1 files changed, 32 insertions, 0 deletions
diff --git a/lib/int_sqrt.c b/lib/int_sqrt.c
new file mode 100644
index 0000000..fd355a9
--- /dev/null
+++ b/lib/int_sqrt.c
@@ -0,0 +1,32 @@
+
+#include <linux/kernel.h>
+#include <linux/module.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);