bed2213d01
Since commit e9c787e65c ("scsi: allocate scsi_cmnd structures as
part of struct request") struct request and struct scsi_cmnd are
adjacent. This means that there is now an alternative to reading
req->special to convert a pointer to a prepared request into a
SCSI command pointer, namely by using blk_mq_rq_to_pdu(). Make
this change where appropriate. Although this patch does not
change any functionality, it slightly improves performance and
slightly improves readability.
Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
47 lines
1,014 B
C
47 lines
1,014 B
C
#ifndef _SCSI_SCSI_TCQ_H
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#define _SCSI_SCSI_TCQ_H
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#include <linux/blkdev.h>
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#include <scsi/scsi_cmnd.h>
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#include <scsi/scsi_device.h>
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#include <scsi/scsi_host.h>
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#define SCSI_NO_TAG (-1) /* identify no tag in use */
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#ifdef CONFIG_BLOCK
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/**
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* scsi_host_find_tag - find the tagged command by host
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* @shost: pointer to scsi_host
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* @tag: tag
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*
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* Note: for devices using multiple hardware queues tag must have been
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* generated by blk_mq_unique_tag().
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**/
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static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
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int tag)
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{
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struct request *req = NULL;
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if (tag == SCSI_NO_TAG)
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return NULL;
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if (shost_use_blk_mq(shost)) {
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u16 hwq = blk_mq_unique_tag_to_hwq(tag);
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if (hwq < shost->tag_set.nr_hw_queues) {
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req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq],
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blk_mq_unique_tag_to_tag(tag));
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}
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} else {
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req = blk_map_queue_find_tag(shost->bqt, tag);
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}
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if (!req)
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return NULL;
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return blk_mq_rq_to_pdu(req);
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}
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#endif /* CONFIG_BLOCK */
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#endif /* _SCSI_SCSI_TCQ_H */
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