[PATCH] reduce MAX_NR_ZONES: use enum to define zones, reformat and comment

Use enum for zones and reformat zones dependent information

Add comments explaning the use of zones and add a zones_t type for zone
numbers.

Line up information that will be #ifdefd by the following patches.

[akpm@osdl.org: comment cleanups]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 45678b036955..2db4229a0066 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -470,7 +470,7 @@ void split_page(struct page *page, unsigned int order);
 #define SECTIONS_MASK           ((1UL << SECTIONS_WIDTH) - 1)
 #define ZONETABLE_MASK          ((1UL << ZONETABLE_SHIFT) - 1)
 
-static inline unsigned long page_zonenum(struct page *page)
+static inline enum zone_type page_zonenum(struct page *page)
 {
         return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
 }
@@ -499,11 +499,12 @@ static inline unsigned long page_to_section(struct page *page)
         return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
 }
 
-static inline void set_page_zone(struct page *page, unsigned long zone)
+static inline void set_page_zone(struct page *page, enum zone_type 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);
@@ -515,7 +516,7 @@ static inline void set_page_section(struct page *page, unsigned long section)
         page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
 }
 
-static inline void set_page_links(struct page *page, unsigned long zone,
+static inline void set_page_links(struct page *page, enum zone_type zone,
         unsigned long node, unsigned long pfn)
 {
         set_page_zone(page, zone);