summaryrefslogtreecommitdiffstats
path: root/arch/sparc64/lib/strncpy_from_user.S
blob: 511c8f136f9575fe9ca045fda3c0d9d56953cb4f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
/*
 * strncpy_from_user.S: Sparc64 strncpy from userspace.
 *
 *  Copyright (C) 1997, 1999 Jakub Jelinek (jj@ultra.linux.cz)
 */

#include <asm/asi.h>
#include <asm/errno.h>

	.data
	.align	8
0:	.xword	0x0101010101010101

	.text
	.align	32

	/* Must return:
	 *
	 * -EFAULT		for an exception
	 * count		if we hit the buffer limit
	 * bytes copied		if we hit a null byte
	 * (without the null byte)
	 *
	 * This implementation assumes:
	 * %o1 is 8 aligned => !(%o2 & 7)
	 * %o0 is 8 aligned (if not, it will be slooooow, but will work)
	 *
	 * This is optimized for the common case:
	 * in my stats, 90% of src are 8 aligned (even on sparc32)
	 * and average length is 18 or so.
	 */

	.globl	__strncpy_from_user
	.type	__strncpy_from_user,#function
__strncpy_from_user:
	/* %o0=dest, %o1=src, %o2=count */
	andcc	%o1, 7, %g0		! IEU1	Group
	bne,pn	%icc, 30f		! CTI
	 add	%o0, %o2, %g3		! IEU0
60:	ldxa	[%o1] %asi, %g1		! Load	Group
	brlez,pn %o2, 10f		! CTI
	 mov	%o0, %o3		! IEU0
50:	sethi	%hi(0b), %o4		! IEU0	Group
	ldx	[%o4 + %lo(0b)], %o4	! Load
	sllx	%o4, 7, %o5		! IEU1	Group
1:	sub	%g1, %o4, %g2		! IEU0	Group
	stx	%g1, [%o0]		! Store
	add	%o0, 8, %o0		! IEU1
	andcc	%g2, %o5, %g0		! IEU1	Group
	bne,pn	%xcc, 5f		! CTI
	 add	%o1, 8, %o1		! IEU0
	cmp	%o0, %g3		! IEU1	Group
	bl,a,pt %xcc, 1b		! CTI
61:	 ldxa	[%o1] %asi, %g1		! Load
10:	retl				! CTI	Group
	 mov	%o2, %o0		! IEU0
5:	srlx	%g2, 32, %g7		! IEU0	Group
	sethi	%hi(0xff00), %o4	! IEU1
	andcc	%g7, %o5, %g0		! IEU1	Group
	be,pn	%icc, 2f		! CTI
	 or	%o4, %lo(0xff00), %o4	! IEU0
	srlx	%g1, 48, %g7		! IEU0	Group
	andcc	%g7, %o4, %g0		! IEU1	Group
	be,pn	%icc, 50f		! CTI
	 andcc	%g7, 0xff, %g0		! IEU1	Group
	be,pn	%icc, 51f		! CTI
	 srlx	%g1, 32, %g7		! IEU0
	andcc	%g7, %o4, %g0		! IEU1	Group
	be,pn	%icc, 52f		! CTI
	 andcc	%g7, 0xff, %g0		! IEU1	Group
	be,pn	%icc, 53f		! CTI
2:	 andcc	%g2, %o5, %g0		! IEU1	Group
	be,pn	%icc, 2f		! CTI
	 srl	%g1, 16, %g7		! IEU0
	andcc	%g7, %o4, %g0		! IEU1	Group
	be,pn	%icc, 54f		! CTI
	 andcc	%g7, 0xff, %g0		! IEU1	Group
	be,pn	%icc, 55f		! CTI
	 andcc	%g1, %o4, %g0		! IEU1	Group
	be,pn	%icc, 56f		! CTI
	 andcc	%g1, 0xff, %g0		! IEU1	Group
	be,a,pn	%icc, 57f		! CTI
	 sub	%o0, %o3, %o0		! IEU0
2:	cmp	%o0, %g3		! IEU1	Group
	bl,a,pt	%xcc, 50b		! CTI
62:	 ldxa	[%o1] %asi, %g1		! Load
	retl				! CTI	Group
	 mov	%o2, %o0		! IEU0
50:	sub	%o0, %o3, %o0
	retl
	 sub	%o0, 8, %o0
51:	sub	%o0, %o3, %o0
	retl
	 sub	%o0, 7, %o0
52:	sub	%o0, %o3, %o0
	retl
	 sub	%o0, 6, %o0
53:	sub	%o0, %o3, %o0
	retl
	 sub	%o0, 5, %o0
54:	sub	%o0, %o3, %o0
	retl
	 sub	%o0, 4, %o0
55:	sub	%o0, %o3, %o0
	retl
	 sub	%o0, 3, %o0
56:	sub	%o0, %o3, %o0
	retl
	 sub	%o0, 2, %o0
57:	retl
	 sub	%o0, 1, %o0
30:	brlez,pn %o2, 3f
	 sub	%g0, %o2, %o3
	add	%o0, %o2, %o0
63:	lduba	[%o1] %asi, %o4
1:	add	%o1, 1, %o1
	brz,pn	%o4, 2f
	 stb	%o4, [%o0 + %o3]
	addcc	%o3, 1, %o3
	bne,pt	%xcc, 1b
64:	 lduba	[%o1] %asi, %o4
3:	retl
	 mov	%o2, %o0
2:	retl
	 add	%o2, %o3, %o0
	.size	__strncpy_from_user, .-__strncpy_from_user

	.section __ex_table,"a"
	.align	4
	.word	60b, __retl_efault
	.word	61b, __retl_efault
	.word	62b, __retl_efault
	.word	63b, __retl_efault
	.word	64b, __retl_efault
	.previous
OpenPOWER on IntegriCloud