[PATCH] squash duplicate page_to_pfn and pfn_to_page

We have architectures where the size of page_to_pfn and pfn_to_page are
significant enough to overall image size that they wish to push them out of
line.  However, in the process we have grown a second copy of the
implementation of each of these routines for each memory model.  Share the
implmentation exposing it either inline or out-of-line as required.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 17 insertions, 42 deletions

diff --git a/include/asm-generic/memory_model.h b/include/asm-generic/memory_model.h
index 0cfb086dd373..8078cbd2c016 100644
--- a/include/asm-generic/memory_model.h
+++ b/include/asm-generic/memory_model.h
@@ -23,29 +23,23 @@
 
 #endif /* CONFIG_DISCONTIGMEM */
 
-#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
-struct page;
-/* this is useful when inlined pfn_to_page is too big */
-extern struct page *pfn_to_page(unsigned long pfn);
-extern unsigned long page_to_pfn(struct page *page);
-#else
 /*
  * supports 3 memory models.
  */
 #if defined(CONFIG_FLATMEM)
 
-#define pfn_to_page(pfn)        (mem_map + ((pfn) - ARCH_PFN_OFFSET))
-#define page_to_pfn(page)       ((unsigned long)((page) - mem_map) + \
+#define __pfn_to_page(pfn)      (mem_map + ((pfn) - ARCH_PFN_OFFSET))
+#define __page_to_pfn(page)     ((unsigned long)((page) - mem_map) + \
                                  ARCH_PFN_OFFSET)
 #elif defined(CONFIG_DISCONTIGMEM)
 
-#define pfn_to_page(pfn)                        \
+#define __pfn_to_page(pfn)                      \
 ({      unsigned long __pfn = (pfn);            \
         unsigned long __nid = arch_pfn_to_nid(pfn);  \
         NODE_DATA(__nid)->node_mem_map + arch_local_page_offset(__pfn, __nid);\
 })
 
-#define page_to_pfn(pg)                                                 \
+#define __page_to_pfn(pg)                                               \
 ({      struct page *__pg = (pg);                                       \
         struct pglist_data *__pgdat = NODE_DATA(page_to_nid(__pg));     \
         (unsigned long)(__pg - __pgdat->node_mem_map) +                 \
@@ -57,18 +51,27 @@ extern unsigned long page_to_pfn(struct page *page);
  * Note: section's mem_map is encorded to reflect its start_pfn.
  * section[i].section_mem_map == mem_map's address - start_pfn;
  */
-#define page_to_pfn(pg)                                 \
+#define __page_to_pfn(pg)                                       \
 ({      struct page *__pg = (pg);                               \
         int __sec = page_to_section(__pg);                      \
         __pg - __section_mem_map_addr(__nr_to_section(__sec));  \
 })
 
-#define pfn_to_page(pfn)                                \
+#define __pfn_to_page(pfn)                              \
 ({      unsigned long __pfn = (pfn);                    \
         struct mem_section *__sec = __pfn_to_section(__pfn);    \
         __section_mem_map_addr(__sec) + __pfn;          \
 })
 #endif /* CONFIG_FLATMEM/DISCONTIGMEM/SPARSEMEM */
+
+#ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
+struct page;
+/* this is useful when inlined pfn_to_page is too big */
+extern struct page *pfn_to_page(unsigned long pfn);
+extern unsigned long page_to_pfn(struct page *page);
+#else
+#define page_to_pfn __page_to_pfn
+#define pfn_to_page __pfn_to_page
 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */
 
 #endif /* __ASSEMBLY__ */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 9dfbe6b7d1c8..5af33186a25f 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2879,42 +2879,14 @@ void *__init alloc_large_system_hash(const char *tablename,
 }
 
 #ifdef CONFIG_OUT_OF_LINE_PFN_TO_PAGE
-/*
- * pfn <-> page translation. out-of-line version.
- * (see asm-generic/memory_model.h)
- */
-#if defined(CONFIG_FLATMEM)
-struct page *pfn_to_page(unsigned long pfn)
-{
-        return mem_map + (pfn - ARCH_PFN_OFFSET);
-}
-unsigned long page_to_pfn(struct page *page)
-{
-        return (page - mem_map) + ARCH_PFN_OFFSET;
-}
-#elif defined(CONFIG_DISCONTIGMEM)
 struct page *pfn_to_page(unsigned long pfn)
 {
-        int nid = arch_pfn_to_nid(pfn);
-        return NODE_DATA(nid)->node_mem_map + arch_local_page_offset(pfn,nid);
+        return __pfn_to_page(pfn);
 }
 unsigned long page_to_pfn(struct page *page)
 {
-        struct pglist_data *pgdat = NODE_DATA(page_to_nid(page));
-        return (page - pgdat->node_mem_map) + pgdat->node_start_pfn;
-}
-#elif defined(CONFIG_SPARSEMEM)
-struct page *pfn_to_page(unsigned long pfn)
-{
-        return __section_mem_map_addr(__pfn_to_section(pfn)) + pfn;
-}
-
-unsigned long page_to_pfn(struct page *page)
-{
-        long section_id = page_to_section(page);
-        return page - __section_mem_map_addr(__nr_to_section(section_id));
+        return __page_to_pfn(page);
 }
-#endif /* CONFIG_FLATMEM/DISCONTIGMME/SPARSEMEM */
 EXPORT_SYMBOL(pfn_to_page);
 EXPORT_SYMBOL(page_to_pfn);
 #endif /* CONFIG_OUT_OF_LINE_PFN_TO_PAGE */