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Commit a77600cd authored by Borislav Petkov's avatar Borislav Petkov
Browse files

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: default avatarBorislav Petkov <bp@suse.de>
parent 84d95ad4

arch/x86/lib/memmove_64.S

+2 −17
Original line number Original line Diff line number Diff line
@@ -5,7 +5,6 @@ 
 * This assembly file is re-written from memmove_64.c file.

 * This assembly file is re-written from memmove_64.c file.

 *	- Copyright 2011 Fenghua Yu <fenghua.yu@intel.com>

 *	- Copyright 2011 Fenghua Yu <fenghua.yu@intel.com>

 */

 */

#define _STRING_C

#include <linux/linkage.h>

#include <linux/linkage.h>

#include <asm/dwarf2.h>

#include <asm/dwarf2.h>

#include <asm/cpufeature.h>

#include <asm/cpufeature.h>
@@ -44,6 +43,8 @@ ENTRY(__memmove) 
	jg 2f

	jg 2f





.Lmemmove_begin_forward:

.Lmemmove_begin_forward:

	ALTERNATIVE "", "movq %rdx, %rcx; rep movsb; retq", X86_FEATURE_ERMS



	/*

	/*

	 * movsq instruction have many startup latency

	 * movsq instruction have many startup latency

	 * so we handle small size by general register.

	 * so we handle small size by general register.
@@ -207,21 +208,5 @@ ENTRY(__memmove) 
13:

13:

	retq

	retq

	CFI_ENDPROC

	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)

ENDPROC(memmove)
 
ENDPROC(memmove)