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| author | James Bottomley <James.Bottomley@steeleye.com> | 2006-08-30 09:45:51 -0400 |
|---|---|---|
| committer | James Bottomley <jejb@mulgrave.il.steeleye.com> | 2006-08-31 11:18:03 -0400 |
| commit | 86e33a296c2c9ed6eece0bfff4ac776f42040504 (patch) | |
| tree | 7c4a11084b233e1899aec6c247435f3478bbd3b5 /include | |
| parent | 492dfb489658dfe4a755fa29dd0e34e9c8bd8fb8 (diff) | |
| download | linux-stable-86e33a296c2c9ed6eece0bfff4ac776f42040504.tar.gz linux-stable-86e33a296c2c9ed6eece0bfff4ac776f42040504.tar.bz2 linux-stable-86e33a296c2c9ed6eece0bfff4ac776f42040504.zip | |
[SCSI] add shared tag map helpers
This patch adds support for sharing tag maps at the host level
(i.e. either every queue [LUN] has its own tag map or there's a single
one for the entire host). This formulation is primarily intended to
help single issue queue hardware, like the aic7xxx
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/scsi/scsi_host.h | 7 | ||||
| -rw-r--r-- | include/scsi/scsi_tcq.h | 14 |
2 files changed, 20 insertions, 1 deletions
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index b3dd90f3e858..39c6f8cc20c3 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -16,6 +16,7 @@ struct scsi_target; struct Scsi_Host; struct scsi_host_cmd_pool; struct scsi_transport_template; +struct blk_queue_tags; /* @@ -466,6 +467,12 @@ struct Scsi_Host { struct scsi_transport_template *transportt; /* + * area to keep a shared tag map (if needed, will be + * NULL if not) + */ + struct blk_queue_tag *bqt; + + /* * The following two fields are protected with host_lock; * however, eh routines can safely access during eh processing * without acquiring the lock. diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h index e47e36a4ef49..4eea254b1ce9 100644 --- a/include/scsi/scsi_tcq.h +++ b/include/scsi/scsi_tcq.h @@ -4,6 +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 @@ -66,7 +67,8 @@ static inline void scsi_activate_tcq(struct scsi_device *sdev, int depth) return; if (!blk_queue_tagged(sdev->request_queue)) - blk_queue_init_tags(sdev->request_queue, depth, NULL); + blk_queue_init_tags(sdev->request_queue, depth, + sdev->host->bqt); scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth); } @@ -131,4 +133,14 @@ 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 void scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth) +{ + shost->bqt = blk_init_tags(depth); +} + #endif /* _SCSI_SCSI_TCQ_H */ |