Re: [PATCH v2] perf: arm_spe: Support heterogeneous ACPI systems

[Leo Yan]

On Wed, Oct 21, 2026 at 10:03:22AM +0800, Johnny.Fan wrote:

> These synthetic devices have no fwnode, so the firmware-described
> IRQ affinity cannot tell which CPUs implement the feature. Pass the
> CPU mask as platform data and have the drivers prefer it over the
> IRQ affinity when present.

Could the MADT-derived CPU masks be exposed through
platform_get_irq_affinity(), so SPE and TRBE can continue using the
common interface without fetching ACPI-specific data?

TBC, I don't know ACPI or GIC. I just thought it might be a neat
approach.

> Apply the same treatment to TRBE, which shares this registration
> code. TRBE must also pass a stable copy of the mask to
> request_percpu_irq_affinity(), since supported_cpus is pruned as
> CPUs are probed.

I wouldn't expect any changes to the SPE or TRBE drivers if
platform_get_irq_affinity() can return the correct CPU mask.

Thanks,
Leo