/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2010 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Fault Management for Nexus Device Drivers
 *
 * In addition to implementing and supporting Fault Management for Device
 * Drivers (ddifm.c), nexus drivers must support their children by
 * reporting FM capabilities, intializing interrupt block cookies
 * for error handling callbacks and caching mapped resources for lookup
 * during the detection of an IO transaction error.
 *
 * It is typically the nexus driver that receives an error indication
 * for a fault that may have occurred in the data path of an IO transaction.
 * Errors may be detected or received via an interrupt, a callback from
 * another subsystem (e.g. a cpu trap) or examination of control data.
 *
 * Upon detection of an error, the nexus has a responsibility to alert
 * its children of the error and the transaction associated with that
 * error.  The actual implementation may vary depending upon the capabilities
 * of the nexus, its underlying hardware and its children.  In this file,
 * we provide support for typical nexus driver fault management tasks.
 *
 * Fault Management Initialization
 *
 *      Nexus drivers must implement two new busops, bus_fm_init() and
 *      bus_fm_fini().  bus_fm_init() is called from a child nexus or device
 *      driver and is expected to initialize any per-child state and return
 *      the FM and error interrupt priority levels of the nexus driver.
 *      Similarly, bus_fm_fini() is called by child drivers and should
 *      clean-up any resources allocated during bus_fm_init().
 *      These functions are called from passive kernel context, typically from
 *      driver attach(9E) and detach(9E) entry points.
 *
 * Error Handler Dispatching
 *
 *      Nexus drivers implemented to support error handler capabilities
 *      should invoke registered error handler callbacks for child drivers
 *      thought to be involved in the error.
 *      ndi_fm_handler_dispatch() is used to invoke
 *      all error handlers and returns one of the following status
 *      indications:
 *
 *      DDI_FM_OK - No errors found by any child
 *      DDI_FM_FATAL - one or more children have detected a fatal error
 *      DDI_FM_NONFATAL - no fatal errors, but one or more children have
 *                            detected a non-fatal error
 *
 *      ndi_fm_handler_dispatch() may be called in any context
 *      subject to the constraints specified by the interrupt iblock cookie
 *      returned during initialization.
 *
 * Protected Accesses
 *
 *      When an access handle is mapped or a DMA handle is bound via the
 *      standard busops, bus_map() or bus_dma_bindhdl(), a child driver
 *      implemented to support DDI_FM_ACCCHK_CAPABLE or
 *      DDI_FM_DMACHK_CAPABLE capabilites
 *      expects the nexus to flag any errors detected for transactions
 *      associated with the mapped or bound handles.
 *
 *      Children nexus or device drivers will set the following flags
 *      in their ddi_device_access or dma_attr_flags when requesting
 *      the an access or DMA handle mapping:
 *
 *      DDI_DMA_FLAGERR - nexus should set error status for any errors
 *                              detected for a failed DMA transaction.
 *      DDI_ACC_FLAGERR - nexus should set error status for any errors
 *                              detected for a failed PIO transaction.
 *
 *      A nexus is expected to provide additional error detection and
 *      handling for handles with these flags set.
 *
 * Exclusive Bus Access
 *
 *      In cases where a driver requires a high level of fault tolerance
 *      for a programmed IO transaction, it is neccessary to grant exclusive
 *      access to the bus resource.  Exclusivity guarantees that a fault
 *      resulting from a transaction on the bus can be easily traced and
 *      reported to the driver requesting the transaction.
 *
 *      Nexus drivers must implement two new busops to support exclusive
 *      access, bus_fm_access_enter() and bus_fm_access_exit().  The IO
 *      framework will use these functions when it must set-up access
 *      handles that set devacc_attr_access to DDI_ACC_CAUTIOUS in
 *      their ddi_device_acc_attr_t request.
 *
 *      Upon receipt of a bus_fm_access_enter() request, the nexus must prevent
 *      all other access requests until it receives bus_fm_access_exit()
 *      for the requested bus instance. bus_fm_access_enter() and
 *      bus_fm_access_exit() may be called from user, kernel or kernel
 *      interrupt context.
 *
 * Access and DMA Handle Caching
 *
 *      To aid a nexus driver in associating access or DMA handles with
 *      a detected error, the nexus should cache all handles that are
 *      associated with DDI_ACC_FLAGERR, DDI_ACC_CAUTIOUS_ACC or
 *      DDI_DMA_FLAGERR requests from its children.  ndi_fmc_insert() is
 *      called by a nexus to cache handles with the above protection flags
 *      and ndi_fmc_remove() is called when that handle is unmapped or
 *      unbound by the requesting child.  ndi_fmc_insert() and
 *      ndi_fmc_remove() may be called from any user or kernel context.
 *
 *      FM cache element is implemented by kmem_cache. The elements are
 *      stored in a doubly-linked searchable list.  When a handle is created,
 *      ndi_fm_insert() allocates an entry from the kmem_cache and inserts
 *      the entry to the head of the list.  When a handle is unmapped
 *      or unbound, ndi_fm_remove() removes its associated cache entry from
 *      the list.
 *
 *      Upon detection of an error, the nexus may invoke ndi_fmc_error() to
 *      iterate over the handle cache of one or more of its FM compliant
 *      children.  A comparison callback function is provided upon each
 *      invocation of ndi_fmc_error() to tell the IO framework if a
 *      handle is associated with an error.  If so, the framework will
 *      set the error status for that handle before returning from
 *      ndi_fmc_error().
 *
 *      ndi_fmc_error() may be called in any context
 *      subject to the constraints specified by the interrupt iblock cookie
 *      returned during initialization of the nexus and its children.
 *
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/debug.h>
#include <sys/sunddi.h>
#include <sys/sunndi.h>
#include <sys/ddi.h>
#include <sys/ndi_impldefs.h>
#include <sys/devctl.h>
#include <sys/nvpair.h>
#include <sys/ddifm.h>
#include <sys/ndifm.h>
#include <sys/spl.h>
#include <sys/sysmacros.h>
#include <sys/devops.h>
#include <sys/atomic.h>
#include <sys/kmem.h>
#include <sys/fm/io/ddi.h>

kmem_cache_t *ndi_fm_entry_cache;

void
ndi_fm_init(void)
{
        ndi_fm_entry_cache = kmem_cache_create("ndi_fm_entry_cache",
            sizeof (ndi_fmcentry_t), 0, NULL, NULL, NULL, NULL, NULL, 0);
}

/*
 * Allocate and initialize a fault management resource cache
 * A fault management cache consists of a set of cache elements that
 * are allocated from "ndi_fm_entry_cache".
 */
/* ARGSUSED */
void
i_ndi_fmc_create(ndi_fmc_t **fcpp, int qlen, ddi_iblock_cookie_t ibc)
{
        ndi_fmc_t *fcp;

        fcp = kmem_zalloc(sizeof (ndi_fmc_t), KM_SLEEP);
        mutex_init(&fcp->fc_lock, NULL, MUTEX_DRIVER, ibc);

        *fcpp = fcp;
}

/*
 * Destroy and resources associated with the given fault management cache.
 */
void
i_ndi_fmc_destroy(ndi_fmc_t *fcp)
{
        ndi_fmcentry_t *fep, *pp;

        if (fcp == NULL)
                return;

        /* Free all the cached entries, this should not happen though */
        mutex_enter(&fcp->fc_lock);
        for (fep = fcp->fc_head; fep != NULL; fep = pp) {
                pp = fep->fce_next;
                kmem_cache_free(ndi_fm_entry_cache, fep);
        }
        mutex_exit(&fcp->fc_lock);
        mutex_destroy(&fcp->fc_lock);
        kmem_free(fcp, sizeof (ndi_fmc_t));
}

/*
 * ndi_fmc_insert -
 *      Add a new entry to the specified cache.
 *
 *      This function must be called at or below LOCK_LEVEL
 */
void
ndi_fmc_insert(dev_info_t *dip, int flag, void *resource, void *bus_specific)
{
        struct dev_info *devi = DEVI(dip);
        ndi_fmc_t *fcp;
        ndi_fmcentry_t *fep, **fpp;
        struct i_ddi_fmhdl *fmhdl;

        ASSERT(devi);

        fmhdl = devi->devi_fmhdl;
        if (fmhdl == NULL) {
                return;
        }

        switch (flag) {
        case DMA_HANDLE:
                if (!DDI_FM_DMA_ERR_CAP(fmhdl->fh_cap)) {
                        return;
                }
                fcp = fmhdl->fh_dma_cache;
                fpp = &((ddi_dma_impl_t *)resource)->dmai_error.err_fep;
                break;
        case ACC_HANDLE:
                if (!DDI_FM_ACC_ERR_CAP(fmhdl->fh_cap)) {
                        i_ddi_drv_ereport_post(dip, DVR_EFMCAP, NULL,
                            DDI_NOSLEEP);
                        return;
                }
                fcp = fmhdl->fh_acc_cache;
                fpp = &((ddi_acc_impl_t *)resource)->ahi_err->err_fep;
                break;
        default:
                ASSERT(0);
                return;
        }

        fep = kmem_cache_alloc(ndi_fm_entry_cache, KM_NOSLEEP);
        if (fep == NULL) {
                atomic_inc_64(&fmhdl->fh_kstat.fek_fmc_full.value.ui64);
                return;
        }

        /*
         * Set-up the handle resource and bus_specific information.
         * Also remember the pointer back to the cache for quick removal.
         */
        fep->fce_bus_specific = bus_specific;
        fep->fce_resource = resource;
        fep->fce_next = NULL;

        /* Add entry to the end of the active list */
        mutex_enter(&fcp->fc_lock);
        ASSERT(*fpp == NULL);
        *fpp = fep;
        fep->fce_prev = fcp->fc_tail;
        if (fcp->fc_tail != NULL)
                fcp->fc_tail->fce_next = fep;
        else
                fcp->fc_head = fep;
        fcp->fc_tail = fep;
        mutex_exit(&fcp->fc_lock);
}

/*
 *      Remove an entry from the specified cache of access or dma mappings
 *
 *      This function must be called at or below LOCK_LEVEL.
 */
void
ndi_fmc_remove(dev_info_t *dip, int flag, const void *resource)
{
        ndi_fmc_t *fcp;
        ndi_fmcentry_t *fep;
        struct dev_info *devi = DEVI(dip);
        struct i_ddi_fmhdl *fmhdl;

        ASSERT(devi);
        ASSERT(flag == DMA_HANDLE || flag == ACC_HANDLE);

        fmhdl = devi->devi_fmhdl;
        if (fmhdl == NULL) {
                return;
        }

        /* Find cache entry pointer for this resource */
        if (flag == DMA_HANDLE) {
                if (!DDI_FM_DMA_ERR_CAP(fmhdl->fh_cap)) {
                        return;
                }
                fcp = fmhdl->fh_dma_cache;

                ASSERT(fcp);

                mutex_enter(&fcp->fc_lock);
                fep = ((ddi_dma_impl_t *)resource)->dmai_error.err_fep;
                ((ddi_dma_impl_t *)resource)->dmai_error.err_fep = NULL;
        } else if (flag == ACC_HANDLE) {
                if (!DDI_FM_ACC_ERR_CAP(fmhdl->fh_cap)) {
                        i_ddi_drv_ereport_post(dip, DVR_EFMCAP, NULL,
                            DDI_NOSLEEP);
                        return;
                }
                fcp = fmhdl->fh_acc_cache;

                ASSERT(fcp);

                mutex_enter(&fcp->fc_lock);
                fep = ((ddi_acc_impl_t *)resource)->ahi_err->err_fep;
                ((ddi_acc_impl_t *)resource)->ahi_err->err_fep = NULL;
        } else {
                return;
        }

        /*
         * Resource not in cache, return
         */
        if (fep == NULL) {
                mutex_exit(&fcp->fc_lock);
                atomic_inc_64(&fmhdl->fh_kstat.fek_fmc_miss.value.ui64);
                return;
        }

        /*
         * Updates to FM cache pointers require us to grab fmc_lock
         * to synchronize access to the cache for ndi_fmc_insert()
         * and ndi_fmc_error()
         */
        if (fep == fcp->fc_head)
                fcp->fc_head = fep->fce_next;
        else
                fep->fce_prev->fce_next = fep->fce_next;
        if (fep == fcp->fc_tail)
                fcp->fc_tail = fep->fce_prev;
        else
                fep->fce_next->fce_prev = fep->fce_prev;
        mutex_exit(&fcp->fc_lock);

        kmem_cache_free(ndi_fm_entry_cache, fep);
}

int
ndi_fmc_entry_error(dev_info_t *dip, int flag, ddi_fm_error_t *derr,
    const void *bus_err_state)
{
        int status, fatal = 0, nonfatal = 0;
        ndi_fmc_t *fcp = NULL;
        ndi_fmcentry_t *fep;
        struct i_ddi_fmhdl *fmhdl;

        ASSERT(flag == DMA_HANDLE || flag == ACC_HANDLE);

        fmhdl = DEVI(dip)->devi_fmhdl;
        ASSERT(fmhdl);
        status = DDI_FM_UNKNOWN;

        if (flag == DMA_HANDLE && DDI_FM_DMA_ERR_CAP(fmhdl->fh_cap)) {
                fcp = fmhdl->fh_dma_cache;
                ASSERT(fcp);
        } else if (flag == ACC_HANDLE && DDI_FM_ACC_ERR_CAP(fmhdl->fh_cap)) {
                fcp = fmhdl->fh_acc_cache;
                ASSERT(fcp);
        }

        if (fcp != NULL) {

                /*
                 * Check active resource entries
                 */
                mutex_enter(&fcp->fc_lock);
                for (fep = fcp->fc_head; fep != NULL; fep = fep->fce_next) {
                        ddi_fmcompare_t compare_func;

                        /*
                         * Compare captured error state with handle
                         * resources.  During the comparison and
                         * subsequent error handling, we block
                         * attempts to free the cache entry.
                         */
                        compare_func = (flag == ACC_HANDLE) ?
                            i_ddi_fm_acc_err_cf_get((ddi_acc_handle_t)
                            fep->fce_resource) :
                            i_ddi_fm_dma_err_cf_get((ddi_dma_handle_t)
                            fep->fce_resource);

                        if (compare_func == NULL) /* unbound or not FLAGERR */
                                continue;

                        status = compare_func(dip, fep->fce_resource,
                            bus_err_state, fep->fce_bus_specific);
                        if (status == DDI_FM_UNKNOWN || status == DDI_FM_OK)
                                continue;

                        if (status == DDI_FM_FATAL)
                                ++fatal;
                        else if (status == DDI_FM_NONFATAL)
                                ++nonfatal;

                        /* Set the error for this resource handle */
                        if (flag == ACC_HANDLE) {
                                ddi_acc_handle_t ap = fep->fce_resource;

                                i_ddi_fm_acc_err_set(ap, derr->fme_ena, status,
                                    DDI_FM_ERR_UNEXPECTED);
                                ddi_fm_acc_err_get(ap, derr, DDI_FME_VERSION);
                                derr->fme_acc_handle = ap;
                        } else {
                                ddi_dma_handle_t dp = fep->fce_resource;

                                i_ddi_fm_dma_err_set(dp, derr->fme_ena, status,
                                    DDI_FM_ERR_UNEXPECTED);
                                ddi_fm_dma_err_get(dp, derr, DDI_FME_VERSION);
                                derr->fme_dma_handle = dp;
                        }
                }
                mutex_exit(&fcp->fc_lock);
        }
        return (fatal ? DDI_FM_FATAL : nonfatal ? DDI_FM_NONFATAL :
            DDI_FM_UNKNOWN);
}

/*
 * Check error state against the handle resource stored in the specified
 * FM cache.  If tdip != NULL, we check only the cache entries for tdip.
 * The caller must ensure that tdip is valid throughout the call and
 * all FM data structures can be safely accesses.
 *
 * If tdip == NULL, we check all children that have registered their
 * FM_DMA_CHK or FM_ACC_CHK capabilities.
 *
 * The following status values may be returned:
 *
 *      DDI_FM_FATAL - if at least one cache entry comparison yields a
 *                      fatal error.
 *
 *      DDI_FM_NONFATAL - if at least one cache entry comparison yields a
 *                      non-fatal error and no comparison yields a fatal error.
 *
 *      DDI_FM_UNKNOWN - cache entry comparisons did not yield fatal or
 *                      non-fatal errors.
 *
 */
int
ndi_fmc_error(dev_info_t *dip, dev_info_t *tdip, int flag, uint64_t ena,
    const void *bus_err_state)
{
        int status, fatal = 0, nonfatal = 0;
        ddi_fm_error_t derr;
        struct i_ddi_fmhdl *fmhdl;
        struct i_ddi_fmtgt *tgt;

        ASSERT(flag == DMA_HANDLE || flag == ACC_HANDLE);

        i_ddi_fm_handler_enter(dip);
        fmhdl = DEVI(dip)->devi_fmhdl;
        ASSERT(fmhdl);

        bzero(&derr, sizeof (ddi_fm_error_t));
        derr.fme_version = DDI_FME_VERSION;
        derr.fme_flag = DDI_FM_ERR_UNEXPECTED;
        derr.fme_ena = ena;

        for (tgt = fmhdl->fh_tgts; tgt != NULL; tgt = tgt->ft_next) {

                if (tdip != NULL && tdip != tgt->ft_dip)
                        continue;

                /*
                 * Attempt to find the entry in this childs handle cache
                 */
                status = ndi_fmc_entry_error(tgt->ft_dip, flag, &derr,
                    bus_err_state);

                if (status == DDI_FM_FATAL)
                        ++fatal;
                else if (status == DDI_FM_NONFATAL)
                        ++nonfatal;
                else
                        continue;

                /*
                 * Call our child to process this error.
                 */
                status = tgt->ft_errhdl->eh_func(tgt->ft_dip, &derr,
                    tgt->ft_errhdl->eh_impl);

                if (status == DDI_FM_FATAL)
                        ++fatal;
                else if (status == DDI_FM_NONFATAL)
                        ++nonfatal;
        }

        i_ddi_fm_handler_exit(dip);

        if (fatal)
                return (DDI_FM_FATAL);
        else if (nonfatal)
                return (DDI_FM_NONFATAL);

        return (DDI_FM_UNKNOWN);
}

int
ndi_fmc_entry_error_all(dev_info_t *dip, int flag, ddi_fm_error_t *derr)
{
        ndi_fmc_t *fcp = NULL;
        ndi_fmcentry_t *fep;
        struct i_ddi_fmhdl *fmhdl;
        int nonfatal = 0;

        ASSERT(flag == DMA_HANDLE || flag == ACC_HANDLE);

        fmhdl = DEVI(dip)->devi_fmhdl;
        ASSERT(fmhdl);

        if (flag == DMA_HANDLE && DDI_FM_DMA_ERR_CAP(fmhdl->fh_cap)) {
                fcp = fmhdl->fh_dma_cache;
                ASSERT(fcp);
        } else if (flag == ACC_HANDLE && DDI_FM_ACC_ERR_CAP(fmhdl->fh_cap)) {
                fcp = fmhdl->fh_acc_cache;
                ASSERT(fcp);
        }

        if (fcp != NULL) {
                /*
                 * Check active resource entries
                 */
                mutex_enter(&fcp->fc_lock);
                for (fep = fcp->fc_head; fep != NULL; fep = fep->fce_next) {
                        ddi_fmcompare_t compare_func;

                        compare_func = (flag == ACC_HANDLE) ?
                            i_ddi_fm_acc_err_cf_get((ddi_acc_handle_t)
                            fep->fce_resource) :
                            i_ddi_fm_dma_err_cf_get((ddi_dma_handle_t)
                            fep->fce_resource);

                        if (compare_func == NULL) /* unbound or not FLAGERR */
                                continue;

                        /* Set the error for this resource handle */
                        nonfatal++;

                        if (flag == ACC_HANDLE) {
                                ddi_acc_handle_t ap = fep->fce_resource;

                                i_ddi_fm_acc_err_set(ap, derr->fme_ena,
                                    DDI_FM_NONFATAL, DDI_FM_ERR_UNEXPECTED);
                                ddi_fm_acc_err_get(ap, derr, DDI_FME_VERSION);
                                derr->fme_acc_handle = ap;
                        } else {
                                ddi_dma_handle_t dp = fep->fce_resource;

                                i_ddi_fm_dma_err_set(dp, derr->fme_ena,
                                    DDI_FM_NONFATAL, DDI_FM_ERR_UNEXPECTED);
                                ddi_fm_dma_err_get(dp, derr, DDI_FME_VERSION);
                                derr->fme_dma_handle = dp;
                        }
                }
                mutex_exit(&fcp->fc_lock);
        }
        return (nonfatal ? DDI_FM_NONFATAL : DDI_FM_UNKNOWN);
}

/*
 * Dispatch registered error handlers for dip.  If tdip != NULL, only
 * the error handler (if available) for tdip is invoked.  Otherwise,
 * all registered error handlers are invoked.
 *
 * The following status values may be returned:
 *
 *      DDI_FM_FATAL - if at least one error handler returns a
 *                      fatal error.
 *
 *      DDI_FM_NONFATAL - if at least one error handler returns a
 *                      non-fatal error and none returned a fatal error.
 *
 *      DDI_FM_UNKNOWN - if at least one error handler returns
 *                      unknown status and none return fatal or non-fatal.
 *
 *      DDI_FM_OK - if all error handlers return DDI_FM_OK
 */
int
ndi_fm_handler_dispatch(dev_info_t *dip, dev_info_t *tdip,
    const ddi_fm_error_t *nerr)
{
        int status;
        int unknown = 0, fatal = 0, nonfatal = 0;
        struct i_ddi_fmhdl *hdl;
        struct i_ddi_fmtgt *tgt;

        status = DDI_FM_UNKNOWN;

        i_ddi_fm_handler_enter(dip);
        hdl = DEVI(dip)->devi_fmhdl;
        tgt = hdl->fh_tgts;
        while (tgt != NULL) {
                if (tdip == NULL || tdip == tgt->ft_dip) {
                        struct i_ddi_errhdl *errhdl;

                        errhdl = tgt->ft_errhdl;
                        status = errhdl->eh_func(tgt->ft_dip, nerr,
                            errhdl->eh_impl);

                        if (status == DDI_FM_FATAL)
                                ++fatal;
                        else if (status == DDI_FM_NONFATAL)
                                ++nonfatal;
                        else if (status == DDI_FM_UNKNOWN)
                                ++unknown;

                        /* Only interested in one target */
                        if (tdip != NULL)
                                break;
                }
                tgt = tgt->ft_next;
        }
        i_ddi_fm_handler_exit(dip);

        if (fatal)
                return (DDI_FM_FATAL);
        else if (nonfatal)
                return (DDI_FM_NONFATAL);
        else if (unknown)
                return (DDI_FM_UNKNOWN);
        else
                return (DDI_FM_OK);
}

/*
 * Set error status for specified access or DMA handle
 *
 * May be called in any context but caller must insure validity of
 * handle.
 */
void
ndi_fm_acc_err_set(ddi_acc_handle_t handle, ddi_fm_error_t *dfe)
{
        i_ddi_fm_acc_err_set(handle, dfe->fme_ena, dfe->fme_status,
            dfe->fme_flag);
}

void
ndi_fm_dma_err_set(ddi_dma_handle_t handle, ddi_fm_error_t *dfe)
{
        i_ddi_fm_dma_err_set(handle, dfe->fme_ena, dfe->fme_status,
            dfe->fme_flag);
}

/*
 * Call parent busop fm initialization routine.
 *
 * Called during driver attach(9E)
 */
int
i_ndi_busop_fm_init(dev_info_t *dip, int tcap, ddi_iblock_cookie_t *ibc)
{
        int pcap;
        dev_info_t *pdip = (dev_info_t *)DEVI(dip)->devi_parent;

        if (dip == ddi_root_node())
                return (ddi_system_fmcap | DDI_FM_EREPORT_CAPABLE);

        /* Valid operation for BUSO_REV_6 and above */
        if (DEVI(pdip)->devi_ops->devo_bus_ops->busops_rev < BUSO_REV_6)
                return (DDI_FM_NOT_CAPABLE);

        if (DEVI(pdip)->devi_ops->devo_bus_ops->bus_fm_init == NULL)
                return (DDI_FM_NOT_CAPABLE);

        pcap = (*DEVI(pdip)->devi_ops->devo_bus_ops->bus_fm_init)
            (pdip, dip, tcap, ibc);

        return (pcap);
}

/*
 * Call parent busop fm clean-up routine.
 *
 * Called during driver detach(9E)
 */
void
i_ndi_busop_fm_fini(dev_info_t *dip)
{
        dev_info_t *pdip = (dev_info_t *)DEVI(dip)->devi_parent;

        if (dip == ddi_root_node())
                return;

        /* Valid operation for BUSO_REV_6 and above */
        if (DEVI(pdip)->devi_ops->devo_bus_ops->busops_rev < BUSO_REV_6)
                return;

        if (DEVI(pdip)->devi_ops->devo_bus_ops->bus_fm_fini == NULL)
                return;

        (*DEVI(pdip)->devi_ops->devo_bus_ops->bus_fm_fini)(pdip, dip);
}

/*
 * The following routines provide exclusive access to a nexus resource
 *
 * These busops may be called in user or kernel driver context.
 */
void
i_ndi_busop_access_enter(dev_info_t *dip, ddi_acc_handle_t handle)
{
        dev_info_t *pdip = (dev_info_t *)DEVI(dip)->devi_parent;

        /* Valid operation for BUSO_REV_6 and above */
        if (DEVI(pdip)->devi_ops->devo_bus_ops->busops_rev < BUSO_REV_6)
                return;

        if (DEVI(pdip)->devi_ops->devo_bus_ops->bus_fm_access_enter == NULL)
                return;

        (*DEVI(pdip)->devi_ops->devo_bus_ops->bus_fm_access_enter)
            (pdip, handle);
}

void
i_ndi_busop_access_exit(dev_info_t *dip, ddi_acc_handle_t handle)
{
        dev_info_t *pdip = (dev_info_t *)DEVI(dip)->devi_parent;

        /* Valid operation for BUSO_REV_6 and above */
        if (DEVI(pdip)->devi_ops->devo_bus_ops->busops_rev < BUSO_REV_6)
                return;

        if (DEVI(pdip)->devi_ops->devo_bus_ops->bus_fm_access_exit == NULL)
                return;

        (*DEVI(pdip)->devi_ops->devo_bus_ops->bus_fm_access_exit)(pdip, handle);
}