1 files changed, 36 insertions, 21 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index d538de901965..ab6e4974f379 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -396,7 +396,9 @@ void split_page(struct page *page, unsigned int order);
  * We are going to use the flags for the page to node mapping if its in
  * there.  This includes the case where there is no node, so it is implicit.
  */
-#define FLAGS_HAS_NODE          (NODES_WIDTH > 0 || NODES_SHIFT == 0)
+#if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
+#define NODE_NOT_IN_PAGE_FLAGS
+#endif
 
 #ifndef PFN_SECTION_SHIFT
 #define PFN_SECTION_SHIFT 0
@@ -411,13 +413,18 @@ void split_page(struct page *page, unsigned int order);
 #define NODES_PGSHIFT           (NODES_PGOFF * (NODES_WIDTH != 0))
 #define ZONES_PGSHIFT           (ZONES_PGOFF * (ZONES_WIDTH != 0))
 
-/* NODE:ZONE or SECTION:ZONE is used to lookup the zone from a page. */
-#if FLAGS_HAS_NODE
-#define ZONETABLE_SHIFT         (NODES_SHIFT + ZONES_SHIFT)
+/* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allcator */
+#ifdef NODE_NOT_IN_PAGEFLAGS
+#define ZONEID_SHIFT            (SECTIONS_SHIFT + ZONES_SHIFT)
 #else
-#define ZONETABLE_SHIFT         (SECTIONS_SHIFT + ZONES_SHIFT)
+#define ZONEID_SHIFT            (NODES_SHIFT + ZONES_SHIFT)
+#endif
+
+#if ZONES_WIDTH > 0
+#define ZONEID_PGSHIFT          ZONES_PGSHIFT
+#else
+#define ZONEID_PGSHIFT          NODES_PGOFF
 #endif
-#define ZONETABLE_PGSHIFT       ZONES_PGSHIFT
 
 #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
 #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
@@ -426,23 +433,25 @@ void split_page(struct page *page, unsigned int order);
 #define ZONES_MASK              ((1UL << ZONES_WIDTH) - 1)
 #define NODES_MASK              ((1UL << NODES_WIDTH) - 1)
 #define SECTIONS_MASK           ((1UL << SECTIONS_WIDTH) - 1)
-#define ZONETABLE_MASK          ((1UL << ZONETABLE_SHIFT) - 1)
+#define ZONEID_MASK             ((1UL << ZONEID_SHIFT) - 1)
 
 static inline enum zone_type page_zonenum(struct page *page)
 {
         return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
 }
 
-struct zone;
-extern struct zone *zone_table[];
-
+/*
+ * The identification function is only used by the buddy allocator for
+ * determining if two pages could be buddies. We are not really
+ * identifying a zone since we could be using a the section number
+ * id if we have not node id available in page flags.
+ * We guarantee only that it will return the same value for two
+ * combinable pages in a zone.
+ */
 static inline int page_zone_id(struct page *page)
 {
-        return (page->flags >> ZONETABLE_PGSHIFT) & ZONETABLE_MASK;
-}
-static inline struct zone *page_zone(struct page *page)
-{
-        return zone_table[page_zone_id(page)];
+        BUILD_BUG_ON(ZONEID_PGSHIFT == 0 && ZONEID_MASK);
+        return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
 }
 
 static inline unsigned long zone_to_nid(struct zone *zone)
@@ -454,13 +463,20 @@ static inline unsigned long zone_to_nid(struct zone *zone)
 #endif
 }
 
+#ifdef NODE_NOT_IN_PAGE_FLAGS
+extern unsigned long page_to_nid(struct page *page);
+#else
 static inline unsigned long page_to_nid(struct page *page)
 {
-        if (FLAGS_HAS_NODE)
-                return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
-        else
-                return zone_to_nid(page_zone(page));
+        return (page->flags >> NODES_PGSHIFT) & NODES_MASK;
 }
+#endif
+
+static inline struct zone *page_zone(struct page *page)
+{
+        return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
+}
+
 static inline unsigned long page_to_section(struct page *page)
 {
         return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
@@ -477,6 +493,7 @@ static inline void set_page_node(struct page *page, unsigned long node)
         page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
         page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
 }
+
 static inline void set_page_section(struct page *page, unsigned long section)
 {
         page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
@@ -947,8 +964,6 @@ extern void mem_init(void);
 extern void show_mem(void);
 extern void si_meminfo(struct sysinfo * val);
 extern void si_meminfo_node(struct sysinfo *val, int nid);
-extern void zonetable_add(struct zone *zone, int nid, enum zone_type zid,
-                                        unsigned long pfn, unsigned long size);
 
 #ifdef CONFIG_NUMA
 extern void setup_per_cpu_pageset(void);