Re: [PATCH v5 0/4] arm64: SPE ACPI enablement
From: Will Deacon <will@kernel.org>
Date: 2019-06-27 16:47:14
Also in:
linux-acpi, lkml
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. https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=for-next/perf Please let me know if you spot any problems. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel