vm_machdep.c revision 6579
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 1.31 1995/01/21 15:34:03 bde 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 55#include <vm/vm.h> 56#include <vm/vm_kern.h> 57 58#ifdef BOUNCE_BUFFERS 59vm_map_t io_map; 60volatile int kvasfreecnt; 61 62 63caddr_t bouncememory; 64int bouncepages, bpwait; 65vm_offset_t *bouncepa; 66int bmwait, bmfreeing; 67 68#define BITS_IN_UNSIGNED (8*sizeof(unsigned)) 69int bounceallocarraysize; 70unsigned *bounceallocarray; 71int bouncefree; 72 73#define SIXTEENMEG (4096*4096) 74#define MAXBKVA 1024 75int maxbkva = MAXBKVA*NBPG; 76 77/* special list that can be used at interrupt time for eventual kva free */ 78struct kvasfree { 79 vm_offset_t addr; 80 vm_offset_t size; 81} kvaf[MAXBKVA]; 82 83 84vm_offset_t vm_bounce_kva(); 85/* 86 * get bounce buffer pages (count physically contiguous) 87 * (only 1 inplemented now) 88 */ 89vm_offset_t 90vm_bounce_page_find(count) 91 int count; 92{ 93 int bit; 94 int s,i; 95 96 if (count != 1) 97 panic("vm_bounce_page_find -- no support for > 1 page yet!!!"); 98 99 s = splbio(); 100retry: 101 for (i = 0; i < bounceallocarraysize; i++) { 102 if (bounceallocarray[i] != 0xffffffff) { 103 bit = ffs(~bounceallocarray[i]); 104 if (bit) { 105 bounceallocarray[i] |= 1 << (bit - 1) ; 106 bouncefree -= count; 107 splx(s); 108 return bouncepa[(i * BITS_IN_UNSIGNED + (bit - 1))]; 109 } 110 } 111 } 112 bpwait = 1; 113 tsleep((caddr_t) &bounceallocarray, PRIBIO, "bncwai", 0); 114 goto retry; 115} 116 117void 118vm_bounce_kva_free(addr, size, now) 119 vm_offset_t addr; 120 vm_offset_t size; 121 int now; 122{ 123 int s = splbio(); 124 kvaf[kvasfreecnt].addr = addr; 125 kvaf[kvasfreecnt].size = size; 126 ++kvasfreecnt; 127 if( now) { 128 /* 129 * this will do wakeups 130 */ 131 vm_bounce_kva(0,0); 132 } else { 133 if (bmwait) { 134 /* 135 * if anyone is waiting on the bounce-map, then wakeup 136 */ 137 wakeup((caddr_t) io_map); 138 bmwait = 0; 139 } 140 } 141 splx(s); 142} 143 144/* 145 * free count bounce buffer pages 146 */ 147void 148vm_bounce_page_free(pa, count) 149 vm_offset_t pa; 150 int count; 151{ 152 int allocindex; 153 int index; 154 int bit; 155 156 if (count != 1) 157 panic("vm_bounce_page_free -- no support for > 1 page yet!!!\n"); 158 159 for(index=0;index<bouncepages;index++) { 160 if( pa == bouncepa[index]) 161 break; 162 } 163 164 if( index == bouncepages) 165 panic("vm_bounce_page_free: invalid bounce buffer"); 166 167 allocindex = index / BITS_IN_UNSIGNED; 168 bit = index % BITS_IN_UNSIGNED; 169 170 bounceallocarray[allocindex] &= ~(1 << bit); 171 172 bouncefree += count; 173 if (bpwait) { 174 bpwait = 0; 175 wakeup((caddr_t) &bounceallocarray); 176 } 177} 178 179/* 180 * allocate count bounce buffer kva pages 181 */ 182vm_offset_t 183vm_bounce_kva(size, waitok) 184 int size; 185 int waitok; 186{ 187 int i; 188 vm_offset_t kva = 0; 189 vm_offset_t off; 190 int s = splbio(); 191more: 192 if (!bmfreeing && kvasfreecnt) { 193 bmfreeing = 1; 194 for (i = 0; i < kvasfreecnt; i++) { 195 for(off=0;off<kvaf[i].size;off+=NBPG) { 196 pmap_kremove( kvaf[i].addr + off); 197 } 198 kmem_free_wakeup(io_map, kvaf[i].addr, 199 kvaf[i].size); 200 } 201 kvasfreecnt = 0; 202 bmfreeing = 0; 203 if( bmwait) { 204 bmwait = 0; 205 wakeup( (caddr_t) io_map); 206 } 207 } 208 209 if( size == 0) { 210 splx(s); 211 return NULL; 212 } 213 214 if ((kva = kmem_alloc_pageable(io_map, size)) == 0) { 215 if( !waitok) { 216 splx(s); 217 return NULL; 218 } 219 bmwait = 1; 220 tsleep((caddr_t) io_map, PRIBIO, "bmwait", 0); 221 goto more; 222 } 223 splx(s); 224 return kva; 225} 226 227/* 228 * same as vm_bounce_kva -- but really allocate (but takes pages as arg) 229 */ 230vm_offset_t 231vm_bounce_kva_alloc(count) 232int count; 233{ 234 int i; 235 vm_offset_t kva; 236 vm_offset_t pa; 237 if( bouncepages == 0) { 238 kva = (vm_offset_t) malloc(count*NBPG, M_TEMP, M_WAITOK); 239 return kva; 240 } 241 kva = vm_bounce_kva(count*NBPG, 1); 242 for(i=0;i<count;i++) { 243 pa = vm_bounce_page_find(1); 244 pmap_kenter(kva + i * NBPG, pa); 245 } 246 return kva; 247} 248 249/* 250 * same as vm_bounce_kva_free -- but really free 251 */ 252void 253vm_bounce_kva_alloc_free(kva, count) 254 vm_offset_t kva; 255 int count; 256{ 257 int i; 258 vm_offset_t pa; 259 if( bouncepages == 0) { 260 free((caddr_t) kva, M_TEMP); 261 return; 262 } 263 for(i = 0; i < count; i++) { 264 pa = pmap_kextract(kva + i * NBPG); 265 vm_bounce_page_free(pa, 1); 266 } 267 vm_bounce_kva_free(kva, count*NBPG, 0); 268} 269 270/* 271 * do the things necessary to the struct buf to implement 272 * bounce buffers... inserted before the disk sort 273 */ 274void 275vm_bounce_alloc(bp) 276 struct buf *bp; 277{ 278 int countvmpg; 279 vm_offset_t vastart, vaend; 280 vm_offset_t vapstart, vapend; 281 vm_offset_t va, kva; 282 vm_offset_t pa; 283 int dobounceflag = 0; 284 int i; 285 286 if (bouncepages == 0) 287 return; 288 289 if (bp->b_flags & B_BOUNCE) { 290 printf("vm_bounce_alloc: called recursively???\n"); 291 return; 292 } 293 294 if (bp->b_bufsize < bp->b_bcount) { 295 printf( 296 "vm_bounce_alloc: b_bufsize(0x%lx) < b_bcount(0x%lx) !!\n", 297 bp->b_bufsize, bp->b_bcount); 298 panic("vm_bounce_alloc"); 299 } 300 301/* 302 * This is not really necessary 303 * if( bp->b_bufsize != bp->b_bcount) { 304 * printf("size: %d, count: %d\n", bp->b_bufsize, bp->b_bcount); 305 * } 306 */ 307 308 309 vastart = (vm_offset_t) bp->b_data; 310 vaend = (vm_offset_t) bp->b_data + bp->b_bufsize; 311 312 vapstart = i386_trunc_page(vastart); 313 vapend = i386_round_page(vaend); 314 countvmpg = (vapend - vapstart) / NBPG; 315 316/* 317 * if any page is above 16MB, then go into bounce-buffer mode 318 */ 319 va = vapstart; 320 for (i = 0; i < countvmpg; i++) { 321 pa = pmap_kextract(va); 322 if (pa >= SIXTEENMEG) 323 ++dobounceflag; 324 if( pa == 0) 325 panic("vm_bounce_alloc: Unmapped page"); 326 va += NBPG; 327 } 328 if (dobounceflag == 0) 329 return; 330 331 if (bouncepages < dobounceflag) 332 panic("Not enough bounce buffers!!!"); 333 334/* 335 * allocate a replacement kva for b_addr 336 */ 337 kva = vm_bounce_kva(countvmpg*NBPG, 1); 338#if 0 339 printf("%s: vapstart: %x, vapend: %x, countvmpg: %d, kva: %x ", 340 (bp->b_flags & B_READ) ? "read":"write", 341 vapstart, vapend, countvmpg, kva); 342#endif 343 va = vapstart; 344 for (i = 0; i < countvmpg; i++) { 345 pa = pmap_kextract(va); 346 if (pa >= SIXTEENMEG) { 347 /* 348 * allocate a replacement page 349 */ 350 vm_offset_t bpa = vm_bounce_page_find(1); 351 pmap_kenter(kva + (NBPG * i), bpa); 352#if 0 353 printf("r(%d): (%x,%x,%x) ", i, va, pa, bpa); 354#endif 355 /* 356 * if we are writing, the copy the data into the page 357 */ 358 if ((bp->b_flags & B_READ) == 0) { 359 bcopy((caddr_t) va, (caddr_t) kva + (NBPG * i), NBPG); 360 } 361 } else { 362 /* 363 * use original page 364 */ 365 pmap_kenter(kva + (NBPG * i), pa); 366 } 367 va += NBPG; 368 } 369 370/* 371 * flag the buffer as being bounced 372 */ 373 bp->b_flags |= B_BOUNCE; 374/* 375 * save the original buffer kva 376 */ 377 bp->b_savekva = bp->b_data; 378/* 379 * put our new kva into the buffer (offset by original offset) 380 */ 381 bp->b_data = (caddr_t) (((vm_offset_t) kva) | 382 ((vm_offset_t) bp->b_savekva & (NBPG - 1))); 383#if 0 384 printf("b_savekva: %x, newva: %x\n", bp->b_savekva, bp->b_data); 385#endif 386 return; 387} 388 389/* 390 * hook into biodone to free bounce buffer 391 */ 392void 393vm_bounce_free(bp) 394 struct buf *bp; 395{ 396 int i; 397 vm_offset_t origkva, bouncekva, bouncekvaend; 398 399/* 400 * if this isn't a bounced buffer, then just return 401 */ 402 if ((bp->b_flags & B_BOUNCE) == 0) 403 return; 404 405/* 406 * This check is not necessary 407 * if (bp->b_bufsize != bp->b_bcount) { 408 * printf("vm_bounce_free: b_bufsize=%d, b_bcount=%d\n", 409 * bp->b_bufsize, bp->b_bcount); 410 * } 411 */ 412 413 origkva = (vm_offset_t) bp->b_savekva; 414 bouncekva = (vm_offset_t) bp->b_data; 415/* 416 printf("free: %d ", bp->b_bufsize); 417*/ 418 419/* 420 * check every page in the kva space for b_addr 421 */ 422 for (i = 0; i < bp->b_bufsize; ) { 423 vm_offset_t mybouncepa; 424 vm_offset_t copycount; 425 426 copycount = i386_round_page(bouncekva + 1) - bouncekva; 427 mybouncepa = pmap_kextract(i386_trunc_page(bouncekva)); 428 429/* 430 * if this is a bounced pa, then process as one 431 */ 432 if ( mybouncepa != pmap_kextract( i386_trunc_page( origkva))) { 433 vm_offset_t tocopy = copycount; 434 if (i + tocopy > bp->b_bufsize) 435 tocopy = bp->b_bufsize - i; 436/* 437 * if this is a read, then copy from bounce buffer into original buffer 438 */ 439 if (bp->b_flags & B_READ) 440 bcopy((caddr_t) bouncekva, (caddr_t) origkva, tocopy); 441/* 442 * free the bounce allocation 443 */ 444 445/* 446 printf("(kva: %x, pa: %x)", bouncekva, mybouncepa); 447*/ 448 vm_bounce_page_free(mybouncepa, 1); 449 } 450 451 origkva += copycount; 452 bouncekva += copycount; 453 i += copycount; 454 } 455 456/* 457 printf("\n"); 458*/ 459/* 460 * add the old kva into the "to free" list 461 */ 462 463 bouncekva= i386_trunc_page((vm_offset_t) bp->b_data); 464 bouncekvaend= i386_round_page((vm_offset_t)bp->b_data + bp->b_bufsize); 465 466/* 467 printf("freeva: %d\n", (bouncekvaend - bouncekva) / NBPG); 468*/ 469 vm_bounce_kva_free( bouncekva, (bouncekvaend - bouncekva), 0); 470 bp->b_data = bp->b_savekva; 471 bp->b_savekva = 0; 472 bp->b_flags &= ~B_BOUNCE; 473 474 return; 475} 476 477 478/* 479 * init the bounce buffer system 480 */ 481void 482vm_bounce_init() 483{ 484 int i; 485 486 kvasfreecnt = 0; 487 488 if (bouncepages == 0) 489 return; 490 491 bounceallocarraysize = (bouncepages + BITS_IN_UNSIGNED - 1) / BITS_IN_UNSIGNED; 492 bounceallocarray = malloc(bounceallocarraysize * sizeof(unsigned), M_TEMP, M_NOWAIT); 493 494 if (!bounceallocarray) 495 panic("Cannot allocate bounce resource array\n"); 496 497 bouncepa = malloc(bouncepages * sizeof(vm_offset_t), M_TEMP, M_NOWAIT); 498 if (!bouncepa) 499 panic("Cannot allocate physical memory array\n"); 500 501 for(i=0;i<bounceallocarraysize;i++) { 502 bounceallocarray[i] = 0xffffffff; 503 } 504 505 for(i=0;i<bouncepages;i++) { 506 vm_offset_t pa; 507 if( (pa = pmap_kextract((vm_offset_t) bouncememory + i * NBPG)) >= SIXTEENMEG) 508 panic("bounce memory out of range"); 509 if( pa == 0) 510 panic("bounce memory not resident"); 511 bouncepa[i] = pa; 512 bounceallocarray[i/(8*sizeof(int))] &= ~(1<<(i%(8*sizeof(int)))); 513 } 514 bouncefree = bouncepages; 515 516} 517#endif /* BOUNCE_BUFFERS */ 518/* 519 * quick version of vm_fault 520 */ 521 522void 523vm_fault_quick( v, prot) 524 vm_offset_t v; 525 int prot; 526{ 527 if( (cpu_class == CPUCLASS_386) && 528 (prot & VM_PROT_WRITE)) 529 vm_fault(&curproc->p_vmspace->vm_map, v, 530 VM_PROT_READ|VM_PROT_WRITE, FALSE); 531 else if( prot & VM_PROT_WRITE) 532 *(volatile char *)v += 0; 533 else 534 *(volatile char *)v; 535} 536 537 538/* 539 * Finish a fork operation, with process p2 nearly set up. 540 * Copy and update the kernel stack and pcb, making the child 541 * ready to run, and marking it so that it can return differently 542 * than the parent. Returns 1 in the child process, 0 in the parent. 543 * We currently double-map the user area so that the stack is at the same 544 * address in each process; in the future we will probably relocate 545 * the frame pointers on the stack after copying. 546 */ 547int 548cpu_fork(p1, p2) 549 register struct proc *p1, *p2; 550{ 551 register struct user *up = p2->p_addr; 552 int offset; 553 extern char kstack[]; 554 extern int mvesp(); 555 556 /* 557 * Copy pcb and stack from proc p1 to p2. 558 * We do this as cheaply as possible, copying only the active 559 * part of the stack. The stack and pcb need to agree; 560 * this is tricky, as the final pcb is constructed by savectx, 561 * but its frame isn't yet on the stack when the stack is copied. 562 * swtch compensates for this when the child eventually runs. 563 * This should be done differently, with a single call 564 * that copies and updates the pcb+stack, 565 * replacing the bcopy and savectx. 566 */ 567 p2->p_addr->u_pcb = p1->p_addr->u_pcb; 568 offset = mvesp() - (int)kstack; 569 bcopy((caddr_t)kstack + offset, (caddr_t)p2->p_addr + offset, 570 (unsigned) ctob(UPAGES) - offset); 571 p2->p_md.md_regs = p1->p_md.md_regs; 572 573 pmap_activate(&p2->p_vmspace->vm_pmap, &up->u_pcb); 574 575 /* 576 * 577 * Arrange for a non-local goto when the new process 578 * is started, to resume here, returning nonzero from setjmp. 579 */ 580 if (savectx(&up->u_pcb, 1)) { 581 /* 582 * Return 1 in child. 583 */ 584 return (1); 585 } 586 return (0); 587} 588 589void 590cpu_exit(p) 591 register struct proc *p; 592{ 593 594#if NNPX > 0 595 npxexit(p); 596#endif /* NNPX */ 597 cnt.v_swtch++; 598 cpu_switch(p); 599 panic("cpu_exit"); 600} 601 602void 603cpu_wait(p) struct proc *p; { 604/* extern vm_map_t upages_map; */ 605 606 /* drop per-process resources */ 607 pmap_remove(vm_map_pmap(u_map), (vm_offset_t) p->p_addr, 608 ((vm_offset_t) p->p_addr) + ctob(UPAGES)); 609 kmem_free(u_map, (vm_offset_t)p->p_addr, ctob(UPAGES)); 610 vmspace_free(p->p_vmspace); 611} 612 613/* 614 * Dump the machine specific header information at the start of a core dump. 615 */ 616int 617cpu_coredump(p, vp, cred) 618 struct proc *p; 619 struct vnode *vp; 620 struct ucred *cred; 621{ 622 623 return (vn_rdwr(UIO_WRITE, vp, (caddr_t) p->p_addr, ctob(UPAGES), 624 (off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, (int *)NULL, 625 p)); 626} 627 628/* 629 * Set a red zone in the kernel stack after the u. area. 630 */ 631void 632setredzone(pte, vaddr) 633 u_short *pte; 634 caddr_t vaddr; 635{ 636/* eventually do this by setting up an expand-down stack segment 637 for ss0: selector, allowing stack access down to top of u. 638 this means though that protection violations need to be handled 639 thru a double fault exception that must do an integral task 640 switch to a known good context, within which a dump can be 641 taken. a sensible scheme might be to save the initial context 642 used by sched (that has physical memory mapped 1:1 at bottom) 643 and take the dump while still in mapped mode */ 644} 645 646/* 647 * Move pages from one kernel virtual address to another. 648 * Both addresses are assumed to reside in the Sysmap, 649 * and size must be a multiple of CLSIZE. 650 */ 651 652void 653pagemove(from, to, size) 654 register caddr_t from, to; 655 int size; 656{ 657 register vm_offset_t pa; 658 659 if (size & CLOFSET) 660 panic("pagemove"); 661 while (size > 0) { 662 pa = pmap_kextract((vm_offset_t)from); 663 if (pa == 0) 664 panic("pagemove 2"); 665 if (pmap_kextract((vm_offset_t)to) != 0) 666 panic("pagemove 3"); 667 pmap_kremove((vm_offset_t)from); 668 pmap_kenter((vm_offset_t)to, pa); 669 from += PAGE_SIZE; 670 to += PAGE_SIZE; 671 size -= PAGE_SIZE; 672 } 673} 674 675/* 676 * Convert kernel VA to physical address 677 */ 678u_long 679kvtop(void *addr) 680{ 681 vm_offset_t va; 682 683 va = pmap_kextract((vm_offset_t)addr); 684 if (va == 0) 685 panic("kvtop: zero page frame"); 686 return((int)va); 687} 688 689/* 690 * Map an IO request into kernel virtual address space. 691 * 692 * All requests are (re)mapped into kernel VA space. 693 * Notice that we use b_bufsize for the size of the buffer 694 * to be mapped. b_bcount might be modified by the driver. 695 */ 696void 697vmapbuf(bp) 698 register struct buf *bp; 699{ 700 register int npf; 701 register caddr_t addr; 702 int off; 703 vm_offset_t kva; 704 vm_offset_t pa, lastv, v; 705 706 if ((bp->b_flags & B_PHYS) == 0) 707 panic("vmapbuf"); 708 709 /* 710 * this is the kva that is to be used for 711 * the temporary kernel mapping 712 */ 713 kva = (vm_offset_t) bp->b_saveaddr; 714 715 lastv = 0; 716 for (addr = (caddr_t)trunc_page(bp->b_data); 717 addr < bp->b_data + bp->b_bufsize; 718 addr += PAGE_SIZE) { 719 720/* 721 * make sure that the pde is valid and held 722 */ 723 v = trunc_page(((vm_offset_t)vtopte(addr))); 724 if (v != lastv) { 725 vm_fault_quick(v, VM_PROT_READ); 726 pa = pmap_kextract( v); 727 vm_page_hold(PHYS_TO_VM_PAGE(pa)); 728 lastv = v; 729 } 730 731/* 732 * do the vm_fault if needed, do the copy-on-write thing when 733 * reading stuff off device into memory. 734 */ 735 vm_fault_quick(addr, 736 (bp->b_flags&B_READ)?(VM_PROT_READ|VM_PROT_WRITE):VM_PROT_READ); 737 pa = pmap_kextract((vm_offset_t) addr); 738/* 739 * hold the data page 740 */ 741 vm_page_hold(PHYS_TO_VM_PAGE(pa)); 742 } 743 744 addr = bp->b_saveaddr = bp->b_data; 745 off = (int)addr & PGOFSET; 746 npf = btoc(round_page(bp->b_bufsize + off)); 747 bp->b_data = (caddr_t) (kva + off); 748 while (npf--) { 749 pa = pmap_kextract((vm_offset_t)addr); 750 if (pa == 0) 751 panic("vmapbuf: null page frame"); 752 pmap_kenter(kva, trunc_page(pa)); 753 addr += PAGE_SIZE; 754 kva += PAGE_SIZE; 755 } 756} 757 758/* 759 * Free the io map PTEs associated with this IO operation. 760 * We also invalidate the TLB entries and restore the original b_addr. 761 */ 762void 763vunmapbuf(bp) 764 register struct buf *bp; 765{ 766 register caddr_t addr; 767 vm_offset_t v,lastv,pa; 768 769 if ((bp->b_flags & B_PHYS) == 0) 770 panic("vunmapbuf"); 771 772 for (addr = (caddr_t)trunc_page((vm_offset_t) bp->b_data); 773 addr < bp->b_data + bp->b_bufsize; 774 addr += NBPG) 775 pmap_kremove((vm_offset_t) addr); 776 777 bp->b_data = bp->b_saveaddr; 778 bp->b_saveaddr = NULL; 779 780/* 781 * unhold the pde, and data pages 782 */ 783 lastv = 0; 784 for (addr = (caddr_t)trunc_page((vm_offset_t) bp->b_data); 785 addr < bp->b_data + bp->b_bufsize; 786 addr += NBPG) { 787 788 /* 789 * release the data page 790 */ 791 pa = pmap_kextract((vm_offset_t) addr); 792 vm_page_unhold(PHYS_TO_VM_PAGE(pa)); 793 794 /* 795 * and unhold the page table 796 */ 797 v = trunc_page(((vm_offset_t)vtopte(addr))); 798 if (v != lastv) { 799 pa = pmap_kextract(v); 800 vm_page_unhold(PHYS_TO_VM_PAGE(pa)); 801 lastv = v; 802 } 803 } 804} 805 806/* 807 * Force reset the processor by invalidating the entire address space! 808 */ 809void 810cpu_reset() { 811 812 /* force a shutdown by unmapping entire address space ! */ 813 bzero((caddr_t) PTD, NBPG); 814 815 /* "good night, sweet prince .... <THUNK!>" */ 816 pmap_update(); 817 /* NOTREACHED */ 818 while(1); 819} 820 821/* 822 * Grow the user stack to allow for 'sp'. This version grows the stack in 823 * chunks of SGROWSIZ. 824 */ 825int 826grow(p, sp) 827 struct proc *p; 828 u_int sp; 829{ 830 unsigned int nss; 831 caddr_t v; 832 struct vmspace *vm = p->p_vmspace; 833 834 if ((caddr_t)sp <= vm->vm_maxsaddr || (unsigned)sp >= (unsigned)USRSTACK) 835 return (1); 836 837 nss = roundup(USRSTACK - (unsigned)sp, PAGE_SIZE); 838 839 if (nss > p->p_rlimit[RLIMIT_STACK].rlim_cur) 840 return (0); 841 842 if (vm->vm_ssize && roundup(vm->vm_ssize << PAGE_SHIFT, 843 SGROWSIZ) < nss) { 844 int grow_amount; 845 /* 846 * If necessary, grow the VM that the stack occupies 847 * to allow for the rlimit. This allows us to not have 848 * to allocate all of the VM up-front in execve (which 849 * is expensive). 850 * Grow the VM by the amount requested rounded up to 851 * the nearest SGROWSIZ to provide for some hysteresis. 852 */ 853 grow_amount = roundup((nss - (vm->vm_ssize << PAGE_SHIFT)), SGROWSIZ); 854 v = (char *)USRSTACK - roundup(vm->vm_ssize << PAGE_SHIFT, 855 SGROWSIZ) - grow_amount; 856 /* 857 * If there isn't enough room to extend by SGROWSIZ, then 858 * just extend to the maximum size 859 */ 860 if (v < vm->vm_maxsaddr) { 861 v = vm->vm_maxsaddr; 862 grow_amount = MAXSSIZ - (vm->vm_ssize << PAGE_SHIFT); 863 } 864 if ((grow_amount == 0) || (vm_map_find(&vm->vm_map, NULL, 0, (vm_offset_t *)&v, 865 grow_amount, FALSE) != KERN_SUCCESS)) { 866 return (0); 867 } 868 vm->vm_ssize += grow_amount >> PAGE_SHIFT; 869 } 870 871 return (1); 872} 873