drivers/perf: hisi: Add support for PCIe PMU

This patchset adds support for HiSilicon PCIe Performance Monitoring
Unit(PMU). It is a PCIe Root Complex integrated End Point(RCiEP) device
added on Hip09. Each PCIe Core has a PMU RCiEP to monitor multi root
ports and all Endpoints downstream these root ports.

HiSilicon PCIe PMU is supported to collect performance data of PCIe bus,
such as: bandwidth, latency etc.

Example usage of counting PCIe rx memory write latency::

  $# perf stat -e hisi_pcie0_core0/rx_mwr_latency/
  $# perf stat -e hisi_pcie0_core0/rx_mwr_cnt/
  $# perf stat -g -e hisi_pcie0_core0/rx_mwr_latency/ -e hisi_pcie0_core0/rx_mwr_cnt/

average rx memory write latency can be calculated like this:
  latency = rx_mwr_latency / rx_mwr_cnt.

Common PMU events and metrics will be described in JSON file, and will be add
in userspace perf tool latter.

Changes since v9:
- Add check in hisi_pcie_pmu_validate_event_group to count counters accurently .
- Link: https://lore.kernel.org/linux-arm-kernel/20210818051246.2...

Changes since v8:
- Remove subevent parameter in attr->config.
- Check the counter scheduling constraints when accepting an event group.
- Link: https://lore.kernel.org/linux-arm-kernel/20210728080932.7...

Changes since v7:
- Drop headerfile cpumask.h and cpuhotplug.h.
- Rename events in perf list: bw->flux, lat->delay, as driver doesn't
  process bandwidth and average latency data.
- Link: https://lore.kernel.org/linux-arm-kernel/1624532384-43002...

Changes since v6:
- Move the driver to drivers/perf/hisilicon.
- Treat content in PMU counter and ext_counter as different PMU events, and
  export them separately.
- Address the comments from Will and Krzysztof.
- Link: https://lore.kernel.org/linux-arm-kernel/1622467951-32114...

Changes since v5:
- Fix some errors when build under ARCH=xtensa.
- Link: https://lore.kernel.org/linux-arm-kernel/1621946795-14046...

Changes since v4:
- Replace irq_set_affinity_hint() with irq_set_affinity().
- Link: https://lore.kernel.org/linux-arm-kernel/1621417741-5229-...

Changes since v3:
- Fix some warnings when build under 32bits architecture.
- Address the comments from John.
- Link: https://lore.kernel.org/linux-arm-kernel/1618490885-44612...

Changes since v2:
- Address the comments from John.
- Link: https://lore.kernel.org/linux-arm-kernel/1617959157-22956...

Changes since v1:
- Drop the internal Reviewed-by tag.
- Fix some build warnings when W=1.
- Link: https://lore.kernel.org/linux-arm-kernel/1617788943-52722...


Qi Liu (2):
  docs: perf: Add description for HiSilicon PCIe PMU driver
  drivers/perf: hisi: Add driver for HiSilicon PCIe PMU

 .../admin-guide/perf/hisi-pcie-pmu.rst        | 106 ++
 MAINTAINERS                                   |   2 +
 drivers/perf/hisilicon/Kconfig                |   9 +
 drivers/perf/hisilicon/Makefile               |   2 +
 drivers/perf/hisilicon/hisi_pcie_pmu.c        | 985 ++++++++++++++++++
 include/linux/cpuhotplug.h                    |   1 +
 6 files changed, 1105 insertions(+)
 create mode 100644 Documentation/admin-guide/perf/hisi-pcie-pmu.rst
 create mode 100644 drivers/perf/hisilicon/hisi_pcie_pmu.c

-- 
2.33.0