Re: [edk2-devel] [PATCH v2 2/2] UefiCpuPkg/BaseXApic[X2]ApicLib: Implements AMD extended cpu topology

["Gerd Hoffmann" <kraxel@redhat.com>]

> +  /// Check if extended toplogy supported
> +  AsmCpuid (CPUID_EXTENDED_FUNCTION, &MaxExtendedCpuIdIndex, NULL, NULL, NULL);
> +  if (MaxExtendedCpuIdIndex >= AMD_CPUID_EXTENDED_TOPOLOGY) {
> +    do {
> +      AsmCpuidEx (
> +        AMD_CPUID_EXTENDED_TOPOLOGY,
> +        TopologyLevel,
> +        &ExtendedTopologyEax.Uint32,
> +        &ExtendedTopologyEbx.Uint32,
> +        &ExtendedTopologyEcx.Uint32,
> +        NULL
> +        );
> +
> +      if (ExtendedTopologyEbx.Bits.LogicalProcessors == CPUID_EXTENDED_TOPOLOGY_LEVEL_TYPE_INVALID) {

Comparing LogicalProcessors with CPUID_EXTENDED_TOPOLOGY_LEVEL_TYPE_*
looks wrong, even though it probably works due to
CPUID_EXTENDED_TOPOLOGY_LEVEL_TYPE_INVALID being zero ...

> +        /// if this fails at first level
> +        /// then will fall back to non-extended topology
> +        break;
> +      }

> +    } while (ExtendedTopologyEbx.Bits.LogicalProcessors != CPUID_EXTENDED_TOPOLOGY_LEVEL_TYPE_INVALID);

Same here.  Also this will never be false because the check above
already quits the loop in that case, so you can simplify this to
"while (true)".

take care,
  Gerd



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