[RFC PATCH 12/12] powerpc/64s: power4 nap fixup in C

[Nicholas Piggin]

Excerpts from Christophe Leroy's message of September 7, 2020 2:48 pm:
> 
> 
> Le 07/09/2020 à 06:02, Nicholas Piggin a écrit :
>> Excerpts from Christophe Leroy's message of September 6, 2020 5:32 pm:
>>>
>>>
>>> Le 05/09/2020 à 19:43, Nicholas Piggin a écrit :
>>>> There is no need for this to be in asm, use the new intrrupt entry wrapper.
>>>>
>>>> Signed-off-by: Nicholas Piggin <npiggin at gmail.com>
>>>> ---
>>>>    arch/powerpc/include/asm/interrupt.h   | 14 ++++++++
>>>>    arch/powerpc/include/asm/processor.h   |  1 +
>>>>    arch/powerpc/include/asm/thread_info.h |  6 ++++
>>>>    arch/powerpc/kernel/exceptions-64s.S   | 45 --------------------------
>>>>    arch/powerpc/kernel/idle_book3s.S      |  4 +++
>>>>    5 files changed, 25 insertions(+), 45 deletions(-)
>>>>
>>>> diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
>>>> index ed0d633ab5aa..3da1dba91386 100644
>>>> --- a/arch/powerpc/include/asm/processor.h
>>>> +++ b/arch/powerpc/include/asm/processor.h
>>>> @@ -424,6 +424,7 @@ extern unsigned long isa300_idle_stop_mayloss(unsigned long psscr_val);
>>>>    extern unsigned long isa206_idle_insn_mayloss(unsigned long type);
>>>>    #ifdef CONFIG_PPC_970_NAP
>>>>    extern void power4_idle_nap(void);
>>>> +extern void power4_idle_nap_return(void);
>>>
>>> Please please please, 'extern' keyword is pointless and deprecated for
>>> function prototypes. Don't add new ones.
>>>
>>> Also, put it outside the #ifdef, so that you can use IS_ENABLED()
>>> instead of #ifdef when using it.
>> 
>> I just copy paste and forget to remove it. I expect someone will do a
>> "cleanup" patch to get rid of them in one go, I find a random assortment
>> of extern and not extern to be even uglier :(
> 
> If we don't want to make fixes backporting a huge headache, some 
> transition with random assortment is the price to pay.
> 
> One day, when 'extern' have become the minority, we can get rid of the 
> few last ones.
> 
> But if someone believe it is not such a problem with backporting, I can 
> provide a cleanup patch now.

I can't really see declarations being a big problem for backporting
or git history. But maybe Michael won't like a patch.

I will try to remember externs though.

Thanks,
Nick