#include <linux/kernel.h>
  #include <asm/div64.h>
  #include <linux/reciprocal_div.h>
  #include <linux/export.h>
  
  /*
   * For a description of the algorithm please have a look at
   * include/linux/reciprocal_div.h
   */
  
  struct reciprocal_value reciprocal_value(u32 d)
  {
  	struct reciprocal_value R;
  	u64 m;
  	int l;
  
  	l = fls(d - 1);
  	m = ((1ULL << 32) * ((1ULL << l) - d));
  	do_div(m, d);
  	++m;
  	R.m = (u32)m;
  	R.sh1 = min(l, 1);
  	R.sh2 = max(l - 1, 0);
  
  	return R;
  }
  EXPORT_SYMBOL(reciprocal_value);