isci: Manage device suspensions during TC terminations.

TCs must be terminated only while the RNC is suspended.  This commit
adds remote device suspensions and resumptions in the abort, reset and
termination paths.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

3 files changed, 154 insertions, 49 deletions

diff --git a/drivers/scsi/isci/remote_device.c b/drivers/scsi/isci/remote_device.c
index 9f03877534d..4f76dcd1cec 100644
--- a/drivers/scsi/isci/remote_device.c
+++ b/drivers/scsi/isci/remote_device.c
@@ -143,6 +143,12 @@ static enum sci_status sci_remote_device_suspend(
                 NULL, NULL);
 }
 
+static int isci_remote_device_suspendcheck(struct isci_remote_device *idev)
+{
+        return test_bit(IDEV_TXRX_SUSPENDED, &idev->flags)
+            || !test_bit(IDEV_ALLOCATED, &idev->flags);
+}
+
 enum sci_status isci_remote_device_suspend(
         struct isci_host *ihost,
         struct isci_remote_device *idev)
@@ -151,18 +157,18 @@ enum sci_status isci_remote_device_suspend(
         unsigned long flags;
 
         spin_lock_irqsave(&ihost->scic_lock, flags);
-
-        if (isci_lookup_device(idev->domain_dev) == NULL) {
+        if (isci_get_device(idev->domain_dev) == NULL) {
                 spin_unlock_irqrestore(&ihost->scic_lock, flags);
                 status = SCI_FAILURE;
         } else {
                 status = sci_remote_device_suspend(idev);
                 spin_unlock_irqrestore(&ihost->scic_lock, flags);
                 if (status == SCI_SUCCESS) {
+                        dev_dbg(&ihost->pdev->dev,
+                                "%s: idev=%p, about to wait\n",
+                                __func__, idev);
                         wait_event(ihost->eventq,
-                                   test_bit(IDEV_TXRX_SUSPENDED, &idev->flags)
-                                || !test_bit(IDEV_ALLOCATED, &idev->flags));
-
+                                   isci_remote_device_suspendcheck(idev));
                         status = test_bit(IDEV_TXRX_SUSPENDED, &idev->flags)
                                         ? SCI_SUCCESS : SCI_FAILURE;
                         dev_dbg(&ihost->pdev->dev,
@@ -171,7 +177,10 @@ enum sci_status isci_remote_device_suspend(
                                 test_bit(IDEV_TXRX_SUSPENDED, &idev->flags)
                                         ? "<suspended>" : "<deallocated!>");
 
-                }
+                } else
+                        dev_dbg(scirdev_to_dev(idev),
+                                 "%s: sci_remote_device_suspend failed, "
+                                 "status = %d\n", __func__, status);
                 isci_put_device(idev);
         }
         return status;
@@ -1218,6 +1227,35 @@ static enum sci_status sci_remote_device_ea_construct(struct isci_port *iport,
         return SCI_SUCCESS;
 }
 
+enum sci_status sci_remote_device_resume(
+        struct isci_remote_device *idev,
+        scics_sds_remote_node_context_callback cb_fn,
+        void *cb_p)
+{
+        enum sci_status status;
+
+        status = sci_remote_node_context_resume(&idev->rnc, cb_fn, cb_p);
+        if (status != SCI_SUCCESS)
+                dev_dbg(scirdev_to_dev(idev), "%s: failed to resume: %d\n",
+                        __func__, status);
+        return status;
+}
+
+enum sci_status isci_remote_device_resume(
+        struct isci_host *ihost,
+        struct isci_remote_device *idev,
+        scics_sds_remote_node_context_callback cb_fn,
+        void *cb_p)
+{
+        unsigned long flags;
+        enum sci_status status;
+
+        spin_lock_irqsave(&ihost->scic_lock, flags);
+        status = sci_remote_device_resume(idev, cb_fn, cb_p);
+        spin_unlock_irqrestore(&ihost->scic_lock, flags);
+
+        return status;
+}
 /**
  * sci_remote_device_start() - This method will start the supplied remote
  *    device.  This method enables normal IO requests to flow through to the
@@ -1244,9 +1282,8 @@ static enum sci_status sci_remote_device_start(struct isci_remote_device *idev,
                 return SCI_FAILURE_INVALID_STATE;
         }
 
-        status = sci_remote_node_context_resume(&idev->rnc,
-                                                     remote_device_resume_done,
-                                                     idev);
+        status = sci_remote_device_resume(idev, remote_device_resume_done,
+                                          idev);
         if (status != SCI_SUCCESS)
                 return status;
 
@@ -1461,26 +1498,29 @@ int isci_remote_device_found(struct domain_device *dev)
 }
 
 enum sci_status isci_remote_device_reset(
+        struct isci_host *ihost,
         struct isci_remote_device *idev)
 {
-        struct isci_host *ihost = dev_to_ihost(idev->domain_dev);
         unsigned long flags;
         enum sci_status status;
 
-        /* Wait for the device suspend. */
-        status = isci_remote_device_suspend(ihost, idev);
+        /* Put the device into a reset state so the suspension will not
+         * automatically resume.
+         */
+        spin_lock_irqsave(&ihost->scic_lock, flags);
+        status = sci_remote_device_reset(idev);
+        spin_unlock_irqrestore(&ihost->scic_lock, flags);
         if (status != SCI_SUCCESS) {
                 dev_dbg(&ihost->pdev->dev,
-                        "%s: isci_remote_device_suspend(%p) returned %d!\n",
+                        "%s: sci_remote_device_reset(%p) returned %d!\n",
                         __func__, idev, status);
                 return status;
         }
-        spin_lock_irqsave(&ihost->scic_lock, flags);
-        status = sci_remote_device_reset(idev);
-        spin_unlock_irqrestore(&ihost->scic_lock, flags);
+        /* Wait for the device suspend. */
+        status = isci_remote_device_suspend(ihost, idev);
         if (status != SCI_SUCCESS) {
                 dev_dbg(&ihost->pdev->dev,
-                        "%s: sci_remote_device_reset(%p) returned %d!\n",
+                        "%s: isci_remote_device_suspend(%p) returned %d!\n",
                         __func__, idev, status);
         }
         return status;
@@ -1497,3 +1537,19 @@ enum sci_status sci_remote_device_abort_requests_pending_abort(
 {
         return sci_remote_device_terminate_requests_checkabort(idev, 1);
 }
+
+enum sci_status isci_remote_device_reset_complete(
+        struct isci_host *ihost,
+        struct isci_remote_device *idev)
+{
+        unsigned long flags;
+        enum sci_status status;
+
+        spin_lock_irqsave(&ihost->scic_lock, flags);
+        status = sci_remote_device_reset_complete(idev);
+        sci_remote_device_resume(idev, NULL, NULL);
+        spin_unlock_irqrestore(&ihost->scic_lock, flags);
+
+        return status;
+}
+
diff --git a/drivers/scsi/isci/remote_device.h b/drivers/scsi/isci/remote_device.h
index ae508ee3366..a6a376e200e 100644
--- a/drivers/scsi/isci/remote_device.h
+++ b/drivers/scsi/isci/remote_device.h
@@ -106,6 +106,16 @@ struct isci_remote_device {
 #define ISCI_REMOTE_DEVICE_START_TIMEOUT 5000
 
 /* device reference routines must be called under sci_lock */
+static inline struct isci_remote_device *isci_get_device(
+        struct domain_device *dev)
+{
+        struct isci_remote_device *idev = dev->lldd_dev;
+
+        if (idev)
+                kref_get(&idev->kref);
+        return idev;
+}
+
 static inline struct isci_remote_device *isci_lookup_device(struct domain_device *dev)
 {
         struct isci_remote_device *idev = dev->lldd_dev;
@@ -345,4 +355,27 @@ int isci_remote_device_is_safe_to_abort(
 enum sci_status
 sci_remote_device_abort_requests_pending_abort(
         struct isci_remote_device *idev);
+
+enum sci_status isci_remote_device_suspend(
+        struct isci_host *ihost,
+        struct isci_remote_device *idev);
+
+enum sci_status sci_remote_device_resume(
+        struct isci_remote_device *idev,
+        scics_sds_remote_node_context_callback cb_fn,
+        void *cb_p);
+
+enum sci_status isci_remote_device_resume(
+        struct isci_host *ihost,
+        struct isci_remote_device *idev,
+        scics_sds_remote_node_context_callback cb_fn,
+        void *cb_p);
+
+enum sci_status isci_remote_device_reset(
+        struct isci_host *ihost,
+        struct isci_remote_device *idev);
+
+enum sci_status isci_remote_device_reset_complete(
+        struct isci_host *ihost,
+        struct isci_remote_device *idev);
 #endif /* !defined(_ISCI_REMOTE_DEVICE_H_) */
diff --git a/drivers/scsi/isci/task.c b/drivers/scsi/isci/task.c
index 374254ede9d..9b8632f33dd 100644
--- a/drivers/scsi/isci/task.c
+++ b/drivers/scsi/isci/task.c
@@ -716,6 +716,8 @@ void isci_terminate_pending_requests(struct isci_host *ihost,
         unsigned long flags;
         LIST_HEAD(list);
 
+        isci_remote_device_suspend(ihost, idev);
+
         spin_lock_irqsave(&ihost->scic_lock, flags);
         list_splice_init(&idev->reqs_in_process, &list);
 
@@ -826,40 +828,47 @@ static int isci_task_send_lu_reset_sas(
 
 int isci_task_lu_reset(struct domain_device *dev, u8 *lun)
 {
-        struct isci_host *isci_host = dev_to_ihost(dev);
+        struct isci_host *ihost = dev_to_ihost(dev);
         struct isci_remote_device *isci_device;
         unsigned long flags;
         int ret;
 
-        spin_lock_irqsave(&isci_host->scic_lock, flags);
+        spin_lock_irqsave(&ihost->scic_lock, flags);
         isci_device = isci_lookup_device(dev);
-        spin_unlock_irqrestore(&isci_host->scic_lock, flags);
+        spin_unlock_irqrestore(&ihost->scic_lock, flags);
 
-        dev_dbg(&isci_host->pdev->dev,
+        dev_dbg(&ihost->pdev->dev,
                 "%s: domain_device=%p, isci_host=%p; isci_device=%p\n",
-                 __func__, dev, isci_host, isci_device);
+                __func__, dev, ihost, isci_device);
 
         if (!isci_device) {
                 /* If the device is gone, stop the escalations. */
-                dev_dbg(&isci_host->pdev->dev, "%s: No dev\n", __func__);
+                dev_dbg(&ihost->pdev->dev, "%s: No dev\n", __func__);
 
                 ret = TMF_RESP_FUNC_COMPLETE;
                 goto out;
         }
+        if (isci_remote_device_suspend(ihost, isci_device) != SCI_SUCCESS) {
+                dev_dbg(&ihost->pdev->dev,
+                        "%s:  device = %p; failed to suspend\n",
+                        __func__, isci_device);
+                ret = TMF_RESP_FUNC_FAILED;
+                goto out;
+        }
 
         /* Send the task management part of the reset. */
         if (dev_is_sata(dev)) {
                 sas_ata_schedule_reset(dev);
                 ret = TMF_RESP_FUNC_COMPLETE;
         } else
-                ret = isci_task_send_lu_reset_sas(isci_host, isci_device, lun);
+                ret = isci_task_send_lu_reset_sas(ihost, isci_device, lun);
 
         /* If the LUN reset worked, all the I/O can now be terminated. */
-        if (ret == TMF_RESP_FUNC_COMPLETE)
+        if (ret == TMF_RESP_FUNC_COMPLETE) {
                 /* Terminate all I/O now. */
-                isci_terminate_pending_requests(isci_host,
-                                                isci_device);
-
+                isci_terminate_pending_requests(ihost, isci_device);
+                isci_remote_device_resume(ihost, isci_device, NULL, NULL);
+        }
  out:
         isci_put_device(isci_device);
         return ret;
@@ -976,7 +985,7 @@ int isci_task_abort_task(struct sas_task *task)
         spin_unlock(&task->task_state_lock);
         spin_unlock_irqrestore(&isci_host->scic_lock, flags);
 
-        dev_dbg(&isci_host->pdev->dev,
+        dev_warn(&isci_host->pdev->dev,
                 "%s: dev = %p, task = %p, old_request == %p\n",
                 __func__, isci_device, task, old_request);
 
@@ -998,7 +1007,7 @@ int isci_task_abort_task(struct sas_task *task)
 
                 ret = TMF_RESP_FUNC_COMPLETE;
 
-                dev_dbg(&isci_host->pdev->dev,
+                dev_warn(&isci_host->pdev->dev,
                         "%s: abort task not needed for %p\n",
                         __func__, task);
                 goto out;
@@ -1022,7 +1031,7 @@ int isci_task_abort_task(struct sas_task *task)
                 /* The request was already being handled by someone else (because
                 * they got to set the state away from started).
                 */
-                dev_dbg(&isci_host->pdev->dev,
+                dev_warn(&isci_host->pdev->dev,
                         "%s:  device = %p; old_request %p already being aborted\n",
                         __func__,
                         isci_device, old_request);
@@ -1035,7 +1044,7 @@ int isci_task_abort_task(struct sas_task *task)
 
                 spin_unlock_irqrestore(&isci_host->scic_lock, flags);
 
-                dev_dbg(&isci_host->pdev->dev,
+                dev_warn(&isci_host->pdev->dev,
                         "%s: %s request"
                         " or complete_in_target (%d), thus no TMF\n",
                         __func__,
@@ -1068,6 +1077,15 @@ int isci_task_abort_task(struct sas_task *task)
                  */
                 perform_termination = 1;
 
+                if (isci_device && !test_bit(IDEV_GONE, &isci_device->flags) &&
+                    (isci_remote_device_suspend(isci_host, isci_device)
+                     != SCI_SUCCESS)) {
+                        dev_warn(&isci_host->pdev->dev,
+                                "%s:  device = %p; failed to suspend\n",
+                                __func__, isci_device);
+                        goto out;
+                }
+
         } else {
                 /* Fill in the tmf stucture */
                 isci_task_build_abort_task_tmf(&tmf, isci_tmf_ssp_task_abort,
@@ -1076,6 +1094,14 @@ int isci_task_abort_task(struct sas_task *task)
 
                 spin_unlock_irqrestore(&isci_host->scic_lock, flags);
 
+                if (isci_remote_device_suspend(isci_host, isci_device)
+                    != SCI_SUCCESS) {
+                        dev_warn(&isci_host->pdev->dev,
+                                "%s:  device = %p; failed to suspend\n",
+                                __func__, isci_device);
+                        goto out;
+                }
+
                 #define ISCI_ABORT_TASK_TIMEOUT_MS 500 /* 1/2 second timeout */
                 ret = isci_task_execute_tmf(isci_host, isci_device, &tmf,
                                             ISCI_ABORT_TASK_TIMEOUT_MS);
@@ -1083,7 +1109,7 @@ int isci_task_abort_task(struct sas_task *task)
                 if (ret == TMF_RESP_FUNC_COMPLETE)
                         perform_termination = 1;
                 else
-                        dev_dbg(&isci_host->pdev->dev,
+                        dev_warn(&isci_host->pdev->dev,
                                 "%s: isci_task_send_tmf failed\n", __func__);
         }
         if (perform_termination) {
@@ -1094,6 +1120,7 @@ int isci_task_abort_task(struct sas_task *task)
                  */
                 isci_terminate_request_core(isci_host, isci_device,
                                             old_request);
+                isci_remote_device_resume(isci_host, isci_device, NULL, NULL);
         }
 
         /* Make sure we do not leave a reference to aborted_io_completion */
@@ -1251,21 +1278,13 @@ static int isci_reset_device(struct isci_host *ihost,
                              struct isci_remote_device *idev)
 {
         int rc;
-        unsigned long flags;
         enum sci_status status;
         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);
 
-        spin_lock_irqsave(&ihost->scic_lock, flags);
-        status = sci_remote_device_reset(idev);
-        spin_unlock_irqrestore(&ihost->scic_lock, flags);
-
-        if (status != SCI_SUCCESS) {
-                dev_dbg(&ihost->pdev->dev,
-                         "%s: sci_remote_device_reset(%p) returned %d!\n",
-                         __func__, idev, status);
+        if (isci_remote_device_reset(ihost, idev) != SCI_SUCCESS) {
                 rc = TMF_RESP_FUNC_FAILED;
                 goto out;
         }
@@ -1281,15 +1300,12 @@ static int isci_reset_device(struct isci_host *ihost,
         isci_remote_device_nuke_requests(ihost, idev);
 
         /* Since all pending TCs have been cleaned, resume the RNC. */
-        spin_lock_irqsave(&ihost->scic_lock, flags);
-        status = sci_remote_device_reset_complete(idev);
-        spin_unlock_irqrestore(&ihost->scic_lock, flags);
+        status = isci_remote_device_reset_complete(ihost, idev);
 
-        if (status != SCI_SUCCESS) {
+        if (status != SCI_SUCCESS)
                 dev_dbg(&ihost->pdev->dev,
-                         "%s: sci_remote_device_reset_complete(%p) "
+                         "%s: isci_remote_device_reset_complete(%p) "
                          "returned %d!\n", __func__, idev, status);
-        }
 
         dev_dbg(&ihost->pdev->dev, "%s: idev %p complete.\n", __func__, idev);
  out:
@@ -1305,7 +1321,7 @@ int isci_task_I_T_nexus_reset(struct domain_device *dev)
         int ret;
 
         spin_lock_irqsave(&ihost->scic_lock, flags);
-        idev = isci_lookup_device(dev);
+        idev = isci_get_device(dev);
         spin_unlock_irqrestore(&ihost->scic_lock, flags);
 
         if (!idev) {