From mboxrd@z Thu Jan 1 00:00:00 1970 From: steve.capper@linaro.org (Steve Capper) Date: Thu, 16 Jan 2014 10:07:43 +0000 Subject: [PATCH V2] arm: mm: Remove hugetlb warning from Coherent DMA allocator Message-ID: <1389866863-24460-1-git-send-email-steve.capper@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org The Coherant DMA allocator allocates pages of high order then splits them up into smaller pages. This splitting logic would run into problems if the allocator was given compound pages. Thus the Coherant DMA allocator was originally incompatible with compound pages existing and, by extension, huge pages. A compile #error was put in place whenever huge pages were enabled. Compatibility with compound pages has since been introduced by the following commit (which merely excludes GFP_COMP pages from being requested by the coherant DMA allocator): ea2e705 ARM: 7172/1: dma: Drop GFP_COMP for DMA memory allocations When huge page support was introduced to ARM, the compile #error in dma-mapping.c was replaced by a #warning when it should have been removed instead. This patch removes the compile #warning in dma-mapping.c when huge pages are enabled. Signed-off-by: Steve Capper --- Changed in V2: commit message completely re-written to give a better justification. --- arch/arm/mm/dma-mapping.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index f61a570..8edd1b5 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -284,9 +284,6 @@ static void __dma_free_buffer(struct page *page, size_t size) } #ifdef CONFIG_MMU -#ifdef CONFIG_HUGETLB_PAGE -#warning ARM Coherent DMA allocator does not (yet) support huge TLB -#endif static void *__alloc_from_contiguous(struct device *dev, size_t size, pgprot_t prot, struct page **ret_page, -- 1.8.1.4