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. Jeremy Linton (4): ACPI/PPTT: Add function to return ACPI 6.3 Identical tokens ACPI/PPTT: Modify node flag detection to find last IDENTICAL arm_pmu: acpi: spe: Add initial MADT/SPE probing perf: arm_spe: Enable ACPI/Platform automatic module loading arch/arm64/include/asm/acpi.h | 3 ++ drivers/acpi/pptt.c | 82 ++++++++++++++++++++++++++++++----- drivers/perf/arm_pmu_acpi.c | 69 +++++++++++++++++++++++++++++ drivers/perf/arm_spe_pmu.c | 11 ++++- include/linux/acpi.h | 5 +++ 5 files changed, 157 insertions(+), 13 deletions(-) -- 2.20.1
