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From: Wang YanQing <udknight@gmail.com>
To: hpa@zytor.com
Cc: tglx@linutronix.de, mingo@redhat.com, x86@kernel.org, bp@suse.de,
	fenghua.yu@intel.com, linux-kernel@vger.kernel.org
Subject: [PATCH] x86: Fix override new_cpu_data.x86 with 486
Date: Thu, 27 Jun 2013 00:26:40 +0800	[thread overview]
Message-ID: <20130626162640.GA19913@udknight> (raw)


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 for ever.

Yes, we will correct this in early_cpu_init,
but it is still a wrong behavior, right? So
just fix it.

I also find maybe we can delete the new_cpu_data,
because we will over write all the information
in early_cpu_init, and before early_cpu_init,
there is no user of new_cpu_data, but this is
another patch in the future.

Signed-off-by: Wang YanQing <udknight@gmail.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 73afd11..733a8ef 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
-- 
1.7.12.4.dirty

             reply	other threads:[~2013-06-26 16:27 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-06-26 16:26 Wang YanQing [this message]
2013-06-26 16:56 ` [PATCH] x86: Fix override new_cpu_data.x86 with 486 Borislav Petkov
2013-06-27 10:54 ` Borislav Petkov
2013-06-28  0:56   ` Wang YanQing
2013-06-28  8:51     ` Borislav Petkov

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