Re: [PATCH 3/3] dma-mapping: move swiotlb dma-phys functions to common header

[Robin Murphy <robin.murphy@arm.com>]

On 17/03/16 22:02, Sinan Kaya wrote:
> Moving the default implementation of swiotlb_dma_to_phys and
> swiotlb_phys_to_dma functions to dma-mapping.h so that we can get
> rid of the duplicate code in multiple ARCH.
>
> Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
> ---
>   arch/arm64/include/asm/dma-mapping.h               | 14 --------------
>   arch/ia64/include/asm/dma-mapping.h                | 14 --------------
>   arch/mips/include/asm/mach-generic/dma-coherence.h | 16 ----------------
>   arch/tile/include/asm/dma-mapping.h                | 14 --------------
>   arch/unicore32/include/asm/dma-mapping.h           | 14 --------------
>   arch/x86/include/asm/dma-mapping.h                 | 13 -------------
>   arch/xtensa/include/asm/dma-mapping.h              | 14 --------------
>   include/linux/dma-mapping.h                        | 14 ++++++++++++++
>   8 files changed, 14 insertions(+), 99 deletions(-)

[...]

> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index 728ef07..871d620 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -683,4 +683,18 @@ static inline int dma_mmap_writecombine(struct device *dev,
>   #define dma_unmap_len_set(PTR, LEN_NAME, VAL)    do { } while (0)
>   #endif
>
> +#ifndef swiotlb_phys_to_dma
> +static inline dma_addr_t swiotlb_phys_to_dma(struct device *dev, phys_addr_t paddr)
> +{
> +         return paddr;
> +}
> +#endif
> +
> +#ifndef swiotlb_dma_to_phys
> +static inline phys_addr_t swiotlb_dma_to_phys(struct device *dev, dma_addr_t daddr)
> +{
> +        return daddr;
> +}
> +#endif
> +
>   #endif
>

Could the default definition not be pushed all the way down into 
swiotlb.c (or at least swiotlb.h)?

Robin.