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>
12 #include <linux/stringify.h>
14 #include <asm/system.h>
15 #include <asm/atomic.h>
18 * Interrupt-safe semaphores..
20 * (C) Copyright 1996 Linus Torvalds
22 * m68k version by Andreas Schwab
29 wait_queue_head_t wait;
36 # define __SEM_DEBUG_INIT(name) \
37 , (long)&(name).__magic
39 # define __SEM_DEBUG_INIT(name)
42 #define __SEMAPHORE_INITIALIZER(name,count) \
43 { ATOMIC_INIT(count), ATOMIC_INIT(0), __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
44 __SEM_DEBUG_INIT(name) }
46 #define __MUTEX_INITIALIZER(name) \
47 __SEMAPHORE_INITIALIZER(name,1)
49 #define __DECLARE_SEMAPHORE_GENERIC(name,count) \
50 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
52 #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
53 #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
55 static inline void sema_init(struct semaphore *sem, int val)
57 *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
60 static inline void init_MUTEX (struct semaphore *sem)
65 static inline void init_MUTEX_LOCKED (struct semaphore *sem)
70 asmlinkage void __down_failed(void /* special register calling convention */);
71 asmlinkage int __down_failed_interruptible(void /* params in registers */);
72 asmlinkage int __down_failed_trylock(void /* params in registers */);
73 asmlinkage void __up_wakeup(void /* special register calling convention */);
75 asmlinkage void __down(struct semaphore * sem);
76 asmlinkage int __down_interruptible(struct semaphore * sem);
77 asmlinkage int __down_trylock(struct semaphore * sem);
78 asmlinkage void __up(struct semaphore * sem);
81 * This is ugly, but we want the default case to fall through.
82 * "down_failed" is a special asm handler that calls the C
83 * routine that actually waits. See arch/m68k/lib/semaphore.S
85 static inline void down(struct semaphore *sem)
87 register struct semaphore *sem1 __asm__ ("%a1") = sem;
90 CHECK_MAGIC(sem->__magic);
94 "| atomic down operation\n\t"
98 LOCK_SECTION_START(".even\n\t")
100 "jbra __down_failed\n"
107 static inline int down_interruptible(struct semaphore *sem)
109 register struct semaphore *sem1 __asm__ ("%a1") = sem;
110 register int result __asm__ ("%d0");
113 CHECK_MAGIC(sem->__magic);
116 __asm__ __volatile__(
117 "| atomic interruptible down operation\n\t"
122 LOCK_SECTION_START(".even\n\t")
124 "jbra __down_failed_interruptible\n"
132 static inline int down_trylock(struct semaphore *sem)
134 register struct semaphore *sem1 __asm__ ("%a1") = sem;
135 register int result __asm__ ("%d0");
138 CHECK_MAGIC(sem->__magic);
141 __asm__ __volatile__(
142 "| atomic down trylock operation\n\t"
147 LOCK_SECTION_START(".even\n\t")
149 "jbra __down_failed_trylock\n"
158 * Note! This is subtle. We jump to wake people up only if
159 * the semaphore was negative (== somebody was waiting on it).
160 * The default case (no contention) will result in NO
161 * jumps for both down() and up().
163 static inline void up(struct semaphore *sem)
165 register struct semaphore *sem1 __asm__ ("%a1") = sem;
168 CHECK_MAGIC(sem->__magic);
171 __asm__ __volatile__(
172 "| atomic up operation\n\t"
176 LOCK_SECTION_START(".even\n\t")
186 #endif /* __ASSEMBLY__ */