IOMMU Archive on lore.kernel.org
 help / color / Atom feed
From: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
To: ulf.hansson@linaro.org, hch@lst.de, m.szyprowski@samsung.com,
	robin.murphy@arm.com, joro@8bytes.org, axboe@kernel.dk
Cc: linux-renesas-soc@vger.kernel.org, linux-mmc@vger.kernel.org,
	linux-block@vger.kernel.org, wsa+renesas@sang-engineering.com,
	iommu@lists.linux-foundation.org
Subject: [PATCH v9 5/5] mmc: queue: Use bigger segments if DMA MAP layer can merge the segments
Date: Fri, 26 Jul 2019 17:31:16 +0900
Message-ID: <1564129876-28261-6-git-send-email-yoshihiro.shimoda.uh@renesas.com> (raw)
In-Reply-To: <1564129876-28261-1-git-send-email-yoshihiro.shimoda.uh@renesas.com>

When the max_segs of a mmc host is smaller than 512, the mmc
subsystem tries to use 512 segments if DMA MAP layer can merge
the segments, and then the mmc subsystem exposes such information
to the block layer by using blk_queue_can_use_dma_map_merging().

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
---
 drivers/mmc/core/queue.c | 35 ++++++++++++++++++++++++++++++++---
 include/linux/mmc/host.h |  1 +
 2 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c
index 7102e2e..25568dc 100644
--- a/drivers/mmc/core/queue.c
+++ b/drivers/mmc/core/queue.c
@@ -21,6 +21,8 @@
 #include "card.h"
 #include "host.h"
 
+#define MMC_DMA_MAP_MERGE_SEGMENTS	512
+
 static inline bool mmc_cqe_dcmd_busy(struct mmc_queue *mq)
 {
 	/* Allow only 1 DCMD at a time */
@@ -193,6 +195,12 @@ static void mmc_queue_setup_discard(struct request_queue *q,
 		blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
 }
 
+static unsigned int mmc_get_max_segments(struct mmc_host *host)
+{
+	return host->can_dma_map_merge ? MMC_DMA_MAP_MERGE_SEGMENTS :
+					 host->max_segs;
+}
+
 /**
  * mmc_init_request() - initialize the MMC-specific per-request data
  * @q: the request queue
@@ -206,7 +214,7 @@ static int __mmc_init_request(struct mmc_queue *mq, struct request *req,
 	struct mmc_card *card = mq->card;
 	struct mmc_host *host = card->host;
 
-	mq_rq->sg = mmc_alloc_sg(host->max_segs, gfp);
+	mq_rq->sg = mmc_alloc_sg(mmc_get_max_segments(host), gfp);
 	if (!mq_rq->sg)
 		return -ENOMEM;
 
@@ -362,13 +370,23 @@ static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card)
 		blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH);
 	blk_queue_max_hw_sectors(mq->queue,
 		min(host->max_blk_count, host->max_req_size / 512));
-	blk_queue_max_segments(mq->queue, host->max_segs);
+	if (host->can_dma_map_merge)
+		WARN(!blk_queue_can_use_dma_map_merging(mq->queue,
+							mmc_dev(host)),
+		     "merging was advertised but not possible");
+	blk_queue_max_segments(mq->queue, mmc_get_max_segments(host));
 
 	if (mmc_card_mmc(card))
 		block_size = card->ext_csd.data_sector_size;
 
 	blk_queue_logical_block_size(mq->queue, block_size);
-	blk_queue_max_segment_size(mq->queue,
+	/*
+	 * After blk_queue_can_use_dma_map_merging() was called with succeed,
+	 * since it calls blk_queue_virt_boundary(), the mmc should not call
+	 * both blk_queue_max_segment_size().
+	 */
+	if (host->can_dma_map_merge)
+		blk_queue_max_segment_size(mq->queue,
 			round_down(host->max_seg_size, block_size));
 
 	dma_set_max_seg_size(mmc_dev(host), queue_max_segment_size(mq->queue));
@@ -418,6 +436,17 @@ int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card)
 	mq->tag_set.cmd_size = sizeof(struct mmc_queue_req);
 	mq->tag_set.driver_data = mq;
 
+	/*
+	 * Since blk_mq_alloc_tag_set() calls .init_request() of mmc_mq_ops,
+	 * the host->can_dma_map_merge should be set before to get max_segs
+	 * from mmc_get_max_segments().
+	 */
+	if (host->max_segs < MMC_DMA_MAP_MERGE_SEGMENTS &&
+	    dma_get_merge_boundary(mmc_dev(host)))
+		host->can_dma_map_merge = 1;
+	else
+		host->can_dma_map_merge = 0;
+
 	ret = blk_mq_alloc_tag_set(&mq->tag_set);
 	if (ret)
 		return ret;
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 4a351cb..c5662b3 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -396,6 +396,7 @@ struct mmc_host {
 	unsigned int		retune_paused:1; /* re-tuning is temporarily disabled */
 	unsigned int		use_blk_mq:1;	/* use blk-mq */
 	unsigned int		retune_crc_disable:1; /* don't trigger retune upon crc */
+	unsigned int		can_dma_map_merge:1; /* merging can be used */
 
 	int			rescan_disable;	/* disable card detection */
 	int			rescan_entered;	/* used with nonremovable devices */
-- 
2.7.4

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

  parent reply index

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-07-26  8:31 [PATCH v9 0/5] treewide: improve R-Car SDHI performance Yoshihiro Shimoda
2019-07-26  8:31 ` [PATCH v9 1/5] dma: Introduce dma_get_merge_boundary() Yoshihiro Shimoda
2019-07-26  8:31 ` [PATCH v9 2/5] iommu/dma: Add a new dma_map_ops of get_merge_boundary() Yoshihiro Shimoda
2019-08-16 19:48   ` Wolfram Sang
2019-08-19 12:45   ` Joerg Roedel
2019-08-19 12:54   ` Robin Murphy
2019-08-20  1:42     ` Yoshihiro Shimoda
2019-07-26  8:31 ` [PATCH v9 3/5] block: sort headers on blk-setting.c Yoshihiro Shimoda
2019-08-16 19:50   ` Wolfram Sang
2019-08-19 14:53     ` Jens Axboe
2019-08-20  1:50       ` Yoshihiro Shimoda
2019-08-22  9:35       ` Wolfram Sang
2019-07-26  8:31 ` [PATCH v9 4/5] block: add a helper function to merge the segments Yoshihiro Shimoda
2019-07-26  8:31 ` Yoshihiro Shimoda [this message]
2019-08-15  7:30 ` [PATCH v9 0/5] treewide: improve R-Car SDHI performance Christoph Hellwig

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1564129876-28261-6-git-send-email-yoshihiro.shimoda.uh@renesas.com \
    --to=yoshihiro.shimoda.uh@renesas.com \
    --cc=axboe@kernel.dk \
    --cc=hch@lst.de \
    --cc=iommu@lists.linux-foundation.org \
    --cc=joro@8bytes.org \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-mmc@vger.kernel.org \
    --cc=linux-renesas-soc@vger.kernel.org \
    --cc=m.szyprowski@samsung.com \
    --cc=robin.murphy@arm.com \
    --cc=ulf.hansson@linaro.org \
    --cc=wsa+renesas@sang-engineering.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

IOMMU Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-iommu/0 linux-iommu/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-iommu linux-iommu/ https://lore.kernel.org/linux-iommu \
		iommu@lists.linux-foundation.org iommu@archiver.kernel.org
	public-inbox-index linux-iommu

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.linux-foundation.lists.iommu


AGPL code for this site: git clone https://public-inbox.org/ public-inbox