[PATCH v2] dma-mapping: Provide write-combine allocations

[Thierry Reding]

On Fri, Jun 27, 2014 at 11:56:58AM +0200, Thierry Reding wrote:
> From: Thierry Reding <treding at nvidia.com>
> 
> Provide an implementation for dma_{alloc,free,mmap}_writecombine() when
> the architecture supports DMA attributes.
> 
> Signed-off-by: Thierry Reding <treding at nvidia.com>
> ---
> Changes in v2:
> - Add a generic dma_mmap_writecombine() function
> 
>  arch/arm/include/asm/dma-mapping.h       | 16 ----------------
>  include/asm-generic/dma-mapping-common.h |  8 --------
>  include/linux/dma-mapping.h              | 26 ++++++++++++++++++++++++++
>  3 files changed, 26 insertions(+), 24 deletions(-)

Ping?

> diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
> index c45b61a4b4a5..85738b200023 100644
> --- a/arch/arm/include/asm/dma-mapping.h
> +++ b/arch/arm/include/asm/dma-mapping.h
> @@ -265,22 +265,6 @@ extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
>  			void *cpu_addr, dma_addr_t dma_addr, size_t size,
>  			struct dma_attrs *attrs);
>  
> -static inline void *dma_alloc_writecombine(struct device *dev, size_t size,
> -				       dma_addr_t *dma_handle, gfp_t flag)
> -{
> -	DEFINE_DMA_ATTRS(attrs);
> -	dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
> -	return dma_alloc_attrs(dev, size, dma_handle, flag, &attrs);
> -}
> -
> -static inline void dma_free_writecombine(struct device *dev, size_t size,
> -				     void *cpu_addr, dma_addr_t dma_handle)
> -{
> -	DEFINE_DMA_ATTRS(attrs);
> -	dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
> -	return dma_free_attrs(dev, size, cpu_addr, dma_handle, &attrs);
> -}
> -
>  /*
>   * This can be called during early boot to increase the size of the atomic
>   * coherent DMA pool above the default value of 256KiB. It must be called
> diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h
> index de8bf89940f8..d137431bf26f 100644
> --- a/include/asm-generic/dma-mapping-common.h
> +++ b/include/asm-generic/dma-mapping-common.h
> @@ -205,14 +205,6 @@ dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr,
>  
>  #define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, NULL)
>  
> -static inline int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
> -		      void *cpu_addr, dma_addr_t dma_addr, size_t size)
> -{
> -	DEFINE_DMA_ATTRS(attrs);
> -	dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
> -	return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, &attrs);
> -}
> -
>  int
>  dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
>  		       void *cpu_addr, dma_addr_t dma_addr, size_t size);
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index 931b70986272..d5d388160f42 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -263,6 +263,32 @@ struct dma_attrs;
>  #define dma_unmap_sg_attrs(dev, sgl, nents, dir, attrs) \
>  	dma_unmap_sg(dev, sgl, nents, dir)
>  
> +#else
> +static inline void *dma_alloc_writecombine(struct device *dev, size_t size,
> +					   dma_addr_t *dma_addr, gfp_t gfp)
> +{
> +	DEFINE_DMA_ATTRS(attrs);
> +	dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
> +	return dma_alloc_attrs(dev, size, dma_addr, gfp, &attrs);
> +}
> +
> +static inline void dma_free_writecombine(struct device *dev, size_t size,
> +					 void *cpu_addr, dma_addr_t dma_addr)
> +{
> +	DEFINE_DMA_ATTRS(attrs);
> +	dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
> +	return dma_free_attrs(dev, size, cpu_addr, dma_addr, &attrs);
> +}
> +
> +static inline int dma_mmap_writecombine(struct device *dev,
> +					struct vm_area_struct *vma,
> +					void *cpu_addr, dma_addr_t dma_addr,
> +					size_t size)
> +{
> +	DEFINE_DMA_ATTRS(attrs);
> +	dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
> +	return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, &attrs);
> +}
>  #endif /* CONFIG_HAVE_DMA_ATTRS */
>  
>  #ifdef CONFIG_NEED_DMA_MAP_STATE
> -- 
> 2.0.0
> 
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