locking: Make sparse work with inline spinlocks and rwlocks
[linux-2.6.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/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) __acquires(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) __releases(lock);
135 #else
136 static inline void do_raw_spin_lock(raw_spinlock_t *lock) __acquires(lock)
137 {
138         __acquire(lock);
139         arch_spin_lock(&lock->raw_lock);
140 }
141
142 static inline void
143 do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags) __acquires(lock)
144 {
145         __acquire(lock);
146         arch_spin_lock_flags(&lock->raw_lock, *flags);
147 }
148
149 static inline int do_raw_spin_trylock(raw_spinlock_t *lock)
150 {
151         return arch_spin_trylock(&(lock)->raw_lock);
152 }
153
154 static inline void do_raw_spin_unlock(raw_spinlock_t *lock) __releases(lock)
155 {
156         arch_spin_unlock(&lock->raw_lock);
157         __release(lock);
158 }
159 #endif
160
161 /*
162  * Define the various spin_lock methods.  Note we define these
163  * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The
164  * various methods are defined as nops in the case they are not
165  * required.
166  */
167 #define raw_spin_trylock(lock)  __cond_lock(lock, _raw_spin_trylock(lock))
168
169 #define raw_spin_lock(lock)     _raw_spin_lock(lock)
170
171 #ifdef CONFIG_DEBUG_LOCK_ALLOC
172 # define raw_spin_lock_nested(lock, subclass) \
173         _raw_spin_lock_nested(lock, subclass)
174
175 # define raw_spin_lock_nest_lock(lock, nest_lock)                       \
176          do {                                                           \
177                  typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
178                  _raw_spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \
179          } while (0)
180 #else
181 # define raw_spin_lock_nested(lock, subclass)           _raw_spin_lock(lock)
182 # define raw_spin_lock_nest_lock(lock, nest_lock)       _raw_spin_lock(lock)
183 #endif
184
185 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
186
187 #define raw_spin_lock_irqsave(lock, flags)                      \
188         do {                                            \
189                 typecheck(unsigned long, flags);        \
190                 flags = _raw_spin_lock_irqsave(lock);   \
191         } while (0)
192
193 #ifdef CONFIG_DEBUG_LOCK_ALLOC
194 #define raw_spin_lock_irqsave_nested(lock, flags, subclass)             \
195         do {                                                            \
196                 typecheck(unsigned long, flags);                        \
197                 flags = _raw_spin_lock_irqsave_nested(lock, subclass);  \
198         } while (0)
199 #else
200 #define raw_spin_lock_irqsave_nested(lock, flags, subclass)             \
201         do {                                                            \
202                 typecheck(unsigned long, flags);                        \
203                 flags = _raw_spin_lock_irqsave(lock);                   \
204         } while (0)
205 #endif
206
207 #else
208
209 #define raw_spin_lock_irqsave(lock, flags)              \
210         do {                                            \
211                 typecheck(unsigned long, flags);        \
212                 _raw_spin_lock_irqsave(lock, flags);    \
213         } while (0)
214
215 #define raw_spin_lock_irqsave_nested(lock, flags, subclass)     \
216         raw_spin_lock_irqsave(lock, flags)
217
218 #endif
219
220 #define raw_spin_lock_irq(lock)         _raw_spin_lock_irq(lock)
221 #define raw_spin_lock_bh(lock)          _raw_spin_lock_bh(lock)
222 #define raw_spin_unlock(lock)           _raw_spin_unlock(lock)
223 #define raw_spin_unlock_irq(lock)       _raw_spin_unlock_irq(lock)
224
225 #define raw_spin_unlock_irqrestore(lock, flags)         \
226         do {                                                    \
227                 typecheck(unsigned long, flags);                \
228                 _raw_spin_unlock_irqrestore(lock, flags);       \
229         } while (0)
230 #define raw_spin_unlock_bh(lock)        _raw_spin_unlock_bh(lock)
231
232 #define raw_spin_trylock_bh(lock) \
233         __cond_lock(lock, _raw_spin_trylock_bh(lock))
234
235 #define raw_spin_trylock_irq(lock) \
236 ({ \
237         local_irq_disable(); \
238         raw_spin_trylock(lock) ? \
239         1 : ({ local_irq_enable(); 0;  }); \
240 })
241
242 #define raw_spin_trylock_irqsave(lock, flags) \
243 ({ \
244         local_irq_save(flags); \
245         raw_spin_trylock(lock) ? \
246         1 : ({ local_irq_restore(flags); 0; }); \
247 })
248
249 /**
250  * raw_spin_can_lock - would raw_spin_trylock() succeed?
251  * @lock: the spinlock in question.
252  */
253 #define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock))
254
255 /* Include rwlock functions */
256 #include <linux/rwlock.h>
257
258 /*
259  * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
260  */
261 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
262 # include <linux/spinlock_api_smp.h>
263 #else
264 # include <linux/spinlock_api_up.h>
265 #endif
266
267 /*
268  * Map the spin_lock functions to the raw variants for PREEMPT_RT=n
269  */
270
271 static inline raw_spinlock_t *spinlock_check(spinlock_t *lock)
272 {
273         return &lock->rlock;
274 }
275
276 #define spin_lock_init(_lock)                           \
277 do {                                                    \
278         spinlock_check(_lock);                          \
279         raw_spin_lock_init(&(_lock)->rlock);            \
280 } while (0)
281
282 static inline void spin_lock(spinlock_t *lock)
283 {
284         raw_spin_lock(&lock->rlock);
285 }
286
287 static inline void spin_lock_bh(spinlock_t *lock)
288 {
289         raw_spin_lock_bh(&lock->rlock);
290 }
291
292 static inline int spin_trylock(spinlock_t *lock)
293 {
294         return raw_spin_trylock(&lock->rlock);
295 }
296
297 #define spin_lock_nested(lock, subclass)                        \
298 do {                                                            \
299         raw_spin_lock_nested(spinlock_check(lock), subclass);   \
300 } while (0)
301
302 #define spin_lock_nest_lock(lock, nest_lock)                            \
303 do {                                                                    \
304         raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock);       \
305 } while (0)
306
307 static inline void spin_lock_irq(spinlock_t *lock)
308 {
309         raw_spin_lock_irq(&lock->rlock);
310 }
311
312 #define spin_lock_irqsave(lock, flags)                          \
313 do {                                                            \
314         raw_spin_lock_irqsave(spinlock_check(lock), flags);     \
315 } while (0)
316
317 #define spin_lock_irqsave_nested(lock, flags, subclass)                 \
318 do {                                                                    \
319         raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \
320 } while (0)
321
322 static inline void spin_unlock(spinlock_t *lock)
323 {
324         raw_spin_unlock(&lock->rlock);
325 }
326
327 static inline void spin_unlock_bh(spinlock_t *lock)
328 {
329         raw_spin_unlock_bh(&lock->rlock);
330 }
331
332 static inline void spin_unlock_irq(spinlock_t *lock)
333 {
334         raw_spin_unlock_irq(&lock->rlock);
335 }
336
337 static inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
338 {
339         raw_spin_unlock_irqrestore(&lock->rlock, flags);
340 }
341
342 static inline int spin_trylock_bh(spinlock_t *lock)
343 {
344         return raw_spin_trylock_bh(&lock->rlock);
345 }
346
347 static inline int spin_trylock_irq(spinlock_t *lock)
348 {
349         return raw_spin_trylock_irq(&lock->rlock);
350 }
351
352 #define spin_trylock_irqsave(lock, flags)                       \
353 ({                                                              \
354         raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
355 })
356
357 static inline void spin_unlock_wait(spinlock_t *lock)
358 {
359         raw_spin_unlock_wait(&lock->rlock);
360 }
361
362 static inline int spin_is_locked(spinlock_t *lock)
363 {
364         return raw_spin_is_locked(&lock->rlock);
365 }
366
367 static inline int spin_is_contended(spinlock_t *lock)
368 {
369         return raw_spin_is_contended(&lock->rlock);
370 }
371
372 static inline int spin_can_lock(spinlock_t *lock)
373 {
374         return raw_spin_can_lock(&lock->rlock);
375 }
376
377 static inline void assert_spin_locked(spinlock_t *lock)
378 {
379         assert_raw_spin_locked(&lock->rlock);
380 }
381
382 /*
383  * Pull the atomic_t declaration:
384  * (asm-mips/atomic.h needs above definitions)
385  */
386 #include <asm/atomic.h>
387 /**
388  * atomic_dec_and_lock - lock on reaching reference count zero
389  * @atomic: the atomic counter
390  * @lock: the spinlock in question
391  *
392  * Decrements @atomic by 1.  If the result is 0, returns true and locks
393  * @lock.  Returns false for all other cases.
394  */
395 extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
396 #define atomic_dec_and_lock(atomic, lock) \
397                 __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
398
399 #endif /* __LINUX_SPINLOCK_H */