x86/lib/memmove_64.S: Convert memmove() to ALTERNATIVE macro

Make it execute the ERMS version if support is present and we're in the
forward memmove() part and remove the unfolded alternatives section
definition.

Signed-off-by: Borislav Petkov <bp@suse.de>

1 files changed, 2 insertions, 17 deletions

diff --git a/arch/x86/lib/memmove_64.S b/arch/x86/lib/memmove_64.S
index bbfa6b269ece..0f8a0d0331b9 100644
--- a/arch/x86/lib/memmove_64.S
+++ b/arch/x86/lib/memmove_64.S
@@ -5,7 +5,6 @@
  * This assembly file is re-written from memmove_64.c file.
  *      - Copyright 2011 Fenghua Yu <fenghua.yu@intel.com>
  */
-#define _STRING_C
 #include <linux/linkage.h>
 #include <asm/dwarf2.h>
 #include <asm/cpufeature.h>
@@ -44,6 +43,8 @@ ENTRY(__memmove)
         jg 2f
 
 .Lmemmove_begin_forward:
+        ALTERNATIVE "", "movq %rdx, %rcx; rep movsb; retq", X86_FEATURE_ERMS
+
         /*
          * movsq instruction have many startup latency
          * so we handle small size by general register.
@@ -207,21 +208,5 @@ ENTRY(__memmove)
 13:
         retq
         CFI_ENDPROC
-
-        .section .altinstr_replacement,"ax"
-.Lmemmove_begin_forward_efs:
-        /* Forward moving data. */
-        movq %rdx, %rcx
-        rep movsb
-        retq
-.Lmemmove_end_forward_efs:
-        .previous
-
-        .section .altinstructions,"a"
-        altinstruction_entry .Lmemmove_begin_forward,           \
-                .Lmemmove_begin_forward_efs,X86_FEATURE_ERMS,   \
-                .Lmemmove_end_forward-.Lmemmove_begin_forward,  \
-                .Lmemmove_end_forward_efs-.Lmemmove_begin_forward_efs,0
-        .previous
 ENDPROC(__memmove)
 ENDPROC(memmove)