Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
[deliverable/linux.git] / include / linux / spinlock.h
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1da177e4
LT
1#ifndef __LINUX_SPINLOCK_H
2#define __LINUX_SPINLOCK_H
3
4/*
fb1c8f93
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5 * include/linux/spinlock.h - generic spinlock/rwlock declarations
6 *
7 * here's the role of the various spinlock/rwlock related include files:
8 *
9 * on SMP builds:
10 *
11 * asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
12 * initializers
13 *
14 * linux/spinlock_types.h:
15 * defines the generic type and initializers
16 *
17 * asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel
18 * implementations, mostly inline assembly code
19 *
20 * (also included on UP-debug builds:)
21 *
22 * linux/spinlock_api_smp.h:
23 * contains the prototypes for the _spin_*() APIs.
24 *
25 * linux/spinlock.h: builds the final spin_*() APIs.
26 *
27 * on UP builds:
28 *
29 * linux/spinlock_type_up.h:
30 * contains the generic, simplified UP spinlock type.
31 * (which is an empty structure on non-debug builds)
32 *
33 * linux/spinlock_types.h:
34 * defines the generic type and initializers
35 *
36 * linux/spinlock_up.h:
37 * contains the __raw_spin_*()/etc. version of UP
38 * builds. (which are NOPs on non-debug, non-preempt
39 * builds)
40 *
41 * (included on UP-non-debug builds:)
42 *
43 * linux/spinlock_api_up.h:
44 * builds the _spin_*() APIs.
45 *
46 * linux/spinlock.h: builds the final spin_*() APIs.
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47 */
48
3f307891 49#include <linux/typecheck.h>
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50#include <linux/preempt.h>
51#include <linux/linkage.h>
52#include <linux/compiler.h>
53#include <linux/thread_info.h>
54#include <linux/kernel.h>
55#include <linux/stringify.h>
676dcb8b 56#include <linux/bottom_half.h>
1da177e4 57
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58#include <asm/system.h>
59
60/*
61 * Must define these before including other files, inline functions need them
62 */
f83b5e32 63#define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
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64
65#define LOCK_SECTION_START(extra) \
66 ".subsection 1\n\t" \
67 extra \
68 ".ifndef " LOCK_SECTION_NAME "\n\t" \
69 LOCK_SECTION_NAME ":\n\t" \
70 ".endif\n"
71
72#define LOCK_SECTION_END \
73 ".previous\n\t"
74
ec701584 75#define __lockfunc __attribute__((section(".spinlock.text")))
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76
77/*
fb1c8f93 78 * Pull the raw_spinlock_t and raw_rwlock_t definitions:
1da177e4 79 */
fb1c8f93 80#include <linux/spinlock_types.h>
1da177e4 81
fb1c8f93 82extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
1da177e4 83
1da177e4 84/*
fb1c8f93 85 * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
1da177e4 86 */
8a25d5de 87#ifdef CONFIG_SMP
fb1c8f93 88# include <asm/spinlock.h>
1da177e4 89#else
fb1c8f93 90# include <linux/spinlock_up.h>
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91#endif
92
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93#ifdef CONFIG_DEBUG_SPINLOCK
94 extern void __spin_lock_init(spinlock_t *lock, const char *name,
95 struct lock_class_key *key);
96# define spin_lock_init(lock) \
97do { \
98 static struct lock_class_key __key; \
99 \
100 __spin_lock_init((lock), #lock, &__key); \
101} while (0)
102
103#else
104# define spin_lock_init(lock) \
105 do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
106#endif
107
108#ifdef CONFIG_DEBUG_SPINLOCK
109 extern void __rwlock_init(rwlock_t *lock, const char *name,
110 struct lock_class_key *key);
111# define rwlock_init(lock) \
112do { \
113 static struct lock_class_key __key; \
114 \
115 __rwlock_init((lock), #lock, &__key); \
116} while (0)
117#else
118# define rwlock_init(lock) \
119 do { *(lock) = RW_LOCK_UNLOCKED; } while (0)
120#endif
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121
122#define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
123
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NP
124#ifdef CONFIG_GENERIC_LOCKBREAK
125#define spin_is_contended(lock) ((lock)->break_lock)
126#else
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127
128#ifdef __raw_spin_is_contended
95c354fe 129#define spin_is_contended(lock) __raw_spin_is_contended(&(lock)->raw_lock)
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130#else
131#define spin_is_contended(lock) (((void)(lock), 0))
132#endif /*__raw_spin_is_contended*/
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133#endif
134
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135/* The lock does not imply full memory barrier. */
136#ifndef ARCH_HAS_SMP_MB_AFTER_LOCK
137static inline void smp_mb__after_lock(void) { smp_mb(); }
138#endif
139
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140/**
141 * spin_unlock_wait - wait until the spinlock gets unlocked
142 * @lock: the spinlock in question.
143 */
144#define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock)
145
1da177e4 146/*
fb1c8f93 147 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
1da177e4 148 */
fb1c8f93
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149#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
150# include <linux/spinlock_api_smp.h>
1da177e4 151#else
fb1c8f93 152# include <linux/spinlock_api_up.h>
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153#endif
154
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155#ifdef CONFIG_DEBUG_SPINLOCK
156 extern void _raw_spin_lock(spinlock_t *lock);
157#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
158 extern int _raw_spin_trylock(spinlock_t *lock);
159 extern void _raw_spin_unlock(spinlock_t *lock);
fb1c8f93 160 extern void _raw_read_lock(rwlock_t *lock);
f5f7eac4 161#define _raw_read_lock_flags(lock, flags) _raw_read_lock(lock)
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162 extern int _raw_read_trylock(rwlock_t *lock);
163 extern void _raw_read_unlock(rwlock_t *lock);
164 extern void _raw_write_lock(rwlock_t *lock);
f5f7eac4 165#define _raw_write_lock_flags(lock, flags) _raw_write_lock(lock)
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166 extern int _raw_write_trylock(rwlock_t *lock);
167 extern void _raw_write_unlock(rwlock_t *lock);
168#else
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169# define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock)
170# define _raw_spin_lock_flags(lock, flags) \
171 __raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
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172# define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
173# define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
fb1c8f93 174# define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
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RH
175# define _raw_read_lock_flags(lock, flags) \
176 __raw_read_lock_flags(&(lock)->raw_lock, *(flags))
fb1c8f93 177# define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
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178# define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
179# define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
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RH
180# define _raw_write_lock_flags(lock, flags) \
181 __raw_write_lock_flags(&(lock)->raw_lock, *(flags))
fb1c8f93 182# define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
8a25d5de 183# define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock)
fb1c8f93 184#endif
1da177e4 185
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IM
186#define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock)
187#define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock)
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188
189/*
190 * Define the various spin_lock and rw_lock methods. Note we define these
191 * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
192 * methods are defined as nops in the case they are not required.
193 */
dcc8e559
JT
194#define spin_trylock(lock) __cond_lock(lock, _spin_trylock(lock))
195#define read_trylock(lock) __cond_lock(lock, _read_trylock(lock))
196#define write_trylock(lock) __cond_lock(lock, _write_trylock(lock))
1da177e4 197
fb1c8f93 198#define spin_lock(lock) _spin_lock(lock)
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IM
199
200#ifdef CONFIG_DEBUG_LOCK_ALLOC
201# define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
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PZ
202# define spin_lock_nest_lock(lock, nest_lock) \
203 do { \
204 typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
205 _spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \
206 } while (0)
8a25d5de
IM
207#else
208# define spin_lock_nested(lock, subclass) _spin_lock(lock)
b7d39aff 209# define spin_lock_nest_lock(lock, nest_lock) _spin_lock(lock)
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210#endif
211
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212#define write_lock(lock) _write_lock(lock)
213#define read_lock(lock) _read_lock(lock)
1da177e4 214
fb1c8f93 215#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
b8e6ec86 216
3f307891
SR
217#define spin_lock_irqsave(lock, flags) \
218 do { \
219 typecheck(unsigned long, flags); \
220 flags = _spin_lock_irqsave(lock); \
221 } while (0)
222#define read_lock_irqsave(lock, flags) \
223 do { \
224 typecheck(unsigned long, flags); \
225 flags = _read_lock_irqsave(lock); \
226 } while (0)
227#define write_lock_irqsave(lock, flags) \
228 do { \
229 typecheck(unsigned long, flags); \
230 flags = _write_lock_irqsave(lock); \
231 } while (0)
cfd3ef23
AV
232
233#ifdef CONFIG_DEBUG_LOCK_ALLOC
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SR
234#define spin_lock_irqsave_nested(lock, flags, subclass) \
235 do { \
236 typecheck(unsigned long, flags); \
237 flags = _spin_lock_irqsave_nested(lock, subclass); \
238 } while (0)
cfd3ef23 239#else
3f307891
SR
240#define spin_lock_irqsave_nested(lock, flags, subclass) \
241 do { \
242 typecheck(unsigned long, flags); \
243 flags = _spin_lock_irqsave(lock); \
244 } while (0)
cfd3ef23
AV
245#endif
246
1da177e4 247#else
b8e6ec86 248
3f307891
SR
249#define spin_lock_irqsave(lock, flags) \
250 do { \
251 typecheck(unsigned long, flags); \
252 _spin_lock_irqsave(lock, flags); \
253 } while (0)
254#define read_lock_irqsave(lock, flags) \
255 do { \
256 typecheck(unsigned long, flags); \
257 _read_lock_irqsave(lock, flags); \
258 } while (0)
259#define write_lock_irqsave(lock, flags) \
260 do { \
261 typecheck(unsigned long, flags); \
262 _write_lock_irqsave(lock, flags); \
263 } while (0)
cfd3ef23
AV
264#define spin_lock_irqsave_nested(lock, flags, subclass) \
265 spin_lock_irqsave(lock, flags)
266
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267#endif
268
269#define spin_lock_irq(lock) _spin_lock_irq(lock)
270#define spin_lock_bh(lock) _spin_lock_bh(lock)
271
272#define read_lock_irq(lock) _read_lock_irq(lock)
273#define read_lock_bh(lock) _read_lock_bh(lock)
274
275#define write_lock_irq(lock) _write_lock_irq(lock)
276#define write_lock_bh(lock) _write_lock_bh(lock)
277
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IM
278/*
279 * We inline the unlock functions in the nondebug case:
280 */
8a25d5de
IM
281#if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || \
282 !defined(CONFIG_SMP)
bda98685
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283# define spin_unlock(lock) _spin_unlock(lock)
284# define read_unlock(lock) _read_unlock(lock)
285# define write_unlock(lock) _write_unlock(lock)
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IM
286# define spin_unlock_irq(lock) _spin_unlock_irq(lock)
287# define read_unlock_irq(lock) _read_unlock_irq(lock)
288# define write_unlock_irq(lock) _write_unlock_irq(lock)
289#else
c75fb88d
PR
290# define spin_unlock(lock) \
291 do {__raw_spin_unlock(&(lock)->raw_lock); __release(lock); } while (0)
292# define read_unlock(lock) \
293 do {__raw_read_unlock(&(lock)->raw_lock); __release(lock); } while (0)
294# define write_unlock(lock) \
295 do {__raw_write_unlock(&(lock)->raw_lock); __release(lock); } while (0)
296# define spin_unlock_irq(lock) \
297do { \
298 __raw_spin_unlock(&(lock)->raw_lock); \
299 __release(lock); \
300 local_irq_enable(); \
301} while (0)
302# define read_unlock_irq(lock) \
303do { \
304 __raw_read_unlock(&(lock)->raw_lock); \
305 __release(lock); \
306 local_irq_enable(); \
307} while (0)
308# define write_unlock_irq(lock) \
309do { \
310 __raw_write_unlock(&(lock)->raw_lock); \
311 __release(lock); \
312 local_irq_enable(); \
313} while (0)
bda98685 314#endif
1da177e4 315
3f307891
SR
316#define spin_unlock_irqrestore(lock, flags) \
317 do { \
318 typecheck(unsigned long, flags); \
319 _spin_unlock_irqrestore(lock, flags); \
320 } while (0)
1da177e4
LT
321#define spin_unlock_bh(lock) _spin_unlock_bh(lock)
322
3f307891
SR
323#define read_unlock_irqrestore(lock, flags) \
324 do { \
325 typecheck(unsigned long, flags); \
326 _read_unlock_irqrestore(lock, flags); \
327 } while (0)
fb1c8f93 328#define read_unlock_bh(lock) _read_unlock_bh(lock)
1da177e4 329
3f307891
SR
330#define write_unlock_irqrestore(lock, flags) \
331 do { \
332 typecheck(unsigned long, flags); \
333 _write_unlock_irqrestore(lock, flags); \
334 } while (0)
fb1c8f93 335#define write_unlock_bh(lock) _write_unlock_bh(lock)
1da177e4 336
dcc8e559 337#define spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock))
1da177e4
LT
338
339#define spin_trylock_irq(lock) \
340({ \
341 local_irq_disable(); \
303912e2 342 spin_trylock(lock) ? \
fb1c8f93 343 1 : ({ local_irq_enable(); 0; }); \
1da177e4
LT
344})
345
346#define spin_trylock_irqsave(lock, flags) \
347({ \
348 local_irq_save(flags); \
303912e2 349 spin_trylock(lock) ? \
fb1c8f93 350 1 : ({ local_irq_restore(flags); 0; }); \
1da177e4
LT
351})
352
e1f4a88c
SS
353#define write_trylock_irqsave(lock, flags) \
354({ \
355 local_irq_save(flags); \
356 write_trylock(lock) ? \
357 1 : ({ local_irq_restore(flags); 0; }); \
358})
359
1da177e4 360/*
fb1c8f93
IM
361 * Pull the atomic_t declaration:
362 * (asm-mips/atomic.h needs above definitions)
1da177e4 363 */
fb1c8f93
IM
364#include <asm/atomic.h>
365/**
366 * atomic_dec_and_lock - lock on reaching reference count zero
367 * @atomic: the atomic counter
368 * @lock: the spinlock in question
dc07e721
BF
369 *
370 * Decrements @atomic by 1. If the result is 0, returns true and locks
371 * @lock. Returns false for all other cases.
1da177e4 372 */
fb1c8f93
IM
373extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
374#define atomic_dec_and_lock(atomic, lock) \
dcc8e559 375 __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
1da177e4
LT
376
377/**
378 * spin_can_lock - would spin_trylock() succeed?
379 * @lock: the spinlock in question.
380 */
fb1c8f93 381#define spin_can_lock(lock) (!spin_is_locked(lock))
1da177e4
LT
382
383#endif /* __LINUX_SPINLOCK_H */
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