x86, head_32: Remove second CPUID detection from default_entry

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>

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index e3725a0..2e8532e 100644 (file)
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -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