blob: 7b70d4629ad4d4755a99e8c788a68c4bd3f7a5a5 [file] [log] [blame]
/*
* <asm/smplock.h>
*
* Default SMP lock implementation
*/
#include <linux/config.h>
#include <linux/interrupt.h>
#include <linux/spinlock.h>
extern spinlock_t kernel_flag;
#ifdef CONFIG_PREEMPT
#define kernel_locked() preempt_get_count()
#else
#define kernel_locked() spin_is_locked(&kernel_flag)
#endif
/*
* Release global kernel lock and global interrupt lock
*/
#define release_kernel_lock(task, cpu) \
do { \
if (unlikely(task->lock_depth >= 0)) \
spin_unlock(&kernel_flag); \
} while (0)
/*
* Re-acquire the kernel lock
*/
#define reacquire_kernel_lock(task) \
do { \
if (unlikely(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.
*/
static inline void lock_kernel(void)
{
#ifdef CONFIG_PREEMPT
if (current->lock_depth == -1)
spin_lock(&kernel_flag);
++current->lock_depth;
#else
if (!++current->lock_depth)
spin_lock(&kernel_flag);
#endif
}
static inline void unlock_kernel(void)
{
if (--current->lock_depth < 0)
spin_unlock(&kernel_flag);
}