[PATCH -v4 01/12] locking/atomic: Introduce inc/dec calls for FETCH-OP flavors

[Davidlohr Bueso]

With the inclusion of atomic FETCH-OP variants, many places in the
kernel can make use of atomic_fetch_$op() to avoid the callers that
need to compute the value/state _before_ the operation. Peter laid
out the machinery but we are still missing the simpler dec,inc calls
(which future patches will make use of).

This patch only deals with the generic code, as at least right now
no arch actually implement them -- which is similar to what the
OP-RETURN primitives currently do.

Signed-off-by: Davidlohr Bueso <dbueso@xxxxxxx>
---

include/asm-generic/atomic-long.h |  22 +++++++
include/linux/atomic.h            | 128 ++++++++++++++++++++++++++++++++++++++
2 files changed, 150 insertions(+)

diff --git a/include/asm-generic/atomic-long.h b/include/asm-generic/atomic-long.h
index 2d0d3cf791ab..288cc9e96395 100644
--- a/include/asm-generic/atomic-long.h
+++ b/include/asm-generic/atomic-long.h
@@ -146,6 +146,28 @@ ATOMIC_LONG_FETCH_OP(xor, _relaxed)
ATOMIC_LONG_FETCH_OP(xor, _acquire)
ATOMIC_LONG_FETCH_OP(xor, _release)

+#undef ATOMIC_LONG_FETCH_OP
+
+#define ATOMIC_LONG_FETCH_INC_DEC_OP(op, mo)					\
+static inline long							\
+atomic_long_fetch_##op##mo(atomic_long_t *l)				\
+{									\
+	ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;		\
+									\
+	return (long)ATOMIC_LONG_PFX(_fetch_##op##mo)(v);		\
+}
+
+ATOMIC_LONG_FETCH_INC_DEC_OP(inc,)
+ATOMIC_LONG_FETCH_INC_DEC_OP(inc, _relaxed)
+ATOMIC_LONG_FETCH_INC_DEC_OP(inc, _acquire)
+ATOMIC_LONG_FETCH_INC_DEC_OP(inc, _release)
+ATOMIC_LONG_FETCH_INC_DEC_OP(dec,)
+ATOMIC_LONG_FETCH_INC_DEC_OP(dec, _relaxed)
+ATOMIC_LONG_FETCH_INC_DEC_OP(dec, _acquire)
+ATOMIC_LONG_FETCH_INC_DEC_OP(dec, _release)
+
+#undef ATOMIC_LONG_FETCH_INC_DEC_OP
+
#define ATOMIC_LONG_OP(op)						\
static __always_inline void						\
atomic_long_##op(long i, atomic_long_t *l)				\
diff --git a/include/linux/atomic.h b/include/linux/atomic.h
index 12d910d61b83..e71835bf60a9 100644
--- a/include/linux/atomic.h
+++ b/include/linux/atomic.h
@@ -188,6 +188,38 @@
#endif
#endif /* atomic_fetch_add_relaxed */

+/* atomic_fetch_inc_relaxed */
+#ifndef atomic_fetch_inc_relaxed
+
+#ifndef atomic_fetch_inc
+#define atomic_fetch_inc(v)	        atomic_fetch_add(1, (v))
+#define atomic_fetch_inc_relaxed(v)	atomic_fetch_add_relaxed(1, (v))
+#define atomic_fetch_inc_acquire(v)	atomic_fetch_add_acquire(1, (v))
+#define atomic_fetch_inc_release(v)	atomic_fetch_add_release(1, (v))
+#else /* atomic_fetch_inc */
+#define atomic_fetch_inc_relaxed	atomic_fetch_inc
+#define atomic_fetch_inc_acquire	atomic_fetch_inc
+#define atomic_fetch_inc_release	atomic_fetch_inc
+#endif /* atomic_fetch_inc */
+
+#else /* atomic_fetch_inc_relaxed */
+
+#ifndef atomic_fetch_inc_acquire
+#define atomic_fetch_inc_acquire(...)					\
+	__atomic_op_acquire(atomic_fetch_inc, __VA_ARGS__)
+#endif
+
+#ifndef atomic_fetch_inc_release
+#define atomic_fetch_inc_release(...)					\
+	__atomic_op_release(atomic_fetch_inc, __VA_ARGS__)
+#endif
+
+#ifndef atomic_fetch_inc
+#define atomic_fetch_inc(...)						\
+	__atomic_op_fence(atomic_fetch_inc, __VA_ARGS__)
+#endif
+#endif /* atomic_fetch_inc_relaxed */
+
/* atomic_fetch_sub_relaxed */
#ifndef atomic_fetch_sub_relaxed
#define atomic_fetch_sub_relaxed	atomic_fetch_sub
@@ -212,6 +244,38 @@
#endif
#endif /* atomic_fetch_sub_relaxed */

+/* atomic_fetch_dec_relaxed */
+#ifndef atomic_fetch_dec_relaxed
+
+#ifndef atomic_fetch_dec
+#define atomic_fetch_dec(v)	        atomic_fetch_sub(1, (v))
+#define atomic_fetch_dec_relaxed(v)	atomic_fetch_sub_relaxed(1, (v))
+#define atomic_fetch_dec_acquire(v)	atomic_fetch_sub_acquire(1, (v))
+#define atomic_fetch_dec_release(v)	atomic_fetch_sub_release(1, (v))
+#else /* atomic_fetch_dec */
+#define atomic_fetch_dec_relaxed	atomic_fetch_dec
+#define atomic_fetch_dec_acquire	atomic_fetch_dec
+#define atomic_fetch_dec_release	atomic_fetch_dec
+#endif /* atomic_fetch_dec */
+
+#else /* atomic_fetch_dec_relaxed */
+
+#ifndef atomic_fetch_dec_acquire
+#define atomic_fetch_dec_acquire(...)					\
+	__atomic_op_acquire(atomic_fetch_dec, __VA_ARGS__)
+#endif
+
+#ifndef atomic_fetch_dec_release
+#define atomic_fetch_dec_release(...)					\
+	__atomic_op_release(atomic_fetch_dec, __VA_ARGS__)
+#endif
+
+#ifndef atomic_fetch_dec
+#define atomic_fetch_dec(...)						\
+	__atomic_op_fence(atomic_fetch_dec, __VA_ARGS__)
+#endif
+#endif /* atomic_fetch_dec_relaxed */
+
/* atomic_fetch_or_relaxed */
#ifndef atomic_fetch_or_relaxed
#define atomic_fetch_or_relaxed	atomic_fetch_or
@@ -697,6 +761,38 @@ static inline int atomic_dec_if_positive(atomic_t *v)
#endif
#endif /* atomic64_fetch_add_relaxed */

+/* atomic64_fetch_inc_relaxed */
+#ifndef atomic64_fetch_inc_relaxed
+
+#ifndef atomic64_fetch_inc
+#define atomic64_fetch_inc(v)		atomic64_fetch_add(1, (v))
+#define atomic64_fetch_inc_relaxed(v)	atomic64_fetch_add_relaxed(1, (v))
+#define atomic64_fetch_inc_acquire(v)	atomic64_fetch_add_acquire(1, (v))
+#define atomic64_fetch_inc_release(v)	atomic64_fetch_add_release(1, (v))
+#else /* atomic64_fetch_inc */
+#define atomic64_fetch_inc_relaxed	atomic64_fetch_inc
+#define atomic64_fetch_inc_acquire	atomic64_fetch_inc
+#define atomic64_fetch_inc_release	atomic64_fetch_inc
+#endif /* atomic64_fetch_inc */
+
+#else /* atomic64_fetch_inc_relaxed */
+
+#ifndef atomic64_fetch_inc_acquire
+#define atomic64_fetch_inc_acquire(...)					\
+	__atomic_op_acquire(atomic64_fetch_inc, __VA_ARGS__)
+#endif
+
+#ifndef atomic64_fetch_inc_release
+#define atomic64_fetch_inc_release(...)					\
+	__atomic_op_release(atomic64_fetch_inc, __VA_ARGS__)
+#endif
+
+#ifndef atomic64_fetch_inc
+#define atomic64_fetch_inc(...)						\
+	__atomic_op_fence(atomic64_fetch_inc, __VA_ARGS__)
+#endif
+#endif /* atomic64_fetch_inc_relaxed */
+
/* atomic64_fetch_sub_relaxed */
#ifndef atomic64_fetch_sub_relaxed
#define atomic64_fetch_sub_relaxed	atomic64_fetch_sub
@@ -721,6 +817,38 @@ static inline int atomic_dec_if_positive(atomic_t *v)
#endif
#endif /* atomic64_fetch_sub_relaxed */

+/* atomic64_fetch_dec_relaxed */
+#ifndef atomic64_fetch_dec_relaxed
+
+#ifndef atomic64_fetch_dec
+#define atomic64_fetch_dec(v)		atomic64_fetch_sub(1, (v))
+#define atomic64_fetch_dec_relaxed(v)	atomic64_fetch_sub_relaxed(1, (v))
+#define atomic64_fetch_dec_acquire(v)	atomic64_fetch_sub_acquire(1, (v))
+#define atomic64_fetch_dec_release(v)	atomic64_fetch_sub_release(1, (v))
+#else /* atomic64_fetch_dec */
+#define atomic64_fetch_dec_relaxed	atomic64_fetch_dec
+#define atomic64_fetch_dec_acquire	atomic64_fetch_dec
+#define atomic64_fetch_dec_release	atomic64_fetch_dec
+#endif /* atomic64_fetch_dec */
+
+#else /* atomic64_fetch_dec_relaxed */
+
+#ifndef atomic64_fetch_dec_acquire
+#define atomic64_fetch_dec_acquire(...)					\
+	__atomic_op_acquire(atomic64_fetch_dec, __VA_ARGS__)
+#endif
+
+#ifndef atomic64_fetch_dec_release
+#define atomic64_fetch_dec_release(...)					\
+	__atomic_op_release(atomic64_fetch_dec, __VA_ARGS__)
+#endif
+
+#ifndef atomic64_fetch_dec
+#define atomic64_fetch_dec(...)						\
+	__atomic_op_fence(atomic64_fetch_dec, __VA_ARGS__)
+#endif
+#endif /* atomic64_fetch_dec_relaxed */
+
/* atomic64_fetch_or_relaxed */
#ifndef atomic64_fetch_or_relaxed
#define atomic64_fetch_or_relaxed	atomic64_fetch_or
--
2.6.6