/* * Copyright (C) 2013 Davidlohr Bueso <davidlohr.bueso@hp.com> * *  Based on the shift-and-subtract algorithm for computing integer *  square root from Guy L. Steele. */ #include <linux/kernel.h>#include <linux/export.h> /** * int_sqrt - rough approximation to sqrt * @x: integer of which to calculate the sqrt * * A very rough approximation to the sqrt() function. */unsigned long int_sqrt(unsigned long x){	unsigned long b, m, y = 0; 	if (x <= 1)		return x; 	m = 1UL << (BITS_PER_LONG - 2);	while (m != 0) {		b = y + m;		y >>= 1; 		if (x >= b) {			x -= b;			y += m;		}		m >>= 2;	} 	return y;}EXPORT_SYMBOL(int_sqrt);