1 #ifndef __LINUX_SPINLOCK_H
2 #define __LINUX_SPINLOCK_H
5 * include/linux/spinlock.h - generic spinlock/rwlock declarations
7 * here's the role of the various spinlock/rwlock related include files:
11 * asm/spinlock_types.h: contains the arch_spinlock_t/arch_rwlock_t and the
14 * linux/spinlock_types.h:
15 * defines the generic type and initializers
17 * asm/spinlock.h: contains the arch_spin_*()/etc. lowlevel
18 * implementations, mostly inline assembly code
20 * (also included on UP-debug builds:)
22 * linux/spinlock_api_smp.h:
23 * contains the prototypes for the _spin_*() APIs.
25 * linux/spinlock.h: builds the final spin_*() APIs.
29 * linux/spinlock_type_up.h:
30 * contains the generic, simplified UP spinlock type.
31 * (which is an empty structure on non-debug builds)
33 * linux/spinlock_types.h:
34 * defines the generic type and initializers
36 * linux/spinlock_up.h:
37 * contains the arch_spin_*()/etc. version of UP
38 * builds. (which are NOPs on non-debug, non-preempt
41 * (included on UP-non-debug builds:)
43 * linux/spinlock_api_up.h:
44 * builds the _spin_*() APIs.
46 * linux/spinlock.h: builds the final spin_*() APIs.
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>
58 #include <asm/system.h>
61 * Must define these before including other files, inline functions need them
63 #define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
65 #define LOCK_SECTION_START(extra) \
68 ".ifndef " LOCK_SECTION_NAME "\n\t" \
69 LOCK_SECTION_NAME ":\n\t" \
72 #define LOCK_SECTION_END \
75 #define __lockfunc __attribute__((section(".spinlock.text")))
78 * Pull the arch_spinlock_t and arch_rwlock_t definitions:
80 #include <linux/spinlock_types.h>
83 * Pull the arch_spin*() functions/declarations (UP-nondebug doesnt need them):
86 # include <asm/spinlock.h>
88 # include <linux/spinlock_up.h>
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) \
96 static struct lock_class_key __key; \
98 __raw_spin_lock_init((lock), #lock, &__key); \
102 # define raw_spin_lock_init(lock) \
103 do { *(lock) = __RAW_SPIN_LOCK_UNLOCKED(lock); } while (0)
106 #define raw_spin_is_locked(lock) arch_spin_is_locked(&(lock)->raw_lock)
108 #ifdef CONFIG_GENERIC_LOCKBREAK
109 #define raw_spin_is_contended(lock) ((lock)->break_lock)
112 #ifdef arch_spin_is_contended
113 #define raw_spin_is_contended(lock) arch_spin_is_contended(&(lock)->raw_lock)
115 #define raw_spin_is_contended(lock) (((void)(lock), 0))
116 #endif /*arch_spin_is_contended*/
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(); }
125 * raw_spin_unlock_wait - wait until the spinlock gets unlocked
126 * @lock: the spinlock in question.
128 #define raw_spin_unlock_wait(lock) arch_spin_unlock_wait(&(lock)->raw_lock)
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);
136 static inline void do_raw_spin_lock(raw_spinlock_t *lock)
138 arch_spin_lock(&lock->raw_lock);
142 do_raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long *flags)
144 arch_spin_lock_flags(&lock->raw_lock, *flags);
147 static inline int do_raw_spin_trylock(raw_spinlock_t *lock)
149 return arch_spin_trylock(&(lock)->raw_lock);
152 static inline void do_raw_spin_unlock(raw_spinlock_t *lock)
154 arch_spin_unlock(&lock->raw_lock);
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
164 #define raw_spin_trylock(lock) __cond_lock(lock, _spin_trylock(lock))
166 #define raw_spin_lock(lock) _spin_lock(lock)
168 #ifdef CONFIG_DEBUG_LOCK_ALLOC
169 # define raw_spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
170 # define raw_spin_lock_nest_lock(lock, nest_lock) \
172 typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
173 _spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \
176 # define raw_spin_lock_nested(lock, subclass) _spin_lock(lock)
177 # define raw_spin_lock_nest_lock(lock, nest_lock) _spin_lock(lock)
180 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
182 #define raw_spin_lock_irqsave(lock, flags) \
184 typecheck(unsigned long, flags); \
185 flags = _spin_lock_irqsave(lock); \
188 #ifdef CONFIG_DEBUG_LOCK_ALLOC
189 #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
191 typecheck(unsigned long, flags); \
192 flags = _spin_lock_irqsave_nested(lock, subclass); \
195 #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
197 typecheck(unsigned long, flags); \
198 flags = _spin_lock_irqsave(lock); \
204 #define raw_spin_lock_irqsave(lock, flags) \
206 typecheck(unsigned long, flags); \
207 _spin_lock_irqsave(lock, flags); \
210 #define raw_spin_lock_irqsave_nested(lock, flags, subclass) \
211 raw_spin_lock_irqsave(lock, flags)
215 #define raw_spin_lock_irq(lock) _spin_lock_irq(lock)
216 #define raw_spin_lock_bh(lock) _spin_lock_bh(lock)
217 #define raw_spin_unlock(lock) _spin_unlock(lock)
218 #define raw_spin_unlock_irq(lock) _spin_unlock_irq(lock)
220 #define raw_spin_unlock_irqrestore(lock, flags) \
222 typecheck(unsigned long, flags); \
223 _spin_unlock_irqrestore(lock, flags); \
225 #define raw_spin_unlock_bh(lock) _spin_unlock_bh(lock)
227 #define raw_spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock))
229 #define raw_spin_trylock_irq(lock) \
231 local_irq_disable(); \
232 raw_spin_trylock(lock) ? \
233 1 : ({ local_irq_enable(); 0; }); \
236 #define raw_spin_trylock_irqsave(lock, flags) \
238 local_irq_save(flags); \
239 raw_spin_trylock(lock) ? \
240 1 : ({ local_irq_restore(flags); 0; }); \
244 * raw_spin_can_lock - would raw_spin_trylock() succeed?
245 * @lock: the spinlock in question.
247 #define raw_spin_can_lock(lock) (!raw_spin_is_locked(lock))
249 /* Include rwlock functions */
250 #include <linux/rwlock.h>
253 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
255 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
256 # include <linux/spinlock_api_smp.h>
258 # include <linux/spinlock_api_up.h>
262 * Map the spin_lock functions to the raw variants for PREEMPT_RT=n
265 static inline raw_spinlock_t *spinlock_check(spinlock_t *lock)
270 #define spin_lock_init(_lock) \
272 spinlock_check(_lock); \
273 raw_spin_lock_init(&(_lock)->rlock); \
276 static inline void spin_lock(spinlock_t *lock)
278 raw_spin_lock(&lock->rlock);
281 static inline void spin_lock_bh(spinlock_t *lock)
283 raw_spin_lock_bh(&lock->rlock);
286 static inline int spin_trylock(spinlock_t *lock)
288 return raw_spin_trylock(&lock->rlock);
291 #define spin_lock_nested(lock, subclass) \
293 raw_spin_lock_nested(spinlock_check(lock), subclass); \
296 #define spin_lock_nest_lock(lock, nest_lock) \
298 raw_spin_lock_nest_lock(spinlock_check(lock), nest_lock); \
301 static inline void spin_lock_irq(spinlock_t *lock)
303 raw_spin_lock_irq(&lock->rlock);
306 #define spin_lock_irqsave(lock, flags) \
308 raw_spin_lock_irqsave(spinlock_check(lock), flags); \
311 #define spin_lock_irqsave_nested(lock, flags, subclass) \
313 raw_spin_lock_irqsave_nested(spinlock_check(lock), flags, subclass); \
316 static inline void spin_unlock(spinlock_t *lock)
318 raw_spin_unlock(&lock->rlock);
321 static inline void spin_unlock_bh(spinlock_t *lock)
323 raw_spin_unlock_bh(&lock->rlock);
326 static inline void spin_unlock_irq(spinlock_t *lock)
328 raw_spin_unlock_irq(&lock->rlock);
331 static inline void spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)
333 raw_spin_unlock_irqrestore(&lock->rlock, flags);
336 static inline int spin_trylock_bh(spinlock_t *lock)
338 return raw_spin_trylock_bh(&lock->rlock);
341 static inline int spin_trylock_irq(spinlock_t *lock)
343 return raw_spin_trylock_irq(&lock->rlock);
346 #define spin_trylock_irqsave(lock, flags) \
348 raw_spin_trylock_irqsave(spinlock_check(lock), flags); \
351 static inline void spin_unlock_wait(spinlock_t *lock)
353 raw_spin_unlock_wait(&lock->rlock);
356 static inline int spin_is_locked(spinlock_t *lock)
358 return raw_spin_is_locked(&lock->rlock);
361 static inline int spin_is_contended(spinlock_t *lock)
363 return raw_spin_is_contended(&lock->rlock);
366 static inline int spin_can_lock(spinlock_t *lock)
368 return raw_spin_can_lock(&lock->rlock);
371 static inline void assert_spin_locked(spinlock_t *lock)
373 assert_raw_spin_locked(&lock->rlock);
377 * Pull the atomic_t declaration:
378 * (asm-mips/atomic.h needs above definitions)
380 #include <asm/atomic.h>
382 * atomic_dec_and_lock - lock on reaching reference count zero
383 * @atomic: the atomic counter
384 * @lock: the spinlock in question
386 * Decrements @atomic by 1. If the result is 0, returns true and locks
387 * @lock. Returns false for all other cases.
389 extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
390 #define atomic_dec_and_lock(atomic, lock) \
391 __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
393 #endif /* __LINUX_SPINLOCK_H */