From efec4b90f1a9b4c80827e4b8c0863334e13b0bf1 Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Thu, 30 Oct 2014 14:45:36 +0100 Subject: [PATCH] scsi: add support for multiple hardware queues Allow a SCSI LLD to declare how many hardware queues it supports by setting Scsi_Host.nr_hw_queues before calling scsi_add_host(). Signed-off-by: Bart Van Assche Reviewed-by: Sagi Grimberg Reviewed-by: Martin K. Petersen Signed-off-by: Christoph Hellwig --- drivers/scsi/scsi_lib.c | 2 +- include/scsi/scsi_host.h | 8 ++++++++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index fc0a8a0c0a34..38f8c85957b6 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -2106,7 +2106,7 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost) memset(&shost->tag_set, 0, sizeof(shost->tag_set)); shost->tag_set.ops = &scsi_mq_ops; - shost->tag_set.nr_hw_queues = 1; + shost->tag_set.nr_hw_queues = shost->nr_hw_queues ? : 1; shost->tag_set.queue_depth = shost->can_queue; shost->tag_set.cmd_size = cmd_size; shost->tag_set.numa_node = NUMA_NO_NODE; diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 5e362489ee88..bb9e27815be5 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -638,6 +638,14 @@ struct Scsi_Host { short unsigned int sg_prot_tablesize; unsigned int max_sectors; unsigned long dma_boundary; + /* + * In scsi-mq mode, the number of hardware queues supported by the LLD. + * + * 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. + */ + unsigned nr_hw_queues; /* * Used to assign serial numbers to the cmds. * Protected by the host lock. -- 2.20.1