Public bug reported:

BugLink: https://bugs.launchpad.net/bugs/2167550

[ Impact ]

This is a patch series as part of the effort to enable Zen 6 client
platform support on Ubuntu Stonking kernel.

The highest frequency a core supports is important to be able to
forecast capacity calculations. This information ideally comes from the
hardware, but the interface that provides it is guarded behind ACPI 6.7.

That means the patches for reading it can't be released until ACPI 6.7.

Since platform schedules are imminent, I decided to add some hardcoded
values. These aren't perfect (some OPNs will vary), but they at least
get capacity calculations closer to right.

They can help platform performance by up to 50%, so they're quite
important.

[ Fix ]

Pick up the following patch series:

1. [PATCH 0/3] Zen6 client CPPC

[ Test plan ]

For max frequency in each core type, confirmed that the max frequency
changes to hard-coded values in the patch accordingly
(/sys/devices/system/cpu/cpufreq/policyX/scaling_max_freq)

1. performance core: 5025000
2. low_power core: 2399000
3. efficiency core: 3524000

[ Were problems could occur ]

This includes refactor for AMD's cpufeq calculation algorithm. Wrong
refactors may impact performance on older Zen platforms.

[ Additional Information ]

https://lore.kernel.org/linux-
pm/[email protected]/

Follow up patches will be posted later using the ACPI 6.7 interface once
the ACPI 6.7 spec is released. We should plan to include them as well
later (even if after platform launches).

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: New

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https://bugs.launchpad.net/bugs/2167550

Title:
  Add support for CPPC values for Zen6

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