1 /* SPDX-License-Identifier: GPL-2.0 */
7  * include/linux/spinlock.h - generic spinlock/rwlock declarations
24  *   (also included on UP-debug builds:)
35  *                        (which is an empty structure on non-debug builds)
44  *                        builds. (which are NOPs on non-debug, non-preempt
47  *   (included on UP-non-debug builds:)
71 #define LOCK_SECTION_NAME ".text..lock."KBUILD_BASENAME
91  * Pull the arch_spin*() functions/declarations (UP-nondebug doesn't need them):
100   extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
103 # define raw_spin_lock_init(lock)					\  argument
107 	__raw_spin_lock_init((lock), #lock, &__key, LD_WAIT_SPIN);	\
111 # define raw_spin_lock_init(lock)				\  argument
112 	do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0)
115 #define raw_spin_is_locked(lock)	arch_spin_is_locked(&(lock)->raw_lock)  argument
118 #define raw_spin_is_contended(lock)	arch_spin_is_contended(&(lock)->raw_lock)  argument
120 #define raw_spin_is_contended(lock)	(((void)(lock), 0))  argument
125  * between program-order earlier lock acquisitions and program-order later
165  * Property (2) upgrades the lock to an RCsc lock.
167  * Since most load-store architectures implement ACQUIRE with an smp_mb() after
179  extern void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock);
180  extern int do_raw_spin_trylock(raw_spinlock_t *lock);
181  extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock);
183 static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock)  in do_raw_spin_lock()  argument
185 	__acquire(lock);  in do_raw_spin_lock()
186 	arch_spin_lock(&lock->raw_lock);  in do_raw_spin_lock()
190 static inline int do_raw_spin_trylock(raw_spinlock_t *lock)  in do_raw_spin_trylock()  argument
192 	int ret = arch_spin_trylock(&(lock)->raw_lock);  in do_raw_spin_trylock()
200 static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock)  in do_raw_spin_unlock()  argument
203 	arch_spin_unlock(&lock->raw_lock);  in do_raw_spin_unlock()
204 	__release(lock);  in do_raw_spin_unlock()
214 #define raw_spin_trylock(lock)	__cond_lock(lock, _raw_spin_trylock(lock))  argument
216 #define raw_spin_lock(lock)	_raw_spin_lock(lock)  argument
219 # define raw_spin_lock_nested(lock, subclass) \  argument
220 	_raw_spin_lock_nested(lock, subclass)
222 # define raw_spin_lock_nest_lock(lock, nest_lock)			\  argument
224 		 typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
225 		 _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map);	\
230  * warns about set-but-not-used variables when building with
233 # define raw_spin_lock_nested(lock, subclass)		\  argument
234 	_raw_spin_lock(((void)(subclass), (lock)))
235 # define raw_spin_lock_nest_lock(lock, nest_lock)	_raw_spin_lock(lock)  argument
240 #define raw_spin_lock_irqsave(lock, flags)			\  argument
243 		flags = _raw_spin_lock_irqsave(lock);	\
247 #define raw_spin_lock_irqsave_nested(lock, flags, subclass)		\  argument
250 		flags = _raw_spin_lock_irqsave_nested(lock, subclass);	\
253 #define raw_spin_lock_irqsave_nested(lock, flags, subclass)		\  argument
256 		flags = _raw_spin_lock_irqsave(lock);			\
262 #define raw_spin_lock_irqsave(lock, flags)		\  argument
265 		_raw_spin_lock_irqsave(lock, flags);	\
268 #define raw_spin_lock_irqsave_nested(lock, flags, subclass)	\  argument
269 	raw_spin_lock_irqsave(lock, flags)
273 #define raw_spin_lock_irq(lock)		_raw_spin_lock_irq(lock)  argument
274 #define raw_spin_lock_bh(lock)		_raw_spin_lock_bh(lock)  argument
275 #define raw_spin_unlock(lock)		_raw_spin_unlock(lock)  argument
276 #define raw_spin_unlock_irq(lock)	_raw_spin_unlock_irq(lock)  argument
278 #define raw_spin_unlock_irqrestore(lock, flags)		\  argument
281 		_raw_spin_unlock_irqrestore(lock, flags);	\
283 #define raw_spin_unlock_bh(lock)	_raw_spin_unlock_bh(lock)  argument
285 #define raw_spin_trylock_bh(lock) \  argument
286 	__cond_lock(lock, _raw_spin_trylock_bh(lock))
288 #define raw_spin_trylock_irq(lock) \  argument
291 	raw_spin_trylock(lock) ? \
295 #define raw_spin_trylock_irqsave(lock, flags) \  argument
298 	raw_spin_trylock(lock) ? \
323 static __always_inline raw_spinlock_t *spinlock_check(spinlock_t *lock)  in spinlock_check()  argument
325 	return &lock->rlock;  in spinlock_check()
330 # define spin_lock_init(lock)					\  argument
334 	__raw_spin_lock_init(spinlock_check(lock),		\
335 			     #lock, &__key, LD_WAIT_CONFIG);	\
348 static __always_inline void spin_lock(spinlock_t *lock)  in spin_lock()  argument
350 	raw_spin_lock(&lock->rlock);  in spin_lock()
353 static __always_inline void spin_lock_bh(spinlock_t *lock)  in spin_lock_bh()  argument
355 	raw_spin_lock_bh(&lock->rlock);  in spin_lock_bh()
358 static __always_inline int spin_trylock(spinlock_t *lock)  in spin_trylock()  argument
360 	return raw_spin_trylock(&lock->rlock);  in spin_trylock()
363 #define spin_lock_nested(lock, subclass)			\  argument
365 	raw_spin_lock_nested(spinlock_check(lock), subclass);	\
368 #define spin_lock_nest_lock(lock, nest_lock)				\  argument
370 	raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock);	\
373 static __always_inline void spin_lock_irq(spinlock_t *lock)  in spin_lock_irq()  argument
375 	raw_spin_lock_irq(&lock->rlock);  in spin_lock_irq()
378 #define spin_lock_irqsave(lock, flags)				\  argument
380 	raw_spin_lock_irqsave(spinlock_check(lock), flags);	\
383 #define spin_lock_irqsave_nested(lock, flags, subclass)			\  argument
385 	raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \
388 static __always_inline void spin_unlock(spinlock_t *lock)  in spin_unlock()  argument
390 	raw_spin_unlock(&lock->rlock);  in spin_unlock()
393 static __always_inline void spin_unlock_bh(spinlock_t *lock)  in spin_unlock_bh()  argument
395 	raw_spin_unlock_bh(&lock->rlock);  in spin_unlock_bh()
398 static __always_inline void spin_unlock_irq(spinlock_t *lock)  in spin_unlock_irq()  argument
400 	raw_spin_unlock_irq(&lock->rlock);  in spin_unlock_irq()
403 static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)  in spin_unlock_irqrestore()  argument
405 	raw_spin_unlock_irqrestore(&lock->rlock, flags);  in spin_unlock_irqrestore()
408 static __always_inline int spin_trylock_bh(spinlock_t *lock)  in spin_trylock_bh()  argument
410 	return raw_spin_trylock_bh(&lock->rlock);  in spin_trylock_bh()
413 static __always_inline int spin_trylock_irq(spinlock_t *lock)  in spin_trylock_irq()  argument
415 	return raw_spin_trylock_irq(&lock->rlock);  in spin_trylock_irq()
418 #define spin_trylock_irqsave(lock, flags)			\  argument
420 	raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
424  * spin_is_locked() - Check whether a spinlock is locked.
425  * @lock: Pointer to the spinlock.
432  * Returns: 1 if @lock is locked, 0 otherwise.
441 static __always_inline int spin_is_locked(spinlock_t *lock)  in spin_is_locked()  argument
443 	return raw_spin_is_locked(&lock->rlock);  in spin_is_locked()
446 static __always_inline int spin_is_contended(spinlock_t *lock)  in spin_is_contended()  argument
448 	return raw_spin_is_contended(&lock->rlock);  in spin_is_contended()
451 #define assert_spin_locked(lock)	assert_raw_spin_locked(&(lock)->rlock)  argument
459  * (asm-mips/atomic.h needs above definitions)
463  * atomic_dec_and_lock - lock on reaching reference count zero
465  * @lock: the spinlock in question
468  * @lock.  Returns false for all other cases.
470 extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
471 #define atomic_dec_and_lock(atomic, lock) \  argument
472 		__cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
474 extern int _atomic_dec_and_lock_irqsave(atomic_t *atomic, spinlock_t *lock,
476 #define atomic_dec_and_lock_irqsave(atomic, lock, flags) \  argument
477 		__cond_lock(lock, _atomic_dec_and_lock_irqsave(atomic, lock, &(flags)))