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Diffstat (limited to 'Documentation/admin-guide/perf/arm-ni.rst')
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diff --git a/Documentation/admin-guide/perf/arm-ni.rst b/Documentation/admin-guide/perf/arm-ni.rst new file mode 100644 index 000000000000..d26a8f697c36 --- /dev/null +++ b/Documentation/admin-guide/perf/arm-ni.rst @@ -0,0 +1,17 @@ +==================================== +Arm Network-on Chip Interconnect PMU +==================================== + +NI-700 and friends implement a distinct PMU for each clock domain within the +interconnect. Correspondingly, the driver exposes multiple PMU devices named +arm_ni_<x>_cd_<y>, where <x> is an (arbitrary) instance identifier and <y> is +the clock domain ID within that particular instance. If multiple NI instances +exist within a system, the PMU devices can be correlated with the underlying +hardware instance via sysfs parentage. + +Each PMU exposes base event aliases for the interface types present in its clock +domain. These require qualifying with the "eventid" and "nodeid" parameters +to specify the event code to count and the interface at which to count it +(per the configured hardware ID as reflected in the xxNI_NODE_INFO register). +The exception is the "cycles" alias for the PMU cycle counter, which is encoded +with the PMU node type and needs no further qualification. |