On Friday 29 August 2014 16:54:25 Will Deacon wrote: > set_arch_dma_coherent_ops is called from of_dma_configure in order to > swizzle the architectural dma-mapping functions over to a cache-coherent > implementation. This is currently implemented only for ARM. > > In anticipation of re-using this mechanism for IOMMU-backed dma-mapping > ops too, this patch replaces the function with a broader > arch_setup_dma_ops callback which is also responsible for setting the > DMA mask and offset as well as selecting the correct mapping functions. > > A further advantage of this split is that it nicely isolates the > of-specific code from the dma-mapping code, allowing potential reuse by > other buses (e.g. PCI) in the future. > > Signed-off-by: Will Deacon <will.dea...@arm.com>
Looks good, just one tiny comment > --- > arch/arm/include/asm/dma-mapping.h | 20 ++++++++++++++---- > drivers/of/platform.c | 42 > ++++++++++---------------------------- > include/linux/dma-mapping.h | 8 +++----- > 3 files changed, 30 insertions(+), 40 deletions(-) > > diff --git a/arch/arm/include/asm/dma-mapping.h > b/arch/arm/include/asm/dma-mapping.h > index c45b61a4b4a5..936125ef3f3f 100644 > --- a/arch/arm/include/asm/dma-mapping.h > +++ b/arch/arm/include/asm/dma-mapping.h > @@ -121,12 +121,24 @@ static inline unsigned long dma_max_pfn(struct device > *dev) > } > #define dma_max_pfn(dev) dma_max_pfn(dev) > > -static inline int set_arch_dma_coherent_ops(struct device *dev) > +static inline void arch_setup_dma_ops(struct device *dev, u64 mask, > + unsigned long offset, bool coherent) > { > - set_dma_ops(dev, &arm_coherent_dma_ops); > - return 0; > + dev->coherent_dma_mask = mask; > + > + /* > + * Set dma_mask to coherent_dma_mask by default if the architecture > + * code has not set it. > + */ > + if (!dev->dma_mask) > + dev->dma_mask = &dev->coherent_dma_mask; > + We are in architecture specific code here, and we know that this architecture has not set up the dev->dma_mask pointer, so we can remove the 'if (!dev->dma_mask)' Arnd _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu