On Friday 02 May 2014 10:58 AM, Russell King - ARM Linux wrote: > On Thu, Apr 24, 2014 at 11:30:05AM -0400, Santosh Shilimkar wrote: >> diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h >> index e701a4d..424fda9 100644 >> --- a/arch/arm/include/asm/dma-mapping.h >> +++ b/arch/arm/include/asm/dma-mapping.h >> @@ -58,22 +58,35 @@ 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); >> + if (!dev) >> + return (dma_addr_t)__pfn_to_bus(pfn); >> + else >> + return (dma_addr_t)__pfn_to_bus(pfn - dev->dma_pfn_offset); > > I really don't trust gcc to do this right, so I think it would be better > to make life easier on the compiler: > > if (dev) > pfn -= dev->dma_pfn_offset; > return (dma_addr_t)__pfn_to_bus(pfn); > This looks better. Will udpate with above. >> static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr) >> { >> - return __bus_to_pfn(addr); >> + if (!dev) >> + return __bus_to_pfn(addr); >> + else >> + return __bus_to_pfn(addr) + dev->dma_pfn_offset; > > and: > > unsigned long pfn = __bus_to_pfn(addr); > > if (dev) > pfn += dev->dma_pfn_offset; > > return pfn; > Ok.. >> } >> >> static inline void *dma_to_virt(struct device *dev, dma_addr_t addr) >> { >> - return (void *)__bus_to_virt((unsigned long)addr); >> + if (!dev) >> + return (void *)__bus_to_virt((unsigned long)addr); >> + else >> + return (void *)__bus_to_virt(__pfn_to_bus(dma_to_pfn(dev, addr))); > > This is quite horrendous. There's easier ways to do this... I assume > you haven't looked at the assembler resulting from this at all with > stuff like the p2v patching enabled? > I haven't. Will check. >> } >> >> static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) >> { >> - return (dma_addr_t)__virt_to_bus((unsigned long)(addr)); >> + if (!dev) >> + return (dma_addr_t)__virt_to_bus((unsigned long)(addr)); >> + else >> + return pfn_to_dma(dev, >> + __bus_to_pfn(__virt_to_bus((unsigned long)(addr)))); > > Same here. > ok. Thanks !! Regards, Santosh -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html