Re: [PATCH 1/3] dma-direct: unify the dma_capable definitions

[Michael Ellerman <mpe@ellerman.id.au>]

Christoph Hellwig <hch@lst.de> writes:
> Currently each architectures that wants to override dma_to_phys and
> phys_to_dma also has to provide dma_capable.  But there isn't really
> any good reason for that.  powerpc and mips just have copies of the
> generic one minus the latests fix, and the arm one was the inspiration
> for said fix, but misses the bus_dma_mask handling.
> Make all architectures use the generic version instead.
>
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/arm/include/asm/dma-direct.h     | 19 -------------------
>  arch/mips/include/asm/dma-direct.h    |  8 --------
>  arch/powerpc/include/asm/dma-direct.h |  9 ---------

Looks OK to me.

Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

cheers

> diff --git a/arch/arm/include/asm/dma-direct.h b/arch/arm/include/asm/dma-direct.h
> index b67e5fc1fe43..7c3001a6a775 100644
> --- a/arch/arm/include/asm/dma-direct.h
> +++ b/arch/arm/include/asm/dma-direct.h
> @@ -14,23 +14,4 @@ static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
>  	return __pfn_to_phys(dma_to_pfn(dev, dev_addr)) + offset;
>  }
>  
> -static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
> -{
> -	u64 limit, mask;
> -
> -	if (!dev->dma_mask)
> -		return 0;
> -
> -	mask = *dev->dma_mask;
> -
> -	limit = (mask + 1) & ~mask;
> -	if (limit && size > limit)
> -		return 0;
> -
> -	if ((addr | (addr + size - 1)) & ~mask)
> -		return 0;
> -
> -	return 1;
> -}
> -
>  #endif /* ASM_ARM_DMA_DIRECT_H */
> diff --git a/arch/mips/include/asm/dma-direct.h b/arch/mips/include/asm/dma-direct.h
> index b5c240806e1b..14e352651ce9 100644
> --- a/arch/mips/include/asm/dma-direct.h
> +++ b/arch/mips/include/asm/dma-direct.h
> @@ -2,14 +2,6 @@
>  #ifndef _MIPS_DMA_DIRECT_H
>  #define _MIPS_DMA_DIRECT_H 1
>  
> -static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
> -{
> -	if (!dev->dma_mask)
> -		return false;
> -
> -	return addr + size - 1 <= *dev->dma_mask;
> -}
> -
>  dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr);
>  phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t daddr);
>  
> diff --git a/arch/powerpc/include/asm/dma-direct.h b/arch/powerpc/include/asm/dma-direct.h
> index a2912b47102c..e29e8a236b8d 100644
> --- a/arch/powerpc/include/asm/dma-direct.h
> +++ b/arch/powerpc/include/asm/dma-direct.h
> @@ -2,15 +2,6 @@
>  #ifndef ASM_POWERPC_DMA_DIRECT_H
>  #define ASM_POWERPC_DMA_DIRECT_H 1
>  
> -static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
> -{
> -	if (!dev->dma_mask)
> -		return false;
> -
> -	return addr + size - 1 <=
> -		min_not_zero(*dev->dma_mask, dev->bus_dma_mask);
> -}
> -
>  static inline dma_addr_t __phys_to_dma(struct device *dev, phys_addr_t paddr)
>  {
>  	if (!dev)
> diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
> index 6db863c3eb93..991f8aa2676e 100644
> --- a/include/linux/dma-direct.h
> +++ b/include/linux/dma-direct.h
> @@ -24,6 +24,7 @@ static inline phys_addr_t __dma_to_phys(struct device *dev, dma_addr_t dev_addr)
>  
>  	return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
>  }
> +#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
>  
>  static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
>  {
> @@ -38,7 +39,6 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
>  
>  	return end <= min_not_zero(*dev->dma_mask, dev->bus_dma_mask);
>  }
> -#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
>  
>  #ifdef CONFIG_ARCH_HAS_FORCE_DMA_UNENCRYPTED
>  bool force_dma_unencrypted(struct device *dev);
> -- 
> 2.20.1