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