#ifndef _M68K_SEMAPHORE_HELPER_H #define _M68K_SEMAPHORE_HELPER_H /* * SMP- and interrupt-safe semaphores helper functions. * * (C) Copyright 1996 Linus Torvalds * * 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(&sem->waking); } #ifndef CONFIG_RMW_INSNS extern spinlock_t semaphore_wake_lock; #endif static inline int waking_non_zero(struct semaphore *sem) { int ret; #ifndef CONFIG_RMW_INSNS unsigned long flags; spin_lock_irqsave(&semaphore_wake_lock, flags); ret = 0; if (atomic_read(&sem->waking) > 0) { atomic_dec(&sem->waking); ret = 1; } spin_unlock_irqrestore(&semaphore_wake_lock, flags); #else int tmp1, tmp2; __asm__ __volatile__ ("1: movel %1,%2\n" " jle 2f\n" " subql #1,%2\n" " casl %1,%2,%3\n" " jne 1b\n" " moveq #1,%0\n" "2:" : "=d" (ret), "=d" (tmp1), "=d" (tmp2) : "m" (sem->waking), "0" (0), "1" (sem->waking)); #endif 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; #ifndef CONFIG_RMW_INSNS unsigned long flags; spin_lock_irqsave(&semaphore_wake_lock, flags); ret = 0; if (atomic_read(&sem->waking) > 0) { atomic_dec(&sem->waking); ret = 1; } else if (signal_pending(tsk)) { atomic_inc(&sem->count); ret = -EINTR; } spin_unlock_irqrestore(&semaphore_wake_lock, flags); #else int tmp1, tmp2; __asm__ __volatile__ ("1: movel %1,%2\n" " jle 2f\n" " subql #1,%2\n" " casl %1,%2,%3\n" " jne 1b\n" " moveq #1,%0\n" " jra %a4\n" "2:" : "=d" (ret), "=d" (tmp1), "=d" (tmp2) : "m" (sem->waking), "i" (&&next), "0" (0), "1" (sem->waking)); if (signal_pending(tsk)) { atomic_inc(&sem->count); ret = -EINTR; } next: #endif 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; #ifndef CONFIG_RMW_INSNS unsigned long flags; spin_lock_irqsave(&semaphore_wake_lock, flags); ret = 1; if (atomic_read(&sem->waking) > 0) { atomic_dec(&sem->waking); ret = 0; } else atomic_inc(&sem->count); spin_unlock_irqrestore(&semaphore_wake_lock, flags); #else int tmp1, tmp2; __asm__ __volatile__ ("1: movel %1,%2\n" " jle 2f\n" " subql #1,%2\n" " casl %1,%2,%3\n" " jne 1b\n" " moveq #0,%0\n" "2:" : "=d" (ret), "=d" (tmp1), "=d" (tmp2) : "m" (sem->waking), "0" (1), "1" (sem->waking)); if (ret) atomic_inc(&sem->count); #endif return ret; } #endif