Re: [PATCH v2 0/5] arm64: SPE ACPI enablement

Will Deacon
2019-05-01T14:15:25Z

Hi Jeremy,

On Fri, Apr 26, 2019 at 05:03:04PM -0500, Jeremy Linton wrote:
> This patch series enables the Arm Statistical Profiling
> Extension (SPE) on ACPI platforms.
>
> This is possible because ACPI 6.3 uses a previously
> reserved field in the MADT to store the SPE interrupt
> number, similarly to how the normal PMU is described.
> If a consistent valid interrupt exists across all the
> cores in the system, a platform device is registered.
> That then triggers the SPE module, which runs as normal.
>
> This version also adds the ability to parse the PPTT for
> IDENTICAL cores. We then use this to sanity check the
> single SPE device we create. This creates a bit of a
> problem with respect to the specification though. The
> specification says that its legal for multiple tree's
> to exist in the PPTT. We handle this fine, but what
> happens in the case of multiple tree's is that the lack
> of a common node with IDENTICAL set forces us to assume
> that there are multiple non IDENTICAL cores in the
> machine.

This looks good to me. Please can you respin, addressing Raphael's
outstanding concerns on the third patch?

Will