kernel: Make SMP support default (and non-optional).
[dragonfly.git] / sys / platform / pc64 / x86_64 / support.s
CommitLineData
d7f50089 1/*-
d7f50089 2 * Copyright (c) 1993 The Regents of the University of California.
c8fe38ae
MD
3 * Copyright (c) 2003 Peter Wemm.
4 * Copyright (c) 2008 The DragonFly Project.
d7f50089
YY
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 $
d7f50089
YY
32 */
33
d7f50089 34#include <machine/asmacros.h>
d7f50089
YY
35#include <machine/pmap.h>
36
37#include "assym.s"
38
39 ALIGN_DATA
d7f50089
YY
40
41 .text
42
43/*
44 * bcopy family
121f93bc 45 * void bzero(void *buf, size_t len)
d7f50089
YY
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
d7f50089
YY
62/* Address: %rdi */
63ENTRY(pagezero)
64 movq $-PAGE_SIZE,%rdx
65 subq %rdx,%rdi
66 xorl %eax,%eax
671:
8f901ed8
MD
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 */
d7f50089
YY
72 addq $32,%rdx
73 jne 1b
8f901ed8 74 /*sfence*/
d7f50089
YY
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 */
0855a2af
JG
99ENTRY(generic_bcopy) /* generic_bcopy is bcopy without FPU */
100ENTRY(ovbcopy) /* our bcopy doesn't use the FPU, so ovbcopy is the same */
d7f50089
YY
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
d7f50089 138ENTRY(reset_dbregs)
0855a2af
JG
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
d7f50089
YY
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:
8f901ed8
MD
173 /*prefetchnta (%rdi,%rax)*/
174 /*addq $64,%rax*/
175 /*jne 1b*/
d7f50089
YY
1762:
177 movq (%rdi,%rdx),%rax
8f901ed8 178 movq %rax,(%rsi,%rdx) /* movnti */
d7f50089 179 movq 8(%rdi,%rdx),%rax
8f901ed8 180 movq %rax,8(%rsi,%rdx) /* movnti */
d7f50089 181 movq 16(%rdi,%rdx),%rax
8f901ed8 182 movq %rax,16(%rsi,%rdx) /* movnti */
d7f50089 183 movq 24(%rdi,%rdx),%rax
8f901ed8 184 movq %rax,24(%rsi,%rdx) /* movnti */
d7f50089
YY
185 addq $32,%rdx
186 jne 2b
8f901ed8 187 /*sfence*/
d7f50089
YY
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 * copyout(from_kernel, to_user, len) - MP SAFE
215 * %rdi, %rsi, %rdx
216 */
217ENTRY(copyout)
218 movq PCPU(curthread),%rax
c8fe38ae 219 movq TD_PCB(%rax), %rax
d7f50089 220 movq $copyout_fault,PCB_ONFAULT(%rax)
93ad6da2 221 movq %rsp,PCB_ONFAULT_SP(%rax)
d7f50089
YY
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/*
48ffc236 239 * XXX STOP USING VM_MAX_USER_ADDRESS.
d7f50089
YY
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 */
48ffc236 244 movq $VM_MAX_USER_ADDRESS,%rcx
d7f50089
YY
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
c8fe38ae 264 movq TD_PCB(%rdx), %rdx
d7f50089
YY
265 movq %rax,PCB_ONFAULT(%rdx)
266 ret
267
268 ALIGN_TEXT
269copyout_fault:
270 movq PCPU(curthread),%rdx
c8fe38ae 271 movq TD_PCB(%rdx), %rdx
d7f50089
YY
272 movq $0,PCB_ONFAULT(%rdx)
273 movq $EFAULT,%rax
274 ret
275
276/*
277 * copyin(from_user, to_kernel, len) - MP SAFE
278 * %rdi, %rsi, %rdx
279 */
280ENTRY(copyin)
281 movq PCPU(curthread),%rax
c8fe38ae 282 movq TD_PCB(%rax), %rax
d7f50089 283 movq $copyin_fault,PCB_ONFAULT(%rax)
93ad6da2 284 movq %rsp,PCB_ONFAULT_SP(%rax)
d7f50089
YY
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
48ffc236 294 movq $VM_MAX_USER_ADDRESS,%rcx
d7f50089
YY
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
c8fe38ae 313 movq TD_PCB(%rdx), %rdx
d7f50089
YY
314 movq %rax,PCB_ONFAULT(%rdx)
315 ret
316
317 ALIGN_TEXT
318copyin_fault:
319 movq PCPU(curthread),%rdx
c8fe38ae 320 movq TD_PCB(%rdx), %rdx
d7f50089
YY
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
c8fe38ae 331 movq TD_PCB(%rcx), %rcx
d7f50089 332 movq $fusufault,PCB_ONFAULT(%rcx)
93ad6da2 333 movq %rsp,PCB_ONFAULT_SP(%rcx)
d7f50089 334
48ffc236 335 movq $VM_MAX_USER_ADDRESS-4,%rax
d7f50089
YY
336 cmpq %rax,%rdi /* verify address is valid */
337 ja fusufault
338
339 movl %esi,%eax /* old */
d7f50089 340 lock
d7f50089
YY
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
c8fe38ae 350 movq TD_PCB(%rcx), %rcx
d7f50089
YY
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
c8fe38ae 360 movq TD_PCB(%rcx), %rcx
d7f50089 361 movq $fusufault,PCB_ONFAULT(%rcx)
93ad6da2 362 movq %rsp,PCB_ONFAULT_SP(%rcx)
d7f50089 363
48ffc236 364 movq $VM_MAX_USER_ADDRESS-4,%rax
d7f50089
YY
365 cmpq %rax,%rdi /* verify address is valid */
366 ja fusufault
367
368 movq %rsi,%rax /* old */
d7f50089 369 lock
d7f50089
YY
370 cmpxchgq %rdx,(%rdi) /* new = %rdx */
371
372 /*
373 * The old value is in %eax. 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
c8fe38ae 379 movq TD_PCB(%rcx), %rcx
d7f50089
YY
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(fuword)
391 movq PCPU(curthread),%rcx
c8fe38ae 392 movq TD_PCB(%rcx), %rcx
d7f50089 393 movq $fusufault,PCB_ONFAULT(%rcx)
93ad6da2 394 movq %rsp,PCB_ONFAULT_SP(%rcx)
d7f50089 395
48ffc236 396 movq $VM_MAX_USER_ADDRESS-8,%rax
d7f50089
YY
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
c8fe38ae 406 movq TD_PCB(%rcx), %rcx
d7f50089 407 movq $fusufault,PCB_ONFAULT(%rcx)
93ad6da2 408 movq %rsp,PCB_ONFAULT_SP(%rcx)
d7f50089 409
48ffc236 410 movq $VM_MAX_USER_ADDRESS-4,%rax
d7f50089
YY
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
c8fe38ae 432 movq TD_PCB(%rcx), %rcx
d7f50089 433 movq $fusufault,PCB_ONFAULT(%rcx)
93ad6da2 434 movq %rsp,PCB_ONFAULT_SP(%rcx)
d7f50089 435
48ffc236 436 movq $VM_MAX_USER_ADDRESS-2,%rax
d7f50089
YY
437 cmpq %rax,%rdi
438 ja fusufault
439
440 movzwl (%rdi),%eax
441 movq $0,PCB_ONFAULT(%rcx)
442 ret
443
444ENTRY(fubyte)
445 movq PCPU(curthread),%rcx
c8fe38ae 446 movq TD_PCB(%rcx), %rcx
d7f50089 447 movq $fusufault,PCB_ONFAULT(%rcx)
93ad6da2 448 movq %rsp,PCB_ONFAULT_SP(%rcx)
d7f50089 449
48ffc236 450 movq $VM_MAX_USER_ADDRESS-1,%rax
d7f50089
YY
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
c8fe38ae 462 movq TD_PCB(%rcx), %rcx
d7f50089
YY
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.
3f938eea 470 *
d7f50089 471 * addr = %rdi, value = %rsi
3f938eea
MD
472 *
473 * Write a long
d7f50089
YY
474 */
475ALTENTRY(suword64)
476ENTRY(suword)
477 movq PCPU(curthread),%rcx
c8fe38ae 478 movq TD_PCB(%rcx), %rcx
d7f50089 479 movq $fusufault,PCB_ONFAULT(%rcx)
93ad6da2 480 movq %rsp,PCB_ONFAULT_SP(%rcx)
d7f50089 481
48ffc236 482 movq $VM_MAX_USER_ADDRESS-8,%rax
d7f50089
YY
483 cmpq %rax,%rdi /* verify address validity */
484 ja fusufault
485
486 movq %rsi,(%rdi)
487 xorl %eax,%eax
488 movq PCPU(curthread),%rcx
c8fe38ae 489 movq TD_PCB(%rcx), %rcx
d7f50089
YY
490 movq %rax,PCB_ONFAULT(%rcx)
491 ret
492
3f938eea
MD
493/*
494 * Write an int
495 */
d7f50089
YY
496ENTRY(suword32)
497 movq PCPU(curthread),%rcx
c8fe38ae 498 movq TD_PCB(%rcx), %rcx
d7f50089 499 movq $fusufault,PCB_ONFAULT(%rcx)
93ad6da2 500 movq %rsp,PCB_ONFAULT_SP(%rcx)
d7f50089 501
48ffc236 502 movq $VM_MAX_USER_ADDRESS-4,%rax
d7f50089
YY
503 cmpq %rax,%rdi /* verify address validity */
504 ja fusufault
505
506 movl %esi,(%rdi)
507 xorl %eax,%eax
508 movq PCPU(curthread),%rcx
c8fe38ae 509 movq TD_PCB(%rcx), %rcx
d7f50089
YY
510 movq %rax,PCB_ONFAULT(%rcx)
511 ret
512
513ENTRY(suword16)
514 movq PCPU(curthread),%rcx
c8fe38ae 515 movq TD_PCB(%rcx), %rcx
d7f50089 516 movq $fusufault,PCB_ONFAULT(%rcx)
93ad6da2 517 movq %rsp,PCB_ONFAULT_SP(%rcx)
d7f50089 518
48ffc236 519 movq $VM_MAX_USER_ADDRESS-2,%rax
d7f50089
YY
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 */
c8fe38ae 526 movq TD_PCB(%rcx), %rcx
d7f50089
YY
527 movq %rax,PCB_ONFAULT(%rcx)
528 ret
529
530ENTRY(subyte)
531 movq PCPU(curthread),%rcx
c8fe38ae 532 movq TD_PCB(%rcx), %rcx
d7f50089 533 movq $fusufault,PCB_ONFAULT(%rcx)
93ad6da2 534 movq %rsp,PCB_ONFAULT_SP(%rcx)
d7f50089 535
48ffc236 536 movq $VM_MAX_USER_ADDRESS-1,%rax
d7f50089
YY
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 */
c8fe38ae 544 movq TD_PCB(%rcx), %rcx
d7f50089
YY
545 movq %rax,PCB_ONFAULT(%rcx)
546 ret
547
548/*
549 * 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(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
c8fe38ae 562 movq TD_PCB(%rcx), %rcx
d7f50089 563 movq $cpystrflt,PCB_ONFAULT(%rcx)
93ad6da2 564 movq %rsp,PCB_ONFAULT_SP(%rcx)
d7f50089 565
48ffc236 566 movq $VM_MAX_USER_ADDRESS,%rax
d7f50089
YY
567
568 /* make sure 'from' is within bounds */
569 subq %rsi,%rax
570 jbe cpystrflt
571
48ffc236 572 /* restrict maxlen to <= VM_MAX_USER_ADDRESS-from */
d7f50089
YY
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 */
48ffc236 596 movq $VM_MAX_USER_ADDRESS,%rax
d7f50089
YY
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
c8fe38ae 609 movq TD_PCB(%rcx), %rcx
d7f50089
YY
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/*
b2b3ffcd 657 * Handling of special x86_64 registers and descriptor tables etc
d7f50089
YY
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 */
5b9f6cc4 673 movl %eax,%gs /* Beware, use wrmsr to set 64 bit base */
d7f50089
YY
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/* setjump, longjump */
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
0bdfdda1
SW
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)
93ad6da2 722 movq %rsp,PCB_ONFAULT_SP(%r8)
0bdfdda1
SW
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 * MSR operations fault handler
736 */
737 ALIGN_TEXT
738msr_onfault:
739 movq PCPU(curthread),%r8
740 movq TD_PCB(%r8), %r8
741 movq $0,PCB_ONFAULT(%r8)
742 movl $EFAULT,%eax
743 ret
744
d7f50089
YY
745/*
746 * Support for BB-profiling (gcc -a). The kernbb program will extract
747 * the data from the kernel.
748 */
749
750 .data
751 ALIGN_DATA
752 .globl bbhead
753bbhead:
754 .quad 0
755
756 .text
757NON_GPROF_ENTRY(__bb_init_func)
758 movq $1,(%rdi)
759 movq bbhead,%rax
760 movq %rax,32(%rdi)
761 movq %rdi,bbhead
762 NON_GPROF_RET