release/src-rt-6.x.4708/linux/linux-2.6.36/arch/sh/include/asm/cmpxchg-irq.h

   1 #ifndef __ASM_SH_CMPXCHG_IRQ_H
   2 #define __ASM_SH_CMPXCHG_IRQ_H
   3
   4 static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val)
   5 {
   6         unsigned long flags, retval;
   7
   8         local_irq_save(flags);
   9         retval = *m;
  10         *m = val;
  11         local_irq_restore(flags);
  12         return retval;
  13 }
  14
  15 static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val)
  16 {
  17         unsigned long flags, retval;
  18
  19         local_irq_save(flags);
  20         retval = *m;
  21         *m = val & 0xff;
  22         local_irq_restore(flags);
  23         return retval;
  24 }
  25
  26 static inline unsigned long __cmpxchg_u32(volatile int *m, unsigned long old,
  27         unsigned long new)
  28 {
  29         __u32 retval;
  30         unsigned long flags;
  31
  32         local_irq_save(flags);
  33         retval = *m;
  34         if (retval == old)
  35                 *m = new;
  36         local_irq_restore(flags);       /* implies memory barrier  */
  37         return retval;
  38 }
  39
  40 #endif /* __ASM_SH_CMPXCHG_IRQ_H */