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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/irqflags.h> | |
54 | #include <linux/thread_info.h> | |
55 | #include <linux/kernel.h> | |
56 | #include <linux/stringify.h> | |
57 | #include <linux/bottom_half.h> | |
58 | #include <asm/barrier.h> | |
59 | ||
60 | ||
61 | /* | |
62 | * Must define these before including other files, inline functions need them | |
63 | */ | |
64 | #define LOCK_SECTION_NAME ".text..lock."KBUILD_BASENAME | |
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 | ||
76 | #define __lockfunc __attribute__((section(".spinlock.text"))) | |
77 | ||
78 | /* | |
79 | * Pull the arch_spinlock_t and arch_rwlock_t definitions: | |
80 | */ | |
81 | #include <linux/spinlock_types.h> | |
82 | ||
83 | /* | |
84 | * Pull the arch_spin*() functions/declarations (UP-nondebug doesn't need them): | |
85 | */ | |
86 | #ifdef CONFIG_SMP | |
87 | # include <asm/spinlock.h> | |
88 | #else | |
89 | # include <linux/spinlock_up.h> | |
90 | #endif | |
91 | ||
92 | #ifdef CONFIG_DEBUG_SPINLOCK | |
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) \ | |
96 | do { \ | |
97 | static struct lock_class_key __key; \ | |
98 | \ | |
99 | __raw_spin_lock_init((lock), #lock, &__key); \ | |
100 | } while (0) | |
101 | ||
102 | #else | |
103 | # define raw_spin_lock_init(lock) \ | |
104 | do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0) | |
105 | #endif | |
106 | ||
107 | #define raw_spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock) | |
108 | ||
109 | #ifdef CONFIG_GENERIC_LOCKBREAK | |
110 | #define raw_spin_is_contended(lock) ((lock)->break_lock) | |
111 | #else | |
112 | ||
113 | #ifdef arch_spin_is_contended | |
114 | #define raw_spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock) | |
115 | #else | |
116 | #define raw_spin_is_contended(lock) (((void)(lock), 0)) | |
117 | #endif /*arch_spin_is_contended*/ | |
118 | #endif | |
119 | ||
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 LOADs and STOREs 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() | |
131 | #endif | |
132 | ||
133 | /** | |
134 | * raw_spin_unlock_wait - wait until the spinlock gets unlocked | |
135 | * @lock: the spinlock in question. | |
136 | */ | |
137 | #define raw_spin_unlock_wait(lock) arch_spin_unlock_wait(&(lock)->raw_lock) | |
138 | ||
139 | #ifdef CONFIG_DEBUG_SPINLOCK | |
140 | extern void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock); | |
141 | #define do_raw_spin_lock_flags(lock, flags) do_raw_spin_lock(lock) | |
142 | extern int do_raw_spin_trylock(raw_spinlock_t *lock); | |
143 | extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock); | |
144 | #else | |
145 | static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock) | |
146 | { | |
147 | __acquire(lock); | |
148 | arch_spin_lock(&lock->raw_lock); | |
149 | } | |
150 | ||
151 | static inline void | |
152 | do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lock) | |
153 | { | |
154 | __acquire(lock); | |
155 | arch_spin_lock_flags(&lock->raw_lock, *flags); | |
156 | } | |
157 | ||
158 | static inline int do_raw_spin_trylock(raw_spinlock_t *lock) | |
159 | { | |
160 | return arch_spin_trylock(&(lock)->raw_lock); | |
161 | } | |
162 | ||
163 | static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock) | |
164 | { | |
165 | arch_spin_unlock(&lock->raw_lock); | |
166 | __release(lock); | |
167 | } | |
168 | #endif | |
169 | ||
170 | /* | |
171 | * Define the various spin_lock methods. Note we define these | |
172 | * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The | |
173 | * various methods are defined as nops in the case they are not | |
174 | * required. | |
175 | */ | |
176 | #define raw_spin_trylock(lock) __cond_lock(lock, _raw_spin_trylock(lock)) | |
177 | ||
178 | #define raw_spin_lock(lock) _raw_spin_lock(lock) | |
179 | ||
180 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
181 | # define raw_spin_lock_nested(lock, subclass) \ | |
182 | _raw_spin_lock_nested(lock, subclass) | |
183 | # define raw_spin_lock_bh_nested(lock, subclass) \ | |
184 | _raw_spin_lock_bh_nested(lock, subclass) | |
185 | ||
186 | # define raw_spin_lock_nest_lock(lock, nest_lock) \ | |
187 | do { \ | |
188 | typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\ | |
189 | _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \ | |
190 | } while (0) | |
191 | #else | |
192 | /* | |
193 | * Always evaluate the 'subclass' argument to avoid that the compiler | |
194 | * warns about set-but-not-used variables when building with | |
195 | * CONFIG_DEBUG_LOCK_ALLOC=n and with W=1. | |
196 | */ | |
197 | # define raw_spin_lock_nested(lock, subclass) \ | |
198 | _raw_spin_lock(((void)(subclass), (lock))) | |
199 | # define raw_spin_lock_nest_lock(lock, nest_lock) _raw_spin_lock(lock) | |
200 | # define raw_spin_lock_bh_nested(lock, subclass) _raw_spin_lock_bh(lock) | |
201 | #endif | |
202 | ||
203 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) | |
204 | ||
205 | #define raw_spin_lock_irqsave(lock, flags) \ | |
206 | do { \ | |
207 | typecheck(unsigned long, flags); \ | |
208 | flags = _raw_spin_lock_irqsave(lock); \ | |
209 | } while (0) | |
210 | ||
211 | #ifdef CONFIG_DEBUG_LOCK_ALLOC | |
212 | #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ | |
213 | do { \ | |
214 | typecheck(unsigned long, flags); \ | |
215 | flags = _raw_spin_lock_irqsave_nested(lock, subclass); \ | |
216 | } while (0) | |
217 | #else | |
218 | #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ | |
219 | do { \ | |
220 | typecheck(unsigned long, flags); \ | |
221 | flags = _raw_spin_lock_irqsave(lock); \ | |
222 | } while (0) | |
223 | #endif | |
224 | ||
225 | #else | |
226 | ||
227 | #define raw_spin_lock_irqsave(lock, flags) \ | |
228 | do { \ | |
229 | typecheck(unsigned long, flags); \ | |
230 | _raw_spin_lock_irqsave(lock, flags); \ | |
231 | } while (0) | |
232 | ||
233 | #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \ | |
234 | raw_spin_lock_irqsave(lock, flags) | |
235 | ||
236 | #endif | |
237 | ||
238 | #define raw_spin_lock_irq(lock) _raw_spin_lock_irq(lock) | |
239 | #define raw_spin_lock_bh(lock) _raw_spin_lock_bh(lock) | |
240 | #define raw_spin_unlock(lock) _raw_spin_unlock(lock) | |
241 | #define raw_spin_unlock_irq(lock) _raw_spin_unlock_irq(lock) | |
242 | ||
243 | #define raw_spin_unlock_irqrestore(lock, flags) \ | |
244 | do { \ | |
245 | typecheck(unsigned long, flags); \ | |
246 | _raw_spin_unlock_irqrestore(lock, flags); \ | |
247 | } while (0) | |
248 | #define raw_spin_unlock_bh(lock) _raw_spin_unlock_bh(lock) | |
249 | ||
250 | #define raw_spin_trylock_bh(lock) \ | |
251 | __cond_lock(lock, _raw_spin_trylock_bh(lock)) | |
252 | ||
253 | #define raw_spin_trylock_irq(lock) \ | |
254 | ({ \ | |
255 | local_irq_disable(); \ | |
256 | raw_spin_trylock(lock) ? \ | |
257 | 1 : ({ local_irq_enable(); 0; }); \ | |
258 | }) | |
259 | ||
260 | #define raw_spin_trylock_irqsave(lock, flags) \ | |
261 | ({ \ | |
262 | local_irq_save(flags); \ | |
263 | raw_spin_trylock(lock) ? \ | |
264 | 1 : ({ local_irq_restore(flags); 0; }); \ | |
265 | }) | |
266 | ||
267 | /** | |
268 | * raw_spin_can_lock - would raw_spin_trylock() succeed? | |
269 | * @lock: the spinlock in question. | |
270 | */ | |
271 | #define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock)) | |
272 | ||
273 | /* Include rwlock functions */ | |
274 | #include <linux/rwlock.h> | |
275 | ||
276 | /* | |
277 | * Pull the _spin_*()/_read_*()/_write_*() functions/declarations: | |
278 | */ | |
279 | #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) | |
280 | # include <linux/spinlock_api_smp.h> | |
281 | #else | |
282 | # include <linux/spinlock_api_up.h> | |
283 | #endif | |
284 | ||
285 | /* | |
286 | * Map the spin_lock functions to the raw variants for PREEMPT_RT=n | |
287 | */ | |
288 | ||
289 | static __always_inline raw_spinlock_t *spinlock_check(spinlock_t *lock) | |
290 | { | |
291 | return &lock->rlock; | |
292 | } | |
293 | ||
294 | #define spin_lock_init(_lock) \ | |
295 | do { \ | |
296 | spinlock_check(_lock); \ | |
297 | raw_spin_lock_init(&(_lock)->rlock); \ | |
298 | } while (0) | |
299 | ||
300 | static __always_inline void spin_lock(spinlock_t *lock) | |
301 | { | |
302 | raw_spin_lock(&lock->rlock); | |
303 | } | |
304 | ||
305 | static __always_inline void spin_lock_bh(spinlock_t *lock) | |
306 | { | |
307 | raw_spin_lock_bh(&lock->rlock); | |
308 | } | |
309 | ||
310 | static __always_inline int spin_trylock(spinlock_t *lock) | |
311 | { | |
312 | return raw_spin_trylock(&lock->rlock); | |
313 | } | |
314 | ||
315 | #define spin_lock_nested(lock, subclass) \ | |
316 | do { \ | |
317 | raw_spin_lock_nested(spinlock_check(lock), subclass); \ | |
318 | } while (0) | |
319 | ||
320 | #define spin_lock_bh_nested(lock, subclass) \ | |
321 | do { \ | |
322 | raw_spin_lock_bh_nested(spinlock_check(lock), subclass);\ | |
323 | } while (0) | |
324 | ||
325 | #define spin_lock_nest_lock(lock, nest_lock) \ | |
326 | do { \ | |
327 | raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock); \ | |
328 | } while (0) | |
329 | ||
330 | static __always_inline void spin_lock_irq(spinlock_t *lock) | |
331 | { | |
332 | raw_spin_lock_irq(&lock->rlock); | |
333 | } | |
334 | ||
335 | #define spin_lock_irqsave(lock, flags) \ | |
336 | do { \ | |
337 | raw_spin_lock_irqsave(spinlock_check(lock), flags); \ | |
338 | } while (0) | |
339 | ||
340 | #define spin_lock_irqsave_nested(lock, flags, subclass) \ | |
341 | do { \ | |
342 | raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \ | |
343 | } while (0) | |
344 | ||
345 | static __always_inline void spin_unlock(spinlock_t *lock) | |
346 | { | |
347 | raw_spin_unlock(&lock->rlock); | |
348 | } | |
349 | ||
350 | static __always_inline void spin_unlock_bh(spinlock_t *lock) | |
351 | { | |
352 | raw_spin_unlock_bh(&lock->rlock); | |
353 | } | |
354 | ||
355 | static __always_inline void spin_unlock_irq(spinlock_t *lock) | |
356 | { | |
357 | raw_spin_unlock_irq(&lock->rlock); | |
358 | } | |
359 | ||
360 | static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags) | |
361 | { | |
362 | raw_spin_unlock_irqrestore(&lock->rlock, flags); | |
363 | } | |
364 | ||
365 | static __always_inline int spin_trylock_bh(spinlock_t *lock) | |
366 | { | |
367 | return raw_spin_trylock_bh(&lock->rlock); | |
368 | } | |
369 | ||
370 | static __always_inline int spin_trylock_irq(spinlock_t *lock) | |
371 | { | |
372 | return raw_spin_trylock_irq(&lock->rlock); | |
373 | } | |
374 | ||
375 | #define spin_trylock_irqsave(lock, flags) \ | |
376 | ({ \ | |
377 | raw_spin_trylock_irqsave(spinlock_check(lock), flags); \ | |
378 | }) | |
379 | ||
380 | static __always_inline void spin_unlock_wait(spinlock_t *lock) | |
381 | { | |
382 | raw_spin_unlock_wait(&lock->rlock); | |
383 | } | |
384 | ||
385 | static __always_inline int spin_is_locked(spinlock_t *lock) | |
386 | { | |
387 | return raw_spin_is_locked(&lock->rlock); | |
388 | } | |
389 | ||
390 | static __always_inline int spin_is_contended(spinlock_t *lock) | |
391 | { | |
392 | return raw_spin_is_contended(&lock->rlock); | |
393 | } | |
394 | ||
395 | static __always_inline int spin_can_lock(spinlock_t *lock) | |
396 | { | |
397 | return raw_spin_can_lock(&lock->rlock); | |
398 | } | |
399 | ||
400 | #define assert_spin_locked(lock) assert_raw_spin_locked(&(lock)->rlock) | |
401 | ||
402 | /* | |
403 | * Pull the atomic_t declaration: | |
404 | * (asm-mips/atomic.h needs above definitions) | |
405 | */ | |
406 | #include <linux/atomic.h> | |
407 | /** | |
408 | * atomic_dec_and_lock - lock on reaching reference count zero | |
409 | * @atomic: the atomic counter | |
410 | * @lock: the spinlock in question | |
411 | * | |
412 | * Decrements @atomic by 1. If the result is 0, returns true and locks | |
413 | * @lock. Returns false for all other cases. | |
414 | */ | |
415 | extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); | |
416 | #define atomic_dec_and_lock(atomic, lock) \ | |
417 | __cond_lock(lock, _atomic_dec_and_lock(atomic, lock)) | |
418 | ||
419 | #endif /* __LINUX_SPINLOCK_H */ |