vserver 1.9.5.x5

[linux-2.6.git] / include / scsi / scsi_tcq.h

diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index 78039d0..e47e36a 100644 (file)
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -13,6 +13,43 @@
 #define SCSI_NO_TAG    (-1)    /* identify no tag in use */
 
 
+
+/**
+ * scsi_get_tag_type - get the type of tag the device supports
+ * @sdev:      the scsi device
+ *
+ * Notes:
+ *     If the drive only supports simple tags, returns MSG_SIMPLE_TAG
+ *     if it supports all tag types, returns MSG_ORDERED_TAG.
+ */
+static inline int scsi_get_tag_type(struct scsi_device *sdev)
+{
+       if (!sdev->tagged_supported)
+               return 0;
+       if (sdev->ordered_tags)
+               return MSG_ORDERED_TAG;
+       if (sdev->simple_tags)
+               return MSG_SIMPLE_TAG;
+       return 0;
+}
+
+static inline void scsi_set_tag_type(struct scsi_device *sdev, int tag)
+{
+       switch (tag) {
+       case MSG_ORDERED_TAG:
+               sdev->ordered_tags = 1;
+               /* fall through */
+       case MSG_SIMPLE_TAG:
+               sdev->simple_tags = 1;
+               break;
+       case 0:
+               /* fall through */
+       default:
+               sdev->ordered_tags = 0;
+               sdev->simple_tags = 0;
+               break;
+       }
+}
 /**
  * scsi_activate_tcq - turn on tag command queueing
  * @SDpnt:     device to turn on TCQ for
@@ -25,11 +62,13 @@
  **/
 static inline void scsi_activate_tcq(struct scsi_device *sdev, int depth)
 {
-        if (sdev->tagged_supported) {
-               if (!blk_queue_tagged(sdev->request_queue))
-                       blk_queue_init_tags(sdev->request_queue, depth, NULL);
-               scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
-        }
+       if (!sdev->tagged_supported)
+               return;
+
+       if (!blk_queue_tagged(sdev->request_queue))
+               blk_queue_init_tags(sdev->request_queue, depth, NULL);
+
+       scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 }
 
 /**
@@ -56,9 +95,10 @@ static inline void scsi_deactivate_tcq(struct scsi_device *sdev, int depth)
 static inline int scsi_populate_tag_msg(struct scsi_cmnd *cmd, char *msg)
 {
         struct request *req = cmd->request;
+       struct scsi_device *sdev = cmd->device;
 
         if (blk_rq_tagged(req)) {
-               if (req->flags & REQ_HARDBARRIER)
+               if (sdev->ordered_tags && req->flags & REQ_HARDBARRIER)
                        *msg++ = MSG_ORDERED_TAG;
                else
                        *msg++ = MSG_SIMPLE_TAG;