Commit 92826e96 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-direct: don't fail on highmem CMA pages in dma_direct_alloc_pages 



When dma_direct_alloc_pages encounters a highmem page it just gives up
currently.  But what we really should do is to try memory using the
page allocator instead - without this platforms with a global highmem
CMA pool will fail all dma_alloc_pages allocations.

Fixes: efa70f2f ("dma-mapping: add a new dma_alloc_pages API")
Reported-by: default avatarMark O'Neill <mao@tumblingdice.co.uk>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 566fb90e

kernel/dma/direct.c

+10 −17
Original line number Diff line number Diff line
@@ -115,7 +115,7 @@ static struct page *dma_direct_alloc_swiotlb(struct device *dev, size_t size) 
}



static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,

		gfp_t gfp)

		gfp_t gfp, bool allow_highmem)

{

	int node = dev_to_node(dev);

	struct page *page = NULL;
@@ -129,10 +129,13 @@ static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size, 
	gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,

					   &phys_limit);

	page = dma_alloc_contiguous(dev, size, gfp);

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

	if (page) {

		if (!dma_coherent_ok(dev, page_to_phys(page), size) ||

		    (!allow_highmem && PageHighMem(page))) {

			dma_free_contiguous(dev, page, size);

			page = NULL;

		}

	}

again:

	if (!page)

		page = alloc_pages_node(node, gfp, get_order(size));
@@ -189,7 +192,7 @@ static void *dma_direct_alloc_no_mapping(struct device *dev, size_t size, 
{

	struct page *page;



	page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO);

	page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO, true);

	if (!page)

		return NULL;
@@ -262,7 +265,7 @@ void *dma_direct_alloc(struct device *dev, size_t size, 
		return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);



	/* we always manually zero the memory once we are done */

	page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO);

	page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO, true);

	if (!page)

		return NULL;
@@ -370,19 +373,9 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size, 
	if (force_dma_unencrypted(dev) && dma_direct_use_pool(dev, gfp))

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



	page = __dma_direct_alloc_pages(dev, size, gfp);

	page = __dma_direct_alloc_pages(dev, size, gfp, false);

	if (!page)

		return NULL;

	if (PageHighMem(page)) {

		/*

		 * Depending on the cma= arguments and per-arch setup

		 * dma_alloc_contiguous could return highmem pages.

		 * Without remapping there is no way to return them here,

		 * so log an error and fail.

		 */

		dev_info(dev, "Rejecting highmem page from CMA.\n");

		goto out_free_pages;

	}



	ret = page_address(page);

	if (dma_set_decrypted(dev, ret, size))