[PATCH 06/14] powerpc/64s: interrupt replay balance the return branch predictor

[Michael Ellerman]

Nicholas Piggin <npiggin at gmail.com> writes:

> The __replay_interrupt code is branched to with bl, but the caller is
> returned to directly with rfid from the interrupt.
>
> Instead return to a return stub that returns to the caller with blr,
> which should do better with the return predictor.
>
> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
> ---
>  arch/powerpc/kernel/exceptions-64s.S | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
> index a04ee0d7f88e..d55201625ea3 100644
> --- a/arch/powerpc/kernel/exceptions-64s.S
> +++ b/arch/powerpc/kernel/exceptions-64s.S
> @@ -1586,7 +1586,7 @@ _GLOBAL(__replay_interrupt)
>  	 * we don't give a damn about, so we don't bother storing them.
>  	 */
>  	mfmsr	r12
> -	mflr	r11
> +	LOAD_REG_ADDR(r11, __replay_interrupt_return)

Can you make it a local label, to make it clear nothing outside the file
returns to there, and to not clutter the symbol map?

cheers