libsas: trim sas_task of slow path infrastructure

The timer and the completion are only used for slow path tasks (smp, and
lldd tmfs), yet we incur the allocation space and cpu setup time for
every fast path task.

Cc: Christoph Hellwig <hch@lst.de>
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

6 files changed, 73 insertions, 46 deletions

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 05acd9e35fc4de..0ab379627e7f2d 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -51,14 +51,14 @@ static void smp_task_timedout(unsigned long _task)
 		task->task_state_flags |= SAS_TASK_STATE_ABORTED;
 	spin_unlock_irqrestore(&task->task_state_lock, flags);
 
-	complete(&task->completion);
+	complete(&task->slow_task->completion);
 }
 
 static void smp_task_done(struct sas_task *task)
 {
-	if (!del_timer(&task->timer))
+	if (!del_timer(&task->slow_task->timer))
 		return;
-	complete(&task->completion);
+	complete(&task->slow_task->completion);
 }
 
 /* Give it some long enough timeout. In seconds. */
@@ -79,7 +79,7 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
 			break;
 		}
 
-		task = sas_alloc_task(GFP_KERNEL);
+		task = sas_alloc_slow_task(GFP_KERNEL);
 		if (!task) {
 			res = -ENOMEM;
 			break;
@@ -91,20 +91,20 @@ static int smp_execute_task(struct domain_device *dev, void *req, int req_size,
 
 		task->task_done = smp_task_done;
 
-		task->timer.data = (unsigned long) task;
-		task->timer.function = smp_task_timedout;
-		task->timer.expires = jiffies + SMP_TIMEOUT*HZ;
-		add_timer(&task->timer);
+		task->slow_task->timer.data = (unsigned long) task;
+		task->slow_task->timer.function = smp_task_timedout;
+		task->slow_task->timer.expires = jiffies + SMP_TIMEOUT*HZ;
+		add_timer(&task->slow_task->timer);
 
 		res = i->dft->lldd_execute_task(task, 1, GFP_KERNEL);
 
 		if (res) {
-			del_timer(&task->timer);
+			del_timer(&task->slow_task->timer);
 			SAS_DPRINTK("executing SMP task failed:%d\n", res);
 			break;
 		}
 
-		wait_for_completion(&task->completion);
+		wait_for_completion(&task->slow_task->completion);
 		res = -ECOMM;
 		if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
 			SAS_DPRINTK("smp task timed out or aborted\n");
diff --git a/drivers/scsi/libsas/sas_init.c b/drivers/scsi/libsas/sas_init.c
index 1bbab3d94a2027..014297c05880d8 100644
--- a/drivers/scsi/libsas/sas_init.c
+++ b/drivers/scsi/libsas/sas_init.c
@@ -48,18 +48,37 @@ struct sas_task *sas_alloc_task(gfp_t flags)
 		INIT_LIST_HEAD(&task->list);
 		spin_lock_init(&task->task_state_lock);
 		task->task_state_flags = SAS_TASK_STATE_PENDING;
-		init_timer(&task->timer);
-		init_completion(&task->completion);
 	}
 
 	return task;
 }
 EXPORT_SYMBOL_GPL(sas_alloc_task);
 
+struct sas_task *sas_alloc_slow_task(gfp_t flags)
+{
+	struct sas_task *task = sas_alloc_task(flags);
+	struct sas_task_slow *slow = kmalloc(sizeof(*slow), flags);
+
+	if (!task || !slow) {
+		if (task)
+			kmem_cache_free(sas_task_cache, task);
+		kfree(slow);
+		return NULL;
+	}
+
+	task->slow_task = slow;
+	init_timer(&slow->timer);
+	init_completion(&slow->completion);
+
+	return task;
+}
+EXPORT_SYMBOL_GPL(sas_alloc_slow_task);
+
 void sas_free_task(struct sas_task *task)
 {
 	if (task) {
 		BUG_ON(!list_empty(&task->list));
+		kfree(task->slow_task);
 		kmem_cache_free(sas_task_cache, task);
 	}
 }
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 676414859872ac..6e795a174a1241 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -1134,9 +1134,13 @@ void sas_task_abort(struct sas_task *task)
 
 	/* Escape for libsas internal commands */
 	if (!sc) {
-		if (!del_timer(&task->timer))
+		struct sas_task_slow *slow = task->slow_task;
+
+		if (!slow)
+			return;
+		if (!del_timer(&slow->timer))
 			return;
-		task->timer.function(task->timer.data);
+		slow->timer.function(slow->timer.data);
 		return;
 	}
 
diff --git a/drivers/scsi/mvsas/mv_sas.c b/drivers/scsi/mvsas/mv_sas.c
index b68a65390f0dc7..d0462b86c96e8f 100644
--- a/drivers/scsi/mvsas/mv_sas.c
+++ b/drivers/scsi/mvsas/mv_sas.c
@@ -1365,9 +1365,9 @@ void mvs_dev_gone(struct domain_device *dev)
 
 static void mvs_task_done(struct sas_task *task)
 {
-	if (!del_timer(&task->timer))
+	if (!del_timer(&task->slow_task->timer))
 		return;
-	complete(&task->completion);
+	complete(&task->slow_task->completion);
 }
 
 static void mvs_tmf_timedout(unsigned long data)
@@ -1375,7 +1375,7 @@ static void mvs_tmf_timedout(unsigned long data)
 	struct sas_task *task = (struct sas_task *)data;
 
 	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
-	complete(&task->completion);
+	complete(&task->slow_task->completion);
 }
 
 #define MVS_TASK_TIMEOUT 20
@@ -1386,7 +1386,7 @@ static int mvs_exec_internal_tmf_task(struct domain_device *dev,
 	struct sas_task *task = NULL;
 
 	for (retry = 0; retry < 3; retry++) {
-		task = sas_alloc_task(GFP_KERNEL);
+		task = sas_alloc_slow_task(GFP_KERNEL);
 		if (!task)
 			return -ENOMEM;
 
@@ -1396,20 +1396,20 @@ static int mvs_exec_internal_tmf_task(struct domain_device *dev,
 		memcpy(&task->ssp_task, parameter, para_len);
 		task->task_done = mvs_task_done;
 
-		task->timer.data = (unsigned long) task;
-		task->timer.function = mvs_tmf_timedout;
-		task->timer.expires = jiffies + MVS_TASK_TIMEOUT*HZ;
-		add_timer(&task->timer);
+		task->slow_task->timer.data = (unsigned long) task;
+		task->slow_task->timer.function = mvs_tmf_timedout;
+		task->slow_task->timer.expires = jiffies + MVS_TASK_TIMEOUT*HZ;
+		add_timer(&task->slow_task->timer);
 
 		res = mvs_task_exec(task, 1, GFP_KERNEL, NULL, 1, tmf);
 
 		if (res) {
-			del_timer(&task->timer);
+			del_timer(&task->slow_task->timer);
 			mv_printk("executing internel task failed:%d\n", res);
 			goto ex_err;
 		}
 
-		wait_for_completion(&task->completion);
+		wait_for_completion(&task->slow_task->completion);
 		res = TMF_RESP_FUNC_FAILED;
 		/* Even TMF timed out, return direct. */
 		if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
index fdbba57a74aec6..b961112395d5e0 100644
--- a/drivers/scsi/pm8001/pm8001_sas.c
+++ b/drivers/scsi/pm8001/pm8001_sas.c
@@ -650,9 +650,9 @@ int pm8001_dev_found(struct domain_device *dev)
 
 static void pm8001_task_done(struct sas_task *task)
 {
-	if (!del_timer(&task->timer))
+	if (!del_timer(&task->slow_task->timer))
 		return;
-	complete(&task->completion);
+	complete(&task->slow_task->completion);
 }
 
 static void pm8001_tmf_timedout(unsigned long data)
@@ -660,7 +660,7 @@ static void pm8001_tmf_timedout(unsigned long data)
 	struct sas_task *task = (struct sas_task *)data;
 
 	task->task_state_flags |= SAS_TASK_STATE_ABORTED;
-	complete(&task->completion);
+	complete(&task->slow_task->completion);
 }
 
 #define PM8001_TASK_TIMEOUT 20
@@ -683,7 +683,7 @@ static int pm8001_exec_internal_tmf_task(struct domain_device *dev,
 	struct pm8001_hba_info *pm8001_ha = pm8001_find_ha_by_dev(dev);
 
 	for (retry = 0; retry < 3; retry++) {
-		task = sas_alloc_task(GFP_KERNEL);
+		task = sas_alloc_slow_task(GFP_KERNEL);
 		if (!task)
 			return -ENOMEM;
 
@@ -691,21 +691,21 @@ static int pm8001_exec_internal_tmf_task(struct domain_device *dev,
 		task->task_proto = dev->tproto;
 		memcpy(&task->ssp_task, parameter, para_len);
 		task->task_done = pm8001_task_done;
-		task->timer.data = (unsigned long)task;
-		task->timer.function = pm8001_tmf_timedout;
-		task->timer.expires = jiffies + PM8001_TASK_TIMEOUT*HZ;
-		add_timer(&task->timer);
+		task->slow_task->timer.data = (unsigned long)task;
+		task->slow_task->timer.function = pm8001_tmf_timedout;
+		task->slow_task->timer.expires = jiffies + PM8001_TASK_TIMEOUT*HZ;
+		add_timer(&task->slow_task->timer);
 
 		res = pm8001_task_exec(task, 1, GFP_KERNEL, 1, tmf);
 
 		if (res) {
-			del_timer(&task->timer);
+			del_timer(&task->slow_task->timer);
 			PM8001_FAIL_DBG(pm8001_ha,
 				pm8001_printk("Executing internal task "
 				"failed\n"));
 			goto ex_err;
 		}
-		wait_for_completion(&task->completion);
+		wait_for_completion(&task->slow_task->completion);
 		res = -TMF_RESP_FUNC_FAILED;
 		/* Even TMF timed out, return direct. */
 		if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
@@ -765,17 +765,17 @@ pm8001_exec_internal_task_abort(struct pm8001_hba_info *pm8001_ha,
 	struct sas_task *task = NULL;
 
 	for (retry = 0; retry < 3; retry++) {
-		task = sas_alloc_task(GFP_KERNEL);
+		task = sas_alloc_slow_task(GFP_KERNEL);
 		if (!task)
 			return -ENOMEM;
 
 		task->dev = dev;
 		task->task_proto = dev->tproto;
 		task->task_done = pm8001_task_done;
-		task->timer.data = (unsigned long)task;
-		task->timer.function = pm8001_tmf_timedout;
-		task->timer.expires = jiffies + PM8001_TASK_TIMEOUT * HZ;
-		add_timer(&task->timer);
+		task->slow_task->timer.data = (unsigned long)task;
+		task->slow_task->timer.function = pm8001_tmf_timedout;
+		task->slow_task->timer.expires = jiffies + PM8001_TASK_TIMEOUT * HZ;
+		add_timer(&task->slow_task->timer);
 
 		res = pm8001_tag_alloc(pm8001_ha, &ccb_tag);
 		if (res)
@@ -789,13 +789,13 @@ pm8001_exec_internal_task_abort(struct pm8001_hba_info *pm8001_ha,
 			pm8001_dev, flag, task_tag, ccb_tag);
 
 		if (res) {
-			del_timer(&task->timer);
+			del_timer(&task->slow_task->timer);
 			PM8001_FAIL_DBG(pm8001_ha,
 				pm8001_printk("Executing internal task "
 				"failed\n"));
 			goto ex_err;
 		}
-		wait_for_completion(&task->completion);
+		wait_for_completion(&task->slow_task->completion);
 		res = TMF_RESP_FUNC_FAILED;
 		/* Even TMF timed out, return direct. */
 		if ((task->task_state_flags & SAS_TASK_STATE_ABORTED)) {
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index 45f9534a6b2498..f66e83b914b802 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -612,10 +612,6 @@ struct sas_task {
 
 	enum   sas_protocol      task_proto;
 
-	/* Used by the discovery code. */
-	struct timer_list     timer;
-	struct completion     completion;
-
 	union {
 		struct sas_ata_task ata_task;
 		struct sas_smp_task smp_task;
@@ -632,8 +628,15 @@ struct sas_task {
 
 	void   *lldd_task;	  /* for use by LLDDs */
 	void   *uldd_task;
+	struct sas_task_slow *slow_task;
+};
 
-	struct work_struct abort_work;
+struct sas_task_slow {
+	/* standard/extra infrastructure for slow path commands (SMP and
+	 * internal lldd commands
+	 */
+	struct timer_list     timer;
+	struct completion     completion;
 };
 
 #define SAS_TASK_STATE_PENDING      1
@@ -643,6 +646,7 @@ struct sas_task {
 #define SAS_TASK_AT_INITIATOR       16
 
 extern struct sas_task *sas_alloc_task(gfp_t flags);
+extern struct sas_task *sas_alloc_slow_task(gfp_t flags);
 extern void sas_free_task(struct sas_task *task);
 
 struct sas_domain_function_template {