Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | #include <asm/assembly.h> |
| 37 | #include <asm/errno.h> |
Helge Deller | 0b3d643 | 2007-01-28 14:52:57 +0100 | [diff] [blame] | 38 | #include <linux/linkage.h> |
Helge Deller | bd3bb8c | 2008-05-02 22:02:48 +0200 | [diff] [blame] | 39 | #include <linux/init.h> |
| 40 | |
| 41 | __HEAD |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 42 | |
| 43 | /* |
| 44 | * get_sr gets the appropriate space value into |
| 45 | * sr1 for kernel/user space access, depending |
| 46 | * on the flag stored in the task structure. |
| 47 | */ |
| 48 | |
| 49 | .macro get_sr |
| 50 | mfctl %cr30,%r1 |
| 51 | ldw TI_SEGMENT(%r1),%r22 |
| 52 | mfsp %sr3,%r1 |
| 53 | or,<> %r22,%r0,%r0 |
| 54 | copy %r0,%r1 |
| 55 | mtsp %r1,%sr1 |
| 56 | .endm |
| 57 | |
| 58 | .macro fixup_branch lbl |
| 59 | ldil L%\lbl, %r1 |
| 60 | ldo R%\lbl(%r1), %r1 |
| 61 | bv %r0(%r1) |
| 62 | .endm |
| 63 | |
| 64 | /* |
| 65 | * long lstrncpy_from_user(char *dst, const char *src, long n) |
| 66 | * |
| 67 | * Returns -EFAULT if exception before terminator, |
| 68 | * N if the entire buffer filled, |
| 69 | * otherwise strlen (i.e. excludes zero byte) |
| 70 | */ |
| 71 | |
Helge Deller | 0b3d643 | 2007-01-28 14:52:57 +0100 | [diff] [blame] | 72 | ENTRY(lstrncpy_from_user) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | .proc |
| 74 | .callinfo NO_CALLS |
| 75 | .entry |
| 76 | comib,= 0,%r24,$lsfu_done |
| 77 | copy %r24,%r23 |
| 78 | get_sr |
| 79 | 1: ldbs,ma 1(%sr1,%r25),%r1 |
| 80 | $lsfu_loop: |
| 81 | stbs,ma %r1,1(%r26) |
| 82 | comib,=,n 0,%r1,$lsfu_done |
| 83 | addib,<>,n -1,%r24,$lsfu_loop |
| 84 | 2: ldbs,ma 1(%sr1,%r25),%r1 |
| 85 | $lsfu_done: |
| 86 | sub %r23,%r24,%r28 |
| 87 | $lsfu_exit: |
| 88 | bv %r0(%r2) |
| 89 | nop |
| 90 | .exit |
Helge Deller | 0b3d643 | 2007-01-28 14:52:57 +0100 | [diff] [blame] | 91 | ENDPROC(lstrncpy_from_user) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 92 | |
| 93 | .section .fixup,"ax" |
| 94 | 3: fixup_branch $lsfu_exit |
| 95 | ldi -EFAULT,%r28 |
| 96 | .previous |
| 97 | |
| 98 | .section __ex_table,"aw" |
Helge Deller | 0b3d643 | 2007-01-28 14:52:57 +0100 | [diff] [blame] | 99 | ASM_ULONG_INSN 1b,3b |
| 100 | ASM_ULONG_INSN 2b,3b |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | .previous |
| 102 | |
| 103 | .procend |
| 104 | |
| 105 | /* |
| 106 | * unsigned long lclear_user(void *to, unsigned long n) |
| 107 | * |
| 108 | * Returns 0 for success. |
| 109 | * otherwise, returns number of bytes not transferred. |
| 110 | */ |
| 111 | |
Helge Deller | 0b3d643 | 2007-01-28 14:52:57 +0100 | [diff] [blame] | 112 | ENTRY(lclear_user) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 113 | .proc |
| 114 | .callinfo NO_CALLS |
| 115 | .entry |
| 116 | comib,=,n 0,%r25,$lclu_done |
| 117 | get_sr |
| 118 | $lclu_loop: |
| 119 | addib,<> -1,%r25,$lclu_loop |
| 120 | 1: stbs,ma %r0,1(%sr1,%r26) |
| 121 | |
| 122 | $lclu_done: |
| 123 | bv %r0(%r2) |
| 124 | copy %r25,%r28 |
| 125 | .exit |
Helge Deller | 0b3d643 | 2007-01-28 14:52:57 +0100 | [diff] [blame] | 126 | ENDPROC(lclear_user) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | |
| 128 | .section .fixup,"ax" |
| 129 | 2: fixup_branch $lclu_done |
| 130 | ldo 1(%r25),%r25 |
| 131 | .previous |
| 132 | |
| 133 | .section __ex_table,"aw" |
Helge Deller | 0b3d643 | 2007-01-28 14:52:57 +0100 | [diff] [blame] | 134 | ASM_ULONG_INSN 1b,2b |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | .previous |
| 136 | |
| 137 | .procend |
| 138 | |
| 139 | /* |
| 140 | * long lstrnlen_user(char *s, long n) |
| 141 | * |
| 142 | * Returns 0 if exception before zero byte or reaching N, |
| 143 | * N+1 if N would be exceeded, |
| 144 | * else strlen + 1 (i.e. includes zero byte). |
| 145 | */ |
| 146 | |
Helge Deller | 0b3d643 | 2007-01-28 14:52:57 +0100 | [diff] [blame] | 147 | ENTRY(lstrnlen_user) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | .proc |
| 149 | .callinfo NO_CALLS |
| 150 | .entry |
| 151 | comib,= 0,%r25,$lslen_nzero |
| 152 | copy %r26,%r24 |
| 153 | get_sr |
| 154 | 1: ldbs,ma 1(%sr1,%r26),%r1 |
| 155 | $lslen_loop: |
| 156 | comib,=,n 0,%r1,$lslen_done |
| 157 | addib,<> -1,%r25,$lslen_loop |
| 158 | 2: ldbs,ma 1(%sr1,%r26),%r1 |
| 159 | $lslen_done: |
| 160 | bv %r0(%r2) |
| 161 | sub %r26,%r24,%r28 |
| 162 | .exit |
| 163 | |
| 164 | $lslen_nzero: |
| 165 | b $lslen_done |
| 166 | ldo 1(%r26),%r26 /* special case for N == 0 */ |
Helge Deller | 0b3d643 | 2007-01-28 14:52:57 +0100 | [diff] [blame] | 167 | ENDPROC(lstrnlen_user) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 168 | |
| 169 | .section .fixup,"ax" |
| 170 | 3: fixup_branch $lslen_done |
| 171 | copy %r24,%r26 /* reset r26 so 0 is returned on fault */ |
| 172 | .previous |
| 173 | |
| 174 | .section __ex_table,"aw" |
Helge Deller | 0b3d643 | 2007-01-28 14:52:57 +0100 | [diff] [blame] | 175 | ASM_ULONG_INSN 1b,3b |
| 176 | ASM_ULONG_INSN 2b,3b |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 177 | .previous |
| 178 | |
| 179 | .procend |
| 180 | |
| 181 | .end |