12  * Simple spin lock operations.  There are two variants, one clears IRQ's
42  * the queue, and the other indicating the current tail. The lock is acquired
47  * We use an xadd covering *both* parts of the lock, to increment the tail and
53 static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock)  in __ticket_spin_lock()  argument
57 	inc = xadd(&lock->tickets, inc);  in __ticket_spin_lock()
63 		inc.head = ACCESS_ONCE(lock->tickets.head);  in __ticket_spin_lock()
65 	barrier();		/* make sure nothing creeps before the lock is taken */  in __ticket_spin_lock()
68 static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock)  in __ticket_spin_trylock()  argument
72 	old.tickets = ACCESS_ONCE(lock->tickets);  in __ticket_spin_trylock()
79 	return cmpxchg(&lock->head_tail, old.head_tail, new.head_tail) == old.head_tail;  in __ticket_spin_trylock()
82 static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock)  in __ticket_spin_unlock()  argument
84 	__add(&lock->tickets.head, 1, UNLOCK_LOCK_PREFIX);  in __ticket_spin_unlock()
87 static inline int __ticket_spin_is_locked(arch_spinlock_t *lock)  in __ticket_spin_is_locked()  argument
89 	struct __raw_tickets tmp = ACCESS_ONCE(lock->tickets);  in __ticket_spin_is_locked()
94 static inline int __ticket_spin_is_contended(arch_spinlock_t *lock)  in __ticket_spin_is_contended()  argument
96 	struct __raw_tickets tmp = ACCESS_ONCE(lock->tickets);  in __ticket_spin_is_contended()
103 static inline int arch_spin_is_locked(arch_spinlock_t *lock)  in arch_spin_is_locked()  argument
105 	return __ticket_spin_is_locked(lock);  in arch_spin_is_locked()
108 static inline int arch_spin_is_contended(arch_spinlock_t *lock)  in arch_spin_is_contended()  argument
110 	return __ticket_spin_is_contended(lock);  in arch_spin_is_contended()
114 static __always_inline void arch_spin_lock(arch_spinlock_t *lock)  in arch_spin_lock()  argument
116 	__ticket_spin_lock(lock);  in arch_spin_lock()
119 static __always_inline int arch_spin_trylock(arch_spinlock_t *lock)  in arch_spin_trylock()  argument
121 	return __ticket_spin_trylock(lock);  in arch_spin_trylock()
124 static __always_inline void arch_spin_unlock(arch_spinlock_t *lock)  in arch_spin_unlock()  argument
126 	__ticket_spin_unlock(lock);  in arch_spin_unlock()
129 static __always_inline void arch_spin_lock_flags(arch_spinlock_t *lock,  in arch_spin_lock_flags()  argument
132 	arch_spin_lock(lock);  in arch_spin_lock_flags()
137 static inline void arch_spin_unlock_wait(arch_spinlock_t *lock)  in arch_spin_unlock_wait()  argument
139 	while (arch_spin_is_locked(lock))  in arch_spin_unlock_wait()
150  * irq-safe write-lock, but readers can get non-irqsafe
159  * @lock: the rwlock in question.
161 static inline int arch_read_can_lock(arch_rwlock_t *lock)  in arch_read_can_lock()  argument
163 	return lock->lock > 0;  in arch_read_can_lock()
168  * @lock: the rwlock in question.
170 static inline int arch_write_can_lock(arch_rwlock_t *lock)  in arch_write_can_lock()  argument
172 	return lock->write == WRITE_LOCK_CMP;  in arch_write_can_lock()
194 static inline int arch_read_trylock(arch_rwlock_t *lock)  in arch_read_trylock()  argument
196 	READ_LOCK_ATOMIC(t) *count = (READ_LOCK_ATOMIC(t) *)lock;  in arch_read_trylock()
204 static inline int arch_write_trylock(arch_rwlock_t *lock)  in arch_write_trylock()  argument
206 	atomic_t *count = (atomic_t *)&lock->write;  in arch_write_trylock()
217 		     :"+m" (rw->lock) : : "memory");  in arch_read_unlock()
226 #define arch_read_lock_flags(lock, flags) arch_read_lock(lock)  argument
227 #define arch_write_lock_flags(lock, flags) arch_write_lock(lock)  argument
235 #define arch_spin_relax(lock)	cpu_relax()  argument
236 #define arch_read_relax(lock)	cpu_relax()  argument
237 #define arch_write_relax(lock)	cpu_relax()  argument