+/** Round up x to next multiple of y. */
+#define ROUND_UP(x, y) ({ \
+ const typeof(y) _divisor = y; \
+ ((x) + _divisor - 1) / _divisor * _divisor; })
+
+/** Round down x to multiple of y. */
+#define ROUND_DOWN(x, y) ({ \
+ const typeof(y) _divisor = y; \
+ (x) / _divisor * _divisor; })
+