[PATCH v4 3/7] [RFC] arm/arm64: introduce is_dma_coherent

[Will Deacon]

On Fri, Oct 10, 2014 at 12:51:44PM +0100, Stefano Stabellini wrote:
> Introduce a function to check whether a device is dma coherent.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
> CC: linux at arm.linux.org.uk
> CC: catalin.marinas at arm.com
> CC: will.deacon at arm.com
> CC: linux-arm-kernel at lists.infradead.org
> ---
>  arch/arm/include/asm/dma-mapping.h   |    6 ++++++
>  arch/arm64/include/asm/dma-mapping.h |    5 +++++
>  2 files changed, 11 insertions(+)
> 
> diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
> index c45b61a..bededbb 100644
> --- a/arch/arm/include/asm/dma-mapping.h
> +++ b/arch/arm/include/asm/dma-mapping.h
> @@ -126,6 +126,12 @@ static inline int set_arch_dma_coherent_ops(struct device *dev)
>  	set_dma_ops(dev, &arm_coherent_dma_ops);
>  	return 0;
>  }
> +
> +static inline bool is_dma_coherent(struct device *dev)
> +{
> +    return (__generic_dma_ops(dev) == &arm_coherent_dma_ops);
> +}

Hmm, what about the IOMMU ops?

Will