blob: a512f07d4feba9bc2dd36f2f1d2f96ee26734348 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * User Space Access Routines
3 *
4 * Copyright (C) 2000-2002 Hewlett-Packard (John Marvin)
5 * Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
6 * Copyright (C) 2001 Matthieu Delahaye <delahaym at esiee.fr>
7 * Copyright (C) 2003 Randolph Chung <tausq with parisc-linux.org>
8 *
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2, or (at your option)
13 * any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24
25/*
26 * These routines still have plenty of room for optimization
27 * (word & doubleword load/store, dual issue, store hints, etc.).
28 */
29
30/*
31 * The following routines assume that space register 3 (sr3) contains
32 * the space id associated with the current users address space.
33 */
34
35
Kyle McMartindfcf7532008-05-22 14:36:31 -040036 .text
37
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#include <asm/assembly.h>
39#include <asm/errno.h>
Helge Deller0b3d6432007-01-28 14:52:57 +010040#include <linux/linkage.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
42 /*
43 * get_sr gets the appropriate space value into
44 * sr1 for kernel/user space access, depending
45 * on the flag stored in the task structure.
46 */
47
48 .macro get_sr
49 mfctl %cr30,%r1
50 ldw TI_SEGMENT(%r1),%r22
51 mfsp %sr3,%r1
52 or,<> %r22,%r0,%r0
53 copy %r0,%r1
54 mtsp %r1,%sr1
55 .endm
56
57 .macro fixup_branch lbl
58 ldil L%\lbl, %r1
59 ldo R%\lbl(%r1), %r1
60 bv %r0(%r1)
61 .endm
62
63 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 * unsigned long lclear_user(void *to, unsigned long n)
65 *
66 * Returns 0 for success.
67 * otherwise, returns number of bytes not transferred.
68 */
69
Helge Deller0b3d6432007-01-28 14:52:57 +010070ENTRY(lclear_user)
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 .proc
72 .callinfo NO_CALLS
73 .entry
74 comib,=,n 0,%r25,$lclu_done
75 get_sr
76$lclu_loop:
77 addib,<> -1,%r25,$lclu_loop
781: stbs,ma %r0,1(%sr1,%r26)
79
80$lclu_done:
81 bv %r0(%r2)
82 copy %r25,%r28
83 .exit
Helge Deller0b3d6432007-01-28 14:52:57 +010084ENDPROC(lclear_user)
Linus Torvalds1da177e2005-04-16 15:20:36 -070085
86 .section .fixup,"ax"
872: fixup_branch $lclu_done
88 ldo 1(%r25),%r25
89 .previous
90
Helge Deller61dbbae2013-10-13 21:11:30 +020091 ASM_EXCEPTIONTABLE_ENTRY(1b,2b)
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
93 .procend
94
95 /*
96 * long lstrnlen_user(char *s, long n)
97 *
98 * Returns 0 if exception before zero byte or reaching N,
99 * N+1 if N would be exceeded,
100 * else strlen + 1 (i.e. includes zero byte).
101 */
102
Helge Deller0b3d6432007-01-28 14:52:57 +0100103ENTRY(lstrnlen_user)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 .proc
105 .callinfo NO_CALLS
106 .entry
107 comib,= 0,%r25,$lslen_nzero
108 copy %r26,%r24
109 get_sr
1101: ldbs,ma 1(%sr1,%r26),%r1
111$lslen_loop:
112 comib,=,n 0,%r1,$lslen_done
113 addib,<> -1,%r25,$lslen_loop
1142: ldbs,ma 1(%sr1,%r26),%r1
115$lslen_done:
116 bv %r0(%r2)
117 sub %r26,%r24,%r28
118 .exit
119
120$lslen_nzero:
121 b $lslen_done
122 ldo 1(%r26),%r26 /* special case for N == 0 */
Helge Deller0b3d6432007-01-28 14:52:57 +0100123ENDPROC(lstrnlen_user)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
125 .section .fixup,"ax"
1263: fixup_branch $lslen_done
127 copy %r24,%r26 /* reset r26 so 0 is returned on fault */
128 .previous
129
Helge Deller61dbbae2013-10-13 21:11:30 +0200130 ASM_EXCEPTIONTABLE_ENTRY(1b,3b)
131 ASM_EXCEPTIONTABLE_ENTRY(2b,3b)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
133 .procend
134
135 .end