1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (2004) Linus Torvalds
5 * Author: Zwane Mwaikambo <zwane@fsmlabs.com>
7 * Copyright (2004, 2005) Ingo Molnar
9 * This file contains the spinlock/rwlock implementations for the
10 * SMP and the DEBUG_SPINLOCK cases. (UP-nondebug inlines them)
12 * Note that some architectures have special knowledge about the
13 * stack frames of these functions in their profile_pc. If you
14 * change anything significant here that could change the stack
15 * frame contact the architecture maintainers.
18 #include <linux/linkage.h>
19 #include <linux/preempt.h>
20 #include <linux/spinlock.h>
21 #include <linux/interrupt.h>
22 #include <linux/debug_locks.h>
23 #include <linux/export.h>
26 * If lockdep is enabled then we use the non-preemption spin-ops
27 * even on CONFIG_PREEMPT, because lockdep assumes that interrupts are
28 * not re-enabled during lock-acquire (which the preempt-spin-ops do):
30 #if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
32 * The __lock_function inlines are taken from
33 * include/linux/spinlock_api_smp.h
36 #define raw_read_can_lock(l) read_can_lock(l)
37 #define raw_write_can_lock(l) write_can_lock(l)
40 * Some architectures can relax in favour of the CPU owning the lock.
42 #ifndef arch_read_relax
43 # define arch_read_relax(l) cpu_relax()
45 #ifndef arch_write_relax
46 # define arch_write_relax(l) cpu_relax()
48 #ifndef arch_spin_relax
49 # define arch_spin_relax(l) cpu_relax()
53 * We build the __lock_function inlines here. They are too large for
54 * inlining all over the place, but here is only one user per function
55 * which embedds them into the calling _lock_function below.
57 * This could be a long-held lock. We both prepare to spin for a long
58 * time (making _this_ CPU preemptable if possible), and we also signal
59 * towards that other CPU that it should break the lock ASAP.
61 #define BUILD_LOCK_OPS(op, locktype) \
62 void __lockfunc __raw_##op##_lock(locktype##_t *lock) \
66 if (likely(do_raw_##op##_trylock(lock))) \
70 if (!(lock)->break_lock) \
71 (lock)->break_lock = 1; \
72 while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\
73 arch_##op##_relax(&lock->raw_lock); \
75 (lock)->break_lock = 0; \
78 unsigned long __lockfunc __raw_##op##_lock_irqsave(locktype##_t *lock) \
80 unsigned long flags; \
84 local_irq_save(flags); \
85 if (likely(do_raw_##op##_trylock(lock))) \
87 local_irq_restore(flags); \
90 if (!(lock)->break_lock) \
91 (lock)->break_lock = 1; \
92 while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\
93 arch_##op##_relax(&lock->raw_lock); \
95 (lock)->break_lock = 0; \
99 void __lockfunc __raw_##op##_lock_irq(locktype##_t *lock) \
101 _raw_##op##_lock_irqsave(lock); \
104 void __lockfunc __raw_##op##_lock_bh(locktype##_t *lock) \
106 unsigned long flags; \
109 /* Careful: we must exclude softirqs too, hence the */ \
110 /* irq-disabling. We use the generic preemption-aware */ \
113 flags = _raw_##op##_lock_irqsave(lock); \
114 local_bh_disable(); \
115 local_irq_restore(flags); \
119 * Build preemption-friendly versions of the following
120 * lock-spinning functions:
122 * __[spin|read|write]_lock()
123 * __[spin|read|write]_lock_irq()
124 * __[spin|read|write]_lock_irqsave()
125 * __[spin|read|write]_lock_bh()
127 BUILD_LOCK_OPS(spin, raw_spinlock);
128 BUILD_LOCK_OPS(read, rwlock);
129 BUILD_LOCK_OPS(write, rwlock);
133 #ifndef CONFIG_INLINE_SPIN_TRYLOCK
134 int __lockfunc _raw_spin_trylock(raw_spinlock_t *lock)
136 return __raw_spin_trylock(lock);
138 EXPORT_SYMBOL(_raw_spin_trylock);
141 #ifndef CONFIG_INLINE_SPIN_TRYLOCK_BH
142 int __lockfunc _raw_spin_trylock_bh(raw_spinlock_t *lock)
144 return __raw_spin_trylock_bh(lock);
146 EXPORT_SYMBOL(_raw_spin_trylock_bh);
149 #ifndef CONFIG_INLINE_SPIN_LOCK
150 void __lockfunc _raw_spin_lock(raw_spinlock_t *lock)
152 __raw_spin_lock(lock);
154 EXPORT_SYMBOL(_raw_spin_lock);
157 #ifndef CONFIG_INLINE_SPIN_LOCK_IRQSAVE
158 unsigned long __lockfunc _raw_spin_lock_irqsave(raw_spinlock_t *lock)
160 return __raw_spin_lock_irqsave(lock);
162 EXPORT_SYMBOL(_raw_spin_lock_irqsave);
165 #ifndef CONFIG_INLINE_SPIN_LOCK_IRQ
166 void __lockfunc _raw_spin_lock_irq(raw_spinlock_t *lock)
168 __raw_spin_lock_irq(lock);
170 EXPORT_SYMBOL(_raw_spin_lock_irq);
173 #ifndef CONFIG_INLINE_SPIN_LOCK_BH
174 void __lockfunc _raw_spin_lock_bh(raw_spinlock_t *lock)
176 __raw_spin_lock_bh(lock);
178 EXPORT_SYMBOL(_raw_spin_lock_bh);
181 #ifdef CONFIG_UNINLINE_SPIN_UNLOCK
182 void __lockfunc _raw_spin_unlock(raw_spinlock_t *lock)
184 __raw_spin_unlock(lock);
186 EXPORT_SYMBOL(_raw_spin_unlock);
189 #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE
190 void __lockfunc _raw_spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags)
192 __raw_spin_unlock_irqrestore(lock, flags);
194 EXPORT_SYMBOL(_raw_spin_unlock_irqrestore);
197 #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQ
198 void __lockfunc _raw_spin_unlock_irq(raw_spinlock_t *lock)
200 __raw_spin_unlock_irq(lock);
202 EXPORT_SYMBOL(_raw_spin_unlock_irq);
205 #ifndef CONFIG_INLINE_SPIN_UNLOCK_BH
206 void __lockfunc _raw_spin_unlock_bh(raw_spinlock_t *lock)
208 __raw_spin_unlock_bh(lock);
210 EXPORT_SYMBOL(_raw_spin_unlock_bh);
213 #ifndef CONFIG_INLINE_READ_TRYLOCK
214 int __lockfunc _raw_read_trylock(rwlock_t *lock)
216 return __raw_read_trylock(lock);
218 EXPORT_SYMBOL(_raw_read_trylock);
221 #ifndef CONFIG_INLINE_READ_LOCK
222 void __lockfunc _raw_read_lock(rwlock_t *lock)
224 __raw_read_lock(lock);
226 EXPORT_SYMBOL(_raw_read_lock);
229 #ifndef CONFIG_INLINE_READ_LOCK_IRQSAVE
230 unsigned long __lockfunc _raw_read_lock_irqsave(rwlock_t *lock)
232 return __raw_read_lock_irqsave(lock);
234 EXPORT_SYMBOL(_raw_read_lock_irqsave);
237 #ifndef CONFIG_INLINE_READ_LOCK_IRQ
238 void __lockfunc _raw_read_lock_irq(rwlock_t *lock)
240 __raw_read_lock_irq(lock);
242 EXPORT_SYMBOL(_raw_read_lock_irq);
245 #ifndef CONFIG_INLINE_READ_LOCK_BH
246 void __lockfunc _raw_read_lock_bh(rwlock_t *lock)
248 __raw_read_lock_bh(lock);
250 EXPORT_SYMBOL(_raw_read_lock_bh);
253 #ifndef CONFIG_INLINE_READ_UNLOCK
254 void __lockfunc _raw_read_unlock(rwlock_t *lock)
256 __raw_read_unlock(lock);
258 EXPORT_SYMBOL(_raw_read_unlock);
261 #ifndef CONFIG_INLINE_READ_UNLOCK_IRQRESTORE
262 void __lockfunc _raw_read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
264 __raw_read_unlock_irqrestore(lock, flags);
266 EXPORT_SYMBOL(_raw_read_unlock_irqrestore);
269 #ifndef CONFIG_INLINE_READ_UNLOCK_IRQ
270 void __lockfunc _raw_read_unlock_irq(rwlock_t *lock)
272 __raw_read_unlock_irq(lock);
274 EXPORT_SYMBOL(_raw_read_unlock_irq);
277 #ifndef CONFIG_INLINE_READ_UNLOCK_BH
278 void __lockfunc _raw_read_unlock_bh(rwlock_t *lock)
280 __raw_read_unlock_bh(lock);
282 EXPORT_SYMBOL(_raw_read_unlock_bh);
285 #ifndef CONFIG_INLINE_WRITE_TRYLOCK
286 int __lockfunc _raw_write_trylock(rwlock_t *lock)
288 return __raw_write_trylock(lock);
290 EXPORT_SYMBOL(_raw_write_trylock);
293 #ifndef CONFIG_INLINE_WRITE_LOCK
294 void __lockfunc _raw_write_lock(rwlock_t *lock)
296 __raw_write_lock(lock);
298 EXPORT_SYMBOL(_raw_write_lock);
301 #ifndef CONFIG_INLINE_WRITE_LOCK_IRQSAVE
302 unsigned long __lockfunc _raw_write_lock_irqsave(rwlock_t *lock)
304 return __raw_write_lock_irqsave(lock);
306 EXPORT_SYMBOL(_raw_write_lock_irqsave);
309 #ifndef CONFIG_INLINE_WRITE_LOCK_IRQ
310 void __lockfunc _raw_write_lock_irq(rwlock_t *lock)
312 __raw_write_lock_irq(lock);
314 EXPORT_SYMBOL(_raw_write_lock_irq);
317 #ifndef CONFIG_INLINE_WRITE_LOCK_BH
318 void __lockfunc _raw_write_lock_bh(rwlock_t *lock)
320 __raw_write_lock_bh(lock);
322 EXPORT_SYMBOL(_raw_write_lock_bh);
325 #ifndef CONFIG_INLINE_WRITE_UNLOCK
326 void __lockfunc _raw_write_unlock(rwlock_t *lock)
328 __raw_write_unlock(lock);
330 EXPORT_SYMBOL(_raw_write_unlock);
333 #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE
334 void __lockfunc _raw_write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
336 __raw_write_unlock_irqrestore(lock, flags);
338 EXPORT_SYMBOL(_raw_write_unlock_irqrestore);
341 #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQ
342 void __lockfunc _raw_write_unlock_irq(rwlock_t *lock)
344 __raw_write_unlock_irq(lock);
346 EXPORT_SYMBOL(_raw_write_unlock_irq);
349 #ifndef CONFIG_INLINE_WRITE_UNLOCK_BH
350 void __lockfunc _raw_write_unlock_bh(rwlock_t *lock)
352 __raw_write_unlock_bh(lock);
354 EXPORT_SYMBOL(_raw_write_unlock_bh);
357 #ifdef CONFIG_DEBUG_LOCK_ALLOC
359 void __lockfunc _raw_spin_lock_nested(raw_spinlock_t *lock, int subclass)
362 spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
363 LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);
365 EXPORT_SYMBOL(_raw_spin_lock_nested);
367 unsigned long __lockfunc _raw_spin_lock_irqsave_nested(raw_spinlock_t *lock,
372 local_irq_save(flags);
374 spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
375 LOCK_CONTENDED_FLAGS(lock, do_raw_spin_trylock, do_raw_spin_lock,
376 do_raw_spin_lock_flags, &flags);
379 EXPORT_SYMBOL(_raw_spin_lock_irqsave_nested);
381 void __lockfunc _raw_spin_lock_nest_lock(raw_spinlock_t *lock,
382 struct lockdep_map *nest_lock)
385 spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
386 LOCK_CONTENDED(lock, do_raw_spin_trylock, do_raw_spin_lock);
388 EXPORT_SYMBOL(_raw_spin_lock_nest_lock);
392 notrace int in_lock_functions(unsigned long addr)
394 /* Linker adds these: start and end of __lockfunc functions */
395 extern char __lock_text_start[], __lock_text_end[];
397 return addr >= (unsigned long)__lock_text_start
398 && addr < (unsigned long)__lock_text_end;
400 EXPORT_SYMBOL(in_lock_functions);