[PATCH v4 1/4] powernv:idle: Add IDLE_STATE_ENTER_SEQ_NORET macro

[Balbir Singh]

On 10/12/16 00:32, Gautham R. Shenoy wrote:
> From: "Gautham R. Shenoy" <ego at linux.vnet.ibm.com>
> 
> Currently all the low-power idle states are expected to wake up
> at reset vector 0x100. Which is why the macro IDLE_STATE_ENTER_SEQ
> that puts the CPU to an idle state and never returns.
> 
> On ISA_300, when the ESL and EC bits in the PSSCR are zero, the
> CPU is expected to wake up at the next instruction of the idle
> instruction.
> 
> This patch adds a new macro named IDLE_STATE_ENTER_SEQ_NORET for the
> no-return variant and reuses the name IDLE_STATE_ENTER_SEQ
> for a variant that allows resuming operation at the instruction next
> to the idle-instruction.
> 
> Signed-off-by: Gautham R. Shenoy <ego at linux.vnet.ibm.com>
> ---
>  arch/powerpc/include/asm/cpuidle.h   |  5 ++++-
>  arch/powerpc/kernel/exceptions-64s.S |  6 +++---
>  arch/powerpc/kernel/idle_book3s.S    | 10 +++++-----
>  3 files changed, 12 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/cpuidle.h b/arch/powerpc/include/asm/cpuidle.h
> index 3919332..0a3255b 100644
> --- a/arch/powerpc/include/asm/cpuidle.h
> +++ b/arch/powerpc/include/asm/cpuidle.h
> @@ -21,7 +21,7 @@
>  
>  /* Idle state entry routines */
>  #ifdef	CONFIG_PPC_P7_NAP
> -#define	IDLE_STATE_ENTER_SEQ(IDLE_INST)				\
> +#define IDLE_STATE_ENTER_SEQ(IDLE_INST)                         \
>  	/* Magic NAP/SLEEP/WINKLE mode enter sequence */	\
>  	std	r0,0(r1);					\
>  	ptesync;						\
> @@ -29,6 +29,9 @@
>  1:	cmpd	cr0,r0,r0;					\
>  	bne	1b;						\
>  	IDLE_INST;						\
> +

Is the power saving magic sequence the same as before for power 9
as well?

Balbir Singh