Re: [PATCH v2 00/17] arm64: Self-hosted trace related errata workarounds

From: Will Deacon
Date: Fri Oct 08 2021 - 05:53:05 EST


On Fri, Oct 08, 2021 at 10:25:03AM +0100, Suzuki K Poulose wrote:
> Hi Will
>
> On 08/10/2021 08:32, Will Deacon wrote:
> > Hi Suzuki,
> >
> > On Tue, Sep 21, 2021 at 02:41:04PM +0100, Suzuki K Poulose wrote:
> > > This series adds CPU erratum work arounds related to the self-hosted
> > > tracing. The list of affected errata handled in this series are :
> > >
> > > * TRBE may overwrite trace in FILL mode
> > > - Arm Neoverse-N2 #2139208
> > > - Cortex-A710 #211985
> > >
> > > * A TSB instruction may not flush the trace completely when executed
> > > in trace prohibited region.
> > >
> > > - Arm Neoverse-N2 #2067961
> > > - Cortex-A710 #2054223
> > >
> > > * TRBE may write to out-of-range address
> > > - Arm Neoverse-N2 #2253138
> > > - Cortex-A710 #2224489
> > >
> > > The series applies on the self-hosted/trbe fixes posted here [0].
> > > A tree containing both the series is available here [1]
> >
> > Any chance you could put the arch/arm64/ bits at the start of the series,
> > please? That way, I can queue them on their own branch which can be shared
> > with the coresight tree.
>
> I could move the bits around. I have a question though.
>
> Will, Catalin, Mathieu,
>
> The workaround for these errata, at least two of them are
> in the TRBE driver patches. Are we happy with enabling the Kconfig
> entry in the kernel, without the CoreSight patches to implement the work
> around ?

I suppose you could move all the Kconfig changes into their own patch and
stick it right at the end in the Coresight tree.

Will