| Paul Mackerras | 14cf11a | 2005-09-26 16:04:21 +1000 | [diff] [blame] | 1 | /* |
| 2 | * String handling functions for PowerPC. |
| 3 | * |
| 4 | * Copyright (C) 1996 Paul Mackerras. |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or |
| 7 | * modify it under the terms of the GNU General Public License |
| 8 | * as published by the Free Software Foundation; either version |
| 9 | * 2 of the License, or (at your option) any later version. |
| 10 | */ |
| Paul Mackerras | 14cf11a | 2005-09-26 16:04:21 +1000 | [diff] [blame] | 11 | #include <asm/processor.h> |
| 12 | #include <asm/errno.h> |
| 13 | #include <asm/ppc_asm.h> |
| 14 | |
| Paul Mackerras | 14cf11a | 2005-09-26 16:04:21 +1000 | [diff] [blame] | 15 | .section __ex_table,"a" |
| 16 | #ifdef CONFIG_PPC64 |
| 17 | .align 3 |
| 18 | #define EXTBL .llong |
| 19 | #else |
| 20 | .align 2 |
| 21 | #define EXTBL .long |
| 22 | #endif |
| 23 | .text |
| 24 | |
| 25 | _GLOBAL(strcpy) |
| 26 | addi r5,r3,-1 |
| 27 | addi r4,r4,-1 |
| 28 | 1: lbzu r0,1(r4) |
| 29 | cmpwi 0,r0,0 |
| 30 | stbu r0,1(r5) |
| 31 | bne 1b |
| 32 | blr |
| 33 | |
| 34 | /* This clears out any unused part of the destination buffer, |
| 35 | just as the libc version does. -- paulus */ |
| 36 | _GLOBAL(strncpy) |
| 37 | cmpwi 0,r5,0 |
| 38 | beqlr |
| 39 | mtctr r5 |
| 40 | addi r6,r3,-1 |
| 41 | addi r4,r4,-1 |
| 42 | 1: lbzu r0,1(r4) |
| 43 | cmpwi 0,r0,0 |
| 44 | stbu r0,1(r6) |
| 45 | bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */ |
| 46 | bnelr /* if we didn't hit a null char, we're done */ |
| 47 | mfctr r5 |
| 48 | cmpwi 0,r5,0 /* any space left in destination buffer? */ |
| 49 | beqlr /* we know r0 == 0 here */ |
| 50 | 2: stbu r0,1(r6) /* clear it out if so */ |
| 51 | bdnz 2b |
| 52 | blr |
| 53 | |
| 54 | _GLOBAL(strcat) |
| 55 | addi r5,r3,-1 |
| 56 | addi r4,r4,-1 |
| 57 | 1: lbzu r0,1(r5) |
| 58 | cmpwi 0,r0,0 |
| 59 | bne 1b |
| 60 | addi r5,r5,-1 |
| 61 | 1: lbzu r0,1(r4) |
| 62 | cmpwi 0,r0,0 |
| 63 | stbu r0,1(r5) |
| 64 | bne 1b |
| 65 | blr |
| 66 | |
| 67 | _GLOBAL(strcmp) |
| 68 | addi r5,r3,-1 |
| 69 | addi r4,r4,-1 |
| 70 | 1: lbzu r3,1(r5) |
| 71 | cmpwi 1,r3,0 |
| 72 | lbzu r0,1(r4) |
| 73 | subf. r3,r0,r3 |
| 74 | beqlr 1 |
| 75 | beq 1b |
| 76 | blr |
| 77 | |
| 78 | _GLOBAL(strlen) |
| 79 | addi r4,r3,-1 |
| 80 | 1: lbzu r0,1(r4) |
| 81 | cmpwi 0,r0,0 |
| 82 | bne 1b |
| 83 | subf r3,r3,r4 |
| 84 | blr |
| 85 | |
| 86 | _GLOBAL(memcmp) |
| 87 | cmpwi 0,r5,0 |
| 88 | ble- 2f |
| 89 | mtctr r5 |
| 90 | addi r6,r3,-1 |
| 91 | addi r4,r4,-1 |
| 92 | 1: lbzu r3,1(r6) |
| 93 | lbzu r0,1(r4) |
| 94 | subf. r3,r0,r3 |
| 95 | bdnzt 2,1b |
| 96 | blr |
| 97 | 2: li r3,0 |
| 98 | blr |
| 99 | |
| 100 | _GLOBAL(memchr) |
| 101 | cmpwi 0,r5,0 |
| 102 | ble- 2f |
| 103 | mtctr r5 |
| 104 | addi r3,r3,-1 |
| 105 | 1: lbzu r0,1(r3) |
| 106 | cmpw 0,r0,r4 |
| 107 | bdnzf 2,1b |
| 108 | beqlr |
| 109 | 2: li r3,0 |
| 110 | blr |
| 111 | |
| 112 | _GLOBAL(__clear_user) |
| 113 | addi r6,r3,-4 |
| 114 | li r3,0 |
| 115 | li r5,0 |
| 116 | cmplwi 0,r4,4 |
| 117 | blt 7f |
| 118 | /* clear a single word */ |
| 119 | 11: stwu r5,4(r6) |
| 120 | beqlr |
| 121 | /* clear word sized chunks */ |
| 122 | andi. r0,r6,3 |
| 123 | add r4,r0,r4 |
| 124 | subf r6,r0,r6 |
| 125 | srwi r0,r4,2 |
| 126 | andi. r4,r4,3 |
| 127 | mtctr r0 |
| 128 | bdz 7f |
| 129 | 1: stwu r5,4(r6) |
| 130 | bdnz 1b |
| 131 | /* clear byte sized chunks */ |
| 132 | 7: cmpwi 0,r4,0 |
| 133 | beqlr |
| 134 | mtctr r4 |
| 135 | addi r6,r6,3 |
| 136 | 8: stbu r5,1(r6) |
| 137 | bdnz 8b |
| 138 | blr |
| 139 | 90: mr r3,r4 |
| 140 | blr |
| 141 | 91: mfctr r3 |
| 142 | slwi r3,r3,2 |
| 143 | add r3,r3,r4 |
| 144 | blr |
| 145 | 92: mfctr r3 |
| 146 | blr |
| 147 | |
| 148 | .section __ex_table,"a" |
| 149 | EXTBL 11b,90b |
| 150 | EXTBL 1b,91b |
| 151 | EXTBL 8b,92b |
| 152 | .text |
| 153 | |
| 154 | _GLOBAL(__strncpy_from_user) |
| 155 | addi r6,r3,-1 |
| 156 | addi r4,r4,-1 |
| 157 | cmpwi 0,r5,0 |
| 158 | beq 2f |
| 159 | mtctr r5 |
| 160 | 1: lbzu r0,1(r4) |
| 161 | cmpwi 0,r0,0 |
| 162 | stbu r0,1(r6) |
| 163 | bdnzf 2,1b /* dec ctr, branch if ctr != 0 && !cr0.eq */ |
| 164 | beq 3f |
| 165 | 2: addi r6,r6,1 |
| 166 | 3: subf r3,r3,r6 |
| 167 | blr |
| 168 | 99: li r3,-EFAULT |
| 169 | blr |
| 170 | |
| 171 | .section __ex_table,"a" |
| 172 | EXTBL 1b,99b |
| 173 | .text |
| 174 | |
| 175 | /* r3 = str, r4 = len (> 0), r5 = top (highest addr) */ |
| 176 | _GLOBAL(__strnlen_user) |
| 177 | addi r7,r3,-1 |
| 178 | subf r6,r7,r5 /* top+1 - str */ |
| 179 | cmplw 0,r4,r6 |
| 180 | bge 0f |
| 181 | mr r6,r4 |
| 182 | 0: mtctr r6 /* ctr = min(len, top - str) */ |
| 183 | 1: lbzu r0,1(r7) /* get next byte */ |
| 184 | cmpwi 0,r0,0 |
| 185 | bdnzf 2,1b /* loop if --ctr != 0 && byte != 0 */ |
| 186 | addi r7,r7,1 |
| 187 | subf r3,r3,r7 /* number of bytes we have looked at */ |
| 188 | beqlr /* return if we found a 0 byte */ |
| 189 | cmpw 0,r3,r4 /* did we look at all len bytes? */ |
| 190 | blt 99f /* if not, must have hit top */ |
| 191 | addi r3,r4,1 /* return len + 1 to indicate no null found */ |
| 192 | blr |
| 193 | 99: li r3,0 /* bad address, return 0 */ |
| 194 | blr |
| 195 | |
| 196 | .section __ex_table,"a" |
| 197 | EXTBL 1b,99b |