aboutsummaryrefslogtreecommitdiff
path: root/include/asm-sparc/spinlock.h
blob: 0cbd87ad491280e620acbbfde7280d21ca1b367e (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
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
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
/* spinlock.h: 32-bit Sparc spinlock support.
 *
 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
 */

#ifndef __SPARC_SPINLOCK_H
#define __SPARC_SPINLOCK_H

#include <linux/threads.h>	/* For NR_CPUS */

#ifndef __ASSEMBLY__

#include <asm/psr.h>

#ifdef CONFIG_DEBUG_SPINLOCK
struct _spinlock_debug {
	unsigned char lock;
	unsigned long owner_pc;
#ifdef CONFIG_PREEMPT
	unsigned int break_lock;
#endif
};
typedef struct _spinlock_debug spinlock_t;

#define SPIN_LOCK_UNLOCKED	(spinlock_t) { 0, 0 }
#define spin_lock_init(lp)	do { *(lp)= SPIN_LOCK_UNLOCKED; } while(0)
#define spin_is_locked(lp)  (*((volatile unsigned char *)(&((lp)->lock))) != 0)
#define spin_unlock_wait(lp)	do { barrier(); } while(*(volatile unsigned char *)(&(lp)->lock))

extern void _do_spin_lock(spinlock_t *lock, char *str);
extern int _spin_trylock(spinlock_t *lock);
extern void _do_spin_unlock(spinlock_t *lock);

#define _raw_spin_trylock(lp)	_spin_trylock(lp)
#define _raw_spin_lock(lock)	_do_spin_lock(lock, "spin_lock")
#define _raw_spin_unlock(lock)	_do_spin_unlock(lock)

struct _rwlock_debug {
	volatile unsigned int lock;
	unsigned long owner_pc;
	unsigned long reader_pc[NR_CPUS];
#ifdef CONFIG_PREEMPT
	unsigned int break_lock;
#endif
};
typedef struct _rwlock_debug rwlock_t;

#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0, {0} }

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

extern void _do_read_lock(rwlock_t *rw, char *str);
extern void _do_read_unlock(rwlock_t *rw, char *str);
extern void _do_write_lock(rwlock_t *rw, char *str);
extern void _do_write_unlock(rwlock_t *rw);

#define _raw_read_lock(lock)	\
do {	unsigned long flags; \
	local_irq_save(flags); \
	_do_read_lock(lock, "read_lock"); \
	local_irq_restore(flags); \
} while(0)

#define _raw_read_unlock(lock) \
do {	unsigned long flags; \
	local_irq_save(flags); \
	_do_read_unlock(lock, "read_unlock"); \
	local_irq_restore(flags); \
} while(0)

#define _raw_write_lock(lock) \
do {	unsigned long flags; \
	local_irq_save(flags); \
	_do_write_lock(lock, "write_lock"); \
	local_irq_restore(flags); \
} while(0)

#define _raw_write_unlock(lock) \
do {	unsigned long flags; \
	local_irq_save(flags); \
	_do_write_unlock(lock); \
	local_irq_restore(flags); \
} while(0)

#else /* !CONFIG_DEBUG_SPINLOCK */

typedef struct {
	unsigned char lock;
#ifdef CONFIG_PREEMPT
	unsigned int break_lock;
#endif
} spinlock_t;

#define SPIN_LOCK_UNLOCKED	(spinlock_t) { 0 }

#define spin_lock_init(lock)   (*((unsigned char *)(lock)) = 0)
#define spin_is_locked(lock)    (*((volatile unsigned char *)(lock)) != 0)

#define spin_unlock_wait(lock) \
do { \
	barrier(); \
} while(*((volatile unsigned char *)lock))

extern __inline__ void _raw_spin_lock(spinlock_t *lock)
{
	__asm__ __volatile__(
	"\n1:\n\t"
	"ldstub	[%0], %%g2\n\t"
	"orcc	%%g2, 0x0, %%g0\n\t"
	"bne,a	2f\n\t"
	" ldub	[%0], %%g2\n\t"
	".subsection	2\n"
	"2:\n\t"
	"orcc	%%g2, 0x0, %%g0\n\t"
	"bne,a	2b\n\t"
	" ldub	[%0], %%g2\n\t"
	"b,a	1b\n\t"
	".previous\n"
	: /* no outputs */
	: "r" (lock)
	: "g2", "memory", "cc");
}

extern __inline__ int _raw_spin_trylock(spinlock_t *lock)
{
	unsigned int result;
	__asm__ __volatile__("ldstub [%1], %0"
			     : "=r" (result)
			     : "r" (lock)
			     : "memory");
	return (result == 0);
}

extern __inline__ void _raw_spin_unlock(spinlock_t *lock)
{
	__asm__ __volatile__("stb %%g0, [%0]" : : "r" (lock) : "memory");
}

/* 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.
 *
 * XXX This might create some problems with my dual spinlock
 * XXX scheme, deadlocks etc. -DaveM
 */
typedef struct {
	volatile unsigned int lock;
#ifdef CONFIG_PREEMPT
	unsigned int break_lock;
#endif
} rwlock_t;

#define RW_LOCK_UNLOCKED (rwlock_t) { 0 }

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


/* Sort of like atomic_t's on Sparc, but even more clever.
 *
 *	------------------------------------
 *	| 24-bit counter           | wlock |  rwlock_t
 *	------------------------------------
 *	 31                       8 7     0
 *
 * wlock signifies the one writer is in or somebody is updating
 * counter. For a writer, if he successfully acquires the wlock,
 * but counter is non-zero, he has to release the lock and wait,
 * till both counter and wlock are zero.
 *
 * Unfortunately this scheme limits us to ~16,000,000 cpus.
 */
extern __inline__ void _read_lock(rwlock_t *rw)
{
	register rwlock_t *lp asm("g1");
	lp = rw;
	__asm__ __volatile__(
	"mov	%%o7, %%g4\n\t"
	"call	___rw_read_enter\n\t"
	" ldstub	[%%g1 + 3], %%g2\n"
	: /* no outputs */
	: "r" (lp)
	: "g2", "g4", "memory", "cc");
}

#define _raw_read_lock(lock) \
do {	unsigned long flags; \
	local_irq_save(flags); \
	_read_lock(lock); \
	local_irq_restore(flags); \
} while(0)

extern __inline__ void _read_unlock(rwlock_t *rw)
{
	register rwlock_t *lp asm("g1");
	lp = rw;
	__asm__ __volatile__(
	"mov	%%o7, %%g4\n\t"
	"call	___rw_read_exit\n\t"
	" ldstub	[%%g1 + 3], %%g2\n"
	: /* no outputs */
	: "r" (lp)
	: "g2", "g4", "memory", "cc");
}

#define _raw_read_unlock(lock) \
do {	unsigned long flags; \
	local_irq_save(flags); \
	_read_unlock(lock); \
	local_irq_restore(flags); \
} while(0)

extern __inline__ void _raw_write_lock(rwlock_t *rw)
{
	register rwlock_t *lp asm("g1");
	lp = rw;
	__asm__ __volatile__(
	"mov	%%o7, %%g4\n\t"
	"call	___rw_write_enter\n\t"
	" ldstub	[%%g1 + 3], %%g2\n"
	: /* no outputs */
	: "r" (lp)
	: "g2", "g4", "memory", "cc");
}

#define _raw_write_unlock(rw)	do { (rw)->lock = 0; } while(0)

#endif /* CONFIG_DEBUG_SPINLOCK */

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

#endif /* !(__ASSEMBLY__) */

#endif /* __SPARC_SPINLOCK_H */