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: wsa+renesas@sang-engineering.com, linux-mmc@vger.kernel.org,
iommu@lists.linux-foundation.org, linux-block@vger.kernel.org,
linux-renesas-soc@vger.kernel.org,
Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Subject: [PATCH v10 1/4] dma: Introduce dma_get_merge_boundary()
Date: Wed, 28 Aug 2019 21:35:40 +0900 [thread overview]
Message-ID: <1566995743-5614-2-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 new DMA API "dma_get_merge_boundary". This function
returns the DMA merge boundary if the DMA layer can merge the segments.
This patch also adds the implementation for a new dma_map_ops pointer.
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>
---
Documentation/DMA-API.txt | 8 ++++++++
include/linux/dma-mapping.h | 6 ++++++
kernel/dma/mapping.c | 11 +++++++++++
3 files changed, 25 insertions(+)
diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt
index e47c63b..9c4dd3d 100644
--- a/Documentation/DMA-API.txt
+++ b/Documentation/DMA-API.txt
@@ -204,6 +204,14 @@ Returns the maximum size of a mapping for the device. The size parameter
of the mapping functions like dma_map_single(), dma_map_page() and
others should not be larger than the returned value.
+::
+
+ unsigned long
+ dma_get_merge_boundary(struct device *dev);
+
+Returns the DMA merge boundary. If the device cannot merge any the DMA address
+segments, the function returns 0.
+
Part Id - Streaming DMA mappings
--------------------------------
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 14702e2..7072b78 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -131,6 +131,7 @@ struct dma_map_ops {
int (*dma_supported)(struct device *dev, u64 mask);
u64 (*get_required_mask)(struct device *dev);
size_t (*max_mapping_size)(struct device *dev);
+ unsigned long (*get_merge_boundary)(struct device *dev);
};
#define DMA_MAPPING_ERROR (~(dma_addr_t)0)
@@ -462,6 +463,7 @@ int dma_set_mask(struct device *dev, u64 mask);
int dma_set_coherent_mask(struct device *dev, u64 mask);
u64 dma_get_required_mask(struct device *dev);
size_t dma_max_mapping_size(struct device *dev);
+unsigned long dma_get_merge_boundary(struct device *dev);
#else /* CONFIG_HAS_DMA */
static inline dma_addr_t dma_map_page_attrs(struct device *dev,
struct page *page, size_t offset, size_t size,
@@ -567,6 +569,10 @@ static inline size_t dma_max_mapping_size(struct device *dev)
{
return 0;
}
+static inline unsigned long dma_get_merge_boundary(struct device *dev)
+{
+ return 0;
+}
#endif /* CONFIG_HAS_DMA */
static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index b0038ca..b3077b5 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -405,3 +405,14 @@ size_t dma_max_mapping_size(struct device *dev)
return size;
}
EXPORT_SYMBOL_GPL(dma_max_mapping_size);
+
+unsigned long dma_get_merge_boundary(struct device *dev)
+{
+ const struct dma_map_ops *ops = get_dma_ops(dev);
+
+ if (!ops || !ops->get_merge_boundary)
+ return 0; /* can't merge */
+
+ return ops->get_merge_boundary(dev);
+}
+EXPORT_SYMBOL_GPL(dma_get_merge_boundary);
--
2.7.4
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 ` Yoshihiro Shimoda [this message]
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 ` [PATCH v10 3/4] block: add a helper function to merge the segments Yoshihiro Shimoda
2019-09-02 21:47 ` 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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