Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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
22#define __raw_spin_is_locked(x) ((x)->slock == 0)
23
24static inline void __raw_spin_lock(raw_spinlock_t *lock)
25{
26 lock->slock = 0;
27}
28
29static inline void
30__raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
31{
32 local_irq_save(flags);
33 lock->slock = 0;
34}
35
36static inline int __raw_spin_trylock(raw_spinlock_t *lock)
37{
38 char oldval = lock->slock;
39
40 lock->slock = 0;
41
42 return oldval > 0;
43}
44
45static inline void __raw_spin_unlock(raw_spinlock_t *lock)
46{
47 lock->slock = 1;
48}
49
50/*
51 * Read-write spinlocks. No debug version.
52 */
53#define __raw_read_lock(lock) do { (void)(lock); } while (0)
54#define __raw_write_lock(lock) do { (void)(lock); } while (0)
55#define __raw_read_trylock(lock) ({ (void)(lock); 1; })
56#define __raw_write_trylock(lock) ({ (void)(lock); 1; })
57#define __raw_read_unlock(lock) do { (void)(lock); } while (0)
58#define __raw_write_unlock(lock) do { (void)(lock); } while (0)
59
60#else /* DEBUG_SPINLOCK */
61#define __raw_spin_is_locked(lock) ((void)(lock), 0)
62/* for sched.c and kernel_lock.c: */
63# define __raw_spin_lock(lock) do { (void)(lock); } while (0)
64# define __raw_spin_unlock(lock) do { (void)(lock); } while (0)
65# define __raw_spin_trylock(lock) ({ (void)(lock); 1; })
66#endif /* DEBUG_SPINLOCK */
67
68#define __raw_read_can_lock(lock) (((void)(lock), 1))
69#define __raw_write_can_lock(lock) (((void)(lock), 1))
70
71#define __raw_spin_unlock_wait(lock) \
72 do { cpu_relax(); } while (__raw_spin_is_locked(lock))
73
74#endif /* __LINUX_SPINLOCK_UP_H */