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Date: Sat, 9 Feb 2013 20:52:52 +0100 From: Borislav Petkov <bp@...en8.de> To: "H. Peter Anvin" <hpa@...or.com> Cc: X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>, Borislav Petkov <bp@...e.de> Subject: [PATCH 3/5] x86, head_32: Remove second CPUID detection from default_entry From: Borislav Petkov <bp@...e.de> 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@...e.de> --- arch/x86/kernel/head_32.S | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-) diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index df0b324d2854..46aa51467c0e 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -409,18 +409,7 @@ 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 */ @@ -446,7 +435,9 @@ 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 -- 1.8.1.3.535.ga923c31 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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