tree 78f1fd8d32bc2227f9851fd271dafd977361662e
parent 1e2541074f038f51df88921af3ea0d134fb1265f
author Sukumar Ghorai <sukumar.ghorai@intel.com> 1695969870 -0700
committer Subrata Banik <subratabanik@google.com> 1696519324 +0000

soc/intel: separate slp-s0 residency counter frequency in LPIT table

Intel platforms use Low Power Idle Table (LPIT) to enumerate platform
Low Power Idle states. There are two types of low power residencies
 a) CPU PKG C10 - read via MSR (Function fixed hardware interface)
 b) Platform Controller Hub (PCH) SLP_S0 - read via memory mapped IO

Ref. https://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf,
section 2.2.1: value of 0 indicates that counter runs at TSC frequency.

Ref. Intel 64 and IA-32 Architectures Software Developer’s Manual (Vol 4)
MSR 0x632: PC10 residency counter is at same frequency as the TSC.
Whereas slp_s0 residency counter running in different frequency.

BUG=b:300440936
TEST=check kernel cpuidle sysfs are created after kernel boot
  cat /sys/devices/system/cpu/cpuidle/low_power_idle_cpu_residency_us
  cat /sys/devices/system/cpu/cpuidle/low_power_idle_system_residency_us

Change-Id: Ibde764551a21b9aecb1c269948f4823548294711
Signed-off-by: Sukumar Ghorai <sukumar.ghorai@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78177
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kapil Porwal <kapilporwal@google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>