x86-64: Slightly shorten copy_page()

%r13 got saved and restored without ever getting touched, so
there's no need to do so.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/4F05D9F9020000780006AA0D@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 8 deletions

diff --git a/arch/x86/lib/copy_page_64.S b/arch/x86/lib/copy_page_64.S
index 01c805ba535..6b34d04d096 100644
--- a/arch/x86/lib/copy_page_64.S
+++ b/arch/x86/lib/copy_page_64.S
@@ -20,14 +20,12 @@ ENDPROC(copy_page_c)
 
 ENTRY(copy_page)
         CFI_STARTPROC
-        subq    $3*8,%rsp
-        CFI_ADJUST_CFA_OFFSET 3*8
+        subq    $2*8,%rsp
+        CFI_ADJUST_CFA_OFFSET 2*8
         movq    %rbx,(%rsp)
         CFI_REL_OFFSET rbx, 0
         movq    %r12,1*8(%rsp)
         CFI_REL_OFFSET r12, 1*8
-        movq    %r13,2*8(%rsp)
-        CFI_REL_OFFSET r13, 2*8
 
         movl    $(4096/64)-5,%ecx
         .p2align 4
@@ -91,10 +89,8 @@ ENTRY(copy_page)
         CFI_RESTORE rbx
         movq    1*8(%rsp),%r12
         CFI_RESTORE r12
-        movq    2*8(%rsp),%r13
-        CFI_RESTORE r13
-        addq    $3*8,%rsp
-        CFI_ADJUST_CFA_OFFSET -3*8
+        addq    $2*8,%rsp
+        CFI_ADJUST_CFA_OFFSET -2*8
         ret
 .Lcopy_page_end:
         CFI_ENDPROC