x86: dma-mapping: fix broken allocation when dma_mask has been provided

Commit 0a2b9a6ea93 ("X86: integrate CMA with DMA-mapping subsystem")
broke memory allocation with dma_mask. This patch fixes possible kernel
ops caused by lack of resetting page variable when jumping to 'again' label.

Reported-by: Konrad Rzeszutek Wilk <konrad@darnok.org>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>

diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 62c9457ccd2f1c4ccad62a757aebdcd520498cc3..c0f420f76cd3b7a65d65536735a1bee1820f89b3 100644 (file)
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -100,7 +100,7 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size,
                                 struct dma_attrs *attrs)
 {
        unsigned long dma_mask;
-       struct page *page = NULL;
+       struct page *page;
        unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
        dma_addr_t addr;
 
@@ -108,6 +108,7 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size,
 
        flag |= __GFP_ZERO;
 again:
+       page = NULL;
        if (!(flag & GFP_ATOMIC))
                page = dma_alloc_from_contiguous(dev, count, get_order(size));
        if (!page)