Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1001 insertions, 0 deletions

diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
new file mode 100644
index 000000000..316a11183
--- /dev/null
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -0,0 +1,1001 @@
+/*
+ * 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>
+ *
+ * This file is licensed under GPLv2.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
+ * USA
+ *
+ */
+
+#include <linux/kthread.h>
+#include <linux/firmware.h>
+#include <linux/export.h>
+#include <linux/ctype.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;
+	int hs = 0, stat = 0;
+
+	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_SG_ERR:
+			hs = DID_PARITY;
+			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:
+			SAS_DPRINTK("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 SAM_STAT_CHECK_CONDITION:
+			memcpy(sc->sense_buffer, ts->buf,
+			       min(SCSI_SENSE_BUFFERSIZE, ts->buf_valid_size));
+			stat = 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 */
+		SAS_DPRINTK("task done but aborted\n");
+		return;
+	}
+
+	if (unlikely(!sc)) {
+		SAS_DPRINTK("task_done called with non existing SCSI cmnd!\n");
+		sas_free_task(task);
+		return;
+	}
+
+	sas_end_task(sc, task);
+	sc->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) */
+
+	task->ssp_task.retry_count = 1;
+	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;
+}
+
+int 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:
+	SAS_DPRINTK("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:
+	cmd->scsi_done(cmd);
+	return 0;
+}
+
+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->core.shost->transportt);
+
+	for (i = 0; i < 5; i++) {
+		SAS_DPRINTK("%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);
+			SAS_DPRINTK("%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) {
+			SAS_DPRINTK("%s: task 0x%p is aborted\n",
+				    __func__, task);
+			return TASK_IS_ABORTED;
+		} else if (si->dft->lldd_query_task) {
+			SAS_DPRINTK("%s: querying task 0x%p\n",
+				    __func__, task);
+			res = si->dft->lldd_query_task(task);
+			switch (res) {
+			case TMF_RESP_FUNC_SUCC:
+				SAS_DPRINTK("%s: task 0x%p at LU\n",
+					    __func__, task);
+				return TASK_IS_AT_LU;
+			case TMF_RESP_FUNC_COMPLETE:
+				SAS_DPRINTK("%s: task 0x%p not at LU\n",
+					    __func__, task);
+				return TASK_IS_NOT_AT_LU;
+			case TMF_RESP_FUNC_FAILED:
+                                SAS_DPRINTK("%s: task 0x%p failed to abort\n",
+                                                __func__, task);
+                                return TASK_ABORT_FAILED;
+                        }
+
+		}
+	}
+	return res;
+}
+
+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->core.shost->transportt);
+
+	int_to_scsilun(cmd->device->lun, &lun);
+
+	SAS_DPRINTK("eh: device %llx LUN %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->core.shost->transportt);
+
+	SAS_DPRINTK("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 void sas_wait_eh(struct domain_device *dev)
+{
+	struct sas_ha_struct *ha = dev->port->ha;
+	DEFINE_WAIT(wait);
+
+	if (dev_is_sata(dev)) {
+		ata_port_wait_eh(dev->sata_dev.ap);
+		return;
+	}
+ retry:
+	spin_lock_irq(&ha->lock);
+
+	while (test_bit(SAS_DEV_EH_PENDING, &dev->state)) {
+		prepare_to_wait(&ha->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
+		spin_unlock_irq(&ha->lock);
+		schedule();
+		spin_lock_irq(&ha->lock);
+	}
+	finish_wait(&ha->eh_wait_q, &wait);
+
+	spin_unlock_irq(&ha->lock);
+
+	/* make sure SCSI EH is complete */
+	if (scsi_host_in_recovery(ha->core.shost)) {
+		msleep(10);
+		goto retry;
+	}
+}
+EXPORT_SYMBOL(sas_wait_eh);
+
+static int sas_queue_reset(struct domain_device *dev, int reset_type,
+			   u64 lun, int wait)
+{
+	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);
+		if (wait)
+			sas_ata_wait_eh(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->core.shost);
+		}
+		spin_unlock_irq(&ha->lock);
+
+		if (wait)
+			sas_wait_eh(dev);
+
+		if (scheduled)
+			return SUCCESS;
+	}
+
+	SAS_DPRINTK("%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
+		SAS_DPRINTK("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, 0);
+
+	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;
+}
+
+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, 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;
+}
+
+/* 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) {
+			SAS_DPRINTK("%s: task 0x%p requests reset\n",
+				    __func__, task);
+			goto reset;
+		}
+
+		SAS_DPRINTK("trying to find task 0x%p\n", task);
+		res = sas_scsi_find_task(task);
+
+		switch (res) {
+		case TASK_IS_DONE:
+			SAS_DPRINTK("%s: task 0x%p is done\n", __func__,
+				    task);
+			sas_eh_finish_cmd(cmd);
+			continue;
+		case TASK_IS_ABORTED:
+			SAS_DPRINTK("%s: task 0x%p is aborted\n",
+				    __func__, task);
+			sas_eh_finish_cmd(cmd);
+			continue;
+		case TASK_IS_AT_LU:
+			SAS_DPRINTK("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) {
+				SAS_DPRINTK("dev %016llx LU %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:
+			SAS_DPRINTK("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;
+				SAS_DPRINTK("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;
+				SAS_DPRINTK("clearing nexus for port:%d\n",
+					    port->id);
+				res = i->dft->lldd_clear_nexus_port(port);
+				if (res == TMF_RESP_FUNC_COMPLETE) {
+					SAS_DPRINTK("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) {
+				SAS_DPRINTK("clear nexus ha\n");
+				res = i->dft->lldd_clear_nexus_ha(ha);
+				if (res == TMF_RESP_FUNC_COMPLETE) {
+					SAS_DPRINTK("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.
+			 */
+			SAS_DPRINTK("error from  device %llx, LUN %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:
+	SAS_DPRINTK("--- 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);
+
+	SAS_DPRINTK("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, &ha->eh_done_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;
+
+	SAS_DPRINTK("--- 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, 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;
+}
+
+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;
+}
+
+#define SAS_DEF_QD 256
+
+int sas_slave_configure(struct scsi_device *scsi_dev)
+{
+	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_slave_configure(scsi_dev, 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 {
+		SAS_DPRINTK("device %llx, LUN %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;
+}
+
+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);
+}
+
+int sas_bios_param(struct scsi_device *scsi_dev,
+			  struct block_device *bdev,
+			  sector_t capacity, int *hsc)
+{
+	hsc[0] = 255;
+	hsc[1] = 63;
+	sector_div(capacity, 255*63);
+	hsc[2] = capacity;
+
+	return 0;
+}
+
+/*
+ * 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 (!del_timer(&slow->timer))
+			return;
+		slow->timer.function(&slow->timer);
+		return;
+	}
+
+	if (dev_is_sata(task->dev)) {
+		sas_ata_task_abort(task);
+	} else {
+		struct request_queue *q = sc->device->request_queue;
+		unsigned long flags;
+
+		spin_lock_irqsave(q->queue_lock, flags);
+		blk_abort_request(sc->request);
+		spin_unlock_irqrestore(q->queue_lock, flags);
+	}
+}
+
+int sas_slave_alloc(struct scsi_device *sdev)
+{
+	if (dev_is_sata(sdev_to_domain_dev(sdev)) && sdev->lun)
+		return -ENXIO;
+
+	return 0;
+}
+
+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);
+}
+
+#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);
+
+EXPORT_SYMBOL_GPL(sas_queuecommand);
+EXPORT_SYMBOL_GPL(sas_target_alloc);
+EXPORT_SYMBOL_GPL(sas_slave_configure);
+EXPORT_SYMBOL_GPL(sas_change_queue_depth);
+EXPORT_SYMBOL_GPL(sas_bios_param);
+EXPORT_SYMBOL_GPL(sas_task_abort);
+EXPORT_SYMBOL_GPL(sas_phy_reset);
+EXPORT_SYMBOL_GPL(sas_eh_device_reset_handler);
+EXPORT_SYMBOL_GPL(sas_eh_target_reset_handler);
+EXPORT_SYMBOL_GPL(sas_slave_alloc);
+EXPORT_SYMBOL_GPL(sas_target_destroy);
+EXPORT_SYMBOL_GPL(sas_ioctl);