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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 */
85#if defined(CONFIG_SMP)
86# 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 Molnarfb1c8f92005-09-10 00:25:56 -070091#define spin_lock_init(lock) do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
92#define rwlock_init(lock) do { *(lock) = RW_LOCK_UNLOCKED; } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
Ingo Molnarfb1c8f92005-09-10 00:25:56 -070094#define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
95
96/**
97 * spin_unlock_wait - wait until the spinlock gets unlocked
98 * @lock: the spinlock in question.
99 */
100#define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock)
101
102/*
103 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
104 */
105#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
106# include <linux/spinlock_api_smp.h>
107#else
108# include <linux/spinlock_api_up.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109#endif
110
111#ifdef CONFIG_DEBUG_SPINLOCK
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700112 extern void _raw_spin_lock(spinlock_t *lock);
113#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
114 extern int _raw_spin_trylock(spinlock_t *lock);
115 extern void _raw_spin_unlock(spinlock_t *lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700117 extern void _raw_read_lock(rwlock_t *lock);
118 extern int _raw_read_trylock(rwlock_t *lock);
119 extern void _raw_read_unlock(rwlock_t *lock);
120 extern void _raw_write_lock(rwlock_t *lock);
121 extern int _raw_write_trylock(rwlock_t *lock);
122 extern void _raw_write_unlock(rwlock_t *lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123#else
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700124# define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
125# define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
126# define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock)
127# define _raw_spin_lock_flags(lock, flags) \
128 __raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
129# define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
130# define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
131# define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
132# define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock)
133# define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
134# define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135#endif
136
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700137#define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock)
138#define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
140/*
141 * Define the various spin_lock and rw_lock methods. Note we define these
142 * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
143 * methods are defined as nops in the case they are not required.
144 */
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700145#define spin_trylock(lock) __cond_lock(_spin_trylock(lock))
146#define read_trylock(lock) __cond_lock(_read_trylock(lock))
147#define write_trylock(lock) __cond_lock(_write_trylock(lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700149#define spin_lock(lock) _spin_lock(lock)
150#define write_lock(lock) _write_lock(lock)
151#define read_lock(lock) _read_lock(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700153#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154#define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock)
155#define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock)
156#define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock)
157#else
158#define spin_lock_irqsave(lock, flags) _spin_lock_irqsave(lock, flags)
159#define read_lock_irqsave(lock, flags) _read_lock_irqsave(lock, flags)
160#define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags)
161#endif
162
163#define spin_lock_irq(lock) _spin_lock_irq(lock)
164#define spin_lock_bh(lock) _spin_lock_bh(lock)
165
166#define read_lock_irq(lock) _read_lock_irq(lock)
167#define read_lock_bh(lock) _read_lock_bh(lock)
168
169#define write_lock_irq(lock) _write_lock_irq(lock)
170#define write_lock_bh(lock) _write_lock_bh(lock)
171
Ingo Molnarbda98682005-10-30 14:59:44 -0800172/*
173 * We inline the unlock functions in the nondebug case:
174 */
175#if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP)
176# define spin_unlock(lock) _spin_unlock(lock)
177# define read_unlock(lock) _read_unlock(lock)
178# define write_unlock(lock) _write_unlock(lock)
179#else
180# define spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
181# define read_unlock(lock) __raw_read_unlock(&(lock)->raw_lock)
182# define write_unlock(lock) __raw_write_unlock(&(lock)->raw_lock)
183#endif
184
185#if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP)
186# define spin_unlock_irq(lock) _spin_unlock_irq(lock)
187# define read_unlock_irq(lock) _read_unlock_irq(lock)
188# define write_unlock_irq(lock) _write_unlock_irq(lock)
189#else
190# define spin_unlock_irq(lock) \
191 do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
192# define read_unlock_irq(lock) \
193 do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
194# define write_unlock_irq(lock) \
195 do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
196#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700198#define spin_unlock_irqrestore(lock, flags) \
199 _spin_unlock_irqrestore(lock, flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200#define spin_unlock_bh(lock) _spin_unlock_bh(lock)
201
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700202#define read_unlock_irqrestore(lock, flags) \
203 _read_unlock_irqrestore(lock, flags)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700204#define read_unlock_bh(lock) _read_unlock_bh(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700206#define write_unlock_irqrestore(lock, flags) \
207 _write_unlock_irqrestore(lock, flags)
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700208#define write_unlock_bh(lock) _write_unlock_bh(lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700210#define spin_trylock_bh(lock) __cond_lock(_spin_trylock_bh(lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211
212#define spin_trylock_irq(lock) \
213({ \
214 local_irq_disable(); \
215 _spin_trylock(lock) ? \
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700216 1 : ({ local_irq_enable(); 0; }); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217})
218
219#define spin_trylock_irqsave(lock, flags) \
220({ \
221 local_irq_save(flags); \
222 _spin_trylock(lock) ? \
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700223 1 : ({ local_irq_restore(flags); 0; }); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224})
225
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700226/*
227 * Pull the atomic_t declaration:
228 * (asm-mips/atomic.h needs above definitions)
229 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230#include <asm/atomic.h>
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700231/**
232 * atomic_dec_and_lock - lock on reaching reference count zero
233 * @atomic: the atomic counter
234 * @lock: the spinlock in question
235 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700237#define atomic_dec_and_lock(atomic, lock) \
238 __cond_lock(_atomic_dec_and_lock(atomic, lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239
240/**
241 * spin_can_lock - would spin_trylock() succeed?
242 * @lock: the spinlock in question.
243 */
Ingo Molnarfb1c8f92005-09-10 00:25:56 -0700244#define spin_can_lock(lock) (!spin_is_locked(lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245
246#endif /* __LINUX_SPINLOCK_H */