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