isci: Redesign device suspension, abort, cleanup.

This commit changes the means by which outstanding I/Os are handled
for cleanup.
The likelihood is that this commit will be broken into smaller pieces,
however that will be a later revision.  Among the changes:

- All completion structures have been removed from the tmf and
abort paths.
- Now using one completed I/O list, with the I/O completed in host bit being
used to select error or normal callback paths.

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

11 files changed, 418 insertions, 1474 deletions

diff --git a/drivers/scsi/isci/host.c b/drivers/scsi/isci/host.c
index d241b5722eb3..25d537e2f5c4 100644
--- a/drivers/scsi/isci/host.c
+++ b/drivers/scsi/isci/host.c
@@ -1089,33 +1089,25 @@ void isci_host_completion_routine(unsigned long data)
 {
 	struct isci_host *ihost = (struct isci_host *)data;
 	struct list_head    completed_request_list;
-	struct list_head    errored_request_list;
 	struct list_head    *current_position;
 	struct list_head    *next_position;
 	struct isci_request *request;
-	struct isci_request *next_request;
 	struct sas_task     *task;
 	u16 active;
 
 	INIT_LIST_HEAD(&completed_request_list);
-	INIT_LIST_HEAD(&errored_request_list);
 
 	spin_lock_irq(&ihost->scic_lock);
 
 	sci_controller_completion_handler(ihost);
 
 	/* Take the lists of completed I/Os from the host. */
-
 	list_splice_init(&ihost->requests_to_complete,
 			 &completed_request_list);
 
-	/* Take the list of errored I/Os from the host. */
-	list_splice_init(&ihost->requests_to_errorback,
-			 &errored_request_list);
-
 	spin_unlock_irq(&ihost->scic_lock);
 
-	/* Process any completions in the lists. */
+	/* Process any completions in the list. */
 	list_for_each_safe(current_position, next_position,
 			   &completed_request_list) {
 
@@ -1123,23 +1115,30 @@ void isci_host_completion_routine(unsigned long data)
 				     completed_node);
 		task = isci_request_access_task(request);
 
-		/* Normal notification (task_done) */
-		dev_dbg(&ihost->pdev->dev,
-			"%s: Normal - request/task = %p/%p\n",
-			__func__,
-			request,
-			task);
 
 		/* Return the task to libsas */
 		if (task != NULL) {
 
 			task->lldd_task = NULL;
-			if (!(task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
-
-				/* If the task is already in the abort path,
-				* the task_done callback cannot be called.
-				*/
-				task->task_done(task);
+			if (!test_bit(IREQ_ABORT_PATH_ACTIVE, &request->flags) &&
+			    !(task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
+				if (test_bit(IREQ_COMPLETE_IN_TARGET,
+					     &request->flags)) {
+
+					/* Normal notification (task_done) */
+					dev_dbg(&ihost->pdev->dev, "%s: Normal"
+						" - request/task = %p/%p\n",
+						__func__, request, task);
+
+					task->task_done(task);
+				} else {
+					dev_warn(&ihost->pdev->dev,
+						 "%s: Error - request/task"
+						 " = %p/%p\n",
+						 __func__, request, task);
+
+					sas_task_abort(task);
+				}
 			}
 		}
 
@@ -1147,44 +1146,6 @@ void isci_host_completion_routine(unsigned long data)
 		isci_free_tag(ihost, request->io_tag);
 		spin_unlock_irq(&ihost->scic_lock);
 	}
-	list_for_each_entry_safe(request, next_request, &errored_request_list,
-				 completed_node) {
-
-		task = isci_request_access_task(request);
-
-		/* Use sas_task_abort */
-		dev_warn(&ihost->pdev->dev,
-			 "%s: Error - request/task = %p/%p\n",
-			 __func__,
-			 request,
-			 task);
-
-		if (task != NULL) {
-
-			/* Put the task into the abort path if it's not there
-			 * already.
-			 */
-			if (!(task->task_state_flags & SAS_TASK_STATE_ABORTED))
-				sas_task_abort(task);
-
-		} else {
-			/* This is a case where the request has completed with a
-			 * status such that it needed further target servicing,
-			 * but the sas_task reference has already been removed
-			 * from the request.  Since it was errored, it was not
-			 * being aborted, so there is nothing to do except free
-			 * it.
-			 */
-
-			spin_lock_irq(&ihost->scic_lock);
-			/* Remove the request from the remote device's list
-			* of pending requests.
-			*/
-			list_del_init(&request->dev_node);
-			isci_free_tag(ihost, request->io_tag);
-			spin_unlock_irq(&ihost->scic_lock);
-		}
-	}
 
 	/* the coalesence timeout doubles at each encoding step, so
 	 * update it based on the ilog2 value of the outstanding requests
@@ -2345,7 +2306,6 @@ static int sci_controller_dma_alloc(struct isci_host *ihost)
 
 		ireq->tc = &ihost->task_context_table[i];
 		ireq->owning_controller = ihost;
-		spin_lock_init(&ireq->state_lock);
 		ireq->request_daddr = dma;
 		ireq->isci_host = ihost;
 		ihost->reqs[i] = ireq;
@@ -2697,6 +2657,10 @@ enum sci_status sci_controller_terminate_request(struct isci_host *ihost,
 		return SCI_FAILURE_INVALID_STATE;
 	}
 	status = sci_io_request_terminate(ireq);
+
+	dev_dbg(&ihost->pdev->dev, "%s: status=%d; ireq=%p; flags=%lx\n",
+		__func__, status, ireq, ireq->flags);
+
 	if ((status == SCI_SUCCESS) &&
 	    !test_bit(IREQ_PENDING_ABORT, &ireq->flags) &&
 	    !test_and_set_bit(IREQ_TC_ABORT_POSTED, &ireq->flags)) {
@@ -2739,6 +2703,8 @@ enum sci_status sci_controller_complete_io(struct isci_host *ihost,
 
 		index = ISCI_TAG_TCI(ireq->io_tag);
 		clear_bit(IREQ_ACTIVE, &ireq->flags);
+		if (test_bit(IREQ_ABORT_PATH_ACTIVE, &ireq->flags))
+			wake_up_all(&ihost->eventq);
 		return SCI_SUCCESS;
 	default:
 		dev_warn(&ihost->pdev->dev, "%s invalid state: %d\n",
diff --git a/drivers/scsi/isci/host.h b/drivers/scsi/isci/host.h
index 7272a0a375f2..eaa13c0be09a 100644
--- a/drivers/scsi/isci/host.h
+++ b/drivers/scsi/isci/host.h
@@ -205,7 +205,6 @@ struct isci_host {
 	wait_queue_head_t eventq;
 	struct tasklet_struct completion_tasklet;
 	struct list_head requests_to_complete;
-	struct list_head requests_to_errorback;
 	spinlock_t scic_lock;
 	struct isci_request *reqs[SCI_MAX_IO_REQUESTS];
 	struct isci_remote_device devices[SCI_MAX_REMOTE_DEVICES];
diff --git a/drivers/scsi/isci/init.c b/drivers/scsi/isci/init.c
index 9e1c83e425ed..39f12703b893 100644
--- a/drivers/scsi/isci/init.c
+++ b/drivers/scsi/isci/init.c
@@ -556,7 +556,6 @@ static struct isci_host *isci_host_alloc(struct pci_dev *pdev, int id)
 	}
 
 	INIT_LIST_HEAD(&ihost->requests_to_complete);
-	INIT_LIST_HEAD(&ihost->requests_to_errorback);
 	for (i = 0; i < SCI_MAX_PORTS; i++) {
 		struct isci_port *iport = &ihost->ports[i];
 
diff --git a/drivers/scsi/isci/remote_device.c b/drivers/scsi/isci/remote_device.c
index 3048e02aeb7b..c47304cea45d 100644
--- a/drivers/scsi/isci/remote_device.c
+++ b/drivers/scsi/isci/remote_device.c
@@ -81,49 +81,6 @@ static enum sci_status sci_remote_device_suspend(struct isci_remote_device *idev
 }
 
 /**
- * isci_remote_device_not_ready() - This function is called by the ihost when
- *    the remote device is not ready. We mark the isci device as ready (not
- *    "ready_for_io") and signal the waiting proccess.
- * @isci_host: This parameter specifies the isci host object.
- * @isci_device: This parameter specifies the remote device
- *
- * sci_lock is held on entrance to this function.
- */
-static void isci_remote_device_not_ready(struct isci_host *ihost,
-				  struct isci_remote_device *idev, u32 reason)
-{
-	struct isci_request *ireq;
-
-	dev_dbg(&ihost->pdev->dev,
-		"%s: isci_device = %p\n", __func__, idev);
-
-	switch (reason) {
-	case SCIC_REMOTE_DEVICE_NOT_READY_STOP_REQUESTED:
-		set_bit(IDEV_GONE, &idev->flags);
-		break;
-	case SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED:
-		set_bit(IDEV_IO_NCQERROR, &idev->flags);
-
-		/* Suspend the remote device so the I/O can be terminated. */
-		sci_remote_device_suspend(idev);
-
-		/* Kill all outstanding requests for the device. */
-		list_for_each_entry(ireq, &idev->reqs_in_process, dev_node) {
-
-			dev_dbg(&ihost->pdev->dev,
-				"%s: isci_device = %p request = %p\n",
-				__func__, idev, ireq);
-
-			sci_controller_terminate_request(ihost, idev, ireq);
-		}
-		/* Fall through into the default case... */
-	default:
-		clear_bit(IDEV_IO_READY, &idev->flags);
-		break;
-	}
-}
-
-/**
  * isci_remote_device_ready() - This function is called by the ihost when the
  *    remote device is ready. We mark the isci device as ready and signal the
  *    waiting proccess.
@@ -142,49 +99,121 @@ static void isci_remote_device_ready(struct isci_host *ihost, struct isci_remote
 		wake_up(&ihost->eventq);
 }
 
-static int isci_remote_device_suspendcheck(struct isci_remote_device *idev)
+static enum sci_status sci_remote_device_terminate_req(
+	struct isci_host *ihost,
+	struct isci_remote_device *idev,
+	int check_abort,
+	struct isci_request *ireq)
+{
+	dev_dbg(&ihost->pdev->dev,
+		"%s: idev=%p; flags=%lx; req=%p; req target=%p\n",
+		__func__, idev, idev->flags, ireq, ireq->target_device);
+
+	if (!test_bit(IREQ_ACTIVE, &ireq->flags) ||
+	    (ireq->target_device != idev) ||
+	    (check_abort && !test_bit(IREQ_PENDING_ABORT, &ireq->flags)))
+		return SCI_SUCCESS;
+
+	set_bit(IREQ_ABORT_PATH_ACTIVE, &ireq->flags);
+
+	return sci_controller_terminate_request(ihost, idev, ireq);
+}
+
+static enum sci_status sci_remote_device_terminate_reqs_checkabort(
+	struct isci_remote_device *idev,
+	int chk)
 {
-	return test_bit(IDEV_TXRX_SUSPENDED, &idev->flags)
-	    || !test_bit(IDEV_ALLOCATED, &idev->flags);
+	struct isci_host *ihost = idev->owning_port->owning_controller;
+	enum sci_status status  = SCI_SUCCESS;
+	u32 i;
+
+	for (i = 0; i < SCI_MAX_IO_REQUESTS; i++) {
+		struct isci_request *ireq = ihost->reqs[i];
+		enum sci_status s;
+
+		s = sci_remote_device_terminate_req(ihost, idev, chk, ireq);
+		if (s != SCI_SUCCESS)
+			status = s;
+	}
+	return status;
 }
 
-enum sci_status isci_remote_device_suspend(
+enum sci_status isci_remote_device_terminate_requests(
 	struct isci_host *ihost,
-	struct isci_remote_device *idev)
+	struct isci_remote_device *idev,
+	struct isci_request *ireq)
 {
-	enum sci_status status;
+	enum sci_status status = SCI_SUCCESS;
 	unsigned long flags;
 
 	spin_lock_irqsave(&ihost->scic_lock, flags);
-	if (isci_get_device(idev->domain_dev) == NULL) {
+	if (isci_get_device(idev) == NULL) {
+		dev_dbg(&ihost->pdev->dev, "%s: failed isci_get_device(idev=%p)\n",
+			__func__, idev);
 		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,
-				   isci_remote_device_suspendcheck(idev));
-			status = test_bit(IDEV_TXRX_SUSPENDED, &idev->flags)
-					? SCI_SUCCESS : SCI_FAILURE;
-			dev_dbg(&ihost->pdev->dev,
-				"%s: idev=%p, wait done, device is %s\n",
-				__func__, idev,
-				test_bit(IDEV_TXRX_SUSPENDED, &idev->flags)
-					? "<suspended>" : "<deallocated!>");
+		dev_dbg(&ihost->pdev->dev,
+			"%s: idev=%p, ireq=%p; started_request_count=%d, "
+				"about to wait\n",
+			__func__, idev, ireq, idev->started_request_count);
+		if (ireq) {
+			/* Terminate a specific TC. */
+			sci_remote_device_terminate_req(ihost, idev, 0, ireq);
+			spin_unlock_irqrestore(&ihost->scic_lock, flags);
+			wait_event(ihost->eventq, !test_bit(IREQ_ACTIVE,
+							    &ireq->flags));
 
-		} else
-			dev_dbg(scirdev_to_dev(idev),
-				 "%s: sci_remote_device_suspend failed, "
-				 "status = %d\n", __func__, status);
+		} else {
+			/* Terminate all TCs. */
+			sci_remote_device_terminate_requests(idev);
+			spin_unlock_irqrestore(&ihost->scic_lock, flags);
+			wait_event(ihost->eventq,
+				   idev->started_request_count == 0);
+		}
+		dev_dbg(&ihost->pdev->dev, "%s: idev=%p, wait done\n",
+			__func__, idev);
 		isci_put_device(idev);
 	}
 	return status;
 }
 
+/**
+* isci_remote_device_not_ready() - This function is called by the ihost when
+*    the remote device is not ready. We mark the isci device as ready (not
+*    "ready_for_io") and signal the waiting proccess.
+* @isci_host: This parameter specifies the isci host object.
+* @isci_device: This parameter specifies the remote device
+*
+* sci_lock is held on entrance to this function.
+*/
+static void isci_remote_device_not_ready(struct isci_host *ihost,
+					 struct isci_remote_device *idev,
+					 u32 reason)
+{
+	dev_dbg(&ihost->pdev->dev,
+		"%s: isci_device = %p\n", __func__, idev);
+
+	switch (reason) {
+	case SCIC_REMOTE_DEVICE_NOT_READY_STOP_REQUESTED:
+		set_bit(IDEV_GONE, &idev->flags);
+		break;
+	case SCIC_REMOTE_DEVICE_NOT_READY_SATA_SDB_ERROR_FIS_RECEIVED:
+		set_bit(IDEV_IO_NCQERROR, &idev->flags);
+
+		/* Suspend the remote device so the I/O can be terminated. */
+		sci_remote_device_suspend(idev);
+
+		/* Kill all outstanding requests for the device. */
+		sci_remote_device_terminate_requests(idev);
+
+		/* Fall through into the default case... */
+	default:
+		clear_bit(IDEV_IO_READY, &idev->flags);
+		break;
+	}
+}
+
 /* called once the remote node context is ready to be freed.
  * The remote device can now report that its stop operation is complete. none
  */
@@ -196,36 +225,10 @@ static void rnc_destruct_done(void *_dev)
 	sci_change_state(&idev->sm, SCI_DEV_STOPPED);
 }
 
-static enum sci_status sci_remote_device_terminate_requests_checkabort(
-	struct isci_remote_device *idev,
-	int check_abort_pending)
-{
-	struct isci_host *ihost = idev->owning_port->owning_controller;
-	enum sci_status status  = SCI_SUCCESS;
-	u32 i;
-
-	for (i = 0; i < SCI_MAX_IO_REQUESTS; i++) {
-		struct isci_request *ireq = ihost->reqs[i];
-		enum sci_status s;
-
-		if (!test_bit(IREQ_ACTIVE, &ireq->flags) ||
-		    (ireq->target_device != idev) ||
-		    (check_abort_pending && !test_bit(IREQ_PENDING_ABORT,
-						      &ireq->flags)))
-			continue;
-
-		s = sci_controller_terminate_request(ihost, idev, ireq);
-		if (s != SCI_SUCCESS)
-			status = s;
-	}
-
-	return status;
-}
-
 enum sci_status sci_remote_device_terminate_requests(
 	struct isci_remote_device *idev)
 {
-	return sci_remote_device_terminate_requests_checkabort(idev, 0);
+	return sci_remote_device_terminate_reqs_checkabort(idev, 0);
 }
 
 enum sci_status sci_remote_device_stop(struct isci_remote_device *idev,
@@ -771,10 +774,6 @@ enum sci_status sci_remote_device_start_task(struct isci_host *ihost,
 		if (status != SCI_SUCCESS)
 			return status;
 
-		status = sci_remote_node_context_start_task(&idev->rnc, ireq);
-		if (status != SCI_SUCCESS)
-			goto out;
-
 		status = sci_request_start(ireq);
 		if (status != SCI_SUCCESS)
 			goto out;
@@ -796,8 +795,9 @@ enum sci_status sci_remote_device_start_task(struct isci_host *ihost,
 		sci_remote_node_context_suspend(
 			&idev->rnc, SCI_SOFTWARE_SUSPENSION,
 			SCI_SOFTWARE_SUSPEND_EXPECTED_EVENT, NULL, NULL);
-		sci_remote_node_context_resume(
-			&idev->rnc, sci_remote_device_continue_request, idev);
+
+		status = sci_remote_node_context_start_task(&idev->rnc, ireq,
+				sci_remote_device_continue_request, idev);
 
 	out:
 		sci_remote_device_start_request(idev, ireq, status);
@@ -811,7 +811,9 @@ enum sci_status sci_remote_device_start_task(struct isci_host *ihost,
 		if (status != SCI_SUCCESS)
 			return status;
 
-		status = sci_remote_node_context_start_task(&idev->rnc, ireq);
+		/* Resume the RNC as needed: */
+		status = sci_remote_node_context_start_task(&idev->rnc, ireq,
+							    NULL, NULL);
 		if (status != SCI_SUCCESS)
 			break;
 
@@ -1322,20 +1324,6 @@ static enum sci_status isci_remote_device_construct(struct isci_port *iport,
 	return status;
 }
 
-void isci_remote_device_nuke_requests(struct isci_host *ihost, struct isci_remote_device *idev)
-{
-	DECLARE_COMPLETION_ONSTACK(aborted_task_completion);
-
-	dev_dbg(&ihost->pdev->dev,
-		"%s: idev = %p\n", __func__, idev);
-
-	/* Cleanup all requests pending for this device. */
-	isci_terminate_pending_requests(ihost, idev);
-
-	dev_dbg(&ihost->pdev->dev,
-		"%s: idev = %p, done\n", __func__, idev);
-}
-
 /**
  * This function builds the isci_remote_device when a libsas dev_found message
  *    is received.
@@ -1495,32 +1483,28 @@ int isci_remote_device_found(struct domain_device *dev)
 	return status == SCI_SUCCESS ? 0 : -ENODEV;
 }
 
-enum sci_status isci_remote_device_reset(
+enum sci_status isci_remote_device_suspend_terminate(
 	struct isci_host *ihost,
-	struct isci_remote_device *idev)
+	struct isci_remote_device *idev,
+	struct isci_request *ireq)
 {
 	unsigned long flags;
 	enum sci_status status;
 
-	/* Put the device into a reset state so the suspension will not
-	 * automatically resume.
-	 */
+	/* Put the device into suspension. */
 	spin_lock_irqsave(&ihost->scic_lock, flags);
-	status = sci_remote_device_reset(idev);
+	sci_remote_device_suspend(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);
-		return status;
-	}
-	/* Wait for the device suspend. */
-	status = isci_remote_device_suspend(ihost, idev);
-	if (status != SCI_SUCCESS) {
+
+	/* Terminate and wait for the completions. */
+	status = isci_remote_device_terminate_requests(ihost, idev, ireq);
+	if (status != SCI_SUCCESS)
 		dev_dbg(&ihost->pdev->dev,
-			"%s: isci_remote_device_suspend(%p) returned %d!\n",
+			"%s: isci_remote_device_terminate_requests(%p) "
+				"returned %d!\n",
 			__func__, idev, status);
-	}
+
+	/* NOTE: RNC resumption is left to the caller! */
 	return status;
 }
 
@@ -1533,7 +1517,7 @@ int isci_remote_device_is_safe_to_abort(
 enum sci_status sci_remote_device_abort_requests_pending_abort(
 	struct isci_remote_device *idev)
 {
-	return sci_remote_device_terminate_requests_checkabort(idev, 1);
+	return sci_remote_device_terminate_reqs_checkabort(idev, 1);
 }
 
 enum sci_status isci_remote_device_reset_complete(
@@ -1545,7 +1529,6 @@ enum sci_status isci_remote_device_reset_complete(
 
 	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 a6a376e200ef..da43698e9eba 100644
--- a/drivers/scsi/isci/remote_device.h
+++ b/drivers/scsi/isci/remote_device.h
@@ -85,7 +85,6 @@ struct isci_remote_device {
 	#define IDEV_GONE 3
 	#define IDEV_IO_READY 4
 	#define IDEV_IO_NCQERROR 5
-	#define IDEV_TXRX_SUSPENDED 6
 	unsigned long flags;
 	struct kref kref;
 	struct isci_port *isci_port;
@@ -107,10 +106,8 @@ struct isci_remote_device {
 
 /* 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)
 {
-	struct isci_remote_device *idev = dev->lldd_dev;
-
 	if (idev)
 		kref_get(&idev->kref);
 	return idev;
@@ -378,4 +375,14 @@ enum sci_status isci_remote_device_reset(
 enum sci_status isci_remote_device_reset_complete(
 	struct isci_host *ihost,
 	struct isci_remote_device *idev);
+
+enum sci_status isci_remote_device_suspend_terminate(
+	struct isci_host *ihost,
+	struct isci_remote_device *idev,
+	struct isci_request *ireq);
+
+enum sci_status isci_remote_device_terminate_requests(
+	struct isci_host *ihost,
+	struct isci_remote_device *idev,
+	struct isci_request *ireq);
 #endif /* !defined(_ISCI_REMOTE_DEVICE_H_) */
diff --git a/drivers/scsi/isci/remote_node_context.c b/drivers/scsi/isci/remote_node_context.c
index 7a8347e51767..feeca17f0f13 100644
--- a/drivers/scsi/isci/remote_node_context.c
+++ b/drivers/scsi/isci/remote_node_context.c
@@ -317,8 +317,6 @@ static void sci_remote_node_context_tx_rx_suspended_state_enter(struct sci_base_
 	struct isci_remote_device *idev = rnc_to_dev(rnc);
 	struct isci_host *ihost = idev->owning_port->owning_controller;
 
-	set_bit(IDEV_TXRX_SUSPENDED, &idev->flags);
-
 	/* Terminate outstanding requests pending abort. */
 	sci_remote_device_abort_requests_pending_abort(idev);
 
@@ -326,16 +324,6 @@ static void sci_remote_node_context_tx_rx_suspended_state_enter(struct sci_base_
 	sci_remote_node_context_continue_state_transitions(rnc);
 }
 
-static void sci_remote_node_context_tx_rx_suspended_state_exit(
-	struct sci_base_state_machine *sm)
-{
-	struct sci_remote_node_context *rnc
-		= container_of(sm, typeof(*rnc), sm);
-	struct isci_remote_device *idev = rnc_to_dev(rnc);
-
-	clear_bit(IDEV_TXRX_SUSPENDED, &idev->flags);
-}
-
 static void sci_remote_node_context_await_suspend_state_exit(
 	struct sci_base_state_machine *sm)
 {
@@ -366,8 +354,6 @@ static const struct sci_base_state sci_remote_node_context_state_table[] = {
 	},
 	[SCI_RNC_TX_RX_SUSPENDED] = {
 		.enter_state = sci_remote_node_context_tx_rx_suspended_state_enter,
-		.exit_state
-			= sci_remote_node_context_tx_rx_suspended_state_exit,
 	},
 	[SCI_RNC_AWAIT_SUSPENSION] = {
 		.exit_state = sci_remote_node_context_await_suspend_state_exit,
@@ -671,8 +657,11 @@ enum sci_status sci_remote_node_context_start_io(struct sci_remote_node_context
 	}
 }
 
-enum sci_status sci_remote_node_context_start_task(struct sci_remote_node_context *sci_rnc,
-							struct isci_request *ireq)
+enum sci_status sci_remote_node_context_start_task(
+	struct sci_remote_node_context *sci_rnc,
+	struct isci_request *ireq,
+	scics_sds_remote_node_context_callback cb_fn,
+	void *cb_p)
 {
 	enum scis_sds_remote_node_context_states state;
 
@@ -684,7 +673,7 @@ enum sci_status sci_remote_node_context_start_task(struct sci_remote_node_contex
 		return SCI_SUCCESS;
 	case SCI_RNC_TX_SUSPENDED:
 	case SCI_RNC_TX_RX_SUSPENDED:
-		sci_remote_node_context_resume(sci_rnc, NULL, NULL);
+		sci_remote_node_context_resume(sci_rnc, cb_fn, cb_p);
 		return SCI_SUCCESS;
 	default:
 		dev_warn(scirdev_to_dev(rnc_to_dev(sci_rnc)),
diff --git a/drivers/scsi/isci/remote_node_context.h b/drivers/scsi/isci/remote_node_context.h
index 5ddf88b53133..2870af14edab 100644
--- a/drivers/scsi/isci/remote_node_context.h
+++ b/drivers/scsi/isci/remote_node_context.h
@@ -211,7 +211,9 @@ enum sci_status sci_remote_node_context_resume(struct sci_remote_node_context *s
 						    scics_sds_remote_node_context_callback cb_fn,
 						    void *cb_p);
 enum sci_status sci_remote_node_context_start_task(struct sci_remote_node_context *sci_rnc,
-							struct isci_request *ireq);
+						   struct isci_request *ireq,
+						   scics_sds_remote_node_context_callback cb_fn,
+						   void *cb_p);
 enum sci_status sci_remote_node_context_start_io(struct sci_remote_node_context *sci_rnc,
 						      struct isci_request *ireq);
 int sci_remote_node_context_is_safe_to_abort(
diff --git a/drivers/scsi/isci/request.c b/drivers/scsi/isci/request.c
index 1f314d0d71d5..f4e80f31423c 100644
--- a/drivers/scsi/isci/request.c
+++ b/drivers/scsi/isci/request.c
@@ -2491,9 +2491,6 @@ static void isci_request_process_response_iu(
  * @request: This parameter is the completed isci_request object.
  * @response_ptr: This parameter specifies the service response for the I/O.
  * @status_ptr: This parameter specifies the exec status for the I/O.
- * @complete_to_host_ptr: This parameter specifies the action to be taken by
- *    the LLDD with respect to completing this request or forcing an abort
- *    condition on the I/O.
  * @open_rej_reason: This parameter specifies the encoded reason for the
  *    abandon-class reject.
  *
@@ -2504,14 +2501,12 @@ static void isci_request_set_open_reject_status(
 	struct sas_task *task,
 	enum service_response *response_ptr,
 	enum exec_status *status_ptr,
-	enum isci_completion_selection *complete_to_host_ptr,
 	enum sas_open_rej_reason open_rej_reason)
 {
 	/* Task in the target is done. */
 	set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
 	*response_ptr                     = SAS_TASK_UNDELIVERED;
 	*status_ptr                       = SAS_OPEN_REJECT;
-	*complete_to_host_ptr             = isci_perform_normal_io_completion;
 	task->task_status.open_rej_reason = open_rej_reason;
 }
 
@@ -2521,9 +2516,6 @@ static void isci_request_set_open_reject_status(
  * @request: This parameter is the completed isci_request object.
  * @response_ptr: This parameter specifies the service response for the I/O.
  * @status_ptr: This parameter specifies the exec status for the I/O.
- * @complete_to_host_ptr: This parameter specifies the action to be taken by
- *    the LLDD with respect to completing this request or forcing an abort
- *    condition on the I/O.
  *
  * none.
  */
@@ -2532,8 +2524,7 @@ static void isci_request_handle_controller_specific_errors(
 	struct isci_request *request,
 	struct sas_task *task,
 	enum service_response *response_ptr,
-	enum exec_status *status_ptr,
-	enum isci_completion_selection *complete_to_host_ptr)
+	enum exec_status *status_ptr)
 {
 	unsigned int cstatus;
 
@@ -2574,9 +2565,6 @@ static void isci_request_handle_controller_specific_errors(
 				*status_ptr = SAS_ABORTED_TASK;
 
 			set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
-
-			*complete_to_host_ptr =
-				isci_perform_normal_io_completion;
 		} else {
 			/* Task in the target is not done. */
 			*response_ptr = SAS_TASK_UNDELIVERED;
@@ -2587,9 +2575,6 @@ static void isci_request_handle_controller_specific_errors(
 				*status_ptr = SAM_STAT_TASK_ABORTED;
 
 			clear_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
-
-			*complete_to_host_ptr =
-				isci_perform_error_io_completion;
 		}
 
 		break;
@@ -2618,8 +2603,6 @@ static void isci_request_handle_controller_specific_errors(
 			*status_ptr = SAS_ABORTED_TASK;
 
 		set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
-
-		*complete_to_host_ptr = isci_perform_normal_io_completion;
 		break;
 
 
@@ -2630,7 +2613,7 @@ static void isci_request_handle_controller_specific_errors(
 
 		isci_request_set_open_reject_status(
 			request, task, response_ptr, status_ptr,
-			complete_to_host_ptr, SAS_OREJ_WRONG_DEST);
+			SAS_OREJ_WRONG_DEST);
 		break;
 
 	case SCU_TASK_OPEN_REJECT_ZONE_VIOLATION:
@@ -2640,56 +2623,56 @@ static void isci_request_handle_controller_specific_errors(
 		 */
 		isci_request_set_open_reject_status(
 			request, task, response_ptr, status_ptr,
-			complete_to_host_ptr, SAS_OREJ_RESV_AB0);
+			SAS_OREJ_RESV_AB0);
 		break;
 
 	case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_1:
 
 		isci_request_set_open_reject_status(
 			request, task, response_ptr, status_ptr,
-			complete_to_host_ptr, SAS_OREJ_RESV_AB1);
+			SAS_OREJ_RESV_AB1);
 		break;
 
 	case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_2:
 
 		isci_request_set_open_reject_status(
 			request, task, response_ptr, status_ptr,
-			complete_to_host_ptr, SAS_OREJ_RESV_AB2);
+			SAS_OREJ_RESV_AB2);
 		break;
 
 	case SCU_TASK_OPEN_REJECT_RESERVED_ABANDON_3:
 
 		isci_request_set_open_reject_status(
 			request, task, response_ptr, status_ptr,
-			complete_to_host_ptr, SAS_OREJ_RESV_AB3);
+			SAS_OREJ_RESV_AB3);
 		break;
 
 	case SCU_TASK_OPEN_REJECT_BAD_DESTINATION:
 
 		isci_request_set_open_reject_status(
 			request, task, response_ptr, status_ptr,
-			complete_to_host_ptr, SAS_OREJ_BAD_DEST);
+			SAS_OREJ_BAD_DEST);
 		break;
 
 	case SCU_TASK_OPEN_REJECT_STP_RESOURCES_BUSY:
 
 		isci_request_set_open_reject_status(
 			request, task, response_ptr, status_ptr,
-			complete_to_host_ptr, SAS_OREJ_STP_NORES);
+			SAS_OREJ_STP_NORES);
 		break;
 
 	case SCU_TASK_OPEN_REJECT_PROTOCOL_NOT_SUPPORTED:
 
 		isci_request_set_open_reject_status(
 			request, task, response_ptr, status_ptr,
-			complete_to_host_ptr, SAS_OREJ_EPROTO);
+			SAS_OREJ_EPROTO);
 		break;
 
 	case SCU_TASK_OPEN_REJECT_CONNECTION_RATE_NOT_SUPPORTED:
 
 		isci_request_set_open_reject_status(
 			request, task, response_ptr, status_ptr,
-			complete_to_host_ptr, SAS_OREJ_CONN_RATE);
+			SAS_OREJ_CONN_RATE);
 		break;
 
 	case SCU_TASK_DONE_LL_R_ERR:
@@ -2721,95 +2704,12 @@ static void isci_request_handle_controller_specific_errors(
 		*response_ptr = SAS_TASK_UNDELIVERED;
 		*status_ptr = SAM_STAT_TASK_ABORTED;
 
-		if (task->task_proto == SAS_PROTOCOL_SMP) {
+		if (task->task_proto == SAS_PROTOCOL_SMP)
 			set_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
-
-			*complete_to_host_ptr = isci_perform_normal_io_completion;
-		} else {
+		else
 			clear_bit(IREQ_COMPLETE_IN_TARGET, &request->flags);
-
-			*complete_to_host_ptr = isci_perform_error_io_completion;
-		}
-		break;
-	}
-}
-
-/**
- * isci_task_save_for_upper_layer_completion() - This function saves the
- *    request for later completion to the upper layer driver.
- * @host: This parameter is a pointer to the host on which the the request
- *    should be queued (either as an error or success).
- * @request: This parameter is the completed request.
- * @response: This parameter is the response code for the completed task.
- * @status: This parameter is the status code for the completed task.
- *
- * none.
- */
-static void isci_task_save_for_upper_layer_completion(
-	struct isci_host *host,
-	struct isci_request *request,
-	enum service_response response,
-	enum exec_status status,
-	enum isci_completion_selection task_notification_selection)
-{
-	struct sas_task *task = isci_request_access_task(request);
-
-	task_notification_selection
-		= isci_task_set_completion_status(task, response, status,
-						  task_notification_selection);
-
-	/* Tasks aborted specifically by a call to the lldd_abort_task
-	 * function should not be completed to the host in the regular path.
-	 */
-	switch (task_notification_selection) {
-
-	case isci_perform_normal_io_completion:
-		/* Normal notification (task_done) */
-
-		/* Add to the completed list. */
-		list_add(&request->completed_node,
-			 &host->requests_to_complete);
-
-		/* Take the request off the device's pending request list. */
-		list_del_init(&request->dev_node);
-		break;
-
-	case isci_perform_aborted_io_completion:
-		/* No notification to libsas because this request is
-		 * already in the abort path.
-		 */
-		/* Wake up whatever process was waiting for this
-		 * request to complete.
-		 */
-		WARN_ON(request->io_request_completion == NULL);
-
-		if (request->io_request_completion != NULL) {
-
-			/* Signal whoever is waiting that this
-			* request is complete.
-			*/
-			complete(request->io_request_completion);
-		}
-		break;
-
-	case isci_perform_error_io_completion:
-		/* Use sas_task_abort */
-		/* Add to the aborted list. */
-		list_add(&request->completed_node,
-			 &host->requests_to_errorback);
-		break;
-
-	default:
-		/* Add to the error to libsas list. */
-		list_add(&request->completed_node,
-			 &host->requests_to_errorback);
 		break;
 	}
-	dev_dbg(&host->pdev->dev,
-		"%s: %d - task = %p, response=%d (%d), status=%d (%d)\n",
-		__func__, task_notification_selection, task,
-		(task) ? task->task_status.resp : 0, response,
-		(task) ? task->task_status.stat : 0, status);
 }
 
 static void isci_process_stp_response(struct sas_task *task, struct dev_to_host_fis *fis)
@@ -2844,9 +2744,6 @@ static void isci_request_io_request_complete(struct isci_host *ihost,
 	struct isci_remote_device *idev = request->target_device;
 	enum service_response response = SAS_TASK_UNDELIVERED;
 	enum exec_status status = SAS_ABORTED_TASK;
-	enum isci_request_status request_status;
-	enum isci_completion_selection complete_to_host
-		= isci_perform_normal_io_completion;
 
 	dev_dbg(&ihost->pdev->dev,
 		"%s: request = %p, task = %p,\n"
@@ -2857,282 +2754,158 @@ static void isci_request_io_request_complete(struct isci_host *ihost,
 		task->data_dir,
 		completion_status);
 
-	spin_lock(&request->state_lock);
-	request_status = request->status;
-
-	/* Decode the request status.  Note that if the request has been
-	 * aborted by a task management function, we don't care
-	 * what the status is.
-	 */
-	switch (request_status) {
-
-	case aborted:
-		/* "aborted" indicates that the request was aborted by a task
-		 * management function, since once a task management request is
-		 * perfomed by the device, the request only completes because
-		 * of the subsequent driver terminate.
-		 *
-		 * Aborted also means an external thread is explicitly managing
-		 * this request, so that we do not complete it up the stack.