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/5.2/sys/i386/i386/vm_machdep.c 122860 2003-11-17 18:22:24Z alc $");
45
46 #include "opt_npx.h"
47 #ifdef PC98
48 #include "opt_pc98.h"
49 #endif
50 #include "opt_reset.h"
51 #include "opt_isa.h"
52 #include "opt_kstack_pages.h"
53
54 #include <sys/param.h>
55 #include <sys/systm.h>
56 #include <sys/malloc.h>
57 #include <sys/proc.h>
58 #include <sys/kse.h>
59 #include <sys/bio.h>
60 #include <sys/buf.h>
61 #include <sys/vnode.h>
62 #include <sys/vmmeter.h>
63 #include <sys/kernel.h>
64 #include <sys/ktr.h>
65 #include <sys/mbuf.h>
66 #include <sys/mutex.h>
67 #include <sys/smp.h>
68 #include <sys/sf_buf.h>
69 #include <sys/sysctl.h>
70 #include <sys/unistd.h>
71
72 #include <machine/cpu.h>
73 #include <machine/md_var.h>
74 #include <machine/pcb.h>
75 #include <machine/pcb_ext.h>
76 #include <machine/vm86.h>
77
78 #include <vm/vm.h>
79 #include <vm/vm_param.h>
80 #include <sys/lock.h>
81 #include <vm/vm_kern.h>
82 #include <vm/vm_page.h>
83 #include <vm/vm_map.h>
84 #include <vm/vm_extern.h>
85
86 #include <sys/user.h>
87
88 #ifdef PC98
89 #include <pc98/pc98/pc98.h>
90 #else
91 #include <i386/isa/isa.h>
92 #endif
93
94 static void cpu_reset_real(void);
95 #ifdef SMP
96 static void cpu_reset_proxy(void);
97 static u_int cpu_reset_proxyid;
98 static volatile u_int cpu_reset_proxy_active;
99 #endif
100 static void sf_buf_init(void *arg);
101 SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL)
102
103 LIST_HEAD(sf_head, sf_buf);
104
105 /*
106 * A hash table of active sendfile(2) buffers
107 */
108 static struct sf_head *sf_buf_active;
109 static u_long sf_buf_hashmask;
110
111 #define SF_BUF_HASH(m) (((m) - vm_page_array) & sf_buf_hashmask)
112
113 static struct sf_head sf_buf_freelist;
114 static u_int sf_buf_alloc_want;
115
116 /*
117 * A lock used to synchronize access to the hash table and free list
118 */
119 static struct mtx sf_buf_lock;
120
121 extern int _ucodesel, _udatasel;
122
123 /*
124 * Finish a fork operation, with process p2 nearly set up.
125 * Copy and update the pcb, set up the stack so that the child
126 * ready to run and return to user mode.
127 */
128 void
129 cpu_fork(td1, p2, td2, flags)
130 register struct thread *td1;
131 register struct proc *p2;
132 struct thread *td2;
133 int flags;
134 {
135 register struct proc *p1;
136 struct pcb *pcb2;
137 struct mdproc *mdp2;
138 #ifdef DEV_NPX
139 register_t savecrit;
140 #endif
141
142 p1 = td1->td_proc;
143 if ((flags & RFPROC) == 0) {
144 if ((flags & RFMEM) == 0) {
145 /* unshare user LDT */
146 struct mdproc *mdp1 = &p1->p_md;
147 struct proc_ldt *pldt = mdp1->md_ldt;
148 if (pldt && pldt->ldt_refcnt > 1) {
149 pldt = user_ldt_alloc(mdp1, pldt->ldt_len);
150 if (pldt == NULL)
151 panic("could not copy LDT");
152 mdp1->md_ldt = pldt;
153 set_user_ldt(mdp1);
154 user_ldt_free(td1);
155 }
156 }
157 return;
158 }
159
160 /* Ensure that p1's pcb is up to date. */
161 #ifdef DEV_NPX
162 if (td1 == curthread)
163 td1->td_pcb->pcb_gs = rgs();
164 savecrit = intr_disable();
165 if (PCPU_GET(fpcurthread) == td1)
166 npxsave(&td1->td_pcb->pcb_save);
167 intr_restore(savecrit);
168 #endif
169
170 /* Point the pcb to the top of the stack */
171 pcb2 = (struct pcb *)(td2->td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;
172 td2->td_pcb = pcb2;
173
174 /* Copy p1's pcb */
175 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
176
177 /* Point mdproc and then copy over td1's contents */
178 mdp2 = &p2->p_md;
179 bcopy(&p1->p_md, mdp2, sizeof(*mdp2));
180
181 /*
182 * Create a new fresh stack for the new process.
183 * Copy the trap frame for the return to user mode as if from a
184 * syscall. This copies most of the user mode register values.
185 * The -16 is so we can expand the trapframe if we go to vm86.
186 */
187 td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1;
188 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
189
190 td2->td_frame->tf_eax = 0; /* Child returns zero */
191 td2->td_frame->tf_eflags &= ~PSL_C; /* success */
192 td2->td_frame->tf_edx = 1;
193
194 /*
195 * Set registers for trampoline to user mode. Leave space for the
196 * return address on stack. These are the kernel mode register values.
197 */
198 #ifdef PAE
199 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdpt);
200 #else
201 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir);
202 #endif
203 pcb2->pcb_edi = 0;
204 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */
205 pcb2->pcb_ebp = 0;
206 pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *);
207 pcb2->pcb_ebx = (int)td2; /* fork_trampoline argument */
208 pcb2->pcb_eip = (int)fork_trampoline;
209 pcb2->pcb_psl = PSL_KERNEL; /* ints disabled */
210 pcb2->pcb_gs = rgs();
211 /*-
212 * pcb2->pcb_dr*: cloned above.
213 * pcb2->pcb_savefpu: cloned above.
214 * pcb2->pcb_flags: cloned above.
215 * pcb2->pcb_onfault: cloned above (always NULL here?).
216 * pcb2->pcb_gs: cloned above.
217 * pcb2->pcb_ext: cleared below.
218 */
219
220 /*
221 * XXX don't copy the i/o pages. this should probably be fixed.
222 */
223 pcb2->pcb_ext = 0;
224
225 /* Copy the LDT, if necessary. */
226 mtx_lock_spin(&sched_lock);
227 if (mdp2->md_ldt != 0) {
228 if (flags & RFMEM) {
229 mdp2->md_ldt->ldt_refcnt++;
230 } else {
231 mdp2->md_ldt = user_ldt_alloc(mdp2,
232 mdp2->md_ldt->ldt_len);
233 if (mdp2->md_ldt == NULL)
234 panic("could not copy LDT");
235 }
236 }
237 mtx_unlock_spin(&sched_lock);
238
239 /*
240 * Now, cpu_switch() can schedule the new process.
241 * pcb_esp is loaded pointing to the cpu_switch() stack frame
242 * containing the return address when exiting cpu_switch.
243 * This will normally be to fork_trampoline(), which will have
244 * %ebx loaded with the new proc's pointer. fork_trampoline()
245 * will set up a stack to call fork_return(p, frame); to complete
246 * the return to user-mode.
247 */
248 }
249
250 /*
251 * Intercept the return address from a freshly forked process that has NOT
252 * been scheduled yet.
253 *
254 * This is needed to make kernel threads stay in kernel mode.
255 */
256 void
257 cpu_set_fork_handler(td, func, arg)
258 struct thread *td;
259 void (*func)(void *);
260 void *arg;
261 {
262 /*
263 * Note that the trap frame follows the args, so the function
264 * is really called like this: func(arg, frame);
265 */
266 td->td_pcb->pcb_esi = (int) func; /* function */
267 td->td_pcb->pcb_ebx = (int) arg; /* first arg */
268 }
269
270 void
271 cpu_exit(struct thread *td)
272 {
273 struct mdproc *mdp;
274 struct pcb *pcb = td->td_pcb;
275
276
277 /* Reset pc->pcb_gs and %gs before possibly invalidating it. */
278 mdp = &td->td_proc->p_md;
279 if (mdp->md_ldt) {
280 td->td_pcb->pcb_gs = _udatasel;
281 load_gs(_udatasel);
282 user_ldt_free(td);
283 }
284 if (pcb->pcb_flags & PCB_DBREGS) {
285 /* disable all hardware breakpoints */
286 reset_dbregs();
287 pcb->pcb_flags &= ~PCB_DBREGS;
288 }
289 }
290
291 void
292 cpu_thread_exit(struct thread *td)
293 {
294 struct pcb *pcb = td->td_pcb;
295 #ifdef DEV_NPX
296 if (td == PCPU_GET(fpcurthread))
297 npxdrop();
298 #endif
299 if (pcb->pcb_flags & PCB_DBREGS) {
300 /* disable all hardware breakpoints */
301 reset_dbregs();
302 pcb->pcb_flags &= ~PCB_DBREGS;
303 }
304 }
305
306 void
307 cpu_thread_clean(struct thread *td)
308 {
309 struct pcb *pcb;
310
311 pcb = td->td_pcb;
312 if (pcb->pcb_ext != 0) {
313 /* XXXKSE XXXSMP not SMP SAFE.. what locks do we have? */
314 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */
315 /*
316 * XXX do we need to move the TSS off the allocated pages
317 * before freeing them? (not done here)
318 */
319 mtx_lock(&Giant);
320 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext,
321 ctob(IOPAGES + 1));
322 mtx_unlock(&Giant);
323 pcb->pcb_ext = 0;
324 }
325 }
326
327 void
328 cpu_thread_swapin(struct thread *td)
329 {
330 }
331
332 void
333 cpu_thread_swapout(struct thread *td)
334 {
335 }
336
337 void
338 cpu_sched_exit(td)
339 register struct thread *td;
340 {
341 }
342
343 void
344 cpu_thread_setup(struct thread *td)
345 {
346
347 td->td_pcb =
348 (struct pcb *)(td->td_kstack + KSTACK_PAGES * PAGE_SIZE) - 1;
349 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb - 16) - 1;
350 td->td_pcb->pcb_ext = NULL;
351 }
352
353 /*
354 * Initialize machine state (pcb and trap frame) for a new thread about to
355 * upcall. Pu t enough state in the new thread's PCB to get it to go back
356 * userret(), where we can intercept it again to set the return (upcall)
357 * Address and stack, along with those from upcals that are from other sources
358 * such as those generated in thread_userret() itself.
359 */
360 void
361 cpu_set_upcall(struct thread *td, struct thread *td0)
362 {
363 struct pcb *pcb2;
364
365 /* Point the pcb to the top of the stack. */
366 pcb2 = td->td_pcb;
367
368 /*
369 * Copy the upcall pcb. This loads kernel regs.
370 * Those not loaded individually below get their default
371 * values here.
372 *
373 * XXXKSE It might be a good idea to simply skip this as
374 * the values of the other registers may be unimportant.
375 * This would remove any requirement for knowing the KSE
376 * at this time (see the matching comment below for
377 * more analysis) (need a good safe default).
378 */
379 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2));
380 pcb2->pcb_flags &= ~(PCB_NPXTRAP|PCB_NPXINITDONE);
381
382 /*
383 * Create a new fresh stack for the new thread.
384 * The -16 is so we can expand the trapframe if we go to vm86.
385 * Don't forget to set this stack value into whatever supplies
386 * the address for the fault handlers.
387 * The contexts are filled in at the time we actually DO the
388 * upcall as only then do we know which KSE we got.
389 */
390 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
391
392 /*
393 * Set registers for trampoline to user mode. Leave space for the
394 * return address on stack. These are the kernel mode register values.
395 */
396 #ifdef PAE
397 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdpt);
398 #else
399 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdir);
400 #endif
401 pcb2->pcb_edi = 0;
402 pcb2->pcb_esi = (int)fork_return; /* trampoline arg */
403 pcb2->pcb_ebp = 0;
404 pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */
405 pcb2->pcb_ebx = (int)td; /* trampoline arg */
406 pcb2->pcb_eip = (int)fork_trampoline;
407 pcb2->pcb_psl &= ~(PSL_I); /* interrupts must be disabled */
408 pcb2->pcb_gs = rgs();
409 /*
410 * If we didn't copy the pcb, we'd need to do the following registers:
411 * pcb2->pcb_dr*: cloned above.
412 * pcb2->pcb_savefpu: cloned above.
413 * pcb2->pcb_flags: cloned above.
414 * pcb2->pcb_onfault: cloned above (always NULL here?).
415 * pcb2->pcb_gs: cloned above. XXXKSE ???
416 * pcb2->pcb_ext: cleared below.
417 */
418 pcb2->pcb_ext = NULL;
419 }
420
421 /*
422 * Set that machine state for performing an upcall that has to
423 * be done in thread_userret() so that those upcalls generated
424 * in thread_userret() itself can be done as well.
425 */
426 void
427 cpu_set_upcall_kse(struct thread *td, struct kse_upcall *ku)
428 {
429
430 /*
431 * Do any extra cleaning that needs to be done.
432 * The thread may have optional components
433 * that are not present in a fresh thread.
434 * This may be a recycled thread so make it look
435 * as though it's newly allocated.
436 */
437 cpu_thread_clean(td);
438
439 /*
440 * Set the trap frame to point at the beginning of the uts
441 * function.
442 */
443 td->td_frame->tf_esp =
444 (int)ku->ku_stack.ss_sp + ku->ku_stack.ss_size - 16;
445 td->td_frame->tf_eip = (int)ku->ku_func;
446
447 /*
448 * Pass the address of the mailbox for this kse to the uts
449 * function as a parameter on the stack.
450 */
451 suword((void *)(td->td_frame->tf_esp + sizeof(void *)),
452 (int)ku->ku_mailbox);
453 }
454
455 /*
456 * Convert kernel VA to physical address
457 */
458 vm_paddr_t
459 kvtop(void *addr)
460 {
461 vm_paddr_t pa;
462
463 pa = pmap_kextract((vm_offset_t)addr);
464 if (pa == 0)
465 panic("kvtop: zero page frame");
466 return (pa);
467 }
468
469 /*
470 * Force reset the processor by invalidating the entire address space!
471 */
472
473 #ifdef SMP
474 static void
475 cpu_reset_proxy()
476 {
477
478 cpu_reset_proxy_active = 1;
479 while (cpu_reset_proxy_active == 1)
480 ; /* Wait for other cpu to see that we've started */
481 stop_cpus((1<<cpu_reset_proxyid));
482 printf("cpu_reset_proxy: Stopped CPU %d\n", cpu_reset_proxyid);
483 DELAY(1000000);
484 cpu_reset_real();
485 }
486 #endif
487
488 void
489 cpu_reset()
490 {
491 #ifdef SMP
492 if (smp_active == 0) {
493 cpu_reset_real();
494 /* NOTREACHED */
495 } else {
496
497 u_int map;
498 int cnt;
499 printf("cpu_reset called on cpu#%d\n", PCPU_GET(cpuid));
500
501 map = PCPU_GET(other_cpus) & ~ stopped_cpus;
502
503 if (map != 0) {
504 printf("cpu_reset: Stopping other CPUs\n");
505 stop_cpus(map); /* Stop all other CPUs */
506 }
507
508 if (PCPU_GET(cpuid) == 0) {
509 DELAY(1000000);
510 cpu_reset_real();
511 /* NOTREACHED */
512 } else {
513 /* We are not BSP (CPU #0) */
514
515 cpu_reset_proxyid = PCPU_GET(cpuid);
516 cpustop_restartfunc = cpu_reset_proxy;
517 cpu_reset_proxy_active = 0;
518 printf("cpu_reset: Restarting BSP\n");
519 started_cpus = (1<<0); /* Restart CPU #0 */
520
521 cnt = 0;
522 while (cpu_reset_proxy_active == 0 && cnt < 10000000)
523 cnt++; /* Wait for BSP to announce restart */
524 if (cpu_reset_proxy_active == 0)
525 printf("cpu_reset: Failed to restart BSP\n");
526 enable_intr();
527 cpu_reset_proxy_active = 2;
528
529 while (1);
530 /* NOTREACHED */
531 }
532 }
533 #else
534 cpu_reset_real();
535 #endif
536 }
537
538 static void
539 cpu_reset_real()
540 {
541
542 #ifdef PC98
543 /*
544 * Attempt to do a CPU reset via CPU reset port.
545 */
546 disable_intr();
547 if ((inb(0x35) & 0xa0) != 0xa0) {
548 outb(0x37, 0x0f); /* SHUT0 = 0. */
549 outb(0x37, 0x0b); /* SHUT1 = 0. */
550 }
551 outb(0xf0, 0x00); /* Reset. */
552 #else
553 /*
554 * Attempt to do a CPU reset via the keyboard controller,
555 * do not turn of the GateA20, as any machine that fails
556 * to do the reset here would then end up in no man's land.
557 */
558
559 #if !defined(BROKEN_KEYBOARD_RESET)
560 outb(IO_KBD + 4, 0xFE);
561 DELAY(500000); /* wait 0.5 sec to see if that did it */
562 printf("Keyboard reset did not work, attempting CPU shutdown\n");
563 DELAY(1000000); /* wait 1 sec for printf to complete */
564 #endif
565 #endif /* PC98 */
566 /* force a shutdown by unmapping entire address space ! */
567 bzero((caddr_t)PTD, NBPTD);
568
569 /* "good night, sweet prince .... <THUNK!>" */
570 invltlb();
571 /* NOTREACHED */
572 while(1);
573 }
574
575 /*
576 * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-))
577 */
578 static void
579 sf_buf_init(void *arg)
580 {
581 struct sf_buf *sf_bufs;
582 vm_offset_t sf_base;
583 int i;
584
585 sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask);
586 LIST_INIT(&sf_buf_freelist);
587 sf_base = kmem_alloc_nofault(kernel_map, nsfbufs * PAGE_SIZE);
588 sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP,
589 M_NOWAIT | M_ZERO);
590 for (i = 0; i < nsfbufs; i++) {
591 sf_bufs[i].kva = sf_base + i * PAGE_SIZE;
592 LIST_INSERT_HEAD(&sf_buf_freelist, &sf_bufs[i], list_entry);
593 }
594 sf_buf_alloc_want = 0;
595 mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF);
596 }
597
598 /*
599 * Get an sf_buf from the freelist. Will block if none are available.
600 */
601 struct sf_buf *
602 sf_buf_alloc(struct vm_page *m)
603 {
604 struct sf_head *hash_list;
605 struct sf_buf *sf;
606 int error;
607
608 hash_list = &sf_buf_active[SF_BUF_HASH(m)];
609 mtx_lock(&sf_buf_lock);
610 LIST_FOREACH(sf, hash_list, list_entry) {
611 if (sf->m == m) {
612 sf->ref_count++;
613 goto done;
614 }
615 }
616 while ((sf = LIST_FIRST(&sf_buf_freelist)) == NULL) {
617 sf_buf_alloc_want++;
618 error = msleep(&sf_buf_freelist, &sf_buf_lock, PVM|PCATCH,
619 "sfbufa", 0);
620 sf_buf_alloc_want--;
621
622 /*
623 * If we got a signal, don't risk going back to sleep.
624 */
625 if (error)
626 goto done;
627 }
628 LIST_REMOVE(sf, list_entry);
629 LIST_INSERT_HEAD(hash_list, sf, list_entry);
630 sf->ref_count = 1;
631 sf->m = m;
632 pmap_qenter(sf->kva, &sf->m, 1);
633 done:
634 mtx_unlock(&sf_buf_lock);
635 return (sf);
636 }
637
638 /*
639 * Detatch mapped page and release resources back to the system.
640 */
641 void
642 sf_buf_free(void *addr, void *args)
643 {
644 struct sf_buf *sf;
645 struct vm_page *m;
646
647 sf = args;
648 mtx_lock(&sf_buf_lock);
649 m = sf->m;
650 sf->ref_count--;
651 if (sf->ref_count == 0) {
652 pmap_qremove((vm_offset_t)addr, 1);
653 sf->m = NULL;
654 LIST_REMOVE(sf, list_entry);
655 LIST_INSERT_HEAD(&sf_buf_freelist, sf, list_entry);
656 if (sf_buf_alloc_want > 0)
657 wakeup_one(&sf_buf_freelist);
658 }
659 mtx_unlock(&sf_buf_lock);
660
661 vm_page_lock_queues();
662 vm_page_unwire(m, 0);
663 /*
664 * Check for the object going away on us. This can
665 * happen since we don't hold a reference to it.
666 * If so, we're responsible for freeing the page.
667 */
668 if (m->wire_count == 0 && m->object == NULL)
669 vm_page_free(m);
670 vm_page_unlock_queues();
671 }
672
673 /*
674 * Software interrupt handler for queued VM system processing.
675 */
676 void
677 swi_vm(void *dummy)
678 {
679 if (busdma_swi_pending != 0)
680 busdma_swi();
681 }
682
683 /*
684 * Tell whether this address is in some physical memory region.
685 * Currently used by the kernel coredump code in order to avoid
686 * dumping the ``ISA memory hole'' which could cause indefinite hangs,
687 * or other unpredictable behaviour.
688 */
689
690 int
691 is_physical_memory(addr)
692 vm_offset_t addr;
693 {
694
695 #ifdef DEV_ISA
696 /* The ISA ``memory hole''. */
697 if (addr >= 0xa0000 && addr < 0x100000)
698 return 0;
699 #endif
700
701 /*
702 * stuff other tests for known memory-mapped devices (PCI?)
703 * here
704 */
705
706 return 1;
707 }
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