From bd1c6ff74ce0bbd8cda6eb7763fa0e2625dfcc8b Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Wed, 4 Nov 2015 13:23:52 +0000 Subject: [PATCH] arm64/dma-mapping: Fix sizes in __iommu_{alloc,free}_attrs The iommu-dma layer does its own size-alignment for coherent DMA allocations based on IOMMU page sizes, but we still need to consider CPU page sizes for the cases where a non-cacheable CPU mapping is created. Whilst everything on the alloc/map path seems to implicitly align things enough to make it work, some functions used by the corresponding unmap/free path do not, which leads to problems freeing odd-sized allocations. Either way it's something we really should be handling explicitly, so do that to make both paths suitably robust. Reported-by: Yong Wu Signed-off-by: Robin Murphy Signed-off-by: Catalin Marinas --- arch/arm64/mm/dma-mapping.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index 131a199..97fd714 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -552,10 +552,14 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, { bool coherent = is_device_dma_coherent(dev); int ioprot = dma_direction_to_prot(DMA_BIDIRECTIONAL, coherent); + size_t iosize = size; void *addr; if (WARN(!dev, "cannot create IOMMU mapping for unknown device\n")) return NULL; + + size = PAGE_ALIGN(size); + /* * Some drivers rely on this, and we probably don't want the * possibility of stale kernel data being read by devices anyway. @@ -566,7 +570,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, struct page **pages; pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, coherent); - pages = iommu_dma_alloc(dev, size, gfp, ioprot, handle, + pages = iommu_dma_alloc(dev, iosize, gfp, ioprot, handle, flush_page); if (!pages) return NULL; @@ -574,7 +578,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, addr = dma_common_pages_remap(pages, size, VM_USERMAP, prot, __builtin_return_address(0)); if (!addr) - iommu_dma_free(dev, pages, size, handle); + iommu_dma_free(dev, pages, iosize, handle); } else { struct page *page; /* @@ -591,7 +595,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, if (!addr) return NULL; - *handle = iommu_dma_map_page(dev, page, 0, size, ioprot); + *handle = iommu_dma_map_page(dev, page, 0, iosize, ioprot); if (iommu_dma_mapping_error(dev, *handle)) { if (coherent) __free_pages(page, get_order(size)); @@ -606,6 +610,9 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size, static void __iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle, struct dma_attrs *attrs) { + size_t iosize = size; + + size = PAGE_ALIGN(size); /* * @cpu_addr will be one of 3 things depending on how it was allocated: * - A remapped array of pages from iommu_dma_alloc(), for all @@ -617,17 +624,17 @@ static void __iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr, * Hence how dodgy the below logic looks... */ if (__in_atomic_pool(cpu_addr, size)) { - iommu_dma_unmap_page(dev, handle, size, 0, NULL); + iommu_dma_unmap_page(dev, handle, iosize, 0, NULL); __free_from_pool(cpu_addr, size); } else if (is_vmalloc_addr(cpu_addr)){ struct vm_struct *area = find_vm_area(cpu_addr); if (WARN_ON(!area || !area->pages)) return; - iommu_dma_free(dev, area->pages, size, &handle); + iommu_dma_free(dev, area->pages, iosize, &handle); dma_common_free_remap(cpu_addr, size, VM_USERMAP); } else { - iommu_dma_unmap_page(dev, handle, size, 0, NULL); + iommu_dma_unmap_page(dev, handle, iosize, 0, NULL); __free_pages(virt_to_page(cpu_addr), get_order(size)); } } -- 2.7.4