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linux/include/asm-generic/atomic-long.h
Will Deacon 4df714be4d locking/atomic: Add atomic_cond_read_acquire() 
smp_cond_load_acquire() provides a way to spin on a variable with acquire
semantics until some conditional expression involving the variable is
satisfied. Architectures such as arm64 can potentially enter a low-power
state, waking up only when the value of the variable changes, which
reduces the system impact of tight polling loops.

This patch makes the same interface available to users of atomic_t,
atomic64_t and atomic_long_t, rather than require messy accesses to the
structure internals.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Jeremy.Linton@arm.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1507810851-306-3-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-25 10:57:24 +02:00

250 lines
6.9 KiB
C
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#ifndef _ASM_GENERIC_ATOMIC_LONG_H
#define _ASM_GENERIC_ATOMIC_LONG_H
/*
* Copyright (C) 2005 Silicon Graphics, Inc.
* Christoph Lameter
*
* Allows to provide arch independent atomic definitions without the need to
* edit all arch specific atomic.h files.
*/
#include <asm/types.h>
/*
* Suppport for atomic_long_t
*
* Casts for parameters are avoided for existing atomic functions in order to
* avoid issues with cast-as-lval under gcc 4.x and other limitations that the
* macros of a platform may have.
*/
#if BITS_PER_LONG == 64
typedef atomic64_t atomic_long_t;
#define ATOMIC_LONG_INIT(i) ATOMIC64_INIT(i)
#define ATOMIC_LONG_PFX(x) atomic64 ## x
#else
typedef atomic_t atomic_long_t;
#define ATOMIC_LONG_INIT(i) ATOMIC_INIT(i)
#define ATOMIC_LONG_PFX(x) atomic ## x
#endif
#define ATOMIC_LONG_READ_OP(mo) \
static inline long atomic_long_read##mo(const atomic_long_t *l) \
{ \
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
\
return (long)ATOMIC_LONG_PFX(_read##mo)(v); \
}
ATOMIC_LONG_READ_OP()
ATOMIC_LONG_READ_OP(_acquire)
#undef ATOMIC_LONG_READ_OP
#define ATOMIC_LONG_SET_OP(mo) \
static inline void atomic_long_set##mo(atomic_long_t *l, long i) \
{ \
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
\
ATOMIC_LONG_PFX(_set##mo)(v, i); \
}
ATOMIC_LONG_SET_OP()
ATOMIC_LONG_SET_OP(_release)
#undef ATOMIC_LONG_SET_OP
#define ATOMIC_LONG_ADD_SUB_OP(op, mo) \
static inline long \
atomic_long_##op##_return##mo(long i, atomic_long_t *l) \
{ \
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
\
return (long)ATOMIC_LONG_PFX(_##op##_return##mo)(i, v); \
}
ATOMIC_LONG_ADD_SUB_OP(add,)
ATOMIC_LONG_ADD_SUB_OP(add, _relaxed)
ATOMIC_LONG_ADD_SUB_OP(add, _acquire)
ATOMIC_LONG_ADD_SUB_OP(add, _release)
ATOMIC_LONG_ADD_SUB_OP(sub,)
ATOMIC_LONG_ADD_SUB_OP(sub, _relaxed)
ATOMIC_LONG_ADD_SUB_OP(sub, _acquire)
ATOMIC_LONG_ADD_SUB_OP(sub, _release)
#undef ATOMIC_LONG_ADD_SUB_OP
#define atomic_long_cmpxchg_relaxed(l, old, new) \
(ATOMIC_LONG_PFX(_cmpxchg_relaxed)((ATOMIC_LONG_PFX(_t) *)(l), \
(old), (new)))
#define atomic_long_cmpxchg_acquire(l, old, new) \
(ATOMIC_LONG_PFX(_cmpxchg_acquire)((ATOMIC_LONG_PFX(_t) *)(l), \
(old), (new)))
#define atomic_long_cmpxchg_release(l, old, new) \
(ATOMIC_LONG_PFX(_cmpxchg_release)((ATOMIC_LONG_PFX(_t) *)(l), \
(old), (new)))
#define atomic_long_cmpxchg(l, old, new) \
(ATOMIC_LONG_PFX(_cmpxchg)((ATOMIC_LONG_PFX(_t) *)(l), (old), (new)))
#define atomic_long_xchg_relaxed(v, new) \
(ATOMIC_LONG_PFX(_xchg_relaxed)((ATOMIC_LONG_PFX(_t) *)(v), (new)))
#define atomic_long_xchg_acquire(v, new) \
(ATOMIC_LONG_PFX(_xchg_acquire)((ATOMIC_LONG_PFX(_t) *)(v), (new)))
#define atomic_long_xchg_release(v, new) \
(ATOMIC_LONG_PFX(_xchg_release)((ATOMIC_LONG_PFX(_t) *)(v), (new)))
#define atomic_long_xchg(v, new) \
(ATOMIC_LONG_PFX(_xchg)((ATOMIC_LONG_PFX(_t) *)(v), (new)))
static __always_inline void atomic_long_inc(atomic_long_t *l)
{
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
ATOMIC_LONG_PFX(_inc)(v);
}
static __always_inline void atomic_long_dec(atomic_long_t *l)
{
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
ATOMIC_LONG_PFX(_dec)(v);
}
#define ATOMIC_LONG_FETCH_OP(op, mo) \
static inline long \
atomic_long_fetch_##op##mo(long i, atomic_long_t *l) \
{ \
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
\
return (long)ATOMIC_LONG_PFX(_fetch_##op##mo)(i, v); \
}
ATOMIC_LONG_FETCH_OP(add, )
ATOMIC_LONG_FETCH_OP(add, _relaxed)
ATOMIC_LONG_FETCH_OP(add, _acquire)
ATOMIC_LONG_FETCH_OP(add, _release)
ATOMIC_LONG_FETCH_OP(sub, )
ATOMIC_LONG_FETCH_OP(sub, _relaxed)
ATOMIC_LONG_FETCH_OP(sub, _acquire)
ATOMIC_LONG_FETCH_OP(sub, _release)
ATOMIC_LONG_FETCH_OP(and, )
ATOMIC_LONG_FETCH_OP(and, _relaxed)
ATOMIC_LONG_FETCH_OP(and, _acquire)
ATOMIC_LONG_FETCH_OP(and, _release)
ATOMIC_LONG_FETCH_OP(andnot, )
ATOMIC_LONG_FETCH_OP(andnot, _relaxed)
ATOMIC_LONG_FETCH_OP(andnot, _acquire)
ATOMIC_LONG_FETCH_OP(andnot, _release)
ATOMIC_LONG_FETCH_OP(or, )
ATOMIC_LONG_FETCH_OP(or, _relaxed)
ATOMIC_LONG_FETCH_OP(or, _acquire)
ATOMIC_LONG_FETCH_OP(or, _release)
ATOMIC_LONG_FETCH_OP(xor, )
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) \
{ \
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
\
ATOMIC_LONG_PFX(_##op)(i, v); \
}
ATOMIC_LONG_OP(add)
ATOMIC_LONG_OP(sub)
ATOMIC_LONG_OP(and)
ATOMIC_LONG_OP(andnot)
ATOMIC_LONG_OP(or)
ATOMIC_LONG_OP(xor)
#undef ATOMIC_LONG_OP
static inline int atomic_long_sub_and_test(long i, atomic_long_t *l)
{
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
return ATOMIC_LONG_PFX(_sub_and_test)(i, v);
}
static inline int atomic_long_dec_and_test(atomic_long_t *l)
{
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
return ATOMIC_LONG_PFX(_dec_and_test)(v);
}
static inline int atomic_long_inc_and_test(atomic_long_t *l)
{
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
return ATOMIC_LONG_PFX(_inc_and_test)(v);
}
static inline int atomic_long_add_negative(long i, atomic_long_t *l)
{
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
return ATOMIC_LONG_PFX(_add_negative)(i, v);
}
#define ATOMIC_LONG_INC_DEC_OP(op, mo) \
static inline long \
atomic_long_##op##_return##mo(atomic_long_t *l) \
{ \
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l; \
\
return (long)ATOMIC_LONG_PFX(_##op##_return##mo)(v); \
}
ATOMIC_LONG_INC_DEC_OP(inc,)
ATOMIC_LONG_INC_DEC_OP(inc, _relaxed)
ATOMIC_LONG_INC_DEC_OP(inc, _acquire)
ATOMIC_LONG_INC_DEC_OP(inc, _release)
ATOMIC_LONG_INC_DEC_OP(dec,)
ATOMIC_LONG_INC_DEC_OP(dec, _relaxed)
ATOMIC_LONG_INC_DEC_OP(dec, _acquire)
ATOMIC_LONG_INC_DEC_OP(dec, _release)
#undef ATOMIC_LONG_INC_DEC_OP
static inline long atomic_long_add_unless(atomic_long_t *l, long a, long u)
{
ATOMIC_LONG_PFX(_t) *v = (ATOMIC_LONG_PFX(_t) *)l;
return (long)ATOMIC_LONG_PFX(_add_unless)(v, a, u);
}
#define atomic_long_inc_not_zero(l) \
ATOMIC_LONG_PFX(_inc_not_zero)((ATOMIC_LONG_PFX(_t) *)(l))
#define atomic_long_cond_read_acquire(v, c) \
ATOMIC_LONG_PFX(_cond_read_acquire)((ATOMIC_LONG_PFX(_t) *)(v), (c))
#endif /* _ASM_GENERIC_ATOMIC_LONG_H */
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