Edit File: scsi_tcq.h
#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 (shost_use_blk_mq(sdev->host)) queue_flag_set_unlocked(QUEUE_FLAG_QUEUED, sdev->request_queue); else if (!blk_queue_tagged(sdev->request_queue)) blk_queue_init_tags(sdev->request_queue, depth, sdev->host->bqt, sdev->host->hostt->tag_alloc_policy); 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) { if (cmd->flags & SCMD_TAGGED) { *msg++ = MSG_SIMPLE_TAG; *msg++ = cmd->request->tag; return 2; } return 0; } static inline struct scsi_cmnd *scsi_mq_find_tag(struct Scsi_Host *shost, int unique_tag) { u16 hwq = blk_mq_unique_tag_to_hwq(unique_tag); struct request *req = NULL; if (hwq < shost->tag_set->nr_hw_queues) req = blk_mq_tag_to_rq(shost->tag_set->tags[hwq], blk_mq_unique_tag_to_tag(unique_tag)); return req ? (struct scsi_cmnd *)req->special : NULL; } /** * scsi_find_tag - find a tagged command by device * @SDpnt: pointer to the ScSI device * @tag: tag generated by blk_mq_unique_tag() * * 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) { if (shost_use_blk_mq(sdev->host)) return scsi_mq_find_tag(sdev->host, 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) { /* * We always have a shared tag map around when using blk-mq. */ if (shost_use_blk_mq(shost)) return 0; /* * 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, shost->hostt->tag_alloc_policy); if (!shost->bqt) return -ENOMEM; } return 0; } /** * scsi_host_find_tag - find the tagged command by host * @shost: pointer to scsi_host * @tag: tag generated by blk_mq_unique_tag() * * 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) { if (shost_use_blk_mq(shost)) return scsi_mq_find_tag(shost, 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 */