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>
25 * If lockdep is enabled then we use the non-preemption spin-ops
26 * even on CONFIG_PREEMPT, because lockdep assumes that interrupts are
27 * not re-enabled during lock-acquire (which the preempt-spin-ops do):
29 #if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
31 * The __lock_function inlines are taken from
32 * include/linux/spinlock_api_smp.h
36 * We build the __lock_function inlines here. They are too large for
37 * inlining all over the place, but here is only one user per function
38 * which embedds them into the calling _lock_function below.
40 * This could be a long-held lock. We both prepare to spin for a long
41 * time (making _this_ CPU preemptable if possible), and we also signal
42 * towards that other CPU that it should break the lock ASAP.
44 #define BUILD_LOCK_OPS(op, locktype) \
45 void __lockfunc __##op##_lock(locktype##_t *lock) \
49 if (likely(_raw_##op##_trylock(lock))) \
53 if (!(lock)->break_lock) \
54 (lock)->break_lock = 1; \
55 while (!op##_can_lock(lock) && (lock)->break_lock) \
56 arch_##op##_relax(&lock->raw_lock); \
58 (lock)->break_lock = 0; \
61 unsigned long __lockfunc __##op##_lock_irqsave(locktype##_t *lock) \
63 unsigned long flags; \
67 local_irq_save(flags); \
68 if (likely(_raw_##op##_trylock(lock))) \
70 local_irq_restore(flags); \
73 if (!(lock)->break_lock) \
74 (lock)->break_lock = 1; \
75 while (!op##_can_lock(lock) && (lock)->break_lock) \
76 arch_##op##_relax(&lock->raw_lock); \
78 (lock)->break_lock = 0; \
82 void __lockfunc __##op##_lock_irq(locktype##_t *lock) \
84 _##op##_lock_irqsave(lock); \
87 void __lockfunc __##op##_lock_bh(locktype##_t *lock) \
89 unsigned long flags; \
92 /* Careful: we must exclude softirqs too, hence the */ \
93 /* irq-disabling. We use the generic preemption-aware */ \
96 flags = _##op##_lock_irqsave(lock); \
98 local_irq_restore(flags); \
102 * Build preemption-friendly versions of the following
103 * lock-spinning functions:
105 * __[spin|read|write]_lock()
106 * __[spin|read|write]_lock_irq()
107 * __[spin|read|write]_lock_irqsave()
108 * __[spin|read|write]_lock_bh()
110 BUILD_LOCK_OPS(spin, spinlock);
111 BUILD_LOCK_OPS(read, rwlock);
112 BUILD_LOCK_OPS(write, rwlock);
116 #ifndef CONFIG_INLINE_SPIN_TRYLOCK
117 int __lockfunc _spin_trylock(spinlock_t *lock)
119 return __spin_trylock(lock);
121 EXPORT_SYMBOL(_spin_trylock);
124 #ifndef CONFIG_INLINE_SPIN_TRYLOCK_BH
125 int __lockfunc _spin_trylock_bh(spinlock_t *lock)
127 return __spin_trylock_bh(lock);
129 EXPORT_SYMBOL(_spin_trylock_bh);
132 #ifndef CONFIG_INLINE_SPIN_LOCK
133 void __lockfunc _spin_lock(spinlock_t *lock)
137 EXPORT_SYMBOL(_spin_lock);
140 #ifndef CONFIG_INLINE_SPIN_LOCK_IRQSAVE
141 unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
143 return __spin_lock_irqsave(lock);
145 EXPORT_SYMBOL(_spin_lock_irqsave);
148 #ifndef CONFIG_INLINE_SPIN_LOCK_IRQ
149 void __lockfunc _spin_lock_irq(spinlock_t *lock)
151 __spin_lock_irq(lock);
153 EXPORT_SYMBOL(_spin_lock_irq);
156 #ifndef CONFIG_INLINE_SPIN_LOCK_BH
157 void __lockfunc _spin_lock_bh(spinlock_t *lock)
159 __spin_lock_bh(lock);
161 EXPORT_SYMBOL(_spin_lock_bh);
164 #ifndef CONFIG_INLINE_SPIN_UNLOCK
165 void __lockfunc _spin_unlock(spinlock_t *lock)
169 EXPORT_SYMBOL(_spin_unlock);
172 #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE
173 void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
175 __spin_unlock_irqrestore(lock, flags);
177 EXPORT_SYMBOL(_spin_unlock_irqrestore);
180 #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQ
181 void __lockfunc _spin_unlock_irq(spinlock_t *lock)
183 __spin_unlock_irq(lock);
185 EXPORT_SYMBOL(_spin_unlock_irq);
188 #ifndef CONFIG_INLINE_SPIN_UNLOCK_BH
189 void __lockfunc _spin_unlock_bh(spinlock_t *lock)
191 __spin_unlock_bh(lock);
193 EXPORT_SYMBOL(_spin_unlock_bh);
196 #ifndef CONFIG_INLINE_READ_TRYLOCK
197 int __lockfunc _read_trylock(rwlock_t *lock)
199 return __read_trylock(lock);
201 EXPORT_SYMBOL(_read_trylock);
204 #ifndef CONFIG_INLINE_READ_LOCK
205 void __lockfunc _read_lock(rwlock_t *lock)
209 EXPORT_SYMBOL(_read_lock);
212 #ifndef CONFIG_INLINE_READ_LOCK_IRQSAVE
213 unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
215 return __read_lock_irqsave(lock);
217 EXPORT_SYMBOL(_read_lock_irqsave);
220 #ifndef CONFIG_INLINE_READ_LOCK_IRQ
221 void __lockfunc _read_lock_irq(rwlock_t *lock)
223 __read_lock_irq(lock);
225 EXPORT_SYMBOL(_read_lock_irq);
228 #ifndef CONFIG_INLINE_READ_LOCK_BH
229 void __lockfunc _read_lock_bh(rwlock_t *lock)
231 __read_lock_bh(lock);
233 EXPORT_SYMBOL(_read_lock_bh);
236 #ifndef CONFIG_INLINE_READ_UNLOCK
237 void __lockfunc _read_unlock(rwlock_t *lock)
241 EXPORT_SYMBOL(_read_unlock);
244 #ifndef CONFIG_INLINE_READ_UNLOCK_IRQRESTORE
245 void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
247 __read_unlock_irqrestore(lock, flags);
249 EXPORT_SYMBOL(_read_unlock_irqrestore);
252 #ifndef CONFIG_INLINE_READ_UNLOCK_IRQ
253 void __lockfunc _read_unlock_irq(rwlock_t *lock)
255 __read_unlock_irq(lock);
257 EXPORT_SYMBOL(_read_unlock_irq);
260 #ifndef CONFIG_INLINE_READ_UNLOCK_BH
261 void __lockfunc _read_unlock_bh(rwlock_t *lock)
263 __read_unlock_bh(lock);
265 EXPORT_SYMBOL(_read_unlock_bh);
268 #ifndef CONFIG_INLINE_WRITE_TRYLOCK
269 int __lockfunc _write_trylock(rwlock_t *lock)
271 return __write_trylock(lock);
273 EXPORT_SYMBOL(_write_trylock);
276 #ifndef CONFIG_INLINE_WRITE_LOCK
277 void __lockfunc _write_lock(rwlock_t *lock)
281 EXPORT_SYMBOL(_write_lock);
284 #ifndef CONFIG_INLINE_WRITE_LOCK_IRQSAVE
285 unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
287 return __write_lock_irqsave(lock);
289 EXPORT_SYMBOL(_write_lock_irqsave);
292 #ifndef CONFIG_INLINE_WRITE_LOCK_IRQ
293 void __lockfunc _write_lock_irq(rwlock_t *lock)
295 __write_lock_irq(lock);
297 EXPORT_SYMBOL(_write_lock_irq);
300 #ifndef CONFIG_INLINE_WRITE_LOCK_BH
301 void __lockfunc _write_lock_bh(rwlock_t *lock)
303 __write_lock_bh(lock);
305 EXPORT_SYMBOL(_write_lock_bh);
308 #ifndef CONFIG_INLINE_WRITE_UNLOCK
309 void __lockfunc _write_unlock(rwlock_t *lock)
311 __write_unlock(lock);
313 EXPORT_SYMBOL(_write_unlock);
316 #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE
317 void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
319 __write_unlock_irqrestore(lock, flags);
321 EXPORT_SYMBOL(_write_unlock_irqrestore);
324 #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQ
325 void __lockfunc _write_unlock_irq(rwlock_t *lock)
327 __write_unlock_irq(lock);
329 EXPORT_SYMBOL(_write_unlock_irq);
332 #ifndef CONFIG_INLINE_WRITE_UNLOCK_BH
333 void __lockfunc _write_unlock_bh(rwlock_t *lock)
335 __write_unlock_bh(lock);
337 EXPORT_SYMBOL(_write_unlock_bh);
340 #ifdef CONFIG_DEBUG_LOCK_ALLOC
342 void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
345 spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
346 LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
348 EXPORT_SYMBOL(_spin_lock_nested);
350 unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock,
355 local_irq_save(flags);
357 spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
358 LOCK_CONTENDED_FLAGS(lock, _raw_spin_trylock, _raw_spin_lock,
359 _raw_spin_lock_flags, &flags);
362 EXPORT_SYMBOL(_spin_lock_irqsave_nested);
364 void __lockfunc _spin_lock_nest_lock(spinlock_t *lock,
365 struct lockdep_map *nest_lock)
368 spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
369 LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
371 EXPORT_SYMBOL(_spin_lock_nest_lock);
375 notrace int in_lock_functions(unsigned long addr)
377 /* Linker adds these: start and end of __lockfunc functions */
378 extern char __lock_text_start[], __lock_text_end[];
380 return addr >= (unsigned long)__lock_text_start
381 && addr < (unsigned long)__lock_text_end;
383 EXPORT_SYMBOL(in_lock_functions);