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

From: Hanjun Guo
Date: Wed Jan 13 2016 - 04:16:15 EST

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

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.