2 * Copyright (c) 1993 The Regents of the University of California.
3 * Copyright (c) 2003 Peter Wemm.
4 * Copyright (c) 2008 The DragonFly Project.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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
31 * $FreeBSD: src/sys/amd64/amd64/support.S,v 1.127 2007/05/23 08:33:04 kib Exp $
34 #include <machine/asmacros.h>
35 #include <machine/pmap.h>
45 * void bzero(void *buf, size_t len)
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 */
80 cld /* compare forwards */
95 * bcopy(src, dst, cnt)
97 * ws@tools.de (Wolfgang Solfrank, TooLs GmbH) +49-228-985800
99 ENTRY(generic_bcopy) /* generic_bcopy is bcopy without FPU */
100 ENTRY(ovbcopy) /* our bcopy doesn't use the FPU, so ovbcopy is the same */
107 cmpq %rcx,%rax /* overlapping && src < dst? */
110 shrq $3,%rcx /* copy by 64-bit words */
111 cld /* nope, copy forwards */
115 andq $7,%rcx /* any bytes left? */
122 addq %rcx,%rdi /* copy backwards */
126 andq $7,%rcx /* any fractional bytes? */
130 movq %rdx,%rcx /* copy remainder by 32-bit words */
139 movq $0x200,%rax /* the manual says that bit 10 must be set to 1 */
140 movq %rax,%dr7 /* disable all breapoints first */
150 * Note: memcpy does not support overlapping copies
154 shrq $3,%rcx /* copy by 64-bit words */
155 cld /* copy forwards */
159 andq $7,%rcx /* any bytes left? */
165 * pagecopy(%rdi=from, %rsi=to)
168 movq $-PAGE_SIZE,%rax
173 /*prefetchnta (%rdi,%rax)*/
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 */
190 /* fillw(pat, base, cnt) */
191 /* %rdi,%rsi, %rdx */
201 /*****************************************************************************/
202 /* copyout and fubyte family */
203 /*****************************************************************************/
205 * Access user memory from inside the kernel. These routines should be
206 * the only places that do this.
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.
214 * std_copyout(from_kernel, to_user, len) - MP SAFE
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? */
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
233 * First, prevent address wrapping.
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.
244 movq $VM_MAX_USER_ADDRESS,%rcx
249 /* bcopy(%rsi, %rdi, %rdx) */
263 movq PCPU(curthread),%rdx
264 movq TD_PCB(%rdx), %rdx
265 movq %rax,PCB_ONFAULT(%rdx)
270 movq PCPU(curthread),%rdx
271 movq TD_PCB(%rdx), %rdx
272 movq $0,PCB_ONFAULT(%rdx)
277 * std_copyin(from_user, to_kernel, len) - MP SAFE
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? */
289 * make sure address is valid
294 movq $VM_MAX_USER_ADDRESS,%rcx
301 shrq $3,%rcx /* copy longword-wise */
306 andb $7,%cl /* copy remaining bytes */
312 movq PCPU(curthread),%rdx
313 movq TD_PCB(%rdx), %rdx
314 movq %rax,PCB_ONFAULT(%rdx)
319 movq PCPU(curthread),%rdx
320 movq TD_PCB(%rdx), %rdx
321 movq $0,PCB_ONFAULT(%rdx)
326 * casuword32. Compare and set user integer. Returns -1 or the current value.
327 * dst = %rdi, old = %rsi, new = %rdx
330 movq PCPU(curthread),%rcx
331 movq TD_PCB(%rcx), %rcx
332 movq $fusufault,PCB_ONFAULT(%rcx)
333 movq %rsp,PCB_ONFAULT_SP(%rcx)
335 movq $VM_MAX_USER_ADDRESS-4,%rax
336 cmpq %rax,%rdi /* verify address is valid */
339 movl %esi,%eax /* old */
341 cmpxchgl %edx,(%rdi) /* new = %edx */
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.
349 movq PCPU(curthread),%rcx
350 movq TD_PCB(%rcx), %rcx
351 movq $0,PCB_ONFAULT(%rcx)
355 * casuword. Compare and set user word. Returns -1 or the current value.
356 * dst = %rdi, old = %rsi, new = %rdx
359 movq PCPU(curthread),%rcx
360 movq TD_PCB(%rcx), %rcx
361 movq $fusufault,PCB_ONFAULT(%rcx)
362 movq %rsp,PCB_ONFAULT_SP(%rcx)
364 movq $VM_MAX_USER_ADDRESS-8,%rax
365 cmpq %rax,%rdi /* verify address is valid */
368 movq %rsi,%rax /* old */
370 cmpxchgq %rdx,(%rdi) /* new = %rdx */
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.
378 movq PCPU(curthread),%rcx
379 movq TD_PCB(%rcx), %rcx
380 movq $0,PCB_ONFAULT(%rcx)
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.
391 movq PCPU(curthread),%rcx
392 movq TD_PCB(%rcx), %rcx
393 movq $fusufault,PCB_ONFAULT(%rcx)
394 movq %rsp,PCB_ONFAULT_SP(%rcx)
396 movq $VM_MAX_USER_ADDRESS-8,%rax
397 cmpq %rax,%rdi /* verify address is valid */
401 movq $0,PCB_ONFAULT(%rcx)
405 movq PCPU(curthread),%rcx
406 movq TD_PCB(%rcx), %rcx
407 movq $fusufault,PCB_ONFAULT(%rcx)
408 movq %rsp,PCB_ONFAULT_SP(%rcx)
410 movq $VM_MAX_USER_ADDRESS-4,%rax
411 cmpq %rax,%rdi /* verify address is valid */
415 movq $0,PCB_ONFAULT(%rcx)
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.
431 movq PCPU(curthread),%rcx
432 movq TD_PCB(%rcx), %rcx
433 movq $fusufault,PCB_ONFAULT(%rcx)
434 movq %rsp,PCB_ONFAULT_SP(%rcx)
436 movq $VM_MAX_USER_ADDRESS-2,%rax
441 movq $0,PCB_ONFAULT(%rcx)
445 movq PCPU(curthread),%rcx
446 movq TD_PCB(%rcx), %rcx
447 movq $fusufault,PCB_ONFAULT(%rcx)
448 movq %rsp,PCB_ONFAULT_SP(%rcx)
450 movq $VM_MAX_USER_ADDRESS-1,%rax
455 movq $0,PCB_ONFAULT(%rcx)
460 movq PCPU(curthread),%rcx
462 movq TD_PCB(%rcx), %rcx
463 movq %rax,PCB_ONFAULT(%rcx)
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.
471 * addr = %rdi, value = %rsi
477 movq PCPU(curthread),%rcx
478 movq TD_PCB(%rcx), %rcx
479 movq $fusufault,PCB_ONFAULT(%rcx)
480 movq %rsp,PCB_ONFAULT_SP(%rcx)
482 movq $VM_MAX_USER_ADDRESS-8,%rax
483 cmpq %rax,%rdi /* verify address validity */
488 movq PCPU(curthread),%rcx
489 movq TD_PCB(%rcx), %rcx
490 movq %rax,PCB_ONFAULT(%rcx)
497 movq PCPU(curthread),%rcx
498 movq TD_PCB(%rcx), %rcx
499 movq $fusufault,PCB_ONFAULT(%rcx)
500 movq %rsp,PCB_ONFAULT_SP(%rcx)
502 movq $VM_MAX_USER_ADDRESS-4,%rax
503 cmpq %rax,%rdi /* verify address validity */
508 movq PCPU(curthread),%rcx
509 movq TD_PCB(%rcx), %rcx
510 movq %rax,PCB_ONFAULT(%rcx)
514 movq PCPU(curthread),%rcx
515 movq TD_PCB(%rcx), %rcx
516 movq $fusufault,PCB_ONFAULT(%rcx)
517 movq %rsp,PCB_ONFAULT_SP(%rcx)
519 movq $VM_MAX_USER_ADDRESS-2,%rax
520 cmpq %rax,%rdi /* verify address validity */
525 movq PCPU(curthread),%rcx /* restore trashed register */
526 movq TD_PCB(%rcx), %rcx
527 movq %rax,PCB_ONFAULT(%rcx)
531 movq PCPU(curthread),%rcx
532 movq TD_PCB(%rcx), %rcx
533 movq $fusufault,PCB_ONFAULT(%rcx)
534 movq %rsp,PCB_ONFAULT_SP(%rcx)
536 movq $VM_MAX_USER_ADDRESS-1,%rax
537 cmpq %rax,%rdi /* verify address validity */
543 movq PCPU(curthread),%rcx /* restore trashed register */
544 movq TD_PCB(%rcx), %rcx
545 movq %rax,PCB_ONFAULT(%rcx)
549 * std_copyinstr(from, to, maxlen, int *lencopied) - MP SAFE
550 * %rdi, %rsi, %rdx, %rcx
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.
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)
566 movq $VM_MAX_USER_ADDRESS,%rax
568 /* make sure 'from' is within bounds */
572 /* restrict maxlen to <= VM_MAX_USER_ADDRESS-from */
590 /* Success -- 0 byte reached */
595 /* rdx is zero - return ENAMETOOLONG or EFAULT */
596 movq $VM_MAX_USER_ADDRESS,%rax
600 movq $ENAMETOOLONG,%rax
607 /* set *lencopied and return %eax */
608 movq PCPU(curthread),%rcx
609 movq TD_PCB(%rcx), %rcx
610 movq $0,PCB_ONFAULT(%rcx)
621 * copystr(from, to, maxlen, int *lencopied) - MP SAFE
622 * %rdi, %rsi, %rdx, %rcx
625 movq %rdx,%r8 /* %r8 = maxlen */
638 /* Success -- 0 byte reached */
643 /* rdx is zero -- return ENAMETOOLONG */
644 movq $ENAMETOOLONG,%rax
650 /* set *lencopied and return %rax */
657 * Handling of special x86_64 registers and descriptor tables etc
660 /* void lgdt(struct region_descriptor *rdp); */
662 /* reload the descriptor table */
665 /* flush the prefetch q */
672 movl %eax,%fs /* Beware, use wrmsr to set 64 bit base */
673 movl %eax,%gs /* Beware, use wrmsr to set 64 bit base */
676 /* reload code selector by turning return into intersegmental return */
683 /*****************************************************************************/
684 /* setjmp, longjmp */
685 /*****************************************************************************/
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); */
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); */
715 * Support for reading MSRs in the safe manner.
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)
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 */
731 movq %rax,PCB_ONFAULT(%r8)
735 * Support for writing MSRs in the safe manner.
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)
747 wrmsr /* Write MSR pointed by %ecx. Accepts
748 hi byte in edx, lo in %eax. */
750 movq %rax,PCB_ONFAULT(%r8)
754 * MSR operations fault handler
758 movq PCPU(curthread),%r8
759 movq TD_PCB(%r8), %r8
760 movq $0,PCB_ONFAULT(%r8)
765 * Support for BB-profiling (gcc -a). The kernbb program will extract
766 * the data from the kernel.
776 NON_GPROF_ENTRY(__bb_init_func)