On 24/08/25 05:38, Randy Dunlap wrote:
On 8/23/25 1:01 PM, Sumit Gupta wrote:
Add sysfs interfaces for Minimum Performance, Maximum Performance
and Performance Limited Register in the cppc_cpufreq driver.
Signed-off-by: Sumit Gupta <sumitg@xxxxxxxxxx>
---
.../ABI/testing/sysfs-devices-system-cpu | 43 +++++++++++++++++++
1 file changed, 43 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index ab8cd337f43a..4bce0dbc48c9 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -327,6 +327,49 @@ Description: Energy performance preference
This file is only present if the cppc-cpufreq driver is in use.
+What: /sys/devices/system/cpu/cpuX/cpufreq/min_perf
+Date: Aug 2025
+Contact: linux-pm@xxxxxxxxxxxxxxx
+Description: Minimum Performance
Preferably these 4 lines above use tab(s) after the ':' for indentation
instead of spaces. (in 3 places, i.e., each sysfs file entry).
Sorry for replying late as I was on vacation.
Sure, will replace spaces with tabs in v3 and add your 'Reviewed-by'.
Thank you,
Sumit Gupta
+
+ Read/write a 32 bits value from/to this file. This file
+ conveys the minimum performance level at which the platform
+ may run. Minimum performance may be set to any performance
+ value in the range [Lowest Performance, Highest Performance],
+ inclusive but must be set to a value that is less than or
+ equal to that specified by the Maximum Performance Register.
+
+ Writing to this file only has meaning when Autonomous Selection
+ is enabled.
+
+ This file is only present if the cppc-cpufreq driver is in use.
+
+What: /sys/devices/system/cpu/cpuX/cpufreq/max_perf
+Date: Aug 2025
+Contact: linux-pm@xxxxxxxxxxxxxxx
+Description: Minimum Performance
+
+ Read/write a 32 bits value from/to this file. This file conveys
+ the maximum performance level at which the platform may run.
+ Maximum performance may be set to any performance value in the
+ range [Lowest Performance, Highest Performance], inclusive.
+
+ Writing to this file only has meaning when Autonomous Selection is
+ enabled.
+
+ This file is only present if the cppc-cpufreq driver is in use.
+
+What: /sys/devices/system/cpu/cpuX/cpufreq/perf_limited
+Date: Aug 2025
+Contact: linux-pm@xxxxxxxxxxxxxxx
+Description: Minimum Performance
+
+ Read/write a 32 bits value from/to this file. This file indicates
+ to OSPM that an unpredictable event has limited processor
+ performance, and the delivered performance may be less than
+ desired/minimum performance.
+
+ This file is only present if the cppc-cpufreq driver is in use.
What: /sys/devices/system/cpu/cpu*/cache/index3/cache_disable_{0,1}
Date: August 2008
Reviewed-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Thanks.
