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

Thierry Reding
2014-06-04T21:32:00Z

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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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