2 * atomic32.c: 32-bit atomic_t implementation
4 * Copyright (C) 2004 Keith M Wesolowski
6 * Based on asm-parisc/atomic.h Copyright (C) 2000 Philipp Rumpf
9 #include <asm/atomic.h>
10 #include <linux/spinlock.h>
11 #include <linux/module.h>
14 #define ATOMIC_HASH_SIZE 4
15 #define ATOMIC_HASH(a) (&__atomic_hash[(((unsigned long)a)>>8) & (ATOMIC_HASH_SIZE-1)])
17 spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] = {
18 [0 ... (ATOMIC_HASH_SIZE-1)] = SPIN_LOCK_UNLOCKED
23 static DEFINE_SPINLOCK(dummy);
24 #define ATOMIC_HASH_SIZE 1
25 #define ATOMIC_HASH(a) (&dummy)
29 int __atomic_add_return(int i, atomic_t *v)
33 spin_lock_irqsave(ATOMIC_HASH(v), flags);
35 ret = (v->counter += i);
37 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
40 EXPORT_SYMBOL(__atomic_add_return);
42 int atomic_cmpxchg(atomic_t *v, int old, int new)
47 spin_lock_irqsave(ATOMIC_HASH(v), flags);
49 if (likely(ret == old))
52 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
56 int atomic_add_unless(atomic_t *v, int a, int u)
61 spin_lock_irqsave(ATOMIC_HASH(v), flags);
65 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
69 /* Atomic operations are already serializing */
70 void atomic_set(atomic_t *v, int i)
74 spin_lock_irqsave(ATOMIC_HASH(v), flags);
76 spin_unlock_irqrestore(ATOMIC_HASH(v), flags);
78 EXPORT_SYMBOL(atomic_set);
80 unsigned long ___set_bit(unsigned long *addr, unsigned long mask)
82 unsigned long old, flags;
84 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
87 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
91 EXPORT_SYMBOL(___set_bit);
93 unsigned long ___clear_bit(unsigned long *addr, unsigned long mask)
95 unsigned long old, flags;
97 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
100 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
104 EXPORT_SYMBOL(___clear_bit);
106 unsigned long ___change_bit(unsigned long *addr, unsigned long mask)
108 unsigned long old, flags;
110 spin_lock_irqsave(ATOMIC_HASH(addr), flags);
113 spin_unlock_irqrestore(ATOMIC_HASH(addr), flags);
117 EXPORT_SYMBOL(___change_bit);