xref: /linux/include/scsi/scsi_tcq.h (revision 63307d015b91e626c97bb82e88054af3d0b74643)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _SCSI_SCSI_TCQ_H
3 #define _SCSI_SCSI_TCQ_H
4 
5 #include <linux/blkdev.h>
6 #include <scsi/scsi_cmnd.h>
7 #include <scsi/scsi_device.h>
8 #include <scsi/scsi_host.h>
9 
10 #define SCSI_NO_TAG	(-1)    /* identify no tag in use */
11 
12 
13 #ifdef CONFIG_BLOCK
14 /**
15  * scsi_host_find_tag - find the tagged command by host
16  * @shost:	pointer to scsi_host
17  * @tag:	tag
18  *
19  * Note: for devices using multiple hardware queues tag must have been
20  * generated by blk_mq_unique_tag().
21  **/
22 static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
23 		int tag)
24 {
25 	struct request *req = NULL;
26 	u16 hwq;
27 
28 	if (tag == SCSI_NO_TAG)
29 		return NULL;
30 
31 	hwq = blk_mq_unique_tag_to_hwq(tag);
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 
37 	if (!req)
38 		return NULL;
39 	return blk_mq_rq_to_pdu(req);
40 }
41 
42 #endif /* CONFIG_BLOCK */
43 #endif /* _SCSI_SCSI_TCQ_H */
44