StarFive StarLink PMU support monitoring L3 memory system PMU events.
Add documentation to describe StarFive StarLink PMU support and it's
usage.
Signed-off-by: Ji Sheng Teoh <jisheng.teoh@xxxxxxxxxxxxxxxx>
---
Documentation/admin-guide/perf/index.rst | 1 +
.../perf/starfive_starlink_pmu.rst | 46 +++++++++++++++++++
2 files changed, 47 insertions(+)
create mode 100644 Documentation/admin-guide/perf/starfive_starlink_pmu.rst
diff --git a/Documentation/admin-guide/perf/index.rst b/Documentation/admin-guide/perf/index.rst
index a2e6f2c81146..c5de7579a71b 100644
--- a/Documentation/admin-guide/perf/index.rst
+++ b/Documentation/admin-guide/perf/index.rst
@@ -13,6 +13,7 @@ Performance monitor support
imx-ddr
qcom_l2_pmu
qcom_l3_pmu
+ starfive_starlink_pmu
arm-ccn
arm-cmn
xgene-pmu
diff --git a/Documentation/admin-guide/perf/starfive_starlink_pmu.rst b/Documentation/admin-guide/perf/starfive_starlink_pmu.rst
new file mode 100644
index 000000000000..2932ddb4eb76
--- /dev/null
+++ b/Documentation/admin-guide/perf/starfive_starlink_pmu.rst
@@ -0,0 +1,46 @@
+================================================
+StarFive StarLink Performance Monitor Unit (PMU)
+================================================
+
+StarFive StarLink Performance Monitor Unit (PMU) exists within the
+StarLink Coherent Network on Chip (CNoC) that connects multiple CPU
+clusters with an L3 memory system.
+
+The uncore PMU supports overflow interrupt, up to 16 programmable 64bit
+event counters, and an independent 64bit cycle counter.
+The PMU can only be accessed via Memory Mapped I/O and are common to the
+cores connected to the same PMU.
+
+Driver exposes supported PMU events in sysfs "events" directory under::
+
+ /sys/bus/event_source/devices/starfive_starlink_pmu/events/
+
+Driver exposes cpu used to handle PMU events in sysfs "cpumask" directory
+under::
+
+ /sys/bus/event_source/devices/starfive_starlink_pmu/cpumask/
+
+Driver describes the format of config (event ID) in sysfs "format" directory
+under::
+
+ /sys/bus/event_source/devices/starfive_starlink_pmu/format/
+
+Example of perf usage::
+
+ $ perf list
+
+ starfive_starlink_pmu/cycles/ [Kernel PMU event]
+ starfive_starlink_pmu/read_hit/ [Kernel PMU event]
+ starfive_starlink_pmu/read_miss/ [Kernel PMU event]
+ starfive_starlink_pmu/read_request/ [Kernel PMU event]
+ starfive_starlink_pmu/release_request/ [Kernel PMU event]
+ starfive_starlink_pmu/write_hit/ [Kernel PMU event]
+ starfive_starlink_pmu/write_miss/ [Kernel PMU event]
+ starfive_starlink_pmu/write_request/ [Kernel PMU event]
+ starfive_starlink_pmu/writeback/ [Kernel PMU event]
+
+
+ $ perf stat -a -e /starfive_starlink_pmu/cycles/ sleep 1
+
+Sampling is not supported. As a result, "perf record" is not supported.
+Attaching to a task is not supported, only system-wide counting is supported.
--
2.25.1
