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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 <yong.wu@mediatek.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Robin Murphy 2015-11-04 13:23:52 +00:00 committed by Catalin Marinas
parent 8005c49d9a
commit bd1c6ff74c
1 changed files with 13 additions and 6 deletions
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19
arch/arm64/mm/dma-mapping.c
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@ -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));
}
}