[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, 14 insertions, 12 deletions

diff --git a/arch/arm/mm/copypage-xscale.c b/arch/arm/mm/copypage-xscale.c
index 01bafafce18..aa9f2ff9dce 100644
--- a/arch/arm/mm/copypage-xscale.c
+++ b/arch/arm/mm/copypage-xscale.c
@@ -113,28 +113,30 @@ void xscale_mc_copy_user_highpage(struct page *to, struct page *from,
 /*
  * XScale optimised clear_user_page
  */
-void __attribute__((naked))
-xscale_mc_clear_user_page(void *kaddr, unsigned long vaddr)
+void
+xscale_mc_clear_user_highpage(struct page *page, unsigned long vaddr)
 {
+        void *kaddr = kmap_atomic(page, KM_USER0);
         asm volatile(
-        "mov    r1, %0                          \n\
+        "mov    r1, %1                          \n\
         mov     r2, #0                          \n\
         mov     r3, #0                          \n\
-1:      mov     ip, r0                          \n\
-        strd    r2, [r0], #8                    \n\
-        strd    r2, [r0], #8                    \n\
-        strd    r2, [r0], #8                    \n\
-        strd    r2, [r0], #8                    \n\
+1:      mov     ip, %0                          \n\
+        strd    r2, [%0], #8                    \n\
+        strd    r2, [%0], #8                    \n\
+        strd    r2, [%0], #8                    \n\
+        strd    r2, [%0], #8                    \n\
         mcr     p15, 0, ip, c7, c10, 1          @ clean D line\n\
         subs    r1, r1, #1                      \n\
         mcr     p15, 0, ip, c7, c6, 1           @ invalidate D line\n\
-        bne     1b                              \n\
-        mov     pc, lr"
+        bne     1b"
         :
-        : "I" (PAGE_SIZE / 32));
+        : "r" (kaddr), "I" (PAGE_SIZE / 32)
+        : "r1", "r2", "r3", "ip");
+        kunmap_atomic(kaddr, KM_USER0);
 }
 
 struct cpu_user_fns xscale_mc_user_fns __initdata = {
-        .cpu_clear_user_page    = xscale_mc_clear_user_page, 
+        .cpu_clear_user_highpage = xscale_mc_clear_user_highpage,
         .cpu_copy_user_highpage = xscale_mc_copy_user_highpage,
 };