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 .text 37 38#include <asm/assembly.h> 39#include <asm/errno.h> 40#include <linux/linkage.h> 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 63 /* 64 * long lstrncpy_from_user(char *dst, const char *src, long n) 65 * 66 * Returns -EFAULT if exception before terminator, 67 * N if the entire buffer filled, 68 * otherwise strlen (i.e. excludes zero byte) 69 */ 70 71ENTRY(lstrncpy_from_user) 72 .proc 73 .callinfo NO_CALLS 74 .entry 75 comib,= 0,%r24,$lsfu_done 76 copy %r24,%r23 77 get_sr 781: ldbs,ma 1(%sr1,%r25),%r1 79$lsfu_loop: 80 stbs,ma %r1,1(%r26) 81 comib,=,n 0,%r1,$lsfu_done 82 addib,<>,n -1,%r24,$lsfu_loop 832: ldbs,ma 1(%sr1,%r25),%r1 84$lsfu_done: 85 sub %r23,%r24,%r28 86$lsfu_exit: 87 bv %r0(%r2) 88 nop 89 .exit 90ENDPROC(lstrncpy_from_user) 91 92 .section .fixup,"ax" 933: fixup_branch $lsfu_exit 94 ldi -EFAULT,%r28 95 .previous 96 97 .section __ex_table,"aw" 98 ASM_ULONG_INSN 1b,3b 99 ASM_ULONG_INSN 2b,3b 100 .previous 101 102 .procend 103 104 /* 105 * unsigned long lclear_user(void *to, unsigned long n) 106 * 107 * Returns 0 for success. 108 * otherwise, returns number of bytes not transferred. 109 */ 110 111ENTRY(lclear_user) 112 .proc 113 .callinfo NO_CALLS 114 .entry 115 comib,=,n 0,%r25,$lclu_done 116 get_sr 117$lclu_loop: 118 addib,<> -1,%r25,$lclu_loop 1191: stbs,ma %r0,1(%sr1,%r26) 120 121$lclu_done: 122 bv %r0(%r2) 123 copy %r25,%r28 124 .exit 125ENDPROC(lclear_user) 126 127 .section .fixup,"ax" 1282: fixup_branch $lclu_done 129 ldo 1(%r25),%r25 130 .previous 131 132 .section __ex_table,"aw" 133 ASM_ULONG_INSN 1b,2b 134 .previous 135 136 .procend 137 138 /* 139 * long lstrnlen_user(char *s, long n) 140 * 141 * Returns 0 if exception before zero byte or reaching N, 142 * N+1 if N would be exceeded, 143 * else strlen + 1 (i.e. includes zero byte). 144 */ 145 146ENTRY(lstrnlen_user) 147 .proc 148 .callinfo NO_CALLS 149 .entry 150 comib,= 0,%r25,$lslen_nzero 151 copy %r26,%r24 152 get_sr 1531: ldbs,ma 1(%sr1,%r26),%r1 154$lslen_loop: 155 comib,=,n 0,%r1,$lslen_done 156 addib,<> -1,%r25,$lslen_loop 1572: ldbs,ma 1(%sr1,%r26),%r1 158$lslen_done: 159 bv %r0(%r2) 160 sub %r26,%r24,%r28 161 .exit 162 163$lslen_nzero: 164 b $lslen_done 165 ldo 1(%r26),%r26 /* special case for N == 0 */ 166ENDPROC(lstrnlen_user) 167 168 .section .fixup,"ax" 1693: fixup_branch $lslen_done 170 copy %r24,%r26 /* reset r26 so 0 is returned on fault */ 171 .previous 172 173 .section __ex_table,"aw" 174 ASM_ULONG_INSN 1b,3b 175 ASM_ULONG_INSN 2b,3b 176 .previous 177 178 .procend 179 180 .end 181