Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mjg59/platf...

[karo-tx-linux.git] / include / scsi / scsi_tcq.h

diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index c247a28259bc77fa453994b3492a457f8b99bb7c..17231385cb3721932bf02910854db0396d973b92 100644 (file)
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -140,8 +140,38 @@ static inline struct scsi_cmnd *scsi_find_tag(struct scsi_device *sdev, int tag)
  */
 static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
 {
-       shost->bqt = blk_init_tags(depth);
-       return shost->bqt ? 0 : -ENOMEM;
+       /*
+        * 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);
+               if (!shost->bqt)
+                       return -ENOMEM;
+       }
+
+       return 0;
+}
+
+/**
+ * scsi_host_find_tag - find the tagged command by host
+ * @shost:     pointer to scsi_host
+ * @tag:       tag of the scsi_cmnd
+ *
+ * Notes:
+ *     Only works with tags allocated by the generic blk layer.
+ **/
+static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
+                                               int tag)
+{
+       struct request *req;
+
+       if (tag != SCSI_NO_TAG) {
+               req = blk_map_queue_find_tag(shost->bqt, tag);
+               return req ? (struct scsi_cmnd *)req->special : NULL;
+       }
+       return NULL;
 }
 
 #endif /* CONFIG_BLOCK */