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("$FreeBSD$");
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 * Require full context restore to get the arguments
400 * in the registers reloaded at return to usermode.
401 */
402 td->td_frame->tf_rip -= td->td_frame->tf_err;
403 td->td_frame->tf_r10 = td->td_frame->tf_rcx;
404 set_pcb_flags(td->td_pcb, PCB_FULL_IRET);
405 break;
406
407 case EJUSTRETURN:
408 break;
409
410 default:
411 if (td->td_proc->p_sysent->sv_errsize) {
412 if (error >= td->td_proc->p_sysent->sv_errsize)
413 error = -1; /* XXX */
414 else
415 error = td->td_proc->p_sysent->sv_errtbl[error];
416 }
417 td->td_frame->tf_rax = error;
418 td->td_frame->tf_rflags |= PSL_C;
419 break;
420 }
421 }
422
423 /*
424 * Initialize machine state (pcb and trap frame) for a new thread about to
425 * upcall. Put enough state in the new thread's PCB to get it to go back
426 * userret(), where we can intercept it again to set the return (upcall)
427 * Address and stack, along with those from upcals that are from other sources
428 * such as those generated in thread_userret() itself.
429 */
430 void
431 cpu_set_upcall(struct thread *td, struct thread *td0)
432 {
433 struct pcb *pcb2;
434
435 /* Point the pcb to the top of the stack. */
436 pcb2 = td->td_pcb;
437
438 /*
439 * Copy the upcall pcb. This loads kernel regs.
440 * Those not loaded individually below get their default
441 * values here.
442 */
443 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2));
444 clear_pcb_flags(pcb2, PCB_FPUINITDONE | PCB_USERFPUINITDONE);
445 pcb2->pcb_save = get_pcb_user_save_pcb(pcb2);
446 bcopy(get_pcb_user_save_td(td0), pcb2->pcb_save,
447 cpu_max_ext_state_size);
448 set_pcb_flags(pcb2, PCB_FULL_IRET);
449
450 /*
451 * Create a new fresh stack for the new thread.
452 */
453 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
454
455 /* If the current thread has the trap bit set (i.e. a debugger had
456 * single stepped the process to the system call), we need to clear
457 * the trap flag from the new frame. Otherwise, the new thread will
458 * receive a (likely unexpected) SIGTRAP when it executes the first
459 * instruction after returning to userland.
460 */
461 td->td_frame->tf_rflags &= ~PSL_T;
462
463 /*
464 * Set registers for trampoline to user mode. Leave space for the
465 * return address on stack. These are the kernel mode register values.
466 */
467 pcb2->pcb_r12 = (register_t)fork_return; /* trampoline arg */
468 pcb2->pcb_rbp = 0;
469 pcb2->pcb_rsp = (register_t)td->td_frame - sizeof(void *); /* trampoline arg */
470 pcb2->pcb_rbx = (register_t)td; /* trampoline arg */
471 pcb2->pcb_rip = (register_t)fork_trampoline;
472 /*
473 * If we didn't copy the pcb, we'd need to do the following registers:
474 * pcb2->pcb_cr3: cloned above.
475 * pcb2->pcb_dr*: cloned above.
476 * pcb2->pcb_savefpu: cloned above.
477 * pcb2->pcb_onfault: cloned above (always NULL here?).
478 * pcb2->pcb_[fg]sbase: cloned above
479 */
480
481 /* Setup to release spin count in fork_exit(). */
482 td->td_md.md_spinlock_count = 1;
483 td->td_md.md_saved_flags = PSL_KERNEL | PSL_I;
484 }
485
486 /*
487 * Set that machine state for performing an upcall that has to
488 * be done in thread_userret() so that those upcalls generated
489 * in thread_userret() itself can be done as well.
490 */
491 void
492 cpu_set_upcall_kse(struct thread *td, void (*entry)(void *), void *arg,
493 stack_t *stack)
494 {
495
496 /*
497 * Do any extra cleaning that needs to be done.
498 * The thread may have optional components
499 * that are not present in a fresh thread.
500 * This may be a recycled thread so make it look
501 * as though it's newly allocated.
502 */
503 cpu_thread_clean(td);
504
505 #ifdef COMPAT_FREEBSD32
506 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
507 /*
508 * Set the trap frame to point at the beginning of the uts
509 * function.
510 */
511 td->td_frame->tf_rbp = 0;
512 td->td_frame->tf_rsp =
513 (((uintptr_t)stack->ss_sp + stack->ss_size - 4) & ~0x0f) - 4;
514 td->td_frame->tf_rip = (uintptr_t)entry;
515
516 /*
517 * Pass the address of the mailbox for this kse to the uts
518 * function as a parameter on the stack.
519 */
520 suword32((void *)(td->td_frame->tf_rsp + sizeof(int32_t)),
521 (uint32_t)(uintptr_t)arg);
522
523 return;
524 }
525 #endif
526
527 /*
528 * Set the trap frame to point at the beginning of the uts
529 * function.
530 */
531 td->td_frame->tf_rbp = 0;
532 td->td_frame->tf_rsp =
533 ((register_t)stack->ss_sp + stack->ss_size) & ~0x0f;
534 td->td_frame->tf_rsp -= 8;
535 td->td_frame->tf_rip = (register_t)entry;
536 td->td_frame->tf_ds = _udatasel;
537 td->td_frame->tf_es = _udatasel;
538 td->td_frame->tf_fs = _ufssel;
539 td->td_frame->tf_gs = _ugssel;
540 td->td_frame->tf_flags = TF_HASSEGS;
541
542 /*
543 * Pass the address of the mailbox for this kse to the uts
544 * function as a parameter on the stack.
545 */
546 td->td_frame->tf_rdi = (register_t)arg;
547 }
548
549 int
550 cpu_set_user_tls(struct thread *td, void *tls_base)
551 {
552 struct pcb *pcb;
553
554 if ((u_int64_t)tls_base >= VM_MAXUSER_ADDRESS)
555 return (EINVAL);
556
557 pcb = td->td_pcb;
558 #ifdef COMPAT_FREEBSD32
559 if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
560 pcb->pcb_gsbase = (register_t)tls_base;
561 return (0);
562 }
563 #endif
564 pcb->pcb_fsbase = (register_t)tls_base;
565 set_pcb_flags(pcb, PCB_FULL_IRET);
566 return (0);
567 }
568
569 #ifdef SMP
570 static void
571 cpu_reset_proxy()
572 {
573
574 cpu_reset_proxy_active = 1;
575 while (cpu_reset_proxy_active == 1)
576 ; /* Wait for other cpu to see that we've started */
577 stop_cpus((1<<cpu_reset_proxyid));
578 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
579 DELAY(1000000);
580 cpu_reset_real();
581 }
582 #endif
583
584 void
585 cpu_reset()
586 {
587 #ifdef SMP
588 cpumask_t map;
589 u_int cnt;
590
591 if (smp_active) {
592 map = PCPU_GET(other_cpus) & ~stopped_cpus;
593 if (map != 0) {
594 printf("cpu_reset: Stopping other CPUs\n");
595 stop_cpus(map);
596 }
597
598 if (PCPU_GET(cpuid) != 0) {
599 cpu_reset_proxyid = PCPU_GET(cpuid);
600 cpustop_restartfunc = cpu_reset_proxy;
601 cpu_reset_proxy_active = 0;
602 printf("cpu_reset: Restarting BSP\n");
603
604 /* Restart CPU #0. */
605 atomic_store_rel_int(&started_cpus, 1 << 0);
606
607 cnt = 0;
608 while (cpu_reset_proxy_active == 0 && cnt < 10000000)
609 cnt++; /* Wait for BSP to announce restart */
610 if (cpu_reset_proxy_active == 0)
611 printf("cpu_reset: Failed to restart BSP\n");
612 enable_intr();
613 cpu_reset_proxy_active = 2;
614
615 while (1);
616 /* NOTREACHED */
617 }
618
619 DELAY(1000000);
620 }
621 #endif
622 cpu_reset_real();
623 /* NOTREACHED */
624 }
625
626 static void
627 cpu_reset_real()
628 {
629 struct region_descriptor null_idt;
630 int b;
631
632 disable_intr();
633
634 /*
635 * Attempt to do a CPU reset via the keyboard controller,
636 * do not turn off GateA20, as any machine that fails
637 * to do the reset here would then end up in no man's land.
638 */
639 outb(IO_KBD + 4, 0xFE);
640 DELAY(500000); /* wait 0.5 sec to see if that did it */
641
642 /*
643 * Attempt to force a reset via the Reset Control register at
644 * I/O port 0xcf9. Bit 2 forces a system reset when it
645 * transitions from 0 to 1. Bit 1 selects the type of reset
646 * to attempt: 0 selects a "soft" reset, and 1 selects a
647 * "hard" reset. We try a "hard" reset. The first write sets
648 * bit 1 to select a "hard" reset and clears bit 2. The
649 * second write forces a 0 -> 1 transition in bit 2 to trigger
650 * a reset.
651 */
652 outb(0xcf9, 0x2);
653 outb(0xcf9, 0x6);
654 DELAY(500000); /* wait 0.5 sec to see if that did it */
655
656 /*
657 * Attempt to force a reset via the Fast A20 and Init register
658 * at I/O port 0x92. Bit 1 serves as an alternate A20 gate.
659 * Bit 0 asserts INIT# when set to 1. We are careful to only
660 * preserve bit 1 while setting bit 0. We also must clear bit
661 * 0 before setting it if it isn't already clear.
662 */
663 b = inb(0x92);
664 if (b != 0xff) {
665 if ((b & 0x1) != 0)
666 outb(0x92, b & 0xfe);
667 outb(0x92, b | 0x1);
668 DELAY(500000); /* wait 0.5 sec to see if that did it */
669 }
670
671 printf("No known reset method worked, attempting CPU shutdown\n");
672 DELAY(1000000); /* wait 1 sec for printf to complete */
673
674 /* Wipe the IDT. */
675 null_idt.rd_limit = 0;
676 null_idt.rd_base = 0;
677 lidt(&null_idt);
678
679 /* "good night, sweet prince .... <THUNK!>" */
680 breakpoint();
681
682 /* NOTREACHED */
683 while(1);
684 }
685
686 /*
687 * Allocate an sf_buf for the given vm_page. On this machine, however, there
688 * is no sf_buf object. Instead, an opaque pointer to the given vm_page is
689 * returned.
690 */
691 struct sf_buf *
692 sf_buf_alloc(struct vm_page *m, int pri)
693 {
694
695 return ((struct sf_buf *)m);
696 }
697
698 /*
699 * Free the sf_buf. In fact, do nothing because there are no resources
700 * associated with the sf_buf.
701 */
702 void
703 sf_buf_free(struct sf_buf *sf)
704 {
705 }
706
707 /*
708 * Software interrupt handler for queued VM system processing.
709 */
710 void
711 swi_vm(void *dummy)
712 {
713 if (busdma_swi_pending != 0)
714 busdma_swi();
715 }
716
717 /*
718 * Tell whether this address is in some physical memory region.
719 * Currently used by the kernel coredump code in order to avoid
720 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
721 * or other unpredictable behaviour.
722 */
723
724 int
725 is_physical_memory(vm_paddr_t addr)
726 {
727
728 #ifdef DEV_ISA
729 /* The ISA ``memory hole''. */
730 if (addr >= 0xa0000 && addr < 0x100000)
731 return 0;
732 #endif
733
734 /*
735 * stuff other tests for known memory-mapped devices (PCI?)
736 * here
737 */
738
739 return 1;
740 }
Cache object: f3f8717ac926d8b02505dc3f162f3215
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