linux/arch/sparc/include/asm/atomic_64.h
David S. Miller 293666b7a1 sparc64: Stop using memory barriers for atomics and locks.
The kernel always executes in the TSO memory model now,
so none of this stuff is necessary any more.

With helpful feedback from Nick Piggin.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-04 09:16:47 -08:00

122 lines
3.4 KiB
C

/* atomic.h: Thankfully the V9 is at least reasonable for this
* stuff.
*
* Copyright (C) 1996, 1997, 2000 David S. Miller (davem@redhat.com)
*/
#ifndef __ARCH_SPARC64_ATOMIC__
#define __ARCH_SPARC64_ATOMIC__
#include <linux/types.h>
#include <asm/system.h>
typedef struct { volatile int counter; } atomic_t;
typedef struct { volatile __s64 counter; } atomic64_t;
#define ATOMIC_INIT(i) { (i) }
#define ATOMIC64_INIT(i) { (i) }
#define atomic_read(v) ((v)->counter)
#define atomic64_read(v) ((v)->counter)
#define atomic_set(v, i) (((v)->counter) = i)
#define atomic64_set(v, i) (((v)->counter) = i)
extern void atomic_add(int, atomic_t *);
extern void atomic64_add(int, atomic64_t *);
extern void atomic_sub(int, atomic_t *);
extern void atomic64_sub(int, atomic64_t *);
extern int atomic_add_ret(int, atomic_t *);
extern int atomic64_add_ret(int, atomic64_t *);
extern int atomic_sub_ret(int, atomic_t *);
extern int atomic64_sub_ret(int, atomic64_t *);
#define atomic_dec_return(v) atomic_sub_ret(1, v)
#define atomic64_dec_return(v) atomic64_sub_ret(1, v)
#define atomic_inc_return(v) atomic_add_ret(1, v)
#define atomic64_inc_return(v) atomic64_add_ret(1, v)
#define atomic_sub_return(i, v) atomic_sub_ret(i, v)
#define atomic64_sub_return(i, v) atomic64_sub_ret(i, v)
#define atomic_add_return(i, v) atomic_add_ret(i, v)
#define atomic64_add_return(i, v) atomic64_add_ret(i, v)
/*
* atomic_inc_and_test - increment and test
* @v: pointer of type atomic_t
*
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
#define atomic_sub_and_test(i, v) (atomic_sub_ret(i, v) == 0)
#define atomic64_sub_and_test(i, v) (atomic64_sub_ret(i, v) == 0)
#define atomic_dec_and_test(v) (atomic_sub_ret(1, v) == 0)
#define atomic64_dec_and_test(v) (atomic64_sub_ret(1, v) == 0)
#define atomic_inc(v) atomic_add(1, v)
#define atomic64_inc(v) atomic64_add(1, v)
#define atomic_dec(v) atomic_sub(1, v)
#define atomic64_dec(v) atomic64_sub(1, v)
#define atomic_add_negative(i, v) (atomic_add_ret(i, v) < 0)
#define atomic64_add_negative(i, v) (atomic64_add_ret(i, v) < 0)
#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
static inline int atomic_add_unless(atomic_t *v, int a, int u)
{
int c, old;
c = atomic_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c != (u);
}
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
#define atomic64_cmpxchg(v, o, n) \
((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
static inline int atomic64_add_unless(atomic64_t *v, long a, long u)
{
long c, old;
c = atomic64_read(v);
for (;;) {
if (unlikely(c == (u)))
break;
old = atomic64_cmpxchg((v), c, c + (a));
if (likely(old == c))
break;
c = old;
}
return c != (u);
}
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
/* Atomic operations are already serializing */
#define smp_mb__before_atomic_dec() barrier()
#define smp_mb__after_atomic_dec() barrier()
#define smp_mb__before_atomic_inc() barrier()
#define smp_mb__after_atomic_inc() barrier()
#include <asm-generic/atomic.h>
#endif /* !(__ARCH_SPARC64_ATOMIC__) */