Commit d541ae55 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-direct: factor out a helper for DMA_ATTR_NO_KERNEL_MAPPING allocations 



Split the code for DMA_ATTR_NO_KERNEL_MAPPING allocations into a separate
helper to make dma_direct_alloc a little more readable.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
parent f3c96222

kernel/dma/direct.c

+20 −11
Original line number Diff line number Diff line
@@ -168,30 +168,39 @@ static void *dma_direct_alloc_from_pool(struct device *dev, size_t size, 
	return ret;

}



void *dma_direct_alloc(struct device *dev, size_t size,

		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)

static void *dma_direct_alloc_no_mapping(struct device *dev, size_t size,

		dma_addr_t *dma_handle, gfp_t gfp)

{

	bool remap = false, set_uncached = false;

	struct page *page;

	void *ret;



	size = PAGE_ALIGN(size);

	if (attrs & DMA_ATTR_NO_WARN)

		gfp |= __GFP_NOWARN;



	if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&

	    !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev)) {

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

	if (!page)

		return NULL;



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

	if (!PageHighMem(page))

		arch_dma_prep_coherent(page, size);

		*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));



	/* return the page pointer as the opaque cookie */

	*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));

	return page;

}



void *dma_direct_alloc(struct device *dev, size_t size,

		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)

{

	bool remap = false, set_uncached = false;

	struct page *page;

	void *ret;



	size = PAGE_ALIGN(size);

	if (attrs & DMA_ATTR_NO_WARN)

		gfp |= __GFP_NOWARN;



	if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&

	    !force_dma_unencrypted(dev) && !is_swiotlb_for_alloc(dev))

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



	if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&

	    !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&

	    !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) &&