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/export.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
35 #define raw_read_can_lock(l) read_can_lock(l)
36 #define raw_write_can_lock(l) write_can_lock(l)
39 * Some architectures can relax in favour of the CPU owning the lock.
41 #ifndef arch_read_relax
42 # define arch_read_relax(l) cpu_relax()
44 #ifndef arch_write_relax
45 # define arch_write_relax(l) cpu_relax()
47 #ifndef arch_spin_relax
48 # define arch_spin_relax(l) cpu_relax()
52 * We build the __lock_function inlines here. They are too large for
53 * inlining all over the place, but here is only one user per function
54 * which embedds them into the calling _lock_function below.
56 * This could be a long-held lock. We both prepare to spin for a long
57 * time (making _this_ CPU preemptable if possible), and we also signal
58 * towards that other CPU that it should break the lock ASAP.
60 #define BUILD_LOCK_OPS(op, locktype) \
61 void __lockfunc __raw_##op##_lock(locktype##_t *lock) \
65 if (likely(do_raw_##op##_trylock(lock))) \
69 if (!(lock)->break_lock) \
70 (lock)->break_lock = 1; \
71 while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\
72 arch_##op##_relax(&lock->raw_lock); \
74 (lock)->break_lock = 0; \
77 unsigned long __lockfunc __raw_##op##_lock_irqsave(locktype##_t *lock) \
79 unsigned long flags; \
83 local_irq_save(flags); \
84 if (likely(do_raw_##op##_trylock(lock))) \
86 local_irq_restore(flags); \
89 if (!(lock)->break_lock) \
90 (lock)->break_lock = 1; \
91 while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\
92 arch_##op##_relax(&lock->raw_lock); \
94 (lock)->break_lock = 0; \
98 void __lockfunc __raw_##op##_lock_irq(locktype##_t *lock) \
100 _raw_##op##_lock_irqsave(lock); \
103 void __lockfunc __raw_##op##_lock_bh(locktype##_t *lock) \
105 unsigned long flags; \
108 /* Careful: we must exclude softirqs too, hence the */ \
109 /* irq-disabling. We use the generic preemption-aware */ \
112 flags = _raw_##op##_lock_irqsave(lock); \
113 local_bh_disable(); \
114 local_irq_restore(flags); \
118 * Build preemption-friendly versions of the following
119 * lock-spinning functions:
121 * __[spin|read|write]_lock()
122 * __[spin|read|write]_lock_irq()
123 * __[spin|read|write]_lock_irqsave()
124 * __[spin|read|write]_lock_bh()
126 BUILD_LOCK_OPS(spin, raw_spinlock);
128 #ifndef CONFIG_PREEMPT_RT_FULL
129 BUILD_LOCK_OPS(read, rwlock);
130 BUILD_LOCK_OPS(write, rwlock);
135 #ifndef CONFIG_INLINE_SPIN_TRYLOCK
136 int __lockfunc _raw_spin_trylock(raw_spinlock_t *lock)
138 return __raw_spin_trylock(lock);
140 EXPORT_SYMBOL(_raw_spin_trylock);
143 #ifndef CONFIG_INLINE_SPIN_TRYLOCK_BH
144 int __lockfunc _raw_spin_trylock_bh(raw_spinlock_t *lock)
146 return __raw_spin_trylock_bh(lock);
148 EXPORT_SYMBOL(_raw_spin_trylock_bh);
151 #ifndef CONFIG_INLINE_SPIN_LOCK
152 void __lockfunc _raw_spin_lock(raw_spinlock_t *lock)
154 __raw_spin_lock(lock);
156 EXPORT_SYMBOL(_raw_spin_lock);
159 #ifndef CONFIG_INLINE_SPIN_LOCK_IRQSAVE
160 unsigned long __lockfunc _raw_spin_lock_irqsave(raw_spinlock_t *lock)
162 return __raw_spin_lock_irqsave(lock);
164 EXPORT_SYMBOL(_raw_spin_lock_irqsave);
167 #ifndef CONFIG_INLINE_SPIN_LOCK_IRQ
168 void __lockfunc _raw_spin_lock_irq(raw_spinlock_t *lock)
170 __raw_spin_lock_irq(lock);
172 EXPORT_SYMBOL(_raw_spin_lock_irq);
175 #ifndef CONFIG_INLINE_SPIN_LOCK_BH
176 void __lockfunc _raw_spin_lock_bh(raw_spinlock_t *lock)
178 __raw_spin_lock_bh(lock);
180 EXPORT_SYMBOL(_raw_spin_lock_bh);
183 #ifdef CONFIG_UNINLINE_SPIN_UNLOCK
184 void __lockfunc _raw_spin_unlock(raw_spinlock_t *lock)
186 __raw_spin_unlock(lock);
188 EXPORT_SYMBOL(_raw_spin_unlock);
191 #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE
192 void __lockfunc _raw_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags)
194 __raw_spin_unlock_irqrestore(lock, flags);
196 EXPORT_SYMBOL(_raw_spin_unlock_irqrestore);
199 #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQ
200 void __lockfunc _raw_spin_unlock_irq(raw_spinlock_t *lock)
202 __raw_spin_unlock_irq(lock);
204 EXPORT_SYMBOL(_raw_spin_unlock_irq);
207 #ifndef CONFIG_INLINE_SPIN_UNLOCK_BH
208 void __lockfunc _raw_spin_unlock_bh(raw_spinlock_t *lock)
210 __raw_spin_unlock_bh(lock);
212 EXPORT_SYMBOL(_raw_spin_unlock_bh);
215 #ifndef CONFIG_PREEMPT_RT_FULL
217 #ifndef CONFIG_INLINE_READ_TRYLOCK
218 int __lockfunc _raw_read_trylock(rwlock_t *lock)
220 return __raw_read_trylock(lock);
222 EXPORT_SYMBOL(_raw_read_trylock);
225 #ifndef CONFIG_INLINE_READ_LOCK
226 void __lockfunc _raw_read_lock(rwlock_t *lock)
228 __raw_read_lock(lock);
230 EXPORT_SYMBOL(_raw_read_lock);
233 #ifndef CONFIG_INLINE_READ_LOCK_IRQSAVE
234 unsigned long __lockfunc _raw_read_lock_irqsave(rwlock_t *lock)
236 return __raw_read_lock_irqsave(lock);
238 EXPORT_SYMBOL(_raw_read_lock_irqsave);
241 #ifndef CONFIG_INLINE_READ_LOCK_IRQ
242 void __lockfunc _raw_read_lock_irq(rwlock_t *lock)
244 __raw_read_lock_irq(lock);
246 EXPORT_SYMBOL(_raw_read_lock_irq);
249 #ifndef CONFIG_INLINE_READ_LOCK_BH
250 void __lockfunc _raw_read_lock_bh(rwlock_t *lock)
252 __raw_read_lock_bh(lock);
254 EXPORT_SYMBOL(_raw_read_lock_bh);
257 #ifndef CONFIG_INLINE_READ_UNLOCK
258 void __lockfunc _raw_read_unlock(rwlock_t *lock)
260 __raw_read_unlock(lock);
262 EXPORT_SYMBOL(_raw_read_unlock);
265 #ifndef CONFIG_INLINE_READ_UNLOCK_IRQRESTORE
266 void __lockfunc _raw_read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
268 __raw_read_unlock_irqrestore(lock, flags);
270 EXPORT_SYMBOL(_raw_read_unlock_irqrestore);
273 #ifndef CONFIG_INLINE_READ_UNLOCK_IRQ
274 void __lockfunc _raw_read_unlock_irq(rwlock_t *lock)
276 __raw_read_unlock_irq(lock);
278 EXPORT_SYMBOL(_raw_read_unlock_irq);
281 #ifndef CONFIG_INLINE_READ_UNLOCK_BH
282 void __lockfunc _raw_read_unlock_bh(rwlock_t *lock)
284 __raw_read_unlock_bh(lock);
286 EXPORT_SYMBOL(_raw_read_unlock_bh);
289 #ifndef CONFIG_INLINE_WRITE_TRYLOCK
290 int __lockfunc _raw_write_trylock(rwlock_t *lock)
292 return __raw_write_trylock(lock);
294 EXPORT_SYMBOL(_raw_write_trylock);
297 #ifndef CONFIG_INLINE_WRITE_LOCK
298 void __lockfunc _raw_write_lock(rwlock_t *lock)
300 __raw_write_lock(lock);
302 EXPORT_SYMBOL(_raw_write_lock);
305 #ifndef CONFIG_INLINE_WRITE_LOCK_IRQSAVE
306 unsigned long __lockfunc _raw_write_lock_irqsave(rwlock_t *lock)
308 return __raw_write_lock_irqsave(lock);
310 EXPORT_SYMBOL(_raw_write_lock_irqsave);
313 #ifndef CONFIG_INLINE_WRITE_LOCK_IRQ
314 void __lockfunc _raw_write_lock_irq(rwlock_t *lock)
316 __raw_write_lock_irq(lock);
318 EXPORT_SYMBOL(_raw_write_lock_irq);
321 #ifndef CONFIG_INLINE_WRITE_LOCK_BH
322 void __lockfunc _raw_write_lock_bh(rwlock_t *lock)
324 __raw_write_lock_bh(lock);
326 EXPORT_SYMBOL(_raw_write_lock_bh);
329 #ifndef CONFIG_INLINE_WRITE_UNLOCK
330 void __lockfunc _raw_write_unlock(rwlock_t *lock)
332 __raw_write_unlock(lock);
334 EXPORT_SYMBOL(_raw_write_unlock);
337 #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE
338 void __lockfunc _raw_write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
340 __raw_write_unlock_irqrestore(lock, flags);
342 EXPORT_SYMBOL(_raw_write_unlock_irqrestore);
345 #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQ
346 void __lockfunc _raw_write_unlock_irq(rwlock_t *lock)
348 __raw_write_unlock_irq(lock);
350 EXPORT_SYMBOL(_raw_write_unlock_irq);
353 #ifndef CONFIG_INLINE_WRITE_UNLOCK_BH
354 void __lockfunc _raw_write_unlock_bh(rwlock_t *lock)
356 __raw_write_unlock_bh(lock);
358 EXPORT_SYMBOL(_raw_write_unlock_bh);
361 #endif /* !PREEMPT_RT_FULL */
363 #ifdef CONFIG_DEBUG_LOCK_ALLOC
365 void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass)
368 spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
369 LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);
371 EXPORT_SYMBOL(_raw_spin_lock_nested);
373 void __lockfunc _raw_spin_lock_bh_nested(raw_spinlock_t *lock, int subclass)
375 __local_bh_disable_ip(_RET_IP_, SOFTIRQ_LOCK_OFFSET);
376 spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
377 LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);
379 EXPORT_SYMBOL(_raw_spin_lock_bh_nested);
381 unsigned long __lockfunc _raw_spin_lock_irqsave_nested(raw_spinlock_t *lock,
386 local_irq_save(flags);
388 spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
389 LOCK_CONTENDED_FLAGS(lock, do_raw_spin_trylock, do_raw_spin_lock,
390 do_raw_spin_lock_flags, &flags);
393 EXPORT_SYMBOL(_raw_spin_lock_irqsave_nested);
395 void __lockfunc _raw_spin_lock_nest_lock(raw_spinlock_t *lock,
396 struct lockdep_map *nest_lock)
399 spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
400 LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);
402 EXPORT_SYMBOL(_raw_spin_lock_nest_lock);
406 notrace int in_lock_functions(unsigned long addr)
408 /* Linker adds these: start and end of __lockfunc functions */
409 extern char __lock_text_start[], __lock_text_end[];
411 return addr >= (unsigned long)__lock_text_start
412 && addr < (unsigned long)__lock_text_end;
414 EXPORT_SYMBOL(in_lock_functions);