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 #define kernel_locked()         spin_is_locked(&kernel_flag)
  14
  15 /*
  16  * Release global kernel lock and global interrupt lock
  17  */
  18 static __inline__ void release_kernel_lock(struct task_struct *task, int cpu)
  19 {
  20         if (task->lock_depth >= 0)
  21                 spin_unlock(&kernel_flag);
  22         release_irqlock(cpu);
  23         __sti();
  24 }
  25
  26 /*
  27  * Re-acquire the kernel lock
  28  */
  29 static __inline__ void reacquire_kernel_lock(struct task_struct *task)
  30 {
  31         if (task->lock_depth >= 0)
  32                 spin_lock(&kernel_flag);
  33 }
  34
  35 /*
  36  * Getting the big kernel lock.
  37  *
  38  * This cannot happen asynchronously,
  39  * so we only need to worry about other
  40  * CPU's.
  41  */
  42 static __inline__ void lock_kernel(void)
  43 {
  44         if (!++current->lock_depth)
  45                 spin_lock(&kernel_flag);
  46 }
  47
  48 static __inline__ void unlock_kernel(void)
  49 {
  50         if (--current->lock_depth < 0)
  51                 spin_unlock(&kernel_flag);
  52 }