include/asm-alpha/smplock.h

   1 /*
   2  * <asm/smplock.h>
   3  *
   4  * Default SMP lock implementation
   5  */
   6
   7 #include <linux/sched.h>
   8 #include <linux/interrupt.h>
   9 #include <linux/spinlock.h>
  10
  11 extern spinlock_t kernel_flag;
  12
  13 /*
  14  * Release global kernel lock and global interrupt lock
  15  */
  16 static __inline__ void release_kernel_lock(struct task_struct *task, int cpu)
  17 {
  18         if (task->lock_depth >= 0)
  19                 spin_unlock(&kernel_flag);
  20         release_irqlock(cpu);
  21         __sti();
  22 }
  23
  24 /*
  25  * Re-acquire the kernel lock
  26  */
  27 static __inline__ void reacquire_kernel_lock(struct task_struct *task)
  28 {
  29         if (task->lock_depth >= 0)
  30                 spin_lock(&kernel_flag);
  31 }
  32
  33 /*
  34  * Getting the big kernel lock.
  35  *
  36  * This cannot happen asynchronously,
  37  * so we only need to worry about other
  38  * CPU's.
  39  */
  40 static __inline__ void lock_kernel(void)
  41 {
  42         if (!++current->lock_depth)
  43                 spin_lock(&kernel_flag);
  44 }
  45
  46 static __inline__ void unlock_kernel(void)
  47 {
  48         if (--current->lock_depth < 0)
  49                 spin_unlock(&kernel_flag);
  50 }