arch/cris/include/asm/cmpxchg.h

   1 #ifndef __ASM_CRIS_CMPXCHG__
   2 #define __ASM_CRIS_CMPXCHG__
   3
   4 #include <linux/irqflags.h>
   5
   6 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
   7 {
   8   /* since Etrax doesn't have any atomic xchg instructions, we need to disable
   9      irq's (if enabled) and do it with move.d's */
  10   unsigned long flags,temp;
  11   local_irq_save(flags); /* save flags, including irq enable bit and shut off irqs */
  12   switch (size) {
  13   case 1:
  14     *((unsigned char *)&temp) = x;
  15     x = *(unsigned char *)ptr;
  16     *(unsigned char *)ptr = *((unsigned char *)&temp);
  17     break;
  18   case 2:
  19     *((unsigned short *)&temp) = x;
  20     x = *(unsigned short *)ptr;
  21     *(unsigned short *)ptr = *((unsigned short *)&temp);
  22     break;
  23   case 4:
  24     temp = x;
  25     x = *(unsigned long *)ptr;
  26     *(unsigned long *)ptr = temp;
  27     break;
  28   }
  29   local_irq_restore(flags); /* restore irq enable bit */
  30   return x;
  31 }
  32
  33 #define xchg(ptr,x) \
  34         ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
  35
  36 #define tas(ptr) (xchg((ptr),1))
  37
  38 #include <asm-generic/cmpxchg-local.h>
  39
  40 /*
  41  * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
  42  * them available.
  43  */
  44 #define cmpxchg_local(ptr, o, n)                                               \
  45         ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
  46                         (unsigned long)(n), sizeof(*(ptr))))
  47 #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
  48
  49 #ifndef CONFIG_SMP
  50 #include <asm-generic/cmpxchg.h>
  51 #endif
  52
  53 #endif /* __ASM_CRIS_CMPXCHG__ */