diff --git a/include/linux/irq.h b/include/linux/irq.h
index 10a0b1a..5c57efb 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -603,6 +603,8 @@
 	return d ? irqd_get_trigger_type(d) : 0;
 }
 
+unsigned int arch_dynirq_lower_bound(unsigned int from);
+
 int __irq_alloc_descs(int irq, unsigned int from, unsigned int cnt, int node,
 		struct module *owner);