From mboxrd@z Thu Jan 1 00:00:00 1970 From: Santosh Shilimkar Subject: [PATCH v2 5/7] ARM: dma: Use dma_pfn_offset for dma address translation Date: Sat, 19 Apr 2014 10:32:50 -0400 Message-ID: <1397917972-6293-6-git-send-email-santosh.shilimkar@ti.com> References: <1397917972-6293-1-git-send-email-santosh.shilimkar@ti.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1397917972-6293-1-git-send-email-santosh.shilimkar@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, Grygorii Strashko , Greg Kroah-Hartman , Russell King , Arnd Bergmann , Olof Johansson , Grant Likely , Rob Herring , Catalin Marinas , Linus Walleij , Santosh Shilimkar List-Id: devicetree@vger.kernel.org From: Grygorii Strashko 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 Cc: Russell King Cc: Arnd Bergmann Cc: Olof Johansson Cc: Grant Likely Cc: Rob Herring Cc: Catalin Marinas Cc: Linus Walleij Signed-off-by: Grygorii Strashko Signed-off-by: Santosh Shilimkar --- arch/arm/include/asm/dma-mapping.h | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index e701a4d..8c12149 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -58,22 +58,31 @@ 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_ERROR_CODE; + 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 0; + 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 NULL; + 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_ERROR_CODE; + return pfn_to_dma(dev, + __bus_to_pfn(__virt_to_bus((unsigned long)(addr)))); } #else -- 1.7.9.5