ARM: 7172/1: dma: Drop GFP_COMP for DMA memory allocations
dma_alloc_coherent 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.
This patch is ported from arch/avr32
(commit 3611553ef985ef7c5863c8a94641738addd04cff).
[swarren: s/HUGETLB_PAGE/HUGETLBFS/ in comment, minor comment cleanup]
Signed-off-by: Sumit Bhattacharya <sumitb@nvidia.com>
Tested-by: Varun Colbert <vcolbert@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index ab58456..1aa664a 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -332,6 +332,15 @@
struct page *page;
void *addr;
+ /*
+ * 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);
+
*handle = ~0;
size = PAGE_ALIGN(size);