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#include <linux/stringify.h> 13 14#include <asm/system.h> 15#include <asm/atomic.h> 16 17/* 18 * Interrupt-safe semaphores.. 19 * 20 * (C) Copyright 1996 Linus Torvalds 21 * 22 * m68k version by Andreas Schwab 23 */ 24 25 26struct semaphore { 27 atomic_t count; 28 atomic_t waking; 29 wait_queue_head_t wait; 30}; 31 32#define __SEMAPHORE_INITIALIZER(name, n) \ 33{ \ 34 .count = ATOMIC_INIT(n), \ 35 .waking = ATOMIC_INIT(0), \ 36 .wait = __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ 37} 38 39#define __DECLARE_SEMAPHORE_GENERIC(name,count) \ 40 struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) 41 42#define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) 43#define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) 44 45static inline void sema_init(struct semaphore *sem, int val) 46{ 47 *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val); 48} 49 50static inline void init_MUTEX (struct semaphore *sem) 51{ 52 sema_init(sem, 1); 53} 54 55static inline void init_MUTEX_LOCKED (struct semaphore *sem) 56{ 57 sema_init(sem, 0); 58} 59 60asmlinkage void __down_failed(void /* special register calling convention */); 61asmlinkage int __down_failed_interruptible(void /* params in registers */); 62asmlinkage int __down_failed_trylock(void /* params in registers */); 63asmlinkage void __up_wakeup(void /* special register calling convention */); 64 65asmlinkage void __down(struct semaphore * sem); 66asmlinkage int __down_interruptible(struct semaphore * sem); 67asmlinkage int __down_trylock(struct semaphore * sem); 68asmlinkage void __up(struct semaphore * sem); 69 70/* 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 74 */ 75static inline void down(struct semaphore *sem) 76{ 77 register struct semaphore *sem1 __asm__ ("%a1") = sem; 78 79 might_sleep(); 80 __asm__ __volatile__( 81 "| atomic down operation\n\t" 82 "subql #1,%0@\n\t" 83 "jmi 2f\n\t" 84 "1:\n" 85 LOCK_SECTION_START(".even\n\t") 86 "2:\tpea 1b\n\t" 87 "jbra __down_failed\n" 88 LOCK_SECTION_END 89 : /* no outputs */ 90 : "a" (sem1) 91 : "memory"); 92} 93 94static inline int down_interruptible(struct semaphore *sem) 95{ 96 register struct semaphore *sem1 __asm__ ("%a1") = sem; 97 register int result __asm__ ("%d0"); 98 99 might_sleep(); 100 __asm__ __volatile__( 101 "| atomic interruptible down operation\n\t" 102 "subql #1,%1@\n\t" 103 "jmi 2f\n\t" 104 "clrl %0\n" 105 "1:\n" 106 LOCK_SECTION_START(".even\n\t") 107 "2:\tpea 1b\n\t" 108 "jbra __down_failed_interruptible\n" 109 LOCK_SECTION_END 110 : "=d" (result) 111 : "a" (sem1) 112 : "memory"); 113 return result; 114} 115 116static inline int down_trylock(struct semaphore *sem) 117{ 118 register struct semaphore *sem1 __asm__ ("%a1") = sem; 119 register int result __asm__ ("%d0"); 120 121 __asm__ __volatile__( 122 "| atomic down trylock operation\n\t" 123 "subql #1,%1@\n\t" 124 "jmi 2f\n\t" 125 "clrl %0\n" 126 "1:\n" 127 LOCK_SECTION_START(".even\n\t") 128 "2:\tpea 1b\n\t" 129 "jbra __down_failed_trylock\n" 130 LOCK_SECTION_END 131 : "=d" (result) 132 : "a" (sem1) 133 : "memory"); 134 return result; 135} 136 137/* 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(). 142 */ 143static inline void up(struct semaphore *sem) 144{ 145 register struct semaphore *sem1 __asm__ ("%a1") = sem; 146 147 __asm__ __volatile__( 148 "| atomic up operation\n\t" 149 "addql #1,%0@\n\t" 150 "jle 2f\n" 151 "1:\n" 152 LOCK_SECTION_START(".even\n\t") 153 "2:\t" 154 "pea 1b\n\t" 155 "jbra __up_wakeup\n" 156 LOCK_SECTION_END 157 : /* no outputs */ 158 : "a" (sem1) 159 : "memory"); 160} 161 162#endif /* __ASSEMBLY__ */ 163 164#endif 165