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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>
55
Linus Torvalds1da177e2005-04-16 15:20:36 -070056#include <asm/system.h>
57
58/*
59 * Must define these before including other files, inline functions need them
60 */
Ustyugov Romanf83b5e32005-09-23 08:42:11 +040061#define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
63#define LOCK_SECTION_START(extra) \
64 ".subsection 1\n\t" \
65 extra \
66 ".ifndef " LOCK_SECTION_NAME "\n\t" \
67 LOCK_SECTION_NAME ":\n\t" \
68 ".endif\n"
69
70#define LOCK_SECTION_END \
71 ".previous\n\t"
72
73#define __lockfunc fastcall __attribute__((section(".spinlock.text")))
74
75/*
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070076 * Pull the raw_spinlock_t and raw_rwlock_t definitions:
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 */
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070078#include <linux/spinlock_types.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070079
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070080extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070082/*
83 * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
84 */
Ingo Molnar8a25d5d2006-07-03 00:24:54 -070085#ifdef CONFIG_SMP
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070086# include <asm/spinlock.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070087#else
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070088# include <linux/spinlock_up.h>
89#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
Ingo Molnar8a25d5d2006-07-03 00:24:54 -070091#ifdef CONFIG_DEBUG_SPINLOCK
92 extern void __spin_lock_init(spinlock_t *lock, const char *name,
93 struct lock_class_key *key);
94# define spin_lock_init(lock) \
95do { \
96 static struct lock_class_key __key; \
97 \
98 __spin_lock_init((lock), #lock, &__key); \
99} while (0)
100
101#else
102# define spin_lock_init(lock) \
103 do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
104#endif
105
106#ifdef CONFIG_DEBUG_SPINLOCK
107 extern void __rwlock_init(rwlock_t *lock, const char *name,
108 struct lock_class_key *key);
109# define rwlock_init(lock) \
110do { \
111 static struct lock_class_key __key; \
112 \
113 __rwlock_init((lock), #lock, &__key); \
114} while (0)
115#else
116# define rwlock_init(lock) \
117 do { *(lock) = RW_LOCK_UNLOCKED; } while (0)
118#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700120#define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
121
122/**
123 * spin_unlock_wait - wait until the spinlock gets unlocked
124 * @lock: the spinlock in question.
125 */
126#define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock)
127
128/*
129 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
130 */
131#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
132# include <linux/spinlock_api_smp.h>
133#else
134# include <linux/spinlock_api_up.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135#endif
136
137#ifdef CONFIG_DEBUG_SPINLOCK
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700138 extern void _raw_spin_lock(spinlock_t *lock);
139#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
140 extern int _raw_spin_trylock(spinlock_t *lock);
141 extern void _raw_spin_unlock(spinlock_t *lock);
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700142 extern void _raw_read_lock(rwlock_t *lock);
143 extern int _raw_read_trylock(rwlock_t *lock);
144 extern void _raw_read_unlock(rwlock_t *lock);
145 extern void _raw_write_lock(rwlock_t *lock);
146 extern int _raw_write_trylock(rwlock_t *lock);
147 extern void _raw_write_unlock(rwlock_t *lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148#else
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700149# define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock)
150# define _raw_spin_lock_flags(lock, flags) \
151 __raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700152# define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
153# define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700154# define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700155# define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700156# define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
157# define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700158# define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700159# define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160#endif
161
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700162#define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock)
163#define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
165/*
166 * Define the various spin_lock and rw_lock methods. Note we define these
167 * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
168 * methods are defined as nops in the case they are not required.
169 */
Josh Triplettdcc8e552006-09-29 02:01:03 -0700170#define spin_trylock(lock) __cond_lock(lock, _spin_trylock(lock))
171#define read_trylock(lock) __cond_lock(lock, _read_trylock(lock))
172#define write_trylock(lock) __cond_lock(lock, _write_trylock(lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700174#define spin_lock(lock) _spin_lock(lock)
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700175
176#ifdef CONFIG_DEBUG_LOCK_ALLOC
177# define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass)
178#else
179# define spin_lock_nested(lock, subclass) _spin_lock(lock)
180#endif
181
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700182#define write_lock(lock) _write_lock(lock)
183#define read_lock(lock) _read_lock(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700185#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186#define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock)
187#define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock)
188#define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock)
189#else
190#define spin_lock_irqsave(lock, flags) _spin_lock_irqsave(lock, flags)
191#define read_lock_irqsave(lock, flags) _read_lock_irqsave(lock, flags)
192#define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags)
193#endif
194
195#define spin_lock_irq(lock) _spin_lock_irq(lock)
196#define spin_lock_bh(lock) _spin_lock_bh(lock)
197
198#define read_lock_irq(lock) _read_lock_irq(lock)
199#define read_lock_bh(lock) _read_lock_bh(lock)
200
201#define write_lock_irq(lock) _write_lock_irq(lock)
202#define write_lock_bh(lock) _write_lock_bh(lock)
203
Ingo Molnarbda98682005-10-30 14:59:44 -0800204/*
205 * We inline the unlock functions in the nondebug case:
206 */
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700207#if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || \
208 !defined(CONFIG_SMP)
Ingo Molnarbda98682005-10-30 14:59:44 -0800209# define spin_unlock(lock) _spin_unlock(lock)
210# define read_unlock(lock) _read_unlock(lock)
211# define write_unlock(lock) _write_unlock(lock)
Ingo Molnarbda98682005-10-30 14:59:44 -0800212# define spin_unlock_irq(lock) _spin_unlock_irq(lock)
213# define read_unlock_irq(lock) _read_unlock_irq(lock)
214# define write_unlock_irq(lock) _write_unlock_irq(lock)
215#else
Ingo Molnar8a25d5d2006-07-03 00:24:54 -0700216# define spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
217# define read_unlock(lock) __raw_read_unlock(&(lock)->raw_lock)
218# define write_unlock(lock) __raw_write_unlock(&(lock)->raw_lock)
Ingo Molnarbda98682005-10-30 14:59:44 -0800219# define spin_unlock_irq(lock) \
220 do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
221# define read_unlock_irq(lock) \
222 do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
223# define write_unlock_irq(lock) \
224 do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
225#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700227#define spin_unlock_irqrestore(lock, flags) \
228 _spin_unlock_irqrestore(lock, flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229#define spin_unlock_bh(lock) _spin_unlock_bh(lock)
230
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700231#define read_unlock_irqrestore(lock, flags) \
232 _read_unlock_irqrestore(lock, flags)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700233#define read_unlock_bh(lock) _read_unlock_bh(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700235#define write_unlock_irqrestore(lock, flags) \
236 _write_unlock_irqrestore(lock, flags)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700237#define write_unlock_bh(lock) _write_unlock_bh(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238
Josh Triplettdcc8e552006-09-29 02:01:03 -0700239#define spin_trylock_bh(lock) __cond_lock(lock, _spin_trylock_bh(lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240
241#define spin_trylock_irq(lock) \
242({ \
243 local_irq_disable(); \
Josh Triplett303912e2006-09-29 02:01:00 -0700244 spin_trylock(lock) ? \
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700245 1 : ({ local_irq_enable(); 0; }); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246})
247
248#define spin_trylock_irqsave(lock, flags) \
249({ \
250 local_irq_save(flags); \
Josh Triplett303912e2006-09-29 02:01:00 -0700251 spin_trylock(lock) ? \
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700252 1 : ({ local_irq_restore(flags); 0; }); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253})
254
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700255/*
256 * Pull the atomic_t declaration:
257 * (asm-mips/atomic.h needs above definitions)
258 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259#include <asm/atomic.h>
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700260/**
261 * atomic_dec_and_lock - lock on reaching reference count zero
262 * @atomic: the atomic counter
263 * @lock: the spinlock in question
264 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700265extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700266#define atomic_dec_and_lock(atomic, lock) \
Josh Triplettdcc8e552006-09-29 02:01:03 -0700267 __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
269/**
270 * spin_can_lock - would spin_trylock() succeed?
271 * @lock: the spinlock in question.
272 */
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700273#define spin_can_lock(lock) (!spin_is_locked(lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
275#endif /* __LINUX_SPINLOCK_H */