Re: [PATCH v3 5/7] ARM: dma: Use dma_pfn_offset for dma address translation
From: Rob Herring <hidden>
Date: 2014-05-02 14:32:59
Also in:
linux-arm-kernel, lkml
On Thu, Apr 24, 2014 at 10:30 AM, Santosh Shilimkar [off-list ref] wrote:
From: Grygorii Strashko <redacted> In most of cases DMA addresses can be performed using offset value of Bus address space relatively to physical address space as following: PFN->DMA: __pfn_to_phys(pfn + [-]dma_pfn_offset) DMA->PFN: __phys_to_pfn(dma_addr) + [-]dma_pfn_offset Cc: Greg Kroah-Hartman <redacted> Cc: Russell King <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org> Cc: Arnd Bergmann <redacted> Cc: Olof Johansson <redacted> Cc: Grant Likely <redacted> Cc: Rob Herring <redacted> Cc: Catalin Marinas <redacted> Cc: Linus Walleij <redacted> Signed-off-by: Grygorii Strashko <redacted> Signed-off-by: Santosh Shilimkar <redacted>
Reviewed-by: Rob Herring <redacted>
quoted hunk ↗ jump to hunk
--- arch/arm/include/asm/dma-mapping.h | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-)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); } 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; } 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))); } 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)))); } #else --1.7.9.5
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