[ARM] clearpage: provide our own clear_user_highpage()

For similar reasons as copy_user_page(), we want to avoid the
additional kmap_atomic if it's unnecessary.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/page.h b/arch/arm/include/asm/page.h
index 1581b8c..77747df 100644
--- a/arch/arm/include/asm/page.h
+++ b/arch/arm/include/asm/page.h
@@ -111,7 +111,7 @@
 struct page;
 
 struct cpu_user_fns {
-	void (*cpu_clear_user_page)(void *p, unsigned long user);
+	void (*cpu_clear_user_highpage)(struct page *page, unsigned long vaddr);
 	void (*cpu_copy_user_highpage)(struct page *to, struct page *from,
 			unsigned long vaddr);
 };
@@ -119,20 +119,21 @@
 #ifdef MULTI_USER
 extern struct cpu_user_fns cpu_user;
 
-#define __cpu_clear_user_page		cpu_user.cpu_clear_user_page
+#define __cpu_clear_user_highpage	cpu_user.cpu_clear_user_highpage
 #define __cpu_copy_user_highpage	cpu_user.cpu_copy_user_highpage
 
 #else
 
-#define __cpu_clear_user_page		__glue(_USER,_clear_user_page)
+#define __cpu_clear_user_highpage	__glue(_USER,_clear_user_highpage)
 #define __cpu_copy_user_highpage	__glue(_USER,_copy_user_highpage)
 
-extern void __cpu_clear_user_page(void *p, unsigned long user);
+extern void __cpu_clear_user_highpage(struct page *page, unsigned long vaddr);
 extern void __cpu_copy_user_highpage(struct page *to, struct page *from,
 			unsigned long vaddr);
 #endif
 
-#define clear_user_page(addr,vaddr,pg)	 __cpu_clear_user_page(addr, vaddr)
+#define clear_user_highpage(page,vaddr)		\
+	 __cpu_clear_user_highpage(page, vaddr)
 
 #define __HAVE_ARCH_COPY_USER_HIGHPAGE
 #define copy_user_highpage(to,from,vaddr,vma)	\