arm64: dma-mapping: Simplify pgprot handling

Since __get_dma_pgprot() does The Right Thing(TM) in the non-coherent
case, and the non-cacheable alias for DMA buffers is private to the
kernel anyway, we can simplify things slightly and make the code more
readable by just using PAGE_KERNEL as the base pgprot.

Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Robin Murphy 2015-07-31 18:28:34 +01:00 committed by Will Deacon
parent b511a65928
commit 97942c2862

View File

@ -144,6 +144,7 @@ static void *__dma_alloc(struct device *dev, size_t size,
struct page *page;
void *ptr, *coherent_ptr;
bool coherent = is_device_dma_coherent(dev);
pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, false);
size = PAGE_ALIGN(size);
@ -171,9 +172,7 @@ static void *__dma_alloc(struct device *dev, size_t size,
/* create a coherent mapping */
page = virt_to_page(ptr);
coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP,
__get_dma_pgprot(attrs,
__pgprot(PROT_NORMAL_NC), false),
NULL);
prot, NULL);
if (!coherent_ptr)
goto no_map;