1 files changed, 32 insertions, 0 deletions

diff --git a/lib/int_sqrt.c b/lib/int_sqrt.c
new file mode 100644
index 000000000000..a5d2cdc5684c
--- /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 = 1 << 30;
+        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);