GNU Linux-libre 4.19.211-gnu1
[releases.git] / include / scsi / scsi_tcq.h
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
27         if (tag == SCSI_NO_TAG)
28                 return NULL;
29
30         if (shost_use_blk_mq(shost)) {
31                 u16 hwq = blk_mq_unique_tag_to_hwq(tag);
32
33                 if (hwq < shost->tag_set.nr_hw_queues) {
34                         req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq],
35                                 blk_mq_unique_tag_to_tag(tag));
36                 }
37         } else {
38                 req = blk_map_queue_find_tag(shost->bqt, tag);
39         }
40
41         if (!req)
42                 return NULL;
43         return blk_mq_rq_to_pdu(req);
44 }
45
46 #endif /* CONFIG_BLOCK */
47 #endif /* _SCSI_SCSI_TCQ_H */