Re: [RFC][PATCH 23/24] atomic: Collapse all atomic_{set,clear}_mask definitions

Vineet Gupta
2015-07-10T09:14:14Z

On Friday 10 July 2015 02:40 PM, Geert Uytterhoeven wrote:
> 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?)
>

ARM + ARC centric :-)

We have the BIC instruction as well which does the same: A & ~B

-Vineet