Re: [PATCH v4 09/11] cpufreq: amd-pstate: implement heterogeneous core topology for highest performance initialization

Borislav Petkov
2024-06-18T21:24:13Z

On Mon, Jun 17, 2024 at 02:59:11PM +0800, Perry Yuan wrote:
> Introduces an optimization to the AMD-Pstate driver by implementing
> a heterogeneous core topology for the initialization of the highest
> performance value while driver loading.
> The two core types supported are "performance" and "efficiency".
> Each core type has different highest performance and frequency values
> configured by the platform. The `amd_pstate` driver needs to identify
> the type of core to correctly set an appropriate highest perf value.
>
> X86_FEATURE_HETERO_CORE_TOPOLOGY is used to identify whether the
> processor support heterogeneous core type by reading CPUID leaf
> Fn_0x80000026_EAX and bit 30. if the bit is set as one, then amd_pstate
> driver will check EBX 30:28 bits to get the core type.

There will be a special ->cpu_type member for that eventually:

https://lore.kernel.org/r/20240617-add-cpu-type-v1-1-b88998c01e76@linux.intel.com

--
Regards/Gruss,
Boris.