For drivers which enable .host_tagset, introduce scsi_cmnd_hctx_index
to retrieve current reply queue index. If valid scsi command is provided,
blk-mq's hw queue's index is returned, otherwise return the queue
mapped from current CPU.
Prepare for converting device's privete reply queue to blk-mq hw queue.
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
include/scsi/scsi_cmnd.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 76ed5e4acd38..23f611a6a9f2 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -9,6 +9,7 @@
#include <linux/types.h>
#include <linux/timer.h>
#include <linux/scatterlist.h>
+#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_request.h>
@@ -332,4 +333,18 @@ static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
return xfer_len;
}
+/* only for drivers which enable .host_tagset */
+static inline unsigned scsi_cmnd_hctx_index(struct Scsi_Host *sh,
+ struct scsi_cmnd *scmd)
+{
+ if (unlikely(!scmd || !scmd->request || !scmd->request->mq_hctx)) {
+ struct blk_mq_queue_map *qmap =
+ &sh->tag_set.map[HCTX_TYPE_DEFAULT];
+
+ return qmap->mq_map[raw_smp_processor_id()];
+ }
+
+ return scmd->request->mq_hctx->queue_num;
+}
+
#endif /* _SCSI_SCSI_CMND_H */
--
2.20.1
