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Commit 1c6a9c97 authored by Vinayak Menon's avatar Vinayak Menon
Browse files

arm64: dma-mapping: fix aliasing issues with non-CMA alloc 



Cache flush and clearing of logical mapping is done right now
only when the allocation is from CMA, for allocation requests
with DMA_ATTR_STRONGLY_ORDERED or DMA_ATTR_NO_KERNEL_MAPPING
set. Extend this to non-CMA allocations too, to avoid cache
aliasing issues.

Change-Id: I133d34d79665ee7159fe384121e933d7768748c2
Signed-off-by: default avatarVinayak Menon <vinmenon@codeaurora.org>
parent 1ccabf65

arch/arm64/mm/dma-mapping.c

+14 −13
Original line number Diff line number Diff line
@@ -164,6 +164,8 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size, 
				  dma_addr_t *dma_handle, gfp_t flags,

				  struct dma_attrs *attrs)

{

	void *addr;



	if (dev == NULL) {

		WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");

		return NULL;
@@ -174,7 +176,6 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size, 
		flags |= GFP_DMA;

	if (dev_get_cma_area(dev) && gfpflags_allow_blocking(flags)) {

		struct page *page;

		void *addr;



		page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,

							get_order(size));
@@ -184,20 +185,20 @@ static void *__dma_alloc_coherent(struct device *dev, size_t size, 
		*dma_handle = phys_to_dma(dev, page_to_phys(page));

		addr = page_address(page);

		memset(addr, 0, size);

	} else {

		addr = swiotlb_alloc_coherent(dev, size, dma_handle, flags);

	}



		if (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs) ||

		    dma_get_attr(DMA_ATTR_STRONGLY_ORDERED, attrs)) {

	if (addr && (dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs) ||

		dma_get_attr(DMA_ATTR_STRONGLY_ORDERED, attrs))) {

		/*

		 * flush the caches here because we can't later

		 */

		__dma_flush_range(addr, addr + size);

			__dma_remap(page, size, 0, true);

		__dma_remap(virt_to_page(addr), size, 0, true);

	}



	return addr;

	} else {

		return swiotlb_alloc_coherent(dev, size, dma_handle, flags);

	}

}



static void __dma_free_coherent(struct device *dev, size_t size,