aboutsummaryrefslogtreecommitdiffstats
path: root/arch/parisc/lib/lusercopy.S
blob: 1bd23ccec17b9a53fb838fdfdf5eb9ab62ccf739 (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
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
/*
 *    User Space Access Routines
 *
 *    Copyright (C) 2000-2002 Hewlett-Packard (John Marvin)
 *    Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
 *    Copyright (C) 2001 Matthieu Delahaye <delahaym at esiee.fr>
 *    Copyright (C) 2003 Randolph Chung <tausq with parisc-linux.org>
 *
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2, or (at your option)
 *    any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/*
 * These routines still have plenty of room for optimization
 * (word & doubleword load/store, dual issue, store hints, etc.).
 */

/*
 * The following routines assume that space register 3 (sr3) contains
 * the space id associated with the current users address space.
 */


	.text
	
#include <asm/assembly.h>
#include <asm/errno.h>
#include <linux/linkage.h>

	/*
	 * get_sr gets the appropriate space value into
	 * sr1 for kernel/user space access, depending
	 * on the flag stored in the task structure.
	 */

	.macro  get_sr
	mfctl       %cr30,%r1
	ldw         TI_SEGMENT(%r1),%r22
	mfsp        %sr3,%r1
	or,<>       %r22,%r0,%r0
	copy        %r0,%r1
	mtsp        %r1,%sr1
	.endm

	.macro fixup_branch lbl
	ldil	    L%\lbl, %r1
	ldo	    R%\lbl(%r1), %r1
	bv          %r0(%r1)
	.endm

	/*
	 * long lstrncpy_from_user(char *dst, const char *src, long n)
	 *
	 * Returns -EFAULT if exception before terminator,
	 *         N if the entire buffer filled,
	 *         otherwise strlen (i.e. excludes zero byte)
	 */

ENTRY(lstrncpy_from_user)
	.proc
	.callinfo NO_CALLS
	.entry
	comib,=     0,%r24,$lsfu_done
	copy        %r24,%r23
	get_sr
1:      ldbs,ma     1(%sr1,%r25),%r1
$lsfu_loop:
	stbs,ma     %r1,1(%r26)
	comib,=,n   0,%r1,$lsfu_done
	addib,<>,n  -1,%r24,$lsfu_loop
2:      ldbs,ma     1(%sr1,%r25),%r1
$lsfu_done:
	sub         %r23,%r24,%r28
$lsfu_exit:
	bv          %r0(%r2)
	nop
	.exit
ENDPROC(lstrncpy_from_user)

	.section .fixup,"ax"
3:      fixup_branch $lsfu_exit
	ldi         -EFAULT,%r28
	.previous

	.section __ex_table,"aw"
	ASM_ULONG_INSN 1b,3b
	ASM_ULONG_INSN 2b,3b
	.previous

	.procend

	/*
	 * unsigned long lclear_user(void *to, unsigned long n)
	 *
	 * Returns 0 for success.
	 * otherwise, returns number of bytes not transferred.
	 */

ENTRY(lclear_user)
	.proc
	.callinfo NO_CALLS
	.entry
	comib,=,n   0,%r25,$lclu_done
	get_sr
$lclu_loop:
	addib,<>    -1,%r25,$lclu_loop
1:      stbs,ma     %r0,1(%sr1,%r26)

$lclu_done:
	bv          %r0(%r2)
	copy        %r25,%r28
	.exit
ENDPROC(lclear_user)

	.section .fixup,"ax"
2:      fixup_branch $lclu_done
	ldo        1(%r25),%r25
	.previous

	.section __ex_table,"aw"
	ASM_ULONG_INSN 1b,2b
	.previous

	.procend

	/*
	 * long lstrnlen_user(char *s, long n)
	 *
	 * Returns 0 if exception before zero byte or reaching N,
	 *         N+1 if N would be exceeded,
	 *         else strlen + 1 (i.e. includes zero byte).
	 */

ENTRY(lstrnlen_user)
	.proc
	.callinfo NO_CALLS
	.entry
	comib,=     0,%r25,$lslen_nzero
	copy	    %r26,%r24
	get_sr
1:      ldbs,ma     1(%sr1,%r26),%r1
$lslen_loop:
	comib,=,n   0,%r1,$lslen_done
	addib,<>    -1,%r25,$lslen_loop
2:      ldbs,ma     1(%sr1,%r26),%r1
$lslen_done:
	bv          %r0(%r2)
	sub	    %r26,%r24,%r28
	.exit

$lslen_nzero:
	b           $lslen_done
	ldo         1(%r26),%r26 /* special case for N == 0 */
ENDPROC(lstrnlen_user)

	.section .fixup,"ax"
3:      fixup_branch $lslen_done
	copy        %r24,%r26    /* reset r26 so 0 is returned on fault */
	.previous

	.section __ex_table,"aw"
	ASM_ULONG_INSN 1b,3b
	ASM_ULONG_INSN 2b,3b
	.previous

	.procend

	.end