Move vmalloc_to_page() to mm/vmalloc.

We already have page table manipulation for vmalloc in vmalloc.c. Move the
vmalloc_to_page() function there as well.

Move the definitions for vmalloc related functions in mm.h to a newly created
section.  A better place would be vmalloc.h but mm.h is basic and may depend
on these functions.  An alternative would be to include vmalloc.h in mm.h
(like done for vmstat.h).

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/linux/mm.h

@@ -231,6 +231,10 @@ static inline int get_page_unless_zero(struct page *page)
 	return atomic_inc_not_zero(&page->_count);
 }
 
+/* Support for virtually mapped pages */
+struct page *vmalloc_to_page(void *addr);
+unsigned long vmalloc_to_pfn(void *addr);
+
 static inline struct page *compound_head(struct page *page)
 {
 	if (unlikely(PageTail(page)))
@@ -1089,8 +1093,6 @@ static inline unsigned long vma_pages(struct vm_area_struct *vma)
 
 pgprot_t vm_get_page_prot(unsigned long vm_flags);
 struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
-struct page *vmalloc_to_page(void *addr);
-unsigned long vmalloc_to_pfn(void *addr);
 int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
 			unsigned long pfn, unsigned long size, pgprot_t);
 int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);

mm/memory.c

@@ -2618,46 +2618,6 @@ int make_pages_present(unsigned long addr, unsigned long end)
 	return ret == len ? 0 : -1;
 }
 
-/* 
- * Map a vmalloc()-space virtual address to the physical page.
- */
-struct page * vmalloc_to_page(void * vmalloc_addr)
-{
-	unsigned long addr = (unsigned long) vmalloc_addr;
-	struct page *page = NULL;
-	pgd_t *pgd = pgd_offset_k(addr);
-	pud_t *pud;
-	pmd_t *pmd;
-	pte_t *ptep, pte;
-
-	if (!pgd_none(*pgd)) {
-		pud = pud_offset(pgd, addr);
-		if (!pud_none(*pud)) {
-			pmd = pmd_offset(pud, addr);
-			if (!pmd_none(*pmd)) {
-				ptep = pte_offset_map(pmd, addr);
-				pte = *ptep;
-				if (pte_present(pte))
-					page = pte_page(pte);
-				pte_unmap(ptep);
-			}
-		}
-	}
-	return page;
-}
-
-EXPORT_SYMBOL(vmalloc_to_page);
-
-/*
- * Map a vmalloc()-space virtual address to the physical page frame number.
- */
-unsigned long vmalloc_to_pfn(void * vmalloc_addr)
-{
-	return page_to_pfn(vmalloc_to_page(vmalloc_addr));
-}
-
-EXPORT_SYMBOL(vmalloc_to_pfn);
-
 #if !defined(__HAVE_ARCH_GATE_AREA)
 
 #if defined(AT_SYSINFO_EHDR)

mm/vmalloc.c

@@ -166,6 +166,44 @@ int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
 }
 EXPORT_SYMBOL_GPL(map_vm_area);
 
+/*
+ * Map a vmalloc()-space virtual address to the physical page.
+ */
+struct page *vmalloc_to_page(void *vmalloc_addr)
+{
+	unsigned long addr = (unsigned long) vmalloc_addr;
+	struct page *page = NULL;
+	pgd_t *pgd = pgd_offset_k(addr);
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *ptep, pte;
+
+	if (!pgd_none(*pgd)) {
+		pud = pud_offset(pgd, addr);
+		if (!pud_none(*pud)) {
+			pmd = pmd_offset(pud, addr);
+			if (!pmd_none(*pmd)) {
+				ptep = pte_offset_map(pmd, addr);
+				pte = *ptep;
+				if (pte_present(pte))
+					page = pte_page(pte);
+				pte_unmap(ptep);
+			}
+		}
+	}
+	return page;
+}
+EXPORT_SYMBOL(vmalloc_to_page);
+
+/*
+ * Map a vmalloc()-space virtual address to the physical page frame number.
+ */
+unsigned long vmalloc_to_pfn(void *vmalloc_addr)
+{
+	return page_to_pfn(vmalloc_to_page(vmalloc_addr));
+}
+EXPORT_SYMBOL(vmalloc_to_pfn);
+
 static struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long flags,
 					    unsigned long start, unsigned long end,
 					    int node, gfp_t gfp_mask)