On Wednesday 31 July 2013 06:56 AM, Russell King - ARM Linux wrote:

On Fri, Jul 12, 2013 at 05:48:13PM -0400, Santosh Shilimkar wrote:

quoted

diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 5b579b9..b2d5937 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h

@@ -47,12 +47,12 @@ static inline int dma_set_mask(struct device *dev, u64 mask)
 #ifndef __arch_pfn_to_dma
 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
 {
-	return (dma_addr_t)__pfn_to_bus(pfn);
+	return (dma_addr_t)__pfn_to_bus(pfn + PHYS_PFN_OFFSET);
 }
 
 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
 {
-	return __bus_to_pfn(addr);
+	return __bus_to_pfn(addr) - PHYS_PFN_OFFSET;
 }
 
 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)

@@ -64,15 +64,16 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
 {
 	return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
 }
+
 #else
 static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
 {
-	return __arch_pfn_to_dma(dev, pfn);
+	return __arch_pfn_to_dma(dev, pfn + PHYS_PFN_OFFSET);
 }
 
 static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
 {
-	return __arch_dma_to_pfn(dev, addr);
+	return __arch_dma_to_pfn(dev, addr) - PHYS_PFN_OFFSET;
 }
 
 static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)

@@ -86,6 +87,13 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
 }
 #endif

Note that I don't think the above are correct - the 'pfn' argument to the
above functions already includes the PFN offset of physical memory -
they're all physical_address >> PAGE_SHIFT values.

Right.
Updated patch pushed into the patch system. (patch 7805/1)

Regards,
Santosh