copy_32.S (9813B)
1/* SPDX-License-Identifier: GPL-2.0-or-later */ 2/* 3 * Memory copy functions for 32-bit PowerPC. 4 * 5 * Copyright (C) 1996-2005 Paul Mackerras. 6 */ 7#include <asm/processor.h> 8#include <asm/cache.h> 9#include <asm/errno.h> 10#include <asm/ppc_asm.h> 11#include <asm/export.h> 12#include <asm/code-patching-asm.h> 13#include <asm/kasan.h> 14 15#define COPY_16_BYTES \ 16 lwz r7,4(r4); \ 17 lwz r8,8(r4); \ 18 lwz r9,12(r4); \ 19 lwzu r10,16(r4); \ 20 stw r7,4(r6); \ 21 stw r8,8(r6); \ 22 stw r9,12(r6); \ 23 stwu r10,16(r6) 24 25#define COPY_16_BYTES_WITHEX(n) \ 268 ## n ## 0: \ 27 lwz r7,4(r4); \ 288 ## n ## 1: \ 29 lwz r8,8(r4); \ 308 ## n ## 2: \ 31 lwz r9,12(r4); \ 328 ## n ## 3: \ 33 lwzu r10,16(r4); \ 348 ## n ## 4: \ 35 stw r7,4(r6); \ 368 ## n ## 5: \ 37 stw r8,8(r6); \ 388 ## n ## 6: \ 39 stw r9,12(r6); \ 408 ## n ## 7: \ 41 stwu r10,16(r6) 42 43#define COPY_16_BYTES_EXCODE(n) \ 449 ## n ## 0: \ 45 addi r5,r5,-(16 * n); \ 46 b 104f; \ 479 ## n ## 1: \ 48 addi r5,r5,-(16 * n); \ 49 b 105f; \ 50 EX_TABLE(8 ## n ## 0b,9 ## n ## 0b); \ 51 EX_TABLE(8 ## n ## 1b,9 ## n ## 0b); \ 52 EX_TABLE(8 ## n ## 2b,9 ## n ## 0b); \ 53 EX_TABLE(8 ## n ## 3b,9 ## n ## 0b); \ 54 EX_TABLE(8 ## n ## 4b,9 ## n ## 1b); \ 55 EX_TABLE(8 ## n ## 5b,9 ## n ## 1b); \ 56 EX_TABLE(8 ## n ## 6b,9 ## n ## 1b); \ 57 EX_TABLE(8 ## n ## 7b,9 ## n ## 1b) 58 59 .text 60 61CACHELINE_BYTES = L1_CACHE_BYTES 62LG_CACHELINE_BYTES = L1_CACHE_SHIFT 63CACHELINE_MASK = (L1_CACHE_BYTES-1) 64 65#ifndef CONFIG_KASAN 66_GLOBAL(memset16) 67 rlwinm. r0 ,r5, 31, 1, 31 68 addi r6, r3, -4 69 beq- 2f 70 rlwimi r4 ,r4 ,16 ,0 ,15 71 mtctr r0 721: stwu r4, 4(r6) 73 bdnz 1b 742: andi. r0, r5, 1 75 beqlr 76 sth r4, 4(r6) 77 blr 78EXPORT_SYMBOL(memset16) 79#endif 80 81/* 82 * Use dcbz on the complete cache lines in the destination 83 * to set them to zero. This requires that the destination 84 * area is cacheable. -- paulus 85 * 86 * During early init, cache might not be active yet, so dcbz cannot be used. 87 * We therefore skip the optimised bloc that uses dcbz. This jump is 88 * replaced by a nop once cache is active. This is done in machine_init() 89 */ 90_GLOBAL_KASAN(memset) 91 cmplwi 0,r5,4 92 blt 7f 93 94 rlwimi r4,r4,8,16,23 95 rlwimi r4,r4,16,0,15 96 97 stw r4,0(r3) 98 beqlr 99 andi. r0,r3,3 100 add r5,r0,r5 101 subf r6,r0,r3 102 cmplwi 0,r4,0 103 /* 104 * Skip optimised bloc until cache is enabled. Will be replaced 105 * by 'bne' during boot to use normal procedure if r4 is not zero 106 */ 1075: b 2f 108 patch_site 5b, patch__memset_nocache 109 110 clrlwi r7,r6,32-LG_CACHELINE_BYTES 111 add r8,r7,r5 112 srwi r9,r8,LG_CACHELINE_BYTES 113 addic. r9,r9,-1 /* total number of complete cachelines */ 114 ble 2f 115 xori r0,r7,CACHELINE_MASK & ~3 116 srwi. r0,r0,2 117 beq 3f 118 mtctr r0 1194: stwu r4,4(r6) 120 bdnz 4b 1213: mtctr r9 122 li r7,4 12310: dcbz r7,r6 124 addi r6,r6,CACHELINE_BYTES 125 bdnz 10b 126 clrlwi r5,r8,32-LG_CACHELINE_BYTES 127 addi r5,r5,4 128 1292: srwi r0,r5,2 130 mtctr r0 131 bdz 6f 1321: stwu r4,4(r6) 133 bdnz 1b 1346: andi. r5,r5,3 135 beqlr 136 mtctr r5 137 addi r6,r6,3 1388: stbu r4,1(r6) 139 bdnz 8b 140 blr 141 1427: cmpwi 0,r5,0 143 beqlr 144 mtctr r5 145 addi r6,r3,-1 1469: stbu r4,1(r6) 147 bdnz 9b 148 blr 149EXPORT_SYMBOL(memset) 150EXPORT_SYMBOL_KASAN(memset) 151 152/* 153 * This version uses dcbz on the complete cache lines in the 154 * destination area to reduce memory traffic. This requires that 155 * the destination area is cacheable. 156 * We only use this version if the source and dest don't overlap. 157 * -- paulus. 158 * 159 * During early init, cache might not be active yet, so dcbz cannot be used. 160 * We therefore jump to generic_memcpy which doesn't use dcbz. This jump is 161 * replaced by a nop once cache is active. This is done in machine_init() 162 */ 163_GLOBAL_KASAN(memmove) 164 cmplw 0,r3,r4 165 bgt backwards_memcpy 166 /* fall through */ 167 168_GLOBAL_KASAN(memcpy) 1691: b generic_memcpy 170 patch_site 1b, patch__memcpy_nocache 171 172 add r7,r3,r5 /* test if the src & dst overlap */ 173 add r8,r4,r5 174 cmplw 0,r4,r7 175 cmplw 1,r3,r8 176 crand 0,0,4 /* cr0.lt &= cr1.lt */ 177 blt generic_memcpy /* if regions overlap */ 178 179 addi r4,r4,-4 180 addi r6,r3,-4 181 neg r0,r3 182 andi. r0,r0,CACHELINE_MASK /* # bytes to start of cache line */ 183 beq 58f 184 185 cmplw 0,r5,r0 /* is this more than total to do? */ 186 blt 63f /* if not much to do */ 187 andi. r8,r0,3 /* get it word-aligned first */ 188 subf r5,r0,r5 189 mtctr r8 190 beq+ 61f 19170: lbz r9,4(r4) /* do some bytes */ 192 addi r4,r4,1 193 addi r6,r6,1 194 stb r9,3(r6) 195 bdnz 70b 19661: srwi. r0,r0,2 197 mtctr r0 198 beq 58f 19972: lwzu r9,4(r4) /* do some words */ 200 stwu r9,4(r6) 201 bdnz 72b 202 20358: srwi. r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */ 204 clrlwi r5,r5,32-LG_CACHELINE_BYTES 205 li r11,4 206 mtctr r0 207 beq 63f 20853: 209 dcbz r11,r6 210 COPY_16_BYTES 211#if L1_CACHE_BYTES >= 32 212 COPY_16_BYTES 213#if L1_CACHE_BYTES >= 64 214 COPY_16_BYTES 215 COPY_16_BYTES 216#if L1_CACHE_BYTES >= 128 217 COPY_16_BYTES 218 COPY_16_BYTES 219 COPY_16_BYTES 220 COPY_16_BYTES 221#endif 222#endif 223#endif 224 bdnz 53b 225 22663: srwi. r0,r5,2 227 mtctr r0 228 beq 64f 22930: lwzu r0,4(r4) 230 stwu r0,4(r6) 231 bdnz 30b 232 23364: andi. r0,r5,3 234 mtctr r0 235 beq+ 65f 236 addi r4,r4,3 237 addi r6,r6,3 23840: lbzu r0,1(r4) 239 stbu r0,1(r6) 240 bdnz 40b 24165: blr 242EXPORT_SYMBOL(memcpy) 243EXPORT_SYMBOL(memmove) 244EXPORT_SYMBOL_KASAN(memcpy) 245EXPORT_SYMBOL_KASAN(memmove) 246 247generic_memcpy: 248 srwi. r7,r5,3 249 addi r6,r3,-4 250 addi r4,r4,-4 251 beq 2f /* if less than 8 bytes to do */ 252 andi. r0,r6,3 /* get dest word aligned */ 253 mtctr r7 254 bne 5f 2551: lwz r7,4(r4) 256 lwzu r8,8(r4) 257 stw r7,4(r6) 258 stwu r8,8(r6) 259 bdnz 1b 260 andi. r5,r5,7 2612: cmplwi 0,r5,4 262 blt 3f 263 lwzu r0,4(r4) 264 addi r5,r5,-4 265 stwu r0,4(r6) 2663: cmpwi 0,r5,0 267 beqlr 268 mtctr r5 269 addi r4,r4,3 270 addi r6,r6,3 2714: lbzu r0,1(r4) 272 stbu r0,1(r6) 273 bdnz 4b 274 blr 2755: subfic r0,r0,4 276 mtctr r0 2776: lbz r7,4(r4) 278 addi r4,r4,1 279 stb r7,4(r6) 280 addi r6,r6,1 281 bdnz 6b 282 subf r5,r0,r5 283 rlwinm. r7,r5,32-3,3,31 284 beq 2b 285 mtctr r7 286 b 1b 287 288_GLOBAL(backwards_memcpy) 289 rlwinm. r7,r5,32-3,3,31 /* r0 = r5 >> 3 */ 290 add r6,r3,r5 291 add r4,r4,r5 292 beq 2f 293 andi. r0,r6,3 294 mtctr r7 295 bne 5f 2961: lwz r7,-4(r4) 297 lwzu r8,-8(r4) 298 stw r7,-4(r6) 299 stwu r8,-8(r6) 300 bdnz 1b 301 andi. r5,r5,7 3022: cmplwi 0,r5,4 303 blt 3f 304 lwzu r0,-4(r4) 305 subi r5,r5,4 306 stwu r0,-4(r6) 3073: cmpwi 0,r5,0 308 beqlr 309 mtctr r5 3104: lbzu r0,-1(r4) 311 stbu r0,-1(r6) 312 bdnz 4b 313 blr 3145: mtctr r0 3156: lbzu r7,-1(r4) 316 stbu r7,-1(r6) 317 bdnz 6b 318 subf r5,r0,r5 319 rlwinm. r7,r5,32-3,3,31 320 beq 2b 321 mtctr r7 322 b 1b 323 324_GLOBAL(__copy_tofrom_user) 325 addi r4,r4,-4 326 addi r6,r3,-4 327 neg r0,r3 328 andi. r0,r0,CACHELINE_MASK /* # bytes to start of cache line */ 329 beq 58f 330 331 cmplw 0,r5,r0 /* is this more than total to do? */ 332 blt 63f /* if not much to do */ 333 andi. r8,r0,3 /* get it word-aligned first */ 334 mtctr r8 335 beq+ 61f 33670: lbz r9,4(r4) /* do some bytes */ 33771: stb r9,4(r6) 338 addi r4,r4,1 339 addi r6,r6,1 340 bdnz 70b 34161: subf r5,r0,r5 342 srwi. r0,r0,2 343 mtctr r0 344 beq 58f 34572: lwzu r9,4(r4) /* do some words */ 34673: stwu r9,4(r6) 347 bdnz 72b 348 349 EX_TABLE(70b,100f) 350 EX_TABLE(71b,101f) 351 EX_TABLE(72b,102f) 352 EX_TABLE(73b,103f) 353 35458: srwi. r0,r5,LG_CACHELINE_BYTES /* # complete cachelines */ 355 clrlwi r5,r5,32-LG_CACHELINE_BYTES 356 li r11,4 357 beq 63f 358 359 /* Here we decide how far ahead to prefetch the source */ 360 li r3,4 361 cmpwi r0,1 362 li r7,0 363 ble 114f 364 li r7,1 365#if MAX_COPY_PREFETCH > 1 366 /* Heuristically, for large transfers we prefetch 367 MAX_COPY_PREFETCH cachelines ahead. For small transfers 368 we prefetch 1 cacheline ahead. */ 369 cmpwi r0,MAX_COPY_PREFETCH 370 ble 112f 371 li r7,MAX_COPY_PREFETCH 372112: mtctr r7 373111: dcbt r3,r4 374 addi r3,r3,CACHELINE_BYTES 375 bdnz 111b 376#else 377 dcbt r3,r4 378 addi r3,r3,CACHELINE_BYTES 379#endif /* MAX_COPY_PREFETCH > 1 */ 380 381114: subf r8,r7,r0 382 mr r0,r7 383 mtctr r8 384 38553: dcbt r3,r4 38654: dcbz r11,r6 387 EX_TABLE(54b,105f) 388/* the main body of the cacheline loop */ 389 COPY_16_BYTES_WITHEX(0) 390#if L1_CACHE_BYTES >= 32 391 COPY_16_BYTES_WITHEX(1) 392#if L1_CACHE_BYTES >= 64 393 COPY_16_BYTES_WITHEX(2) 394 COPY_16_BYTES_WITHEX(3) 395#if L1_CACHE_BYTES >= 128 396 COPY_16_BYTES_WITHEX(4) 397 COPY_16_BYTES_WITHEX(5) 398 COPY_16_BYTES_WITHEX(6) 399 COPY_16_BYTES_WITHEX(7) 400#endif 401#endif 402#endif 403 bdnz 53b 404 cmpwi r0,0 405 li r3,4 406 li r7,0 407 bne 114b 408 40963: srwi. r0,r5,2 410 mtctr r0 411 beq 64f 41230: lwzu r0,4(r4) 41331: stwu r0,4(r6) 414 bdnz 30b 415 41664: andi. r0,r5,3 417 mtctr r0 418 beq+ 65f 41940: lbz r0,4(r4) 42041: stb r0,4(r6) 421 addi r4,r4,1 422 addi r6,r6,1 423 bdnz 40b 42465: li r3,0 425 blr 426 427/* read fault, initial single-byte copy */ 428100: li r9,0 429 b 90f 430/* write fault, initial single-byte copy */ 431101: li r9,1 43290: subf r5,r8,r5 433 li r3,0 434 b 99f 435/* read fault, initial word copy */ 436102: li r9,0 437 b 91f 438/* write fault, initial word copy */ 439103: li r9,1 44091: li r3,2 441 b 99f 442 443/* 444 * this stuff handles faults in the cacheline loop and branches to either 445 * 104f (if in read part) or 105f (if in write part), after updating r5 446 */ 447 COPY_16_BYTES_EXCODE(0) 448#if L1_CACHE_BYTES >= 32 449 COPY_16_BYTES_EXCODE(1) 450#if L1_CACHE_BYTES >= 64 451 COPY_16_BYTES_EXCODE(2) 452 COPY_16_BYTES_EXCODE(3) 453#if L1_CACHE_BYTES >= 128 454 COPY_16_BYTES_EXCODE(4) 455 COPY_16_BYTES_EXCODE(5) 456 COPY_16_BYTES_EXCODE(6) 457 COPY_16_BYTES_EXCODE(7) 458#endif 459#endif 460#endif 461 462/* read fault in cacheline loop */ 463104: li r9,0 464 b 92f 465/* fault on dcbz (effectively a write fault) */ 466/* or write fault in cacheline loop */ 467105: li r9,1 46892: li r3,LG_CACHELINE_BYTES 469 mfctr r8 470 add r0,r0,r8 471 b 106f 472/* read fault in final word loop */ 473108: li r9,0 474 b 93f 475/* write fault in final word loop */ 476109: li r9,1 47793: andi. r5,r5,3 478 li r3,2 479 b 99f 480/* read fault in final byte loop */ 481110: li r9,0 482 b 94f 483/* write fault in final byte loop */ 484111: li r9,1 48594: li r5,0 486 li r3,0 487/* 488 * At this stage the number of bytes not copied is 489 * r5 + (ctr << r3), and r9 is 0 for read or 1 for write. 490 */ 49199: mfctr r0 492106: slw r3,r0,r3 493 add. r3,r3,r5 494 beq 120f /* shouldn't happen */ 495 cmpwi 0,r9,0 496 bne 120f 497/* for a read fault, first try to continue the copy one byte at a time */ 498 mtctr r3 499130: lbz r0,4(r4) 500131: stb r0,4(r6) 501 addi r4,r4,1 502 addi r6,r6,1 503 bdnz 130b 504/* then clear out the destination: r3 bytes starting at 4(r6) */ 505132: mfctr r3 506120: blr 507 508 EX_TABLE(30b,108b) 509 EX_TABLE(31b,109b) 510 EX_TABLE(40b,110b) 511 EX_TABLE(41b,111b) 512 EX_TABLE(130b,132b) 513 EX_TABLE(131b,120b) 514 515EXPORT_SYMBOL(__copy_tofrom_user)