include/asm-s390/smplock.h

   1 /*
   2  *  include/asm-s390/smplock.h
   3  *
   4  *  S390 version
   5  *
   6  *  Derived from "include/asm-i386/smplock.h"
   7  */
   8
   9 #include <linux/interrupt.h>
  10 #include <linux/spinlock.h>
  11
  12 extern spinlock_t kernel_flag;
  13
  14 #define kernel_locked()                spin_is_locked(&kernel_flag)
  15
  16 /*
  17  * Release global kernel lock and global interrupt lock
  18  */
  19 #define release_kernel_lock(task, cpu)     \
  20 do {                                       \
  21         if (task->lock_depth >= 0)         \
  22                 spin_unlock(&kernel_flag); \
  23         release_irqlock(cpu);              \
  24         __sti();                           \
  25 } while (0)
  26
  27 /*
  28  * Re-acquire the kernel lock
  29  */
  30 #define reacquire_kernel_lock(task)        \
  31 do {                                       \
  32         if (task->lock_depth >= 0)         \
  33                 spin_lock(&kernel_flag);   \
  34 } while (0)
  35
  36
  37 /*
  38  * Getting the big kernel lock.
  39  *
  40  * This cannot happen asynchronously,
  41  * so we only need to worry about other
  42  * CPU's.
  43  */
  44 /*
  45  * Getting the big kernel lock.
  46  *
  47  * This cannot happen asynchronously,
  48  * so we only need to worry about other
  49  * CPU's.
  50  */
  51 extern __inline__ void lock_kernel(void)
  52 {
  53         if (!++current->lock_depth)
  54                 spin_lock(&kernel_flag);
  55 }
  56
  57 extern __inline__ void unlock_kernel(void)
  58 {
  59         if (--current->lock_depth < 0)
  60                 spin_unlock(&kernel_flag);
  61 }
  62