1#ifndef _M68K_SEMAPHORE_H 2#define _M68K_SEMAPHORE_H 3 4#define RW_LOCK_BIAS 0x01000000 5 6#ifndef __ASSEMBLY__ 7 8#include <linux/linkage.h> 9#include <linux/wait.h> 10#include <linux/spinlock.h> 11#include <linux/rwsem.h> 12 13#include <asm/system.h> 14#include <asm/atomic.h> 15 16/* 17 * Interrupt-safe semaphores.. 18 * 19 * (C) Copyright 1996 Linus Torvalds 20 * 21 * m68k version by Andreas Schwab 22 */ 23 24 25struct semaphore { 26 atomic_t count; 27 atomic_t waking; 28 wait_queue_head_t wait; 29#if WAITQUEUE_DEBUG 30 long __magic; 31#endif 32}; 33 34#if WAITQUEUE_DEBUG 35# define __SEM_DEBUG_INIT(name) \ 36 , (long)&(name).__magic 37#else 38# define __SEM_DEBUG_INIT(name) 39#endif 40 41#define __SEMAPHORE_INITIALIZER(name,count) \ 42{ ATOMIC_INIT(count), ATOMIC_INIT(0), __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ 43 __SEM_DEBUG_INIT(name) } 44 45#define __MUTEX_INITIALIZER(name) \ 46 __SEMAPHORE_INITIALIZER(name,1) 47 48#define __DECLARE_SEMAPHORE_GENERIC(name,count) \ 49 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) 50 51#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) 52#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) 53 54extern inline void sema_init (struct semaphore *sem, int val) 55{ 56 *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val); 57} 58 59static inline void init_MUTEX (struct semaphore *sem) 60{ 61 sema_init(sem, 1); 62} 63 64static inline void init_MUTEX_LOCKED (struct semaphore *sem) 65{ 66 sema_init(sem, 0); 67} 68 69asmlinkage void __down_failed(void /* special register calling convention */); 70asmlinkage int __down_failed_interruptible(void /* params in registers */); 71asmlinkage int __down_failed_trylock(void /* params in registers */); 72asmlinkage void __up_wakeup(void /* special register calling convention */); 73 74asmlinkage void __down(struct semaphore * sem); 75asmlinkage int __down_interruptible(struct semaphore * sem); 76asmlinkage int __down_trylock(struct semaphore * sem); 77asmlinkage void __up(struct semaphore * sem); 78 79/* 80 * This is ugly, but we want the default case to fall through. 81 * "down_failed" is a special asm handler that calls the C 82 * routine that actually waits. See arch/m68k/lib/semaphore.S 83 */ 84extern inline void down(struct semaphore * sem) 85{ 86 register struct semaphore *sem1 __asm__ ("%a1") = sem; 87 88#if WAITQUEUE_DEBUG 89 CHECK_MAGIC(sem->__magic); 90#endif 91 92 __asm__ __volatile__( 93 "| atomic down operation\n\t" 94 "subql #1,%0@\n\t" 95 "jmi 2f\n\t" 96 "1:\n" 97 LOCK_SECTION_START(".even\n\t") 98 "2:\tpea 1b\n\t" 99 "jbra __down_failed\n" 100 LOCK_SECTION_END 101 : /* no outputs */ 102 : "a" (sem1) 103 : "memory"); 104} 105 106extern inline int down_interruptible(struct semaphore * sem) 107{ 108 register struct semaphore *sem1 __asm__ ("%a1") = sem; 109 register int result __asm__ ("%d0"); 110 111#if WAITQUEUE_DEBUG 112 CHECK_MAGIC(sem->__magic); 113#endif 114 115 __asm__ __volatile__( 116 "| atomic interruptible down operation\n\t" 117 "subql #1,%1@\n\t" 118 "jmi 2f\n\t" 119 "clrl %0\n" 120 "1:\n" 121 LOCK_SECTION_START(".even\n\t") 122 "2:\tpea 1b\n\t" 123 "jbra __down_failed_interruptible\n" 124 LOCK_SECTION_END 125 : "=d" (result) 126 : "a" (sem1) 127 : "memory"); 128 return result; 129} 130 131extern inline int down_trylock(struct semaphore * sem) 132{ 133 register struct semaphore *sem1 __asm__ ("%a1") = sem; 134 register int result __asm__ ("%d0"); 135 136#if WAITQUEUE_DEBUG 137 CHECK_MAGIC(sem->__magic); 138#endif 139 140 __asm__ __volatile__( 141 "| atomic down trylock operation\n\t" 142 "subql #1,%1@\n\t" 143 "jmi 2f\n\t" 144 "clrl %0\n" 145 "1:\n" 146 LOCK_SECTION_START(".even\n\t") 147 "2:\tpea 1b\n\t" 148 "jbra __down_failed_trylock\n" 149 LOCK_SECTION_END 150 : "=d" (result) 151 : "a" (sem1) 152 : "memory"); 153 return result; 154} 155 156/* 157 * Note! This is subtle. We jump to wake people up only if 158 * the semaphore was negative (== somebody was waiting on it). 159 * The default case (no contention) will result in NO 160 * jumps for both down() and up(). 161 */ 162extern inline void up(struct semaphore * sem) 163{ 164 register struct semaphore *sem1 __asm__ ("%a1") = sem; 165 166#if WAITQUEUE_DEBUG 167 CHECK_MAGIC(sem->__magic); 168#endif 169 170 __asm__ __volatile__( 171 "| atomic up operation\n\t" 172 "addql #1,%0@\n\t" 173 "jle 2f\n" 174 "1:\n" 175 LOCK_SECTION_START(".even\n\t") 176 "2:\t" 177 "pea 1b\n\t" 178 "jbra __up_wakeup\n" 179 LOCK_SECTION_END 180 : /* no outputs */ 181 : "a" (sem1) 182 : "memory"); 183} 184 185 186static inline int sem_getcount(struct semaphore *sem) 187{ 188 return atomic_read(&sem->count); 189} 190 191#endif /* __ASSEMBLY__ */ 192 193#endif 194