Re: [PATCH v6 10/10] arm_mpam: detect and enable MPAM-Fb PCC support

[Andre Przywara]

Hi Ben,

On 7/31/26 10:22, Ben Horgan wrote:
> Hi Andre,
>
> On 7/31/26 09:16, Andre Przywara wrote:
> > Hi Ben,
> >
> > On 7/30/26 18:13, Ben Horgan wrote:
> > > Hi Andre,
> > >
> > > On 7/30/26 16:25, Andre Przywara wrote:
> > > > The Arm MPAM-Fb specification [1] describes a protocol to access MSC
> > > > registers through a firmware interface. This requires a shared memory
> > > > region to hold the message, and a mailbox to trigger the access.
> > > > For ACPI this is wrapped as a PCC channel, described using existing
> > > > ACPI abstractions.
> > > >
> > > > Add code to parse those PCC table descriptions associated with an MSC,
> > > > and store the parsed information in the MSC struct.
> > > > There can be multiple PCC channels, and each channel can serve multiple
> > > > MSCs, so we need to keep track of the channel usage, using a list and
> > > > a refcount.
> > > >
> > > > This will be used by the MPAM-Fb access wrapper code.
> > > >
> > > > [1] https://developer.arm.com/documentation/den0144/latest
> > > >
> > > > Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> > > > Tested-by: Ritwick Sharma <ritwick.sharma@xxxxxxx>
> > > Ritwick gave his Tested-by for the series on v5. Any reason to just add the tag on this patch?
> >
> > submitting-patches.rst says:
> > "Both Tested-by and Reviewed-by tags, once received on mailing list from tester or reviewer, should
> > be added by author to the *applicable* patches when sending next versions."
> >
> > I think this system relies on MPAM-Fb, so he couldn't test each patch in isolation, but "just" that
> > MPAM-Fb works, which is what only patch 10/10 enables.
> >
> > So I find tags given for the whole series always tricky to handle, but in this case I figured patch
> > 10/10 would be the right target.
>
> Ok, yes. I agree with that principle - I'm still learning how these things are done. Perhaps patch 8
> would have been relevant too.

That's actually a good point, will do this.

Thanks,
Andre

> > > I guess patch 9 has significant enough changes to drop tags but I don't see it for the others.
> >
> > Well, even smaller changes could ruin a whole thing, but IIUC in this case Ritwick's setup doesn't
> > even enable error IRQs, so this part wasn't tested anyway.
>
>
> > Cheers,
> > Andre.