[PATCH 0/4] CPUID-less CPU fixes and improvements

[Andy Lutomirski]

*** PATCHES 1 and 2 MAY BE 4.9 MATERIAL ***

Alan Cox pointed out that the 486 isn't the only supported CPU that
doesn't have CPUID.  Let's clean up the mess.

Patch 1 is intended to be an easy fix: it makes sync_core() work
without CPUID on all 32-bit kernels.  It should be quite safe.  This
will have a negligible performance cost during boot on kernels built
for newer CPUs.  With this in place, patch 2 reverts the buggy 486
check I added.

Patches 3 and 4 are meant to improve the situation.  Patch 3 cleans
up the Intel microcode loader and patch 4 (which depends on patch 3)
stops using CPUID in sync_core() altogether.

Andy Lutomirski (4):
  x86/asm/32: Make sync_core() handle missing CPUID on all 32-bit
    kernels
  Revert "x86/boot: Fail the boot if !M486 and CPUID is missing"
  x86/microcode/intel: Replace sync_core() with cpuid_eax(1)
  x86/asm: Change sync_core() to use MOV to CR2 to serialize

 arch/x86/boot/cpu.c                   |  6 ------
 arch/x86/include/asm/processor.h      | 31 ++++++++-----------------------
 arch/x86/kernel/cpu/microcode/intel.c |  6 +++---
 3 files changed, 11 insertions(+), 32 deletions(-)

-- 
2.9.3