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_npx.h" 48 #ifdef PC98 49 #include "opt_pc98.h" 50 #endif 51 #include "opt_reset.h" 52 #include "opt_cpu.h" 53 54 #include <sys/param.h> 55 #include <sys/systm.h> 56 #include <sys/bio.h> 57 #include <sys/buf.h> 58 #include <sys/kse.h> 59 #include <sys/kernel.h> 60 #include <sys/ktr.h> 61 #include <sys/lock.h> 62 #include <sys/malloc.h> 63 #include <sys/mbuf.h> 64 #include <sys/mutex.h> 65 #include <sys/proc.h> 66 #include <sys/sf_buf.h> 67 #include <sys/smp.h> 68 #include <sys/sysctl.h> 69 #include <sys/unistd.h> 70 #include <sys/vnode.h> 71 #include <sys/vmmeter.h> 72 73 #include <machine/cpu.h> 74 #include <machine/cputypes.h> 75 #include <machine/md_var.h> 76 #include <machine/pcb.h> 77 #include <machine/pcb_ext.h> 78 #include <machine/vm86.h> 79 80 #ifdef CPU_ELAN 81 #include <machine/elan_mmcr.h> 82 #endif 83 84 #include <vm/vm.h> 85 #include <vm/vm_extern.h> 86 #include <vm/vm_kern.h> 87 #include <vm/vm_page.h> 88 #include <vm/vm_map.h> 89 #include <vm/vm_param.h> 90 91 #ifdef PC98 92 #include <pc98/pc98/pc98.h> 93 #else 94 #include <i386/isa/isa.h> 95 #endif 96 97 #ifndef NSFBUFS 98 #define NSFBUFS (512 + maxusers * 16) 99 #endif 100 101 static void cpu_reset_real(void); 102 static void sf_buf_init(void *arg); 103 SYSINIT(sock_sf, SI_SUB_MBUF, SI_ORDER_ANY, sf_buf_init, NULL) 104 105 LIST_HEAD(sf_head, sf_buf); 106 107 /* 108 * A hash table of active sendfile(2) buffers 109 */ 110 static struct sf_head *sf_buf_active; 111 static u_long sf_buf_hashmask; 112 113 #define SF_BUF_HASH(m) (((m) - vm_page_array) & sf_buf_hashmask) 114 115 static TAILQ_HEAD(, sf_buf) sf_buf_freelist; 116 static u_int sf_buf_alloc_want; 117 118 /* 119 * A lock used to synchronize access to the hash table and free list 120 */ 121 static struct mtx sf_buf_lock; 122 123 extern int _ucodesel, _udatasel; 124 125 /* 126 * Finish a fork operation, with process p2 nearly set up. 127 * Copy and update the pcb, set up the stack so that the child 128 * ready to run and return to user mode. 129 */ 130 void 131 cpu_fork(td1, p2, td2, flags) 132 register struct thread *td1; 133 register struct proc *p2; 134 struct thread *td2; 135 int flags; 136 { 137 register struct proc *p1; 138 struct pcb *pcb2; 139 struct mdproc *mdp2; 140 #ifdef DEV_NPX 141 register_t savecrit; 142 #endif 143 144 p1 = td1->td_proc; 145 if ((flags & RFPROC) == 0) { 146 if ((flags & RFMEM) == 0) { 147 /* unshare user LDT */ 148 struct mdproc *mdp1 = &p1->p_md; 149 struct proc_ldt *pldt = mdp1->md_ldt; 150 if (pldt && pldt->ldt_refcnt > 1) { 151 pldt = user_ldt_alloc(mdp1, pldt->ldt_len); 152 if (pldt == NULL) 153 panic("could not copy LDT"); 154 mdp1->md_ldt = pldt; 155 set_user_ldt(mdp1); 156 user_ldt_free(td1); 157 } 158 } 159 return; 160 } 161 162 /* Ensure that p1's pcb is up to date. */ 163 #ifdef DEV_NPX 164 if (td1 == curthread) 165 td1->td_pcb->pcb_gs = rgs(); 166 savecrit = intr_disable(); 167 if (PCPU_GET(fpcurthread) == td1) 168 npxsave(&td1->td_pcb->pcb_save); 169 intr_restore(savecrit); 170 #endif 171 172 /* Point the pcb to the top of the stack */ 173 pcb2 = (struct pcb *)(td2->td_kstack + 174 td2->td_kstack_pages * PAGE_SIZE) - 1; 175 td2->td_pcb = pcb2; 176 177 /* Copy p1's pcb */ 178 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 179 180 /* Point mdproc and then copy over td1's contents */ 181 mdp2 = &p2->p_md; 182 bcopy(&p1->p_md, mdp2, sizeof(*mdp2)); 183 184 /* 185 * Create a new fresh stack for the new process. 186 * Copy the trap frame for the return to user mode as if from a 187 * syscall. This copies most of the user mode register values. 188 * The -16 is so we can expand the trapframe if we go to vm86. 189 */ 190 td2->td_frame = (struct trapframe *)((caddr_t)td2->td_pcb - 16) - 1; 191 bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe)); 192 193 td2->td_frame->tf_eax = 0; /* Child returns zero */ 194 td2->td_frame->tf_eflags &= ~PSL_C; /* success */ 195 td2->td_frame->tf_edx = 1; 196 197 /* 198 * Set registers for trampoline to user mode. Leave space for the 199 * return address on stack. These are the kernel mode register values. 200 */ 201 #ifdef PAE 202 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdpt); 203 #else 204 pcb2->pcb_cr3 = vtophys(vmspace_pmap(p2->p_vmspace)->pm_pdir); 205 #endif 206 pcb2->pcb_edi = 0; 207 pcb2->pcb_esi = (int)fork_return; /* fork_trampoline argument */ 208 pcb2->pcb_ebp = 0; 209 pcb2->pcb_esp = (int)td2->td_frame - sizeof(void *); 210 pcb2->pcb_ebx = (int)td2; /* fork_trampoline argument */ 211 pcb2->pcb_eip = (int)fork_trampoline; 212 pcb2->pcb_psl = PSL_KERNEL; /* ints disabled */ 213 pcb2->pcb_gs = rgs(); 214 /*- 215 * pcb2->pcb_dr*: cloned above. 216 * pcb2->pcb_savefpu: cloned above. 217 * pcb2->pcb_flags: cloned above. 218 * pcb2->pcb_onfault: cloned above (always NULL here?). 219 * pcb2->pcb_gs: cloned above. 220 * pcb2->pcb_ext: cleared below. 221 */ 222 223 /* 224 * XXX don't copy the i/o pages. this should probably be fixed. 225 */ 226 pcb2->pcb_ext = 0; 227 228 /* Copy the LDT, if necessary. */ 229 mtx_lock_spin(&sched_lock); 230 if (mdp2->md_ldt != 0) { 231 if (flags & RFMEM) { 232 mdp2->md_ldt->ldt_refcnt++; 233 } else { 234 mdp2->md_ldt = user_ldt_alloc(mdp2, 235 mdp2->md_ldt->ldt_len); 236 if (mdp2->md_ldt == NULL) 237 panic("could not copy LDT"); 238 } 239 } 240 mtx_unlock_spin(&sched_lock); 241 242 /* 243 * Now, cpu_switch() can schedule the new process. 244 * pcb_esp is loaded pointing to the cpu_switch() stack frame 245 * containing the return address when exiting cpu_switch. 246 * This will normally be to fork_trampoline(), which will have 247 * %ebx loaded with the new proc's pointer. fork_trampoline() 248 * will set up a stack to call fork_return(p, frame); to complete 249 * the return to user-mode. 250 */ 251 } 252 253 /* 254 * Intercept the return address from a freshly forked process that has NOT 255 * been scheduled yet. 256 * 257 * This is needed to make kernel threads stay in kernel mode. 258 */ 259 void 260 cpu_set_fork_handler(td, func, arg) 261 struct thread *td; 262 void (*func)(void *); 263 void *arg; 264 { 265 /* 266 * Note that the trap frame follows the args, so the function 267 * is really called like this: func(arg, frame); 268 */ 269 td->td_pcb->pcb_esi = (int) func; /* function */ 270 td->td_pcb->pcb_ebx = (int) arg; /* first arg */ 271 } 272 273 void 274 cpu_exit(struct thread *td) 275 { 276 struct mdproc *mdp; 277 struct pcb *pcb = td->td_pcb; 278 279 280 /* Reset pc->pcb_gs and %gs before possibly invalidating it. */ 281 mdp = &td->td_proc->p_md; 282 if (mdp->md_ldt) { 283 td->td_pcb->pcb_gs = _udatasel; 284 load_gs(_udatasel); 285 user_ldt_free(td); 286 } 287 if (pcb->pcb_flags & PCB_DBREGS) { 288 /* disable all hardware breakpoints */ 289 reset_dbregs(); 290 pcb->pcb_flags &= ~PCB_DBREGS; 291 } 292 } 293 294 void 295 cpu_thread_exit(struct thread *td) 296 { 297 struct pcb *pcb = td->td_pcb; 298 #ifdef DEV_NPX 299 if (td == PCPU_GET(fpcurthread)) 300 npxdrop(); 301 #endif 302 if (pcb->pcb_flags & PCB_DBREGS) { 303 /* disable all hardware breakpoints */ 304 reset_dbregs(); 305 pcb->pcb_flags &= ~PCB_DBREGS; 306 } 307 } 308 309 void 310 cpu_thread_clean(struct thread *td) 311 { 312 struct pcb *pcb; 313 314 pcb = td->td_pcb; 315 if (pcb->pcb_ext != 0) { 316 /* XXXKSE XXXSMP not SMP SAFE.. what locks do we have? */ 317 /* if (pcb->pcb_ext->ext_refcount-- == 1) ?? */ 318 /* 319 * XXX do we need to move the TSS off the allocated pages 320 * before freeing them? (not done here) 321 */ 322 kmem_free(kernel_map, (vm_offset_t)pcb->pcb_ext, 323 ctob(IOPAGES + 1)); 324 pcb->pcb_ext = 0; 325 } 326 } 327 328 void 329 cpu_thread_swapin(struct thread *td) 330 { 331 } 332 333 void 334 cpu_thread_swapout(struct thread *td) 335 { 336 } 337 338 void 339 cpu_thread_setup(struct thread *td) 340 { 341 342 td->td_pcb = (struct pcb *)(td->td_kstack + 343 td->td_kstack_pages * PAGE_SIZE) - 1; 344 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb - 16) - 1; 345 td->td_pcb->pcb_ext = NULL; 346 } 347 348 /* 349 * Initialize machine state (pcb and trap frame) for a new thread about to 350 * upcall. Pu t enough state in the new thread's PCB to get it to go back 351 * userret(), where we can intercept it again to set the return (upcall) 352 * Address and stack, along with those from upcals that are from other sources 353 * such as those generated in thread_userret() itself. 354 */ 355 void 356 cpu_set_upcall(struct thread *td, struct thread *td0) 357 { 358 struct pcb *pcb2; 359 360 /* Point the pcb to the top of the stack. */ 361 pcb2 = td->td_pcb; 362 363 /* 364 * Copy the upcall pcb. This loads kernel regs. 365 * Those not loaded individually below get their default 366 * values here. 367 * 368 * XXXKSE It might be a good idea to simply skip this as 369 * the values of the other registers may be unimportant. 370 * This would remove any requirement for knowing the KSE 371 * at this time (see the matching comment below for 372 * more analysis) (need a good safe default). 373 */ 374 bcopy(td0->td_pcb, pcb2, sizeof(*pcb2)); 375 pcb2->pcb_flags &= ~(PCB_NPXTRAP|PCB_NPXINITDONE); 376 377 /* 378 * Create a new fresh stack for the new thread. 379 * The -16 is so we can expand the trapframe if we go to vm86. 380 * Don't forget to set this stack value into whatever supplies 381 * the address for the fault handlers. 382 * The contexts are filled in at the time we actually DO the 383 * upcall as only then do we know which KSE we got. 384 */ 385 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 386 387 /* 388 * Set registers for trampoline to user mode. Leave space for the 389 * return address on stack. These are the kernel mode register values. 390 */ 391 #ifdef PAE 392 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdpt); 393 #else 394 pcb2->pcb_cr3 = vtophys(vmspace_pmap(td->td_proc->p_vmspace)->pm_pdir); 395 #endif 396 pcb2->pcb_edi = 0; 397 pcb2->pcb_esi = (int)fork_return; /* trampoline arg */ 398 pcb2->pcb_ebp = 0; 399 pcb2->pcb_esp = (int)td->td_frame - sizeof(void *); /* trampoline arg */ 400 pcb2->pcb_ebx = (int)td; /* trampoline arg */ 401 pcb2->pcb_eip = (int)fork_trampoline; 402 pcb2->pcb_psl &= ~(PSL_I); /* interrupts must be disabled */ 403 pcb2->pcb_gs = rgs(); 404 /* 405 * If we didn't copy the pcb, we'd need to do the following registers: 406 * pcb2->pcb_dr*: cloned above. 407 * pcb2->pcb_savefpu: cloned above. 408 * pcb2->pcb_flags: cloned above. 409 * pcb2->pcb_onfault: cloned above (always NULL here?). 410 * pcb2->pcb_gs: cloned above. XXXKSE ??? 411 * pcb2->pcb_ext: cleared below. 412 */ 413 pcb2->pcb_ext = NULL; 414 } 415 416 /* 417 * Set that machine state for performing an upcall that has to 418 * be done in thread_userret() so that those upcalls generated 419 * in thread_userret() itself can be done as well. 420 */ 421 void 422 cpu_set_upcall_kse(struct thread *td, struct kse_upcall *ku) 423 { 424 425 /* 426 * Do any extra cleaning that needs to be done. 427 * The thread may have optional components 428 * that are not present in a fresh thread. 429 * This may be a recycled thread so make it look 430 * as though it's newly allocated. 431 */ 432 cpu_thread_clean(td); 433 434 /* 435 * Set the trap frame to point at the beginning of the uts 436 * function. 437 */ 438 td->td_frame->tf_ebp = 0; 439 td->td_frame->tf_esp = 440 (int)ku->ku_stack.ss_sp + ku->ku_stack.ss_size - 16; 441 td->td_frame->tf_eip = (int)ku->ku_func; 442 443 /* 444 * Pass the address of the mailbox for this kse to the uts 445 * function as a parameter on the stack. 446 */ 447 suword((void *)(td->td_frame->tf_esp + sizeof(void *)), 448 (int)ku->ku_mailbox); 449 } 450 451 /* 452 * Convert kernel VA to physical address 453 */ 454 vm_paddr_t 455 kvtop(void *addr) 456 { 457 vm_paddr_t pa; 458 459 pa = pmap_kextract((vm_offset_t)addr); 460 if (pa == 0) 461 panic("kvtop: zero page frame"); 462 return (pa); 463 } 464 465 void 466 cpu_reset() 467 { 468 #ifdef SMP 469 u_int map; 470 471 if (smp_active) { 472 map = PCPU_GET(other_cpus) & ~stopped_cpus; 473 if (map != 0) { 474 printf("cpu_reset: Stopping other CPUs\n"); 475 stop_cpus(map); 476 } 477 DELAY(1000000); 478 } 479 #endif 480 cpu_reset_real(); 481 /* NOTREACHED */ 482 } 483 484 static void 485 cpu_reset_real() 486 { 487 488 #ifdef CPU_ELAN 489 if (elan_mmcr != NULL) 490 elan_mmcr->RESCFG = 1; 491 #endif 492 493 if (cpu == CPU_GEODE1100) { 494 /* Attempt Geode's own reset */ 495 outl(0xcf8, 0x80009044ul); 496 outl(0xcfc, 0xf); 497 } 498 499 #ifdef PC98 500 /* 501 * Attempt to do a CPU reset via CPU reset port. 502 */ 503 disable_intr(); 504 if ((inb(0x35) & 0xa0) != 0xa0) { 505 outb(0x37, 0x0f); /* SHUT0 = 0. */ 506 outb(0x37, 0x0b); /* SHUT1 = 0. */ 507 } 508 outb(0xf0, 0x00); /* Reset. */ 509 #else 510 #if !defined(BROKEN_KEYBOARD_RESET) 511 /* 512 * Attempt to do a CPU reset via the keyboard controller, 513 * do not turn off GateA20, as any machine that fails 514 * to do the reset here would then end up in no man's land. 515 */ 516 outb(IO_KBD + 4, 0xFE); 517 DELAY(500000); /* wait 0.5 sec to see if that did it */ 518 printf("Keyboard reset did not work, attempting CPU shutdown\n"); 519 DELAY(1000000); /* wait 1 sec for printf to complete */ 520 #endif 521 #endif /* PC98 */ 522 523 /* Force a shutdown by unmapping entire address space. */ 524 bzero((caddr_t)PTD, NBPTD); 525 526 /* "good night, sweet prince .... <THUNK!>" */ 527 invltlb(); 528 /* NOTREACHED */ 529 while(1); 530 } 531 532 /* 533 * Allocate a pool of sf_bufs (sendfile(2) or "super-fast" if you prefer. :-)) 534 */ 535 static void 536 sf_buf_init(void *arg) 537 { 538 struct sf_buf *sf_bufs; 539 vm_offset_t sf_base; 540 int i; 541 542 nsfbufs = NSFBUFS; 543 TUNABLE_INT_FETCH("kern.ipc.nsfbufs", &nsfbufs); 544 545 sf_buf_active = hashinit(nsfbufs, M_TEMP, &sf_buf_hashmask); 546 TAILQ_INIT(&sf_buf_freelist); 547 sf_base = kmem_alloc_nofault(kernel_map, nsfbufs * PAGE_SIZE); 548 sf_bufs = malloc(nsfbufs * sizeof(struct sf_buf), M_TEMP, 549 M_NOWAIT | M_ZERO); 550 for (i = 0; i < nsfbufs; i++) { 551 sf_bufs[i].kva = sf_base + i * PAGE_SIZE; 552 TAILQ_INSERT_TAIL(&sf_buf_freelist, &sf_bufs[i], free_entry); 553 } 554 sf_buf_alloc_want = 0; 555 mtx_init(&sf_buf_lock, "sf_buf", NULL, MTX_DEF); 556 } 557 558 /* 559 * Get an sf_buf from the freelist. Will block if none are available. 560 */ 561 struct sf_buf * 562 sf_buf_alloc(struct vm_page *m, int flags) 563 { 564 pt_entry_t opte, *ptep; 565 struct sf_head *hash_list; 566 struct sf_buf *sf; 567 int error; 568 569 hash_list = &sf_buf_active[SF_BUF_HASH(m)]; 570 mtx_lock(&sf_buf_lock); 571 LIST_FOREACH(sf, hash_list, list_entry) { 572 if (sf->m == m) { 573 sf->ref_count++; 574 if (sf->ref_count == 1) { 575 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry); 576 nsfbufsused++; 577 nsfbufspeak = imax(nsfbufspeak, nsfbufsused); 578 } 579 goto done; 580 } 581 } 582 while ((sf = TAILQ_FIRST(&sf_buf_freelist)) == NULL) { 583 if (flags & SFB_NOWAIT) 584 goto done; 585 sf_buf_alloc_want++; 586 mbstat.sf_allocwait++; 587 error = msleep(&sf_buf_freelist, &sf_buf_lock, 588 (flags & SFB_CATCH) ? PCATCH | PVM : PVM, "sfbufa", 0); 589 sf_buf_alloc_want--; 590 591 /* 592 * If we got a signal, don't risk going back to sleep. 593 */ 594 if (error) 595 goto done; 596 } 597 TAILQ_REMOVE(&sf_buf_freelist, sf, free_entry); 598 if (sf->m != NULL) 599 LIST_REMOVE(sf, list_entry); 600 LIST_INSERT_HEAD(hash_list, sf, list_entry); 601 sf->ref_count = 1; 602 sf->m = m; 603 nsfbufsused++; 604 nsfbufspeak = imax(nsfbufspeak, nsfbufsused); 605 606 /* 607 * Update the sf_buf's virtual-to-physical mapping, flushing the 608 * virtual address from the TLB only if the PTE implies that the old 609 * mapping has been used. Since the reference count for the sf_buf's 610 * old mapping was zero, that mapping is not currently in use. 611 * Consequently, there is no need to exchange the old and new PTEs 612 * atomically, even under PAE. 613 */ 614 ptep = vtopte(sf->kva); 615 opte = *ptep; 616 *ptep = VM_PAGE_TO_PHYS(m) | pgeflag | PG_RW | PG_V; 617 if ((opte & (PG_A | PG_V)) == (PG_A | PG_V)) 618 pmap_invalidate_page(kernel_pmap, sf->kva); 619 done: 620 mtx_unlock(&sf_buf_lock); 621 return (sf); 622 } 623 624 /* 625 * Remove a reference from the given sf_buf, adding it to the free 626 * list when its reference count reaches zero. A freed sf_buf still, 627 * however, retains its virtual-to-physical mapping until it is 628 * recycled or reactivated by sf_buf_alloc(9). 629 */ 630 void 631 sf_buf_free(struct sf_buf *sf) 632 { 633 634 mtx_lock(&sf_buf_lock); 635 sf->ref_count--; 636 if (sf->ref_count == 0) { 637 TAILQ_INSERT_TAIL(&sf_buf_freelist, sf, free_entry); 638 nsfbufsused--; 639 if (sf_buf_alloc_want > 0) 640 wakeup_one(&sf_buf_freelist); 641 } 642 mtx_unlock(&sf_buf_lock); 643 } 644 645 /* 646 * Software interrupt handler for queued VM system processing. 647 */ 648 void 649 swi_vm(void *dummy) 650 { 651 if (busdma_swi_pending != 0) 652 busdma_swi(); 653 } 654 655 /* 656 * Tell whether this address is in some physical memory region. 657 * Currently used by the kernel coredump code in order to avoid 658 * dumping the ``ISA memory hole'' which could cause indefinite hangs, 659 * or other unpredictable behaviour. 660 */ 661 662 int 663 is_physical_memory(vm_paddr_t addr) 664 { 665 666 #ifdef DEV_ISA 667 /* The ISA ``memory hole''. */ 668 if (addr >= 0xa0000 && addr < 0x100000) 669 return 0; 670 #endif 671 672 /* 673 * stuff other tests for known memory-mapped devices (PCI?) 674 * here 675 */ 676 677 return 1; 678 } 679