[PATCH RFC v2 14/18] scsi: libsas: Queue SMP commands as requests

[John Garry <john.garry@huawei.com>]

Send SMP commands through the block layer so that each command gets a
unique tag associated.

In future we can now also take advantage of the block layer request
timeout handling.

Function sas_task_complete_internal() is what the LLDD calls to signal
that the CQ is complete and this calls into the SCSI midlayer. And then
sas_blk_end_sync_rq() is called when the request completes.

Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/libsas/sas_expander.c  | 13 +++----------
 drivers/scsi/libsas/sas_internal.h  |  3 +++
 drivers/scsi/libsas/sas_scsi_host.c | 16 ++++++++++++++++
 3 files changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index b833de062f88..d0bf63286b7d 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -66,20 +66,13 @@ static int smp_execute_task_sg(struct domain_device *dev,
 		task->task_proto = dev->tproto;
 		task->smp_task.smp_req = *req;
 		task->smp_task.smp_resp = *resp;
-
-		task->task_done = sas_task_internal_done;
+		task->task_done = sas_task_complete_internal;
 
 		task->slow_task->timer.function = sas_task_internal_timedout;
 		task->slow_task->timer.expires = jiffies + SMP_TIMEOUT*HZ;
 		add_timer(&task->slow_task->timer);
-
-		res = i->dft->lldd_execute_task(task, GFP_KERNEL);
-
-		if (res) {
-			del_timer(&task->slow_task->timer);
-			pr_notice("executing SMP task failed:%d\n", res);
-			break;
-		}
+		rq->end_io = sas_blk_end_sync_rq;
+		blk_execute_rq_nowait(rq, true);
 
 		wait_for_completion(&task->slow_task->completion);
 		res = -ECOMM;
diff --git a/drivers/scsi/libsas/sas_internal.h b/drivers/scsi/libsas/sas_internal.h
index 13d0ffaada93..52cfa75d432b 100644
--- a/drivers/scsi/libsas/sas_internal.h
+++ b/drivers/scsi/libsas/sas_internal.h
@@ -99,6 +99,9 @@ int sas_execute_tmf(struct domain_device *device, void *parameter,
 		    int para_len, int force_phy_id,
 		    struct sas_tmf_task *tmf);
 
+void sas_task_complete_internal(struct sas_task *task);
+void sas_blk_end_sync_rq(struct request *rq, blk_status_t error);
+
 #ifdef CONFIG_SCSI_SAS_HOST_SMP
 extern void sas_smp_host_handler(struct bsg_job *job, struct Scsi_Host *shost);
 #else
diff --git a/drivers/scsi/libsas/sas_scsi_host.c b/drivers/scsi/libsas/sas_scsi_host.c
index 3abb1d622a32..f0566f4512b2 100644
--- a/drivers/scsi/libsas/sas_scsi_host.c
+++ b/drivers/scsi/libsas/sas_scsi_host.c
@@ -926,6 +926,16 @@ void sas_task_internal_done(struct sas_task *task)
 	complete(&task->slow_task->completion);
 }
 
+void sas_task_complete_internal(struct sas_task *task)
+{
+	struct request *rq = sas_rq_from_task(task);
+	struct scsi_cmnd *scmd = blk_mq_rq_to_pdu(rq);
+
+	del_timer(&task->slow_task->timer);
+
+	scsi_done(scmd);
+}
+
 void sas_task_internal_timedout(struct timer_list *t)
 {
 	struct sas_task_slow *slow = from_timer(slow, t, timer);
@@ -947,6 +957,12 @@ void sas_task_internal_timedout(struct timer_list *t)
 #define TASK_TIMEOUT			(20 * HZ)
 #define TASK_RETRY			3
 
+void sas_blk_end_sync_rq(struct request *rq, blk_status_t error)
+{
+	struct sas_task *task = sas_rq_to_task(rq);
+	complete(&task->slow_task->completion);
+}
+
 static int sas_execute_internal_abort(struct domain_device *device,
 				      enum sas_internal_abort type, u16 tag,
 				      unsigned int qid, void *data)
-- 
2.26.2