1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
|
/*
* bitops.c: atomic operations which got too long to be inlined all over
* the place.
*
* Copyright 1999 Philipp Rumpf (prumpf@tux.org)
* Copyright 2000 Grant Grundler (grundler@cup.hp.com)
*/
#include <linux/config.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <asm/system.h>
#include <asm/atomic.h>
#ifdef CONFIG_SMP
spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] = {
[0 ... (ATOMIC_HASH_SIZE-1)] = SPIN_LOCK_UNLOCKED
};
#endif
spinlock_t __atomic_lock = SPIN_LOCK_UNLOCKED;
#ifdef __LP64__
unsigned long __xchg64(unsigned long x, unsigned long *ptr)
{
unsigned long temp, flags;
SPIN_LOCK_IRQSAVE(ATOMIC_HASH(ptr), flags);
temp = *ptr;
*ptr = x;
SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(ptr), flags);
return temp;
}
#endif
unsigned long __xchg32(int x, int *ptr)
{
unsigned long flags;
unsigned long temp;
SPIN_LOCK_IRQSAVE(ATOMIC_HASH(ptr), flags);
(long) temp = (long) *ptr; /* XXX - sign extension wanted? */
*ptr = x;
SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(ptr), flags);
return temp;
}
unsigned long __xchg8(char x, char *ptr)
{
unsigned long flags;
unsigned long temp;
SPIN_LOCK_IRQSAVE(ATOMIC_HASH(ptr), flags);
(long) temp = (long) *ptr; /* XXX - sign extension wanted? */
*ptr = x;
SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(ptr), flags);
return temp;
}
#ifdef __LP64__
unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new)
{
unsigned long flags;
unsigned long prev;
SPIN_LOCK_IRQSAVE(ATOMIC_HASH(ptr), flags);
if ((prev = *ptr) == old)
*ptr = new;
SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(ptr), flags);
return prev;
}
#endif
unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new)
{
unsigned long flags;
unsigned int prev;
SPIN_LOCK_IRQSAVE(ATOMIC_HASH(ptr), flags);
if ((prev = *ptr) == old)
*ptr = new;
SPIN_UNLOCK_IRQRESTORE(ATOMIC_HASH(ptr), flags);
return (unsigned long)prev;
}
|
