mm: enable set_page_section() only if CONFIG_SPARSEMEM and !CONFIG_SPARSEMEM_VMEMMAP

set_page_section() is meaningful only in CONFIG_SPARSEMEM and
!CONFIG_SPARSEMEM_VMEMMAP context.  Move it to proper place and amend
accordingly functions which are using it.

Signed-off-by: Daniel Kiper <dkiper@net-space.pl>
Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Author: dkiper

include/linux/mm.h

@@ -682,6 +682,12 @@ static inline struct zone *page_zone(struct page *page)
 }
 
 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
+static inline void set_page_section(struct page *page, unsigned long section)
+{
+	page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
+	page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
+}
+
 static inline unsigned long page_to_section(struct page *page)
 {
 	return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
@@ -700,18 +706,14 @@ static inline void set_page_node(struct page *page, unsigned long node)
 	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);
-	page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
-}
-
 static inline void set_page_links(struct page *page, enum zone_type zone,
 	unsigned long node, unsigned long pfn)
 {
 	set_page_zone(page, zone);
 	set_page_node(page, node);
+#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
 	set_page_section(page, pfn_to_section_nr(pfn));
+#endif
 }
 
 /*