr_next) {
                                if (tring->mr_index == 0)
                                        continue;
                                for (j = 0; j < nrings; j++) {
                                        if (rings[j] == tring)
                                                break;
                                }
                                if (j >= nrings)
                                        break;
                        }
                        if (tring == NULL)
                                return (ENOSPC);
                        if (mac_group_mov_ring(mip, group, tring) != 0)
                                return (ENOSPC);
                        if (mac_group_mov_ring(mip, defgrp, ring) != 0) {
                                (void) mac_group_mov_ring(mip, defgrp, tring);
                                return (ENOSPC);
                        }
                }
                ASSERT(ring->mr_gh == (mac_group_handle_t)defgrp);
                return (0);
        }

        defgrp = MAC_DEFAULT_TX_GROUP(mip);
        if (ring == (mac_ring_t *)mip->mi_default_tx_ring) {
                /*
                 * See if we can get a spare ring to replace the default
                 * ring.
                 */
                if (defgrp->mrg_cur_count == 1) {
                        /*
                         * Need to get a ring from another client, see if
                         * there are any clients that can be moved to
                         * the default group, thereby freeing some rings.
                         */
                        for (i = 0; i < mip->mi_tx_group_count; i++) {
                                tgrp = &mip->mi_tx_groups[i];
                                if (tgrp->mrg_state ==
                                    MAC_GROUP_STATE_REGISTERED) {
                                        continue;
                                }
                                mcip = MAC_GROUP_ONLY_CLIENT(tgrp);
                                if (mcip == NULL)
                                        mcip = mac_get_grp_primary(tgrp);
                                ASSERT(mcip != NULL);
                                mrp = MCIP_RESOURCE_PROPS(mcip);
                                if ((mrp->mrp_mask & MRP_TX_RINGS) == 0) {
                                        ASSERT(tgrp->mrg_cur_count == 1);
                                        /*
                                         * If this ring is part of the
                                         * rings asked by the share we cannot
                                         * use it as the default ring.
                                         */
                                        for (j = 0; j < nrings; j++) {
                                                if (rings[j] == tgrp->mrg_rings)
                                                        break;
                                        }
                                        if (j < nrings)
                                                continue;
                                        mac_tx_client_quiesce(
                                            (mac_client_handle_t)mcip);
                                        mac_tx_switch_group(mcip, tgrp,
                                            defgrp);
                                        mac_tx_client_restart(
                                            (mac_client_handle_t)mcip);
                                        break;
                                }
                        }
                        /*
                         * All the rings are reserved, can't give up the
                         * default ring.
                         */
                        if (defgrp->mrg_cur_count <= 1)
                                return (ENOSPC);
                }
                /*
                 * Swap the default ring with another.
                 */
                for (tring = defgrp->mrg_rings; tring != NULL;
                    tring = tring->mr_next) {
                        /*
                         * If this ring is part of the rings asked by the
                         * share we cannot use it as the default ring.
                         */
                        for (j = 0; j < nrings; j++) {
                                if (rings[j] == tring)
                                        break;
                        }
                        if (j >= nrings)
                                break;
                }
                ASSERT(tring != NULL);
                mip->mi_default_tx_ring = (mac_ring_handle_t)tring;
                return (0);
        }
        /*
         * The Tx ring is with a group reserved by a MAC client. See if
         * we can swap it.
         */
        ASSERT(group->mrg_state == MAC_GROUP_STATE_RESERVED);
        mcip = MAC_GROUP_ONLY_CLIENT(group);
        if (mcip == NULL)
                mcip = mac_get_grp_primary(group);
        ASSERT(mcip !=  NULL);
        mrp = MCIP_RESOURCE_PROPS(mcip);
        mac_tx_client_quiesce((mac_client_handle_t)mcip);
        if ((mrp->mrp_mask & MRP_TX_RINGS) == 0) {
                ASSERT(group->mrg_cur_count == 1);
                /* Put this mac client in the default group */
                mac_tx_switch_group(mcip, group, defgrp);
        } else {
                /*
                 * Switch this ring with some other ring from
                 * the default group.
                 */
                for (tring = defgrp->mrg_rings; tring != NULL;
                    tring = tring->mr_next) {
                        if (tring == (mac_ring_t *)mip->mi_default_tx_ring)
                                continue;
                        /*
                         * If this ring is part of the rings asked by the
                         * share we cannot use it for swapping.
                         */
                        for (j = 0; j < nrings; j++) {
                                if (rings[j] == tring)
                                        break;
                        }
                        if (j >= nrings)
                                break;
                }
                if (tring == NULL) {
                        mac_tx_client_restart((mac_client_handle_t)mcip);
                        return (ENOSPC);
                }
                if (mac_group_mov_ring(mip, group, tring) != 0) {
                        mac_tx_client_restart((mac_client_handle_t)mcip);
                        return (ENOSPC);
                }
                if (mac_group_mov_ring(mip, defgrp, ring) != 0) {
                        (void) mac_group_mov_ring(mip, defgrp, tring);
                        mac_tx_client_restart((mac_client_handle_t)mcip);
                        return (ENOSPC);
                }
        }
        mac_tx_client_restart((mac_client_handle_t)mcip);
        ASSERT(ring->mr_gh == (mac_group_handle_t)defgrp);
        return (0);
}

/*
 * Populate a zero-ring group with rings. If the share is non-NULL,
 * the rings are chosen according to that share.
 * Invoked after allocating a new RX or TX group through
 * mac_reserve_rx_group() or mac_reserve_tx_group(), respectively.
 * Returns zero on success, an errno otherwise.
 */
int
i_mac_group_allocate_rings(mac_impl_t *mip, mac_ring_type_t ring_type,
    mac_group_t *src_group, mac_group_t *new_group, mac_share_handle_t share,
    uint32_t ringcnt)
{
        mac_ring_t **rings, *ring;
        uint_t nrings;
        int rv = 0, i = 0, j;

        ASSERT((ring_type == MAC_RING_TYPE_RX &&
            mip->mi_rx_group_type == MAC_GROUP_TYPE_DYNAMIC) ||
            (ring_type == MAC_RING_TYPE_TX &&
            mip->mi_tx_group_type == MAC_GROUP_TYPE_DYNAMIC));

        /*
         * First find the rings to allocate to the group.
         */
        if (share != 0) {
                /* get rings through ms_squery() */
                mip->mi_share_capab.ms_squery(share, ring_type, NULL, &nrings);
                ASSERT(nrings != 0);
                rings = kmem_alloc(nrings * sizeof (mac_ring_handle_t),
                    KM_SLEEP);
                mip->mi_share_capab.ms_squery(share, ring_type,
                    (mac_ring_handle_t *)rings, &nrings);
                for (i = 0; i < nrings; i++) {
                        /*
                         * If we have given this ring to a non-default
                         * group, we need to check if we can get this
                         * ring.
                         */
                        ring = rings[i];
                        if (ring->mr_gh != (mac_group_handle_t)src_group ||
                            ring == (mac_ring_t *)mip->mi_default_tx_ring) {
                                if (mac_reclaim_ring_from_grp(mip, ring_type,
                                    ring, rings, nrings) != 0) {
                                        rv = ENOSPC;
                                        goto bail;
                                }
                        }
                }
        } else {
                /*
                 * Pick one ring from default group.
                 *
                 * for now pick the second ring which requires the first ring
                 * at index 0 to stay in the default group, since it is the
                 * ring which carries the multicast traffic.
                 * We need a better way for a driver to indicate this,
                 * for example a per-ring flag.
                 */
                rings = kmem_alloc(ringcnt * sizeof (mac_ring_handle_t),
                    KM_SLEEP);
                for (ring = src_group->mrg_rings; ring != NULL;
                    ring = ring->mr_next) {
                        if (ring_type == MAC_RING_TYPE_RX &&
                            ring->mr_index == 0) {
                                continue;
                        }
                        if (ring_type == MAC_RING_TYPE_TX &&
                            ring == (mac_ring_t *)mip->mi_default_tx_ring) {
                                continue;
                        }
                        rings[i++] = ring;
                        if (i == ringcnt)
                                break;
                }
                ASSERT(ring != NULL);
                nrings = i;
                /* Not enough rings as required */
                if (nrings != ringcnt) {
                        rv = ENOSPC;
                        goto bail;
                }
        }

        switch (ring_type) {
        case MAC_RING_TYPE_RX:
                if (src_group->mrg_cur_count - nrings < 1) {
                        /* we ran out of rings */
                        rv = ENOSPC;
                        goto bail;
                }

                /* move receive rings to new group */
                for (i = 0; i < nrings; i++) {
                        rv = mac_group_mov_ring(mip, new_group, rings[i]);
                        if (rv != 0) {
                                /* move rings back on failure */
                                for (j = 0; j < i; j++) {
                                        (void) mac_group_mov_ring(mip,
                                            src_group, rings[j]);
                                }
                                goto bail;
                        }
                }
                break;

        case MAC_RING_TYPE_TX: {
                mac_ring_t *tmp_ring;

                /* move the TX rings to the new group */
                for (i = 0; i < nrings; i++) {
                        /* get the desired ring */
                        tmp_ring = mac_reserve_tx_ring(mip, rings[i]);
                        if (tmp_ring == NULL) {
                                rv = ENOSPC;
                                goto bail;
                        }
                        ASSERT(tmp_ring == rings[i]);
                        rv = mac_group_mov_ring(mip, new_group, rings[i]);
                        if (rv != 0) {
                                /* cleanup on failure */
                                for (j = 0; j < i; j++) {
                                        (void) mac_group_mov_ring(mip,
                                            MAC_DEFAULT_TX_GROUP(mip),
                                            rings[j]);
                                }
                                goto bail;
                        }
                }
                break;
        }
        }

        /* add group to share */
        if (share != 0)
                mip->mi_share_capab.ms_sadd(share, new_group->mrg_driver);

bail:
        /* free temporary array of rings */
        kmem_free(rings, nrings * sizeof (mac_ring_handle_t));

        return (rv);
}

void
mac_group_add_client(mac_group_t *grp, mac_client_impl_t *mcip)
{
        mac_grp_client_t *mgcp;

        for (mgcp = grp->mrg_clients; mgcp != NULL; mgcp = mgcp->mgc_next) {
                if (mgcp->mgc_client == mcip)
                        break;
        }

        ASSERT(mgcp == NULL);

        mgcp = kmem_zalloc(sizeof (mac_grp_client_t), KM_SLEEP);
        mgcp->mgc_client = mcip;
        mgcp->mgc_next = grp->mrg_clients;
        grp->mrg_clients = mgcp;
}

void
mac_group_remove_client(mac_group_t *grp, mac_client_impl_t *mcip)
{
        mac_grp_client_t *mgcp, **pprev;

        for (pprev = &grp->mrg_clients, mgcp = *pprev; mgcp != NULL;
            pprev = &mgcp->mgc_next, mgcp = *pprev) {
                if (mgcp->mgc_client == mcip)
                        break;
        }

        ASSERT(mgcp != NULL);

        *pprev = mgcp->mgc_next;
        kmem_free(mgcp, sizeof (mac_grp_client_t));
}

/*
 * Return true if any client on this group explicitly asked for HW
 * rings (of type mask) or have a bound share.
 */
static boolean_t
i_mac_clients_hw(mac_group_t *grp, uint32_t mask)
{
        mac_grp_client_t        *mgcip;
        mac_client_impl_t       *mcip;
        mac_resource_props_t    *mrp;

        for (mgcip = grp->mrg_clients; mgcip != NULL; mgcip = mgcip->mgc_next) {
                mcip = mgcip->mgc_client;
                mrp = MCIP_RESOURCE_PROPS(mcip);
                if (mcip->mci_share != 0 || (mrp->mrp_mask & mask) != 0)
                        return (B_TRUE);
        }

        return (B_FALSE);
}

/*
 * Finds an available group and exclusively reserves it for a client.
 * The group is chosen to suit the flow's resource controls (bandwidth and
 * fanout requirements) and the address type.
 * If the requestor is the pimary MAC then return the group with the
 * largest number of rings, otherwise the default ring when available.
 */
mac_group_t *
mac_reserve_rx_group(mac_client_impl_t *mcip, uint8_t *mac_addr, boolean_t move)
{
        mac_share_handle_t      share = mcip->mci_share;
        mac_impl_t              *mip = mcip->mci_mip;
        mac_group_t             *grp = NULL;
        int                     i;
        int                     err = 0;
        mac_address_t           *map;
        mac_resource_props_t    *mrp = MCIP_RESOURCE_PROPS(mcip);
        int                     nrings;
        int                     donor_grp_rcnt;
        boolean_t               need_exclgrp = B_FALSE;
        int                     need_rings = 0;
        mac_group_t             *candidate_grp = NULL;
        mac_client_impl_t       *gclient;
        mac_group_t             *donorgrp = NULL;
        boolean_t               rxhw = mrp->mrp_mask & MRP_RX_RINGS;
        boolean_t               unspec = mrp->mrp_mask & MRP_RXRINGS_UNSPEC;
        boolean_t               isprimary;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mip));

        isprimary = mcip->mci_flent->fe_type & FLOW_PRIMARY_MAC;

        /*
         * Check if a group already has this MAC address (case of VLANs)
         * unless we are moving this MAC client from one group to another.
         */
        if (!move && (map = mac_find_macaddr(mip, mac_addr)) != NULL) {
                if (map->ma_group != NULL)
                        return (map->ma_group);
        }

        if (mip->mi_rx_groups == NULL || mip->mi_rx_group_count == 0)
                return (NULL);

        /*
         * If this client is requesting exclusive MAC access then
         * return NULL to ensure the client uses the default group.
         */
        if (mcip->mci_state_flags & MCIS_EXCLUSIVE)
                return (NULL);

        /* For dynamic groups default unspecified to 1 */
        if (rxhw && unspec &&
            mip->mi_rx_group_type == MAC_GROUP_TYPE_DYNAMIC) {
                mrp->mrp_nrxrings = 1;
        }

        /*
         * For static grouping we allow only specifying rings=0 and
         * unspecified
         */
        if (rxhw && mrp->mrp_nrxrings > 0 &&
            mip->mi_rx_group_type == MAC_GROUP_TYPE_STATIC) {
                return (NULL);
        }

        if (rxhw) {
                /*
                 * We have explicitly asked for a group (with nrxrings,
                 * if unspec).
                 */
                if (unspec || mrp->mrp_nrxrings > 0) {
                        need_exclgrp = B_TRUE;
                        need_rings = mrp->mrp_nrxrings;
                } else if (mrp->mrp_nrxrings == 0) {
                        /*
                         * We have asked for a software group.
                         */
                        return (NULL);
                }
        } else if (isprimary && mip->mi_nactiveclients == 1 &&
            mip->mi_rx_group_type == MAC_GROUP_TYPE_DYNAMIC) {
                /*
                 * If the primary is the only active client on this
                 * mip and we have not asked for any rings, we give
                 * it the default group so that the primary gets to
                 * use all the rings.
                 */
                return (NULL);
        }

        /* The group that can donate rings */
        donorgrp = mip->mi_rx_donor_grp;

        /*
         * The number of rings that the default group can donate.
         * We need to leave at least one ring.
         */
        donor_grp_rcnt = donorgrp->mrg_cur_count - 1;

        /*
         * Try to exclusively reserve a RX group.
         *
         * For flows requiring HW_DEFAULT_RING (unicast flow of the primary
         * client), try to reserve the a non-default RX group and give
         * it all the rings from the donor group, except the default ring
         *
         * For flows requiring HW_RING (unicast flow of other clients), try
         * to reserve non-default RX group with the specified number of
         * rings, if available.
         *
         * For flows that have not asked for software or hardware ring,
         * try to reserve a non-default group with 1 ring, if available.
         */
        for (i = 1; i < mip->mi_rx_group_count; i++) {
                grp = &mip->mi_rx_groups[i];

                DTRACE_PROBE3(rx__group__trying, char *, mip->mi_name,
                    int, grp->mrg_index, mac_group_state_t, grp->mrg_state);

                /*
                 * Check if this group could be a candidate group for
                 * eviction if we need a group for this MAC client,
                 * but there aren't any. A candidate group is one
                 * that didn't ask for an exclusive group, but got
                 * one and it has enough rings (combined with what
                 * the donor group can donate) for the new MAC
                 * client.
                 */
                if (grp->mrg_state >= MAC_GROUP_STATE_RESERVED) {
                        /*
                         * If the donor group is not the default
                         * group, don't bother looking for a candidate
                         * group. If we don't have enough rings we
                         * will check if the primary group can be
                         * vacated.
                         */
                        if (candidate_grp == NULL &&
                            donorgrp == MAC_DEFAULT_RX_GROUP(mip)) {
                                if (!i_mac_clients_hw(grp, MRP_RX_RINGS) &&
                                    (unspec ||
                                    (grp->mrg_cur_count + donor_grp_rcnt >=
                                    need_rings))) {
                                        candidate_grp = grp;
                                }
                        }
                        continue;
                }
                /*
                 * This group could already be SHARED by other multicast
                 * flows on this client. In that case, the group would
                 * be shared and has already been started.
                 */
                ASSERT(grp->mrg_state != MAC_GROUP_STATE_UNINIT);

                if ((grp->mrg_state == MAC_GROUP_STATE_REGISTERED) &&
                    (mac_start_group(grp) != 0)) {
                        continue;
                }

                if (mip->mi_rx_group_type != MAC_GROUP_TYPE_DYNAMIC)
                        break;
                ASSERT(grp->mrg_cur_count == 0);

                /*
                 * Populate the group. Rings should be taken
                 * from the donor group.
                 */
                nrings = rxhw ? need_rings : isprimary ? donor_grp_rcnt: 1;

                /*
                 * If the donor group can't donate, let's just walk and
                 * see if someone can vacate a group, so that we have
                 * enough rings for this, unless we already have
                 * identified a candiate group..
                 */
                if (nrings <= donor_grp_rcnt) {
                        err = i_mac_group_allocate_rings(mip, MAC_RING_TYPE_RX,
                            donorgrp, grp, share, nrings);
                        if (err == 0) {
                                /*
                                 * For a share i_mac_group_allocate_rings gets
                                 * the rings from the driver, let's populate
                                 * the property for the client now.
                                 */
                                if (share != 0) {
                                        mac_client_set_rings(
                                            (mac_client_handle_t)mcip,
                                            grp->mrg_cur_count, -1);
                                }
                                if (mac_is_primary_client(mcip) && !rxhw)
                                        mip->mi_rx_donor_grp = grp;
                                break;
                        }
                }

                DTRACE_PROBE3(rx__group__reserve__alloc__rings, char *,
                    mip->mi_name, int, grp->mrg_index, int, err);

                /*
                 * It's a dynamic group but the grouping operation
                 * failed.
                 */
                mac_stop_group(grp);
        }

        /* We didn't find an exclusive group for this MAC client */
        if (i >= mip->mi_rx_group_count) {

                if (!need_exclgrp)
                        return (NULL);

                /*
                 * If we found a candidate group then move the
                 * existing MAC client from the candidate_group to the
                 * default group and give the candidate_group to the
                 * new MAC client. If we didn't find a candidate
                 * group, then check if the primary is in its own
                 * group and if it can make way for this MAC client.
                 */
                if (candidate_grp == NULL &&
                    donorgrp != MAC_DEFAULT_RX_GROUP(mip) &&
                    donorgrp->mrg_cur_count >= need_rings) {
                        candidate_grp = donorgrp;
                }
                if (candidate_grp != NULL) {
                        boolean_t       prim_grp = B_FALSE;

                        /*
                         * Switch the existing MAC client from the
                         * candidate group to the default group. If
                         * the candidate group is the donor group,
                         * then after the switch we need to update the
                         * donor group too.
                         */
                        grp = candidate_grp;
                        gclient = grp->mrg_clients->mgc_client;
                        VERIFY3P(gclient, !=, NULL);
                        if (grp == mip->mi_rx_donor_grp)
                                prim_grp = B_TRUE;
                        if (mac_rx_switch_group(gclient, grp,
                            MAC_DEFAULT_RX_GROUP(mip)) != 0) {
                                return (NULL);
                        }
                        if (prim_grp) {
                                mip->mi_rx_donor_grp =
                                    MAC_DEFAULT_RX_GROUP(mip);
                                donorgrp = MAC_DEFAULT_RX_GROUP(mip);
                        }

                        /*
                         * Now give this group with the required rings
                         * to this MAC client.
                         */
                        ASSERT(grp->mrg_state == MAC_GROUP_STATE_REGISTERED);
                        if (mac_start_group(grp) != 0)
                                return (NULL);

                        if (mip->mi_rx_group_type != MAC_GROUP_TYPE_DYNAMIC)
                                return (grp);

                        donor_grp_rcnt = donorgrp->mrg_cur_count - 1;
                        ASSERT(grp->mrg_cur_count == 0);
                        ASSERT(donor_grp_rcnt >= need_rings);
                        err = i_mac_group_allocate_rings(mip, MAC_RING_TYPE_RX,
                            donorgrp, grp, share, need_rings);
                        if (err == 0) {
                                /*
                                 * For a share i_mac_group_allocate_rings gets
                                 * the rings from the driver, let's populate
                                 * the property for the client now.
                                 */
                                if (share != 0) {
                                        mac_client_set_rings(
                                            (mac_client_handle_t)mcip,
                                            grp->mrg_cur_count, -1);
                                }
                                DTRACE_PROBE2(rx__group__reserved,
                                    char *, mip->mi_name, int, grp->mrg_index);
                                return (grp);
                        }
                        DTRACE_PROBE3(rx__group__reserve__alloc__rings, char *,
                            mip->mi_name, int, grp->mrg_index, int, err);
                        mac_stop_group(grp);
                }
                return (NULL);
        }
        ASSERT(grp != NULL);

        DTRACE_PROBE2(rx__group__reserved,
            char *, mip->mi_name, int, grp->mrg_index);
        return (grp);
}

/*
 * mac_rx_release_group()
 *
 * Release the group when it has no remaining clients. The group is
 * stopped and its shares are removed and all rings are assigned back
 * to default group. This should never be called against the default
 * group.
 */
void
mac_release_rx_group(mac_client_impl_t *mcip, mac_group_t *group)
{
        mac_impl_t              *mip = mcip->mci_mip;
        mac_ring_t              *ring;

        ASSERT(group != MAC_DEFAULT_RX_GROUP(mip));
        ASSERT(MAC_GROUP_NO_CLIENT(group) == B_TRUE);

        if (mip->mi_rx_donor_grp == group)
                mip->mi_rx_donor_grp = MAC_DEFAULT_RX_GROUP(mip);

        /*
         * This is the case where there are no clients left. Any
         * SRS etc on this group have also be quiesced.
         */
        for (ring = group->mrg_rings; ring != NULL; ring = ring->mr_next) {
                if (ring->mr_classify_type == MAC_HW_CLASSIFIER) {
                        ASSERT(group->mrg_state == MAC_GROUP_STATE_RESERVED);
                        /*
                         * Remove the SRS associated with the HW ring.
                         * As a result, polling will be disabled.
                         */
                        ring->mr_srs = NULL;
                }
                ASSERT(group->mrg_state < MAC_GROUP_STATE_RESERVED ||
                    ring->mr_state == MR_INUSE);
                if (ring->mr_state == MR_INUSE) {
                        mac_stop_ring(ring);
                        ring->mr_flag = 0;
                }
        }

        /* remove group from share */
        if (mcip->mci_share != 0) {
                mip->mi_share_capab.ms_sremove(mcip->mci_share,
                    group->mrg_driver);
        }

        if (mip->mi_rx_group_type == MAC_GROUP_TYPE_DYNAMIC) {
                mac_ring_t *ring;

                /*
                 * Rings were dynamically allocated to group.
                 * Move rings back to default group.
                 */
                while ((ring = group->mrg_rings) != NULL) {
                        (void) mac_group_mov_ring(mip, mip->mi_rx_donor_grp,
                            ring);
                }
        }
        mac_stop_group(group);
        /*
         * Possible improvement: See if we can assign the group just released
         * to a another client of the mip
         */
}

/*
 * Move the MAC address from fgrp to tgrp.
 */
static int
mac_rx_move_macaddr(mac_client_impl_t *mcip, mac_group_t *fgrp,
    mac_group_t *tgrp)
{
        mac_impl_t              *mip = mcip->mci_mip;
        uint8_t                 maddr[MAXMACADDRLEN];
        int                     err = 0;
        uint16_t                vid;
        mac_unicast_impl_t      *muip;
        boolean_t               use_hw;

        mac_rx_client_quiesce((mac_client_handle_t)mcip);
        VERIFY3P(mcip->mci_unicast, !=, NULL);
        bcopy(mcip->mci_unicast->ma_addr, maddr, mcip->mci_unicast->ma_len);

        /*
         * Does the client require MAC address hardware classifiction?
         */
        use_hw = (mcip->mci_state_flags & MCIS_UNICAST_HW) != 0;
        vid = i_mac_flow_vid(mcip->mci_flent);

        /*
         * You can never move an address that is shared by multiple
         * clients. mac_datapath_setup() ensures that clients sharing
         * an address are placed on the default group. This guarantees
         * that a non-default group will only ever have one client and
         * thus make full use of HW filters.
         */
        if (mac_check_macaddr_shared(mcip->mci_unicast))
                return (EINVAL);

        err = mac_remove_macaddr_vlan(mcip->mci_unicast, vid);

        if (err != 0) {
                mac_rx_client_restart((mac_client_handle_t)mcip);
                return (err);
        }

        /*
         * If this isn't the primary MAC address then the
         * mac_address_t has been freed by the last call to
         * mac_remove_macaddr_vlan(). In any case, NULL the reference
         * to avoid a dangling pointer.
         */
        mcip->mci_unicast = NULL;

        /*
         * We also have to NULL all the mui_map references -- sun4v
         * strikes again!
         */
        rw_enter(&mcip->mci_rw_lock, RW_WRITER);
        for (muip = mcip->mci_unicast_list; muip != NULL; muip = muip->mui_next)
                muip->mui_map = NULL;
        rw_exit(&mcip->mci_rw_lock);

        /*
         * Program the H/W Classifier first, if this fails we need not
         * proceed with the other stuff.
         */
        if ((err = mac_add_macaddr_vlan(mip, tgrp, maddr, vid, use_hw)) != 0) {
                int err2;

                /* Revert back the H/W Classifier */
                err2 = mac_add_macaddr_vlan(mip, fgrp, maddr, vid, use_hw);

                if (err2 != 0) {
                        cmn_err(CE_WARN, "Failed to revert HW classification"
                            " on MAC %s, for client %s: %d.", mip->mi_name,
                            mcip->mci_name, err2);
                }

                mac_rx_client_restart((mac_client_handle_t)mcip);
                return (err);
        }

        /*
         * Get a reference to the new mac_address_t and update the
         * client's reference. Then restart the client and add the
         * other clients of this MAC addr (if they exsit).
         */
        mcip->mci_unicast = mac_find_macaddr(mip, maddr);
        rw_enter(&mcip->mci_rw_lock, RW_WRITER);
        for (muip = mcip->mci_unicast_list; muip != NULL; muip = muip->mui_next)
                muip->mui_map = mcip->mci_unicast;
        rw_exit(&mcip->mci_rw_lock);
        mac_rx_client_restart((mac_client_handle_t)mcip);
        return (0);
}

/*
 * Switch the MAC client from one group to another. This means we need
 * to remove the MAC address from the group, remove the MAC client,
 * teardown the SRSs and revert the group state. Then, we add the client
 * to the destination group, set the SRSs, and add the MAC address to the
 * group.
 */
int
mac_rx_switch_group(mac_client_impl_t *mcip, mac_group_t *fgrp,
    mac_group_t *tgrp)
{
        int                     err;
        mac_group_state_t       next_state;
        mac_client_impl_t       *group_only_mcip;
        mac_client_impl_t       *gmcip;
        mac_impl_t              *mip = mcip->mci_mip;
        mac_grp_client_t        *mgcp;

        VERIFY3P(fgrp, ==, mcip->mci_flent->fe_rx_ring_group);

        if ((err = mac_rx_move_macaddr(mcip, fgrp, tgrp)) != 0)
                return (err);

        /*
         * If the group is marked as reserved and in use by a single
         * client, then there is an SRS to teardown.
         */
        if (fgrp->mrg_state == MAC_GROUP_STATE_RESERVED &&
            MAC_GROUP_ONLY_CLIENT(fgrp) != NULL) {
                mac_rx_srs_group_teardown(mcip->mci_flent, B_TRUE);
        }

        /*
         * If we are moving the client from a non-default group, then
         * we know that any additional clients on this group share the
         * same MAC address. Since we moved the MAC address filter, we
         * need to move these clients too.
         *
         * If we are moving the client from the default group and its
         * MAC address has VLAN clients, then we must move those
         * clients as well.
         *
         * In both cases the idea is the same: we moved the MAC
         * address filter to the tgrp, so we must move all clients
         * using that MAC address to tgrp as well.
         */
        if (fgrp != MAC_DEFAULT_RX_GROUP(mip)) {
                mgcp = fgrp->mrg_clients;
                while (mgcp != NULL) {
                        gmcip = mgcp->mgc_client;
                        mgcp = mgcp->mgc_next;
                        mac_group_remove_client(fgrp, gmcip);
                        mac_group_add_client(tgrp, gmcip);
                        gmcip->mci_flent->fe_rx_ring_group = tgrp;
                }
                mac_release_rx_group(mcip, fgrp);
                VERIFY3B(MAC_GROUP_NO_CLIENT(fgrp), ==, B_TRUE);
                mac_set_group_state(fgrp, MAC_GROUP_STATE_REGISTERED);
        } else {
                mac_group_remove_client(fgrp, mcip);
                mac_group_add_client(tgrp, mcip);
                mcip->mci_flent->fe_rx_ring_group = tgrp;

                /*
                 * If there are other clients (VLANs) sharing this address
                 * then move them too.
                 */
                if (mac_check_macaddr_shared(mcip->mci_unicast)) {
                        /*
                         * We need to move all the clients that are using
                         * this MAC address.
                         */
                        mgcp = fgrp->mrg_clients;
                        while (mgcp != NULL) {
                                gmcip = mgcp->mgc_client;
                                mgcp = mgcp->mgc_next;
                                if (mcip->mci_unicast == gmcip->mci_unicast) {
                                        mac_group_remove_client(fgrp, gmcip);
                                        mac_group_add_client(tgrp, gmcip);
                                        gmcip->mci_flent->fe_rx_ring_group =
                                            tgrp;
                                }
                        }
                }

                /*
                 * The default group still handles multicast and
                 * broadcast traffic; it won't transition to
                 * MAC_GROUP_STATE_REGISTERED.
                 */
                if (fgrp->mrg_state == MAC_GROUP_STATE_RESERVED)
                        mac_rx_group_unmark(fgrp, MR_CONDEMNED);
                mac_set_group_state(fgrp, MAC_GROUP_STATE_SHARED);
        }

        next_state = mac_group_next_state(tgrp, &group_only_mcip,
            MAC_DEFAULT_RX_GROUP(mip), B_TRUE);
        mac_set_group_state(tgrp, next_state);

        /*
         * If the destination group is reserved, then setup the SRSes.
         * Otherwise make sure to use SW classification.
         */
        if (tgrp->mrg_state == MAC_GROUP_STATE_RESERVED) {
                mac_rx_srs_group_setup(mcip, mcip->mci_flent, SRST_LINK);
                mac_fanout_setup(mcip, mcip->mci_flent,
                    MCIP_RESOURCE_PROPS(mcip), mac_rx_deliver, mcip, NULL);
                mac_rx_group_unmark(tgrp, MR_INCIPIENT);
        } else {
                mac_rx_switch_grp_to_sw(tgrp);
        }

        return (0);
}

/*
 * Reserves a TX group for the specified share. Invoked by mac_tx_srs_setup()
 * when a share was allocated to the client.
 */
mac_group_t *
mac_reserve_tx_group(mac_client_impl_t *mcip, boolean_t move)
{
        mac_impl_t              *mip = mcip->mci_mip;
        mac_group_t             *grp = NULL;
        int                     rv;
        int                     i;
        int                     err;
        mac_group_t             *defgrp;
        mac_share_handle_t      share = mcip->mci_share;
        mac_resource_props_t    *mrp = MCIP_RESOURCE_PROPS(mcip);
        int                     nrings;
        int                     defnrings;
        boolean_t               need_exclgrp = B_FALSE;
        int                     need_rings = 0;
        mac_group_t             *candidate_grp = NULL;
        mac_client_impl_t       *gclient;
        mac_resource_props_t    *gmrp;
        boolean_t               txhw = mrp->mrp_mask & MRP_TX_RINGS;
        boolean_t               unspec = mrp->mrp_mask & MRP_TXRINGS_UNSPEC;
        boolean_t               isprimary;

        isprimary = mcip->mci_flent->fe_type & FLOW_PRIMARY_MAC;

        /*
         * When we come here for a VLAN on the primary (dladm create-vlan),
         * we need to pair it along with the primary (to keep it consistent
         * with the RX side). So, we check if the primary is already assigned
         * to a group and return the group if so. The other way is also
         * true, i.e. the VLAN is already created and now we are plumbing
         * the primary.
         */
        if (!move && isprimary) {
                for (gclient = mip->mi_clients_list; gclient != NULL;
                    gclient = gclient->mci_client_next) {
                        if (gclient->mci_flent->fe_type & FLOW_PRIMARY_MAC &&
                            gclient->mci_flent->fe_tx_ring_group != NULL) {
                                return (gclient->mci_flent->fe_tx_ring_group);
                        }
                }
        }

        if (mip->mi_tx_groups == NULL || mip->mi_tx_group_count == 0)
                return (NULL);

        /* For dynamic groups, default unspec to 1 */
        if (txhw && unspec &&
            mip->mi_tx_group_type == MAC_GROUP_TYPE_DYNAMIC) {
                mrp->mrp_ntxrings = 1;
        }
        /*
         * For static grouping we allow only specifying rings=0 and
         * unspecified
         */
        if (txhw && mrp->mrp_ntxrings > 0 &&
            mip->mi_tx_group_type == MAC_GROUP_TYPE_STATIC) {
                return (NULL);
        }

        if (txhw) {
                /*
                 * We have explicitly asked for a group (with ntxrings,
                 * if unspec).
                 */
                if (unspec || mrp->mrp_ntxrings > 0) {
                        need_exclgrp = B_TRUE;
                        need_rings = mrp->mrp_ntxrings;
                } else if (mrp->mrp_ntxrings == 0) {
                        /*
                         * We have asked for a software group.
                         */
                        return (NULL);
                }
        }
        defgrp = MAC_DEFAULT_TX_GROUP(mip);
        /*
         * The number of rings that the default group can donate.
         * We need to leave at least one ring - the default ring - in
         * this group.
         */
        defnrings = defgrp->mrg_cur_count - 1;

        /*
         * Primary gets default group unless explicitly told not
         * to  (i.e. rings > 0).
         */
        if (isprimary && !need_exclgrp)
                return (NULL);

        nrings = (mrp->mrp_mask & MRP_TX_RINGS) != 0 ? mrp->mrp_ntxrings : 1;
        for (i = 0; i <  mip->mi_tx_group_count; i++) {
                grp = &mip->mi_tx_groups[i];
                if ((grp->mrg_state == MAC_GROUP_STATE_RESERVED) ||
                    (grp->mrg_state == MAC_GROUP_STATE_UNINIT)) {
                        /*
                         * Select a candidate for replacement if we don't
                         * get an exclusive group. A candidate group is one
                         * that didn't ask for an exclusive group, but got
                         * one and it has enough rings (combined with what
                         * the default group can donate) for the new MAC
                         * client.
                         */
                        if (grp->mrg_state == MAC_GROUP_STATE_RESERVED &&
                            candidate_grp == NULL) {
                                gclient = MAC_GROUP_ONLY_CLIENT(grp);
                                VERIFY3P(gclient, !=, NULL);
                                gmrp = MCIP_RESOURCE_PROPS(gclient);
                                if (gclient->mci_share == 0 &&
                                    (gmrp->mrp_mask & MRP_TX_RINGS) == 0 &&
                                    (unspec ||
                                    (grp->mrg_cur_count + defnrings) >=
                                    need_rings)) {
                                        candidate_grp = grp;
                                }
                        }
                        continue;
                }
                /*
                 * If the default can't donate let's just walk and
                 * see if someone can vacate a group, so that we have
                 * enough rings for this.
                 */
                if (mip->mi_tx_group_type != MAC_GROUP_TYPE_DYNAMIC ||
                    nrings <= defnrings) {
                        if (grp->mrg_state == MAC_GROUP_STATE_REGISTERED) {
                                rv = mac_start_group(grp);
                                ASSERT(rv == 0);
                        }
                        break;
                }
        }

        /* The default group */
        if (i >= mip->mi_tx_group_count) {
                /*
                 * If we need an exclusive group and have identified a
                 * candidate group we switch the MAC client from the
                 * candidate group to the default group and give the
                 * candidate group to this client.
                 */
                if (need_exclgrp && candidate_grp != NULL) {
                        /*
                         * Switch the MAC client from the candidate
                         * group to the default group. We know the
                         * candidate_grp came from a reserved group
                         * and thus only has one client.
                         */
                        grp = candidate_grp;
                        gclient = MAC_GROUP_ONLY_CLIENT(grp);
                        VERIFY3P(gclient, !=, NULL);
                        mac_tx_client_quiesce((mac_client_handle_t)gclient);
                        mac_tx_switch_group(gclient, grp, defgrp);
                        mac_tx_client_restart((mac_client_handle_t)gclient);

                        /*
                         * Give the candidate group with the specified number
                         * of rings to this MAC client.
                         */
                        ASSERT(grp->mrg_state == MAC_GROUP_STATE_REGISTERED);
                        rv = mac_start_group(grp);
                        ASSERT(rv == 0);

                        if (mip->mi_tx_group_type != MAC_GROUP_TYPE_DYNAMIC)
                                return (grp);

                        ASSERT(grp->mrg_cur_count == 0);
                        ASSERT(defgrp->mrg_cur_count > need_rings);

                        err = i_mac_group_allocate_rings(mip, MAC_RING_TYPE_TX,
                            defgrp, grp, share, need_rings);
                        if (err == 0) {
                                /*
                                 * For a share i_mac_group_allocate_rings gets
                                 * the rings from the driver, let's populate
                                 * the property for the client now.
                                 */
                                if (share != 0) {
                                        mac_client_set_rings(
                                            (mac_client_handle_t)mcip, -1,
                                            grp->mrg_cur_count);
                                }
                                mip->mi_tx_group_free--;
                                return (grp);
                        }
                        DTRACE_PROBE3(tx__group__reserve__alloc__rings, char *,
                            mip->mi_name, int, grp->mrg_index, int, err);
                        mac_stop_group(grp);
                }
                return (NULL);
        }
        /*
         * We got an exclusive group, but it is not dynamic.
         */
        if (mip->mi_tx_group_type != MAC_GROUP_TYPE_DYNAMIC) {
                mip->mi_tx_group_free--;
                return (grp);
        }

        rv = i_mac_group_allocate_rings(mip, MAC_RING_TYPE_TX, defgrp, grp,
            share, nrings);
        if (rv != 0) {
                DTRACE_PROBE3(tx__group__reserve__alloc__rings,
                    char *, mip->mi_name, int, grp->mrg_index, int, rv);
                mac_stop_group(grp);
                return (NULL);
        }
        /*
         * For a share i_mac_group_allocate_rings gets the rings from the
         * driver, let's populate the property for the client now.
         */
        if (share != 0) {
                mac_client_set_rings((mac_client_handle_t)mcip, -1,
                    grp->mrg_cur_count);
        }
        mip->mi_tx_group_free--;
        return (grp);
}

void
mac_release_tx_group(mac_client_impl_t *mcip, mac_group_t *grp)
{
        mac_impl_t              *mip = mcip->mci_mip;
        mac_share_handle_t      share = mcip->mci_share;
        mac_ring_t              *ring;
        mac_soft_ring_set_t     *srs = MCIP_TX_SRS(mcip);
        mac_group_t             *defgrp;

        defgrp = MAC_DEFAULT_TX_GROUP(mip);
        if (srs != NULL) {
                if (srs->srs_soft_ring_count > 0) {
                        for (ring = grp->mrg_rings; ring != NULL;
                            ring = ring->mr_next) {
                                ASSERT(mac_tx_srs_ring_present(srs, ring));
                                mac_tx_invoke_callbacks(mcip,
                                    (mac_tx_cookie_t)
                                    mac_tx_srs_get_soft_ring(srs, ring));
                                mac_tx_srs_del_ring(srs, ring);
                        }
                } else {
                        ASSERT(srs->srs_tx.st_arg2 != NULL);
                        srs->srs_tx.st_arg2 = NULL;
                        mac_srs_stat_delete(srs);
                }
        }
        if (share != 0)
                mip->mi_share_capab.ms_sremove(share, grp->mrg_driver);

        /* move the ring back to the pool */
        if (mip->mi_tx_group_type == MAC_GROUP_TYPE_DYNAMIC) {
                while ((ring = grp->mrg_rings) != NULL)
                        (void) mac_group_mov_ring(mip, defgrp, ring);
        }
        mac_stop_group(grp);
        mip->mi_tx_group_free++;
}

/*
 * Disassociate a MAC client from a group, i.e go through the rings in the
 * group and delete all the soft rings tied to them.
 */
static void
mac_tx_dismantle_soft_rings(mac_group_t *fgrp, flow_entry_t *flent)
{
        mac_client_impl_t       *mcip = flent->fe_mcip;
        mac_soft_ring_set_t     *tx_srs;
        mac_srs_tx_t            *tx;
        mac_ring_t              *ring;

        tx_srs = flent->fe_tx_srs;
        tx = &tx_srs->srs_tx;

        /* Single ring case we haven't created any soft rings */
        if (tx->st_mode == SRS_TX_BW || tx->st_mode == SRS_TX_SERIALIZE ||
            tx->st_mode == SRS_TX_DEFAULT) {
                tx->st_arg2 = NULL;
                mac_srs_stat_delete(tx_srs);
        /* Fanout case, where we have to dismantle the soft rings */
        } else {
                for (ring = fgrp->mrg_rings; ring != NULL;
                    ring = ring->mr_next) {
                        ASSERT(mac_tx_srs_ring_present(tx_srs, ring));
                        mac_tx_invoke_callbacks(mcip,
                            (mac_tx_cookie_t)mac_tx_srs_get_soft_ring(tx_srs,
                            ring));
                        mac_tx_srs_del_ring(tx_srs, ring);
                }
                ASSERT(tx->st_arg2 == NULL);
        }
}

/*
 * Switch the MAC client from one group to another. This means we need
 * to remove the MAC client, teardown the SRSs and revert the group state.
 * Then, we add the client to the destination roup, set the SRSs etc.
 */
void
mac_tx_switch_group(mac_client_impl_t *mcip, mac_group_t *fgrp,
    mac_group_t *tgrp)
{
        mac_client_impl_t       *group_only_mcip;
        mac_impl_t              *mip = mcip->mci_mip;
        flow_entry_t            *flent = mcip->mci_flent;
        mac_group_t             *defgrp;
        mac_grp_client_t        *mgcp;
        mac_client_impl_t       *gmcip;
        flow_entry_t            *gflent;

        defgrp = MAC_DEFAULT_TX_GROUP(mip);
        ASSERT(fgrp == flent->fe_tx_ring_group);

        if (fgrp == defgrp) {
                /*
                 * If this is the primary we need to find any VLANs on
                 * the primary and move them too.
                 */
                mac_group_remove_client(fgrp, mcip);
                mac_tx_dismantle_soft_rings(fgrp, flent);
                if (mac_check_macaddr_shared(mcip->mci_unicast)) {
                        mgcp = fgrp->mrg_clients;
                        while (mgcp != NULL) {
                                gmcip = mgcp->mgc_client;
                                mgcp = mgcp->mgc_next;
                                if (mcip->mci_unicast != gmcip->mci_unicast)
                                        continue;
                                mac_tx_client_quiesce(
                                    (mac_client_handle_t)gmcip);

                                gflent = gmcip->mci_flent;
                                mac_group_remove_client(fgrp, gmcip);
                                mac_tx_dismantle_soft_rings(fgrp, gflent);

                                mac_group_add_client(tgrp, gmcip);
                                gflent->fe_tx_ring_group = tgrp;
                                /* We could directly set this to SHARED */
                                tgrp->mrg_state = mac_group_next_state(tgrp,
                                    &group_only_mcip, defgrp, B_FALSE);

                                mac_tx_srs_group_setup(gmcip, gflent,
                                    SRST_LINK);
                                mac_fanout_setup(gmcip, gflent,
                                    MCIP_RESOURCE_PROPS(gmcip), mac_rx_deliver,
                                    gmcip, NULL);

                                mac_tx_client_restart(
                                    (mac_client_handle_t)gmcip);
                        }
                }
                if (MAC_GROUP_NO_CLIENT(fgrp)) {
                        mac_ring_t      *ring;
                        int             cnt;
                        int             ringcnt;

                        fgrp->mrg_state = MAC_GROUP_STATE_REGISTERED;
                        /*
                         * Additionally, we also need to stop all
                         * the rings in the default group, except
                         * the default ring. The reason being
                         * this group won't be released since it is
                         * the default group, so the rings won't
                         * be stopped otherwise.
                         */
                        ringcnt = fgrp->mrg_cur_count;
                        ring = fgrp->mrg_rings;
                        for (cnt = 0; cnt < ringcnt; cnt++) {
                                if (ring->mr_state == MR_INUSE &&
                                    ring !=
                                    (mac_ring_t *)mip->mi_default_tx_ring) {
                                        mac_stop_ring(ring);
                                        ring->mr_flag = 0;
                                }
                                ring = ring->mr_next;
                        }
                } else if (MAC_GROUP_ONLY_CLIENT(fgrp) != NULL) {
                        fgrp->mrg_state = MAC_GROUP_STATE_RESERVED;
                } else {
                        ASSERT(fgrp->mrg_state == MAC_GROUP_STATE_SHARED);
                }
        } else {
                /*
                 * We could have VLANs sharing the non-default group with
                 * the primary.
                 */
                mgcp = fgrp->mrg_clients;
                while (mgcp != NULL) {
                        gmcip = mgcp->mgc_client;
                        mgcp = mgcp->mgc_next;
                        if (gmcip == mcip)
                                continue;
                        mac_tx_client_quiesce((mac_client_handle_t)gmcip);
                        gflent = gmcip->mci_flent;

                        mac_group_remove_client(fgrp, gmcip);
                        mac_tx_dismantle_soft_rings(fgrp, gflent);

                        mac_group_add_client(tgrp, gmcip);
                        gflent->fe_tx_ring_group = tgrp;
                        /* We could directly set this to SHARED */
                        tgrp->mrg_state = mac_group_next_state(tgrp,
                            &group_only_mcip, defgrp, B_FALSE);
                        mac_tx_srs_group_setup(gmcip, gflent, SRST_LINK);
                        mac_fanout_setup(gmcip, gflent,
                            MCIP_RESOURCE_PROPS(gmcip), mac_rx_deliver,
                            gmcip, NULL);

                        mac_tx_client_restart((mac_client_handle_t)gmcip);
                }
                mac_group_remove_client(fgrp, mcip);
                mac_release_tx_group(mcip, fgrp);
                fgrp->mrg_state = MAC_GROUP_STATE_REGISTERED;
        }

        /* Add it to the tgroup */
        mac_group_add_client(tgrp, mcip);
        flent->fe_tx_ring_group = tgrp;
        tgrp->mrg_state = mac_group_next_state(tgrp, &group_only_mcip,
            defgrp, B_FALSE);

        mac_tx_srs_group_setup(mcip, flent, SRST_LINK);
        mac_fanout_setup(mcip, flent, MCIP_RESOURCE_PROPS(mcip),
            mac_rx_deliver, mcip, NULL);
}

/*
 * This is a 1-time control path activity initiated by the client (IP).
 * The mac perimeter protects against other simultaneous control activities,
 * for example an ioctl that attempts to change the degree of fanout and
 * increase or decrease the number of softrings associated with this Tx SRS.
 */
static mac_tx_notify_cb_t *
mac_client_tx_notify_add(mac_client_impl_t *mcip,
    mac_tx_notify_t notify, void *arg)
{
        mac_cb_info_t *mcbi;
        mac_tx_notify_cb_t *mtnfp;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mcip->mci_mip));

        mtnfp = kmem_zalloc(sizeof (mac_tx_notify_cb_t), KM_SLEEP);
        mtnfp->mtnf_fn = notify;
        mtnfp->mtnf_arg = arg;
        mtnfp->mtnf_link.mcb_objp = mtnfp;
        mtnfp->mtnf_link.mcb_objsize = sizeof (mac_tx_notify_cb_t);
        mtnfp->mtnf_link.mcb_flags = MCB_TX_NOTIFY_CB_T;

        mcbi = &mcip->mci_tx_notify_cb_info;
        mutex_enter(mcbi->mcbi_lockp);
        mac_callback_add(mcbi, &mcip->mci_tx_notify_cb_list, &mtnfp->mtnf_link);
        mutex_exit(mcbi->mcbi_lockp);
        return (mtnfp);
}

static void
mac_client_tx_notify_remove(mac_client_impl_t *mcip, mac_tx_notify_cb_t *mtnfp)
{
        mac_cb_info_t   *mcbi;
        mac_cb_t        **cblist;

        ASSERT(MAC_PERIM_HELD((mac_handle_t)mcip->mci_mip));

        if (!mac_callback_find(&mcip->mci_tx_notify_cb_info,
            &mcip->mci_tx_notify_cb_list, &mtnfp->mtnf_link)) {
                cmn_err(CE_WARN,
                    "mac_client_tx_notify_remove: callback not "
                    "found, mcip 0x%p mtnfp 0x%p", (void *)mcip, (void *)mtnfp);
                return;
        }

        mcbi = &mcip->mci_tx_notify_cb_info;
        cblist = &mcip->mci_tx_notify_cb_list;
        mutex_enter(mcbi->mcbi_lockp);
        if (mac_callback_remove(mcbi, cblist, &mtnfp->mtnf_link))
                kmem_free(mtnfp, sizeof (mac_tx_notify_cb_t));
        else
                mac_callback_remove_wait(&mcip->mci_tx_notify_cb_info);
        mutex_exit(mcbi->mcbi_lockp);
}

/*
 * mac_client_tx_notify():
 * call to add and remove flow control callback routine.
 */
mac_tx_notify_handle_t
mac_client_tx_notify(mac_client_handle_t mch, mac_tx_notify_t callb_func,
    void *ptr)
{
        mac_client_impl_t       *mcip = (mac_client_impl_t *)mch;
        mac_tx_notify_cb_t      *mtnfp = NULL;

        i_mac_perim_enter(mcip->mci_mip);

        if (callb_func != NULL) {
                /* Add a notify callback */
                mtnfp = mac_client_tx_notify_add(mcip, callb_func, ptr);
        } else {
                mac_client_tx_notify_remove(mcip, (mac_tx_notify_cb_t *)ptr);
        }
        i_mac_perim_exit(mcip->mci_mip);

        return ((mac_tx_notify_handle_t)mtnfp);
}

void
mac_bridge_vectors(mac_bridge_tx_t txf, mac_bridge_rx_t rxf,
    mac_bridge_ref_t reff, mac_bridge_ls_t lsf)
{
        mac_bridge_tx_cb = txf;
        mac_bridge_rx_cb = rxf;
        mac_bridge_ref_cb = reff;
        mac_bridge_ls_cb = lsf;
}

int
mac_bridge_set(mac_handle_t mh, mac_handle_t link)
{
        mac_impl_t *mip = (mac_impl_t *)mh;
        int retv;

        mutex_enter(&mip->mi_bridge_lock);
        if (mip->mi_bridge_link == NULL) {
                mip->mi_bridge_link = link;
                retv = 0;
        } else {
                retv = EBUSY;
        }
        mutex_exit(&mip->mi_bridge_lock);
        if (retv == 0) {
                mac_poll_state_change(mh, B_FALSE);
                mac_capab_update(mh);
        }
        return (retv);
}

/*
 * Disable bridging on the indicated link.
 */
void
mac_bridge_clear(mac_handle_t mh, mac_handle_t link)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        mutex_enter(&mip->mi_bridge_lock);
        ASSERT(mip->mi_bridge_link == link);
        mip->mi_bridge_link = NULL;
        mutex_exit(&mip->mi_bridge_lock);
        mac_poll_state_change(mh, B_TRUE);
        mac_capab_update(mh);
}

void
mac_no_active(mac_handle_t mh)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        i_mac_perim_enter(mip);
        mip->mi_state_flags |= MIS_NO_ACTIVE;
        i_mac_perim_exit(mip);
}

/*
 * Walk the primary VLAN clients whenever the primary's rings property
 * changes and update the mac_resource_props_t for the VLAN's client.
 * We need to do this since we don't support setting these properties
 * on the primary's VLAN clients, but the VLAN clients have to
 * follow the primary w.r.t the rings property.
 */
void
mac_set_prim_vlan_rings(mac_impl_t  *mip, mac_resource_props_t *mrp)
{
        mac_client_impl_t       *vmcip;
        mac_resource_props_t    *vmrp;

        for (vmcip = mip->mi_clients_list; vmcip != NULL;
            vmcip = vmcip->mci_client_next) {
                if (!(vmcip->mci_flent->fe_type & FLOW_PRIMARY_MAC) ||
                    mac_client_vid((mac_client_handle_t)vmcip) ==
                    VLAN_ID_NONE) {
                        continue;
                }
                vmrp = MCIP_RESOURCE_PROPS(vmcip);

                vmrp->mrp_nrxrings =  mrp->mrp_nrxrings;
                if (mrp->mrp_mask & MRP_RX_RINGS)
                        vmrp->mrp_mask |= MRP_RX_RINGS;
                else if (vmrp->mrp_mask & MRP_RX_RINGS)
                        vmrp->mrp_mask &= ~MRP_RX_RINGS;

                vmrp->mrp_ntxrings =  mrp->mrp_ntxrings;
                if (mrp->mrp_mask & MRP_TX_RINGS)
                        vmrp->mrp_mask |= MRP_TX_RINGS;
                else if (vmrp->mrp_mask & MRP_TX_RINGS)
                        vmrp->mrp_mask &= ~MRP_TX_RINGS;

                if (mrp->mrp_mask & MRP_RXRINGS_UNSPEC)
                        vmrp->mrp_mask |= MRP_RXRINGS_UNSPEC;
                else
                        vmrp->mrp_mask &= ~MRP_RXRINGS_UNSPEC;

                if (mrp->mrp_mask & MRP_TXRINGS_UNSPEC)
                        vmrp->mrp_mask |= MRP_TXRINGS_UNSPEC;
                else
                        vmrp->mrp_mask &= ~MRP_TXRINGS_UNSPEC;
        }
}

/*
 * We are adding or removing ring(s) from a group. The source for taking
 * rings is the default group. The destination for giving rings back is
 * the default group.
 */
int
mac_group_ring_modify(mac_client_impl_t *mcip, mac_group_t *group,
    mac_group_t *defgrp)
{
        mac_resource_props_t    *mrp = MCIP_RESOURCE_PROPS(mcip);
        uint_t                  modify;
        int                     count;
        mac_ring_t              *ring;
        mac_ring_t              *next;
        mac_impl_t              *mip = mcip->mci_mip;
        mac_ring_t              **rings;
        uint_t                  ringcnt;
        int                     i = 0;
        boolean_t               rx_group = group->mrg_type == MAC_RING_TYPE_RX;
        int                     start;
        int                     end;
        mac_group_t             *tgrp;
        int                     j;
        int                     rv = 0;

        /*
         * If we are asked for just a group, we give 1 ring, else
         * the specified number of rings.
         */
        if (rx_group) {
                ringcnt = (mrp->mrp_mask & MRP_RXRINGS_UNSPEC) ? 1:
                    mrp->mrp_nrxrings;
        } else {
                ringcnt = (mrp->mrp_mask & MRP_TXRINGS_UNSPEC) ? 1:
                    mrp->mrp_ntxrings;
        }

        /* don't allow modifying rings for a share for now. */
        ASSERT(mcip->mci_share == 0);

        if (ringcnt == group->mrg_cur_count)
                return (0);

        if (group->mrg_cur_count > ringcnt) {
                modify = group->mrg_cur_count - ringcnt;
                if (rx_group) {
                        if (mip->mi_rx_donor_grp == group) {
                                ASSERT(mac_is_primary_client(mcip));
                                mip->mi_rx_donor_grp = defgrp;
                        } else {
                                defgrp = mip->mi_rx_donor_grp;
                        }
                }
                ring = group->mrg_rings;
                rings = kmem_alloc(modify * sizeof (mac_ring_handle_t),
                    KM_SLEEP);
                j = 0;
                for (count = 0; count < modify; count++) {
                        next = ring->mr_next;
                        rv = mac_group_mov_ring(mip, defgrp, ring);
                        if (rv != 0) {
                                /* cleanup on failure */
                                for (j = 0; j < count; j++) {
                                        (void) mac_group_mov_ring(mip, group,
                                            rings[j]);
                                }
                                break;
                        }
                        rings[j++] = ring;
                        ring = next;
                }
                kmem_free(rings, modify * sizeof (mac_ring_handle_t));
                return (rv);
        }
        if (ringcnt >= MAX_RINGS_PER_GROUP)
                return (EINVAL);

        modify = ringcnt - group->mrg_cur_count;

        if (rx_group) {
                if (group != mip->mi_rx_donor_grp)
                        defgrp = mip->mi_rx_donor_grp;
                else
                        /*
                         * This is the donor group with all the remaining
                         * rings. Default group now gets to be the donor
                         */
                        mip->mi_rx_donor_grp = defgrp;
                start = 1;
                end = mip->mi_rx_group_count;
        } else {
                start = 0;
                end = mip->mi_tx_group_count - 1;
        }
        /*
         * If the default doesn't have any rings, lets see if we can
         * take rings given to an h/w client that doesn't need it.
         * For now, we just see if there is  any one client that can donate
         * all the required rings.
         */
        if (defgrp->mrg_cur_count < (modify + 1)) {
                for (i = start; i < end; i++) {
                        if (rx_group) {
                                tgrp = &mip->mi_rx_groups[i];
                                if (tgrp == group || tgrp->mrg_state <
                                    MAC_GROUP_STATE_RESERVED) {
                                        continue;
                                }
                                if (i_mac_clients_hw(tgrp, MRP_RX_RINGS))
                                        continue;
                                mcip = tgrp->mrg_clients->mgc_client;
                                VERIFY3P(mcip, !=, NULL);
                                if ((tgrp->mrg_cur_count +
                                    defgrp->mrg_cur_count) < (modify + 1)) {
                                        continue;
                                }
                                if (mac_rx_switch_group(mcip, tgrp,
                                    defgrp) != 0) {
                                        return (ENOSPC);
                                }
                        } else {
                                tgrp = &mip->mi_tx_groups[i];
                                if (tgrp == group || tgrp->mrg_state <
                                    MAC_GROUP_STATE_RESERVED) {
                                        continue;
                                }
                                if (i_mac_clients_hw(tgrp, MRP_TX_RINGS))
                                        continue;
                                mcip = tgrp->mrg_clients->mgc_client;
                                VERIFY3P(mcip, !=, NULL);
                                if ((tgrp->mrg_cur_count +
                                    defgrp->mrg_cur_count) < (modify + 1)) {
                                        continue;
                                }
                                /* OK, we can switch this to s/w */
                                mac_tx_client_quiesce(
                                    (mac_client_handle_t)mcip);
                                mac_tx_switch_group(mcip, tgrp, defgrp);
                                mac_tx_client_restart(
                                    (mac_client_handle_t)mcip);
                        }
                }
                if (defgrp->mrg_cur_count < (modify + 1))
                        return (ENOSPC);
        }
        if ((rv = i_mac_group_allocate_rings(mip, group->mrg_type, defgrp,
            group, mcip->mci_share, modify)) != 0) {
                return (rv);
        }
        return (0);
}

/*
 * Given the poolname in mac_resource_props, find the cpupart
 * that is associated with this pool.  The cpupart will be used
 * later for finding the cpus to be bound to the networking threads.
 *
 * use_default is set B_TRUE if pools are enabled and pool_default
 * is returned.  This avoids a 2nd lookup to set the poolname
 * for pool-effective.
 *
 * returns:
 *
 *    NULL -   pools are disabled or if the 'cpus' property is set.
 *    cpupart of pool_default  - pools are enabled and the pool
 *             is not available or poolname is blank
 *    cpupart of named pool    - pools are enabled and the pool
 *             is available.
 */
cpupart_t *
mac_pset_find(mac_resource_props_t *mrp, boolean_t *use_default)
{
        pool_t          *pool;
        cpupart_t       *cpupart;

        *use_default = B_FALSE;

        /* CPUs property is set */
        if (mrp->mrp_mask & MRP_CPUS)
                return (NULL);

        ASSERT(pool_lock_held());

        /* Pools are disabled, no pset */
        if (pool_state == POOL_DISABLED)
                return (NULL);

        /* Pools property is set */
        if (mrp->mrp_mask & MRP_POOL) {
                if ((pool = pool_lookup_pool_by_name(mrp->mrp_pool)) == NULL) {
                        /* Pool not found */
                        DTRACE_PROBE1(mac_pset_find_no_pool, char *,
                            mrp->mrp_pool);
                        *use_default = B_TRUE;
                        pool = pool_default;
                }
        /* Pools property is not set */
        } else {
                *use_default = B_TRUE;
                pool = pool_default;
        }

        /* Find the CPU pset that corresponds to the pool */
        mutex_enter(&cpu_lock);
        if ((cpupart = cpupart_find(pool->pool_pset->pset_id)) == NULL) {
                DTRACE_PROBE1(mac_find_pset_no_pset, psetid_t,
                    pool->pool_pset->pset_id);
        }
        mutex_exit(&cpu_lock);

        return (cpupart);
}

void
mac_set_pool_effective(boolean_t use_default, cpupart_t *cpupart,
    mac_resource_props_t *mrp, mac_resource_props_t *emrp)
{
        ASSERT(pool_lock_held());

        if (cpupart != NULL) {
                emrp->mrp_mask |= MRP_POOL;
                if (use_default) {
                        (void) strcpy(emrp->mrp_pool,
                            "pool_default");
                } else {
                        ASSERT(strlen(mrp->mrp_pool) != 0);
                        (void) strcpy(emrp->mrp_pool,
                            mrp->mrp_pool);
                }
        } else {
                emrp->mrp_mask &= ~MRP_POOL;
                bzero(emrp->mrp_pool, MAXPATHLEN);
        }
}

struct mac_pool_arg {
        char            mpa_poolname[MAXPATHLEN];
        pool_event_t    mpa_what;
};

/*ARGSUSED*/
static uint_t
mac_pool_link_update(mod_hash_key_t key, mod_hash_val_t *val, void *arg)
{
        struct mac_pool_arg     *mpa = arg;
        mac_impl_t              *mip = (mac_impl_t *)val;
        mac_client_impl_t       *mcip;
        mac_resource_props_t    *mrp, *emrp;
        boolean_t               pool_update = B_FALSE;
        boolean_t               pool_clear = B_FALSE;
        boolean_t               use_default = B_FALSE;
        cpupart_t               *cpupart = NULL;

        mrp = kmem_zalloc(sizeof (*mrp), KM_SLEEP);
        i_mac_perim_enter(mip);
        for (mcip = mip->mi_clients_list; mcip != NULL;
            mcip = mcip->mci_client_next) {
                pool_update = B_FALSE;
                pool_clear = B_FALSE;
                use_default = B_FALSE;
                mac_client_get_resources((mac_client_handle_t)mcip, mrp);
                emrp = MCIP_EFFECTIVE_PROPS(mcip);

                /*
                 * When pools are enabled
                 */
                if ((mpa->mpa_what == POOL_E_ENABLE) &&
                    ((mrp->mrp_mask & MRP_CPUS) == 0)) {
                        mrp->mrp_mask |= MRP_POOL;
                        pool_update = B_TRUE;
                }

                /*
                 * When pools are disabled
                 */
                if ((mpa->mpa_what == POOL_E_DISABLE) &&
                    ((mrp->mrp_mask & MRP_CPUS) == 0)) {
                        mrp->mrp_mask |= MRP_POOL;
                        pool_clear = B_TRUE;
                }

                /*
                 * Look for links with the pool property set and the poolname
                 * matching the one which is changing.
                 */
                if (strcmp(mrp->mrp_pool, mpa->mpa_poolname) == 0) {
                        /*
                         * The pool associated with the link has changed.
                         */
                        if (mpa->mpa_what == POOL_E_CHANGE) {
                                mrp->mrp_mask |= MRP_POOL;
                                pool_update = B_TRUE;
                        }
                }

                /*
                 * This link is associated with pool_default and
                 * pool_default has changed.
                 */
                if ((mpa->mpa_what == POOL_E_CHANGE) &&
                    (strcmp(emrp->mrp_pool, "pool_default") == 0) &&
                    (strcmp(mpa->mpa_poolname, "pool_default") == 0)) {
                        mrp->mrp_mask |= MRP_POOL;
                        pool_update = B_TRUE;
                }

                /*
                 * Get new list of cpus for the pool, bind network
                 * threads to new list of cpus and update resources.
                 */
                if (pool_update) {
                        if (MCIP_DATAPATH_SETUP(mcip)) {
                                pool_lock();
                                cpupart = mac_pset_find(mrp, &use_default);
                                mac_fanout_setup(mcip, mcip->mci_flent, mrp,
                                    mac_rx_deliver, mcip, cpupart);
                                mac_set_pool_effective(use_default, cpupart,
                                    mrp, emrp);
                                pool_unlock();
                        }
                        mac_update_resources(mrp, MCIP_RESOURCE_PROPS(mcip),
                            B_FALSE);
                }

                /*
                 * Clear the effective pool and bind network threads
                 * to any available CPU.
                 */
                if (pool_clear) {
                        if (MCIP_DATAPATH_SETUP(mcip)) {
                                emrp->mrp_mask &= ~MRP_POOL;
                                bzero(emrp->mrp_pool, MAXPATHLEN);
                                mac_fanout_setup(mcip, mcip->mci_flent, mrp,
                                    mac_rx_deliver, mcip, NULL);
                        }
                        mac_update_resources(mrp, MCIP_RESOURCE_PROPS(mcip),
                            B_FALSE);
                }
        }
        i_mac_perim_exit(mip);
        kmem_free(mrp, sizeof (*mrp));
        return (MH_WALK_CONTINUE);
}

static void
mac_pool_update(void *arg)
{
        mod_hash_walk(i_mac_impl_hash, mac_pool_link_update, arg);
        kmem_free(arg, sizeof (struct mac_pool_arg));
}

/*
 * Callback function to be executed when a noteworthy pool event
 * takes place.
 */
/* ARGSUSED */
static void
mac_pool_event_cb(pool_event_t what, poolid_t id, void *arg)
{
        pool_t                  *pool;
        char                    *poolname = NULL;
        struct mac_pool_arg     *mpa;

        pool_lock();
        mpa = kmem_zalloc(sizeof (struct mac_pool_arg), KM_SLEEP);

        switch (what) {
        case POOL_E_ENABLE:
        case POOL_E_DISABLE:
                break;

        case POOL_E_CHANGE:
                pool = pool_lookup_pool_by_id(id);
                if (pool == NULL) {
                        kmem_free(mpa, sizeof (struct mac_pool_arg));
                        pool_unlock();
                        return;
                }
                pool_get_name(pool, &poolname);
                (void) strlcpy(mpa->mpa_poolname, poolname,
                    sizeof (mpa->mpa_poolname));
                break;

        default:
                kmem_free(mpa, sizeof (struct mac_pool_arg));
                pool_unlock();
                return;
        }
        pool_unlock();

        mpa->mpa_what = what;

        mac_pool_update(mpa);
}

/*
 * Set effective rings property. This could be called from datapath_setup/
 * datapath_teardown or set-linkprop.
 * If the group is reserved we just go ahead and set the effective rings.
 * Additionally, for TX this could mean the default group has lost/gained
 * some rings, so if the default group is reserved, we need to adjust the
 * effective rings for the default group clients. For RX, if we are working
 * with the non-default group, we just need to reset the effective props
 * for the default group clients.
 */
void
mac_set_rings_effective(mac_client_impl_t *mcip)
{
        mac_impl_t              *mip = mcip->mci_mip;
        mac_group_t             *grp;
        mac_group_t             *defgrp;
        flow_entry_t            *flent = mcip->mci_flent;
        mac_resource_props_t    *emrp = MCIP_EFFECTIVE_PROPS(mcip);
        mac_grp_client_t        *mgcp;
        mac_client_impl_t       *gmcip;

        grp = flent->fe_rx_ring_group;
        if (grp != NULL) {
                defgrp = MAC_DEFAULT_RX_GROUP(mip);
                /*
                 * If we have reserved a group, set the effective rings
                 * to the ring count in the group.
                 */
                if (grp->mrg_state == MAC_GROUP_STATE_RESERVED) {
                        emrp->mrp_mask |= MRP_RX_RINGS;
                        emrp->mrp_nrxrings = grp->mrg_cur_count;
                }

                /*
                 * We go through the clients in the shared group and
                 * reset the effective properties. It is possible this
                 * might have already been done for some client (i.e.
                 * if some client is being moved to a group that is
                 * already shared). The case where the default group is
                 * RESERVED is taken care of above (note in the RX side if
                 * there is a non-default group, the default group is always
                 * SHARED).
                 */
                if (grp != defgrp || grp->mrg_state == MAC_GROUP_STATE_SHARED) {
                        if (grp->mrg_state == MAC_GROUP_STATE_SHARED)
                                mgcp = grp->mrg_clients;
                        else
                                mgcp = defgrp->mrg_clients;
                        while (mgcp != NULL) {
                                gmcip = mgcp->mgc_client;
                                emrp = MCIP_EFFECTIVE_PROPS(gmcip);
                                if (emrp->mrp_mask & MRP_RX_RINGS) {
                                        emrp->mrp_mask &= ~MRP_RX_RINGS;
                                        emrp->mrp_nrxrings = 0;
                                }
                                mgcp = mgcp->mgc_next;
                        }
                }
        }

        /* Now the TX side */
        grp = flent->fe_tx_ring_group;
        if (grp != NULL) {
                defgrp = MAC_DEFAULT_TX_GROUP(mip);

                if (grp->mrg_state == MAC_GROUP_STATE_RESERVED) {
                        emrp->mrp_mask |= MRP_TX_RINGS;
                        emrp->mrp_ntxrings = grp->mrg_cur_count;
                } else if (grp->mrg_state == MAC_GROUP_STATE_SHARED) {
                        mgcp = grp->mrg_clients;
                        while (mgcp != NULL) {
                                gmcip = mgcp->mgc_client;
                                emrp = MCIP_EFFECTIVE_PROPS(gmcip);
                                if (emrp->mrp_mask & MRP_TX_RINGS) {
                                        emrp->mrp_mask &= ~MRP_TX_RINGS;
                                        emrp->mrp_ntxrings = 0;
                                }
                                mgcp = mgcp->mgc_next;
                        }
                }

                /*
                 * If the group is not the default group and the default
                 * group is reserved, the ring count in the default group
                 * might have changed, update it.
                 */
                if (grp != defgrp &&
                    defgrp->mrg_state == MAC_GROUP_STATE_RESERVED) {
                        gmcip = MAC_GROUP_ONLY_CLIENT(defgrp);
                        emrp = MCIP_EFFECTIVE_PROPS(gmcip);
                        emrp->mrp_ntxrings = defgrp->mrg_cur_count;
                }
        }
        emrp = MCIP_EFFECTIVE_PROPS(mcip);
}

/*
 * Check if the primary is in the default group. If so, see if we
 * can give it a an exclusive group now that another client is
 * being configured. We take the primary out of the default group
 * because the multicast/broadcast packets for the all the clients
 * will land in the default ring in the default group which means
 * any client in the default group, even if it is the only on in
 * the group, will lose exclusive access to the rings, hence
 * polling.
 */
mac_client_impl_t *
mac_check_primary_relocation(mac_client_impl_t *mcip, boolean_t rxhw)
{
        mac_impl_t              *mip = mcip->mci_mip;
        mac_group_t             *defgrp = MAC_DEFAULT_RX_GROUP(mip);
        flow_entry_t            *flent = mcip->mci_flent;
        mac_resource_props_t    *mrp = MCIP_RESOURCE_PROPS(mcip);
        uint8_t                 *mac_addr;
        mac_group_t             *ngrp;

        /*
         * Check if the primary is in the default group, if not
         * or if it is explicitly configured to be in the default
         * group OR set the RX rings property, return.
         */
        if (flent->fe_rx_ring_group != defgrp || mrp->mrp_mask & MRP_RX_RINGS)
                return (NULL);

        /*
         * If the new client needs an exclusive group and we
         * don't have another for the primary, return.
         */
        if (rxhw && mip->mi_rxhwclnt_avail < 2)
                return (NULL);

        mac_addr = flent->fe_flow_desc.fd_dst_mac;
        /*
         * We call this when we are setting up the datapath for
         * the first non-primary.
         */
        ASSERT(mip->mi_nactiveclients == 2);

        /*
         * OK, now we have the primary that needs to be relocated.
         */
        ngrp =  mac_reserve_rx_group(mcip, mac_addr, B_TRUE);
        if (ngrp == NULL)
                return (NULL);
        if (mac_rx_switch_group(mcip, defgrp, ngrp) != 0) {
                mac_stop_group(ngrp);
                return (NULL);
        }
        return (mcip);
}

void
mac_transceiver_init(mac_impl_t *mip)
{
        if (mac_capab_get((mac_handle_t)mip, MAC_CAPAB_TRANSCEIVER,
            &mip->mi_transceiver)) {
                /*
                 * The driver set a flag that we don't know about. In this case,
                 * we need to warn about that case and ignore this capability.
                 */
                if (mip->mi_transceiver.mct_flags != 0) {
                        dev_err(mip->mi_dip, CE_WARN, "driver set transceiver "
                            "flags to invalid value: 0x%x, ignoring "
                            "capability", mip->mi_transceiver.mct_flags);
                        bzero(&mip->mi_transceiver,
                            sizeof (mac_capab_transceiver_t));
                }
        } else {
                        bzero(&mip->mi_transceiver,
                            sizeof (mac_capab_transceiver_t));
        }
}

int
mac_transceiver_count(mac_handle_t mh, uint_t *countp)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        ASSERT(MAC_PERIM_HELD(mh));

        if (mip->mi_transceiver.mct_ntransceivers == 0)
                return (ENOTSUP);

        *countp = mip->mi_transceiver.mct_ntransceivers;
        return (0);
}

int
mac_transceiver_info(mac_handle_t mh, uint_t tranid, boolean_t *present,
    boolean_t *usable)
{
        int ret;
        mac_transceiver_info_t info;

        mac_impl_t *mip = (mac_impl_t *)mh;

        ASSERT(MAC_PERIM_HELD(mh));

        if (mip->mi_transceiver.mct_info == NULL ||
            mip->mi_transceiver.mct_ntransceivers == 0)
                return (ENOTSUP);

        if (tranid >= mip->mi_transceiver.mct_ntransceivers)
                return (EINVAL);

        bzero(&info, sizeof (mac_transceiver_info_t));
        if ((ret = mip->mi_transceiver.mct_info(mip->mi_driver, tranid,
            &info)) != 0) {
                return (ret);
        }

        *present = info.mti_present;
        *usable = info.mti_usable;
        return (0);
}

int
mac_transceiver_read(mac_handle_t mh, uint_t tranid, uint_t page, void *buf,
    size_t nbytes, off_t offset, size_t *nread)
{
        int ret;
        size_t nr;
        mac_impl_t *mip = (mac_impl_t *)mh;

        ASSERT(MAC_PERIM_HELD(mh));

        if (mip->mi_transceiver.mct_read == NULL)
                return (ENOTSUP);

        if (tranid >= mip->mi_transceiver.mct_ntransceivers)
                return (EINVAL);

        /*
         * All supported pages today are 256 bytes wide. Make sure offset +
         * nbytes never exceeds that.
         */
        if (offset < 0 || offset >= 256 || nbytes > 256 ||
            offset + nbytes > 256)
                return (EINVAL);

        if (nread == NULL)
                nread = &nr;
        ret = mip->mi_transceiver.mct_read(mip->mi_driver, tranid, page, buf,
            nbytes, offset, nread);
        if (ret == 0 && *nread > nbytes) {
                dev_err(mip->mi_dip, CE_PANIC, "driver wrote %lu bytes into "
                    "%lu byte sized buffer, possible memory corruption",
                    *nread, nbytes);
        }

        return (ret);
}

void
mac_led_init(mac_impl_t *mip)
{
        mip->mi_led_modes = MAC_LED_DEFAULT;

        if (!mac_capab_get((mac_handle_t)mip, MAC_CAPAB_LED, &mip->mi_led)) {
                bzero(&mip->mi_led, sizeof (mac_capab_led_t));
                return;
        }

        if (mip->mi_led.mcl_flags != 0) {
                dev_err(mip->mi_dip, CE_WARN, "driver set led capability "
                    "flags to invalid value: 0x%x, ignoring "
                    "capability", mip->mi_transceiver.mct_flags);
                bzero(&mip->mi_led, sizeof (mac_capab_led_t));
                return;
        }

        if ((mip->mi_led.mcl_modes & ~MAC_LED_ALL) != 0) {
                dev_err(mip->mi_dip, CE_WARN, "driver set led capability "
                    "supported modes to invalid value: 0x%x, ignoring "
                    "capability", mip->mi_transceiver.mct_flags);
                bzero(&mip->mi_led, sizeof (mac_capab_led_t));
                return;
        }
}

int
mac_led_get(mac_handle_t mh, mac_led_mode_t *supported, mac_led_mode_t *active)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        ASSERT(MAC_PERIM_HELD(mh));

        if (mip->mi_led.mcl_set == NULL)
                return (ENOTSUP);

        *supported = mip->mi_led.mcl_modes;
        *active = mip->mi_led_modes;

        return (0);
}

/*
 * Update and multiplex the various LED requests. We only ever send one LED to
 * the underlying driver at a time. As such, we end up multiplexing all
 * requested states and picking one to send down to the driver.
 */
int
mac_led_set(mac_handle_t mh, mac_led_mode_t desired)
{
        int ret;
        mac_led_mode_t driver;

        mac_impl_t *mip = (mac_impl_t *)mh;

        ASSERT(MAC_PERIM_HELD(mh));

        /*
         * If we've been passed a desired value of zero, that indicates that
         * we're basically resetting to the value of zero, which is our default
         * value.
         */
        if (desired == 0)
                desired = MAC_LED_DEFAULT;

        if (mip->mi_led.mcl_set == NULL)
                return (ENOTSUP);

        /*
         * Catch both values that we don't know about and those that the driver
         * doesn't support.
         */
        if ((desired & ~MAC_LED_ALL) != 0)
                return (EINVAL);

        if ((desired & ~mip->mi_led.mcl_modes) != 0)
                return (ENOTSUP);

        /*
         * If we have the same value, then there is nothing to do.
         */
        if (desired == mip->mi_led_modes)
                return (0);

        /*
         * Based on the desired value, determine what to send to the driver. We
         * only will send a single bit to the driver at any given time. IDENT
         * takes priority over OFF or ON. We also let OFF take priority over the
         * rest.
         */
        if (desired & MAC_LED_IDENT) {
                driver = MAC_LED_IDENT;
        } else if (desired & MAC_LED_OFF) {
                driver = MAC_LED_OFF;
        } else if (desired & MAC_LED_ON) {
                driver = MAC_LED_ON;
        } else {
                driver = MAC_LED_DEFAULT;
        }

        if ((ret = mip->mi_led.mcl_set(mip->mi_driver, driver, 0)) == 0) {
                mip->mi_led_modes = desired;
        }

        return (ret);
}

/*
 * Send packets through the Tx ring ('mrh') or through the default
 * handler if no ring is specified. Before passing the packet down to
 * the MAC provider, emulate any hardware offloads which have been
 * requested but are not supported by the provider.
 */
mblk_t *
mac_ring_tx(mac_handle_t mh, mac_ring_handle_t mrh, mblk_t *mp)
{
        mac_impl_t *mip = (mac_impl_t *)mh;

        if (mrh == NULL)
                mrh = mip->mi_default_tx_ring;

        if (mrh == NULL)
                return (mip->mi_tx(mip->mi_driver, mp));
        else
                return (mac_hwring_tx(mrh, mp));
}

/*
 * This is the final stop before reaching the underlying MAC provider.
 * This is also where the bridging hook is inserted. Packets that are
 * bridged will return through mac_bridge_tx(), with rh nulled out if
 * the bridge chooses to send output on a different link due to
 * forwarding.
 */
mblk_t *
mac_provider_tx(mac_impl_t *mip, mac_ring_handle_t rh, mblk_t *mp,
    mac_client_impl_t *mcip)
{
        /*
         * If there is a bound Hybrid I/O share, send packets through
         * the default tx ring. When there's a bound Hybrid I/O share,
         * the tx rings of this client are mapped in the guest domain
         * and not accessible from here.
         */
        if (mcip->mci_state_flags & MCIS_SHARE_BOUND)
                rh = mip->mi_default_tx_ring;

        if (mip->mi_promisc_list != NULL)
                mac_promisc_dispatch(mip, mp, mcip, B_FALSE);

        if (mip->mi_bridge_link == NULL)
                return (mac_ring_tx((mac_handle_t)mip, rh, mp));
        else
                return (mac_bridge_tx(mip, rh, mp));
}