Introduce SINGLE_ZONE

Signed-off-by: Christoph Lameter <clameter@sgi.com>

Index: linux-2.6.17-mm6/include/linux/mmzone.h
===================================================================
--- linux-2.6.17-mm6.orig/include/linux/mmzone.h	2006-07-05 23:27:53.251773767 -0700
+++ linux-2.6.17-mm6/include/linux/mmzone.h	2006-07-05 23:32:15.251141520 -0700
@@ -424,6 +424,26 @@ unsigned long __init node_memmap_size_by
 /*
  * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
  */
+#ifdef SINGLE_ZONE
+#define zone_idx(zone)		0
+
+static inline int populated_zone(struct zone *zone)
+{
+	return 1;
+}
+
+static inline int is_normal_idx(int idx)
+{
+	return 1;
+}
+
+static inline int is_normal(struct zone *zone)
+{
+	return 1;
+}
+
+#else
+
 #define zone_idx(zone)		((zone) - (zone)->zone_pgdat->node_zones)
 
 static inline int populated_zone(struct zone *zone)
Index: linux-2.6.17-mm6/include/linux/mm.h
===================================================================
--- linux-2.6.17-mm6.orig/include/linux/mm.h	2006-07-05 23:32:04.193233853 -0700
+++ linux-2.6.17-mm6/include/linux/mm.h	2006-07-05 23:32:15.252118022 -0700
@@ -469,16 +469,37 @@ void split_page(struct page *page, unsig
 #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
 #endif
 
+#ifdef SINGLE_ZONE
+static inline unsigned long page_zonenum(struct page *page)
+{
+	return ZONE_NORMAL;
+}
+
+static inline void set_page_zone(struct page *page, unsigned long zone)
+{
+	BUG_ON(zone);
+}
+
+#else
+
 #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)
 
 static inline unsigned long page_zonenum(struct page *page)
 {
 	return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
 }
 
+static inline void set_page_zone(struct page *page, unsigned long zone)
+{
+	page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
+	page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
+}
+#endif
+
+#define NODES_MASK		((1UL << NODES_WIDTH) - 1)
+#define SECTIONS_MASK		((1UL << SECTIONS_WIDTH) - 1)
+#define ZONETABLE_MASK		((1UL << ZONETABLE_SHIFT) - 1)
+
 struct zone;
 extern struct zone *zone_table[];
 
@@ -503,11 +524,6 @@ static inline unsigned long page_to_sect
 	return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
 }
 
-static inline void set_page_zone(struct page *page, unsigned long zone)
-{
-	page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
-	page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
-}
 static inline void set_page_node(struct page *page, unsigned long node)
 {
 	page->flags &= ~(NODES_MASK << NODES_PGSHIFT);