From 86e33a296c2c9ed6eece0bfff4ac776f42040504 Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Wed, 30 Aug 2006 09:45:51 -0400 Subject: [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 --- include/scsi/scsi_host.h | 7 +++++++ include/scsi/scsi_tcq.h | 14 +++++++++++++- 2 files changed, 20 insertions(+), 1 deletion(-) (limited to 'include/scsi') diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index b3dd90f3e85..39c6f8cc20c 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; /* @@ -465,6 +466,12 @@ struct Scsi_Host { struct scsi_host_template *hostt; 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 diff --git a/include/scsi/scsi_tcq.h b/include/scsi/scsi_tcq.h index e47e36a4ef4..4eea254b1ce 100644 --- a/include/scsi/scsi_tcq.h +++ b/include/scsi/scsi_tcq.h @@ -4,6 +4,7 @@ #include #include #include +#include #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 */ -- cgit v1.2.3-70-g09d2