| Message ID | 1393535872-20915-2-git-send-email-santosh.shilimkar@ti.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Feb 28, 2014 at 5:17 AM, Santosh Shilimkar <santosh.shilimkar@ti.com> wrote: > From: Grygorii Strashko <grygorii.strashko@ti.com> > > 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 <linux@arm.linux.org.uk> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Olof Johansson <olof@lixom.net> > Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> > Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> This looks like exactly what I need to proceed to multiplatform on Integrator. Acked-by: Linus Walleij <linus.walleij@linaro.org> Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wednesday 05 March 2014 12:45 PM, Linus Walleij wrote: > On Fri, Feb 28, 2014 at 5:17 AM, Santosh Shilimkar > <santosh.shilimkar@ti.com> wrote: > >> From: Grygorii Strashko <grygorii.strashko@ti.com> >> >> 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 <linux@arm.linux.org.uk> >> Cc: Arnd Bergmann <arnd@arndb.de> >> Cc: Olof Johansson <olof@lixom.net> >> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> >> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> > > This looks like exactly what I need to proceed to multiplatform on > Integrator. > Acked-by: Linus Walleij <linus.walleij@linaro.org> > Thanks Linus. Just to make folks aware on the thread, after some more inputs and discussion at connect, looks like we need to make this work for other arch's too. So am going to move dma_pfn_offset from archdata to device_dma_parameters so that arch code as well as driver code should be able to access/modify the pfn offset. Regards, Santosh -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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