Commit 856250ba authored by Sumit Gupta's avatar Sumit Gupta Committed by Rafael J. Wysocki
Browse files

cpufreq: CPPC: Add sysfs documentation for perf_limited 



Add ABI documentation for the Performance Limited Register sysfs
interface in the cppc_cpufreq driver.

Signed-off-by: default avatarSumit Gupta <sumitg@nvidia.com>
Reviewed-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Reviewed-by: default avatarPierre Gondois <pierre.gondois@arm.com>
Reviewed-by: default avatarLifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/20260206142658.72583-8-sumitg@nvidia.com


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 13c45a26

Documentation/ABI/testing/sysfs-devices-system-cpu

+18 −0
Original line number Diff line number Diff line
@@ -327,6 +327,24 @@ Description: Energy performance preference 


		This file is only present if the cppc-cpufreq driver is in use.



What:		/sys/devices/system/cpu/cpuX/cpufreq/perf_limited

Date:		February 2026

Contact:	linux-pm@vger.kernel.org

Description:	Performance Limited



		Read to check if platform throttling (thermal/power/current

		limits) caused delivered performance to fall below the

		requested level. A non-zero value indicates throttling occurred.



		Write the bitmask of bits to clear:



		  - 0x1 = clear bit 0 (desired performance excursion)

		  - 0x2 = clear bit 1 (minimum performance excursion)

		  - 0x3 = clear both bits



		The platform sets these bits; OSPM can only clear them.



		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