[PATCH v4 0/6] Support for autonomous selection in cppc_cpufreq

Lifeng Zheng
2025-01-13T12:21:14Z

Add sysfs interfaces for CPPC autonomous selection in the cppc_cpufreq
driver.

The patch series is organized in two parts:

- patch 1-4 refactor out the general CPPC register get and set functions
in cppc_acpi.c

- patches 5-6 expose sysfs files for users to control CPPC autonomous
selection when supported

---
Since Pierre and me have discussed about whether or not to show
auto_act_window and energy_perf when auto_select is disabled. It seems
like whether to show these two files has their own points. We'd like to
ask for some advice.

Relevant discussion:
[1] https://lore.kernel.org/all/522721da-1a5c-439c-96a8-d0300dd0f906@huawei.com/

Changelog:

v4:

- add REG_OPTIONAL and IS_OPTIONAL_CPC_REG to judge if a cpc register is
an optional one
- check whether the register is optional before CPC_SUPPORTED check in
cppc_get_reg_val() and cppc_set_reg_val()
- check the register's type in cppc_set_reg_val()
- add macros to generally implement registers getting and setting
functions
- move some logic codes from cppc_cpufreq.c to cppc_acpi.c
- replace cppc_get_auto_sel_caps() by cppc_get_auto_sel()

v3:

- change cppc_get_reg() and cppc_set_reg() name to cppc_get_reg_val() and
cppc_set_reg_val()
- extract cppc_get_reg_val_in_pcc() and cppc_set_reg_val_in_pcc()
- return the result of cpc_read() in cppc_get_reg_val()
- add pr_debug() in cppc_get_reg_val_in_pcc() when pcc_ss_id < 0
- rename 'cpunum' to 'cpu' in cppc_get_reg_val()
- move some macros from drivers/cpufreq/cppc_cpufreq.c to
include/acpi/cppc_acpi.h with a CPPC_XXX prefix

v2:

- fix some incorrect placeholder
- change kstrtoul to kstrtobool in store_auto_select

Lifeng Zheng (6):
ACPI: CPPC: Add IS_OPTIONAL_CPC_REG macro
ACPI: CPPC: Add cppc_get_reg_val and cppc_set_reg_val function
ACPI: CPPC: Add macros to generally implement registers getting and
setting functions
ACPI: CPPC: Refactor register value get and set ABIs
ACPI: CPPC: Add autonomous selection ABIs
cpufreq: CPPC: Support for autonomous selection in cppc_cpufreq

.../ABI/testing/sysfs-devices-system-cpu | 54 +++
drivers/acpi/cppc_acpi.c | 332 +++++++++---------
drivers/cpufreq/amd-pstate.c | 3 +-
drivers/cpufreq/cppc_cpufreq.c | 109 ++++++
include/acpi/cppc_acpi.h | 30 +-
5 files changed, 359 insertions(+), 169 deletions(-)

--
2.33.0