1/*- 2 * Copyright (c) 1993 The Regents of the University of California. 3 * Copyright (c) 2003 Peter Wemm. 4 * Copyright (c) 2008 The DragonFly Project. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $FreeBSD: src/sys/amd64/amd64/support.S,v 1.127 2007/05/23 08:33:04 kib Exp $ 32 */ 33 34#include <machine/asmacros.h> 35#include <machine/pmap.h> 36 37#include "assym.s" 38 39 ALIGN_DATA 40 41 .text 42 43/* 44 * bzero(ptr:%rdi, bytes:%rsi) 45 * 46 * Using rep stosq is 70% faster than a %rax loop and almost as fast as 47 * a %xmm0 loop on a modern intel cpu. 48 * 49 * Do not use non-termportal instructions here as we do not know the caller's 50 * intent. 51 */ 52ENTRY(bzero) 53 movq %rsi,%rcx 54 xorl %eax,%eax 55 shrq $3,%rcx 56 cld 57 rep 58 stosq 59 movq %rsi,%rcx 60 andq $7,%rcx 61 rep 62 stosb 63 ret 64END(bzero) 65 66/* 67 * pagezero(ptr:%rdi) 68 * 69 * Using rep stosq is nearly as fast as using %xmm0 on a modern intel cpu, 70 * and about 70% faster than a %rax loop. 71 * 72 * Do not use non-termportal instructions here as we do not know the caller's 73 * intent. 74 */ 75ENTRY(pagezero) 76 movq $PAGE_SIZE>>3,%rcx 77 xorl %eax,%eax 78 cld 79 rep 80 stosq 81 ret 82END(pagezero) 83 84/* 85 * bcmp(ptr:%rdi, ptr:%rsi, bytes:%rdx) 86 */ 87ENTRY(bcmp) 88 movq %rdx,%rcx 89 shrq $3,%rcx 90 cld /* compare forwards */ 91 repe 92 cmpsq 93 jne 1f 94 95 movq %rdx,%rcx 96 andq $7,%rcx 97 repe 98 cmpsb 991: 100 setne %al 101 movsbl %al,%eax 102 ret 103END(bcmp) 104 105/* 106 * bcopy(src:%rdi, dst:%rsi, cnt:%rdx) 107 * 108 * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800 109 */ 110ENTRY(bcopy) 111 xchgq %rsi,%rdi 112 movq %rdx,%rcx 113 114 movq %rdi,%rax 115 subq %rsi,%rax 116 cmpq %rcx,%rax /* overlapping && src < dst? */ 117 jb 1f 118 119 shrq $3,%rcx /* copy by 64-bit words */ 120 cld /* nope, copy forwards */ 121 rep 122 movsq 123 movq %rdx,%rcx 124 andq $7,%rcx /* any bytes left? */ 125 rep 126 movsb 127 ret 128 129 ALIGN_TEXT 1301: 131 addq %rcx,%rdi /* copy backwards */ 132 addq %rcx,%rsi 133 decq %rdi 134 decq %rsi 135 andq $7,%rcx /* any fractional bytes? */ 136 std 137 rep 138 movsb 139 movq %rdx,%rcx /* copy by 32-bit words */ 140 shrq $3,%rcx 141 subq $7,%rsi 142 subq $7,%rdi 143 rep 144 movsq 145 cld 146 ret 147END(bcopy) 148 149ENTRY(reset_dbregs) 150 movq $0x200,%rax /* the manual says that bit 10 must be set to 1 */ 151 movq %rax,%dr7 /* disable all breapoints first */ 152 movq $0,%rax 153 movq %rax,%dr0 154 movq %rax,%dr1 155 movq %rax,%dr2 156 movq %rax,%dr3 157 movq %rax,%dr6 158 ret 159END(reset_dbregs) 160 161/* 162 * memcpy(dst:%rdi, src:%rsi, bytes:%rdx) 163 * 164 * Note: memcpy does not support overlapping copies 165 */ 166ENTRY(memcpy) 167 movq %rdi,%r8 168 movq %rdx,%rcx 169 shrq $3,%rcx /* copy by 64-bit words */ 170 cld /* copy forwards */ 171 rep 172 movsq 173 movq %rdx,%rcx 174 andq $7,%rcx /* any bytes left? */ 175 rep 176 movsb 177 movq %r8,%rax 178 ret 179END(memcpy) 180 181/* fillw(pat, base, cnt) */ 182/* %rdi,%rsi, %rdx */ 183ENTRY(fillw) 184 movq %rdi,%rax 185 movq %rsi,%rdi 186 movq %rdx,%rcx 187 cld 188 rep 189 stosw 190 ret 191END(fillw) 192 193/*****************************************************************************/ 194/* copyout and fubyte family */ 195/*****************************************************************************/ 196/* 197 * Access user memory from inside the kernel. These routines should be 198 * the only places that do this. 199 * 200 * These routines set curpcb->onfault for the time they execute. When a 201 * protection violation occurs inside the functions, the trap handler 202 * returns to *curpcb->onfault instead of the function. 203 */ 204 205/* 206 * uint64_t:%rax kreadmem64(addr:%rdi) 207 * 208 * Read kernel or user memory with fault protection. 209 */ 210ENTRY(kreadmem64) 211 movq PCPU(curthread),%rcx 212 movq TD_PCB(%rcx), %rcx 213 movq $kreadmem64fault,PCB_ONFAULT(%rcx) 214 movq %rsp,PCB_ONFAULT_SP(%rcx) 215 216 movq (%rdi),%rax 217 movq $0,PCB_ONFAULT(%rcx) 218 ret 219 220kreadmem64fault: 221 movq PCPU(curthread),%rcx 222 xorl %eax,%eax 223 movq TD_PCB(%rcx),%rcx 224 movq %rax,PCB_ONFAULT(%rcx) 225 decq %rax 226 ret 227END(kreadmem64) 228 229/* 230 * std_copyout(from_kernel, to_user, len) - MP SAFE 231 * %rdi, %rsi, %rdx 232 */ 233ENTRY(std_copyout) 234 movq PCPU(curthread),%rax 235 movq TD_PCB(%rax), %rax 236 movq $copyout_fault,PCB_ONFAULT(%rax) 237 movq %rsp,PCB_ONFAULT_SP(%rax) 238 testq %rdx,%rdx /* anything to do? */ 239 jz done_copyout 240 241 /* 242 * Check explicitly for non-user addresses. If 486 write protection 243 * is being used, this check is essential because we are in kernel 244 * mode so the h/w does not provide any protection against writing 245 * kernel addresses. 246 */ 247 248 /* 249 * First, prevent address wrapping. 250 */ 251 movq %rsi,%rax 252 addq %rdx,%rax 253 jc copyout_fault 254/* 255 * XXX STOP USING VM_MAX_USER_ADDRESS. 256 * It is an end address, not a max, so every time it is used correctly it 257 * looks like there is an off by one error, and of course it caused an off 258 * by one error in several places. 259 */ 260 movq $VM_MAX_USER_ADDRESS,%rcx 261 cmpq %rcx,%rax 262 ja copyout_fault 263 264 xchgq %rdi,%rsi 265 /* bcopy(%rsi, %rdi, %rdx) */ 266 movq %rdx,%rcx 267 268 shrq $3,%rcx 269 cld 270 rep 271 movsq 272 movb %dl,%cl 273 andb $7,%cl 274 rep 275 movsb 276 277done_copyout: 278 xorl %eax,%eax 279 movq PCPU(curthread),%rdx 280 movq TD_PCB(%rdx), %rdx 281 movq %rax,PCB_ONFAULT(%rdx) 282 ret 283 284 ALIGN_TEXT 285copyout_fault: 286 movq PCPU(curthread),%rdx 287 movq TD_PCB(%rdx), %rdx 288 movq $0,PCB_ONFAULT(%rdx) 289 movq $EFAULT,%rax 290 ret 291END(std_copyout) 292 293/* 294 * std_copyin(from_user, to_kernel, len) - MP SAFE 295 * %rdi, %rsi, %rdx 296 */ 297ENTRY(std_copyin) 298 movq PCPU(curthread),%rax 299 movq TD_PCB(%rax), %rax 300 movq $copyin_fault,PCB_ONFAULT(%rax) 301 movq %rsp,PCB_ONFAULT_SP(%rax) 302 testq %rdx,%rdx /* anything to do? */ 303 jz done_copyin 304 305 /* 306 * make sure address is valid 307 */ 308 movq %rdi,%rax 309 addq %rdx,%rax 310 jc copyin_fault 311 movq $VM_MAX_USER_ADDRESS,%rcx 312 cmpq %rcx,%rax 313 ja copyin_fault 314 315 xchgq %rdi,%rsi 316 movq %rdx,%rcx 317 movb %cl,%al 318 shrq $3,%rcx /* copy longword-wise */ 319 cld 320 rep 321 movsq 322 movb %al,%cl 323 andb $7,%cl /* copy remaining bytes */ 324 rep 325 movsb 326 327done_copyin: 328 xorl %eax,%eax 329 movq PCPU(curthread),%rdx 330 movq TD_PCB(%rdx), %rdx 331 movq %rax,PCB_ONFAULT(%rdx) 332 ret 333 334 ALIGN_TEXT 335copyin_fault: 336 movq PCPU(curthread),%rdx 337 movq TD_PCB(%rdx), %rdx 338 movq $0,PCB_ONFAULT(%rdx) 339 movq $EFAULT,%rax 340 ret 341END(std_copyin) 342 343/* 344 * casu32 - Compare and set user integer. Returns -1 or the current value. 345 * dst = %rdi, old = %rsi, new = %rdx 346 */ 347ENTRY(casu32) 348 movq PCPU(curthread),%rcx 349 movq TD_PCB(%rcx), %rcx 350 movq $fusufault,PCB_ONFAULT(%rcx) 351 movq %rsp,PCB_ONFAULT_SP(%rcx) 352 353 movq $VM_MAX_USER_ADDRESS-4,%rax 354 cmpq %rax,%rdi /* verify address is valid */ 355 ja fusufault 356 357 movl %esi,%eax /* old */ 358 lock 359 cmpxchgl %edx,(%rdi) /* new = %edx */ 360 361 /* 362 * The old value is in %eax. If the store succeeded it will be the 363 * value we expected (old) from before the store, otherwise it will 364 * be the current value. 365 */ 366 367 movq PCPU(curthread),%rcx 368 movq TD_PCB(%rcx), %rcx 369 movq $0,PCB_ONFAULT(%rcx) 370 ret 371END(casu32) 372 373/* 374 * swapu32 - Swap int in user space. ptr = %rdi, val = %rsi 375 */ 376ENTRY(std_swapu32) 377 movq PCPU(curthread),%rcx 378 movq TD_PCB(%rcx), %rcx 379 movq $fusufault,PCB_ONFAULT(%rcx) 380 movq %rsp,PCB_ONFAULT_SP(%rcx) 381 382 movq $VM_MAX_USER_ADDRESS-4,%rax 383 cmpq %rax,%rdi /* verify address is valid */ 384 ja fusufault 385 386 movq %rsi,%rax /* old */ 387 xchgl %eax,(%rdi) 388 389 /* 390 * The old value is in %rax. If the store succeeded it will be the 391 * value we expected (old) from before the store, otherwise it will 392 * be the current value. 393 */ 394 395 movq PCPU(curthread),%rcx 396 movq TD_PCB(%rcx), %rcx 397 movq $0,PCB_ONFAULT(%rcx) 398 ret 399END(std_swapu32) 400 401/* 402 * casu64 - Compare and set user word. Returns -1 or the current value. 403 * dst = %rdi, old = %rsi, new = %rdx 404 */ 405ENTRY(casu64) 406 movq PCPU(curthread),%rcx 407 movq TD_PCB(%rcx), %rcx 408 movq $fusufault,PCB_ONFAULT(%rcx) 409 movq %rsp,PCB_ONFAULT_SP(%rcx) 410 411 movq $VM_MAX_USER_ADDRESS-8,%rax 412 cmpq %rax,%rdi /* verify address is valid */ 413 ja fusufault 414 415 movq %rsi,%rax /* old */ 416 lock 417 cmpxchgq %rdx,(%rdi) /* new = %rdx */ 418 419 /* 420 * The old value is in %rax. If the store succeeded it will be the 421 * value we expected (old) from before the store, otherwise it will 422 * be the current value. 423 */ 424 425 movq PCPU(curthread),%rcx 426 movq TD_PCB(%rcx), %rcx 427 movq $0,PCB_ONFAULT(%rcx) 428 ret 429END(casu64) 430 431/* 432 * swapu64 - Swap long in user space. ptr = %rdi, val = %rsi 433 */ 434ENTRY(std_swapu64) 435 movq PCPU(curthread),%rcx 436 movq TD_PCB(%rcx), %rcx 437 movq $fusufault,PCB_ONFAULT(%rcx) 438 movq %rsp,PCB_ONFAULT_SP(%rcx) 439 440 movq $VM_MAX_USER_ADDRESS-8,%rax 441 cmpq %rax,%rdi /* verify address is valid */ 442 ja fusufault 443 444 movq %rsi,%rax /* old */ 445 xchgq %rax,(%rdi) 446 447 /* 448 * The old value is in %rax. If the store succeeded it will be the 449 * value we expected (old) from before the store, otherwise it will 450 * be the current value. 451 */ 452 453 movq PCPU(curthread),%rcx 454 movq TD_PCB(%rcx), %rcx 455 movq $0,PCB_ONFAULT(%rcx) 456 ret 457END(std_swapu64) 458 459/* 460 * Fetch (load) a 64-bit word, a 32-bit word, a 16-bit word, or an 8-bit 461 * byte from user memory. All these functions are MPSAFE. 462 * addr = %rdi 463 */ 464 465ENTRY(std_fuword64) 466 movq PCPU(curthread),%rcx 467 movq TD_PCB(%rcx), %rcx 468 movq $fusufault,PCB_ONFAULT(%rcx) 469 movq %rsp,PCB_ONFAULT_SP(%rcx) 470 471 movq $VM_MAX_USER_ADDRESS-8,%rax 472 cmpq %rax,%rdi /* verify address is valid */ 473 ja fusufault 474 475 movq (%rdi),%rax 476 movq $0,PCB_ONFAULT(%rcx) 477 ret 478END(std_fuword64) 479 480ENTRY(std_fuword32) 481 movq PCPU(curthread),%rcx 482 movq TD_PCB(%rcx), %rcx 483 movq $fusufault,PCB_ONFAULT(%rcx) 484 movq %rsp,PCB_ONFAULT_SP(%rcx) 485 486 movq $VM_MAX_USER_ADDRESS-4,%rax 487 cmpq %rax,%rdi /* verify address is valid */ 488 ja fusufault 489 490 movl (%rdi),%eax 491 movq $0,PCB_ONFAULT(%rcx) 492 ret 493END(std_fuword32) 494 495ENTRY(std_fubyte) 496 movq PCPU(curthread),%rcx 497 movq TD_PCB(%rcx), %rcx 498 movq $fusufault,PCB_ONFAULT(%rcx) 499 movq %rsp,PCB_ONFAULT_SP(%rcx) 500 501 movq $VM_MAX_USER_ADDRESS-1,%rax 502 cmpq %rax,%rdi 503 ja fusufault 504 505 movzbl (%rdi),%eax 506 movq $0,PCB_ONFAULT(%rcx) 507 ret 508 509 ALIGN_TEXT 510fusufault: 511 movq PCPU(curthread),%rcx 512 xorl %eax,%eax 513 movq TD_PCB(%rcx), %rcx 514 movq %rax,PCB_ONFAULT(%rcx) 515 decq %rax 516 ret 517END(std_fubyte) 518 519/* 520 * Store a 64-bit word, a 32-bit word, a 16-bit word, or an 8-bit byte to 521 * user memory. All these functions are MPSAFE. 522 * 523 * addr = %rdi, value = %rsi 524 * 525 * Write a long 526 */ 527ENTRY(std_suword64) 528 movq PCPU(curthread),%rcx 529 movq TD_PCB(%rcx), %rcx 530 movq $fusufault,PCB_ONFAULT(%rcx) 531 movq %rsp,PCB_ONFAULT_SP(%rcx) 532 533 movq $VM_MAX_USER_ADDRESS-8,%rax 534 cmpq %rax,%rdi /* verify address validity */ 535 ja fusufault 536 537 movq %rsi,(%rdi) 538 xorl %eax,%eax 539 movq PCPU(curthread),%rcx 540 movq TD_PCB(%rcx), %rcx 541 movq %rax,PCB_ONFAULT(%rcx) 542 ret 543END(std_suword64) 544 545/* 546 * Write an int 547 */ 548ENTRY(std_suword32) 549 movq PCPU(curthread),%rcx 550 movq TD_PCB(%rcx), %rcx 551 movq $fusufault,PCB_ONFAULT(%rcx) 552 movq %rsp,PCB_ONFAULT_SP(%rcx) 553 554 movq $VM_MAX_USER_ADDRESS-4,%rax 555 cmpq %rax,%rdi /* verify address validity */ 556 ja fusufault 557 558 movl %esi,(%rdi) 559 xorl %eax,%eax 560 movq PCPU(curthread),%rcx 561 movq TD_PCB(%rcx), %rcx 562 movq %rax,PCB_ONFAULT(%rcx) 563 ret 564END(std_suword32) 565 566ENTRY(std_subyte) 567 movq PCPU(curthread),%rcx 568 movq TD_PCB(%rcx), %rcx 569 movq $fusufault,PCB_ONFAULT(%rcx) 570 movq %rsp,PCB_ONFAULT_SP(%rcx) 571 572 movq $VM_MAX_USER_ADDRESS-1,%rax 573 cmpq %rax,%rdi /* verify address validity */ 574 ja fusufault 575 576 movl %esi,%eax 577 movb %al,(%rdi) 578 xorl %eax,%eax 579 movq PCPU(curthread),%rcx /* restore trashed register */ 580 movq TD_PCB(%rcx), %rcx 581 movq %rax,PCB_ONFAULT(%rcx) 582 ret 583END(std_subyte) 584 585/* 586 * std_copyinstr(from, to, maxlen, int *lencopied) - MP SAFE 587 * %rdi, %rsi, %rdx, %rcx 588 * 589 * copy a string from from to to, stop when a 0 character is reached. 590 * return ENAMETOOLONG if string is longer than maxlen, and 591 * EFAULT on protection violations. If lencopied is non-zero, 592 * return the actual length in *lencopied. 593 */ 594ENTRY(std_copyinstr) 595 movq %rdx,%r8 /* %r8 = maxlen */ 596 movq %rcx,%r9 /* %r9 = *len */ 597 xchgq %rdi,%rsi /* %rdi = from, %rsi = to */ 598 movq PCPU(curthread),%rcx 599 movq TD_PCB(%rcx), %rcx 600 movq $cpystrflt,PCB_ONFAULT(%rcx) 601 movq %rsp,PCB_ONFAULT_SP(%rcx) 602 603 movq $VM_MAX_USER_ADDRESS,%rax 604 605 /* make sure 'from' is within bounds */ 606 subq %rsi,%rax 607 jbe cpystrflt 608 609 /* restrict maxlen to <= VM_MAX_USER_ADDRESS-from */ 610 cmpq %rdx,%rax 611 jae 1f 612 movq %rax,%rdx 613 movq %rax,%r8 6141: 615 incq %rdx 616 cld 617 6182: 619 decq %rdx 620 jz 3f 621 622 lodsb 623 stosb 624 orb %al,%al 625 jnz 2b 626 627 /* Success -- 0 byte reached */ 628 decq %rdx 629 xorl %eax,%eax 630 jmp cpystrflt_x 6313: 632 /* rdx is zero - return ENAMETOOLONG or EFAULT */ 633 movq $VM_MAX_USER_ADDRESS,%rax 634 cmpq %rax,%rsi 635 jae cpystrflt 6364: 637 movq $ENAMETOOLONG,%rax 638 jmp cpystrflt_x 639 640cpystrflt: 641 movq $EFAULT,%rax 642 643cpystrflt_x: 644 /* set *lencopied and return %eax */ 645 movq PCPU(curthread),%rcx 646 movq TD_PCB(%rcx), %rcx 647 movq $0,PCB_ONFAULT(%rcx) 648 649 testq %r9,%r9 650 jz 1f 651 subq %rdx,%r8 652 movq %r8,(%r9) 6531: 654 ret 655END(std_copyinstr) 656 657/* 658 * copystr(from, to, maxlen, int *lencopied) - MP SAFE 659 * %rdi, %rsi, %rdx, %rcx 660 */ 661ENTRY(copystr) 662 movq %rdx,%r8 /* %r8 = maxlen */ 663 664 xchgq %rdi,%rsi 665 incq %rdx 666 cld 6671: 668 decq %rdx 669 jz 4f 670 lodsb 671 stosb 672 orb %al,%al 673 jnz 1b 674 675 /* Success -- 0 byte reached */ 676 decq %rdx 677 xorl %eax,%eax 678 jmp 6f 6794: 680 /* rdx is zero -- return ENAMETOOLONG */ 681 movq $ENAMETOOLONG,%rax 682 6836: 684 685 testq %rcx,%rcx 686 jz 7f 687 /* set *lencopied and return %rax */ 688 subq %rdx,%r8 689 movq %r8,(%rcx) 6907: 691 ret 692END(copystr) 693 694/* 695 * Handling of special x86_64 registers and descriptor tables etc 696 * %rdi 697 */ 698/* void lgdt(struct region_descriptor *rdp); */ 699ENTRY(lgdt) 700 /* reload the descriptor table */ 701 lgdt (%rdi) 702 703 /* flush the prefetch q */ 704 jmp 1f 705 nop 7061: 707 movl $KDSEL,%eax 708 movl %eax,%ds 709 movl %eax,%es 710 movl %eax,%fs /* Beware, use wrmsr to set 64 bit base */ 711 movl %eax,%gs /* Beware, use wrmsr to set 64 bit base */ 712 movl %eax,%ss 713 714 /* reload code selector by turning return into intersegmental return */ 715 popq %rax 716 pushq $KCSEL 717 pushq %rax 718 MEXITCOUNT 719 lretq 720END(lgdt) 721 722/*****************************************************************************/ 723/* setjmp, longjmp */ 724/*****************************************************************************/ 725 726ENTRY(setjmp) 727 movq %rbx,0(%rdi) /* save rbx */ 728 movq %rsp,8(%rdi) /* save rsp */ 729 movq %rbp,16(%rdi) /* save rbp */ 730 movq %r12,24(%rdi) /* save r12 */ 731 movq %r13,32(%rdi) /* save r13 */ 732 movq %r14,40(%rdi) /* save r14 */ 733 movq %r15,48(%rdi) /* save r15 */ 734 movq 0(%rsp),%rdx /* get rta */ 735 movq %rdx,56(%rdi) /* save rip */ 736 xorl %eax,%eax /* return(0); */ 737 ret 738END(setjmp) 739 740ENTRY(longjmp) 741 movq 0(%rdi),%rbx /* restore rbx */ 742 movq 8(%rdi),%rsp /* restore rsp */ 743 movq 16(%rdi),%rbp /* restore rbp */ 744 movq 24(%rdi),%r12 /* restore r12 */ 745 movq 32(%rdi),%r13 /* restore r13 */ 746 movq 40(%rdi),%r14 /* restore r14 */ 747 movq 48(%rdi),%r15 /* restore r15 */ 748 movq 56(%rdi),%rdx /* get rta */ 749 movq %rdx,0(%rsp) /* put in return frame */ 750 xorl %eax,%eax /* return(1); */ 751 incl %eax 752 ret 753END(longjmp) 754 755/* 756 * Support for reading MSRs in the safe manner. 757 */ 758ENTRY(rdmsr_safe) 759/* int rdmsr_safe(u_int msr, uint64_t *data) */ 760 movq PCPU(curthread),%r8 761 movq TD_PCB(%r8), %r8 762 movq $msr_onfault,PCB_ONFAULT(%r8) 763 movq %rsp,PCB_ONFAULT_SP(%r8) 764 movl %edi,%ecx 765 rdmsr /* Read MSR pointed by %ecx. Returns 766 hi byte in edx, lo in %eax */ 767 salq $32,%rdx /* sign-shift %rdx left */ 768 movl %eax,%eax /* zero-extend %eax -> %rax */ 769 orq %rdx,%rax 770 movq %rax,(%rsi) 771 xorq %rax,%rax 772 movq %rax,PCB_ONFAULT(%r8) 773 ret 774END(rdmsr_safe) 775 776/* 777 * Support for writing MSRs in the safe manner. 778 */ 779ENTRY(wrmsr_safe) 780/* int wrmsr_safe(u_int msr, uint64_t data) */ 781 movq PCPU(curthread),%r8 782 movq TD_PCB(%r8), %r8 783 movq $msr_onfault,PCB_ONFAULT(%r8) 784 movq %rsp,PCB_ONFAULT_SP(%r8) 785 movl %edi,%ecx 786 movl %esi,%eax 787 sarq $32,%rsi 788 movl %esi,%edx 789 wrmsr /* Write MSR pointed by %ecx. Accepts 790 hi byte in edx, lo in %eax. */ 791 xorq %rax,%rax 792 movq %rax,PCB_ONFAULT(%r8) 793 ret 794END(wrmsr_safe) 795 796/* 797 * MSR operations fault handler 798 */ 799 ALIGN_TEXT 800msr_onfault: 801 movq PCPU(curthread),%r8 802 movq TD_PCB(%r8), %r8 803 movq $0,PCB_ONFAULT(%r8) 804 movl $EFAULT,%eax 805 ret 806