smplock.h
上传用户:lgb322
上传日期:2013-02-24
资源大小:30529k
文件大小:1k
- /*
- * <asm/smplock.h>
- *
- * i386 SMP lock implementation
- */
- #include <linux/interrupt.h>
- #include <linux/spinlock.h>
- #include <linux/sched.h>
- #include <asm/current.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.
- */
- static __inline__ void lock_kernel(void)
- {
- #if 1
- if (!++current->lock_depth)
- spin_lock(&kernel_flag);
- #else
- __asm__ __volatile__(
- "incl %1nt"
- "jne 9f"
- spin_lock_string
- "n9:"
- :"=m" (__dummy_lock(&kernel_flag)),
- "=m" (current->lock_depth));
- #endif
- }
- static __inline__ void unlock_kernel(void)
- {
- if (current->lock_depth < 0)
- BUG();
- #if 1
- if (--current->lock_depth < 0)
- spin_unlock(&kernel_flag);
- #else
- __asm__ __volatile__(
- "decl %1nt"
- "jns 9fnt"
- spin_unlock_string
- "n9:"
- :"=m" (__dummy_lock(&kernel_flag)),
- "=m" (current->lock_depth));
- #endif
- }