Re: [PATCH 1/6] iommu/qcom: Use the asid read from device-tree if specified

From: Rob Clark
Date: Tue May 31 2022 - 12:15:32 EST


On Tue, May 31, 2022 at 8:46 AM Will Deacon <will@xxxxxxxxxx> wrote:
>
> On Fri, May 27, 2022 at 11:28:56PM +0200, Konrad Dybcio wrote:
> > From: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx>
> >
> > As specified in this driver, the context banks are 0x1000 apart.
> > Problem is that sometimes the context number (our asid) does not
> > match this logic and we end up using the wrong one: this starts
> > being a problem in the case that we need to send TZ commands
> > to do anything on a specific context.
>
> I don't understand this. The ASID is a software construct, so it shouldn't
> matter what we use. If it does matter, then please can you explain why? The
> fact that the context banks are 0x1000 apart seems unrelated.

I think the connection is that mapping from ctx bank to ASID is 1:1

BR,
-R