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Commit 92f66f84 authored by Catalin Marinas's avatar Catalin Marinas
Browse files

arm64: Fix the DMA mmap and get_sgtable API with DMA_ATTR_FORCE_CONTIGUOUS 



While honouring the DMA_ATTR_FORCE_CONTIGUOUS on arm64 (commit
44176bb3: "arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to
IOMMU"), the existing uses of dma_mmap_attrs() and dma_get_sgtable()
have been broken by passing a physically contiguous vm_struct with an
invalid pages pointer through the common iommu API.

Since the coherent allocation with DMA_ATTR_FORCE_CONTIGUOUS uses CMA,
this patch simply reuses the existing swiotlb logic for mmap and
get_sgtable.

Note that the current implementation of get_sgtable (both swiotlb and
iommu) is broken if dma_declare_coherent_memory() is used since such
memory does not have a corresponding struct page. To be addressed in a
subsequent patch.

Fixes: 44176bb3 ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU")
Reported-by: default avatarAndrzej Hajda <a.hajda@samsung.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: default avatarRobin Murphy <robin.murphy@arm.com>
Tested-by: default avatarAndrzej Hajda <a.hajda@samsung.com>
Reviewed-by: default avatarAndrzej Hajda <a.hajda@samsung.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 2f9a0bec

arch/arm64/mm/dma-mapping.c

+49 −16
Original line number Diff line number Diff line
@@ -308,24 +308,15 @@ static void __swiotlb_sync_sg_for_device(struct device *dev, 
				       sg->length, dir);

}



static int __swiotlb_mmap(struct device *dev,

			  struct vm_area_struct *vma,

			  void *cpu_addr, dma_addr_t dma_addr, size_t size,

			  unsigned long attrs)

static int __swiotlb_mmap_pfn(struct vm_area_struct *vma,

			      unsigned long pfn, size_t size)

{

	int ret = -ENXIO;

	unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >>

					PAGE_SHIFT;

	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;

	unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;

	unsigned long off = vma->vm_pgoff;



	vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,

					     is_device_dma_coherent(dev));



	if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))

		return ret;



	if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {

		ret = remap_pfn_range(vma, vma->vm_start,

				      pfn + off,
@@ -336,19 +327,43 @@ static int __swiotlb_mmap(struct device *dev, 
	return ret;

}



static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,

				 void *cpu_addr, dma_addr_t handle, size_t size,

static int __swiotlb_mmap(struct device *dev,

			  struct vm_area_struct *vma,

			  void *cpu_addr, dma_addr_t dma_addr, size_t size,

			  unsigned long attrs)

{

	int ret;

	unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT;



	vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,

					     is_device_dma_coherent(dev));



	if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))

		return ret;



	return __swiotlb_mmap_pfn(vma, pfn, size);

}



static int __swiotlb_get_sgtable_page(struct sg_table *sgt,

				      struct page *page, size_t size)

{

	int ret = sg_alloc_table(sgt, 1, GFP_KERNEL);



	if (!ret)

		sg_set_page(sgt->sgl, phys_to_page(dma_to_phys(dev, handle)),

			    PAGE_ALIGN(size), 0);

		sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);



	return ret;

}



static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,

				 void *cpu_addr, dma_addr_t handle, size_t size,

				 unsigned long attrs)

{

	struct page *page = phys_to_page(dma_to_phys(dev, handle));



	return __swiotlb_get_sgtable_page(sgt, page, size);

}



static int __swiotlb_dma_supported(struct device *hwdev, u64 mask)

{

	if (swiotlb)
@@ -703,6 +718,15 @@ static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, 
	if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))

		return ret;



	if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {

		/*

		 * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,

		 * hence in the vmalloc space.

		 */

		unsigned long pfn = vmalloc_to_pfn(cpu_addr);

		return __swiotlb_mmap_pfn(vma, pfn, size);

	}



	area = find_vm_area(cpu_addr);

	if (WARN_ON(!area || !area->pages))

		return -ENXIO;
@@ -717,6 +741,15 @@ static int __iommu_get_sgtable(struct device *dev, struct sg_table *sgt, 
	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;

	struct vm_struct *area = find_vm_area(cpu_addr);



	if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {

		/*

		 * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,

		 * hence in the vmalloc space.

		 */

		struct page *page = vmalloc_to_page(cpu_addr);

		return __swiotlb_get_sgtable_page(sgt, page, size);

	}



	if (WARN_ON(!area || !area->pages))

		return -ENXIO;