From 92f66f84d9695d07adf9bc987bbcce4bf9b8e87c Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Tue, 25 Apr 2017 15:42:31 +0100 Subject: [PATCH] arm64: Fix the DMA mmap and get_sgtable API with DMA_ATTR_FORCE_CONTIGUOUS While honouring the DMA_ATTR_FORCE_CONTIGUOUS on arm64 (commit 44176bb38fa4: "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: 44176bb38fa4 ("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU") Reported-by: Andrzej Hajda Cc: Geert Uytterhoeven Acked-by: Robin Murphy Tested-by: Andrzej Hajda Reviewed-by: Andrzej Hajda Signed-off-by: Catalin Marinas --- arch/arm64/mm/dma-mapping.c | 65 ++++++++++++++++++++++++++++--------- 1 file changed, 49 insertions(+), 16 deletions(-) diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index f7b54019ef55..c9e53dec3695 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -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, - unsigned long attrs) +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;