fedora core 6 1.2949 + vserver 2.2.0

[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..cf4c219 100644 (file)
--- a/include/scsi/scsi_tcq.h
+++ b/include/scsi/scsi_tcq.h
@@ -4,7 +4,7 @@
 #include <linux/blkdev.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_device.h>
-
+#include <scsi/scsi_host.h>
 
 #define MSG_SIMPLE_TAG 0x20
 #define MSG_HEAD_TAG   0x21
@@ -13,6 +13,44 @@
 #define SCSI_NO_TAG    (-1)    /* identify no tag in use */
 
 
+#ifdef CONFIG_BLOCK
+
+/**
+ * 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 +63,14 @@
  **/
 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,
+                                   sdev->host->bqt);
+
+       scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
 }
 
 /**
@@ -56,9 +97,10 @@ 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->cmd_flags & REQ_HARDBARRIER)
                        *msg++ = MSG_ORDERED_TAG;
                else
                        *msg++ = MSG_SIMPLE_TAG;
@@ -91,4 +133,36 @@ static inline struct scsi_cmnd *scsi_find_tag(struct scsi_device *sdev, int tag)
        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)
+{
+       shost->bqt = blk_init_tags(depth);
+       return shost->bqt ? 0 : -ENOMEM;
+}
+
+/**
+ * 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 */
 #endif /* _SCSI_SCSI_TCQ_H */