[PATCH 23/23] ARM: dma-mapping: Drop GFP_COMP for DMA memory allocations
From: Hiroshi Doyu <hidden>
Date: 2013-06-26 09:28:26
Also in:
linux-iommu, linux-tegra
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
arm_iommu_alloc_attrs wants to split pages after allocation in order to reduce the memory footprint. This does not work well with GFP_COMP pages, so drop this flag before allocation. (ref: ea2e7057c0234cfb8b09467d8f137760d371fc72) Signed-off-by: Hiroshi Doyu <redacted> --- arch/arm/mm/dma-mapping.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7f9b179..cad35a3 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c@@ -1322,6 +1322,13 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size, struct page **pages; void *addr = NULL; + /* Following is a work-around (a.k.a. hack) to prevent pages + * with __GFP_COMP being passed to split_page() which cannot + * handle them. The real problem is that this flag probably + * should be 0 on ARM as it is not supported on this + * platform--see CONFIG_HUGETLB_PAGE. */ + gfp &= ~(__GFP_COMP); + *handle = DMA_ERROR_CODE; size = PAGE_ALIGN(size);
--
1.8.1.5