| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.13 105/172] x86: dma-mapping: fix GFP_ATOMIC macro usage | Date | Tue, 4 Mar 2014 12:03:09 -0800 |
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3.13-stable review patch. If anyone has any objections, please let me know.
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From: Marek Szyprowski <m.szyprowski@samsung.com>
commit c091c71ad2218fc50a07b3d1dab85783f3b77efd upstream.
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.
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- arch/x86/kernel/pci-dma.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/arch/x86/kernel/pci-dma.c +++ b/arch/x86/kernel/pci-dma.c @@ -100,8 +100,10 @@ void *dma_generic_alloc_coherent(struct 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)
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