| Message ID | 1397917972-6293-6-git-send-email-santosh.shilimkar@ti.com |
|---|---|
| State | New |
| Headers | show |
On Sat, Apr 19, 2014 at 10:32:50AM -0400, Santosh Shilimkar 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 > > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Russell King <linux@arm.linux.org.uk> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Olof Johansson <olof@lixom.net> > Cc: Grant Likely <grant.likely@linaro.org> > Cc: Rob Herring <robh+dt@kernel.org> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Linus Walleij <linus.walleij@linaro.org> > Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> > Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> > --- > 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); How do ISA devices (iow, those which pass a NULL device) work with this? This looks to me like it ends up breaking some drivers. I've also seen some drivers (such as the Freescale FEC driver) which perform DMA coherent allocations with a NULL device - technically, that's a bug in the driver, but the above change will cause them to regress.
On Saturday 19 April 2014 03:43 PM, Russell King - ARM Linux wrote: > On Sat, Apr 19, 2014 at 10:32:50AM -0400, Santosh Shilimkar 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 >> >> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> >> Cc: Russell King <linux@arm.linux.org.uk> >> Cc: Arnd Bergmann <arnd@arndb.de> >> Cc: Olof Johansson <olof@lixom.net> >> Cc: Grant Likely <grant.likely@linaro.org> >> Cc: Rob Herring <robh+dt@kernel.org> >> Cc: Catalin Marinas <catalin.marinas@arm.com> >> Cc: Linus Walleij <linus.walleij@linaro.org> >> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> >> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> >> --- >> 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); > > How do ISA devices (iow, those which pass a NULL device) work with this? > This looks to me like it ends up breaking some drivers. > > I've also seen some drivers (such as the Freescale FEC driver) which > perform DMA coherent allocations with a NULL device - technically, that's > a bug in the driver, but the above change will cause them to regress. > Good point. We can keep the NULL case working as well... static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long 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 will update the patch accordingly. 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/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