1#ifndef __LINUX_SPINLOCK_UP_H
2#define __LINUX_SPINLOCK_UP_H
3
4#ifndef __LINUX_SPINLOCK_H
5# error "please don't include this file directly"
6#endif
7
8/*
9 * include/linux/spinlock_up.h - UP-debug version of spinlocks.
10 *
11 * portions Copyright 2005, Red Hat, Inc., Ingo Molnar
12 * Released under the General Public License (GPL).
13 *
14 * In the debug case, 1 means unlocked, 0 means locked. (the values
15 * are inverted, to catch initialization bugs)
16 *
17 * No atomicity anywhere, we are on UP.
18 */
19
20#ifdef CONFIG_DEBUG_SPINLOCK
21#define __raw_spin_is_locked(x)		((x)->slock == 0)
22
23static inline void __raw_spin_lock(raw_spinlock_t *lock)
24{
25	lock->slock = 0;
26}
27
28static inline void
29__raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
30{
31	local_irq_save(flags);
32	lock->slock = 0;
33}
34
35static inline int __raw_spin_trylock(raw_spinlock_t *lock)
36{
37	char oldval = lock->slock;
38
39	lock->slock = 0;
40
41	return oldval > 0;
42}
43
44static inline void __raw_spin_unlock(raw_spinlock_t *lock)
45{
46	lock->slock = 1;
47}
48
49/*
50 * Read-write spinlocks. No debug version.
51 */
52#define __raw_read_lock(lock)		do { (void)(lock); } while (0)
53#define __raw_write_lock(lock)		do { (void)(lock); } while (0)
54#define __raw_read_trylock(lock)	({ (void)(lock); 1; })
55#define __raw_write_trylock(lock)	({ (void)(lock); 1; })
56#define __raw_read_unlock(lock)		do { (void)(lock); } while (0)
57#define __raw_write_unlock(lock)	do { (void)(lock); } while (0)
58
59#else /* DEBUG_SPINLOCK */
60#define __raw_spin_is_locked(lock)	((void)(lock), 0)
61/* for sched.c and kernel_lock.c: */
62# define __raw_spin_lock(lock)		do { (void)(lock); } while (0)
63# define __raw_spin_unlock(lock)	do { (void)(lock); } while (0)
64# define __raw_spin_trylock(lock)	({ (void)(lock); 1; })
65#endif /* DEBUG_SPINLOCK */
66
67#define __raw_read_can_lock(lock)	(((void)(lock), 1))
68#define __raw_write_can_lock(lock)	(((void)(lock), 1))
69
70#define __raw_spin_unlock_wait(lock) \
71		do { cpu_relax(); } while (__raw_spin_is_locked(lock))
72
73#endif /* __LINUX_SPINLOCK_UP_H */
74