mirror of
https://github.com/adulau/aha.git
synced 2024-12-29 12:16:20 +00:00
4aff5e2333
Right now ->flags is a bit of a mess: some are request types, and others are just modifiers. Clean this up by splitting it into ->cmd_type and ->cmd_flags. This allows introduction of generic Linux block message types, useful for sending generic Linux commands to block devices. Signed-off-by: Jens Axboe <axboe@suse.de>
147 lines
3.6 KiB
C
147 lines
3.6 KiB
C
#ifndef _SCSI_SCSI_TCQ_H
|
|
#define _SCSI_SCSI_TCQ_H
|
|
|
|
#include <linux/blkdev.h>
|
|
#include <scsi/scsi_cmnd.h>
|
|
#include <scsi/scsi_device.h>
|
|
#include <scsi/scsi_host.h>
|
|
|
|
|
|
#define MSG_SIMPLE_TAG 0x20
|
|
#define MSG_HEAD_TAG 0x21
|
|
#define MSG_ORDERED_TAG 0x22
|
|
|
|
#define SCSI_NO_TAG (-1) /* identify no tag in use */
|
|
|
|
|
|
|
|
/**
|
|
* scsi_get_tag_type - get the type of tag the device supports
|
|
* @sdev: the scsi device
|
|
*
|
|
* Notes:
|
|
* If the drive only supports simple tags, returns MSG_SIMPLE_TAG
|
|
* if it supports all tag types, returns MSG_ORDERED_TAG.
|
|
*/
|
|
static inline int scsi_get_tag_type(struct scsi_device *sdev)
|
|
{
|
|
if (!sdev->tagged_supported)
|
|
return 0;
|
|
if (sdev->ordered_tags)
|
|
return MSG_ORDERED_TAG;
|
|
if (sdev->simple_tags)
|
|
return MSG_SIMPLE_TAG;
|
|
return 0;
|
|
}
|
|
|
|
static inline void scsi_set_tag_type(struct scsi_device *sdev, int tag)
|
|
{
|
|
switch (tag) {
|
|
case MSG_ORDERED_TAG:
|
|
sdev->ordered_tags = 1;
|
|
/* fall through */
|
|
case MSG_SIMPLE_TAG:
|
|
sdev->simple_tags = 1;
|
|
break;
|
|
case 0:
|
|
/* fall through */
|
|
default:
|
|
sdev->ordered_tags = 0;
|
|
sdev->simple_tags = 0;
|
|
break;
|
|
}
|
|
}
|
|
/**
|
|
* scsi_activate_tcq - turn on tag command queueing
|
|
* @SDpnt: device to turn on TCQ for
|
|
* @depth: queue depth
|
|
*
|
|
* Notes:
|
|
* Eventually, I hope depth would be the maximum depth
|
|
* the device could cope with and the real queue depth
|
|
* would be adjustable from 0 to depth.
|
|
**/
|
|
static inline void scsi_activate_tcq(struct scsi_device *sdev, int depth)
|
|
{
|
|
if (!sdev->tagged_supported)
|
|
return;
|
|
|
|
if (!blk_queue_tagged(sdev->request_queue))
|
|
blk_queue_init_tags(sdev->request_queue, depth,
|
|
sdev->host->bqt);
|
|
|
|
scsi_adjust_queue_depth(sdev, scsi_get_tag_type(sdev), depth);
|
|
}
|
|
|
|
/**
|
|
* scsi_deactivate_tcq - turn off tag command queueing
|
|
* @SDpnt: device to turn off TCQ for
|
|
**/
|
|
static inline void scsi_deactivate_tcq(struct scsi_device *sdev, int depth)
|
|
{
|
|
if (blk_queue_tagged(sdev->request_queue))
|
|
blk_queue_free_tags(sdev->request_queue);
|
|
scsi_adjust_queue_depth(sdev, 0, depth);
|
|
}
|
|
|
|
/**
|
|
* scsi_populate_tag_msg - place a tag message in a buffer
|
|
* @SCpnt: pointer to the Scsi_Cmnd for the tag
|
|
* @msg: pointer to the area to place the tag
|
|
*
|
|
* Notes:
|
|
* designed to create the correct type of tag message for the
|
|
* particular request. Returns the size of the tag message.
|
|
* May return 0 if TCQ is disabled for this device.
|
|
**/
|
|
static inline int scsi_populate_tag_msg(struct scsi_cmnd *cmd, char *msg)
|
|
{
|
|
struct request *req = cmd->request;
|
|
struct scsi_device *sdev = cmd->device;
|
|
|
|
if (blk_rq_tagged(req)) {
|
|
if (sdev->ordered_tags && req->cmd_flags & REQ_HARDBARRIER)
|
|
*msg++ = MSG_ORDERED_TAG;
|
|
else
|
|
*msg++ = MSG_SIMPLE_TAG;
|
|
*msg++ = req->tag;
|
|
return 2;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* scsi_find_tag - find a tagged command by device
|
|
* @SDpnt: pointer to the ScSI device
|
|
* @tag: the tag number
|
|
*
|
|
* Notes:
|
|
* Only works with tags allocated by the generic blk layer.
|
|
**/
|
|
static inline struct scsi_cmnd *scsi_find_tag(struct scsi_device *sdev, int tag)
|
|
{
|
|
|
|
struct request *req;
|
|
|
|
if (tag != SCSI_NO_TAG) {
|
|
req = blk_queue_find_tag(sdev->request_queue, tag);
|
|
return req ? (struct scsi_cmnd *)req->special : NULL;
|
|
}
|
|
|
|
/* single command, look in space */
|
|
return sdev->current_cmnd;
|
|
}
|
|
|
|
/**
|
|
* scsi_init_shared_tag_map - create a shared tag map
|
|
* @shost: the host to share the tag map among all devices
|
|
* @depth: the total depth of the map
|
|
*/
|
|
static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
|
|
{
|
|
shost->bqt = blk_init_tags(depth);
|
|
return shost->bqt ? 0 : -ENOMEM;
|
|
}
|
|
|
|
#endif /* _SCSI_SCSI_TCQ_H */
|