[PATCH RFC v2 16/18] scsi: core: Add scsi_alloc_request_hwq()

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

Add a variant of scsi_alloc_request() which allocates a request for a
specific hw queue.

Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/scsi_lib.c  | 12 ++++++++++++
 include/scsi/scsi_cmnd.h |  3 +++
 2 files changed, 15 insertions(+)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 8c8b4c6767d9..443afaf52c14 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1137,6 +1137,18 @@ struct request *scsi_alloc_request(struct request_queue *q,
 }
 EXPORT_SYMBOL_GPL(scsi_alloc_request);
 
+struct request *scsi_alloc_request_hwq(struct request_queue *q,
+		unsigned int op, blk_mq_req_flags_t flags, unsigned int hwq)
+{
+	struct request *rq;
+
+	rq = blk_mq_alloc_request_hctx(q, op, flags, hwq);
+	if (!IS_ERR(rq))
+		scsi_initialize_rq(rq);
+	return rq;
+}
+EXPORT_SYMBOL_GPL(scsi_alloc_request_hwq);
+
 /*
  * Only called when the request isn't completed by SCSI, and not freed by
  * SCSI
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index e47df5836070..e69bb6baad47 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -394,4 +394,7 @@ extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
 struct request *scsi_alloc_request(struct request_queue *q,
 		unsigned int op, blk_mq_req_flags_t flags);
 
+struct request *scsi_alloc_request_hwq(struct request_queue *q,
+		unsigned int op, blk_mq_req_flags_t flags, unsigned int hwq);
+
 #endif /* _SCSI_SCSI_CMND_H */
-- 
2.26.2