vm_machdep.c revision 7090
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 1.33 1995/03/01 23:59:21 davidg 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/user.h> 52 53#include <machine/cpu.h> 54#include <machine/md_var.h> 55 56#include <vm/vm.h> 57#include <vm/vm_kern.h> 58 59#ifdef BOUNCE_BUFFERS 60vm_map_t io_map; 61volatile int kvasfreecnt; 62 63 64caddr_t bouncememory; 65int bouncepages, bpwait; 66vm_offset_t *bouncepa; 67int bmwait, bmfreeing; 68 69#define BITS_IN_UNSIGNED (8*sizeof(unsigned)) 70int bounceallocarraysize; 71unsigned *bounceallocarray; 72int bouncefree; 73 74#define SIXTEENMEG (4096*4096) 75#define MAXBKVA 1024 76int maxbkva = MAXBKVA*NBPG; 77 78/* special list that can be used at interrupt time for eventual kva free */ 79struct kvasfree { 80 vm_offset_t addr; 81 vm_offset_t size; 82} kvaf[MAXBKVA]; 83 84 85vm_offset_t vm_bounce_kva(); 86/* 87 * get bounce buffer pages (count physically contiguous) 88 * (only 1 inplemented now) 89 */ 90vm_offset_t 91vm_bounce_page_find(count) 92 int count; 93{ 94 int bit; 95 int s,i; 96 97 if (count != 1) 98 panic("vm_bounce_page_find -- no support for > 1 page yet!!!"); 99 100 s = splbio(); 101retry: 102 for (i = 0; i < bounceallocarraysize; i++) { 103 if (bounceallocarray[i] != 0xffffffff) { 104 bit = ffs(~bounceallocarray[i]); 105 if (bit) { 106 bounceallocarray[i] |= 1 << (bit - 1) ; 107 bouncefree -= count; 108 splx(s); 109 return bouncepa[(i * BITS_IN_UNSIGNED + (bit - 1))]; 110 } 111 } 112 } 113 bpwait = 1; 114 tsleep((caddr_t) &bounceallocarray, PRIBIO, "bncwai", 0); 115 goto retry; 116} 117 118void 119vm_bounce_kva_free(addr, size, now) 120 vm_offset_t addr; 121 vm_offset_t size; 122 int now; 123{ 124 int s = splbio(); 125 kvaf[kvasfreecnt].addr = addr; 126 kvaf[kvasfreecnt].size = size; 127 ++kvasfreecnt; 128 if( now) { 129 /* 130 * this will do wakeups 131 */ 132 vm_bounce_kva(0,0); 133 } else { 134 if (bmwait) { 135 /* 136 * if anyone is waiting on the bounce-map, then wakeup 137 */ 138 wakeup((caddr_t) io_map); 139 bmwait = 0; 140 } 141 } 142 splx(s); 143} 144 145/* 146 * free count bounce buffer pages 147 */ 148void 149vm_bounce_page_free(pa, count) 150 vm_offset_t pa; 151 int count; 152{ 153 int allocindex; 154 int index; 155 int bit; 156 157 if (count != 1) 158 panic("vm_bounce_page_free -- no support for > 1 page yet!!!\n"); 159 160 for(index=0;index<bouncepages;index++) { 161 if( pa == bouncepa[index]) 162 break; 163 } 164 165 if( index == bouncepages) 166 panic("vm_bounce_page_free: invalid bounce buffer"); 167 168 allocindex = index / BITS_IN_UNSIGNED; 169 bit = index % BITS_IN_UNSIGNED; 170 171 bounceallocarray[allocindex] &= ~(1 << bit); 172 173 bouncefree += count; 174 if (bpwait) { 175 bpwait = 0; 176 wakeup((caddr_t) &bounceallocarray); 177 } 178} 179 180/* 181 * allocate count bounce buffer kva pages 182 */ 183vm_offset_t 184vm_bounce_kva(size, waitok) 185 int size; 186 int waitok; 187{ 188 int i; 189 vm_offset_t kva = 0; 190 vm_offset_t off; 191 int s = splbio(); 192more: 193 if (!bmfreeing && kvasfreecnt) { 194 bmfreeing = 1; 195 for (i = 0; i < kvasfreecnt; i++) { 196 for(off=0;off<kvaf[i].size;off+=NBPG) { 197 pmap_kremove( kvaf[i].addr + off); 198 } 199 kmem_free_wakeup(io_map, kvaf[i].addr, 200 kvaf[i].size); 201 } 202 kvasfreecnt = 0; 203 bmfreeing = 0; 204 if( bmwait) { 205 bmwait = 0; 206 wakeup( (caddr_t) io_map); 207 } 208 } 209 210 if( size == 0) { 211 splx(s); 212 return NULL; 213 } 214 215 if ((kva = kmem_alloc_pageable(io_map, size)) == 0) { 216 if( !waitok) { 217 splx(s); 218 return NULL; 219 } 220 bmwait = 1; 221 tsleep((caddr_t) io_map, PRIBIO, "bmwait", 0); 222 goto more; 223 } 224 splx(s); 225 return kva; 226} 227 228/* 229 * same as vm_bounce_kva -- but really allocate (but takes pages as arg) 230 */ 231vm_offset_t 232vm_bounce_kva_alloc(count) 233int count; 234{ 235 int i; 236 vm_offset_t kva; 237 vm_offset_t pa; 238 if( bouncepages == 0) { 239 kva = (vm_offset_t) malloc(count*NBPG, M_TEMP, M_WAITOK); 240 return kva; 241 } 242 kva = vm_bounce_kva(count*NBPG, 1); 243 for(i=0;i<count;i++) { 244 pa = vm_bounce_page_find(1); 245 pmap_kenter(kva + i * NBPG, pa); 246 } 247 return kva; 248} 249 250/* 251 * same as vm_bounce_kva_free -- but really free 252 */ 253void 254vm_bounce_kva_alloc_free(kva, count) 255 vm_offset_t kva; 256 int count; 257{ 258 int i; 259 vm_offset_t pa; 260 if( bouncepages == 0) { 261 free((caddr_t) kva, M_TEMP); 262 return; 263 } 264 for(i = 0; i < count; i++) { 265 pa = pmap_kextract(kva + i * NBPG); 266 vm_bounce_page_free(pa, 1); 267 } 268 vm_bounce_kva_free(kva, count*NBPG, 0); 269} 270 271/* 272 * do the things necessary to the struct buf to implement 273 * bounce buffers... inserted before the disk sort 274 */ 275void 276vm_bounce_alloc(bp) 277 struct buf *bp; 278{ 279 int countvmpg; 280 vm_offset_t vastart, vaend; 281 vm_offset_t vapstart, vapend; 282 vm_offset_t va, kva; 283 vm_offset_t pa; 284 int dobounceflag = 0; 285 int i; 286 287 if (bouncepages == 0) 288 return; 289 290 if (bp->b_flags & B_BOUNCE) { 291 printf("vm_bounce_alloc: called recursively???\n"); 292 return; 293 } 294 295 if (bp->b_bufsize < bp->b_bcount) { 296 printf( 297 "vm_bounce_alloc: b_bufsize(0x%lx) < b_bcount(0x%lx) !!\n", 298 bp->b_bufsize, bp->b_bcount); 299 panic("vm_bounce_alloc"); 300 } 301 302/* 303 * This is not really necessary 304 * if( bp->b_bufsize != bp->b_bcount) { 305 * printf("size: %d, count: %d\n", bp->b_bufsize, bp->b_bcount); 306 * } 307 */ 308 309 310 vastart = (vm_offset_t) bp->b_data; 311 vaend = (vm_offset_t) bp->b_data + bp->b_bufsize; 312 313 vapstart = i386_trunc_page(vastart); 314 vapend = i386_round_page(vaend); 315 countvmpg = (vapend - vapstart) / NBPG; 316 317/* 318 * if any page is above 16MB, then go into bounce-buffer mode 319 */ 320 va = vapstart; 321 for (i = 0; i < countvmpg; i++) { 322 pa = pmap_kextract(va); 323 if (pa >= SIXTEENMEG) 324 ++dobounceflag; 325 if( pa == 0) 326 panic("vm_bounce_alloc: Unmapped page"); 327 va += NBPG; 328 } 329 if (dobounceflag == 0) 330 return; 331 332 if (bouncepages < dobounceflag) 333 panic("Not enough bounce buffers!!!"); 334 335/* 336 * allocate a replacement kva for b_addr 337 */ 338 kva = vm_bounce_kva(countvmpg*NBPG, 1); 339#if 0 340 printf("%s: vapstart: %x, vapend: %x, countvmpg: %d, kva: %x ", 341 (bp->b_flags & B_READ) ? "read":"write", 342 vapstart, vapend, countvmpg, kva); 343#endif 344 va = vapstart; 345 for (i = 0; i < countvmpg; i++) { 346 pa = pmap_kextract(va); 347 if (pa >= SIXTEENMEG) { 348 /* 349 * allocate a replacement page 350 */ 351 vm_offset_t bpa = vm_bounce_page_find(1); 352 pmap_kenter(kva + (NBPG * i), bpa); 353#if 0 354 printf("r(%d): (%x,%x,%x) ", i, va, pa, bpa); 355#endif 356 /* 357 * if we are writing, the copy the data into the page 358 */ 359 if ((bp->b_flags & B_READ) == 0) { 360 bcopy((caddr_t) va, (caddr_t) kva + (NBPG * i), NBPG); 361 } 362 } else { 363 /* 364 * use original page 365 */ 366 pmap_kenter(kva + (NBPG * i), pa); 367 } 368 va += NBPG; 369 } 370 371/* 372 * flag the buffer as being bounced 373 */ 374 bp->b_flags |= B_BOUNCE; 375/* 376 * save the original buffer kva 377 */ 378 bp->b_savekva = bp->b_data; 379/* 380 * put our new kva into the buffer (offset by original offset) 381 */ 382 bp->b_data = (caddr_t) (((vm_offset_t) kva) | 383 ((vm_offset_t) bp->b_savekva & (NBPG - 1))); 384#if 0 385 printf("b_savekva: %x, newva: %x\n", bp->b_savekva, bp->b_data); 386#endif 387 return; 388} 389 390/* 391 * hook into biodone to free bounce buffer 392 */ 393void 394vm_bounce_free(bp) 395 struct buf *bp; 396{ 397 int i; 398 vm_offset_t origkva, bouncekva, bouncekvaend; 399 400/* 401 * if this isn't a bounced buffer, then just return 402 */ 403 if ((bp->b_flags & B_BOUNCE) == 0) 404 return; 405 406/* 407 * This check is not necessary 408 * if (bp->b_bufsize != bp->b_bcount) { 409 * printf("vm_bounce_free: b_bufsize=%d, b_bcount=%d\n", 410 * bp->b_bufsize, bp->b_bcount); 411 * } 412 */ 413 414 origkva = (vm_offset_t) bp->b_savekva; 415 bouncekva = (vm_offset_t) bp->b_data; 416/* 417 printf("free: %d ", bp->b_bufsize); 418*/ 419 420/* 421 * check every page in the kva space for b_addr 422 */ 423 for (i = 0; i < bp->b_bufsize; ) { 424 vm_offset_t mybouncepa; 425 vm_offset_t copycount; 426 427 copycount = i386_round_page(bouncekva + 1) - bouncekva; 428 mybouncepa = pmap_kextract(i386_trunc_page(bouncekva)); 429 430/* 431 * if this is a bounced pa, then process as one 432 */ 433 if ( mybouncepa != pmap_kextract( i386_trunc_page( origkva))) { 434 vm_offset_t tocopy = copycount; 435 if (i + tocopy > bp->b_bufsize) 436 tocopy = bp->b_bufsize - i; 437/* 438 * if this is a read, then copy from bounce buffer into original buffer 439 */ 440 if (bp->b_flags & B_READ) 441 bcopy((caddr_t) bouncekva, (caddr_t) origkva, tocopy); 442/* 443 * free the bounce allocation 444 */ 445 446/* 447 printf("(kva: %x, pa: %x)", bouncekva, mybouncepa); 448*/ 449 vm_bounce_page_free(mybouncepa, 1); 450 } 451 452 origkva += copycount; 453 bouncekva += copycount; 454 i += copycount; 455 } 456 457/* 458 printf("\n"); 459*/ 460/* 461 * add the old kva into the "to free" list 462 */ 463 464 bouncekva= i386_trunc_page((vm_offset_t) bp->b_data); 465 bouncekvaend= i386_round_page((vm_offset_t)bp->b_data + bp->b_bufsize); 466 467/* 468 printf("freeva: %d\n", (bouncekvaend - bouncekva) / NBPG); 469*/ 470 vm_bounce_kva_free( bouncekva, (bouncekvaend - bouncekva), 0); 471 bp->b_data = bp->b_savekva; 472 bp->b_savekva = 0; 473 bp->b_flags &= ~B_BOUNCE; 474 475 return; 476} 477 478 479/* 480 * init the bounce buffer system 481 */ 482void 483vm_bounce_init() 484{ 485 int i; 486 487 kvasfreecnt = 0; 488 489 if (bouncepages == 0) 490 return; 491 492 bounceallocarraysize = (bouncepages + BITS_IN_UNSIGNED - 1) / BITS_IN_UNSIGNED; 493 bounceallocarray = malloc(bounceallocarraysize * sizeof(unsigned), M_TEMP, M_NOWAIT); 494 495 if (!bounceallocarray) 496 panic("Cannot allocate bounce resource array\n"); 497 498 bouncepa = malloc(bouncepages * sizeof(vm_offset_t), M_TEMP, M_NOWAIT); 499 if (!bouncepa) 500 panic("Cannot allocate physical memory array\n"); 501 502 for(i=0;i<bounceallocarraysize;i++) { 503 bounceallocarray[i] = 0xffffffff; 504 } 505 506 for(i=0;i<bouncepages;i++) { 507 vm_offset_t pa; 508 if( (pa = pmap_kextract((vm_offset_t) bouncememory + i * NBPG)) >= SIXTEENMEG) 509 panic("bounce memory out of range"); 510 if( pa == 0) 511 panic("bounce memory not resident"); 512 bouncepa[i] = pa; 513 bounceallocarray[i/(8*sizeof(int))] &= ~(1<<(i%(8*sizeof(int)))); 514 } 515 bouncefree = bouncepages; 516 517} 518#endif /* BOUNCE_BUFFERS */ 519/* 520 * quick version of vm_fault 521 */ 522 523void 524vm_fault_quick( v, prot) 525 vm_offset_t v; 526 int prot; 527{ 528 if (prot & VM_PROT_WRITE) 529 subyte((char *)v, fubyte((char *)v)); 530 else 531 (void) fubyte((char *)v); 532} 533 534 535/* 536 * Finish a fork operation, with process p2 nearly set up. 537 * Copy and update the kernel stack and pcb, making the child 538 * ready to run, and marking it so that it can return differently 539 * than the parent. Returns 1 in the child process, 0 in the parent. 540 * We currently double-map the user area so that the stack is at the same 541 * address in each process; in the future we will probably relocate 542 * the frame pointers on the stack after copying. 543 */ 544int 545cpu_fork(p1, p2) 546 register struct proc *p1, *p2; 547{ 548 register struct user *up = p2->p_addr; 549 int offset; 550 551 /* 552 * Copy pcb and stack from proc p1 to p2. 553 * We do this as cheaply as possible, copying only the active 554 * part of the stack. The stack and pcb need to agree; 555 * this is tricky, as the final pcb is constructed by savectx, 556 * but its frame isn't yet on the stack when the stack is copied. 557 * swtch compensates for this when the child eventually runs. 558 * This should be done differently, with a single call 559 * that copies and updates the pcb+stack, 560 * replacing the bcopy and savectx. 561 */ 562 p2->p_addr->u_pcb = p1->p_addr->u_pcb; 563 offset = mvesp() - (int)kstack; 564 bcopy((caddr_t)kstack + offset, (caddr_t)p2->p_addr + offset, 565 (unsigned) ctob(UPAGES) - offset); 566 p2->p_md.md_regs = p1->p_md.md_regs; 567 568 pmap_activate(&p2->p_vmspace->vm_pmap, &up->u_pcb); 569 570 /* 571 * 572 * Arrange for a non-local goto when the new process 573 * is started, to resume here, returning nonzero from setjmp. 574 */ 575 if (savectx(&up->u_pcb, 1)) { 576 /* 577 * Return 1 in child. 578 */ 579 return (1); 580 } 581 return (0); 582} 583 584void 585cpu_exit(p) 586 register struct proc *p; 587{ 588 589#if NNPX > 0 590 npxexit(p); 591#endif /* NNPX */ 592 cnt.v_swtch++; 593 cpu_switch(p); 594 panic("cpu_exit"); 595} 596 597void 598cpu_wait(p) struct proc *p; { 599/* extern vm_map_t upages_map; */ 600 601 /* drop per-process resources */ 602 pmap_remove(vm_map_pmap(u_map), (vm_offset_t) p->p_addr, 603 ((vm_offset_t) p->p_addr) + ctob(UPAGES)); 604 kmem_free(u_map, (vm_offset_t)p->p_addr, ctob(UPAGES)); 605 vmspace_free(p->p_vmspace); 606} 607 608/* 609 * Dump the machine specific header information at the start of a core dump. 610 */ 611int 612cpu_coredump(p, vp, cred) 613 struct proc *p; 614 struct vnode *vp; 615 struct ucred *cred; 616{ 617 618 return (vn_rdwr(UIO_WRITE, vp, (caddr_t) p->p_addr, ctob(UPAGES), 619 (off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, (int *)NULL, 620 p)); 621} 622 623/* 624 * Set a red zone in the kernel stack after the u. area. 625 */ 626void 627setredzone(pte, vaddr) 628 u_short *pte; 629 caddr_t vaddr; 630{ 631/* eventually do this by setting up an expand-down stack segment 632 for ss0: selector, allowing stack access down to top of u. 633 this means though that protection violations need to be handled 634 thru a double fault exception that must do an integral task 635 switch to a known good context, within which a dump can be 636 taken. a sensible scheme might be to save the initial context 637 used by sched (that has physical memory mapped 1:1 at bottom) 638 and take the dump while still in mapped mode */ 639} 640 641/* 642 * Move pages from one kernel virtual address to another. 643 * Both addresses are assumed to reside in the Sysmap, 644 * and size must be a multiple of CLSIZE. 645 */ 646 647void 648pagemove(from, to, size) 649 register caddr_t from, to; 650 int size; 651{ 652 register vm_offset_t pa; 653 654 if (size & CLOFSET) 655 panic("pagemove"); 656 while (size > 0) { 657 pa = pmap_kextract((vm_offset_t)from); 658 if (pa == 0) 659 panic("pagemove 2"); 660 if (pmap_kextract((vm_offset_t)to) != 0) 661 panic("pagemove 3"); 662 pmap_kremove((vm_offset_t)from); 663 pmap_kenter((vm_offset_t)to, pa); 664 from += PAGE_SIZE; 665 to += PAGE_SIZE; 666 size -= PAGE_SIZE; 667 } 668} 669 670/* 671 * Convert kernel VA to physical address 672 */ 673u_long 674kvtop(void *addr) 675{ 676 vm_offset_t va; 677 678 va = pmap_kextract((vm_offset_t)addr); 679 if (va == 0) 680 panic("kvtop: zero page frame"); 681 return((int)va); 682} 683 684/* 685 * Map an IO request into kernel virtual address space. 686 * 687 * All requests are (re)mapped into kernel VA space. 688 * Notice that we use b_bufsize for the size of the buffer 689 * to be mapped. b_bcount might be modified by the driver. 690 */ 691void 692vmapbuf(bp) 693 register struct buf *bp; 694{ 695 register int npf; 696 register caddr_t addr; 697 int off; 698 vm_offset_t kva; 699 vm_offset_t pa, lastv, v; 700 701 if ((bp->b_flags & B_PHYS) == 0) 702 panic("vmapbuf"); 703 704 /* 705 * this is the kva that is to be used for 706 * the temporary kernel mapping 707 */ 708 kva = (vm_offset_t) bp->b_saveaddr; 709 710 lastv = 0; 711 for (addr = (caddr_t)trunc_page(bp->b_data); 712 addr < bp->b_data + bp->b_bufsize; 713 addr += PAGE_SIZE) { 714 715/* 716 * make sure that the pde is valid and held 717 */ 718 v = trunc_page(((vm_offset_t)vtopte(addr))); 719 if (v != lastv) { 720 vm_fault_quick(v, VM_PROT_READ); 721 pa = pmap_kextract( v); 722 vm_page_hold(PHYS_TO_VM_PAGE(pa)); 723 lastv = v; 724 } 725 726/* 727 * do the vm_fault if needed, do the copy-on-write thing when 728 * reading stuff off device into memory. 729 */ 730 vm_fault_quick(addr, 731 (bp->b_flags&B_READ)?(VM_PROT_READ|VM_PROT_WRITE):VM_PROT_READ); 732 pa = pmap_kextract((vm_offset_t) addr); 733/* 734 * hold the data page 735 */ 736 vm_page_hold(PHYS_TO_VM_PAGE(pa)); 737 } 738 739 addr = bp->b_saveaddr = bp->b_data; 740 off = (int)addr & PGOFSET; 741 npf = btoc(round_page(bp->b_bufsize + off)); 742 bp->b_data = (caddr_t) (kva + off); 743 while (npf--) { 744 pa = pmap_kextract((vm_offset_t)addr); 745 if (pa == 0) 746 panic("vmapbuf: null page frame"); 747 pmap_kenter(kva, trunc_page(pa)); 748 addr += PAGE_SIZE; 749 kva += PAGE_SIZE; 750 } 751} 752 753/* 754 * Free the io map PTEs associated with this IO operation. 755 * We also invalidate the TLB entries and restore the original b_addr. 756 */ 757void 758vunmapbuf(bp) 759 register struct buf *bp; 760{ 761 register caddr_t addr; 762 vm_offset_t v,lastv,pa; 763 764 if ((bp->b_flags & B_PHYS) == 0) 765 panic("vunmapbuf"); 766 767 for (addr = (caddr_t)trunc_page((vm_offset_t) bp->b_data); 768 addr < bp->b_data + bp->b_bufsize; 769 addr += NBPG) 770 pmap_kremove((vm_offset_t) addr); 771 772 bp->b_data = bp->b_saveaddr; 773 bp->b_saveaddr = NULL; 774 775/* 776 * unhold the pde, and data pages 777 */ 778 lastv = 0; 779 for (addr = (caddr_t)trunc_page((vm_offset_t) bp->b_data); 780 addr < bp->b_data + bp->b_bufsize; 781 addr += NBPG) { 782 783 /* 784 * release the data page 785 */ 786 pa = pmap_kextract((vm_offset_t) addr); 787 vm_page_unhold(PHYS_TO_VM_PAGE(pa)); 788 789 /* 790 * and unhold the page table 791 */ 792 v = trunc_page(((vm_offset_t)vtopte(addr))); 793 if (v != lastv) { 794 pa = pmap_kextract(v); 795 vm_page_unhold(PHYS_TO_VM_PAGE(pa)); 796 lastv = v; 797 } 798 } 799} 800 801/* 802 * Force reset the processor by invalidating the entire address space! 803 */ 804void 805cpu_reset() { 806 807 /* force a shutdown by unmapping entire address space ! */ 808 bzero((caddr_t) PTD, NBPG); 809 810 /* "good night, sweet prince .... <THUNK!>" */ 811 pmap_update(); 812 /* NOTREACHED */ 813 while(1); 814} 815 816/* 817 * Grow the user stack to allow for 'sp'. This version grows the stack in 818 * chunks of SGROWSIZ. 819 */ 820int 821grow(p, sp) 822 struct proc *p; 823 u_int sp; 824{ 825 unsigned int nss; 826 caddr_t v; 827 struct vmspace *vm = p->p_vmspace; 828 829 if ((caddr_t)sp <= vm->vm_maxsaddr || (unsigned)sp >= (unsigned)USRSTACK) 830 return (1); 831 832 nss = roundup(USRSTACK - (unsigned)sp, PAGE_SIZE); 833 834 if (nss > p->p_rlimit[RLIMIT_STACK].rlim_cur) 835 return (0); 836 837 if (vm->vm_ssize && roundup(vm->vm_ssize << PAGE_SHIFT, 838 SGROWSIZ) < nss) { 839 int grow_amount; 840 /* 841 * If necessary, grow the VM that the stack occupies 842 * to allow for the rlimit. This allows us to not have 843 * to allocate all of the VM up-front in execve (which 844 * is expensive). 845 * Grow the VM by the amount requested rounded up to 846 * the nearest SGROWSIZ to provide for some hysteresis. 847 */ 848 grow_amount = roundup((nss - (vm->vm_ssize << PAGE_SHIFT)), SGROWSIZ); 849 v = (char *)USRSTACK - roundup(vm->vm_ssize << PAGE_SHIFT, 850 SGROWSIZ) - grow_amount; 851 /* 852 * If there isn't enough room to extend by SGROWSIZ, then 853 * just extend to the maximum size 854 */ 855 if (v < vm->vm_maxsaddr) { 856 v = vm->vm_maxsaddr; 857 grow_amount = MAXSSIZ - (vm->vm_ssize << PAGE_SHIFT); 858 } 859 if ((grow_amount == 0) || (vm_map_find(&vm->vm_map, NULL, 0, (vm_offset_t *)&v, 860 grow_amount, FALSE) != KERN_SUCCESS)) { 861 return (0); 862 } 863 vm->vm_ssize += grow_amount >> PAGE_SHIFT; 864 } 865 866 return (1); 867} 868