Details | Last modification | View Log | RSS feed
| Rev | Author | Line No. | Line |
|---|---|---|---|
| 422 | giacomo | 1 | #ifndef __LINUX_SPINLOCK_H |
| 2 | #define __LINUX_SPINLOCK_H |
||
| 3 | |||
| 4 | /* |
||
| 5 | * include/linux/spinlock.h - generic locking declarations |
||
| 6 | */ |
||
| 7 | |||
| 8 | #include <linux/config.h> |
||
| 9 | #include <linux/preempt.h> |
||
| 10 | #include <linux/linkage.h> |
||
| 11 | #include <linux/compiler.h> |
||
| 12 | #include <linux/thread_info.h> |
||
| 13 | #include <linux/kernel.h> |
||
| 14 | #include <linux/stringify.h> |
||
| 15 | |||
| 16 | #include <asm/processor.h> /* for cpu relax */ |
||
| 17 | #include <asm/system.h> |
||
| 18 | |||
| 19 | /* |
||
| 20 | * Must define these before including other files, inline functions need them |
||
| 21 | */ |
||
| 22 | #define LOCK_SECTION_NAME \ |
||
| 23 | ".text.lock." __stringify(KBUILD_BASENAME) |
||
| 24 | |||
| 25 | #define LOCK_SECTION_START(extra) \ |
||
| 26 | ".subsection 1\n\t" \ |
||
| 27 | extra \ |
||
| 28 | ".ifndef " LOCK_SECTION_NAME "\n\t" \ |
||
| 29 | LOCK_SECTION_NAME ":\n\t" \ |
||
| 30 | ".endif\n\t" |
||
| 31 | |||
| 32 | #define LOCK_SECTION_END \ |
||
| 33 | ".previous\n\t" |
||
| 34 | |||
| 35 | /* |
||
| 36 | * If CONFIG_SMP is set, pull in the _raw_* definitions |
||
| 37 | */ |
||
| 38 | #ifdef CONFIG_SMP |
||
| 39 | #include <asm/spinlock.h> |
||
| 40 | |||
| 41 | #else |
||
| 42 | |||
| 43 | #if !defined(CONFIG_PREEMPT) && !defined(CONFIG_DEBUG_SPINLOCK) |
||
| 44 | # define atomic_dec_and_lock(atomic,lock) atomic_dec_and_test(atomic) |
||
| 45 | # define ATOMIC_DEC_AND_LOCK |
||
| 46 | #endif |
||
| 47 | |||
| 48 | #ifdef CONFIG_DEBUG_SPINLOCK |
||
| 49 | |||
| 50 | #define SPINLOCK_MAGIC 0x1D244B3C |
||
| 51 | typedef struct { |
||
| 52 | unsigned long magic; |
||
| 53 | volatile unsigned long lock; |
||
| 54 | volatile unsigned int babble; |
||
| 55 | const char *module; |
||
| 56 | char *owner; |
||
| 57 | int oline; |
||
| 58 | } spinlock_t; |
||
| 59 | #define SPIN_LOCK_UNLOCKED (spinlock_t) { SPINLOCK_MAGIC, 0, 10, __FILE__ , NULL, 0} |
||
| 60 | |||
| 61 | #define spin_lock_init(x) \ |
||
| 62 | do { \ |
||
| 63 | (x)->magic = SPINLOCK_MAGIC; \ |
||
| 64 | (x)->lock = 0; \ |
||
| 65 | (x)->babble = 5; \ |
||
| 66 | (x)->module = __FILE__; \ |
||
| 67 | (x)->owner = NULL; \ |
||
| 68 | (x)->oline = 0; \ |
||
| 69 | } while (0) |
||
| 70 | |||
| 71 | #define CHECK_LOCK(x) \ |
||
| 72 | do { \ |
||
| 73 | if ((x)->magic != SPINLOCK_MAGIC) { \ |
||
| 74 | printk(KERN_ERR "%s:%d: spin_is_locked on uninitialized spinlock %p.\n", \ |
||
| 75 | __FILE__, __LINE__, (x)); \ |
||
| 76 | } \ |
||
| 77 | } while(0) |
||
| 78 | |||
| 79 | #define _raw_spin_lock(x) \ |
||
| 80 | do { \ |
||
| 81 | CHECK_LOCK(x); \ |
||
| 82 | if ((x)->lock&&(x)->babble) { \ |
||
| 83 | (x)->babble--; \ |
||
| 84 | printk("%s:%d: spin_lock(%s:%p) already locked by %s/%d\n", \ |
||
| 85 | __FILE__,__LINE__, (x)->module, \ |
||
| 86 | (x), (x)->owner, (x)->oline); \ |
||
| 87 | } \ |
||
| 88 | (x)->lock = 1; \ |
||
| 89 | (x)->owner = __FILE__; \ |
||
| 90 | (x)->oline = __LINE__; \ |
||
| 91 | } while (0) |
||
| 92 | |||
| 93 | /* without debugging, spin_is_locked on UP always says |
||
| 94 | * FALSE. --> printk if already locked. */ |
||
| 95 | #define spin_is_locked(x) \ |
||
| 96 | ({ \ |
||
| 97 | CHECK_LOCK(x); \ |
||
| 98 | if ((x)->lock&&(x)->babble) { \ |
||
| 99 | (x)->babble--; \ |
||
| 100 | printk("%s:%d: spin_is_locked(%s:%p) already locked by %s/%d\n", \ |
||
| 101 | __FILE__,__LINE__, (x)->module, \ |
||
| 102 | (x), (x)->owner, (x)->oline); \ |
||
| 103 | } \ |
||
| 104 | 0; \ |
||
| 105 | }) |
||
| 106 | |||
| 107 | /* without debugging, spin_trylock on UP always says |
||
| 108 | * TRUE. --> printk if already locked. */ |
||
| 109 | #define _raw_spin_trylock(x) \ |
||
| 110 | ({ \ |
||
| 111 | CHECK_LOCK(x); \ |
||
| 112 | if ((x)->lock&&(x)->babble) { \ |
||
| 113 | (x)->babble--; \ |
||
| 114 | printk("%s:%d: spin_trylock(%s:%p) already locked by %s/%d\n", \ |
||
| 115 | __FILE__,__LINE__, (x)->module, \ |
||
| 116 | (x), (x)->owner, (x)->oline); \ |
||
| 117 | } \ |
||
| 118 | (x)->lock = 1; \ |
||
| 119 | (x)->owner = __FILE__; \ |
||
| 120 | (x)->oline = __LINE__; \ |
||
| 121 | 1; \ |
||
| 122 | }) |
||
| 123 | |||
| 124 | #define spin_unlock_wait(x) \ |
||
| 125 | do { \ |
||
| 126 | CHECK_LOCK(x); \ |
||
| 127 | if ((x)->lock&&(x)->babble) { \ |
||
| 128 | (x)->babble--; \ |
||
| 129 | printk("%s:%d: spin_unlock_wait(%s:%p) owned by %s/%d\n", \ |
||
| 130 | __FILE__,__LINE__, (x)->module, (x), \ |
||
| 131 | (x)->owner, (x)->oline); \ |
||
| 132 | }\ |
||
| 133 | } while (0) |
||
| 134 | |||
| 135 | #define _raw_spin_unlock(x) \ |
||
| 136 | do { \ |
||
| 137 | CHECK_LOCK(x); \ |
||
| 138 | if (!(x)->lock&&(x)->babble) { \ |
||
| 139 | (x)->babble--; \ |
||
| 140 | printk("%s:%d: spin_unlock(%s:%p) not locked\n", \ |
||
| 141 | __FILE__,__LINE__, (x)->module, (x));\ |
||
| 142 | } \ |
||
| 143 | (x)->lock = 0; \ |
||
| 144 | } while (0) |
||
| 145 | #else |
||
| 146 | /* |
||
| 147 | * gcc versions before ~2.95 have a nasty bug with empty initializers. |
||
| 148 | */ |
||
| 149 | #if (__GNUC__ > 2) |
||
| 150 | typedef struct { } spinlock_t; |
||
| 151 | #define SPIN_LOCK_UNLOCKED (spinlock_t) { } |
||
| 152 | #else |
||
| 153 | typedef struct { int gcc_is_buggy; } spinlock_t; |
||
| 154 | #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } |
||
| 155 | #endif |
||
| 156 | |||
| 157 | /* |
||
| 158 | * If CONFIG_SMP is unset, declare the _raw_* definitions as nops |
||
| 159 | */ |
||
| 160 | #define spin_lock_init(lock) do { (void)(lock); } while(0) |
||
| 161 | #define _raw_spin_lock(lock) do { (void)(lock); } while(0) |
||
| 162 | #define spin_is_locked(lock) ((void)(lock), 0) |
||
| 163 | #define _raw_spin_trylock(lock) ((void)(lock), 1) |
||
| 164 | #define spin_unlock_wait(lock) do { (void)(lock); } while(0) |
||
| 165 | #define _raw_spin_unlock(lock) do { (void)(lock); } while(0) |
||
| 166 | #endif /* CONFIG_DEBUG_SPINLOCK */ |
||
| 167 | |||
| 168 | /* RW spinlocks: No debug version */ |
||
| 169 | |||
| 170 | #if (__GNUC__ > 2) |
||
| 171 | typedef struct { } rwlock_t; |
||
| 172 | #define RW_LOCK_UNLOCKED (rwlock_t) { } |
||
| 173 | #else |
||
| 174 | typedef struct { int gcc_is_buggy; } rwlock_t; |
||
| 175 | #define RW_LOCK_UNLOCKED (rwlock_t) { 0 } |
||
| 176 | #endif |
||
| 177 | |||
| 178 | #define rwlock_init(lock) do { (void)(lock); } while(0) |
||
| 179 | #define _raw_read_lock(lock) do { (void)(lock); } while(0) |
||
| 180 | #define _raw_read_unlock(lock) do { (void)(lock); } while(0) |
||
| 181 | #define _raw_write_lock(lock) do { (void)(lock); } while(0) |
||
| 182 | #define _raw_write_unlock(lock) do { (void)(lock); } while(0) |
||
| 183 | #define _raw_write_trylock(lock) ({ (void)(lock); (1); }) |
||
| 184 | |||
| 185 | #endif /* !SMP */ |
||
| 186 | |||
| 187 | /* |
||
| 188 | * Define the various spin_lock and rw_lock methods. Note we define these |
||
| 189 | * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various |
||
| 190 | * methods are defined as nops in the case they are not required. |
||
| 191 | */ |
||
| 192 | #define spin_trylock(lock) ({preempt_disable(); _raw_spin_trylock(lock) ? \ |
||
| 193 | 1 : ({preempt_enable(); 0;});}) |
||
| 194 | |||
| 195 | #define write_trylock(lock) ({preempt_disable();_raw_write_trylock(lock) ? \ |
||
| 196 | 1 : ({preempt_enable(); 0;});}) |
||
| 197 | |||
| 198 | /* Where's read_trylock? */ |
||
| 199 | |||
| 200 | #if defined(CONFIG_SMP) && defined(CONFIG_PREEMPT) |
||
| 201 | void __preempt_spin_lock(spinlock_t *lock); |
||
| 202 | void __preempt_write_lock(rwlock_t *lock); |
||
| 203 | |||
| 204 | #define spin_lock(lock) \ |
||
| 205 | do { \ |
||
| 206 | preempt_disable(); \ |
||
| 207 | if (unlikely(!_raw_spin_trylock(lock))) \ |
||
| 208 | __preempt_spin_lock(lock); \ |
||
| 209 | } while (0) |
||
| 210 | |||
| 211 | #define write_lock(lock) \ |
||
| 212 | do { \ |
||
| 213 | preempt_disable(); \ |
||
| 214 | if (unlikely(!_raw_write_trylock(lock))) \ |
||
| 215 | __preempt_write_lock(lock); \ |
||
| 216 | } while (0) |
||
| 217 | |||
| 218 | #else |
||
| 219 | #define spin_lock(lock) \ |
||
| 220 | do { \ |
||
| 221 | preempt_disable(); \ |
||
| 222 | _raw_spin_lock(lock); \ |
||
| 223 | } while(0) |
||
| 224 | |||
| 225 | #define write_lock(lock) \ |
||
| 226 | do { \ |
||
| 227 | preempt_disable(); \ |
||
| 228 | _raw_write_lock(lock); \ |
||
| 229 | } while(0) |
||
| 230 | #endif |
||
| 231 | |||
| 232 | #define read_lock(lock) \ |
||
| 233 | do { \ |
||
| 234 | preempt_disable(); \ |
||
| 235 | _raw_read_lock(lock); \ |
||
| 236 | } while(0) |
||
| 237 | |||
| 238 | #define spin_unlock(lock) \ |
||
| 239 | do { \ |
||
| 240 | _raw_spin_unlock(lock); \ |
||
| 241 | preempt_enable(); \ |
||
| 242 | } while (0) |
||
| 243 | |||
| 244 | #define write_unlock(lock) \ |
||
| 245 | do { \ |
||
| 246 | _raw_write_unlock(lock); \ |
||
| 247 | preempt_enable(); \ |
||
| 248 | } while(0) |
||
| 249 | |||
| 250 | #define read_unlock(lock) \ |
||
| 251 | do { \ |
||
| 252 | _raw_read_unlock(lock); \ |
||
| 253 | preempt_enable(); \ |
||
| 254 | } while(0) |
||
| 255 | |||
| 256 | #define spin_lock_irqsave(lock, flags) \ |
||
| 257 | do { \ |
||
| 258 | local_irq_save(flags); \ |
||
| 259 | preempt_disable(); \ |
||
| 260 | _raw_spin_lock(lock); \ |
||
| 261 | } while (0) |
||
| 262 | |||
| 263 | #define spin_lock_irq(lock) \ |
||
| 264 | do { \ |
||
| 265 | local_irq_disable(); \ |
||
| 266 | preempt_disable(); \ |
||
| 267 | _raw_spin_lock(lock); \ |
||
| 268 | } while (0) |
||
| 269 | |||
| 270 | #define spin_lock_bh(lock) \ |
||
| 271 | do { \ |
||
| 272 | local_bh_disable(); \ |
||
| 273 | preempt_disable(); \ |
||
| 274 | _raw_spin_lock(lock); \ |
||
| 275 | } while (0) |
||
| 276 | |||
| 277 | #define read_lock_irqsave(lock, flags) \ |
||
| 278 | do { \ |
||
| 279 | local_irq_save(flags); \ |
||
| 280 | preempt_disable(); \ |
||
| 281 | _raw_read_lock(lock); \ |
||
| 282 | } while (0) |
||
| 283 | |||
| 284 | #define read_lock_irq(lock) \ |
||
| 285 | do { \ |
||
| 286 | local_irq_disable(); \ |
||
| 287 | preempt_disable(); \ |
||
| 288 | _raw_read_lock(lock); \ |
||
| 289 | } while (0) |
||
| 290 | |||
| 291 | #define read_lock_bh(lock) \ |
||
| 292 | do { \ |
||
| 293 | local_bh_disable(); \ |
||
| 294 | preempt_disable(); \ |
||
| 295 | _raw_read_lock(lock); \ |
||
| 296 | } while (0) |
||
| 297 | |||
| 298 | #define write_lock_irqsave(lock, flags) \ |
||
| 299 | do { \ |
||
| 300 | local_irq_save(flags); \ |
||
| 301 | preempt_disable(); \ |
||
| 302 | _raw_write_lock(lock); \ |
||
| 303 | } while (0) |
||
| 304 | |||
| 305 | #define write_lock_irq(lock) \ |
||
| 306 | do { \ |
||
| 307 | local_irq_disable(); \ |
||
| 308 | preempt_disable(); \ |
||
| 309 | _raw_write_lock(lock); \ |
||
| 310 | } while (0) |
||
| 311 | |||
| 312 | #define write_lock_bh(lock) \ |
||
| 313 | do { \ |
||
| 314 | local_bh_disable(); \ |
||
| 315 | preempt_disable(); \ |
||
| 316 | _raw_write_lock(lock); \ |
||
| 317 | } while (0) |
||
| 318 | |||
| 319 | #define spin_unlock_irqrestore(lock, flags) \ |
||
| 320 | do { \ |
||
| 321 | _raw_spin_unlock(lock); \ |
||
| 322 | local_irq_restore(flags); \ |
||
| 323 | preempt_enable(); \ |
||
| 324 | } while (0) |
||
| 325 | |||
| 326 | #define _raw_spin_unlock_irqrestore(lock, flags) \ |
||
| 327 | do { \ |
||
| 328 | _raw_spin_unlock(lock); \ |
||
| 329 | local_irq_restore(flags); \ |
||
| 330 | } while (0) |
||
| 331 | |||
| 332 | #define spin_unlock_irq(lock) \ |
||
| 333 | do { \ |
||
| 334 | _raw_spin_unlock(lock); \ |
||
| 335 | local_irq_enable(); \ |
||
| 336 | preempt_enable(); \ |
||
| 337 | } while (0) |
||
| 338 | |||
| 339 | #define spin_unlock_bh(lock) \ |
||
| 340 | do { \ |
||
| 341 | _raw_spin_unlock(lock); \ |
||
| 342 | preempt_enable(); \ |
||
| 343 | local_bh_enable(); \ |
||
| 344 | } while (0) |
||
| 345 | |||
| 346 | #define read_unlock_irqrestore(lock, flags) \ |
||
| 347 | do { \ |
||
| 348 | _raw_read_unlock(lock); \ |
||
| 349 | local_irq_restore(flags); \ |
||
| 350 | preempt_enable(); \ |
||
| 351 | } while (0) |
||
| 352 | |||
| 353 | #define read_unlock_irq(lock) \ |
||
| 354 | do { \ |
||
| 355 | _raw_read_unlock(lock); \ |
||
| 356 | local_irq_enable(); \ |
||
| 357 | preempt_enable(); \ |
||
| 358 | } while (0) |
||
| 359 | |||
| 360 | #define read_unlock_bh(lock) \ |
||
| 361 | do { \ |
||
| 362 | _raw_read_unlock(lock); \ |
||
| 363 | preempt_enable(); \ |
||
| 364 | local_bh_enable(); \ |
||
| 365 | } while (0) |
||
| 366 | |||
| 367 | #define write_unlock_irqrestore(lock, flags) \ |
||
| 368 | do { \ |
||
| 369 | _raw_write_unlock(lock); \ |
||
| 370 | local_irq_restore(flags); \ |
||
| 371 | preempt_enable(); \ |
||
| 372 | } while (0) |
||
| 373 | |||
| 374 | #define write_unlock_irq(lock) \ |
||
| 375 | do { \ |
||
| 376 | _raw_write_unlock(lock); \ |
||
| 377 | local_irq_enable(); \ |
||
| 378 | preempt_enable(); \ |
||
| 379 | } while (0) |
||
| 380 | |||
| 381 | #define write_unlock_bh(lock) \ |
||
| 382 | do { \ |
||
| 383 | _raw_write_unlock(lock); \ |
||
| 384 | preempt_enable(); \ |
||
| 385 | local_bh_enable(); \ |
||
| 386 | } while (0) |
||
| 387 | |||
| 388 | #define spin_trylock_bh(lock) ({ local_bh_disable(); preempt_disable(); \ |
||
| 389 | _raw_spin_trylock(lock) ? 1 : \ |
||
| 390 | ({preempt_enable(); local_bh_enable(); 0;});}) |
||
| 391 | |||
| 392 | /* "lock on reference count zero" */ |
||
| 393 | #ifndef ATOMIC_DEC_AND_LOCK |
||
| 394 | #include <asm/atomic.h> |
||
| 395 | extern int atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); |
||
| 396 | #endif |
||
| 397 | |||
| 398 | /* |
||
| 399 | * bit-based spin_lock() |
||
| 400 | * |
||
| 401 | * Don't use this unless you really need to: spin_lock() and spin_unlock() |
||
| 402 | * are significantly faster. |
||
| 403 | */ |
||
| 404 | static inline void bit_spin_lock(int bitnum, unsigned long *addr) |
||
| 405 | { |
||
| 406 | /* |
||
| 407 | * Assuming the lock is uncontended, this never enters |
||
| 408 | * the body of the outer loop. If it is contended, then |
||
| 409 | * within the inner loop a non-atomic test is used to |
||
| 410 | * busywait with less bus contention for a good time to |
||
| 411 | * attempt to acquire the lock bit. |
||
| 412 | */ |
||
| 413 | preempt_disable(); |
||
| 414 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
||
| 415 | while (test_and_set_bit(bitnum, addr)) { |
||
| 416 | while (test_bit(bitnum, addr)) |
||
| 417 | cpu_relax(); |
||
| 418 | } |
||
| 419 | #endif |
||
| 420 | } |
||
| 421 | |||
| 422 | /* |
||
| 423 | * Return true if it was acquired |
||
| 424 | */ |
||
| 425 | static inline int bit_spin_trylock(int bitnum, unsigned long *addr) |
||
| 426 | { |
||
| 427 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
||
| 428 | int ret; |
||
| 429 | |||
| 430 | preempt_disable(); |
||
| 431 | ret = !test_and_set_bit(bitnum, addr); |
||
| 432 | if (!ret) |
||
| 433 | preempt_enable(); |
||
| 434 | return ret; |
||
| 435 | #else |
||
| 436 | preempt_disable(); |
||
| 437 | return 1; |
||
| 438 | #endif |
||
| 439 | } |
||
| 440 | |||
| 441 | /* |
||
| 442 | * bit-based spin_unlock() |
||
| 443 | */ |
||
| 444 | static inline void bit_spin_unlock(int bitnum, unsigned long *addr) |
||
| 445 | { |
||
| 446 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
||
| 447 | BUG_ON(!test_bit(bitnum, addr)); |
||
| 448 | smp_mb__before_clear_bit(); |
||
| 449 | clear_bit(bitnum, addr); |
||
| 450 | #endif |
||
| 451 | preempt_enable(); |
||
| 452 | } |
||
| 453 | |||
| 454 | /* |
||
| 455 | * Return true if the lock is held. |
||
| 456 | */ |
||
| 457 | static inline int bit_spin_is_locked(int bitnum, unsigned long *addr) |
||
| 458 | { |
||
| 459 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
||
| 460 | return test_bit(bitnum, addr); |
||
| 461 | #elif defined CONFIG_PREEMPT |
||
| 462 | return preempt_count(); |
||
| 463 | #else |
||
| 464 | return 1; |
||
| 465 | #endif |
||
| 466 | } |
||
| 467 | |||
| 468 | #endif /* __LINUX_SPINLOCK_H */ |