1 #ifndef _LWK_SPINLOCK_H
2 #define _LWK_SPINLOCK_H
5 * include/lwk/spinlock.h - generic spinlock/rwlock declarations
7 * here's the role of the various spinlock/rwlock related include files:
9 * arch/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
12 * lwk/spinlock_types.h:
13 * defines the generic type and initializers
15 * arch/spinlock.h: contains the __raw_spin_*()/etc. lowlevel
16 * implementations, mostly inline assembly code
18 * lwk/spinlock_api_smp.h:
19 * contains the prototypes for the _spin_*() APIs.
21 * lwk/spinlock.h: builds the final spin_*() APIs.
23 * lwk/spinlock.h: builds the final spin_*() APIs.
26 #include <lwk/kernel.h>
27 #include <lwk/linkage.h>
28 #include <lwk/compiler.h>
29 #include <lwk/stringify.h>
30 #include <arch/system.h>
33 * Must define these before including other files, inline functions need them
35 #define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
37 #define LOCK_SECTION_START(extra) \
40 ".ifndef " LOCK_SECTION_NAME "\n\t" \
41 LOCK_SECTION_NAME ":\n\t" \
44 #define LOCK_SECTION_END \
47 #define __lockfunc fastcall __attribute__((section(".spinlock.text")))
50 * Pull the raw_spinlock_t and raw_rwlock_t definitions:
52 #include <lwk/spinlock_types.h>
54 extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
57 * Pull the __raw*() functions/declarations:
59 # include <arch/spinlock.h>
61 #define spin_lock_init(lock) do { *(lock) = (spinlock_t)SPIN_LOCK_UNLOCKED; } while (0)
62 #define rwlock_init(lock) do { *(lock) = (rwlock_t)RW_LOCK_UNLOCKED; } while (0)
64 #define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
67 * spin_unlock_wait - wait until the spinlock gets unlocked
68 * @lock: the spinlock in question.
70 #define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock)
73 * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
75 #include <lwk/spinlock_api_smp.h>
77 #ifdef CONFIG_DEBUG_SPINLOCK
78 extern void _raw_spin_lock(spinlock_t *lock);
79 #define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
80 extern int _raw_spin_trylock(spinlock_t *lock);
81 extern void _raw_spin_unlock(spinlock_t *lock);
83 extern void _raw_read_lock(rwlock_t *lock);
84 extern int _raw_read_trylock(rwlock_t *lock);
85 extern void _raw_read_unlock(rwlock_t *lock);
86 extern void _raw_write_lock(rwlock_t *lock);
87 extern int _raw_write_trylock(rwlock_t *lock);
88 extern void _raw_write_unlock(rwlock_t *lock);
90 # define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
91 # define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
92 # define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock)
93 # define _raw_spin_lock_flags(lock, flags) \
94 __raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
95 # define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
96 # define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
97 # define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
98 # define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock)
99 # define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
100 # define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
103 #define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock)
104 #define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock)
107 * Define the various spin_lock and rw_lock methods.
109 #define spin_trylock(lock) __cond_lock(_spin_trylock(lock))
110 #define read_trylock(lock) __cond_lock(_read_trylock(lock))
111 #define write_trylock(lock) __cond_lock(_write_trylock(lock))
113 #define spin_lock(lock) _spin_lock(lock)
114 #define write_lock(lock) _write_lock(lock)
115 #define read_lock(lock) _read_lock(lock)
117 #define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock)
118 #define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock)
119 #define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock)
121 #define spin_lock_irq(lock) _spin_lock_irq(lock)
122 #define spin_lock_bh(lock) _spin_lock_bh(lock)
124 #define read_lock_irq(lock) _read_lock_irq(lock)
125 #define read_lock_bh(lock) _read_lock_bh(lock)
127 #define write_lock_irq(lock) _write_lock_irq(lock)
128 #define write_lock_bh(lock) _write_lock_bh(lock)
131 * We inline the unlock functions in the nondebug case:
133 #if defined(CONFIG_DEBUG_SPINLOCK)
134 # define spin_unlock(lock) _spin_unlock(lock)
135 # define read_unlock(lock) _read_unlock(lock)
136 # define write_unlock(lock) _write_unlock(lock)
138 # define spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
139 # define read_unlock(lock) __raw_read_unlock(&(lock)->raw_lock)
140 # define write_unlock(lock) __raw_write_unlock(&(lock)->raw_lock)
143 #if defined(CONFIG_DEBUG_SPINLOCK)
144 # define spin_unlock_irq(lock) _spin_unlock_irq(lock)
145 # define read_unlock_irq(lock) _read_unlock_irq(lock)
146 # define write_unlock_irq(lock) _write_unlock_irq(lock)
148 # define spin_unlock_irq(lock) \
149 do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
150 # define read_unlock_irq(lock) \
151 do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
152 # define write_unlock_irq(lock) \
153 do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
156 #define spin_unlock_irqrestore(lock, flags) \
157 _spin_unlock_irqrestore(lock, flags)
158 #define spin_unlock_bh(lock) _spin_unlock_bh(lock)
160 #define read_unlock_irqrestore(lock, flags) \
161 _read_unlock_irqrestore(lock, flags)
162 #define read_unlock_bh(lock) _read_unlock_bh(lock)
164 #define write_unlock_irqrestore(lock, flags) \
165 _write_unlock_irqrestore(lock, flags)
166 #define write_unlock_bh(lock) _write_unlock_bh(lock)
168 #define spin_trylock_bh(lock) __cond_lock(_spin_trylock_bh(lock))
170 #define spin_trylock_irq(lock) \
172 local_irq_disable(); \
173 _spin_trylock(lock) ? \
174 1 : ({ local_irq_enable(); 0; }); \
177 #define spin_trylock_irqsave(lock, flags) \
179 local_irq_save(flags); \
180 _spin_trylock(lock) ? \
181 1 : ({ local_irq_restore(flags); 0; }); \
185 * Pull the atomic_t declaration:
186 * (asm-mips/atomic.h needs above definitions)
188 #include <arch/atomic.h>
190 * atomic_dec_and_lock - lock on reaching reference count zero
191 * @atomic: the atomic counter
192 * @lock: the spinlock in question
194 extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
195 #define atomic_dec_and_lock(atomic, lock) \
196 __cond_lock(_atomic_dec_and_lock(atomic, lock))
199 * spin_can_lock - would spin_trylock() succeed?
200 * @lock: the spinlock in question.
202 #define spin_can_lock(lock) (!spin_is_locked(lock))
204 #endif /* _LWK_SPINLOCK_H */