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 32#include <asm/asm.h> 33#include <asm/asm-offsets.h> 34#include <asm/export.h> 35#include <asm/regdef.h> 36 37#define dst a0 38#define src a1 39#define len a2 40 41/* 42 * Spec 43 * 44 * memcpy copies len bytes from src to dst and sets v0 to dst. 45 * It assumes that 46 * - src and dst don't overlap 47 * - src is readable 48 * - dst is writable 49 * memcpy uses the standard calling convention 50 * 51 * __copy_user copies up to len bytes from src to dst and sets a2 (len) to 52 * the number of uncopied bytes due to an exception caused by a read or write. 53 * __copy_user assumes that src and dst don't overlap, and that the call is 54 * implementing one of the following: 55 * copy_to_user 56 * - src is readable (no exceptions when reading src) 57 * copy_from_user 58 * - dst is writable (no exceptions when writing dst) 59 * __copy_user uses a non-standard calling convention; see 60 * include/asm-mips/uaccess.h 61 * 62 * When an exception happens on a load, the handler must 63 # ensure that all of the destination buffer is overwritten to prevent 64 * leaking information to user mode programs. 65 */ 66 67/* 68 * Implementation 69 */ 70 71/* 72 * The exception handler for loads requires that: 73 * 1- AT contain the address of the byte just past the end of the source 74 * of the copy, 75 * 2- src_entry <= src < AT, and 76 * 3- (dst - src) == (dst_entry - src_entry), 77 * The _entry suffix denotes values when __copy_user was called. 78 * 79 * (1) is set up up by uaccess.h and maintained by not writing AT in copy_user 80 * (2) is met by incrementing src by the number of bytes copied 81 * (3) is met by not doing loads between a pair of increments of dst and src 82 * 83 * The exception handlers for stores adjust len (if necessary) and return. 84 * These handlers do not need to overwrite any data. 85 * 86 * For __rmemcpy and memmove an exception is always a kernel bug, therefore 87 * they're not protected. 88 */ 89 90/* Instruction type */ 91#define LD_INSN 1 92#define ST_INSN 2 93/* Pretech type */ 94#define SRC_PREFETCH 1 95#define DST_PREFETCH 2 96#define LEGACY_MODE 1 97#define EVA_MODE 2 98#define USEROP 1 99#define KERNELOP 2 100 101/* 102 * Wrapper to add an entry in the exception table 103 * in case the insn causes a memory exception. 104 * Arguments: 105 * insn : Load/store instruction 106 * type : Instruction type 107 * reg : Register 108 * addr : Address 109 * handler : Exception handler 110 */ 111 112#define EXC(insn, type, reg, addr, handler) \ 113 .if \mode == LEGACY_MODE; \ 1149: insn reg, addr; \ 115 .section __ex_table,"a"; \ 116 PTR 9b, handler; \ 117 .previous; \ 118 /* This is assembled in EVA mode */ \ 119 .else; \ 120 /* If loading from user or storing to user */ \ 121 .if ((\from == USEROP) && (type == LD_INSN)) || \ 122 ((\to == USEROP) && (type == ST_INSN)); \ 1239: __BUILD_EVA_INSN(insn##e, reg, addr); \ 124 .section __ex_table,"a"; \ 125 PTR 9b, handler; \ 126 .previous; \ 127 .else; \ 128 /* \ 129 * Still in EVA, but no need for \ 130 * exception handler or EVA insn \ 131 */ \ 132 insn reg, addr; \ 133 .endif; \ 134 .endif 135 136/* 137 * Only on the 64-bit kernel we can made use of 64-bit registers. 138 */ 139#ifdef CONFIG_64BIT 140#define USE_DOUBLE 141#endif 142 143#ifdef USE_DOUBLE 144 145#define LOADK ld /* No exception */ 146#define LOAD(reg, addr, handler) EXC(ld, LD_INSN, reg, addr, handler) 147#define LOADL(reg, addr, handler) EXC(ldl, LD_INSN, reg, addr, handler) 148#define LOADR(reg, addr, handler) EXC(ldr, LD_INSN, reg, addr, handler) 149#define STOREL(reg, addr, handler) EXC(sdl, ST_INSN, reg, addr, handler) 150#define STORER(reg, addr, handler) EXC(sdr, ST_INSN, reg, addr, handler) 151#define STORE(reg, addr, handler) EXC(sd, ST_INSN, reg, addr, handler) 152#define ADD daddu 153#define SUB dsubu 154#define SRL dsrl 155#define SRA dsra 156#define SLL dsll 157#define SLLV dsllv 158#define SRLV dsrlv 159#define NBYTES 8 160#define LOG_NBYTES 3 161 162/* 163 * As we are sharing code base with the mips32 tree (which use the o32 ABI 164 * register definitions). We need to redefine the register definitions from 165 * the n64 ABI register naming to the o32 ABI register naming. 166 */ 167#undef t0 168#undef t1 169#undef t2 170#undef t3 171#define t0 $8 172#define t1 $9 173#define t2 $10 174#define t3 $11 175#define t4 $12 176#define t5 $13 177#define t6 $14 178#define t7 $15 179 180#else 181 182#define LOADK lw /* No exception */ 183#define LOAD(reg, addr, handler) EXC(lw, LD_INSN, reg, addr, handler) 184#define LOADL(reg, addr, handler) EXC(lwl, LD_INSN, reg, addr, handler) 185#define LOADR(reg, addr, handler) EXC(lwr, LD_INSN, reg, addr, handler) 186#define STOREL(reg, addr, handler) EXC(swl, ST_INSN, reg, addr, handler) 187#define STORER(reg, addr, handler) EXC(swr, ST_INSN, reg, addr, handler) 188#define STORE(reg, addr, handler) EXC(sw, ST_INSN, reg, addr, handler) 189#define ADD addu 190#define SUB subu 191#define SRL srl 192#define SLL sll 193#define SRA sra 194#define SLLV sllv 195#define SRLV srlv 196#define NBYTES 4 197#define LOG_NBYTES 2 198 199#endif /* USE_DOUBLE */ 200 201#define LOADB(reg, addr, handler) EXC(lb, LD_INSN, reg, addr, handler) 202#define STOREB(reg, addr, handler) EXC(sb, ST_INSN, reg, addr, handler) 203 204#define _PREF(hint, addr, type) \ 205 .if \mode == LEGACY_MODE; \ 206 PREF(hint, addr); \ 207 .else; \ 208 .if ((\from == USEROP) && (type == SRC_PREFETCH)) || \ 209 ((\to == USEROP) && (type == DST_PREFETCH)); \ 210 /* \ 211 * PREFE has only 9 bits for the offset \ 212 * compared to PREF which has 16, so it may \ 213 * need to use the $at register but this \ 214 * register should remain intact because it's \ 215 * used later on. Therefore use $v1. \ 216 */ \ 217 .set at=v1; \ 218 PREFE(hint, addr); \ 219 .set noat; \ 220 .else; \ 221 PREF(hint, addr); \ 222 .endif; \ 223 .endif 224 225#define PREFS(hint, addr) _PREF(hint, addr, SRC_PREFETCH) 226#define PREFD(hint, addr) _PREF(hint, addr, DST_PREFETCH) 227 228#ifdef CONFIG_CPU_LITTLE_ENDIAN 229#define LDFIRST LOADR 230#define LDREST LOADL 231#define STFIRST STORER 232#define STREST STOREL 233#define SHIFT_DISCARD SLLV 234#else 235#define LDFIRST LOADL 236#define LDREST LOADR 237#define STFIRST STOREL 238#define STREST STORER 239#define SHIFT_DISCARD SRLV 240#endif 241 242#define FIRST(unit) ((unit)*NBYTES) 243#define REST(unit) (FIRST(unit)+NBYTES-1) 244#define UNIT(unit) FIRST(unit) 245 246#define ADDRMASK (NBYTES-1) 247 248 .text 249 .set noreorder 250#ifndef CONFIG_CPU_DADDI_WORKAROUNDS 251 .set noat 252#else 253 .set at=v1 254#endif 255 256 .align 5 257 258 /* 259 * Macro to build the __copy_user common code 260 * Arguments: 261 * mode : LEGACY_MODE or EVA_MODE 262 * from : Source operand. USEROP or KERNELOP 263 * to : Destination operand. USEROP or KERNELOP 264 */ 265 .macro __BUILD_COPY_USER mode, from, to 266 267 /* initialize __memcpy if this the first time we execute this macro */ 268 .ifnotdef __memcpy 269 .set __memcpy, 1 270 .hidden __memcpy /* make sure it does not leak */ 271 .endif 272 273 /* 274 * Note: dst & src may be unaligned, len may be 0 275 * Temps 276 */ 277#define rem t8 278 279 R10KCBARRIER(0(ra)) 280 /* 281 * The "issue break"s below are very approximate. 282 * Issue delays for dcache fills will perturb the schedule, as will 283 * load queue full replay traps, etc. 284 * 285 * If len < NBYTES use byte operations. 286 */ 287 PREFS( 0, 0(src) ) 288 PREFD( 1, 0(dst) ) 289 sltu t2, len, NBYTES 290 and t1, dst, ADDRMASK 291 PREFS( 0, 1*32(src) ) 292 PREFD( 1, 1*32(dst) ) 293 bnez t2, .Lcopy_bytes_checklen\@ 294 and t0, src, ADDRMASK 295 PREFS( 0, 2*32(src) ) 296 PREFD( 1, 2*32(dst) ) 297#ifndef CONFIG_CPU_MIPSR6 298 bnez t1, .Ldst_unaligned\@ 299 nop 300 bnez t0, .Lsrc_unaligned_dst_aligned\@ 301#else 302 or t0, t0, t1 303 bnez t0, .Lcopy_unaligned_bytes\@ 304#endif 305 /* 306 * use delay slot for fall-through 307 * src and dst are aligned; need to compute rem 308 */ 309.Lboth_aligned\@: 310 SRL t0, len, LOG_NBYTES+3 # +3 for 8 units/iter 311 beqz t0, .Lcleanup_both_aligned\@ # len < 8*NBYTES 312 and rem, len, (8*NBYTES-1) # rem = len % (8*NBYTES) 313 PREFS( 0, 3*32(src) ) 314 PREFD( 1, 3*32(dst) ) 315 .align 4 3161: 317 R10KCBARRIER(0(ra)) 318 LOAD(t0, UNIT(0)(src), .Ll_exc\@) 319 LOAD(t1, UNIT(1)(src), .Ll_exc_copy\@) 320 LOAD(t2, UNIT(2)(src), .Ll_exc_copy\@) 321 LOAD(t3, UNIT(3)(src), .Ll_exc_copy\@) 322 SUB len, len, 8*NBYTES 323 LOAD(t4, UNIT(4)(src), .Ll_exc_copy\@) 324 LOAD(t7, UNIT(5)(src), .Ll_exc_copy\@) 325 STORE(t0, UNIT(0)(dst), .Ls_exc_p8u\@) 326 STORE(t1, UNIT(1)(dst), .Ls_exc_p7u\@) 327 LOAD(t0, UNIT(6)(src), .Ll_exc_copy\@) 328 LOAD(t1, UNIT(7)(src), .Ll_exc_copy\@) 329 ADD src, src, 8*NBYTES 330 ADD dst, dst, 8*NBYTES 331 STORE(t2, UNIT(-6)(dst), .Ls_exc_p6u\@) 332 STORE(t3, UNIT(-5)(dst), .Ls_exc_p5u\@) 333 STORE(t4, UNIT(-4)(dst), .Ls_exc_p4u\@) 334 STORE(t7, UNIT(-3)(dst), .Ls_exc_p3u\@) 335 STORE(t0, UNIT(-2)(dst), .Ls_exc_p2u\@) 336 STORE(t1, UNIT(-1)(dst), .Ls_exc_p1u\@) 337 PREFS( 0, 8*32(src) ) 338 PREFD( 1, 8*32(dst) ) 339 bne len, rem, 1b 340 nop 341 342 /* 343 * len == rem == the number of bytes left to copy < 8*NBYTES 344 */ 345.Lcleanup_both_aligned\@: 346 beqz len, .Ldone\@ 347 sltu t0, len, 4*NBYTES 348 bnez t0, .Lless_than_4units\@ 349 and rem, len, (NBYTES-1) # rem = len % NBYTES 350 /* 351 * len >= 4*NBYTES 352 */ 353 LOAD( t0, UNIT(0)(src), .Ll_exc\@) 354 LOAD( t1, UNIT(1)(src), .Ll_exc_copy\@) 355 LOAD( t2, UNIT(2)(src), .Ll_exc_copy\@) 356 LOAD( t3, UNIT(3)(src), .Ll_exc_copy\@) 357 SUB len, len, 4*NBYTES 358 ADD src, src, 4*NBYTES 359 R10KCBARRIER(0(ra)) 360 STORE(t0, UNIT(0)(dst), .Ls_exc_p4u\@) 361 STORE(t1, UNIT(1)(dst), .Ls_exc_p3u\@) 362 STORE(t2, UNIT(2)(dst), .Ls_exc_p2u\@) 363 STORE(t3, UNIT(3)(dst), .Ls_exc_p1u\@) 364 .set reorder /* DADDI_WAR */ 365 ADD dst, dst, 4*NBYTES 366 beqz len, .Ldone\@ 367 .set noreorder 368.Lless_than_4units\@: 369 /* 370 * rem = len % NBYTES 371 */ 372 beq rem, len, .Lcopy_bytes\@ 373 nop 3741: 375 R10KCBARRIER(0(ra)) 376 LOAD(t0, 0(src), .Ll_exc\@) 377 ADD src, src, NBYTES 378 SUB len, len, NBYTES 379 STORE(t0, 0(dst), .Ls_exc_p1u\@) 380 .set reorder /* DADDI_WAR */ 381 ADD dst, dst, NBYTES 382 bne rem, len, 1b 383 .set noreorder 384 385#ifndef CONFIG_CPU_MIPSR6 386 /* 387 * src and dst are aligned, need to copy rem bytes (rem < NBYTES) 388 * A loop would do only a byte at a time with possible branch 389 * mispredicts. Can't do an explicit LOAD dst,mask,or,STORE 390 * because can't assume read-access to dst. Instead, use 391 * STREST dst, which doesn't require read access to dst. 392 * 393 * This code should perform better than a simple loop on modern, 394 * wide-issue mips processors because the code has fewer branches and 395 * more instruction-level parallelism. 396 */ 397#define bits t2 398 beqz len, .Ldone\@ 399 ADD t1, dst, len # t1 is just past last byte of dst 400 li bits, 8*NBYTES 401 SLL rem, len, 3 # rem = number of bits to keep 402 LOAD(t0, 0(src), .Ll_exc\@) 403 SUB bits, bits, rem # bits = number of bits to discard 404 SHIFT_DISCARD t0, t0, bits 405 STREST(t0, -1(t1), .Ls_exc\@) 406 jr ra 407 move len, zero 408.Ldst_unaligned\@: 409 /* 410 * dst is unaligned 411 * t0 = src & ADDRMASK 412 * t1 = dst & ADDRMASK; T1 > 0 413 * len >= NBYTES 414 * 415 * Copy enough bytes to align dst 416 * Set match = (src and dst have same alignment) 417 */ 418#define match rem 419 LDFIRST(t3, FIRST(0)(src), .Ll_exc\@) 420 ADD t2, zero, NBYTES 421 LDREST(t3, REST(0)(src), .Ll_exc_copy\@) 422 SUB t2, t2, t1 # t2 = number of bytes copied 423 xor match, t0, t1 424 R10KCBARRIER(0(ra)) 425 STFIRST(t3, FIRST(0)(dst), .Ls_exc\@) 426 beq len, t2, .Ldone\@ 427 SUB len, len, t2 428 ADD dst, dst, t2 429 beqz match, .Lboth_aligned\@ 430 ADD src, src, t2 431 432.Lsrc_unaligned_dst_aligned\@: 433 SRL t0, len, LOG_NBYTES+2 # +2 for 4 units/iter 434 PREFS( 0, 3*32(src) ) 435 beqz t0, .Lcleanup_src_unaligned\@ 436 and rem, len, (4*NBYTES-1) # rem = len % 4*NBYTES 437 PREFD( 1, 3*32(dst) ) 4381: 439/* 440 * Avoid consecutive LD*'s to the same register since some mips 441 * implementations can't issue them in the same cycle. 442 * It's OK to load FIRST(N+1) before REST(N) because the two addresses 443 * are to the same unit (unless src is aligned, but it's not). 444 */ 445 R10KCBARRIER(0(ra)) 446 LDFIRST(t0, FIRST(0)(src), .Ll_exc\@) 447 LDFIRST(t1, FIRST(1)(src), .Ll_exc_copy\@) 448 SUB len, len, 4*NBYTES 449 LDREST(t0, REST(0)(src), .Ll_exc_copy\@) 450 LDREST(t1, REST(1)(src), .Ll_exc_copy\@) 451 LDFIRST(t2, FIRST(2)(src), .Ll_exc_copy\@) 452 LDFIRST(t3, FIRST(3)(src), .Ll_exc_copy\@) 453 LDREST(t2, REST(2)(src), .Ll_exc_copy\@) 454 LDREST(t3, REST(3)(src), .Ll_exc_copy\@) 455 PREFS( 0, 9*32(src) ) # 0 is PREF_LOAD (not streamed) 456 ADD src, src, 4*NBYTES 457#ifdef CONFIG_CPU_SB1 458 nop # improves slotting 459#endif 460 STORE(t0, UNIT(0)(dst), .Ls_exc_p4u\@) 461 STORE(t1, UNIT(1)(dst), .Ls_exc_p3u\@) 462 STORE(t2, UNIT(2)(dst), .Ls_exc_p2u\@) 463 STORE(t3, UNIT(3)(dst), .Ls_exc_p1u\@) 464 PREFD( 1, 9*32(dst) ) # 1 is PREF_STORE (not streamed) 465 .set reorder /* DADDI_WAR */ 466 ADD dst, dst, 4*NBYTES 467 bne len, rem, 1b 468 .set noreorder 469 470.Lcleanup_src_unaligned\@: 471 beqz len, .Ldone\@ 472 and rem, len, NBYTES-1 # rem = len % NBYTES 473 beq rem, len, .Lcopy_bytes\@ 474 nop 4751: 476 R10KCBARRIER(0(ra)) 477 LDFIRST(t0, FIRST(0)(src), .Ll_exc\@) 478 LDREST(t0, REST(0)(src), .Ll_exc_copy\@) 479 ADD src, src, NBYTES 480 SUB len, len, NBYTES 481 STORE(t0, 0(dst), .Ls_exc_p1u\@) 482 .set reorder /* DADDI_WAR */ 483 ADD dst, dst, NBYTES 484 bne len, rem, 1b 485 .set noreorder 486 487#endif /* !CONFIG_CPU_MIPSR6 */ 488.Lcopy_bytes_checklen\@: 489 beqz len, .Ldone\@ 490 nop 491.Lcopy_bytes\@: 492 /* 0 < len < NBYTES */ 493 R10KCBARRIER(0(ra)) 494#define COPY_BYTE(N) \ 495 LOADB(t0, N(src), .Ll_exc\@); \ 496 SUB len, len, 1; \ 497 beqz len, .Ldone\@; \ 498 STOREB(t0, N(dst), .Ls_exc_p1\@) 499 500 COPY_BYTE(0) 501 COPY_BYTE(1) 502#ifdef USE_DOUBLE 503 COPY_BYTE(2) 504 COPY_BYTE(3) 505 COPY_BYTE(4) 506 COPY_BYTE(5) 507#endif 508 LOADB(t0, NBYTES-2(src), .Ll_exc\@) 509 SUB len, len, 1 510 jr ra 511 STOREB(t0, NBYTES-2(dst), .Ls_exc_p1\@) 512.Ldone\@: 513 jr ra 514 nop 515 516#ifdef CONFIG_CPU_MIPSR6 517.Lcopy_unaligned_bytes\@: 5181: 519 COPY_BYTE(0) 520 COPY_BYTE(1) 521 COPY_BYTE(2) 522 COPY_BYTE(3) 523 COPY_BYTE(4) 524 COPY_BYTE(5) 525 COPY_BYTE(6) 526 COPY_BYTE(7) 527 ADD src, src, 8 528 b 1b 529 ADD dst, dst, 8 530#endif /* CONFIG_CPU_MIPSR6 */ 531 .if __memcpy == 1 532 END(memcpy) 533 .set __memcpy, 0 534 .hidden __memcpy 535 .endif 536 537.Ll_exc_copy\@: 538 /* 539 * Copy bytes from src until faulting load address (or until a 540 * lb faults) 541 * 542 * When reached by a faulting LDFIRST/LDREST, THREAD_BUADDR($28) 543 * may be more than a byte beyond the last address. 544 * Hence, the lb below may get an exception. 545 * 546 * Assumes src < THREAD_BUADDR($28) 547 */ 548 LOADK t0, TI_TASK($28) 549 nop 550 LOADK t0, THREAD_BUADDR(t0) 5511: 552 LOADB(t1, 0(src), .Ll_exc\@) 553 ADD src, src, 1 554 sb t1, 0(dst) # can't fault -- we're copy_from_user 555 .set reorder /* DADDI_WAR */ 556 ADD dst, dst, 1 557 bne src, t0, 1b 558 .set noreorder 559.Ll_exc\@: 560 LOADK t0, TI_TASK($28) 561 nop 562 LOADK t0, THREAD_BUADDR(t0) # t0 is just past last good address 563 nop 564 SUB len, AT, t0 # len number of uncopied bytes 565 bnez t6, .Ldone\@ /* Skip the zeroing part if inatomic */ 566 /* 567 * Here's where we rely on src and dst being incremented in tandem, 568 * See (3) above. 569 * dst += (fault addr - src) to put dst at first byte to clear 570 */ 571 ADD dst, t0 # compute start address in a1 572 SUB dst, src 573 /* 574 * Clear len bytes starting at dst. Can't call __bzero because it 575 * might modify len. An inefficient loop for these rare times... 576 */ 577 .set reorder /* DADDI_WAR */ 578 SUB src, len, 1 579 beqz len, .Ldone\@ 580 .set noreorder 5811: sb zero, 0(dst) 582 ADD dst, dst, 1 583#ifndef CONFIG_CPU_DADDI_WORKAROUNDS 584 bnez src, 1b 585 SUB src, src, 1 586#else 587 .set push 588 .set noat 589 li v1, 1 590 bnez src, 1b 591 SUB src, src, v1 592 .set pop 593#endif 594 jr ra 595 nop 596 597 598#define SEXC(n) \ 599 .set reorder; /* DADDI_WAR */ \ 600.Ls_exc_p ## n ## u\@: \ 601 ADD len, len, n*NBYTES; \ 602 jr ra; \ 603 .set noreorder 604 605SEXC(8) 606SEXC(7) 607SEXC(6) 608SEXC(5) 609SEXC(4) 610SEXC(3) 611SEXC(2) 612SEXC(1) 613 614.Ls_exc_p1\@: 615 .set reorder /* DADDI_WAR */ 616 ADD len, len, 1 617 jr ra 618 .set noreorder 619.Ls_exc\@: 620 jr ra 621 nop 622 .endm 623 624 .align 5 625LEAF(memmove) 626EXPORT_SYMBOL(memmove) 627 ADD t0, a0, a2 628 ADD t1, a1, a2 629 sltu t0, a1, t0 # dst + len <= src -> memcpy 630 sltu t1, a0, t1 # dst >= src + len -> memcpy 631 and t0, t1 632 beqz t0, .L__memcpy 633 move v0, a0 /* return value */ 634 beqz a2, .Lr_out 635 END(memmove) 636 637 /* fall through to __rmemcpy */ 638LEAF(__rmemcpy) /* a0=dst a1=src a2=len */ 639 sltu t0, a1, a0 640 beqz t0, .Lr_end_bytes_up # src >= dst 641 nop 642 ADD a0, a2 # dst = dst + len 643 ADD a1, a2 # src = src + len 644 645.Lr_end_bytes: 646 R10KCBARRIER(0(ra)) 647 lb t0, -1(a1) 648 SUB a2, a2, 0x1 649 sb t0, -1(a0) 650 SUB a1, a1, 0x1 651 .set reorder /* DADDI_WAR */ 652 SUB a0, a0, 0x1 653 bnez a2, .Lr_end_bytes 654 .set noreorder 655 656.Lr_out: 657 jr ra 658 move a2, zero 659 660.Lr_end_bytes_up: 661 R10KCBARRIER(0(ra)) 662 lb t0, (a1) 663 SUB a2, a2, 0x1 664 sb t0, (a0) 665 ADD a1, a1, 0x1 666 .set reorder /* DADDI_WAR */ 667 ADD a0, a0, 0x1 668 bnez a2, .Lr_end_bytes_up 669 .set noreorder 670 671 jr ra 672 move a2, zero 673 END(__rmemcpy) 674 675/* 676 * t6 is used as a flag to note inatomic mode. 677 */ 678LEAF(__copy_user_inatomic) 679EXPORT_SYMBOL(__copy_user_inatomic) 680 b __copy_user_common 681 li t6, 1 682 END(__copy_user_inatomic) 683 684/* 685 * A combined memcpy/__copy_user 686 * __copy_user sets len to 0 for success; else to an upper bound of 687 * the number of uncopied bytes. 688 * memcpy sets v0 to dst. 689 */ 690 .align 5 691LEAF(memcpy) /* a0=dst a1=src a2=len */ 692EXPORT_SYMBOL(memcpy) 693 move v0, dst /* return value */ 694.L__memcpy: 695FEXPORT(__copy_user) 696EXPORT_SYMBOL(__copy_user) 697 li t6, 0 /* not inatomic */ 698__copy_user_common: 699 /* Legacy Mode, user <-> user */ 700 __BUILD_COPY_USER LEGACY_MODE USEROP USEROP 701 702#ifdef CONFIG_EVA 703 704/* 705 * For EVA we need distinct symbols for reading and writing to user space. 706 * This is because we need to use specific EVA instructions to perform the 707 * virtual <-> physical translation when a virtual address is actually in user 708 * space 709 */ 710 711LEAF(__copy_user_inatomic_eva) 712EXPORT_SYMBOL(__copy_user_inatomic_eva) 713 b __copy_from_user_common 714 li t6, 1 715 END(__copy_user_inatomic_eva) 716 717/* 718 * __copy_from_user (EVA) 719 */ 720 721LEAF(__copy_from_user_eva) 722EXPORT_SYMBOL(__copy_from_user_eva) 723 li t6, 0 /* not inatomic */ 724__copy_from_user_common: 725 __BUILD_COPY_USER EVA_MODE USEROP KERNELOP 726END(__copy_from_user_eva) 727 728 729 730/* 731 * __copy_to_user (EVA) 732 */ 733 734LEAF(__copy_to_user_eva) 735EXPORT_SYMBOL(__copy_to_user_eva) 736__BUILD_COPY_USER EVA_MODE KERNELOP USEROP 737END(__copy_to_user_eva) 738 739/* 740 * __copy_in_user (EVA) 741 */ 742 743LEAF(__copy_in_user_eva) 744EXPORT_SYMBOL(__copy_in_user_eva) 745__BUILD_COPY_USER EVA_MODE USEROP USEROP 746END(__copy_in_user_eva) 747 748#endif 749