[PATCH] mm: split highorder pages

Have an explicit mm call to split higher order pages into individual pages.
 Should help to avoid bugs and be more explicit about the code's intention.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Chris Zankel <chris@zankel.net>
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 7 deletions

diff --git a/arch/xtensa/mm/pgtable.c b/arch/xtensa/mm/pgtable.c
index cbc56aedf13e..7d28914d11cb 100644
--- a/arch/xtensa/mm/pgtable.c
+++ b/arch/xtensa/mm/pgtable.c
@@ -21,13 +21,9 @@ pte_t* pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
         p = (pte_t*) __get_free_pages(GFP_KERNEL|__GFP_REPEAT, COLOR_ORDER);
 
         if (likely(p)) {
-                struct page *page;
+                split_page(virt_to_page(p), COLOR_ORDER);
 
                 for (i = 0; i < COLOR_SIZE; i++) {
-                        page = virt_to_page(p);
-
-                        set_page_count(page, 1);
-
                         if (ADDR_COLOR(p) == color)
                                 pte = p;
                         else
@@ -55,9 +51,9 @@ struct page* pte_alloc_one(struct mm_struct *mm, unsigned long address)
         p = alloc_pages(GFP_KERNEL | __GFP_REPEAT, PTE_ORDER);
 
         if (likely(p)) {
-                for (i = 0; i < PAGE_ORDER; i++) {
-                        set_page_count(p, 1);
+                split_page(p, COLOR_ORDER);
 
+                for (i = 0; i < PAGE_ORDER; i++) {
                         if (PADDR_COLOR(page_address(p)) == color)
                                 page = p;
                         else