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