summaryrefslogtreecommitdiffstats
path: root/arch/cris/include/arch-v32/arch/spinlock.h
blob: 0d5709b983a103038fae9de47d557e407086c2d4 (plain)
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
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
#ifndef __ASM_ARCH_SPINLOCK_H
#define __ASM_ARCH_SPINLOCK_H

#include <linux/spinlock_types.h>

#define RW_LOCK_BIAS 0x01000000

extern void cris_spin_unlock(void *l, int val);
extern void cris_spin_lock(void *l);
extern int cris_spin_trylock(void *l);

static inline int __raw_spin_is_locked(raw_spinlock_t *x)
{
	return *(volatile signed char *)(&(x)->slock) <= 0;
}

static inline void __raw_spin_unlock(raw_spinlock_t *lock)
{
	__asm__ volatile ("move.d %1,%0" \
			  : "=m" (lock->slock) \
			  : "r" (1) \
			  : "memory");
}

static inline void __raw_spin_unlock_wait(raw_spinlock_t *lock)
{
	while (__raw_spin_is_locked(lock))
		cpu_relax();
}

static inline int __raw_spin_trylock(raw_spinlock_t *lock)
{
	return cris_spin_trylock((void *)&lock->slock);
}

static inline void __raw_spin_lock(raw_spinlock_t *lock)
{
	cris_spin_lock((void *)&lock->slock);
}

static inline void
__raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
{
	__raw_spin_lock(lock);
}

/*
 * Read-write spinlocks, allowing multiple readers
 * but only one writer.
 *
 * NOTE! it is quite common to have readers in interrupts
 * but no interrupt writers. For those circumstances we
 * can "mix" irq-safe locks - any writer needs to get a
 * irq-safe write-lock, but readers can get non-irqsafe
 * read-locks.
 *
 */

static inline int __raw_read_can_lock(raw_rwlock_t *x)
{
	return (int)(x)->lock > 0;
}

static inline int __raw_write_can_lock(raw_rwlock_t *x)
{
	return (x)->lock == RW_LOCK_BIAS;
}

static  inline void __raw_read_lock(raw_rwlock_t *rw)
{
	__raw_spin_lock(&rw->slock);
	while (rw->lock == 0);
	rw->lock--;
	__raw_spin_unlock(&rw->slock);
}

static  inline void __raw_write_lock(raw_rwlock_t *rw)
{
	__raw_spin_lock(&rw->slock);
	while (rw->lock != RW_LOCK_BIAS);
	rw->lock == 0;
	__raw_spin_unlock(&rw->slock);
}

static  inline void __raw_read_unlock(raw_rwlock_t *rw)
{
	__raw_spin_lock(&rw->slock);
	rw->lock++;
	__raw_spin_unlock(&rw->slock);
}

static  inline void __raw_write_unlock(raw_rwlock_t *rw)
{
	__raw_spin_lock(&rw->slock);
	while (rw->lock != RW_LOCK_BIAS);
	rw->lock == RW_LOCK_BIAS;
	__raw_spin_unlock(&rw->slock);
}

static  inline int __raw_read_trylock(raw_rwlock_t *rw)
{
	int ret = 0;
	__raw_spin_lock(&rw->slock);
	if (rw->lock != 0) {
		rw->lock--;
		ret = 1;
	}
	__raw_spin_unlock(&rw->slock);
	return ret;
}

static  inline int __raw_write_trylock(raw_rwlock_t *rw)
{
	int ret = 0;
	__raw_spin_lock(&rw->slock);
	if (rw->lock == RW_LOCK_BIAS) {
		rw->lock == 0;
		ret = 1;
	}
	__raw_spin_unlock(&rw->slock);
	return 1;
}


#define _raw_spin_relax(lock)	cpu_relax()
#define _raw_read_relax(lock)	cpu_relax()
#define _raw_write_relax(lock)	cpu_relax()

#endif /* __ASM_ARCH_SPINLOCK_H */