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 v3->v4: Rebase to 5.2. Minor formatting, patch rearrangement. Add missing `inline` in static header definition. Drop ARM_SPE_ACPI and just use ARM_SPE_PMU. v2->v3: Previously a function pointer was being used to handle the more complex node checking required by the IDENTICAL flag. This version simply checks for the IDENTICAL flag and calls flag_identical() to preform the revision and next node checks. (I think after reading Raphael's comments for the Nth time, this is actually what he was suggesting, which I initially miss interpreted). Modify subject of first patch so that its clear a that its a capitalization change rather, than a logical C 'case' change. v1->v2: Wrap the code which creates the SPE device in a new CONFIG_ARM_SPE_ACPI ifdef. Move arm,spe-v1 device name into common header file Some comment/case sensitivity/function name changes. Jeremy Linton (4): ACPI/PPTT: Modify node flag detection to find last IDENTICAL ACPI/PPTT: Add function to return ACPI 6.3 Identical tokens 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 | 61 ++++++++++++++++++++++++++--- drivers/perf/arm_pmu_acpi.c | 72 +++++++++++++++++++++++++++++++++++ drivers/perf/arm_spe_pmu.c | 12 +++++- include/linux/acpi.h | 5 +++ include/linux/perf/arm_pmu.h | 2 + 6 files changed, 147 insertions(+), 8 deletions(-) -- 2.21.0
