mm: page_alloc: move set_zone_contiguous() into mm_init.c

set_zone_contiguous() is only used in mm init/hotplug, and
clear_zone_contiguous() only used in hotplug, move them from page_alloc.c
to the more appropriate file.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Kefeng Wang <[e-mail]>
Cc: David Hildenbrand <[e-mail]>
Cc: "Huang, Ying" <[e-mail]>
Cc: Iurii Zaikin <[e-mail]>
Cc: Kees Cook <[e-mail]>
Cc: Len Brown <[e-mail]>
Cc: Luis Chamberlain <[e-mail]>
Cc: Mike Rapoport (IBM) <[e-mail]>
Cc: Oscar Salvador <[e-mail]>
Cc: Pavel Machek <[e-mail]>
Cc: Rafael J. Wysocki <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

include/linux/memory_hotplug.h

···
 static inline void __remove_memory(u64 start, u64 size) {}
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 
-extern void set_zone_contiguous(struct zone *zone);
-extern void clear_zone_contiguous(struct zone *zone);
-
 #ifdef CONFIG_MEMORY_HOTPLUG
 extern void __ref free_area_init_core_hotplug(struct pglist_data *pgdat);
 extern int __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags);

mm/internal.h

···
 	return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
 }
 
+void set_zone_contiguous(struct zone *zone);
+
+static inline void clear_zone_contiguous(struct zone *zone)
+{
+	zone->contiguous = false;
+}
+
 extern int __isolate_free_page(struct page *page, unsigned int order);
 extern void __putback_isolated_page(struct page *page, unsigned int order,
 				    int mt);

mm/mm_init.c

···
 }
 #endif
 
+void set_zone_contiguous(struct zone *zone)
+{
+	unsigned long block_start_pfn = zone->zone_start_pfn;
+	unsigned long block_end_pfn;
+
+	block_end_pfn = pageblock_end_pfn(block_start_pfn);
+	for (; block_start_pfn < zone_end_pfn(zone);
+			block_start_pfn = block_end_pfn,
+			 block_end_pfn += pageblock_nr_pages) {
+
+		block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
+
+		if (!__pageblock_pfn_to_page(block_start_pfn,
+					     block_end_pfn, zone))
+			return;
+		cond_resched();
+	}
+
+	/* We confirm that there is no hole */
+	zone->contiguous = true;
+}
+
 void __init page_alloc_init_late(void)
 {
 	struct zone *zone;

mm/page_alloc.c

···
 	return start_page;
 }
 
-void set_zone_contiguous(struct zone *zone)
-{
-	unsigned long block_start_pfn = zone->zone_start_pfn;
-	unsigned long block_end_pfn;
-
-	block_end_pfn = pageblock_end_pfn(block_start_pfn);
-	for (; block_start_pfn < zone_end_pfn(zone);
-			block_start_pfn = block_end_pfn,
-			 block_end_pfn += pageblock_nr_pages) {
-
-		block_end_pfn = min(block_end_pfn, zone_end_pfn(zone));
-
-		if (!__pageblock_pfn_to_page(block_start_pfn,
-					     block_end_pfn, zone))
-			return;
-		cond_resched();
-	}
-
-	/* We confirm that there is no hole */
-	zone->contiguous = true;
-}
-
-void clear_zone_contiguous(struct zone *zone)
-{
-	zone->contiguous = false;
-}
-
 /*
  * The order of subdivision here is critical for the IO subsystem.
  * Please do not alter this order without good reasons and regression