Re: [PATCH 13/15] x86/cpu: Make CONFIG_X86_CX8 unconditional

From: Arnd Bergmann
Date: Fri Apr 25 2025 - 08:10:55 EST


On Fri, Apr 25, 2025, at 10:42, Ingo Molnar wrote:
> @@ -257,7 +256,7 @@ config X86_MINIMUM_CPU_FAMILY
> int
> default "64" if X86_64
> default "6" if X86_32 && (MPENTIUM4 || MPENTIUMM || MPENTIUMIII ||
> MPENTIUMII || M686 || MVIAC3_2 || MVIAC7 || MEFFICEON || MATOM || MK7)
> - default "5" if X86_32 && X86_CX8
> + default "5" if X86_32
> default "4"
>

I just noticed this one: the final 'default "4"' is no longer possible
here and can be removed. All the remaining CPUs report family "5" or
higher.

There is an old issue for some rare CPUs (Geode LX and Crusoe) that
support CMOV but report family=6. These to boot a kernel with X86_MINIMUM_CPU_FAMILY=6 because it triggers the boot time check.

Arnd