/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009 Yahoo! Inc.
 * Copyright (c) 2011-2015 LSI Corp.
 * Copyright (c) 2013-2015 Avago Technologies
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * Avago Technologies (LSI) MPT-Fusion Host Adapter FreeBSD
 */

/* Communications core for Avago Technologies (LSI) MPT2 */

/* TODO Move headers to mpsvar */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/selinfo.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/module.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/bio.h>
#include <sys/malloc.h>
#include <sys/uio.h>
#include <sys/sysctl.h>
#include <sys/smp.h>
#include <sys/queue.h>
#include <sys/kthread.h>
#include <sys/taskqueue.h>
#include <sys/endian.h>
#include <sys/eventhandler.h>
#include <sys/sbuf.h>
#include <sys/priv.h>

#include <machine/bus.h>
#include <machine/resource.h>
#include <sys/rman.h>
#include <sys/proc.h>

#include <dev/pci/pcivar.h>

#include <cam/cam.h>
#include <cam/scsi/scsi_all.h>

#include <dev/mps/mpi/mpi2_type.h>
#include <dev/mps/mpi/mpi2.h>
#include <dev/mps/mpi/mpi2_ioc.h>
#include <dev/mps/mpi/mpi2_sas.h>
#include <dev/mps/mpi/mpi2_cnfg.h>
#include <dev/mps/mpi/mpi2_init.h>
#include <dev/mps/mpi/mpi2_tool.h>
#include <dev/mps/mps_ioctl.h>
#include <dev/mps/mpsvar.h>
#include <dev/mps/mps_table.h>

static int mps_diag_reset(struct mps_softc *sc, int sleep_flag);
static int mps_init_queues(struct mps_softc *sc);
static void mps_resize_queues(struct mps_softc *sc);
static int mps_message_unit_reset(struct mps_softc *sc, int sleep_flag);
static int mps_transition_operational(struct mps_softc *sc);
static int mps_iocfacts_allocate(struct mps_softc *sc, uint8_t attaching);
static void mps_iocfacts_free(struct mps_softc *sc);
static void mps_startup(void *arg);
static int mps_send_iocinit(struct mps_softc *sc);
static int mps_alloc_queues(struct mps_softc *sc);
static int mps_alloc_hw_queues(struct mps_softc *sc);
static int mps_alloc_replies(struct mps_softc *sc);
static int mps_alloc_requests(struct mps_softc *sc);
static int mps_attach_log(struct mps_softc *sc);
static __inline void mps_complete_command(struct mps_softc *sc,
    struct mps_command *cm);
static void mps_dispatch_event(struct mps_softc *sc, uintptr_t data,
    MPI2_EVENT_NOTIFICATION_REPLY *reply);
static void mps_config_complete(struct mps_softc *sc, struct mps_command *cm);
static void mps_periodic(void *);
static int mps_reregister_events(struct mps_softc *sc);
static void mps_enqueue_request(struct mps_softc *sc, struct mps_command *cm);
static int mps_get_iocfacts(struct mps_softc *sc, MPI2_IOC_FACTS_REPLY *facts);
static int mps_wait_db_ack(struct mps_softc *sc, int timeout, int sleep_flag);
static int mps_debug_sysctl(SYSCTL_HANDLER_ARGS);
static int mps_dump_reqs(SYSCTL_HANDLER_ARGS);
static void mps_parse_debug(struct mps_softc *sc, char *list);

SYSCTL_NODE(_hw, OID_AUTO, mps, CTLFLAG_RD | CTLFLAG_MPSAFE, 0,
    "MPS Driver Parameters");

MALLOC_DEFINE(M_MPT2, "mps", "mpt2 driver memory");
MALLOC_DECLARE(M_MPSUSER);

/*
 * Do a "Diagnostic Reset" aka a hard reset.  This should get the chip out of
 * any state and back to its initialization state machine.
 */
static char mpt2_reset_magic[] = { 0x00, 0x0f, 0x04, 0x0b, 0x02, 0x07, 0x0d };

/* Added this union to smoothly convert le64toh cm->cm_desc.Words.
 * Compiler only support unint64_t to be passed as argument.
 * Otherwise it will throw below error
 * "aggregate value used where an integer was expected"
 */

typedef union {
        u64 word;
        struct {
                u32 low;
                u32 high;
        } u;
} request_descriptor_t;

/* Rate limit chain-fail messages to 1 per minute */
static struct timeval mps_chainfail_interval = { 60, 0 };

/* 
 * sleep_flag can be either CAN_SLEEP or NO_SLEEP.
 * If this function is called from process context, it can sleep
 * and there is no harm to sleep, in case if this fuction is called
 * from Interrupt handler, we can not sleep and need NO_SLEEP flag set.
 * based on sleep flags driver will call either msleep, pause or DELAY.
 * msleep and pause are of same variant, but pause is used when mps_mtx
 * is not hold by driver.
 *
 */
static int
mps_diag_reset(struct mps_softc *sc,int sleep_flag)
{
        uint32_t reg;
        int i, error, tries = 0;
        uint8_t first_wait_done = FALSE;

        mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);

        /* Clear any pending interrupts */
        mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);

        /*
         * Force NO_SLEEP for threads prohibited to sleep
         * e.a Thread from interrupt handler are prohibited to sleep.
         */
        if (curthread->td_no_sleeping != 0)
                sleep_flag = NO_SLEEP;

        mps_dprint(sc, MPS_INIT, "sequence start, sleep_flag= %d\n", sleep_flag);

        /* Push the magic sequence */
        error = ETIMEDOUT;
        while (tries++ < 20) {
                for (i = 0; i < sizeof(mpt2_reset_magic); i++)
                        mps_regwrite(sc, MPI2_WRITE_SEQUENCE_OFFSET,
                            mpt2_reset_magic[i]);
                /* wait 100 msec */
                if (mtx_owned(&sc->mps_mtx) && sleep_flag == CAN_SLEEP)
                        msleep(&sc->msleep_fake_chan, &sc->mps_mtx, 0,
                            "mpsdiag", hz/10);
                else if (sleep_flag == CAN_SLEEP)
                        pause("mpsdiag", hz/10);
                else
                        DELAY(100 * 1000);

                reg = mps_regread(sc, MPI2_HOST_DIAGNOSTIC_OFFSET);
                if (reg & MPI2_DIAG_DIAG_WRITE_ENABLE) {
                        error = 0;
                        break;
                }
        }
        if (error) {
                mps_dprint(sc, MPS_INIT, "sequence failed, error=%d, exit\n",
                    error);
                return (error);
        }

        /* Send the actual reset.  XXX need to refresh the reg? */
        reg |= MPI2_DIAG_RESET_ADAPTER;
        mps_dprint(sc, MPS_INIT, "sequence success, sending reset, reg= 0x%x\n",
                reg);
        mps_regwrite(sc, MPI2_HOST_DIAGNOSTIC_OFFSET, reg);

        /* Wait up to 300 seconds in 50ms intervals */
        error = ETIMEDOUT;
        for (i = 0; i < 6000; i++) {
                /*
                 * Wait 50 msec. If this is the first time through, wait 256
                 * msec to satisfy Diag Reset timing requirements.
                 */
                if (first_wait_done) {
                        if (mtx_owned(&sc->mps_mtx) && sleep_flag == CAN_SLEEP)
                                msleep(&sc->msleep_fake_chan, &sc->mps_mtx, 0,
                                    "mpsdiag", hz/20);
                        else if (sleep_flag == CAN_SLEEP)
                                pause("mpsdiag", hz/20);
                        else
                                DELAY(50 * 1000);
                } else {
                        DELAY(256 * 1000);
                        first_wait_done = TRUE;
                }
                /*
                 * Check for the RESET_ADAPTER bit to be cleared first, then
                 * wait for the RESET state to be cleared, which takes a little
                 * longer.
                 */
                reg = mps_regread(sc, MPI2_HOST_DIAGNOSTIC_OFFSET);
                if (reg & MPI2_DIAG_RESET_ADAPTER) {
                        continue;
                }
                reg = mps_regread(sc, MPI2_DOORBELL_OFFSET);
                if ((reg & MPI2_IOC_STATE_MASK) != MPI2_IOC_STATE_RESET) {
                        error = 0;
                        break;
                }
        }
        if (error) {
                mps_dprint(sc, MPS_INIT, "reset failed, error= %d, exit\n",
                    error);
                return (error);
        }

        mps_regwrite(sc, MPI2_WRITE_SEQUENCE_OFFSET, 0x0);
        mps_dprint(sc, MPS_INIT, "diag reset success, exit\n");

        return (0);
}

static int
mps_message_unit_reset(struct mps_softc *sc, int sleep_flag)
{
        int error;

        MPS_FUNCTRACE(sc);

        mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);

        error = 0;
        mps_regwrite(sc, MPI2_DOORBELL_OFFSET,
            MPI2_FUNCTION_IOC_MESSAGE_UNIT_RESET <<
            MPI2_DOORBELL_FUNCTION_SHIFT);

        if (mps_wait_db_ack(sc, 5, sleep_flag) != 0) {
                mps_dprint(sc, MPS_INIT|MPS_FAULT,
                    "Doorbell handshake failed\n");
                error = ETIMEDOUT;
        }

        mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);
        return (error);
}

static int
mps_transition_ready(struct mps_softc *sc)
{
        uint32_t reg, state;
        int error, tries = 0;
        int sleep_flags;

        MPS_FUNCTRACE(sc);
        /* If we are in attach call, do not sleep */
        sleep_flags = (sc->mps_flags & MPS_FLAGS_ATTACH_DONE)
                                        ? CAN_SLEEP:NO_SLEEP;
        error = 0;

        mps_dprint(sc, MPS_INIT, "%s entered, sleep_flags= %d\n",
           __func__, sleep_flags);

        while (tries++ < 1200) {
                reg = mps_regread(sc, MPI2_DOORBELL_OFFSET);
                mps_dprint(sc, MPS_INIT, "  Doorbell= 0x%x\n", reg);

                /*
                 * Ensure the IOC is ready to talk.  If it's not, try
                 * resetting it.
                 */
                if (reg & MPI2_DOORBELL_USED) {
                        mps_dprint(sc, MPS_INIT, "  Not ready, sending diag "
                            "reset\n");
                        mps_diag_reset(sc, sleep_flags);
                        DELAY(50000);
                        continue;
                }

                /* Is the adapter owned by another peer? */
                if ((reg & MPI2_DOORBELL_WHO_INIT_MASK) ==
                    (MPI2_WHOINIT_PCI_PEER << MPI2_DOORBELL_WHO_INIT_SHIFT)) {
                        mps_dprint(sc, MPS_INIT|MPS_FAULT, "IOC is under the "
                            "control of another peer host, aborting "
                            "initialization.\n");
                        error = ENXIO;
                        break;
                }
                
                state = reg & MPI2_IOC_STATE_MASK;
                if (state == MPI2_IOC_STATE_READY) {
                        /* Ready to go! */
                        error = 0;
                        break;
                } else if (state == MPI2_IOC_STATE_FAULT) {
                        mps_dprint(sc, MPS_INIT|MPS_FAULT, "IOC in fault "
                            "state 0x%x, resetting\n",
                            state & MPI2_DOORBELL_FAULT_CODE_MASK);
                        mps_diag_reset(sc, sleep_flags);
                } else if (state == MPI2_IOC_STATE_OPERATIONAL) {
                        /* Need to take ownership */
                        mps_message_unit_reset(sc, sleep_flags);
                } else if (state == MPI2_IOC_STATE_RESET) {
                        /* Wait a bit, IOC might be in transition */
                        mps_dprint(sc, MPS_INIT|MPS_FAULT,
                            "IOC in unexpected reset state\n");
                } else {
                        mps_dprint(sc, MPS_INIT|MPS_FAULT,
                            "IOC in unknown state 0x%x\n", state);
                        error = EINVAL;
                        break;
                }

                /* Wait 50ms for things to settle down. */
                DELAY(50000);
        }

        if (error)
                mps_dprint(sc, MPS_INIT|MPS_FAULT,
                    "Cannot transition IOC to ready\n");
        mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);

        return (error);
}

static int
mps_transition_operational(struct mps_softc *sc)
{
        uint32_t reg, state;
        int error;

        MPS_FUNCTRACE(sc);

        error = 0;
        reg = mps_regread(sc, MPI2_DOORBELL_OFFSET);
        mps_dprint(sc, MPS_INIT, "%s entered, Doorbell= 0x%x\n", __func__, reg);

        state = reg & MPI2_IOC_STATE_MASK;
        if (state != MPI2_IOC_STATE_READY) {
                mps_dprint(sc, MPS_INIT, "IOC not ready\n");
                if ((error = mps_transition_ready(sc)) != 0) {
                        mps_dprint(sc, MPS_INIT|MPS_FAULT, 
                            "failed to transition ready, exit\n");
                        return (error);
                }
        }

        error = mps_send_iocinit(sc);
        mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);

        return (error);
}

static void
mps_resize_queues(struct mps_softc *sc)
{
        u_int reqcr, prireqcr, maxio, sges_per_frame;

        /*
         * Size the queues. Since the reply queues always need one free
         * entry, we'll deduct one reply message here.  The LSI documents
         * suggest instead to add a count to the request queue, but I think
         * that it's better to deduct from reply queue.
         */
        prireqcr = MAX(1, sc->max_prireqframes);
        prireqcr = MIN(prireqcr, sc->facts->HighPriorityCredit);

        reqcr = MAX(2, sc->max_reqframes);
        reqcr = MIN(reqcr, sc->facts->RequestCredit);

        sc->num_reqs = prireqcr + reqcr;
        sc->num_prireqs = prireqcr;
        sc->num_replies = MIN(sc->max_replyframes + sc->max_evtframes,
            sc->facts->MaxReplyDescriptorPostQueueDepth) - 1;

        /* Store the request frame size in bytes rather than as 32bit words */
        sc->reqframesz = sc->facts->IOCRequestFrameSize * 4;

        /*
         * Max IO Size is Page Size * the following:
         * ((SGEs per frame - 1 for chain element) * Max Chain Depth)
         * + 1 for no chain needed in last frame
         *
         * If user suggests a Max IO size to use, use the smaller of the
         * user's value and the calculated value as long as the user's
         * value is larger than 0. The user's value is in pages.
         */
        sges_per_frame = sc->reqframesz / sizeof(MPI2_SGE_SIMPLE64) - 1;
        maxio = (sges_per_frame * sc->facts->MaxChainDepth + 1) * PAGE_SIZE;

        /*
         * If I/O size limitation requested, then use it and pass up to CAM.
         * If not, use maxphys as an optimization hint, but report HW limit.
         */
        if (sc->max_io_pages > 0) {
                maxio = min(maxio, sc->max_io_pages * PAGE_SIZE);
                sc->maxio = maxio;
        } else {
                sc->maxio = maxio;
                maxio = min(maxio, maxphys);
        }

        sc->num_chains = (maxio / PAGE_SIZE + sges_per_frame - 2) /
            sges_per_frame * reqcr;
        if (sc->max_chains > 0 && sc->max_chains < sc->num_chains)
                sc->num_chains = sc->max_chains;

        /*
         * Figure out the number of MSIx-based queues.  If the firmware or
         * user has done something crazy and not allowed enough credit for
         * the queues to be useful then don't enable multi-queue.
         */
        if (sc->facts->MaxMSIxVectors < 2)
                sc->msi_msgs = 1;

        if (sc->msi_msgs > 1) {
                sc->msi_msgs = MIN(sc->msi_msgs, mp_ncpus);
                sc->msi_msgs = MIN(sc->msi_msgs, sc->facts->MaxMSIxVectors);
                if (sc->num_reqs / sc->msi_msgs < 2)
                        sc->msi_msgs = 1;
        }

        mps_dprint(sc, MPS_INIT, "Sized queues to q=%d reqs=%d replies=%d\n",
            sc->msi_msgs, sc->num_reqs, sc->num_replies);
}

/*
 * This is called during attach and when re-initializing due to a Diag Reset.
 * IOC Facts is used to allocate many of the structures needed by the driver.
 * If called from attach, de-allocation is not required because the driver has
 * not allocated any structures yet, but if called from a Diag Reset, previously
 * allocated structures based on IOC Facts will need to be freed and re-
 * allocated bases on the latest IOC Facts.
 */
static int
mps_iocfacts_allocate(struct mps_softc *sc, uint8_t attaching)
{
        int error;
        Mpi2IOCFactsReply_t saved_facts;
        uint8_t saved_mode, reallocating;

        mps_dprint(sc, MPS_INIT|MPS_TRACE, "%s entered\n", __func__);

        /* Save old IOC Facts and then only reallocate if Facts have changed */
        if (!attaching) {
                bcopy(sc->facts, &saved_facts, sizeof(MPI2_IOC_FACTS_REPLY));
        }

        /*
         * Get IOC Facts.  In all cases throughout this function, panic if doing
         * a re-initialization and only return the error if attaching so the OS
         * can handle it.
         */
        if ((error = mps_get_iocfacts(sc, sc->facts)) != 0) {
                if (attaching) {
                        mps_dprint(sc, MPS_INIT|MPS_FAULT, "Failed to get "
                            "IOC Facts with error %d, exit\n", error);
                        return (error);
                } else {
                        panic("%s failed to get IOC Facts with error %d\n",
                            __func__, error);
                }
        }

        MPS_DPRINT_PAGE(sc, MPS_XINFO, iocfacts, sc->facts);

        snprintf(sc->fw_version, sizeof(sc->fw_version), 
            "%02d.%02d.%02d.%02d", 
            sc->facts->FWVersion.Struct.Major,
            sc->facts->FWVersion.Struct.Minor,
            sc->facts->FWVersion.Struct.Unit,
            sc->facts->FWVersion.Struct.Dev);

        snprintf(sc->msg_version, sizeof(sc->msg_version), "%d.%d",
            (sc->facts->MsgVersion & MPI2_IOCFACTS_MSGVERSION_MAJOR_MASK) >>
            MPI2_IOCFACTS_MSGVERSION_MAJOR_SHIFT, 
            (sc->facts->MsgVersion & MPI2_IOCFACTS_MSGVERSION_MINOR_MASK) >>
            MPI2_IOCFACTS_MSGVERSION_MINOR_SHIFT);

        mps_dprint(sc, MPS_INFO, "Firmware: %s, Driver: %s\n", sc->fw_version,
            MPS_DRIVER_VERSION);
        mps_dprint(sc, MPS_INFO, "IOCCapabilities: %b\n",
             sc->facts->IOCCapabilities,
            "\20" "\3ScsiTaskFull" "\4DiagTrace" "\5SnapBuf" "\6ExtBuf"
            "\7EEDP" "\10BiDirTarg" "\11Multicast" "\14TransRetry" "\15IR"
            "\16EventReplay" "\17RaidAccel" "\20MSIXIndex" "\21HostDisc");

        /*
         * If the chip doesn't support event replay then a hard reset will be
         * required to trigger a full discovery.  Do the reset here then
         * retransition to Ready.  A hard reset might have already been done,
         * but it doesn't hurt to do it again.  Only do this if attaching, not
         * for a Diag Reset.
         */
        if (attaching && ((sc->facts->IOCCapabilities &
            MPI2_IOCFACTS_CAPABILITY_EVENT_REPLAY) == 0)) {
                mps_dprint(sc, MPS_INIT, "No event replay, resetting\n");
                mps_diag_reset(sc, NO_SLEEP);
                if ((error = mps_transition_ready(sc)) != 0) {
                        mps_dprint(sc, MPS_INIT|MPS_FAULT, "Failed to "
                            "transition to ready with error %d, exit\n",
                            error);
                        return (error);
                }
        }

        /*
         * Set flag if IR Firmware is loaded.  If the RAID Capability has
         * changed from the previous IOC Facts, log a warning, but only if
         * checking this after a Diag Reset and not during attach.
         */
        saved_mode = sc->ir_firmware;
        if (sc->facts->IOCCapabilities &
            MPI2_IOCFACTS_CAPABILITY_INTEGRATED_RAID)
                sc->ir_firmware = 1;
        if (!attaching) {
                if (sc->ir_firmware != saved_mode) {
                        mps_dprint(sc, MPS_INIT|MPS_FAULT, "new IR/IT mode "
                            "in IOC Facts does not match previous mode\n");
                }
        }

        /* Only deallocate and reallocate if relevant IOC Facts have changed */
        reallocating = FALSE;
        sc->mps_flags &= ~MPS_FLAGS_REALLOCATED;

        if ((!attaching) &&
            ((saved_facts.MsgVersion != sc->facts->MsgVersion) ||
            (saved_facts.HeaderVersion != sc->facts->HeaderVersion) ||
            (saved_facts.MaxChainDepth != sc->facts->MaxChainDepth) ||
            (saved_facts.RequestCredit != sc->facts->RequestCredit) ||
            (saved_facts.ProductID != sc->facts->ProductID) ||
            (saved_facts.IOCCapabilities != sc->facts->IOCCapabilities) ||
            (saved_facts.IOCRequestFrameSize !=
            sc->facts->IOCRequestFrameSize) ||
            (saved_facts.MaxTargets != sc->facts->MaxTargets) ||
            (saved_facts.MaxSasExpanders != sc->facts->MaxSasExpanders) ||
            (saved_facts.MaxEnclosures != sc->facts->MaxEnclosures) ||
            (saved_facts.HighPriorityCredit != sc->facts->HighPriorityCredit) ||
            (saved_facts.MaxReplyDescriptorPostQueueDepth !=
            sc->facts->MaxReplyDescriptorPostQueueDepth) ||
            (saved_facts.ReplyFrameSize != sc->facts->ReplyFrameSize) ||
            (saved_facts.MaxVolumes != sc->facts->MaxVolumes) ||
            (saved_facts.MaxPersistentEntries !=
            sc->facts->MaxPersistentEntries))) {
                reallocating = TRUE;

                /* Record that we reallocated everything */
                sc->mps_flags |= MPS_FLAGS_REALLOCATED;
        }

        /*
         * Some things should be done if attaching or re-allocating after a Diag
         * Reset, but are not needed after a Diag Reset if the FW has not
         * changed.
         */
        if (attaching || reallocating) {
                /*
                 * Check if controller supports FW diag buffers and set flag to
                 * enable each type.
                 */
                if (sc->facts->IOCCapabilities &
                    MPI2_IOCFACTS_CAPABILITY_DIAG_TRACE_BUFFER)
                        sc->fw_diag_buffer_list[MPI2_DIAG_BUF_TYPE_TRACE].
                            enabled = TRUE;
                if (sc->facts->IOCCapabilities &
                    MPI2_IOCFACTS_CAPABILITY_SNAPSHOT_BUFFER)
                        sc->fw_diag_buffer_list[MPI2_DIAG_BUF_TYPE_SNAPSHOT].
                            enabled = TRUE;
                if (sc->facts->IOCCapabilities &
                    MPI2_IOCFACTS_CAPABILITY_EXTENDED_BUFFER)
                        sc->fw_diag_buffer_list[MPI2_DIAG_BUF_TYPE_EXTENDED].
                            enabled = TRUE;

                /*
                 * Set flag if EEDP is supported and if TLR is supported.
                 */
                if (sc->facts->IOCCapabilities & MPI2_IOCFACTS_CAPABILITY_EEDP)
                        sc->eedp_enabled = TRUE;
                if (sc->facts->IOCCapabilities & MPI2_IOCFACTS_CAPABILITY_TLR)
                        sc->control_TLR = TRUE;

                mps_resize_queues(sc);

                /*
                 * Initialize all Tail Queues
                 */
                TAILQ_INIT(&sc->req_list);
                TAILQ_INIT(&sc->high_priority_req_list);
                TAILQ_INIT(&sc->chain_list);
                TAILQ_INIT(&sc->tm_list);
        }

        /*
         * If doing a Diag Reset and the FW is significantly different
         * (reallocating will be set above in IOC Facts comparison), then all
         * buffers based on the IOC Facts will need to be freed before they are
         * reallocated.
         */
        if (reallocating) {
                mps_iocfacts_free(sc);
                mpssas_realloc_targets(sc, saved_facts.MaxTargets +
                    saved_facts.MaxVolumes);
        }

        /*
         * Any deallocation has been completed.  Now start reallocating
         * if needed.  Will only need to reallocate if attaching or if the new
         * IOC Facts are different from the previous IOC Facts after a Diag
         * Reset. Targets have already been allocated above if needed.
         */
        error = 0;
        while (attaching || reallocating) {
                if ((error = mps_alloc_hw_queues(sc)) != 0)
                        break;
                if ((error = mps_alloc_replies(sc)) != 0)
                        break;
                if ((error = mps_alloc_requests(sc)) != 0)
                        break;
                if ((error = mps_alloc_queues(sc)) != 0)
                        break;

                break;
        }
        if (error) {
                mps_dprint(sc, MPS_INIT|MPS_FAULT,
                    "Failed to alloc queues with error %d\n", error);
                mps_free(sc);
                return (error);
        }

        /* Always initialize the queues */
        bzero(sc->free_queue, sc->fqdepth * 4);
        mps_init_queues(sc);

        /*
         * Always get the chip out of the reset state, but only panic if not
         * attaching.  If attaching and there is an error, that is handled by
         * the OS.
         */
        error = mps_transition_operational(sc);
        if (error != 0) {
                mps_dprint(sc, MPS_INIT|MPS_FAULT, "Failed to "
                    "transition to operational with error %d\n", error);
                mps_free(sc);
                return (error);
        }

        /*
         * Finish the queue initialization.
         * These are set here instead of in mps_init_queues() because the
         * IOC resets these values during the state transition in
         * mps_transition_operational().  The free index is set to 1
         * because the corresponding index in the IOC is set to 0, and the
         * IOC treats the queues as full if both are set to the same value.
         * Hence the reason that the queue can't hold all of the possible
         * replies.
         */
        sc->replypostindex = 0;
        mps_regwrite(sc, MPI2_REPLY_FREE_HOST_INDEX_OFFSET, sc->replyfreeindex);
        mps_regwrite(sc, MPI2_REPLY_POST_HOST_INDEX_OFFSET, 0);

        /*
         * Attach the subsystems so they can prepare their event masks.
         * XXX Should be dynamic so that IM/IR and user modules can attach
         */
        error = 0;
        while (attaching) {
                mps_dprint(sc, MPS_INIT, "Attaching subsystems\n");
                if ((error = mps_attach_log(sc)) != 0)
                        break;
                if ((error = mps_attach_sas(sc)) != 0)
                        break;
                if ((error = mps_attach_user(sc)) != 0)
                        break;
                break;
        }
        if (error) {
                mps_dprint(sc, MPS_INIT|MPS_FAULT, "Failed to attach all "
                    "subsystems: error %d\n", error);
                mps_free(sc);
                return (error);
        }

        /*
         * XXX If the number of MSI-X vectors changes during re-init, this
         * won't see it and adjust.
         */
        if (attaching && (error = mps_pci_setup_interrupts(sc)) != 0) {
                mps_dprint(sc, MPS_INIT|MPS_FAULT, "Failed to setup "
                    "interrupts\n");
                mps_free(sc);
                return (error);
        }

        /*
         * Set flag if this is a WD controller.  This shouldn't ever change, but
         * reset it after a Diag Reset, just in case.
         */
        sc->WD_available = FALSE;
        if (pci_get_device(sc->mps_dev) == MPI2_MFGPAGE_DEVID_SSS6200)
                sc->WD_available = TRUE;

        return (error);
}

/*
 * This is called if memory is being free (during detach for example) and when
 * buffers need to be reallocated due to a Diag Reset.
 */
static void
mps_iocfacts_free(struct mps_softc *sc)
{
        struct mps_command *cm;
        int i;

        mps_dprint(sc, MPS_TRACE, "%s\n", __func__);

        if (sc->free_busaddr != 0)
                bus_dmamap_unload(sc->queues_dmat, sc->queues_map);
        if (sc->free_queue != NULL)
                bus_dmamem_free(sc->queues_dmat, sc->free_queue,
                    sc->queues_map);
        if (sc->queues_dmat != NULL)
                bus_dma_tag_destroy(sc->queues_dmat);

        if (sc->chain_frames != NULL) {
                bus_dmamap_unload(sc->chain_dmat, sc->chain_map);
                bus_dmamem_free(sc->chain_dmat, sc->chain_frames,
                    sc->chain_map);
        }
        if (sc->chain_dmat != NULL)
                bus_dma_tag_destroy(sc->chain_dmat);

        if (sc->sense_busaddr != 0)
                bus_dmamap_unload(sc->sense_dmat, sc->sense_map);
        if (sc->sense_frames != NULL)
                bus_dmamem_free(sc->sense_dmat, sc->sense_frames,
                    sc->sense_map);
        if (sc->sense_dmat != NULL)
                bus_dma_tag_destroy(sc->sense_dmat);

        if (sc->reply_busaddr != 0)
                bus_dmamap_unload(sc->reply_dmat, sc->reply_map);
        if (sc->reply_frames != NULL)
                bus_dmamem_free(sc->reply_dmat, sc->reply_frames,
                    sc->reply_map);
        if (sc->reply_dmat != NULL)
                bus_dma_tag_destroy(sc->reply_dmat);

        if (sc->req_busaddr != 0)
                bus_dmamap_unload(sc->req_dmat, sc->req_map);
        if (sc->req_frames != NULL)
                bus_dmamem_free(sc->req_dmat, sc->req_frames, sc->req_map);
        if (sc->req_dmat != NULL)
                bus_dma_tag_destroy(sc->req_dmat);

        if (sc->chains != NULL)
                free(sc->chains, M_MPT2);
        if (sc->commands != NULL) {
                for (i = 1; i < sc->num_reqs; i++) {
                        cm = &sc->commands[i];
                        bus_dmamap_destroy(sc->buffer_dmat, cm->cm_dmamap);
                }
                free(sc->commands, M_MPT2);
        }
        if (sc->buffer_dmat != NULL)
                bus_dma_tag_destroy(sc->buffer_dmat);

        mps_pci_free_interrupts(sc);
        free(sc->queues, M_MPT2);
        sc->queues = NULL;
}

/* 
 * The terms diag reset and hard reset are used interchangeably in the MPI
 * docs to mean resetting the controller chip.  In this code diag reset
 * cleans everything up, and the hard reset function just sends the reset
 * sequence to the chip.  This should probably be refactored so that every
 * subsystem gets a reset notification of some sort, and can clean up
 * appropriately.
 */
int
mps_reinit(struct mps_softc *sc)
{
        int error;
        struct mpssas_softc *sassc;

        sassc = sc->sassc;

        MPS_FUNCTRACE(sc);

        mtx_assert(&sc->mps_mtx, MA_OWNED);

        mps_dprint(sc, MPS_INIT|MPS_INFO, "Reinitializing controller\n");
        if (sc->mps_flags & MPS_FLAGS_DIAGRESET) {
                mps_dprint(sc, MPS_INIT, "Reset already in progress\n");
                return 0;
        }

        /* make sure the completion callbacks can recognize they're getting
         * a NULL cm_reply due to a reset.
         */
        sc->mps_flags |= MPS_FLAGS_DIAGRESET;

        /*
         * Mask interrupts here.
         */
        mps_dprint(sc, MPS_INIT, "masking interrupts and resetting\n");
        mps_mask_intr(sc);

        error = mps_diag_reset(sc, CAN_SLEEP);
        if (error != 0) {
                /* XXXSL No need to panic here */
                panic("%s hard reset failed with error %d\n",
                    __func__, error);
        }

        /* Restore the PCI state, including the MSI-X registers */
        mps_pci_restore(sc);

        /* Give the I/O subsystem special priority to get itself prepared */
        mpssas_handle_reinit(sc);

        /*
         * Get IOC Facts and allocate all structures based on this information.
         * The attach function will also call mps_iocfacts_allocate at startup.
         * If relevant values have changed in IOC Facts, this function will free
         * all of the memory based on IOC Facts and reallocate that memory.
         */
        if ((error = mps_iocfacts_allocate(sc, FALSE)) != 0) {
                panic("%s IOC Facts based allocation failed with error %d\n",
                    __func__, error);
        }

        /*
         * Mapping structures will be re-allocated after getting IOC Page8, so
         * free these structures here.
         */
        mps_mapping_exit(sc);

        /*
         * The static page function currently read is IOC Page8.  Others can be
         * added in future.  It's possible that the values in IOC Page8 have
         * changed after a Diag Reset due to user modification, so always read
         * these.  Interrupts are masked, so unmask them before getting config
         * pages.
         */
        mps_unmask_intr(sc);
        sc->mps_flags &= ~MPS_FLAGS_DIAGRESET;
        mps_base_static_config_pages(sc);

        /*
         * Some mapping info is based in IOC Page8 data, so re-initialize the
         * mapping tables.
         */
        mps_mapping_initialize(sc);

        /*
         * Restart will reload the event masks clobbered by the reset, and
         * then enable the port.
         */
        mps_reregister_events(sc);

        /* the end of discovery will release the simq, so we're done. */
        mps_dprint(sc, MPS_INIT|MPS_XINFO, "Finished sc %p post %u free %u\n", 
            sc, sc->replypostindex, sc->replyfreeindex);

        mpssas_release_simq_reinit(sassc);
        mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);

        return 0;
}

/* Wait for the chip to ACK a word that we've put into its FIFO 
 * Wait for <timeout> seconds. In single loop wait for busy loop
 * for 500 microseconds.
 * Total is [ 0.5 * (2000 * <timeout>) ] in miliseconds.
 * */
static int
mps_wait_db_ack(struct mps_softc *sc, int timeout, int sleep_flag)
{

        u32 cntdn, count;
        u32 int_status;
        u32 doorbell;

        count = 0;
        cntdn = (sleep_flag == CAN_SLEEP) ? 1000*timeout : 2000*timeout;
        do {
                int_status = mps_regread(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET);
                if (!(int_status & MPI2_HIS_SYS2IOC_DB_STATUS)) {
                        mps_dprint(sc, MPS_TRACE, 
                        "%s: successful count(%d), timeout(%d)\n",
                        __func__, count, timeout);
                return 0;
                } else if (int_status & MPI2_HIS_IOC2SYS_DB_STATUS) {
                        doorbell = mps_regread(sc, MPI2_DOORBELL_OFFSET);
                        if ((doorbell & MPI2_IOC_STATE_MASK) ==
                                MPI2_IOC_STATE_FAULT) {
                                mps_dprint(sc, MPS_FAULT, 
                                        "fault_state(0x%04x)!\n", doorbell);
                                return (EFAULT);
                        }
                } else if (int_status == 0xFFFFFFFF)
                        goto out;

                /* If it can sleep, sleep for 1 milisecond, else busy loop for 
                * 0.5 milisecond */
                if (mtx_owned(&sc->mps_mtx) && sleep_flag == CAN_SLEEP)
                        msleep(&sc->msleep_fake_chan, &sc->mps_mtx, 0, 
                        "mpsdba", hz/1000);
                else if (sleep_flag == CAN_SLEEP)
                        pause("mpsdba", hz/1000);
                else
                        DELAY(500);
                count++;
        } while (--cntdn);

        out:
        mps_dprint(sc, MPS_FAULT, "%s: failed due to timeout count(%d), "
                "int_status(%x)!\n", __func__, count, int_status);
        return (ETIMEDOUT);

}

/* Wait for the chip to signal that the next word in its FIFO can be fetched */
static int
mps_wait_db_int(struct mps_softc *sc)
{
        int retry;

        for (retry = 0; retry < MPS_DB_MAX_WAIT; retry++) {
                if ((mps_regread(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET) &
                    MPI2_HIS_IOC2SYS_DB_STATUS) != 0)
                        return (0);
                DELAY(2000);
        }
        return (ETIMEDOUT);
}

/* Step through the synchronous command state machine, i.e. "Doorbell mode" */
static int
mps_request_sync(struct mps_softc *sc, void *req, MPI2_DEFAULT_REPLY *reply,
    int req_sz, int reply_sz, int timeout)
{
        uint32_t *data32;
        uint16_t *data16;
        int i, count, ioc_sz, residual;
        int sleep_flags = CAN_SLEEP;

        if (curthread->td_no_sleeping != 0)
                sleep_flags = NO_SLEEP;

        /* Step 1 */
        mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);

        /* Step 2 */
        if (mps_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_USED)
                return (EBUSY);

        /* Step 3
         * Announce that a message is coming through the doorbell.  Messages
         * are pushed at 32bit words, so round up if needed.
         */
        count = (req_sz + 3) / 4;
        mps_regwrite(sc, MPI2_DOORBELL_OFFSET,
            (MPI2_FUNCTION_HANDSHAKE << MPI2_DOORBELL_FUNCTION_SHIFT) |
            (count << MPI2_DOORBELL_ADD_DWORDS_SHIFT));

        /* Step 4 */
        if (mps_wait_db_int(sc) ||
            (mps_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_USED) == 0) {
                mps_dprint(sc, MPS_FAULT, "Doorbell failed to activate\n");
                return (ENXIO);
        }
        mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
        if (mps_wait_db_ack(sc, 5, sleep_flags) != 0) {
                mps_dprint(sc, MPS_FAULT, "Doorbell handshake failed\n");
                return (ENXIO);
        }

        /* Step 5 */
        /* Clock out the message data synchronously in 32-bit dwords*/
        data32 = (uint32_t *)req;
        for (i = 0; i < count; i++) {
                mps_regwrite(sc, MPI2_DOORBELL_OFFSET, htole32(data32[i]));
                if (mps_wait_db_ack(sc, 5, sleep_flags) != 0) {
                        mps_dprint(sc, MPS_FAULT,
                            "Timeout while writing doorbell\n");
                        return (ENXIO);
                }
        }

        /* Step 6 */
        /* Clock in the reply in 16-bit words.  The total length of the
         * message is always in the 4th byte, so clock out the first 2 words
         * manually, then loop the rest.
         */
        data16 = (uint16_t *)reply;
        if (mps_wait_db_int(sc) != 0) {
                mps_dprint(sc, MPS_FAULT, "Timeout reading doorbell 0\n");
                return (ENXIO);
        }
        data16[0] =
            mps_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_DATA_MASK;
        mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
        if (mps_wait_db_int(sc) != 0) {
                mps_dprint(sc, MPS_FAULT, "Timeout reading doorbell 1\n");
                return (ENXIO);
        }
        data16[1] =
            mps_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_DATA_MASK;
        mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);

        /* Number of 32bit words in the message */
        ioc_sz = reply->MsgLength;

        /*
         * Figure out how many 16bit words to clock in without overrunning.
         * The precision loss with dividing reply_sz can safely be
         * ignored because the messages can only be multiples of 32bits.
         */
        residual = 0;
        count = MIN((reply_sz / 4), ioc_sz) * 2;
        if (count < ioc_sz * 2) {
                residual = ioc_sz * 2 - count;
                mps_dprint(sc, MPS_ERROR, "Driver error, throwing away %d "
                    "residual message words\n", residual);
        }

        for (i = 2; i < count; i++) {
                if (mps_wait_db_int(sc) != 0) {
                        mps_dprint(sc, MPS_FAULT,
                            "Timeout reading doorbell %d\n", i);
                        return (ENXIO);
                }
                data16[i] = mps_regread(sc, MPI2_DOORBELL_OFFSET) &
                    MPI2_DOORBELL_DATA_MASK;
                mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
        }

        /*
         * Pull out residual words that won't fit into the provided buffer.
         * This keeps the chip from hanging due to a driver programming
         * error.
         */
        while (residual--) {
                if (mps_wait_db_int(sc) != 0) {
                        mps_dprint(sc, MPS_FAULT,
                            "Timeout reading doorbell\n");
                        return (ENXIO);
                }
                (void)mps_regread(sc, MPI2_DOORBELL_OFFSET);
                mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);
        }

        /* Step 7 */
        if (mps_wait_db_int(sc) != 0) {
                mps_dprint(sc, MPS_FAULT, "Timeout waiting to exit doorbell\n");
                return (ENXIO);
        }
        if (mps_regread(sc, MPI2_DOORBELL_OFFSET) & MPI2_DOORBELL_USED)
                mps_dprint(sc, MPS_FAULT, "Warning, doorbell still active\n");
        mps_regwrite(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET, 0x0);

        return (0);
}

static void
mps_enqueue_request(struct mps_softc *sc, struct mps_command *cm)
{
        request_descriptor_t rd;
        MPS_FUNCTRACE(sc);
        mps_dprint(sc, MPS_TRACE, "SMID %u cm %p ccb %p\n",
            cm->cm_desc.Default.SMID, cm, cm->cm_ccb);

        if (sc->mps_flags & MPS_FLAGS_ATTACH_DONE && !(sc->mps_flags & MPS_FLAGS_SHUTDOWN))
                mtx_assert(&sc->mps_mtx, MA_OWNED);

        if (++sc->io_cmds_active > sc->io_cmds_highwater)
                sc->io_cmds_highwater++;
        rd.u.low = cm->cm_desc.Words.Low;
        rd.u.high = cm->cm_desc.Words.High;
        rd.word = htole64(rd.word);

        KASSERT(cm->cm_state == MPS_CM_STATE_BUSY,
            ("command not busy, state = %u\n", cm->cm_state));
        cm->cm_state = MPS_CM_STATE_INQUEUE;

        /* TODO-We may need to make below regwrite atomic */
        mps_regwrite(sc, MPI2_REQUEST_DESCRIPTOR_POST_LOW_OFFSET,
            rd.u.low);
        mps_regwrite(sc, MPI2_REQUEST_DESCRIPTOR_POST_HIGH_OFFSET,
            rd.u.high);
}

/*
 * Just the FACTS, ma'am.
 */
static int
mps_get_iocfacts(struct mps_softc *sc, MPI2_IOC_FACTS_REPLY *facts)
{
        MPI2_DEFAULT_REPLY *reply;
        MPI2_IOC_FACTS_REQUEST request;
        int error, req_sz, reply_sz, retry = 0;

        MPS_FUNCTRACE(sc);
        mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);

        req_sz = sizeof(MPI2_IOC_FACTS_REQUEST);
        reply_sz = sizeof(MPI2_IOC_FACTS_REPLY);
        reply = (MPI2_DEFAULT_REPLY *)facts;

        /*
         * Retry sending the initialization sequence. Sometimes, especially with
         * older firmware, the initialization process fails. Retrying allows the
         * error to clear in the firmware.
         */
        bzero(&request, req_sz);
        request.Function = MPI2_FUNCTION_IOC_FACTS;
        while (retry < 5) {
                error = mps_request_sync(sc, &request, reply, req_sz, reply_sz, 5);
                if (error == 0)
                        break;
                mps_dprint(sc, MPS_FAULT, "%s failed retry %d\n", __func__, retry);
                DELAY(1000);
                retry++;
        }

        return (error);
}

static int
mps_send_iocinit(struct mps_softc *sc)
{
        MPI2_IOC_INIT_REQUEST   init;
        MPI2_DEFAULT_REPLY      reply;
        int req_sz, reply_sz, error, retry = 0;
        struct timeval now;
        uint64_t time_in_msec;

        MPS_FUNCTRACE(sc);
        mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);

        /* Do a quick sanity check on proper initialization */
        if ((sc->pqdepth == 0) || (sc->fqdepth == 0) || (sc->reqframesz == 0)
            || (sc->replyframesz == 0)) {
                mps_dprint(sc, MPS_INIT|MPS_ERROR,
                    "Driver not fully initialized for IOCInit\n");
                return (EINVAL);
        }

        req_sz = sizeof(MPI2_IOC_INIT_REQUEST);
        reply_sz = sizeof(MPI2_IOC_INIT_REPLY);
        bzero(&init, req_sz);
        bzero(&reply, reply_sz);

        /*
         * Fill in the init block.  Note that most addresses are
         * deliberately in the lower 32bits of memory.  This is a micro-
         * optimzation for PCI/PCIX, though it's not clear if it helps PCIe.
         */
        init.Function = MPI2_FUNCTION_IOC_INIT;
        init.WhoInit = MPI2_WHOINIT_HOST_DRIVER;
        init.MsgVersion = htole16(MPI2_VERSION);
        init.HeaderVersion = htole16(MPI2_HEADER_VERSION);
        init.SystemRequestFrameSize = htole16((uint16_t)(sc->reqframesz / 4));
        init.ReplyDescriptorPostQueueDepth = htole16(sc->pqdepth);
        init.ReplyFreeQueueDepth = htole16(sc->fqdepth);
        init.SenseBufferAddressHigh = 0;
        init.SystemReplyAddressHigh = 0;
        init.SystemRequestFrameBaseAddress.High = 0;
        init.SystemRequestFrameBaseAddress.Low = htole32((uint32_t)sc->req_busaddr);
        init.ReplyDescriptorPostQueueAddress.High = 0;
        init.ReplyDescriptorPostQueueAddress.Low = htole32((uint32_t)sc->post_busaddr);
        init.ReplyFreeQueueAddress.High = 0;
        init.ReplyFreeQueueAddress.Low = htole32((uint32_t)sc->free_busaddr);
        getmicrotime(&now);
        time_in_msec = (now.tv_sec * 1000 + now.tv_usec/1000);
        init.TimeStamp.High = htole32((time_in_msec >> 32) & 0xFFFFFFFF);
        init.TimeStamp.Low = htole32(time_in_msec & 0xFFFFFFFF);
        /*
         * Retry sending the initialization sequence. Sometimes, especially with
         * older firmware, the initialization process fails. Retrying allows the
         * error to clear in the firmware.
         */
        while (retry < 5) {
                error = mps_request_sync(sc, &init, &reply, req_sz, reply_sz, 5);
                if ((reply.IOCStatus & MPI2_IOCSTATUS_MASK) != MPI2_IOCSTATUS_SUCCESS)
                        error = ENXIO;
                if (error == 0)
                        break;
                mps_dprint(sc, MPS_FAULT, "%s failed retry %d\n", __func__, retry);
                DELAY(1000);
                retry++;
        }

        mps_dprint(sc, MPS_INIT, "IOCInit status= 0x%x\n", reply.IOCStatus);
        mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);
        return (error);
}

void
mps_memaddr_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
        bus_addr_t *addr;

        addr = arg;
        *addr = segs[0].ds_addr;
}

void
mps_memaddr_wait_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
        struct mps_busdma_context *ctx;
        int need_unload, need_free;

        ctx = (struct mps_busdma_context *)arg;
        need_unload = 0;
        need_free = 0;

        mps_lock(ctx->softc);
        ctx->error = error;
        ctx->completed = 1;
        if ((error == 0) && (ctx->abandoned == 0)) {
                *ctx->addr = segs[0].ds_addr;
        } else {
                if (nsegs != 0)
                        need_unload = 1;
                if (ctx->abandoned != 0)
                        need_free = 1;
        }
        if (need_free == 0)
                wakeup(ctx);

        mps_unlock(ctx->softc);

        if (need_unload != 0) {
                bus_dmamap_unload(ctx->buffer_dmat,
                                  ctx->buffer_dmamap);
                *ctx->addr = 0;
        }

        if (need_free != 0)
                free(ctx, M_MPSUSER);
}

static int
mps_alloc_queues(struct mps_softc *sc)
{
        struct mps_queue *q;
        u_int nq, i;

        nq = sc->msi_msgs;
        mps_dprint(sc, MPS_INIT|MPS_XINFO, "Allocating %d I/O queues\n", nq);

        sc->queues = malloc(sizeof(struct mps_queue) * nq, M_MPT2,
            M_NOWAIT|M_ZERO);
        if (sc->queues == NULL)
                return (ENOMEM);

        for (i = 0; i < nq; i++) {
                q = &sc->queues[i];
                mps_dprint(sc, MPS_INIT, "Configuring queue %d %p\n", i, q);
                q->sc = sc;
                q->qnum = i;
        }

        return (0);
}

static int
mps_alloc_hw_queues(struct mps_softc *sc)
{
        bus_dma_template_t t;
        bus_addr_t queues_busaddr;
        uint8_t *queues;
        int qsize, fqsize, pqsize;

        /*
         * The reply free queue contains 4 byte entries in multiples of 16 and
         * aligned on a 16 byte boundary. There must always be an unused entry.
         * This queue supplies fresh reply frames for the firmware to use.
         *
         * The reply descriptor post queue contains 8 byte entries in
         * multiples of 16 and aligned on a 16 byte boundary.  This queue
         * contains filled-in reply frames sent from the firmware to the host.
         *
         * These two queues are allocated together for simplicity.
         */
        sc->fqdepth = roundup2(sc->num_replies + 1, 16);
        sc->pqdepth = roundup2(sc->num_replies + 1, 16);
        fqsize= sc->fqdepth * 4;
        pqsize = sc->pqdepth * 8;
        qsize = fqsize + pqsize;

        bus_dma_template_init(&t, sc->mps_parent_dmat);
        BUS_DMA_TEMPLATE_FILL(&t, BD_ALIGNMENT(16), BD_MAXSIZE(qsize),
            BD_MAXSEGSIZE(qsize), BD_NSEGMENTS(1),
            BD_LOWADDR(BUS_SPACE_MAXADDR_32BIT));
        if (bus_dma_template_tag(&t, &sc->queues_dmat)) {
                mps_dprint(sc, MPS_ERROR, "Cannot allocate queues DMA tag\n");
                return (ENOMEM);
        }
        if (bus_dmamem_alloc(sc->queues_dmat, (void **)&queues, BUS_DMA_NOWAIT,
            &sc->queues_map)) {
                mps_dprint(sc, MPS_ERROR, "Cannot allocate queues memory\n");
                return (ENOMEM);
        }
        bzero(queues, qsize);
        bus_dmamap_load(sc->queues_dmat, sc->queues_map, queues, qsize,
            mps_memaddr_cb, &queues_busaddr, 0);

        sc->free_queue = (uint32_t *)queues;
        sc->free_busaddr = queues_busaddr;
        sc->post_queue = (MPI2_REPLY_DESCRIPTORS_UNION *)(queues + fqsize);
        sc->post_busaddr = queues_busaddr + fqsize;
        mps_dprint(sc, MPS_INIT, "free queue busaddr= %#016jx size= %d\n",
            (uintmax_t)sc->free_busaddr, fqsize);
        mps_dprint(sc, MPS_INIT, "reply queue busaddr= %#016jx size= %d\n",
            (uintmax_t)sc->post_busaddr, pqsize);

        return (0);
}

static int
mps_alloc_replies(struct mps_softc *sc)
{
        bus_dma_template_t t;
        int rsize, num_replies;

        /* Store the reply frame size in bytes rather than as 32bit words */
        sc->replyframesz = sc->facts->ReplyFrameSize * 4;

        /*
         * sc->num_replies should be one less than sc->fqdepth.  We need to
         * allocate space for sc->fqdepth replies, but only sc->num_replies
         * replies can be used at once.
         */
        num_replies = max(sc->fqdepth, sc->num_replies);

        rsize = sc->replyframesz * num_replies; 
        bus_dma_template_init(&t, sc->mps_parent_dmat);
        BUS_DMA_TEMPLATE_FILL(&t, BD_ALIGNMENT(4), BD_MAXSIZE(rsize),
            BD_MAXSEGSIZE(rsize), BD_NSEGMENTS(1),
            BD_LOWADDR(BUS_SPACE_MAXADDR_32BIT));
        if (bus_dma_template_tag(&t, &sc->reply_dmat)) {
                mps_dprint(sc, MPS_ERROR, "Cannot allocate replies DMA tag\n");
                return (ENOMEM);
        }
        if (bus_dmamem_alloc(sc->reply_dmat, (void **)&sc->reply_frames,
            BUS_DMA_NOWAIT, &sc->reply_map)) {
                mps_dprint(sc, MPS_ERROR, "Cannot allocate replies memory\n");
                return (ENOMEM);
        }
        bzero(sc->reply_frames, rsize);
        bus_dmamap_load(sc->reply_dmat, sc->reply_map, sc->reply_frames, rsize,
            mps_memaddr_cb, &sc->reply_busaddr, 0);

        mps_dprint(sc, MPS_INIT, "reply frames busaddr= %#016jx size= %d\n",
            (uintmax_t)sc->reply_busaddr, rsize);

        return (0);
}

static void
mps_load_chains_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
        struct mps_softc *sc = arg;
        struct mps_chain *chain;
        bus_size_t bo;
        int i, o, s;

        if (error != 0)
                return;

        for (i = 0, o = 0, s = 0; s < nsegs; s++) {
                KASSERT(segs[s].ds_addr + segs[s].ds_len - 1 <= BUS_SPACE_MAXADDR_32BIT,
                    ("mps: Bad segment address %#jx len %#jx\n", (uintmax_t)segs[s].ds_addr,
                        (uintmax_t)segs[s].ds_len));
                for (bo = 0; bo + sc->reqframesz <= segs[s].ds_len;
                    bo += sc->reqframesz) {
                        chain = &sc->chains[i++];
                        chain->chain =(MPI2_SGE_IO_UNION *)(sc->chain_frames+o);
                        chain->chain_busaddr = segs[s].ds_addr + bo;
                        o += sc->reqframesz;
                        mps_free_chain(sc, chain);
                }
                if (bo != segs[s].ds_len)
                        o += segs[s].ds_len - bo;
        }
        sc->chain_free_lowwater = i;
}

static int
mps_alloc_requests(struct mps_softc *sc)
{
        bus_dma_template_t t;
        struct mps_command *cm;
        int i, rsize, nsegs;

        rsize = sc->reqframesz * sc->num_reqs;
        bus_dma_template_init(&t, sc->mps_parent_dmat);
        BUS_DMA_TEMPLATE_FILL(&t, BD_ALIGNMENT(16), BD_MAXSIZE(rsize),
            BD_MAXSEGSIZE(rsize), BD_NSEGMENTS(1),
            BD_LOWADDR(BUS_SPACE_MAXADDR_32BIT));
        if (bus_dma_template_tag(&t, &sc->req_dmat)) {
                mps_dprint(sc, MPS_ERROR, "Cannot allocate request DMA tag\n");
                return (ENOMEM);
        }
        if (bus_dmamem_alloc(sc->req_dmat, (void **)&sc->req_frames,
            BUS_DMA_NOWAIT, &sc->req_map)) {
                mps_dprint(sc, MPS_ERROR, "Cannot allocate request memory\n");
                return (ENOMEM);
        }
        bzero(sc->req_frames, rsize);
        bus_dmamap_load(sc->req_dmat, sc->req_map, sc->req_frames, rsize,
            mps_memaddr_cb, &sc->req_busaddr, 0);
        mps_dprint(sc, MPS_INIT, "request frames busaddr= %#016jx size= %d\n",
            (uintmax_t)sc->req_busaddr, rsize);

        sc->chains = malloc(sizeof(struct mps_chain) * sc->num_chains, M_MPT2,
            M_NOWAIT | M_ZERO);
        if (!sc->chains) {
                mps_dprint(sc, MPS_ERROR, "Cannot allocate chain memory\n");
                return (ENOMEM);
        }
        rsize = sc->reqframesz * sc->num_chains;
        bus_dma_template_clone(&t, sc->req_dmat);
        BUS_DMA_TEMPLATE_FILL(&t, BD_MAXSIZE(rsize), BD_MAXSEGSIZE(rsize),
            BD_NSEGMENTS(howmany(rsize, PAGE_SIZE)),
            BD_BOUNDARY(BUS_SPACE_MAXSIZE_32BIT+1));
        if (bus_dma_template_tag(&t, &sc->chain_dmat)) {
                mps_dprint(sc, MPS_ERROR, "Cannot allocate chain DMA tag\n");
                return (ENOMEM);
        }
        if (bus_dmamem_alloc(sc->chain_dmat, (void **)&sc->chain_frames,
            BUS_DMA_NOWAIT | BUS_DMA_ZERO, &sc->chain_map)) {
                mps_dprint(sc, MPS_ERROR, "Cannot allocate chain memory\n");
                return (ENOMEM);
        }
        if (bus_dmamap_load(sc->chain_dmat, sc->chain_map, sc->chain_frames,
            rsize, mps_load_chains_cb, sc, BUS_DMA_NOWAIT)) {
                mps_dprint(sc, MPS_ERROR, "Cannot load chain memory\n");
                bus_dmamem_free(sc->chain_dmat, sc->chain_frames,
                    sc->chain_map);
                return (ENOMEM);
        }

        rsize = MPS_SENSE_LEN * sc->num_reqs;
        bus_dma_template_clone(&t, sc->req_dmat);
        BUS_DMA_TEMPLATE_FILL(&t, BD_ALIGNMENT(1), BD_MAXSIZE(rsize),
            BD_MAXSEGSIZE(rsize));
        if (bus_dma_template_tag(&t, &sc->sense_dmat)) {
                mps_dprint(sc, MPS_ERROR, "Cannot allocate sense DMA tag\n");
                return (ENOMEM);
        }
        if (bus_dmamem_alloc(sc->sense_dmat, (void **)&sc->sense_frames,
            BUS_DMA_NOWAIT, &sc->sense_map)) {
                mps_dprint(sc, MPS_ERROR, "Cannot allocate sense memory\n");
                return (ENOMEM);
        }
        bzero(sc->sense_frames, rsize);
        bus_dmamap_load(sc->sense_dmat, sc->sense_map, sc->sense_frames, rsize,
            mps_memaddr_cb, &sc->sense_busaddr, 0);
        mps_dprint(sc, MPS_INIT, "sense frames busaddr= %#016jx size= %d\n",
            (uintmax_t)sc->sense_busaddr, rsize);

        nsegs = (sc->maxio / PAGE_SIZE) + 1;
        bus_dma_template_init(&t, sc->mps_parent_dmat);
        BUS_DMA_TEMPLATE_FILL(&t, BD_MAXSIZE(BUS_SPACE_MAXSIZE_32BIT),
            BD_NSEGMENTS(nsegs), BD_MAXSEGSIZE(BUS_SPACE_MAXSIZE_24BIT),
            BD_FLAGS(BUS_DMA_ALLOCNOW), BD_LOCKFUNC(busdma_lock_mutex),
            BD_LOCKFUNCARG(&sc->mps_mtx),
            BD_BOUNDARY(BUS_SPACE_MAXSIZE_32BIT+1));
        if (bus_dma_template_tag(&t, &sc->buffer_dmat)) {
                mps_dprint(sc, MPS_ERROR, "Cannot allocate buffer DMA tag\n");
                return (ENOMEM);
        }

        /*
         * SMID 0 cannot be used as a free command per the firmware spec.
         * Just drop that command instead of risking accounting bugs.
         */
        sc->commands = malloc(sizeof(struct mps_command) * sc->num_reqs,
            M_MPT2, M_WAITOK | M_ZERO);
        for (i = 1; i < sc->num_reqs; i++) {
                cm = &sc->commands[i];
                cm->cm_req = sc->req_frames + i * sc->reqframesz;
                cm->cm_req_busaddr = sc->req_busaddr + i * sc->reqframesz;
                cm->cm_sense = &sc->sense_frames[i];
                cm->cm_sense_busaddr = sc->sense_busaddr + i * MPS_SENSE_LEN;
                cm->cm_desc.Default.SMID = i;
                cm->cm_sc = sc;
                cm->cm_state = MPS_CM_STATE_BUSY;
                TAILQ_INIT(&cm->cm_chain_list);
                callout_init_mtx(&cm->cm_callout, &sc->mps_mtx, 0);

                /* XXX Is a failure here a critical problem? */
                if (bus_dmamap_create(sc->buffer_dmat, 0, &cm->cm_dmamap) == 0)
                        if (i <= sc->num_prireqs)
                                mps_free_high_priority_command(sc, cm);
                        else
                                mps_free_command(sc, cm);
                else {
                        panic("failed to allocate command %d\n", i);
                        sc->num_reqs = i;
                        break;
                }
        }

        return (0);
}

static int
mps_init_queues(struct mps_softc *sc)
{
        int i;

        memset((uint8_t *)sc->post_queue, 0xff, sc->pqdepth * 8);

        /*
         * According to the spec, we need to use one less reply than we
         * have space for on the queue.  So sc->num_replies (the number we
         * use) should be less than sc->fqdepth (allocated size).
         */
        if (sc->num_replies >= sc->fqdepth)
                return (EINVAL);

        /*
         * Initialize all of the free queue entries.
         */
        for (i = 0; i < sc->fqdepth; i++)
                sc->free_queue[i] = sc->reply_busaddr + (i * sc->replyframesz);
        sc->replyfreeindex = sc->num_replies;

        return (0);
}

/* Get the driver parameter tunables.  Lowest priority are the driver defaults.
 * Next are the global settings, if they exist.  Highest are the per-unit
 * settings, if they exist.
 */
void
mps_get_tunables(struct mps_softc *sc)
{
        char tmpstr[80], mps_debug[80];

        /* XXX default to some debugging for now */
        sc->mps_debug = MPS_INFO|MPS_FAULT;
        sc->disable_msix = 0;
        sc->disable_msi = 0;
        sc->max_msix = MPS_MSIX_MAX;
        sc->max_chains = MPS_CHAIN_FRAMES;
        sc->max_io_pages = MPS_MAXIO_PAGES;
        sc->enable_ssu = MPS_SSU_ENABLE_SSD_DISABLE_HDD;
        sc->spinup_wait_time = DEFAULT_SPINUP_WAIT;
        sc->use_phynum = 1;
        sc->max_reqframes = MPS_REQ_FRAMES;
        sc->max_prireqframes = MPS_PRI_REQ_FRAMES;
        sc->max_replyframes = MPS_REPLY_FRAMES;
        sc->max_evtframes = MPS_EVT_REPLY_FRAMES;

        /*
         * Grab the global variables.
         */
        bzero(mps_debug, 80);
        if (TUNABLE_STR_FETCH("hw.mps.debug_level", mps_debug, 80) != 0)
                mps_parse_debug(sc, mps_debug);
        TUNABLE_INT_FETCH("hw.mps.disable_msix", &sc->disable_msix);
        TUNABLE_INT_FETCH("hw.mps.disable_msi", &sc->disable_msi);
        TUNABLE_INT_FETCH("hw.mps.max_msix", &sc->max_msix);
        TUNABLE_INT_FETCH("hw.mps.max_chains", &sc->max_chains);
        TUNABLE_INT_FETCH("hw.mps.max_io_pages", &sc->max_io_pages);
        TUNABLE_INT_FETCH("hw.mps.enable_ssu", &sc->enable_ssu);
        TUNABLE_INT_FETCH("hw.mps.spinup_wait_time", &sc->spinup_wait_time);
        TUNABLE_INT_FETCH("hw.mps.use_phy_num", &sc->use_phynum);
        TUNABLE_INT_FETCH("hw.mps.max_reqframes", &sc->max_reqframes);
        TUNABLE_INT_FETCH("hw.mps.max_prireqframes", &sc->max_prireqframes);
        TUNABLE_INT_FETCH("hw.mps.max_replyframes", &sc->max_replyframes);
        TUNABLE_INT_FETCH("hw.mps.max_evtframes", &sc->max_evtframes);

        /* Grab the unit-instance variables */
        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.debug_level",
            device_get_unit(sc->mps_dev));
        bzero(mps_debug, 80);
        if (TUNABLE_STR_FETCH(tmpstr, mps_debug, 80) != 0)
                mps_parse_debug(sc, mps_debug);

        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.disable_msix",
            device_get_unit(sc->mps_dev));
        TUNABLE_INT_FETCH(tmpstr, &sc->disable_msix);

        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.disable_msi",
            device_get_unit(sc->mps_dev));
        TUNABLE_INT_FETCH(tmpstr, &sc->disable_msi);

        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_msix",
            device_get_unit(sc->mps_dev));
        TUNABLE_INT_FETCH(tmpstr, &sc->max_msix);

        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_chains",
            device_get_unit(sc->mps_dev));
        TUNABLE_INT_FETCH(tmpstr, &sc->max_chains);

        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_io_pages",
            device_get_unit(sc->mps_dev));
        TUNABLE_INT_FETCH(tmpstr, &sc->max_io_pages);

        bzero(sc->exclude_ids, sizeof(sc->exclude_ids));
        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.exclude_ids",
            device_get_unit(sc->mps_dev));
        TUNABLE_STR_FETCH(tmpstr, sc->exclude_ids, sizeof(sc->exclude_ids));

        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.enable_ssu",
            device_get_unit(sc->mps_dev));
        TUNABLE_INT_FETCH(tmpstr, &sc->enable_ssu);

        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.spinup_wait_time",
            device_get_unit(sc->mps_dev));
        TUNABLE_INT_FETCH(tmpstr, &sc->spinup_wait_time);

        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.use_phy_num",
            device_get_unit(sc->mps_dev));
        TUNABLE_INT_FETCH(tmpstr, &sc->use_phynum);

        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_reqframes",
            device_get_unit(sc->mps_dev));
        TUNABLE_INT_FETCH(tmpstr, &sc->max_reqframes);

        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_prireqframes",
            device_get_unit(sc->mps_dev));
        TUNABLE_INT_FETCH(tmpstr, &sc->max_prireqframes);

        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_replyframes",
            device_get_unit(sc->mps_dev));
        TUNABLE_INT_FETCH(tmpstr, &sc->max_replyframes);

        snprintf(tmpstr, sizeof(tmpstr), "dev.mps.%d.max_evtframes",
            device_get_unit(sc->mps_dev));
        TUNABLE_INT_FETCH(tmpstr, &sc->max_evtframes);

}

static void
mps_setup_sysctl(struct mps_softc *sc)
{
        struct sysctl_ctx_list  *sysctl_ctx = NULL;
        struct sysctl_oid       *sysctl_tree = NULL;
        char tmpstr[80], tmpstr2[80];

        /*
         * Setup the sysctl variable so the user can change the debug level
         * on the fly.
         */
        snprintf(tmpstr, sizeof(tmpstr), "MPS controller %d",
            device_get_unit(sc->mps_dev));
        snprintf(tmpstr2, sizeof(tmpstr2), "%d", device_get_unit(sc->mps_dev));

        sysctl_ctx = device_get_sysctl_ctx(sc->mps_dev);
        if (sysctl_ctx != NULL)
                sysctl_tree = device_get_sysctl_tree(sc->mps_dev);

        if (sysctl_tree == NULL) {
                sysctl_ctx_init(&sc->sysctl_ctx);
                sc->sysctl_tree = SYSCTL_ADD_NODE(&sc->sysctl_ctx,
                    SYSCTL_STATIC_CHILDREN(_hw_mps), OID_AUTO, tmpstr2,
                    CTLFLAG_RD | CTLFLAG_MPSAFE, 0, tmpstr);
                if (sc->sysctl_tree == NULL)
                        return;
                sysctl_ctx = &sc->sysctl_ctx;
                sysctl_tree = sc->sysctl_tree;
        }

        SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "debug_level", CTLTYPE_STRING | CTLFLAG_RW |CTLFLAG_MPSAFE,
            sc, 0, mps_debug_sysctl, "A", "mps debug level");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "disable_msix", CTLFLAG_RD, &sc->disable_msix, 0,
            "Disable the use of MSI-X interrupts");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "disable_msi", CTLFLAG_RD, &sc->disable_msi, 0,
            "Disable the use of MSI interrupts");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "max_msix", CTLFLAG_RD, &sc->max_msix, 0,
            "User-defined maximum number of MSIX queues");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "msix_msgs", CTLFLAG_RD, &sc->msi_msgs, 0,
            "Negotiated number of MSIX queues");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "max_reqframes", CTLFLAG_RD, &sc->max_reqframes, 0,
            "Total number of allocated request frames");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "max_prireqframes", CTLFLAG_RD, &sc->max_prireqframes, 0,
            "Total number of allocated high priority request frames");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "max_replyframes", CTLFLAG_RD, &sc->max_replyframes, 0,
            "Total number of allocated reply frames");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "max_evtframes", CTLFLAG_RD, &sc->max_evtframes, 0,
            "Total number of event frames allocated");

        SYSCTL_ADD_STRING(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "firmware_version", CTLFLAG_RD, sc->fw_version,
            strlen(sc->fw_version), "firmware version");

        SYSCTL_ADD_STRING(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "driver_version", CTLFLAG_RD, MPS_DRIVER_VERSION,
            strlen(MPS_DRIVER_VERSION), "driver version");

        SYSCTL_ADD_STRING(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "msg_version", CTLFLAG_RD, sc->msg_version,
            strlen(sc->msg_version), "message interface version (deprecated)");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "io_cmds_active", CTLFLAG_RD,
            &sc->io_cmds_active, 0, "number of currently active commands");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "io_cmds_highwater", CTLFLAG_RD,
            &sc->io_cmds_highwater, 0, "maximum active commands seen");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "chain_free", CTLFLAG_RD,
            &sc->chain_free, 0, "number of free chain elements");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "chain_free_lowwater", CTLFLAG_RD,
            &sc->chain_free_lowwater, 0,"lowest number of free chain elements");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "max_chains", CTLFLAG_RD,
            &sc->max_chains, 0,"maximum chain frames that will be allocated");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "max_io_pages", CTLFLAG_RD,
            &sc->max_io_pages, 0,"maximum pages to allow per I/O (if <1 use "
            "IOCFacts)");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "enable_ssu", CTLFLAG_RW, &sc->enable_ssu, 0,
            "enable SSU to SATA SSD/HDD at shutdown");

        SYSCTL_ADD_UQUAD(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "chain_alloc_fail", CTLFLAG_RD,
            &sc->chain_alloc_fail, "chain allocation failures");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "spinup_wait_time", CTLFLAG_RD,
            &sc->spinup_wait_time, DEFAULT_SPINUP_WAIT, "seconds to wait for "
            "spinup after SATA ID error");

        SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "mapping_table_dump",
            CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, sc, 0,
            mps_mapping_dump, "A", "Mapping Table Dump");

        SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "encl_table_dump",
            CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, sc, 0,
            mps_mapping_encl_dump, "A", "Enclosure Table Dump");

        SYSCTL_ADD_PROC(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "dump_reqs",
            CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_SKIP | CTLFLAG_MPSAFE,
            sc, 0, mps_dump_reqs, "I", "Dump Active Requests");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "dump_reqs_alltypes", CTLFLAG_RW,
            &sc->dump_reqs_alltypes, 0,
            "dump all request types not just inqueue");

        SYSCTL_ADD_INT(sysctl_ctx, SYSCTL_CHILDREN(sysctl_tree),
            OID_AUTO, "use_phy_num", CTLFLAG_RD, &sc->use_phynum, 0,
            "Use the phy number for enumeration");
}

static struct mps_debug_string {
        char    *name;
        int     flag;
} mps_debug_strings[] = {
        {"info", MPS_INFO},
        {"fault", MPS_FAULT},
        {"event", MPS_EVENT},
        {"log", MPS_LOG},
        {"recovery", MPS_RECOVERY},
        {"error", MPS_ERROR},
        {"init", MPS_INIT},
        {"xinfo", MPS_XINFO},
        {"user", MPS_USER},
        {"mapping", MPS_MAPPING},
        {"trace", MPS_TRACE}
};

enum mps_debug_level_combiner {
        COMB_NONE,
        COMB_ADD,
        COMB_SUB
};

static int
mps_debug_sysctl(SYSCTL_HANDLER_ARGS)
{
        struct mps_softc *sc;
        struct mps_debug_string *string;
        struct sbuf *sbuf;
        char *buffer;
        size_t sz;
        int i, len, debug, error;

        sc = (struct mps_softc *)arg1;

        error = sysctl_wire_old_buffer(req, 0);
        if (error != 0)
                return (error);

        sbuf = sbuf_new_for_sysctl(NULL, NULL, 128, req);
        debug = sc->mps_debug;

        sbuf_printf(sbuf, "%#x", debug);

        sz = sizeof(mps_debug_strings) / sizeof(mps_debug_strings[0]);
        for (i = 0; i < sz; i++) {
                string = &mps_debug_strings[i];
                if (debug & string->flag)
                        sbuf_printf(sbuf, ",%s", string->name);
        }

        error = sbuf_finish(sbuf);
        sbuf_delete(sbuf);

        if (error || req->newptr == NULL)
                return (error);

        len = req->newlen - req->newidx;
        if (len == 0)
                return (0);

        buffer = malloc(len, M_MPT2, M_ZERO|M_WAITOK);
        error = SYSCTL_IN(req, buffer, len);

        mps_parse_debug(sc, buffer);

        free(buffer, M_MPT2);
        return (error);
}

static void
mps_parse_debug(struct mps_softc *sc, char *list)
{
        struct mps_debug_string *string;
        enum mps_debug_level_combiner op;
        char *token, *endtoken;
        size_t sz;
        int flags, i;

        if (list == NULL || *list == '\0')
                return;

        if (*list == '+') {
                op = COMB_ADD;
                list++;
        } else if (*list == '-') {
                op = COMB_SUB;
                list++;
        } else
                op = COMB_NONE;
        if (*list == '\0')
                return;

        flags = 0;
        sz = sizeof(mps_debug_strings) / sizeof(mps_debug_strings[0]);
        while ((token = strsep(&list, ":,")) != NULL) {
                /* Handle integer flags */
                flags |= strtol(token, &endtoken, 0);
                if (token != endtoken)
                        continue;

                /* Handle text flags */
                for (i = 0; i < sz; i++) {
                        string = &mps_debug_strings[i];
                        if (strcasecmp(token, string->name) == 0) {
                                flags |= string->flag;
                                break;
                        }
                }
        }

        switch (op) {
        case COMB_NONE:
                sc->mps_debug = flags;
                break;
        case COMB_ADD:
                sc->mps_debug |= flags;
                break;
        case COMB_SUB:
                sc->mps_debug &= (~flags);
                break;
        }

        return;
}

struct mps_dumpreq_hdr {
        uint32_t        smid;
        uint32_t        state;
        uint32_t        numframes;
        uint32_t        deschi;
        uint32_t        desclo;
};

static int
mps_dump_reqs(SYSCTL_HANDLER_ARGS)
{
        struct mps_softc *sc;
        struct mps_chain *chain, *chain1;
        struct mps_command *cm;
        struct mps_dumpreq_hdr hdr;
        struct sbuf *sb;
        uint32_t smid, state;
        int i, numreqs, error = 0;

        sc = (struct mps_softc *)arg1;

        if ((error = priv_check(curthread, PRIV_DRIVER)) != 0) {
                printf("priv check error %d\n", error);
                return (error);
        }

        state = MPS_CM_STATE_INQUEUE;
        smid = 1;
        numreqs = sc->num_reqs;

        if (req->newptr != NULL)
                return (EINVAL);

        if (smid == 0 || smid > sc->num_reqs)
                return (EINVAL);
        if (numreqs <= 0 || (numreqs + smid > sc->num_reqs))
                numreqs = sc->num_reqs;
        sb = sbuf_new_for_sysctl(NULL, NULL, 4096, req);

        /* Best effort, no locking */
        for (i = smid; i < numreqs; i++) {
                cm = &sc->commands[i];
                if ((sc->dump_reqs_alltypes == 0) && (cm->cm_state != state))
                        continue;
                hdr.smid = i;
                hdr.state = cm->cm_state;
                hdr.numframes = 1;
                hdr.deschi = cm->cm_desc.Words.High;
                hdr.desclo = cm->cm_desc.Words.Low;
                TAILQ_FOREACH_SAFE(chain, &cm->cm_chain_list, chain_link,
                   chain1)
                        hdr.numframes++;
                sbuf_bcat(sb, &hdr, sizeof(hdr));
                sbuf_bcat(sb, cm->cm_req, 128);
                TAILQ_FOREACH_SAFE(chain, &cm->cm_chain_list, chain_link,
                    chain1)
                        sbuf_bcat(sb, chain->chain, 128);
        }

        error = sbuf_finish(sb);
        sbuf_delete(sb);
        return (error);
}

int
mps_attach(struct mps_softc *sc)
{
        int error;

        MPS_FUNCTRACE(sc);
        mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);

        mtx_init(&sc->mps_mtx, "MPT2SAS lock", NULL, MTX_DEF);
        callout_init_mtx(&sc->periodic, &sc->mps_mtx, 0);
        callout_init_mtx(&sc->device_check_callout, &sc->mps_mtx, 0);
        TAILQ_INIT(&sc->event_list);
        timevalclear(&sc->lastfail);

        if ((error = mps_transition_ready(sc)) != 0) {
                mps_dprint(sc, MPS_INIT|MPS_FAULT, "failed to transition "
                    "ready\n");
                return (error);
        }

        sc->facts = malloc(sizeof(MPI2_IOC_FACTS_REPLY), M_MPT2,
            M_ZERO|M_NOWAIT);
        if(!sc->facts) {
                mps_dprint(sc, MPS_INIT|MPS_FAULT, "Cannot allocate memory, "
                    "exit\n");
                return (ENOMEM);
        }

        /*
         * Get IOC Facts and allocate all structures based on this information.
         * A Diag Reset will also call mps_iocfacts_allocate and re-read the IOC
         * Facts. If relevant values have changed in IOC Facts, this function
         * will free all of the memory based on IOC Facts and reallocate that
         * memory.  If this fails, any allocated memory should already be freed.
         */
        if ((error = mps_iocfacts_allocate(sc, TRUE)) != 0) {
                mps_dprint(sc, MPS_INIT|MPS_FAULT, "IOC Facts based allocation "
                    "failed with error %d, exit\n", error);
                return (error);
        }

        /* Start the periodic watchdog check on the IOC Doorbell */
        mps_periodic(sc);

        /*
         * The portenable will kick off discovery events that will drive the
         * rest of the initialization process.  The CAM/SAS module will
         * hold up the boot sequence until discovery is complete.
         */
        sc->mps_ich.ich_func = mps_startup;
        sc->mps_ich.ich_arg = sc;
        if (config_intrhook_establish(&sc->mps_ich) != 0) {
                mps_dprint(sc, MPS_INIT|MPS_ERROR,
                    "Cannot establish MPS config hook\n");
                error = EINVAL;
        }

        /*
         * Allow IR to shutdown gracefully when shutdown occurs.
         */
        sc->shutdown_eh = EVENTHANDLER_REGISTER(shutdown_final,
            mpssas_ir_shutdown, sc, SHUTDOWN_PRI_DEFAULT);

        if (sc->shutdown_eh == NULL)
                mps_dprint(sc, MPS_INIT|MPS_ERROR,
                    "shutdown event registration failed\n");

        mps_setup_sysctl(sc);

        sc->mps_flags |= MPS_FLAGS_ATTACH_DONE;
        mps_dprint(sc, MPS_INIT, "%s exit error= %d\n", __func__, error);

        return (error);
}

/* Run through any late-start handlers. */
static void
mps_startup(void *arg)
{
        struct mps_softc *sc;

        sc = (struct mps_softc *)arg;
        mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);

        mps_lock(sc);
        mps_unmask_intr(sc);

        /* initialize device mapping tables */
        mps_base_static_config_pages(sc);
        mps_mapping_initialize(sc);
        mpssas_startup(sc);
        mps_unlock(sc);

        mps_dprint(sc, MPS_INIT, "disestablish config intrhook\n");
        config_intrhook_disestablish(&sc->mps_ich);
        sc->mps_ich.ich_arg = NULL;

        mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);
}

/* Periodic watchdog.  Is called with the driver lock already held. */
static void
mps_periodic(void *arg)
{
        struct mps_softc *sc;
        uint32_t db;

        sc = (struct mps_softc *)arg;
        if (sc->mps_flags & MPS_FLAGS_SHUTDOWN)
                return;

        db = mps_regread(sc, MPI2_DOORBELL_OFFSET);
        if ((db & MPI2_IOC_STATE_MASK) == MPI2_IOC_STATE_FAULT) {
                mps_dprint(sc, MPS_FAULT, "IOC Fault 0x%08x, Resetting\n", db);
                mps_reinit(sc);
        }

        callout_reset_sbt(&sc->periodic, MPS_PERIODIC_DELAY * SBT_1S, 0,
            mps_periodic, sc, C_PREL(1));
}

static void
mps_log_evt_handler(struct mps_softc *sc, uintptr_t data,
    MPI2_EVENT_NOTIFICATION_REPLY *event)
{
        MPI2_EVENT_DATA_LOG_ENTRY_ADDED *entry;

        MPS_DPRINT_EVENT(sc, generic, event);

        switch (event->Event) {
        case MPI2_EVENT_LOG_DATA:
                mps_dprint(sc, MPS_EVENT, "MPI2_EVENT_LOG_DATA:\n");
                if (sc->mps_debug & MPS_EVENT)
                        hexdump(event->EventData, event->EventDataLength, NULL, 0);
                break;
        case MPI2_EVENT_LOG_ENTRY_ADDED:
                entry = (MPI2_EVENT_DATA_LOG_ENTRY_ADDED *)event->EventData;
                mps_dprint(sc, MPS_EVENT, "MPI2_EVENT_LOG_ENTRY_ADDED event "
                    "0x%x Sequence %d:\n", entry->LogEntryQualifier,
                     entry->LogSequence);
                break;
        default:
                break;
        }
        return;
}

static int
mps_attach_log(struct mps_softc *sc)
{
        u32 events[MPI2_EVENT_NOTIFY_EVENTMASK_WORDS];

        bzero(events, 16);
        setbit(events, MPI2_EVENT_LOG_DATA);
        setbit(events, MPI2_EVENT_LOG_ENTRY_ADDED);

        mps_register_events(sc, events, mps_log_evt_handler, NULL,
            &sc->mps_log_eh);

        return (0);
}

static int
mps_detach_log(struct mps_softc *sc)
{

        if (sc->mps_log_eh != NULL)
                mps_deregister_events(sc, sc->mps_log_eh);
        return (0);
}

/*
 * Free all of the driver resources and detach submodules.  Should be called
 * without the lock held.
 */
int
mps_free(struct mps_softc *sc)
{
        int error;

        mps_dprint(sc, MPS_INIT, "%s entered\n", __func__);
        /* Turn off the watchdog */
        mps_lock(sc);
        sc->mps_flags |= MPS_FLAGS_SHUTDOWN;
        mps_unlock(sc);
        /* Lock must not be held for this */
        callout_drain(&sc->periodic);
        callout_drain(&sc->device_check_callout);

        if (((error = mps_detach_log(sc)) != 0) ||
            ((error = mps_detach_sas(sc)) != 0)) {
                mps_dprint(sc, MPS_INIT|MPS_FAULT, "failed to detach "
                    "subsystems, exit\n");
                return (error);
        }

        mps_detach_user(sc);

        /* Put the IOC back in the READY state. */
        mps_lock(sc);
        if ((error = mps_transition_ready(sc)) != 0) {
                mps_unlock(sc);
                return (error);
        }
        mps_unlock(sc);

        if (sc->facts != NULL)
                free(sc->facts, M_MPT2);

        /*
         * Free all buffers that are based on IOC Facts.  A Diag Reset may need
         * to free these buffers too.
         */
        mps_iocfacts_free(sc);

        if (sc->sysctl_tree != NULL)
                sysctl_ctx_free(&sc->sysctl_ctx);

        /* Deregister the shutdown function */
        if (sc->shutdown_eh != NULL)
                EVENTHANDLER_DEREGISTER(shutdown_final, sc->shutdown_eh);

        mtx_destroy(&sc->mps_mtx);
        mps_dprint(sc, MPS_INIT, "%s exit\n", __func__);

        return (0);
}

static __inline void
mps_complete_command(struct mps_softc *sc, struct mps_command *cm)
{
        MPS_FUNCTRACE(sc);

        if (cm == NULL) {
                mps_dprint(sc, MPS_ERROR, "Completing NULL command\n");
                return;
        }

        KASSERT(cm->cm_state == MPS_CM_STATE_INQUEUE,
            ("command not inqueue, state = %u\n", cm->cm_state));
        cm->cm_state = MPS_CM_STATE_BUSY; 
        if (cm->cm_flags & MPS_CM_FLAGS_POLLED)
                cm->cm_flags |= MPS_CM_FLAGS_COMPLETE;

        if (cm->cm_complete != NULL) {
                mps_dprint(sc, MPS_TRACE,
                           "%s cm %p calling cm_complete %p data %p reply %p\n",
                           __func__, cm, cm->cm_complete, cm->cm_complete_data,
                           cm->cm_reply);
                cm->cm_complete(sc, cm);
        }

        if (cm->cm_flags & MPS_CM_FLAGS_WAKEUP) {
                mps_dprint(sc, MPS_TRACE, "waking up %p\n", cm);
                wakeup(cm);
        }

        if (cm->cm_sc->io_cmds_active != 0) {
                cm->cm_sc->io_cmds_active--;
        } else {
                mps_dprint(sc, MPS_ERROR, "Warning: io_cmds_active is "
                    "out of sync - resynching to 0\n");
        }
}

static void
mps_sas_log_info(struct mps_softc *sc , u32 log_info)
{
        union loginfo_type {
                u32     loginfo;
                struct {
                        u32     subcode:16;
                        u32     code:8;
                        u32     originator:4;
                        u32     bus_type:4;
                } dw;
        };
        union loginfo_type sas_loginfo;
        char *originator_str = NULL;

        sas_loginfo.loginfo = log_info;
        if (sas_loginfo.dw.bus_type != 3 /*SAS*/)
                return;

        /* each nexus loss loginfo */
        if (log_info == 0x31170000)
                return;

        /* eat the loginfos associated with task aborts */
        if ((log_info == 30050000 || log_info ==
            0x31140000 || log_info == 0x31130000))
                return;

        switch (sas_loginfo.dw.originator) {
        case 0:
                originator_str = "IOP";
                break;
        case 1:
                originator_str = "PL";
                break;
        case 2:
                originator_str = "IR";
                break;
}

        mps_dprint(sc, MPS_LOG, "log_info(0x%08x): originator(%s), "
        "code(0x%02x), sub_code(0x%04x)\n", log_info,
        originator_str, sas_loginfo.dw.code,
        sas_loginfo.dw.subcode);
}

static void
mps_display_reply_info(struct mps_softc *sc, uint8_t *reply)
{
        MPI2DefaultReply_t *mpi_reply;
        u16 sc_status;

        mpi_reply = (MPI2DefaultReply_t*)reply;
        sc_status = le16toh(mpi_reply->IOCStatus);
        if (sc_status & MPI2_IOCSTATUS_FLAG_LOG_INFO_AVAILABLE)
                mps_sas_log_info(sc, le32toh(mpi_reply->IOCLogInfo));
}
void
mps_intr(void *data)
{
        struct mps_softc *sc;
        uint32_t status;

        sc = (struct mps_softc *)data;
        mps_dprint(sc, MPS_TRACE, "%s\n", __func__);

        /*
         * Check interrupt status register to flush the bus.  This is
         * needed for both INTx interrupts and driver-driven polling
         */
        status = mps_regread(sc, MPI2_HOST_INTERRUPT_STATUS_OFFSET);
        if ((status & MPI2_HIS_REPLY_DESCRIPTOR_INTERRUPT) == 0)
                return;

        mps_lock(sc);
        mps_intr_locked(data);
        mps_unlock(sc);
        return;
}

/*
 * In theory, MSI/MSIX interrupts shouldn't need to read any registers on the
 * chip.  Hopefully this theory is correct.
 */
void
mps_intr_msi(void *data)
{
        struct mps_softc *sc;

        sc = (struct mps_softc *)data;
        mps_dprint(sc, MPS_TRACE, "%s\n", __func__);
        mps_lock(sc);
        mps_intr_locked(data);
        mps_unlock(sc);
        return;
}

/*
 * The locking is overly broad and simplistic, but easy to deal with for now.
 */
void
mps_intr_locked(void *data)
{
        MPI2_REPLY_DESCRIPTORS_UNION *desc;
        MPI2_DIAG_RELEASE_REPLY *rel_rep;
        mps_fw_diagnostic_buffer_t *pBuffer;
        struct mps_softc *sc;
        struct mps_command *cm = NULL;
        uint64_t tdesc;
        uint8_t flags;
        u_int pq;

        sc = (struct mps_softc *)data;

        pq = sc->replypostindex;
        mps_dprint(sc, MPS_TRACE,
            "%s sc %p starting with replypostindex %u\n", 
            __func__, sc, sc->replypostindex);

        for ( ;; ) {
                cm = NULL;
                desc = &sc->post_queue[sc->replypostindex];

                /*
                 * Copy and clear out the descriptor so that any reentry will
                 * immediately know that this descriptor has already been
                 * looked at.  There is unfortunate casting magic because the
                 * MPI API doesn't have a cardinal 64bit type.
                 */
                tdesc = 0xffffffffffffffff;
                tdesc = atomic_swap_64((uint64_t *)desc, tdesc);
                desc = (MPI2_REPLY_DESCRIPTORS_UNION *)&tdesc;

                flags = desc->Default.ReplyFlags &
                    MPI2_RPY_DESCRIPT_FLAGS_TYPE_MASK;
                if ((flags == MPI2_RPY_DESCRIPT_FLAGS_UNUSED)
                 || (le32toh(desc->Words.High) == 0xffffffff))
                        break;

                /* increment the replypostindex now, so that event handlers
                 * and cm completion handlers which decide to do a diag
                 * reset can zero it without it getting incremented again
                 * afterwards, and we break out of this loop on the next
                 * iteration since the reply post queue has been cleared to
                 * 0xFF and all descriptors look unused (which they are).
                 */
                if (++sc->replypostindex >= sc->pqdepth)
                        sc->replypostindex = 0;

                switch (flags) {
                case MPI2_RPY_DESCRIPT_FLAGS_SCSI_IO_SUCCESS:
                        cm = &sc->commands[le16toh(desc->SCSIIOSuccess.SMID)];
                        cm->cm_reply = NULL;
                        break;
                case MPI2_RPY_DESCRIPT_FLAGS_ADDRESS_REPLY:
                {
                        uint32_t baddr;
                        uint8_t *reply;

                        /*
                         * Re-compose the reply address from the address
                         * sent back from the chip.  The ReplyFrameAddress
                         * is the lower 32 bits of the physical address of
                         * particular reply frame.  Convert that address to
                         * host format, and then use that to provide the
                         * offset against the virtual address base
                         * (sc->reply_frames).
                         */
                        baddr = le32toh(desc->AddressReply.ReplyFrameAddress);
                        reply = sc->reply_frames +
                                (baddr - ((uint32_t)sc->reply_busaddr));
                        /*
                         * Make sure the reply we got back is in a valid
                         * range.  If not, go ahead and panic here, since
                         * we'll probably panic as soon as we deference the
                         * reply pointer anyway.
                         */
                        if ((reply < sc->reply_frames)
                         || (reply > (sc->reply_frames +
                             (sc->fqdepth * sc->replyframesz)))) {
                                printf("%s: WARNING: reply %p out of range!\n",
                                       __func__, reply);
                                printf("%s: reply_frames %p, fqdepth %d, "
                                       "frame size %d\n", __func__,
                                       sc->reply_frames, sc->fqdepth,
                                       sc->replyframesz);
                                printf("%s: baddr %#x,\n", __func__, baddr);
                                /* LSI-TODO. See Linux Code for Graceful exit */
                                panic("Reply address out of range");
                        }
                        if (le16toh(desc->AddressReply.SMID) == 0) {
                                if (((MPI2_DEFAULT_REPLY *)reply)->Function ==
                                    MPI2_FUNCTION_DIAG_BUFFER_POST) {
                                        /*
                                         * If SMID is 0 for Diag Buffer Post,
                                         * this implies that the reply is due to
                                         * a release function with a status that
                                         * the buffer has been released.  Set
                                         * the buffer flags accordingly.
                                         */
                                        rel_rep =
                                            (MPI2_DIAG_RELEASE_REPLY *)reply;
                                        if ((le16toh(rel_rep->IOCStatus) &
                                            MPI2_IOCSTATUS_MASK) ==
                                            MPI2_IOCSTATUS_DIAGNOSTIC_RELEASED)
                                        {
                                                pBuffer =
                                                    &sc->fw_diag_buffer_list[
                                                    rel_rep->BufferType];
                                                pBuffer->valid_data = TRUE;
                                                pBuffer->owned_by_firmware =
                                                    FALSE;
                                                pBuffer->immediate = FALSE;
                                        }
                                } else
                                        mps_dispatch_event(sc, baddr,
                                            (MPI2_EVENT_NOTIFICATION_REPLY *)
                                            reply);
                        } else {
                                /*
                                 * Ignore commands not in INQUEUE state
                                 * since they've already been completed
                                 * via another path.
                                 */
                                cm = &sc->commands[
                                    le16toh(desc->AddressReply.SMID)];
                                if (cm->cm_state == MPS_CM_STATE_INQUEUE) {
                                        cm->cm_reply = reply;
                                        cm->cm_reply_data = le32toh(
                                            desc->AddressReply.ReplyFrameAddress);
                                } else {
                                        mps_dprint(sc, MPS_RECOVERY,
                                            "Bad state for ADDRESS_REPLY status,"
                                            " ignoring state %d cm %p\n",
                                            cm->cm_state, cm);
                                }
                        }
                        break;
                }
                case MPI2_RPY_DESCRIPT_FLAGS_TARGETASSIST_SUCCESS:
                case MPI2_RPY_DESCRIPT_FLAGS_TARGET_COMMAND_BUFFER:
                case MPI2_RPY_DESCRIPT_FLAGS_RAID_ACCELERATOR_SUCCESS:
                default:
                        /* Unhandled */
                        mps_dprint(sc, MPS_ERROR, "Unhandled reply 0x%x\n",
                            desc->Default.ReplyFlags);
                        cm = NULL;
                        break;
                }
                

                if (cm != NULL) {
                        // Print Error reply frame
                        if (cm->cm_reply)
                                mps_display_reply_info(sc,cm->cm_reply);
                        mps_complete_command(sc, cm);
                }
        }

        if (pq != sc->replypostindex) {
                mps_dprint(sc, MPS_TRACE, "%s sc %p writing postindex %d\n",
                    __func__, sc, sc->replypostindex);
                mps_regwrite(sc, MPI2_REPLY_POST_HOST_INDEX_OFFSET,
                    sc->replypostindex);
        }

        return;
}

static void
mps_dispatch_event(struct mps_softc *sc, uintptr_t data,
    MPI2_EVENT_NOTIFICATION_REPLY *reply)
{
        struct mps_event_handle *eh;
        int event, handled = 0;

        event = le16toh(reply->Event);
        TAILQ_FOREACH(eh, &sc->event_list, eh_list) {
                if (isset(eh->mask, event)) {
                        eh->callback(sc, data, reply);
                        handled++;
                }
        }

        if (handled == 0)
                mps_dprint(sc, MPS_EVENT, "Unhandled event 0x%x\n", le16toh(event));

        /*
         * This is the only place that the event/reply should be freed.
         * Anything wanting to hold onto the event data should have
         * already copied it into their own storage.
         */
        mps_free_reply(sc, data);
}

static void
mps_reregister_events_complete(struct mps_softc *sc, struct mps_command *cm)
{
        mps_dprint(sc, MPS_TRACE, "%s\n", __func__);

        if (cm->cm_reply)
                MPS_DPRINT_EVENT(sc, generic,
                        (MPI2_EVENT_NOTIFICATION_REPLY *)cm->cm_reply);

        mps_free_command(sc, cm);

        /* next, send a port enable */
        mpssas_startup(sc);
}

/*
 * For both register_events and update_events, the caller supplies a bitmap
 * of events that it _wants_.  These functions then turn that into a bitmask
 * suitable for the controller.
 */
int
mps_register_events(struct mps_softc *sc, u32 *mask,
    mps_evt_callback_t *cb, void *data, struct mps_event_handle **handle)
{
        struct mps_event_handle *eh;
        int error = 0;

        eh = malloc(sizeof(struct mps_event_handle), M_MPT2, M_WAITOK|M_ZERO);
        eh->callback = cb;
        eh->data = data;
        TAILQ_INSERT_TAIL(&sc->event_list, eh, eh_list);
        if (mask != NULL)
                error = mps_update_events(sc, eh, mask);
        *handle = eh;

        return (error);
}

int
mps_update_events(struct mps_softc *sc, struct mps_event_handle *handle,
    u32 *mask)
{
        MPI2_EVENT_NOTIFICATION_REQUEST *evtreq;
        MPI2_EVENT_NOTIFICATION_REPLY *reply = NULL;
        struct mps_command *cm;
        int error, i;

        mps_dprint(sc, MPS_TRACE, "%s\n", __func__);

        if ((mask != NULL) && (handle != NULL))
                bcopy(mask, &handle->mask[0], sizeof(u32) * 
                                MPI2_EVENT_NOTIFY_EVENTMASK_WORDS);
    
        for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                sc->event_mask[i] = -1;

        for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                sc->event_mask[i] &= ~handle->mask[i];

        if ((cm = mps_alloc_command(sc)) == NULL)
                return (EBUSY);
        evtreq = (MPI2_EVENT_NOTIFICATION_REQUEST *)cm->cm_req;
        evtreq->Function = MPI2_FUNCTION_EVENT_NOTIFICATION;
        evtreq->MsgFlags = 0;
        evtreq->SASBroadcastPrimitiveMasks = 0;
#ifdef MPS_DEBUG_ALL_EVENTS
        {
                u_char fullmask[16];
                memset(fullmask, 0x00, 16);
                bcopy(fullmask, &evtreq->EventMasks[0], sizeof(u32) * 
                                MPI2_EVENT_NOTIFY_EVENTMASK_WORDS);
        }
#else
        for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                evtreq->EventMasks[i] =
                    htole32(sc->event_mask[i]);
#endif
        cm->cm_desc.Default.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_DEFAULT_TYPE;
        cm->cm_data = NULL;

        error = mps_wait_command(sc, &cm, 60, 0);
        if (cm != NULL)
                reply = (MPI2_EVENT_NOTIFICATION_REPLY *)cm->cm_reply;
        if ((reply == NULL) ||
            (reply->IOCStatus & MPI2_IOCSTATUS_MASK) != MPI2_IOCSTATUS_SUCCESS)
                error = ENXIO;

        if (reply)
                MPS_DPRINT_EVENT(sc, generic, reply);

        mps_dprint(sc, MPS_TRACE, "%s finished error %d\n", __func__, error);

        if (cm != NULL)
                mps_free_command(sc, cm);
        return (error);
}

static int
mps_reregister_events(struct mps_softc *sc)
{
        MPI2_EVENT_NOTIFICATION_REQUEST *evtreq;
        struct mps_command *cm;
        struct mps_event_handle *eh;
        int error, i;

        mps_dprint(sc, MPS_TRACE, "%s\n", __func__);

        /* first, reregister events */

        for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                sc->event_mask[i] = -1;

        TAILQ_FOREACH(eh, &sc->event_list, eh_list) {
                for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                        sc->event_mask[i] &= ~eh->mask[i];
        }

        if ((cm = mps_alloc_command(sc)) == NULL)
                return (EBUSY);
        evtreq = (MPI2_EVENT_NOTIFICATION_REQUEST *)cm->cm_req;
        evtreq->Function = MPI2_FUNCTION_EVENT_NOTIFICATION;
        evtreq->MsgFlags = 0;
        evtreq->SASBroadcastPrimitiveMasks = 0;
#ifdef MPS_DEBUG_ALL_EVENTS
        {
                u_char fullmask[16];
                memset(fullmask, 0x00, 16);
                bcopy(fullmask, &evtreq->EventMasks[0], sizeof(u32) *
                        MPI2_EVENT_NOTIFY_EVENTMASK_WORDS);
        }
#else
        for (i = 0; i < MPI2_EVENT_NOTIFY_EVENTMASK_WORDS; i++)
                evtreq->EventMasks[i] =
                    htole32(sc->event_mask[i]);
#endif
        cm->cm_desc.Default.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_DEFAULT_TYPE;
        cm->cm_data = NULL;
        cm->cm_complete = mps_reregister_events_complete;

        error = mps_map_command(sc, cm);

        mps_dprint(sc, MPS_TRACE, "%s finished with error %d\n", __func__,
            error);
        return (error);
}

void
mps_deregister_events(struct mps_softc *sc, struct mps_event_handle *handle)
{

        TAILQ_REMOVE(&sc->event_list, handle, eh_list);
        free(handle, M_MPT2);
}

/*
 * Add a chain element as the next SGE for the specified command.
 * Reset cm_sge and cm_sgesize to indicate all the available space.
 */
static int
mps_add_chain(struct mps_command *cm)
{
        MPI2_SGE_CHAIN64 *sgc;
        struct mps_chain *chain;
        u_int space;

        if (cm->cm_sglsize < MPS_SGC_SIZE)
                panic("MPS: Need SGE Error Code\n");

        chain = mps_alloc_chain(cm->cm_sc);
        if (chain == NULL)
                return (ENOBUFS);

        space = cm->cm_sc->reqframesz;

        /*
         * Note: a double-linked list is used to make it easier to
         * walk for debugging.
         */
        TAILQ_INSERT_TAIL(&cm->cm_chain_list, chain, chain_link);

        sgc = (MPI2_SGE_CHAIN64 *)&cm->cm_sge->MpiChain;
        sgc->Length = htole16(space);
        sgc->NextChainOffset = 0;
        /* TODO Looks like bug in Setting sgc->Flags. 
         *      sgc->Flags = ( MPI2_SGE_FLAGS_CHAIN_ELEMENT | MPI2_SGE_FLAGS_64_BIT_ADDRESSING |
         *                  MPI2_SGE_FLAGS_SYSTEM_ADDRESS) << MPI2_SGE_FLAGS_SHIFT
         *      This is fine.. because we are not using simple element. In case of 
         *      MPI2_SGE_CHAIN64, we have separate Length and Flags field.
         */
        sgc->Flags = MPI2_SGE_FLAGS_CHAIN_ELEMENT | MPI2_SGE_FLAGS_64_BIT_ADDRESSING;
        sgc->Address.High = htole32(chain->chain_busaddr >> 32);
        sgc->Address.Low = htole32(chain->chain_busaddr);

        cm->cm_sge = (MPI2_SGE_IO_UNION *)&chain->chain->MpiSimple;
        cm->cm_sglsize = space;
        return (0);
}

/*
 * Add one scatter-gather element (chain, simple, transaction context)
 * to the scatter-gather list for a command.  Maintain cm_sglsize and
 * cm_sge as the remaining size and pointer to the next SGE to fill
 * in, respectively.
 */
int
mps_push_sge(struct mps_command *cm, void *sgep, size_t len, int segsleft)
{
        MPI2_SGE_TRANSACTION_UNION *tc = sgep;
        MPI2_SGE_SIMPLE64 *sge = sgep;
        int error, type;
        uint32_t saved_buf_len, saved_address_low, saved_address_high;

        type = (tc->Flags & MPI2_SGE_FLAGS_ELEMENT_MASK);

#ifdef INVARIANTS
        switch (type) {
        case MPI2_SGE_FLAGS_TRANSACTION_ELEMENT: {
                if (len != tc->DetailsLength + 4)
                        panic("TC %p length %u or %zu?", tc,
                            tc->DetailsLength + 4, len);
                }
                break;
        case MPI2_SGE_FLAGS_CHAIN_ELEMENT:
                /* Driver only uses 64-bit chain elements */
                if (len != MPS_SGC_SIZE)
                        panic("CHAIN %p length %u or %zu?", sgep,
                            MPS_SGC_SIZE, len);
                break;
        case MPI2_SGE_FLAGS_SIMPLE_ELEMENT:
                /* Driver only uses 64-bit SGE simple elements */
                if (len != MPS_SGE64_SIZE)
                        panic("SGE simple %p length %u or %zu?", sge,
                            MPS_SGE64_SIZE, len);
                if (((le32toh(sge->FlagsLength) >> MPI2_SGE_FLAGS_SHIFT) &
                    MPI2_SGE_FLAGS_ADDRESS_SIZE) == 0)
                        panic("SGE simple %p not marked 64-bit?", sge);

                break;
        default:
                panic("Unexpected SGE %p, flags %02x", tc, tc->Flags);
        }
#endif

        /*
         * case 1: 1 more segment, enough room for it
         * case 2: 2 more segments, enough room for both
         * case 3: >=2 more segments, only enough room for 1 and a chain
         * case 4: >=1 more segment, enough room for only a chain
         * case 5: >=1 more segment, no room for anything (error)
         */

        /*
         * There should be room for at least a chain element, or this
         * code is buggy.  Case (5).
         */
        if (cm->cm_sglsize < MPS_SGC_SIZE)
                panic("MPS: Need SGE Error Code\n");

        if (segsleft >= 1 && cm->cm_sglsize < len + MPS_SGC_SIZE) {
                /*
                 * 1 or more segment, enough room for only a chain.
                 * Hope the previous element wasn't a Simple entry
                 * that needed to be marked with
                 * MPI2_SGE_FLAGS_LAST_ELEMENT.  Case (4).
                 */
                if ((error = mps_add_chain(cm)) != 0)
                        return (error);
        }

        if (segsleft >= 2 &&
            cm->cm_sglsize < len + MPS_SGC_SIZE + MPS_SGE64_SIZE) {
                /*
                 * There are 2 or more segments left to add, and only
                 * enough room for 1 and a chain.  Case (3).
                 *
                 * Mark as last element in this chain if necessary.
                 */
                if (type == MPI2_SGE_FLAGS_SIMPLE_ELEMENT) {
                        sge->FlagsLength |= htole32(
                            MPI2_SGE_FLAGS_LAST_ELEMENT << MPI2_SGE_FLAGS_SHIFT);
                }

                /*
                 * Add the item then a chain.  Do the chain now,
                 * rather than on the next iteration, to simplify
                 * understanding the code.
                 */
                cm->cm_sglsize -= len;
                bcopy(sgep, cm->cm_sge, len);
                cm->cm_sge = (MPI2_SGE_IO_UNION *)((uintptr_t)cm->cm_sge + len);
                return (mps_add_chain(cm));
        }

#ifdef INVARIANTS
        /* Case 1: 1 more segment, enough room for it. */
        if (segsleft == 1 && cm->cm_sglsize < len)
                panic("1 seg left and no room? %u versus %zu",
                    cm->cm_sglsize, len);

        /* Case 2: 2 more segments, enough room for both */
        if (segsleft == 2 && cm->cm_sglsize < len + MPS_SGE64_SIZE)
                panic("2 segs left and no room? %u versus %zu",
                    cm->cm_sglsize, len);
#endif

        if (segsleft == 1 && type == MPI2_SGE_FLAGS_SIMPLE_ELEMENT) {
                /*
                 * If this is a bi-directional request, need to account for that
                 * here.  Save the pre-filled sge values.  These will be used
                 * either for the 2nd SGL or for a single direction SGL.  If
                 * cm_out_len is non-zero, this is a bi-directional request, so
                 * fill in the OUT SGL first, then the IN SGL, otherwise just
                 * fill in the IN SGL.  Note that at this time, when filling in
                 * 2 SGL's for a bi-directional request, they both use the same
                 * DMA buffer (same cm command).
                 */
                saved_buf_len = le32toh(sge->FlagsLength) & 0x00FFFFFF;
                saved_address_low = sge->Address.Low;
                saved_address_high = sge->Address.High;
                if (cm->cm_out_len) {
                        sge->FlagsLength = htole32(cm->cm_out_len |
                            ((uint32_t)(MPI2_SGE_FLAGS_SIMPLE_ELEMENT |
                            MPI2_SGE_FLAGS_END_OF_BUFFER |
                            MPI2_SGE_FLAGS_HOST_TO_IOC |
                            MPI2_SGE_FLAGS_64_BIT_ADDRESSING) <<
                            MPI2_SGE_FLAGS_SHIFT));
                        cm->cm_sglsize -= len;
                        bcopy(sgep, cm->cm_sge, len);
                        cm->cm_sge = (MPI2_SGE_IO_UNION *)((uintptr_t)cm->cm_sge
                            + len);
                }
                saved_buf_len |=
                    ((uint32_t)(MPI2_SGE_FLAGS_SIMPLE_ELEMENT |
                    MPI2_SGE_FLAGS_END_OF_BUFFER |
                    MPI2_SGE_FLAGS_LAST_ELEMENT |
                    MPI2_SGE_FLAGS_END_OF_LIST |
                    MPI2_SGE_FLAGS_64_BIT_ADDRESSING) <<
                    MPI2_SGE_FLAGS_SHIFT);
                if (cm->cm_flags & MPS_CM_FLAGS_DATAIN) {
                        saved_buf_len |=
                            ((uint32_t)(MPI2_SGE_FLAGS_IOC_TO_HOST) <<
                            MPI2_SGE_FLAGS_SHIFT);
                } else {
                        saved_buf_len |=
                            ((uint32_t)(MPI2_SGE_FLAGS_HOST_TO_IOC) <<
                            MPI2_SGE_FLAGS_SHIFT);
                }
                sge->FlagsLength = htole32(saved_buf_len);
                sge->Address.Low = saved_address_low;
                sge->Address.High = saved_address_high;
        }

        cm->cm_sglsize -= len;
        bcopy(sgep, cm->cm_sge, len);
        cm->cm_sge = (MPI2_SGE_IO_UNION *)((uintptr_t)cm->cm_sge + len);
        return (0);
}

/*
 * Add one dma segment to the scatter-gather list for a command.
 */
int
mps_add_dmaseg(struct mps_command *cm, vm_paddr_t pa, size_t len, u_int flags,
    int segsleft)
{
        MPI2_SGE_SIMPLE64 sge;

        /*
         * This driver always uses 64-bit address elements for simplicity.
         */
        bzero(&sge, sizeof(sge));
        flags |= MPI2_SGE_FLAGS_SIMPLE_ELEMENT |
            MPI2_SGE_FLAGS_64_BIT_ADDRESSING;
        sge.FlagsLength = htole32(len | (flags << MPI2_SGE_FLAGS_SHIFT));
        mps_from_u64(pa, &sge.Address);

        return (mps_push_sge(cm, &sge, sizeof sge, segsleft));
}

static void
mps_data_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
        struct mps_softc *sc;
        struct mps_command *cm;
        u_int i, dir, sflags;

        cm = (struct mps_command *)arg;
        sc = cm->cm_sc;

        /*
         * In this case, just print out a warning and let the chip tell the
         * user they did the wrong thing.
         */
        if ((cm->cm_max_segs != 0) && (nsegs > cm->cm_max_segs)) {
                mps_dprint(sc, MPS_ERROR,
                           "%s: warning: busdma returned %d segments, "
                           "more than the %d allowed\n", __func__, nsegs,
                           cm->cm_max_segs);
        }

        /*
         * Set up DMA direction flags.  Bi-directional requests are also handled
         * here.  In that case, both direction flags will be set.
         */
        sflags = 0;
        if (cm->cm_flags & MPS_CM_FLAGS_SMP_PASS) {
                /*
                 * We have to add a special case for SMP passthrough, there
                 * is no easy way to generically handle it.  The first
                 * S/G element is used for the command (therefore the
                 * direction bit needs to be set).  The second one is used
                 * for the reply.  We'll leave it to the caller to make
                 * sure we only have two buffers.
                 */
                /*
                 * Even though the busdma man page says it doesn't make
                 * sense to have both direction flags, it does in this case.
                 * We have one s/g element being accessed in each direction.
                 */
                dir = BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD;

                /*
                 * Set the direction flag on the first buffer in the SMP
                 * passthrough request.  We'll clear it for the second one.
                 */
                sflags |= MPI2_SGE_FLAGS_DIRECTION |
                          MPI2_SGE_FLAGS_END_OF_BUFFER;
        } else if (cm->cm_flags & MPS_CM_FLAGS_DATAOUT) {
                sflags |= MPI2_SGE_FLAGS_HOST_TO_IOC;
                dir = BUS_DMASYNC_PREWRITE;
        } else
                dir = BUS_DMASYNC_PREREAD;

        for (i = 0; i < nsegs; i++) {
                if ((cm->cm_flags & MPS_CM_FLAGS_SMP_PASS) && (i != 0)) {
                        sflags &= ~MPI2_SGE_FLAGS_DIRECTION;
                }
                error = mps_add_dmaseg(cm, segs[i].ds_addr, segs[i].ds_len,
                    sflags, nsegs - i);
                if (error != 0) {
                        /* Resource shortage, roll back! */
                        if (ratecheck(&sc->lastfail, &mps_chainfail_interval))
                                mps_dprint(sc, MPS_INFO, "Out of chain frames, "
                                    "consider increasing hw.mps.max_chains.\n");
                        cm->cm_flags |= MPS_CM_FLAGS_CHAIN_FAILED;
                        /*
                         * mpr_complete_command can only be called on commands
                         * that are in the queue. Since this is an error path
                         * which gets called before we enqueue, update the state
                         * to meet this requirement before we complete it.
                         */
                        cm->cm_state = MPS_CM_STATE_INQUEUE;
                        mps_complete_command(sc, cm);
                        return;
                }
        }

        bus_dmamap_sync(sc->buffer_dmat, cm->cm_dmamap, dir);
        mps_enqueue_request(sc, cm);

        return;
}

static void
mps_data_cb2(void *arg, bus_dma_segment_t *segs, int nsegs, bus_size_t mapsize,
             int error)
{
        mps_data_cb(arg, segs, nsegs, error);
}

/*
 * This is the routine to enqueue commands ansynchronously.
 * Note that the only error path here is from bus_dmamap_load(), which can
 * return EINPROGRESS if it is waiting for resources.  Other than this, it's
 * assumed that if you have a command in-hand, then you have enough credits
 * to use it.
 */
int
mps_map_command(struct mps_softc *sc, struct mps_command *cm)
{
        int error = 0;

        if (cm->cm_flags & MPS_CM_FLAGS_USE_UIO) {
                error = bus_dmamap_load_uio(sc->buffer_dmat, cm->cm_dmamap,
                    &cm->cm_uio, mps_data_cb2, cm, 0);
        } else if (cm->cm_flags & MPS_CM_FLAGS_USE_CCB) {
                error = bus_dmamap_load_ccb(sc->buffer_dmat, cm->cm_dmamap,
                    cm->cm_data, mps_data_cb, cm, 0);
        } else if ((cm->cm_data != NULL) && (cm->cm_length != 0)) {
                error = bus_dmamap_load(sc->buffer_dmat, cm->cm_dmamap,
                    cm->cm_data, cm->cm_length, mps_data_cb, cm, 0);
        } else {
                /* Add a zero-length element as needed */
                if (cm->cm_sge != NULL)
                        mps_add_dmaseg(cm, 0, 0, 0, 1);
                mps_enqueue_request(sc, cm);    
        }

        return (error);
}

/*
 * This is the routine to enqueue commands synchronously.  An error of
 * EINPROGRESS from mps_map_command() is ignored since the command will
 * be executed and enqueued automatically.  Other errors come from msleep().
 */
int
mps_wait_command(struct mps_softc *sc, struct mps_command **cmp, int timeout,
    int sleep_flag)
{
        int error, rc;
        struct timeval cur_time, start_time;
        struct mps_command *cm = *cmp;

        if (sc->mps_flags & MPS_FLAGS_DIAGRESET) 
                return  EBUSY;

        cm->cm_complete = NULL;
        cm->cm_flags |= MPS_CM_FLAGS_POLLED;
        error = mps_map_command(sc, cm);
        if ((error != 0) && (error != EINPROGRESS))
                return (error);

        /*
         * Check for context and wait for 50 mSec at a time until time has
         * expired or the command has finished.  If msleep can't be used, need
         * to poll.
         */
        if (curthread->td_no_sleeping != 0)
                sleep_flag = NO_SLEEP;
        getmicrouptime(&start_time);
        if (mtx_owned(&sc->mps_mtx) && sleep_flag == CAN_SLEEP) {
                cm->cm_flags |= MPS_CM_FLAGS_WAKEUP;
                error = msleep(cm, &sc->mps_mtx, 0, "mpswait", timeout*hz);
                if (error == EWOULDBLOCK) {
                        /*
                         * Record the actual elapsed time in the case of a
                         * timeout for the message below.
                         */
                        getmicrouptime(&cur_time);
                        timevalsub(&cur_time, &start_time);
                }
        } else {
                while ((cm->cm_flags & MPS_CM_FLAGS_COMPLETE) == 0) {
                        mps_intr_locked(sc);
                        if (sleep_flag == CAN_SLEEP)
                                pause("mpswait", hz/20);
                        else
                                DELAY(50000);
                
                        getmicrouptime(&cur_time);
                        timevalsub(&cur_time, &start_time);
                        if (cur_time.tv_sec > timeout) {
                                error = EWOULDBLOCK;
                                break;
                        }
                }
        }

        if (error == EWOULDBLOCK) {
                if (cm->cm_timeout_handler == NULL) {
                        mps_dprint(sc, MPS_FAULT, "Calling Reinit from %s, timeout=%d,"
                            " elapsed=%jd\n", __func__, timeout,
                            (intmax_t)cur_time.tv_sec);
                        rc = mps_reinit(sc);
                        mps_dprint(sc, MPS_FAULT, "Reinit %s\n", (rc == 0) ? "success" :
                            "failed");
                } else
                        cm->cm_timeout_handler(sc, cm);
                if (sc->mps_flags & MPS_FLAGS_REALLOCATED) {
                        /*
                         * Tell the caller that we freed the command in a
                         * reinit.
                         */
                        *cmp = NULL;
                }
                error = ETIMEDOUT;
        }
        return (error);
}

/*
 * The MPT driver had a verbose interface for config pages.  In this driver,
 * reduce it to much simpler terms, similar to the Linux driver.
 */
int
mps_read_config_page(struct mps_softc *sc, struct mps_config_params *params)
{
        MPI2_CONFIG_REQUEST *req;
        struct mps_command *cm;
        int error;

        if (sc->mps_flags & MPS_FLAGS_BUSY) {
                return (EBUSY);
        }

        cm = mps_alloc_command(sc);
        if (cm == NULL) {
                return (EBUSY);
        }

        req = (MPI2_CONFIG_REQUEST *)cm->cm_req;
        req->Function = MPI2_FUNCTION_CONFIG;
        req->Action = params->action;
        req->SGLFlags = 0;
        req->ChainOffset = 0;
        req->PageAddress = params->page_address;
        if (params->hdr.Struct.PageType == MPI2_CONFIG_PAGETYPE_EXTENDED) {
                MPI2_CONFIG_EXTENDED_PAGE_HEADER *hdr;

                hdr = &params->hdr.Ext;
                req->ExtPageType = hdr->ExtPageType;
                req->ExtPageLength = hdr->ExtPageLength;
                req->Header.PageType = MPI2_CONFIG_PAGETYPE_EXTENDED;
                req->Header.PageLength = 0; /* Must be set to zero */
                req->Header.PageNumber = hdr->PageNumber;
                req->Header.PageVersion = hdr->PageVersion;
        } else {
                MPI2_CONFIG_PAGE_HEADER *hdr;

                hdr = &params->hdr.Struct;
                req->Header.PageType = hdr->PageType;
                req->Header.PageNumber = hdr->PageNumber;
                req->Header.PageLength = hdr->PageLength;
                req->Header.PageVersion = hdr->PageVersion;
        }

        cm->cm_data = params->buffer;
        cm->cm_length = params->length;
        if (cm->cm_data != NULL) {
                cm->cm_sge = &req->PageBufferSGE;
                cm->cm_sglsize = sizeof(MPI2_SGE_IO_UNION);
                cm->cm_flags = MPS_CM_FLAGS_SGE_SIMPLE | MPS_CM_FLAGS_DATAIN;
        } else
                cm->cm_sge = NULL;
        cm->cm_desc.Default.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_DEFAULT_TYPE;

        cm->cm_complete_data = params;
        if (params->callback != NULL) {
                cm->cm_complete = mps_config_complete;
                return (mps_map_command(sc, cm));
        } else {
                error = mps_wait_command(sc, &cm, 0, CAN_SLEEP);
                if (error) {
                        mps_dprint(sc, MPS_FAULT,
                            "Error %d reading config page\n", error);
                        if (cm != NULL)
                                mps_free_command(sc, cm);
                        return (error);
                }
                mps_config_complete(sc, cm);
        }

        return (0);
}

int
mps_write_config_page(struct mps_softc *sc, struct mps_config_params *params)
{
        return (EINVAL);
}

static void
mps_config_complete(struct mps_softc *sc, struct mps_command *cm)
{
        MPI2_CONFIG_REPLY *reply;
        struct mps_config_params *params;

        MPS_FUNCTRACE(sc);
        params = cm->cm_complete_data;

        if (cm->cm_data != NULL) {
                bus_dmamap_sync(sc->buffer_dmat, cm->cm_dmamap,
                    BUS_DMASYNC_POSTREAD);
                bus_dmamap_unload(sc->buffer_dmat, cm->cm_dmamap);
        }

        /*
         * XXX KDM need to do more error recovery?  This results in the
         * device in question not getting probed.
         */
        if ((cm->cm_flags & MPS_CM_FLAGS_ERROR_MASK) != 0) {
                params->status = MPI2_IOCSTATUS_BUSY;
                goto done;
        }

        reply = (MPI2_CONFIG_REPLY *)cm->cm_reply;
        if (reply == NULL) {
                params->status = MPI2_IOCSTATUS_BUSY;
                goto done;
        }
        params->status = reply->IOCStatus;
        if (params->hdr.Struct.PageType == MPI2_CONFIG_PAGETYPE_EXTENDED) {
                params->hdr.Ext.ExtPageType = reply->ExtPageType;
                params->hdr.Ext.ExtPageLength = reply->ExtPageLength;
                params->hdr.Ext.PageType = reply->Header.PageType;
                params->hdr.Ext.PageNumber = reply->Header.PageNumber;
                params->hdr.Ext.PageVersion = reply->Header.PageVersion;
        } else {
                params->hdr.Struct.PageType = reply->Header.PageType;
                params->hdr.Struct.PageNumber = reply->Header.PageNumber;
                params->hdr.Struct.PageLength = reply->Header.PageLength;
                params->hdr.Struct.PageVersion = reply->Header.PageVersion;
        }

done:
        mps_free_command(sc, cm);
        if (params->callback != NULL)
                params->callback(sc, params);

        return;
}