1 /* SPDX-License-Identifier: GPL-2.0 */ 1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* memmove.S: Simple memmove implementation. 2 /* memmove.S: Simple memmove implementation.
3 * 3 *
4 * Copyright (C) 1997, 2004 David S. Miller (d 4 * Copyright (C) 1997, 2004 David S. Miller (davem@redhat.com)
5 * Copyright (C) 1996, 1997, 1998, 1999 Jakub 5 * Copyright (C) 1996, 1997, 1998, 1999 Jakub Jelinek (jj@ultra.linux.cz)
6 */ 6 */
7 7
8 #include <linux/export.h> 8 #include <linux/export.h>
9 #include <linux/linkage.h> 9 #include <linux/linkage.h>
10 10
11 .text 11 .text
12 ENTRY(memmove) /* o0=dst o1=src o2=len */ 12 ENTRY(memmove) /* o0=dst o1=src o2=len */
13 brz,pn %o2, 99f 13 brz,pn %o2, 99f
14 mov %o0, %g1 14 mov %o0, %g1
15 15
16 cmp %o0, %o1 16 cmp %o0, %o1
17 bleu,pt %xcc, 2f 17 bleu,pt %xcc, 2f
18 add %o1, %o2, %g7 18 add %o1, %o2, %g7
19 cmp %g7, %o0 19 cmp %g7, %o0
20 bleu,pt %xcc, memcpy 20 bleu,pt %xcc, memcpy
21 add %o0, %o2, %o5 21 add %o0, %o2, %o5
22 sub %g7, 1, %o1 22 sub %g7, 1, %o1
23 23
24 sub %o5, 1, %o0 24 sub %o5, 1, %o0
25 1: ldub [%o1], %g7 25 1: ldub [%o1], %g7
26 subcc %o2, 1, %o2 26 subcc %o2, 1, %o2
27 sub %o1, 1, %o1 27 sub %o1, 1, %o1
28 stb %g7, [%o0] 28 stb %g7, [%o0]
29 bne,pt %icc, 1b 29 bne,pt %icc, 1b
30 sub %o0, 1, %o0 30 sub %o0, 1, %o0
31 99: 31 99:
32 retl 32 retl
33 mov %g1, %o0 33 mov %g1, %o0
34 34
35 /* We can't just call memcpy for these 35 /* We can't just call memcpy for these memmove cases. On some
36 * chips the memcpy uses cache initial 36 * chips the memcpy uses cache initializing stores and when dst
37 * and src are close enough, those can 37 * and src are close enough, those can clobber the source data
38 * before we've loaded it in. 38 * before we've loaded it in.
39 */ 39 */
40 2: or %o0, %o1, %g7 40 2: or %o0, %o1, %g7
41 or %o2, %g7, %g7 41 or %o2, %g7, %g7
42 andcc %g7, 0x7, %g0 42 andcc %g7, 0x7, %g0
43 bne,pn %xcc, 4f 43 bne,pn %xcc, 4f
44 nop 44 nop
45 45
46 3: ldx [%o1], %g7 46 3: ldx [%o1], %g7
47 add %o1, 8, %o1 47 add %o1, 8, %o1
48 subcc %o2, 8, %o2 48 subcc %o2, 8, %o2
49 add %o0, 8, %o0 49 add %o0, 8, %o0
50 bne,pt %icc, 3b 50 bne,pt %icc, 3b
51 stx %g7, [%o0 - 0x8] 51 stx %g7, [%o0 - 0x8]
52 ba,a,pt %xcc, 99b 52 ba,a,pt %xcc, 99b
53 53
54 4: ldub [%o1], %g7 54 4: ldub [%o1], %g7
55 add %o1, 1, %o1 55 add %o1, 1, %o1
56 subcc %o2, 1, %o2 56 subcc %o2, 1, %o2
57 add %o0, 1, %o0 57 add %o0, 1, %o0
58 bne,pt %icc, 4b 58 bne,pt %icc, 4b
59 stb %g7, [%o0 - 0x1] 59 stb %g7, [%o0 - 0x1]
60 ba,a,pt %xcc, 99b 60 ba,a,pt %xcc, 99b
61 ENDPROC(memmove) 61 ENDPROC(memmove)
62 EXPORT_SYMBOL(memmove) 62 EXPORT_SYMBOL(memmove)
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