Commit 2e2b5479 authored by Wenchao Chen's avatar Wenchao Chen Committed by Ulf Hansson
Browse files

mmc: core: Allow dynamical updates of the number of requests for hsq 



To allow dynamical updates of the current number of used in-flight
requests, let's move away from using a hard-coded value to a use a
corresponding variable in the struct mmc_host.

This can be valuable when optimizing for certain I/O request sequences, as
shown by subsequent changes.

Signed-off-by: default avatarWenchao Chen <wenchao.chen@unisoc.com>
Link: https://lore.kernel.org/r/20230919074707.25517-2-wenchao.chen@unisoc.com


[Ulf: Re-wrote the commitmsg to clarify the change]
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent d7133797

drivers/mmc/core/queue.c

+1 −5
Original line number Diff line number Diff line
@@ -260,11 +260,7 @@ static blk_status_t mmc_mq_queue_rq(struct blk_mq_hw_ctx *hctx, 
		}

		break;

	case MMC_ISSUE_ASYNC:

		/*

		 * For MMC host software queue, we only allow 2 requests in

		 * flight to avoid a long latency.

		 */

		if (host->hsq_enabled && mq->in_flight[issue_type] > 2) {

		if (host->hsq_enabled && mq->in_flight[issue_type] > host->hsq_depth) {

			spin_unlock_irq(&mq->lock);

			return BLK_STS_RESOURCE;

		}

drivers/mmc/host/mmc_hsq.c

+1 −0
Original line number Diff line number Diff line
@@ -337,6 +337,7 @@ int mmc_hsq_init(struct mmc_hsq *hsq, struct mmc_host *mmc) 
	hsq->mmc = mmc;

	hsq->mmc->cqe_private = hsq;

	mmc->cqe_ops = &mmc_hsq_ops;

	mmc->hsq_depth = HSQ_NORMAL_DEPTH;



	for (i = 0; i < HSQ_NUM_SLOTS; i++)

		hsq->tag_slot[i] = HSQ_INVALID_TAG;

drivers/mmc/host/mmc_hsq.h

+6 −0
Original line number Diff line number Diff line
@@ -5,6 +5,12 @@ 
#define HSQ_NUM_SLOTS	64

#define HSQ_INVALID_TAG	HSQ_NUM_SLOTS



/*

 * For MMC host software queue, we only allow 2 requests in

 * flight to avoid a long latency.

 */

#define HSQ_NORMAL_DEPTH	2



struct hsq_slot {

	struct mmc_request *mrq;

};

include/linux/mmc/host.h

+1 −0
Original line number Diff line number Diff line
@@ -526,6 +526,7 @@ struct mmc_host { 


	/* Host Software Queue support */

	bool			hsq_enabled;

	int			hsq_depth;



	u32			err_stats[MMC_ERR_MAX];

	unsigned long		private[] ____cacheline_aligned;