[mirror_ubuntu-artful-kernel.git] / include / scsi / 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 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,
			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 */
Commit	Line	Data
1da177e4 LT	1	#ifndef _SCSI_SCSI_TCQ_H
	2	#define _SCSI_SCSI_TCQ_H
	3
	4	#include <linux/blkdev.h>
	5	#include <scsi/scsi_cmnd.h>
	6	#include <scsi/scsi_device.h>
86e33a29	7	#include <scsi/scsi_host.h>
1da177e4	8
1da177e4 LT	9	#define SCSI_NO_TAG (-1) /* identify no tag in use */
	10
	11
9361401e	12	#ifdef CONFIG_BLOCK
d285203c	13	static inline struct scsi_cmnd scsi_mq_find_tag(struct Scsi_Host shost,
1ee8e889	14	int unique_tag)
d285203c	15	{
1ee8e889 BVA	16	u16 hwq = blk_mq_unique_tag_to_hwq(unique_tag);
1ee8e889 BVA	17	struct request *req = NULL;
d285203c	18
1ee8e889 BVA	19	if (hwq < shost->tag_set.nr_hw_queues)
	20	req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq],
	21	blk_mq_unique_tag_to_tag(unique_tag));
d285203c CH	22	return req ? (struct scsi_cmnd *)req->special : NULL;
	23	}
	24
1da177e4 LT	25	/**
	26	* scsi_find_tag - find a tagged command by device
	27	* @SDpnt: pointer to the ScSI device
1ee8e889	28	* @tag: tag generated by blk_mq_unique_tag()
1da177e4 LT	29	*
	30	* Notes:
	31	* Only works with tags allocated by the generic blk layer.
	32	**/
	33	static inline struct scsi_cmnd scsi_find_tag(struct scsi_device sdev, int tag)
	34	{
1da177e4 LT	35	struct request *req;
	36
	37	if (tag != SCSI_NO_TAG) {
d285203c	38	if (shost_use_blk_mq(sdev->host))
1ee8e889	39	return scsi_mq_find_tag(sdev->host, tag);
d285203c	40
1ee8e889	41	req = blk_queue_find_tag(sdev->request_queue, tag);
1da177e4 LT	42	return req ? (struct scsi_cmnd *)req->special : NULL;
	43	}
	44
	45	/* single command, look in space */
	46	return sdev->current_cmnd;
	47	}
	48
d285203c	49
86e33a29 JB	50	/**
	51	* scsi_init_shared_tag_map - create a shared tag map
	52	* @shost: the host to share the tag map among all devices
	53	* @depth: the total depth of the map
	54	*/
deb81d80	55	static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
86e33a29	56	{
d285203c CH	57	/*
	58	* We always have a shared tag map around when using blk-mq.
	59	*/
	60	if (shost_use_blk_mq(shost))
	61	return 0;
	62
3070f69b JA	63	/*
	64	* If the shared tag map isn't already initialized, do it now.
	65	* This saves callers from having to check ->bqt when setting up
	66	* devices on the shared host (for libata)
	67	*/
	68	if (!shost->bqt) {
ee1b6f7a SL	69	shost->bqt = blk_init_tags(depth,
ee1b6f7a SL	70	shost->hostt->tag_alloc_policy);
3070f69b JA	71	if (!shost->bqt)
	72	return -ENOMEM;
	73	}
	74
	75	return 0;
86e33a29 JB	76	}
86e33a29 JB	77
f583f492 DS	78	/**
	79	* scsi_host_find_tag - find the tagged command by host
	80	* @shost: pointer to scsi_host
1ee8e889	81	* @tag: tag generated by blk_mq_unique_tag()
f583f492 DS	82	*
	83	* Notes:
	84	* Only works with tags allocated by the generic blk layer.
	85	**/
	86	static inline struct scsi_cmnd scsi_host_find_tag(struct Scsi_Host shost,
	87	int tag)
	88	{
	89	struct request *req;
	90
	91	if (tag != SCSI_NO_TAG) {
d285203c	92	if (shost_use_blk_mq(shost))
1ee8e889	93	return scsi_mq_find_tag(shost, tag);
f583f492 DS	94	req = blk_map_queue_find_tag(shost->bqt, tag);
	95	return req ? (struct scsi_cmnd *)req->special : NULL;
	96	}
	97	return NULL;
	98	}
	99
9361401e	100	#endif /* CONFIG_BLOCK */
1da177e4	101	#endif /* _SCSI_SCSI_TCQ_H */