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;
32 #define __SEMAPHORE_INITIALIZER(name, n) \
34 .count = ATOMIC_INIT(n), \
35 .waking = ATOMIC_INIT(0), \
36 .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \
39 #define __DECLARE_SEMAPHORE_GENERIC(name,count) \
40 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count)
42 #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1)
43 #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0)
45 static inline void sema_init(struct semaphore *sem, int val)
47 *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val);
50 static inline void init_MUTEX (struct semaphore *sem)
55 static inline void init_MUTEX_LOCKED (struct semaphore *sem)
60 asmlinkage void __down_failed(void /* special register calling convention */);
61 asmlinkage int __down_failed_interruptible(void /* params in registers */);
62 asmlinkage int __down_failed_trylock(void /* params in registers */);
63 asmlinkage void __up_wakeup(void /* special register calling convention */);
65 asmlinkage void __down(struct semaphore * sem);
66 asmlinkage int __down_interruptible(struct semaphore * sem);
67 asmlinkage int __down_trylock(struct semaphore * sem);
68 asmlinkage void __up(struct semaphore * sem);
71 * This is ugly, but we want the default case to fall through.
72 * "down_failed" is a special asm handler that calls the C
73 * routine that actually waits. See arch/m68k/lib/semaphore.S
75 static inline void down(struct semaphore *sem)
77 register struct semaphore *sem1 __asm__ ("%a1") = sem;
81 "| atomic down operation\n\t"
85 LOCK_SECTION_START(".even\n\t")
87 "jbra __down_failed\n"
94 static inline int down_interruptible(struct semaphore *sem)
96 register struct semaphore *sem1 __asm__ ("%a1") = sem;
97 register int result __asm__ ("%d0");
100 __asm__ __volatile__(
101 "| atomic interruptible down operation\n\t"
106 LOCK_SECTION_START(".even\n\t")
108 "jbra __down_failed_interruptible\n"
116 static inline int down_trylock(struct semaphore *sem)
118 register struct semaphore *sem1 __asm__ ("%a1") = sem;
119 register int result __asm__ ("%d0");
121 __asm__ __volatile__(
122 "| atomic down trylock operation\n\t"
127 LOCK_SECTION_START(".even\n\t")
129 "jbra __down_failed_trylock\n"
138 * Note! This is subtle. We jump to wake people up only if
139 * the semaphore was negative (== somebody was waiting on it).
140 * The default case (no contention) will result in NO
141 * jumps for both down() and up().
143 static inline void up(struct semaphore *sem)
145 register struct semaphore *sem1 __asm__ ("%a1") = sem;
147 __asm__ __volatile__(
148 "| atomic up operation\n\t"
152 LOCK_SECTION_START(".even\n\t")
162 #endif /* __ASSEMBLY__ */