Commit 78bc7278 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-direct: warn if there is no pool for force unencrypted allocations 



Instead of blindly running into a blocking operation for a non-blocking gfp,
return NULL and spew an error.  Note that Kconfig prevents this for all
currently relevant platforms, and this is just a debug check.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
parent 955f58f7

kernel/dma/direct.c

+5 −4
Original line number Diff line number Diff line
@@ -159,6 +159,9 @@ static void *dma_direct_alloc_from_pool(struct device *dev, size_t size, 
	u64 phys_mask;

	void *ret;



	if (WARN_ON_ONCE(!IS_ENABLED(CONFIG_DMA_COHERENT_POOL)))

		return NULL;



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

					   &phys_mask);

	page = dma_alloc_from_pool(dev, size, &ret, gfp, dma_coherent_ok);
@@ -243,8 +246,7 @@ void *dma_direct_alloc(struct device *dev, size_t size, 
	 * Decrypting memory may block, so allocate the memory from the atomic

	 * pools if we can't block.

	 */

	if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&

	    force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&

	if (force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&

	    !is_swiotlb_for_alloc(dev))

		return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
@@ -354,8 +356,7 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size, 
	struct page *page;

	void *ret;



	if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&

	    force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&

	if (force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp) &&

	    !is_swiotlb_for_alloc(dev))

		return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);