vm_machdep.c revision 12819
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 * $Id: vm_machdep.c,v 1.48 1995/12/11 04:55:01 dyson Exp $ 42 */ 43 44#include "npx.h" 45#include <sys/param.h> 46#include <sys/systm.h> 47#include <sys/proc.h> 48#include <sys/malloc.h> 49#include <sys/buf.h> 50#include <sys/vnode.h> 51#include <sys/vmmeter.h> 52 53#include <machine/clock.h> 54#include <machine/cpu.h> 55#include <machine/md_var.h> 56 57#include <vm/vm.h> 58#include <vm/vm_param.h> 59#include <vm/vm_prot.h> 60#include <vm/lock.h> 61#include <vm/vm_kern.h> 62#include <vm/vm_page.h> 63#include <vm/vm_map.h> 64#include <vm/vm_extern.h> 65 66#include <sys/user.h> 67 68#include <i386/isa/isa.h> 69 70static void vm_fault_quick __P((caddr_t v, int prot)); 71 72#ifdef BOUNCE_BUFFERS 73static vm_offset_t 74 vm_bounce_kva __P((int size, int waitok)); 75static void vm_bounce_kva_free __P((vm_offset_t addr, vm_offset_t size, 76 int now)); 77static vm_offset_t 78 vm_bounce_page_find __P((int count)); 79static void vm_bounce_page_free __P((vm_offset_t pa, int count)); 80 81static volatile int kvasfreecnt; 82 83caddr_t bouncememory; 84int bouncepages; 85static int bpwait; 86static vm_offset_t *bouncepa; 87static int bmwait, bmfreeing; 88 89#define BITS_IN_UNSIGNED (8*sizeof(unsigned)) 90static int bounceallocarraysize; 91static unsigned *bounceallocarray; 92static int bouncefree; 93 94#define SIXTEENMEG (4096*4096) 95#define MAXBKVA 1024 96int maxbkva = MAXBKVA*NBPG; 97 98/* special list that can be used at interrupt time for eventual kva free */ 99static struct kvasfree { 100 vm_offset_t addr; 101 vm_offset_t size; 102} kvaf[MAXBKVA]; 103 104/* 105 * get bounce buffer pages (count physically contiguous) 106 * (only 1 inplemented now) 107 */ 108static vm_offset_t 109vm_bounce_page_find(count) 110 int count; 111{ 112 int bit; 113 int s,i; 114 115 if (count != 1) 116 panic("vm_bounce_page_find -- no support for > 1 page yet!!!"); 117 118 s = splbio(); 119retry: 120 for (i = 0; i < bounceallocarraysize; i++) { 121 if (bounceallocarray[i] != 0xffffffff) { 122 bit = ffs(~bounceallocarray[i]); 123 if (bit) { 124 bounceallocarray[i] |= 1 << (bit - 1) ; 125 bouncefree -= count; 126 splx(s); 127 return bouncepa[(i * BITS_IN_UNSIGNED + (bit - 1))]; 128 } 129 } 130 } 131 bpwait = 1; 132 tsleep((caddr_t) &bounceallocarray, PRIBIO, "bncwai", 0); 133 goto retry; 134} 135 136static void 137vm_bounce_kva_free(addr, size, now) 138 vm_offset_t addr; 139 vm_offset_t size; 140 int now; 141{ 142 int s = splbio(); 143 kvaf[kvasfreecnt].addr = addr; 144 kvaf[kvasfreecnt].size = size; 145 ++kvasfreecnt; 146 if( now) { 147 /* 148 * this will do wakeups 149 */ 150 vm_bounce_kva(0,0); 151 } else { 152 if (bmwait) { 153 /* 154 * if anyone is waiting on the bounce-map, then wakeup 155 */ 156 wakeup((caddr_t) io_map); 157 bmwait = 0; 158 } 159 } 160 splx(s); 161} 162 163/* 164 * free count bounce buffer pages 165 */ 166static void 167vm_bounce_page_free(pa, count) 168 vm_offset_t pa; 169 int count; 170{ 171 int allocindex; 172 int index; 173 int bit; 174 175 if (count != 1) 176 panic("vm_bounce_page_free -- no support for > 1 page yet!!!"); 177 178 for(index=0;index<bouncepages;index++) { 179 if( pa == bouncepa[index]) 180 break; 181 } 182 183 if( index == bouncepages) 184 panic("vm_bounce_page_free: invalid bounce buffer"); 185 186 allocindex = index / BITS_IN_UNSIGNED; 187 bit = index % BITS_IN_UNSIGNED; 188 189 bounceallocarray[allocindex] &= ~(1 << bit); 190 191 bouncefree += count; 192 if (bpwait) { 193 bpwait = 0; 194 wakeup((caddr_t) &bounceallocarray); 195 } 196} 197 198/* 199 * allocate count bounce buffer kva pages 200 */ 201static vm_offset_t 202vm_bounce_kva(size, waitok) 203 int size; 204 int waitok; 205{ 206 int i; 207 vm_offset_t kva = 0; 208 vm_offset_t off; 209 int s = splbio(); 210more: 211 if (!bmfreeing && kvasfreecnt) { 212 bmfreeing = 1; 213 for (i = 0; i < kvasfreecnt; i++) { 214 for(off=0;off<kvaf[i].size;off+=NBPG) { 215 pmap_kremove( kvaf[i].addr + off); 216 } 217 kmem_free_wakeup(io_map, kvaf[i].addr, 218 kvaf[i].size); 219 } 220 kvasfreecnt = 0; 221 bmfreeing = 0; 222 if( bmwait) { 223 bmwait = 0; 224 wakeup( (caddr_t) io_map); 225 } 226 } 227 228 if( size == 0) { 229 splx(s); 230 return NULL; 231 } 232 233 if ((kva = kmem_alloc_pageable(io_map, size)) == 0) { 234 if( !waitok) { 235 splx(s); 236 return NULL; 237 } 238 bmwait = 1; 239 tsleep((caddr_t) io_map, PRIBIO, "bmwait", 0); 240 goto more; 241 } 242 splx(s); 243 return kva; 244} 245 246/* 247 * same as vm_bounce_kva -- but really allocate (but takes pages as arg) 248 */ 249vm_offset_t 250vm_bounce_kva_alloc(count) 251int count; 252{ 253 int i; 254 vm_offset_t kva; 255 vm_offset_t pa; 256 if( bouncepages == 0) { 257 kva = (vm_offset_t) malloc(count*NBPG, M_TEMP, M_WAITOK); 258 return kva; 259 } 260 kva = vm_bounce_kva(count*NBPG, 1); 261 for(i=0;i<count;i++) { 262 pa = vm_bounce_page_find(1); 263 pmap_kenter(kva + i * NBPG, pa); 264 } 265 return kva; 266} 267 268/* 269 * same as vm_bounce_kva_free -- but really free 270 */ 271void 272vm_bounce_kva_alloc_free(kva, count) 273 vm_offset_t kva; 274 int count; 275{ 276 int i; 277 vm_offset_t pa; 278 if( bouncepages == 0) { 279 free((caddr_t) kva, M_TEMP); 280 return; 281 } 282 for(i = 0; i < count; i++) { 283 pa = pmap_kextract(kva + i * NBPG); 284 vm_bounce_page_free(pa, 1); 285 } 286 vm_bounce_kva_free(kva, count*NBPG, 0); 287} 288 289/* 290 * do the things necessary to the struct buf to implement 291 * bounce buffers... inserted before the disk sort 292 */ 293void 294vm_bounce_alloc(bp) 295 struct buf *bp; 296{ 297 int countvmpg; 298 vm_offset_t vastart, vaend; 299 vm_offset_t vapstart, vapend; 300 vm_offset_t va, kva; 301 vm_offset_t pa; 302 int dobounceflag = 0; 303 int i; 304 305 if (bouncepages == 0) 306 return; 307 308 if (bp->b_flags & B_BOUNCE) { 309 printf("vm_bounce_alloc: called recursively???\n"); 310 return; 311 } 312 313 if (bp->b_bufsize < bp->b_bcount) { 314 printf( 315 "vm_bounce_alloc: b_bufsize(0x%lx) < b_bcount(0x%lx) !!\n", 316 bp->b_bufsize, bp->b_bcount); 317 panic("vm_bounce_alloc"); 318 } 319 320/* 321 * This is not really necessary 322 * if( bp->b_bufsize != bp->b_bcount) { 323 * printf("size: %d, count: %d\n", bp->b_bufsize, bp->b_bcount); 324 * } 325 */ 326 327 328 vastart = (vm_offset_t) bp->b_data; 329 vaend = (vm_offset_t) bp->b_data + bp->b_bufsize; 330 331 vapstart = i386_trunc_page(vastart); 332 vapend = i386_round_page(vaend); 333 countvmpg = (vapend - vapstart) / NBPG; 334 335/* 336 * if any page is above 16MB, then go into bounce-buffer mode 337 */ 338 va = vapstart; 339 for (i = 0; i < countvmpg; i++) { 340 pa = pmap_kextract(va); 341 if (pa >= SIXTEENMEG) 342 ++dobounceflag; 343 if( pa == 0) 344 panic("vm_bounce_alloc: Unmapped page"); 345 va += NBPG; 346 } 347 if (dobounceflag == 0) 348 return; 349 350 if (bouncepages < dobounceflag) 351 panic("Not enough bounce buffers!!!"); 352 353/* 354 * allocate a replacement kva for b_addr 355 */ 356 kva = vm_bounce_kva(countvmpg*NBPG, 1); 357#if 0 358 printf("%s: vapstart: %x, vapend: %x, countvmpg: %d, kva: %x ", 359 (bp->b_flags & B_READ) ? "read":"write", 360 vapstart, vapend, countvmpg, kva); 361#endif 362 va = vapstart; 363 for (i = 0; i < countvmpg; i++) { 364 pa = pmap_kextract(va); 365 if (pa >= SIXTEENMEG) { 366 /* 367 * allocate a replacement page 368 */ 369 vm_offset_t bpa = vm_bounce_page_find(1); 370 pmap_kenter(kva + (NBPG * i), bpa); 371#if 0 372 printf("r(%d): (%x,%x,%x) ", i, va, pa, bpa); 373#endif 374 /* 375 * if we are writing, the copy the data into the page 376 */ 377 if ((bp->b_flags & B_READ) == 0) { 378 bcopy((caddr_t) va, (caddr_t) kva + (NBPG * i), NBPG); 379 } 380 } else { 381 /* 382 * use original page 383 */ 384 pmap_kenter(kva + (NBPG * i), pa); 385 } 386 va += NBPG; 387 } 388 389/* 390 * flag the buffer as being bounced 391 */ 392 bp->b_flags |= B_BOUNCE; 393/* 394 * save the original buffer kva 395 */ 396 bp->b_savekva = bp->b_data; 397/* 398 * put our new kva into the buffer (offset by original offset) 399 */ 400 bp->b_data = (caddr_t) (((vm_offset_t) kva) | 401 ((vm_offset_t) bp->b_savekva & (NBPG - 1))); 402#if 0 403 printf("b_savekva: %x, newva: %x\n", bp->b_savekva, bp->b_data); 404#endif 405 return; 406} 407 408/* 409 * hook into biodone to free bounce buffer 410 */ 411void 412vm_bounce_free(bp) 413 struct buf *bp; 414{ 415 int i; 416 vm_offset_t origkva, bouncekva, bouncekvaend; 417 418/* 419 * if this isn't a bounced buffer, then just return 420 */ 421 if ((bp->b_flags & B_BOUNCE) == 0) 422 return; 423 424/* 425 * This check is not necessary 426 * if (bp->b_bufsize != bp->b_bcount) { 427 * printf("vm_bounce_free: b_bufsize=%d, b_bcount=%d\n", 428 * bp->b_bufsize, bp->b_bcount); 429 * } 430 */ 431 432 origkva = (vm_offset_t) bp->b_savekva; 433 bouncekva = (vm_offset_t) bp->b_data; 434/* 435 printf("free: %d ", bp->b_bufsize); 436*/ 437 438/* 439 * check every page in the kva space for b_addr 440 */ 441 for (i = 0; i < bp->b_bufsize; ) { 442 vm_offset_t mybouncepa; 443 vm_offset_t copycount; 444 445 copycount = i386_round_page(bouncekva + 1) - bouncekva; 446 mybouncepa = pmap_kextract(i386_trunc_page(bouncekva)); 447 448/* 449 * if this is a bounced pa, then process as one 450 */ 451 if ( mybouncepa != pmap_kextract( i386_trunc_page( origkva))) { 452 vm_offset_t tocopy = copycount; 453 if (i + tocopy > bp->b_bufsize) 454 tocopy = bp->b_bufsize - i; 455/* 456 * if this is a read, then copy from bounce buffer into original buffer 457 */ 458 if (bp->b_flags & B_READ) 459 bcopy((caddr_t) bouncekva, (caddr_t) origkva, tocopy); 460/* 461 * free the bounce allocation 462 */ 463 464/* 465 printf("(kva: %x, pa: %x)", bouncekva, mybouncepa); 466*/ 467 vm_bounce_page_free(mybouncepa, 1); 468 } 469 470 origkva += copycount; 471 bouncekva += copycount; 472 i += copycount; 473 } 474 475/* 476 printf("\n"); 477*/ 478/* 479 * add the old kva into the "to free" list 480 */ 481 482 bouncekva= i386_trunc_page((vm_offset_t) bp->b_data); 483 bouncekvaend= i386_round_page((vm_offset_t)bp->b_data + bp->b_bufsize); 484 485/* 486 printf("freeva: %d\n", (bouncekvaend - bouncekva) / NBPG); 487*/ 488 vm_bounce_kva_free( bouncekva, (bouncekvaend - bouncekva), 0); 489 bp->b_data = bp->b_savekva; 490 bp->b_savekva = 0; 491 bp->b_flags &= ~B_BOUNCE; 492 493 return; 494} 495 496 497/* 498 * init the bounce buffer system 499 */ 500void 501vm_bounce_init() 502{ 503 int i; 504 505 kvasfreecnt = 0; 506 507 if (bouncepages == 0) 508 return; 509 510 bounceallocarraysize = (bouncepages + BITS_IN_UNSIGNED - 1) / BITS_IN_UNSIGNED; 511 bounceallocarray = malloc(bounceallocarraysize * sizeof(unsigned), M_TEMP, M_NOWAIT); 512 513 if (!bounceallocarray) 514 panic("Cannot allocate bounce resource array"); 515 516 bouncepa = malloc(bouncepages * sizeof(vm_offset_t), M_TEMP, M_NOWAIT); 517 if (!bouncepa) 518 panic("Cannot allocate physical memory array"); 519 520 for(i=0;i<bounceallocarraysize;i++) { 521 bounceallocarray[i] = 0xffffffff; 522 } 523 524 for(i=0;i<bouncepages;i++) { 525 vm_offset_t pa; 526 if( (pa = pmap_kextract((vm_offset_t) bouncememory + i * NBPG)) >= SIXTEENMEG) 527 panic("bounce memory out of range"); 528 if( pa == 0) 529 panic("bounce memory not resident"); 530 bouncepa[i] = pa; 531 bounceallocarray[i/(8*sizeof(int))] &= ~(1<<(i%(8*sizeof(int)))); 532 } 533 bouncefree = bouncepages; 534 535} 536#endif /* BOUNCE_BUFFERS */ 537 538/* 539 * quick version of vm_fault 540 */ 541static void 542vm_fault_quick(v, prot) 543 caddr_t v; 544 int prot; 545{ 546 if (prot & VM_PROT_WRITE) 547 subyte(v, fubyte(v)); 548 else 549 fubyte(v); 550} 551 552/* 553 * Finish a fork operation, with process p2 nearly set up. 554 * Copy and update the kernel stack and pcb, making the child 555 * ready to run, and marking it so that it can return differently 556 * than the parent. Returns 1 in the child process, 0 in the parent. 557 * We currently double-map the user area so that the stack is at the same 558 * address in each process; in the future we will probably relocate 559 * the frame pointers on the stack after copying. 560 */ 561int 562cpu_fork(p1, p2) 563 register struct proc *p1, *p2; 564{ 565 register struct user *up = p2->p_addr; 566 int offset; 567 568 /* 569 * Copy pcb and stack from proc p1 to p2. 570 * We do this as cheaply as possible, copying only the active 571 * part of the stack. The stack and pcb need to agree; 572 * this is tricky, as the final pcb is constructed by savectx, 573 * but its frame isn't yet on the stack when the stack is copied. 574 * swtch compensates for this when the child eventually runs. 575 * This should be done differently, with a single call 576 * that copies and updates the pcb+stack, 577 * replacing the bcopy and savectx. 578 */ 579 p2->p_addr->u_pcb = p1->p_addr->u_pcb; 580 offset = mvesp() - (int)kstack; 581 bcopy((caddr_t)kstack + offset, (caddr_t)p2->p_addr + offset, 582 (unsigned) ctob(UPAGES) - offset); 583 p2->p_md.md_regs = p1->p_md.md_regs; 584 585 pmap_activate(&p2->p_vmspace->vm_pmap, &up->u_pcb); 586 587 /* 588 * 589 * Arrange for a non-local goto when the new process 590 * is started, to resume here, returning nonzero from setjmp. 591 */ 592 if (savectx(&up->u_pcb, 1)) { 593 /* 594 * Return 1 in child. 595 */ 596 return (1); 597 } 598 return (0); 599} 600 601void 602cpu_exit(p) 603 register struct proc *p; 604{ 605 606#if NNPX > 0 607 npxexit(p); 608#endif /* NNPX */ 609 cnt.v_swtch++; 610 cpu_switch(p); 611 panic("cpu_exit"); 612} 613 614void 615cpu_wait(p) struct proc *p; { 616/* extern vm_map_t upages_map; */ 617 618 /* drop per-process resources */ 619 pmap_remove(vm_map_pmap(u_map), (vm_offset_t) p->p_addr, 620 ((vm_offset_t) p->p_addr) + ctob(UPAGES)); 621 kmem_free(u_map, (vm_offset_t)p->p_addr, ctob(UPAGES)); 622 vmspace_free(p->p_vmspace); 623} 624 625/* 626 * Dump the machine specific header information at the start of a core dump. 627 */ 628int 629cpu_coredump(p, vp, cred) 630 struct proc *p; 631 struct vnode *vp; 632 struct ucred *cred; 633{ 634 635 return (vn_rdwr(UIO_WRITE, vp, (caddr_t) p->p_addr, ctob(UPAGES), 636 (off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, (int *)NULL, 637 p)); 638} 639 640#ifdef notyet 641static void 642setredzone(pte, vaddr) 643 u_short *pte; 644 caddr_t vaddr; 645{ 646/* eventually do this by setting up an expand-down stack segment 647 for ss0: selector, allowing stack access down to top of u. 648 this means though that protection violations need to be handled 649 thru a double fault exception that must do an integral task 650 switch to a known good context, within which a dump can be 651 taken. a sensible scheme might be to save the initial context 652 used by sched (that has physical memory mapped 1:1 at bottom) 653 and take the dump while still in mapped mode */ 654} 655#endif 656 657/* 658 * Convert kernel VA to physical address 659 */ 660u_long 661kvtop(void *addr) 662{ 663 vm_offset_t va; 664 665 va = pmap_kextract((vm_offset_t)addr); 666 if (va == 0) 667 panic("kvtop: zero page frame"); 668 return((int)va); 669} 670 671/* 672 * Map an IO request into kernel virtual address space. 673 * 674 * All requests are (re)mapped into kernel VA space. 675 * Notice that we use b_bufsize for the size of the buffer 676 * to be mapped. b_bcount might be modified by the driver. 677 */ 678void 679vmapbuf(bp) 680 register struct buf *bp; 681{ 682 register int npf; 683 register caddr_t addr; 684 int off; 685 vm_offset_t kva; 686 vm_offset_t pa; 687 688 if ((bp->b_flags & B_PHYS) == 0) 689 panic("vmapbuf"); 690 691 /* 692 * this is the kva that is to be used for 693 * the temporary kernel mapping 694 */ 695 kva = (vm_offset_t) bp->b_saveaddr; 696 697 for (addr = (caddr_t)trunc_page(bp->b_data); 698 addr < bp->b_data + bp->b_bufsize; 699 addr += PAGE_SIZE) { 700 701/* 702 * do the vm_fault if needed, do the copy-on-write thing when 703 * reading stuff off device into memory. 704 */ 705 vm_fault_quick(addr, 706 (bp->b_flags&B_READ)?(VM_PROT_READ|VM_PROT_WRITE):VM_PROT_READ); 707 pa = pmap_kextract((vm_offset_t) addr); 708 if (pa == 0) 709 panic("vmapbuf: page not present"); 710/* 711 * hold the data page 712 */ 713#ifdef DIAGNOSTIC 714 if( VM_PAGE_TO_PHYS(PHYS_TO_VM_PAGE(pa)) != pa) 715 panic("vmapbuf: confused PHYS_TO_VM_PAGE mapping"); 716#endif 717 vm_page_hold(PHYS_TO_VM_PAGE(pa)); 718 } 719 720 addr = bp->b_saveaddr = bp->b_data; 721 off = (int)addr & PGOFSET; 722 npf = btoc(round_page(bp->b_bufsize + off)); 723 bp->b_data = (caddr_t) (kva + off); 724 while (npf--) { 725 pa = pmap_kextract((vm_offset_t)addr); 726 if (pa == 0) 727 panic("vmapbuf: null page frame"); 728 pmap_kenter(kva, trunc_page(pa)); 729 addr += PAGE_SIZE; 730 kva += PAGE_SIZE; 731 } 732} 733 734/* 735 * Free the io map PTEs associated with this IO operation. 736 * We also invalidate the TLB entries and restore the original b_addr. 737 */ 738void 739vunmapbuf(bp) 740 register struct buf *bp; 741{ 742 register caddr_t addr; 743 vm_offset_t pa; 744 745 if ((bp->b_flags & B_PHYS) == 0) 746 panic("vunmapbuf"); 747 748 for (addr = (caddr_t)trunc_page((vm_offset_t) bp->b_data); 749 addr < bp->b_data + bp->b_bufsize; 750 addr += NBPG) 751 pmap_kremove((vm_offset_t) addr); 752 753 bp->b_data = bp->b_saveaddr; 754 bp->b_saveaddr = NULL; 755 756/* 757 * unhold the pde, and data pages 758 */ 759 for (addr = (caddr_t)trunc_page((vm_offset_t) bp->b_data); 760 addr < bp->b_data + bp->b_bufsize; 761 addr += NBPG) { 762 /* 763 * release the data page 764 */ 765 pa = pmap_kextract((vm_offset_t) addr); 766 vm_page_unhold(PHYS_TO_VM_PAGE(pa)); 767 } 768} 769 770/* 771 * Force reset the processor by invalidating the entire address space! 772 */ 773void 774cpu_reset() { 775 776 /* 777 * Attempt to do a CPU reset via the keyboard controller, 778 * do not turn of the GateA20, as any machine that fails 779 * to do the reset here would then end up in no man's land. 780 */ 781 782#ifndef BROKEN_KEYBOARD_RESET 783 outb(IO_KBD + 4, 0xFE); 784 DELAY(500000); /* wait 0.5 sec to see if that did it */ 785 printf("Keyboard reset did not work, attempting CPU shutdown\n"); 786 DELAY(1000000); /* wait 1 sec for printf to complete */ 787#endif 788 789 /* force a shutdown by unmapping entire address space ! */ 790 bzero((caddr_t) PTD, NBPG); 791 792 /* "good night, sweet prince .... <THUNK!>" */ 793 pmap_update(); 794 /* NOTREACHED */ 795 while(1); 796} 797 798/* 799 * Grow the user stack to allow for 'sp'. This version grows the stack in 800 * chunks of SGROWSIZ. 801 */ 802int 803grow(p, sp) 804 struct proc *p; 805 u_int sp; 806{ 807 unsigned int nss; 808 caddr_t v; 809 struct vmspace *vm = p->p_vmspace; 810 811 if ((caddr_t)sp <= vm->vm_maxsaddr || (unsigned)sp >= (unsigned)USRSTACK) 812 return (1); 813 814 nss = roundup(USRSTACK - (unsigned)sp, PAGE_SIZE); 815 816 if (nss > p->p_rlimit[RLIMIT_STACK].rlim_cur) 817 return (0); 818 819 if (vm->vm_ssize && roundup(vm->vm_ssize << PAGE_SHIFT, 820 SGROWSIZ) < nss) { 821 int grow_amount; 822 /* 823 * If necessary, grow the VM that the stack occupies 824 * to allow for the rlimit. This allows us to not have 825 * to allocate all of the VM up-front in execve (which 826 * is expensive). 827 * Grow the VM by the amount requested rounded up to 828 * the nearest SGROWSIZ to provide for some hysteresis. 829 */ 830 grow_amount = roundup((nss - (vm->vm_ssize << PAGE_SHIFT)), SGROWSIZ); 831 v = (char *)USRSTACK - roundup(vm->vm_ssize << PAGE_SHIFT, 832 SGROWSIZ) - grow_amount; 833 /* 834 * If there isn't enough room to extend by SGROWSIZ, then 835 * just extend to the maximum size 836 */ 837 if (v < vm->vm_maxsaddr) { 838 v = vm->vm_maxsaddr; 839 grow_amount = MAXSSIZ - (vm->vm_ssize << PAGE_SHIFT); 840 } 841 if ((grow_amount == 0) || (vm_map_find(&vm->vm_map, NULL, 0, (vm_offset_t *)&v, 842 grow_amount, FALSE) != KERN_SUCCESS)) { 843 return (0); 844 } 845 vm->vm_ssize += grow_amount >> PAGE_SHIFT; 846 } 847 848 return (1); 849} 850 851/* 852 * prototype routine to implement the pre-zeroed page mechanism 853 * this routine is called from the idle loop. 854 */ 855int 856vm_page_zero_idle() { 857 vm_page_t m; 858 if ((cnt.v_free_count > cnt.v_interrupt_free_min) && 859 (m = vm_page_queue_free.tqh_first)) { 860 TAILQ_REMOVE(&vm_page_queue_free, m, pageq); 861 enable_intr(); 862 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 863 disable_intr(); 864 TAILQ_INSERT_HEAD(&vm_page_queue_zero, m, pageq); 865 ++vm_page_zero_count; 866 return 1; 867 } 868 return 0; 869} 870