Re: [PATCH 13/13] atomics/treewide: make test ops optional

From: Geert Uytterhoeven
Date: Wed May 23 2018 - 09:10:13 EST


On Wed, May 23, 2018 at 3:35 PM, Mark Rutland <mark.rutland@xxxxxxx> wrote:
> Some of the atomics return the result of a test applied after the atomic
> operation, and almost all architectures implement these as trivial
> wrappers around the underlying atomic. Specifically:
>
> * <atomic>_inc_and_test(v) is (<atomic>_inc_return(v) == 0)
>
> * <atomic>_dec_and_test(v) is (<atomic>_dec_return(v) == 0)
>
> * <atomic>_sub_and_test(i, v) is (<atomic>_sub_return(i, v) == 0)
>
> * <atomic>_add_negative(i, v) is (<atomic>_add_return(i, v) < 0)
>
> Rather than have these definitions duplicated in all architectures, with
> minor inconsistencies in formatting and documentation, let's make these
> operations optional, with default fallbacks as above. Implementations
> must now provide a preprocessor symbol.
>
> The instrumented atomics are updated accordingly.
>
> Both x86 and m68k have custom implementations, which are left as-is,
> given preprocessor symbols to avoid being overridden.
>
> There should be no functional change as a result of this patch.
>
> Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>

> arch/m68k/include/asm/atomic.h | 4 +

For m68k:
Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds