5c7dd7acc3
repo: https://github.com/T-head-Semi/linux commit: b1313fe517ca3703119dcc99ef3bbf75ab42bcfb Change-Id: I6cbb35294024ea3a66140e311f4bb705fd7fd626
30 lines
1.2 KiB
ReStructuredText
30 lines
1.2 KiB
ReStructuredText
==================================
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ARM DynamIQ Shared Unit (DSU) PMU
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==================================
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ARM DynamIQ Shared Unit integrates one or more cores with an L3 memory system,
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control logic and external interfaces to form a multicore cluster. The PMU
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allows counting the various events related to the L3 cache, Snoop Control Unit
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etc, using 32bit independent counters. It also provides a 64bit cycle counter.
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The PMU can only be accessed via CPU system registers and are common to the
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cores connected to the same DSU. Like most of the other uncore PMUs, DSU
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PMU doesn't support process specific events and cannot be used in sampling mode.
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The DSU provides a bitmap for a subset of implemented events via hardware
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registers. There is no way for the driver to determine if the other events
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are available or not. Hence the driver exposes only those events advertised
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by the DSU, in "events" directory under::
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/sys/bus/event_sources/devices/arm_dsu_<N>/
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The user should refer to the TRM of the product to figure out the supported events
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and use the raw event code for the unlisted events.
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The driver also exposes the CPUs connected to the DSU instance in "associated_cpus".
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e.g usage::
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perf stat -a -e arm_dsu_0/cycles/
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