1 #ifndef __LINUX_SPINLOCK_H
2 #define __LINUX_SPINLOCK_H
3
4 /*
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.
47 */
48
49 #include <linux/typecheck.h>
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>
56 #include <linux/bottom_half.h>
57
58 #include <asm/system.h>
59
60 /*
61 * Must define these before including other files, inline functions need them
62 */
63 #define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
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
75 #define __lockfunc __attribute__((section(".spinlock.text")))
76
77 /*
78 * Pull the raw_spinlock_t and raw_rwlock_t definitions:
79 */
80 #include <linux/spinlock_types.h>
81
82 extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
83
84 /*
85 * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
86 */
87 #ifdef CONFIG_SMP
88 # include <asm/spinlock.h>
89 #else
90 # include <linux/spinlock_up.h>
91 #endif
92
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) \
97 do { \
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) \
112 do { \
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
121
122 #define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
123
124 #ifdef CONFIG_GENERIC_LOCKBREAK
125 #define spin_is_contended(lock) ((lock)->break_lock)
126 #else
127
128 #ifdef __raw_spin_is_contended
129 #define spin_is_contended(lock) __raw_spin_is_contended(&(lock)->raw_lock)
130 #else
131 #define spin_is_contended(lock) (((void)(lock), 0))
132 #endif /*__raw_spin_is_contended*/
133 #endif
134
135 /* The lock does not imply full memory barrier. */
136 #ifndef ARCH_HAS_SMP_MB_AFTER_LOCK
137 static inline void smp_mb__after_lock(void) { smp_mb(); }
138 #endif
139
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
146 /*
147 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
148 */
149 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
150 # include <linux/spinlock_api_smp.h>
151 #else
152 # include <linux/spinlock_api_up.h>
153 #endif
154
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);
160 extern void _raw_read_lock(rwlock_t *lock);
161 #define _raw_read_lock_flags(lock, flags) _raw_read_lock(lock)
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);
165 #define _raw_write_lock_flags(lock, flags) _raw_write_lock(lock)
166 extern int _raw_write_trylock(rwlock_t *lock);
167 extern void _raw_write_unlock(rwlock_t *lock);
168 #else
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))
172 # define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
173 # define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
174 # define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
175 # define _raw_read_lock_flags(lock, flags) \
176 __raw_read_lock_flags(&(lock)->raw_lock, *(flags))
177 # define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
178 # define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
179 # define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
180 # define _raw_write_lock_flags(lock, flags) \
181 __raw_write_lock_flags(&(lock)->raw_lock, *(flags))
182 # define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
183 # define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock)
184 #endif
185
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)
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 */
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))
197
198 #define spin_lock(lock) _spin_lock(lock)
199
200 #ifdef CONFIG_DEBUG_LOCK_ALLOC
201 # define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
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)
207 #else
208 # define spin_lock_nested(lock, subclass) _spin_lock(lock)
209 # define spin_lock_nest_lock(lock, nest_lock) _spin_lock(lock)
210 #endif
211
212 #define write_lock(lock) _write_lock(lock)
213 #define read_lock(lock) _read_lock(lock)
214
215 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
216
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)
232
233 #ifdef CONFIG_DEBUG_LOCK_ALLOC
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)
239 #else
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)
245 #endif
246
247 #else
248
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)
264 #define spin_lock_irqsave_nested(lock, flags, subclass) \
265 spin_lock_irqsave(lock, flags)
266
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
278 /*
279 * We inline the unlock functions in the nondebug case:
280 */
281 #if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || \
282 !defined(CONFIG_SMP)
283 # define spin_unlock(lock) _spin_unlock(lock)
284 # define read_unlock(lock) _read_unlock(lock)
285 # define write_unlock(lock) _write_unlock(lock)
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
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) \
297 do { \
298 __raw_spin_unlock(&(lock)->raw_lock); \
299 __release(lock); \
300 local_irq_enable(); \
301 } while (0)
302 # define read_unlock_irq(lock) \
303 do { \
304 __raw_read_unlock(&(lock)->raw_lock); \
305 __release(lock); \
306 local_irq_enable(); \
307 } while (0)
308 # define write_unlock_irq(lock) \
309 do { \
310 __raw_write_unlock(&(lock)->raw_lock); \
311 __release(lock); \
312 local_irq_enable(); \
313 } while (0)
314 #endif
315
316 #define spin_unlock_irqrestore(lock, flags) \
317 do { \
318 typecheck(unsigned long, flags); \
319 _spin_unlock_irqrestore(lock, flags); \
320 } while (0)
321 #define spin_unlock_bh(lock) _spin_unlock_bh(lock)
322
323 #define read_unlock_irqrestore(lock, flags) \
324 do { \
325 typecheck(unsigned long, flags); \
326 _read_unlock_irqrestore(lock, flags); \
327 } while (0)
328 #define read_unlock_bh(lock) _read_unlock_bh(lock)
329
330 #define write_unlock_irqrestore(lock, flags) \
331 do { \
332 typecheck(unsigned long, flags); \
333 _write_unlock_irqrestore(lock, flags); \
334 } while (0)
335 #define write_unlock_bh(lock) _write_unlock_bh(lock)
336
337 #define spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock))
338
339 #define spin_trylock_irq(lock) \
340 ({ \
341 local_irq_disable(); \
342 spin_trylock(lock) ? \
343 1 : ({ local_irq_enable(); 0; }); \
344 })
345
346 #define spin_trylock_irqsave(lock, flags) \
347 ({ \
348 local_irq_save(flags); \
349 spin_trylock(lock) ? \
350 1 : ({ local_irq_restore(flags); 0; }); \
351 })
352
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
360 /*
361 * Pull the atomic_t declaration:
362 * (asm-mips/atomic.h needs above definitions)
363 */
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
369 *
370 * Decrements @atomic by 1. If the result is 0, returns true and locks
371 * @lock. Returns false for all other cases.
372 */
373 extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
374 #define atomic_dec_and_lock(atomic, lock) \
375 __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
376
377 /**
378 * spin_can_lock - would spin_trylock() succeed?
379 * @lock: the spinlock in question.
380 */
381 #define spin_can_lock(lock) (!spin_is_locked(lock))
382
383 #endif /* __LINUX_SPINLOCK_H */
384
|
This page was automatically generated by the
LXR engine.
|