diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c
index 10e663a..452d6f2 100644
--- a/kernel/irq/generic-chip.c
+++ b/kernel/irq/generic-chip.c
@@ -275,7 +275,7 @@
 	if (d->gc)
 		return -EBUSY;
 
-	numchips = d->revmap_size / irqs_per_chip;
+	numchips = DIV_ROUND_UP(d->revmap_size, irqs_per_chip);
 	if (!numchips)
 		return -EINVAL;