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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 | #ifndef _M68K_SEMAPHORE_H #define _M68K_SEMAPHORE_H #define RW_LOCK_BIAS 0x01000000 #ifndef __ASSEMBLY__ #include <linux/linkage.h> #include <linux/wait.h> #include <linux/spinlock.h> #include <asm/system.h> #include <asm/atomic.h> /* * Interrupt-safe semaphores.. * * (C) Copyright 1996 Linus Torvalds * * m68k version by Andreas Schwab */ struct semaphore { atomic_t count; atomic_t waking; wait_queue_head_t wait; #if WAITQUEUE_DEBUG long __magic; #endif }; #if WAITQUEUE_DEBUG # define __SEM_DEBUG_INIT(name) \ , (long)&(name).__magic #else # define __SEM_DEBUG_INIT(name) #endif #define __SEMAPHORE_INITIALIZER(name,count) \ { ATOMIC_INIT(count), ATOMIC_INIT(0), __WAIT_QUEUE_HEAD_INITIALIZER((name).wait) \ __SEM_DEBUG_INIT(name) } #define __MUTEX_INITIALIZER(name) \ __SEMAPHORE_INITIALIZER(name,1) #define __DECLARE_SEMAPHORE_GENERIC(name,count) \ struct semaphore name = __SEMAPHORE_INITIALIZER(name,count) #define DECLARE_MUTEX(name) __DECLARE_SEMAPHORE_GENERIC(name,1) #define DECLARE_MUTEX_LOCKED(name) __DECLARE_SEMAPHORE_GENERIC(name,0) extern inline void sema_init (struct semaphore *sem, int val) { *sem = (struct semaphore)__SEMAPHORE_INITIALIZER(*sem, val); } static inline void init_MUTEX (struct semaphore *sem) { sema_init(sem, 1); } static inline void init_MUTEX_LOCKED (struct semaphore *sem) { sema_init(sem, 0); } asmlinkage void __down_failed(void /* special register calling convention */); asmlinkage int __down_failed_interruptible(void /* params in registers */); asmlinkage int __down_failed_trylock(void /* params in registers */); asmlinkage void __up_wakeup(void /* special register calling convention */); asmlinkage void __down(struct semaphore * sem); asmlinkage int __down_interruptible(struct semaphore * sem); asmlinkage int __down_trylock(struct semaphore * sem); asmlinkage void __up(struct semaphore * sem); /* * This is ugly, but we want the default case to fall through. * "down_failed" is a special asm handler that calls the C * routine that actually waits. See arch/m68k/lib/semaphore.S */ extern inline void down(struct semaphore * sem) { register struct semaphore *sem1 __asm__ ("%a1") = sem; #if WAITQUEUE_DEBUG CHECK_MAGIC(sem->__magic); #endif __asm__ __volatile__( "| atomic down operation\n\t" "subql #1,%0@\n\t" "jmi 2f\n\t" "1:\n" ".section .text.lock,\"ax\"\n" ".even\n" "2:\tpea 1b\n\t" "jbra __down_failed\n" ".previous" : /* no outputs */ : "a" (sem1) : "memory"); } extern inline int down_interruptible(struct semaphore * sem) { register struct semaphore *sem1 __asm__ ("%a1") = sem; register int result __asm__ ("%d0"); #if WAITQUEUE_DEBUG CHECK_MAGIC(sem->__magic); #endif __asm__ __volatile__( "| atomic interruptible down operation\n\t" "subql #1,%1@\n\t" "jmi 2f\n\t" "clrl %0\n" "1:\n" ".section .text.lock,\"ax\"\n" ".even\n" "2:\tpea 1b\n\t" "jbra __down_failed_interruptible\n" ".previous" : "=d" (result) : "a" (sem1) : "%d0", "memory"); return result; } extern inline int down_trylock(struct semaphore * sem) { register struct semaphore *sem1 __asm__ ("%a1") = sem; register int result __asm__ ("%d0"); #if WAITQUEUE_DEBUG CHECK_MAGIC(sem->__magic); #endif __asm__ __volatile__( "| atomic down trylock operation\n\t" "subql #1,%1@\n\t" "jmi 2f\n\t" "clrl %0\n" "1:\n" ".section .text.lock,\"ax\"\n" ".even\n" "2:\tpea 1b\n\t" "jbra __down_failed_trylock\n" ".previous" : "=d" (result) : "a" (sem1) : "%d0", "memory"); return result; } /* * Note! This is subtle. We jump to wake people up only if * the semaphore was negative (== somebody was waiting on it). * The default case (no contention) will result in NO * jumps for both down() and up(). */ extern inline void up(struct semaphore * sem) { register struct semaphore *sem1 __asm__ ("%a1") = sem; #if WAITQUEUE_DEBUG CHECK_MAGIC(sem->__magic); #endif __asm__ __volatile__( "| atomic up operation\n\t" "addql #1,%0@\n\t" "jle 2f\n" "1:\n" ".section .text.lock,\"ax\"\n" ".even\n" "2:\t" "pea 1b\n\t" "jbra __up_wakeup\n" ".previous" : /* no outputs */ : "a" (sem1) : "memory"); } /* rw mutexes (should that be mutices? =) -- throw rw * spinlocks and semaphores together, and this is what we * end up with... * * m68k version by Roman Zippel */ struct rw_semaphore { atomic_t count; volatile unsigned char write_bias_granted; volatile unsigned char read_bias_granted; volatile unsigned char pad1; volatile unsigned char pad2; wait_queue_head_t wait; wait_queue_head_t write_bias_wait; #if WAITQUEUE_DEBUG long __magic; atomic_t readers; atomic_t writers; #endif }; #if WAITQUEUE_DEBUG #define __RWSEM_DEBUG_INIT , ATOMIC_INIT(0), ATOMIC_INIT(0) #else #define __RWSEM_DEBUG_INIT /* */ #endif #define __RWSEM_INITIALIZER(name,count) \ { ATOMIC_INIT(count), 0, 0, 0, 0, __WAIT_QUEUE_HEAD_INITIALIZER((name).wait), \ __WAIT_QUEUE_HEAD_INITIALIZER((name).write_bias_wait) \ __SEM_DEBUG_INIT(name) __RWSEM_DEBUG_INIT } #define __DECLARE_RWSEM_GENERIC(name,count) \ struct rw_semaphore name = __RWSEM_INITIALIZER(name,count) #define DECLARE_RWSEM(name) __DECLARE_RWSEM_GENERIC(name,RW_LOCK_BIAS) #define DECLARE_RWSEM_READ_LOCKED(name) __DECLARE_RWSEM_GENERIC(name,RW_LOCK_BIAS-1) #define DECLARE_RWSEM_WRITE_LOCKED(name) __DECLARE_RWSEM_GENERIC(name,0) extern inline void init_rwsem(struct rw_semaphore *sem) { atomic_set(&sem->count, RW_LOCK_BIAS); sem->read_bias_granted = 0; sem->write_bias_granted = 0; init_waitqueue_head(&sem->wait); init_waitqueue_head(&sem->write_bias_wait); #if WAITQUEUE_DEBUG sem->__magic = (long)&sem->__magic; atomic_set(&sem->readers, 0); atomic_set(&sem->writers, 0); #endif } extern inline void down_read(struct rw_semaphore *sem) { register struct rw_semaphore *__sem __asm__ ("%a1") = sem; #if WAITQUEUE_DEBUG if (sem->__magic != (long)&sem->__magic) BUG(); #endif __asm__ __volatile__( "| atomic down_read operation\n\t" "subql #1,%0@\n\t" "jmi 2f\n" "1:\n" ".section .text.lock,\"ax\"\n" ".even\n" "2:\n\t" "pea 1b\n\t" "jbra __down_read_failed\n" ".previous" : /* no outputs */ : "a" (__sem) : "memory"); #if WAITQUEUE_DEBUG if (sem->write_bias_granted) BUG(); if (atomic_read(&sem->writers)) BUG(); atomic_inc(&sem->readers); #endif } extern inline void down_write(struct rw_semaphore *sem) { register struct rw_semaphore *__sem __asm__ ("%a1") = sem; #if WAITQUEUE_DEBUG if (sem->__magic != (long)&sem->__magic) BUG(); #endif __asm__ __volatile__( "| atomic down_write operation\n\t" "subl %1,%0@\n\t" "jne 2f\n" "1:\n" ".section .text.lock,\"ax\"\n" ".even\n" "2:\n\t" "pea 1b\n\t" "jbra __down_write_failed\n" ".previous" : /* no outputs */ : "a" (__sem), "id" (RW_LOCK_BIAS) : "memory"); #if WAITQUEUE_DEBUG if (atomic_read(&sem->writers)) BUG(); if (atomic_read(&sem->readers)) BUG(); if (sem->read_bias_granted) BUG(); if (sem->write_bias_granted) BUG(); atomic_inc(&sem->writers); #endif } /* When a reader does a release, the only significant * case is when there was a writer waiting, and we've * bumped the count to 0: we must wake the writer up. */ extern inline void __up_read(struct rw_semaphore *sem) { register struct rw_semaphore *__sem __asm__ ("%a1") = sem; __asm__ __volatile__( "| atomic up_read operation\n\t" "addql #1,%0@\n\t" "jeq 2f\n" "1:\n" ".section .text.lock,\"ax\"\n" ".even\n" "2:\n\t" "pea 1b\n\t" "jbra __rwsem_wake\n" ".previous" : /* no outputs */ : "a" (__sem) : "memory"); } extern inline void up_read(struct rw_semaphore *sem) { #if WAITQUEUE_DEBUG if (sem->write_bias_granted) BUG(); if (atomic_read(&sem->writers)) BUG(); atomic_dec(&sem->readers); #endif __up_read(sem); } /* releasing the writer is easy -- just release it and * wake up any sleepers. */ extern inline void __up_write(struct rw_semaphore *sem) { register struct rw_semaphore *__sem __asm__ ("%a1") = sem; __asm__ __volatile__( "| atomic up_write operation\n\t" "addl %1,%0@\n\t" "jcs 2f\n" "1:\n" ".section .text.lock,\"ax\"\n" ".even\n" "2:\n\t" "pea 1b\n\t" "jbra __rwsem_wake\n" ".previous" : /* no outputs */ : "a" (__sem), "id" (RW_LOCK_BIAS) : "memory"); } extern inline void up_write(struct rw_semaphore *sem) { #if WAITQUEUE_DEBUG if (sem->read_bias_granted) BUG(); if (sem->write_bias_granted) BUG(); if (atomic_read(&sem->readers)) BUG(); if (atomic_read(&sem->writers) != 1) BUG(); atomic_dec(&sem->writers); #endif __up_write(sem); } #endif /* __ASSEMBLY__ */ #endif |