Re: [PATCH v6 02/17] s390: define get_cycles macro for arch-override

From: Heiko Carstens
Date: Mon Apr 25 2022 - 05:43:34 EST


On Sat, Apr 23, 2022 at 11:26:08PM +0200, Jason A. Donenfeld wrote:
> S390x defines a get_cycles() function, but it forgot to do the usual
> `#define get_cycles get_cycles` dance, making it impossible for generic
> code to see if an arch-specific function was defined.
>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Heiko Carstens <hca@xxxxxxxxxxxxx>
> Cc: Vasily Gorbik <gor@xxxxxxxxxxxxx>
> Cc: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
> Cc: Christian Borntraeger <borntraeger@xxxxxxxxxxxxx>
> Cc: Sven Schnelle <svens@xxxxxxxxxxxxx>
> Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx>
> ---
> arch/s390/include/asm/timex.h | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/s390/include/asm/timex.h b/arch/s390/include/asm/timex.h
> index 2cfce42aa7fc..ce878e85b6e4 100644
> --- a/arch/s390/include/asm/timex.h
> +++ b/arch/s390/include/asm/timex.h
> @@ -197,6 +197,7 @@ static inline cycles_t get_cycles(void)
> {
> return (cycles_t) get_tod_clock() >> 2;
> }
> +#define get_cycles get_cycles

As far as I can tell this doesn't change anything, since the
asm-generic timex.h header file is not included/used at all on s390
(and if it would, this would have resulted in a compile error).

FWIW, the compiled code also tells me that the s390 specific
get_cycles() version is already used.

Is any of your subsequent patches making sure that the asm generic
header file gets included everywhere? Otherwise I don't see the point
of this patch.