x86: dma-mapping: fix GFP_ATOMIC macro usage

GFP_ATOMIC is not a single gfp flag, but a macro which expands to the other
flags, where meaningful is the LACK of __GFP_WAIT flag. To check if caller
wants to perform an atomic allocation, the code must test for a lack of the
__GFP_WAIT flag. This patch fixes the issue introduced in v3.5-rc1.

CC: stable@vger.kernel.org
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>

diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 872079a67e4d262151dfdbe74f537033be5ebcc0..f7d0672481fd7c328682d601467313acb586280a 100644 (file)
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -100,8 +100,10 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size,
        flag |= __GFP_ZERO;
 again:
        page = NULL;
-       if (!(flag & GFP_ATOMIC))
+       /* CMA can be used only in the context which permits sleeping */
+       if (flag & __GFP_WAIT)
                page = dma_alloc_from_contiguous(dev, count, get_order(size));
+       /* fallback */
        if (!page)
                page = alloc_pages_node(dev_to_node(dev), flag, get_order(size));
        if (!page)