memory-hotplug: add move_pfn_range()

Add move_pfn_range(), a wrapper to call move_pfn_range_left() or
move_pfn_range_right().

No functional change. This will be utilized by a later patch.

Link: http://lkml.kernel.org/r/1462816419-4479-2-git-send-email-arbab@linux.vnet.ibm.com
Signed-off-by: Reza Arbab <arbab@linux.vnet.ibm.com>
Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Andrew Banman <abanman@sgi.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Zhang Zhen <zhenzhang.zhang@huawei.com>
Cc: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index e3cbdca..a86a66c 100644 (file)
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -449,6 +449,25 @@ out_fail:
        return -1;
 }
 
+static struct zone * __meminit move_pfn_range(int zone_shift,
+               unsigned long start_pfn, unsigned long end_pfn)
+{
+       struct zone *zone = page_zone(pfn_to_page(start_pfn));
+       int ret = 0;
+
+       if (zone_shift < 0)
+               ret = move_pfn_range_left(zone + zone_shift, zone,
+                                         start_pfn, end_pfn);
+       else if (zone_shift)
+               ret = move_pfn_range_right(zone, zone + zone_shift,
+                                          start_pfn, end_pfn);
+
+       if (ret)
+               return NULL;
+
+       return zone + zone_shift;
+}
+
 static void __meminit grow_pgdat_span(struct pglist_data *pgdat, unsigned long start_pfn,
                                      unsigned long end_pfn)
 {
@@ -1039,6 +1058,7 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
        int nid;
        int ret;
        struct memory_notify arg;
+       int zone_shift = 0;
 
        /*
         * This doesn't need a lock to do pfn_to_page().
@@ -1053,18 +1073,16 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ
                return -EINVAL;
 
        if (online_type == MMOP_ONLINE_KERNEL &&
-           zone_idx(zone) == ZONE_MOVABLE) {
-               if (move_pfn_range_left(zone - 1, zone, pfn, pfn + nr_pages))
-                       return -EINVAL;
-       }
+           zone_idx(zone) == ZONE_MOVABLE)
+               zone_shift = -1;
+
        if (online_type == MMOP_ONLINE_MOVABLE &&
-           zone_idx(zone) == ZONE_MOVABLE - 1) {
-               if (move_pfn_range_right(zone, zone + 1, pfn, pfn + nr_pages))
-                       return -EINVAL;
-       }
+           zone_idx(zone) == ZONE_MOVABLE - 1)
+               zone_shift = 1;
 
-       /* Previous code may changed the zone of the pfn range */
-       zone = page_zone(pfn_to_page(pfn));
+       zone = move_pfn_range(zone_shift, pfn, pfn + nr_pages);
+       if (!zone)
+               return -EINVAL;
 
        arg.start_pfn = pfn;
        arg.nr_pages = nr_pages;