xref: /linux/include/scsi/scsi_tcq.h (revision 4246b92cf9fb32da8d8b060c92d8302797c6fbea)
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>
7 #include <scsi/scsi_host.h>
8 
9 #define SCSI_NO_TAG	(-1)    /* identify no tag in use */
10 
11 
12 #ifdef CONFIG_BLOCK
13 /**
14  * scsi_host_find_tag - find the tagged command by host
15  * @shost:	pointer to scsi_host
16  * @tag:	tag
17  *
18  * Note: for devices using multiple hardware queues tag must have been
19  * generated by blk_mq_unique_tag().
20  **/
21 static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
22 		int tag)
23 {
24 	struct request *req = NULL;
25 
26 	if (tag == SCSI_NO_TAG)
27 		return NULL;
28 
29 	if (shost_use_blk_mq(shost)) {
30 		u16 hwq = blk_mq_unique_tag_to_hwq(tag);
31 
32 		if (hwq < shost->tag_set.nr_hw_queues) {
33 			req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq],
34 				blk_mq_unique_tag_to_tag(tag));
35 		}
36 	} else {
37 		req = blk_map_queue_find_tag(shost->bqt, tag);
38 	}
39 
40 	if (!req)
41 		return NULL;
42 	return blk_mq_rq_to_pdu(req);
43 }
44 
45 #endif /* CONFIG_BLOCK */
46 #endif /* _SCSI_SCSI_TCQ_H */
47