Variorum does not support the ARM Neoverse N1 SoC platform

[amarathe84]

The Ampere Altra Max platform (nvhpc1) is based on a single 80-core Neoverse N1 SoC. Variorum does not support this platform as Variorum is only aware of the big.LITTLE SoC in the ARM universe.

The Variorum port for ARM needs to expand support for the Neoverse N1 chip for the following APIs already supported for the big.LITTLE ARM SoC:

Power telemetry

Power telemetry must be sampled from the power*_input files present in /sys/class/hwmon/hwmon*/ exposed by sysfs. The sensor labels (strings) present in power*_label may be used to tag power sensor in the output.

Temperature telemetry

Thermal telemetry must be sampled from the temp*_input files present in /sys/class/hwmon/hwmon*/ exposed by sysfs. The sensor labels (strings) present in temp*_label may be used to tag thermal sensor in the output.

Clocks telemtry

Clocks (instantaneous frequency) must be gathered from the /sys/devices/system/cpu/cpufreq/policy*/scaling_cur_freq files exposed by sysfs. The clocks may be reported per core or per processor based on what is supported on the target ARM platform. On the Neoverse N1 chip, per-core clocks are supported.

Frequency control

Frequency control must be specified using the /sys/devices/system/cpu/cpufreq/policy*/scaling_setspeed files exposed by sysfs. This control interface may be available per core or per processor based on what is supported on the target ARM platform. On the Neoverse N1 chip, per-core frequency control is supported.

The code changes to support the Neoverse N1 platform must be backward/cross-compatible with the ARM Juno r2 platform. The documentation for ARM should be updated to reflect these changes.