1 #ifndef _SCSI_SCSI_TCQ_H
2 #define _SCSI_SCSI_TCQ_H
4 #include <linux/blkdev.h>
5 #include <scsi/scsi_cmnd.h>
6 #include <scsi/scsi_device.h>
7 #include <scsi/scsi_host.h>
9 #define MSG_SIMPLE_TAG 0x20
10 #define MSG_HEAD_TAG 0x21
11 #define MSG_ORDERED_TAG 0x22
12 #define MSG_ACA_TAG 0x24 /* unsupported */
14 #define SCSI_NO_TAG (-1) /* identify no tag in use */
20 * scsi_get_tag_type - get the type of tag the device supports
21 * @sdev: the scsi device
24 * If the drive only supports simple tags, returns MSG_SIMPLE_TAG
25 * if it supports all tag types, returns MSG_ORDERED_TAG.
27 static inline int scsi_get_tag_type(struct scsi_device
*sdev
)
29 if (!sdev
->tagged_supported
)
31 if (sdev
->ordered_tags
)
32 return MSG_ORDERED_TAG
;
33 if (sdev
->simple_tags
)
34 return MSG_SIMPLE_TAG
;
38 static inline void scsi_set_tag_type(struct scsi_device
*sdev
, int tag
)
42 sdev
->ordered_tags
= 1;
45 sdev
->simple_tags
= 1;
50 sdev
->ordered_tags
= 0;
51 sdev
->simple_tags
= 0;
56 * scsi_activate_tcq - turn on tag command queueing
57 * @SDpnt: device to turn on TCQ for
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.
65 static inline void scsi_activate_tcq(struct scsi_device
*sdev
, int depth
)
67 if (!sdev
->tagged_supported
)
70 if (!shost_use_blk_mq(sdev
->host
) &&
71 !blk_queue_tagged(sdev
->request_queue
))
72 blk_queue_init_tags(sdev
->request_queue
, depth
,
75 scsi_adjust_queue_depth(sdev
, scsi_get_tag_type(sdev
), depth
);
79 * scsi_deactivate_tcq - turn off tag command queueing
80 * @SDpnt: device to turn off TCQ for
82 static inline void scsi_deactivate_tcq(struct scsi_device
*sdev
, int depth
)
84 if (!shost_use_blk_mq(sdev
->host
) &&
85 blk_queue_tagged(sdev
->request_queue
))
86 blk_queue_free_tags(sdev
->request_queue
);
87 scsi_adjust_queue_depth(sdev
, 0, depth
);
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
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.
100 static inline int scsi_populate_tag_msg(struct scsi_cmnd
*cmd
, char *msg
)
102 struct request
*req
= cmd
->request
;
104 if (blk_rq_tagged(req
)) {
105 *msg
++ = MSG_SIMPLE_TAG
;
113 static inline struct scsi_cmnd
*scsi_mq_find_tag(struct Scsi_Host
*shost
,
114 unsigned int hw_ctx
, int tag
)
118 req
= blk_mq_tag_to_rq(shost
->tag_set
.tags
[hw_ctx
], tag
);
119 return req
? (struct scsi_cmnd
*)req
->special
: NULL
;
123 * scsi_find_tag - find a tagged command by device
124 * @SDpnt: pointer to the ScSI device
125 * @tag: the tag number
128 * Only works with tags allocated by the generic blk layer.
130 static inline struct scsi_cmnd
*scsi_find_tag(struct scsi_device
*sdev
, int tag
)
134 if (tag
!= SCSI_NO_TAG
) {
135 if (shost_use_blk_mq(sdev
->host
))
136 return scsi_mq_find_tag(sdev
->host
, 0, tag
);
138 req
= blk_queue_find_tag(sdev
->request_queue
, tag
);
139 return req
? (struct scsi_cmnd
*)req
->special
: NULL
;
142 /* single command, look in space */
143 return sdev
->current_cmnd
;
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
152 static inline int scsi_init_shared_tag_map(struct Scsi_Host
*shost
, int depth
)
155 * We always have a shared tag map around when using blk-mq.
157 if (shost_use_blk_mq(shost
))
161 * 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)
166 shost
->bqt
= blk_init_tags(depth
);
175 * scsi_host_find_tag - find the tagged command by host
176 * @shost: pointer to scsi_host
177 * @tag: tag of the scsi_cmnd
180 * Only works with tags allocated by the generic blk layer.
182 static inline struct scsi_cmnd
*scsi_host_find_tag(struct Scsi_Host
*shost
,
187 if (tag
!= SCSI_NO_TAG
) {
188 if (shost_use_blk_mq(shost
))
189 return scsi_mq_find_tag(shost
, 0, tag
);
190 req
= blk_map_queue_find_tag(shost
->bqt
, tag
);
191 return req
? (struct scsi_cmnd
*)req
->special
: NULL
;
196 #endif /* CONFIG_BLOCK */
197 #endif /* _SCSI_SCSI_TCQ_H */
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