ARM: dma-mapping: push buffer ownership down into dma-mapping.c (4ea0d737) · Commits · e / devices / android_kernel_xiaomi_markw

arch/arm/include/asm/dma-mapping.h

+25 −14

Original line number	Diff line number	Diff line
		@@ -56,47 +56,58 @@ static inline dma_addr_t virt_to_dma(struct device dev, void addr)
		}
		#endif

		/*
		* Private support functions: these are not part of the API and are
		* liable to change. Drivers must not use these.
		*/
		extern void dma_cache_maint(const void *kaddr, size_t size, int rw);
		extern void dma_cache_maint_page(struct page *page, unsigned long offset,
		size_t size, int rw);

		/*
		* The DMA API is built upon the notion of "buffer ownership". A buffer
		* is either exclusively owned by the CPU (and therefore may be accessed
		* by it) or exclusively owned by the DMA device. These helper functions
		* represent the transitions between these two ownership states.
		*
		* As above, these are private support functions and not part of the API.
		* Drivers must not use these.
		* Note, however, that on later ARMs, this notion does not work due to
		* speculative prefetches. We model our approach on the assumption that
		* the CPU does do speculative prefetches, which means we clean caches
		* before transfers and delay cache invalidation until transfer completion.
		*
		* Private support functions: these are not part of the API and are
		* liable to change. Drivers must not use these.
		*/
		static inline void __dma_single_cpu_to_dev(const void *kaddr, size_t size,
		enum dma_data_direction dir)
		{
		extern void ___dma_single_cpu_to_dev(const void *, size_t,
		enum dma_data_direction);

		if (!arch_is_coherent())
		dma_cache_maint(kaddr, size, dir);
		___dma_single_cpu_to_dev(kaddr, size, dir);
		}

		static inline void __dma_single_dev_to_cpu(const void *kaddr, size_t size,
		enum dma_data_direction dir)
		{
		/* nothing to do */
		extern void ___dma_single_dev_to_cpu(const void *, size_t,
		enum dma_data_direction);

		if (!arch_is_coherent())
		___dma_single_dev_to_cpu(kaddr, size, dir);
		}

		static inline void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
		size_t size, enum dma_data_direction dir)
		{
		extern void ___dma_page_cpu_to_dev(struct page *, unsigned long,
		size_t, enum dma_data_direction);

		if (!arch_is_coherent())
		dma_cache_maint_page(page, off, size, dir);
		___dma_page_cpu_to_dev(page, off, size, dir);
		}

		static inline void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
		size_t size, enum dma_data_direction dir)
		{
		/* nothing to do */
		extern void ___dma_page_dev_to_cpu(struct page *, unsigned long,
		size_t, enum dma_data_direction);

		if (!arch_is_coherent())
		___dma_page_dev_to_cpu(page, off, size, dir);
		}

		/*

arch/arm/mm/dma-mapping.c

+30 −4

Original line number	Diff line number	Diff line
		@@ -404,7 +404,7 @@ EXPORT_SYMBOL(dma_free_coherent);
		* platforms with CONFIG_DMABOUNCE.
		* Use the driver DMA support - see dma-mapping.h (dma_sync_*)
		*/
		void dma_cache_maint(const void *start, size_t size, int direction)
		static void dma_cache_maint(const void *start, size_t size, int direction)
		{
		void (inner_op)(const void , const void *);
		void (*outer_op)(unsigned long, unsigned long);
		@@ -431,7 +431,20 @@ void dma_cache_maint(const void *start, size_t size, int direction)
		inner_op(start, start + size);
		outer_op(__pa(start), __pa(start) + size);
		}
		EXPORT_SYMBOL(dma_cache_maint);

		void ___dma_single_cpu_to_dev(const void *kaddr, size_t size,
		enum dma_data_direction dir)
		{
		dma_cache_maint(kaddr, size, dir);
		}
		EXPORT_SYMBOL(___dma_single_cpu_to_dev);

		void ___dma_single_dev_to_cpu(const void *kaddr, size_t size,
		enum dma_data_direction dir)
		{
		/* nothing to do */
		}
		EXPORT_SYMBOL(___dma_single_dev_to_cpu);

		static void dma_cache_maint_contiguous(struct page *page, unsigned long offset,
		size_t size, int direction)
		@@ -474,7 +487,7 @@ static void dma_cache_maint_contiguous(struct page *page, unsigned long offset,
		outer_op(paddr, paddr + size);
		}

		void dma_cache_maint_page(struct page *page, unsigned long offset,
		static void dma_cache_maint_page(struct page *page, unsigned long offset,
		size_t size, int dir)
		{
		/*
		@@ -499,7 +512,20 @@ void dma_cache_maint_page(struct page *page, unsigned long offset,
		left -= len;
		} while (left);
		}
		EXPORT_SYMBOL(dma_cache_maint_page);

		void ___dma_page_cpu_to_dev(struct page *page, unsigned long off,
		size_t size, enum dma_data_direction dir)
		{
		dma_cache_maint_page(page, off, size, dir);
		}
		EXPORT_SYMBOL(___dma_page_cpu_to_dev);

		void ___dma_page_dev_to_cpu(struct page *page, unsigned long off,
		size_t size, enum dma_data_direction dir)
		{
		/* nothing to do */
		}
		EXPORT_SYMBOL(___dma_page_dev_to_cpu);

		/**
		* dma_map_sg - map a set of SG buffers for streaming mode DMA