Line data Source code
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 arch_spinlock_t/arch_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 arch_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 arch_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 arch_spinlock_t and arch_rwlock_t definitions:
79 : */
80 : #include <linux/spinlock_types.h>
81 :
82 : /*
83 : * Pull the arch_spin*() functions/declarations (UP-nondebug doesnt need them):
84 : */
85 : #ifdef CONFIG_SMP
86 : # include <asm/spinlock.h>
87 : #else
88 : # include <linux/spinlock_up.h>
89 : #endif
90 :
91 : #ifdef CONFIG_DEBUG_SPINLOCK
92 : extern void __raw_spin_lock_init(raw_spinlock_t *lock, const char *name,
93 : struct lock_class_key *key);
94 : # define raw_spin_lock_init(lock) \
95 : do { \
96 : static struct lock_class_key __key; \
97 : \
98 : __raw_spin_lock_init((lock), #lock, &__key); \
99 : } while (0)
100 :
101 : #else
102 : # define raw_spin_lock_init(lock) \
103 : do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0)
104 : #endif
105 :
106 : #define raw_spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock)
107 :
108 : #ifdef CONFIG_GENERIC_LOCKBREAK
109 : #define raw_spin_is_contended(lock) ((lock)->break_lock)
110 : #else
111 :
112 : #ifdef arch_spin_is_contended
113 : #define raw_spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock)
114 : #else
115 : #define raw_spin_is_contended(lock) (((void)(lock), 0))
116 : #endif /*arch_spin_is_contended*/
117 : #endif
118 :
119 : /* The lock does not imply full memory barrier. */
120 : #ifndef ARCH_HAS_SMP_MB_AFTER_LOCK
121 : static inline void smp_mb__after_lock(void) { smp_mb(); }
122 : #endif
123 :
124 : /**
125 : * raw_spin_unlock_wait - wait until the spinlock gets unlocked
126 : * @lock: the spinlock in question.
127 : */
128 : #define raw_spin_unlock_wait(lock) arch_spin_unlock_wait(&(lock)->raw_lock)
129 :
130 : #ifdef CONFIG_DEBUG_SPINLOCK
131 : extern void do_raw_spin_lock(raw_spinlock_t *lock);
132 : #define do_raw_spin_lock_flags(lock, flags) do_raw_spin_lock(lock)
133 : extern int do_raw_spin_trylock(raw_spinlock_t *lock);
134 : extern void do_raw_spin_unlock(raw_spinlock_t *lock);
135 : #else
136 : static inline void do_raw_spin_lock(raw_spinlock_t *lock)
137 : {
138 : arch_spin_lock(&lock->raw_lock);
139 : }
140 :
141 : static inline void
142 : do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags)
143 : {
144 : arch_spin_lock_flags(&lock->raw_lock, *flags);
145 : }
146 :
147 : static inline int do_raw_spin_trylock(raw_spinlock_t *lock)
148 : {
149 : return arch_spin_trylock(&(lock)->raw_lock);
150 : }
151 :
152 : static inline void do_raw_spin_unlock(raw_spinlock_t *lock)
153 : {
154 254 : arch_spin_unlock(&lock->raw_lock);
155 127 : }
156 : #endif
157 :
158 : /*
159 : * Define the various spin_lock methods. Note we define these
160 : * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The
161 : * various methods are defined as nops in the case they are not
162 : * required.
163 : */
164 : #define raw_spin_trylock(lock) __cond_lock(lock, _raw_spin_trylock(lock))
165 :
166 : #define raw_spin_lock(lock) _raw_spin_lock(lock)
167 :
168 : #ifdef CONFIG_DEBUG_LOCK_ALLOC
169 : # define raw_spin_lock_nested(lock, subclass) \
170 : _raw_spin_lock_nested(lock, subclass)
171 :
172 : # define raw_spin_lock_nest_lock(lock, nest_lock) \
173 : do { \
174 : typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
175 : _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \
176 : } while (0)
177 : #else
178 : # define raw_spin_lock_nested(lock, subclass) _raw_spin_lock(lock)
179 : # define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock)
180 : #endif
181 :
182 : #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
183 :
184 : #define raw_spin_lock_irqsave(lock, flags) \
185 : do { \
186 : typecheck(unsigned long, flags); \
187 : flags = _raw_spin_lock_irqsave(lock); \
188 : } while (0)
189 :
190 : #ifdef CONFIG_DEBUG_LOCK_ALLOC
191 : #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
192 : do { \
193 : typecheck(unsigned long, flags); \
194 : flags = _raw_spin_lock_irqsave_nested(lock, subclass); \
195 : } while (0)
196 : #else
197 : #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
198 : do { \
199 : typecheck(unsigned long, flags); \
200 : flags = _raw_spin_lock_irqsave(lock); \
201 : } while (0)
202 : #endif
203 :
204 : #else
205 :
206 : #define raw_spin_lock_irqsave(lock, flags) \
207 : do { \
208 : typecheck(unsigned long, flags); \
209 : _raw_spin_lock_irqsave(lock, flags); \
210 : } while (0)
211 :
212 : #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
213 : raw_spin_lock_irqsave(lock, flags)
214 :
215 : #endif
216 :
217 : #define raw_spin_lock_irq(lock) _raw_spin_lock_irq(lock)
218 : #define raw_spin_lock_bh(lock) _raw_spin_lock_bh(lock)
219 : #define raw_spin_unlock(lock) _raw_spin_unlock(lock)
220 : #define raw_spin_unlock_irq(lock) _raw_spin_unlock_irq(lock)
221 :
222 : #define raw_spin_unlock_irqrestore(lock, flags) \
223 : do { \
224 : typecheck(unsigned long, flags); \
225 : _raw_spin_unlock_irqrestore(lock, flags); \
226 : } while (0)
227 : #define raw_spin_unlock_bh(lock) _raw_spin_unlock_bh(lock)
228 :
229 : #define raw_spin_trylock_bh(lock) \
230 : __cond_lock(lock, _raw_spin_trylock_bh(lock))
231 :
232 : #define raw_spin_trylock_irq(lock) \
233 : ({ \
234 : local_irq_disable(); \
235 : raw_spin_trylock(lock) ? \
236 : 1 : ({ local_irq_enable(); 0; }); \
237 : })
238 :
239 : #define raw_spin_trylock_irqsave(lock, flags) \
240 : ({ \
241 : local_irq_save(flags); \
242 : raw_spin_trylock(lock) ? \
243 : 1 : ({ local_irq_restore(flags); 0; }); \
244 : })
245 :
246 : /**
247 : * raw_spin_can_lock - would raw_spin_trylock() succeed?
248 : * @lock: the spinlock in question.
249 : */
250 : #define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock))
251 :
252 : /* Include rwlock functions */
253 : #include <linux/rwlock.h>
254 :
255 : /*
256 : * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
257 : */
258 : #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
259 : # include <linux/spinlock_api_smp.h>
260 : #else
261 : # include <linux/spinlock_api_up.h>
262 : #endif
263 :
264 : /*
265 : * Map the spin_lock functions to the raw variants for PREEMPT_RT=n
266 : */
267 :
268 : static inline raw_spinlock_t *spinlock_check(spinlock_t *lock)
269 : {
270 : return &lock->rlock;
271 : }
272 :
273 : #define spin_lock_init(_lock) \
274 : do { \
275 : spinlock_check(_lock); \
276 : raw_spin_lock_init(&(_lock)->rlock); \
277 : } while (0)
278 :
279 : static inline void spin_lock(spinlock_t *lock)
280 : {
281 77 : raw_spin_lock(&lock->rlock);
282 77 : }
283 :
284 : static inline void spin_lock_bh(spinlock_t *lock)
285 : {
286 : raw_spin_lock_bh(&lock->rlock);
287 : }
288 :
289 : static inline int spin_trylock(spinlock_t *lock)
290 : {
291 : return raw_spin_trylock(&lock->rlock);
292 : }
293 :
294 : #define spin_lock_nested(lock, subclass) \
295 : do { \
296 : raw_spin_lock_nested(spinlock_check(lock), subclass); \
297 : } while (0)
298 :
299 : #define spin_lock_nest_lock(lock, nest_lock) \
300 : do { \
301 : raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock); \
302 : } while (0)
303 :
304 : static inline void spin_lock_irq(spinlock_t *lock)
305 : {
306 : raw_spin_lock_irq(&lock->rlock);
307 : }
308 :
309 : #define spin_lock_irqsave(lock, flags) \
310 : do { \
311 : raw_spin_lock_irqsave(spinlock_check(lock), flags); \
312 : } while (0)
313 :
314 : #define spin_lock_irqsave_nested(lock, flags, subclass) \
315 : do { \
316 : raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \
317 : } while (0)
318 :
319 : static inline void spin_unlock(spinlock_t *lock)
320 : {
321 254 : raw_spin_unlock(&lock->rlock);
322 127 : }
323 :
324 : static inline void spin_unlock_bh(spinlock_t *lock)
325 : {
326 : raw_spin_unlock_bh(&lock->rlock);
327 : }
328 :
329 : static inline void spin_unlock_irq(spinlock_t *lock)
330 : {
331 : raw_spin_unlock_irq(&lock->rlock);
332 : }
333 :
334 : static inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
335 : {
336 : raw_spin_unlock_irqrestore(&lock->rlock, flags);
337 : }
338 :
339 : static inline int spin_trylock_bh(spinlock_t *lock)
340 : {
341 : return raw_spin_trylock_bh(&lock->rlock);
342 : }
343 :
344 : static inline int spin_trylock_irq(spinlock_t *lock)
345 : {
346 : return raw_spin_trylock_irq(&lock->rlock);
347 : }
348 :
349 : #define spin_trylock_irqsave(lock, flags) \
350 : ({ \
351 : raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
352 : })
353 :
354 : static inline void spin_unlock_wait(spinlock_t *lock)
355 : {
356 : raw_spin_unlock_wait(&lock->rlock);
357 : }
358 :
359 : static inline int spin_is_locked(spinlock_t *lock)
360 : {
361 : return raw_spin_is_locked(&lock->rlock);
362 : }
363 :
364 : static inline int spin_is_contended(spinlock_t *lock)
365 : {
366 : return raw_spin_is_contended(&lock->rlock);
367 : }
368 :
369 : static inline int spin_can_lock(spinlock_t *lock)
370 : {
371 : return raw_spin_can_lock(&lock->rlock);
372 : }
373 :
374 : static inline void assert_spin_locked(spinlock_t *lock)
375 : {
376 : assert_raw_spin_locked(&lock->rlock);
377 : }
378 :
379 : /*
380 : * Pull the atomic_t declaration:
381 : * (asm-mips/atomic.h needs above definitions)
382 : */
383 : #include <asm/atomic.h>
384 : /**
385 : * atomic_dec_and_lock - lock on reaching reference count zero
386 : * @atomic: the atomic counter
387 : * @lock: the spinlock in question
388 : *
389 : * Decrements @atomic by 1. If the result is 0, returns true and locks
390 : * @lock. Returns false for all other cases.
391 : */
392 : extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
393 1 : #define atomic_dec_and_lock(atomic, lock) \
394 : __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
395 :
396 : #endif /* __LINUX_SPINLOCK_H */
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