// SPDX-License-Identifier: GPL-2.0-only
/*
 * Serial Attached SCSI (SAS) class SCSI Host glue.
 *
 * Copyright (C) 2005 Adaptec, Inc.  All rights reserved.
 * Copyright (C) 2005 Luben Tuikov <luben_tuikov@adaptec.com>
 */

#include <linux/kthread.h>
#include <linux/firmware.h>
#include <linux/export.h>
#include <linux/ctype.h>
#include <linux/hex.h>
#include <linux/kernel.h>

#include "sas_internal.h"

#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_tcq.h>
#include <scsi/scsi.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_transport.h>
#include <scsi/scsi_transport_sas.h>
#include <scsi/sas_ata.h>
#include "scsi_sas_internal.h"
#include "scsi_transport_api.h"
#include "scsi_priv.h"

#include <linux/err.h>
#include <linux/blkdev.h>
#include <linux/freezer.h>
#include <linux/gfp.h>
#include <linux/scatterlist.h>
#include <linux/libata.h>

/* record final status and free the task */
static void sas_end_task(struct scsi_cmnd *sc, struct sas_task *task)
{
        struct task_status_struct *ts = &task->task_status;
        enum scsi_host_status hs = DID_OK;
        enum exec_status stat = SAS_SAM_STAT_GOOD;

        if (ts->resp == SAS_TASK_UNDELIVERED) {
                /* transport error */
                hs = DID_NO_CONNECT;
        } else { /* ts->resp == SAS_TASK_COMPLETE */
                /* task delivered, what happened afterwards? */
                switch (ts->stat) {
                case SAS_DEV_NO_RESPONSE:
                case SAS_INTERRUPTED:
                case SAS_PHY_DOWN:
                case SAS_NAK_R_ERR:
                case SAS_OPEN_TO:
                        hs = DID_NO_CONNECT;
                        break;
                case SAS_DATA_UNDERRUN:
                        scsi_set_resid(sc, ts->residual);
                        if (scsi_bufflen(sc) - scsi_get_resid(sc) < sc->underflow)
                                hs = DID_ERROR;
                        break;
                case SAS_DATA_OVERRUN:
                        hs = DID_ERROR;
                        break;
                case SAS_QUEUE_FULL:
                        hs = DID_SOFT_ERROR; /* retry */
                        break;
                case SAS_DEVICE_UNKNOWN:
                        hs = DID_BAD_TARGET;
                        break;
                case SAS_OPEN_REJECT:
                        if (ts->open_rej_reason == SAS_OREJ_RSVD_RETRY)
                                hs = DID_SOFT_ERROR; /* retry */
                        else
                                hs = DID_ERROR;
                        break;
                case SAS_PROTO_RESPONSE:
                        pr_notice("LLDD:%s sent SAS_PROTO_RESP for an SSP task; please report this\n",
                                  task->dev->port->ha->sas_ha_name);
                        break;
                case SAS_ABORTED_TASK:
                        hs = DID_ABORT;
                        break;
                case SAS_SAM_STAT_CHECK_CONDITION:
                        memcpy(sc->sense_buffer, ts->buf,
                               min(SCSI_SENSE_BUFFERSIZE, ts->buf_valid_size));
                        stat = SAS_SAM_STAT_CHECK_CONDITION;
                        break;
                default:
                        stat = ts->stat;
                        break;
                }
        }

        sc->result = (hs << 16) | stat;
        ASSIGN_SAS_TASK(sc, NULL);
        sas_free_task(task);
}

static void sas_scsi_task_done(struct sas_task *task)
{
        struct scsi_cmnd *sc = task->uldd_task;
        struct domain_device *dev = task->dev;
        struct sas_ha_struct *ha = dev->port->ha;
        unsigned long flags;

        spin_lock_irqsave(&dev->done_lock, flags);
        if (test_bit(SAS_HA_FROZEN, &ha->state))
                task = NULL;
        else
                ASSIGN_SAS_TASK(sc, NULL);
        spin_unlock_irqrestore(&dev->done_lock, flags);

        if (unlikely(!task)) {
                /* task will be completed by the error handler */
                pr_debug("task done but aborted\n");
                return;
        }

        if (unlikely(!sc)) {
                pr_debug("task_done called with non existing SCSI cmnd!\n");
                sas_free_task(task);
                return;
        }

        sas_end_task(sc, task);
        scsi_done(sc);
}

static struct sas_task *sas_create_task(struct scsi_cmnd *cmd,
                                               struct domain_device *dev,
                                               gfp_t gfp_flags)
{
        struct sas_task *task = sas_alloc_task(gfp_flags);
        struct scsi_lun lun;

        if (!task)
                return NULL;

        task->uldd_task = cmd;
        ASSIGN_SAS_TASK(cmd, task);

        task->dev = dev;
        task->task_proto = task->dev->tproto; /* BUG_ON(!SSP) */

        int_to_scsilun(cmd->device->lun, &lun);
        memcpy(task->ssp_task.LUN, &lun.scsi_lun, 8);
        task->ssp_task.task_attr = TASK_ATTR_SIMPLE;
        task->ssp_task.cmd = cmd;

        task->scatter = scsi_sglist(cmd);
        task->num_scatter = scsi_sg_count(cmd);
        task->total_xfer_len = scsi_bufflen(cmd);
        task->data_dir = cmd->sc_data_direction;

        task->task_done = sas_scsi_task_done;

        return task;
}

enum scsi_qc_status sas_queuecommand(struct Scsi_Host *host,
                                     struct scsi_cmnd *cmd)
{
        struct sas_internal *i = to_sas_internal(host->transportt);
        struct domain_device *dev = cmd_to_domain_dev(cmd);
        struct sas_task *task;
        int res = 0;

        /* If the device fell off, no sense in issuing commands */
        if (test_bit(SAS_DEV_GONE, &dev->state)) {
                cmd->result = DID_BAD_TARGET << 16;
                goto out_done;
        }

        if (dev_is_sata(dev)) {
                spin_lock_irq(dev->sata_dev.ap->lock);
                res = ata_sas_queuecmd(cmd, dev->sata_dev.ap);
                spin_unlock_irq(dev->sata_dev.ap->lock);
                return res;
        }

        task = sas_create_task(cmd, dev, GFP_ATOMIC);
        if (!task)
                return SCSI_MLQUEUE_HOST_BUSY;

        res = i->dft->lldd_execute_task(task, GFP_ATOMIC);
        if (res)
                goto out_free_task;
        return 0;

out_free_task:
        pr_debug("lldd_execute_task returned: %d\n", res);
        ASSIGN_SAS_TASK(cmd, NULL);
        sas_free_task(task);
        if (res == -SAS_QUEUE_FULL)
                cmd->result = DID_SOFT_ERROR << 16; /* retry */
        else
                cmd->result = DID_ERROR << 16;
out_done:
        scsi_done(cmd);
        return 0;
}
EXPORT_SYMBOL_GPL(sas_queuecommand);

static void sas_eh_finish_cmd(struct scsi_cmnd *cmd)
{
        struct sas_ha_struct *sas_ha = SHOST_TO_SAS_HA(cmd->device->host);
        struct domain_device *dev = cmd_to_domain_dev(cmd);
        struct sas_task *task = TO_SAS_TASK(cmd);

        /* At this point, we only get called following an actual abort
         * of the task, so we should be guaranteed not to be racing with
         * any completions from the LLD.  Task is freed after this.
         */
        sas_end_task(cmd, task);

        if (dev_is_sata(dev)) {
                /* defer commands to libata so that libata EH can
                 * handle ata qcs correctly
                 */
                list_move_tail(&cmd->eh_entry, &sas_ha->eh_ata_q);
                return;
        }

        /* now finish the command and move it on to the error
         * handler done list, this also takes it off the
         * error handler pending list.
         */
        scsi_eh_finish_cmd(cmd, &sas_ha->eh_done_q);
}

static void sas_scsi_clear_queue_lu(struct list_head *error_q, struct scsi_cmnd *my_cmd)
{
        struct scsi_cmnd *cmd, *n;

        list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
                if (cmd->device->sdev_target == my_cmd->device->sdev_target &&
                    cmd->device->lun == my_cmd->device->lun)
                        sas_eh_finish_cmd(cmd);
        }
}

static void sas_scsi_clear_queue_I_T(struct list_head *error_q,
                                     struct domain_device *dev)
{
        struct scsi_cmnd *cmd, *n;

        list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
                struct domain_device *x = cmd_to_domain_dev(cmd);

                if (x == dev)
                        sas_eh_finish_cmd(cmd);
        }
}

static void sas_scsi_clear_queue_port(struct list_head *error_q,
                                      struct asd_sas_port *port)
{
        struct scsi_cmnd *cmd, *n;

        list_for_each_entry_safe(cmd, n, error_q, eh_entry) {
                struct domain_device *dev = cmd_to_domain_dev(cmd);
                struct asd_sas_port *x = dev->port;

                if (x == port)
                        sas_eh_finish_cmd(cmd);
        }
}

enum task_disposition {
        TASK_IS_DONE,
        TASK_IS_ABORTED,
        TASK_IS_AT_LU,
        TASK_IS_NOT_AT_LU,
        TASK_ABORT_FAILED,
};

static enum task_disposition sas_scsi_find_task(struct sas_task *task)
{
        unsigned long flags;
        int i, res;
        struct sas_internal *si =
                to_sas_internal(task->dev->port->ha->shost->transportt);

        for (i = 0; i < 5; i++) {
                pr_notice("%s: aborting task 0x%p\n", __func__, task);
                res = si->dft->lldd_abort_task(task);

                spin_lock_irqsave(&task->task_state_lock, flags);
                if (task->task_state_flags & SAS_TASK_STATE_DONE) {
                        spin_unlock_irqrestore(&task->task_state_lock, flags);
                        pr_debug("%s: task 0x%p is done\n", __func__, task);
                        return TASK_IS_DONE;
                }
                spin_unlock_irqrestore(&task->task_state_lock, flags);

                if (res == TMF_RESP_FUNC_COMPLETE) {
                        pr_notice("%s: task 0x%p is aborted\n",
                                  __func__, task);
                        return TASK_IS_ABORTED;
                } else if (si->dft->lldd_query_task) {
                        pr_notice("%s: querying task 0x%p\n", __func__, task);
                        res = si->dft->lldd_query_task(task);
                        switch (res) {
                        case TMF_RESP_FUNC_SUCC:
                                pr_notice("%s: task 0x%p at LU\n", __func__,
                                          task);
                                return TASK_IS_AT_LU;
                        case TMF_RESP_FUNC_COMPLETE:
                                pr_notice("%s: task 0x%p not at LU\n",
                                          __func__, task);
                                return TASK_IS_NOT_AT_LU;
                        case TMF_RESP_FUNC_FAILED:
                                pr_notice("%s: task 0x%p failed to abort\n",
                                          __func__, task);
                                return TASK_ABORT_FAILED;
                        default:
                                pr_notice("%s: task 0x%p result code %d not handled\n",
                                          __func__, task, res);
                        }
                }
        }
        return TASK_ABORT_FAILED;
}

static int sas_recover_lu(struct domain_device *dev, struct scsi_cmnd *cmd)
{
        int res = TMF_RESP_FUNC_FAILED;
        struct scsi_lun lun;
        struct sas_internal *i =
                to_sas_internal(dev->port->ha->shost->transportt);

        int_to_scsilun(cmd->device->lun, &lun);

        pr_notice("eh: device %016llx LUN 0x%llx has the task\n",
                  SAS_ADDR(dev->sas_addr),
                  cmd->device->lun);

        if (i->dft->lldd_abort_task_set)
                res = i->dft->lldd_abort_task_set(dev, lun.scsi_lun);

        if (res == TMF_RESP_FUNC_FAILED) {
                if (i->dft->lldd_clear_task_set)
                        res = i->dft->lldd_clear_task_set(dev, lun.scsi_lun);
        }

        if (res == TMF_RESP_FUNC_FAILED) {
                if (i->dft->lldd_lu_reset)
                        res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
        }

        return res;
}

static int sas_recover_I_T(struct domain_device *dev)
{
        int res = TMF_RESP_FUNC_FAILED;
        struct sas_internal *i =
                to_sas_internal(dev->port->ha->shost->transportt);

        pr_notice("I_T nexus reset for dev %016llx\n",
                  SAS_ADDR(dev->sas_addr));

        if (i->dft->lldd_I_T_nexus_reset)
                res = i->dft->lldd_I_T_nexus_reset(dev);

        return res;
}

/* take a reference on the last known good phy for this device */
struct sas_phy *sas_get_local_phy(struct domain_device *dev)
{
        struct sas_ha_struct *ha = dev->port->ha;
        struct sas_phy *phy;
        unsigned long flags;

        /* a published domain device always has a valid phy, it may be
         * stale, but it is never NULL
         */
        BUG_ON(!dev->phy);

        spin_lock_irqsave(&ha->phy_port_lock, flags);
        phy = dev->phy;
        get_device(&phy->dev);
        spin_unlock_irqrestore(&ha->phy_port_lock, flags);

        return phy;
}
EXPORT_SYMBOL_GPL(sas_get_local_phy);

static int sas_queue_reset(struct domain_device *dev, int reset_type, u64 lun)
{
        struct sas_ha_struct *ha = dev->port->ha;
        int scheduled = 0, tries = 100;

        /* ata: promote lun reset to bus reset */
        if (dev_is_sata(dev)) {
                sas_ata_schedule_reset(dev);
                return SUCCESS;
        }

        while (!scheduled && tries--) {
                spin_lock_irq(&ha->lock);
                if (!test_bit(SAS_DEV_EH_PENDING, &dev->state) &&
                    !test_bit(reset_type, &dev->state)) {
                        scheduled = 1;
                        ha->eh_active++;
                        list_add_tail(&dev->ssp_dev.eh_list_node, &ha->eh_dev_q);
                        set_bit(SAS_DEV_EH_PENDING, &dev->state);
                        set_bit(reset_type, &dev->state);
                        int_to_scsilun(lun, &dev->ssp_dev.reset_lun);
                        scsi_schedule_eh(ha->shost);
                }
                spin_unlock_irq(&ha->lock);

                if (scheduled)
                        return SUCCESS;
        }

        pr_warn("%s reset of %s failed\n",
                reset_type == SAS_DEV_LU_RESET ? "LUN" : "Bus",
                dev_name(&dev->rphy->dev));

        return FAILED;
}

int sas_eh_abort_handler(struct scsi_cmnd *cmd)
{
        int res = TMF_RESP_FUNC_FAILED;
        struct sas_task *task = TO_SAS_TASK(cmd);
        struct Scsi_Host *host = cmd->device->host;
        struct domain_device *dev = cmd_to_domain_dev(cmd);
        struct sas_internal *i = to_sas_internal(host->transportt);
        unsigned long flags;

        if (!i->dft->lldd_abort_task)
                return FAILED;

        spin_lock_irqsave(host->host_lock, flags);
        /* We cannot do async aborts for SATA devices */
        if (dev_is_sata(dev) && !host->host_eh_scheduled) {
                spin_unlock_irqrestore(host->host_lock, flags);
                return FAILED;
        }
        spin_unlock_irqrestore(host->host_lock, flags);

        if (task)
                res = i->dft->lldd_abort_task(task);
        else
                pr_notice("no task to abort\n");
        if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
                return SUCCESS;

        return FAILED;
}
EXPORT_SYMBOL_GPL(sas_eh_abort_handler);

/* Attempt to send a LUN reset message to a device */
int sas_eh_device_reset_handler(struct scsi_cmnd *cmd)
{
        int res;
        struct scsi_lun lun;
        struct Scsi_Host *host = cmd->device->host;
        struct domain_device *dev = cmd_to_domain_dev(cmd);
        struct sas_internal *i = to_sas_internal(host->transportt);

        if (current != host->ehandler)
                return sas_queue_reset(dev, SAS_DEV_LU_RESET, cmd->device->lun);

        int_to_scsilun(cmd->device->lun, &lun);

        if (!i->dft->lldd_lu_reset)
                return FAILED;

        res = i->dft->lldd_lu_reset(dev, lun.scsi_lun);
        if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE)
                return SUCCESS;

        return FAILED;
}
EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);

int sas_eh_target_reset_handler(struct scsi_cmnd *cmd)
{
        int res;
        struct Scsi_Host *host = cmd->device->host;
        struct domain_device *dev = cmd_to_domain_dev(cmd);
        struct sas_internal *i = to_sas_internal(host->transportt);

        if (current != host->ehandler)
                return sas_queue_reset(dev, SAS_DEV_RESET, 0);

        if (!i->dft->lldd_I_T_nexus_reset)
                return FAILED;

        res = i->dft->lldd_I_T_nexus_reset(dev);
        if (res == TMF_RESP_FUNC_SUCC || res == TMF_RESP_FUNC_COMPLETE ||
            res == -ENODEV)
                return SUCCESS;

        return FAILED;
}
EXPORT_SYMBOL_GPL(sas_eh_target_reset_handler);

/* Try to reset a device */
static int try_to_reset_cmd_device(struct scsi_cmnd *cmd)
{
        int res;
        struct Scsi_Host *shost = cmd->device->host;

        if (!shost->hostt->eh_device_reset_handler)
                goto try_target_reset;

        res = shost->hostt->eh_device_reset_handler(cmd);
        if (res == SUCCESS)
                return res;

try_target_reset:
        if (shost->hostt->eh_target_reset_handler)
                return shost->hostt->eh_target_reset_handler(cmd);

        return FAILED;
}

static void sas_eh_handle_sas_errors(struct Scsi_Host *shost, struct list_head *work_q)
{
        struct scsi_cmnd *cmd, *n;
        enum task_disposition res = TASK_IS_DONE;
        int tmf_resp, need_reset;
        struct sas_internal *i = to_sas_internal(shost->transportt);
        unsigned long flags;
        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
        LIST_HEAD(done);

        /* clean out any commands that won the completion vs eh race */
        list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
                struct domain_device *dev = cmd_to_domain_dev(cmd);
                struct sas_task *task;

                spin_lock_irqsave(&dev->done_lock, flags);
                /* by this point the lldd has either observed
                 * SAS_HA_FROZEN and is leaving the task alone, or has
                 * won the race with eh and decided to complete it
                 */
                task = TO_SAS_TASK(cmd);
                spin_unlock_irqrestore(&dev->done_lock, flags);

                if (!task)
                        list_move_tail(&cmd->eh_entry, &done);
        }

 Again:
        list_for_each_entry_safe(cmd, n, work_q, eh_entry) {
                struct sas_task *task = TO_SAS_TASK(cmd);

                list_del_init(&cmd->eh_entry);

                spin_lock_irqsave(&task->task_state_lock, flags);
                need_reset = task->task_state_flags & SAS_TASK_NEED_DEV_RESET;
                spin_unlock_irqrestore(&task->task_state_lock, flags);

                if (need_reset) {
                        pr_notice("%s: task 0x%p requests reset\n",
                                  __func__, task);
                        goto reset;
                }

                pr_debug("trying to find task 0x%p\n", task);
                res = sas_scsi_find_task(task);

                switch (res) {
                case TASK_IS_DONE:
                        pr_notice("%s: task 0x%p is done\n", __func__,
                                    task);
                        sas_eh_finish_cmd(cmd);
                        continue;
                case TASK_IS_ABORTED:
                        pr_notice("%s: task 0x%p is aborted\n",
                                  __func__, task);
                        sas_eh_finish_cmd(cmd);
                        continue;
                case TASK_IS_AT_LU:
                        pr_info("task 0x%p is at LU: lu recover\n", task);
 reset:
                        tmf_resp = sas_recover_lu(task->dev, cmd);
                        if (tmf_resp == TMF_RESP_FUNC_COMPLETE) {
                                pr_notice("dev %016llx LU 0x%llx is recovered\n",
                                          SAS_ADDR(task->dev),
                                          cmd->device->lun);
                                sas_eh_finish_cmd(cmd);
                                sas_scsi_clear_queue_lu(work_q, cmd);
                                goto Again;
                        }
                        fallthrough;
                case TASK_IS_NOT_AT_LU:
                case TASK_ABORT_FAILED:
                        pr_notice("task 0x%p is not at LU: I_T recover\n",
                                  task);
                        tmf_resp = sas_recover_I_T(task->dev);
                        if (tmf_resp == TMF_RESP_FUNC_COMPLETE ||
                            tmf_resp == -ENODEV) {
                                struct domain_device *dev = task->dev;
                                pr_notice("I_T %016llx recovered\n",
                                          SAS_ADDR(task->dev->sas_addr));
                                sas_eh_finish_cmd(cmd);
                                sas_scsi_clear_queue_I_T(work_q, dev);
                                goto Again;
                        }
                        /* Hammer time :-) */
                        try_to_reset_cmd_device(cmd);
                        if (i->dft->lldd_clear_nexus_port) {
                                struct asd_sas_port *port = task->dev->port;
                                pr_debug("clearing nexus for port:%d\n",
                                          port->id);
                                res = i->dft->lldd_clear_nexus_port(port);
                                if (res == TMF_RESP_FUNC_COMPLETE) {
                                        pr_notice("clear nexus port:%d succeeded\n",
                                                  port->id);
                                        sas_eh_finish_cmd(cmd);
                                        sas_scsi_clear_queue_port(work_q,
                                                                  port);
                                        goto Again;
                                }
                        }
                        if (i->dft->lldd_clear_nexus_ha) {
                                pr_debug("clear nexus ha\n");
                                res = i->dft->lldd_clear_nexus_ha(ha);
                                if (res == TMF_RESP_FUNC_COMPLETE) {
                                        pr_notice("clear nexus ha succeeded\n");
                                        sas_eh_finish_cmd(cmd);
                                        goto clear_q;
                                }
                        }
                        /* If we are here -- this means that no amount
                         * of effort could recover from errors.  Quite
                         * possibly the HA just disappeared.
                         */
                        pr_err("error from device %016llx, LUN 0x%llx couldn't be recovered in any way\n",
                               SAS_ADDR(task->dev->sas_addr),
                               cmd->device->lun);

                        sas_eh_finish_cmd(cmd);
                        goto clear_q;
                }
        }
 out:
        list_splice_tail(&done, work_q);
        list_splice_tail_init(&ha->eh_ata_q, work_q);
        return;

 clear_q:
        pr_debug("--- Exit %s -- clear_q\n", __func__);
        list_for_each_entry_safe(cmd, n, work_q, eh_entry)
                sas_eh_finish_cmd(cmd);
        goto out;
}

static void sas_eh_handle_resets(struct Scsi_Host *shost)
{
        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
        struct sas_internal *i = to_sas_internal(shost->transportt);

        /* handle directed resets to sas devices */
        spin_lock_irq(&ha->lock);
        while (!list_empty(&ha->eh_dev_q)) {
                struct domain_device *dev;
                struct ssp_device *ssp;

                ssp = list_entry(ha->eh_dev_q.next, typeof(*ssp), eh_list_node);
                list_del_init(&ssp->eh_list_node);
                dev = container_of(ssp, typeof(*dev), ssp_dev);
                kref_get(&dev->kref);
                WARN_ONCE(dev_is_sata(dev), "ssp reset to ata device?\n");

                spin_unlock_irq(&ha->lock);

                if (test_and_clear_bit(SAS_DEV_LU_RESET, &dev->state))
                        i->dft->lldd_lu_reset(dev, ssp->reset_lun.scsi_lun);

                if (test_and_clear_bit(SAS_DEV_RESET, &dev->state))
                        i->dft->lldd_I_T_nexus_reset(dev);

                sas_put_device(dev);
                spin_lock_irq(&ha->lock);
                clear_bit(SAS_DEV_EH_PENDING, &dev->state);
                ha->eh_active--;
        }
        spin_unlock_irq(&ha->lock);
}


void sas_scsi_recover_host(struct Scsi_Host *shost)
{
        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
        LIST_HEAD(eh_work_q);
        int tries = 0;
        bool retry;

retry:
        tries++;
        retry = true;
        spin_lock_irq(shost->host_lock);
        list_splice_init(&shost->eh_cmd_q, &eh_work_q);
        spin_unlock_irq(shost->host_lock);

        pr_notice("Enter %s busy: %d failed: %d\n",
                  __func__, scsi_host_busy(shost), shost->host_failed);
        /*
         * Deal with commands that still have SAS tasks (i.e. they didn't
         * complete via the normal sas_task completion mechanism),
         * SAS_HA_FROZEN gives eh dominion over all sas_task completion.
         */
        set_bit(SAS_HA_FROZEN, &ha->state);
        sas_eh_handle_sas_errors(shost, &eh_work_q);
        clear_bit(SAS_HA_FROZEN, &ha->state);
        if (list_empty(&eh_work_q))
                goto out;

        /*
         * Now deal with SCSI commands that completed ok but have a an error
         * code (and hopefully sense data) attached.  This is roughly what
         * scsi_unjam_host does, but we skip scsi_eh_abort_cmds because any
         * command we see here has no sas_task and is thus unknown to the HA.
         */
        sas_ata_eh(shost, &eh_work_q);
        if (!scsi_eh_get_sense(&eh_work_q, &ha->eh_done_q))
                scsi_eh_ready_devs(shost, &eh_work_q, &ha->eh_done_q);

out:
        sas_eh_handle_resets(shost);

        /* now link into libata eh --- if we have any ata devices */
        sas_ata_strategy_handler(shost);

        scsi_eh_flush_done_q(&ha->eh_done_q);

        /* check if any new eh work was scheduled during the last run */
        spin_lock_irq(&ha->lock);
        if (ha->eh_active == 0) {
                shost->host_eh_scheduled = 0;
                retry = false;
        }
        spin_unlock_irq(&ha->lock);

        if (retry)
                goto retry;

        pr_notice("--- Exit %s: busy: %d failed: %d tries: %d\n",
                  __func__, scsi_host_busy(shost),
                  shost->host_failed, tries);
}

int sas_ioctl(struct scsi_device *sdev, unsigned int cmd, void __user *arg)
{
        struct domain_device *dev = sdev_to_domain_dev(sdev);

        if (dev_is_sata(dev))
                return ata_sas_scsi_ioctl(dev->sata_dev.ap, sdev, cmd, arg);

        return -EINVAL;
}
EXPORT_SYMBOL_GPL(sas_ioctl);

struct domain_device *sas_find_dev_by_rphy(struct sas_rphy *rphy)
{
        struct Scsi_Host *shost = dev_to_shost(rphy->dev.parent);
        struct sas_ha_struct *ha = SHOST_TO_SAS_HA(shost);
        struct domain_device *found_dev = NULL;
        int i;
        unsigned long flags;

        spin_lock_irqsave(&ha->phy_port_lock, flags);
        for (i = 0; i < ha->num_phys; i++) {
                struct asd_sas_port *port = ha->sas_port[i];
                struct domain_device *dev;

                spin_lock(&port->dev_list_lock);
                list_for_each_entry(dev, &port->dev_list, dev_list_node) {
                        if (rphy == dev->rphy) {
                                found_dev = dev;
                                spin_unlock(&port->dev_list_lock);
                                goto found;
                        }
                }
                spin_unlock(&port->dev_list_lock);
        }
 found:
        spin_unlock_irqrestore(&ha->phy_port_lock, flags);

        return found_dev;
}

int sas_target_alloc(struct scsi_target *starget)
{
        struct sas_rphy *rphy = dev_to_rphy(starget->dev.parent);
        struct domain_device *found_dev = sas_find_dev_by_rphy(rphy);

        if (!found_dev)
                return -ENODEV;

        kref_get(&found_dev->kref);
        starget->hostdata = found_dev;
        return 0;
}
EXPORT_SYMBOL_GPL(sas_target_alloc);

#define SAS_DEF_QD 256

int sas_sdev_configure(struct scsi_device *scsi_dev, struct queue_limits *lim)
{
        struct domain_device *dev = sdev_to_domain_dev(scsi_dev);

        BUG_ON(dev->rphy->identify.device_type != SAS_END_DEVICE);

        if (dev_is_sata(dev)) {
                ata_sas_sdev_configure(scsi_dev, lim, dev->sata_dev.ap);
                return 0;
        }

        sas_read_port_mode_page(scsi_dev);

        if (scsi_dev->tagged_supported) {
                scsi_change_queue_depth(scsi_dev, SAS_DEF_QD);
        } else {
                pr_notice("device %016llx, LUN 0x%llx doesn't support TCQ\n",
                          SAS_ADDR(dev->sas_addr), scsi_dev->lun);
                scsi_change_queue_depth(scsi_dev, 1);
        }

        scsi_dev->allow_restart = 1;

        return 0;
}
EXPORT_SYMBOL_GPL(sas_sdev_configure);

int sas_change_queue_depth(struct scsi_device *sdev, int depth)
{
        struct domain_device *dev = sdev_to_domain_dev(sdev);

        if (dev_is_sata(dev))
                return ata_change_queue_depth(dev->sata_dev.ap, sdev, depth);

        if (!sdev->tagged_supported)
                depth = 1;
        return scsi_change_queue_depth(sdev, depth);
}
EXPORT_SYMBOL_GPL(sas_change_queue_depth);

int sas_bios_param(struct scsi_device *scsi_dev,
                          struct gendisk *unused,
                          sector_t capacity, int *hsc)
{
        hsc[0] = 255;
        hsc[1] = 63;
        sector_div(capacity, 255*63);
        hsc[2] = capacity;

        return 0;
}
EXPORT_SYMBOL_GPL(sas_bios_param);

void sas_task_internal_done(struct sas_task *task)
{
        timer_delete(&task->slow_task->timer);
        complete(&task->slow_task->completion);
}

void sas_task_internal_timedout(struct timer_list *t)
{
        struct sas_task_slow *slow = timer_container_of(slow, t, timer);
        struct sas_task *task = slow->task;
        bool is_completed = true;
        unsigned long flags;

        spin_lock_irqsave(&task->task_state_lock, flags);
        if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
                task->task_state_flags |= SAS_TASK_STATE_ABORTED;
                is_completed = false;
        }
        spin_unlock_irqrestore(&task->task_state_lock, flags);

        if (!is_completed)
                complete(&task->slow_task->completion);
}

#define TASK_TIMEOUT                    (20 * HZ)
#define TASK_RETRY                      3

static int sas_execute_internal_abort(struct domain_device *device,
                                      enum sas_internal_abort type, u16 tag,
                                      unsigned int qid, void *data)
{
        struct sas_ha_struct *ha = device->port->ha;
        struct sas_internal *i = to_sas_internal(ha->shost->transportt);
        struct sas_task *task = NULL;
        int res, retry;

        for (retry = 0; retry < TASK_RETRY; retry++) {
                task = sas_alloc_slow_task(GFP_KERNEL);
                if (!task)
                        return -ENOMEM;

                task->dev = device;
                task->task_proto = SAS_PROTOCOL_INTERNAL_ABORT;
                task->task_done = sas_task_internal_done;
                task->slow_task->timer.function = sas_task_internal_timedout;
                task->slow_task->timer.expires = jiffies + TASK_TIMEOUT;
                add_timer(&task->slow_task->timer);

                task->abort_task.tag = tag;
                task->abort_task.type = type;
                task->abort_task.qid = qid;

                res = i->dft->lldd_execute_task(task, GFP_KERNEL);
                if (res) {
                        timer_delete_sync(&task->slow_task->timer);
                        pr_err("Executing internal abort failed %016llx (%d)\n",
                               SAS_ADDR(device->sas_addr), res);
                        break;
                }

                wait_for_completion(&task->slow_task->completion);
                res = TMF_RESP_FUNC_FAILED;

                /* Even if the internal abort timed out, return direct. */
                if (task->task_state_flags & SAS_TASK_STATE_ABORTED) {
                        bool quit = true;

                        if (i->dft->lldd_abort_timeout)
                                quit = i->dft->lldd_abort_timeout(task, data);
                        else
                                pr_err("Internal abort: timeout %016llx\n",
                                       SAS_ADDR(device->sas_addr));
                        res = -EIO;
                        if (quit)
                                break;
                }

                if (task->task_status.resp == SAS_TASK_COMPLETE &&
                        task->task_status.stat == SAS_SAM_STAT_GOOD) {
                        res = TMF_RESP_FUNC_COMPLETE;
                        break;
                }

                if (task->task_status.resp == SAS_TASK_COMPLETE &&
                        task->task_status.stat == TMF_RESP_FUNC_SUCC) {
                        res = TMF_RESP_FUNC_SUCC;
                        break;
                }

                pr_err("Internal abort: task to dev %016llx response: 0x%x status 0x%x\n",
                       SAS_ADDR(device->sas_addr), task->task_status.resp,
                       task->task_status.stat);
                sas_free_task(task);
                task = NULL;
        }
        BUG_ON(retry == TASK_RETRY && task != NULL);
        sas_free_task(task);
        return res;
}

int sas_execute_internal_abort_single(struct domain_device *device, u16 tag,
                                      unsigned int qid, void *data)
{
        return sas_execute_internal_abort(device, SAS_INTERNAL_ABORT_SINGLE,
                                          tag, qid, data);
}
EXPORT_SYMBOL_GPL(sas_execute_internal_abort_single);

int sas_execute_internal_abort_dev(struct domain_device *device,
                                   unsigned int qid, void *data)
{
        return sas_execute_internal_abort(device, SAS_INTERNAL_ABORT_DEV,
                                          SCSI_NO_TAG, qid, data);
}
EXPORT_SYMBOL_GPL(sas_execute_internal_abort_dev);

int sas_execute_tmf(struct domain_device *device, void *parameter,
                    int para_len, int force_phy_id,
                    struct sas_tmf_task *tmf)
{
        struct sas_task *task;
        struct sas_internal *i =
                to_sas_internal(device->port->ha->shost->transportt);
        int res, retry;

        for (retry = 0; retry < TASK_RETRY; retry++) {
                task = sas_alloc_slow_task(GFP_KERNEL);
                if (!task)
                        return -ENOMEM;

                task->dev = device;
                task->task_proto = device->tproto;

                if (dev_is_sata(device)) {
                        task->ata_task.device_control_reg_update = 1;
                        if (force_phy_id >= 0) {
                                task->ata_task.force_phy = true;
                                task->ata_task.force_phy_id = force_phy_id;
                        }
                        memcpy(&task->ata_task.fis, parameter, para_len);
                } else {
                        memcpy(&task->ssp_task, parameter, para_len);
                }

                task->task_done = sas_task_internal_done;
                task->tmf = tmf;

                task->slow_task->timer.function = sas_task_internal_timedout;
                task->slow_task->timer.expires = jiffies + TASK_TIMEOUT;
                add_timer(&task->slow_task->timer);

                res = i->dft->lldd_execute_task(task, GFP_KERNEL);
                if (res) {
                        timer_delete_sync(&task->slow_task->timer);
                        pr_err("executing TMF task failed %016llx (%d)\n",
                               SAS_ADDR(device->sas_addr), res);
                        break;
                }

                wait_for_completion(&task->slow_task->completion);

                if (i->dft->lldd_tmf_exec_complete)
                        i->dft->lldd_tmf_exec_complete(device);

                res = TMF_RESP_FUNC_FAILED;

                if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
                        if (!(task->task_state_flags & SAS_TASK_STATE_DONE)) {
                                pr_err("TMF task timeout for %016llx and not done\n",
                                       SAS_ADDR(device->sas_addr));
                                if (i->dft->lldd_tmf_aborted)
                                        i->dft->lldd_tmf_aborted(task);
                                break;
                        }
                        pr_warn("TMF task timeout for %016llx and done\n",
                                SAS_ADDR(device->sas_addr));
                }

                if (task->task_status.resp == SAS_TASK_COMPLETE &&
                    task->task_status.stat == TMF_RESP_FUNC_COMPLETE) {
                        res = TMF_RESP_FUNC_COMPLETE;
                        break;
                }

                if (task->task_status.resp == SAS_TASK_COMPLETE &&
                    task->task_status.stat == TMF_RESP_FUNC_SUCC) {
                        res = TMF_RESP_FUNC_SUCC;
                        break;
                }

                if (task->task_status.resp == SAS_TASK_COMPLETE &&
                    task->task_status.stat == SAS_DATA_UNDERRUN) {
                        /* no error, but return the number of bytes of
                         * underrun
                         */
                        pr_warn("TMF task to dev %016llx resp: 0x%x sts 0x%x underrun\n",
                                SAS_ADDR(device->sas_addr),
                                task->task_status.resp,
                                task->task_status.stat);
                        res = task->task_status.residual;
                        break;
                }

                if (task->task_status.resp == SAS_TASK_COMPLETE &&
                    task->task_status.stat == SAS_DATA_OVERRUN) {
                        pr_warn("TMF task blocked task error %016llx\n",
                                SAS_ADDR(device->sas_addr));
                        res = -EMSGSIZE;
                        break;
                }

                if (task->task_status.resp == SAS_TASK_COMPLETE &&
                    task->task_status.stat == SAS_OPEN_REJECT) {
                        pr_warn("TMF task open reject failed  %016llx\n",
                                SAS_ADDR(device->sas_addr));
                        res = -EIO;
                } else {
                        pr_warn("TMF task to dev %016llx resp: 0x%x status 0x%x\n",
                                SAS_ADDR(device->sas_addr),
                                task->task_status.resp,
                                task->task_status.stat);
                }
                sas_free_task(task);
                task = NULL;
        }

        if (retry == TASK_RETRY)
                pr_warn("executing TMF for %016llx failed after %d attempts!\n",
                        SAS_ADDR(device->sas_addr), TASK_RETRY);
        sas_free_task(task);

        return res;
}

static int sas_execute_ssp_tmf(struct domain_device *device, u8 *lun,
                               struct sas_tmf_task *tmf)
{
        struct sas_ssp_task ssp_task;

        if (!(device->tproto & SAS_PROTOCOL_SSP))
                return TMF_RESP_FUNC_ESUPP;

        memcpy(ssp_task.LUN, lun, 8);

        return sas_execute_tmf(device, &ssp_task, sizeof(ssp_task), -1, tmf);
}

int sas_abort_task_set(struct domain_device *dev, u8 *lun)
{
        struct sas_tmf_task tmf_task = {
                .tmf = TMF_ABORT_TASK_SET,
        };

        return sas_execute_ssp_tmf(dev, lun, &tmf_task);
}
EXPORT_SYMBOL_GPL(sas_abort_task_set);

int sas_clear_task_set(struct domain_device *dev, u8 *lun)
{
        struct sas_tmf_task tmf_task = {
                .tmf = TMF_CLEAR_TASK_SET,
        };

        return sas_execute_ssp_tmf(dev, lun, &tmf_task);
}
EXPORT_SYMBOL_GPL(sas_clear_task_set);

int sas_lu_reset(struct domain_device *dev, u8 *lun)
{
        struct sas_tmf_task tmf_task = {
                .tmf = TMF_LU_RESET,
        };

        return sas_execute_ssp_tmf(dev, lun, &tmf_task);
}
EXPORT_SYMBOL_GPL(sas_lu_reset);

int sas_query_task(struct sas_task *task, u16 tag)
{
        struct sas_tmf_task tmf_task = {
                .tmf = TMF_QUERY_TASK,
                .tag_of_task_to_be_managed = tag,
        };
        struct scsi_cmnd *cmnd = task->uldd_task;
        struct domain_device *dev = task->dev;
        struct scsi_lun lun;

        int_to_scsilun(cmnd->device->lun, &lun);

        return sas_execute_ssp_tmf(dev, lun.scsi_lun, &tmf_task);
}
EXPORT_SYMBOL_GPL(sas_query_task);

int sas_abort_task(struct sas_task *task, u16 tag)
{
        struct sas_tmf_task tmf_task = {
                .tmf = TMF_ABORT_TASK,
                .tag_of_task_to_be_managed = tag,
        };
        struct scsi_cmnd *cmnd = task->uldd_task;
        struct domain_device *dev = task->dev;
        struct scsi_lun lun;

        int_to_scsilun(cmnd->device->lun, &lun);

        return sas_execute_ssp_tmf(dev, lun.scsi_lun, &tmf_task);
}
EXPORT_SYMBOL_GPL(sas_abort_task);

/*
 * Tell an upper layer that it needs to initiate an abort for a given task.
 * This should only ever be called by an LLDD.
 */
void sas_task_abort(struct sas_task *task)
{
        struct scsi_cmnd *sc = task->uldd_task;

        /* Escape for libsas internal commands */
        if (!sc) {
                struct sas_task_slow *slow = task->slow_task;

                if (!slow)
                        return;
                if (!timer_delete(&slow->timer))
                        return;
                slow->timer.function(&slow->timer);
                return;
        }

        if (dev_is_sata(task->dev))
                sas_ata_task_abort(task);
        else
                blk_abort_request(scsi_cmd_to_rq(sc));
}
EXPORT_SYMBOL_GPL(sas_task_abort);

int sas_sdev_init(struct scsi_device *sdev)
{
        if (dev_is_sata(sdev_to_domain_dev(sdev)) && sdev->lun)
                return -ENXIO;

        return 0;
}
EXPORT_SYMBOL_GPL(sas_sdev_init);

void sas_target_destroy(struct scsi_target *starget)
{
        struct domain_device *found_dev = starget->hostdata;

        if (!found_dev)
                return;

        starget->hostdata = NULL;
        sas_put_device(found_dev);
}
EXPORT_SYMBOL_GPL(sas_target_destroy);

#define SAS_STRING_ADDR_SIZE    16

int sas_request_addr(struct Scsi_Host *shost, u8 *addr)
{
        int res;
        const struct firmware *fw;

        res = request_firmware(&fw, "sas_addr", &shost->shost_gendev);
        if (res)
                return res;

        if (fw->size < SAS_STRING_ADDR_SIZE) {
                res = -ENODEV;
                goto out;
        }

        res = hex2bin(addr, fw->data, strnlen(fw->data, SAS_ADDR_SIZE * 2) / 2);
        if (res)
                goto out;

out:
        release_firmware(fw);
        return res;
}
EXPORT_SYMBOL_GPL(sas_request_addr);