[deliverable/linux.git] / include / linux / smp_lock.h

#ifndef __LINUX_SMPLOCK_H
#define __LINUX_SMPLOCK_H

#ifdef CONFIG_LOCK_KERNEL
#include <linux/sched.h>

#define kernel_locked()		(current->lock_depth >= 0)

extern int __lockfunc __reacquire_kernel_lock(void);
extern void __lockfunc __release_kernel_lock(void);

/*
 * Release/re-acquire global kernel lock for the scheduler
 */
#define release_kernel_lock(tsk) do { 		\
	if (unlikely((tsk)->lock_depth >= 0))	\
		__release_kernel_lock();	\
} while (0)

static inline int reacquire_kernel_lock(struct task_struct *task)
{
	if (unlikely(task->lock_depth >= 0))
		return __reacquire_kernel_lock();
	return 0;
}

extern void __lockfunc lock_kernel(void)	__acquires(kernel_lock);
extern void __lockfunc unlock_kernel(void)	__releases(kernel_lock);

/*
 * Various legacy drivers don't really need the BKL in a specific
 * function, but they *do* need to know that the BKL became available.
 * This function just avoids wrapping a bunch of lock/unlock pairs
 * around code which doesn't really need it.
 */
static inline void cycle_kernel_lock(void)
{
	lock_kernel();
	unlock_kernel();
}

#else

#define lock_kernel()				do { } while(0)
#define unlock_kernel()				do { } while(0)
#define release_kernel_lock(task)		do { } while(0)
#define cycle_kernel_lock()			do { } while(0)
#define reacquire_kernel_lock(task)		0
#define kernel_locked()				1

#endif /* CONFIG_LOCK_KERNEL */
#endif /* __LINUX_SMPLOCK_H */
Commit	Line	Data
1da177e4 LT	1	#ifndef __LINUX_SMPLOCK_H
	2	#define __LINUX_SMPLOCK_H
	3
f037360f	4	#ifdef CONFIG_LOCK_KERNEL
1da177e4	5	#include <linux/sched.h>
1da177e4	6
1da177e4 LT	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
1da177e4 LT	20	static inline int reacquire_kernel_lock(struct task_struct *task)
	21	{
	22	if (unlikely(task->lock_depth >= 0))
6478d880	23	return __reacquire_kernel_lock();
1da177e4 LT	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
0b280676 JC	30	/*
	31	* Various legacy drivers don't really need the BKL in a specific
	32	* function, but they do need to know that the BKL became available.
	33	* This function just avoids wrapping a bunch of lock/unlock pairs
	34	* around code which doesn't really need it.
	35	*/
	36	static inline void cycle_kernel_lock(void)
	37	{
	38	lock_kernel();
	39	unlock_kernel();
	40	}
	41
1da177e4 LT	42	#else
	43
	44	#define lock_kernel() do { } while(0)
	45	#define unlock_kernel() do { } while(0)
	46	#define release_kernel_lock(task) do { } while(0)
0b280676	47	#define cycle_kernel_lock() do { } while(0)
1da177e4 LT	48	#define reacquire_kernel_lock(task) 0
	49	#define kernel_locked() 1
	50
	51	#endif /* CONFIG_LOCK_KERNEL */
	52	#endif /* __LINUX_SMPLOCK_H */