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[PATCH 2/4] Revert "x86/boot: Fail the boot if !M486 and CPUID is missing"

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This reverts commit ed68d7e9b9cfb64f3045ffbcb108df03c09a0f98.

The patch wasn't quite correct -- there are non-Intel (and hence
non-486) CPUs that we support that don't have CPUID.  Since we no
longer require CPUID for sync_core(), just revert the patch.

In principle, we should try to do better at identifying CPUID-less
CPUs in early boot, but that's more complicated.

Reported-by: One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk>
Cc: Matthew Whitehead <tedheadster@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
 arch/x86/boot/cpu.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/arch/x86/boot/cpu.c b/arch/x86/boot/cpu.c
index 4224ede43b4e..26240dde081e 100644
--- a/arch/x86/boot/cpu.c
+++ b/arch/x86/boot/cpu.c
@@ -87,12 +87,6 @@ int validate_cpu(void)
 		return -1;
 	}
 
-	if (CONFIG_X86_MINIMUM_CPU_FAMILY <= 4 && !IS_ENABLED(CONFIG_M486) &&
-	    !has_eflag(X86_EFLAGS_ID)) {
-		printf("This kernel requires a CPU with the CPUID instruction.  Build with CONFIG_M486=y to run on this CPU.\n");
-		return -1;
-	}
-
 	if (err_flags) {
 		puts("This kernel requires the following features "
 		     "not present on the CPU:\n");
-- 
2.9.3

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[PATCH 2/4] Revert "x86/boot: Fail the boot if !M486 and CPUID is missing" Andy Lutomirski <luto@kernel.org> - 2016-11-30 21:40 +0100
  Re: [PATCH 2/4] Revert "x86/boot: Fail the boot if !M486 and CPUID  is missing" Peter Zijlstra <peterz@infradead.org> - 2016-12-01 07:00 +0100
    Re: [PATCH 2/4] Revert "x86/boot: Fail the boot if !M486 and CPUID  is missing" Borislav Petkov <bp@alien8.de> - 2016-12-01 10:10 +0100
      Re: [PATCH 2/4] Revert "x86/boot: Fail the boot if !M486 and CPUID  is missing" Thomas Gleixner <tglx@linutronix.de> - 2016-12-01 11:20 +0100
        [PATCH] x86/CPU: Add X86_FEATURE_CPUID Borislav Petkov <bp@alien8.de> - 2016-12-01 12:20 +0100
          Re: [PATCH] x86/CPU: Add X86_FEATURE_CPUID Andy Lutomirski <luto@amacapital.net> - 2016-12-01 18:10 +0100
      Re: [PATCH 2/4] Revert "x86/boot: Fail the boot if !M486 and CPUID is missing" Andy Lutomirski <luto@amacapital.net> - 2016-12-02 01:40 +0100
    Re: [PATCH 2/4] Revert "x86/boot: Fail the boot if !M486 and CPUID is missing" Andy Lutomirski <luto@amacapital.net> - 2016-12-01 18:10 +0100

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