[PATCH v8 08/19] arm/xen: get_dma_ops: return xen_dma_ops if we are running as xen_initial_domain

[Stefano Stabellini]

Russell,
are you OK with this patch?


On Thu, 17 Oct 2013, Stefano Stabellini wrote:
> We can't simply override arm_dma_ops with xen_dma_ops because devices
> are allowed to have their own dma_ops and they take precedence over
> arm_dma_ops. When running on Xen as initial domain, we always want
> xen_dma_ops to be the one in use.
> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini at eu.citrix.com>
> Suggested-by: Catalin Marinas <catalin.marinas at arm.com>
> CC: will.deacon at arm.com
> CC: linux at arm.linux.org.uk
> 
> Changes in v7:
> - return xen_dma_ops only if we are the initial domain;
> - rename __get_dma_ops to __generic_dma_ops.
> ---
>  arch/arm/include/asm/dma-mapping.h |   13 ++++++++++++-
>  1 files changed, 12 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
> index 01b5a3d..f5945d4 100644
> --- a/arch/arm/include/asm/dma-mapping.h
> +++ b/arch/arm/include/asm/dma-mapping.h
> @@ -12,17 +12,28 @@
>  #include <asm/memory.h>
>  #include <asm/cacheflush.h>
>  
> +#include <xen/xen.h>
> +#include <asm/xen/hypervisor.h>
> +
>  #define DMA_ERROR_CODE	(~0)
>  extern struct dma_map_ops arm_dma_ops;
>  extern struct dma_map_ops arm_coherent_dma_ops;
>  
> -static inline struct dma_map_ops *get_dma_ops(struct device *dev)
> +static inline struct dma_map_ops *__generic_dma_ops(struct device *dev)
>  {
>  	if (dev && dev->archdata.dma_ops)
>  		return dev->archdata.dma_ops;
>  	return &arm_dma_ops;
>  }
>  
> +static inline struct dma_map_ops *get_dma_ops(struct device *dev)
> +{
> +	if (xen_initial_domain())
> +		return xen_dma_ops;
> +	else
> +		return __generic_dma_ops(dev);
> +}
> +
>  static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops)
>  {
>  	BUG_ON(!dev);
> -- 
> 1.7.2.5
>