#include <linux/compiler.h>
  #include <linux/gcd.h>
  #include <linux/export.h>
  #include <linux/lcm.h>
  
  /* Lowest common multiple */
  unsigned long lcm(unsigned long a, unsigned long b)
  {
  	if (a && b)
  		return (a / gcd(a, b)) * b;
  	else
  		return 0;
  }
  EXPORT_SYMBOL_GPL(lcm);
  
  unsigned long lcm_not_zero(unsigned long a, unsigned long b)
  {
  	unsigned long l = lcm(a, b);
  
  	if (l)
  		return l;
  
  	return (b ? : a);
  }
  EXPORT_SYMBOL_GPL(lcm_not_zero);