[PATCH 3.16 090/204] mm/memory_hotplug: define find_{smallest|biggest}_section_pfn as unsigned long

[Ben Hutchings]

3.16.52-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: YASUAKI ISHIMATSU <yasu.isimatu@xxxxxxxxx>

commit d09b0137d204bebeaafed672bc5a244e9ac92edb upstream.

find_{smallest|biggest}_section_pfn()s find the smallest/biggest section
and return the pfn of the section.  But the functions are defined as int.
So the functions always return 0x00000000 - 0xffffffff.  It means if
memory address is over 16TB, the functions does not work correctly.

To handle 64 bit value, the patch defines
find_{smallest|biggest}_section_pfn() as unsigned long.

Fixes: 815121d2b5cd ("memory_hotplug: clear zone when removing the memory")
Link: http://lkml.kernel.org/r/d9d5593a-d0a4-c4be-ab08-493df59a85c6@xxxxxxxxx
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Xishi Qiu <qiuxishi@xxxxxxxxxx>
Cc: Reza Arbab <arbab@xxxxxxxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 mm/memory_hotplug.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -520,7 +520,7 @@ EXPORT_SYMBOL_GPL(__add_pages);
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */
-static int find_smallest_section_pfn(int nid, struct zone *zone,
+static unsigned long find_smallest_section_pfn(int nid, struct zone *zone,
 				     unsigned long start_pfn,
 				     unsigned long end_pfn)
 {
@@ -545,7 +545,7 @@ static int find_smallest_section_pfn(int
 }
 
 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */
-static int find_biggest_section_pfn(int nid, struct zone *zone,
+static unsigned long find_biggest_section_pfn(int nid, struct zone *zone,
 				    unsigned long start_pfn,
 				    unsigned long end_pfn)
 {