X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Fscsi%2Fscsi_tcq.h;h=cf4c219c0b5cb9ab758046737b2ca814164b01a0;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=78039d0f1a57ca1771ca61dda4206d38a8d2a245;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git

diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h
index 78039d0f1..cf4c219c0 100644
--- 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 */