Commit bdb01301 authored by Hannes Reinecke's avatar Hannes Reinecke Committed by Jens Axboe
Browse files

scsi: Add host and host template flag 'host_tagset' 



Add Host and host template flag 'host_tagset' so hostwide tagset can be
shared on multiple reply queues after the SCSI device's reply queue is
converted to blk-mq hw queue.

[jpg: Update comment on .can_queue and add Scsi_Host.host_tagset]

Signed-off-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarJohn Garry <john.garry@huawei.com>
Tested-by: Don Brace<don.brace@microsemi.com> #SCSI resv cmds patches used
Tested-by: default avatarDouglas Gilbert <dgilbert@interlog.com>
Acked-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent f5ace5ef

drivers/scsi/hosts.c

+1 −0
Original line number Diff line number Diff line
@@ -421,6 +421,7 @@ struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) 
	shost->cmd_per_lun = sht->cmd_per_lun;

	shost->unchecked_isa_dma = sht->unchecked_isa_dma;

	shost->no_write_same = sht->no_write_same;

	shost->host_tagset = sht->host_tagset;



	if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler)

		shost->eh_deadline = -1;

drivers/scsi/scsi_lib.c

+2 −0
Original line number Diff line number Diff line
@@ -1891,6 +1891,8 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost) 
	tag_set->flags |=

		BLK_ALLOC_POLICY_TO_MQ_FLAG(shost->hostt->tag_alloc_policy);

	tag_set->driver_data = shost;

	if (shost->host_tagset)

		tag_set->flags |= BLK_MQ_F_TAG_HCTX_SHARED;



	return blk_mq_alloc_tag_set(tag_set);

}

include/scsi/scsi_host.h

+8 −1
Original line number Diff line number Diff line
@@ -436,6 +436,9 @@ struct scsi_host_template { 
	/* True if the controller does not support WRITE SAME */

	unsigned no_write_same:1;



	/* True if the host uses host-wide tagspace */

	unsigned host_tagset:1;



	/*

	 * Countdown for host blocking with no commands outstanding.

	 */
@@ -603,7 +606,8 @@ struct Scsi_Host { 
	 *

	 * Note: it is assumed that each hardware queue has a queue depth of

	 * can_queue. In other words, the total queue depth per host

	 * is nr_hw_queues * can_queue.

	 * is nr_hw_queues * can_queue. However, for when host_tagset is set,

	 * the total queue depth is can_queue.

	 */

	unsigned nr_hw_queues;

	unsigned active_mode:2;
@@ -634,6 +638,9 @@ struct Scsi_Host { 
	/* The controller does not support WRITE SAME */

	unsigned no_write_same:1;



	/* True if the host uses host-wide tagspace */

	unsigned host_tagset:1;



	/* Host responded with short (<36 bytes) INQUIRY result */

	unsigned short_inquiry:1;

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