Linux kernel mirror (for testing)
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linux
1#ifndef __LINUX_SPINLOCK_H
2#define __LINUX_SPINLOCK_H
3
4/*
5 * 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.
47 */
48
49#include <linux/config.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
57#include <asm/system.h>
58
59/*
60 * Must define these before including other files, inline functions need them
61 */
62#define LOCK_SECTION_NAME \
63 ".text.lock." __stringify(KBUILD_BASENAME)
64
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
75#define __lockfunc fastcall __attribute__((section(".spinlock.text")))
76
77/*
78 * Pull the raw_spinlock_t and raw_rwlock_t definitions:
79 */
80#include <linux/spinlock_types.h>
81
82extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
83
84/*
85 * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
86 */
87#if defined(CONFIG_SMP)
88# include <asm/spinlock.h>
89#else
90# include <linux/spinlock_up.h>
91#endif
92
93#define spin_lock_init(lock) do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
94#define rwlock_init(lock) do { *(lock) = RW_LOCK_UNLOCKED; } while (0)
95
96#define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
97
98/**
99 * spin_unlock_wait - wait until the spinlock gets unlocked
100 * @lock: the spinlock in question.
101 */
102#define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock)
103
104/*
105 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
106 */
107#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
108# include <linux/spinlock_api_smp.h>
109#else
110# include <linux/spinlock_api_up.h>
111#endif
112
113#ifdef CONFIG_DEBUG_SPINLOCK
114 extern void _raw_spin_lock(spinlock_t *lock);
115#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
116 extern int _raw_spin_trylock(spinlock_t *lock);
117 extern void _raw_spin_unlock(spinlock_t *lock);
118
119 extern void _raw_read_lock(rwlock_t *lock);
120 extern int _raw_read_trylock(rwlock_t *lock);
121 extern void _raw_read_unlock(rwlock_t *lock);
122 extern void _raw_write_lock(rwlock_t *lock);
123 extern int _raw_write_trylock(rwlock_t *lock);
124 extern void _raw_write_unlock(rwlock_t *lock);
125#else
126# define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
127# define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
128# define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock)
129# define _raw_spin_lock_flags(lock, flags) \
130 __raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
131# define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
132# define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
133# define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
134# define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock)
135# define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
136# define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
137#endif
138
139#define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock)
140#define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock)
141
142/*
143 * Define the various spin_lock and rw_lock methods. Note we define these
144 * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
145 * methods are defined as nops in the case they are not required.
146 */
147#define spin_trylock(lock) __cond_lock(_spin_trylock(lock))
148#define read_trylock(lock) __cond_lock(_read_trylock(lock))
149#define write_trylock(lock) __cond_lock(_write_trylock(lock))
150
151#define spin_lock(lock) _spin_lock(lock)
152#define write_lock(lock) _write_lock(lock)
153#define read_lock(lock) _read_lock(lock)
154
155#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
156#define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock)
157#define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock)
158#define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock)
159#else
160#define spin_lock_irqsave(lock, flags) _spin_lock_irqsave(lock, flags)
161#define read_lock_irqsave(lock, flags) _read_lock_irqsave(lock, flags)
162#define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags)
163#endif
164
165#define spin_lock_irq(lock) _spin_lock_irq(lock)
166#define spin_lock_bh(lock) _spin_lock_bh(lock)
167
168#define read_lock_irq(lock) _read_lock_irq(lock)
169#define read_lock_bh(lock) _read_lock_bh(lock)
170
171#define write_lock_irq(lock) _write_lock_irq(lock)
172#define write_lock_bh(lock) _write_lock_bh(lock)
173
174#define spin_unlock(lock) _spin_unlock(lock)
175#define write_unlock(lock) _write_unlock(lock)
176#define read_unlock(lock) _read_unlock(lock)
177
178#define spin_unlock_irqrestore(lock, flags) \
179 _spin_unlock_irqrestore(lock, flags)
180#define spin_unlock_irq(lock) _spin_unlock_irq(lock)
181#define spin_unlock_bh(lock) _spin_unlock_bh(lock)
182
183#define read_unlock_irqrestore(lock, flags) \
184 _read_unlock_irqrestore(lock, flags)
185#define read_unlock_irq(lock) _read_unlock_irq(lock)
186#define read_unlock_bh(lock) _read_unlock_bh(lock)
187
188#define write_unlock_irqrestore(lock, flags) \
189 _write_unlock_irqrestore(lock, flags)
190#define write_unlock_irq(lock) _write_unlock_irq(lock)
191#define write_unlock_bh(lock) _write_unlock_bh(lock)
192
193#define spin_trylock_bh(lock) __cond_lock(_spin_trylock_bh(lock))
194
195#define spin_trylock_irq(lock) \
196({ \
197 local_irq_disable(); \
198 _spin_trylock(lock) ? \
199 1 : ({ local_irq_enable(); 0; }); \
200})
201
202#define spin_trylock_irqsave(lock, flags) \
203({ \
204 local_irq_save(flags); \
205 _spin_trylock(lock) ? \
206 1 : ({ local_irq_restore(flags); 0; }); \
207})
208
209/*
210 * Pull the atomic_t declaration:
211 * (asm-mips/atomic.h needs above definitions)
212 */
213#include <asm/atomic.h>
214/**
215 * atomic_dec_and_lock - lock on reaching reference count zero
216 * @atomic: the atomic counter
217 * @lock: the spinlock in question
218 */
219extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
220#define atomic_dec_and_lock(atomic, lock) \
221 __cond_lock(_atomic_dec_and_lock(atomic, lock))
222
223/**
224 * spin_can_lock - would spin_trylock() succeed?
225 * @lock: the spinlock in question.
226 */
227#define spin_can_lock(lock) (!spin_is_locked(lock))
228
229#endif /* __LINUX_SPINLOCK_H */