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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 | * | |
fb3a6bbc | 11 | * asm/spinlock_types.h: contains the arch_spinlock_t/arch_rwlock_t and the |
fb1c8f93 IM |
12 | * initializers |
13 | * | |
14 | * linux/spinlock_types.h: | |
15 | * defines the generic type and initializers | |
16 | * | |
0199c4e6 | 17 | * asm/spinlock.h: contains the arch_spin_*()/etc. lowlevel |
fb1c8f93 IM |
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: | |
0199c4e6 | 37 | * contains the arch_spin_*()/etc. version of UP |
fb1c8f93 IM |
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> | |
df9ee292 | 53 | #include <linux/irqflags.h> |
1da177e4 LT |
54 | #include <linux/thread_info.h> |
55 | #include <linux/kernel.h> | |
56 | #include <linux/stringify.h> | |
676dcb8b | 57 | #include <linux/bottom_half.h> |
96f951ed | 58 | #include <asm/barrier.h> |
1da177e4 | 59 | |
1da177e4 LT |
60 | |
61 | /* | |
62 | * Must define these before including other files, inline functions need them | |
63 | */ | |
75ddb0e8 | 64 | #define LOCK_SECTION_NAME ".text..lock."KBUILD_BASENAME |
1da177e4 LT |
65 | |
66 | #define LOCK_SECTION_START(extra) \ | |
67 | ".subsection 1\n\t" \ | |
68 | extra \ | |
69 | ".ifndef " LOCK_SECTION_NAME "\n\t" \ | |
70 | LOCK_SECTION_NAME ":\n\t" \ | |
71 | ".endif\n" | |
72 | ||
73 | #define LOCK_SECTION_END \ | |
74 | ".previous\n\t" | |
75 | ||
ec701584 | 76 | #define __lockfunc __attribute__((section(".spinlock.text"))) |
1da177e4 LT |
77 | |
78 | /* | |
fb3a6bbc | 79 | * Pull the arch_spinlock_t and arch_rwlock_t definitions: |
1da177e4 | 80 | */ |
fb1c8f93 | 81 | #include <linux/spinlock_types.h> |
1da177e4 | 82 | |
1da177e4 | 83 | /* |
25985edc | 84 | * Pull the arch_spin*() functions/declarations (UP-nondebug doesn't 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 | 92 | #ifdef CONFIG_DEBUG_SPINLOCK |
c2f21ce2 TG |
93 | extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name, |
94 | struct lock_class_key *key); | |
95 | # define raw_spin_lock_init(lock) \ | |
8a25d5de IM |
96 | do { \ |
97 | static struct lock_class_key __key; \ | |
98 | \ | |
c2f21ce2 | 99 | __raw_spin_lock_init((lock), #lock, &__key); \ |
8a25d5de IM |
100 | } while (0) |
101 | ||
102 | #else | |
c2f21ce2 TG |
103 | # define raw_spin_lock_init(lock) \ |
104 | do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0) | |
8a25d5de IM |
105 | #endif |
106 | ||
c2f21ce2 | 107 | #define raw_spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock) |
fb1c8f93 | 108 | |
95c354fe | 109 | #ifdef CONFIG_GENERIC_LOCKBREAK |
c2f21ce2 | 110 | #define raw_spin_is_contended(lock) ((lock)->break_lock) |
95c354fe | 111 | #else |
a5ef7ca0 | 112 | |
0199c4e6 | 113 | #ifdef arch_spin_is_contended |
c2f21ce2 | 114 | #define raw_spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock) |
a5ef7ca0 | 115 | #else |
c2f21ce2 | 116 | #define raw_spin_is_contended(lock) (((void)(lock), 0)) |
0199c4e6 | 117 | #endif /*arch_spin_is_contended*/ |
95c354fe NP |
118 | #endif |
119 | ||
e0acd0a6 ON |
120 | /* |
121 | * Despite its name it doesn't necessarily has to be a full barrier. | |
122 | * It should only guarantee that a STORE before the critical section | |
123 | * can not be reordered with a LOAD inside this section. | |
124 | * spin_lock() is the one-way barrier, this LOAD can not escape out | |
125 | * of the region. So the default implementation simply ensures that | |
126 | * a STORE can not move into the critical section, smp_wmb() should | |
127 | * serialize it with another STORE done by spin_lock(). | |
128 | */ | |
129 | #ifndef smp_mb__before_spinlock | |
130 | #define smp_mb__before_spinlock() smp_wmb() | |
ad462769 JO |
131 | #endif |
132 | ||
01352fb8 PM |
133 | /* |
134 | * Place this after a lock-acquisition primitive to guarantee that | |
135 | * an UNLOCK+LOCK pair act as a full barrier. This guarantee applies | |
136 | * if the UNLOCK and LOCK are executed by the same CPU or if the | |
137 | * UNLOCK and LOCK operate on the same lock variable. | |
138 | */ | |
139 | #ifndef smp_mb__after_unlock_lock | |
140 | #define smp_mb__after_unlock_lock() do { } while (0) | |
141 | #endif | |
142 | ||
fb1c8f93 | 143 | /** |
c2f21ce2 | 144 | * raw_spin_unlock_wait - wait until the spinlock gets unlocked |
fb1c8f93 IM |
145 | * @lock: the spinlock in question. |
146 | */ | |
c2f21ce2 | 147 | #define raw_spin_unlock_wait(lock) arch_spin_unlock_wait(&(lock)->raw_lock) |
fb1c8f93 | 148 | |
fb1c8f93 | 149 | #ifdef CONFIG_DEBUG_SPINLOCK |
b97c4bc1 | 150 | extern void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock); |
9828ea9d TG |
151 | #define do_raw_spin_lock_flags(lock, flags) do_raw_spin_lock(lock) |
152 | extern int do_raw_spin_trylock(raw_spinlock_t *lock); | |
b97c4bc1 | 153 | extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock); |
fb1c8f93 | 154 | #else |
b97c4bc1 | 155 | static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock) |
c2f21ce2 | 156 | { |
b97c4bc1 | 157 | __acquire(lock); |
c2f21ce2 TG |
158 | arch_spin_lock(&lock->raw_lock); |
159 | } | |
160 | ||
161 | static inline void | |
b97c4bc1 | 162 | do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lock) |
c2f21ce2 | 163 | { |
b97c4bc1 | 164 | __acquire(lock); |
c2f21ce2 TG |
165 | arch_spin_lock_flags(&lock->raw_lock, *flags); |
166 | } | |
167 | ||
9828ea9d | 168 | static inline int do_raw_spin_trylock(raw_spinlock_t *lock) |
c2f21ce2 TG |
169 | { |
170 | return arch_spin_trylock(&(lock)->raw_lock); | |
171 | } | |
172 | ||
b97c4bc1 | 173 | static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) |
c2f21ce2 TG |
174 | { |
175 | arch_spin_unlock(&lock->raw_lock); | |
b97c4bc1 | 176 | __release(lock); |
c2f21ce2 | 177 | } |
fb1c8f93 | 178 | #endif |
1da177e4 | 179 | |
1da177e4 | 180 | /* |
ef12f109 TG |
181 | * Define the various spin_lock methods. Note we define these |
182 | * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The | |
183 | * various methods are defined as nops in the case they are not | |
184 | * required. | |
1da177e4 | 185 | */ |
9c1721aa | 186 | #define raw_spin_trylock(lock) __cond_lock(lock, _raw_spin_trylock(lock)) |
1da177e4 | 187 | |
9c1721aa | 188 | #define raw_spin_lock(lock) _raw_spin_lock(lock) |
8a25d5de IM |
189 | |
190 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
9c1721aa TG |
191 | # define raw_spin_lock_nested(lock, subclass) \ |
192 | _raw_spin_lock_nested(lock, subclass) | |
193 | ||
c2f21ce2 | 194 | # define raw_spin_lock_nest_lock(lock, nest_lock) \ |
b7d39aff PZ |
195 | do { \ |
196 | typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\ | |
9c1721aa | 197 | _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \ |
b7d39aff | 198 | } while (0) |
8a25d5de | 199 | #else |
4999201a BVA |
200 | /* |
201 | * Always evaluate the 'subclass' argument to avoid that the compiler | |
202 | * warns about set-but-not-used variables when building with | |
203 | * CONFIG_DEBUG_LOCK_ALLOC=n and with W=1. | |
204 | */ | |
205 | # define raw_spin_lock_nested(lock, subclass) \ | |
206 | _raw_spin_lock(((void)(subclass), (lock))) | |
9c1721aa | 207 | # define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock) |
8a25d5de IM |
208 | #endif |
209 | ||
fb1c8f93 | 210 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) |
b8e6ec86 | 211 | |
c2f21ce2 | 212 | #define raw_spin_lock_irqsave(lock, flags) \ |
3f307891 SR |
213 | do { \ |
214 | typecheck(unsigned long, flags); \ | |
9c1721aa | 215 | flags = _raw_spin_lock_irqsave(lock); \ |
3f307891 | 216 | } while (0) |
cfd3ef23 AV |
217 | |
218 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
c2f21ce2 | 219 | #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ |
3f307891 SR |
220 | do { \ |
221 | typecheck(unsigned long, flags); \ | |
9c1721aa | 222 | flags = _raw_spin_lock_irqsave_nested(lock, subclass); \ |
3f307891 | 223 | } while (0) |
cfd3ef23 | 224 | #else |
c2f21ce2 | 225 | #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ |
3f307891 SR |
226 | do { \ |
227 | typecheck(unsigned long, flags); \ | |
9c1721aa | 228 | flags = _raw_spin_lock_irqsave(lock); \ |
3f307891 | 229 | } while (0) |
cfd3ef23 AV |
230 | #endif |
231 | ||
1da177e4 | 232 | #else |
b8e6ec86 | 233 | |
c2f21ce2 | 234 | #define raw_spin_lock_irqsave(lock, flags) \ |
3f307891 SR |
235 | do { \ |
236 | typecheck(unsigned long, flags); \ | |
9c1721aa | 237 | _raw_spin_lock_irqsave(lock, flags); \ |
3f307891 | 238 | } while (0) |
ef12f109 | 239 | |
c2f21ce2 TG |
240 | #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ |
241 | raw_spin_lock_irqsave(lock, flags) | |
cfd3ef23 | 242 | |
1da177e4 LT |
243 | #endif |
244 | ||
9c1721aa TG |
245 | #define raw_spin_lock_irq(lock) _raw_spin_lock_irq(lock) |
246 | #define raw_spin_lock_bh(lock) _raw_spin_lock_bh(lock) | |
247 | #define raw_spin_unlock(lock) _raw_spin_unlock(lock) | |
248 | #define raw_spin_unlock_irq(lock) _raw_spin_unlock_irq(lock) | |
1da177e4 | 249 | |
c2f21ce2 TG |
250 | #define raw_spin_unlock_irqrestore(lock, flags) \ |
251 | do { \ | |
252 | typecheck(unsigned long, flags); \ | |
9c1721aa | 253 | _raw_spin_unlock_irqrestore(lock, flags); \ |
3f307891 | 254 | } while (0) |
9c1721aa | 255 | #define raw_spin_unlock_bh(lock) _raw_spin_unlock_bh(lock) |
1da177e4 | 256 | |
9c1721aa TG |
257 | #define raw_spin_trylock_bh(lock) \ |
258 | __cond_lock(lock, _raw_spin_trylock_bh(lock)) | |
1da177e4 | 259 | |
c2f21ce2 | 260 | #define raw_spin_trylock_irq(lock) \ |
1da177e4 LT |
261 | ({ \ |
262 | local_irq_disable(); \ | |
c2f21ce2 | 263 | raw_spin_trylock(lock) ? \ |
fb1c8f93 | 264 | 1 : ({ local_irq_enable(); 0; }); \ |
1da177e4 LT |
265 | }) |
266 | ||
c2f21ce2 | 267 | #define raw_spin_trylock_irqsave(lock, flags) \ |
1da177e4 LT |
268 | ({ \ |
269 | local_irq_save(flags); \ | |
c2f21ce2 | 270 | raw_spin_trylock(lock) ? \ |
fb1c8f93 | 271 | 1 : ({ local_irq_restore(flags); 0; }); \ |
1da177e4 LT |
272 | }) |
273 | ||
c2f21ce2 TG |
274 | /** |
275 | * raw_spin_can_lock - would raw_spin_trylock() succeed? | |
276 | * @lock: the spinlock in question. | |
277 | */ | |
278 | #define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock)) | |
279 | ||
280 | /* Include rwlock functions */ | |
281 | #include <linux/rwlock.h> | |
282 | ||
283 | /* | |
284 | * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: | |
285 | */ | |
286 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) | |
287 | # include <linux/spinlock_api_smp.h> | |
288 | #else | |
289 | # include <linux/spinlock_api_up.h> | |
290 | #endif | |
291 | ||
292 | /* | |
293 | * Map the spin_lock functions to the raw variants for PREEMPT_RT=n | |
294 | */ | |
295 | ||
296 | static inline raw_spinlock_t *spinlock_check(spinlock_t *lock) | |
297 | { | |
298 | return &lock->rlock; | |
299 | } | |
300 | ||
301 | #define spin_lock_init(_lock) \ | |
302 | do { \ | |
303 | spinlock_check(_lock); \ | |
304 | raw_spin_lock_init(&(_lock)->rlock); \ | |
305 | } while (0) | |
306 | ||
307 | static inline void spin_lock(spinlock_t *lock) | |
308 | { | |
309 | raw_spin_lock(&lock->rlock); | |
310 | } | |
311 | ||
312 | static inline void spin_lock_bh(spinlock_t *lock) | |
313 | { | |
314 | raw_spin_lock_bh(&lock->rlock); | |
315 | } | |
316 | ||
317 | static inline int spin_trylock(spinlock_t *lock) | |
318 | { | |
319 | return raw_spin_trylock(&lock->rlock); | |
320 | } | |
321 | ||
322 | #define spin_lock_nested(lock, subclass) \ | |
323 | do { \ | |
324 | raw_spin_lock_nested(spinlock_check(lock), subclass); \ | |
325 | } while (0) | |
326 | ||
327 | #define spin_lock_nest_lock(lock, nest_lock) \ | |
328 | do { \ | |
329 | raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock); \ | |
330 | } while (0) | |
331 | ||
332 | static inline void spin_lock_irq(spinlock_t *lock) | |
333 | { | |
334 | raw_spin_lock_irq(&lock->rlock); | |
335 | } | |
336 | ||
337 | #define spin_lock_irqsave(lock, flags) \ | |
338 | do { \ | |
339 | raw_spin_lock_irqsave(spinlock_check(lock), flags); \ | |
340 | } while (0) | |
341 | ||
342 | #define spin_lock_irqsave_nested(lock, flags, subclass) \ | |
343 | do { \ | |
344 | raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \ | |
345 | } while (0) | |
346 | ||
347 | static inline void spin_unlock(spinlock_t *lock) | |
348 | { | |
349 | raw_spin_unlock(&lock->rlock); | |
350 | } | |
351 | ||
352 | static inline void spin_unlock_bh(spinlock_t *lock) | |
353 | { | |
354 | raw_spin_unlock_bh(&lock->rlock); | |
355 | } | |
356 | ||
357 | static inline void spin_unlock_irq(spinlock_t *lock) | |
358 | { | |
359 | raw_spin_unlock_irq(&lock->rlock); | |
360 | } | |
361 | ||
362 | static inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags) | |
363 | { | |
364 | raw_spin_unlock_irqrestore(&lock->rlock, flags); | |
365 | } | |
366 | ||
367 | static inline int spin_trylock_bh(spinlock_t *lock) | |
368 | { | |
369 | return raw_spin_trylock_bh(&lock->rlock); | |
370 | } | |
371 | ||
372 | static inline int spin_trylock_irq(spinlock_t *lock) | |
373 | { | |
374 | return raw_spin_trylock_irq(&lock->rlock); | |
375 | } | |
376 | ||
377 | #define spin_trylock_irqsave(lock, flags) \ | |
378 | ({ \ | |
379 | raw_spin_trylock_irqsave(spinlock_check(lock), flags); \ | |
380 | }) | |
381 | ||
382 | static inline void spin_unlock_wait(spinlock_t *lock) | |
383 | { | |
384 | raw_spin_unlock_wait(&lock->rlock); | |
385 | } | |
386 | ||
387 | static inline int spin_is_locked(spinlock_t *lock) | |
388 | { | |
389 | return raw_spin_is_locked(&lock->rlock); | |
390 | } | |
391 | ||
392 | static inline int spin_is_contended(spinlock_t *lock) | |
393 | { | |
394 | return raw_spin_is_contended(&lock->rlock); | |
395 | } | |
396 | ||
397 | static inline int spin_can_lock(spinlock_t *lock) | |
398 | { | |
399 | return raw_spin_can_lock(&lock->rlock); | |
400 | } | |
401 | ||
4ebc1b4b | 402 | #define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock) |
c2f21ce2 | 403 | |
1da177e4 | 404 | /* |
fb1c8f93 IM |
405 | * Pull the atomic_t declaration: |
406 | * (asm-mips/atomic.h needs above definitions) | |
1da177e4 | 407 | */ |
60063497 | 408 | #include <linux/atomic.h> |
fb1c8f93 IM |
409 | /** |
410 | * atomic_dec_and_lock - lock on reaching reference count zero | |
411 | * @atomic: the atomic counter | |
412 | * @lock: the spinlock in question | |
dc07e721 BF |
413 | * |
414 | * Decrements @atomic by 1. If the result is 0, returns true and locks | |
415 | * @lock. Returns false for all other cases. | |
1da177e4 | 416 | */ |
fb1c8f93 IM |
417 | extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); |
418 | #define atomic_dec_and_lock(atomic, lock) \ | |
dcc8e559 | 419 | __cond_lock(lock, _atomic_dec_and_lock(atomic, lock)) |
1da177e4 | 420 | |
1da177e4 | 421 | #endif /* __LINUX_SPINLOCK_H */ |