| #ifndef _SCSI_SCSI_TCQ_H |
| #define _SCSI_SCSI_TCQ_H |
| |
| #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 |
| #define MSG_ORDERED_TAG 0x22 |
| #define MSG_ACA_TAG 0x24 /* unsupported */ |
| |
| #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 |
| * @depth: queue depth |
| * |
| * Notes: |
| * Eventually, I hope depth would be the maximum depth |
| * the device could cope with and the real queue depth |
| * would be adjustable from 0 to depth. |
| **/ |
| static inline void scsi_activate_tcq(struct scsi_device *sdev, int 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); |
| } |
| |
| /** |
| * scsi_deactivate_tcq - turn off tag command queueing |
| * @SDpnt: device to turn off TCQ for |
| **/ |
| static inline void scsi_deactivate_tcq(struct scsi_device *sdev, int depth) |
| { |
| if (blk_queue_tagged(sdev->request_queue)) |
| blk_queue_free_tags(sdev->request_queue); |
| scsi_adjust_queue_depth(sdev, 0, depth); |
| } |
| |
| /** |
| * scsi_populate_tag_msg - place a tag message in a buffer |
| * @SCpnt: pointer to the Scsi_Cmnd for the tag |
| * @msg: pointer to the area to place the tag |
| * |
| * Notes: |
| * designed to create the correct type of tag message for the |
| * particular request. Returns the size of the tag message. |
| * May return 0 if TCQ is disabled for this device. |
| **/ |
| static inline int scsi_populate_tag_msg(struct scsi_cmnd *cmd, char *msg) |
| { |
| struct request *req = cmd->request; |
| |
| if (blk_rq_tagged(req)) { |
| *msg++ = MSG_SIMPLE_TAG; |
| *msg++ = req->tag; |
| return 2; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * scsi_find_tag - find a tagged command by device |
| * @SDpnt: pointer to the ScSI device |
| * @tag: the tag number |
| * |
| * Notes: |
| * Only works with tags allocated by the generic blk layer. |
| **/ |
| static inline struct scsi_cmnd *scsi_find_tag(struct scsi_device *sdev, int tag) |
| { |
| |
| struct request *req; |
| |
| if (tag != SCSI_NO_TAG) { |
| req = blk_queue_find_tag(sdev->request_queue, tag); |
| return req ? (struct scsi_cmnd *)req->special : NULL; |
| } |
| |
| /* single command, look in space */ |
| 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) |
| { |
| /* |
| * If the shared tag map isn't already initialized, do it now. |
| * This saves callers from having to check ->bqt when setting up |
| * devices on the shared host (for libata) |
| */ |
| if (!shost->bqt) { |
| shost->bqt = blk_init_tags(depth); |
| if (!shost->bqt) |
| return -ENOMEM; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * 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 */ |