summaryrefslogtreecommitdiffstats
path: root/arch/parisc/lib/lusercopy.S
blob: a512f07d4feba9bc2dd36f2f1d2f96ee26734348 (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
/*
 *    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

	/*
	 * 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

	ASM_EXCEPTIONTABLE_ENTRY(1b,2b)

	.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

	ASM_EXCEPTIONTABLE_ENTRY(1b,3b)
	ASM_EXCEPTIONTABLE_ENTRY(2b,3b)

	.procend

	.end