x86: Improve cmpxchg16b_emu.S

- don't include unneeded headers
- don't open-code PER_CPU_VAR()
- drop redundant entry point label
- complete unwind annotations
- use .L prefix on local label to not clutter the symbol table

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/542290BC020000780003807D@mail.emea.novell.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/arch/x86/lib/cmpxchg16b_emu.S b/arch/x86/lib/cmpxchg16b_emu.S
index 1e572c5..40a1725 100644 (file)
--- a/arch/x86/lib/cmpxchg16b_emu.S
+++ b/arch/x86/lib/cmpxchg16b_emu.S
@@ -6,15 +6,8 @@
  *
  */
 #include <linux/linkage.h>
-#include <asm/alternative-asm.h>
-#include <asm/frame.h>
 #include <asm/dwarf2.h>
-
-#ifdef CONFIG_SMP
-#define SEG_PREFIX %gs:
-#else
-#define SEG_PREFIX
-#endif
+#include <asm/percpu.h>
 
 .text
 
@@ -39,24 +32,25 @@ CFI_STARTPROC
 # *atomic* on a single cpu (as provided by the this_cpu_xx class of
 # macros).
 #
-this_cpu_cmpxchg16b_emu:
-       pushf
+       pushfq_cfi
        cli
 
-       cmpq SEG_PREFIX(%rsi), %rax
-       jne not_same
-       cmpq SEG_PREFIX 8(%rsi), %rdx
-       jne not_same
+       cmpq PER_CPU_VAR((%rsi)), %rax
+       jne .Lnot_same
+       cmpq PER_CPU_VAR(8(%rsi)), %rdx
+       jne .Lnot_same
 
-       movq %rbx, SEG_PREFIX(%rsi)
-       movq %rcx, SEG_PREFIX 8(%rsi)
+       movq %rbx, PER_CPU_VAR((%rsi))
+       movq %rcx, PER_CPU_VAR(8(%rsi))
 
-       popf
+       CFI_REMEMBER_STATE
+       popfq_cfi
        mov $1, %al
        ret
 
- not_same:
-       popf
+       CFI_RESTORE_STATE
+.Lnot_same:
+       popfq_cfi
        xor %al,%al
        ret