Linux v2.6.15-rc6
[pohmelfs.git] / include / linux / spinlock.h
blob0e9682c9def5e0d1a198486435618978829d33ac
1 #ifndef __LINUX_SPINLOCK_H
2 #define __LINUX_SPINLOCK_H
4 /*
5 * include/linux/spinlock.h - generic spinlock/rwlock declarations
7 * here's the role of the various spinlock/rwlock related include files:
9 * on SMP builds:
11 * asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
12 * initializers
14 * linux/spinlock_types.h:
15 * defines the generic type and initializers
17 * asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel
18 * implementations, mostly inline assembly code
20 * (also included on UP-debug builds:)
22 * linux/spinlock_api_smp.h:
23 * contains the prototypes for the _spin_*() APIs.
25 * linux/spinlock.h: builds the final spin_*() APIs.
27 * on UP builds:
29 * linux/spinlock_type_up.h:
30 * contains the generic, simplified UP spinlock type.
31 * (which is an empty structure on non-debug builds)
33 * linux/spinlock_types.h:
34 * defines the generic type and initializers
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)
41 * (included on UP-non-debug builds:)
43 * linux/spinlock_api_up.h:
44 * builds the _spin_*() APIs.
46 * linux/spinlock.h: builds the final spin_*() APIs.
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>
57 #include <asm/system.h>
60 * Must define these before including other files, inline functions need them
62 #define LOCK_SECTION_NAME \
63 ".text.lock." __stringify(KBUILD_BASENAME)
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"
72 #define LOCK_SECTION_END \
73 ".previous\n\t"
75 #define __lockfunc fastcall __attribute__((section(".spinlock.text")))
78 * Pull the raw_spinlock_t and raw_rwlock_t definitions:
80 #include <linux/spinlock_types.h>
82 extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
85 * Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
87 #if defined(CONFIG_SMP)
88 # include <asm/spinlock.h>
89 #else
90 # include <linux/spinlock_up.h>
91 #endif
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)
96 #define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
98 /**
99 * spin_unlock_wait - wait until the spinlock gets unlocked
100 * @lock: the spinlock in question.
102 #define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock)
105 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
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
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);
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
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)
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.
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))
151 #define spin_lock(lock) _spin_lock(lock)
152 #define write_lock(lock) _write_lock(lock)
153 #define read_lock(lock) _read_lock(lock)
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
165 #define spin_lock_irq(lock) _spin_lock_irq(lock)
166 #define spin_lock_bh(lock) _spin_lock_bh(lock)
168 #define read_lock_irq(lock) _read_lock_irq(lock)
169 #define read_lock_bh(lock) _read_lock_bh(lock)
171 #define write_lock_irq(lock) _write_lock_irq(lock)
172 #define write_lock_bh(lock) _write_lock_bh(lock)
175 * We inline the unlock functions in the nondebug case:
177 #if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP)
178 # define spin_unlock(lock) _spin_unlock(lock)
179 # define read_unlock(lock) _read_unlock(lock)
180 # define write_unlock(lock) _write_unlock(lock)
181 #else
182 # define spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
183 # define read_unlock(lock) __raw_read_unlock(&(lock)->raw_lock)
184 # define write_unlock(lock) __raw_write_unlock(&(lock)->raw_lock)
185 #endif
187 #if defined(CONFIG_DEBUG_SPINLOCK) || defined(CONFIG_PREEMPT) || !defined(CONFIG_SMP)
188 # define spin_unlock_irq(lock) _spin_unlock_irq(lock)
189 # define read_unlock_irq(lock) _read_unlock_irq(lock)
190 # define write_unlock_irq(lock) _write_unlock_irq(lock)
191 #else
192 # define spin_unlock_irq(lock) \
193 do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
194 # define read_unlock_irq(lock) \
195 do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
196 # define write_unlock_irq(lock) \
197 do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
198 #endif
200 #define spin_unlock_irqrestore(lock, flags) \
201 _spin_unlock_irqrestore(lock, flags)
202 #define spin_unlock_bh(lock) _spin_unlock_bh(lock)
204 #define read_unlock_irqrestore(lock, flags) \
205 _read_unlock_irqrestore(lock, flags)
206 #define read_unlock_bh(lock) _read_unlock_bh(lock)
208 #define write_unlock_irqrestore(lock, flags) \
209 _write_unlock_irqrestore(lock, flags)
210 #define write_unlock_bh(lock) _write_unlock_bh(lock)
212 #define spin_trylock_bh(lock) __cond_lock(_spin_trylock_bh(lock))
214 #define spin_trylock_irq(lock) \
215 ({ \
216 local_irq_disable(); \
217 _spin_trylock(lock) ? \
218 1 : ({ local_irq_enable(); 0; }); \
221 #define spin_trylock_irqsave(lock, flags) \
222 ({ \
223 local_irq_save(flags); \
224 _spin_trylock(lock) ? \
225 1 : ({ local_irq_restore(flags); 0; }); \
229 * Pull the atomic_t declaration:
230 * (asm-mips/atomic.h needs above definitions)
232 #include <asm/atomic.h>
234 * atomic_dec_and_lock - lock on reaching reference count zero
235 * @atomic: the atomic counter
236 * @lock: the spinlock in question
238 extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
239 #define atomic_dec_and_lock(atomic, lock) \
240 __cond_lock(_atomic_dec_and_lock(atomic, lock))
243 * spin_can_lock - would spin_trylock() succeed?
244 * @lock: the spinlock in question.
246 #define spin_can_lock(lock) (!spin_is_locked(lock))
248 #endif /* __LINUX_SPINLOCK_H */