[PATCH 07/11] powerpc: make dma_cache_sync a no-op

[Christophe LEROY]

Le 03/10/2017 à 12:43, Christoph Hellwig a écrit :
> powerpc does not implement DMA_ATTR_NON_CONSISTENT allocations, so it
> doesn't make any sense to do any work in dma_cache_sync given that it
> must be a no-op when dma_alloc_attrs returns coherent memory.
What about arch/powerpc/mm/dma-noncoherent.c ?

Powerpc 8xx doesn't have coherent memory.

Christophe

> 
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> ---
>   arch/powerpc/include/asm/dma-mapping.h | 2 --
>   1 file changed, 2 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
> index eaece3d3e225..320846442bfb 100644
> --- a/arch/powerpc/include/asm/dma-mapping.h
> +++ b/arch/powerpc/include/asm/dma-mapping.h
> @@ -144,8 +144,6 @@ static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
>   static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
>   		enum dma_data_direction direction)
>   {
> -	BUG_ON(direction == DMA_NONE);
> -	__dma_sync(vaddr, size, (int)direction);
>   }
>   
>   #endif /* __KERNEL__ */
>