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Subject[PATCH v2 14/15] x86/lib/memmove_64.S: Convert memmove() to ALTERNATIVE macro
Date
From: Borislav Petkov <bp@suse.de>

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>
---
arch/x86/lib/memmove_64.S | 19 ++-----------------
1 file 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)
--
2.2.0.33.gc18b867


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