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1/* $Id: atomic.h,v 1.22 2001/07/11 23:56:07 davem 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/config.h>
12#include <linux/types.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
58#define atomic_sub_and_test(i, v) (atomic_sub_ret(i, v) == 0)
59#define atomic64_sub_and_test(i, v) (atomic64_sub_ret(i, v) == 0)
60
61#define atomic_dec_and_test(v) (atomic_sub_ret(1, v) == 0)
62#define atomic64_dec_and_test(v) (atomic64_sub_ret(1, v) == 0)
63
64#define atomic_inc(v) atomic_add(1, v)
65#define atomic64_inc(v) atomic64_add(1, v)
66
67#define atomic_dec(v) atomic_sub(1, v)
68#define atomic64_dec(v) atomic64_sub(1, v)
69
70#define atomic_add_negative(i, v) (atomic_add_ret(i, v) < 0)
71#define atomic64_add_negative(i, v) (atomic64_add_ret(i, v) < 0)
72
73/* Atomic operations are already serializing */
74#ifdef CONFIG_SMP
75#define smp_mb__before_atomic_dec() membar("#StoreLoad | #LoadLoad")
76#define smp_mb__after_atomic_dec() membar("#StoreLoad | #StoreStore")
77#define smp_mb__before_atomic_inc() membar("#StoreLoad | #LoadLoad")
78#define smp_mb__after_atomic_inc() membar("#StoreLoad | #StoreStore")
79#else
80#define smp_mb__before_atomic_dec() barrier()
81#define smp_mb__after_atomic_dec() barrier()
82#define smp_mb__before_atomic_inc() barrier()
83#define smp_mb__after_atomic_inc() barrier()
84#endif
85
86#endif /* !(__ARCH_SPARC64_ATOMIC__) */