Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
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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 * Simple spin lock operations. There are two variants, one clears IRQ's
11 * on the local processor, one does not.
12 *
13 * We make no fairness assumptions. They have a cost.
14 */
15
16#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
17#define __raw_spin_is_locked(x) ((x)->lock != 0)
18#define __raw_spin_unlock_wait(x) \
19 do { cpu_relax(); } while ((x)->lock)
20
21static inline void __raw_spin_unlock(raw_spinlock_t * lock)
22{
23 mb();
24 lock->lock = 0;
25}
26
27static inline void __raw_spin_lock(raw_spinlock_t * lock)
28{
29 long tmp;
30
31 __asm__ __volatile__(
32 "1: ldl_l %0,%1\n"
33 " bne %0,2f\n"
34 " lda %0,1\n"
35 " stl_c %0,%1\n"
36 " beq %0,2f\n"
37 " mb\n"
38 ".subsection 2\n"
39 "2: ldl %0,%1\n"
40 " bne %0,2b\n"
41 " br 1b\n"
42 ".previous"
43 : "=&r" (tmp), "=m" (lock->lock)
44 : "m"(lock->lock) : "memory");
45}
46
47static inline int __raw_spin_trylock(raw_spinlock_t *lock)
48{
49 return !test_and_set_bit(0, &lock->lock);
50}
51
52/***********************************************************/
53
54static inline int __raw_read_can_lock(raw_rwlock_t *lock)
55{
56 return (lock->lock & 1) == 0;
57}
58
59static inline int __raw_write_can_lock(raw_rwlock_t *lock)
60{
61 return lock->lock == 0;
62}
63
64static inline void __raw_read_lock(raw_rwlock_t *lock)
65{
66 long regx;
67
68 __asm__ __volatile__(
69 "1: ldl_l %1,%0\n"
70 " blbs %1,6f\n"
71 " subl %1,2,%1\n"
72 " stl_c %1,%0\n"
73 " beq %1,6f\n"
74 " mb\n"
75 ".subsection 2\n"
76 "6: ldl %1,%0\n"
77 " blbs %1,6b\n"
78 " br 1b\n"
79 ".previous"
80 : "=m" (*lock), "=&r" (regx)
81 : "m" (*lock) : "memory");
82}
83
84static inline void __raw_write_lock(raw_rwlock_t *lock)
85{
86 long regx;
87
88 __asm__ __volatile__(
89 "1: ldl_l %1,%0\n"
90 " bne %1,6f\n"
91 " lda %1,1\n"
92 " stl_c %1,%0\n"
93 " beq %1,6f\n"
94 " mb\n"
95 ".subsection 2\n"
96 "6: ldl %1,%0\n"
97 " bne %1,6b\n"
98 " br 1b\n"
99 ".previous"
100 : "=m" (*lock), "=&r" (regx)
101 : "m" (*lock) : "memory");
102}
103
104static inline int __raw_read_trylock(raw_rwlock_t * lock)
105{
106 long regx;
107 int success;
108
109 __asm__ __volatile__(
110 "1: ldl_l %1,%0\n"
111 " lda %2,0\n"
112 " blbs %1,2f\n"
113 " subl %1,2,%2\n"
114 " stl_c %2,%0\n"
115 " beq %2,6f\n"
116 "2: mb\n"
117 ".subsection 2\n"
118 "6: br 1b\n"
119 ".previous"
120 : "=m" (*lock), "=&r" (regx), "=&r" (success)
121 : "m" (*lock) : "memory");
122
123 return success;
124}
125
126static inline int __raw_write_trylock(raw_rwlock_t * lock)
127{
128 long regx;
129 int success;
130
131 __asm__ __volatile__(
132 "1: ldl_l %1,%0\n"
133 " lda %2,0\n"
134 " bne %1,2f\n"
135 " lda %2,1\n"
136 " stl_c %2,%0\n"
137 " beq %2,6f\n"
138 "2: mb\n"
139 ".subsection 2\n"
140 "6: br 1b\n"
141 ".previous"
142 : "=m" (*lock), "=&r" (regx), "=&r" (success)
143 : "m" (*lock) : "memory");
144
145 return success;
146}
147
148static inline void __raw_read_unlock(raw_rwlock_t * lock)
149{
150 long regx;
151 __asm__ __volatile__(
152 " mb\n"
153 "1: ldl_l %1,%0\n"
154 " addl %1,2,%1\n"
155 " stl_c %1,%0\n"
156 " beq %1,6f\n"
157 ".subsection 2\n"
158 "6: br 1b\n"
159 ".previous"
160 : "=m" (*lock), "=&r" (regx)
161 : "m" (*lock) : "memory");
162}
163
164static inline void __raw_write_unlock(raw_rwlock_t * lock)
165{
166 mb();
167 lock->lock = 0;
168}
169
170#endif /* _ALPHA_SPINLOCK_H */