ftrace: irqs off smp_processor_id() fix
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / spinlock.c
CommitLineData
1da177e4
LT
1/*
2 * Copyright (2004) Linus Torvalds
3 *
4 * Author: Zwane Mwaikambo <zwane@fsmlabs.com>
5 *
fb1c8f93
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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)
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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.
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15 */
16
1da177e4
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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>
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22#include <linux/module.h>
23
1da177e4
LT
24int __lockfunc _spin_trylock(spinlock_t *lock)
25{
26 preempt_disable();
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IM
27 if (_raw_spin_trylock(lock)) {
28 spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
1da177e4 29 return 1;
8a25d5de 30 }
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31
32 preempt_enable();
33 return 0;
34}
35EXPORT_SYMBOL(_spin_trylock);
36
37int __lockfunc _read_trylock(rwlock_t *lock)
38{
39 preempt_disable();
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IM
40 if (_raw_read_trylock(lock)) {
41 rwlock_acquire_read(&lock->dep_map, 0, 1, _RET_IP_);
1da177e4 42 return 1;
8a25d5de 43 }
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44
45 preempt_enable();
46 return 0;
47}
48EXPORT_SYMBOL(_read_trylock);
49
50int __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 }
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57
58 preempt_enable();
59 return 0;
60}
61EXPORT_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 */
95c354fe 68#if !defined(CONFIG_GENERIC_LOCKBREAK) || defined(CONFIG_DEBUG_LOCK_ALLOC)
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69
70void __lockfunc _read_lock(rwlock_t *lock)
71{
72 preempt_disable();
8a25d5de 73 rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
4fe87745 74 LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
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75}
76EXPORT_SYMBOL(_read_lock);
77
78unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
79{
80 unsigned long flags;
81
82 local_irq_save(flags);
83 preempt_disable();
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84 spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
85 /*
86 * On lockdep we dont want the hand-coded irq-enable of
87 * _raw_spin_lock_flags() code, because lockdep assumes
88 * that interrupts are not re-enabled during lock-acquire:
89 */
ca58abcb 90#ifdef CONFIG_LOCKDEP
4fe87745 91 LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
8a25d5de 92#else
fb1c8f93 93 _raw_spin_lock_flags(lock, &flags);
8a25d5de 94#endif
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95 return flags;
96}
97EXPORT_SYMBOL(_spin_lock_irqsave);
98
99void __lockfunc _spin_lock_irq(spinlock_t *lock)
100{
101 local_irq_disable();
102 preempt_disable();
8a25d5de 103 spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
4fe87745 104 LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
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105}
106EXPORT_SYMBOL(_spin_lock_irq);
107
108void __lockfunc _spin_lock_bh(spinlock_t *lock)
109{
110 local_bh_disable();
111 preempt_disable();
8a25d5de 112 spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
4fe87745 113 LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
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114}
115EXPORT_SYMBOL(_spin_lock_bh);
116
117unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
118{
119 unsigned long flags;
120
121 local_irq_save(flags);
122 preempt_disable();
8a25d5de 123 rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
4fe87745 124 LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
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125 return flags;
126}
127EXPORT_SYMBOL(_read_lock_irqsave);
128
129void __lockfunc _read_lock_irq(rwlock_t *lock)
130{
131 local_irq_disable();
132 preempt_disable();
8a25d5de 133 rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
4fe87745 134 LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
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135}
136EXPORT_SYMBOL(_read_lock_irq);
137
138void __lockfunc _read_lock_bh(rwlock_t *lock)
139{
140 local_bh_disable();
141 preempt_disable();
8a25d5de 142 rwlock_acquire_read(&lock->dep_map, 0, 0, _RET_IP_);
4fe87745 143 LOCK_CONTENDED(lock, _raw_read_trylock, _raw_read_lock);
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144}
145EXPORT_SYMBOL(_read_lock_bh);
146
147unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
148{
149 unsigned long flags;
150
151 local_irq_save(flags);
152 preempt_disable();
8a25d5de 153 rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
4fe87745 154 LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
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155 return flags;
156}
157EXPORT_SYMBOL(_write_lock_irqsave);
158
159void __lockfunc _write_lock_irq(rwlock_t *lock)
160{
161 local_irq_disable();
162 preempt_disable();
8a25d5de 163 rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
4fe87745 164 LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
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165}
166EXPORT_SYMBOL(_write_lock_irq);
167
168void __lockfunc _write_lock_bh(rwlock_t *lock)
169{
170 local_bh_disable();
171 preempt_disable();
8a25d5de 172 rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
4fe87745 173 LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
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LT
174}
175EXPORT_SYMBOL(_write_lock_bh);
176
177void __lockfunc _spin_lock(spinlock_t *lock)
178{
179 preempt_disable();
8a25d5de 180 spin_acquire(&lock->dep_map, 0, 0, _RET_IP_);
4fe87745 181 LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
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LT
182}
183
184EXPORT_SYMBOL(_spin_lock);
185
186void __lockfunc _write_lock(rwlock_t *lock)
187{
188 preempt_disable();
8a25d5de 189 rwlock_acquire(&lock->dep_map, 0, 0, _RET_IP_);
4fe87745 190 LOCK_CONTENDED(lock, _raw_write_trylock, _raw_write_lock);
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LT
191}
192
193EXPORT_SYMBOL(_write_lock);
194
195#else /* CONFIG_PREEMPT: */
196
197/*
198 * This could be a long-held lock. We both prepare to spin for a long
199 * time (making _this_ CPU preemptable if possible), and we also signal
200 * towards that other CPU that it should break the lock ASAP.
201 *
202 * (We do this in a function because inlining it would be excessive.)
203 */
204
205#define BUILD_LOCK_OPS(op, locktype) \
206void __lockfunc _##op##_lock(locktype##_t *lock) \
207{ \
1da177e4 208 for (;;) { \
ee25e96f 209 preempt_disable(); \
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210 if (likely(_raw_##op##_trylock(lock))) \
211 break; \
212 preempt_enable(); \
ee25e96f 213 \
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214 if (!(lock)->break_lock) \
215 (lock)->break_lock = 1; \
216 while (!op##_can_lock(lock) && (lock)->break_lock) \
ef6edc97 217 _raw_##op##_relax(&lock->raw_lock); \
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218 } \
219 (lock)->break_lock = 0; \
220} \
221 \
222EXPORT_SYMBOL(_##op##_lock); \
223 \
224unsigned long __lockfunc _##op##_lock_irqsave(locktype##_t *lock) \
225{ \
226 unsigned long flags; \
227 \
1da177e4 228 for (;;) { \
ee25e96f 229 preempt_disable(); \
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LT
230 local_irq_save(flags); \
231 if (likely(_raw_##op##_trylock(lock))) \
232 break; \
233 local_irq_restore(flags); \
1da177e4 234 preempt_enable(); \
ee25e96f 235 \
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236 if (!(lock)->break_lock) \
237 (lock)->break_lock = 1; \
238 while (!op##_can_lock(lock) && (lock)->break_lock) \
ef6edc97 239 _raw_##op##_relax(&lock->raw_lock); \
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240 } \
241 (lock)->break_lock = 0; \
242 return flags; \
243} \
244 \
245EXPORT_SYMBOL(_##op##_lock_irqsave); \
246 \
247void __lockfunc _##op##_lock_irq(locktype##_t *lock) \
248{ \
249 _##op##_lock_irqsave(lock); \
250} \
251 \
252EXPORT_SYMBOL(_##op##_lock_irq); \
253 \
254void __lockfunc _##op##_lock_bh(locktype##_t *lock) \
255{ \
256 unsigned long flags; \
257 \
258 /* */ \
259 /* Careful: we must exclude softirqs too, hence the */ \
260 /* irq-disabling. We use the generic preemption-aware */ \
261 /* function: */ \
262 /**/ \
263 flags = _##op##_lock_irqsave(lock); \
264 local_bh_disable(); \
265 local_irq_restore(flags); \
266} \
267 \
268EXPORT_SYMBOL(_##op##_lock_bh)
269
270/*
271 * Build preemption-friendly versions of the following
272 * lock-spinning functions:
273 *
274 * _[spin|read|write]_lock()
275 * _[spin|read|write]_lock_irq()
276 * _[spin|read|write]_lock_irqsave()
277 * _[spin|read|write]_lock_bh()
278 */
279BUILD_LOCK_OPS(spin, spinlock);
280BUILD_LOCK_OPS(read, rwlock);
281BUILD_LOCK_OPS(write, rwlock);
282
283#endif /* CONFIG_PREEMPT */
284
8a25d5de
IM
285#ifdef CONFIG_DEBUG_LOCK_ALLOC
286
287void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
288{
289 preempt_disable();
290 spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
4fe87745 291 LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
8a25d5de
IM
292}
293
294EXPORT_SYMBOL(_spin_lock_nested);
cfd3ef23
AV
295unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass)
296{
297 unsigned long flags;
298
299 local_irq_save(flags);
300 preempt_disable();
301 spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
302 /*
303 * On lockdep we dont want the hand-coded irq-enable of
304 * _raw_spin_lock_flags() code, because lockdep assumes
305 * that interrupts are not re-enabled during lock-acquire:
306 */
ca58abcb 307#ifdef CONFIG_LOCKDEP
4fe87745 308 LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
cfd3ef23
AV
309#else
310 _raw_spin_lock_flags(lock, &flags);
311#endif
312 return flags;
313}
314
315EXPORT_SYMBOL(_spin_lock_irqsave_nested);
8a25d5de
IM
316
317#endif
318
1da177e4
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319void __lockfunc _spin_unlock(spinlock_t *lock)
320{
8a25d5de 321 spin_release(&lock->dep_map, 1, _RET_IP_);
1da177e4
LT
322 _raw_spin_unlock(lock);
323 preempt_enable();
324}
325EXPORT_SYMBOL(_spin_unlock);
326
327void __lockfunc _write_unlock(rwlock_t *lock)
328{
8a25d5de 329 rwlock_release(&lock->dep_map, 1, _RET_IP_);
1da177e4
LT
330 _raw_write_unlock(lock);
331 preempt_enable();
332}
333EXPORT_SYMBOL(_write_unlock);
334
335void __lockfunc _read_unlock(rwlock_t *lock)
336{
8a25d5de 337 rwlock_release(&lock->dep_map, 1, _RET_IP_);
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LT
338 _raw_read_unlock(lock);
339 preempt_enable();
340}
341EXPORT_SYMBOL(_read_unlock);
342
343void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
344{
8a25d5de 345 spin_release(&lock->dep_map, 1, _RET_IP_);
1da177e4
LT
346 _raw_spin_unlock(lock);
347 local_irq_restore(flags);
348 preempt_enable();
349}
350EXPORT_SYMBOL(_spin_unlock_irqrestore);
351
352void __lockfunc _spin_unlock_irq(spinlock_t *lock)
353{
8a25d5de 354 spin_release(&lock->dep_map, 1, _RET_IP_);
1da177e4
LT
355 _raw_spin_unlock(lock);
356 local_irq_enable();
357 preempt_enable();
358}
359EXPORT_SYMBOL(_spin_unlock_irq);
360
361void __lockfunc _spin_unlock_bh(spinlock_t *lock)
362{
8a25d5de 363 spin_release(&lock->dep_map, 1, _RET_IP_);
1da177e4 364 _raw_spin_unlock(lock);
10f02d1c 365 preempt_enable_no_resched();
8a25d5de 366 local_bh_enable_ip((unsigned long)__builtin_return_address(0));
1da177e4
LT
367}
368EXPORT_SYMBOL(_spin_unlock_bh);
369
370void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
371{
8a25d5de 372 rwlock_release(&lock->dep_map, 1, _RET_IP_);
1da177e4
LT
373 _raw_read_unlock(lock);
374 local_irq_restore(flags);
375 preempt_enable();
376}
377EXPORT_SYMBOL(_read_unlock_irqrestore);
378
379void __lockfunc _read_unlock_irq(rwlock_t *lock)
380{
8a25d5de 381 rwlock_release(&lock->dep_map, 1, _RET_IP_);
1da177e4
LT
382 _raw_read_unlock(lock);
383 local_irq_enable();
384 preempt_enable();
385}
386EXPORT_SYMBOL(_read_unlock_irq);
387
388void __lockfunc _read_unlock_bh(rwlock_t *lock)
389{
8a25d5de 390 rwlock_release(&lock->dep_map, 1, _RET_IP_);
1da177e4 391 _raw_read_unlock(lock);
10f02d1c 392 preempt_enable_no_resched();
8a25d5de 393 local_bh_enable_ip((unsigned long)__builtin_return_address(0));
1da177e4
LT
394}
395EXPORT_SYMBOL(_read_unlock_bh);
396
397void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
398{
8a25d5de 399 rwlock_release(&lock->dep_map, 1, _RET_IP_);
1da177e4
LT
400 _raw_write_unlock(lock);
401 local_irq_restore(flags);
402 preempt_enable();
403}
404EXPORT_SYMBOL(_write_unlock_irqrestore);
405
406void __lockfunc _write_unlock_irq(rwlock_t *lock)
407{
8a25d5de 408 rwlock_release(&lock->dep_map, 1, _RET_IP_);
1da177e4
LT
409 _raw_write_unlock(lock);
410 local_irq_enable();
411 preempt_enable();
412}
413EXPORT_SYMBOL(_write_unlock_irq);
414
415void __lockfunc _write_unlock_bh(rwlock_t *lock)
416{
8a25d5de 417 rwlock_release(&lock->dep_map, 1, _RET_IP_);
1da177e4 418 _raw_write_unlock(lock);
10f02d1c 419 preempt_enable_no_resched();
8a25d5de 420 local_bh_enable_ip((unsigned long)__builtin_return_address(0));
1da177e4
LT
421}
422EXPORT_SYMBOL(_write_unlock_bh);
423
424int __lockfunc _spin_trylock_bh(spinlock_t *lock)
425{
426 local_bh_disable();
427 preempt_disable();
8a25d5de
IM
428 if (_raw_spin_trylock(lock)) {
429 spin_acquire(&lock->dep_map, 0, 1, _RET_IP_);
1da177e4 430 return 1;
8a25d5de 431 }
1da177e4 432
10f02d1c 433 preempt_enable_no_resched();
8a25d5de 434 local_bh_enable_ip((unsigned long)__builtin_return_address(0));
1da177e4
LT
435 return 0;
436}
437EXPORT_SYMBOL(_spin_trylock_bh);
438
439int in_lock_functions(unsigned long addr)
440{
441 /* Linker adds these: start and end of __lockfunc functions */
442 extern char __lock_text_start[], __lock_text_end[];
443
444 return addr >= (unsigned long)__lock_text_start
445 && addr < (unsigned long)__lock_text_end;
446}
447EXPORT_SYMBOL(in_lock_functions);