xref: /openbmc/linux/arch/parisc/lib/bitops.c (revision 87c2ce3b)
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/config.h>
10 #include <linux/kernel.h>
11 #include <linux/spinlock.h>
12 #include <asm/system.h>
13 #include <asm/atomic.h>
14 
15 #ifdef CONFIG_SMP
16 raw_spinlock_t __atomic_hash[ATOMIC_HASH_SIZE] __lock_aligned = {
17 	[0 ... (ATOMIC_HASH_SIZE-1)]  = __RAW_SPIN_LOCK_UNLOCKED
18 };
19 #endif
20 
21 #ifdef __LP64__
22 unsigned long __xchg64(unsigned long x, unsigned long *ptr)
23 {
24 	unsigned long temp, flags;
25 
26 	_atomic_spin_lock_irqsave(ptr, flags);
27 	temp = *ptr;
28 	*ptr = x;
29 	_atomic_spin_unlock_irqrestore(ptr, flags);
30 	return temp;
31 }
32 #endif
33 
34 unsigned long __xchg32(int x, int *ptr)
35 {
36 	unsigned long flags;
37 	long temp;
38 
39 	_atomic_spin_lock_irqsave(ptr, flags);
40 	temp = (long) *ptr;	/* XXX - sign extension wanted? */
41 	*ptr = x;
42 	_atomic_spin_unlock_irqrestore(ptr, flags);
43 	return (unsigned long)temp;
44 }
45 
46 
47 unsigned long __xchg8(char x, char *ptr)
48 {
49 	unsigned long flags;
50 	long temp;
51 
52 	_atomic_spin_lock_irqsave(ptr, flags);
53 	temp = (long) *ptr;	/* XXX - sign extension wanted? */
54 	*ptr = x;
55 	_atomic_spin_unlock_irqrestore(ptr, flags);
56 	return (unsigned long)temp;
57 }
58 
59 
60 #ifdef __LP64__
61 unsigned long __cmpxchg_u64(volatile unsigned long *ptr, unsigned long old, unsigned long new)
62 {
63 	unsigned long flags;
64 	unsigned long prev;
65 
66 	_atomic_spin_lock_irqsave(ptr, flags);
67 	if ((prev = *ptr) == old)
68 		*ptr = new;
69 	_atomic_spin_unlock_irqrestore(ptr, flags);
70 	return prev;
71 }
72 #endif
73 
74 unsigned long __cmpxchg_u32(volatile unsigned int *ptr, unsigned int old, unsigned int new)
75 {
76 	unsigned long flags;
77 	unsigned int prev;
78 
79 	_atomic_spin_lock_irqsave(ptr, flags);
80 	if ((prev = *ptr) == old)
81 		*ptr = new;
82 	_atomic_spin_unlock_irqrestore(ptr, flags);
83 	return (unsigned long)prev;
84 }
85