x86: Fix for cache computation on AMD legacy cpus.
Some legacy AMD CPUs and hypervisors have the _cpuid_ '0x8000_001D'
set to Zero, thus resulting in zeroed-out computed cache values.
This patch reintroduces the old way of cache computation as a
fail-safe option to handle these exceptions.
Fixed 'level4_cache_size' value through handle_amd().
Fixed for 2.39 via:
commit dcad5c8578130de c7f35fd5b088530 4b59f9f543
Author: Sajan Karumanchi <email address hidden>
Date: Tue Aug 1 15:20:55 2023 +0000
x86: Fix for cache computation on AMD legacy cpus.
Some legacy AMD CPUs and hypervisors have the _cpuid_ '0x8000_001D'
set to Zero, thus resulting in zeroed-out computed cache values.
This patch reintroduces the old way of cache computation as a
fail-safe option to handle these exceptions.
Fixed 'level4_cache_size' value through handle_amd().
Reviewed-by: Premachandra Mallappa <email address hidden>
Tested-by: Florian Weimer <email address hidden>
It seems that we are still missing the backport to 2.37.