locking: Convert __raw_spin* functions to arch_spin*
[linux-2.6.git] / kernel / spinlock.c
1 /*
2  * Copyright (2004) Linus Torvalds
3  *
4  * Author: Zwane Mwaikambo <zwane@fsmlabs.com>
5  *
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)
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.
15  */
16
17 #include <linux/linkage.h>
18 #include <linux/preempt.h>
19 #include <linux/spinlock.h>
20 #include <linux/interrupt.h>
21 #include <linux/debug_locks.h>
22 #include <linux/module.h>
23
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
35 /*
36  * We build the __lock_function inlines here. They are too large for
37  * inlining all over the place, but here is only one user per function
38  * which embedds them into the calling _lock_function below.
39  *
40  * This could be a long-held lock. We both prepare to spin for a long
41  * time (making _this_ CPU preemptable if possible), and we also signal
42  * towards that other CPU that it should break the lock ASAP.
43  */
44 #define BUILD_LOCK_OPS(op, locktype)                                    \
45 void __lockfunc __##op##_lock(locktype##_t *lock)                       \
46 {                                                                       \
47         for (;;) {                                                      \
48                 preempt_disable();                                      \
49                 if (likely(_raw_##op##_trylock(lock)))                  \
50                         break;                                          \
51                 preempt_enable();                                       \
52                                                                         \
53                 if (!(lock)->break_lock)                                \
54                         (lock)->break_lock = 1;                         \
55                 while (!op##_can_lock(lock) && (lock)->break_lock)      \
56                         arch_##op##_relax(&lock->raw_lock);             \
57         }                                                               \
58         (lock)->break_lock = 0;                                         \
59 }                                                                       \
60                                                                         \
61 unsigned long __lockfunc __##op##_lock_irqsave(locktype##_t *lock)      \
62 {                                                                       \
63         unsigned long flags;                                            \
64                                                                         \
65         for (;;) {                                                      \
66                 preempt_disable();                                      \
67                 local_irq_save(flags);                                  \
68                 if (likely(_raw_##op##_trylock(lock)))                  \
69                         break;                                          \
70                 local_irq_restore(flags);                               \
71                 preempt_enable();                                       \
72                                                                         \
73                 if (!(lock)->break_lock)                                \
74                         (lock)->break_lock = 1;                         \
75                 while (!op##_can_lock(lock) && (lock)->break_lock)      \
76                         arch_##op##_relax(&lock->raw_lock);             \
77         }                                                               \
78         (lock)->break_lock = 0;                                         \
79         return flags;                                                   \
80 }                                                                       \
81                                                                         \
82 void __lockfunc __##op##_lock_irq(locktype##_t *lock)                   \
83 {                                                                       \
84         _##op##_lock_irqsave(lock);                                     \
85 }                                                                       \
86                                                                         \
87 void __lockfunc __##op##_lock_bh(locktype##_t *lock)                    \
88 {                                                                       \
89         unsigned long flags;                                            \
90                                                                         \
91         /*                                                      */      \
92         /* Careful: we must exclude softirqs too, hence the     */      \
93         /* irq-disabling. We use the generic preemption-aware   */      \
94         /* function:                                            */      \
95         /**/                                                            \
96         flags = _##op##_lock_irqsave(lock);                             \
97         local_bh_disable();                                             \
98         local_irq_restore(flags);                                       \
99 }                                                                       \
100
101 /*
102  * Build preemption-friendly versions of the following
103  * lock-spinning functions:
104  *
105  *         __[spin|read|write]_lock()
106  *         __[spin|read|write]_lock_irq()
107  *         __[spin|read|write]_lock_irqsave()
108  *         __[spin|read|write]_lock_bh()
109  */
110 BUILD_LOCK_OPS(spin, spinlock);
111 BUILD_LOCK_OPS(read, rwlock);
112 BUILD_LOCK_OPS(write, rwlock);
113
114 #endif
115
116 #ifndef CONFIG_INLINE_SPIN_TRYLOCK
117 int __lockfunc _spin_trylock(spinlock_t *lock)
118 {
119         return __spin_trylock(lock);
120 }
121 EXPORT_SYMBOL(_spin_trylock);
122 #endif
123
124 #ifndef CONFIG_INLINE_SPIN_TRYLOCK_BH
125 int __lockfunc _spin_trylock_bh(spinlock_t *lock)
126 {
127         return __spin_trylock_bh(lock);
128 }
129 EXPORT_SYMBOL(_spin_trylock_bh);
130 #endif
131
132 #ifndef CONFIG_INLINE_SPIN_LOCK
133 void __lockfunc _spin_lock(spinlock_t *lock)
134 {
135         __spin_lock(lock);
136 }
137 EXPORT_SYMBOL(_spin_lock);
138 #endif
139
140 #ifndef CONFIG_INLINE_SPIN_LOCK_IRQSAVE
141 unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)
142 {
143         return __spin_lock_irqsave(lock);
144 }
145 EXPORT_SYMBOL(_spin_lock_irqsave);
146 #endif
147
148 #ifndef CONFIG_INLINE_SPIN_LOCK_IRQ
149 void __lockfunc _spin_lock_irq(spinlock_t *lock)
150 {
151         __spin_lock_irq(lock);
152 }
153 EXPORT_SYMBOL(_spin_lock_irq);
154 #endif
155
156 #ifndef CONFIG_INLINE_SPIN_LOCK_BH
157 void __lockfunc _spin_lock_bh(spinlock_t *lock)
158 {
159         __spin_lock_bh(lock);
160 }
161 EXPORT_SYMBOL(_spin_lock_bh);
162 #endif
163
164 #ifndef CONFIG_INLINE_SPIN_UNLOCK
165 void __lockfunc _spin_unlock(spinlock_t *lock)
166 {
167         __spin_unlock(lock);
168 }
169 EXPORT_SYMBOL(_spin_unlock);
170 #endif
171
172 #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQRESTORE
173 void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
174 {
175         __spin_unlock_irqrestore(lock, flags);
176 }
177 EXPORT_SYMBOL(_spin_unlock_irqrestore);
178 #endif
179
180 #ifndef CONFIG_INLINE_SPIN_UNLOCK_IRQ
181 void __lockfunc _spin_unlock_irq(spinlock_t *lock)
182 {
183         __spin_unlock_irq(lock);
184 }
185 EXPORT_SYMBOL(_spin_unlock_irq);
186 #endif
187
188 #ifndef CONFIG_INLINE_SPIN_UNLOCK_BH
189 void __lockfunc _spin_unlock_bh(spinlock_t *lock)
190 {
191         __spin_unlock_bh(lock);
192 }
193 EXPORT_SYMBOL(_spin_unlock_bh);
194 #endif
195
196 #ifndef CONFIG_INLINE_READ_TRYLOCK
197 int __lockfunc _read_trylock(rwlock_t *lock)
198 {
199         return __read_trylock(lock);
200 }
201 EXPORT_SYMBOL(_read_trylock);
202 #endif
203
204 #ifndef CONFIG_INLINE_READ_LOCK
205 void __lockfunc _read_lock(rwlock_t *lock)
206 {
207         __read_lock(lock);
208 }
209 EXPORT_SYMBOL(_read_lock);
210 #endif
211
212 #ifndef CONFIG_INLINE_READ_LOCK_IRQSAVE
213 unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)
214 {
215         return __read_lock_irqsave(lock);
216 }
217 EXPORT_SYMBOL(_read_lock_irqsave);
218 #endif
219
220 #ifndef CONFIG_INLINE_READ_LOCK_IRQ
221 void __lockfunc _read_lock_irq(rwlock_t *lock)
222 {
223         __read_lock_irq(lock);
224 }
225 EXPORT_SYMBOL(_read_lock_irq);
226 #endif
227
228 #ifndef CONFIG_INLINE_READ_LOCK_BH
229 void __lockfunc _read_lock_bh(rwlock_t *lock)
230 {
231         __read_lock_bh(lock);
232 }
233 EXPORT_SYMBOL(_read_lock_bh);
234 #endif
235
236 #ifndef CONFIG_INLINE_READ_UNLOCK
237 void __lockfunc _read_unlock(rwlock_t *lock)
238 {
239         __read_unlock(lock);
240 }
241 EXPORT_SYMBOL(_read_unlock);
242 #endif
243
244 #ifndef CONFIG_INLINE_READ_UNLOCK_IRQRESTORE
245 void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
246 {
247         __read_unlock_irqrestore(lock, flags);
248 }
249 EXPORT_SYMBOL(_read_unlock_irqrestore);
250 #endif
251
252 #ifndef CONFIG_INLINE_READ_UNLOCK_IRQ
253 void __lockfunc _read_unlock_irq(rwlock_t *lock)
254 {
255         __read_unlock_irq(lock);
256 }
257 EXPORT_SYMBOL(_read_unlock_irq);
258 #endif
259
260 #ifndef CONFIG_INLINE_READ_UNLOCK_BH
261 void __lockfunc _read_unlock_bh(rwlock_t *lock)
262 {
263         __read_unlock_bh(lock);
264 }
265 EXPORT_SYMBOL(_read_unlock_bh);
266 #endif
267
268 #ifndef CONFIG_INLINE_WRITE_TRYLOCK
269 int __lockfunc _write_trylock(rwlock_t *lock)
270 {
271         return __write_trylock(lock);
272 }
273 EXPORT_SYMBOL(_write_trylock);
274 #endif
275
276 #ifndef CONFIG_INLINE_WRITE_LOCK
277 void __lockfunc _write_lock(rwlock_t *lock)
278 {
279         __write_lock(lock);
280 }
281 EXPORT_SYMBOL(_write_lock);
282 #endif
283
284 #ifndef CONFIG_INLINE_WRITE_LOCK_IRQSAVE
285 unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)
286 {
287         return __write_lock_irqsave(lock);
288 }
289 EXPORT_SYMBOL(_write_lock_irqsave);
290 #endif
291
292 #ifndef CONFIG_INLINE_WRITE_LOCK_IRQ
293 void __lockfunc _write_lock_irq(rwlock_t *lock)
294 {
295         __write_lock_irq(lock);
296 }
297 EXPORT_SYMBOL(_write_lock_irq);
298 #endif
299
300 #ifndef CONFIG_INLINE_WRITE_LOCK_BH
301 void __lockfunc _write_lock_bh(rwlock_t *lock)
302 {
303         __write_lock_bh(lock);
304 }
305 EXPORT_SYMBOL(_write_lock_bh);
306 #endif
307
308 #ifndef CONFIG_INLINE_WRITE_UNLOCK
309 void __lockfunc _write_unlock(rwlock_t *lock)
310 {
311         __write_unlock(lock);
312 }
313 EXPORT_SYMBOL(_write_unlock);
314 #endif
315
316 #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQRESTORE
317 void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)
318 {
319         __write_unlock_irqrestore(lock, flags);
320 }
321 EXPORT_SYMBOL(_write_unlock_irqrestore);
322 #endif
323
324 #ifndef CONFIG_INLINE_WRITE_UNLOCK_IRQ
325 void __lockfunc _write_unlock_irq(rwlock_t *lock)
326 {
327         __write_unlock_irq(lock);
328 }
329 EXPORT_SYMBOL(_write_unlock_irq);
330 #endif
331
332 #ifndef CONFIG_INLINE_WRITE_UNLOCK_BH
333 void __lockfunc _write_unlock_bh(rwlock_t *lock)
334 {
335         __write_unlock_bh(lock);
336 }
337 EXPORT_SYMBOL(_write_unlock_bh);
338 #endif
339
340 #ifdef CONFIG_DEBUG_LOCK_ALLOC
341
342 void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass)
343 {
344         preempt_disable();
345         spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
346         LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
347 }
348 EXPORT_SYMBOL(_spin_lock_nested);
349
350 unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock,
351                                                    int subclass)
352 {
353         unsigned long flags;
354
355         local_irq_save(flags);
356         preempt_disable();
357         spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
358         LOCK_CONTENDED_FLAGS(lock, _raw_spin_trylock, _raw_spin_lock,
359                                 _raw_spin_lock_flags, &flags);
360         return flags;
361 }
362 EXPORT_SYMBOL(_spin_lock_irqsave_nested);
363
364 void __lockfunc _spin_lock_nest_lock(spinlock_t *lock,
365                                      struct lockdep_map *nest_lock)
366 {
367         preempt_disable();
368         spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_);
369         LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
370 }
371 EXPORT_SYMBOL(_spin_lock_nest_lock);
372
373 #endif
374
375 notrace int in_lock_functions(unsigned long addr)
376 {
377         /* Linker adds these: start and end of __lockfunc functions */
378         extern char __lock_text_start[], __lock_text_end[];
379
380         return addr >= (unsigned long)__lock_text_start
381         && addr < (unsigned long)__lock_text_end;
382 }
383 EXPORT_SYMBOL(in_lock_functions);