Commit ee1ef05d authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Joerg Roedel
Browse files

iommu/dma: Refactor iommu_dma_alloc, part 2 



All the logic in iommu_dma_alloc that deals with page allocation from
the CMA or page allocators can be split into a self-contained helper,
and we can than map the result of that or the atomic pool allocation
with the iommu later.  This also allows reusing __iommu_dma_free to
tear down the allocations and MMU mappings when the IOMMU mapping
fails.

Based on a patch from Robin Murphy.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 9ad5d6ed

drivers/iommu/dma-iommu.c

+35 −30
Original line number Diff line number Diff line
@@ -972,35 +972,14 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr, 
	__iommu_dma_free(dev, size, cpu_addr);

}



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

		dma_addr_t *handle, gfp_t gfp, unsigned long attrs)

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

		struct page **pagep, gfp_t gfp, unsigned long attrs)

{

	bool coherent = dev_is_dma_coherent(dev);

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

	size_t alloc_size = PAGE_ALIGN(size);

	struct page *page = NULL;

	void *cpu_addr;



	gfp |= __GFP_ZERO;



	if (gfpflags_allow_blocking(gfp) &&

	    !(attrs & DMA_ATTR_FORCE_CONTIGUOUS))

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



	if (!gfpflags_allow_blocking(gfp) && !coherent) {

		cpu_addr = dma_alloc_from_pool(alloc_size, &page, gfp);

		if (!cpu_addr)

			return NULL;



		*handle = __iommu_dma_map(dev, page_to_phys(page), size,

					  ioprot);

		if (*handle == DMA_MAPPING_ERROR) {

			dma_free_from_pool(cpu_addr, alloc_size);

			return NULL;

		}

		return cpu_addr;

	}



	if (gfpflags_allow_blocking(gfp))

		page = dma_alloc_from_contiguous(dev, alloc_size >> PAGE_SHIFT,

						 get_order(alloc_size),
@@ -1010,33 +989,59 @@ static void *iommu_dma_alloc(struct device *dev, size_t size, 
	if (!page)

		return NULL;



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

	if (*handle == DMA_MAPPING_ERROR)

		goto out_free_pages;



	if (!coherent || PageHighMem(page)) {

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



		cpu_addr = dma_common_contiguous_remap(page, alloc_size,

				VM_USERMAP, prot, __builtin_return_address(0));

		if (!cpu_addr)

			goto out_unmap;

			goto out_free_pages;



		if (!coherent)

			arch_dma_prep_coherent(page, size);

	} else {

		cpu_addr = page_address(page);

	}



	*pagep = page;

	memset(cpu_addr, 0, alloc_size);

	return cpu_addr;

out_unmap:

	__iommu_dma_unmap(dev, *handle, size);

out_free_pages:

	if (!dma_release_from_contiguous(dev, page, alloc_size >> PAGE_SHIFT))

		__free_pages(page, get_order(alloc_size));

	return NULL;

}



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

		dma_addr_t *handle, gfp_t gfp, unsigned long attrs)

{

	bool coherent = dev_is_dma_coherent(dev);

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

	struct page *page = NULL;

	void *cpu_addr;



	gfp |= __GFP_ZERO;



	if (gfpflags_allow_blocking(gfp) &&

	    !(attrs & DMA_ATTR_FORCE_CONTIGUOUS))

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



	if (!gfpflags_allow_blocking(gfp) && !coherent)

		cpu_addr = dma_alloc_from_pool(PAGE_ALIGN(size), &page, gfp);

	else

		cpu_addr = iommu_dma_alloc_pages(dev, size, &page, gfp, attrs);

	if (!cpu_addr)

		return NULL;



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

	if (*handle == DMA_MAPPING_ERROR) {

		__iommu_dma_free(dev, size, cpu_addr);

		return NULL;

	}



	return cpu_addr;

}



static int __iommu_dma_mmap_pfn(struct vm_area_struct *vma,

			      unsigned long pfn, size_t size)

{

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