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1da177e4 LT |
1 | #ifndef __LINUX_SPINLOCK_H |
2 | #define __LINUX_SPINLOCK_H | |
3 | ||
4 | /* | |
fb1c8f93 IM |
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. | |
1da177e4 LT |
47 | */ |
48 | ||
3f307891 | 49 | #include <linux/typecheck.h> |
1da177e4 LT |
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 | |
1da177e4 LT |
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 |
1da177e4 LT |
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"))) |
1da177e4 LT |
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 | 82 | extern 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> |
1da177e4 LT |
91 | #endif |
92 | ||
8a25d5de IM |
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 | |
fb1c8f93 IM |
121 | |
122 | #define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock) | |
123 | ||
95c354fe NP |
124 | #ifdef CONFIG_GENERIC_LOCKBREAK |
125 | #define spin_is_contended(lock) ((lock)->break_lock) | |
126 | #else | |
a5ef7ca0 KM |
127 | |
128 | #ifdef __raw_spin_is_contended | |
95c354fe | 129 | #define spin_is_contended(lock) __raw_spin_is_contended(&(lock)->raw_lock) |
a5ef7ca0 KM |
130 | #else |
131 | #define spin_is_contended(lock) (((void)(lock), 0)) | |
132 | #endif /*__raw_spin_is_contended*/ | |
95c354fe NP |
133 | #endif |
134 | ||
ad462769 JO |
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 | ||
fb1c8f93 IM |
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 | ||
fb1c8f93 IM |
146 | #ifdef CONFIG_DEBUG_SPINLOCK |
147 | extern void _raw_spin_lock(spinlock_t *lock); | |
148 | #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) | |
149 | extern int _raw_spin_trylock(spinlock_t *lock); | |
150 | extern void _raw_spin_unlock(spinlock_t *lock); | |
fb1c8f93 | 151 | extern void _raw_read_lock(rwlock_t *lock); |
f5f7eac4 | 152 | #define _raw_read_lock_flags(lock, flags) _raw_read_lock(lock) |
fb1c8f93 IM |
153 | extern int _raw_read_trylock(rwlock_t *lock); |
154 | extern void _raw_read_unlock(rwlock_t *lock); | |
155 | extern void _raw_write_lock(rwlock_t *lock); | |
f5f7eac4 | 156 | #define _raw_write_lock_flags(lock, flags) _raw_write_lock(lock) |
fb1c8f93 IM |
157 | extern int _raw_write_trylock(rwlock_t *lock); |
158 | extern void _raw_write_unlock(rwlock_t *lock); | |
159 | #else | |
fb1c8f93 IM |
160 | # define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock) |
161 | # define _raw_spin_lock_flags(lock, flags) \ | |
162 | __raw_spin_lock_flags(&(lock)->raw_lock, *(flags)) | |
8a25d5de IM |
163 | # define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock) |
164 | # define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock) | |
fb1c8f93 | 165 | # define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock) |
f5f7eac4 RH |
166 | # define _raw_read_lock_flags(lock, flags) \ |
167 | __raw_read_lock_flags(&(lock)->raw_lock, *(flags)) | |
fb1c8f93 | 168 | # define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock) |
8a25d5de IM |
169 | # define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock) |
170 | # define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock) | |
f5f7eac4 RH |
171 | # define _raw_write_lock_flags(lock, flags) \ |
172 | __raw_write_lock_flags(&(lock)->raw_lock, *(flags)) | |
fb1c8f93 | 173 | # define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock) |
8a25d5de | 174 | # define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock) |
fb1c8f93 | 175 | #endif |
1da177e4 | 176 | |
fb1c8f93 IM |
177 | #define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock) |
178 | #define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock) | |
1da177e4 LT |
179 | |
180 | /* | |
181 | * Define the various spin_lock and rw_lock methods. Note we define these | |
182 | * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various | |
183 | * methods are defined as nops in the case they are not required. | |
184 | */ | |
dcc8e559 JT |
185 | #define spin_trylock(lock) __cond_lock(lock, _spin_trylock(lock)) |
186 | #define read_trylock(lock) __cond_lock(lock, _read_trylock(lock)) | |
187 | #define write_trylock(lock) __cond_lock(lock, _write_trylock(lock)) | |
1da177e4 | 188 | |
fb1c8f93 | 189 | #define spin_lock(lock) _spin_lock(lock) |
8a25d5de IM |
190 | |
191 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
192 | # define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass) | |
b7d39aff PZ |
193 | # define spin_lock_nest_lock(lock, nest_lock) \ |
194 | do { \ | |
195 | typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\ | |
196 | _spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \ | |
197 | } while (0) | |
8a25d5de IM |
198 | #else |
199 | # define spin_lock_nested(lock, subclass) _spin_lock(lock) | |
b7d39aff | 200 | # define spin_lock_nest_lock(lock, nest_lock) _spin_lock(lock) |
8a25d5de IM |
201 | #endif |
202 | ||
fb1c8f93 IM |
203 | #define write_lock(lock) _write_lock(lock) |
204 | #define read_lock(lock) _read_lock(lock) | |
1da177e4 | 205 | |
fb1c8f93 | 206 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
b8e6ec86 | 207 | |
3f307891 SR |
208 | #define spin_lock_irqsave(lock, flags) \ |
209 | do { \ | |
210 | typecheck(unsigned long, flags); \ | |
211 | flags = _spin_lock_irqsave(lock); \ | |
212 | } while (0) | |
213 | #define read_lock_irqsave(lock, flags) \ | |
214 | do { \ | |
215 | typecheck(unsigned long, flags); \ | |
216 | flags = _read_lock_irqsave(lock); \ | |
217 | } while (0) | |
218 | #define write_lock_irqsave(lock, flags) \ | |
219 | do { \ | |
220 | typecheck(unsigned long, flags); \ | |
221 | flags = _write_lock_irqsave(lock); \ | |
222 | } while (0) | |
cfd3ef23 AV |
223 | |
224 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
3f307891 SR |
225 | #define spin_lock_irqsave_nested(lock, flags, subclass) \ |
226 | do { \ | |
227 | typecheck(unsigned long, flags); \ | |
228 | flags = _spin_lock_irqsave_nested(lock, subclass); \ | |
229 | } while (0) | |
cfd3ef23 | 230 | #else |
3f307891 SR |
231 | #define spin_lock_irqsave_nested(lock, flags, subclass) \ |
232 | do { \ | |
233 | typecheck(unsigned long, flags); \ | |
234 | flags = _spin_lock_irqsave(lock); \ | |
235 | } while (0) | |
cfd3ef23 AV |
236 | #endif |
237 | ||
1da177e4 | 238 | #else |
b8e6ec86 | 239 | |
3f307891 SR |
240 | #define spin_lock_irqsave(lock, flags) \ |
241 | do { \ | |
242 | typecheck(unsigned long, flags); \ | |
243 | _spin_lock_irqsave(lock, flags); \ | |
244 | } while (0) | |
245 | #define read_lock_irqsave(lock, flags) \ | |
246 | do { \ | |
247 | typecheck(unsigned long, flags); \ | |
248 | _read_lock_irqsave(lock, flags); \ | |
249 | } while (0) | |
250 | #define write_lock_irqsave(lock, flags) \ | |
251 | do { \ | |
252 | typecheck(unsigned long, flags); \ | |
253 | _write_lock_irqsave(lock, flags); \ | |
254 | } while (0) | |
cfd3ef23 AV |
255 | #define spin_lock_irqsave_nested(lock, flags, subclass) \ |
256 | spin_lock_irqsave(lock, flags) | |
257 | ||
1da177e4 LT |
258 | #endif |
259 | ||
260 | #define spin_lock_irq(lock) _spin_lock_irq(lock) | |
261 | #define spin_lock_bh(lock) _spin_lock_bh(lock) | |
1da177e4 LT |
262 | #define read_lock_irq(lock) _read_lock_irq(lock) |
263 | #define read_lock_bh(lock) _read_lock_bh(lock) | |
1da177e4 LT |
264 | #define write_lock_irq(lock) _write_lock_irq(lock) |
265 | #define write_lock_bh(lock) _write_lock_bh(lock) | |
bb7bed08 HC |
266 | #define spin_unlock(lock) _spin_unlock(lock) |
267 | #define read_unlock(lock) _read_unlock(lock) | |
268 | #define write_unlock(lock) _write_unlock(lock) | |
269 | #define spin_unlock_irq(lock) _spin_unlock_irq(lock) | |
270 | #define read_unlock_irq(lock) _read_unlock_irq(lock) | |
271 | #define write_unlock_irq(lock) _write_unlock_irq(lock) | |
1da177e4 | 272 | |
3f307891 SR |
273 | #define spin_unlock_irqrestore(lock, flags) \ |
274 | do { \ | |
275 | typecheck(unsigned long, flags); \ | |
276 | _spin_unlock_irqrestore(lock, flags); \ | |
277 | } while (0) | |
1da177e4 LT |
278 | #define spin_unlock_bh(lock) _spin_unlock_bh(lock) |
279 | ||
3f307891 SR |
280 | #define read_unlock_irqrestore(lock, flags) \ |
281 | do { \ | |
282 | typecheck(unsigned long, flags); \ | |
283 | _read_unlock_irqrestore(lock, flags); \ | |
284 | } while (0) | |
fb1c8f93 | 285 | #define read_unlock_bh(lock) _read_unlock_bh(lock) |
1da177e4 | 286 | |
3f307891 SR |
287 | #define write_unlock_irqrestore(lock, flags) \ |
288 | do { \ | |
289 | typecheck(unsigned long, flags); \ | |
290 | _write_unlock_irqrestore(lock, flags); \ | |
291 | } while (0) | |
fb1c8f93 | 292 | #define write_unlock_bh(lock) _write_unlock_bh(lock) |
1da177e4 | 293 | |
dcc8e559 | 294 | #define spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock)) |
1da177e4 LT |
295 | |
296 | #define spin_trylock_irq(lock) \ | |
297 | ({ \ | |
298 | local_irq_disable(); \ | |
303912e2 | 299 | spin_trylock(lock) ? \ |
fb1c8f93 | 300 | 1 : ({ local_irq_enable(); 0; }); \ |
1da177e4 LT |
301 | }) |
302 | ||
303 | #define spin_trylock_irqsave(lock, flags) \ | |
304 | ({ \ | |
305 | local_irq_save(flags); \ | |
303912e2 | 306 | spin_trylock(lock) ? \ |
fb1c8f93 | 307 | 1 : ({ local_irq_restore(flags); 0; }); \ |
1da177e4 LT |
308 | }) |
309 | ||
e1f4a88c SS |
310 | #define write_trylock_irqsave(lock, flags) \ |
311 | ({ \ | |
312 | local_irq_save(flags); \ | |
313 | write_trylock(lock) ? \ | |
314 | 1 : ({ local_irq_restore(flags); 0; }); \ | |
315 | }) | |
316 | ||
1da177e4 | 317 | /* |
fb1c8f93 IM |
318 | * Pull the atomic_t declaration: |
319 | * (asm-mips/atomic.h needs above definitions) | |
1da177e4 | 320 | */ |
fb1c8f93 IM |
321 | #include <asm/atomic.h> |
322 | /** | |
323 | * atomic_dec_and_lock - lock on reaching reference count zero | |
324 | * @atomic: the atomic counter | |
325 | * @lock: the spinlock in question | |
dc07e721 BF |
326 | * |
327 | * Decrements @atomic by 1. If the result is 0, returns true and locks | |
328 | * @lock. Returns false for all other cases. | |
1da177e4 | 329 | */ |
fb1c8f93 IM |
330 | extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); |
331 | #define atomic_dec_and_lock(atomic, lock) \ | |
dcc8e559 | 332 | __cond_lock(lock, _atomic_dec_and_lock(atomic, lock)) |
1da177e4 LT |
333 | |
334 | /** | |
335 | * spin_can_lock - would spin_trylock() succeed? | |
336 | * @lock: the spinlock in question. | |
337 | */ | |
fb1c8f93 | 338 | #define spin_can_lock(lock) (!spin_is_locked(lock)) |
1da177e4 | 339 | |
69d0ee73 HC |
340 | /* |
341 | * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: | |
342 | */ | |
343 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) | |
344 | # include <linux/spinlock_api_smp.h> | |
345 | #else | |
346 | # include <linux/spinlock_api_up.h> | |
347 | #endif | |
348 | ||
1da177e4 | 349 | #endif /* __LINUX_SPINLOCK_H */ |