[PATCH v3 13/28] mm: define __init_reserved_page_zone function

[Frank van der Linden <fvdl@google.com>]

Sometimes page structs must be unconditionally initialized
as reserved, regardless of DEFERRED_STRUCT_PAGE_INIT.

Define a function, __init_reserved_page_zone, containing
code that already did all of the work in init_reserved_page,
and make it available for use.

Signed-off-by: Frank van der Linden <fvdl@google.com>
---
 mm/internal.h |  1 +
 mm/mm_init.c  | 38 +++++++++++++++++++++++---------------
 2 files changed, 24 insertions(+), 15 deletions(-)

diff --git a/mm/internal.h b/mm/internal.h
index 109ef30fee11..57662141930e 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -1448,6 +1448,7 @@ static inline bool pte_needs_soft_dirty_wp(struct vm_area_struct *vma, pte_t pte
 
 void __meminit __init_single_page(struct page *page, unsigned long pfn,
 				unsigned long zone, int nid);
+void __meminit __init_reserved_page_zone(unsigned long pfn, int nid);
 
 /* shrinker related functions */
 unsigned long shrink_slab(gfp_t gfp_mask, int nid, struct mem_cgroup *memcg,
diff --git a/mm/mm_init.c b/mm/mm_init.c
index 9f1e41c3dde6..925ed6564572 100644
--- a/mm/mm_init.c
+++ b/mm/mm_init.c
@@ -650,6 +650,28 @@ static inline void fixup_hashdist(void)
 static inline void fixup_hashdist(void) {}
 #endif /* CONFIG_NUMA */
 
+/*
+ * Initialize a reserved page unconditionally, finding its zone first.
+ */
+void __meminit __init_reserved_page_zone(unsigned long pfn, int nid)
+{
+	pg_data_t *pgdat;
+	int zid;
+
+	pgdat = NODE_DATA(nid);
+
+	for (zid = 0; zid < MAX_NR_ZONES; zid++) {
+		struct zone *zone = &pgdat->node_zones[zid];
+
+		if (zone_spans_pfn(zone, pfn))
+			break;
+	}
+	__init_single_page(pfn_to_page(pfn), pfn, zid, nid);
+
+	if (pageblock_aligned(pfn))
+		set_pageblock_migratetype(pfn_to_page(pfn), MIGRATE_MOVABLE);
+}
+
 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
 static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
 {
@@ -708,24 +730,10 @@ defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
 
 static void __meminit init_reserved_page(unsigned long pfn, int nid)
 {
-	pg_data_t *pgdat;
-	int zid;
-
 	if (early_page_initialised(pfn, nid))
 		return;
 
-	pgdat = NODE_DATA(nid);
-
-	for (zid = 0; zid < MAX_NR_ZONES; zid++) {
-		struct zone *zone = &pgdat->node_zones[zid];
-
-		if (zone_spans_pfn(zone, pfn))
-			break;
-	}
-	__init_single_page(pfn_to_page(pfn), pfn, zid, nid);
-
-	if (pageblock_aligned(pfn))
-		set_pageblock_migratetype(pfn_to_page(pfn), MIGRATE_MOVABLE);
+	__init_reserved_page_zone(pfn, nid);
 }
 #else
 static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {}
-- 
2.48.1.502.g6dc24dfdaf-goog