[PATCH 00/14] arm_pmu: ACPI support

Mark Rutland mark.rutland at arm.com
Fri Mar 10 03:04:37 PST 2017


This series implements ACPI support in the ARM PMU code. It borrows some code
from Jeremy's series [1], but takes a different approach to probing and
association, using the usual hotplug state machine, minimising external changes
required, and simplifying the relationship with the common arm_pmu code.

The first few patches are preparatory cleanup/refactoring, with the latter half
of the series being specific to ACPI support.

The series is based on my IRQ rework patches [2]. I've pushed the whole series
out to the arm/perf/acpi branch [3] of my kernel.org repo.

Due to the innards of the hotplug callback framework, it's not entirely
safe to register a PMU in a hotplug callback. Due to this, we can only
associated hotplugged CPUs with a PMU if a matching CPU was around at
probe time. A similar restriction already applies to DT systems. We may
be able to relax this with some future work.

I've given this some testing on a Juno platform (using SPIs). To see that IRQs
are correctly associated, I've tested with the following:

  $ taskset -c ${SOME_CPU_HERE} perf record \
    -e armv8_pmuv3_0/cpu_cycles/ \
    -e armv8_pmuv3_1/cpu_cycles/ \
    cat /proc/interrupts
I've also booted with nr_cpus temporarily capped (passing maxcpus=) to test the
association logic. This has also been tested in a VM using PPIs; I do not have
access to a host machine which itself uses PPIs.


[1] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-January/482397.html
[2] http://lists.infradead.org/pipermail/linux-arm-kernel/2017-March/492891.html
[3] git://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git arm/perf/acpi

Mark Rutland (14):
  drivers/perf: arm_pmu: remove pointless PMU disabling
  drivers/perf: arm_pmu: define armpmu_init_fn
  drivers/perf: arm_pmu: fold init into alloc
  drivers/perf: arm_pmu: factor out pmu registration
  drivers/perf: arm_pmu: simplify cpu_pmu_request_irqs()
  drivers/perf: arm_pmu: handle no platform_device
  drivers/perf: arm_pmu: rename irq request/free functions
  drivers/perf: arm_pmu: split cpu-local irq request/free
  drivers/perf: arm_pmu: move irq request/free into probe
  drivers/perf: arm_pmu: split out platform device probe logic
  arm64: add function to get a cpu's MADT GICC table
  arm64: kill acpi_set_mailbox_entry()
  drivers/perf: arm_pmu: add ACPI framework
  arm64: pmuv3: use arm_pmu ACPI framework

 arch/arm64/include/asm/acpi.h             |   7 +-
 arch/arm64/kernel/acpi_parking_protocol.c |  38 +--
 arch/arm64/kernel/perf_event.c            |  26 +-
 arch/arm64/kernel/smp.c                   |  19 +-
 drivers/perf/Kconfig                      |   4 +
 drivers/perf/Makefile                     |   3 +-
 drivers/perf/arm_pmu.c                    | 383 ++++++++----------------------
 drivers/perf/arm_pmu_acpi.c               | 237 ++++++++++++++++++
 drivers/perf/arm_pmu_platform.c           | 235 ++++++++++++++++++
 include/linux/cpuhotplug.h                |   1 +
 include/linux/perf/arm_pmu.h              |  22 +-
 11 files changed, 626 insertions(+), 349 deletions(-)
 create mode 100644 drivers/perf/arm_pmu_acpi.c
 create mode 100644 drivers/perf/arm_pmu_platform.c


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