Commit 633d5fce authored by David Rientjes's avatar David Rientjes Committed by Christoph Hellwig
Browse files

dma-direct: always align allocation size in dma_direct_alloc_pages() 



dma_alloc_contiguous() does size >> PAGE_SHIFT and set_memory_decrypted()
works at page granularity.  It's necessary to page align the allocation
size in dma_direct_alloc_pages() for consistent behavior.

This also fixes an issue when arch_dma_prep_coherent() is called on an
unaligned allocation size for dma_alloc_need_uncached() when
CONFIG_DMA_DIRECT_REMAP is disabled but CONFIG_ARCH_HAS_DMA_SET_UNCACHED
is enabled.

Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 26749b32

kernel/dma/direct.c

+10 −7
Original line number Diff line number Diff line
@@ -112,11 +112,12 @@ static inline bool dma_should_free_from_pool(struct device *dev, 
static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,

		gfp_t gfp, unsigned long attrs)

{

	size_t alloc_size = PAGE_ALIGN(size);

	int node = dev_to_node(dev);

	struct page *page = NULL;

	u64 phys_limit;



	WARN_ON_ONCE(!PAGE_ALIGNED(size));



	if (attrs & DMA_ATTR_NO_WARN)

		gfp |= __GFP_NOWARN;
@@ -124,14 +125,14 @@ static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size, 
	gfp &= ~__GFP_ZERO;

	gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,

					   &phys_limit);

	page = dma_alloc_contiguous(dev, alloc_size, gfp);

	page = dma_alloc_contiguous(dev, size, gfp);

	if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {

		dma_free_contiguous(dev, page, alloc_size);

		dma_free_contiguous(dev, page, size);

		page = NULL;

	}

again:

	if (!page)

		page = alloc_pages_node(node, gfp, get_order(alloc_size));

		page = alloc_pages_node(node, gfp, get_order(size));

	if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {

		dma_free_contiguous(dev, page, size);

		page = NULL;
@@ -158,8 +159,10 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size, 
	struct page *page;

	void *ret;



	size = PAGE_ALIGN(size);



	if (dma_should_alloc_from_pool(dev, gfp, attrs)) {

		ret = dma_alloc_from_pool(dev, PAGE_ALIGN(size), &page, gfp);

		ret = dma_alloc_from_pool(dev, size, &page, gfp);

		if (!ret)

			return NULL;

		goto done;
@@ -183,10 +186,10 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size, 
	     dma_alloc_need_uncached(dev, attrs)) ||

	    (IS_ENABLED(CONFIG_DMA_REMAP) && PageHighMem(page))) {

		/* remove any dirty cache lines on the kernel alias */

		arch_dma_prep_coherent(page, PAGE_ALIGN(size));

		arch_dma_prep_coherent(page, size);



		/* create a coherent mapping */

		ret = dma_common_contiguous_remap(page, PAGE_ALIGN(size),

		ret = dma_common_contiguous_remap(page, size,

				dma_pgprot(dev, PAGE_KERNEL, attrs),

				__builtin_return_address(0));

		if (!ret)

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