#ifndef _M68K_SEMAPHORE_H #define _M68K_SEMAPHORE_H #define RW_LOCK_BIAS 0x01000000 #ifndef __ASSEMBLY__ #include <linux/linkage.h> #include <linux/wait.h> #include <linux/spinlock.h> #include <linux/rwsem.h> #include <linux/stringify.h> #include <asm/system.h> #include <asm/atomic.h> /* * Interrupt-safe semaphores.. * * (C) Copyright 1996 Linus Torvalds * * m68k version by Andreas Schwab */ struct semaphore { atomic_t count; atomic_t waking; wait_queue_head_t wait; }; #define __SEMAPHORE_INITIALIZER(name, n) \ { \ .count = ATOMIC_INIT(n), \ .waking = ATOMIC_INIT(0), \ .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ } #define __MUTEX_INITIALIZER(name) \ __SEMAPHORE_INITIALIZER(name,1) #define __DECLARE_SEMAPHORE_GENERIC(name,count) \ struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) static inline void sema_init(struct semaphore *sem, int val) { *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val); } static inline void init_MUTEX (struct semaphore *sem) { sema_init(sem, 1); } static inline void init_MUTEX_LOCKED (struct semaphore *sem) { sema_init(sem, 0); } asmlinkage void __down_failed(void /* special register calling convention */); asmlinkage int __down_failed_interruptible(void /* params in registers */); asmlinkage int __down_failed_trylock(void /* params in registers */); asmlinkage void __up_wakeup(void /* special register calling convention */); asmlinkage void __down(struct semaphore * sem); asmlinkage int __down_interruptible(struct semaphore * sem); asmlinkage int __down_trylock(struct semaphore * sem); asmlinkage void __up(struct semaphore * sem); /* * This is ugly, but we want the default case to fall through. * "down_failed" is a special asm handler that calls the C * routine that actually waits. See arch/m68k/lib/semaphore.S */ static inline void down(struct semaphore *sem) { register struct semaphore *sem1 __asm__ ("%a1") = sem; might_sleep(); __asm__ __volatile__( "| atomic down operation\n\t" "subql #1,%0@\n\t" "jmi 2f\n\t" "1:\n" LOCK_SECTION_START(".even\n\t") "2:\tpea 1b\n\t" "jbra __down_failed\n" LOCK_SECTION_END : /* no outputs */ : "a" (sem1) : "memory"); } static inline int down_interruptible(struct semaphore *sem) { register struct semaphore *sem1 __asm__ ("%a1") = sem; register int result __asm__ ("%d0"); might_sleep(); __asm__ __volatile__( "| atomic interruptible down operation\n\t" "subql #1,%1@\n\t" "jmi 2f\n\t" "clrl %0\n" "1:\n" LOCK_SECTION_START(".even\n\t") "2:\tpea 1b\n\t" "jbra __down_failed_interruptible\n" LOCK_SECTION_END : "=d" (result) : "a" (sem1) : "memory"); return result; } static inline int down_trylock(struct semaphore *sem) { register struct semaphore *sem1 __asm__ ("%a1") = sem; register int result __asm__ ("%d0"); __asm__ __volatile__( "| atomic down trylock operation\n\t" "subql #1,%1@\n\t" "jmi 2f\n\t" "clrl %0\n" "1:\n" LOCK_SECTION_START(".even\n\t") "2:\tpea 1b\n\t" "jbra __down_failed_trylock\n" LOCK_SECTION_END : "=d" (result) : "a" (sem1) : "memory"); return result; } /* * Note! This is subtle. We jump to wake people up only if * the semaphore was negative (== somebody was waiting on it). * The default case (no contention) will result in NO * jumps for both down() and up(). */ static inline void up(struct semaphore *sem) { register struct semaphore *sem1 __asm__ ("%a1") = sem; __asm__ __volatile__( "| atomic up operation\n\t" "addql #1,%0@\n\t" "jle 2f\n" "1:\n" LOCK_SECTION_START(".even\n\t") "2:\t" "pea 1b\n\t" "jbra __up_wakeup\n" LOCK_SECTION_END : /* no outputs */ : "a" (sem1) : "memory"); } #endif /* __ASSEMBLY__ */ #endif