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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
Linus Torvalds1da177e2005-04-16 15:20:36 -070049#include <linux/preempt.h>
50#include <linux/linkage.h>
51#include <linux/compiler.h>
52#include <linux/thread_info.h>
53#include <linux/kernel.h>
54#include <linux/stringify.h>
Andrew Morton676dcb82006-12-06 20:31:30 -080055#include <linux/bottom_half.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
Linus Torvalds1da177e2005-04-16 15:20:36 -070057#include <asm/system.h>
58
59/*
60 * Must define these before including other files, inline functions need them
61 */
Ustyugov Romanf83b5e32005-09-23 08:42:11 +040062#define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64#define LOCK_SECTION_START(extra) \
65 ".subsection 1\n\t" \
66 extra \
67 ".ifndef " LOCK_SECTION_NAME "\n\t" \
68 LOCK_SECTION_NAME ":\n\t" \
69 ".endif\n"
70
71#define LOCK_SECTION_END \
72 ".previous\n\t"
73
Harvey Harrisonec701582008-02-08 04:19:55 -080074#define __lockfunc __attribute__((section(".spinlock.text")))
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76/*
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070077 * Pull the raw_spinlock_t and raw_rwlock_t definitions:
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 */
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070079#include <linux/spinlock_types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070081extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070083/*
84 * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
85 */
Ingo Molnar8a25d5d2006-07-03 00:24:54 -070086#ifdef CONFIG_SMP
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070087# include <asm/spinlock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070088#else
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070089# include <linux/spinlock_up.h>
90#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
Ingo Molnar8a25d5d2006-07-03 00:24:54 -070092#ifdef CONFIG_DEBUG_SPINLOCK
93 extern void __spin_lock_init(spinlock_t *lock, const char *name,
94 struct lock_class_key *key);
95# define spin_lock_init(lock) \
96do { \
97 static struct lock_class_key __key; \
98 \
99 __spin_lock_init((lock), #lock, &__key); \
100} while (0)
101
102#else
103# define spin_lock_init(lock) \
104 do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
105#endif
106
107#ifdef CONFIG_DEBUG_SPINLOCK
108 extern void __rwlock_init(rwlock_t *lock, const char *name,
109 struct lock_class_key *key);
110# define rwlock_init(lock) \
111do { \
112 static struct lock_class_key __key; \
113 \
114 __rwlock_init((lock), #lock, &__key); \
115} while (0)
116#else
117# define rwlock_init(lock) \
118 do { *(lock) = RW_LOCK_UNLOCKED; } while (0)
119#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700121#define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
122
Nick Piggin95c354f2008-01-30 13:31:20 +0100123#ifdef CONFIG_GENERIC_LOCKBREAK
124#define spin_is_contended(lock) ((lock)->break_lock)
125#else
126#define spin_is_contended(lock) __raw_spin_is_contended(&(lock)->raw_lock)
127#endif
128
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700129/**
130 * spin_unlock_wait - wait until the spinlock gets unlocked
131 * @lock: the spinlock in question.
132 */
133#define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock)
134
135/*
136 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
137 */
138#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
139# include <linux/spinlock_api_smp.h>
140#else
141# include <linux/spinlock_api_up.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142#endif
143
144#ifdef CONFIG_DEBUG_SPINLOCK
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700145 extern void _raw_spin_lock(spinlock_t *lock);
146#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
147 extern int _raw_spin_trylock(spinlock_t *lock);
148 extern void _raw_spin_unlock(spinlock_t *lock);
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700149 extern void _raw_read_lock(rwlock_t *lock);
150 extern int _raw_read_trylock(rwlock_t *lock);
151 extern void _raw_read_unlock(rwlock_t *lock);
152 extern void _raw_write_lock(rwlock_t *lock);
153 extern int _raw_write_trylock(rwlock_t *lock);
154 extern void _raw_write_unlock(rwlock_t *lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155#else
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700156# define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock)
157# define _raw_spin_lock_flags(lock, flags) \
158 __raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700159# define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
160# define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700161# define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700162# define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700163# define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
164# define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700165# define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700166# define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167#endif
168
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700169#define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock)
170#define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171
172/*
173 * Define the various spin_lock and rw_lock methods. Note we define these
174 * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
175 * methods are defined as nops in the case they are not required.
176 */
Josh Triplettdcc8e552006-09-29 02:01:03 -0700177#define spin_trylock(lock) __cond_lock(lock, _spin_trylock(lock))
178#define read_trylock(lock) __cond_lock(lock, _read_trylock(lock))
179#define write_trylock(lock) __cond_lock(lock, _write_trylock(lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700181#define spin_lock(lock) _spin_lock(lock)
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700182
183#ifdef CONFIG_DEBUG_LOCK_ALLOC
184# define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
185#else
186# define spin_lock_nested(lock, subclass) _spin_lock(lock)
187#endif
188
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700189#define write_lock(lock) _write_lock(lock)
190#define read_lock(lock) _read_lock(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700192#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
Linus Torvaldsb8e6ec82006-11-26 16:27:17 -0800193
194#define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock)
195#define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock)
196#define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock)
Arjan van de Vencfd3ef22006-11-25 11:09:37 -0800197
198#ifdef CONFIG_DEBUG_LOCK_ALLOC
Linus Torvaldsb8e6ec82006-11-26 16:27:17 -0800199#define spin_lock_irqsave_nested(lock, flags, subclass) \
200 flags = _spin_lock_irqsave_nested(lock, subclass)
Arjan van de Vencfd3ef22006-11-25 11:09:37 -0800201#else
Linus Torvaldsb8e6ec82006-11-26 16:27:17 -0800202#define spin_lock_irqsave_nested(lock, flags, subclass) \
203 flags = _spin_lock_irqsave(lock)
Arjan van de Vencfd3ef22006-11-25 11:09:37 -0800204#endif
205
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206#else
Linus Torvaldsb8e6ec82006-11-26 16:27:17 -0800207
208#define spin_lock_irqsave(lock, flags) _spin_lock_irqsave(lock, flags)
209#define read_lock_irqsave(lock, flags) _read_lock_irqsave(lock, flags)
210#define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags)
Arjan van de Vencfd3ef22006-11-25 11:09:37 -0800211#define spin_lock_irqsave_nested(lock, flags, subclass) \
212 spin_lock_irqsave(lock, flags)
213
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214#endif
215
216#define spin_lock_irq(lock) _spin_lock_irq(lock)
217#define spin_lock_bh(lock) _spin_lock_bh(lock)
218
219#define read_lock_irq(lock) _read_lock_irq(lock)
220#define read_lock_bh(lock) _read_lock_bh(lock)
221
222#define write_lock_irq(lock) _write_lock_irq(lock)
223#define write_lock_bh(lock) _write_lock_bh(lock)
224
Ingo Molnarbda98682005-10-30 14:59:44 -0800225/*
226 * We inline the unlock functions in the nondebug case:
227 */
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700228#if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || \
229 !defined(CONFIG_SMP)
Ingo Molnarbda98682005-10-30 14:59:44 -0800230# define spin_unlock(lock) _spin_unlock(lock)
231# define read_unlock(lock) _read_unlock(lock)
232# define write_unlock(lock) _write_unlock(lock)
Ingo Molnarbda98682005-10-30 14:59:44 -0800233# define spin_unlock_irq(lock) _spin_unlock_irq(lock)
234# define read_unlock_irq(lock) _read_unlock_irq(lock)
235# define write_unlock_irq(lock) _write_unlock_irq(lock)
236#else
Pavel Roskinc75fb882007-02-10 01:46:37 -0800237# define spin_unlock(lock) \
238 do {__raw_spin_unlock(&(lock)->raw_lock); __release(lock); } while (0)
239# define read_unlock(lock) \
240 do {__raw_read_unlock(&(lock)->raw_lock); __release(lock); } while (0)
241# define write_unlock(lock) \
242 do {__raw_write_unlock(&(lock)->raw_lock); __release(lock); } while (0)
243# define spin_unlock_irq(lock) \
244do { \
245 __raw_spin_unlock(&(lock)->raw_lock); \
246 __release(lock); \
247 local_irq_enable(); \
248} while (0)
249# define read_unlock_irq(lock) \
250do { \
251 __raw_read_unlock(&(lock)->raw_lock); \
252 __release(lock); \
253 local_irq_enable(); \
254} while (0)
255# define write_unlock_irq(lock) \
256do { \
257 __raw_write_unlock(&(lock)->raw_lock); \
258 __release(lock); \
259 local_irq_enable(); \
260} while (0)
Ingo Molnarbda98682005-10-30 14:59:44 -0800261#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700263#define spin_unlock_irqrestore(lock, flags) \
Linus Torvaldsb8e6ec82006-11-26 16:27:17 -0800264 _spin_unlock_irqrestore(lock, flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265#define spin_unlock_bh(lock) _spin_unlock_bh(lock)
266
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700267#define read_unlock_irqrestore(lock, flags) \
Linus Torvaldsb8e6ec82006-11-26 16:27:17 -0800268 _read_unlock_irqrestore(lock, flags)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700269#define read_unlock_bh(lock) _read_unlock_bh(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700271#define write_unlock_irqrestore(lock, flags) \
Linus Torvaldsb8e6ec82006-11-26 16:27:17 -0800272 _write_unlock_irqrestore(lock, flags)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700273#define write_unlock_bh(lock) _write_unlock_bh(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
Josh Triplettdcc8e552006-09-29 02:01:03 -0700275#define spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276
277#define spin_trylock_irq(lock) \
278({ \
279 local_irq_disable(); \
Josh Triplett303912e2006-09-29 02:01:00 -0700280 spin_trylock(lock) ? \
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700281 1 : ({ local_irq_enable(); 0; }); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282})
283
284#define spin_trylock_irqsave(lock, flags) \
285({ \
286 local_irq_save(flags); \
Josh Triplett303912e2006-09-29 02:01:00 -0700287 spin_trylock(lock) ? \
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700288 1 : ({ local_irq_restore(flags); 0; }); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289})
290
Satyam Sharmae1f4a882007-07-15 23:39:24 -0700291#define write_trylock_irqsave(lock, flags) \
292({ \
293 local_irq_save(flags); \
294 write_trylock(lock) ? \
295 1 : ({ local_irq_restore(flags); 0; }); \
296})
297
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700298/*
299 * Pull the atomic_t declaration:
300 * (asm-mips/atomic.h needs above definitions)
301 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302#include <asm/atomic.h>
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700303/**
304 * atomic_dec_and_lock - lock on reaching reference count zero
305 * @atomic: the atomic counter
306 * @lock: the spinlock in question
J. Bruce Fieldsdc07e722008-04-07 15:59:05 -0400307 *
308 * Decrements @atomic by 1. If the result is 0, returns true and locks
309 * @lock. Returns false for all other cases.
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700310 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700312#define atomic_dec_and_lock(atomic, lock) \
Josh Triplettdcc8e552006-09-29 02:01:03 -0700313 __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314
315/**
316 * spin_can_lock - would spin_trylock() succeed?
317 * @lock: the spinlock in question.
318 */
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700319#define spin_can_lock(lock) (!spin_is_locked(lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320
321#endif /* __LINUX_SPINLOCK_H */