| Message ID | 20180618101919.51973-10-mark.rutland@arm.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | atomics: API cleanups | expand |
On Mon, Jun 18, 2018 at 11:19:10AM +0100, Mark Rutland wrote: > As a step towards unifying the atomic/atomic64/atomic_long APIs, this > patch converts the arch/alpha implementation of atomic64_add_unless() into > an implementation of atomic64_fetch_add_unless(). > > A wrapper in <linux/atomic.h> will build atomic_add_unless() atop of > this, provided it is given a preprocessor definition. > > No functional change is intended as a result of this patch. > > Signed-off-by: Mark Rutland <mark.rutland@arm.com> > Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> > Cc: Boqun Feng <boqun.feng@gmail.com> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Richard Henderson <rth@twiddle.net> > Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> > Cc: Matt Turner <mattst88@gmail.com> > --- > arch/alpha/include/asm/atomic.h | 23 ++++++++++++----------- > 1 file changed, 12 insertions(+), 11 deletions(-) > > diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h > index 4a800a3424a3..dcb7bbeeae02 100644 > --- a/arch/alpha/include/asm/atomic.h > +++ b/arch/alpha/include/asm/atomic.h > @@ -238,35 +238,36 @@ static __inline__ int atomic_fetch_add_unless(atomic_t *v, int a, int u) > #define atomic_fetch_add_unless atomic_fetch_add_unless > > /** > - * atomic64_add_unless - add unless the number is a given value > + * atomic64_fetch_add_unless - add unless the number is a given value > * @v: pointer of type atomic64_t > * @a: the amount to add to v... > * @u: ...unless v is equal to u. > * > * Atomically adds @a to @v, so long as it was not @u. > - * Returns true iff @v was not @u. > + * Returns the old value of @v. > */ > -static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) > +static __inline__ int atomic64_fetch_add_unless(atomic64_t *v, long a, long u) Don't you want a 64-bit return type (e.g. long) here? Will
On Mon, Jun 18, 2018 at 04:54:40PM +0100, Will Deacon wrote: > On Mon, Jun 18, 2018 at 11:19:10AM +0100, Mark Rutland wrote: > > /** > > - * atomic64_add_unless - add unless the number is a given value > > + * atomic64_fetch_add_unless - add unless the number is a given value > > * @v: pointer of type atomic64_t > > * @a: the amount to add to v... > > * @u: ...unless v is equal to u. > > * > > * Atomically adds @a to @v, so long as it was not @u. > > - * Returns true iff @v was not @u. > > + * Returns the old value of @v. > > */ > > -static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) > > +static __inline__ int atomic64_fetch_add_unless(atomic64_t *v, long a, long u) > Whoops; yes. From a scan of the series, I messed that up in the instrumentation, too, but the rest sems fine. I'll fix those up and push out an updated branch. Thanks, Mark.
* Mark Rutland <mark.rutland@arm.com> wrote: > On Mon, Jun 18, 2018 at 04:54:40PM +0100, Will Deacon wrote: > > On Mon, Jun 18, 2018 at 11:19:10AM +0100, Mark Rutland wrote: > > > /** > > > - * atomic64_add_unless - add unless the number is a given value > > > + * atomic64_fetch_add_unless - add unless the number is a given value > > > * @v: pointer of type atomic64_t > > > * @a: the amount to add to v... > > > * @u: ...unless v is equal to u. > > > * > > > * Atomically adds @a to @v, so long as it was not @u. > > > - * Returns true iff @v was not @u. > > > + * Returns the old value of @v. > > > */ > > > -static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) > > > +static __inline__ int atomic64_fetch_add_unless(atomic64_t *v, long a, long u) > > > > Whoops; yes. > > From a scan of the series, I messed that up in the instrumentation, too, > but the rest sems fine. > > I'll fix those up and push out an updated branch. Please send out an updated series via email as well once it has all settled down. Thanks! Ingo
diff --git a/arch/alpha/include/asm/atomic.h b/arch/alpha/include/asm/atomic.h index 4a800a3424a3..dcb7bbeeae02 100644 --- a/arch/alpha/include/asm/atomic.h +++ b/arch/alpha/include/asm/atomic.h @@ -238,35 +238,36 @@ static __inline__ int atomic_fetch_add_unless(atomic_t *v, int a, int u) #define atomic_fetch_add_unless atomic_fetch_add_unless /** - * atomic64_add_unless - add unless the number is a given value + * atomic64_fetch_add_unless - add unless the number is a given value * @v: pointer of type atomic64_t * @a: the amount to add to v... * @u: ...unless v is equal to u. * * Atomically adds @a to @v, so long as it was not @u. - * Returns true iff @v was not @u. + * Returns the old value of @v. */ -static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u) +static __inline__ int atomic64_fetch_add_unless(atomic64_t *v, long a, long u) { - long c, tmp; + long c, new, old; smp_mb(); __asm__ __volatile__( - "1: ldq_l %[tmp],%[mem]\n" - " cmpeq %[tmp],%[u],%[c]\n" - " addq %[tmp],%[a],%[tmp]\n" + "1: ldq_l %[old],%[mem]\n" + " cmpeq %[old],%[u],%[c]\n" + " addq %[old],%[a],%[new]\n" " bne %[c],2f\n" - " stq_c %[tmp],%[mem]\n" - " beq %[tmp],3f\n" + " stq_c %[new],%[mem]\n" + " beq %[new],3f\n" "2:\n" ".subsection 2\n" "3: br 1b\n" ".previous" - : [tmp] "=&r"(tmp), [c] "=&r"(c) + : [old] "=&r"(old), [new] "=&r"(new), [c] "=&r"(c) : [mem] "m"(*v), [a] "rI"(a), [u] "rI"(u) : "memory"); smp_mb(); - return !c; + return old; } +#define atomic64_fetch_add_unless atomic64_fetch_add_unless /* * atomic64_dec_if_positive - decrement by 1 if old value positive