[patch 27/60] x86 setup: add a near jump to serialize %cr0 on 386/486

[Greg KH <gregkh@suse.de>]

2.6.23-stable review patch.  If anyone has any objections, please let us
know.

------------------
From: H. Peter Anvin <hpa@zytor.com>

patch 7ed192906a2144ebc8ca2925a85d27b9c5355668 in mainline.

The 386 and 486 needs a jump immediately after setting %cr0 in order
to serialize the pipeline.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 arch/i386/boot/pmjump.S |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/i386/boot/pmjump.S
+++ b/arch/i386/boot/pmjump.S
@@ -31,14 +31,14 @@ protected_mode_jump:
 	xorl	%ebx, %ebx		# Flag to indicate this is a boot
 	movl	%edx, %esi		# Pointer to boot_params table
 	movl	%eax, 2f		# Patch ljmpl instruction
-	jmp	1f			# Short jump to flush instruction q.
 
-1:
 	movw	$__BOOT_DS, %cx
 
 	movl	%cr0, %edx
 	orb	$1, %dl			# Protected mode (PE) bit
 	movl	%edx, %cr0
+	jmp	1f			# Short jump to serialize on 386/486
+1:
 
 	movw	%cx, %ds
 	movw	%cx, %es

-- 
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