include/scsi/scsi_tcq.h

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