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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#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>
James Bottomley86e33a22006-08-30 09:45:51 -04007#include <scsi/scsi_host.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07008
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#define MSG_SIMPLE_TAG 0x20
10#define MSG_HEAD_TAG 0x21
11#define MSG_ORDERED_TAG 0x22
Nicholas Bellingere66ecd52011-05-19 20:19:14 -070012#define MSG_ACA_TAG 0x24 /* unsupported */
Linus Torvalds1da177e2005-04-16 15:20:36 -070013
14#define SCSI_NO_TAG (-1) /* identify no tag in use */
15
16
David Howells93614012006-09-30 20:45:40 +020017#ifdef CONFIG_BLOCK
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
19/**
20 * scsi_get_tag_type - get the type of tag the device supports
21 * @sdev: the scsi device
22 *
23 * Notes:
24 * If the drive only supports simple tags, returns MSG_SIMPLE_TAG
25 * if it supports all tag types, returns MSG_ORDERED_TAG.
26 */
27static inline int scsi_get_tag_type(struct scsi_device *sdev)
28{
29 if (!sdev->tagged_supported)
30 return 0;
31 if (sdev->ordered_tags)
32 return MSG_ORDERED_TAG;
33 if (sdev->simple_tags)
34 return MSG_SIMPLE_TAG;
35 return 0;
36}
37
38static inline void scsi_set_tag_type(struct scsi_device *sdev, int tag)
39{
40 switch (tag) {
41 case MSG_ORDERED_TAG:
42 sdev->ordered_tags = 1;
43 /* fall through */
44 case MSG_SIMPLE_TAG:
45 sdev->simple_tags = 1;
46 break;
47 case 0:
48 /* fall through */
49 default:
50 sdev->ordered_tags = 0;
51 sdev->simple_tags = 0;
52 break;
53 }
54}
55/**
56 * scsi_activate_tcq - turn on tag command queueing
57 * @SDpnt: device to turn on TCQ for
58 * @depth: queue depth
59 *
60 * Notes:
61 * Eventually, I hope depth would be the maximum depth
62 * the device could cope with and the real queue depth
63 * would be adjustable from 0 to depth.
64 **/
65static inline void scsi_activate_tcq(struct scsi_device *sdev, int depth)
66{
67 if (!sdev->tagged_supported)
68 return;
69
Christoph Hellwigd2852032014-01-17 12:06:53 +010070 if (!shost_use_blk_mq(sdev->host) &&
71 blk_queue_tagged(sdev->request_queue))
James Bottomley86e33a22006-08-30 09:45:51 -040072 blk_queue_init_tags(sdev->request_queue, depth,
73 sdev->host->bqt);
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
75 scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
76}
77
78/**
79 * scsi_deactivate_tcq - turn off tag command queueing
80 * @SDpnt: device to turn off TCQ for
81 **/
82static inline void scsi_deactivate_tcq(struct scsi_device *sdev, int depth)
83{
Christoph Hellwigd2852032014-01-17 12:06:53 +010084 if (!shost_use_blk_mq(sdev->host) &&
85 blk_queue_tagged(sdev->request_queue))
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 blk_queue_free_tags(sdev->request_queue);
87 scsi_adjust_queue_depth(sdev, 0, depth);
88}
89
90/**
91 * scsi_populate_tag_msg - place a tag message in a buffer
92 * @SCpnt: pointer to the Scsi_Cmnd for the tag
93 * @msg: pointer to the area to place the tag
94 *
95 * Notes:
96 * designed to create the correct type of tag message for the
97 * particular request. Returns the size of the tag message.
98 * May return 0 if TCQ is disabled for this device.
99 **/
100static inline int scsi_populate_tag_msg(struct scsi_cmnd *cmd, char *msg)
101{
102 struct request *req = cmd->request;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103
104 if (blk_rq_tagged(req)) {
Tejun Heo9cbbdca2010-09-03 11:56:16 +0200105 *msg++ = MSG_SIMPLE_TAG;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 *msg++ = req->tag;
107 return 2;
108 }
109
110 return 0;
111}
112
Christoph Hellwigd2852032014-01-17 12:06:53 +0100113static inline struct scsi_cmnd *scsi_mq_find_tag(struct Scsi_Host *shost,
114 unsigned int hw_ctx, int tag)
115{
116 struct request *req;
117
118 req = blk_mq_tag_to_rq(shost->tag_set.tags[hw_ctx], tag);
119 return req ? (struct scsi_cmnd *)req->special : NULL;
120}
121
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122/**
123 * scsi_find_tag - find a tagged command by device
124 * @SDpnt: pointer to the ScSI device
125 * @tag: the tag number
126 *
127 * Notes:
128 * Only works with tags allocated by the generic blk layer.
129 **/
130static inline struct scsi_cmnd *scsi_find_tag(struct scsi_device *sdev, int tag)
131{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 struct request *req;
133
134 if (tag != SCSI_NO_TAG) {
Christoph Hellwigd2852032014-01-17 12:06:53 +0100135 if (shost_use_blk_mq(sdev->host))
136 return scsi_mq_find_tag(sdev->host, 0, tag);
137
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 req = blk_queue_find_tag(sdev->request_queue, tag);
139 return req ? (struct scsi_cmnd *)req->special : NULL;
140 }
141
142 /* single command, look in space */
143 return sdev->current_cmnd;
144}
145
Christoph Hellwigd2852032014-01-17 12:06:53 +0100146
James Bottomley86e33a22006-08-30 09:45:51 -0400147/**
148 * scsi_init_shared_tag_map - create a shared tag map
149 * @shost: the host to share the tag map among all devices
150 * @depth: the total depth of the map
151 */
James Bottomleydeb81d82006-09-01 09:28:48 -0400152static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
James Bottomley86e33a22006-08-30 09:45:51 -0400153{
Jens Axboe3070f692008-10-27 19:20:59 +0100154 /*
Christoph Hellwigd2852032014-01-17 12:06:53 +0100155 * We always have a shared tag map around when using blk-mq.
156 */
157 if (shost_use_blk_mq(shost))
158 return 0;
159
160 /*
Jens Axboe3070f692008-10-27 19:20:59 +0100161 * If the shared tag map isn't already initialized, do it now.
162 * This saves callers from having to check ->bqt when setting up
163 * devices on the shared host (for libata)
164 */
165 if (!shost->bqt) {
166 shost->bqt = blk_init_tags(depth);
167 if (!shost->bqt)
168 return -ENOMEM;
169 }
170
171 return 0;
James Bottomley86e33a22006-08-30 09:45:51 -0400172}
173
David C Somayajuluf583f492006-10-04 08:27:25 +0200174/**
175 * scsi_host_find_tag - find the tagged command by host
176 * @shost: pointer to scsi_host
177 * @tag: tag of the scsi_cmnd
178 *
179 * Notes:
180 * Only works with tags allocated by the generic blk layer.
181 **/
182static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
183 int tag)
184{
185 struct request *req;
186
187 if (tag != SCSI_NO_TAG) {
Christoph Hellwigd2852032014-01-17 12:06:53 +0100188 if (shost_use_blk_mq(shost))
189 return scsi_mq_find_tag(shost, 0, tag);
David C Somayajuluf583f492006-10-04 08:27:25 +0200190 req = blk_map_queue_find_tag(shost->bqt, tag);
191 return req ? (struct scsi_cmnd *)req->special : NULL;
192 }
193 return NULL;
194}
195
David Howells93614012006-09-30 20:45:40 +0200196#endif /* CONFIG_BLOCK */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197#endif /* _SCSI_SCSI_TCQ_H */