dma_generic_alloc_coherent() firstly attempts to allocate by
dma_alloc_from_contiguous() if CONFIG_DMA_CMA is enabled. But the memory
region allocated by it may not fit within the device's DMA mask.
This change makes it fall back to usual alloc_pages_node() allocation
for such cases.
Signed-off-by: Akinobu Mita <akinobu.m...@gmail.com>
Cc: Marek Szyprowski <m.szyprow...@samsung.com>
Cc: Konrad Rzeszutek Wilk <konrad.w...@oracle.com>
Cc: David Woodhouse <dw...@infradead.org>
Cc: Don Dutile <ddut...@redhat.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Ingo Molnar <mi...@redhat.com>
Cc: "H. Peter Anvin" <h...@zytor.com>
Cc: Andi Kleen <a...@firstfloor.org>
Cc: x...@kernel.org
Cc: io...@lists.linux-foundation.org
---
arch/x86/kernel/pci-dma.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index a0ffe44..f15bf8d 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -100,8 +100,13 @@ void *dma_generic_alloc_coherent(struct device *dev,
size_t size,
again:
page = NULL;
/* CMA can be used only in the context which permits sleeping */
- if (flag & __GFP_WAIT)
+ if (flag & __GFP_WAIT) {
page = dma_alloc_from_contiguous(dev, count, get_order(size));
+ if (page && page_to_phys(page) + size > dma_mask) {
+ dma_release_from_contiguous(dev, page, count);
+ page = NULL;
+ }
+ }
/* fallback */
if (!page)
page = alloc_pages_node(dev_to_node(dev), flag,
get_order(size));
--
1.8.3.2
--
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