Re: [PATCH V2 03/10] irqchip,GICv3,ACPI: Add redistributor support via GICC structures.

[Hanjun Guo]

On 2016/1/13 16:35, Marc Zyngier wrote:
> On 13/01/16 01:52, Hanjun Guo wrote:
> > On 2016/1/13 0:45, Tomasz Nowicki wrote:
> > > On 12.01.2016 13:03, Marc Zyngier wrote:
> > >
> > >   > +    typer = readq_relaxed(redist_base + GICR_TYPER);
> > >   > +    /* don't map reserved page as it's buggy to access it */
> > >   > +    size = (typer & GICR_TYPER_VLPIS) ? SZ_64K * 3 : SZ_64K * 2;
> > >
> > > [...]
> > >
> > > > Also, please map the whole region for the
> > > > redistributor as we have on the DT side (4 64kB pages for VLPIS capable
> > > > redistributors).
> > >
> > > Hanjun, is it something you had problem with?
> >
> > Yes, for D02, it use 3 64kB pages for GICv4, it removed the reserved
> > page. In DT case, it has "stride" binding so it can support no standard
> > cases, seems that we can introduce "stride" for ACPI too.
>
> I don't think there is any need for that, assuming this system only
> exposes its redistributors via the ACPI GICC structure. In which case, I
> don't think it hurts to have overlapping mappings: For redistributors A
> and B, we never touch A[3] (the reserved page), but we will access B[0].

I think so, thanks for the clarify. I think we need to clarify the spec
first and interpret it in the right way.

Thanks
Hanjun