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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 | ||
1da177e4 LT |
49 | #include <linux/preempt.h> |
50 | #include <linux/linkage.h> | |
51 | #include <linux/compiler.h> | |
52 | #include <linux/thread_info.h> | |
53 | #include <linux/kernel.h> | |
54 | #include <linux/stringify.h> | |
676dcb8b | 55 | #include <linux/bottom_half.h> |
1da177e4 | 56 | |
1da177e4 LT |
57 | #include <asm/system.h> |
58 | ||
59 | /* | |
60 | * Must define these before including other files, inline functions need them | |
61 | */ | |
f83b5e32 | 62 | #define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME |
1da177e4 LT |
63 | |
64 | #define LOCK_SECTION_START(extra) \ | |
65 | ".subsection 1\n\t" \ | |
66 | extra \ | |
67 | ".ifndef " LOCK_SECTION_NAME "\n\t" \ | |
68 | LOCK_SECTION_NAME ":\n\t" \ | |
69 | ".endif\n" | |
70 | ||
71 | #define LOCK_SECTION_END \ | |
72 | ".previous\n\t" | |
73 | ||
74 | #define __lockfunc fastcall __attribute__((section(".spinlock.text"))) | |
75 | ||
76 | /* | |
fb1c8f93 | 77 | * Pull the raw_spinlock_t and raw_rwlock_t definitions: |
1da177e4 | 78 | */ |
fb1c8f93 | 79 | #include <linux/spinlock_types.h> |
1da177e4 | 80 | |
fb1c8f93 | 81 | extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock); |
1da177e4 | 82 | |
1da177e4 | 83 | /* |
fb1c8f93 | 84 | * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them): |
1da177e4 | 85 | */ |
8a25d5de | 86 | #ifdef CONFIG_SMP |
fb1c8f93 | 87 | # include <asm/spinlock.h> |
1da177e4 | 88 | #else |
fb1c8f93 | 89 | # include <linux/spinlock_up.h> |
1da177e4 LT |
90 | #endif |
91 | ||
8a25d5de IM |
92 | #ifdef CONFIG_DEBUG_SPINLOCK |
93 | extern void __spin_lock_init(spinlock_t *lock, const char *name, | |
94 | struct lock_class_key *key); | |
95 | # define spin_lock_init(lock) \ | |
96 | do { \ | |
97 | static struct lock_class_key __key; \ | |
98 | \ | |
99 | __spin_lock_init((lock), #lock, &__key); \ | |
100 | } while (0) | |
101 | ||
102 | #else | |
103 | # define spin_lock_init(lock) \ | |
104 | do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0) | |
105 | #endif | |
106 | ||
107 | #ifdef CONFIG_DEBUG_SPINLOCK | |
108 | extern void __rwlock_init(rwlock_t *lock, const char *name, | |
109 | struct lock_class_key *key); | |
110 | # define rwlock_init(lock) \ | |
111 | do { \ | |
112 | static struct lock_class_key __key; \ | |
113 | \ | |
114 | __rwlock_init((lock), #lock, &__key); \ | |
115 | } while (0) | |
116 | #else | |
117 | # define rwlock_init(lock) \ | |
118 | do { *(lock) = RW_LOCK_UNLOCKED; } while (0) | |
119 | #endif | |
fb1c8f93 IM |
120 | |
121 | #define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock) | |
122 | ||
95c354fe NP |
123 | #ifdef CONFIG_GENERIC_LOCKBREAK |
124 | #define spin_is_contended(lock) ((lock)->break_lock) | |
125 | #else | |
126 | #define spin_is_contended(lock) __raw_spin_is_contended(&(lock)->raw_lock) | |
127 | #endif | |
128 | ||
fb1c8f93 IM |
129 | /** |
130 | * spin_unlock_wait - wait until the spinlock gets unlocked | |
131 | * @lock: the spinlock in question. | |
132 | */ | |
133 | #define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock) | |
134 | ||
1da177e4 | 135 | /* |
fb1c8f93 | 136 | * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: |
1da177e4 | 137 | */ |
fb1c8f93 IM |
138 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
139 | # include <linux/spinlock_api_smp.h> | |
1da177e4 | 140 | #else |
fb1c8f93 | 141 | # include <linux/spinlock_api_up.h> |
1da177e4 LT |
142 | #endif |
143 | ||
fb1c8f93 IM |
144 | #ifdef CONFIG_DEBUG_SPINLOCK |
145 | extern void _raw_spin_lock(spinlock_t *lock); | |
146 | #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) | |
147 | extern int _raw_spin_trylock(spinlock_t *lock); | |
148 | extern void _raw_spin_unlock(spinlock_t *lock); | |
fb1c8f93 IM |
149 | extern void _raw_read_lock(rwlock_t *lock); |
150 | extern int _raw_read_trylock(rwlock_t *lock); | |
151 | extern void _raw_read_unlock(rwlock_t *lock); | |
152 | extern void _raw_write_lock(rwlock_t *lock); | |
153 | extern int _raw_write_trylock(rwlock_t *lock); | |
154 | extern void _raw_write_unlock(rwlock_t *lock); | |
155 | #else | |
fb1c8f93 IM |
156 | # define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock) |
157 | # define _raw_spin_lock_flags(lock, flags) \ | |
158 | __raw_spin_lock_flags(&(lock)->raw_lock, *(flags)) | |
8a25d5de IM |
159 | # define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock) |
160 | # define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock) | |
fb1c8f93 | 161 | # define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock) |
fb1c8f93 | 162 | # define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock) |
8a25d5de IM |
163 | # define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock) |
164 | # define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock) | |
fb1c8f93 | 165 | # define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock) |
8a25d5de | 166 | # define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock) |
fb1c8f93 | 167 | #endif |
1da177e4 | 168 | |
fb1c8f93 IM |
169 | #define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock) |
170 | #define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock) | |
1da177e4 LT |
171 | |
172 | /* | |
173 | * Define the various spin_lock and rw_lock methods. Note we define these | |
174 | * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various | |
175 | * methods are defined as nops in the case they are not required. | |
176 | */ | |
dcc8e559 JT |
177 | #define spin_trylock(lock) __cond_lock(lock, _spin_trylock(lock)) |
178 | #define read_trylock(lock) __cond_lock(lock, _read_trylock(lock)) | |
179 | #define write_trylock(lock) __cond_lock(lock, _write_trylock(lock)) | |
1da177e4 | 180 | |
fb1c8f93 | 181 | #define spin_lock(lock) _spin_lock(lock) |
8a25d5de IM |
182 | |
183 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
184 | # define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass) | |
185 | #else | |
186 | # define spin_lock_nested(lock, subclass) _spin_lock(lock) | |
187 | #endif | |
188 | ||
fb1c8f93 IM |
189 | #define write_lock(lock) _write_lock(lock) |
190 | #define read_lock(lock) _read_lock(lock) | |
1da177e4 | 191 | |
fb1c8f93 | 192 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
b8e6ec86 LT |
193 | |
194 | #define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock) | |
195 | #define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock) | |
196 | #define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock) | |
cfd3ef23 AV |
197 | |
198 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
b8e6ec86 LT |
199 | #define spin_lock_irqsave_nested(lock, flags, subclass) \ |
200 | flags = _spin_lock_irqsave_nested(lock, subclass) | |
cfd3ef23 | 201 | #else |
b8e6ec86 LT |
202 | #define spin_lock_irqsave_nested(lock, flags, subclass) \ |
203 | flags = _spin_lock_irqsave(lock) | |
cfd3ef23 AV |
204 | #endif |
205 | ||
1da177e4 | 206 | #else |
b8e6ec86 LT |
207 | |
208 | #define spin_lock_irqsave(lock, flags) _spin_lock_irqsave(lock, flags) | |
209 | #define read_lock_irqsave(lock, flags) _read_lock_irqsave(lock, flags) | |
210 | #define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags) | |
cfd3ef23 AV |
211 | #define spin_lock_irqsave_nested(lock, flags, subclass) \ |
212 | spin_lock_irqsave(lock, flags) | |
213 | ||
1da177e4 LT |
214 | #endif |
215 | ||
216 | #define spin_lock_irq(lock) _spin_lock_irq(lock) | |
217 | #define spin_lock_bh(lock) _spin_lock_bh(lock) | |
218 | ||
219 | #define read_lock_irq(lock) _read_lock_irq(lock) | |
220 | #define read_lock_bh(lock) _read_lock_bh(lock) | |
221 | ||
222 | #define write_lock_irq(lock) _write_lock_irq(lock) | |
223 | #define write_lock_bh(lock) _write_lock_bh(lock) | |
224 | ||
bda98685 IM |
225 | /* |
226 | * We inline the unlock functions in the nondebug case: | |
227 | */ | |
8a25d5de IM |
228 | #if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || \ |
229 | !defined(CONFIG_SMP) | |
bda98685 IM |
230 | # define spin_unlock(lock) _spin_unlock(lock) |
231 | # define read_unlock(lock) _read_unlock(lock) | |
232 | # define write_unlock(lock) _write_unlock(lock) | |
bda98685 IM |
233 | # define spin_unlock_irq(lock) _spin_unlock_irq(lock) |
234 | # define read_unlock_irq(lock) _read_unlock_irq(lock) | |
235 | # define write_unlock_irq(lock) _write_unlock_irq(lock) | |
236 | #else | |
c75fb88d PR |
237 | # define spin_unlock(lock) \ |
238 | do {__raw_spin_unlock(&(lock)->raw_lock); __release(lock); } while (0) | |
239 | # define read_unlock(lock) \ | |
240 | do {__raw_read_unlock(&(lock)->raw_lock); __release(lock); } while (0) | |
241 | # define write_unlock(lock) \ | |
242 | do {__raw_write_unlock(&(lock)->raw_lock); __release(lock); } while (0) | |
243 | # define spin_unlock_irq(lock) \ | |
244 | do { \ | |
245 | __raw_spin_unlock(&(lock)->raw_lock); \ | |
246 | __release(lock); \ | |
247 | local_irq_enable(); \ | |
248 | } while (0) | |
249 | # define read_unlock_irq(lock) \ | |
250 | do { \ | |
251 | __raw_read_unlock(&(lock)->raw_lock); \ | |
252 | __release(lock); \ | |
253 | local_irq_enable(); \ | |
254 | } while (0) | |
255 | # define write_unlock_irq(lock) \ | |
256 | do { \ | |
257 | __raw_write_unlock(&(lock)->raw_lock); \ | |
258 | __release(lock); \ | |
259 | local_irq_enable(); \ | |
260 | } while (0) | |
bda98685 | 261 | #endif |
1da177e4 | 262 | |
fb1c8f93 | 263 | #define spin_unlock_irqrestore(lock, flags) \ |
b8e6ec86 | 264 | _spin_unlock_irqrestore(lock, flags) |
1da177e4 LT |
265 | #define spin_unlock_bh(lock) _spin_unlock_bh(lock) |
266 | ||
fb1c8f93 | 267 | #define read_unlock_irqrestore(lock, flags) \ |
b8e6ec86 | 268 | _read_unlock_irqrestore(lock, flags) |
fb1c8f93 | 269 | #define read_unlock_bh(lock) _read_unlock_bh(lock) |
1da177e4 | 270 | |
fb1c8f93 | 271 | #define write_unlock_irqrestore(lock, flags) \ |
b8e6ec86 | 272 | _write_unlock_irqrestore(lock, flags) |
fb1c8f93 | 273 | #define write_unlock_bh(lock) _write_unlock_bh(lock) |
1da177e4 | 274 | |
dcc8e559 | 275 | #define spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock)) |
1da177e4 LT |
276 | |
277 | #define spin_trylock_irq(lock) \ | |
278 | ({ \ | |
279 | local_irq_disable(); \ | |
303912e2 | 280 | spin_trylock(lock) ? \ |
fb1c8f93 | 281 | 1 : ({ local_irq_enable(); 0; }); \ |
1da177e4 LT |
282 | }) |
283 | ||
284 | #define spin_trylock_irqsave(lock, flags) \ | |
285 | ({ \ | |
286 | local_irq_save(flags); \ | |
303912e2 | 287 | spin_trylock(lock) ? \ |
fb1c8f93 | 288 | 1 : ({ local_irq_restore(flags); 0; }); \ |
1da177e4 LT |
289 | }) |
290 | ||
e1f4a88c SS |
291 | #define write_trylock_irqsave(lock, flags) \ |
292 | ({ \ | |
293 | local_irq_save(flags); \ | |
294 | write_trylock(lock) ? \ | |
295 | 1 : ({ local_irq_restore(flags); 0; }); \ | |
296 | }) | |
297 | ||
e81ce1f7 HC |
298 | /* |
299 | * Locks two spinlocks l1 and l2. | |
300 | * l1_first indicates if spinlock l1 should be taken first. | |
301 | */ | |
302 | static inline void double_spin_lock(spinlock_t *l1, spinlock_t *l2, | |
303 | bool l1_first) | |
304 | __acquires(l1) | |
305 | __acquires(l2) | |
306 | { | |
307 | if (l1_first) { | |
308 | spin_lock(l1); | |
309 | spin_lock(l2); | |
310 | } else { | |
311 | spin_lock(l2); | |
312 | spin_lock(l1); | |
313 | } | |
314 | } | |
315 | ||
316 | /* | |
317 | * Unlocks two spinlocks l1 and l2. | |
318 | * l1_taken_first indicates if spinlock l1 was taken first and therefore | |
319 | * should be released after spinlock l2. | |
320 | */ | |
321 | static inline void double_spin_unlock(spinlock_t *l1, spinlock_t *l2, | |
322 | bool l1_taken_first) | |
323 | __releases(l1) | |
324 | __releases(l2) | |
325 | { | |
326 | if (l1_taken_first) { | |
327 | spin_unlock(l2); | |
328 | spin_unlock(l1); | |
329 | } else { | |
330 | spin_unlock(l1); | |
331 | spin_unlock(l2); | |
332 | } | |
333 | } | |
334 | ||
1da177e4 | 335 | /* |
fb1c8f93 IM |
336 | * Pull the atomic_t declaration: |
337 | * (asm-mips/atomic.h needs above definitions) | |
1da177e4 | 338 | */ |
fb1c8f93 IM |
339 | #include <asm/atomic.h> |
340 | /** | |
341 | * atomic_dec_and_lock - lock on reaching reference count zero | |
342 | * @atomic: the atomic counter | |
343 | * @lock: the spinlock in question | |
1da177e4 | 344 | */ |
fb1c8f93 IM |
345 | extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); |
346 | #define atomic_dec_and_lock(atomic, lock) \ | |
dcc8e559 | 347 | __cond_lock(lock, _atomic_dec_and_lock(atomic, lock)) |
1da177e4 LT |
348 | |
349 | /** | |
350 | * spin_can_lock - would spin_trylock() succeed? | |
351 | * @lock: the spinlock in question. | |
352 | */ | |
fb1c8f93 | 353 | #define spin_can_lock(lock) (!spin_is_locked(lock)) |
1da177e4 LT |
354 | |
355 | #endif /* __LINUX_SPINLOCK_H */ |