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/* $Id: smplock.h,v 1.2 1999/10/09 00:01:43 ralf Exp $
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Default SMP lock implementation
*/
#include <linux/interrupt.h>
#include <linux/spinlock.h>
extern spinlock_t kernel_flag;
#define kernel_locked() spin_is_locked(&kernel_flag)
/*
* Release global kernel lock and global interrupt lock
*/
#define release_kernel_lock(task, cpu) \
do { \
if (task->lock_depth >= 0) \
spin_unlock(&kernel_flag); \
release_irqlock(cpu); \
__sti(); \
} while (0)
/*
* Re-acquire the kernel lock
*/
#define reacquire_kernel_lock(task) \
do { \
if (task->lock_depth >= 0) \
spin_lock(&kernel_flag); \
} while (0)
/*
* Getting the big kernel lock.
*
* This cannot happen asynchronously,
* so we only need to worry about other
* CPU's.
*/
extern __inline__ void lock_kernel(void)
{
if (!++current->lock_depth)
spin_lock(&kernel_flag);
}
extern __inline__ void unlock_kernel(void)
{
if (--current->lock_depth < 0)
spin_unlock(&kernel_flag);
}
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