[PATCH 0/3] x86: Make processor vendor selection available without EXPERT

[Vincent Mailhol]

Restricting a kernel build to a known CPU vendor currently requires
enabling EXPERT.

Make PROCESSOR_SELECT available without EXPERT. It remains disabled by
default, preserving support for all applicable CPU vendors in existing
configurations.

This allows someone to deselect the irrelevant CPU vendors when building
a kernel for a specific machine without having to navigate in the EXPERT
menu option. Doing that reduces the questions asked when doing a

  make oldconfig

during a kernel update.

This also simplifies kernel trimming when building for a given
machine. In comparison to an x86_64 defconfig, the final vmlinux.o
image size decreases by 0.35% for an Intel-only configuration and by
8.88% for an AMD-only one.

In addition to the above, several CPU-specific options lack proper
dependencies and remain available when support for their processor
vendor has been disabled.

The first two patches fix the missing CPU_SUP_* dependencies by
properly gating features that would otherwise be useless without that
specific CPU vendor support, namely:

  - Intel and Zhaoxin machine-check extensions
  - legacy AMD NUMA detection

The third and final patch is the main change and removes the EXPERT
dependency from PROCESSOR_SELECT.

Signed-off-by: Vincent Mailhol <mailhol@xxxxxxxxxx>
---
Vincent Mailhol (3):
      x86/mce: Add CPU_SUP_* dependencies for Intel/Zhaoxin MCE features
      x86/numa: Add CPU_SUP_AMD dependency for legacy AMD NUMA
      x86/cpu: don't gate PROCESSOR_SELECT with EXPERT

 arch/x86/Kconfig     |  4 ++--
 arch/x86/Kconfig.cpu | 22 +++++-----------------
 2 files changed, 7 insertions(+), 19 deletions(-)
---
base-commit: 36aad21d50d1af3f6954bb0c988257a908202477
change-id: 20261030-processor_select_is_not_an_expert_feature-4f329d352ec3

Best regards,
--  
Vincent Mailhol <mailhol@xxxxxxxxxx>