1 /*-
2 * Copyright (c) 1982, 1986 The Regents of the University of California.
3 * Copyright (c) 1989, 1990 William Jolitz
4 * Copyright (c) 1994 John Dyson
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * the Systems Programming Group of the University of Utah Computer
9 * Science Department, and William Jolitz.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the University of
22 * California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 * may be used to endorse or promote products derived from this software
25 * without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91
40 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
41 */
42
43 #include <sys/cdefs.h>
44 __FBSDID("$FreeBSD: releng/8.4/sys/amd64/amd64/vm_machdep.c 237009 2012-06-13 15:25:52Z jhb $");
45
46 #include "opt_isa.h"
47 #include "opt_cpu.h"
48 #include "opt_compat.h"
49
50 #include <sys/param.h>
51 #include <sys/systm.h>
52 #include <sys/bio.h>
53 #include <sys/buf.h>
54 #include <sys/kernel.h>
55 #include <sys/ktr.h>
56 #include <sys/lock.h>
57 #include <sys/malloc.h>
58 #include <sys/mbuf.h>
59 #include <sys/mutex.h>
60 #include <sys/pioctl.h>
61 #include <sys/proc.h>
62 #include <sys/sf_buf.h>
63 #include <sys/smp.h>
64 #include <sys/sysctl.h>
65 #include <sys/sysent.h>
66 #include <sys/unistd.h>
67 #include <sys/vnode.h>
68 #include <sys/vmmeter.h>
69
70 #include <machine/cpu.h>
71 #include <machine/md_var.h>
72 #include <machine/pcb.h>
73 #include <machine/specialreg.h>
74 #include <machine/tss.h>
75
76 #include <vm/vm.h>
77 #include <vm/vm_extern.h>
78 #include <vm/vm_kern.h>
79 #include <vm/vm_page.h>
80 #include <vm/vm_map.h>
81 #include <vm/vm_param.h>
82
83 #include <amd64/isa/isa.h>
84
85 static void cpu_reset_real(void);
86 #ifdef SMP
87 static void cpu_reset_proxy(void);
88 static u_int cpu_reset_proxyid;
89 static volatile u_int cpu_reset_proxy_active;
90 #endif
91
92 struct savefpu *
93 get_pcb_user_save_td(struct thread *td)
94 {
95 vm_offset_t p;
96
97 p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE -
98 cpu_max_ext_state_size;
99 KASSERT((p % 64) == 0, ("Unaligned pcb_user_save area"));
100 return ((struct savefpu *)p);
101 }
102
103 struct savefpu *
104 get_pcb_user_save_pcb(struct pcb *pcb)
105 {
106 vm_offset_t p;
107
108 p = (vm_offset_t)(pcb + 1);
109 return ((struct savefpu *)p);
110 }
111
112 struct pcb *
113 get_pcb_td(struct thread *td)
114 {
115 vm_offset_t p;
116
117 p = td->td_kstack + td->td_kstack_pages * PAGE_SIZE -
118 cpu_max_ext_state_size - sizeof(struct pcb);
119 return ((struct pcb *)p);
120 }
121
122 void *
123 alloc_fpusave(int flags)
124 {
125 struct pcb *res;
126 struct savefpu_ymm *sf;
127
128 res = malloc(cpu_max_ext_state_size, M_DEVBUF, flags);
129 if (use_xsave) {
130 sf = (struct savefpu_ymm *)res;
131 bzero(&sf->sv_xstate.sx_hd, sizeof(sf->sv_xstate.sx_hd));
132 sf->sv_xstate.sx_hd.xstate_bv = xsave_mask;
133 }
134 return (res);
135 }
136
137 /*
138 * Finish a fork operation, with process p2 nearly set up.
139 * Copy and update the pcb, set up the stack so that the child
140 * ready to run and return to user mode.
141 */
142 void
143 cpu_fork(td1, p2, td2, flags)
144 register struct thread *td1;
145 register struct proc *p2;
146 struct thread *td2;
147 int flags;
148 {
149 register struct proc *p1;
150 struct pcb *pcb2;
151 struct mdproc *mdp1, *mdp2;
152 struct proc_ldt *pldt;
153 pmap_t pmap2;
154
155 p1 = td1->td_proc;
156 if ((flags & RFPROC) == 0) {
157 if ((flags & RFMEM) == 0) {
158 /* unshare user LDT */
159 mdp1 = &p1->p_md;
160 mtx_lock(&dt_lock);
161 if ((pldt = mdp1->md_ldt) != NULL &&
162 pldt->ldt_refcnt > 1 &&
163 user_ldt_alloc(p1, 1) == NULL)
164 panic("could not copy LDT");
165 mtx_unlock(&dt_lock);
166 }
167 return;
168 }
169
170 /* Ensure that td1's pcb is up to date. */
171 fpuexit(td1);
172
173 /* Point the pcb to the top of the stack */
174 pcb2 = get_pcb_td(td2);
175 td2->td_pcb = pcb2;
176
177 /* Copy td1's pcb */
178 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
179
180 /* Properly initialize pcb_save */
181 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2);
182 bcopy(get_pcb_user_save_td(td1), get_pcb_user_save_pcb(pcb2),
183 cpu_max_ext_state_size);
184
185 /* Point mdproc and then copy over td1's contents */
186 mdp2 = &p2->p_md;
187 bcopy(&p1->p_md, mdp2, sizeof(*mdp2));
188
189 /*
190 * Create a new fresh stack for the new process.
191 * Copy the trap frame for the return to user mode as if from a
192 * syscall. This copies most of the user mode register values.
193 */
194 td2->td_frame = (struct trapframe *)td2->td_pcb - 1;
195 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
196
197 td2->td_frame->tf_rax = 0; /* Child returns zero */
198 td2->td_frame->tf_rflags &= ~PSL_C; /* success */
199 td2->td_frame->tf_rdx = 1;
200
201 /*
202 * If the parent process has the trap bit set (i.e. a debugger had
203 * single stepped the process to the system call), we need to clear
204 * the trap flag from the new frame unless the debugger had set PF_FORK
205 * on the parent. Otherwise, the child will receive a (likely
206 * unexpected) SIGTRAP when it executes the first instruction after
207 * returning to userland.
208 */
209 if ((p1->p_pfsflags & PF_FORK) == 0)
210 td2->td_frame->tf_rflags &= ~PSL_T;
211
212 /*
213 * Set registers for trampoline to user mode. Leave space for the
214 * return address on stack. These are the kernel mode register values.
215 */
216 pmap2 = vmspace_pmap(p2->p_vmspace);
217 pcb2->pcb_cr3 = DMAP_TO_PHYS((vm_offset_t)pmap2->pm_pml4);
218 pcb2->pcb_r12 = (register_t)fork_return; /* fork_trampoline argument */
219 pcb2->pcb_rbp = 0;
220 pcb2->pcb_rsp = (register_t)td2->td_frame - sizeof(void *);
221 pcb2->pcb_rbx = (register_t)td2; /* fork_trampoline argument */
222 pcb2->pcb_rip = (register_t)fork_trampoline;
223 /*-
224 * pcb2->pcb_dr*: cloned above.
225 * pcb2->pcb_savefpu: cloned above.
226 * pcb2->pcb_flags: cloned above.
227 * pcb2->pcb_onfault: cloned above (always NULL here?).
228 * pcb2->pcb_[fg]sbase: cloned above
229 */
230
231 /* Setup to release spin count in fork_exit(). */
232 td2->td_md.md_spinlock_count = 1;
233 td2->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
234
235 /* As an i386, do not copy io permission bitmap. */
236 pcb2->pcb_tssp = NULL;
237
238 /* New segment registers. */
239 set_pcb_flags(pcb2, PCB_FULL_IRET);
240
241 /* Copy the LDT, if necessary. */
242 mdp1 = &td1->td_proc->p_md;
243 mdp2 = &p2->p_md;
244 mtx_lock(&dt_lock);
245 if (mdp1->md_ldt != NULL) {
246 if (flags & RFMEM) {
247 mdp1->md_ldt->ldt_refcnt++;
248 mdp2->md_ldt = mdp1->md_ldt;
249 bcopy(&mdp1->md_ldt_sd, &mdp2->md_ldt_sd, sizeof(struct
250 system_segment_descriptor));
251 } else {
252 mdp2->md_ldt = NULL;
253 mdp2->md_ldt = user_ldt_alloc(p2, 0);
254 if (mdp2->md_ldt == NULL)
255 panic("could not copy LDT");
256 amd64_set_ldt_data(td2, 0, max_ldt_segment,
257 (struct user_segment_descriptor *)
258 mdp1->md_ldt->ldt_base);
259 }
260 } else
261 mdp2->md_ldt = NULL;
262 mtx_unlock(&dt_lock);
263
264 /*
265 * Now, cpu_switch() can schedule the new process.
266 * pcb_rsp is loaded pointing to the cpu_switch() stack frame
267 * containing the return address when exiting cpu_switch.
268 * This will normally be to fork_trampoline(), which will have
269 * %ebx loaded with the new proc's pointer. fork_trampoline()
270 * will set up a stack to call fork_return(p, frame); to complete
271 * the return to user-mode.
272 */
273 }
274
275 /*
276 * Intercept the return address from a freshly forked process that has NOT
277 * been scheduled yet.
278 *
279 * This is needed to make kernel threads stay in kernel mode.
280 */
281 void
282 cpu_set_fork_handler(td, func, arg)
283 struct thread *td;
284 void (*func)(void *);
285 void *arg;
286 {
287 /*
288 * Note that the trap frame follows the args, so the function
289 * is really called like this: func(arg, frame);
290 */
291 td->td_pcb->pcb_r12 = (long) func; /* function */
292 td->td_pcb->pcb_rbx = (long) arg; /* first arg */
293 }
294
295 void
296 cpu_exit(struct thread *td)
297 {
298
299 /*
300 * If this process has a custom LDT, release it.
301 */
302 mtx_lock(&dt_lock);
303 if (td->td_proc->p_md.md_ldt != 0)
304 user_ldt_free(td);
305 else
306 mtx_unlock(&dt_lock);
307 }
308
309 void
310 cpu_thread_exit(struct thread *td)
311 {
312 struct pcb *pcb;
313
314 critical_enter();
315 if (td == PCPU_GET(fpcurthread))
316 fpudrop();
317 critical_exit();
318
319 pcb = td->td_pcb;
320
321 /* Disable any hardware breakpoints. */
322 if (pcb->pcb_flags & PCB_DBREGS) {
323 reset_dbregs();
324 clear_pcb_flags(pcb, PCB_DBREGS);
325 }
326 }
327
328 void
329 cpu_thread_clean(struct thread *td)
330 {
331 struct pcb *pcb;
332
333 pcb = td->td_pcb;
334
335 /*
336 * Clean TSS/iomap
337 */
338 if (pcb->pcb_tssp != NULL) {
339 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_tssp,
340 ctob(IOPAGES + 1));
341 pcb->pcb_tssp = NULL;
342 }
343 }
344
345 void
346 cpu_thread_swapin(struct thread *td)
347 {
348 }
349
350 void
351 cpu_thread_swapout(struct thread *td)
352 {
353 }
354
355 void
356 cpu_thread_alloc(struct thread *td)
357 {
358 struct pcb *pcb;
359 struct xstate_hdr *xhdr;
360
361 td->td_pcb = pcb = get_pcb_td(td);
362 td->td_frame = (struct trapframe *)pcb - 1;
363 pcb->pcb_save = get_pcb_user_save_pcb(pcb);
364 if (use_xsave) {
365 xhdr = (struct xstate_hdr *)(pcb->pcb_save + 1);
366 bzero(xhdr, sizeof(*xhdr));
367 xhdr->xstate_bv = xsave_mask;
368 }
369 }
370
371 void
372 cpu_thread_free(struct thread *td)
373 {
374
375 cpu_thread_clean(td);
376 }
377
378 void
379 cpu_set_syscall_retval(struct thread *td, int error)
380 {
381
382 switch (error) {
383 case 0:
384 td->td_frame->tf_rax = td->td_retval[0];
385 td->td_frame->tf_rdx = td->td_retval[1];
386 td->td_frame->tf_rflags &= ~PSL_C;
387 break;
388
389 case ERESTART:
390 /*
391 * Reconstruct pc, we know that 'syscall' is 2 bytes,
392 * lcall $X,y is 7 bytes, int 0x80 is 2 bytes.
393 * We saved this in tf_err.
394 * %r10 (which was holding the value of %rcx) is restored
395 * for the next iteration.
396 * %r10 restore is only required for freebsd/amd64 processes,
397 * but shall be innocent for any ia32 ABI.
398 */
399 td->td_frame->tf_rip -= td->td_frame->tf_err;
400 td->td_frame->tf_r10 = td->td_frame->tf_rcx;
401 break;
402
403 case EJUSTRETURN:
404 break;
405
406 default:
407 if (td->td_proc->p_sysent->sv_errsize) {
408 if (error >= td->td_proc->p_sysent->sv_errsize)
409 error = -1; /* XXX */
410 else
411 error = td->td_proc->p_sysent->sv_errtbl[error];
412 }
413 td->td_frame->tf_rax = error;
414 td->td_frame->tf_rflags |= PSL_C;
415 break;
416 }
417 }
418
419 /*
420 * Initialize machine state (pcb and trap frame) for a new thread about to
421 * upcall. Put enough state in the new thread's PCB to get it to go back
422 * userret(), where we can intercept it again to set the return (upcall)
423 * Address and stack, along with those from upcals that are from other sources
424 * such as those generated in thread_userret() itself.
425 */
426 void
427 cpu_set_upcall(struct thread *td, struct thread *td0)
428 {
429 struct pcb *pcb2;
430
431 /* Point the pcb to the top of the stack. */
432 pcb2 = td->td_pcb;
433
434 /*
435 * Copy the upcall pcb. This loads kernel regs.
436 * Those not loaded individually below get their default
437 * values here.
438 */
439 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2));
440 clear_pcb_flags(pcb2, PCB_FPUINITDONE | PCB_USERFPUINITDONE);
441 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2);
442 bcopy(get_pcb_user_save_td(td0), pcb2->pcb_save,
443 cpu_max_ext_state_size);
444 set_pcb_flags(pcb2, PCB_FULL_IRET);
445
446 /*
447 * Create a new fresh stack for the new thread.
448 */
449 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
450
451 /* If the current thread has the trap bit set (i.e. a debugger had
452 * single stepped the process to the system call), we need to clear
453 * the trap flag from the new frame. Otherwise, the new thread will
454 * receive a (likely unexpected) SIGTRAP when it executes the first
455 * instruction after returning to userland.
456 */
457 td->td_frame->tf_rflags &= ~PSL_T;
458
459 /*
460 * Set registers for trampoline to user mode. Leave space for the
461 * return address on stack. These are the kernel mode register values.
462 */
463 pcb2->pcb_r12 = (register_t)fork_return; /* trampoline arg */
464 pcb2->pcb_rbp = 0;
465 pcb2->pcb_rsp = (register_t)td->td_frame - sizeof(void *); /* trampoline arg */
466 pcb2->pcb_rbx = (register_t)td; /* trampoline arg */
467 pcb2->pcb_rip = (register_t)fork_trampoline;
468 /*
469 * If we didn't copy the pcb, we'd need to do the following registers:
470 * pcb2->pcb_cr3: cloned above.
471 * pcb2->pcb_dr*: cloned above.
472 * pcb2->pcb_savefpu: cloned above.
473 * pcb2->pcb_onfault: cloned above (always NULL here?).
474 * pcb2->pcb_[fg]sbase: cloned above
475 */
476
477 /* Setup to release spin count in fork_exit(). */
478 td->td_md.md_spinlock_count = 1;
479 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
480 }
481
482 /*
483 * Set that machine state for performing an upcall that has to
484 * be done in thread_userret() so that those upcalls generated
485 * in thread_userret() itself can be done as well.
486 */
487 void
488 cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg,
489 stack_t *stack)
490 {
491
492 /*
493 * Do any extra cleaning that needs to be done.
494 * The thread may have optional components
495 * that are not present in a fresh thread.
496 * This may be a recycled thread so make it look
497 * as though it's newly allocated.
498 */
499 cpu_thread_clean(td);
500
501 #ifdef COMPAT_FREEBSD32
502 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
503 /*
504 * Set the trap frame to point at the beginning of the uts
505 * function.
506 */
507 td->td_frame->tf_rbp = 0;
508 td->td_frame->tf_rsp =
509 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
510 td->td_frame->tf_rip = (uintptr_t)entry;
511
512 /*
513 * Pass the address of the mailbox for this kse to the uts
514 * function as a parameter on the stack.
515 */
516 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)),
517 (uint32_t)(uintptr_t)arg);
518
519 return;
520 }
521 #endif
522
523 /*
524 * Set the trap frame to point at the beginning of the uts
525 * function.
526 */
527 td->td_frame->tf_rbp = 0;
528 td->td_frame->tf_rsp =
529 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f;
530 td->td_frame->tf_rsp -= 8;
531 td->td_frame->tf_rip = (register_t)entry;
532 td->td_frame->tf_ds = _udatasel;
533 td->td_frame->tf_es = _udatasel;
534 td->td_frame->tf_fs = _ufssel;
535 td->td_frame->tf_gs = _ugssel;
536 td->td_frame->tf_flags = TF_HASSEGS;
537
538 /*
539 * Pass the address of the mailbox for this kse to the uts
540 * function as a parameter on the stack.
541 */
542 td->td_frame->tf_rdi = (register_t)arg;
543 }
544
545 int
546 cpu_set_user_tls(struct thread *td, void *tls_base)
547 {
548 struct pcb *pcb;
549
550 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS)
551 return (EINVAL);
552
553 pcb = td->td_pcb;
554 #ifdef COMPAT_FREEBSD32
555 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
556 pcb->pcb_gsbase = (register_t)tls_base;
557 return (0);
558 }
559 #endif
560 pcb->pcb_fsbase = (register_t)tls_base;
561 set_pcb_flags(pcb, PCB_FULL_IRET);
562 return (0);
563 }
564
565 #ifdef SMP
566 static void
567 cpu_reset_proxy()
568 {
569
570 cpu_reset_proxy_active = 1;
571 while (cpu_reset_proxy_active == 1)
572 ; /* Wait for other cpu to see that we've started */
573 stop_cpus((1<<cpu_reset_proxyid));
574 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
575 DELAY(1000000);
576 cpu_reset_real();
577 }
578 #endif
579
580 void
581 cpu_reset()
582 {
583 #ifdef SMP
584 cpumask_t map;
585 u_int cnt;
586
587 if (smp_active) {
588 map = PCPU_GET(other_cpus) & ~stopped_cpus;
589 if (map != 0) {
590 printf("cpu_reset: Stopping other CPUs\n");
591 stop_cpus(map);
592 }
593
594 if (PCPU_GET(cpuid) != 0) {
595 cpu_reset_proxyid = PCPU_GET(cpuid);
596 cpustop_restartfunc = cpu_reset_proxy;
597 cpu_reset_proxy_active = 0;
598 printf("cpu_reset: Restarting BSP\n");
599
600 /* Restart CPU #0. */
601 atomic_store_rel_int(&started_cpus, 1 << 0);
602
603 cnt = 0;
604 while (cpu_reset_proxy_active == 0 && cnt < 10000000)
605 cnt++; /* Wait for BSP to announce restart */
606 if (cpu_reset_proxy_active == 0)
607 printf("cpu_reset: Failed to restart BSP\n");
608 enable_intr();
609 cpu_reset_proxy_active = 2;
610
611 while (1);
612 /* NOTREACHED */
613 }
614
615 DELAY(1000000);
616 }
617 #endif
618 cpu_reset_real();
619 /* NOTREACHED */
620 }
621
622 static void
623 cpu_reset_real()
624 {
625 struct region_descriptor null_idt;
626 int b;
627
628 disable_intr();
629
630 /*
631 * Attempt to do a CPU reset via the keyboard controller,
632 * do not turn off GateA20, as any machine that fails
633 * to do the reset here would then end up in no man's land.
634 */
635 outb(IO_KBD + 4, 0xFE);
636 DELAY(500000); /* wait 0.5 sec to see if that did it */
637
638 /*
639 * Attempt to force a reset via the Reset Control register at
640 * I/O port 0xcf9. Bit 2 forces a system reset when it
641 * transitions from 0 to 1. Bit 1 selects the type of reset
642 * to attempt: 0 selects a "soft" reset, and 1 selects a
643 * "hard" reset. We try a "hard" reset. The first write sets
644 * bit 1 to select a "hard" reset and clears bit 2. The
645 * second write forces a 0 -> 1 transition in bit 2 to trigger
646 * a reset.
647 */
648 outb(0xcf9, 0x2);
649 outb(0xcf9, 0x6);
650 DELAY(500000); /* wait 0.5 sec to see if that did it */
651
652 /*
653 * Attempt to force a reset via the Fast A20 and Init register
654 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate.
655 * Bit 0 asserts INIT# when set to 1. We are careful to only
656 * preserve bit 1 while setting bit 0. We also must clear bit
657 * 0 before setting it if it isn't already clear.
658 */
659 b = inb(0x92);
660 if (b != 0xff) {
661 if ((b & 0x1) != 0)
662 outb(0x92, b & 0xfe);
663 outb(0x92, b | 0x1);
664 DELAY(500000); /* wait 0.5 sec to see if that did it */
665 }
666
667 printf("No known reset method worked, attempting CPU shutdown\n");
668 DELAY(1000000); /* wait 1 sec for printf to complete */
669
670 /* Wipe the IDT. */
671 null_idt.rd_limit = 0;
672 null_idt.rd_base = 0;
673 lidt(&null_idt);
674
675 /* "good night, sweet prince .... <THUNK!>" */
676 breakpoint();
677
678 /* NOTREACHED */
679 while(1);
680 }
681
682 /*
683 * Allocate an sf_buf for the given vm_page. On this machine, however, there
684 * is no sf_buf object. Instead, an opaque pointer to the given vm_page is
685 * returned.
686 */
687 struct sf_buf *
688 sf_buf_alloc(struct vm_page *m, int pri)
689 {
690
691 return ((struct sf_buf *)m);
692 }
693
694 /*
695 * Free the sf_buf. In fact, do nothing because there are no resources
696 * associated with the sf_buf.
697 */
698 void
699 sf_buf_free(struct sf_buf *sf)
700 {
701 }
702
703 /*
704 * Software interrupt handler for queued VM system processing.
705 */
706 void
707 swi_vm(void *dummy)
708 {
709 if (busdma_swi_pending != 0)
710 busdma_swi();
711 }
712
713 /*
714 * Tell whether this address is in some physical memory region.
715 * Currently used by the kernel coredump code in order to avoid
716 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
717 * or other unpredictable behaviour.
718 */
719
720 int
721 is_physical_memory(vm_paddr_t addr)
722 {
723
724 #ifdef DEV_ISA
725 /* The ISA ``memory hole''. */
726 if (addr >= 0xa0000 && addr < 0x100000)
727 return 0;
728 #endif
729
730 /*
731 * stuff other tests for known memory-mapped devices (PCI?)
732 * here
733 */
734
735 return 1;
736 }
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