6  * Simple spin lock operations.
34 static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock)  in arch_spin_value_unlocked()  argument
36 	return lock.slock == 0;  in arch_spin_value_unlocked()
39 static inline int arch_spin_is_locked(arch_spinlock_t *lock)  in arch_spin_is_locked()  argument
41 	return !arch_spin_value_unlocked(READ_ONCE(*lock));  in arch_spin_is_locked()
45  * This returns the old value in the lock, so we succeeded
46  * in getting the lock if the return value is 0.
48 static inline unsigned long __arch_spin_trylock(arch_spinlock_t *lock)  in __arch_spin_trylock()  argument
62 	: "r" (token), "r" (&lock->slock)  in __arch_spin_trylock()
68 static inline int arch_spin_trylock(arch_spinlock_t *lock)  in arch_spin_trylock()  argument
70 	return __arch_spin_trylock(lock) == 0;  in arch_spin_trylock()
76  * there is no point spinning on a lock if the holder of the lock
79  * rest of our timeslice to the lock holder.
81  * So that we can tell which virtual processor is holding a lock,
82  * we put 0x80000000 | smp_processor_id() in the lock when it is
89 void splpar_spin_yield(arch_spinlock_t *lock);
90 void splpar_rw_yield(arch_rwlock_t *lock);
92 static inline void splpar_spin_yield(arch_spinlock_t *lock) {}  in splpar_spin_yield()  argument
93 static inline void splpar_rw_yield(arch_rwlock_t *lock) {}  in splpar_rw_yield()  argument
96 static inline void spin_yield(arch_spinlock_t *lock)  in spin_yield()  argument
99 		splpar_spin_yield(lock);  in spin_yield()
104 static inline void rw_yield(arch_rwlock_t *lock)  in rw_yield()  argument
107 		splpar_rw_yield(lock);  in rw_yield()
112 static inline void arch_spin_lock(arch_spinlock_t *lock)  in arch_spin_lock()  argument
115 		if (likely(__arch_spin_trylock(lock) == 0))  in arch_spin_lock()
120 				splpar_spin_yield(lock);  in arch_spin_lock()
121 		} while (unlikely(lock->slock != 0));  in arch_spin_lock()
127 void arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags)  in arch_spin_lock_flags()  argument
132 		if (likely(__arch_spin_trylock(lock) == 0))  in arch_spin_lock_flags()
139 				splpar_spin_yield(lock);  in arch_spin_lock_flags()
140 		} while (unlikely(lock->slock != 0));  in arch_spin_lock_flags()
147 static inline void arch_spin_unlock(arch_spinlock_t *lock)  in arch_spin_unlock()  argument
151 	lock->slock = 0;  in arch_spin_unlock()
161  * irq-safe write-lock, but readers can get non-irqsafe
174  * This returns the old value in the lock + 1,
175  * so we got a read lock if the return value is > 0.
190 	: "r" (&rw->lock)  in __arch_read_trylock()
197  * This returns the old value in the lock,
198  * so we got the write lock if the return value is 0.
213 	: "r" (token), "r" (&rw->lock)  in __arch_write_trylock()
228 		} while (unlikely(rw->lock < 0));  in arch_read_lock()
242 		} while (unlikely(rw->lock != 0));  in arch_write_lock()
269 	: "r"(&rw->lock)  in arch_read_unlock()
277 	rw->lock = 0;  in arch_write_unlock()
280 #define arch_spin_relax(lock)	spin_yield(lock)  argument
281 #define arch_read_relax(lock)	rw_yield(lock)  argument
282 #define arch_write_relax(lock)	rw_yield(lock)  argument