arm: fix "arm: fix pci_set_consistent_dma_mask for dmabounce devices"

This fixes the regression caused by the commit 6fee48cd330c68
("dma-mapping: arm: use generic pci_set_dma_mask and
pci_set_consistent_dma_mask").

ARM needs to clip the dma coherent mask for dmabounce devices. This
restores the old trick.

Note that strictly speaking, the DMA API doesn't allow architectures to do
such but I'm not sure it's worth adding the new API to set the dma mask
that allows architectures to clip it.

Reported-by: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index ce29b8151198..ba8319ae5fcc 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -102,6 +102,9 @@ static inline u64 dma_get_mask(struct device *dev)
         return DMA_BIT_MASK(32);
 }
 
+#ifdef ARCH_HAS_DMA_SET_COHERENT_MASK
+int dma_set_coherent_mask(struct device *dev, u64 mask);
+#else
 static inline int dma_set_coherent_mask(struct device *dev, u64 mask)
 {
         if (!dma_supported(dev, mask))
@@ -109,6 +112,7 @@ static inline int dma_set_coherent_mask(struct device *dev, u64 mask)
         dev->coherent_dma_mask = mask;
         return 0;
 }
+#endif
 
 extern u64 dma_get_required_mask(struct device *dev);