1/* $Id: atomic.h,v 1.1.1.1 2007/08/03 18:53:36 Exp $
2 * atomic.h: Thankfully the V9 is at least reasonable for this
3 *           stuff.
4 *
5 * Copyright (C) 1996, 1997, 2000 David S. Miller (davem@redhat.com)
6 */
7
8#ifndef __ARCH_SPARC64_ATOMIC__
9#define __ARCH_SPARC64_ATOMIC__
10
11#include <linux/types.h>
12#include <asm/system.h>
13
14typedef struct { volatile int counter; } atomic_t;
15typedef struct { volatile __s64 counter; } atomic64_t;
16
17#define ATOMIC_INIT(i)		{ (i) }
18#define ATOMIC64_INIT(i)	{ (i) }
19
20#define atomic_read(v)		((v)->counter)
21#define atomic64_read(v)	((v)->counter)
22
23#define atomic_set(v, i)	(((v)->counter) = i)
24#define atomic64_set(v, i)	(((v)->counter) = i)
25
26extern void atomic_add(int, atomic_t *);
27extern void atomic64_add(int, atomic64_t *);
28extern void atomic_sub(int, atomic_t *);
29extern void atomic64_sub(int, atomic64_t *);
30
31extern int atomic_add_ret(int, atomic_t *);
32extern int atomic64_add_ret(int, atomic64_t *);
33extern int atomic_sub_ret(int, atomic_t *);
34extern int atomic64_sub_ret(int, atomic64_t *);
35
36#define atomic_dec_return(v) atomic_sub_ret(1, v)
37#define atomic64_dec_return(v) atomic64_sub_ret(1, v)
38
39#define atomic_inc_return(v) atomic_add_ret(1, v)
40#define atomic64_inc_return(v) atomic64_add_ret(1, v)
41
42#define atomic_sub_return(i, v) atomic_sub_ret(i, v)
43#define atomic64_sub_return(i, v) atomic64_sub_ret(i, v)
44
45#define atomic_add_return(i, v) atomic_add_ret(i, v)
46#define atomic64_add_return(i, v) atomic64_add_ret(i, v)
47
48/*
49 * atomic_inc_and_test - increment and test
50 * @v: pointer of type atomic_t
51 *
52 * Atomically increments @v by 1
53 * and returns true if the result is zero, or false for all
54 * other cases.
55 */
56#define atomic_inc_and_test(v) (atomic_inc_return(v) == 0)
57#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
58
59#define atomic_sub_and_test(i, v) (atomic_sub_ret(i, v) == 0)
60#define atomic64_sub_and_test(i, v) (atomic64_sub_ret(i, v) == 0)
61
62#define atomic_dec_and_test(v) (atomic_sub_ret(1, v) == 0)
63#define atomic64_dec_and_test(v) (atomic64_sub_ret(1, v) == 0)
64
65#define atomic_inc(v) atomic_add(1, v)
66#define atomic64_inc(v) atomic64_add(1, v)
67
68#define atomic_dec(v) atomic_sub(1, v)
69#define atomic64_dec(v) atomic64_sub(1, v)
70
71#define atomic_add_negative(i, v) (atomic_add_ret(i, v) < 0)
72#define atomic64_add_negative(i, v) (atomic64_add_ret(i, v) < 0)
73
74#define atomic_cmpxchg(v, o, n) (cmpxchg(&((v)->counter), (o), (n)))
75#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
76
77static __inline__ int atomic_add_unless(atomic_t *v, int a, int u)
78{
79	int c, old;
80	c = atomic_read(v);
81	for (;;) {
82		if (unlikely(c == (u)))
83			break;
84		old = atomic_cmpxchg((v), c, c + (a));
85		if (likely(old == c))
86			break;
87		c = old;
88	}
89	return c != (u);
90}
91
92#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
93
94#define atomic64_cmpxchg(v, o, n) \
95	((__typeof__((v)->counter))cmpxchg(&((v)->counter), (o), (n)))
96#define atomic64_xchg(v, new) (xchg(&((v)->counter), new))
97
98static __inline__ int atomic64_add_unless(atomic64_t *v, long a, long u)
99{
100	long c, old;
101	c = atomic64_read(v);
102	for (;;) {
103		if (unlikely(c == (u)))
104			break;
105		old = atomic64_cmpxchg((v), c, c + (a));
106		if (likely(old == c))
107			break;
108		c = old;
109	}
110	return c != (u);
111}
112
113#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
114
115/* Atomic operations are already serializing */
116#ifdef CONFIG_SMP
117#define smp_mb__before_atomic_dec()	membar_storeload_loadload();
118#define smp_mb__after_atomic_dec()	membar_storeload_storestore();
119#define smp_mb__before_atomic_inc()	membar_storeload_loadload();
120#define smp_mb__after_atomic_inc()	membar_storeload_storestore();
121#else
122#define smp_mb__before_atomic_dec()	barrier()
123#define smp_mb__after_atomic_dec()	barrier()
124#define smp_mb__before_atomic_inc()	barrier()
125#define smp_mb__after_atomic_inc()	barrier()
126#endif
127
128#include <asm-generic/atomic.h>
129#endif /* !(__ARCH_SPARC64_ATOMIC__) */
130