x86, head_32: Remove i386 pieces

Remove code fragments detecting a 386 CPU since we don't support those
anymore. Also, do not do alignment checks because they're done only at
CPL3. Also, no need to preserve EFLAGS.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1360592538-10643-2-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

1 files changed, 5 insertions, 17 deletions

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index c8932c79e78b..a9c5cc851285 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -394,30 +394,21 @@ default_entry:
         jz 1f                           # Did we do this already?
         call *%eax
 1:
-        
-/* check if it is 486 or 386. */
+
 /*
- * XXX - this does a lot of unnecessary setup.  Alignment checks don't
- * apply at our cpl of 0 and the stack ought to be aligned already, and
- * we don't need to preserve eflags.
+ * Check if it is 486
  */
         movl $-1,X86_CPUID      # -1 for no CPUID initially
-        movb $3,X86             # at least 386
+        movb $4,X86             # at least 486
         pushfl                  # push EFLAGS
         popl %eax               # get EFLAGS
         movl %eax,%ecx          # save original EFLAGS
-        xorl $0x240000,%eax     # flip AC and ID bits in 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
-        pushl %ecx              # restore original EFLAGS
-        popfl
-        testl $0x40000,%eax     # check if AC bit changed
-        je is386
-
-        movb $4,X86             # at least 486
         testl $0x200000,%eax    # check if ID bit changed
         je is486
 
@@ -445,10 +436,7 @@ default_entry:
         movl %edx,X86_CAPABILITY
 
 is486:  movl $0x50022,%ecx      # set AM, WP, NE and MP
-        jmp 2f
-
-is386:  movl $2,%ecx            # set MP
-2:      movl %cr0,%eax
+        movl %cr0,%eax
         andl $0x80000011,%eax   # Save PG,PE,ET
         orl %ecx,%eax
         movl %eax,%cr0