Nicolas Pitre | 7549423 | 2005-11-01 19:52:23 +0000 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/arm/lib/copy_template.s |
| 3 | * |
| 4 | * Code template for optimized memory copy functions |
| 5 | * |
| 6 | * Author: Nicolas Pitre |
| 7 | * Created: Sep 28, 2005 |
| 8 | * Copyright: MontaVista Software, Inc. |
| 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 version 2 as |
| 12 | * published by the Free Software Foundation. |
| 13 | */ |
| 14 | |
| 15 | /* |
| 16 | * This can be used to enable code to cacheline align the source pointer. |
| 17 | * Experiments on tested architectures (StrongARM and XScale) didn't show |
| 18 | * this a worthwhile thing to do. That might be different in the future. |
| 19 | */ |
| 20 | //#define CALGN(code...) code |
| 21 | #define CALGN(code...) |
| 22 | |
| 23 | /* |
| 24 | * Theory of operation |
| 25 | * ------------------- |
| 26 | * |
| 27 | * This file provides the core code for a forward memory copy used in |
| 28 | * the implementation of memcopy(), copy_to_user() and copy_from_user(). |
| 29 | * |
| 30 | * The including file must define the following accessor macros |
| 31 | * according to the need of the given function: |
| 32 | * |
| 33 | * ldr1w ptr reg abort |
| 34 | * |
| 35 | * This loads one word from 'ptr', stores it in 'reg' and increments |
| 36 | * 'ptr' to the next word. The 'abort' argument is used for fixup tables. |
| 37 | * |
| 38 | * ldr4w ptr reg1 reg2 reg3 reg4 abort |
| 39 | * ldr8w ptr, reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort |
| 40 | * |
| 41 | * This loads four or eight words starting from 'ptr', stores them |
| 42 | * in provided registers and increments 'ptr' past those words. |
| 43 | * The'abort' argument is used for fixup tables. |
| 44 | * |
| 45 | * ldr1b ptr reg cond abort |
| 46 | * |
| 47 | * Similar to ldr1w, but it loads a byte and increments 'ptr' one byte. |
| 48 | * It also must apply the condition code if provided, otherwise the |
| 49 | * "al" condition is assumed by default. |
| 50 | * |
| 51 | * str1w ptr reg abort |
| 52 | * str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort |
| 53 | * str1b ptr reg cond abort |
| 54 | * |
| 55 | * Same as their ldr* counterparts, but data is stored to 'ptr' location |
| 56 | * rather than being loaded. |
| 57 | * |
| 58 | * enter reg1 reg2 |
| 59 | * |
| 60 | * Preserve the provided registers on the stack plus any additional |
| 61 | * data as needed by the implementation including this code. Called |
| 62 | * upon code entry. |
| 63 | * |
| 64 | * exit reg1 reg2 |
| 65 | * |
| 66 | * Restore registers with the values previously saved with the |
| 67 | * 'preserv' macro. Called upon code termination. |
| 68 | */ |
| 69 | |
| 70 | |
| 71 | enter r4, lr |
| 72 | |
| 73 | subs r2, r2, #4 |
| 74 | blt 8f |
| 75 | ands ip, r0, #3 |
| 76 | PLD( pld [r1, #0] ) |
| 77 | bne 9f |
| 78 | ands ip, r1, #3 |
| 79 | bne 10f |
| 80 | |
| 81 | 1: subs r2, r2, #(28) |
| 82 | stmfd sp!, {r5 - r8} |
| 83 | blt 5f |
| 84 | |
| 85 | CALGN( ands ip, r1, #31 ) |
| 86 | CALGN( rsb r3, ip, #32 ) |
| 87 | CALGN( sbcnes r4, r3, r2 ) @ C is always set here |
| 88 | CALGN( bcs 2f ) |
| 89 | CALGN( adr r4, 6f ) |
| 90 | CALGN( subs r2, r2, r3 ) @ C gets set |
| 91 | CALGN( add pc, r4, ip ) |
| 92 | |
| 93 | PLD( pld [r1, #0] ) |
| 94 | 2: PLD( subs r2, r2, #96 ) |
| 95 | PLD( pld [r1, #28] ) |
| 96 | PLD( blt 4f ) |
| 97 | PLD( pld [r1, #60] ) |
| 98 | PLD( pld [r1, #92] ) |
| 99 | |
| 100 | 3: PLD( pld [r1, #124] ) |
| 101 | 4: ldr8w r1, r3, r4, r5, r6, r7, r8, ip, lr, abort=20f |
| 102 | subs r2, r2, #32 |
| 103 | str8w r0, r3, r4, r5, r6, r7, r8, ip, lr, abort=20f |
| 104 | bge 3b |
| 105 | PLD( cmn r2, #96 ) |
| 106 | PLD( bge 4b ) |
| 107 | |
| 108 | 5: ands ip, r2, #28 |
| 109 | rsb ip, ip, #32 |
| 110 | addne pc, pc, ip @ C is always clear here |
| 111 | b 7f |
| 112 | 6: nop |
| 113 | ldr1w r1, r3, abort=20f |
| 114 | ldr1w r1, r4, abort=20f |
| 115 | ldr1w r1, r5, abort=20f |
| 116 | ldr1w r1, r6, abort=20f |
| 117 | ldr1w r1, r7, abort=20f |
| 118 | ldr1w r1, r8, abort=20f |
| 119 | ldr1w r1, lr, abort=20f |
| 120 | |
| 121 | add pc, pc, ip |
| 122 | nop |
| 123 | nop |
| 124 | str1w r0, r3, abort=20f |
| 125 | str1w r0, r4, abort=20f |
| 126 | str1w r0, r5, abort=20f |
| 127 | str1w r0, r6, abort=20f |
| 128 | str1w r0, r7, abort=20f |
| 129 | str1w r0, r8, abort=20f |
| 130 | str1w r0, lr, abort=20f |
| 131 | |
| 132 | CALGN( bcs 2b ) |
| 133 | |
| 134 | 7: ldmfd sp!, {r5 - r8} |
| 135 | |
| 136 | 8: movs r2, r2, lsl #31 |
| 137 | ldr1b r1, r3, ne, abort=21f |
| 138 | ldr1b r1, r4, cs, abort=21f |
| 139 | ldr1b r1, ip, cs, abort=21f |
| 140 | str1b r0, r3, ne, abort=21f |
| 141 | str1b r0, r4, cs, abort=21f |
| 142 | str1b r0, ip, cs, abort=21f |
| 143 | |
| 144 | exit r4, pc |
| 145 | |
| 146 | 9: rsb ip, ip, #4 |
| 147 | cmp ip, #2 |
| 148 | ldr1b r1, r3, gt, abort=21f |
| 149 | ldr1b r1, r4, ge, abort=21f |
| 150 | ldr1b r1, lr, abort=21f |
| 151 | str1b r0, r3, gt, abort=21f |
| 152 | str1b r0, r4, ge, abort=21f |
| 153 | subs r2, r2, ip |
| 154 | str1b r0, lr, abort=21f |
| 155 | blt 8b |
| 156 | ands ip, r1, #3 |
| 157 | beq 1b |
| 158 | |
| 159 | 10: bic r1, r1, #3 |
| 160 | cmp ip, #2 |
| 161 | ldr1w r1, lr, abort=21f |
| 162 | beq 17f |
| 163 | bgt 18f |
| 164 | |
| 165 | |
| 166 | .macro forward_copy_shift pull push |
| 167 | |
| 168 | subs r2, r2, #28 |
| 169 | blt 14f |
| 170 | |
| 171 | CALGN( ands ip, r1, #31 ) |
| 172 | CALGN( rsb ip, ip, #32 ) |
| 173 | CALGN( sbcnes r4, ip, r2 ) @ C is always set here |
| 174 | CALGN( subcc r2, r2, ip ) |
| 175 | CALGN( bcc 15f ) |
| 176 | |
| 177 | 11: stmfd sp!, {r5 - r9} |
| 178 | |
| 179 | PLD( pld [r1, #0] ) |
| 180 | PLD( subs r2, r2, #96 ) |
| 181 | PLD( pld [r1, #28] ) |
| 182 | PLD( blt 13f ) |
| 183 | PLD( pld [r1, #60] ) |
| 184 | PLD( pld [r1, #92] ) |
| 185 | |
| 186 | 12: PLD( pld [r1, #124] ) |
| 187 | 13: ldr4w r1, r4, r5, r6, r7, abort=19f |
| 188 | mov r3, lr, pull #\pull |
| 189 | subs r2, r2, #32 |
| 190 | ldr4w r1, r8, r9, ip, lr, abort=19f |
| 191 | orr r3, r3, r4, push #\push |
| 192 | mov r4, r4, pull #\pull |
| 193 | orr r4, r4, r5, push #\push |
| 194 | mov r5, r5, pull #\pull |
| 195 | orr r5, r5, r6, push #\push |
| 196 | mov r6, r6, pull #\pull |
| 197 | orr r6, r6, r7, push #\push |
| 198 | mov r7, r7, pull #\pull |
| 199 | orr r7, r7, r8, push #\push |
| 200 | mov r8, r8, pull #\pull |
| 201 | orr r8, r8, r9, push #\push |
| 202 | mov r9, r9, pull #\pull |
| 203 | orr r9, r9, ip, push #\push |
| 204 | mov ip, ip, pull #\pull |
| 205 | orr ip, ip, lr, push #\push |
| 206 | str8w r0, r3, r4, r5, r6, r7, r8, r9, ip, , abort=19f |
| 207 | bge 12b |
| 208 | PLD( cmn r2, #96 ) |
| 209 | PLD( bge 13b ) |
| 210 | |
| 211 | ldmfd sp!, {r5 - r9} |
| 212 | |
| 213 | 14: ands ip, r2, #28 |
| 214 | beq 16f |
| 215 | |
| 216 | 15: mov r3, lr, pull #\pull |
| 217 | ldr1w r1, lr, abort=21f |
| 218 | subs ip, ip, #4 |
| 219 | orr r3, r3, lr, push #\push |
| 220 | str1w r0, r3, abort=21f |
| 221 | bgt 15b |
| 222 | CALGN( cmp r2, #0 ) |
| 223 | CALGN( bge 11b ) |
| 224 | |
| 225 | 16: sub r1, r1, #(\push / 8) |
| 226 | b 8b |
| 227 | |
| 228 | .endm |
| 229 | |
| 230 | |
| 231 | forward_copy_shift pull=8 push=24 |
| 232 | |
| 233 | 17: forward_copy_shift pull=16 push=16 |
| 234 | |
| 235 | 18: forward_copy_shift pull=24 push=8 |
| 236 | |
| 237 | |
| 238 | /* |
Alexey Dobriyan | 7f927fc | 2006-03-28 01:56:53 -0800 | [diff] [blame] | 239 | * Abort preamble and completion macros. |
Nicolas Pitre | 7549423 | 2005-11-01 19:52:23 +0000 | [diff] [blame] | 240 | * If a fixup handler is required then those macros must surround it. |
| 241 | * It is assumed that the fixup code will handle the private part of |
| 242 | * the exit macro. |
| 243 | */ |
| 244 | |
| 245 | .macro copy_abort_preamble |
| 246 | 19: ldmfd sp!, {r5 - r9} |
| 247 | b 21f |
| 248 | 20: ldmfd sp!, {r5 - r8} |
| 249 | 21: |
| 250 | .endm |
| 251 | |
| 252 | .macro copy_abort_end |
| 253 | ldmfd sp!, {r4, pc} |
| 254 | .endm |
| 255 | |