2 * Copyright (2004) Linus Torvalds
4 * Author: Zwane Mwaikambo <zwane@fsmlabs.com>
6 * Copyright (2004, 2005) Ingo Molnar
8 * This file contains the spinlock/rwlock implementations for the
9 * SMP and the DEBUG_SPINLOCK cases. (UP-nondebug inlines them)
11 * Note that some architectures have special knowledge about the
12 * stack frames of these functions in their profile_pc. If you
13 * change anything significant here that could change the stack
14 * frame contact the architecture maintainers.
17 #include <linux/linkage.h>
18 #include <linux/preempt.h>
19 #include <linux/spinlock.h>
20 #include <linux/interrupt.h>
21 #include <linux/debug_locks.h>
22 #include <linux/module.h>
24 int __lockfunc
_spin_trylock(spinlock_t
*lock
)
26 return __spin_trylock(lock
);
28 EXPORT_SYMBOL(_spin_trylock
);
30 int __lockfunc
_read_trylock(rwlock_t
*lock
)
32 return __read_trylock(lock
);
34 EXPORT_SYMBOL(_read_trylock
);
36 int __lockfunc
_write_trylock(rwlock_t
*lock
)
38 return __write_trylock(lock
);
40 EXPORT_SYMBOL(_write_trylock
);
43 * If lockdep is enabled then we use the non-preemption spin-ops
44 * even on CONFIG_PREEMPT, because lockdep assumes that interrupts are
45 * not re-enabled during lock-acquire (which the preempt-spin-ops do):
47 #if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
49 void __lockfunc
_read_lock(rwlock_t
*lock
)
53 EXPORT_SYMBOL(_read_lock
);
55 unsigned long __lockfunc
_spin_lock_irqsave(spinlock_t
*lock
)
57 return __spin_lock_irqsave(lock
);
59 EXPORT_SYMBOL(_spin_lock_irqsave
);
61 void __lockfunc
_spin_lock_irq(spinlock_t
*lock
)
63 __spin_lock_irq(lock
);
65 EXPORT_SYMBOL(_spin_lock_irq
);
67 void __lockfunc
_spin_lock_bh(spinlock_t
*lock
)
71 EXPORT_SYMBOL(_spin_lock_bh
);
73 unsigned long __lockfunc
_read_lock_irqsave(rwlock_t
*lock
)
75 return __read_lock_irqsave(lock
);
77 EXPORT_SYMBOL(_read_lock_irqsave
);
79 void __lockfunc
_read_lock_irq(rwlock_t
*lock
)
81 __read_lock_irq(lock
);
83 EXPORT_SYMBOL(_read_lock_irq
);
85 void __lockfunc
_read_lock_bh(rwlock_t
*lock
)
89 EXPORT_SYMBOL(_read_lock_bh
);
91 unsigned long __lockfunc
_write_lock_irqsave(rwlock_t
*lock
)
93 return __write_lock_irqsave(lock
);
95 EXPORT_SYMBOL(_write_lock_irqsave
);
97 void __lockfunc
_write_lock_irq(rwlock_t
*lock
)
99 __write_lock_irq(lock
);
101 EXPORT_SYMBOL(_write_lock_irq
);
103 void __lockfunc
_write_lock_bh(rwlock_t
*lock
)
105 __write_lock_bh(lock
);
107 EXPORT_SYMBOL(_write_lock_bh
);
109 void __lockfunc
_spin_lock(spinlock_t
*lock
)
113 EXPORT_SYMBOL(_spin_lock
);
115 void __lockfunc
_write_lock(rwlock_t
*lock
)
119 EXPORT_SYMBOL(_write_lock
);
121 #else /* CONFIG_PREEMPT: */
124 * This could be a long-held lock. We both prepare to spin for a long
125 * time (making _this_ CPU preemptable if possible), and we also signal
126 * towards that other CPU that it should break the lock ASAP.
128 * (We do this in a function because inlining it would be excessive.)
131 #define BUILD_LOCK_OPS(op, locktype) \
132 void __lockfunc _##op##_lock(locktype##_t *lock) \
136 if (likely(_raw_##op##_trylock(lock))) \
140 if (!(lock)->break_lock) \
141 (lock)->break_lock = 1; \
142 while (!op##_can_lock(lock) && (lock)->break_lock) \
143 _raw_##op##_relax(&lock->raw_lock); \
145 (lock)->break_lock = 0; \
148 EXPORT_SYMBOL(_##op##_lock); \
150 unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock) \
152 unsigned long flags; \
156 local_irq_save(flags); \
157 if (likely(_raw_##op##_trylock(lock))) \
159 local_irq_restore(flags); \
162 if (!(lock)->break_lock) \
163 (lock)->break_lock = 1; \
164 while (!op##_can_lock(lock) && (lock)->break_lock) \
165 _raw_##op##_relax(&lock->raw_lock); \
167 (lock)->break_lock = 0; \
171 EXPORT_SYMBOL(_##op##_lock_irqsave); \
173 void __lockfunc _##op##_lock_irq(locktype##_t *lock) \
175 _##op##_lock_irqsave(lock); \
178 EXPORT_SYMBOL(_##op##_lock_irq); \
180 void __lockfunc _##op##_lock_bh(locktype##_t *lock) \
182 unsigned long flags; \
185 /* Careful: we must exclude softirqs too, hence the */ \
186 /* irq-disabling. We use the generic preemption-aware */ \
189 flags = _##op##_lock_irqsave(lock); \
190 local_bh_disable(); \
191 local_irq_restore(flags); \
194 EXPORT_SYMBOL(_##op##_lock_bh)
197 * Build preemption-friendly versions of the following
198 * lock-spinning functions:
200 * _[spin|read|write]_lock()
201 * _[spin|read|write]_lock_irq()
202 * _[spin|read|write]_lock_irqsave()
203 * _[spin|read|write]_lock_bh()
205 BUILD_LOCK_OPS(spin
, spinlock
);
206 BUILD_LOCK_OPS(read
, rwlock
);
207 BUILD_LOCK_OPS(write
, rwlock
);
209 #endif /* CONFIG_PREEMPT */
211 #ifdef CONFIG_DEBUG_LOCK_ALLOC
213 void __lockfunc
_spin_lock_nested(spinlock_t
*lock
, int subclass
)
216 spin_acquire(&lock
->dep_map
, subclass
, 0, _RET_IP_
);
217 LOCK_CONTENDED(lock
, _raw_spin_trylock
, _raw_spin_lock
);
219 EXPORT_SYMBOL(_spin_lock_nested
);
221 unsigned long __lockfunc
_spin_lock_irqsave_nested(spinlock_t
*lock
, int subclass
)
225 local_irq_save(flags
);
227 spin_acquire(&lock
->dep_map
, subclass
, 0, _RET_IP_
);
228 LOCK_CONTENDED_FLAGS(lock
, _raw_spin_trylock
, _raw_spin_lock
,
229 _raw_spin_lock_flags
, &flags
);
232 EXPORT_SYMBOL(_spin_lock_irqsave_nested
);
234 void __lockfunc
_spin_lock_nest_lock(spinlock_t
*lock
,
235 struct lockdep_map
*nest_lock
)
238 spin_acquire_nest(&lock
->dep_map
, 0, 0, nest_lock
, _RET_IP_
);
239 LOCK_CONTENDED(lock
, _raw_spin_trylock
, _raw_spin_lock
);
241 EXPORT_SYMBOL(_spin_lock_nest_lock
);
245 void __lockfunc
_spin_unlock(spinlock_t
*lock
)
249 EXPORT_SYMBOL(_spin_unlock
);
251 void __lockfunc
_write_unlock(rwlock_t
*lock
)
253 __write_unlock(lock
);
255 EXPORT_SYMBOL(_write_unlock
);
257 void __lockfunc
_read_unlock(rwlock_t
*lock
)
261 EXPORT_SYMBOL(_read_unlock
);
263 void __lockfunc
_spin_unlock_irqrestore(spinlock_t
*lock
, unsigned long flags
)
265 __spin_unlock_irqrestore(lock
, flags
);
267 EXPORT_SYMBOL(_spin_unlock_irqrestore
);
269 void __lockfunc
_spin_unlock_irq(spinlock_t
*lock
)
271 __spin_unlock_irq(lock
);
273 EXPORT_SYMBOL(_spin_unlock_irq
);
275 void __lockfunc
_spin_unlock_bh(spinlock_t
*lock
)
277 __spin_unlock_bh(lock
);
279 EXPORT_SYMBOL(_spin_unlock_bh
);
281 void __lockfunc
_read_unlock_irqrestore(rwlock_t
*lock
, unsigned long flags
)
283 __read_unlock_irqrestore(lock
, flags
);
285 EXPORT_SYMBOL(_read_unlock_irqrestore
);
287 void __lockfunc
_read_unlock_irq(rwlock_t
*lock
)
289 __read_unlock_irq(lock
);
291 EXPORT_SYMBOL(_read_unlock_irq
);
293 void __lockfunc
_read_unlock_bh(rwlock_t
*lock
)
295 __read_unlock_bh(lock
);
297 EXPORT_SYMBOL(_read_unlock_bh
);
299 void __lockfunc
_write_unlock_irqrestore(rwlock_t
*lock
, unsigned long flags
)
301 __write_unlock_irqrestore(lock
, flags
);
303 EXPORT_SYMBOL(_write_unlock_irqrestore
);
305 void __lockfunc
_write_unlock_irq(rwlock_t
*lock
)
307 __write_unlock_irq(lock
);
309 EXPORT_SYMBOL(_write_unlock_irq
);
311 void __lockfunc
_write_unlock_bh(rwlock_t
*lock
)
313 __write_unlock_bh(lock
);
315 EXPORT_SYMBOL(_write_unlock_bh
);
317 int __lockfunc
_spin_trylock_bh(spinlock_t
*lock
)
319 return __spin_trylock_bh(lock
);
321 EXPORT_SYMBOL(_spin_trylock_bh
);
323 notrace
int in_lock_functions(unsigned long addr
)
325 /* Linker adds these: start and end of __lockfunc functions */
326 extern char __lock_text_start
[], __lock_text_end
[];
328 return addr
>= (unsigned long)__lock_text_start
329 && addr
< (unsigned long)__lock_text_end
;
331 EXPORT_SYMBOL(in_lock_functions
);