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
__raw_spin_lock(raw_spinlock_t * lock)23 static inline void __raw_spin_lock(raw_spinlock_t *lock)
24 {
25 lock->slock = 0;
26 }
27
28 static inline void
__raw_spin_lock_flags(raw_spinlock_t * lock,unsigned long flags)29 __raw_spin_lock_flags(raw_spinlock_t *lock, unsigned long flags)
30 {
31 local_irq_save(flags);
32 lock->slock = 0;
33 }
34
__raw_spin_trylock(raw_spinlock_t * lock)35 static 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
__raw_spin_unlock(raw_spinlock_t * lock)44 static 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_spin_is_contended(lock) (((void)(lock), 0))
68
69 #define __raw_read_can_lock(lock) (((void)(lock), 1))
70 #define __raw_write_can_lock(lock) (((void)(lock), 1))
71
72 #define __raw_spin_unlock_wait(lock) \
73 do { cpu_relax(); } while (__raw_spin_is_locked(lock))
74
75 #endif /* __LINUX_SPINLOCK_UP_H */
76