1 /*
2 * bitops.c: atomic operations which got too long to be inlined all over
3 * the place.
4 *
5 * Copyright 1999 Philipp Rumpf (prumpf@tux.org)
6 * Copyright 2000 Grant Grundler (grundler@cup.hp.com)
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/spinlock.h>
11 #include <linux/atomic.h>
12
13 #ifdef CONFIG_SMP
14 arch_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
15 [0 ... (ATOMIC_HASH_SIZE-1)] = __ARCH_SPIN_LOCK_UNLOCKED
16 };
17 #endif
18
19 #ifdef CONFIG_64BIT
__xchg64(unsigned long x,unsigned long * ptr)20 unsigned long __xchg64(unsigned long x, unsigned long *ptr)
21 {
22 unsigned long temp, flags;
23
24 _atomic_spin_lock_irqsave(ptr, flags);
25 temp = *ptr;
26 *ptr = x;
27 _atomic_spin_unlock_irqrestore(ptr, flags);
28 return temp;
29 }
30 #endif
31
__xchg32(int x,int * ptr)32 unsigned long __xchg32(int x, int *ptr)
33 {
34 unsigned long flags;
35 long temp;
36
37 _atomic_spin_lock_irqsave(ptr, flags);
38 temp = (long) *ptr; /* XXX - sign extension wanted? */
39 *ptr = x;
40 _atomic_spin_unlock_irqrestore(ptr, flags);
41 return (unsigned long)temp;
42 }
43
44
__xchg8(char x,char * ptr)45 unsigned long __xchg8(char x, char *ptr)
46 {
47 unsigned long flags;
48 long temp;
49
50 _atomic_spin_lock_irqsave(ptr, flags);
51 temp = (long) *ptr; /* XXX - sign extension wanted? */
52 *ptr = x;
53 _atomic_spin_unlock_irqrestore(ptr, flags);
54 return (unsigned long)temp;
55 }
56
57
58 #ifdef CONFIG_64BIT
__cmpxchg_u64(volatile unsigned long * ptr,unsigned long old,unsigned long new)59 unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new)
60 {
61 unsigned long flags;
62 unsigned long prev;
63
64 _atomic_spin_lock_irqsave(ptr, flags);
65 if ((prev = *ptr) == old)
66 *ptr = new;
67 _atomic_spin_unlock_irqrestore(ptr, flags);
68 return prev;
69 }
70 #endif
71
__cmpxchg_u32(volatile unsigned int * ptr,unsigned int old,unsigned int new)72 unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new)
73 {
74 unsigned long flags;
75 unsigned int prev;
76
77 _atomic_spin_lock_irqsave(ptr, flags);
78 if ((prev = *ptr) == old)
79 *ptr = new;
80 _atomic_spin_unlock_irqrestore(ptr, flags);
81 return (unsigned long)prev;
82 }
83