1/* 2 * This file is subject to the terms and conditions of the GNU General Public 3 * License. See the file "COPYING" in the main directory of this archive 4 * for more details. 5 * 6 * Unified implementation of memcpy, memmove and the __copy_user backend. 7 * 8 * Copyright (C) 1998, 99, 2000, 01, 2002 Ralf Baechle (ralf@gnu.org) 9 * Copyright (C) 1999, 2000, 01, 2002 Silicon Graphics, Inc. 10 * Copyright (C) 2002 Broadcom, Inc. 11 * memcpy/copy_user author: Mark Vandevoorde 12 * Copyright (C) 2007 Maciej W. Rozycki 13 * Copyright (C) 2014 Imagination Technologies Ltd. 14 * 15 * Mnemonic names for arguments to memcpy/__copy_user 16 */ 17 18/* 19 * Hack to resolve longstanding prefetch issue 20 * 21 * Prefetching may be fatal on some systems if we're prefetching beyond the 22 * end of memory on some systems. It's also a seriously bad idea on non 23 * dma-coherent systems. 24 */ 25#ifdef CONFIG_DMA_NONCOHERENT 26#undef CONFIG_CPU_HAS_PREFETCH 27#endif 28#ifdef CONFIG_MIPS_MALTA 29#undef CONFIG_CPU_HAS_PREFETCH 30#endif 31#ifdef CONFIG_CPU_MIPSR6 32#undef CONFIG_CPU_HAS_PREFETCH 33#endif 34 35#include <asm/asm.h> 36#include <asm/asm-offsets.h> 37#include <asm/export.h> 38#include <asm/regdef.h> 39 40#define dst a0 41#define src a1 42#define len a2 43 44/* 45 * Spec 46 * 47 * memcpy copies len bytes from src to dst and sets v0 to dst. 48 * It assumes that 49 * - src and dst don't overlap 50 * - src is readable 51 * - dst is writable 52 * memcpy uses the standard calling convention 53 * 54 * __copy_user copies up to len bytes from src to dst and sets a2 (len) to 55 * the number of uncopied bytes due to an exception caused by a read or write. 56 * __copy_user assumes that src and dst don't overlap, and that the call is 57 * implementing one of the following: 58 * copy_to_user 59 * - src is readable (no exceptions when reading src) 60 * copy_from_user 61 * - dst is writable (no exceptions when writing dst) 62 * __copy_user uses a non-standard calling convention; see 63 * include/asm-mips/uaccess.h 64 * 65 * When an exception happens on a load, the handler must 66 # ensure that all of the destination buffer is overwritten to prevent 67 * leaking information to user mode programs. 68 */ 69 70/* 71 * Implementation 72 */ 73 74/* 75 * The exception handler for loads requires that: 76 * 1- AT contain the address of the byte just past the end of the source 77 * of the copy, 78 * 2- src_entry <= src < AT, and 79 * 3- (dst - src) == (dst_entry - src_entry), 80 * The _entry suffix denotes values when __copy_user was called. 81 * 82 * (1) is set up up by uaccess.h and maintained by not writing AT in copy_user 83 * (2) is met by incrementing src by the number of bytes copied 84 * (3) is met by not doing loads between a pair of increments of dst and src 85 * 86 * The exception handlers for stores adjust len (if necessary) and return. 87 * These handlers do not need to overwrite any data. 88 * 89 * For __rmemcpy and memmove an exception is always a kernel bug, therefore 90 * they're not protected. 91 */ 92 93/* Instruction type */ 94#define LD_INSN 1 95#define ST_INSN 2 96/* Pretech type */ 97#define SRC_PREFETCH 1 98#define DST_PREFETCH 2 99#define LEGACY_MODE 1 100#define EVA_MODE 2 101#define USEROP 1 102#define KERNELOP 2 103 104/* 105 * Wrapper to add an entry in the exception table 106 * in case the insn causes a memory exception. 107 * Arguments: 108 * insn : Load/store instruction 109 * type : Instruction type 110 * reg : Register 111 * addr : Address 112 * handler : Exception handler 113 */ 114 115#define EXC(insn, type, reg, addr, handler) \ 116 .if \mode == LEGACY_MODE; \ 1179: insn reg, addr; \ 118 .section __ex_table,"a"; \ 119 PTR 9b, handler; \ 120 .previous; \ 121 /* This is assembled in EVA mode */ \ 122 .else; \ 123 /* If loading from user or storing to user */ \ 124 .if ((\from == USEROP) && (type == LD_INSN)) || \ 125 ((\to == USEROP) && (type == ST_INSN)); \ 1269: __BUILD_EVA_INSN(insn##e, reg, addr); \ 127 .section __ex_table,"a"; \ 128 PTR 9b, handler; \ 129 .previous; \ 130 .else; \ 131 /* \ 132 * Still in EVA, but no need for \ 133 * exception handler or EVA insn \ 134 */ \ 135 insn reg, addr; \ 136 .endif; \ 137 .endif 138 139/* 140 * Only on the 64-bit kernel we can made use of 64-bit registers. 141 */ 142#ifdef CONFIG_64BIT 143#define USE_DOUBLE 144#endif 145 146#ifdef USE_DOUBLE 147 148#define LOADK ld /* No exception */ 149#define LOAD(reg, addr, handler) EXC(ld, LD_INSN, reg, addr, handler) 150#define LOADL(reg, addr, handler) EXC(ldl, LD_INSN, reg, addr, handler) 151#define LOADR(reg, addr, handler) EXC(ldr, LD_INSN, reg, addr, handler) 152#define STOREL(reg, addr, handler) EXC(sdl, ST_INSN, reg, addr, handler) 153#define STORER(reg, addr, handler) EXC(sdr, ST_INSN, reg, addr, handler) 154#define STORE(reg, addr, handler) EXC(sd, ST_INSN, reg, addr, handler) 155#define ADD daddu 156#define SUB dsubu 157#define SRL dsrl 158#define SRA dsra 159#define SLL dsll 160#define SLLV dsllv 161#define SRLV dsrlv 162#define NBYTES 8 163#define LOG_NBYTES 3 164 165/* 166 * As we are sharing code base with the mips32 tree (which use the o32 ABI 167 * register definitions). We need to redefine the register definitions from 168 * the n64 ABI register naming to the o32 ABI register naming. 169 */ 170#undef t0 171#undef t1 172#undef t2 173#undef t3 174#define t0 $8 175#define t1 $9 176#define t2 $10 177#define t3 $11 178#define t4 $12 179#define t5 $13 180#define t6 $14 181#define t7 $15 182 183#else 184 185#define LOADK lw /* No exception */ 186#define LOAD(reg, addr, handler) EXC(lw, LD_INSN, reg, addr, handler) 187#define LOADL(reg, addr, handler) EXC(lwl, LD_INSN, reg, addr, handler) 188#define LOADR(reg, addr, handler) EXC(lwr, LD_INSN, reg, addr, handler) 189#define STOREL(reg, addr, handler) EXC(swl, ST_INSN, reg, addr, handler) 190#define STORER(reg, addr, handler) EXC(swr, ST_INSN, reg, addr, handler) 191#define STORE(reg, addr, handler) EXC(sw, ST_INSN, reg, addr, handler) 192#define ADD addu 193#define SUB subu 194#define SRL srl 195#define SLL sll 196#define SRA sra 197#define SLLV sllv 198#define SRLV srlv 199#define NBYTES 4 200#define LOG_NBYTES 2 201 202#endif /* USE_DOUBLE */ 203 204#define LOADB(reg, addr, handler) EXC(lb, LD_INSN, reg, addr, handler) 205#define STOREB(reg, addr, handler) EXC(sb, ST_INSN, reg, addr, handler) 206 207#ifdef CONFIG_CPU_HAS_PREFETCH 208# define _PREF(hint, addr, type) \ 209 .if \mode == LEGACY_MODE; \ 210 kernel_pref(hint, addr); \ 211 .else; \ 212 .if ((\from == USEROP) && (type == SRC_PREFETCH)) || \ 213 ((\to == USEROP) && (type == DST_PREFETCH)); \ 214 /* \ 215 * PREFE has only 9 bits for the offset \ 216 * compared to PREF which has 16, so it may \ 217 * need to use the $at register but this \ 218 * register should remain intact because it's \ 219 * used later on. Therefore use $v1. \ 220 */ \ 221 .set at=v1; \ 222 user_pref(hint, addr); \ 223 .set noat; \ 224 .else; \ 225 kernel_pref(hint, addr); \ 226 .endif; \ 227 .endif 228#else 229# define _PREF(hint, addr, type) 230#endif 231 232#define PREFS(hint, addr) _PREF(hint, addr, SRC_PREFETCH) 233#define PREFD(hint, addr) _PREF(hint, addr, DST_PREFETCH) 234 235#ifdef CONFIG_CPU_LITTLE_ENDIAN 236#define LDFIRST LOADR 237#define LDREST LOADL 238#define STFIRST STORER 239#define STREST STOREL 240#define SHIFT_DISCARD SLLV 241#else 242#define LDFIRST LOADL 243#define LDREST LOADR 244#define STFIRST STOREL 245#define STREST STORER 246#define SHIFT_DISCARD SRLV 247#endif 248 249#define FIRST(unit) ((unit)*NBYTES) 250#define REST(unit) (FIRST(unit)+NBYTES-1) 251#define UNIT(unit) FIRST(unit) 252 253#define ADDRMASK (NBYTES-1) 254 255 .text 256 .set noreorder 257#ifndef CONFIG_CPU_DADDI_WORKAROUNDS 258 .set noat 259#else 260 .set at=v1 261#endif 262 263 .align 5 264 265 /* 266 * Macro to build the __copy_user common code 267 * Arguments: 268 * mode : LEGACY_MODE or EVA_MODE 269 * from : Source operand. USEROP or KERNELOP 270 * to : Destination operand. USEROP or KERNELOP 271 */ 272 .macro __BUILD_COPY_USER mode, from, to 273 274 /* initialize __memcpy if this the first time we execute this macro */ 275 .ifnotdef __memcpy 276 .set __memcpy, 1 277 .hidden __memcpy /* make sure it does not leak */ 278 .endif 279 280 /* 281 * Note: dst & src may be unaligned, len may be 0 282 * Temps 283 */ 284#define rem t8 285 286 R10KCBARRIER(0(ra)) 287 /* 288 * The "issue break"s below are very approximate. 289 * Issue delays for dcache fills will perturb the schedule, as will 290 * load queue full replay traps, etc. 291 * 292 * If len < NBYTES use byte operations. 293 */ 294 PREFS( 0, 0(src) ) 295 PREFD( 1, 0(dst) ) 296 sltu t2, len, NBYTES 297 and t1, dst, ADDRMASK 298 PREFS( 0, 1*32(src) ) 299 PREFD( 1, 1*32(dst) ) 300 bnez t2, .Lcopy_bytes_checklen\@ 301 and t0, src, ADDRMASK 302 PREFS( 0, 2*32(src) ) 303 PREFD( 1, 2*32(dst) ) 304#ifdef CONFIG_CPU_HAS_LOAD_STORE_LR 305 bnez t1, .Ldst_unaligned\@ 306 nop 307 bnez t0, .Lsrc_unaligned_dst_aligned\@ 308#else 309 or t0, t0, t1 310 bnez t0, .Lcopy_unaligned_bytes\@ 311#endif 312 /* 313 * use delay slot for fall-through 314 * src and dst are aligned; need to compute rem 315 */ 316.Lboth_aligned\@: 317 SRL t0, len, LOG_NBYTES+3 # +3 for 8 units/iter 318 beqz t0, .Lcleanup_both_aligned\@ # len < 8*NBYTES 319 and rem, len, (8*NBYTES-1) # rem = len % (8*NBYTES) 320 PREFS( 0, 3*32(src) ) 321 PREFD( 1, 3*32(dst) ) 322 .align 4 3231: 324 R10KCBARRIER(0(ra)) 325 LOAD(t0, UNIT(0)(src), .Ll_exc\@) 326 LOAD(t1, UNIT(1)(src), .Ll_exc_copy\@) 327 LOAD(t2, UNIT(2)(src), .Ll_exc_copy\@) 328 LOAD(t3, UNIT(3)(src), .Ll_exc_copy\@) 329 SUB len, len, 8*NBYTES 330 LOAD(t4, UNIT(4)(src), .Ll_exc_copy\@) 331 LOAD(t7, UNIT(5)(src), .Ll_exc_copy\@) 332 STORE(t0, UNIT(0)(dst), .Ls_exc_p8u\@) 333 STORE(t1, UNIT(1)(dst), .Ls_exc_p7u\@) 334 LOAD(t0, UNIT(6)(src), .Ll_exc_copy\@) 335 LOAD(t1, UNIT(7)(src), .Ll_exc_copy\@) 336 ADD src, src, 8*NBYTES 337 ADD dst, dst, 8*NBYTES 338 STORE(t2, UNIT(-6)(dst), .Ls_exc_p6u\@) 339 STORE(t3, UNIT(-5)(dst), .Ls_exc_p5u\@) 340 STORE(t4, UNIT(-4)(dst), .Ls_exc_p4u\@) 341 STORE(t7, UNIT(-3)(dst), .Ls_exc_p3u\@) 342 STORE(t0, UNIT(-2)(dst), .Ls_exc_p2u\@) 343 STORE(t1, UNIT(-1)(dst), .Ls_exc_p1u\@) 344 PREFS( 0, 8*32(src) ) 345 PREFD( 1, 8*32(dst) ) 346 bne len, rem, 1b 347 nop 348 349 /* 350 * len == rem == the number of bytes left to copy < 8*NBYTES 351 */ 352.Lcleanup_both_aligned\@: 353 beqz len, .Ldone\@ 354 sltu t0, len, 4*NBYTES 355 bnez t0, .Lless_than_4units\@ 356 and rem, len, (NBYTES-1) # rem = len % NBYTES 357 /* 358 * len >= 4*NBYTES 359 */ 360 LOAD( t0, UNIT(0)(src), .Ll_exc\@) 361 LOAD( t1, UNIT(1)(src), .Ll_exc_copy\@) 362 LOAD( t2, UNIT(2)(src), .Ll_exc_copy\@) 363 LOAD( t3, UNIT(3)(src), .Ll_exc_copy\@) 364 SUB len, len, 4*NBYTES 365 ADD src, src, 4*NBYTES 366 R10KCBARRIER(0(ra)) 367 STORE(t0, UNIT(0)(dst), .Ls_exc_p4u\@) 368 STORE(t1, UNIT(1)(dst), .Ls_exc_p3u\@) 369 STORE(t2, UNIT(2)(dst), .Ls_exc_p2u\@) 370 STORE(t3, UNIT(3)(dst), .Ls_exc_p1u\@) 371 .set reorder /* DADDI_WAR */ 372 ADD dst, dst, 4*NBYTES 373 beqz len, .Ldone\@ 374 .set noreorder 375.Lless_than_4units\@: 376 /* 377 * rem = len % NBYTES 378 */ 379 beq rem, len, .Lcopy_bytes\@ 380 nop 3811: 382 R10KCBARRIER(0(ra)) 383 LOAD(t0, 0(src), .Ll_exc\@) 384 ADD src, src, NBYTES 385 SUB len, len, NBYTES 386 STORE(t0, 0(dst), .Ls_exc_p1u\@) 387 .set reorder /* DADDI_WAR */ 388 ADD dst, dst, NBYTES 389 bne rem, len, 1b 390 .set noreorder 391 392#ifdef CONFIG_CPU_HAS_LOAD_STORE_LR 393 /* 394 * src and dst are aligned, need to copy rem bytes (rem < NBYTES) 395 * A loop would do only a byte at a time with possible branch 396 * mispredicts. Can't do an explicit LOAD dst,mask,or,STORE 397 * because can't assume read-access to dst. Instead, use 398 * STREST dst, which doesn't require read access to dst. 399 * 400 * This code should perform better than a simple loop on modern, 401 * wide-issue mips processors because the code has fewer branches and 402 * more instruction-level parallelism. 403 */ 404#define bits t2 405 beqz len, .Ldone\@ 406 ADD t1, dst, len # t1 is just past last byte of dst 407 li bits, 8*NBYTES 408 SLL rem, len, 3 # rem = number of bits to keep 409 LOAD(t0, 0(src), .Ll_exc\@) 410 SUB bits, bits, rem # bits = number of bits to discard 411 SHIFT_DISCARD t0, t0, bits 412 STREST(t0, -1(t1), .Ls_exc\@) 413 jr ra 414 move len, zero 415.Ldst_unaligned\@: 416 /* 417 * dst is unaligned 418 * t0 = src & ADDRMASK 419 * t1 = dst & ADDRMASK; T1 > 0 420 * len >= NBYTES 421 * 422 * Copy enough bytes to align dst 423 * Set match = (src and dst have same alignment) 424 */ 425#define match rem 426 LDFIRST(t3, FIRST(0)(src), .Ll_exc\@) 427 ADD t2, zero, NBYTES 428 LDREST(t3, REST(0)(src), .Ll_exc_copy\@) 429 SUB t2, t2, t1 # t2 = number of bytes copied 430 xor match, t0, t1 431 R10KCBARRIER(0(ra)) 432 STFIRST(t3, FIRST(0)(dst), .Ls_exc\@) 433 beq len, t2, .Ldone\@ 434 SUB len, len, t2 435 ADD dst, dst, t2 436 beqz match, .Lboth_aligned\@ 437 ADD src, src, t2 438 439.Lsrc_unaligned_dst_aligned\@: 440 SRL t0, len, LOG_NBYTES+2 # +2 for 4 units/iter 441 PREFS( 0, 3*32(src) ) 442 beqz t0, .Lcleanup_src_unaligned\@ 443 and rem, len, (4*NBYTES-1) # rem = len % 4*NBYTES 444 PREFD( 1, 3*32(dst) ) 4451: 446/* 447 * Avoid consecutive LD*'s to the same register since some mips 448 * implementations can't issue them in the same cycle. 449 * It's OK to load FIRST(N+1) before REST(N) because the two addresses 450 * are to the same unit (unless src is aligned, but it's not). 451 */ 452 R10KCBARRIER(0(ra)) 453 LDFIRST(t0, FIRST(0)(src), .Ll_exc\@) 454 LDFIRST(t1, FIRST(1)(src), .Ll_exc_copy\@) 455 SUB len, len, 4*NBYTES 456 LDREST(t0, REST(0)(src), .Ll_exc_copy\@) 457 LDREST(t1, REST(1)(src), .Ll_exc_copy\@) 458 LDFIRST(t2, FIRST(2)(src), .Ll_exc_copy\@) 459 LDFIRST(t3, FIRST(3)(src), .Ll_exc_copy\@) 460 LDREST(t2, REST(2)(src), .Ll_exc_copy\@) 461 LDREST(t3, REST(3)(src), .Ll_exc_copy\@) 462 PREFS( 0, 9*32(src) ) # 0 is PREF_LOAD (not streamed) 463 ADD src, src, 4*NBYTES 464#ifdef CONFIG_CPU_SB1 465 nop # improves slotting 466#endif 467 STORE(t0, UNIT(0)(dst), .Ls_exc_p4u\@) 468 STORE(t1, UNIT(1)(dst), .Ls_exc_p3u\@) 469 STORE(t2, UNIT(2)(dst), .Ls_exc_p2u\@) 470 STORE(t3, UNIT(3)(dst), .Ls_exc_p1u\@) 471 PREFD( 1, 9*32(dst) ) # 1 is PREF_STORE (not streamed) 472 .set reorder /* DADDI_WAR */ 473 ADD dst, dst, 4*NBYTES 474 bne len, rem, 1b 475 .set noreorder 476 477.Lcleanup_src_unaligned\@: 478 beqz len, .Ldone\@ 479 and rem, len, NBYTES-1 # rem = len % NBYTES 480 beq rem, len, .Lcopy_bytes\@ 481 nop 4821: 483 R10KCBARRIER(0(ra)) 484 LDFIRST(t0, FIRST(0)(src), .Ll_exc\@) 485 LDREST(t0, REST(0)(src), .Ll_exc_copy\@) 486 ADD src, src, NBYTES 487 SUB len, len, NBYTES 488 STORE(t0, 0(dst), .Ls_exc_p1u\@) 489 .set reorder /* DADDI_WAR */ 490 ADD dst, dst, NBYTES 491 bne len, rem, 1b 492 .set noreorder 493 494#endif /* CONFIG_CPU_HAS_LOAD_STORE_LR */ 495.Lcopy_bytes_checklen\@: 496 beqz len, .Ldone\@ 497 nop 498.Lcopy_bytes\@: 499 /* 0 < len < NBYTES */ 500 R10KCBARRIER(0(ra)) 501#define COPY_BYTE(N) \ 502 LOADB(t0, N(src), .Ll_exc\@); \ 503 SUB len, len, 1; \ 504 beqz len, .Ldone\@; \ 505 STOREB(t0, N(dst), .Ls_exc_p1\@) 506 507 COPY_BYTE(0) 508 COPY_BYTE(1) 509#ifdef USE_DOUBLE 510 COPY_BYTE(2) 511 COPY_BYTE(3) 512 COPY_BYTE(4) 513 COPY_BYTE(5) 514#endif 515 LOADB(t0, NBYTES-2(src), .Ll_exc\@) 516 SUB len, len, 1 517 jr ra 518 STOREB(t0, NBYTES-2(dst), .Ls_exc_p1\@) 519.Ldone\@: 520 jr ra 521 nop 522 523#ifndef CONFIG_CPU_HAS_LOAD_STORE_LR 524.Lcopy_unaligned_bytes\@: 5251: 526 COPY_BYTE(0) 527 COPY_BYTE(1) 528 COPY_BYTE(2) 529 COPY_BYTE(3) 530 COPY_BYTE(4) 531 COPY_BYTE(5) 532 COPY_BYTE(6) 533 COPY_BYTE(7) 534 ADD src, src, 8 535 b 1b 536 ADD dst, dst, 8 537#endif /* !CONFIG_CPU_HAS_LOAD_STORE_LR */ 538 .if __memcpy == 1 539 END(memcpy) 540 .set __memcpy, 0 541 .hidden __memcpy 542 .endif 543 544.Ll_exc_copy\@: 545 /* 546 * Copy bytes from src until faulting load address (or until a 547 * lb faults) 548 * 549 * When reached by a faulting LDFIRST/LDREST, THREAD_BUADDR($28) 550 * may be more than a byte beyond the last address. 551 * Hence, the lb below may get an exception. 552 * 553 * Assumes src < THREAD_BUADDR($28) 554 */ 555 LOADK t0, TI_TASK($28) 556 nop 557 LOADK t0, THREAD_BUADDR(t0) 5581: 559 LOADB(t1, 0(src), .Ll_exc\@) 560 ADD src, src, 1 561 sb t1, 0(dst) # can't fault -- we're copy_from_user 562 .set reorder /* DADDI_WAR */ 563 ADD dst, dst, 1 564 bne src, t0, 1b 565 .set noreorder 566.Ll_exc\@: 567 LOADK t0, TI_TASK($28) 568 nop 569 LOADK t0, THREAD_BUADDR(t0) # t0 is just past last good address 570 nop 571 SUB len, AT, t0 # len number of uncopied bytes 572 jr ra 573 nop 574 575#define SEXC(n) \ 576 .set reorder; /* DADDI_WAR */ \ 577.Ls_exc_p ## n ## u\@: \ 578 ADD len, len, n*NBYTES; \ 579 jr ra; \ 580 .set noreorder 581 582SEXC(8) 583SEXC(7) 584SEXC(6) 585SEXC(5) 586SEXC(4) 587SEXC(3) 588SEXC(2) 589SEXC(1) 590 591.Ls_exc_p1\@: 592 .set reorder /* DADDI_WAR */ 593 ADD len, len, 1 594 jr ra 595 .set noreorder 596.Ls_exc\@: 597 jr ra 598 nop 599 .endm 600 601 .align 5 602LEAF(memmove) 603EXPORT_SYMBOL(memmove) 604 ADD t0, a0, a2 605 ADD t1, a1, a2 606 sltu t0, a1, t0 # dst + len <= src -> memcpy 607 sltu t1, a0, t1 # dst >= src + len -> memcpy 608 and t0, t1 609 beqz t0, .L__memcpy 610 move v0, a0 /* return value */ 611 beqz a2, .Lr_out 612 END(memmove) 613 614 /* fall through to __rmemcpy */ 615LEAF(__rmemcpy) /* a0=dst a1=src a2=len */ 616 sltu t0, a1, a0 617 beqz t0, .Lr_end_bytes_up # src >= dst 618 nop 619 ADD a0, a2 # dst = dst + len 620 ADD a1, a2 # src = src + len 621 622.Lr_end_bytes: 623 R10KCBARRIER(0(ra)) 624 lb t0, -1(a1) 625 SUB a2, a2, 0x1 626 sb t0, -1(a0) 627 SUB a1, a1, 0x1 628 .set reorder /* DADDI_WAR */ 629 SUB a0, a0, 0x1 630 bnez a2, .Lr_end_bytes 631 .set noreorder 632 633.Lr_out: 634 jr ra 635 move a2, zero 636 637.Lr_end_bytes_up: 638 R10KCBARRIER(0(ra)) 639 lb t0, (a1) 640 SUB a2, a2, 0x1 641 sb t0, (a0) 642 ADD a1, a1, 0x1 643 .set reorder /* DADDI_WAR */ 644 ADD a0, a0, 0x1 645 bnez a2, .Lr_end_bytes_up 646 .set noreorder 647 648 jr ra 649 move a2, zero 650 END(__rmemcpy) 651 652/* 653 * A combined memcpy/__copy_user 654 * __copy_user sets len to 0 for success; else to an upper bound of 655 * the number of uncopied bytes. 656 * memcpy sets v0 to dst. 657 */ 658 .align 5 659LEAF(memcpy) /* a0=dst a1=src a2=len */ 660EXPORT_SYMBOL(memcpy) 661 move v0, dst /* return value */ 662.L__memcpy: 663FEXPORT(__copy_user) 664EXPORT_SYMBOL(__copy_user) 665 /* Legacy Mode, user <-> user */ 666 __BUILD_COPY_USER LEGACY_MODE USEROP USEROP 667 668#ifdef CONFIG_EVA 669 670/* 671 * For EVA we need distinct symbols for reading and writing to user space. 672 * This is because we need to use specific EVA instructions to perform the 673 * virtual <-> physical translation when a virtual address is actually in user 674 * space 675 */ 676 677/* 678 * __copy_from_user (EVA) 679 */ 680 681LEAF(__copy_from_user_eva) 682EXPORT_SYMBOL(__copy_from_user_eva) 683 __BUILD_COPY_USER EVA_MODE USEROP KERNELOP 684END(__copy_from_user_eva) 685 686 687 688/* 689 * __copy_to_user (EVA) 690 */ 691 692LEAF(__copy_to_user_eva) 693EXPORT_SYMBOL(__copy_to_user_eva) 694__BUILD_COPY_USER EVA_MODE KERNELOP USEROP 695END(__copy_to_user_eva) 696 697/* 698 * __copy_in_user (EVA) 699 */ 700 701LEAF(__copy_in_user_eva) 702EXPORT_SYMBOL(__copy_in_user_eva) 703__BUILD_COPY_USER EVA_MODE USEROP USEROP 704END(__copy_in_user_eva) 705 706#endif 707