aboutsummaryrefslogtreecommitdiffstats
path: root/include/asm-alpha/spinlock.h
blob: 80780dba9986fb47b78c204e5c23ab6b77a2fddf (plain) (blame)
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
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
#ifndef _ALPHA_SPINLOCK_H
#define _ALPHA_SPINLOCK_H

#include <linux/config.h>
#include <asm/system.h>
#include <linux/kernel.h>
#include <asm/current.h>


/*
 * Simple spin lock operations.  There are two variants, one clears IRQ's
 * on the local processor, one does not.
 *
 * We make no fairness assumptions. They have a cost.
 */

typedef struct {
	volatile unsigned int lock;
#ifdef CONFIG_DEBUG_SPINLOCK
	int on_cpu;
	int line_no;
	void *previous;
	struct task_struct * task;
	const char *base_file;
#endif
} spinlock_t;

#ifdef CONFIG_DEBUG_SPINLOCK
#define SPIN_LOCK_UNLOCKED	(spinlock_t){ 0, -1, 0, NULL, NULL, NULL }
#else
#define SPIN_LOCK_UNLOCKED	(spinlock_t){ 0 }
#endif

#define spin_lock_init(x)	do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
#define spin_is_locked(x)	((x)->lock != 0)
#define spin_unlock_wait(x)	do { barrier(); } while ((x)->lock)

#ifdef CONFIG_DEBUG_SPINLOCK
extern void _raw_spin_unlock(spinlock_t * lock);
extern void debug_spin_lock(spinlock_t * lock, const char *, int);
extern int debug_spin_trylock(spinlock_t * lock, const char *, int);
#define _raw_spin_lock(LOCK) \
	debug_spin_lock(LOCK, __BASE_FILE__, __LINE__)
#define _raw_spin_trylock(LOCK) \
	debug_spin_trylock(LOCK, __BASE_FILE__, __LINE__)
#else
static inline void _raw_spin_unlock(spinlock_t * lock)
{
	mb();
	lock->lock = 0;
}

static inline void _raw_spin_lock(spinlock_t * lock)
{
	long tmp;

	__asm__ __volatile__(
	"1:	ldl_l	%0,%1\n"
	"	bne	%0,2f\n"
	"	lda	%0,1\n"
	"	stl_c	%0,%1\n"
	"	beq	%0,2f\n"
	"	mb\n"
	".subsection 2\n"
	"2:	ldl	%0,%1\n"
	"	bne	%0,2b\n"
	"	br	1b\n"
	".previous"
	: "=&r" (tmp), "=m" (lock->lock)
	: "m"(lock->lock) : "memory");
}

static inline int _raw_spin_trylock(spinlock_t *lock)
{
	return !test_and_set_bit(0, &lock->lock);
}
#endif /* CONFIG_DEBUG_SPINLOCK */

#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)

/***********************************************************/

typedef struct {
	volatile unsigned int lock;
} rwlock_t;

#define RW_LOCK_UNLOCKED	(rwlock_t){ 0 }

#define rwlock_init(x)		do { *(x) = RW_LOCK_UNLOCKED; } while(0)

static inline int read_can_lock(rwlock_t *lock)
{
	return (lock->lock & 1) == 0;
}

static inline int write_can_lock(rwlock_t *lock)
{
	return lock->lock == 0;
}

#ifdef CONFIG_DEBUG_RWLOCK
extern void _raw_write_lock(rwlock_t * lock);
extern void _raw_read_lock(rwlock_t * lock);
#else
static inline void _raw_write_lock(rwlock_t * lock)
{
	long regx;

	__asm__ __volatile__(
	"1:	ldl_l	%1,%0\n"
	"	bne	%1,6f\n"
	"	lda	%1,1\n"
	"	stl_c	%1,%0\n"
	"	beq	%1,6f\n"
	"	mb\n"
	".subsection 2\n"
	"6:	ldl	%1,%0\n"
	"	bne	%1,6b\n"
	"	br	1b\n"
	".previous"
	: "=m" (*lock), "=&r" (regx)
	: "m" (*lock) : "memory");
}

static inline void _raw_read_lock(rwlock_t * lock)
{
	long regx;

	__asm__ __volatile__(
	"1:	ldl_l	%1,%0\n"
	"	blbs	%1,6f\n"
	"	subl	%1,2,%1\n"
	"	stl_c	%1,%0\n"
	"	beq	%1,6f\n"
	"	mb\n"
	".subsection 2\n"
	"6:	ldl	%1,%0\n"
	"	blbs	%1,6b\n"
	"	br	1b\n"
	".previous"
	: "=m" (*lock), "=&r" (regx)
	: "m" (*lock) : "memory");
}
#endif /* CONFIG_DEBUG_RWLOCK */

static inline int _raw_read_trylock(rwlock_t * lock)
{
	long regx;
	int success;

	__asm__ __volatile__(
	"1:	ldl_l	%1,%0\n"
	"	lda	%2,0\n"
	"	blbs	%1,2f\n"
	"	subl	%1,2,%2\n"
	"	stl_c	%2,%0\n"
	"	beq	%2,6f\n"
	"2:	mb\n"
	".subsection 2\n"
	"6:	br	1b\n"
	".previous"
	: "=m" (*lock), "=&r" (regx), "=&r" (success)
	: "m" (*lock) : "memory");

	return success;
}

static inline int _raw_write_trylock(rwlock_t * lock)
{
	long regx;
	int success;

	__asm__ __volatile__(
	"1:	ldl_l	%1,%0\n"
	"	lda	%2,0\n"
	"	bne	%1,2f\n"
	"	lda	%2,1\n"
	"	stl_c	%2,%0\n"
	"	beq	%2,6f\n"
	"2:	mb\n"
	".subsection 2\n"
	"6:	br	1b\n"
	".previous"
	: "=m" (*lock), "=&r" (regx), "=&r" (success)
	: "m" (*lock) : "memory");

	return success;
}

static inline void _raw_write_unlock(rwlock_t * lock)
{
	mb();
	lock->lock = 0;
}

static inline void _raw_read_unlock(rwlock_t * lock)
{
	long regx;
	__asm__ __volatile__(
	"	mb\n"
	"1:	ldl_l	%1,%0\n"
	"	addl	%1,2,%1\n"
	"	stl_c	%1,%0\n"
	"	beq	%1,6f\n"
	".subsection 2\n"
	"6:	br	1b\n"
	".previous"
	: "=m" (*lock), "=&r" (regx)
	: "m" (*lock) : "memory");
}

#endif /* _ALPHA_SPINLOCK_H */