[PATCH 0/1] Interface to represent PAPR firmware attributes

[Pratik R. Sampat]

RFC --> v1
RFC: https://lkml.org/lkml/2021/6/4/791

Changelog:
Overhaul in interface design to the following:
/sys/firmware/papr/energy_scale_info/
   |-- <id>/
     |-- desc
     |-- value
     |-- value_desc (if exists)
   |-- <id>/
     |-- desc
     |-- value
     |-- value_desc (if exists)

Also 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             |  21 +-
 arch/powerpc/kvm/trace_hv.h                   |   1 +
 arch/powerpc/platforms/pseries/Makefile       |   3 +-
 .../pseries/papr_platform_attributes.c        | 292 ++++++++++++++++++
 5 files changed, 341 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

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2.30.2