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	Original line	Diff line number	Diff line
	@@ -219,7 +219,8 @@ static u64 get_coherent_dma_mask(struct device *dev)
	return mask;		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		* 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;		phys_addr_t end = base + size;
	while (size > 0) {		while (size > 0) {
	void *ptr = kmap_atomic(page);		void *ptr = kmap_atomic(page);
			if (!dma_get_attr(DMA_ATTR_SKIP_ZEROING, attrs))
	memset(ptr, 0, PAGE_SIZE);		memset(ptr, 0, PAGE_SIZE);
	dmac_flush_range(ptr, ptr + PAGE_SIZE);		dmac_flush_range(ptr, ptr + PAGE_SIZE);
	kunmap_atomic(ptr);		kunmap_atomic(ptr);
	@@ -239,6 +241,7 @@ static void __dma_clear_buffer(struct page *page, size_t size)
	outer_flush_range(base, end);		outer_flush_range(base, end);
	} else {		} else {
	void *ptr = page_address(page);		void *ptr = page_address(page);
			if (!dma_get_attr(DMA_ATTR_SKIP_ZEROING, attrs))
	memset(ptr, 0, size);		memset(ptr, 0, size);
	dmac_flush_range(ptr, ptr + size);		dmac_flush_range(ptr, ptr + size);
	outer_flush_range(__pa(ptr), __pa(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++)		for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
	__free_page(p);		__free_page(p);

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

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

	page = pfn_to_page(pfn);		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 (PageHighMem(page)) {
	if (no_kernel_mapping) {		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);		pfn = pfn_to_page(pfn);

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

	for (i = 0; i < count; i++)		for (i = 0; i < count; i++)
	pages[i] = page + 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;		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;		i += 1 << order;
	count -= 1 << order;		count -= 1 << order;
	}		}