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#include "kernel/kern.h"
#include "calibrate.h"

int cal_cycles=0;

/* Runtime Calibration */
int calibrate_cycle()
{
  long long i;
  struct timespec start,end,diff;
 
  if (cal_cycles != 0) return 0;



  kern_cli();
  __asm__ __volatile__ ("xorl %%eax,%%eax\n\t"
                          "cpuid\n\t"
                          :::"eax","ebx","ecx","edx");
  kern_gettime(&start);
  for (i=0;i<CALIBRATION_DELTA;i++)
    __asm__ __volatile__ ("xorl %%eax,%%eax\n\t"
                          "cpuid\n\t"
                          :::"eax","ebx","ecx","edx");
  __asm__ __volatile__ ("xorl %%eax,%%eax\n\t"
                          "cpuid\n\t"
                          :::"eax","ebx","ecx","edx");
  kern_gettime(&end);
  kern_sti();
 
  SUBTIMESPEC(&end,&start,&diff);
  cal_cycles = TIMESPEC2USEC(&diff);
 
  cprintf("Calibration usec/[%d cycles] = %d\n",CALIBRATION_DELTA,cal_cycles);

  return 0;

}

void eat(TIME wait) {

    int exec_cycles=0;
    int i=0;
   
    exec_cycles = (long long)(wait) * CALIBRATION_DELTA / cal_cycles;

    /* Execution delay */
    for (i=0;i<exec_cycles;i++)
    __asm__ __volatile__ ("xorl %%eax,%%eax\n\t"
                          "cpuid\n\t"
                          :::"eax","ebx","ecx","edx");

}