task.c

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/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 * redistributing this file, you may do so under either license.
 *
 * GPL LICENSE SUMMARY
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of version 2 of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
 * The full GNU General Public License is included in this distribution
 * in the file called LICENSE.GPL.
 *
 * BSD LICENSE
 *
 * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *   * 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.
 *   * Neither the name of Intel Corporation nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
 * OWNER 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.
 */

#include <linux/completion.h>
#include <linux/irqflags.h>
#include "sas.h"
#include <scsi/libsas.h>
#include "remote_device.h"
#include "remote_node_context.h"
#include "isci.h"
#include "request.h"
#include "task.h"
#include "host.h"

static void isci_task_refuse(struct isci_host *ihost, struct sas_task *task,
                 enum service_response response,
                 enum exec_status status)

{
    unsigned long flags;

    /* Normal notification (task_done) */
    dev_dbg(&ihost->pdev->dev, "%s: task = %p, response=%d, status=%d\n",
        __func__, task, response, status);

    spin_lock_irqsave(&task->task_state_lock, flags);

    task->task_status.resp = response;
    task->task_status.stat = status;

    /* Normal notification (task_done) */
    task->task_state_flags |= SAS_TASK_STATE_DONE;
    task->task_state_flags &= ~(SAS_TASK_AT_INITIATOR |
                    SAS_TASK_STATE_PENDING);
    task->lldd_task = NULL;
    spin_unlock_irqrestore(&task->task_state_lock, flags);

    task->task_done(task);
}

#define for_each_sas_task(num, task) \
    for (; num > 0; num--,\
         task = list_entry(task->list.next, struct sas_task, list))


static inline int isci_device_io_ready(struct isci_remote_device *idev,
                       struct sas_task *task)
{
    return idev ? test_bit(IDEV_IO_READY, &idev->flags) ||
              (test_bit(IDEV_IO_NCQERROR, &idev->flags) &&
               isci_task_is_ncq_recovery(task))
            : 0;
}
int isci_task_execute_task(struct sas_task *task, int num, gfp_t gfp_flags)
{
    struct isci_host *ihost = dev_to_ihost(task->dev);
    struct isci_remote_device *idev;
    unsigned long flags;
    bool io_ready;
    u16 tag;

    dev_dbg(&ihost->pdev->dev, "%s: num=%d\n", __func__, num);

    for_each_sas_task(num, task) {
        enum sci_status status = SCI_FAILURE;

        spin_lock_irqsave(&ihost->scic_lock, flags);
        idev = isci_lookup_device(task->dev);
        io_ready = isci_device_io_ready(idev, task);
        tag = isci_alloc_tag(ihost);
        spin_unlock_irqrestore(&ihost->scic_lock, flags);

        dev_dbg(&ihost->pdev->dev,
            "task: %p, num: %d dev: %p idev: %p:%#lx cmd = %p\n",
            task, num, task->dev, idev, idev ? idev->flags : 0,
            task->uldd_task);

        if (!idev) {
            isci_task_refuse(ihost, task, SAS_TASK_UNDELIVERED,
                     SAS_DEVICE_UNKNOWN);
        } else if (!io_ready || tag == SCI_CONTROLLER_INVALID_IO_TAG) {
            /* Indicate QUEUE_FULL so that the scsi midlayer
             * retries.
              */
            isci_task_refuse(ihost, task, SAS_TASK_COMPLETE,
                     SAS_QUEUE_FULL);
        } else {
            /* There is a device and it's ready for I/O. */
            spin_lock_irqsave(&task->task_state_lock, flags);

            if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
                /* The I/O was aborted. */
                spin_unlock_irqrestore(&task->task_state_lock,
                               flags);

                isci_task_refuse(ihost, task,
                         SAS_TASK_UNDELIVERED,
                         SAM_STAT_TASK_ABORTED);
            } else {
                task->task_state_flags |= SAS_TASK_AT_INITIATOR;
                spin_unlock_irqrestore(&task->task_state_lock, flags);

                /* build and send the request. */
                status = isci_request_execute(ihost, idev, task, tag);

                if (status != SCI_SUCCESS) {

                    spin_lock_irqsave(&task->task_state_lock, flags);
                    /* Did not really start this command. */
                    task->task_state_flags &= ~SAS_TASK_AT_INITIATOR;
                    spin_unlock_irqrestore(&task->task_state_lock, flags);

                    if (test_bit(IDEV_GONE, &idev->flags)) {

                        /* Indicate that the device
                         * is gone.
                         */
                        isci_task_refuse(ihost, task,
                            SAS_TASK_UNDELIVERED,
                            SAS_DEVICE_UNKNOWN);
                    } else {
                        /* Indicate QUEUE_FULL so that
                         * the scsi midlayer retries.
                         * If the request failed for
                         * remote device reasons, it
                         * gets returned as
                         * SAS_TASK_UNDELIVERED next
                         * time through.
                         */
                        isci_task_refuse(ihost, task,
                            SAS_TASK_COMPLETE,
                            SAS_QUEUE_FULL);
                    }
                }
            }
        }
        if (status != SCI_SUCCESS && tag != SCI_CONTROLLER_INVALID_IO_TAG) {
            spin_lock_irqsave(&ihost->scic_lock, flags);
            /* command never hit the device, so just free
             * the tci and skip the sequence increment
             */
            isci_tci_free(ihost, ISCI_TAG_TCI(tag));
            spin_unlock_irqrestore(&ihost->scic_lock, flags);
        }
        isci_put_device(idev);
    }
    return 0;
}

static struct isci_request *isci_task_request_build(struct isci_host *ihost,
                            struct isci_remote_device *idev,
                            u16 tag, struct isci_tmf *isci_tmf)
{
    enum sci_status status = SCI_FAILURE;
    struct isci_request *ireq = NULL;
    struct domain_device *dev;

    dev_dbg(&ihost->pdev->dev,
        "%s: isci_tmf = %p\n", __func__, isci_tmf);

    dev = idev->domain_dev;

    /* do common allocation and init of request object. */
    ireq = isci_tmf_request_from_tag(ihost, isci_tmf, tag);
    if (!ireq)
        return NULL;

    /* let the core do it's construct. */
    status = sci_task_request_construct(ihost, idev, tag,
                         ireq);

    if (status != SCI_SUCCESS) {
        dev_warn(&ihost->pdev->dev,
             "%s: sci_task_request_construct failed - "
             "status = 0x%x\n",
             __func__,
             status);
        return NULL;
    }

    /* XXX convert to get this from task->tproto like other drivers */
    if (dev->dev_type == SAS_END_DEV) {
        isci_tmf->proto = SAS_PROTOCOL_SSP;
        status = sci_task_request_construct_ssp(ireq);
        if (status != SCI_SUCCESS)
            return NULL;
    }

    return ireq;
}

static int isci_task_execute_tmf(struct isci_host *ihost,
                 struct isci_remote_device *idev,
                 struct isci_tmf *tmf, unsigned long timeout_ms)
{
    DECLARE_COMPLETION_ONSTACK(completion);
    enum sci_task_status status = SCI_TASK_FAILURE;
    struct isci_request *ireq;
    int ret = TMF_RESP_FUNC_FAILED;
    unsigned long flags;
    unsigned long timeleft;
    u16 tag;

    spin_lock_irqsave(&ihost->scic_lock, flags);
    tag = isci_alloc_tag(ihost);
    spin_unlock_irqrestore(&ihost->scic_lock, flags);

    if (tag == SCI_CONTROLLER_INVALID_IO_TAG)
        return ret;

    /* sanity check, return TMF_RESP_FUNC_FAILED
     * if the device is not there and ready.
     */
    if (!idev ||
        (!test_bit(IDEV_IO_READY, &idev->flags) &&
         !test_bit(IDEV_IO_NCQERROR, &idev->flags))) {
        dev_dbg(&ihost->pdev->dev,
            "%s: idev = %p not ready (%#lx)\n",
            __func__,
            idev, idev ? idev->flags : 0);
        goto err_tci;
    } else
        dev_dbg(&ihost->pdev->dev,
            "%s: idev = %p\n",
            __func__, idev);

    /* Assign the pointer to the TMF's completion kernel wait structure. */
    tmf->complete = &completion;
    tmf->status = SCI_FAILURE_TIMEOUT;

    ireq = isci_task_request_build(ihost, idev, tag, tmf);
    if (!ireq)
        goto err_tci;

    spin_lock_irqsave(&ihost->scic_lock, flags);

    /* start the TMF io. */
    status = sci_controller_start_task(ihost, idev, ireq);

    if (status != SCI_TASK_SUCCESS) {
        dev_dbg(&ihost->pdev->dev,
             "%s: start_io failed - status = 0x%x, request = %p\n",
             __func__,
             status,
             ireq);
        spin_unlock_irqrestore(&ihost->scic_lock, flags);
        goto err_tci;
    }
    spin_unlock_irqrestore(&ihost->scic_lock, flags);

    /* The RNC must be unsuspended before the TMF can get a response. */
    isci_remote_device_resume_from_abort(ihost, idev);

    /* Wait for the TMF to complete, or a timeout. */
    timeleft = wait_for_completion_timeout(&completion,
                           msecs_to_jiffies(timeout_ms));

    if (timeleft == 0) {
        /* The TMF did not complete - this could be because
         * of an unplug.  Terminate the TMF request now.
         */
        isci_remote_device_suspend_terminate(ihost, idev, ireq);
    }

    isci_print_tmf(ihost, tmf);

    if (tmf->status == SCI_SUCCESS)
        ret =  TMF_RESP_FUNC_COMPLETE;
    else if (tmf->status == SCI_FAILURE_IO_RESPONSE_VALID) {
        dev_dbg(&ihost->pdev->dev,
            "%s: tmf.status == "
            "SCI_FAILURE_IO_RESPONSE_VALID\n",
            __func__);
        ret =  TMF_RESP_FUNC_COMPLETE;
    }
    /* Else - leave the default "failed" status alone. */

    dev_dbg(&ihost->pdev->dev,
        "%s: completed request = %p\n",
        __func__,
        ireq);

    return ret;

 err_tci:
    spin_lock_irqsave(&ihost->scic_lock, flags);
    isci_tci_free(ihost, ISCI_TAG_TCI(tag));
    spin_unlock_irqrestore(&ihost->scic_lock, flags);

    return ret;
}

static void isci_task_build_tmf(struct isci_tmf *tmf,
                enum isci_tmf_function_codes code)
{
    memset(tmf, 0, sizeof(*tmf));
    tmf->tmf_code = code;
}

static void isci_task_build_abort_task_tmf(struct isci_tmf *tmf,
                       enum isci_tmf_function_codes code,
                       struct isci_request *old_request)
{
    isci_task_build_tmf(tmf, code);
    tmf->io_tag = old_request->io_tag;
}

static int isci_task_send_lu_reset_sas(
    struct isci_host *isci_host,
    struct isci_remote_device *isci_device,
    u8 *lun)
{
    struct isci_tmf tmf;
    int ret = TMF_RESP_FUNC_FAILED;

    dev_dbg(&isci_host->pdev->dev,
        "%s: isci_host = %p, isci_device = %p\n",
        __func__, isci_host, isci_device);
    /* Send the LUN reset to the target.  By the time the call returns,
     * the TMF has fully exected in the target (in which case the return
     * value is "TMF_RESP_FUNC_COMPLETE", or the request timed-out (or
     * was otherwise unable to be executed ("TMF_RESP_FUNC_FAILED").
     */
    isci_task_build_tmf(&tmf, isci_tmf_ssp_lun_reset);

    #define ISCI_LU_RESET_TIMEOUT_MS 2000 /* 2 second timeout. */
    ret = isci_task_execute_tmf(isci_host, isci_device, &tmf, ISCI_LU_RESET_TIMEOUT_MS);

    if (ret == TMF_RESP_FUNC_COMPLETE)
        dev_dbg(&isci_host->pdev->dev,
            "%s: %p: TMF_LU_RESET passed\n",
            __func__, isci_device);
    else
        dev_dbg(&isci_host->pdev->dev,
            "%s: %p: TMF_LU_RESET failed (%x)\n",
            __func__, isci_device, ret);

    return ret;
}

int isci_task_lu_reset(struct domain_device *dev, u8 *lun)
{
    struct isci_host *ihost = dev_to_ihost(dev);
    struct isci_remote_device *idev;
    unsigned long flags;
    int ret = TMF_RESP_FUNC_COMPLETE;

    spin_lock_irqsave(&ihost->scic_lock, flags);
    idev = isci_get_device(dev->lldd_dev);
    spin_unlock_irqrestore(&ihost->scic_lock, flags);

    dev_dbg(&ihost->pdev->dev,
        "%s: domain_device=%p, isci_host=%p; isci_device=%p\n",
        __func__, dev, ihost, idev);

    if (!idev) {
        /* If the device is gone, escalate to I_T_Nexus_Reset. */
        dev_dbg(&ihost->pdev->dev, "%s: No dev\n", __func__);

        ret = TMF_RESP_FUNC_FAILED;
        goto out;
    }

    /* Suspend the RNC, kill all TCs */
    if (isci_remote_device_suspend_terminate(ihost, idev, NULL)
        != SCI_SUCCESS) {
        /* The suspend/terminate only fails if isci_get_device fails */
        ret = TMF_RESP_FUNC_FAILED;
        goto out;
    }
    /* All pending I/Os have been terminated and cleaned up. */
    if (!test_bit(IDEV_GONE, &idev->flags)) {
        if (dev_is_sata(dev))
            sas_ata_schedule_reset(dev);
        else
            /* Send the task management part of the reset. */
            ret = isci_task_send_lu_reset_sas(ihost, idev, lun);
    }
 out:
    isci_put_device(idev);
    return ret;
}


/*   int (*lldd_clear_nexus_port)(struct asd_sas_port *); */
int isci_task_clear_nexus_port(struct asd_sas_port *port)
{
    return TMF_RESP_FUNC_FAILED;
}



int isci_task_clear_nexus_ha(struct sas_ha_struct *ha)
{
    return TMF_RESP_FUNC_FAILED;
}

/* Task Management Functions. Must be called from process context.   */

int isci_task_abort_task(struct sas_task *task)
{
    struct isci_host *ihost = dev_to_ihost(task->dev);
    DECLARE_COMPLETION_ONSTACK(aborted_io_completion);
    struct isci_request       *old_request = NULL;
    struct isci_remote_device *idev = NULL;
    struct isci_tmf           tmf;
    int                       ret = TMF_RESP_FUNC_FAILED;
    unsigned long             flags;

    /* Get the isci_request reference from the task.  Note that
     * this check does not depend on the pending request list
     * in the device, because tasks driving resets may land here
     * after completion in the core.
     */
    spin_lock_irqsave(&ihost->scic_lock, flags);
    spin_lock(&task->task_state_lock);

    old_request = task->lldd_task;

    /* If task is already done, the request isn't valid */
    if (!(task->task_state_flags & SAS_TASK_STATE_DONE) &&
        (task->task_state_flags & SAS_TASK_AT_INITIATOR) &&
        old_request)
        idev = isci_get_device(task->dev->lldd_dev);

    spin_unlock(&task->task_state_lock);
    spin_unlock_irqrestore(&ihost->scic_lock, flags);

    dev_warn(&ihost->pdev->dev,
         "%s: dev = %p (%s%s), task = %p, old_request == %p\n",
         __func__, idev,
         (dev_is_sata(task->dev) ? "STP/SATA"
                     : ((dev_is_expander(task->dev))
                        ? "SMP"
                        : "SSP")),
         ((idev) ? ((test_bit(IDEV_GONE, &idev->flags))
               ? " IDEV_GONE"
               : "")
             : " <NULL>"),
         task, old_request);

    /* Device reset conditions signalled in task_state_flags are the
     * responsbility of libsas to observe at the start of the error
     * handler thread.
     */
    if (!idev || !old_request) {
        /* The request has already completed and there
        * is nothing to do here other than to set the task
        * done bit, and indicate that the task abort function
        * was successful.
        */
        spin_lock_irqsave(&task->task_state_lock, flags);
        task->task_state_flags |= SAS_TASK_STATE_DONE;
        task->task_state_flags &= ~(SAS_TASK_AT_INITIATOR |
                        SAS_TASK_STATE_PENDING);
        spin_unlock_irqrestore(&task->task_state_lock, flags);

        ret = TMF_RESP_FUNC_COMPLETE;

        dev_warn(&ihost->pdev->dev,
             "%s: abort task not needed for %p\n",
             __func__, task);
        goto out;
    }
    /* Suspend the RNC, kill the TC */
    if (isci_remote_device_suspend_terminate(ihost, idev, old_request)
        != SCI_SUCCESS) {
        dev_warn(&ihost->pdev->dev,
             "%s: isci_remote_device_reset_terminate(dev=%p, "
                 "req=%p, task=%p) failed\n",
             __func__, idev, old_request, task);
        ret = TMF_RESP_FUNC_FAILED;
        goto out;
    }
    spin_lock_irqsave(&ihost->scic_lock, flags);

    if (task->task_proto == SAS_PROTOCOL_SMP ||
        sas_protocol_ata(task->task_proto) ||
        test_bit(IREQ_COMPLETE_IN_TARGET, &old_request->flags) ||
        test_bit(IDEV_GONE, &idev->flags)) {

        spin_unlock_irqrestore(&ihost->scic_lock, flags);

        /* No task to send, so explicitly resume the device here */
        isci_remote_device_resume_from_abort(ihost, idev);

        dev_warn(&ihost->pdev->dev,
             "%s: %s request"
                 " or complete_in_target (%d), "
                 "or IDEV_GONE (%d), thus no TMF\n",
             __func__,
             ((task->task_proto == SAS_PROTOCOL_SMP)
              ? "SMP"
              : (sas_protocol_ata(task->task_proto)
                ? "SATA/STP"
                : "<other>")
              ),
             test_bit(IREQ_COMPLETE_IN_TARGET,
                  &old_request->flags),
             test_bit(IDEV_GONE, &idev->flags));

        spin_lock_irqsave(&task->task_state_lock, flags);
        task->task_state_flags &= ~(SAS_TASK_AT_INITIATOR |
                        SAS_TASK_STATE_PENDING);
        task->task_state_flags |= SAS_TASK_STATE_DONE;
        spin_unlock_irqrestore(&task->task_state_lock, flags);

        ret = TMF_RESP_FUNC_COMPLETE;
    } else {
        /* Fill in the tmf stucture */
        isci_task_build_abort_task_tmf(&tmf, isci_tmf_ssp_task_abort,
                           old_request);

        spin_unlock_irqrestore(&ihost->scic_lock, flags);

        /* Send the task management request. */
        #define ISCI_ABORT_TASK_TIMEOUT_MS 500 /* 1/2 second timeout */
        ret = isci_task_execute_tmf(ihost, idev, &tmf,
                        ISCI_ABORT_TASK_TIMEOUT_MS);
    }
out:
    dev_warn(&ihost->pdev->dev,
         "%s: Done; dev = %p, task = %p , old_request == %p\n",
         __func__, idev, task, old_request);
    isci_put_device(idev);
    return ret;
}

int isci_task_abort_task_set(
    struct domain_device *d_device,
    u8 *lun)
{
    return TMF_RESP_FUNC_FAILED;
}


int isci_task_clear_aca(
    struct domain_device *d_device,
    u8 *lun)
{
    return TMF_RESP_FUNC_FAILED;
}



int isci_task_clear_task_set(
    struct domain_device *d_device,
    u8 *lun)
{
    return TMF_RESP_FUNC_FAILED;
}


int isci_task_query_task(
    struct sas_task *task)
{
    /* See if there is a pending device reset for this device. */
    if (task->task_state_flags & SAS_TASK_NEED_DEV_RESET)
        return TMF_RESP_FUNC_FAILED;
    else
        return TMF_RESP_FUNC_SUCC;
}

/*
 * isci_task_request_complete() - This function is called by the sci core when
 *    an task request completes.
 * @ihost: This parameter specifies the ISCI host object
 * @ireq: This parameter is the completed isci_request object.
 * @completion_status: This parameter specifies the completion status from the
 *    sci core.
 *
 * none.
 */
void
isci_task_request_complete(struct isci_host *ihost,
               struct isci_request *ireq,
               enum sci_task_status completion_status)
{
    struct isci_tmf *tmf = isci_request_access_tmf(ireq);
    struct completion *tmf_complete = NULL;

    dev_dbg(&ihost->pdev->dev,
        "%s: request = %p, status=%d\n",
        __func__, ireq, completion_status);

    set_bit(IREQ_COMPLETE_IN_TARGET, &ireq->flags);

    if (tmf) {
        tmf->status = completion_status;

        if (tmf->proto == SAS_PROTOCOL_SSP) {
            memcpy(&tmf->resp.resp_iu,
                   &ireq->ssp.rsp,
                   SSP_RESP_IU_MAX_SIZE);
        } else if (tmf->proto == SAS_PROTOCOL_SATA) {
            memcpy(&tmf->resp.d2h_fis,
                   &ireq->stp.rsp,
                   sizeof(struct dev_to_host_fis));
        }
        /* PRINT_TMF( ((struct isci_tmf *)request->task)); */
        tmf_complete = tmf->complete;
    }
    sci_controller_complete_io(ihost, ireq->target_device, ireq);
    /* set the 'terminated' flag handle to make sure it cannot be terminated
     *  or completed again.
     */
    set_bit(IREQ_TERMINATED, &ireq->flags);

    if (test_and_clear_bit(IREQ_ABORT_PATH_ACTIVE, &ireq->flags))
        wake_up_all(&ihost->eventq);

    if (!test_bit(IREQ_NO_AUTO_FREE_TAG, &ireq->flags))
        isci_free_tag(ihost, ireq->io_tag);

    /* The task management part completes last. */
    if (tmf_complete)
        complete(tmf_complete);
}

static int isci_reset_device(struct isci_host *ihost,
                 struct domain_device *dev,
                 struct isci_remote_device *idev)
{
    int rc = TMF_RESP_FUNC_COMPLETE, reset_stat = -1;
    struct sas_phy *phy = sas_get_local_phy(dev);
    struct isci_port *iport = dev->port->lldd_port;

    dev_dbg(&ihost->pdev->dev, "%s: idev %p\n", __func__, idev);

    /* Suspend the RNC, terminate all outstanding TCs. */
    if (isci_remote_device_suspend_terminate(ihost, idev, NULL)
        != SCI_SUCCESS) {
        rc = TMF_RESP_FUNC_FAILED;
        goto out;
    }
    /* Note that since the termination for outstanding requests succeeded,
     * this function will return success.  This is because the resets will
     * only fail if the device has been removed (ie. hotplug), and the
     * primary duty of this function is to cleanup tasks, so that is the
     * relevant status.
     */
    if (!test_bit(IDEV_GONE, &idev->flags)) {
        if (scsi_is_sas_phy_local(phy)) {
            struct isci_phy *iphy = &ihost->phys[phy->number];

            reset_stat = isci_port_perform_hard_reset(ihost, iport,
                                  iphy);
        } else
            reset_stat = sas_phy_reset(phy, !dev_is_sata(dev));
    }
    /* Explicitly resume the RNC here, since there was no task sent. */
    isci_remote_device_resume_from_abort(ihost, idev);

    dev_dbg(&ihost->pdev->dev, "%s: idev %p complete, reset_stat=%d.\n",
        __func__, idev, reset_stat);
 out:
    sas_put_local_phy(phy);
    return rc;
}

int isci_task_I_T_nexus_reset(struct domain_device *dev)
{
    struct isci_host *ihost = dev_to_ihost(dev);
    struct isci_remote_device *idev;
    unsigned long flags;
    int ret;

    spin_lock_irqsave(&ihost->scic_lock, flags);
    idev = isci_get_device(dev->lldd_dev);
    spin_unlock_irqrestore(&ihost->scic_lock, flags);

    if (!idev) {
        /* XXX: need to cleanup any ireqs targeting this
         * domain_device
         */
        ret = TMF_RESP_FUNC_COMPLETE;
        goto out;
    }

    ret = isci_reset_device(ihost, dev, idev);
 out:
    isci_put_device(idev);
    return ret;
}