include/asm-mips/smplock.h

   1 /* $Id: smplock.h,v 1.2 1999/10/09 00:01:43 ralf Exp $
   2  *
   3  * This file is subject to the terms and conditions of the GNU General Public
   4  * License.  See the file "COPYING" in the main directory of this archive
   5  * for more details.
   6  *
   7  * Default SMP lock implementation
   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 extern __inline__ void lock_kernel(void)
  45 {
  46         if (!++current->lock_depth)
  47                 spin_lock(&kernel_flag);
  48 }
  49
  50 extern __inline__ void unlock_kernel(void)
  51 {
  52         if (--current->lock_depth < 0)
  53                 spin_unlock(&kernel_flag);
  54 }