Merge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC driver updates from Arnd Bergmann:
 "Driver updates for ARM SoCs, including a couple of newly added
  drivers:

   - The Qualcomm external bus interface 2 (EBI2), used in some of their
     mobile phone chips for connecting flash memory, LCD displays or
     other peripherals

   - Secure monitor firmware for Amlogic SoCs, and an NVMEM driver for
     the EFUSE based on that firmware interface.

   - Perf support for the AppliedMicro X-Gene performance monitor unit

   - Reset driver for STMicroelectronics STM32

   - Reset driver for SocioNext UniPhier SoCs

  Aside from these, there are minor updates to SoC-specific bus,
  clocksource, firmware, pinctrl, reset, rtc and pmic drivers"

* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (50 commits)
  bus: qcom-ebi2: depend on HAS_IOMEM
  pinctrl: mvebu: orion5x: Generalise mv88f5181l support for 88f5181
  clk: mvebu: Add clk support for the orion5x SoC mv88f5181
  dt-bindings: EXYNOS: Add Exynos5433 PMU compatible
  clocksource: exynos_mct: Add the support for ARM64
  perf: xgene: Add APM X-Gene SoC Performance Monitoring Unit driver
  Documentation: Add documentation for APM X-Gene SoC PMU DTS binding
  MAINTAINERS: Add entry for APM X-Gene SoC PMU driver
  bus: qcom: add EBI2 driver
  bus: qcom: add EBI2 device tree bindings
  rtc: rtc-pm8xxx: Add support for pm8018 rtc
  nvmem: amlogic: Add Amlogic Meson EFUSE driver
  firmware: Amlogic: Add secure monitor driver
  soc: qcom: smd: Reset rx tail rather than tx
  memory: atmel-sdramc: fix a possible NULL dereference
  reset: hi6220: allow to compile test driver on other architectures
  reset: zynq: add driver Kconfig option
  reset: sunxi: add driver Kconfig option
  reset: stm32: add driver Kconfig option
  reset: socfpga: add driver Kconfig option
  ...

1 files changed, 48 insertions, 0 deletions

diff --git a/Documentation/perf/xgene-pmu.txt b/Documentation/perf/xgene-pmu.txt
new file mode 100644
index 000000000000..d7cff4454e5b
--- /dev/null
+++ b/Documentation/perf/xgene-pmu.txt
@@ -0,0 +1,48 @@
+APM X-Gene SoC Performance Monitoring Unit (PMU)
+================================================
+
+X-Gene SoC PMU consists of various independent system device PMUs such as
+L3 cache(s), I/O bridge(s), memory controller bridge(s) and memory
+controller(s). These PMU devices are loosely architected to follow the
+same model as the PMU for ARM cores. The PMUs share the same top level
+interrupt and status CSR region.
+
+PMU (perf) driver
+-----------------
+
+The xgene-pmu driver registers several perf PMU drivers. Each of the perf
+driver provides description of its available events and configuration options
+in sysfs, see /sys/devices/<l3cX/iobX/mcbX/mcX>/.
+
+The "format" directory describes format of the config (event ID),
+config1 (agent ID) fields of the perf_event_attr structure. The "events"
+directory provides configuration templates for all supported event types that
+can be used with perf tool. For example, "l3c0/bank-fifo-full/" is an
+equivalent of "l3c0/config=0x0b/".
+
+Most of the SoC PMU has a specific list of agent ID used for monitoring
+performance of a specific datapath. For example, agents of a L3 cache can be
+a specific CPU or an I/O bridge. Each PMU has a set of 2 registers capable of
+masking the agents from which the request come from. If the bit with
+the bit number corresponding to the agent is set, the event is counted only if
+it is caused by a request from that agent. Each agent ID bit is inversely mapped
+to a corresponding bit in "config1" field. By default, the event will be
+counted for all agent requests (config1 = 0x0). For all the supported agents of
+each PMU, please refer to APM X-Gene User Manual.
+
+Each perf driver also provides a "cpumask" sysfs attribute, which contains a
+single CPU ID of the processor which will be used to handle all the PMU events.
+
+Example for perf tool use:
+
+ / # perf list | grep -e l3c -e iob -e mcb -e mc
+   l3c0/ackq-full/                                    [Kernel PMU event]
+ <...>
+   mcb1/mcb-csw-stall/                                [Kernel PMU event]
+
+ / # perf stat -a -e l3c0/read-miss/,mcb1/csw-write-request/ sleep 1
+
+ / # perf stat -a -e l3c0/read-miss,config1=0xfffffffffffffffe/ sleep 1
+
+The driver does not support sampling, therefore "perf record" will
+not work. Per-task (without "-a") perf sessions are not supported.