1/* SPDX-License-Identifier: GPL-2.0 */
2/* copy_in_user.S: Copy from userspace to userspace.
3 *
4 * Copyright (C) 1999, 2000, 2004 David S. Miller (davem@redhat.com)
5 */
6
7#include <linux/export.h>
8#include <linux/linkage.h>
9#include <asm/asi.h>
10
11#define XCC xcc
12
13#define EX(x,y,z) \
1498: x,y; \
15 .section __ex_table,"a";\
16 .align 4; \
17 .word 98b, z; \
18 .text; \
19 .align 4;
20
21#define EX_O4(x,y) EX(x,y,__retl_o4_plus_8)
22#define EX_O2_4(x,y) EX(x,y,__retl_o2_plus_4)
23#define EX_O2_1(x,y) EX(x,y,__retl_o2_plus_1)
24
25 .register %g2,#scratch
26 .register %g3,#scratch
27
28 .text
29__retl_o4_plus_8:
30 add %o4, %o2, %o4
31 retl
32 add %o4, 8, %o0
33__retl_o2_plus_4:
34 retl
35 add %o2, 4, %o0
36__retl_o2_plus_1:
37 retl
38 add %o2, 1, %o0
39
40 .align 32
41
42 /* Don't try to get too fancy here, just nice and
43 * simple. This is predominantly used for well aligned
44 * small copies in the compat layer. It is also used
45 * to copy register windows around during thread cloning.
46 */
47
48ENTRY(raw_copy_in_user) /* %o0=dst, %o1=src, %o2=len */
49 cmp %o2, 0
50 be,pn %XCC, 85f
51 or %o0, %o1, %o3
52 cmp %o2, 16
53 bleu,a,pn %XCC, 80f
54 or %o3, %o2, %o3
55
56 /* 16 < len <= 64 */
57 andcc %o3, 0x7, %g0
58 bne,pn %XCC, 90f
59 nop
60
61 andn %o2, 0x7, %o4
62 and %o2, 0x7, %o2
631: subcc %o4, 0x8, %o4
64 EX_O4(ldxa [%o1] %asi, %o5)
65 EX_O4(stxa %o5, [%o0] %asi)
66 add %o1, 0x8, %o1
67 bgu,pt %XCC, 1b
68 add %o0, 0x8, %o0
69 andcc %o2, 0x4, %g0
70 be,pt %XCC, 1f
71 nop
72 sub %o2, 0x4, %o2
73 EX_O2_4(lduwa [%o1] %asi, %o5)
74 EX_O2_4(stwa %o5, [%o0] %asi)
75 add %o1, 0x4, %o1
76 add %o0, 0x4, %o0
771: cmp %o2, 0
78 be,pt %XCC, 85f
79 nop
80 ba,pt %xcc, 90f
81 nop
82
8380: /* 0 < len <= 16 */
84 andcc %o3, 0x3, %g0
85 bne,pn %XCC, 90f
86 nop
87
8882:
89 subcc %o2, 4, %o2
90 EX_O2_4(lduwa [%o1] %asi, %g1)
91 EX_O2_4(stwa %g1, [%o0] %asi)
92 add %o1, 4, %o1
93 bgu,pt %XCC, 82b
94 add %o0, 4, %o0
95
9685: retl
97 clr %o0
98
99 .align 32
10090:
101 subcc %o2, 1, %o2
102 EX_O2_1(lduba [%o1] %asi, %g1)
103 EX_O2_1(stba %g1, [%o0] %asi)
104 add %o1, 1, %o1
105 bgu,pt %XCC, 90b
106 add %o0, 1, %o0
107 retl
108 clr %o0
109ENDPROC(raw_copy_in_user)
110EXPORT_SYMBOL(raw_copy_in_user)
111

source code of linux/arch/sparc/lib/copy_in_user.S