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>

diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index c8932c7..a9c5cc8 100644 (file)
--- 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