| Message ID | a82d2ce0db8d1511ea91bb37ef8432ce33b4719e.1438363644.git.robin.murphy@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Jul 31, 2015 at 06:28:34PM +0100, Robin Murphy wrote: > 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> > Signed-off-by: Robin Murphy <robin.murphy@arm.com> > --- > arch/arm64/mm/dma-mapping.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index e5d74cd..0bcc4bc 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -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; Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index e5d74cd..0bcc4bc 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -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;
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> Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- arch/arm64/mm/dma-mapping.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)