Re: [PATCH v4 1/9] dt-bindings: host1x: Add iommu-map property

[Mikko Perttunen]

On 3/1/22 20:12, Robin Murphy wrote:
> On 2022-03-01 16:14, cyndis@xxxxxxxx wrote:
> > From: Mikko Perttunen <mperttunen@xxxxxxxxxx>
> >
> > Add schema information for specifying context stream IDs. This uses
> > the standard iommu-map property.
> >
> > Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
> > ---
> > v3:
> > * New patch
> > v4:
> > * Remove memory-contexts subnode.
> > ---
> >   .../bindings/display/tegra/nvidia,tegra20-host1x.yaml        | 5 +++++
> >   1 file changed, 5 insertions(+)
> >
> > diff --git 
> > a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.yaml 
> > b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.yaml 
> >
> > index 4fd513efb0f7..0adeb03b9e3a 100644
> > --- 
> > a/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.yaml 
> >
> > +++ 
> > b/Documentation/devicetree/bindings/display/tegra/nvidia,tegra20-host1x.yaml 
> >
> > @@ -144,6 +144,11 @@ allOf:
> >           reset-names:
> >             maxItems: 1
> > +        iommu-map:
> > +          description: Specification of stream IDs available for 
> > memory context device
> > +            use. Should be a mapping of IDs 0..n to IOMMU entries 
> > corresponding to
>
> Nit: maybe "context IDs 0..n" for maximum possible clarity?

I left it at "IDs" since there is no "context ID" or similar concept in 
the hardware, so I thought to leave it just as a kind of an 'abstract ID 
as used in iommu-map property'.

> Either way, though, I'm happy that if the simplest and most 
> straightforward approach works, then it's the best choice.

I am happy as well, this is certainly much cleaner than the mess in the 
downstream driver :)

> Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>
>
> Cheers,
> Robin.

Thanks!
Mikko

> > +            usable stream IDs.
> > +
> >         required:
> >           - reg-names