1 #ifdef __KERNEL__
2 #ifndef __ASM_SPINLOCK_H
3 #define __ASM_SPINLOCK_H
4
5 /*
6 * Simple spin lock operations.
7 */
8
9 typedef struct {
10 volatile unsigned long lock;
11 volatile unsigned long owner_pc;
12 volatile unsigned long owner_cpu;
13 } spinlock_t;
14
15 #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0, 0, 0 }
16 #define spin_lock_init(lp) do { (lp)->lock = 0; } while(0)
17 #define spin_unlock_wait(lp) do { barrier(); } while((lp)->lock)
18 #define spin_is_locked(x) ((x)->lock != 0)
19
20 extern void _spin_lock(spinlock_t *lock);
21 extern void _spin_unlock(spinlock_t *lock);
22 extern int spin_trylock(spinlock_t *lock);
23
24 #define spin_lock(lp) _spin_lock(lp)
25 #define spin_unlock(lp) _spin_unlock(lp)
26
27 extern unsigned long __spin_trylock(volatile unsigned long *lock);
28
29 /*
30 * Read-write spinlocks, allowing multiple readers
31 * but only one writer.
32 *
33 * NOTE! it is quite common to have readers in interrupts
34 * but no interrupt writers. For those circumstances we
35 * can "mix" irq-safe locks - any writer needs to get a
36 * irq-safe write-lock, but readers can get non-irqsafe
37 * read-locks.
38 */
39 typedef struct {
40 volatile unsigned long lock;
41 volatile unsigned long owner_pc;
42 } rwlock_t;
43
44 #define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 }
45 #define rwlock_init(lp) do { *(lp) = RW_LOCK_UNLOCKED; } while(0)
46
47 extern void _read_lock(rwlock_t *rw);
48 extern void _read_unlock(rwlock_t *rw);
49 extern void _write_lock(rwlock_t *rw);
50 extern void _write_unlock(rwlock_t *rw);
51
52 #define read_lock(rw) _read_lock(rw)
53 #define write_lock(rw) _write_lock(rw)
54 #define write_unlock(rw) _write_unlock(rw)
55 #define read_unlock(rw) _read_unlock(rw)
56
57 #endif /* __ASM_SPINLOCK_H */
58 #endif /* __KERNEL__ */
59
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