include/asm-cris/system.h

   1 #ifndef __ASM_CRIS_SYSTEM_H
   2 #define __ASM_CRIS_SYSTEM_H
   3
   4 #include <asm/arch/system.h>
   5
   6 /* the switch_to macro calls resume, an asm function in entry.S which does the actual
   7  * task switching.
   8  */
   9
  10 extern struct task_struct *resume(struct task_struct *prev, struct task_struct *next, int);
  11 #define switch_to(prev,next,last) last = resume(prev,next, \
  12                                          (int)&((struct task_struct *)0)->thread)
  13
  14 #define barrier() __asm__ __volatile__("": : :"memory")
  15 #define mb() barrier()
  16 #define rmb() mb()
  17 #define wmb() mb()
  18 #define read_barrier_depends() do { } while(0)
  19 #define set_mb(var, value)  do { var = value; mb(); } while (0)
  20 #define set_wmb(var, value) do { var = value; wmb(); } while (0)
  21
  22 #ifdef CONFIG_SMP
  23 #define smp_mb()        mb()
  24 #define smp_rmb()       rmb()
  25 #define smp_wmb()       wmb()
  26 #define smp_read_barrier_depends()     read_barrier_depends()
  27 #else
  28 #define smp_mb()        barrier()
  29 #define smp_rmb()       barrier()
  30 #define smp_wmb()       barrier()
  31 #define smp_read_barrier_depends()     do { } while(0)
  32 #endif
  33
  34 #define iret()
  35
  36 /*
  37  * disable hlt during certain critical i/o operations
  38  */
  39 #define HAVE_DISABLE_HLT
  40 void disable_hlt(void);
  41 void enable_hlt(void);
  42
  43 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
  44 {
  45   /* since Etrax doesn't have any atomic xchg instructions, we need to disable
  46      irq's (if enabled) and do it with move.d's */
  47   unsigned long flags,temp;
  48   local_save_flags(flags); /* save flags, including irq enable bit */
  49   local_irq_disable();             /* shut off irq's */
  50   switch (size) {
  51   case 1:
  52     *((unsigned char *)&temp) = x;
  53     x = *(unsigned char *)ptr;
  54     *(unsigned char *)ptr = *((unsigned char *)&temp);
  55     break;
  56   case 2:
  57     *((unsigned short *)&temp) = x;
  58     x = *(unsigned short *)ptr;
  59     *(unsigned short *)ptr = *((unsigned short *)&temp);
  60     break;
  61   case 4:
  62     temp = x;
  63     x = *(unsigned long *)ptr;
  64     *(unsigned long *)ptr = temp;
  65     break;
  66   }
  67   local_irq_restore(flags); /* restore irq enable bit */
  68   return x;
  69 }
  70
  71 #define arch_align_stack(x) (x)
  72
  73 void default_idle(void);
  74
  75 #endif