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Date: Fri, 10 Jul 2015 11:10:33 +0200
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Subject: Re: [RFC][PATCH 23/24] atomic: Collapse all atomic_{set,clear}_mask definitions
From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Linux-Arch <linux-arch@vger.kernel.org>,
        Richard Henderson <rth@twiddle.net>,
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        Russell King <linux@arm.linux.org.uk>,
        Will Deacon <will.deacon@arm.com>,
        =?UTF-8?Q?H=C3=A5vard_Skinnemoen?= <hskinnemoen@gmail.com>,
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        Heiko Carstens <heiko.carstens@de.ibm.com>,
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Hi Peter,

On Thu, Jul 9, 2015 at 7:29 PM, Peter Zijlstra <peterz@infradead.org> wrote:
> --- a/include/linux/atomic.h
> +++ b/include/linux/atomic.h
> @@ -28,6 +28,23 @@ static inline int atomic_add_unless(atom
>  #define atomic_inc_not_zero(v)         atomic_add_unless((v), 1, 0)
>  #endif
>
> +#ifndef atomic_nand
> +static inline void atomic_nand(int i, atomic_t *v)
> +{
> +       atomic_and(~i, v);

That sounds like a misnomer...

Your NAND is "A & ~B", while my[*] NAND is "~(A & B)"?

[*] https://en.wikipedia.org/wiki/NAND_logic

What about atomic_clear()? (Is atomic_bic() too ARM-centric?)

> +}
> +#endif
> +
> +static inline __deprecated void atomic_clear_mask(unsigned int mask, atomic_t *v)
> +{
> +       atomic_nand(mask, v);
> +}

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

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
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