scsi: add support for multiple hardware queues in scsi_(host_)find_tag

Modify scsi_find_tag() and scsi_host_find_tag() such that these
functions can translate a tag generated by blk_mq_unique_tag().

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index 56ed843..7529c6a 100644 (file)
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -111,18 +111,21 @@ static inline int scsi_populate_tag_msg(struct scsi_cmnd *cmd, char *msg)
 }
 
 static inline struct scsi_cmnd *scsi_mq_find_tag(struct Scsi_Host *shost,
-               unsigned int hw_ctx, int tag)
+                                                int unique_tag)
 {
-       struct request *req;
+       u16 hwq = blk_mq_unique_tag_to_hwq(unique_tag);
+       struct request *req = NULL;
 
-       req = blk_mq_tag_to_rq(shost->tag_set.tags[hw_ctx], tag);
+       if (hwq < shost->tag_set.nr_hw_queues)
+               req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq],
+                                      blk_mq_unique_tag_to_tag(unique_tag));
        return req ? (struct scsi_cmnd *)req->special : NULL;
 }
 
 /**
  * scsi_find_tag - find a tagged command by device
  * @SDpnt:     pointer to the ScSI device
- * @tag:       the tag number
+ * @tag:       tag generated by blk_mq_unique_tag()
  *
  * Notes:
  *     Only works with tags allocated by the generic blk layer.
@@ -133,9 +136,9 @@ static inline struct scsi_cmnd *scsi_find_tag(struct scsi_device *sdev, int tag)
 
         if (tag != SCSI_NO_TAG) {
                if (shost_use_blk_mq(sdev->host))
-                       return scsi_mq_find_tag(sdev->host, 0, tag);
+                       return scsi_mq_find_tag(sdev->host, tag);
 
-               req = blk_queue_find_tag(sdev->request_queue, tag);
+               req = blk_queue_find_tag(sdev->request_queue, tag);
                return req ? (struct scsi_cmnd *)req->special : NULL;
        }
 
@@ -174,7 +177,7 @@ static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
 /**
  * scsi_host_find_tag - find the tagged command by host
  * @shost:     pointer to scsi_host
- * @tag:       tag of the scsi_cmnd
+ * @tag:       tag generated by blk_mq_unique_tag()
  *
  * Notes:
  *     Only works with tags allocated by the generic blk layer.
@@ -186,7 +189,7 @@ static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
 
        if (tag != SCSI_NO_TAG) {
                if (shost_use_blk_mq(shost))
-                       return scsi_mq_find_tag(shost, 0, tag);
+                       return scsi_mq_find_tag(shost, tag);
                req = blk_map_queue_find_tag(shost->bqt, tag);
                return req ? (struct scsi_cmnd *)req->special : NULL;
        }