Currently io_uring support is only available in the block layer. This RFC is to extend support of mq_poll in the scsi layer. megaraid_sas and mpt3sas driver will be immediate users of this interface. Both the drivers can use mq_poll only if it has exposed more than one nr_hw_queues. Waiting for below changes to enable shared host tag support. https://patchwork.kernel.org/cover/11724429/ Signed-off-by: Kashyap Desai <kashyap.desai@xxxxxxxxxxxx> --- drivers/scsi/scsi_lib.c | 16 ++++++++++++++++ include/scsi/scsi_cmnd.h | 1 + include/scsi/scsi_host.h | 3 +++ 3 files changed, 20 insertions(+) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 780cf084e366..7a3c59d2dfcc 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1802,6 +1802,19 @@ static void scsi_mq_exit_request(struct blk_mq_tag_set *set, struct request *rq, cmd->sense_buffer); } + +static int scsi_mq_poll(struct blk_mq_hw_ctx *hctx) +{ + struct request_queue *q = hctx->queue; + struct scsi_device *sdev = q->queuedata; + struct Scsi_Host *shost = sdev->host; + + if (shost->hostt->mq_poll) + return shost->hostt->mq_poll(shost, hctx->queue_num); + + return 0; +} + static int scsi_map_queues(struct blk_mq_tag_set *set) { struct Scsi_Host *shost = container_of(set, struct Scsi_Host, tag_set); @@ -1869,6 +1882,7 @@ static const struct blk_mq_ops scsi_mq_ops_no_commit = { .cleanup_rq = scsi_cleanup_rq, .busy = scsi_mq_lld_busy, .map_queues = scsi_map_queues, + .poll = scsi_mq_poll, }; @@ -1897,6 +1911,7 @@ static const struct blk_mq_ops scsi_mq_ops = { .cleanup_rq = scsi_cleanup_rq, .busy = scsi_mq_lld_busy, .map_queues = scsi_map_queues, + .poll = scsi_mq_poll, }; struct request_queue *scsi_mq_alloc_queue(struct scsi_device *sdev) @@ -1929,6 +1944,7 @@ int scsi_mq_setup_tags(struct Scsi_Host *shost) else tag_set->ops = &scsi_mq_ops_no_commit; tag_set->nr_hw_queues = shost->nr_hw_queues ? : 1; + tag_set->nr_maps = shost->nr_maps ? : 1; tag_set->queue_depth = shost->can_queue; tag_set->cmd_size = cmd_size; tag_set->numa_node = NUMA_NO_NODE; diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h index e76bac4d14c5..5844374a85b1 100644 --- a/include/scsi/scsi_cmnd.h +++ b/include/scsi/scsi_cmnd.h @@ -9,6 +9,7 @@ #include <linux/types.h> #include <linux/timer.h> #include <linux/scatterlist.h> +#include <scsi/scsi_host.h> #include <scsi/scsi_device.h> #include <scsi/scsi_request.h> diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index 701f178b20ae..d34602c68d0b 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -269,6 +269,8 @@ struct scsi_host_template { * Status: OPTIONAL */ int (* map_queues)(struct Scsi_Host *shost); + + int (* mq_poll)(struct Scsi_Host *shost, unsigned int queue_num); /* * Check if scatterlists need to be padded for DMA draining. @@ -610,6 +612,7 @@ struct Scsi_Host { * the total queue depth is can_queue. */ unsigned nr_hw_queues; + unsigned nr_maps; unsigned active_mode:2; unsigned unchecked_isa_dma:1;
