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x86, head_32: Remove second CPUID detection from default_entry

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We do that once earlier now and cache it into new_cpu_data.cpuid_level
so no need for the EFLAGS.ID toggling dance anymore.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1360592538-10643-4-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
This commit is contained in:
Borislav Petkov 2013-02-11 15:22:17 +01:00 committed by H. Peter Anvin
parent 9efb58de91
commit c3a22a26d0
1 changed files with 4 additions and 13 deletions
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17
arch/x86/kernel/head_32.S
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@ -399,18 +399,7 @@ default_entry:
/*
* Check if it is 486
*/
movl $-1,X86_CPUID # -1 for no CPUID initially
movb $4,X86 # at least 486
pushfl # push EFLAGS
popl %eax # get EFLAGS
movl %eax,%ecx # save original EFLAGS
xorl $0x200000,%eax # flip ID bit in EFLAGS
pushl %eax # copy to EFLAGS
popfl # set EFLAGS
pushfl # get new EFLAGS
popl %eax # put it in eax
xorl %ecx,%eax # change in flags
testl $0x200000,%eax # check if ID bit changed
cmpl $-1,X86_CPUID
je is486
/* get vendor info */
@ -436,7 +425,9 @@ default_entry:
movb %cl,X86_MASK
movl %edx,X86_CAPABILITY
is486: movl $0x50022,%ecx # set AM, WP, NE and MP
is486:
movb $4,X86
movl $0x50022,%ecx # set AM, WP, NE and MP
movl %cr0,%eax
andl $0x80000011,%eax # Save PG,PE,ET
orl %ecx,%eax