On some systems, the boost ratio cannot be accurately calculated
using linear interpolation of CPPC performance values because the
performance-to-frequency mapping is not linear across all cores.
This series introduces support for the CPPC HighestFreq register. This
register is under a proposal with ASWG at the moment and trending for
inclusion in ACPI 6.7.
This optionally provides the actual highest frequency eliminating
the need for interpolation. When available, this frequency value is used
for more accurate CPU capacity calculations and boost ratio determination.
This series adds support for the ACPI 6.7 proposal. It require's Sumit's
CPPC v4 patches.
---
v3:
* Rebase on Sumit's CPPCv4 v3 submission [1]
* Drop "Revert "ACPI: CPPC: Adjust debug messages in amd_set_max_freq_ratio() to warn"
as this was merged through the PM tree already in 7.1-rc3.
* Add tags for Prateek.
v2:
* Drop CPPC v4 patches, these are submitted separately by Sumit Gupta [2]
Link: https://lore.kernel.org/linux-pm/20260514194822.1841748-1-sumitg@nvidia.com/ [1]
Link: https://lore.kernel.org/linux-pm/20260430142430.755437-1-sumitg@nvidia.com/ [2]
Mario Limonciello (4):
ACPI: CPPC: Add support for reading HighestFreq
ACPI: CPPC: Refactor boost ratio handling
cpufreq/acpi-cpufreq: Use amd_get_boost_ratio()
cpufreq/amd-pstate: Get highest freq from CPPC if available
arch/x86/kernel/acpi/cppc.c | 122 ++++++++++++++++++---------------
drivers/acpi/cppc_acpi.c | 31 ++++++---
drivers/cpufreq/acpi-cpufreq.c | 17 +++--
drivers/cpufreq/amd-pstate.c | 18 +++--
include/acpi/cppc_acpi.h | 16 ++++-
5 files changed, 123 insertions(+), 81 deletions(-)
--
2.54.0