blob: f0ca7a7a17572f5843d27a782e4d882f4152aea7 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef __LINUX_SPINLOCK_H
2#define __LINUX_SPINLOCK_H
3
4/*
Ingo Molnarfb1c8f92005-09-10 00:25:56 -07005 * 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 raw_spinlock_t/raw_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 __raw_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 __raw_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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070047 */
48
Steven Rostedt3f3078912008-07-25 01:45:25 -070049#include <linux/typecheck.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070050#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>
Andrew Morton676dcb82006-12-06 20:31:30 -080056#include <linux/bottom_half.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
Linus Torvalds1da177e2005-04-16 15:20:36 -070058#include <asm/system.h>
59
60/*
61 * Must define these before including other files, inline functions need them
62 */
Ustyugov Romanf83b5e32005-09-23 08:42:11 +040063#define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
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
Harvey Harrisonec701582008-02-08 04:19:55 -080075#define __lockfunc __attribute__((section(".spinlock.text")))
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77/*
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070078 * Pull the raw_spinlock_t and raw_rwlock_t definitions:
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 */
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070080#include <linux/spinlock_types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070082extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070084/*
85 * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
86 */
Ingo Molnar8a25d5d2006-07-03 00:24:54 -070087#ifdef CONFIG_SMP
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070088# include <asm/spinlock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070089#else
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070090# include <linux/spinlock_up.h>
91#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
Ingo Molnar8a25d5d2006-07-03 00:24:54 -070093#ifdef CONFIG_DEBUG_SPINLOCK
94 extern void __spin_lock_init(spinlock_t *lock, const char *name,
95 struct lock_class_key *key);
96# define spin_lock_init(lock) \
97do { \
98 static struct lock_class_key __key; \
99 \
100 __spin_lock_init((lock), #lock, &__key); \
101} while (0)
102
103#else
104# define spin_lock_init(lock) \
105 do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
106#endif
107
108#ifdef CONFIG_DEBUG_SPINLOCK
109 extern void __rwlock_init(rwlock_t *lock, const char *name,
110 struct lock_class_key *key);
111# define rwlock_init(lock) \
112do { \
113 static struct lock_class_key __key; \
114 \
115 __rwlock_init((lock), #lock, &__key); \
116} while (0)
117#else
118# define rwlock_init(lock) \
119 do { *(lock) = RW_LOCK_UNLOCKED; } while (0)
120#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700122#define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
123
Nick Piggin95c354f2008-01-30 13:31:20 +0100124#ifdef CONFIG_GENERIC_LOCKBREAK
125#define spin_is_contended(lock) ((lock)->break_lock)
126#else
Kyle McMartina5ef7ca2009-02-08 17:39:58 -0500127
128#ifdef __raw_spin_is_contended
Nick Piggin95c354f2008-01-30 13:31:20 +0100129#define spin_is_contended(lock) __raw_spin_is_contended(&(lock)->raw_lock)
Kyle McMartina5ef7ca2009-02-08 17:39:58 -0500130#else
131#define spin_is_contended(lock) (((void)(lock), 0))
132#endif /*__raw_spin_is_contended*/
Nick Piggin95c354f2008-01-30 13:31:20 +0100133#endif
134
Jiri Olsaad462762009-07-08 12:10:31 +0000135/* The lock does not imply full memory barrier. */
136#ifndef ARCH_HAS_SMP_MB_AFTER_LOCK
137static inline void smp_mb__after_lock(void) { smp_mb(); }
138#endif
139
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700140/**
141 * spin_unlock_wait - wait until the spinlock gets unlocked
142 * @lock: the spinlock in question.
143 */
144#define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock)
145
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146#ifdef CONFIG_DEBUG_SPINLOCK
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700147 extern void _raw_spin_lock(spinlock_t *lock);
148#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
149 extern int _raw_spin_trylock(spinlock_t *lock);
150 extern void _raw_spin_unlock(spinlock_t *lock);
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700151 extern void _raw_read_lock(rwlock_t *lock);
Robin Holtf5f7eac2009-04-02 16:59:46 -0700152#define _raw_read_lock_flags(lock, flags) _raw_read_lock(lock)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700153 extern int _raw_read_trylock(rwlock_t *lock);
154 extern void _raw_read_unlock(rwlock_t *lock);
155 extern void _raw_write_lock(rwlock_t *lock);
Robin Holtf5f7eac2009-04-02 16:59:46 -0700156#define _raw_write_lock_flags(lock, flags) _raw_write_lock(lock)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700157 extern int _raw_write_trylock(rwlock_t *lock);
158 extern void _raw_write_unlock(rwlock_t *lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159#else
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700160# define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock)
161# define _raw_spin_lock_flags(lock, flags) \
162 __raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700163# define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
164# define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700165# define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
Robin Holtf5f7eac2009-04-02 16:59:46 -0700166# define _raw_read_lock_flags(lock, flags) \
167 __raw_read_lock_flags(&(lock)->raw_lock, *(flags))
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700168# define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700169# define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
170# define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
Robin Holtf5f7eac2009-04-02 16:59:46 -0700171# define _raw_write_lock_flags(lock, flags) \
172 __raw_write_lock_flags(&(lock)->raw_lock, *(flags))
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700173# define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700174# define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175#endif
176
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700177#define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock)
178#define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179
180/*
181 * Define the various spin_lock and rw_lock methods. Note we define these
182 * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
183 * methods are defined as nops in the case they are not required.
184 */
Josh Triplettdcc8e552006-09-29 02:01:03 -0700185#define spin_trylock(lock) __cond_lock(lock, _spin_trylock(lock))
186#define read_trylock(lock) __cond_lock(lock, _read_trylock(lock))
187#define write_trylock(lock) __cond_lock(lock, _write_trylock(lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700189#define spin_lock(lock) _spin_lock(lock)
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700190
191#ifdef CONFIG_DEBUG_LOCK_ALLOC
192# define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
Peter Zijlstrab7d39af2008-08-11 09:30:24 +0200193# define spin_lock_nest_lock(lock, nest_lock) \
194 do { \
195 typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\
196 _spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \
197 } while (0)
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700198#else
199# define spin_lock_nested(lock, subclass) _spin_lock(lock)
Peter Zijlstrab7d39af2008-08-11 09:30:24 +0200200# define spin_lock_nest_lock(lock, nest_lock) _spin_lock(lock)
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700201#endif
202
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700203#define write_lock(lock) _write_lock(lock)
204#define read_lock(lock) _read_lock(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700206#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
Linus Torvaldsb8e6ec82006-11-26 16:27:17 -0800207
Steven Rostedt3f3078912008-07-25 01:45:25 -0700208#define spin_lock_irqsave(lock, flags) \
209 do { \
210 typecheck(unsigned long, flags); \
211 flags = _spin_lock_irqsave(lock); \
212 } while (0)
213#define read_lock_irqsave(lock, flags) \
214 do { \
215 typecheck(unsigned long, flags); \
216 flags = _read_lock_irqsave(lock); \
217 } while (0)
218#define write_lock_irqsave(lock, flags) \
219 do { \
220 typecheck(unsigned long, flags); \
221 flags = _write_lock_irqsave(lock); \
222 } while (0)
Arjan van de Vencfd3ef22006-11-25 11:09:37 -0800223
224#ifdef CONFIG_DEBUG_LOCK_ALLOC
Steven Rostedt3f3078912008-07-25 01:45:25 -0700225#define spin_lock_irqsave_nested(lock, flags, subclass) \
226 do { \
227 typecheck(unsigned long, flags); \
228 flags = _spin_lock_irqsave_nested(lock, subclass); \
229 } while (0)
Arjan van de Vencfd3ef22006-11-25 11:09:37 -0800230#else
Steven Rostedt3f3078912008-07-25 01:45:25 -0700231#define spin_lock_irqsave_nested(lock, flags, subclass) \
232 do { \
233 typecheck(unsigned long, flags); \
234 flags = _spin_lock_irqsave(lock); \
235 } while (0)
Arjan van de Vencfd3ef22006-11-25 11:09:37 -0800236#endif
237
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238#else
Linus Torvaldsb8e6ec82006-11-26 16:27:17 -0800239
Steven Rostedt3f3078912008-07-25 01:45:25 -0700240#define spin_lock_irqsave(lock, flags) \
241 do { \
242 typecheck(unsigned long, flags); \
243 _spin_lock_irqsave(lock, flags); \
244 } while (0)
245#define read_lock_irqsave(lock, flags) \
246 do { \
247 typecheck(unsigned long, flags); \
248 _read_lock_irqsave(lock, flags); \
249 } while (0)
250#define write_lock_irqsave(lock, flags) \
251 do { \
252 typecheck(unsigned long, flags); \
253 _write_lock_irqsave(lock, flags); \
254 } while (0)
Arjan van de Vencfd3ef22006-11-25 11:09:37 -0800255#define spin_lock_irqsave_nested(lock, flags, subclass) \
256 spin_lock_irqsave(lock, flags)
257
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258#endif
259
260#define spin_lock_irq(lock) _spin_lock_irq(lock)
261#define spin_lock_bh(lock) _spin_lock_bh(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262#define read_lock_irq(lock) _read_lock_irq(lock)
263#define read_lock_bh(lock) _read_lock_bh(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264#define write_lock_irq(lock) _write_lock_irq(lock)
265#define write_lock_bh(lock) _write_lock_bh(lock)
Heiko Carstensbb7bed02009-08-31 14:43:38 +0200266#define spin_unlock(lock) _spin_unlock(lock)
267#define read_unlock(lock) _read_unlock(lock)
268#define write_unlock(lock) _write_unlock(lock)
269#define spin_unlock_irq(lock) _spin_unlock_irq(lock)
270#define read_unlock_irq(lock) _read_unlock_irq(lock)
271#define write_unlock_irq(lock) _write_unlock_irq(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272
Steven Rostedt3f3078912008-07-25 01:45:25 -0700273#define spin_unlock_irqrestore(lock, flags) \
274 do { \
275 typecheck(unsigned long, flags); \
276 _spin_unlock_irqrestore(lock, flags); \
277 } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278#define spin_unlock_bh(lock) _spin_unlock_bh(lock)
279
Steven Rostedt3f3078912008-07-25 01:45:25 -0700280#define read_unlock_irqrestore(lock, flags) \
281 do { \
282 typecheck(unsigned long, flags); \
283 _read_unlock_irqrestore(lock, flags); \
284 } while (0)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700285#define read_unlock_bh(lock) _read_unlock_bh(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286
Steven Rostedt3f3078912008-07-25 01:45:25 -0700287#define write_unlock_irqrestore(lock, flags) \
288 do { \
289 typecheck(unsigned long, flags); \
290 _write_unlock_irqrestore(lock, flags); \
291 } while (0)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700292#define write_unlock_bh(lock) _write_unlock_bh(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
Josh Triplettdcc8e552006-09-29 02:01:03 -0700294#define spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295
296#define spin_trylock_irq(lock) \
297({ \
298 local_irq_disable(); \
Josh Triplett303912e2006-09-29 02:01:00 -0700299 spin_trylock(lock) ? \
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700300 1 : ({ local_irq_enable(); 0; }); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301})
302
303#define spin_trylock_irqsave(lock, flags) \
304({ \
305 local_irq_save(flags); \
Josh Triplett303912e2006-09-29 02:01:00 -0700306 spin_trylock(lock) ? \
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700307 1 : ({ local_irq_restore(flags); 0; }); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308})
309
Satyam Sharmae1f4a882007-07-15 23:39:24 -0700310#define write_trylock_irqsave(lock, flags) \
311({ \
312 local_irq_save(flags); \
313 write_trylock(lock) ? \
314 1 : ({ local_irq_restore(flags); 0; }); \
315})
316
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700317/*
318 * Pull the atomic_t declaration:
319 * (asm-mips/atomic.h needs above definitions)
320 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700321#include <asm/atomic.h>
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700322/**
323 * atomic_dec_and_lock - lock on reaching reference count zero
324 * @atomic: the atomic counter
325 * @lock: the spinlock in question
J. Bruce Fieldsdc07e722008-04-07 15:59:05 -0400326 *
327 * Decrements @atomic by 1. If the result is 0, returns true and locks
328 * @lock. Returns false for all other cases.
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700329 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700331#define atomic_dec_and_lock(atomic, lock) \
Josh Triplettdcc8e552006-09-29 02:01:03 -0700332 __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333
334/**
335 * spin_can_lock - would spin_trylock() succeed?
336 * @lock: the spinlock in question.
337 */
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700338#define spin_can_lock(lock) (!spin_is_locked(lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339
Heiko Carstens69d0ee72009-08-31 14:43:36 +0200340/*
341 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
342 */
343#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
344# include <linux/spinlock_api_smp.h>
345#else
346# include <linux/spinlock_api_up.h>
347#endif
348
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349#endif /* __LINUX_SPINLOCK_H */