On Intel processors, the core frequency can be reduced below OS request,
when the current temperature reaches the TCC (Thermal Control Circuit)
activation temperature.
The default TCC activation temperature is specified by
MSR_IA32_TEMPERATURE_TARGET. However, it can be adjusted by specifying an
offset in degrees C, using the TCC Offset bits in the same MSR register.
This patch introduces a cooling devices driver that utilizes the TCC
Offset feature. The bigger the current cooling state is, the lower the
effective TCC activation temperature is, so that the processors can be
throttled earlier before system critical overheats.
Note that, on different platforms, the behavior might be different on
how fast the setting takes effect, and how much the CPU frequency is
reduced.
This patch has been tested on a KabyLake mobile platform from me, and also
on a CometLake platform from Doug.
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Tested by: Doug Smythies <dsmythies@telus.net>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210412125901.12549-1-rui.zhang@intel.com
This functionality has nothing to do with MCE, move it to the thermal
framework and untangle it from MCE.
Requested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Tested-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Link: https://lkml.kernel.org/r/20210202121003.GD18075@zn.tnic
This cleans up the directory a bit, now that we have several other
platforms using platform-specific sub-directories. Compile-tested with
ARCH=x86 defconfig and the drivers explicitly enabled with menuconfig.
Signed-off-by: Amit Kucheria <amit.kucheria@linaro.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Zhang Rui