Merge "arm: Skip DMA zeroing completely only if specified" (638630f4) · Commits · e / devices / android_kernel_sony_msm8994

arch/arm/mm/dma-mapping.c

+15 −8

Original line number	Diff line number	Diff line
		@@ -219,7 +219,8 @@ static u64 get_coherent_dma_mask(struct device *dev)
		return mask;
		}

		static void __dma_clear_buffer(struct page *page, size_t size)
		static void __dma_clear_buffer(struct page *page, size_t size,
		struct dma_attrs *attrs)
		{
		/*
		* Ensure that the allocated pages are zeroed, and that any data
		@@ -230,6 +231,7 @@ static void __dma_clear_buffer(struct page *page, size_t size)
		phys_addr_t end = base + size;
		while (size > 0) {
		void *ptr = kmap_atomic(page);
		if (!dma_get_attr(DMA_ATTR_SKIP_ZEROING, attrs))
		memset(ptr, 0, PAGE_SIZE);
		dmac_flush_range(ptr, ptr + PAGE_SIZE);
		kunmap_atomic(ptr);
		@@ -239,6 +241,7 @@ static void __dma_clear_buffer(struct page *page, size_t size)
		outer_flush_range(base, end);
		} else {
		void *ptr = page_address(page);
		if (!dma_get_attr(DMA_ATTR_SKIP_ZEROING, attrs))
		memset(ptr, 0, size);
		dmac_flush_range(ptr, ptr + size);
		outer_flush_range(__pa(ptr), __pa(ptr) + size);
		@@ -265,7 +268,7 @@ static struct page __dma_alloc_buffer(struct device dev, size_t size, gfp_t gf
		for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
		__free_page(p);

		__dma_clear_buffer(page, size);
		__dma_clear_buffer(page, size, NULL);

		return page;
		}
		@@ -627,8 +630,12 @@ static void __alloc_from_contiguous(struct device dev, size_t size,

		page = pfn_to_page(pfn);

		if (!dma_get_attr(DMA_ATTR_SKIP_ZEROING, attrs))
		__dma_clear_buffer(page, size);
		/*
		* skip completely if we neither need to zero nor sync.
		*/
		if (!(dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs) &&
		dma_get_attr(DMA_ATTR_SKIP_ZEROING, attrs)))
		__dma_clear_buffer(page, size, attrs);

		if (PageHighMem(page)) {
		if (no_kernel_mapping) {
		@@ -1170,7 +1177,7 @@ static struct page *__iommu_alloc_buffer(struct device dev, size_t size,

		pfn = pfn_to_page(pfn);

		__dma_clear_buffer(page, size);
		__dma_clear_buffer(page, size, NULL);

		for (i = 0; i < count; i++)
		pages[i] = page + i;
		@@ -1199,7 +1206,7 @@ static struct page *__iommu_alloc_buffer(struct device dev, size_t size,
		pages[i + j] = pages[i] + j;
		}

		__dma_clear_buffer(pages[i], PAGE_SIZE << order);
		__dma_clear_buffer(pages[i], PAGE_SIZE << order, NULL);
		i += 1 << order;
		count -= 1 << order;
		}