[RFC 1/5] ARM: dev_archdata: add private iommu extension

[Grant Likely]

On Sun, Sep 25, 2011 at 01:58:53PM +0300, Ohad Ben-Cohen wrote:
> Add a private iommu pointer to the ARM-specific arch data in the
> device struct, which will be used to attach iommu-specific data
> to devices which require iommu support.
> 
> Different iommu implementations (on different platforms) will attach
> different types of data to this pointer, so 'void *' is currently used
> (the downside is reduced typesafety).
> 
> Note: ia64, x86 and sparc have this exact iommu extension as well, and
> if others are likely to adopt it too, we might want to consider
> adding this to the device struct itself directly.
> 
> Signed-off-by: Ohad Ben-Cohen <ohad at wizery.com>
> Cc: Russell King <linux at arm.linux.org.uk>
> Cc: Arnd Bergmann <arnd at arndb.de>
> Cc: Grant Likely <grant.likely at secretlab.ca>
> ---
>  arch/arm/include/asm/device.h |    3 +++
>  1 files changed, 3 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h
> index 9f390ce..6615f03 100644
> --- a/arch/arm/include/asm/device.h
> +++ b/arch/arm/include/asm/device.h
> @@ -10,6 +10,9 @@ struct dev_archdata {
>  #ifdef CONFIG_DMABOUNCE
>  	struct dmabounce_device_info *dmabounce;
>  #endif
> +#ifdef CONFIG_IOMMU_API
> +	void *iommu; /* private IOMMU data */
> +#endif

Blech.  Oh well.  Not much point in doing something different if x86
uses a void*.

g.