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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-07 21:23:40 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-07 21:23:40 -0700 |
commit | 6afd563d4bbc1924b7de9e053324c007e0d36476 (patch) | |
tree | 619c2270f6f09ce8c9eb7f6aa448f07f67ffa8e8 /Documentation/perf/xgene-pmu.txt | |
parent | b4f33f6ddd0c218e12454e1379de3aaa73f2e8dc (diff) | |
parent | d6db68b2deaa0158d25b236edffcf6dd2117208f (diff) | |
download | linux-stable-6afd563d4bbc1924b7de9e053324c007e0d36476.tar.gz linux-stable-6afd563d4bbc1924b7de9e053324c007e0d36476.tar.bz2 linux-stable-6afd563d4bbc1924b7de9e053324c007e0d36476.zip |
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
...
Diffstat (limited to 'Documentation/perf/xgene-pmu.txt')
-rw-r--r-- | Documentation/perf/xgene-pmu.txt | 48 |
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. |