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#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 SCSI_NO_TAG (-1) /* identify no tag in use */
#ifdef CONFIG_BLOCK
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);
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 */
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