Merge git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/v4l-dvb
[linux-2.6] / include / linux / smp_lock.h
1 #ifndef __LINUX_SMPLOCK_H
2 #define __LINUX_SMPLOCK_H
3
4 #ifdef CONFIG_LOCK_KERNEL
5 #include <linux/sched.h>
6
7 #define kernel_locked()         (current->lock_depth >= 0)
8
9 extern int __lockfunc __reacquire_kernel_lock(void);
10 extern void __lockfunc __release_kernel_lock(void);
11
12 /*
13  * Release/re-acquire global kernel lock for the scheduler
14  */
15 #define release_kernel_lock(tsk) do {           \
16         if (unlikely((tsk)->lock_depth >= 0))   \
17                 __release_kernel_lock();        \
18 } while (0)
19
20 static inline int reacquire_kernel_lock(struct task_struct *task)
21 {
22         if (unlikely(task->lock_depth >= 0))
23                 return __reacquire_kernel_lock();
24         return 0;
25 }
26
27 extern void __lockfunc lock_kernel(void)        __acquires(kernel_lock);
28 extern void __lockfunc unlock_kernel(void)      __releases(kernel_lock);
29
30 #else
31
32 #define lock_kernel()                           do { } while(0)
33 #define unlock_kernel()                         do { } while(0)
34 #define release_kernel_lock(task)               do { } while(0)
35 #define reacquire_kernel_lock(task)             0
36 #define kernel_locked()                         1
37
38 #endif /* CONFIG_LOCK_KERNEL */
39 #endif /* __LINUX_SMPLOCK_H */