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 36#include <asm/assembly.h> 37#include <asm/errno.h> 38#include <linux/linkage.h> 39#include <linux/init.h> 40 41 __HEAD 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 72ENTRY(lstrncpy_from_user) 73 .proc 74 .callinfo NO_CALLS 75 .entry 76 comib,= 0,%r24,$lsfu_done 77 copy %r24,%r23 78 get_sr 791: ldbs,ma 1(%sr1,%r25),%r1 80$lsfu_loop: 81 stbs,ma %r1,1(%r26) 82 comib,=,n 0,%r1,$lsfu_done 83 addib,<>,n -1,%r24,$lsfu_loop 842: 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 91ENDPROC(lstrncpy_from_user) 92 93 .section .fixup,"ax" 943: fixup_branch $lsfu_exit 95 ldi -EFAULT,%r28 96 .previous 97 98 .section __ex_table,"aw" 99 ASM_ULONG_INSN 1b,3b 100 ASM_ULONG_INSN 2b,3b 101 .previous 102 103 .procend 104 105 /* 106 * unsigned long lclear_user(void *to, unsigned long n) 107 * 108 * Returns 0 for success. 109 * otherwise, returns number of bytes not transferred. 110 */ 111 112ENTRY(lclear_user) 113 .proc 114 .callinfo NO_CALLS 115 .entry 116 comib,=,n 0,%r25,$lclu_done 117 get_sr 118$lclu_loop: 119 addib,<> -1,%r25,$lclu_loop 1201: stbs,ma %r0,1(%sr1,%r26) 121 122$lclu_done: 123 bv %r0(%r2) 124 copy %r25,%r28 125 .exit 126ENDPROC(lclear_user) 127 128 .section .fixup,"ax" 1292: fixup_branch $lclu_done 130 ldo 1(%r25),%r25 131 .previous 132 133 .section __ex_table,"aw" 134 ASM_ULONG_INSN 1b,2b 135 .previous 136 137 .procend 138 139 /* 140 * long lstrnlen_user(char *s, long n) 141 * 142 * Returns 0 if exception before zero byte or reaching N, 143 * N+1 if N would be exceeded, 144 * else strlen + 1 (i.e. includes zero byte). 145 */ 146 147ENTRY(lstrnlen_user) 148 .proc 149 .callinfo NO_CALLS 150 .entry 151 comib,= 0,%r25,$lslen_nzero 152 copy %r26,%r24 153 get_sr 1541: ldbs,ma 1(%sr1,%r26),%r1 155$lslen_loop: 156 comib,=,n 0,%r1,$lslen_done 157 addib,<> -1,%r25,$lslen_loop 1582: ldbs,ma 1(%sr1,%r26),%r1 159$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 */ 167ENDPROC(lstrnlen_user) 168 169 .section .fixup,"ax" 1703: fixup_branch $lslen_done 171 copy %r24,%r26 /* reset r26 so 0 is returned on fault */ 172 .previous 173 174 .section __ex_table,"aw" 175 ASM_ULONG_INSN 1b,3b 176 ASM_ULONG_INSN 2b,3b 177 .previous 178 179 .procend 180 181 .end 182