Currently limited to Zen 3, AMD has revealed their work on a brand new CPU frequency control mechanism "amd-pstate".
What's this for then? Well, it was previously announced that AMD along with Valve were working on it with a talk that was presented during the X.Org Developers Conference 2021. Seems this is it and they're ready to properly introduce it. Announced on the Linux Kernel mailing list from developer Huang Rui:
The new mechanism is based on Collaborative processor performance control (CPPC) which is finer grain frequency management than legacy ACPI hardware P-States. Current AMD CPU platforms are using the ACPI P-states driver to manage CPU frequency and clocks with switching only in 3 P-states. AMD P-States is to replace the ACPI P-states controls, allows a flexible, low-latency interface for the Linux kernel to directly communicate the performance hints to hardware.
"amd-pstate" leverages the Linux kernel governors such as *schedutil*, *ondemand*, etc. to manage the performance hints which are provided by CPPC hardware functionality. The first version for amd-pstate is to support one of the Zen3 processors, and we will support more in future after we verify the hardware and SBIOS functionalities.
There's a bit more of an explanation available in part 19 of the patchset, which goes over plenty more of the technical details if you want the real nitty-gritty.
Great to see AMD continue to advance their processors on Linux. Hopefully this will provide a better overall experience for all workloads, especially gaming. Highly likely this will benefit the likes of the Steam Deck too, which will be using a special Zen 2 AMD APU.