include/asm-sh/smplock.h

   1 #ifndef __ASM_SH_SMPLOCK_H
   2 #define __ASM_SH_SMPLOCK_H
   3
   4 /*
   5  * This file is subject to the terms and conditions of the GNU General Public
   6  * License.  See the file "COPYING" in the main directory of this archive
   7  * for more details.
   8  */
   9
  10 #include <linux/config.h>
  11
  12 #ifndef CONFIG_SMP
  13
  14 #define lock_kernel()                           do { } while(0)
  15 #define unlock_kernel()                         do { } while(0)
  16 #define release_kernel_lock(task, cpu, depth)   ((depth) = 1)
  17 #define reacquire_kernel_lock(task, cpu, depth) do { } while(0)
  18
  19 #else
  20
  21 #error "We do not support SMP on SH yet"
  22 /*
  23  * Default SMP lock implementation
  24  */
  25
  26 #include <linux/interrupt.h>
  27 #include <asm/spinlock.h>
  28
  29 extern spinlock_t kernel_flag;
  30
  31 /*
  32  * Getting the big kernel lock.
  33  *
  34  * This cannot happen asynchronously,
  35  * so we only need to worry about other
  36  * CPU's.
  37  */
  38 extern __inline__ void lock_kernel(void)
  39 {
  40         if (!++current->lock_depth)
  41                 spin_lock(&kernel_flag);
  42 }
  43
  44 extern __inline__ void unlock_kernel(void)
  45 {
  46         if (--current->lock_depth < 0)
  47                 spin_unlock(&kernel_flag);
  48 }
  49
  50 /*
  51  * Release global kernel lock and global interrupt lock
  52  */
  53 #define release_kernel_lock(task, cpu) \
  54 do { \
  55         if (task->lock_depth >= 0) \
  56                 spin_unlock(&kernel_flag); \
  57         release_irqlock(cpu); \
  58         __sti(); \
  59 } while (0)
  60
  61 /*
  62  * Re-acquire the kernel lock
  63  */
  64 #define reacquire_kernel_lock(task) \
  65 do { \
  66         if (task->lock_depth >= 0) \
  67                 spin_lock(&kernel_flag); \
  68 } while (0)
  69
  70 #endif /* CONFIG_SMP */
  71
  72 #endif /* __ASM_SH_SMPLOCK_H */