kernel/tools/power/cpupower/utils/helpers/misc.c, branch linux-rolling-stable

cpupower: Allow control of boost feature on non-x86 based systems with boost support.

2025-08-15T16:49:14Z

The cpufreq subsystem has a generic sysfs interface for controlling boost (/sys/devices/system/cpu/cpufreq/boost). The sysfs interface can be used to enable boost control from the cpupower command on non-x86 platforms as well. So, allow boost controlling on non-x86 system if boost sysfs file exists. The set subcommand enables/disables the boost feature using the following syntax: cpupower set --boost 1 cpupower set --boost 0 The --boost option is an alias for --turbo-boost. We provided the neutral option name because the name "turbo boost" is specific to Intel technology. The frequency-info subcommand displays the enabled/disabled state of the boost feature as follows: boost state support: Active: yes (or no) Link: https://lore.kernel.org/r/20250522061122.2149188-3-fj5851bi@fujitsu.com Signed-off-by: Shinji Nomoto Signed-off-by: Shuah Khan

cpupower: Add turbo-boost support in cpupower

2023-07-18T22:07:01Z

If boost sysfs (/sys/devices/system/cpu/cpufreq/boost) file is present turbo-boost is feature is supported in the hardware. By default this feature should be enabled. But to disable/enable it write to the sysfs file. Use the same to control this feature via cpupower. To enable: cpupower set --turbo-boost 1 To disable: cpupower set --turbo-boost 0 Acked-by: Huang Rui Reviewed-by: Gautham R. Shenoy Reviewed-by: Mario Limonciello Signed-off-by: Wyes Karny Tested-by: Perry Yuan Signed-off-by: Shuah Khan

cpupower: Add support for amd_pstate mode change

2023-07-18T22:06:56Z

amd_pstate supports changing of its mode dynamically via `status` sysfs file. Add the same capability in cpupower. To change the mode to active mode use below command: cpupower set --amd-pstate-mode active Acked-by: Huang Rui Reviewed-by: Gautham R. Shenoy Reviewed-by: Mario Limonciello Signed-off-by: Wyes Karny Tested-by: Perry Yuan Signed-off-by: Shuah Khan

cpupower: Add EPP value change support

2023-07-18T22:06:49Z

amd_pstate and intel_pstate active mode drivers support energy performance preference feature. Through this user can convey it's energy/performance preference to platform. Add this value change capability to cpupower. To change the EPP value use below command: cpupower set --epp performance Reviewed-by: Mario Limonciello Signed-off-by: Wyes Karny Tested-by: Perry Yuan Acked-by: Huang Rui Signed-off-by: Shuah Khan

cpupower: Recognise amd-pstate active mode driver

2023-07-18T22:06:36Z

amd-pstate active mode driver name is "amd-pstate-epp". Use common prefix for string matching condition to recognise amd-pstate active mode driver. Reviewed-by: Gautham R. Shenoy Signed-off-by: Wyes Karny Reviewed-by: Mario Limonciello Tested-by: Perry Yuan Acked-by: Huang Rui Signed-off-by: Shuah Khan

cpupower: Move print_speed function into misc helper

2022-02-23T01:37:07Z

The print_speed can be as a common function, and expose it into misc helper header. Then it can be used on other helper files as well. Reviewed-by: Shuah Khan Signed-off-by: Huang Rui Signed-off-by: Shuah Khan

cpupower: Enable boost state support for AMD P-State module

2022-02-23T01:37:01Z

The legacy ACPI hardware P-States function has 3 P-States on ACPI table, the CPU frequency only can be switched between the 3 P-States. While the processor supports the boost state, it will have another boost state that the frequency can be higher than P0 state, and the state can be decoded by the function of decode_pstates() and read by amd_pci_get_num_boost_states(). However, the new AMD P-State function is different than legacy ACPI hardware P-State on AMD processors. That has a finer grain frequency range between the highest and lowest frequency. And boost frequency is actually the frequency which is mapped on highest performance ratio. The similar previous P0 frequency is mapped on nominal performance ratio. If the highest performance on the processor is higher than nominal performance, then we think the current processor supports the boost state. And it uses amd_pstate_boost_init() to initialize boost for AMD P-State function. Reviewed-by: Shuah Khan Signed-off-by: Huang Rui Signed-off-by: Shuah Khan

cpupower: Add the function to check AMD P-State enabled

2022-02-23T01:36:32Z

The processor with AMD P-State function also supports legacy ACPI hardware P-States feature as well. Once driver sets AMD P-State eanbled, the processor will respond the finer grain AMD P-State feature instead of legacy ACPI P-States. So it introduces the cpupower_amd_pstate_enabled() to check whether the current kernel enables AMD P-State or AMD CPUFreq module. Reviewed-by: Shuah Khan Signed-off-by: Huang Rui Signed-off-by: Shuah Khan

cpupower: Add cpuid cap flag for MSR_AMD_HWCR support

2021-01-26T16:40:45Z

Remove the family check for accessing the MSR_AMD_HWCR MSR and replace it with a cpupower cap flag. This update also allows for the removal of the local cpupower_cpu_info variable in cpufreq_has_boost_support() since we no longer need it to check the family. Signed-off-by: Nathan Fontenot Reviewed-by: Robert Richter Signed-off-by: Shuah Khan

cpupower: Correct macro name for CPB caps flag

2021-01-26T16:40:08Z

The name is Core Performance Boost (CPB) for the cpuid flag. Correct cpuid caps flag to use this name (instead of CBP). Signed-off-by: Robert Richter Signed-off-by: Nathan Fontenot Signed-off-by: Shuah Khan