From 6ba99411b858bd70bae966633561e698cd6de38c Mon Sep 17 00:00:00 2001 From: Yoshihiro Shimoda Date: Wed, 28 Aug 2019 21:35:40 +0900 Subject: dma-mapping: introduce dma_get_merge_boundary() 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 Reviewed-by: Simon Horman Signed-off-by: Christoph Hellwig --- include/linux/dma-mapping.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/dma-mapping.h') diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 48ebe8295987..de41a4f0b9f6 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) @@ -467,6 +468,7 @@ 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, @@ -572,6 +574,10 @@ 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, -- cgit