[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/mm/copypage-v4wt.c b/arch/arm/mm/copypage-v4wt.c
index 86c2cfd..b8a345d 100644
--- a/arch/arm/mm/copypage-v4wt.c
+++ b/arch/arm/mm/copypage-v4wt.c
@@ -60,29 +60,29 @@
*
* 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,
};