perf: Add driver for Arm NI-700 interconnect PMU

2024-09-06T11:58:28Z

The Arm NI-700 Network-on-Chip Interconnect has a relatively straightforward design with a hierarchy of voltage, power, and clock domains, where each clock domain then contains a number of interface units and a PMU which can monitor events thereon. As such, it begets a relatively straightforward driver to interface those PMUs with perf. Even more so than with arm-cmn, users will require detailed knowledge of the wider system topology in order to meaningfully analyse anything, since the interconnect itself cannot know what lies beyond the boundary of each inscrutably-numbered interface. Given that, for now they are also expected to refer to the NI-700 documentation for the relevant event IDs to provide as well. An identifier is implemented so we can come back and add jevents if anyone really wants to. Signed-off-by: Robin Murphy Link: https://lore.kernel.org/r/9933058d0ab8138c78a61cd6852ea5d5ff48e393.1725470837.git.robin.murphy@arm.com Signed-off-by: Will Deacon

kernel/Documentation/admin-guide/perf/arm-ni.rst, branch 0x221E-v0.0.1-v6.19

perf: Add driver for Arm NI-700 interconnect PMU