include/asm-s390/smplock.h

/*
 *  include/asm-s390/smplock.h
 *
 *  S390 version
 *
 *  Derived from "include/asm-i386/smplock.h"
 */

#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.
 */
/*
 * 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);
}