| #ifndef _H8300_SEMAPHORE_HELPER_H |
| #define _H8300_SEMAPHORE_HELPER_H |
| |
| /* |
| * SMP- and interrupt-safe semaphores helper functions. |
| * |
| * (C) Copyright 1996 Linus Torvalds |
| * |
| * based on |
| * m68k version by Andreas Schwab |
| */ |
| |
| #include <linux/errno.h> |
| |
| /* |
| * These two _must_ execute atomically wrt each other. |
| */ |
| static inline void wake_one_more(struct semaphore * sem) |
| { |
| atomic_inc((atomic_t *)&sem->sleepers); |
| } |
| |
| static inline int waking_non_zero(struct semaphore *sem) |
| { |
| int ret; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&semaphore_wake_lock, flags); |
| ret = 0; |
| if (sem->sleepers > 0) { |
| sem->sleepers--; |
| ret = 1; |
| } |
| spin_unlock_irqrestore(&semaphore_wake_lock, flags); |
| return ret; |
| } |
| |
| /* |
| * waking_non_zero_interruptible: |
| * 1 got the lock |
| * 0 go to sleep |
| * -EINTR interrupted |
| */ |
| static inline int waking_non_zero_interruptible(struct semaphore *sem, |
| struct task_struct *tsk) |
| { |
| int ret; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&semaphore_wake_lock, flags); |
| ret = 0; |
| if (sem->sleepers > 0) { |
| sem->sleepers--; |
| ret = 1; |
| } else if (signal_pending(tsk)) { |
| atomic_inc(&sem->count); |
| ret = -EINTR; |
| } |
| spin_unlock_irqrestore(&semaphore_wake_lock, flags); |
| return ret; |
| } |
| |
| /* |
| * waking_non_zero_trylock: |
| * 1 failed to lock |
| * 0 got the lock |
| */ |
| static inline int waking_non_zero_trylock(struct semaphore *sem) |
| { |
| int ret; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&semaphore_wake_lock, flags); |
| ret = 1; |
| if (sem->sleepers <= 0) |
| atomic_inc(&sem->count); |
| else { |
| sem->sleepers--; |
| ret = 0; |
| } |
| spin_unlock_irqrestore(&semaphore_wake_lock, flags); |
| return ret; |
| } |
| |
| #endif |