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 * 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 70ENTRY_CFI(lclear_user) 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,$lclu_loop 781: stbs,ma %r0,1(%sr1,%r26) 79 80$lclu_done: 81 bv %r0(%r2) 82 copy %r25,%r28 83 .exit 84ENDPROC_CFI(lclear_user) 85 86 .section .fixup,"ax" 872: fixup_branch $lclu_done 88 ldo 1(%r25),%r25 89 .previous 90 91 ASM_EXCEPTIONTABLE_ENTRY(1b,2b) 92 93 .procend 94 95 /* 96 * long lstrnlen_user(char *s, long n) 97 * 98 * Returns 0 if exception before zero byte or reaching N, 99 * N+1 if N would be exceeded, 100 * else strlen + 1 (i.e. includes zero byte). 101 */ 102 103ENTRY_CFI(lstrnlen_user) 104 .proc 105 .callinfo NO_CALLS 106 .entry 107 comib,= 0,%r25,$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 */ 123ENDPROC_CFI(lstrnlen_user) 124 125 .section .fixup,"ax" 1263: fixup_branch $lslen_done 127 copy %r24,%r26 /* reset r26 so 0 is returned on fault */ 128 .previous 129 130 ASM_EXCEPTIONTABLE_ENTRY(1b,3b) 131 ASM_EXCEPTIONTABLE_ENTRY(2b,3b) 132 133 .procend 134 135 .end 136