include/asm-ppc/smplock.h

   1 /*
   2  * <asm/smplock.h>
   3  *
   4  * Default SMP lock implementation
   5  */
   6 #ifdef __KERNEL__
   7 #include <linux/interrupt.h>
   8 #include <linux/spinlock.h>
   9
  10 extern spinlock_t kernel_flag;
  11
  12 #define kernel_locked()         spin_is_locked(&kernel_flag)
  13
  14 /*
  15  * Release global kernel lock and global interrupt lock
  16  */
  17 #define release_kernel_lock(task, cpu) \
  18 do { \
  19         if (task->lock_depth >= 0) \
  20                 spin_unlock(&kernel_flag); \
  21         release_irqlock(cpu); \
  22         __sti(); \
  23 } while (0)
  24
  25 /*
  26  * Re-acquire the kernel lock
  27  */
  28 #define reacquire_kernel_lock(task) \
  29 do { \
  30         if (task->lock_depth >= 0) \
  31                 spin_lock(&kernel_flag); \
  32 } while (0)
  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 extern __inline__ void lock_kernel(void)
  43 {
  44         if (!++current->lock_depth)
  45                 spin_lock(&kernel_flag);
  46 }
  47
  48 extern __inline__ void unlock_kernel(void)
  49 {
  50         if (--current->lock_depth < 0)
  51                 spin_unlock(&kernel_flag);
  52 }
  53 #endif /* __KERNEL__ */