Commit 274b3f7b authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-contiguous: cleanup dma_alloc_contiguous 



Split out a cma_alloc_aligned helper to deal with the "interesting"
calling conventions for cma_alloc, which then allows to the main
function to be written straight forward.  This also takes advantage
of the fact that NULL dev arguments have been gone from the DMA API
for a while.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarNicolin Chen <nicoleotsuka@gmail.com>
Reviewed-by: default avatarBarry Song <song.bao.hua@hisilicon.com>
parent 23efed6f

kernel/dma/contiguous.c

+14 −17
Original line number Diff line number Diff line
@@ -215,6 +215,13 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages, 
	return cma_release(dev_get_cma_area(dev), pages, count);

}



static struct page *cma_alloc_aligned(struct cma *cma, size_t size, gfp_t gfp)

{

	unsigned int align = min(get_order(size), CONFIG_CMA_ALIGNMENT);



	return cma_alloc(cma, size >> PAGE_SHIFT, align, gfp & __GFP_NOWARN);

}



/**

 * dma_alloc_contiguous() - allocate contiguous pages

 * @dev:   Pointer to device for which the allocation is performed.
@@ -231,24 +238,14 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages, 
 */

struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp)

{

	size_t count = size >> PAGE_SHIFT;

	struct page *page = NULL;

	struct cma *cma = NULL;



	if (dev && dev->cma_area)

		cma = dev->cma_area;

	else if (count > 1)

		cma = dma_contiguous_default_area;



	/* CMA can be used only in the context which permits sleeping */

	if (cma && gfpflags_allow_blocking(gfp)) {

		size_t align = get_order(size);

		size_t cma_align = min_t(size_t, align, CONFIG_CMA_ALIGNMENT);



		page = cma_alloc(cma, count, cma_align, gfp & __GFP_NOWARN);

	}



	return page;

	if (!gfpflags_allow_blocking(gfp))

		return NULL;

	if (dev->cma_area)

		return cma_alloc_aligned(dev->cma_area, size, gfp);

	if (size <= PAGE_SIZE || !dma_contiguous_default_area)

		return NULL;

	return cma_alloc_aligned(dma_contiguous_default_area, size, gfp);

}



/**

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