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1da177e4 LT |
1 | /* |
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 | ||
dfcf753b KM |
36 | .text |
37 | ||
1da177e4 LT |
38 | #include <asm/assembly.h> |
39 | #include <asm/errno.h> | |
0b3d643f | 40 | #include <linux/linkage.h> |
1da177e4 LT |
41 | |
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 | ||
1da177e4 LT |
63 | /* |
64 | * 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 | ||
0b3d643f | 70 | ENTRY(lclear_user) |
1da177e4 LT |
71 | .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 | |
78 | 1: stbs,ma %r0,1(%sr1,%r26) | |
79 | ||
80 | $lclu_done: | |
81 | bv %r0(%r2) | |
82 | copy %r25,%r28 | |
83 | .exit | |
0b3d643f | 84 | ENDPROC(lclear_user) |
1da177e4 LT |
85 | |
86 | .section .fixup,"ax" | |
87 | 2: fixup_branch $lclu_done | |
88 | ldo 1(%r25),%r25 | |
89 | .previous | |
90 | ||
61dbbaeb | 91 | ASM_EXCEPTIONTABLE_ENTRY(1b,2b) |
1da177e4 LT |
92 | |
93 | .procend | |
94 | ||
95 | /* | |
96 | * long lstrnlen_user(char *s, long n) | |
97 | * | |
98 | * Returns 0 if exception before zero byte or reaching N, | |
99 | * N+1 if N would be exceeded, | |
100 | * else strlen + 1 (i.e. includes zero byte). | |
101 | */ | |
102 | ||
0b3d643f | 103 | ENTRY(lstrnlen_user) |
1da177e4 LT |
104 | .proc |
105 | .callinfo NO_CALLS | |
106 | .entry | |
107 | comib,= 0,%r25,$lslen_nzero | |
108 | copy %r26,%r24 | |
109 | get_sr | |
110 | 1: ldbs,ma 1(%sr1,%r26),%r1 | |
111 | $lslen_loop: | |
112 | comib,=,n 0,%r1,$lslen_done | |
113 | addib,<> -1,%r25,$lslen_loop | |
114 | 2: 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 */ | |
0b3d643f | 123 | ENDPROC(lstrnlen_user) |
1da177e4 LT |
124 | |
125 | .section .fixup,"ax" | |
126 | 3: fixup_branch $lslen_done | |
127 | copy %r24,%r26 /* reset r26 so 0 is returned on fault */ | |
128 | .previous | |
129 | ||
61dbbaeb HD |
130 | ASM_EXCEPTIONTABLE_ENTRY(1b,3b) |
131 | ASM_EXCEPTIONTABLE_ENTRY(2b,3b) | |
1da177e4 LT |
132 | |
133 | .procend | |
134 | ||
135 | .end |