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Commit f74f7e57 authored by Russell King's avatar Russell King
Browse files

ARM: use flush_kernel_dcache_area() for dmabounce 



After copying data from the bounce buffer to the real buffer, use
flush_kernel_dcache_page() to ensure that data is written back in
manner coherent with future userspace mappings.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent 2c9b9c84

arch/arm/common/dmabounce.c

+4 −8
Original line number Diff line number Diff line
@@ -308,15 +308,11 @@ static inline void unmap_single(struct device *dev, dma_addr_t dma_addr, 
			memcpy(ptr, buf->safe, size);



			/*

			 * DMA buffers must have the same cache properties

			 * as if they were really used for DMA - which means

			 * data must be written back to RAM.  Note that

			 * we don't use dmac_flush_range() here for the

			 * bidirectional case because we know the cache

			 * lines will be coherent with the data written.

			 * Since we may have written to a page cache page,

			 * we need to ensure that the data will be coherent

			 * with user mappings.

			 */

			dmac_clean_range(ptr, ptr + size);

			outer_clean_range(__pa(ptr), __pa(ptr) + size);

			__cpuc_flush_kernel_dcache_area(ptr, size);

		}

		free_safe_buffer(dev->archdata.dmabounce, buf);

	}