Merge remote-tracking branch 'asoc/topic/omap' into asoc-next
[firefly-linux-kernel-4.4.55.git] / include / linux / spinlock.h
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 /* The lock does not imply full memory barrier. */
121 #ifndef ARCH_HAS_SMP_MB_AFTER_LOCK
122 static inline void smp_mb__after_lock(void) { smp_mb(); }
123 #endif
124
125 /**
126  * raw_spin_unlock_wait - wait until the spinlock gets unlocked
127  * @lock: the spinlock in question.
128  */
129 #define raw_spin_unlock_wait(lock)      arch_spin_unlock_wait(&(lock)->raw_lock)
130
131 #ifdef CONFIG_DEBUG_SPINLOCK
132  extern void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock);
133 #define do_raw_spin_lock_flags(lock, flags) do_raw_spin_lock(lock)
134  extern int do_raw_spin_trylock(raw_spinlock_t *lock);
135  extern void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock);
136 #else
137 static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock)
138 {
139         __acquire(lock);
140         arch_spin_lock(&lock->raw_lock);
141 }
142
143 static inline void
144 do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lock)
145 {
146         __acquire(lock);
147         arch_spin_lock_flags(&lock->raw_lock, *flags);
148 }
149
150 static inline int do_raw_spin_trylock(raw_spinlock_t *lock)
151 {
152         return arch_spin_trylock(&(lock)->raw_lock);
153 }
154
155 static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock)
156 {
157         arch_spin_unlock(&lock->raw_lock);
158         __release(lock);
159 }
160 #endif
161
162 /*
163  * Define the various spin_lock methods.  Note we define these
164  * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The
165  * various methods are defined as nops in the case they are not
166  * required.
167  */
168 #define raw_spin_trylock(lock)  __cond_lock(lock, _raw_spin_trylock(lock))
169
170 #define raw_spin_lock(lock)     _raw_spin_lock(lock)
171
172 #ifdef CONFIG_DEBUG_LOCK_ALLOC
173 # define raw_spin_lock_nested(lock, subclass) \
174         _raw_spin_lock_nested(lock, subclass)
175
176 # define raw_spin_lock_nest_lock(lock, nest_lock)                       \
177          do {                                                           \
178                  typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
179                  _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \
180          } while (0)
181 #else
182 # define raw_spin_lock_nested(lock, subclass)           _raw_spin_lock(lock)
183 # define raw_spin_lock_nest_lock(lock, nest_lock)       _raw_spin_lock(lock)
184 #endif
185
186 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
187
188 #define raw_spin_lock_irqsave(lock, flags)                      \
189         do {                                            \
190                 typecheck(unsigned long, flags);        \
191                 flags = _raw_spin_lock_irqsave(lock);   \
192         } while (0)
193
194 #ifdef CONFIG_DEBUG_LOCK_ALLOC
195 #define raw_spin_lock_irqsave_nested(lock, flags, subclass)             \
196         do {                                                            \
197                 typecheck(unsigned long, flags);                        \
198                 flags = _raw_spin_lock_irqsave_nested(lock, subclass);  \
199         } while (0)
200 #else
201 #define raw_spin_lock_irqsave_nested(lock, flags, subclass)             \
202         do {                                                            \
203                 typecheck(unsigned long, flags);                        \
204                 flags = _raw_spin_lock_irqsave(lock);                   \
205         } while (0)
206 #endif
207
208 #else
209
210 #define raw_spin_lock_irqsave(lock, flags)              \
211         do {                                            \
212                 typecheck(unsigned long, flags);        \
213                 _raw_spin_lock_irqsave(lock, flags);    \
214         } while (0)
215
216 #define raw_spin_lock_irqsave_nested(lock, flags, subclass)     \
217         raw_spin_lock_irqsave(lock, flags)
218
219 #endif
220
221 #define raw_spin_lock_irq(lock)         _raw_spin_lock_irq(lock)
222 #define raw_spin_lock_bh(lock)          _raw_spin_lock_bh(lock)
223 #define raw_spin_unlock(lock)           _raw_spin_unlock(lock)
224 #define raw_spin_unlock_irq(lock)       _raw_spin_unlock_irq(lock)
225
226 #define raw_spin_unlock_irqrestore(lock, flags)         \
227         do {                                                    \
228                 typecheck(unsigned long, flags);                \
229                 _raw_spin_unlock_irqrestore(lock, flags);       \
230         } while (0)
231 #define raw_spin_unlock_bh(lock)        _raw_spin_unlock_bh(lock)
232
233 #define raw_spin_trylock_bh(lock) \
234         __cond_lock(lock, _raw_spin_trylock_bh(lock))
235
236 #define raw_spin_trylock_irq(lock) \
237 ({ \
238         local_irq_disable(); \
239         raw_spin_trylock(lock) ? \
240         1 : ({ local_irq_enable(); 0;  }); \
241 })
242
243 #define raw_spin_trylock_irqsave(lock, flags) \
244 ({ \
245         local_irq_save(flags); \
246         raw_spin_trylock(lock) ? \
247         1 : ({ local_irq_restore(flags); 0; }); \
248 })
249
250 /**
251  * raw_spin_can_lock - would raw_spin_trylock() succeed?
252  * @lock: the spinlock in question.
253  */
254 #define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock))
255
256 /* Include rwlock functions */
257 #include <linux/rwlock.h>
258
259 /*
260  * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
261  */
262 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
263 # include <linux/spinlock_api_smp.h>
264 #else
265 # include <linux/spinlock_api_up.h>
266 #endif
267
268 /*
269  * Map the spin_lock functions to the raw variants for PREEMPT_RT=n
270  */
271
272 static inline raw_spinlock_t *spinlock_check(spinlock_t *lock)
273 {
274         return &lock->rlock;
275 }
276
277 #define spin_lock_init(_lock)                           \
278 do {                                                    \
279         spinlock_check(_lock);                          \
280         raw_spin_lock_init(&(_lock)->rlock);            \
281 } while (0)
282
283 static inline void spin_lock(spinlock_t *lock)
284 {
285         raw_spin_lock(&lock->rlock);
286 }
287
288 static inline void spin_lock_bh(spinlock_t *lock)
289 {
290         raw_spin_lock_bh(&lock->rlock);
291 }
292
293 static inline int spin_trylock(spinlock_t *lock)
294 {
295         return raw_spin_trylock(&lock->rlock);
296 }
297
298 #define spin_lock_nested(lock, subclass)                        \
299 do {                                                            \
300         raw_spin_lock_nested(spinlock_check(lock), subclass);   \
301 } while (0)
302
303 #define spin_lock_nest_lock(lock, nest_lock)                            \
304 do {                                                                    \
305         raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock);       \
306 } while (0)
307
308 static inline void spin_lock_irq(spinlock_t *lock)
309 {
310         raw_spin_lock_irq(&lock->rlock);
311 }
312
313 #define spin_lock_irqsave(lock, flags)                          \
314 do {                                                            \
315         raw_spin_lock_irqsave(spinlock_check(lock), flags);     \
316 } while (0)
317
318 #define spin_lock_irqsave_nested(lock, flags, subclass)                 \
319 do {                                                                    \
320         raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \
321 } while (0)
322
323 static inline void spin_unlock(spinlock_t *lock)
324 {
325         raw_spin_unlock(&lock->rlock);
326 }
327
328 static inline void spin_unlock_bh(spinlock_t *lock)
329 {
330         raw_spin_unlock_bh(&lock->rlock);
331 }
332
333 static inline void spin_unlock_irq(spinlock_t *lock)
334 {
335         raw_spin_unlock_irq(&lock->rlock);
336 }
337
338 static inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
339 {
340         raw_spin_unlock_irqrestore(&lock->rlock, flags);
341 }
342
343 static inline int spin_trylock_bh(spinlock_t *lock)
344 {
345         return raw_spin_trylock_bh(&lock->rlock);
346 }
347
348 static inline int spin_trylock_irq(spinlock_t *lock)
349 {
350         return raw_spin_trylock_irq(&lock->rlock);
351 }
352
353 #define spin_trylock_irqsave(lock, flags)                       \
354 ({                                                              \
355         raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
356 })
357
358 static inline void spin_unlock_wait(spinlock_t *lock)
359 {
360         raw_spin_unlock_wait(&lock->rlock);
361 }
362
363 static inline int spin_is_locked(spinlock_t *lock)
364 {
365         return raw_spin_is_locked(&lock->rlock);
366 }
367
368 static inline int spin_is_contended(spinlock_t *lock)
369 {
370         return raw_spin_is_contended(&lock->rlock);
371 }
372
373 static inline int spin_can_lock(spinlock_t *lock)
374 {
375         return raw_spin_can_lock(&lock->rlock);
376 }
377
378 #define assert_spin_locked(lock)        assert_raw_spin_locked(&(lock)->rlock)
379
380 /*
381  * Pull the atomic_t declaration:
382  * (asm-mips/atomic.h needs above definitions)
383  */
384 #include <linux/atomic.h>
385 /**
386  * atomic_dec_and_lock - lock on reaching reference count zero
387  * @atomic: the atomic counter
388  * @lock: the spinlock in question
389  *
390  * Decrements @atomic by 1.  If the result is 0, returns true and locks
391  * @lock.  Returns false for all other cases.
392  */
393 extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
394 #define atomic_dec_and_lock(atomic, lock) \
395                 __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
396
397 #endif /* __LINUX_SPINLOCK_H */