Re: [PATCH v5 0/4] arm64: SPE ACPI enablement
From: Will Deacon
Date: Thu Jun 27 2019 - 12:47:14 EST
On Wed, Jun 26, 2019 at 04:37:14PM -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.
> We also add 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.
> v4->v5: Remove error returns from arm_spe_acpi_register_device()
> Add some review/test tags
Cheers, I've pushed this out with the acks and typo fixes.
Please let me know if you spot any problems.