LXR linux/include/scsi/scsi

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _SCSI_SCSI_TCQ_H
   3#define _SCSI_SCSI_TCQ_H
   4
   5#include <linux/blkdev.h>
   6#include <scsi/scsi_cmnd.h>
   7#include <scsi/scsi_device.h>
   8#include <scsi/scsi_host.h>
   9
  10#define SCSI_NO_TAG     (-1)    /* identify no tag in use */
  11
  12
  13#ifdef CONFIG_BLOCK
  14/**
  15 * scsi_host_find_tag - find the tagged command by host
  16 * @shost:      pointer to scsi_host
  17 * @tag:        tag
  18 *
  19 * Note: for devices using multiple hardware queues tag must have been
  20 * generated by blk_mq_unique_tag().
  21 **/
  22static inline struct scsi_cmnd *scsi_host_find_tag(struct Scsi_Host *shost,
  23                int tag)
  24{
  25        struct request *req = NULL;
  26        u16 hwq;
  27
  28        if (tag == SCSI_NO_TAG)
  29                return NULL;
  30
  31        hwq = blk_mq_unique_tag_to_hwq(tag);
  32        if (hwq < shost->tag_set.nr_hw_queues) {
  33                req = blk_mq_tag_to_rq(shost->tag_set.tags[hwq],
  34                                        blk_mq_unique_tag_to_tag(tag));
  35        }
  36
  37        if (!req || !blk_mq_request_started(req))
  38                return NULL;
  39        return blk_mq_rq_to_pdu(req);
  40}
  41
  42#endif /* CONFIG_BLOCK */
  43#endif /* _SCSI_SCSI_TCQ_H */
  44