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>

1 files changed, 4 insertions, 13 deletions

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index e3725a0f4327..2e8532e7c80a 100644
--- 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