RFC: https://lkml.org/lkml/2021/6/4/791 PATCH v1: https://lkml.org/lkml/2021/6/16/805 PATCH v2: https://lkml.org/lkml/2021/7/6/138 Changelog v2 --> v3 Based on a comment from Guatham: 1. Added a versioning check after the H_CALL is made to bail out when the version from the firmware is inconsistent with that in the kernel Also, have implemented a POC using this interface for the powerpc-utils' ppc64_cpu --frequency command-line tool to utilize this information in userspace. The POC for the new interface has been hosted here: https://github.com/pratiksampat/powerpc-utils/tree/H_GET_ENERGY_SCALE_INFO_v2 Sample output from the powerpc-utils tool is as follows: # ppc64_cpu --frequency Power and Performance Mode: XXXX Idle Power Saver Status : XXXX Processor Folding Status : XXXX --> Printed if Idle power save status is supported Platform reported frequencies --> Frequencies reported from the platform's H_CALL i.e PAPR interface min : NNNN GHz max : NNNN GHz static : NNNN GHz Tool Computed frequencies min : NNNN GHz (cpu XX) max : NNNN GHz (cpu XX) avg : NNNN GHz Pratik R. Sampat (1): powerpc/pseries: Interface to represent PAPR firmware attributes .../sysfs-firmware-papr-energy-scale-info | 26 ++ arch/powerpc/include/asm/hvcall.h | 24 +- arch/powerpc/kvm/trace_hv.h | 1 + arch/powerpc/platforms/pseries/Makefile | 3 +- .../pseries/papr_platform_attributes.c | 320 ++++++++++++++++++ 5 files changed, 372 insertions(+), 2 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-firmware-papr-energy-scale-info create mode 100644 arch/powerpc/platforms/pseries/papr_platform_attributes.c -- 2.31.1
