[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>

1 files changed, 12 insertions, 12 deletions

diff --git a/arch/arm/mm/copypage-v4wt.c b/arch/arm/mm/copypage-v4wt.c
index 86c2cfdbde03..b8a345d6e77e 100644
--- a/arch/arm/mm/copypage-v4wt.c
+++ b/arch/arm/mm/copypage-v4wt.c
@@ -60,29 +60,29 @@ void v4wt_copy_user_highpage(struct page *to, struct page *from,
  *
  * Same story as above.
  */
-void __attribute__((naked))
-v4wt_clear_user_page(void *kaddr, unsigned long vaddr)
+void v4wt_clear_user_highpage(struct page *page, unsigned long vaddr)
 {
+        void *kaddr = kmap_atomic(page, KM_USER0);
         asm("\
-        str     lr, [sp, #-4]!\n\
-        mov     r1, %0                          @ 1\n\
+        mov     r1, %1                          @ 1\n\
         mov     r2, #0                          @ 1\n\
         mov     r3, #0                          @ 1\n\
         mov     ip, #0                          @ 1\n\
         mov     lr, #0                          @ 1\n\
-1:      stmia   r0!, {r2, r3, ip, lr}           @ 4\n\
-        stmia   r0!, {r2, r3, ip, lr}           @ 4\n\
-        stmia   r0!, {r2, r3, ip, lr}           @ 4\n\
-        stmia   r0!, {r2, r3, ip, lr}           @ 4\n\
+1:      stmia   %0!, {r2, r3, ip, lr}           @ 4\n\
+        stmia   %0!, {r2, r3, ip, lr}           @ 4\n\
+        stmia   %0!, {r2, r3, ip, lr}           @ 4\n\
+        stmia   %0!, {r2, r3, ip, lr}           @ 4\n\
         subs    r1, r1, #1                      @ 1\n\
         bne     1b                              @ 1\n\
-        mcr     p15, 0, r2, c7, c7, 0           @ flush ID cache\n\
-        ldr     pc, [sp], #4"
+        mcr     p15, 0, r2, c7, c7, 0           @ flush ID cache"
         :
-        : "I" (PAGE_SIZE / 64));
+        : "r" (kaddr), "I" (PAGE_SIZE / 64)
+        : "r1", "r2", "r3", "ip", "lr");
+        kunmap_atomic(kaddr, KM_USER0);
 }
 
 struct cpu_user_fns v4wt_user_fns __initdata = {
-        .cpu_clear_user_page    = v4wt_clear_user_page,
+        .cpu_clear_user_highpage = v4wt_clear_user_highpage,
         .cpu_copy_user_highpage = v4wt_copy_user_highpage,
 };