1 #ifndef _M68K_SEMAPHORE_H
2 #define _M68K_SEMAPHORE_H
4 #define RW_LOCK_BIAS 0x01000000
8 #include <linux/linkage.h>
9 #include <linux/wait.h>
10 #include <linux/spinlock.h>
11 #include <linux/rwsem.h>
13 #include <asm/system.h>
14 #include <asm/atomic.h>
17 * Interrupt-safe semaphores..
19 * (C) Copyright 1996 Linus Torvalds
21 * m68k version by Andreas Schwab
28 wait_queue_head_t wait;
35 # define __SEM_DEBUG_INIT(name) \
36 , (long)&(name).__magic
38 # define __SEM_DEBUG_INIT(name)
41 #define __SEMAPHORE_INITIALIZER(name,count) \
42 { ATOMIC_INIT(count), ATOMIC_INIT(0), __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
43 __SEM_DEBUG_INIT(name) }
45 #define __MUTEX_INITIALIZER(name) \
46 __SEMAPHORE_INITIALIZER(name,1)
48 #define __DECLARE_SEMAPHORE_GENERIC(name,count) \
49 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
51 #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
52 #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
54 extern inline void sema_init (struct semaphore *sem, int val)
56 *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
59 static inline void init_MUTEX (struct semaphore *sem)
64 static inline void init_MUTEX_LOCKED (struct semaphore *sem)
69 asmlinkage void __down_failed(void /* special register calling convention */);
70 asmlinkage int __down_failed_interruptible(void /* params in registers */);
71 asmlinkage int __down_failed_trylock(void /* params in registers */);
72 asmlinkage void __up_wakeup(void /* special register calling convention */);
74 asmlinkage void __down(struct semaphore * sem);
75 asmlinkage int __down_interruptible(struct semaphore * sem);
76 asmlinkage int __down_trylock(struct semaphore * sem);
77 asmlinkage void __up(struct semaphore * sem);
79 extern spinlock_t semaphore_wake_lock;
82 * This is ugly, but we want the default case to fall through.
83 * "down_failed" is a special asm handler that calls the C
84 * routine that actually waits. See arch/m68k/lib/semaphore.S
86 extern inline void down(struct semaphore * sem)
89 CHECK_MAGIC(sem->__magic);
93 "| atomic down operation\n\t"
95 "lea %%pc@(1f), %%a0\n\t"
101 : "cc", "%a0", "%a1", "memory");
104 extern inline int down_interruptible(struct semaphore * sem)
109 CHECK_MAGIC(sem->__magic);
112 __asm__ __volatile__(
113 "| atomic down operation\n\t"
115 "lea %%pc@(1f), %%a0\n\t"
116 "subql #1, %%a1@\n\t"
117 "jmi __down_failed_interruptible\n\t"
119 "1: movel %%d0, %0\n"
122 : "cc", "%d0", "%a0", "%a1", "memory");
126 extern inline int down_trylock(struct semaphore * sem)
128 register struct semaphore *sem1 __asm__ ("%a1") = sem;
129 register int result __asm__ ("%d0");
132 CHECK_MAGIC(sem->__magic);
135 __asm__ __volatile__(
136 "| atomic down trylock operation\n\t"
141 ".section .text.lock,\"ax\"\n"
144 "jbra __down_failed_trylock\n"
153 * Note! This is subtle. We jump to wake people up only if
154 * the semaphore was negative (== somebody was waiting on it).
155 * The default case (no contention) will result in NO
156 * jumps for both down() and up().
158 extern inline void up(struct semaphore * sem)
161 CHECK_MAGIC(sem->__magic);
164 __asm__ __volatile__(
165 "| atomic up operation\n\t"
167 "lea %%pc@(1f), %%a0\n\t"
168 "addql #1, %%a1@\n\t"
173 : "cc", "%a0", "%a1", "memory");
176 #endif /* __ASSEMBLY__ */