spinlock.h (fb3a6bbc912b12347614e5742c7c61416cdb0ca0) spinlock.h (e5931943d02bf751b1ec849c0d2ade23d76a8d41)
1/*
2 * include/asm-s390/spinlock.h
3 *
4 * S390 version
5 * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
7 *
8 * Derived from "include/asm-i386/spinlock.h"

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108 * irq-safe write-lock, but readers can get non-irqsafe
109 * read-locks.
110 */
111
112/**
113 * read_can_lock - would read_trylock() succeed?
114 * @lock: the rwlock in question.
115 */
1/*
2 * include/asm-s390/spinlock.h
3 *
4 * S390 version
5 * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
7 *
8 * Derived from "include/asm-i386/spinlock.h"

--- 99 unchanged lines hidden (view full) ---

108 * irq-safe write-lock, but readers can get non-irqsafe
109 * read-locks.
110 */
111
112/**
113 * read_can_lock - would read_trylock() succeed?
114 * @lock: the rwlock in question.
115 */
116#define __raw_read_can_lock(x) ((int)(x)->lock >= 0)
116#define arch_read_can_lock(x) ((int)(x)->lock >= 0)
117
118/**
119 * write_can_lock - would write_trylock() succeed?
120 * @lock: the rwlock in question.
121 */
117
118/**
119 * write_can_lock - would write_trylock() succeed?
120 * @lock: the rwlock in question.
121 */
122#define __raw_write_can_lock(x) ((x)->lock == 0)
122#define arch_write_can_lock(x) ((x)->lock == 0)
123
124extern void _raw_read_lock_wait(arch_rwlock_t *lp);
125extern void _raw_read_lock_wait_flags(arch_rwlock_t *lp, unsigned long flags);
126extern int _raw_read_trylock_retry(arch_rwlock_t *lp);
127extern void _raw_write_lock_wait(arch_rwlock_t *lp);
128extern void _raw_write_lock_wait_flags(arch_rwlock_t *lp, unsigned long flags);
129extern int _raw_write_trylock_retry(arch_rwlock_t *lp);
130
123
124extern void _raw_read_lock_wait(arch_rwlock_t *lp);
125extern void _raw_read_lock_wait_flags(arch_rwlock_t *lp, unsigned long flags);
126extern int _raw_read_trylock_retry(arch_rwlock_t *lp);
127extern void _raw_write_lock_wait(arch_rwlock_t *lp);
128extern void _raw_write_lock_wait_flags(arch_rwlock_t *lp, unsigned long flags);
129extern int _raw_write_trylock_retry(arch_rwlock_t *lp);
130
131static inline void __raw_read_lock(arch_rwlock_t *rw)
131static inline void arch_read_lock(arch_rwlock_t *rw)
132{
133 unsigned int old;
134 old = rw->lock & 0x7fffffffU;
135 if (_raw_compare_and_swap(&rw->lock, old, old + 1) != old)
136 _raw_read_lock_wait(rw);
137}
138
132{
133 unsigned int old;
134 old = rw->lock & 0x7fffffffU;
135 if (_raw_compare_and_swap(&rw->lock, old, old + 1) != old)
136 _raw_read_lock_wait(rw);
137}
138
139static inline void __raw_read_lock_flags(arch_rwlock_t *rw, unsigned long flags)
139static inline void arch_read_lock_flags(arch_rwlock_t *rw, unsigned long flags)
140{
141 unsigned int old;
142 old = rw->lock & 0x7fffffffU;
143 if (_raw_compare_and_swap(&rw->lock, old, old + 1) != old)
144 _raw_read_lock_wait_flags(rw, flags);
145}
146
140{
141 unsigned int old;
142 old = rw->lock & 0x7fffffffU;
143 if (_raw_compare_and_swap(&rw->lock, old, old + 1) != old)
144 _raw_read_lock_wait_flags(rw, flags);
145}
146
147static inline void __raw_read_unlock(arch_rwlock_t *rw)
147static inline void arch_read_unlock(arch_rwlock_t *rw)
148{
149 unsigned int old, cmp;
150
151 old = rw->lock;
152 do {
153 cmp = old;
154 old = _raw_compare_and_swap(&rw->lock, old, old - 1);
155 } while (cmp != old);
156}
157
148{
149 unsigned int old, cmp;
150
151 old = rw->lock;
152 do {
153 cmp = old;
154 old = _raw_compare_and_swap(&rw->lock, old, old - 1);
155 } while (cmp != old);
156}
157
158static inline void __raw_write_lock(arch_rwlock_t *rw)
158static inline void arch_write_lock(arch_rwlock_t *rw)
159{
160 if (unlikely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) != 0))
161 _raw_write_lock_wait(rw);
162}
163
159{
160 if (unlikely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) != 0))
161 _raw_write_lock_wait(rw);
162}
163
164static inline void __raw_write_lock_flags(arch_rwlock_t *rw, unsigned long flags)
164static inline void arch_write_lock_flags(arch_rwlock_t *rw, unsigned long flags)
165{
166 if (unlikely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) != 0))
167 _raw_write_lock_wait_flags(rw, flags);
168}
169
165{
166 if (unlikely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) != 0))
167 _raw_write_lock_wait_flags(rw, flags);
168}
169
170static inline void __raw_write_unlock(arch_rwlock_t *rw)
170static inline void arch_write_unlock(arch_rwlock_t *rw)
171{
172 _raw_compare_and_swap(&rw->lock, 0x80000000, 0);
173}
174
171{
172 _raw_compare_and_swap(&rw->lock, 0x80000000, 0);
173}
174
175static inline int __raw_read_trylock(arch_rwlock_t *rw)
175static inline int arch_read_trylock(arch_rwlock_t *rw)
176{
177 unsigned int old;
178 old = rw->lock & 0x7fffffffU;
179 if (likely(_raw_compare_and_swap(&rw->lock, old, old + 1) == old))
180 return 1;
181 return _raw_read_trylock_retry(rw);
182}
183
176{
177 unsigned int old;
178 old = rw->lock & 0x7fffffffU;
179 if (likely(_raw_compare_and_swap(&rw->lock, old, old + 1) == old))
180 return 1;
181 return _raw_read_trylock_retry(rw);
182}
183
184static inline int __raw_write_trylock(arch_rwlock_t *rw)
184static inline int arch_write_trylock(arch_rwlock_t *rw)
185{
186 if (likely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0))
187 return 1;
188 return _raw_write_trylock_retry(rw);
189}
190
191#define arch_read_relax(lock) cpu_relax()
192#define arch_write_relax(lock) cpu_relax()
193
194#endif /* __ASM_SPINLOCK_H */
185{
186 if (likely(_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0))
187 return 1;
188 return _raw_write_trylock_retry(rw);
189}
190
191#define arch_read_relax(lock) cpu_relax()
192#define arch_write_relax(lock) cpu_relax()
193
194#endif /* __ASM_SPINLOCK_H */