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 * 4. 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 * bcopy family 45 * void bzero(void *buf, size_t len) 46 */ 47 48/* done */ 49ENTRY(bzero) 50 movq %rsi,%rcx 51 xorl %eax,%eax 52 shrq $3,%rcx 53 cld 54 rep 55 stosq 56 movq %rsi,%rcx 57 andq $7,%rcx 58 rep 59 stosb 60 ret 61 62/* Address: %rdi */ 63ENTRY(pagezero) 64 movq $-PAGE_SIZE,%rdx 65 subq %rdx,%rdi 66 xorl %eax,%eax 671: 68 movq %rax,(%rdi,%rdx) /* movnti */ 69 movq %rax,8(%rdi,%rdx) /* movnti */ 70 movq %rax,16(%rdi,%rdx) /* movnti */ 71 movq %rax,24(%rdi,%rdx) /* movnti */ 72 addq $32,%rdx 73 jne 1b 74 /*sfence*/ 75 ret 76 77ENTRY(bcmp) 78 movq %rdx,%rcx 79 shrq $3,%rcx 80 cld /* compare forwards */ 81 repe 82 cmpsq 83 jne 1f 84 85 movq %rdx,%rcx 86 andq $7,%rcx 87 repe 88 cmpsb 891: 90 setne %al 91 movsbl %al,%eax 92 ret 93 94/* 95 * bcopy(src, dst, cnt) 96 * rdi, rsi, rdx 97 * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800 98 */ 99ENTRY(generic_bcopy) /* generic_bcopy is bcopy without FPU */ 100ENTRY(ovbcopy) /* our bcopy doesn't use the FPU, so ovbcopy is the same */ 101ENTRY(bcopy) 102 xchgq %rsi,%rdi 103 movq %rdx,%rcx 104 105 movq %rdi,%rax 106 subq %rsi,%rax 107 cmpq %rcx,%rax /* overlapping && src < dst? */ 108 jb 1f 109 110 shrq $3,%rcx /* copy by 64-bit words */ 111 cld /* nope, copy forwards */ 112 rep 113 movsq 114 movq %rdx,%rcx 115 andq $7,%rcx /* any bytes left? */ 116 rep 117 movsb 118 ret 119 120 /* ALIGN_TEXT */ 1211: 122 addq %rcx,%rdi /* copy backwards */ 123 addq %rcx,%rsi 124 decq %rdi 125 decq %rsi 126 andq $7,%rcx /* any fractional bytes? */ 127 std 128 rep 129 movsb 130 movq %rdx,%rcx /* copy remainder by 32-bit words */ 131 shrq $3,%rcx 132 subq $7,%rsi 133 subq $7,%rdi 134 rep 135 movsq 136 cld 137 ret 138ENTRY(reset_dbregs) 139 movq $0x200,%rax /* the manual says that bit 10 must be set to 1 */ 140 movq %rax,%dr7 /* disable all breapoints first */ 141 movq $0,%rax 142 movq %rax,%dr0 143 movq %rax,%dr1 144 movq %rax,%dr2 145 movq %rax,%dr3 146 movq %rax,%dr6 147 ret 148 149/* 150 * Note: memcpy does not support overlapping copies 151 */ 152ENTRY(memcpy) 153 movq %rdx,%rcx 154 shrq $3,%rcx /* copy by 64-bit words */ 155 cld /* copy forwards */ 156 rep 157 movsq 158 movq %rdx,%rcx 159 andq $7,%rcx /* any bytes left? */ 160 rep 161 movsb 162 ret 163 164/* 165 * pagecopy(%rdi=from, %rsi=to) 166 */ 167ENTRY(pagecopy) 168 movq $-PAGE_SIZE,%rax 169 movq %rax,%rdx 170 subq %rax,%rdi 171 subq %rax,%rsi 1721: 173 /*prefetchnta (%rdi,%rax)*/ 174 /*addq $64,%rax*/ 175 /*jne 1b*/ 1762: 177 movq (%rdi,%rdx),%rax 178 movq %rax,(%rsi,%rdx) /* movnti */ 179 movq 8(%rdi,%rdx),%rax 180 movq %rax,8(%rsi,%rdx) /* movnti */ 181 movq 16(%rdi,%rdx),%rax 182 movq %rax,16(%rsi,%rdx) /* movnti */ 183 movq 24(%rdi,%rdx),%rax 184 movq %rax,24(%rsi,%rdx) /* movnti */ 185 addq $32,%rdx 186 jne 2b 187 /*sfence*/ 188 ret 189 190/* fillw(pat, base, cnt) */ 191/* %rdi,%rsi, %rdx */ 192ENTRY(fillw) 193 movq %rdi,%rax 194 movq %rsi,%rdi 195 movq %rdx,%rcx 196 cld 197 rep 198 stosw 199 ret 200 201/*****************************************************************************/ 202/* copyout and fubyte family */ 203/*****************************************************************************/ 204/* 205 * Access user memory from inside the kernel. These routines should be 206 * the only places that do this. 207 * 208 * These routines set curpcb->onfault for the time they execute. When a 209 * protection violation occurs inside the functions, the trap handler 210 * returns to *curpcb->onfault instead of the function. 211 */ 212 213/* 214 * std_copyout(from_kernel, to_user, len) - MP SAFE 215 * %rdi, %rsi, %rdx 216 */ 217ENTRY(std_copyout) 218 movq PCPU(curthread),%rax 219 movq TD_PCB(%rax), %rax 220 movq $copyout_fault,PCB_ONFAULT(%rax) 221 movq %rsp,PCB_ONFAULT_SP(%rax) 222 testq %rdx,%rdx /* anything to do? */ 223 jz done_copyout 224 225 /* 226 * Check explicitly for non-user addresses. If 486 write protection 227 * is being used, this check is essential because we are in kernel 228 * mode so the h/w does not provide any protection against writing 229 * kernel addresses. 230 */ 231 232 /* 233 * First, prevent address wrapping. 234 */ 235 movq %rsi,%rax 236 addq %rdx,%rax 237 jc copyout_fault 238/* 239 * XXX STOP USING VM_MAX_USER_ADDRESS. 240 * It is an end address, not a max, so every time it is used correctly it 241 * looks like there is an off by one error, and of course it caused an off 242 * by one error in several places. 243 */ 244 movq $VM_MAX_USER_ADDRESS,%rcx 245 cmpq %rcx,%rax 246 ja copyout_fault 247 248 xchgq %rdi,%rsi 249 /* bcopy(%rsi, %rdi, %rdx) */ 250 movq %rdx,%rcx 251 252 shrq $3,%rcx 253 cld 254 rep 255 movsq 256 movb %dl,%cl 257 andb $7,%cl 258 rep 259 movsb 260 261done_copyout: 262 xorl %eax,%eax 263 movq PCPU(curthread),%rdx 264 movq TD_PCB(%rdx), %rdx 265 movq %rax,PCB_ONFAULT(%rdx) 266 ret 267 268 ALIGN_TEXT 269copyout_fault: 270 movq PCPU(curthread),%rdx 271 movq TD_PCB(%rdx), %rdx 272 movq $0,PCB_ONFAULT(%rdx) 273 movq $EFAULT,%rax 274 ret 275 276/* 277 * std_copyin(from_user, to_kernel, len) - MP SAFE 278 * %rdi, %rsi, %rdx 279 */ 280ENTRY(std_copyin) 281 movq PCPU(curthread),%rax 282 movq TD_PCB(%rax), %rax 283 movq $copyin_fault,PCB_ONFAULT(%rax) 284 movq %rsp,PCB_ONFAULT_SP(%rax) 285 testq %rdx,%rdx /* anything to do? */ 286 jz done_copyin 287 288 /* 289 * make sure address is valid 290 */ 291 movq %rdi,%rax 292 addq %rdx,%rax 293 jc copyin_fault 294 movq $VM_MAX_USER_ADDRESS,%rcx 295 cmpq %rcx,%rax 296 ja copyin_fault 297 298 xchgq %rdi,%rsi 299 movq %rdx,%rcx 300 movb %cl,%al 301 shrq $3,%rcx /* copy longword-wise */ 302 cld 303 rep 304 movsq 305 movb %al,%cl 306 andb $7,%cl /* copy remaining bytes */ 307 rep 308 movsb 309 310done_copyin: 311 xorl %eax,%eax 312 movq PCPU(curthread),%rdx 313 movq TD_PCB(%rdx), %rdx 314 movq %rax,PCB_ONFAULT(%rdx) 315 ret 316 317 ALIGN_TEXT 318copyin_fault: 319 movq PCPU(curthread),%rdx 320 movq TD_PCB(%rdx), %rdx 321 movq $0,PCB_ONFAULT(%rdx) 322 movq $EFAULT,%rax 323 ret 324 325/* 326 * casuword32. Compare and set user integer. Returns -1 or the current value. 327 * dst = %rdi, old = %rsi, new = %rdx 328 */ 329ENTRY(casuword32) 330 movq PCPU(curthread),%rcx 331 movq TD_PCB(%rcx), %rcx 332 movq $fusufault,PCB_ONFAULT(%rcx) 333 movq %rsp,PCB_ONFAULT_SP(%rcx) 334 335 movq $VM_MAX_USER_ADDRESS-4,%rax 336 cmpq %rax,%rdi /* verify address is valid */ 337 ja fusufault 338 339 movl %esi,%eax /* old */ 340 lock 341 cmpxchgl %edx,(%rdi) /* new = %edx */ 342 343 /* 344 * The old value is in %eax. If the store succeeded it will be the 345 * value we expected (old) from before the store, otherwise it will 346 * be the current value. 347 */ 348 349 movq PCPU(curthread),%rcx 350 movq TD_PCB(%rcx), %rcx 351 movq $0,PCB_ONFAULT(%rcx) 352 ret 353 354/* 355 * casuword. Compare and set user word. Returns -1 or the current value. 356 * dst = %rdi, old = %rsi, new = %rdx 357 */ 358ENTRY(casuword) 359 movq PCPU(curthread),%rcx 360 movq TD_PCB(%rcx), %rcx 361 movq $fusufault,PCB_ONFAULT(%rcx) 362 movq %rsp,PCB_ONFAULT_SP(%rcx) 363 364 movq $VM_MAX_USER_ADDRESS-8,%rax 365 cmpq %rax,%rdi /* verify address is valid */ 366 ja fusufault 367 368 movq %rsi,%rax /* old */ 369 lock 370 cmpxchgq %rdx,(%rdi) /* new = %rdx */ 371 372 /* 373 * The old value is in %rax. If the store succeeded it will be the 374 * value we expected (old) from before the store, otherwise it will 375 * be the current value. 376 */ 377 378 movq PCPU(curthread),%rcx 379 movq TD_PCB(%rcx), %rcx 380 movq $0,PCB_ONFAULT(%rcx) 381 ret 382 383/* 384 * Fetch (load) a 64-bit word, a 32-bit word, a 16-bit word, or an 8-bit 385 * byte from user memory. All these functions are MPSAFE. 386 * addr = %rdi 387 */ 388 389ALTENTRY(fuword64) 390ENTRY(std_fuword) 391 movq PCPU(curthread),%rcx 392 movq TD_PCB(%rcx), %rcx 393 movq $fusufault,PCB_ONFAULT(%rcx) 394 movq %rsp,PCB_ONFAULT_SP(%rcx) 395 396 movq $VM_MAX_USER_ADDRESS-8,%rax 397 cmpq %rax,%rdi /* verify address is valid */ 398 ja fusufault 399 400 movq (%rdi),%rax 401 movq $0,PCB_ONFAULT(%rcx) 402 ret 403 404ENTRY(fuword32) 405 movq PCPU(curthread),%rcx 406 movq TD_PCB(%rcx), %rcx 407 movq $fusufault,PCB_ONFAULT(%rcx) 408 movq %rsp,PCB_ONFAULT_SP(%rcx) 409 410 movq $VM_MAX_USER_ADDRESS-4,%rax 411 cmpq %rax,%rdi /* verify address is valid */ 412 ja fusufault 413 414 movl (%rdi),%eax 415 movq $0,PCB_ONFAULT(%rcx) 416 ret 417 418/* 419 * fuswintr() and suswintr() are specialized variants of fuword16() and 420 * suword16(), respectively. They are called from the profiling code, 421 * potentially at interrupt time. If they fail, that's okay; good things 422 * will happen later. They always fail for now, until the trap code is 423 * able to deal with this. 424 */ 425ALTENTRY(suswintr) 426ENTRY(fuswintr) 427 movq $-1,%rax 428 ret 429 430ENTRY(fuword16) 431 movq PCPU(curthread),%rcx 432 movq TD_PCB(%rcx), %rcx 433 movq $fusufault,PCB_ONFAULT(%rcx) 434 movq %rsp,PCB_ONFAULT_SP(%rcx) 435 436 movq $VM_MAX_USER_ADDRESS-2,%rax 437 cmpq %rax,%rdi 438 ja fusufault 439 440 movzwl (%rdi),%eax 441 movq $0,PCB_ONFAULT(%rcx) 442 ret 443 444ENTRY(std_fubyte) 445 movq PCPU(curthread),%rcx 446 movq TD_PCB(%rcx), %rcx 447 movq $fusufault,PCB_ONFAULT(%rcx) 448 movq %rsp,PCB_ONFAULT_SP(%rcx) 449 450 movq $VM_MAX_USER_ADDRESS-1,%rax 451 cmpq %rax,%rdi 452 ja fusufault 453 454 movzbl (%rdi),%eax 455 movq $0,PCB_ONFAULT(%rcx) 456 ret 457 458 ALIGN_TEXT 459fusufault: 460 movq PCPU(curthread),%rcx 461 xorl %eax,%eax 462 movq TD_PCB(%rcx), %rcx 463 movq %rax,PCB_ONFAULT(%rcx) 464 decq %rax 465 ret 466 467/* 468 * Store a 64-bit word, a 32-bit word, a 16-bit word, or an 8-bit byte to 469 * user memory. All these functions are MPSAFE. 470 * 471 * addr = %rdi, value = %rsi 472 * 473 * Write a long 474 */ 475ALTENTRY(suword64) 476ENTRY(std_suword) 477 movq PCPU(curthread),%rcx 478 movq TD_PCB(%rcx), %rcx 479 movq $fusufault,PCB_ONFAULT(%rcx) 480 movq %rsp,PCB_ONFAULT_SP(%rcx) 481 482 movq $VM_MAX_USER_ADDRESS-8,%rax 483 cmpq %rax,%rdi /* verify address validity */ 484 ja fusufault 485 486 movq %rsi,(%rdi) 487 xorl %eax,%eax 488 movq PCPU(curthread),%rcx 489 movq TD_PCB(%rcx), %rcx 490 movq %rax,PCB_ONFAULT(%rcx) 491 ret 492 493/* 494 * Write an int 495 */ 496ENTRY(std_suword32) 497 movq PCPU(curthread),%rcx 498 movq TD_PCB(%rcx), %rcx 499 movq $fusufault,PCB_ONFAULT(%rcx) 500 movq %rsp,PCB_ONFAULT_SP(%rcx) 501 502 movq $VM_MAX_USER_ADDRESS-4,%rax 503 cmpq %rax,%rdi /* verify address validity */ 504 ja fusufault 505 506 movl %esi,(%rdi) 507 xorl %eax,%eax 508 movq PCPU(curthread),%rcx 509 movq TD_PCB(%rcx), %rcx 510 movq %rax,PCB_ONFAULT(%rcx) 511 ret 512 513ENTRY(suword16) 514 movq PCPU(curthread),%rcx 515 movq TD_PCB(%rcx), %rcx 516 movq $fusufault,PCB_ONFAULT(%rcx) 517 movq %rsp,PCB_ONFAULT_SP(%rcx) 518 519 movq $VM_MAX_USER_ADDRESS-2,%rax 520 cmpq %rax,%rdi /* verify address validity */ 521 ja fusufault 522 523 movw %si,(%rdi) 524 xorl %eax,%eax 525 movq PCPU(curthread),%rcx /* restore trashed register */ 526 movq TD_PCB(%rcx), %rcx 527 movq %rax,PCB_ONFAULT(%rcx) 528 ret 529 530ENTRY(std_subyte) 531 movq PCPU(curthread),%rcx 532 movq TD_PCB(%rcx), %rcx 533 movq $fusufault,PCB_ONFAULT(%rcx) 534 movq %rsp,PCB_ONFAULT_SP(%rcx) 535 536 movq $VM_MAX_USER_ADDRESS-1,%rax 537 cmpq %rax,%rdi /* verify address validity */ 538 ja fusufault 539 540 movl %esi,%eax 541 movb %al,(%rdi) 542 xorl %eax,%eax 543 movq PCPU(curthread),%rcx /* restore trashed register */ 544 movq TD_PCB(%rcx), %rcx 545 movq %rax,PCB_ONFAULT(%rcx) 546 ret 547 548/* 549 * std_copyinstr(from, to, maxlen, int *lencopied) - MP SAFE 550 * %rdi, %rsi, %rdx, %rcx 551 * 552 * copy a string from from to to, stop when a 0 character is reached. 553 * return ENAMETOOLONG if string is longer than maxlen, and 554 * EFAULT on protection violations. If lencopied is non-zero, 555 * return the actual length in *lencopied. 556 */ 557ENTRY(std_copyinstr) 558 movq %rdx,%r8 /* %r8 = maxlen */ 559 movq %rcx,%r9 /* %r9 = *len */ 560 xchgq %rdi,%rsi /* %rdi = from, %rsi = to */ 561 movq PCPU(curthread),%rcx 562 movq TD_PCB(%rcx), %rcx 563 movq $cpystrflt,PCB_ONFAULT(%rcx) 564 movq %rsp,PCB_ONFAULT_SP(%rcx) 565 566 movq $VM_MAX_USER_ADDRESS,%rax 567 568 /* make sure 'from' is within bounds */ 569 subq %rsi,%rax 570 jbe cpystrflt 571 572 /* restrict maxlen to <= VM_MAX_USER_ADDRESS-from */ 573 cmpq %rdx,%rax 574 jae 1f 575 movq %rax,%rdx 576 movq %rax,%r8 5771: 578 incq %rdx 579 cld 580 5812: 582 decq %rdx 583 jz 3f 584 585 lodsb 586 stosb 587 orb %al,%al 588 jnz 2b 589 590 /* Success -- 0 byte reached */ 591 decq %rdx 592 xorl %eax,%eax 593 jmp cpystrflt_x 5943: 595 /* rdx is zero - return ENAMETOOLONG or EFAULT */ 596 movq $VM_MAX_USER_ADDRESS,%rax 597 cmpq %rax,%rsi 598 jae cpystrflt 5994: 600 movq $ENAMETOOLONG,%rax 601 jmp cpystrflt_x 602 603cpystrflt: 604 movq $EFAULT,%rax 605 606cpystrflt_x: 607 /* set *lencopied and return %eax */ 608 movq PCPU(curthread),%rcx 609 movq TD_PCB(%rcx), %rcx 610 movq $0,PCB_ONFAULT(%rcx) 611 612 testq %r9,%r9 613 jz 1f 614 subq %rdx,%r8 615 movq %r8,(%r9) 6161: 617 ret 618 619 620/* 621 * copystr(from, to, maxlen, int *lencopied) - MP SAFE 622 * %rdi, %rsi, %rdx, %rcx 623 */ 624ENTRY(copystr) 625 movq %rdx,%r8 /* %r8 = maxlen */ 626 627 xchgq %rdi,%rsi 628 incq %rdx 629 cld 6301: 631 decq %rdx 632 jz 4f 633 lodsb 634 stosb 635 orb %al,%al 636 jnz 1b 637 638 /* Success -- 0 byte reached */ 639 decq %rdx 640 xorl %eax,%eax 641 jmp 6f 6424: 643 /* rdx is zero -- return ENAMETOOLONG */ 644 movq $ENAMETOOLONG,%rax 645 6466: 647 648 testq %rcx,%rcx 649 jz 7f 650 /* set *lencopied and return %rax */ 651 subq %rdx,%r8 652 movq %r8,(%rcx) 6537: 654 ret 655 656/* 657 * Handling of special x86_64 registers and descriptor tables etc 658 * %rdi 659 */ 660/* void lgdt(struct region_descriptor *rdp); */ 661ENTRY(lgdt) 662 /* reload the descriptor table */ 663 lgdt (%rdi) 664 665 /* flush the prefetch q */ 666 jmp 1f 667 nop 6681: 669 movl $KDSEL,%eax 670 movl %eax,%ds 671 movl %eax,%es 672 movl %eax,%fs /* Beware, use wrmsr to set 64 bit base */ 673 movl %eax,%gs /* Beware, use wrmsr to set 64 bit base */ 674 movl %eax,%ss 675 676 /* reload code selector by turning return into intersegmental return */ 677 popq %rax 678 pushq $KCSEL 679 pushq %rax 680 MEXITCOUNT 681 lretq 682 683/*****************************************************************************/ 684/* setjmp, longjmp */ 685/*****************************************************************************/ 686 687ENTRY(setjmp) 688 movq %rbx,0(%rdi) /* save rbx */ 689 movq %rsp,8(%rdi) /* save rsp */ 690 movq %rbp,16(%rdi) /* save rbp */ 691 movq %r12,24(%rdi) /* save r12 */ 692 movq %r13,32(%rdi) /* save r13 */ 693 movq %r14,40(%rdi) /* save r14 */ 694 movq %r15,48(%rdi) /* save r15 */ 695 movq 0(%rsp),%rdx /* get rta */ 696 movq %rdx,56(%rdi) /* save rip */ 697 xorl %eax,%eax /* return(0); */ 698 ret 699 700ENTRY(longjmp) 701 movq 0(%rdi),%rbx /* restore rbx */ 702 movq 8(%rdi),%rsp /* restore rsp */ 703 movq 16(%rdi),%rbp /* restore rbp */ 704 movq 24(%rdi),%r12 /* restore r12 */ 705 movq 32(%rdi),%r13 /* restore r13 */ 706 movq 40(%rdi),%r14 /* restore r14 */ 707 movq 48(%rdi),%r15 /* restore r15 */ 708 movq 56(%rdi),%rdx /* get rta */ 709 movq %rdx,0(%rsp) /* put in return frame */ 710 xorl %eax,%eax /* return(1); */ 711 incl %eax 712 ret 713 714/* 715 * Support for reading MSRs in the safe manner. 716 */ 717ENTRY(rdmsr_safe) 718/* int rdmsr_safe(u_int msr, uint64_t *data) */ 719 movq PCPU(curthread),%r8 720 movq TD_PCB(%r8), %r8 721 movq $msr_onfault,PCB_ONFAULT(%r8) 722 movq %rsp,PCB_ONFAULT_SP(%r8) 723 movl %edi,%ecx 724 rdmsr /* Read MSR pointed by %ecx. Returns 725 hi byte in edx, lo in %eax */ 726 salq $32,%rdx /* sign-shift %rdx left */ 727 movl %eax,%eax /* zero-extend %eax -> %rax */ 728 orq %rdx,%rax 729 movq %rax,(%rsi) 730 xorq %rax,%rax 731 movq %rax,PCB_ONFAULT(%r8) 732 ret 733 734/* 735 * Support for writing MSRs in the safe manner. 736 */ 737ENTRY(wrmsr_safe) 738/* int wrmsr_safe(u_int msr, uint64_t data) */ 739 movq PCPU(curthread),%r8 740 movq TD_PCB(%r8), %r8 741 movq $msr_onfault,PCB_ONFAULT(%r8) 742 movq %rsp,PCB_ONFAULT_SP(%rcx) 743 movl %edi,%ecx 744 movl %esi,%eax 745 sarq $32,%rsi 746 movl %esi,%edx 747 wrmsr /* Write MSR pointed by %ecx. Accepts 748 hi byte in edx, lo in %eax. */ 749 xorq %rax,%rax 750 movq %rax,PCB_ONFAULT(%r8) 751 ret 752 753/* 754 * MSR operations fault handler 755 */ 756 ALIGN_TEXT 757msr_onfault: 758 movq PCPU(curthread),%r8 759 movq TD_PCB(%r8), %r8 760 movq $0,PCB_ONFAULT(%r8) 761 movl $EFAULT,%eax 762 ret 763 764/* 765 * Support for BB-profiling (gcc -a). The kernbb program will extract 766 * the data from the kernel. 767 */ 768 769 .data 770 ALIGN_DATA 771 .globl bbhead 772bbhead: 773 .quad 0 774 775 .text 776NON_GPROF_ENTRY(__bb_init_func) 777 movq $1,(%rdi) 778 movq bbhead,%rax 779 movq %rax,32(%rdi) 780 movq %rdi,bbhead 781 NON_GPROF_RET 782