1/* SPDX-License-Identifier: GPL-2.0 */
2/* memmove.S: Simple memmove implementation.
3 *
4 * Copyright (C) 1997, 2004 David S. Miller (davem@redhat.com)
5 * Copyright (C) 1996, 1997, 1998, 1999 Jakub Jelinek (jj@ultra.linux.cz)
6 */
7
8#include <linux/linkage.h>
9#include <asm/export.h>
10
11	.text
12ENTRY(memmove) /* o0=dst o1=src o2=len */
13	brz,pn		%o2, 99f
14	 mov		%o0, %g1
15
16	cmp		%o0, %o1
17	bleu,pt		%xcc, 2f
18	 add		%o1, %o2, %g7
19	cmp		%g7, %o0
20	bleu,pt		%xcc, memcpy
21	 add		%o0, %o2, %o5
22	sub		%g7, 1, %o1
23
24	sub		%o5, 1, %o0
251:	ldub		[%o1], %g7
26	subcc		%o2, 1, %o2
27	sub		%o1, 1, %o1
28	stb		%g7, [%o0]
29	bne,pt		%icc, 1b
30	 sub		%o0, 1, %o0
3199:
32	retl
33	 mov		%g1, %o0
34
35	/* We can't just call memcpy for these memmove cases.  On some
36	 * chips the memcpy uses cache initializing stores and when dst
37	 * and src are close enough, those can clobber the source data
38	 * before we've loaded it in.
39	 */
402:	or		%o0, %o1, %g7
41	or		%o2, %g7, %g7
42	andcc		%g7, 0x7, %g0
43	bne,pn		%xcc, 4f
44	 nop
45
463:	ldx		[%o1], %g7
47	add		%o1, 8, %o1
48	subcc		%o2, 8, %o2
49	add		%o0, 8, %o0
50	bne,pt		%icc, 3b
51	 stx		%g7, [%o0 - 0x8]
52	ba,a,pt		%xcc, 99b
53
544:	ldub		[%o1], %g7
55	add		%o1, 1, %o1
56	subcc		%o2, 1, %o2
57	add		%o0, 1, %o0
58	bne,pt		%icc, 4b
59	 stb		%g7, [%o0 - 0x1]
60	ba,a,pt		%xcc, 99b
61ENDPROC(memmove)
62EXPORT_SYMBOL(memmove)
63