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1/*
2 * atomic32.c: 32-bit atomic_t implementation
3 *
4 * Copyright (C) 2004 Keith M Wesolowski
5 * Copyright (C) 2007 Kyle McMartin
6 *
7 * Based on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf
8 */
9
10#include <linux/atomic.h>
11#include <linux/spinlock.h>
12#include <linux/module.h>
13
14#ifdef CONFIG_SMP
15#define ATOMIC_HASH_SIZE 4
16#define ATOMIC_HASH(a) (&__atomic_hash[(((unsigned long)a)>>8) & (ATOMIC_HASH_SIZE-1)])
17
18spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] = {
19 [0 ... (ATOMIC_HASH_SIZE-1)] = __SPIN_LOCK_UNLOCKED(__atomic_hash)
20};
21
22#else /* SMP */
23
24static DEFINE_SPINLOCK(dummy);
25#define ATOMIC_HASH_SIZE 1
26#define ATOMIC_HASH(a) (&dummy)
27
28#endif /* SMP */
29
30int __atomic_add_return(int i, atomic_t *v)
31{
32 int ret;
33 unsigned long flags;
34 spin_lock_irqsave(ATOMIC_HASH(v), flags);
35
36 ret = (v->counter += i);
37
38 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
39 return ret;
40}
41EXPORT_SYMBOL(__atomic_add_return);
42
43int atomic_cmpxchg(atomic_t *v, int old, int new)
44{
45 int ret;
46 unsigned long flags;
47
48 spin_lock_irqsave(ATOMIC_HASH(v), flags);
49 ret = v->counter;
50 if (likely(ret == old))
51 v->counter = new;
52
53 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
54 return ret;
55}
56EXPORT_SYMBOL(atomic_cmpxchg);
57
58int __atomic_add_unless(atomic_t *v, int a, int u)
59{
60 int ret;
61 unsigned long flags;
62
63 spin_lock_irqsave(ATOMIC_HASH(v), flags);
64 ret = v->counter;
65 if (ret != u)
66 v->counter += a;
67 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
68 return ret;
69}
70EXPORT_SYMBOL(__atomic_add_unless);
71
72/* Atomic operations are already serializing */
73void atomic_set(atomic_t *v, int i)
74{
75 unsigned long flags;
76
77 spin_lock_irqsave(ATOMIC_HASH(v), flags);
78 v->counter = i;
79 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
80}
81EXPORT_SYMBOL(atomic_set);
82
83unsigned long ___set_bit(unsigned long *addr, unsigned long mask)
84{
85 unsigned long old, flags;
86
87 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
88 old = *addr;
89 *addr = old | mask;
90 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
91
92 return old & mask;
93}
94EXPORT_SYMBOL(___set_bit);
95
96unsigned long ___clear_bit(unsigned long *addr, unsigned long mask)
97{
98 unsigned long old, flags;
99
100 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
101 old = *addr;
102 *addr = old & ~mask;
103 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
104
105 return old & mask;
106}
107EXPORT_SYMBOL(___clear_bit);
108
109unsigned long ___change_bit(unsigned long *addr, unsigned long mask)
110{
111 unsigned long old, flags;
112
113 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
114 old = *addr;
115 *addr = old ^ mask;
116 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
117
118 return old & mask;
119}
120EXPORT_SYMBOL(___change_bit);
121
122unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new)
123{
124 unsigned long flags;
125 u32 prev;
126
127 spin_lock_irqsave(ATOMIC_HASH(ptr), flags);
128 if ((prev = *ptr) == old)
129 *ptr = new;
130 spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags);
131
132 return (unsigned long)prev;
133}
134EXPORT_SYMBOL(__cmpxchg_u32);
1/*
2 * atomic32.c: 32-bit atomic_t implementation
3 *
4 * Copyright (C) 2004 Keith M Wesolowski
5 * Copyright (C) 2007 Kyle McMartin
6 *
7 * Based on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf
8 */
9
10#include <linux/atomic.h>
11#include <linux/spinlock.h>
12#include <linux/module.h>
13
14#ifdef CONFIG_SMP
15#define ATOMIC_HASH_SIZE 4
16#define ATOMIC_HASH(a) (&__atomic_hash[(((unsigned long)a)>>8) & (ATOMIC_HASH_SIZE-1)])
17
18spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] = {
19 [0 ... (ATOMIC_HASH_SIZE-1)] = __SPIN_LOCK_UNLOCKED(__atomic_hash)
20};
21
22#else /* SMP */
23
24static DEFINE_SPINLOCK(dummy);
25#define ATOMIC_HASH_SIZE 1
26#define ATOMIC_HASH(a) (&dummy)
27
28#endif /* SMP */
29
30int __atomic_add_return(int i, atomic_t *v)
31{
32 int ret;
33 unsigned long flags;
34 spin_lock_irqsave(ATOMIC_HASH(v), flags);
35
36 ret = (v->counter += i);
37
38 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
39 return ret;
40}
41EXPORT_SYMBOL(__atomic_add_return);
42
43int atomic_cmpxchg(atomic_t *v, int old, int new)
44{
45 int ret;
46 unsigned long flags;
47
48 spin_lock_irqsave(ATOMIC_HASH(v), flags);
49 ret = v->counter;
50 if (likely(ret == old))
51 v->counter = new;
52
53 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
54 return ret;
55}
56EXPORT_SYMBOL(atomic_cmpxchg);
57
58int __atomic_add_unless(atomic_t *v, int a, int u)
59{
60 int ret;
61 unsigned long flags;
62
63 spin_lock_irqsave(ATOMIC_HASH(v), flags);
64 ret = v->counter;
65 if (ret != u)
66 v->counter += a;
67 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
68 return ret;
69}
70EXPORT_SYMBOL(__atomic_add_unless);
71
72/* Atomic operations are already serializing */
73void atomic_set(atomic_t *v, int i)
74{
75 unsigned long flags;
76
77 spin_lock_irqsave(ATOMIC_HASH(v), flags);
78 v->counter = i;
79 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
80}
81EXPORT_SYMBOL(atomic_set);
82
83unsigned long ___set_bit(unsigned long *addr, unsigned long mask)
84{
85 unsigned long old, flags;
86
87 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
88 old = *addr;
89 *addr = old | mask;
90 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
91
92 return old & mask;
93}
94EXPORT_SYMBOL(___set_bit);
95
96unsigned long ___clear_bit(unsigned long *addr, unsigned long mask)
97{
98 unsigned long old, flags;
99
100 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
101 old = *addr;
102 *addr = old & ~mask;
103 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
104
105 return old & mask;
106}
107EXPORT_SYMBOL(___clear_bit);
108
109unsigned long ___change_bit(unsigned long *addr, unsigned long mask)
110{
111 unsigned long old, flags;
112
113 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
114 old = *addr;
115 *addr = old ^ mask;
116 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
117
118 return old & mask;
119}
120EXPORT_SYMBOL(___change_bit);
121
122unsigned long __cmpxchg_u32(volatile u32 *ptr, u32 old, u32 new)
123{
124 unsigned long flags;
125 u32 prev;
126
127 spin_lock_irqsave(ATOMIC_HASH(ptr), flags);
128 if ((prev = *ptr) == old)
129 *ptr = new;
130 spin_unlock_irqrestore(ATOMIC_HASH(ptr), flags);
131
132 return (unsigned long)prev;
133}
134EXPORT_SYMBOL(__cmpxchg_u32);