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Commit 072bebc0 authored by Robin Murphy's avatar Robin Murphy Committed by Joerg Roedel
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iommu/dma: Refactor iommu_dma_alloc 



Shuffle around the self-contained atomic and non-contiguous cases to
return early and get out of the way of the CMA case that we're about to
work on next.

Signed-off-by: default avatarRobin Murphy <robin.murphy@arm.com>
[hch: slight changes to the code flow]
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent bcf4b9c4

drivers/iommu/dma-iommu.c

+30 −30
Original line number Diff line number Diff line
@@ -973,14 +973,19 @@ static void *iommu_dma_alloc(struct device *dev, size_t size, 
{

	bool coherent = dev_is_dma_coherent(dev);

	int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);

	pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);

	size_t iosize = size;

	struct page *page;

	void *addr;



	size = PAGE_ALIGN(size);

	gfp |= __GFP_ZERO;



	if (gfpflags_allow_blocking(gfp) &&

	    !(attrs & DMA_ATTR_FORCE_CONTIGUOUS))

		return iommu_dma_alloc_remap(dev, iosize, handle, gfp, attrs);



	if (!gfpflags_allow_blocking(gfp)) {

		struct page *page;

		/*

		 * In atomic context we can't remap anything, so we'll only

		 * get the virtually contiguous buffer we need by way of a
@@ -1002,11 +1007,10 @@ static void *iommu_dma_alloc(struct device *dev, size_t size, 
				__free_pages(page, get_order(size));

			else

				dma_free_from_pool(addr, size);

			addr = NULL;

			return NULL;

		}

		return addr;

	}

	} else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {

		pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);

		struct page *page;



	page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,

					 get_order(size), gfp & __GFP_NOWARN);
@@ -1014,27 +1018,23 @@ static void *iommu_dma_alloc(struct device *dev, size_t size, 
		return NULL;



	*handle = __iommu_dma_map(dev, page_to_phys(page), iosize, ioprot);

		if (*handle == DMA_MAPPING_ERROR) {

			dma_release_from_contiguous(dev, page,

						    size >> PAGE_SHIFT);

			return NULL;

		}

		addr = dma_common_contiguous_remap(page, size, VM_USERMAP,

						   prot,

	if (*handle == DMA_MAPPING_ERROR)

		goto out_free_pages;



	addr = dma_common_contiguous_remap(page, size, VM_USERMAP, prot,

			__builtin_return_address(0));

		if (addr) {

	if (!addr)

		goto out_unmap;



	if (!coherent)

		arch_dma_prep_coherent(page, iosize);

	memset(addr, 0, size);

		} else {

			__iommu_dma_unmap(dev, *handle, iosize);

			dma_release_from_contiguous(dev, page,

						    size >> PAGE_SHIFT);

		}

	} else {

		addr = iommu_dma_alloc_remap(dev, iosize, handle, gfp, attrs);

	}

	return addr;

out_unmap:

	__iommu_dma_unmap(dev, *handle, iosize);

out_free_pages:

	dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);

	return NULL;

}



static int __iommu_dma_mmap_pfn(struct vm_area_struct *vma,