forked from Minki/linux
efc3c1df5f
Since we got rid of ordered tag support in 2010 the prime use case of switching on and off ordered tags has been obsolete. The other function of enabling/disabling tagging entirely has only been correctly implemented by the 53c700 driver and isn't generally useful. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com Reviewed-by: Hannes Reinecke <hare@suse.de>
134 lines
3.1 KiB
C
134 lines
3.1 KiB
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 MSG_SIMPLE_TAG 0x20
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#define MSG_HEAD_TAG 0x21
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#define MSG_ORDERED_TAG 0x22
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#define MSG_ACA_TAG 0x24 /* unsupported */
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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_get_tag_type - get the type of tag the device supports
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* @sdev: the scsi device
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*/
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static inline int scsi_get_tag_type(struct scsi_device *sdev)
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{
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if (!sdev->tagged_supported)
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return 0;
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if (sdev->simple_tags)
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return MSG_SIMPLE_TAG;
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return 0;
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}
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static inline void scsi_set_tag_type(struct scsi_device *sdev, int tag)
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{
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switch (tag) {
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case MSG_ORDERED_TAG:
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case MSG_SIMPLE_TAG:
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sdev->simple_tags = 1;
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break;
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case 0:
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/* fall through */
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default:
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sdev->simple_tags = 0;
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break;
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}
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}
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static inline struct scsi_cmnd *scsi_mq_find_tag(struct Scsi_Host *shost,
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int unique_tag)
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{
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u16 hwq = blk_mq_unique_tag_to_hwq(unique_tag);
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struct request *req = NULL;
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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(unique_tag));
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return req ? (struct scsi_cmnd *)req->special : NULL;
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}
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/**
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* scsi_find_tag - find a tagged command by device
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* @SDpnt: pointer to the ScSI device
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* @tag: tag generated by blk_mq_unique_tag()
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*
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* Notes:
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* Only works with tags allocated by the generic blk layer.
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**/
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static inline struct scsi_cmnd *scsi_find_tag(struct scsi_device *sdev, int tag)
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{
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struct request *req;
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if (tag != SCSI_NO_TAG) {
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if (shost_use_blk_mq(sdev->host))
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return scsi_mq_find_tag(sdev->host, tag);
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req = blk_queue_find_tag(sdev->request_queue, tag);
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return req ? (struct scsi_cmnd *)req->special : NULL;
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}
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/* single command, look in space */
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return sdev->current_cmnd;
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}
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/**
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* scsi_init_shared_tag_map - create a shared tag map
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* @shost: the host to share the tag map among all devices
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* @depth: the total depth of the map
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*/
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static inline int scsi_init_shared_tag_map(struct Scsi_Host *shost, int depth)
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{
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/*
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* We always have a shared tag map around when using blk-mq.
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*/
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if (shost_use_blk_mq(shost))
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return 0;
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/*
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* If the shared tag map isn't already initialized, do it now.
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* This saves callers from having to check ->bqt when setting up
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* devices on the shared host (for libata)
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*/
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if (!shost->bqt) {
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shost->bqt = blk_init_tags(depth);
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if (!shost->bqt)
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return -ENOMEM;
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}
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return 0;
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}
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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 generated by blk_mq_unique_tag()
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*
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* Notes:
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* Only works with tags allocated by the generic blk layer.
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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;
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if (tag != SCSI_NO_TAG) {
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if (shost_use_blk_mq(shost))
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return scsi_mq_find_tag(shost, tag);
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req = blk_map_queue_find_tag(shost->bqt, tag);
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return req ? (struct scsi_cmnd *)req->special : NULL;
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}
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return NULL;
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}
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#endif /* CONFIG_BLOCK */
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#endif /* _SCSI_SCSI_TCQ_H */
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