Revert "[PATCH] Enforce "unsigned long flags;" when spinlocking"
[sfrench/cifs-2.6.git] / include / linux / spinlock.h
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/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
56 #include <asm/system.h>
57
58 /*
59  * Must define these before including other files, inline functions need them
60  */
61 #define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
62
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 /*
76  * Pull the raw_spinlock_t and raw_rwlock_t definitions:
77  */
78 #include <linux/spinlock_types.h>
79
80 extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
81
82 /*
83  * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
84  */
85 #ifdef CONFIG_SMP
86 # include <asm/spinlock.h>
87 #else
88 # include <linux/spinlock_up.h>
89 #endif
90
91 #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)                                   \
95 do {                                                            \
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)                                      \
110 do {                                                            \
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
119
120 #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>
135 #endif
136
137 #ifdef CONFIG_DEBUG_SPINLOCK
138  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);
142  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);
148 #else
149 # 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))
152 # define _raw_spin_trylock(lock)        __raw_spin_trylock(&(lock)->raw_lock)
153 # define _raw_spin_unlock(lock)         __raw_spin_unlock(&(lock)->raw_lock)
154 # define _raw_read_lock(rwlock)         __raw_read_lock(&(rwlock)->raw_lock)
155 # define _raw_read_trylock(rwlock)      __raw_read_trylock(&(rwlock)->raw_lock)
156 # define _raw_read_unlock(rwlock)       __raw_read_unlock(&(rwlock)->raw_lock)
157 # define _raw_write_lock(rwlock)        __raw_write_lock(&(rwlock)->raw_lock)
158 # define _raw_write_trylock(rwlock)     __raw_write_trylock(&(rwlock)->raw_lock)
159 # define _raw_write_unlock(rwlock)      __raw_write_unlock(&(rwlock)->raw_lock)
160 #endif
161
162 #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)
164
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  */
170 #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))
173
174 #define spin_lock(lock)                 _spin_lock(lock)
175
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
182 #define write_lock(lock)                _write_lock(lock)
183 #define read_lock(lock)                 _read_lock(lock)
184
185 #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
186
187 #define spin_lock_irqsave(lock, flags)  flags = _spin_lock_irqsave(lock)
188 #define read_lock_irqsave(lock, flags)  flags = _read_lock_irqsave(lock)
189 #define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock)
190
191 #ifdef CONFIG_DEBUG_LOCK_ALLOC
192 #define spin_lock_irqsave_nested(lock, flags, subclass) \
193         flags = _spin_lock_irqsave_nested(lock, subclass)
194 #else
195 #define spin_lock_irqsave_nested(lock, flags, subclass) \
196         flags = _spin_lock_irqsave(lock)
197 #endif
198
199 #else
200
201 #define spin_lock_irqsave(lock, flags)  _spin_lock_irqsave(lock, flags)
202 #define read_lock_irqsave(lock, flags)  _read_lock_irqsave(lock, flags)
203 #define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags)
204 #define spin_lock_irqsave_nested(lock, flags, subclass) \
205         spin_lock_irqsave(lock, flags)
206
207 #endif
208
209 #define spin_lock_irq(lock)             _spin_lock_irq(lock)
210 #define spin_lock_bh(lock)              _spin_lock_bh(lock)
211
212 #define read_lock_irq(lock)             _read_lock_irq(lock)
213 #define read_lock_bh(lock)              _read_lock_bh(lock)
214
215 #define write_lock_irq(lock)            _write_lock_irq(lock)
216 #define write_lock_bh(lock)             _write_lock_bh(lock)
217
218 /*
219  * We inline the unlock functions in the nondebug case:
220  */
221 #if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || \
222         !defined(CONFIG_SMP)
223 # define spin_unlock(lock)              _spin_unlock(lock)
224 # define read_unlock(lock)              _read_unlock(lock)
225 # define write_unlock(lock)             _write_unlock(lock)
226 # define spin_unlock_irq(lock)          _spin_unlock_irq(lock)
227 # define read_unlock_irq(lock)          _read_unlock_irq(lock)
228 # define write_unlock_irq(lock)         _write_unlock_irq(lock)
229 #else
230 # define spin_unlock(lock)              __raw_spin_unlock(&(lock)->raw_lock)
231 # define read_unlock(lock)              __raw_read_unlock(&(lock)->raw_lock)
232 # define write_unlock(lock)             __raw_write_unlock(&(lock)->raw_lock)
233 # define spin_unlock_irq(lock) \
234     do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
235 # define read_unlock_irq(lock) \
236     do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
237 # define write_unlock_irq(lock) \
238     do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
239 #endif
240
241 #define spin_unlock_irqrestore(lock, flags) \
242                                         _spin_unlock_irqrestore(lock, flags)
243 #define spin_unlock_bh(lock)            _spin_unlock_bh(lock)
244
245 #define read_unlock_irqrestore(lock, flags) \
246                                         _read_unlock_irqrestore(lock, flags)
247 #define read_unlock_bh(lock)            _read_unlock_bh(lock)
248
249 #define write_unlock_irqrestore(lock, flags) \
250                                         _write_unlock_irqrestore(lock, flags)
251 #define write_unlock_bh(lock)           _write_unlock_bh(lock)
252
253 #define spin_trylock_bh(lock)   __cond_lock(lock, _spin_trylock_bh(lock))
254
255 #define spin_trylock_irq(lock) \
256 ({ \
257         local_irq_disable(); \
258         spin_trylock(lock) ? \
259         1 : ({ local_irq_enable(); 0;  }); \
260 })
261
262 #define spin_trylock_irqsave(lock, flags) \
263 ({ \
264         local_irq_save(flags); \
265         spin_trylock(lock) ? \
266         1 : ({ local_irq_restore(flags); 0; }); \
267 })
268
269 /*
270  * Pull the atomic_t declaration:
271  * (asm-mips/atomic.h needs above definitions)
272  */
273 #include <asm/atomic.h>
274 /**
275  * atomic_dec_and_lock - lock on reaching reference count zero
276  * @atomic: the atomic counter
277  * @lock: the spinlock in question
278  */
279 extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
280 #define atomic_dec_and_lock(atomic, lock) \
281                 __cond_lock(lock, _atomic_dec_and_lock(atomic, lock))
282
283 /**
284  * spin_can_lock - would spin_trylock() succeed?
285  * @lock: the spinlock in question.
286  */
287 #define spin_can_lock(lock)     (!spin_is_locked(lock))
288
289 #endif /* __LINUX_SPINLOCK_H */