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>

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",

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];

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];
 

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_) */

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)),

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(

drivers/scsi/isci/request.h

@@ -60,23 +60,6 @@
 #include "host.h"
 #include "scu_task_context.h"
 
-/**
- * struct isci_request_status - This enum defines the possible states of an I/O
- *    request.
- *
- *
- */
-enum isci_request_status {
-	unallocated = 0x00,
-	allocated   = 0x01,
-	started     = 0x02,
-	completed   = 0x03,
-	aborting    = 0x04,
-	aborted     = 0x05,
-	terminating = 0x06,
-	dead        = 0x07
-};
-
 /**
  * isci_stp_request - extra request infrastructure to handle pio/atapi protocol
  * @pio_len - number of bytes requested at PIO setup
@@ -97,13 +80,13 @@ struct isci_stp_request {
 };
 
 struct isci_request {
-	enum isci_request_status status;
 	#define IREQ_COMPLETE_IN_TARGET 0
 	#define IREQ_TERMINATED 1
 	#define IREQ_TMF 2
 	#define IREQ_ACTIVE 3
 	#define IREQ_PENDING_ABORT 4 /* Set == device was not suspended yet */
 	#define IREQ_TC_ABORT_POSTED 5
+	#define IREQ_ABORT_PATH_ACTIVE 6
 	unsigned long flags;
 	/* XXX kill ttype and ttype_ptr, allocate full sas_task */
 	union ttype_ptr_union {
@@ -115,7 +98,6 @@ struct isci_request {
 	struct list_head completed_node;
 	/* For use in the reqs_in_process list: */
 	struct list_head dev_node;
-	spinlock_t state_lock;
 	dma_addr_t request_daddr;
 	dma_addr_t zero_scatter_daddr;
 	unsigned int num_sg_entries;
@@ -304,92 +286,6 @@ sci_io_request_get_dma_addr(struct isci_request *ireq, void *virt_addr)
 	return ireq->request_daddr + (requested_addr - base_addr);
 }
 
-/**
- * isci_request_change_state() - This function sets the status of the request
- *    object.
- * @request: This parameter points to the isci_request object
- * @status: This Parameter is the new status of the object
- *
- */
-static inline enum isci_request_status
-isci_request_change_state(struct isci_request *isci_request,
-			  enum isci_request_status status)
-{
-	enum isci_request_status old_state;
-	unsigned long flags;
-
-	dev_dbg(&isci_request->isci_host->pdev->dev,
-		"%s: isci_request = %p, state = 0x%x\n",
-		__func__,
-		isci_request,
-		status);
-
-	BUG_ON(isci_request == NULL);
-
-	spin_lock_irqsave(&isci_request->state_lock, flags);
-	old_state = isci_request->status;
-	isci_request->status = status;
-	spin_unlock_irqrestore(&isci_request->state_lock, flags);
-
-	return old_state;
-}
-
-/**
- * isci_request_change_started_to_newstate() - This function sets the status of
- *    the request object.
- * @request: This parameter points to the isci_request object
- * @status: This Parameter is the new status of the object
- *
- * state previous to any change.
- */
-static inline enum isci_request_status
-isci_request_change_started_to_newstate(struct isci_request *isci_request,
-					struct completion *completion_ptr,
-					enum isci_request_status newstate)
-{
-	enum isci_request_status old_state;
-	unsigned long flags;
-
-	spin_lock_irqsave(&isci_request->state_lock, flags);
-
-	old_state = isci_request->status;
-
-	if (old_state == started || old_state == aborting) {
-		BUG_ON(isci_request->io_request_completion != NULL);
-
-		isci_request->io_request_completion = completion_ptr;
-		isci_request->status = newstate;
-	}
-
-	spin_unlock_irqrestore(&isci_request->state_lock, flags);
-
-	dev_dbg(&isci_request->isci_host->pdev->dev,
-		"%s: isci_request = %p, old_state = 0x%x\n",
-		__func__,
-		isci_request,
-		old_state);
-
-	return old_state;
-}
-
-/**
- * isci_request_change_started_to_aborted() - This function sets the status of
- *    the request object.
- * @request: This parameter points to the isci_request object
- * @completion_ptr: This parameter is saved as the kernel completion structure
- *    signalled when the old request completes.
- *
- * state previous to any change.
- */
-static inline enum isci_request_status
-isci_request_change_started_to_aborted(struct isci_request *isci_request,
-				       struct completion *completion_ptr)
-{
-	return isci_request_change_started_to_newstate(isci_request,
-						       completion_ptr,
-						       aborted);
-}
-
 #define isci_request_access_task(req) ((req)->ttype_ptr.io_task_ptr)
 
 #define isci_request_access_tmf(req) ((req)->ttype_ptr.tmf_task_ptr)
@@ -399,8 +295,6 @@ struct isci_request *isci_tmf_request_from_tag(struct isci_host *ihost,
 					       u16 tag);
 int isci_request_execute(struct isci_host *ihost, struct isci_remote_device *idev,
 			 struct sas_task *task, u16 tag);
-void isci_terminate_pending_requests(struct isci_host *ihost,
-				     struct isci_remote_device *idev);
 enum sci_status
 sci_task_request_construct(struct isci_host *ihost,
 			    struct isci_remote_device *idev,

drivers/scsi/isci/task.h

@@ -62,19 +62,6 @@
 
 struct isci_request;
 
-/**
- * enum isci_tmf_cb_state - This enum defines the possible states in which the
- *    TMF callback function is invoked during the TMF execution process.
- *
- *
- */
-enum isci_tmf_cb_state {
-
-	isci_tmf_init_state = 0,
-	isci_tmf_started,
-	isci_tmf_timed_out
-};
-
 /**
  * enum isci_tmf_function_codes - This enum defines the possible preparations
  *    of task management requests.
@@ -87,6 +74,7 @@ enum isci_tmf_function_codes {
 	isci_tmf_ssp_task_abort = TMF_ABORT_TASK,
 	isci_tmf_ssp_lun_reset  = TMF_LU_RESET,
 };
+
 /**
  * struct isci_tmf - This class represents the task management object which
  *    acts as an interface to libsas for processing task management requests
@@ -106,15 +94,6 @@ struct isci_tmf {
 	u16 io_tag;
 	enum isci_tmf_function_codes tmf_code;
 	int status;
-
-	/* The optional callback function allows the user process to
-	 * track the TMF transmit / timeout conditions.
-	 */
-	void (*cb_state_func)(
-		enum isci_tmf_cb_state,
-		struct isci_tmf *, void *);
-	void *cb_data;
-
 };
 
 static inline void isci_print_tmf(struct isci_host *ihost, struct isci_tmf *tmf)
@@ -208,113 +187,4 @@ int isci_queuecommand(
 	struct scsi_cmnd *scsi_cmd,
 	void (*donefunc)(struct scsi_cmnd *));
 
-/**
- * enum isci_completion_selection - This enum defines the possible actions to
- *    take with respect to a given request's notification back to libsas.
- *
- *
- */
-enum isci_completion_selection {
-
-	isci_perform_normal_io_completion,      /* Normal notify (task_done) */
-	isci_perform_aborted_io_completion,     /* No notification.   */
-	isci_perform_error_io_completion        /* Use sas_task_abort */
-};
-
-/**
- * isci_task_set_completion_status() - This function sets the completion status
- *    for the request.
- * @task: 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.
- *
-* @return The new notification mode for the request.
-*/
-static inline enum isci_completion_selection
-isci_task_set_completion_status(
-	struct sas_task *task,
-	enum service_response response,
-	enum exec_status status,
-	enum isci_completion_selection task_notification_selection)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&task->task_state_lock, flags);
-
-	/* If a device reset is being indicated, make sure the I/O
-	* is in the error path.
-	*/
-	if (task->task_state_flags & SAS_TASK_NEED_DEV_RESET) {
-		/* Fail the I/O to make sure it goes into the error path. */
-		response = SAS_TASK_UNDELIVERED;
-		status = SAM_STAT_TASK_ABORTED;
-
-		task_notification_selection = isci_perform_error_io_completion;
-	}
-	task->task_status.resp = response;
-	task->task_status.stat = status;
-
-	switch (task->task_proto) {
-
-	case SAS_PROTOCOL_SATA:
-	case SAS_PROTOCOL_STP:
-	case SAS_PROTOCOL_SATA | SAS_PROTOCOL_STP:
-
-		if (task_notification_selection
-		    == isci_perform_error_io_completion) {
-			/* SATA/STP I/O has it's own means of scheduling device
-			* error handling on the normal path.
-			*/
-			task_notification_selection
-				= isci_perform_normal_io_completion;
-		}
-		break;
-	default:
-		break;
-	}
-
-	switch (task_notification_selection) {
-
-	case isci_perform_error_io_completion:
-
-		if (task->task_proto == SAS_PROTOCOL_SMP) {
-			/* There is no error escalation in the SMP case.
-			 * Convert to a normal completion to avoid the
-			 * timeout in the discovery path and to let the
-			 * next action take place quickly.
-			 */
-			task_notification_selection
-				= isci_perform_normal_io_completion;
-
-			/* Fall through to the normal case... */
-		} else {
-			/* Use sas_task_abort */
-			/* Leave SAS_TASK_STATE_DONE clear
-			 * Leave SAS_TASK_AT_INITIATOR set.
-			 */
-			break;
-		}
-
-	case isci_perform_aborted_io_completion:
-		/* This path can occur with task-managed requests as well as
-		 * requests terminated because of LUN or device resets.
-		 */
-		/* Fall through to the normal case... */
-	case isci_perform_normal_io_completion:
-		/* Normal notification (task_done) */
-		task->task_state_flags |= SAS_TASK_STATE_DONE;
-		task->task_state_flags &= ~(SAS_TASK_AT_INITIATOR |
-					    SAS_TASK_STATE_PENDING);
-		break;
-	default:
-		WARN_ONCE(1, "unknown task_notification_selection: %d\n",
-			 task_notification_selection);
-		break;
-	}
-
-	spin_unlock_irqrestore(&task->task_state_lock, flags);
-
-	return task_notification_selection;
-
-}
 #endif /* !defined(_SCI_TASK_H_) */