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 v10 3/4] block: add a helper function to merge the segments
Date: Wed, 28 Aug 2019 21:35:42 +0900 [thread overview]
Message-ID: <1566995743-5614-4-git-send-email-yoshihiro.shimoda.uh@renesas.com> (raw)
In-Reply-To: <1566995743-5614-1-git-send-email-yoshihiro.shimoda.uh@renesas.com>
This patch adds a helper function whether a queue can merge
the segments by the DMA MAP layer (e.g. via IOMMU).
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au
---
block/blk-settings.c | 23 +++++++++++++++++++++++
include/linux/blkdev.h | 2 ++
2 files changed, 25 insertions(+)
diff --git a/block/blk-settings.c b/block/blk-settings.c
index 2c18312..c3632fc 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -12,6 +12,7 @@
#include <linux/lcm.h>
#include <linux/jiffies.h>
#include <linux/gfp.h>
+#include <linux/dma-mapping.h>
#include "blk.h"
#include "blk-wbt.h"
@@ -832,6 +833,28 @@ void blk_queue_write_cache(struct request_queue *q, bool wc, bool fua)
}
EXPORT_SYMBOL_GPL(blk_queue_write_cache);
+/**
+ * blk_queue_can_use_dma_map_merging - configure queue for merging segments.
+ * @q: the request queue for the device
+ * @dev: the device pointer for dma
+ *
+ * Tell the block layer about merging the segments by dma map of @q.
+ */
+bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
+ struct device *dev)
+{
+ unsigned long boundary = dma_get_merge_boundary(dev);
+
+ if (!boundary)
+ return false;
+
+ /* No need to update max_segment_size. see blk_queue_virt_boundary() */
+ blk_queue_virt_boundary(q, boundary);
+
+ return true;
+}
+EXPORT_SYMBOL_GPL(blk_queue_can_use_dma_map_merging);
+
static int __init blk_settings_init(void)
{
blk_max_low_pfn = max_low_pfn - 1;
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1ac7901..d62d6e2 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -1086,6 +1086,8 @@ extern void blk_queue_dma_alignment(struct request_queue *, int);
extern void blk_queue_update_dma_alignment(struct request_queue *, int);
extern void blk_queue_rq_timeout(struct request_queue *, unsigned int);
extern void blk_queue_write_cache(struct request_queue *q, bool enabled, bool fua);
+extern bool blk_queue_can_use_dma_map_merging(struct request_queue *q,
+ struct device *dev);
/*
* Number of physical segments as sent to the device.
--
2.7.4
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next prev parent reply other threads:[~2019-08-28 12:37 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-28 12:35 [PATCH v10 0/4] treewide: improve R-Car SDHI performance Yoshihiro Shimoda
2019-08-28 12:35 ` [PATCH v10 1/4] dma: Introduce dma_get_merge_boundary() Yoshihiro Shimoda
2019-08-28 12:35 ` [PATCH v10 2/4] iommu/dma: Add a new dma_map_ops of get_merge_boundary() Yoshihiro Shimoda
2019-08-28 12:35 ` Yoshihiro Shimoda [this message]
2019-09-02 21:47 ` [PATCH v10 3/4] block: add a helper function to merge the segments Jens Axboe
2019-09-03 4:59 ` Yoshihiro Shimoda
2019-09-03 6:33 ` hch
2019-09-03 6:42 ` Yoshihiro Shimoda
2019-08-28 12:35 ` [PATCH v10 4/4] mmc: queue: Use bigger segments if DMA MAP layer can " Yoshihiro Shimoda
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