Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1#ifndef _ALPHA_SPINLOCK_H
2#define _ALPHA_SPINLOCK_H
3
4#include <linux/config.h>
5#include <asm/system.h>
6#include <linux/kernel.h>
7#include <asm/current.h>
8
9
10/*
11 * Simple spin lock operations. There are two variants, one clears IRQ's
12 * on the local processor, one does not.
13 *
14 * We make no fairness assumptions. They have a cost.
15 */
16
17typedef struct {
18 volatile unsigned int lock;
19#ifdef CONFIG_DEBUG_SPINLOCK
20 int on_cpu;
21 int line_no;
22 void *previous;
23 struct task_struct * task;
24 const char *base_file;
25#endif
26} spinlock_t;
27
28#ifdef CONFIG_DEBUG_SPINLOCK
29#define SPIN_LOCK_UNLOCKED (spinlock_t){ 0, -1, 0, NULL, NULL, NULL }
30#else
31#define SPIN_LOCK_UNLOCKED (spinlock_t){ 0 }
32#endif
33
34#define spin_lock_init(x) do { *(x) = SPIN_LOCK_UNLOCKED; } while(0)
35#define spin_is_locked(x) ((x)->lock != 0)
36#define spin_unlock_wait(x) do { barrier(); } while ((x)->lock)
37
38#ifdef CONFIG_DEBUG_SPINLOCK
39extern void _raw_spin_unlock(spinlock_t * lock);
40extern void debug_spin_lock(spinlock_t * lock, const char *, int);
41extern int debug_spin_trylock(spinlock_t * lock, const char *, int);
42#define _raw_spin_lock(LOCK) \
43 debug_spin_lock(LOCK, __BASE_FILE__, __LINE__)
44#define _raw_spin_trylock(LOCK) \
45 debug_spin_trylock(LOCK, __BASE_FILE__, __LINE__)
46#else
47static inline void _raw_spin_unlock(spinlock_t * lock)
48{
49 mb();
50 lock->lock = 0;
51}
52
53static inline void _raw_spin_lock(spinlock_t * lock)
54{
55 long tmp;
56
57 __asm__ __volatile__(
58 "1: ldl_l %0,%1\n"
59 " bne %0,2f\n"
60 " lda %0,1\n"
61 " stl_c %0,%1\n"
62 " beq %0,2f\n"
63 " mb\n"
64 ".subsection 2\n"
65 "2: ldl %0,%1\n"
66 " bne %0,2b\n"
67 " br 1b\n"
68 ".previous"
69 : "=&r" (tmp), "=m" (lock->lock)
70 : "m"(lock->lock) : "memory");
71}
72
73static inline int _raw_spin_trylock(spinlock_t *lock)
74{
75 return !test_and_set_bit(0, &lock->lock);
76}
77#endif /* CONFIG_DEBUG_SPINLOCK */
78
79#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
80
81/***********************************************************/
82
83typedef struct {
84 volatile unsigned int lock;
85} rwlock_t;
86
87#define RW_LOCK_UNLOCKED (rwlock_t){ 0 }
88
89#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0)
90
91static inline int read_can_lock(rwlock_t *lock)
92{
93 return (lock->lock & 1) == 0;
94}
95
96static inline int write_can_lock(rwlock_t *lock)
97{
98 return lock->lock == 0;
99}
100
101#ifdef CONFIG_DEBUG_RWLOCK
102extern void _raw_write_lock(rwlock_t * lock);
103extern void _raw_read_lock(rwlock_t * lock);
104#else
105static inline void _raw_write_lock(rwlock_t * lock)
106{
107 long regx;
108
109 __asm__ __volatile__(
110 "1: ldl_l %1,%0\n"
111 " bne %1,6f\n"
112 " lda %1,1\n"
113 " stl_c %1,%0\n"
114 " beq %1,6f\n"
115 " mb\n"
116 ".subsection 2\n"
117 "6: ldl %1,%0\n"
118 " bne %1,6b\n"
119 " br 1b\n"
120 ".previous"
121 : "=m" (*lock), "=&r" (regx)
122 : "m" (*lock) : "memory");
123}
124
125static inline void _raw_read_lock(rwlock_t * lock)
126{
127 long regx;
128
129 __asm__ __volatile__(
130 "1: ldl_l %1,%0\n"
131 " blbs %1,6f\n"
132 " subl %1,2,%1\n"
133 " stl_c %1,%0\n"
134 " beq %1,6f\n"
135 " mb\n"
136 ".subsection 2\n"
137 "6: ldl %1,%0\n"
138 " blbs %1,6b\n"
139 " br 1b\n"
140 ".previous"
141 : "=m" (*lock), "=&r" (regx)
142 : "m" (*lock) : "memory");
143}
144#endif /* CONFIG_DEBUG_RWLOCK */
145
146static inline int _raw_read_trylock(rwlock_t * lock)
147{
148 long regx;
149 int success;
150
151 __asm__ __volatile__(
152 "1: ldl_l %1,%0\n"
153 " lda %2,0\n"
154 " blbs %1,2f\n"
155 " subl %1,2,%2\n"
156 " stl_c %2,%0\n"
157 " beq %2,6f\n"
158 "2: mb\n"
159 ".subsection 2\n"
160 "6: br 1b\n"
161 ".previous"
162 : "=m" (*lock), "=&r" (regx), "=&r" (success)
163 : "m" (*lock) : "memory");
164
165 return success;
166}
167
168static inline int _raw_write_trylock(rwlock_t * lock)
169{
170 long regx;
171 int success;
172
173 __asm__ __volatile__(
174 "1: ldl_l %1,%0\n"
175 " lda %2,0\n"
176 " bne %1,2f\n"
177 " lda %2,1\n"
178 " stl_c %2,%0\n"
179 " beq %2,6f\n"
180 "2: mb\n"
181 ".subsection 2\n"
182 "6: br 1b\n"
183 ".previous"
184 : "=m" (*lock), "=&r" (regx), "=&r" (success)
185 : "m" (*lock) : "memory");
186
187 return success;
188}
189
190static inline void _raw_write_unlock(rwlock_t * lock)
191{
192 mb();
193 lock->lock = 0;
194}
195
196static inline void _raw_read_unlock(rwlock_t * lock)
197{
198 long regx;
199 __asm__ __volatile__(
200 " mb\n"
201 "1: ldl_l %1,%0\n"
202 " addl %1,2,%1\n"
203 " stl_c %1,%0\n"
204 " beq %1,6f\n"
205 ".subsection 2\n"
206 "6: br 1b\n"
207 ".previous"
208 : "=m" (*lock), "=&r" (regx)
209 : "m" (*lock) : "memory");
210}
211
212#endif /* _ALPHA_SPINLOCK_H */