[V2,0/3] hwmon (coretemp): Add support for dynamic tjmax/ttarget

Message

Zhang Rui Nov. 13, 2022, 3:31 p.m. UTC

Tjmax value retrieved from MSR_IA32_TEMPERATURE_TARGET can be changed at
runtime when the Intel SST-PP (Intel Speed Select Technology - Performance
Profile) level is changed. As a result, the ttarget temperature also changes.

Enhance the coretemp driver to always use updated tjmax when it can be
retrieved from MSR_IA32_TEMPERATURE_TARGET.

When tjmax can not be retrieved from MSR_IA32_TEMPERATURE_TARGET, stick with
previous behavior and always use static value. Plus that ttarget is not
available in this case.

The same dynaimic tjmax enhancement, for driver/thermal drivers can be found
at https://patchwork.kernel.org/project/linux-pm/list/?series=693050

thanks,
rui

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Changes since V1:
- rearrange the code to avoid forward declaration
- optimize logic to check target temperature support only once
- coding style changes