From: Grygorii Strashko <[email protected]> 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 This patch introduces new field dma_pfn_offset in ARM dev_archdata structure which has to be filed per-device at arch init time (simplest way is to use Platform bus notifier to handle BUS_NOTIFY_ADD_DEVICE event) and updates DMA address translation routines in order to accommodate bus offset value by default. Cc: Russell King <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Olof Johansson <[email protected]> Signed-off-by: Grygorii Strashko <[email protected]> Signed-off-by: Santosh Shilimkar <[email protected]> --- arch/arm/include/asm/device.h | 1 + arch/arm/include/asm/dma-mapping.h | 17 +++++++++++++---- 2 files changed, 14 insertions(+), 4 deletions(-) diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h index dc662fc..861961c 100644 --- a/arch/arm/include/asm/device.h +++ b/arch/arm/include/asm/device.h @@ -8,6 +8,7 @@ struct dev_archdata { struct dma_map_ops *dma_ops; + unsigned long dma_pfn_offset; #ifdef CONFIG_DMABOUNCE struct dmabounce_device_info *dmabounce; #endif diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index e701a4d..247ed72 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->archdata.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->archdata.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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
