[PATCH v2 repost 3/7] mm: add a function to get the max pfn

Expose the function to get the max pfn, so it can be used in the
virtio-balloon device driver.

Signed-off-by: Liang Li <>
Cc: Andrew Morton <>
Cc: Vlastimil Babka <>
Cc: Mel Gorman <>
Cc: Michael S. Tsirkin <>
Cc: Paolo Bonzini <>
Cc: Cornelia Huck <>
Cc: Amit Shah <>
---
 mm/page_alloc.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8b3e134..7da61ad 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4517,6 +4517,12 @@ void show_free_areas(unsigned int filter)
 	show_swap_cache_info();
 }
 
+unsigned long get_max_pfn(void)
+{
+	return max_pfn;
+}
+EXPORT_SYMBOL(get_max_pfn);
+
 static void zoneref_set_zone(struct zone *zone, struct zoneref *zoneref)
 {
 	zoneref->zone = zone;
-- 
1.9.1