1 // SPDX-License-Identifier: GPL-2.0-only
8  * - Contrary to plain rtmutexes, spinlocks and rwlocks are state
9  *   preserving. The task state is saved before blocking on the underlying
10  *   rtmutex, and restored when the lock has been acquired. Regular wakeups
11  *   during that time are redirected to the saved state so no wake up is
14  * - Non RT spin/rwlocks disable preemption and eventually interrupts.
19  *   rcu_read_lock() across the lock held section.
28  * __might_resched() skips the state check as rtlocks are state
40 	lockdep_assert(!current->pi_blocked_on);  in rtlock_lock()
46 static __always_inline void __rt_spin_lock(spinlock_t *lock)  in __rt_spin_lock()  argument
49 	rtlock_lock(&lock->lock);  in __rt_spin_lock()
54 void __sched rt_spin_lock(spinlock_t *lock)  in rt_spin_lock()  argument
56 	spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);  in rt_spin_lock()
57 	__rt_spin_lock(lock);  in rt_spin_lock()
62 void __sched rt_spin_lock_nested(spinlock_t *lock, int subclass)  in rt_spin_lock_nested()  argument
64 	spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);  in rt_spin_lock_nested()
65 	__rt_spin_lock(lock);  in rt_spin_lock_nested()
69 void __sched rt_spin_lock_nest_lock(spinlock_t *lock,  in rt_spin_lock_nest_lock()  argument
72 	spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);  in rt_spin_lock_nest_lock()
73 	__rt_spin_lock(lock);  in rt_spin_lock_nest_lock()
78 void __sched rt_spin_unlock(spinlock_t *lock)  in rt_spin_unlock()  argument
80 	spin_release(&lock->dep_map, _RET_IP_);  in rt_spin_unlock()
84 	if (unlikely(!rt_mutex_cmpxchg_release(&lock->lock, current, NULL)))  in rt_spin_unlock()
85 		rt_mutex_slowunlock(&lock->lock);  in rt_spin_unlock()
90  * Wait for the lock to get unlocked: instead of polling for an unlock
91  * (like raw spinlocks do), lock and unlock, to force the kernel to
94 void __sched rt_spin_lock_unlock(spinlock_t *lock)  in rt_spin_lock_unlock()  argument
96 	spin_lock(lock);  in rt_spin_lock_unlock()
97 	spin_unlock(lock);  in rt_spin_lock_unlock()
101 static __always_inline int __rt_spin_trylock(spinlock_t *lock)  in __rt_spin_trylock()  argument
105 	if (unlikely(!rt_mutex_cmpxchg_acquire(&lock->lock, NULL, current)))  in __rt_spin_trylock()
106 		ret = rt_mutex_slowtrylock(&lock->lock);  in __rt_spin_trylock()
109 		spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);  in __rt_spin_trylock()
116 int __sched rt_spin_trylock(spinlock_t *lock)  in rt_spin_trylock()  argument
118 	return __rt_spin_trylock(lock);  in rt_spin_trylock()
122 int __sched rt_spin_trylock_bh(spinlock_t *lock)  in rt_spin_trylock_bh()  argument
127 	ret = __rt_spin_trylock(lock);  in rt_spin_trylock_bh()
135 void __rt_spin_lock_init(spinlock_t *lock, const char *name,  in __rt_spin_lock_init()  argument
140 	debug_check_no_locks_freed((void *)lock, sizeof(*lock));  in __rt_spin_lock_init()
141 	lockdep_init_map_type(&lock->dep_map, name, key, 0, LD_WAIT_CONFIG,  in __rt_spin_lock_init()
148  * RT-specific reader/writer locks
150 #define rwbase_set_and_save_current_state(state)	\  argument
157 rwbase_rtmutex_lock_state(struct rt_mutex_base *rtm, unsigned int state)  in rwbase_rtmutex_lock_state()  argument
165 rwbase_rtmutex_slowlock_locked(struct rt_mutex_base *rtm, unsigned int state)  in rwbase_rtmutex_slowlock_locked()  argument
187 #define rwbase_signal_pending_state(state, current)	(0)  argument
204 	ret = rwbase_read_trylock(&rwlock->rwbase);  in rt_read_trylock()
206 		rwlock_acquire_read(&rwlock->dep_map, 0, 1, _RET_IP_);  in rt_read_trylock()
218 	ret = rwbase_write_trylock(&rwlock->rwbase);  in rt_write_trylock()
220 		rwlock_acquire(&rwlock->dep_map, 0, 1, _RET_IP_);  in rt_write_trylock()
231 	rwlock_acquire_read(&rwlock->dep_map, 0, 0, _RET_IP_);  in rt_read_lock()
232 	rwbase_read_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT);  in rt_read_lock()
241 	rwlock_acquire(&rwlock->dep_map, 0, 0, _RET_IP_);  in rt_write_lock()
242 	rwbase_write_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT);  in rt_write_lock()
252 	rwlock_acquire(&rwlock->dep_map, subclass, 0, _RET_IP_);  in rt_write_lock_nested()
253 	rwbase_write_lock(&rwlock->rwbase, TASK_RTLOCK_WAIT);  in rt_write_lock_nested()
262 	rwlock_release(&rwlock->dep_map, _RET_IP_);  in rt_read_unlock()
265 	rwbase_read_unlock(&rwlock->rwbase, TASK_RTLOCK_WAIT);  in rt_read_unlock()
271 	rwlock_release(&rwlock->dep_map, _RET_IP_);  in rt_write_unlock()
274 	rwbase_write_unlock(&rwlock->rwbase);  in rt_write_unlock()
283 	lockdep_init_map_wait(&rwlock->dep_map, name, key, 0, LD_WAIT_CONFIG);  in __rt_rwlock_init()