Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (2004) Linus Torvalds |
| 3 | * |
| 4 | * Author: Zwane Mwaikambo <zwane@fsmlabs.com> |
| 5 | * |
Ingo Molnar | fb1c8f9 | 2005-09-10 00:25:56 -0700 | [diff] [blame] | 6 | * Copyright (2004, 2005) Ingo Molnar |
| 7 | * |
| 8 | * This file contains the spinlock/rwlock implementations for the |
| 9 | * SMP and the DEBUG_SPINLOCK cases. (UP-nondebug inlines them) |
Andi Kleen | 0cb91a2 | 2006-09-26 10:52:28 +0200 | [diff] [blame] | 10 | * |
| 11 | * Note that some architectures have special knowledge about the |
| 12 | * stack frames of these functions in their profile_pc. If you |
| 13 | * change anything significant here that could change the stack |
| 14 | * frame contact the architecture maintainers. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | */ |
| 16 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #include <linux/linkage.h> |
| 18 | #include <linux/preempt.h> |
| 19 | #include <linux/spinlock.h> |
| 20 | #include <linux/interrupt.h> |
Ingo Molnar | 8a25d5d | 2006-07-03 00:24:54 -0700 | [diff] [blame] | 21 | #include <linux/debug_locks.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <linux/module.h> |
| 23 | |
Thomas Gleixner | 8e13c7b | 2009-11-09 15:21:41 +0000 | [diff] [blame] | 24 | /* |
| 25 | * If lockdep is enabled then we use the non-preemption spin-ops |
| 26 | * even on CONFIG_PREEMPT, because lockdep assumes that interrupts are |
| 27 | * not re-enabled during lock-acquire (which the preempt-spin-ops do): |
| 28 | */ |
| 29 | #if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC) |
| 30 | /* |
| 31 | * The __lock_function inlines are taken from |
| 32 | * include/linux/spinlock_api_smp.h |
| 33 | */ |
| 34 | #else |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 35 | #define raw_read_can_lock(l) read_can_lock(l) |
| 36 | #define raw_write_can_lock(l) write_can_lock(l) |
Thomas Gleixner | 8e13c7b | 2009-11-09 15:21:41 +0000 | [diff] [blame] | 37 | /* |
| 38 | * We build the __lock_function inlines here. They are too large for |
| 39 | * inlining all over the place, but here is only one user per function |
| 40 | * which embedds them into the calling _lock_function below. |
| 41 | * |
| 42 | * This could be a long-held lock. We both prepare to spin for a long |
| 43 | * time (making _this_ CPU preemptable if possible), and we also signal |
| 44 | * towards that other CPU that it should break the lock ASAP. |
| 45 | */ |
| 46 | #define BUILD_LOCK_OPS(op, locktype) \ |
| 47 | void __lockfunc __##op##_lock(locktype##_t *lock) \ |
| 48 | { \ |
| 49 | for (;;) { \ |
| 50 | preempt_disable(); \ |
| 51 | if (likely(_raw_##op##_trylock(lock))) \ |
| 52 | break; \ |
| 53 | preempt_enable(); \ |
| 54 | \ |
| 55 | if (!(lock)->break_lock) \ |
| 56 | (lock)->break_lock = 1; \ |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 57 | while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\ |
Thomas Gleixner | 0199c4e | 2009-12-02 20:01:25 +0100 | [diff] [blame] | 58 | arch_##op##_relax(&lock->raw_lock); \ |
Thomas Gleixner | 8e13c7b | 2009-11-09 15:21:41 +0000 | [diff] [blame] | 59 | } \ |
| 60 | (lock)->break_lock = 0; \ |
| 61 | } \ |
| 62 | \ |
| 63 | unsigned long __lockfunc __##op##_lock_irqsave(locktype##_t *lock) \ |
| 64 | { \ |
| 65 | unsigned long flags; \ |
| 66 | \ |
| 67 | for (;;) { \ |
| 68 | preempt_disable(); \ |
| 69 | local_irq_save(flags); \ |
| 70 | if (likely(_raw_##op##_trylock(lock))) \ |
| 71 | break; \ |
| 72 | local_irq_restore(flags); \ |
| 73 | preempt_enable(); \ |
| 74 | \ |
| 75 | if (!(lock)->break_lock) \ |
| 76 | (lock)->break_lock = 1; \ |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 77 | while (!raw_##op##_can_lock(lock) && (lock)->break_lock)\ |
Thomas Gleixner | 0199c4e | 2009-12-02 20:01:25 +0100 | [diff] [blame] | 78 | arch_##op##_relax(&lock->raw_lock); \ |
Thomas Gleixner | 8e13c7b | 2009-11-09 15:21:41 +0000 | [diff] [blame] | 79 | } \ |
| 80 | (lock)->break_lock = 0; \ |
| 81 | return flags; \ |
| 82 | } \ |
| 83 | \ |
| 84 | void __lockfunc __##op##_lock_irq(locktype##_t *lock) \ |
| 85 | { \ |
| 86 | _##op##_lock_irqsave(lock); \ |
| 87 | } \ |
| 88 | \ |
| 89 | void __lockfunc __##op##_lock_bh(locktype##_t *lock) \ |
| 90 | { \ |
| 91 | unsigned long flags; \ |
| 92 | \ |
| 93 | /* */ \ |
| 94 | /* Careful: we must exclude softirqs too, hence the */ \ |
| 95 | /* irq-disabling. We use the generic preemption-aware */ \ |
| 96 | /* function: */ \ |
| 97 | /**/ \ |
| 98 | flags = _##op##_lock_irqsave(lock); \ |
| 99 | local_bh_disable(); \ |
| 100 | local_irq_restore(flags); \ |
| 101 | } \ |
| 102 | |
| 103 | /* |
| 104 | * Build preemption-friendly versions of the following |
| 105 | * lock-spinning functions: |
| 106 | * |
| 107 | * __[spin|read|write]_lock() |
| 108 | * __[spin|read|write]_lock_irq() |
| 109 | * __[spin|read|write]_lock_irqsave() |
| 110 | * __[spin|read|write]_lock_bh() |
| 111 | */ |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 112 | BUILD_LOCK_OPS(spin, raw_spinlock); |
Thomas Gleixner | 8e13c7b | 2009-11-09 15:21:41 +0000 | [diff] [blame] | 113 | BUILD_LOCK_OPS(read, rwlock); |
| 114 | BUILD_LOCK_OPS(write, rwlock); |
| 115 | |
| 116 | #endif |
| 117 | |
Thomas Gleixner | b7b40ad | 2009-11-09 21:01:59 +0100 | [diff] [blame] | 118 | #ifndef CONFIG_INLINE_SPIN_TRYLOCK |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 119 | int __lockfunc _spin_trylock(raw_spinlock_t *lock) |
Thomas Gleixner | b7b40ad | 2009-11-09 21:01:59 +0100 | [diff] [blame] | 120 | { |
| 121 | return __spin_trylock(lock); |
| 122 | } |
| 123 | EXPORT_SYMBOL(_spin_trylock); |
| 124 | #endif |
| 125 | |
| 126 | #ifndef CONFIG_INLINE_SPIN_TRYLOCK_BH |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 127 | int __lockfunc _spin_trylock_bh(raw_spinlock_t *lock) |
Thomas Gleixner | b7b40ad | 2009-11-09 21:01:59 +0100 | [diff] [blame] | 128 | { |
| 129 | return __spin_trylock_bh(lock); |
| 130 | } |
| 131 | EXPORT_SYMBOL(_spin_trylock_bh); |
| 132 | #endif |
| 133 | |
| 134 | #ifndef CONFIG_INLINE_SPIN_LOCK |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 135 | void __lockfunc _spin_lock(raw_spinlock_t *lock) |
Thomas Gleixner | b7b40ad | 2009-11-09 21:01:59 +0100 | [diff] [blame] | 136 | { |
| 137 | __spin_lock(lock); |
| 138 | } |
| 139 | EXPORT_SYMBOL(_spin_lock); |
| 140 | #endif |
| 141 | |
| 142 | #ifndef CONFIG_INLINE_SPIN_LOCK_IRQSAVE |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 143 | unsigned long __lockfunc _spin_lock_irqsave(raw_spinlock_t *lock) |
Thomas Gleixner | b7b40ad | 2009-11-09 21:01:59 +0100 | [diff] [blame] | 144 | { |
| 145 | return __spin_lock_irqsave(lock); |
| 146 | } |
| 147 | EXPORT_SYMBOL(_spin_lock_irqsave); |
| 148 | #endif |
| 149 | |
| 150 | #ifndef CONFIG_INLINE_SPIN_LOCK_IRQ |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 151 | void __lockfunc _spin_lock_irq(raw_spinlock_t *lock) |
Thomas Gleixner | b7b40ad | 2009-11-09 21:01:59 +0100 | [diff] [blame] | 152 | { |
| 153 | __spin_lock_irq(lock); |
| 154 | } |
| 155 | EXPORT_SYMBOL(_spin_lock_irq); |
| 156 | #endif |
| 157 | |
| 158 | #ifndef CONFIG_INLINE_SPIN_LOCK_BH |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 159 | void __lockfunc _spin_lock_bh(raw_spinlock_t *lock) |
Thomas Gleixner | b7b40ad | 2009-11-09 21:01:59 +0100 | [diff] [blame] | 160 | { |
| 161 | __spin_lock_bh(lock); |
| 162 | } |
| 163 | EXPORT_SYMBOL(_spin_lock_bh); |
| 164 | #endif |
| 165 | |
| 166 | #ifndef CONFIG_INLINE_SPIN_UNLOCK |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 167 | void __lockfunc _spin_unlock(raw_spinlock_t *lock) |
Thomas Gleixner | b7b40ad | 2009-11-09 21:01:59 +0100 | [diff] [blame] | 168 | { |
| 169 | __spin_unlock(lock); |
| 170 | } |
| 171 | EXPORT_SYMBOL(_spin_unlock); |
| 172 | #endif |
| 173 | |
| 174 | #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 175 | void __lockfunc _spin_unlock_irqrestore(raw_spinlock_t *lock, unsigned long flags) |
Thomas Gleixner | b7b40ad | 2009-11-09 21:01:59 +0100 | [diff] [blame] | 176 | { |
| 177 | __spin_unlock_irqrestore(lock, flags); |
| 178 | } |
| 179 | EXPORT_SYMBOL(_spin_unlock_irqrestore); |
| 180 | #endif |
| 181 | |
| 182 | #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQ |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 183 | void __lockfunc _spin_unlock_irq(raw_spinlock_t *lock) |
Thomas Gleixner | b7b40ad | 2009-11-09 21:01:59 +0100 | [diff] [blame] | 184 | { |
| 185 | __spin_unlock_irq(lock); |
| 186 | } |
| 187 | EXPORT_SYMBOL(_spin_unlock_irq); |
| 188 | #endif |
| 189 | |
| 190 | #ifndef CONFIG_INLINE_SPIN_UNLOCK_BH |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 191 | void __lockfunc _spin_unlock_bh(raw_spinlock_t *lock) |
Thomas Gleixner | b7b40ad | 2009-11-09 21:01:59 +0100 | [diff] [blame] | 192 | { |
| 193 | __spin_unlock_bh(lock); |
| 194 | } |
| 195 | EXPORT_SYMBOL(_spin_unlock_bh); |
| 196 | #endif |
| 197 | |
| 198 | #ifndef CONFIG_INLINE_READ_TRYLOCK |
| 199 | int __lockfunc _read_trylock(rwlock_t *lock) |
| 200 | { |
| 201 | return __read_trylock(lock); |
| 202 | } |
| 203 | EXPORT_SYMBOL(_read_trylock); |
| 204 | #endif |
| 205 | |
| 206 | #ifndef CONFIG_INLINE_READ_LOCK |
| 207 | void __lockfunc _read_lock(rwlock_t *lock) |
| 208 | { |
| 209 | __read_lock(lock); |
| 210 | } |
| 211 | EXPORT_SYMBOL(_read_lock); |
| 212 | #endif |
| 213 | |
| 214 | #ifndef CONFIG_INLINE_READ_LOCK_IRQSAVE |
| 215 | unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock) |
| 216 | { |
| 217 | return __read_lock_irqsave(lock); |
| 218 | } |
| 219 | EXPORT_SYMBOL(_read_lock_irqsave); |
| 220 | #endif |
| 221 | |
| 222 | #ifndef CONFIG_INLINE_READ_LOCK_IRQ |
| 223 | void __lockfunc _read_lock_irq(rwlock_t *lock) |
| 224 | { |
| 225 | __read_lock_irq(lock); |
| 226 | } |
| 227 | EXPORT_SYMBOL(_read_lock_irq); |
| 228 | #endif |
| 229 | |
| 230 | #ifndef CONFIG_INLINE_READ_LOCK_BH |
| 231 | void __lockfunc _read_lock_bh(rwlock_t *lock) |
| 232 | { |
| 233 | __read_lock_bh(lock); |
| 234 | } |
| 235 | EXPORT_SYMBOL(_read_lock_bh); |
| 236 | #endif |
| 237 | |
| 238 | #ifndef CONFIG_INLINE_READ_UNLOCK |
| 239 | void __lockfunc _read_unlock(rwlock_t *lock) |
| 240 | { |
| 241 | __read_unlock(lock); |
| 242 | } |
| 243 | EXPORT_SYMBOL(_read_unlock); |
| 244 | #endif |
| 245 | |
| 246 | #ifndef CONFIG_INLINE_READ_UNLOCK_IRQRESTORE |
| 247 | void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags) |
| 248 | { |
| 249 | __read_unlock_irqrestore(lock, flags); |
| 250 | } |
| 251 | EXPORT_SYMBOL(_read_unlock_irqrestore); |
| 252 | #endif |
| 253 | |
| 254 | #ifndef CONFIG_INLINE_READ_UNLOCK_IRQ |
| 255 | void __lockfunc _read_unlock_irq(rwlock_t *lock) |
| 256 | { |
| 257 | __read_unlock_irq(lock); |
| 258 | } |
| 259 | EXPORT_SYMBOL(_read_unlock_irq); |
| 260 | #endif |
| 261 | |
| 262 | #ifndef CONFIG_INLINE_READ_UNLOCK_BH |
| 263 | void __lockfunc _read_unlock_bh(rwlock_t *lock) |
| 264 | { |
| 265 | __read_unlock_bh(lock); |
| 266 | } |
| 267 | EXPORT_SYMBOL(_read_unlock_bh); |
| 268 | #endif |
| 269 | |
| 270 | #ifndef CONFIG_INLINE_WRITE_TRYLOCK |
| 271 | int __lockfunc _write_trylock(rwlock_t *lock) |
| 272 | { |
| 273 | return __write_trylock(lock); |
| 274 | } |
| 275 | EXPORT_SYMBOL(_write_trylock); |
| 276 | #endif |
| 277 | |
| 278 | #ifndef CONFIG_INLINE_WRITE_LOCK |
| 279 | void __lockfunc _write_lock(rwlock_t *lock) |
| 280 | { |
| 281 | __write_lock(lock); |
| 282 | } |
| 283 | EXPORT_SYMBOL(_write_lock); |
| 284 | #endif |
| 285 | |
| 286 | #ifndef CONFIG_INLINE_WRITE_LOCK_IRQSAVE |
| 287 | unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock) |
| 288 | { |
| 289 | return __write_lock_irqsave(lock); |
| 290 | } |
| 291 | EXPORT_SYMBOL(_write_lock_irqsave); |
| 292 | #endif |
| 293 | |
| 294 | #ifndef CONFIG_INLINE_WRITE_LOCK_IRQ |
| 295 | void __lockfunc _write_lock_irq(rwlock_t *lock) |
| 296 | { |
| 297 | __write_lock_irq(lock); |
| 298 | } |
| 299 | EXPORT_SYMBOL(_write_lock_irq); |
| 300 | #endif |
| 301 | |
| 302 | #ifndef CONFIG_INLINE_WRITE_LOCK_BH |
| 303 | void __lockfunc _write_lock_bh(rwlock_t *lock) |
| 304 | { |
| 305 | __write_lock_bh(lock); |
| 306 | } |
| 307 | EXPORT_SYMBOL(_write_lock_bh); |
| 308 | #endif |
| 309 | |
| 310 | #ifndef CONFIG_INLINE_WRITE_UNLOCK |
| 311 | void __lockfunc _write_unlock(rwlock_t *lock) |
| 312 | { |
| 313 | __write_unlock(lock); |
| 314 | } |
| 315 | EXPORT_SYMBOL(_write_unlock); |
| 316 | #endif |
| 317 | |
| 318 | #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE |
| 319 | void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags) |
| 320 | { |
| 321 | __write_unlock_irqrestore(lock, flags); |
| 322 | } |
| 323 | EXPORT_SYMBOL(_write_unlock_irqrestore); |
| 324 | #endif |
| 325 | |
| 326 | #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQ |
| 327 | void __lockfunc _write_unlock_irq(rwlock_t *lock) |
| 328 | { |
| 329 | __write_unlock_irq(lock); |
| 330 | } |
| 331 | EXPORT_SYMBOL(_write_unlock_irq); |
| 332 | #endif |
| 333 | |
| 334 | #ifndef CONFIG_INLINE_WRITE_UNLOCK_BH |
| 335 | void __lockfunc _write_unlock_bh(rwlock_t *lock) |
| 336 | { |
| 337 | __write_unlock_bh(lock); |
| 338 | } |
| 339 | EXPORT_SYMBOL(_write_unlock_bh); |
| 340 | #endif |
| 341 | |
Thomas Gleixner | 8e13c7b | 2009-11-09 15:21:41 +0000 | [diff] [blame] | 342 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
| 343 | |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 344 | void __lockfunc _spin_lock_nested(raw_spinlock_t *lock, int subclass) |
Thomas Gleixner | 8e13c7b | 2009-11-09 15:21:41 +0000 | [diff] [blame] | 345 | { |
| 346 | preempt_disable(); |
| 347 | spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_); |
| 348 | LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock); |
| 349 | } |
| 350 | EXPORT_SYMBOL(_spin_lock_nested); |
| 351 | |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 352 | unsigned long __lockfunc _spin_lock_irqsave_nested(raw_spinlock_t *lock, |
Thomas Gleixner | 8e13c7b | 2009-11-09 15:21:41 +0000 | [diff] [blame] | 353 | int subclass) |
| 354 | { |
| 355 | unsigned long flags; |
| 356 | |
| 357 | local_irq_save(flags); |
| 358 | preempt_disable(); |
| 359 | spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_); |
| 360 | LOCK_CONTENDED_FLAGS(lock, _raw_spin_trylock, _raw_spin_lock, |
| 361 | _raw_spin_lock_flags, &flags); |
| 362 | return flags; |
| 363 | } |
| 364 | EXPORT_SYMBOL(_spin_lock_irqsave_nested); |
| 365 | |
Thomas Gleixner | c2f21ce | 2009-12-02 20:02:59 +0100 | [diff] [blame^] | 366 | void __lockfunc _spin_lock_nest_lock(raw_spinlock_t *lock, |
Thomas Gleixner | 8e13c7b | 2009-11-09 15:21:41 +0000 | [diff] [blame] | 367 | struct lockdep_map *nest_lock) |
| 368 | { |
| 369 | preempt_disable(); |
| 370 | spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_); |
| 371 | LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock); |
| 372 | } |
| 373 | EXPORT_SYMBOL(_spin_lock_nest_lock); |
| 374 | |
| 375 | #endif |
| 376 | |
Steven Rostedt | 0764d23 | 2008-05-12 21:20:44 +0200 | [diff] [blame] | 377 | notrace int in_lock_functions(unsigned long addr) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 378 | { |
| 379 | /* Linker adds these: start and end of __lockfunc functions */ |
| 380 | extern char __lock_text_start[], __lock_text_end[]; |
| 381 | |
| 382 | return addr >= (unsigned long)__lock_text_start |
| 383 | && addr < (unsigned long)__lock_text_end; |
| 384 | } |
| 385 | EXPORT_SYMBOL(in_lock_functions); |