Re: [PATCH v3 2/2] perf: arm_pmu_acpi: Support heterogeneous ACPI systems

[Leo Yan <leo.yan@arm.com>]

Hi Johnny,

On Mon, Nov 02, 2026 at 04:41:52PM +0800, Johnny.Fan wrote:

[...]

> Group the CPUs by (hetero id, interrupt) and register one platform
> device per group. A GSI may be shared between groups with
> non-overlapping CPU masks, so only unregister the GSI mapping once no
> successfully registered device uses it, as the mapping is not reference
> counted.

This is fine for me in general. For CPU grouping, we would prefter to
use MIDR rather than hetid, as events should be able to migrate between
CPUs with the same MIDR.

My concern is that we need particular change in SPE/TRBE drivers to
retrieve IRQ affinity based on this change. It is better to improve
fwnode layer to provide a general way for retrieve IRQ affinity. I did
a bit experiment with using swnode and seems it makes sense.

I would also consolidate CPU PMU device registration. That means we need
to extend the device registration to support SPI. We also need to update
PMU platform driver for ACPI device probe.

Based on above idea, I would fold your patch into my series (but I will
drop the first patch for changing TRBE/SPE drivers). I will keep you as
the author but please bear me a bit that I may refactor it to fit into
the extensions. Hope this is fine for you.

Thanks,
Leo