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authorRichard Zhao <rizhao@nvidia.com>2013-06-20 20:31:00 +0800
committerMarek Szyprowski <m.szyprowski@samsung.com>2013-06-28 15:14:29 +0200
commit5b91a98c61abe914e6a80d7dc15e435c47ea0004 (patch)
treec3008ef76f84869617457031453e79e56686a543 /arch/arm
parent63c181922f25371b7d24ef63d4e15887ff23a088 (diff)
downloadlinux-0-day-5b91a98c61abe914e6a80d7dc15e435c47ea0004.tar.gz
linux-0-day-5b91a98c61abe914e6a80d7dc15e435c47ea0004.tar.xz
ARM: dma: Drop __GFP_COMP for iommu dma memory allocations
__iommu_alloc_buffer 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 One failure example is snd_malloc_dev_pages call dma_alloc_coherent with __GFP_COMP. Signed-off-by: Richard Zhao <rizhao@nvidia.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/mm/dma-mapping.c9
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 97926b1277b2c..22c7d7eb35a0e 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1328,6 +1328,15 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
if (gfp & GFP_ATOMIC)
return __iommu_alloc_atomic(dev, size, handle);
+ /*
+ * 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_HUGETLBFS.
+ */
+ gfp &= ~(__GFP_COMP);
+
pages = __iommu_alloc_buffer(dev, size, gfp, attrs);
if (!pages)
return NULL;