diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index 6c80d0a..34343f5 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -527,6 +527,16 @@
 	return test_bit(ZONE_OOM_LOCKED, &zone->flags);
 }
 
+static inline unsigned zone_end_pfn(const struct zone *zone)
+{
+	return zone->zone_start_pfn + zone->spanned_pages;
+}
+
+static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
+{
+	return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);
+}
+
 /*
  * The "priority" of VM scanning is how much of the queues we will scan in one
  * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the