#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 op, res, one; op = x; res = 0; one = 1UL << (BITS_PER_LONG - 2); while (one > op) one >>= 2; while (one != 0) { if (op >= res + one) { op = op - (res + one); res = res + 2 * one; } res /= 2; one /= 4; } return res; } EXPORT_SYMBOL(int_sqrt);