[v2 1/1] ARM: dma-mapping: Call arm_dma_set_mask() if no ->set_dma_mask()

[hdoyu@nvidia.com (Hiroshi Doyu)]

struct dma_map_ops iommu_ops doesn't have ->set_dma_mask, which causes
crash when dma_set_mask() is called from some driver.

Signed-off-by: Hiroshi Doyu <hdoyu@nvidia.com>
---
 arch/arm/include/asm/dma-mapping.h |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 5b579b9..63cc49c 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -14,6 +14,7 @@
 #define DMA_ERROR_CODE	(~0)
 extern struct dma_map_ops arm_dma_ops;
 extern struct dma_map_ops arm_coherent_dma_ops;
+extern int arm_dma_set_mask(struct device *dev, u64 dma_mask);
 
 static inline struct dma_map_ops *get_dma_ops(struct device *dev)
 {
@@ -32,7 +33,13 @@ static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops)
 
 static inline int dma_set_mask(struct device *dev, u64 mask)
 {
-	return get_dma_ops(dev)->set_dma_mask(dev, mask);
+	struct dma_map_ops *ops = get_dma_ops(dev);
+	BUG_ON(!ops);
+
+	if (ops->set_dma_mask)
+		return ops->set_dma_mask(dev, mask);
+
+	return arm_dma_set_mask(dev, mask);
 }
 
 #ifdef __arch_page_to_dma
@@ -112,8 +119,6 @@ static inline void dma_free_noncoherent(struct device *dev, size_t size,
 
 extern int dma_supported(struct device *dev, u64 mask);
 
-extern int arm_dma_set_mask(struct device *dev, u64 dma_mask);
-
 /**
  * arm_dma_alloc - allocate consistent memory for DMA
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
-- 
1.7.9.5