scsi: use host wide tags by default
This patch changes the !blk-mq path to the same defaults as the blk-mq
I/O path by always enabling block tagging, and always using host wide
tags. We've had blk-mq available for a few releases so bugs with
this mode should have been ironed out, and this ensures we get better
coverage of over tagging setup over different configs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index b27977e..4416b10 100644
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -10,91 +10,36 @@
#ifdef CONFIG_BLOCK
-static inline struct scsi_cmnd *scsi_mq_find_tag(struct Scsi_Host *shost,
- int unique_tag)
-{
- u16 hwq = blk_mq_unique_tag_to_hwq(unique_tag);
- struct request *req = NULL;
-
- 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: tag generated by blk_mq_unique_tag()
- *
- * Notes:
- * Only works with tags allocated by the generic blk layer.
- **/
-static inline struct scsi_cmnd *scsi_find_tag(struct scsi_device *sdev, int tag)
-{
- struct request *req;
-
- if (tag != SCSI_NO_TAG) {
- if (shost_use_blk_mq(sdev->host))
- return scsi_mq_find_tag(sdev->host, tag);
-
- req = blk_queue_find_tag(sdev->request_queue, tag);
- return req ? (struct scsi_cmnd *)req->special : NULL;
- }
-
- /* single command, look in space */
- return sdev->current_cmnd;
-}
-
-
-/**
- * scsi_init_shared_tag_map - create a shared tag map
- * @shost: the host to share the tag map among all devices
- * @depth: the total depth of the map
- */
-static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
-{
- /*
- * We always have a shared tag map around when using blk-mq.
- */
- if (shost_use_blk_mq(shost))
- return 0;
-
- /*
- * If the shared tag map isn't already initialized, do it now.
- * This saves callers from having to check ->bqt when setting up
- * devices on the shared host (for libata)
- */
- if (!shost->bqt) {
- shost->bqt = blk_init_tags(depth,
- shost->hostt->tag_alloc_policy);
- if (!shost->bqt)
- return -ENOMEM;
- }
-
- return 0;
-}
-
/**
* scsi_host_find_tag - find the tagged command by host
* @shost: pointer to scsi_host
- * @tag: tag generated by blk_mq_unique_tag()
+ * @tag: tag
*
- * Notes:
- * Only works with tags allocated by the generic blk layer.
+ * Note: for devices using multiple hardware queues tag must have been
+ * generated by blk_mq_unique_tag().
**/
static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
- int tag)
+ int tag)
{
- struct request *req;
+ struct request *req = NULL;
- if (tag != SCSI_NO_TAG) {
- if (shost_use_blk_mq(shost))
- return scsi_mq_find_tag(shost, tag);
+ if (tag == SCSI_NO_TAG)
+ return NULL;
+
+ if (shost_use_blk_mq(shost)) {
+ u16 hwq = blk_mq_unique_tag_to_hwq(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(tag));
+ }
+ } else {
req = blk_map_queue_find_tag(shost->bqt, tag);
- return req ? (struct scsi_cmnd *)req->special : NULL;
}
- return NULL;
+
+ if (!req)
+ return NULL;
+ return req->special;
}
#endif /* CONFIG_BLOCK */