[SCSI] 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: Xiangliang Yu <yuxiangl@marvell.com>
Acked-by: Jack Wang <jack_wang@usish.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index 29a8cc7..ae33706 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -613,10 +613,6 @@
 
 	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;
@@ -633,8 +629,15 @@
 
 	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
@@ -644,6 +647,7 @@
 #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 {