swh:1:snp:c3bf2749e3476071fa748f67b0ffa2fdc5fe49d9
Raw File
Tip revision: a5abba989deceb731047425812d268daf7536575 authored by Linus Torvalds on 08 March 2011, 05:09:37 UTC
Linux 2.6.38-rc8
Tip revision: a5abba9
smp_lock.h
#ifndef __LINUX_SMPLOCK_H
#define __LINUX_SMPLOCK_H

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

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(const char *func, const char *file, int line)
__acquires(kernel_lock);

extern void __lockfunc
_unlock_kernel(const char *func, const char *file, int line)
__releases(kernel_lock);

#define lock_kernel() do {					\
	_lock_kernel(__func__, __FILE__, __LINE__);		\
} while (0)

#define unlock_kernel()	do {					\
	_unlock_kernel(__func__, __FILE__, __LINE__);		\
} while (0)

/*
 * 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

#ifdef CONFIG_BKL /* provoke build bug if not set */
#define lock_kernel()
#define unlock_kernel()
#define cycle_kernel_lock()			do { } while(0)
#endif /* CONFIG_BKL */

#define release_kernel_lock(task)		do { } while(0)
#define reacquire_kernel_lock(task)		0

#endif /* CONFIG_LOCK_KERNEL */
#endif /* __LINUX_SMPLOCK_H */
back to top