linux-kernel - [tip:x86/cpu] x86: Fix override new_cpu

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Date:	Fri, 5 Jul 2013 07:25:00 -0700
From:	tip-bot for Wang YanQing <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	linux-kernel@...r.kernel.org, hpa@...or.com, mingo@...nel.org,
	tglx@...utronix.de, hpa@...ux.intel.com, bp@...e.de,
	udknight@...il.com
Subject: [tip:x86/cpu] x86: Fix override new_cpu_data.x86 with 486

Commit-ID:  237d1548543312fcc8c99d302ab68fbf8ef6f97f
Gitweb:     http://git.kernel.org/tip/237d1548543312fcc8c99d302ab68fbf8ef6f97f
Author:     Wang YanQing <udknight@...il.com>
AuthorDate: Fri, 28 Jun 2013 22:45:16 +0800
Committer:  H. Peter Anvin <hpa@...ux.intel.com>
CommitDate: Fri, 28 Jun 2013 15:27:29 -0700

x86: Fix override new_cpu_data.x86 with 486

We should set X86 to 486 before use cpuid to detect the cpu type, if
we set X86 to 486 after cpuid, then we will get 486 until cpu_detect
runs.

Signed-off-by: Wang YanQing <udknight@...il.com>
Link: http://lkml.kernel.org/r/20130628144516.GA2177@udknight
Acked-by: Borislav Petkov <bp@...e.de>
Signed-off-by: H. Peter Anvin <hpa@...ux.intel.com>
---
 arch/x86/kernel/head_32.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index e65ddc6..fe79573 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -410,6 +410,7 @@ enable_paging:
 /*
  * Check if it is 486
  */
+	movb $4,X86			# at least 486
 	cmpl $-1,X86_CPUID
 	je is486
 
@@ -437,7 +438,6 @@ enable_paging:
 	movl %edx,X86_CAPABILITY
 
 is486:
-	movb $4,X86
 	movl $0x50022,%ecx	# set AM, WP, NE and MP
 	movl %cr0,%eax
 	andl $0x80000011,%eax	# Save PG,PE,ET
--
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