linux/include/scsi/scsi_tcq.h
Christoph Hellwig 64d513ac31 scsi: use host wide tags by default
This patch changes the !blk-mq path to the same defaults as the blk-mq
I/O path by always enabling block tagging, and always using host wide
tags.  We've had blk-mq available for a few releases so bugs with
this mode should have been ironed out, and this ensures we get better
coverage of over tagging setup over different configs.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>
2015-11-09 17:11:57 -08:00

47 lines
1005 B
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 SCSI_NO_TAG (-1) /* identify no tag in use */
#ifdef CONFIG_BLOCK
/**
* scsi_host_find_tag - find the tagged command by host
* @shost: pointer to scsi_host
* @tag: tag
*
* Note: for devices using multiple hardware queues tag must have been
* generated by blk_mq_unique_tag().
**/
static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
int tag)
{
struct request *req = NULL;
if (tag == SCSI_NO_TAG)
return NULL;
if (shost_use_blk_mq(shost)) {
u16 hwq = blk_mq_unique_tag_to_hwq(tag);
if (hwq < shost->tag_set.nr_hw_queues) {
req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq],
blk_mq_unique_tag_to_tag(tag));
}
} else {
req = blk_map_queue_find_tag(shost->bqt, tag);
}
if (!req)
return NULL;
return req->special;
}
#endif /* CONFIG_BLOCK */
#endif /* _SCSI_SCSI_TCQ_H */