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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - include/scsi/scsi_tcq.h
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>
9 #define MSG_SIMPLE_TAG 0x20
10 #define MSG_HEAD_TAG 0x21
11 #define MSG_ORDERED_TAG 0x22
13 #define SCSI_NO_TAG (-1) /* identify no tag in use */
18 * scsi_get_tag_type - get the type of tag the device supports
19 * @sdev: the scsi device
22 * If the drive only supports simple tags, returns MSG_SIMPLE_TAG
23 * if it supports all tag types, returns MSG_ORDERED_TAG.
25 static inline int scsi_get_tag_type(struct scsi_device
*sdev
)
27 if (!sdev
->tagged_supported
)
29 if (sdev
->ordered_tags
)
30 return MSG_ORDERED_TAG
;
31 if (sdev
->simple_tags
)
32 return MSG_SIMPLE_TAG
;
36 static inline void scsi_set_tag_type(struct scsi_device
*sdev
, int tag
)
40 sdev
->ordered_tags
= 1;
43 sdev
->simple_tags
= 1;
48 sdev
->ordered_tags
= 0;
49 sdev
->simple_tags
= 0;
54 * scsi_activate_tcq - turn on tag command queueing
55 * @SDpnt: device to turn on TCQ for
59 * Eventually, I hope depth would be the maximum depth
60 * the device could cope with and the real queue depth
61 * would be adjustable from 0 to depth.
63 static inline void scsi_activate_tcq(struct scsi_device
*sdev
, int depth
)
65 if (!sdev
->tagged_supported
)
68 if (!blk_queue_tagged(sdev
->request_queue
))
69 blk_queue_init_tags(sdev
->request_queue
, depth
, NULL
);
71 scsi_adjust_queue_depth(sdev
, scsi_get_tag_type(sdev
), depth
);
75 * scsi_deactivate_tcq - turn off tag command queueing
76 * @SDpnt: device to turn off TCQ for
78 static inline void scsi_deactivate_tcq(struct scsi_device
*sdev
, int depth
)
80 if (blk_queue_tagged(sdev
->request_queue
))
81 blk_queue_free_tags(sdev
->request_queue
);
82 scsi_adjust_queue_depth(sdev
, 0, depth
);
86 * scsi_populate_tag_msg - place a tag message in a buffer
87 * @SCpnt: pointer to the Scsi_Cmnd for the tag
88 * @msg: pointer to the area to place the tag
91 * designed to create the correct type of tag message for the
92 * particular request. Returns the size of the tag message.
93 * May return 0 if TCQ is disabled for this device.
95 static inline int scsi_populate_tag_msg(struct scsi_cmnd
*cmd
, char *msg
)
97 struct request
*req
= cmd
->request
;
98 struct scsi_device
*sdev
= cmd
->device
;
100 if (blk_rq_tagged(req
)) {
101 if (sdev
->ordered_tags
&& req
->flags
& REQ_HARDBARRIER
)
102 *msg
++ = MSG_ORDERED_TAG
;
104 *msg
++ = MSG_SIMPLE_TAG
;
113 * scsi_find_tag - find a tagged command by device
114 * @SDpnt: pointer to the ScSI device
115 * @tag: the tag number
118 * Only works with tags allocated by the generic blk layer.
120 static inline struct scsi_cmnd
*scsi_find_tag(struct scsi_device
*sdev
, int tag
)
125 if (tag
!= SCSI_NO_TAG
) {
126 req
= blk_queue_find_tag(sdev
->request_queue
, tag
);
127 return req
? (struct scsi_cmnd
*)req
->special
: NULL
;
130 /* single command, look in space */
131 return sdev
->current_cmnd
;
134 #endif /* _SCSI_SCSI_TCQ_H */