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1da177e4 LT |
1 | /* |
2 | * Copyright (2004) Linus Torvalds | |
3 | * | |
4 | * Author: Zwane Mwaikambo <zwane@fsmlabs.com> | |
5 | * | |
fb1c8f93 IM |
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) | |
0cb91a22 AK |
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. | |
1da177e4 LT |
15 | */ |
16 | ||
1da177e4 LT |
17 | #include <linux/linkage.h> |
18 | #include <linux/preempt.h> | |
19 | #include <linux/spinlock.h> | |
20 | #include <linux/interrupt.h> | |
8a25d5de | 21 | #include <linux/debug_locks.h> |
1da177e4 LT |
22 | #include <linux/module.h> |
23 | ||
1da177e4 LT |
24 | int __lockfunc _spin_trylock(spinlock_t *lock) |
25 | { | |
26 | preempt_disable(); | |
8a25d5de IM |
27 | if (_raw_spin_trylock(lock)) { |
28 | spin_acquire(&lock->dep_map, 0, 1, _RET_IP_); | |
1da177e4 | 29 | return 1; |
8a25d5de | 30 | } |
1da177e4 LT |
31 | |
32 | preempt_enable(); | |
33 | return 0; | |
34 | } | |
35 | EXPORT_SYMBOL(_spin_trylock); | |
36 | ||
37 | int __lockfunc _read_trylock(rwlock_t *lock) | |
38 | { | |
39 | preempt_disable(); | |
8a25d5de IM |
40 | if (_raw_read_trylock(lock)) { |
41 | rwlock_acquire_read(&lock->dep_map, 0, 1, _RET_IP_); | |
1da177e4 | 42 | return 1; |
8a25d5de | 43 | } |
1da177e4 LT |
44 | |
45 | preempt_enable(); | |
46 | return 0; | |
47 | } | |
48 | EXPORT_SYMBOL(_read_trylock); | |
49 | ||
50 | int __lockfunc _write_trylock(rwlock_t *lock) | |
51 | { | |
52 | preempt_disable(); | |
8a25d5de IM |
53 | if (_raw_write_trylock(lock)) { |
54 | rwlock_acquire(&lock->dep_map, 0, 1, _RET_IP_); | |
1da177e4 | 55 | return 1; |
8a25d5de | 56 | } |
1da177e4 LT |
57 | |
58 | preempt_enable(); | |
59 | return 0; | |
60 | } | |
61 | EXPORT_SYMBOL(_write_trylock); | |
62 | ||
8a25d5de IM |
63 | /* |
64 | * If lockdep is enabled then we use the non-preemption spin-ops | |
65 | * even on CONFIG_PREEMPT, because lockdep assumes that interrupts are | |
66 | * not re-enabled during lock-acquire (which the preempt-spin-ops do): | |
67 | */ | |
68 | #if !defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP) || \ | |
fc47e7b5 | 69 | defined(CONFIG_DEBUG_LOCK_ALLOC) |
1da177e4 LT |
70 | |
71 | void __lockfunc _read_lock(rwlock_t *lock) | |
72 | { | |
73 | preempt_disable(); | |
8a25d5de | 74 | rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_); |
1da177e4 LT |
75 | _raw_read_lock(lock); |
76 | } | |
77 | EXPORT_SYMBOL(_read_lock); | |
78 | ||
79 | unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock) | |
80 | { | |
81 | unsigned long flags; | |
82 | ||
83 | local_irq_save(flags); | |
84 | preempt_disable(); | |
8a25d5de IM |
85 | spin_acquire(&lock->dep_map, 0, 0, _RET_IP_); |
86 | /* | |
87 | * On lockdep we dont want the hand-coded irq-enable of | |
88 | * _raw_spin_lock_flags() code, because lockdep assumes | |
89 | * that interrupts are not re-enabled during lock-acquire: | |
90 | */ | |
91 | #ifdef CONFIG_PROVE_LOCKING | |
92 | _raw_spin_lock(lock); | |
93 | #else | |
fb1c8f93 | 94 | _raw_spin_lock_flags(lock, &flags); |
8a25d5de | 95 | #endif |
1da177e4 LT |
96 | return flags; |
97 | } | |
98 | EXPORT_SYMBOL(_spin_lock_irqsave); | |
99 | ||
100 | void __lockfunc _spin_lock_irq(spinlock_t *lock) | |
101 | { | |
102 | local_irq_disable(); | |
103 | preempt_disable(); | |
8a25d5de | 104 | spin_acquire(&lock->dep_map, 0, 0, _RET_IP_); |
1da177e4 LT |
105 | _raw_spin_lock(lock); |
106 | } | |
107 | EXPORT_SYMBOL(_spin_lock_irq); | |
108 | ||
109 | void __lockfunc _spin_lock_bh(spinlock_t *lock) | |
110 | { | |
111 | local_bh_disable(); | |
112 | preempt_disable(); | |
8a25d5de | 113 | spin_acquire(&lock->dep_map, 0, 0, _RET_IP_); |
1da177e4 LT |
114 | _raw_spin_lock(lock); |
115 | } | |
116 | EXPORT_SYMBOL(_spin_lock_bh); | |
117 | ||
118 | unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock) | |
119 | { | |
120 | unsigned long flags; | |
121 | ||
122 | local_irq_save(flags); | |
123 | preempt_disable(); | |
8a25d5de | 124 | rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_); |
1da177e4 LT |
125 | _raw_read_lock(lock); |
126 | return flags; | |
127 | } | |
128 | EXPORT_SYMBOL(_read_lock_irqsave); | |
129 | ||
130 | void __lockfunc _read_lock_irq(rwlock_t *lock) | |
131 | { | |
132 | local_irq_disable(); | |
133 | preempt_disable(); | |
8a25d5de | 134 | rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_); |
1da177e4 LT |
135 | _raw_read_lock(lock); |
136 | } | |
137 | EXPORT_SYMBOL(_read_lock_irq); | |
138 | ||
139 | void __lockfunc _read_lock_bh(rwlock_t *lock) | |
140 | { | |
141 | local_bh_disable(); | |
142 | preempt_disable(); | |
8a25d5de | 143 | rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_); |
1da177e4 LT |
144 | _raw_read_lock(lock); |
145 | } | |
146 | EXPORT_SYMBOL(_read_lock_bh); | |
147 | ||
148 | unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock) | |
149 | { | |
150 | unsigned long flags; | |
151 | ||
152 | local_irq_save(flags); | |
153 | preempt_disable(); | |
8a25d5de | 154 | rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_); |
1da177e4 LT |
155 | _raw_write_lock(lock); |
156 | return flags; | |
157 | } | |
158 | EXPORT_SYMBOL(_write_lock_irqsave); | |
159 | ||
160 | void __lockfunc _write_lock_irq(rwlock_t *lock) | |
161 | { | |
162 | local_irq_disable(); | |
163 | preempt_disable(); | |
8a25d5de | 164 | rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_); |
1da177e4 LT |
165 | _raw_write_lock(lock); |
166 | } | |
167 | EXPORT_SYMBOL(_write_lock_irq); | |
168 | ||
169 | void __lockfunc _write_lock_bh(rwlock_t *lock) | |
170 | { | |
171 | local_bh_disable(); | |
172 | preempt_disable(); | |
8a25d5de | 173 | rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_); |
1da177e4 LT |
174 | _raw_write_lock(lock); |
175 | } | |
176 | EXPORT_SYMBOL(_write_lock_bh); | |
177 | ||
178 | void __lockfunc _spin_lock(spinlock_t *lock) | |
179 | { | |
180 | preempt_disable(); | |
8a25d5de | 181 | spin_acquire(&lock->dep_map, 0, 0, _RET_IP_); |
1da177e4 LT |
182 | _raw_spin_lock(lock); |
183 | } | |
184 | ||
185 | EXPORT_SYMBOL(_spin_lock); | |
186 | ||
187 | void __lockfunc _write_lock(rwlock_t *lock) | |
188 | { | |
189 | preempt_disable(); | |
8a25d5de | 190 | rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_); |
1da177e4 LT |
191 | _raw_write_lock(lock); |
192 | } | |
193 | ||
194 | EXPORT_SYMBOL(_write_lock); | |
195 | ||
196 | #else /* CONFIG_PREEMPT: */ | |
197 | ||
198 | /* | |
199 | * This could be a long-held lock. We both prepare to spin for a long | |
200 | * time (making _this_ CPU preemptable if possible), and we also signal | |
201 | * towards that other CPU that it should break the lock ASAP. | |
202 | * | |
203 | * (We do this in a function because inlining it would be excessive.) | |
204 | */ | |
205 | ||
206 | #define BUILD_LOCK_OPS(op, locktype) \ | |
207 | void __lockfunc _##op##_lock(locktype##_t *lock) \ | |
208 | { \ | |
1da177e4 | 209 | for (;;) { \ |
ee25e96f | 210 | preempt_disable(); \ |
1da177e4 LT |
211 | if (likely(_raw_##op##_trylock(lock))) \ |
212 | break; \ | |
213 | preempt_enable(); \ | |
ee25e96f | 214 | \ |
1da177e4 LT |
215 | if (!(lock)->break_lock) \ |
216 | (lock)->break_lock = 1; \ | |
217 | while (!op##_can_lock(lock) && (lock)->break_lock) \ | |
218 | cpu_relax(); \ | |
1da177e4 LT |
219 | } \ |
220 | (lock)->break_lock = 0; \ | |
221 | } \ | |
222 | \ | |
223 | EXPORT_SYMBOL(_##op##_lock); \ | |
224 | \ | |
225 | unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock) \ | |
226 | { \ | |
227 | unsigned long flags; \ | |
228 | \ | |
1da177e4 | 229 | for (;;) { \ |
ee25e96f | 230 | preempt_disable(); \ |
1da177e4 LT |
231 | local_irq_save(flags); \ |
232 | if (likely(_raw_##op##_trylock(lock))) \ | |
233 | break; \ | |
234 | local_irq_restore(flags); \ | |
1da177e4 | 235 | preempt_enable(); \ |
ee25e96f | 236 | \ |
1da177e4 LT |
237 | if (!(lock)->break_lock) \ |
238 | (lock)->break_lock = 1; \ | |
239 | while (!op##_can_lock(lock) && (lock)->break_lock) \ | |
240 | cpu_relax(); \ | |
1da177e4 LT |
241 | } \ |
242 | (lock)->break_lock = 0; \ | |
243 | return flags; \ | |
244 | } \ | |
245 | \ | |
246 | EXPORT_SYMBOL(_##op##_lock_irqsave); \ | |
247 | \ | |
248 | void __lockfunc _##op##_lock_irq(locktype##_t *lock) \ | |
249 | { \ | |
250 | _##op##_lock_irqsave(lock); \ | |
251 | } \ | |
252 | \ | |
253 | EXPORT_SYMBOL(_##op##_lock_irq); \ | |
254 | \ | |
255 | void __lockfunc _##op##_lock_bh(locktype##_t *lock) \ | |
256 | { \ | |
257 | unsigned long flags; \ | |
258 | \ | |
259 | /* */ \ | |
260 | /* Careful: we must exclude softirqs too, hence the */ \ | |
261 | /* irq-disabling. We use the generic preemption-aware */ \ | |
262 | /* function: */ \ | |
263 | /**/ \ | |
264 | flags = _##op##_lock_irqsave(lock); \ | |
265 | local_bh_disable(); \ | |
266 | local_irq_restore(flags); \ | |
267 | } \ | |
268 | \ | |
269 | EXPORT_SYMBOL(_##op##_lock_bh) | |
270 | ||
271 | /* | |
272 | * Build preemption-friendly versions of the following | |
273 | * lock-spinning functions: | |
274 | * | |
275 | * _[spin|read|write]_lock() | |
276 | * _[spin|read|write]_lock_irq() | |
277 | * _[spin|read|write]_lock_irqsave() | |
278 | * _[spin|read|write]_lock_bh() | |
279 | */ | |
280 | BUILD_LOCK_OPS(spin, spinlock); | |
281 | BUILD_LOCK_OPS(read, rwlock); | |
282 | BUILD_LOCK_OPS(write, rwlock); | |
283 | ||
284 | #endif /* CONFIG_PREEMPT */ | |
285 | ||
8a25d5de IM |
286 | #ifdef CONFIG_DEBUG_LOCK_ALLOC |
287 | ||
288 | void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass) | |
289 | { | |
290 | preempt_disable(); | |
291 | spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_); | |
292 | _raw_spin_lock(lock); | |
293 | } | |
294 | ||
295 | EXPORT_SYMBOL(_spin_lock_nested); | |
296 | ||
297 | #endif | |
298 | ||
1da177e4 LT |
299 | void __lockfunc _spin_unlock(spinlock_t *lock) |
300 | { | |
8a25d5de | 301 | spin_release(&lock->dep_map, 1, _RET_IP_); |
1da177e4 LT |
302 | _raw_spin_unlock(lock); |
303 | preempt_enable(); | |
304 | } | |
305 | EXPORT_SYMBOL(_spin_unlock); | |
306 | ||
307 | void __lockfunc _write_unlock(rwlock_t *lock) | |
308 | { | |
8a25d5de | 309 | rwlock_release(&lock->dep_map, 1, _RET_IP_); |
1da177e4 LT |
310 | _raw_write_unlock(lock); |
311 | preempt_enable(); | |
312 | } | |
313 | EXPORT_SYMBOL(_write_unlock); | |
314 | ||
315 | void __lockfunc _read_unlock(rwlock_t *lock) | |
316 | { | |
8a25d5de | 317 | rwlock_release(&lock->dep_map, 1, _RET_IP_); |
1da177e4 LT |
318 | _raw_read_unlock(lock); |
319 | preempt_enable(); | |
320 | } | |
321 | EXPORT_SYMBOL(_read_unlock); | |
322 | ||
323 | void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags) | |
324 | { | |
8a25d5de | 325 | spin_release(&lock->dep_map, 1, _RET_IP_); |
1da177e4 LT |
326 | _raw_spin_unlock(lock); |
327 | local_irq_restore(flags); | |
328 | preempt_enable(); | |
329 | } | |
330 | EXPORT_SYMBOL(_spin_unlock_irqrestore); | |
331 | ||
332 | void __lockfunc _spin_unlock_irq(spinlock_t *lock) | |
333 | { | |
8a25d5de | 334 | spin_release(&lock->dep_map, 1, _RET_IP_); |
1da177e4 LT |
335 | _raw_spin_unlock(lock); |
336 | local_irq_enable(); | |
337 | preempt_enable(); | |
338 | } | |
339 | EXPORT_SYMBOL(_spin_unlock_irq); | |
340 | ||
341 | void __lockfunc _spin_unlock_bh(spinlock_t *lock) | |
342 | { | |
8a25d5de | 343 | spin_release(&lock->dep_map, 1, _RET_IP_); |
1da177e4 | 344 | _raw_spin_unlock(lock); |
10f02d1c | 345 | preempt_enable_no_resched(); |
8a25d5de | 346 | local_bh_enable_ip((unsigned long)__builtin_return_address(0)); |
1da177e4 LT |
347 | } |
348 | EXPORT_SYMBOL(_spin_unlock_bh); | |
349 | ||
350 | void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags) | |
351 | { | |
8a25d5de | 352 | rwlock_release(&lock->dep_map, 1, _RET_IP_); |
1da177e4 LT |
353 | _raw_read_unlock(lock); |
354 | local_irq_restore(flags); | |
355 | preempt_enable(); | |
356 | } | |
357 | EXPORT_SYMBOL(_read_unlock_irqrestore); | |
358 | ||
359 | void __lockfunc _read_unlock_irq(rwlock_t *lock) | |
360 | { | |
8a25d5de | 361 | rwlock_release(&lock->dep_map, 1, _RET_IP_); |
1da177e4 LT |
362 | _raw_read_unlock(lock); |
363 | local_irq_enable(); | |
364 | preempt_enable(); | |
365 | } | |
366 | EXPORT_SYMBOL(_read_unlock_irq); | |
367 | ||
368 | void __lockfunc _read_unlock_bh(rwlock_t *lock) | |
369 | { | |
8a25d5de | 370 | rwlock_release(&lock->dep_map, 1, _RET_IP_); |
1da177e4 | 371 | _raw_read_unlock(lock); |
10f02d1c | 372 | preempt_enable_no_resched(); |
8a25d5de | 373 | local_bh_enable_ip((unsigned long)__builtin_return_address(0)); |
1da177e4 LT |
374 | } |
375 | EXPORT_SYMBOL(_read_unlock_bh); | |
376 | ||
377 | void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags) | |
378 | { | |
8a25d5de | 379 | rwlock_release(&lock->dep_map, 1, _RET_IP_); |
1da177e4 LT |
380 | _raw_write_unlock(lock); |
381 | local_irq_restore(flags); | |
382 | preempt_enable(); | |
383 | } | |
384 | EXPORT_SYMBOL(_write_unlock_irqrestore); | |
385 | ||
386 | void __lockfunc _write_unlock_irq(rwlock_t *lock) | |
387 | { | |
8a25d5de | 388 | rwlock_release(&lock->dep_map, 1, _RET_IP_); |
1da177e4 LT |
389 | _raw_write_unlock(lock); |
390 | local_irq_enable(); | |
391 | preempt_enable(); | |
392 | } | |
393 | EXPORT_SYMBOL(_write_unlock_irq); | |
394 | ||
395 | void __lockfunc _write_unlock_bh(rwlock_t *lock) | |
396 | { | |
8a25d5de | 397 | rwlock_release(&lock->dep_map, 1, _RET_IP_); |
1da177e4 | 398 | _raw_write_unlock(lock); |
10f02d1c | 399 | preempt_enable_no_resched(); |
8a25d5de | 400 | local_bh_enable_ip((unsigned long)__builtin_return_address(0)); |
1da177e4 LT |
401 | } |
402 | EXPORT_SYMBOL(_write_unlock_bh); | |
403 | ||
404 | int __lockfunc _spin_trylock_bh(spinlock_t *lock) | |
405 | { | |
406 | local_bh_disable(); | |
407 | preempt_disable(); | |
8a25d5de IM |
408 | if (_raw_spin_trylock(lock)) { |
409 | spin_acquire(&lock->dep_map, 0, 1, _RET_IP_); | |
1da177e4 | 410 | return 1; |
8a25d5de | 411 | } |
1da177e4 | 412 | |
10f02d1c | 413 | preempt_enable_no_resched(); |
8a25d5de | 414 | local_bh_enable_ip((unsigned long)__builtin_return_address(0)); |
1da177e4 LT |
415 | return 0; |
416 | } | |
417 | EXPORT_SYMBOL(_spin_trylock_bh); | |
418 | ||
419 | int in_lock_functions(unsigned long addr) | |
420 | { | |
421 | /* Linker adds these: start and end of __lockfunc functions */ | |
422 | extern char __lock_text_start[], __lock_text_end[]; | |
423 | ||
424 | return addr >= (unsigned long)__lock_text_start | |
425 | && addr < (unsigned long)__lock_text_end; | |
426 | } | |
427 | EXPORT_SYMBOL(in_lock_functions); |