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
|
/*
* BK Id: SCCS/s.spinlock.h 1.9 08/21/01 16:07:48 trini
*/
#ifndef __ASM_SPINLOCK_H
#define __ASM_SPINLOCK_H
#include <asm/system.h>
#undef SPINLOCK_DEBUG
/*
* Simple spin lock operations.
*/
typedef struct {
volatile unsigned long lock;
#ifdef SPINLOCK_DEBUG
volatile unsigned long owner_pc;
volatile unsigned long owner_cpu;
#endif
} spinlock_t;
#ifdef __KERNEL__
#if SPINLOCK_DEBUG
#define SPINLOCK_DEBUG_INIT , 0, 0
#else
#define SPINLOCK_DEBUG_INIT /* */
#endif
#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 SPINLOCK_DEBUG_INIT }
#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(spin_is_locked(x))
#ifndef SPINLOCK_DEBUG
static inline void spin_lock(spinlock_t *lock)
{
unsigned long tmp;
__asm__ __volatile__(
"b 1f # spin_lock\n\
2: lwzx %0,0,%1\n\
cmpwi 0,%0,0\n\
bne+ 2b\n\
1: lwarx %0,0,%1\n\
cmpwi 0,%0,0\n\
bne- 2b\n\
stwcx. %2,0,%1\n\
bne- 2b\n\
isync"
: "=&r"(tmp)
: "r"(&lock->lock), "r"(1)
: "cr0", "memory");
}
static inline void spin_unlock(spinlock_t *lock)
{
__asm__ __volatile__("eieio # spin_unlock": : :"memory");
lock->lock = 0;
}
#define spin_trylock(lock) (!test_and_set_bit(0,(lock)))
#else
extern void _spin_lock(spinlock_t *lock);
extern void _spin_unlock(spinlock_t *lock);
extern int spin_trylock(spinlock_t *lock);
extern unsigned long __spin_trylock(volatile unsigned long *lock);
#define spin_lock(lp) _spin_lock(lp)
#define spin_unlock(lp) _spin_unlock(lp)
#endif
/*
* 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.
*/
typedef struct {
volatile unsigned long lock;
#ifdef SPINLOCK_DEBUG
volatile unsigned long owner_pc;
#endif
} rwlock_t;
#if SPINLOCK_DEBUG
#define RWLOCK_DEBUG_INIT , 0
#else
#define RWLOCK_DEBUG_INIT /* */
#endif
#define RW_LOCK_UNLOCKED (rwlock_t) { 0 RWLOCK_DEBUG_INIT }
#define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0)
#ifndef SPINLOCK_DEBUG
static __inline__ void read_lock(rwlock_t *rw)
{
unsigned int tmp;
__asm__ __volatile__(
"b 2f # read_lock\n\
1: lwzx %0,0,%1\n\
cmpwi 0,%0,0\n\
blt+ 1b\n\
2: lwarx %0,0,%1\n\
addic. %0,%0,1\n\
ble- 1b\n\
stwcx. %0,0,%1\n\
bne- 2b\n\
isync"
: "=&r"(tmp)
: "r"(&rw->lock)
: "cr0", "memory");
}
static __inline__ void read_unlock(rwlock_t *rw)
{
unsigned int tmp;
__asm__ __volatile__(
"eieio # read_unlock\n\
1: lwarx %0,0,%1\n\
addic %0,%0,-1\n\
stwcx. %0,0,%1\n\
bne- 1b"
: "=&r"(tmp)
: "r"(&rw->lock)
: "cr0", "memory");
}
static __inline__ void write_lock(rwlock_t *rw)
{
unsigned int tmp;
__asm__ __volatile__(
"b 2f # write_lock\n\
1: lwzx %0,0,%1\n\
cmpwi 0,%0,0\n\
bne+ 1b\n\
2: lwarx %0,0,%1\n\
cmpwi 0,%0,0\n\
bne- 1b\n\
stwcx. %2,0,%1\n\
bne- 2b\n\
isync"
: "=&r"(tmp)
: "r"(&rw->lock), "r"(-1)
: "cr0", "memory");
}
static __inline__ void write_unlock(rwlock_t *rw)
{
__asm__ __volatile__("eieio # write_unlock": : :"memory");
rw->lock = 0;
}
#else
extern void _read_lock(rwlock_t *rw);
extern void _read_unlock(rwlock_t *rw);
extern void _write_lock(rwlock_t *rw);
extern void _write_unlock(rwlock_t *rw);
#define read_lock(rw) _read_lock(rw)
#define write_lock(rw) _write_lock(rw)
#define write_unlock(rw) _write_unlock(rw)
#define read_unlock(rw) _read_unlock(rw)
#endif
#endif /* __ASM_SPINLOCK_H */
#endif /* __KERNEL__ */
|
