Re: [PATCH v2] devicetree: Add generic IOMMU device tree bindings

[Thierry Reding <thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

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On Fri, May 30, 2014 at 09:01:19PM +0200, Arnd Bergmann wrote:
> On Friday 30 May 2014 12:22:32 Dave Martin wrote:
> > > +
> > > +Examples:
> > > +=========
> > > +
> > > +Single-master IOMMU:
> > > +--------------------
> > > +
> > > +	iommu {
> > > +		#address-cells = <0>;
> > > +		#size-cells = <0>;
> > > +	};
> > > +
> > > +	master {
> > > +		iommus = <&/iommu>;
> > > +	};
> > > +
> > > +Multiple-master IOMMU with fixed associations:
> > > +----------------------------------------------
> > > +
> > > +	/* multiple-master IOMMU */
> > > +	iommu {
> > > +		/*
> > > +		 * Masters are statically associated with this IOMMU and
> > > +		 * address translation is always enabled.
> > > +		 */
> > > +		#address-cells = <0>;
> > > +		#size-cells = <0>;
> > 
> > In this example, can different translations be set up for the different
> > masters?
> > 
> > With no cells available to contain any sort of ID, it looks like this
> > is not possible.
> 
> Correct, this example is for an IOMMU that does not use IDs but has a
> shared address space for all devices.

Couldn't these device all still have separate address spaces?

Thierry

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