pmap.c revision 5910
1/* 2 * Copyright (c) 1991 Regents of the University of California. 3 * All rights reserved. 4 * Copyright (c) 1994 John S. Dyson 5 * All rights reserved. 6 * Copyright (c) 1994 David Greenman 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * the Systems Programming Group of the University of Utah Computer 11 * Science Department and William Jolitz of UUNET Technologies Inc. 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * from: @(#)pmap.c 7.7 (Berkeley) 5/12/91 42 * $Id: pmap.c,v 1.43 1995/01/24 09:56:32 davidg Exp $ 43 */ 44 45/* 46 * Derived from hp300 version by Mike Hibler, this version by William 47 * Jolitz uses a recursive map [a pde points to the page directory] to 48 * map the page tables using the pagetables themselves. This is done to 49 * reduce the impact on kernel virtual memory for lots of sparse address 50 * space, and to reduce the cost of memory to each process. 51 * 52 * Derived from: hp300/@(#)pmap.c 7.1 (Berkeley) 12/5/90 53 */ 54/* 55 * Major modifications by John S. Dyson primarily to support 56 * pageable page tables, eliminating pmap_attributes, 57 * discontiguous memory pages, and using more efficient string 58 * instructions. Jan 13, 1994. Further modifications on Mar 2, 1994, 59 * general clean-up and efficiency mods. 60 */ 61 62/* 63 * Manages physical address maps. 64 * 65 * In addition to hardware address maps, this 66 * module is called upon to provide software-use-only 67 * maps which may or may not be stored in the same 68 * form as hardware maps. These pseudo-maps are 69 * used to store intermediate results from copy 70 * operations to and from address spaces. 71 * 72 * Since the information managed by this module is 73 * also stored by the logical address mapping module, 74 * this module may throw away valid virtual-to-physical 75 * mappings at almost any time. However, invalidations 76 * of virtual-to-physical mappings must be done as 77 * requested. 78 * 79 * In order to cope with hardware architectures which 80 * make virtual-to-physical map invalidates expensive, 81 * this module may delay invalidate or reduced protection 82 * operations until such time as they are actually 83 * necessary. This module is given full information as 84 * to which processors are currently using which maps, 85 * and to when physical maps must be made correct. 86 */ 87 88#include <sys/param.h> 89#include <sys/systm.h> 90#include <sys/proc.h> 91#include <sys/malloc.h> 92#include <sys/user.h> 93 94#include <vm/vm.h> 95#include <vm/vm_kern.h> 96#include <vm/vm_page.h> 97 98#include <i386/include/cputypes.h> 99 100#include <i386/isa/isa.h> 101 102/* 103 * Allocate various and sundry SYSMAPs used in the days of old VM 104 * and not yet converted. XXX. 105 */ 106#define BSDVM_COMPAT 1 107 108/* 109 * Get PDEs and PTEs for user/kernel address space 110 */ 111#define pmap_pde(m, v) (&((m)->pm_pdir[((vm_offset_t)(v) >> PD_SHIFT)&1023])) 112#define pdir_pde(m, v) (m[((vm_offset_t)(v) >> PD_SHIFT)&1023]) 113 114#define pmap_pte_pa(pte) (*(int *)(pte) & PG_FRAME) 115 116#define pmap_pde_v(pte) ((*(int *)pte & PG_V) != 0) 117#define pmap_pte_w(pte) ((*(int *)pte & PG_W) != 0) 118#define pmap_pte_m(pte) ((*(int *)pte & PG_M) != 0) 119#define pmap_pte_u(pte) ((*(int *)pte & PG_U) != 0) 120#define pmap_pte_v(pte) ((*(int *)pte & PG_V) != 0) 121 122#define pmap_pte_set_w(pte, v) ((v)?(*(int *)pte |= PG_W):(*(int *)pte &= ~PG_W)) 123#define pmap_pte_set_prot(pte, v) ((*(int *)pte &= ~PG_PROT), (*(int *)pte |= (v))) 124 125/* 126 * Given a map and a machine independent protection code, 127 * convert to a vax protection code. 128 */ 129#define pte_prot(m, p) (protection_codes[p]) 130int protection_codes[8]; 131 132struct pmap kernel_pmap_store; 133pmap_t kernel_pmap; 134 135vm_offset_t phys_avail[6]; /* 2 entries + 1 null */ 136vm_offset_t avail_start; /* PA of first available physical page */ 137vm_offset_t avail_end; /* PA of last available physical page */ 138vm_size_t mem_size; /* memory size in bytes */ 139vm_offset_t virtual_avail; /* VA of first avail page (after kernel bss) */ 140vm_offset_t virtual_end; /* VA of last avail page (end of kernel AS) */ 141int i386pagesperpage; /* PAGE_SIZE / I386_PAGE_SIZE */ 142boolean_t pmap_initialized = FALSE; /* Has pmap_init completed? */ 143vm_offset_t vm_first_phys, vm_last_phys; 144 145static inline int pmap_is_managed(); 146static inline void *vm_get_pmap(); 147static inline void vm_put_pmap(); 148static void i386_protection_init(); 149static void pmap_alloc_pv_entry(); 150static inline pv_entry_t get_pv_entry(); 151inline void pmap_use_pt(); 152inline void pmap_unuse_pt(); 153int nkpt; 154 155 156extern vm_offset_t clean_sva, clean_eva; 157extern int cpu_class; 158 159#if BSDVM_COMPAT 160#include <sys/msgbuf.h> 161 162/* 163 * All those kernel PT submaps that BSD is so fond of 164 */ 165pt_entry_t *CMAP1, *CMAP2, *ptmmap; 166caddr_t CADDR1, CADDR2, ptvmmap; 167pt_entry_t *msgbufmap; 168struct msgbuf *msgbufp; 169 170#endif 171 172void 173init_pv_entries(int); 174 175/* 176 * Routine: pmap_pte 177 * Function: 178 * Extract the page table entry associated 179 * with the given map/virtual_address pair. 180 * [ what about induced faults -wfj] 181 */ 182 183inline pt_entry_t * const 184pmap_pte(pmap, va) 185 register pmap_t pmap; 186 vm_offset_t va; 187{ 188 189 if (pmap && *pmap_pde(pmap, va)) { 190 vm_offset_t frame = (int) pmap->pm_pdir[PTDPTDI] & PG_FRAME; 191 192 /* are we current address space or kernel? */ 193 if ((pmap == kernel_pmap) || (frame == ((int) PTDpde & PG_FRAME))) 194 return ((pt_entry_t *) vtopte(va)); 195 /* otherwise, we are alternate address space */ 196 else { 197 if (frame != ((int) APTDpde & PG_FRAME)) { 198 APTDpde = pmap->pm_pdir[PTDPTDI]; 199 pmap_update(); 200 } 201 return ((pt_entry_t *) avtopte(va)); 202 } 203 } 204 return (0); 205} 206 207/* 208 * Routine: pmap_extract 209 * Function: 210 * Extract the physical page address associated 211 * with the given map/virtual_address pair. 212 */ 213 214vm_offset_t 215pmap_extract(pmap, va) 216 register pmap_t pmap; 217 vm_offset_t va; 218{ 219 vm_offset_t pa; 220 221 if (pmap && *pmap_pde(pmap, va)) { 222 vm_offset_t frame = (int) pmap->pm_pdir[PTDPTDI] & PG_FRAME; 223 224 /* are we current address space or kernel? */ 225 if ((pmap == kernel_pmap) 226 || (frame == ((int) PTDpde & PG_FRAME))) { 227 pa = *(int *) vtopte(va); 228 /* otherwise, we are alternate address space */ 229 } else { 230 if (frame != ((int) APTDpde & PG_FRAME)) { 231 APTDpde = pmap->pm_pdir[PTDPTDI]; 232 pmap_update(); 233 } 234 pa = *(int *) avtopte(va); 235 } 236 return ((pa & PG_FRAME) | (va & ~PG_FRAME)); 237 } 238 return 0; 239 240} 241 242/* 243 * determine if a page is managed (memory vs. device) 244 */ 245static inline int 246pmap_is_managed(pa) 247 vm_offset_t pa; 248{ 249 int i; 250 251 if (!pmap_initialized) 252 return 0; 253 254 for (i = 0; phys_avail[i + 1]; i += 2) { 255 if (pa >= phys_avail[i] && pa < phys_avail[i + 1]) 256 return 1; 257 } 258 return 0; 259} 260 261/* 262 * find the vm_page_t of a pte (only) given va of pte and pmap 263 */ 264__inline vm_page_t 265pmap_pte_vm_page(pmap, pt) 266 pmap_t pmap; 267 vm_offset_t pt; 268{ 269 vm_page_t m; 270 271 pt = i386_trunc_page(pt); 272 pt = (pt - UPT_MIN_ADDRESS) / NBPG; 273 pt = ((vm_offset_t) pmap->pm_pdir[pt]) & PG_FRAME; 274 m = PHYS_TO_VM_PAGE(pt); 275 return m; 276} 277 278/* 279 * Wire a page table page 280 */ 281inline void 282pmap_use_pt(pmap, va) 283 pmap_t pmap; 284 vm_offset_t va; 285{ 286 vm_offset_t pt; 287 288 if ((va >= UPT_MIN_ADDRESS) || !pmap_initialized) 289 return; 290 291 pt = (vm_offset_t) vtopte(va); 292 vm_page_hold(pmap_pte_vm_page(pmap, pt)); 293} 294 295/* 296 * Unwire a page table page 297 */ 298inline void 299pmap_unuse_pt(pmap, va) 300 pmap_t pmap; 301 vm_offset_t va; 302{ 303 vm_offset_t pt; 304 vm_page_t m; 305 306 if ((va >= UPT_MIN_ADDRESS) || !pmap_initialized) 307 return; 308 309 pt = (vm_offset_t) vtopte(va); 310 m = pmap_pte_vm_page(pmap, pt); 311 vm_page_unhold(m); 312 if (pmap != kernel_pmap && 313 (m->hold_count == 0) && 314 (m->wire_count == 0) && 315 (va < KPT_MIN_ADDRESS)) { 316 vm_page_deactivate(m); 317 } 318} 319 320/* [ macro again?, should I force kstack into user map here? -wfj ] */ 321void 322pmap_activate(pmap, pcbp) 323 register pmap_t pmap; 324 struct pcb *pcbp; 325{ 326 PMAP_ACTIVATE(pmap, pcbp); 327} 328 329/* 330 * Bootstrap the system enough to run with virtual memory. 331 * Map the kernel's code and data, and allocate the system page table. 332 * 333 * On the I386 this is called after mapping has already been enabled 334 * and just syncs the pmap module with what has already been done. 335 * [We can't call it easily with mapping off since the kernel is not 336 * mapped with PA == VA, hence we would have to relocate every address 337 * from the linked base (virtual) address "KERNBASE" to the actual 338 * (physical) address starting relative to 0] 339 */ 340 341#define DMAPAGES 8 342void 343pmap_bootstrap(firstaddr, loadaddr) 344 vm_offset_t firstaddr; 345 vm_offset_t loadaddr; 346{ 347#if BSDVM_COMPAT 348 vm_offset_t va; 349 pt_entry_t *pte; 350 351#endif 352 353 avail_start = firstaddr + DMAPAGES * NBPG; 354 355 virtual_avail = (vm_offset_t) KERNBASE + avail_start; 356 virtual_end = VM_MAX_KERNEL_ADDRESS; 357 i386pagesperpage = PAGE_SIZE / NBPG; 358 359 /* 360 * Initialize protection array. 361 */ 362 i386_protection_init(); 363 364 /* 365 * The kernel's pmap is statically allocated so we don't have to use 366 * pmap_create, which is unlikely to work correctly at this part of 367 * the boot sequence. 368 */ 369 kernel_pmap = &kernel_pmap_store; 370 371 kernel_pmap->pm_pdir = (pd_entry_t *) (KERNBASE + IdlePTD); 372 373 simple_lock_init(&kernel_pmap->pm_lock); 374 kernel_pmap->pm_count = 1; 375 nkpt = NKPT; 376 377#if BSDVM_COMPAT 378 /* 379 * Allocate all the submaps we need 380 */ 381#define SYSMAP(c, p, v, n) \ 382 v = (c)va; va += ((n)*NBPG); p = pte; pte += (n); 383 384 va = virtual_avail; 385 pte = pmap_pte(kernel_pmap, va); 386 387 SYSMAP(caddr_t, CMAP1, CADDR1, 1) 388 SYSMAP(caddr_t, CMAP2, CADDR2, 1) 389 SYSMAP(caddr_t, ptmmap, ptvmmap, 1) 390 SYSMAP(struct msgbuf *, msgbufmap, msgbufp, 1) 391 virtual_avail = va; 392#endif 393 /* 394 * Reserve special hunk of memory for use by bus dma as a bounce 395 * buffer (contiguous virtual *and* physical memory). 396 */ 397 { 398 extern vm_offset_t isaphysmem; 399 400 isaphysmem = va; 401 402 virtual_avail = pmap_map(va, firstaddr, 403 firstaddr + DMAPAGES * NBPG, VM_PROT_ALL); 404 } 405 406 *(int *) CMAP1 = *(int *) CMAP2 = *(int *) PTD = 0; 407 pmap_update(); 408 409} 410 411/* 412 * Initialize the pmap module. 413 * Called by vm_init, to initialize any structures that the pmap 414 * system needs to map virtual memory. 415 * pmap_init has been enhanced to support in a fairly consistant 416 * way, discontiguous physical memory. 417 */ 418void 419pmap_init(phys_start, phys_end) 420 vm_offset_t phys_start, phys_end; 421{ 422 vm_offset_t addr; 423 vm_size_t npg, s; 424 int i; 425 426 /* 427 * Now that kernel map has been allocated, we can mark as unavailable 428 * regions which we have mapped in locore. 429 */ 430 addr = atdevbase; 431 (void) vm_map_find(kernel_map, NULL, (vm_offset_t) 0, 432 &addr, (0x100000 - 0xa0000), FALSE); 433 434 addr = (vm_offset_t) KERNBASE + IdlePTD; 435 vm_object_reference(kernel_object); 436 (void) vm_map_find(kernel_map, kernel_object, addr, 437 &addr, (4 + NKPDE) * NBPG, FALSE); 438 439 /* 440 * calculate the number of pv_entries needed 441 */ 442 vm_first_phys = phys_avail[0]; 443 for (i = 0; phys_avail[i + 1]; i += 2); 444 npg = (phys_avail[(i - 2) + 1] - vm_first_phys) / NBPG; 445 446 /* 447 * Allocate memory for random pmap data structures. Includes the 448 * pv_head_table. 449 */ 450 s = (vm_size_t) (sizeof(struct pv_entry) * npg); 451 s = i386_round_page(s); 452 addr = (vm_offset_t) kmem_alloc(kernel_map, s); 453 pv_table = (pv_entry_t) addr; 454 455 /* 456 * init the pv free list 457 */ 458 init_pv_entries(npg); 459 /* 460 * Now it is safe to enable pv_table recording. 461 */ 462 pmap_initialized = TRUE; 463} 464 465/* 466 * Used to map a range of physical addresses into kernel 467 * virtual address space. 468 * 469 * For now, VM is already on, we only need to map the 470 * specified memory. 471 */ 472vm_offset_t 473pmap_map(virt, start, end, prot) 474 vm_offset_t virt; 475 vm_offset_t start; 476 vm_offset_t end; 477 int prot; 478{ 479 while (start < end) { 480 pmap_enter(kernel_pmap, virt, start, prot, FALSE); 481 virt += PAGE_SIZE; 482 start += PAGE_SIZE; 483 } 484 return (virt); 485} 486 487/* 488 * Create and return a physical map. 489 * 490 * If the size specified for the map 491 * is zero, the map is an actual physical 492 * map, and may be referenced by the 493 * hardware. 494 * 495 * If the size specified is non-zero, 496 * the map will be used in software only, and 497 * is bounded by that size. 498 * 499 * [ just allocate a ptd and mark it uninitialize -- should we track 500 * with a table which process has which ptd? -wfj ] 501 */ 502 503pmap_t 504pmap_create(size) 505 vm_size_t size; 506{ 507 register pmap_t pmap; 508 509 /* 510 * Software use map does not need a pmap 511 */ 512 if (size) 513 return (NULL); 514 515 pmap = (pmap_t) malloc(sizeof *pmap, M_VMPMAP, M_WAITOK); 516 bzero(pmap, sizeof(*pmap)); 517 pmap_pinit(pmap); 518 return (pmap); 519} 520 521 522struct pmaplist { 523 struct pmaplist *next; 524}; 525 526static inline void * 527vm_get_pmap() 528{ 529 struct pmaplist *rtval; 530 531 rtval = (struct pmaplist *) kmem_alloc(kernel_map, ctob(1)); 532 bzero(rtval, ctob(1)); 533 return rtval; 534} 535 536static inline void 537vm_put_pmap(up) 538 struct pmaplist *up; 539{ 540 kmem_free(kernel_map, (vm_offset_t) up, ctob(1)); 541} 542 543/* 544 * Initialize a preallocated and zeroed pmap structure, 545 * such as one in a vmspace structure. 546 */ 547void 548pmap_pinit(pmap) 549 register struct pmap *pmap; 550{ 551 /* 552 * No need to allocate page table space yet but we do need a valid 553 * page directory table. 554 */ 555 pmap->pm_pdir = (pd_entry_t *) vm_get_pmap(); 556 557 /* wire in kernel global address entries */ 558 bcopy(PTD + KPTDI, pmap->pm_pdir + KPTDI, nkpt * PTESIZE); 559 560 /* install self-referential address mapping entry */ 561 *(int *) (pmap->pm_pdir + PTDPTDI) = 562 ((int) pmap_kextract((vm_offset_t) pmap->pm_pdir)) | PG_V | PG_KW; 563 564 pmap->pm_count = 1; 565 simple_lock_init(&pmap->pm_lock); 566} 567 568/* 569 * grow the number of kernel page table entries, if needed 570 */ 571 572vm_page_t nkpg; 573vm_offset_t kernel_vm_end; 574 575void 576pmap_growkernel(vm_offset_t addr) 577{ 578 struct proc *p; 579 struct pmap *pmap; 580 int s; 581 582 s = splhigh(); 583 if (kernel_vm_end == 0) { 584 kernel_vm_end = KERNBASE; 585 nkpt = 0; 586 while (pdir_pde(PTD, kernel_vm_end)) { 587 kernel_vm_end = (kernel_vm_end + NBPG * NPTEPG) & ~(NBPG * NPTEPG - 1); 588 ++nkpt; 589 } 590 } 591 addr = (addr + NBPG * NPTEPG) & ~(NBPG * NPTEPG - 1); 592 while (kernel_vm_end < addr) { 593 if (pdir_pde(PTD, kernel_vm_end)) { 594 kernel_vm_end = (kernel_vm_end + NBPG * NPTEPG) & ~(NBPG * NPTEPG - 1); 595 continue; 596 } 597 ++nkpt; 598 if (!nkpg) { 599 nkpg = vm_page_alloc(kernel_object, 0, VM_ALLOC_SYSTEM); 600 if (!nkpg) 601 panic("pmap_growkernel: no memory to grow kernel"); 602 vm_page_wire(nkpg); 603 vm_page_remove(nkpg); 604 pmap_zero_page(VM_PAGE_TO_PHYS(nkpg)); 605 } 606 pdir_pde(PTD, kernel_vm_end) = (pd_entry_t) (VM_PAGE_TO_PHYS(nkpg) | PG_V | PG_KW); 607 nkpg = NULL; 608 609 for (p = (struct proc *) allproc; p != NULL; p = p->p_next) { 610 if (p->p_vmspace) { 611 pmap = &p->p_vmspace->vm_pmap; 612 *pmap_pde(pmap, kernel_vm_end) = pdir_pde(PTD, kernel_vm_end); 613 } 614 } 615 kernel_vm_end = (kernel_vm_end + NBPG * NPTEPG) & ~(NBPG * NPTEPG - 1); 616 } 617 splx(s); 618} 619 620/* 621 * Retire the given physical map from service. 622 * Should only be called if the map contains 623 * no valid mappings. 624 */ 625void 626pmap_destroy(pmap) 627 register pmap_t pmap; 628{ 629 int count; 630 631 if (pmap == NULL) 632 return; 633 634 simple_lock(&pmap->pm_lock); 635 count = --pmap->pm_count; 636 simple_unlock(&pmap->pm_lock); 637 if (count == 0) { 638 pmap_release(pmap); 639 free((caddr_t) pmap, M_VMPMAP); 640 } 641} 642 643/* 644 * Release any resources held by the given physical map. 645 * Called when a pmap initialized by pmap_pinit is being released. 646 * Should only be called if the map contains no valid mappings. 647 */ 648void 649pmap_release(pmap) 650 register struct pmap *pmap; 651{ 652 vm_put_pmap((struct pmaplist *) pmap->pm_pdir); 653} 654 655/* 656 * Add a reference to the specified pmap. 657 */ 658void 659pmap_reference(pmap) 660 pmap_t pmap; 661{ 662 if (pmap != NULL) { 663 simple_lock(&pmap->pm_lock); 664 pmap->pm_count++; 665 simple_unlock(&pmap->pm_lock); 666 } 667} 668 669#define PV_FREELIST_MIN ((NBPG / sizeof (struct pv_entry)) / 2) 670 671/* 672 * Data for the pv entry allocation mechanism 673 */ 674int pv_freelistcnt; 675pv_entry_t pv_freelist; 676vm_offset_t pvva; 677int npvvapg; 678 679/* 680 * free the pv_entry back to the free list 681 */ 682inline static void 683free_pv_entry(pv) 684 pv_entry_t pv; 685{ 686 if (!pv) 687 return; 688 ++pv_freelistcnt; 689 pv->pv_next = pv_freelist; 690 pv_freelist = pv; 691} 692 693/* 694 * get a new pv_entry, allocating a block from the system 695 * when needed. 696 * the memory allocation is performed bypassing the malloc code 697 * because of the possibility of allocations at interrupt time. 698 */ 699static inline pv_entry_t 700get_pv_entry() 701{ 702 pv_entry_t tmp; 703 704 /* 705 * get more pv_entry pages if needed 706 */ 707 if (pv_freelistcnt < PV_FREELIST_MIN || pv_freelist == 0) { 708 pmap_alloc_pv_entry(); 709 } 710 /* 711 * get a pv_entry off of the free list 712 */ 713 --pv_freelistcnt; 714 tmp = pv_freelist; 715 pv_freelist = tmp->pv_next; 716 return tmp; 717} 718 719/* 720 * this *strange* allocation routine *statistically* eliminates the 721 * *possibility* of a malloc failure (*FATAL*) for a pv_entry_t data structure. 722 * also -- this code is MUCH MUCH faster than the malloc equiv... 723 */ 724static void 725pmap_alloc_pv_entry() 726{ 727 /* 728 * do we have any pre-allocated map-pages left? 729 */ 730 if (npvvapg) { 731 vm_page_t m; 732 733 /* 734 * we do this to keep recursion away 735 */ 736 pv_freelistcnt += PV_FREELIST_MIN; 737 /* 738 * allocate a physical page out of the vm system 739 */ 740 m = vm_page_alloc(kernel_object, 741 pvva - vm_map_min(kernel_map), VM_ALLOC_INTERRUPT); 742 if (m) { 743 int newentries; 744 int i; 745 pv_entry_t entry; 746 747 newentries = (NBPG / sizeof(struct pv_entry)); 748 /* 749 * wire the page 750 */ 751 vm_page_wire(m); 752 m->flags &= ~PG_BUSY; 753 /* 754 * let the kernel see it 755 */ 756 pmap_kenter(pvva, VM_PAGE_TO_PHYS(m)); 757 758 entry = (pv_entry_t) pvva; 759 /* 760 * update the allocation pointers 761 */ 762 pvva += NBPG; 763 --npvvapg; 764 765 /* 766 * free the entries into the free list 767 */ 768 for (i = 0; i < newentries; i++) { 769 free_pv_entry(entry); 770 entry++; 771 } 772 } 773 pv_freelistcnt -= PV_FREELIST_MIN; 774 } 775 if (!pv_freelist) 776 panic("get_pv_entry: cannot get a pv_entry_t"); 777} 778 779 780 781/* 782 * init the pv_entry allocation system 783 */ 784#define PVSPERPAGE 64 785void 786init_pv_entries(npg) 787 int npg; 788{ 789 /* 790 * allocate enough kvm space for PVSPERPAGE entries per page (lots) 791 * kvm space is fairly cheap, be generous!!! (the system can panic if 792 * this is too small.) 793 */ 794 npvvapg = ((npg * PVSPERPAGE) * sizeof(struct pv_entry) + NBPG - 1) / NBPG; 795 pvva = kmem_alloc_pageable(kernel_map, npvvapg * NBPG); 796 /* 797 * get the first batch of entries 798 */ 799 free_pv_entry(get_pv_entry()); 800} 801 802static pt_entry_t * 803get_pt_entry(pmap) 804 pmap_t pmap; 805{ 806 vm_offset_t frame = (int) pmap->pm_pdir[PTDPTDI] & PG_FRAME; 807 808 /* are we current address space or kernel? */ 809 if (pmap == kernel_pmap || frame == ((int) PTDpde & PG_FRAME)) { 810 return PTmap; 811 } 812 /* otherwise, we are alternate address space */ 813 if (frame != ((int) APTDpde & PG_FRAME)) { 814 APTDpde = pmap->pm_pdir[PTDPTDI]; 815 pmap_update(); 816 } 817 return APTmap; 818} 819 820/* 821 * If it is the first entry on the list, it is actually 822 * in the header and we must copy the following entry up 823 * to the header. Otherwise we must search the list for 824 * the entry. In either case we free the now unused entry. 825 */ 826void 827pmap_remove_entry(pmap, pv, va) 828 struct pmap *pmap; 829 pv_entry_t pv; 830 vm_offset_t va; 831{ 832 pv_entry_t npv; 833 int s; 834 835 s = splhigh(); 836 if (pmap == pv->pv_pmap && va == pv->pv_va) { 837 npv = pv->pv_next; 838 if (npv) { 839 *pv = *npv; 840 free_pv_entry(npv); 841 } else { 842 pv->pv_pmap = NULL; 843 } 844 } else { 845 for (npv = pv->pv_next; npv; npv = npv->pv_next) { 846 if (pmap == npv->pv_pmap && va == npv->pv_va) { 847 break; 848 } 849 pv = npv; 850 } 851 if (npv) { 852 pv->pv_next = npv->pv_next; 853 free_pv_entry(npv); 854 } 855 } 856 splx(s); 857} 858 859/* 860 * Remove the given range of addresses from the specified map. 861 * 862 * It is assumed that the start and end are properly 863 * rounded to the page size. 864 */ 865void 866pmap_remove(pmap, sva, eva) 867 struct pmap *pmap; 868 register vm_offset_t sva; 869 register vm_offset_t eva; 870{ 871 register pt_entry_t *ptp, *ptq; 872 vm_offset_t pa; 873 register pv_entry_t pv; 874 vm_offset_t va; 875 vm_page_t m; 876 pt_entry_t oldpte; 877 878 if (pmap == NULL) 879 return; 880 881 ptp = get_pt_entry(pmap); 882 883 /* 884 * special handling of removing one page. a very 885 * common operation and easy to short circuit some 886 * code. 887 */ 888 if ((sva + NBPG) == eva) { 889 890 if (*pmap_pde(pmap, sva) == 0) 891 return; 892 893 ptq = ptp + i386_btop(sva); 894 895 if (!*ptq) 896 return; 897 /* 898 * Update statistics 899 */ 900 if (pmap_pte_w(ptq)) 901 pmap->pm_stats.wired_count--; 902 pmap->pm_stats.resident_count--; 903 904 pa = pmap_pte_pa(ptq); 905 oldpte = *ptq; 906 *ptq = 0; 907 908 if (pmap_is_managed(pa)) { 909 if ((int) oldpte & PG_M) { 910 if ((sva < USRSTACK || sva > UPT_MAX_ADDRESS) || 911 (sva >= USRSTACK && sva < USRSTACK + (UPAGES * NBPG))) { 912 if (sva < clean_sva || sva >= clean_eva) { 913 PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL; 914 } 915 } 916 } 917 pv = pa_to_pvh(pa); 918 pmap_remove_entry(pmap, pv, sva); 919 } 920 pmap_unuse_pt(pmap, sva); 921 pmap_update(); 922 return; 923 } 924 sva = i386_btop(sva); 925 eva = i386_btop(eva); 926 927 while (sva < eva) { 928 /* 929 * Weed out invalid mappings. Note: we assume that the page 930 * directory table is always allocated, and in kernel virtual. 931 */ 932 933 if (*pmap_pde(pmap, i386_ptob(sva)) == 0) { 934 /* We can race ahead here, straight to next pde.. */ 935 sva = ((sva + NPTEPG) & ~(NPTEPG - 1)); 936 continue; 937 } 938 ptq = ptp + sva; 939 940 /* 941 * search for page table entries, use string operations that 942 * are much faster than explicitly scanning when page tables 943 * are not fully populated. 944 */ 945 if (*ptq == 0) { 946 vm_offset_t pdnxt = ((sva + NPTEPG) & ~(NPTEPG - 1)); 947 vm_offset_t nscan = pdnxt - sva; 948 int found = 0; 949 950 if ((nscan + sva) > eva) 951 nscan = eva - sva; 952 953 asm("xorl %%eax,%%eax;cld;repe;scasl;jz 1f;incl %%eax;1:;" : 954 "=D"(ptq), "=a"(found) : "c"(nscan), "0"(ptq) : "cx"); 955 956 if (!found) { 957 sva = pdnxt; 958 continue; 959 } 960 ptq -= 1; 961 962 sva = ptq - ptp; 963 } 964 /* 965 * Update statistics 966 */ 967 oldpte = *ptq; 968 if (((int) oldpte) & PG_W) 969 pmap->pm_stats.wired_count--; 970 pmap->pm_stats.resident_count--; 971 972 /* 973 * Invalidate the PTEs. XXX: should cluster them up and 974 * invalidate as many as possible at once. 975 */ 976 *ptq = 0; 977 978 va = i386_ptob(sva); 979 980 /* 981 * Remove from the PV table (raise IPL since we may be called 982 * at interrupt time). 983 */ 984 pa = ((int) oldpte) & PG_FRAME; 985 if (!pmap_is_managed(pa)) { 986 pmap_unuse_pt(pmap, va); 987 ++sva; 988 continue; 989 } 990 if ((int) oldpte & PG_M) { 991 if ((va < USRSTACK || va > UPT_MAX_ADDRESS) || 992 (va >= USRSTACK && va < USRSTACK + (UPAGES * NBPG))) { 993 if (va < clean_sva || va >= clean_eva) { 994 PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL; 995 } 996 } 997 } 998 pv = pa_to_pvh(pa); 999 pmap_remove_entry(pmap, pv, va); 1000 pmap_unuse_pt(pmap, va); 1001 ++sva; 1002 } 1003 pmap_update(); 1004} 1005 1006/* 1007 * Routine: pmap_remove_all 1008 * Function: 1009 * Removes this physical page from 1010 * all physical maps in which it resides. 1011 * Reflects back modify bits to the pager. 1012 * 1013 * Notes: 1014 * Original versions of this routine were very 1015 * inefficient because they iteratively called 1016 * pmap_remove (slow...) 1017 */ 1018void 1019pmap_remove_all(pa) 1020 vm_offset_t pa; 1021{ 1022 register pv_entry_t pv, npv; 1023 register pt_entry_t *pte, *ptp; 1024 vm_offset_t va; 1025 struct pmap *pmap; 1026 vm_page_t m; 1027 int s; 1028 int anyvalid = 0; 1029 1030 /* 1031 * Not one of ours 1032 */ 1033 /* 1034 * XXX this makes pmap_page_protect(NONE) illegal for non-managed 1035 * pages! 1036 */ 1037 if (!pmap_is_managed(pa)) 1038 return; 1039 1040 pa = i386_trunc_page(pa); 1041 pv = pa_to_pvh(pa); 1042 m = PHYS_TO_VM_PAGE(pa); 1043 1044 s = splhigh(); 1045 while (pv->pv_pmap != NULL) { 1046 pmap = pv->pv_pmap; 1047 ptp = get_pt_entry(pmap); 1048 va = pv->pv_va; 1049 pte = ptp + i386_btop(va); 1050 if (pmap_pte_w(pte)) 1051 pmap->pm_stats.wired_count--; 1052 if (*pte) { 1053 pmap->pm_stats.resident_count--; 1054 anyvalid++; 1055 1056 /* 1057 * Update the vm_page_t clean and reference bits. 1058 */ 1059 if ((int) *pte & PG_M) { 1060 if ((va < USRSTACK || va > UPT_MAX_ADDRESS) || 1061 (va >= USRSTACK && va < USRSTACK + (UPAGES * NBPG))) { 1062 if (va < clean_sva || va >= clean_eva) { 1063 PHYS_TO_VM_PAGE(pa)->dirty |= VM_PAGE_BITS_ALL; 1064 } 1065 } 1066 } 1067 *pte = 0; 1068 pmap_unuse_pt(pmap, va); 1069 } 1070 npv = pv->pv_next; 1071 if (npv) { 1072 *pv = *npv; 1073 free_pv_entry(npv); 1074 } else { 1075 pv->pv_pmap = NULL; 1076 } 1077 } 1078 splx(s); 1079 if (anyvalid) 1080 pmap_update(); 1081} 1082 1083 1084/* 1085 * Set the physical protection on the 1086 * specified range of this map as requested. 1087 */ 1088void 1089pmap_protect(pmap, sva, eva, prot) 1090 register pmap_t pmap; 1091 vm_offset_t sva, eva; 1092 vm_prot_t prot; 1093{ 1094 register pt_entry_t *pte; 1095 register vm_offset_t va; 1096 int i386prot; 1097 register pt_entry_t *ptp; 1098 int evap = i386_btop(eva); 1099 int anyvalid = 0;; 1100 1101 if (pmap == NULL) 1102 return; 1103 1104 if ((prot & VM_PROT_READ) == VM_PROT_NONE) { 1105 pmap_remove(pmap, sva, eva); 1106 return; 1107 } 1108 if (prot & VM_PROT_WRITE) 1109 return; 1110 1111 ptp = get_pt_entry(pmap); 1112 1113 va = sva; 1114 while (va < eva) { 1115 int found = 0; 1116 int svap; 1117 vm_offset_t nscan; 1118 1119 /* 1120 * Page table page is not allocated. Skip it, we don't want to 1121 * force allocation of unnecessary PTE pages just to set the 1122 * protection. 1123 */ 1124 if (!*pmap_pde(pmap, va)) { 1125 /* XXX: avoid address wrap around */ 1126 nextpde: 1127 if (va >= i386_trunc_pdr((vm_offset_t) - 1)) 1128 break; 1129 va = i386_round_pdr(va + PAGE_SIZE); 1130 continue; 1131 } 1132 pte = ptp + i386_btop(va); 1133 1134 if (*pte == 0) { 1135 /* 1136 * scan for a non-empty pte 1137 */ 1138 svap = pte - ptp; 1139 nscan = ((svap + NPTEPG) & ~(NPTEPG - 1)) - svap; 1140 1141 if (nscan + svap > evap) 1142 nscan = evap - svap; 1143 1144 found = 0; 1145 if (nscan) 1146 asm("xorl %%eax,%%eax;cld;repe;scasl;jz 1f;incl %%eax;1:;" : 1147 "=D"(pte), "=a"(found) : "c"(nscan), "0"(pte) : "cx"); 1148 1149 if (!found) 1150 goto nextpde; 1151 1152 pte -= 1; 1153 svap = pte - ptp; 1154 1155 va = i386_ptob(svap); 1156 } 1157 anyvalid++; 1158 1159 i386prot = pte_prot(pmap, prot); 1160 if (va < UPT_MAX_ADDRESS) { 1161 i386prot |= PG_u; 1162 if (va >= UPT_MIN_ADDRESS) 1163 i386prot |= PG_RW; 1164 } 1165 pmap_pte_set_prot(pte, i386prot); 1166 va += PAGE_SIZE; 1167 } 1168 if (anyvalid) 1169 pmap_update(); 1170} 1171 1172/* 1173 * Insert the given physical page (p) at 1174 * the specified virtual address (v) in the 1175 * target physical map with the protection requested. 1176 * 1177 * If specified, the page will be wired down, meaning 1178 * that the related pte can not be reclaimed. 1179 * 1180 * NB: This is the only routine which MAY NOT lazy-evaluate 1181 * or lose information. That is, this routine must actually 1182 * insert this page into the given map NOW. 1183 */ 1184void 1185pmap_enter(pmap, va, pa, prot, wired) 1186 register pmap_t pmap; 1187 vm_offset_t va; 1188 register vm_offset_t pa; 1189 vm_prot_t prot; 1190 boolean_t wired; 1191{ 1192 register pt_entry_t *pte; 1193 register pt_entry_t npte; 1194 vm_offset_t opa; 1195 int ptevalid = 0; 1196 1197 if (pmap == NULL) 1198 return; 1199 1200 va = i386_trunc_page(va); 1201 pa = i386_trunc_page(pa); 1202 if (va > VM_MAX_KERNEL_ADDRESS) 1203 panic("pmap_enter: toobig"); 1204 1205 /* 1206 * Page Directory table entry not valid, we need a new PT page 1207 */ 1208 if (*pmap_pde(pmap, va) == 0) { 1209 printf("kernel page directory invalid pdir=0x%x, va=0x%x\n", pmap->pm_pdir[PTDPTDI], va); 1210 panic("invalid kernel page directory"); 1211 } 1212 pte = pmap_pte(pmap, va); 1213 opa = pmap_pte_pa(pte); 1214 1215 /* 1216 * Mapping has not changed, must be protection or wiring change. 1217 */ 1218 if (opa == pa) { 1219 /* 1220 * Wiring change, just update stats. We don't worry about 1221 * wiring PT pages as they remain resident as long as there 1222 * are valid mappings in them. Hence, if a user page is wired, 1223 * the PT page will be also. 1224 */ 1225 if (wired && !pmap_pte_w(pte)) 1226 pmap->pm_stats.wired_count++; 1227 else if (!wired && pmap_pte_w(pte)) 1228 pmap->pm_stats.wired_count--; 1229 1230 goto validate; 1231 } 1232 /* 1233 * Mapping has changed, invalidate old range and fall through to 1234 * handle validating new mapping. 1235 */ 1236 if (opa) { 1237 pmap_remove(pmap, va, va + PAGE_SIZE); 1238 } 1239 /* 1240 * Enter on the PV list if part of our managed memory Note that we 1241 * raise IPL while manipulating pv_table since pmap_enter can be 1242 * called at interrupt time. 1243 */ 1244 if (pmap_is_managed(pa)) { 1245 register pv_entry_t pv, npv; 1246 int s; 1247 1248 pv = pa_to_pvh(pa); 1249 s = splhigh(); 1250 /* 1251 * No entries yet, use header as the first entry 1252 */ 1253 if (pv->pv_pmap == NULL) { 1254 pv->pv_va = va; 1255 pv->pv_pmap = pmap; 1256 pv->pv_next = NULL; 1257 } 1258 /* 1259 * There is at least one other VA mapping this page. Place 1260 * this entry after the header. 1261 */ 1262 else { 1263 npv = get_pv_entry(); 1264 npv->pv_va = va; 1265 npv->pv_pmap = pmap; 1266 npv->pv_next = pv->pv_next; 1267 pv->pv_next = npv; 1268 } 1269 splx(s); 1270 } 1271 1272 /* 1273 * Increment counters 1274 */ 1275 pmap->pm_stats.resident_count++; 1276 if (wired) 1277 pmap->pm_stats.wired_count++; 1278 1279validate: 1280 /* 1281 * Now validate mapping with desired protection/wiring. 1282 */ 1283 npte = (pt_entry_t) ((int) (pa | pte_prot(pmap, prot) | PG_V)); 1284 1285 /* 1286 * When forking (copy-on-write, etc): A process will turn off write 1287 * permissions for any of its writable pages. If the data (object) is 1288 * only referred to by one process, the processes map is modified 1289 * directly as opposed to using the object manipulation routine. When 1290 * using pmap_protect, the modified bits are not kept in the vm_page_t 1291 * data structure. Therefore, when using pmap_enter in vm_fault to 1292 * bring back writability of a page, there has been no memory of the 1293 * modified or referenced bits except at the pte level. this clause 1294 * supports the carryover of the modified and used (referenced) bits. 1295 */ 1296 if (pa == opa) 1297 (int) npte |= (int) *pte & (PG_M | PG_U); 1298 1299 1300 if (wired) 1301 (int) npte |= PG_W; 1302 if (va < UPT_MIN_ADDRESS) 1303 (int) npte |= PG_u; 1304 else if (va < UPT_MAX_ADDRESS) 1305 (int) npte |= PG_u | PG_RW; 1306 1307 if (*pte != npte) { 1308 if (*pte) 1309 ptevalid++; 1310 *pte = npte; 1311 } 1312 if (ptevalid) { 1313 pmap_update(); 1314 } else { 1315 pmap_use_pt(pmap, va); 1316 } 1317} 1318 1319/* 1320 * Add a list of wired pages to the kva 1321 * this routine is only used for temporary 1322 * kernel mappings that do not need to have 1323 * page modification or references recorded. 1324 * Note that old mappings are simply written 1325 * over. The page *must* be wired. 1326 */ 1327void 1328pmap_qenter(va, m, count) 1329 vm_offset_t va; 1330 vm_page_t *m; 1331 int count; 1332{ 1333 int i; 1334 int anyvalid = 0; 1335 register pt_entry_t *pte; 1336 1337 for (i = 0; i < count; i++) { 1338 pte = vtopte(va + i * NBPG); 1339 if (*pte) 1340 anyvalid++; 1341 *pte = (pt_entry_t) ((int) (VM_PAGE_TO_PHYS(m[i]) | PG_RW | PG_V | PG_W)); 1342 } 1343 if (anyvalid) 1344 pmap_update(); 1345} 1346/* 1347 * this routine jerks page mappings from the 1348 * kernel -- it is meant only for temporary mappings. 1349 */ 1350void 1351pmap_qremove(va, count) 1352 vm_offset_t va; 1353 int count; 1354{ 1355 int i; 1356 register pt_entry_t *pte; 1357 1358 for (i = 0; i < count; i++) { 1359 pte = vtopte(va + i * NBPG); 1360 *pte = 0; 1361 } 1362 pmap_update(); 1363} 1364 1365/* 1366 * add a wired page to the kva 1367 * note that in order for the mapping to take effect -- you 1368 * should do a pmap_update after doing the pmap_kenter... 1369 */ 1370void 1371pmap_kenter(va, pa) 1372 vm_offset_t va; 1373 register vm_offset_t pa; 1374{ 1375 register pt_entry_t *pte; 1376 int wasvalid = 0; 1377 1378 pte = vtopte(va); 1379 1380 if (*pte) 1381 wasvalid++; 1382 1383 *pte = (pt_entry_t) ((int) (pa | PG_RW | PG_V | PG_W)); 1384 1385 if (wasvalid) 1386 pmap_update(); 1387} 1388 1389/* 1390 * remove a page from the kernel pagetables 1391 */ 1392void 1393pmap_kremove(va) 1394 vm_offset_t va; 1395{ 1396 register pt_entry_t *pte; 1397 1398 pte = vtopte(va); 1399 1400 *pte = (pt_entry_t) 0; 1401 pmap_update(); 1402} 1403 1404/* 1405 * this code makes some *MAJOR* assumptions: 1406 * 1. Current pmap & pmap exists. 1407 * 2. Not wired. 1408 * 3. Read access. 1409 * 4. No page table pages. 1410 * 5. Tlbflush is deferred to calling procedure. 1411 * 6. Page IS managed. 1412 * but is *MUCH* faster than pmap_enter... 1413 */ 1414 1415static inline void 1416pmap_enter_quick(pmap, va, pa) 1417 register pmap_t pmap; 1418 vm_offset_t va; 1419 register vm_offset_t pa; 1420{ 1421 register pt_entry_t *pte; 1422 register pv_entry_t pv, npv; 1423 int s; 1424 1425 /* 1426 * Enter on the PV list if part of our managed memory Note that we 1427 * raise IPL while manipulating pv_table since pmap_enter can be 1428 * called at interrupt time. 1429 */ 1430 1431 pte = vtopte(va); 1432 1433 /* a fault on the page table might occur here */ 1434 if (*pte) { 1435 pmap_remove(pmap, va, va + PAGE_SIZE); 1436 } 1437 pv = pa_to_pvh(pa); 1438 s = splhigh(); 1439 /* 1440 * No entries yet, use header as the first entry 1441 */ 1442 if (pv->pv_pmap == NULL) { 1443 pv->pv_pmap = pmap; 1444 pv->pv_va = va; 1445 pv->pv_next = NULL; 1446 } 1447 /* 1448 * There is at least one other VA mapping this page. Place this entry 1449 * after the header. 1450 */ 1451 else { 1452 npv = get_pv_entry(); 1453 npv->pv_va = va; 1454 npv->pv_pmap = pmap; 1455 npv->pv_next = pv->pv_next; 1456 pv->pv_next = npv; 1457 } 1458 splx(s); 1459 1460 /* 1461 * Increment counters 1462 */ 1463 pmap->pm_stats.resident_count++; 1464 1465 /* 1466 * Now validate mapping with desired protection/wiring. 1467 */ 1468 *pte = (pt_entry_t) ((int) (pa | PG_V | PG_u)); 1469 1470 pmap_use_pt(pmap, va); 1471 1472 return; 1473} 1474 1475#define MAX_INIT_PT (1024*2048) 1476/* 1477 * pmap_object_init_pt preloads the ptes for a given object 1478 * into the specified pmap. This eliminates the blast of soft 1479 * faults on process startup and immediately after an mmap. 1480 */ 1481void 1482pmap_object_init_pt(pmap, addr, object, offset, size) 1483 pmap_t pmap; 1484 vm_offset_t addr; 1485 vm_object_t object; 1486 vm_offset_t offset; 1487 vm_offset_t size; 1488{ 1489 vm_offset_t tmpoff; 1490 vm_page_t p; 1491 int bits; 1492 int objbytes; 1493 1494 if (!pmap || ((size > MAX_INIT_PT) && 1495 (object->resident_page_count > (MAX_INIT_PT / NBPG)))) { 1496 return; 1497 } 1498 if (!vm_object_lock_try(object)) 1499 return; 1500 1501 /* 1502 * if we are processing a major portion of the object, then scan the 1503 * entire thing. 1504 */ 1505 if (size > (object->size >> 2)) { 1506 objbytes = size; 1507 1508 for (p = object->memq.tqh_first; 1509 ((objbytes > 0) && (p != NULL)); 1510 p = p->listq.tqe_next) { 1511 1512 tmpoff = p->offset; 1513 if (tmpoff < offset) { 1514 continue; 1515 } 1516 tmpoff -= offset; 1517 if (tmpoff >= size) { 1518 continue; 1519 } 1520 if ((p->bmapped == 0) && 1521 (p->busy == 0) && 1522 ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && 1523 (p->flags & (PG_BUSY | PG_FICTITIOUS | PG_CACHE)) == 0) { 1524 vm_page_hold(p); 1525 pmap_enter_quick(pmap, addr + tmpoff, VM_PAGE_TO_PHYS(p)); 1526 vm_page_unhold(p); 1527 } 1528 objbytes -= NBPG; 1529 } 1530 } else { 1531 /* 1532 * else lookup the pages one-by-one. 1533 */ 1534 for (tmpoff = 0; tmpoff < size; tmpoff += NBPG) { 1535 p = vm_page_lookup(object, tmpoff + offset); 1536 if (p && (p->bmapped == 0) && 1537 (p->busy == 0) && 1538 ((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && 1539 (p->flags & (PG_BUSY | PG_FICTITIOUS | PG_CACHE)) == 0) { 1540 vm_page_hold(p); 1541 pmap_enter_quick(pmap, addr + tmpoff, VM_PAGE_TO_PHYS(p)); 1542 vm_page_unhold(p); 1543 } 1544 } 1545 } 1546 vm_object_unlock(object); 1547} 1548 1549/* 1550 * pmap_prefault provides a quick way of clustering 1551 * pagefaults into a processes address space. It is a "cousin" 1552 * of pmap_object_init_pt, except it runs at page fault time instead 1553 * of mmap time. 1554 */ 1555#define PFBAK 2 1556#define PFFOR 2 1557#define PAGEORDER_SIZE (PFBAK+PFFOR) 1558 1559static int pmap_prefault_pageorder[] = { 1560 -NBPG, NBPG, -2 * NBPG, 2 * NBPG 1561}; 1562 1563void 1564pmap_prefault(pmap, addra, entry, object) 1565 pmap_t pmap; 1566 vm_offset_t addra; 1567 vm_map_entry_t entry; 1568 vm_object_t object; 1569{ 1570 int i; 1571 vm_offset_t starta, enda; 1572 vm_offset_t offset, addr; 1573 vm_page_t m; 1574 int pageorder_index; 1575 1576 if (entry->object.vm_object != object) 1577 return; 1578 1579 if (pmap != &curproc->p_vmspace->vm_pmap) 1580 return; 1581 1582 starta = addra - PFBAK * NBPG; 1583 if (starta < entry->start) { 1584 starta = entry->start; 1585 } else if (starta > addra) 1586 starta = 0; 1587 1588 enda = addra + PFFOR * NBPG; 1589 if (enda > entry->end) 1590 enda = entry->end; 1591 1592 for (i = 0; i < PAGEORDER_SIZE; i++) { 1593 vm_object_t lobject; 1594 pt_entry_t *pte; 1595 1596 addr = addra + pmap_prefault_pageorder[i]; 1597 if (addr < starta || addr >= enda) 1598 continue; 1599 1600 pte = vtopte(addr); 1601 if (*pte) 1602 continue; 1603 1604 offset = (addr - entry->start) + entry->offset; 1605 lobject = object; 1606 for (m = vm_page_lookup(lobject, offset); 1607 (!m && lobject->shadow); 1608 lobject = lobject->shadow) { 1609 1610 offset += lobject->shadow_offset; 1611 m = vm_page_lookup(lobject->shadow, offset); 1612 } 1613 1614 /* 1615 * give-up when a page is not in memory 1616 */ 1617 if (m == NULL) 1618 break; 1619 1620 if ((m->bmapped == 0) && 1621 (m->busy == 0) && 1622 ((m->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && 1623 (m->flags & (PG_CACHE | PG_BUSY | PG_FICTITIOUS)) == 0) { 1624 /* 1625 * test results show that the system is faster when 1626 * pages are activated. 1627 */ 1628 if ((m->flags & PG_ACTIVE) == 0) 1629 vm_page_activate(m); 1630 vm_page_hold(m); 1631 pmap_enter_quick(pmap, addr, VM_PAGE_TO_PHYS(m)); 1632 vm_page_unhold(m); 1633 } 1634 } 1635} 1636 1637/* 1638 * Routine: pmap_change_wiring 1639 * Function: Change the wiring attribute for a map/virtual-address 1640 * pair. 1641 * In/out conditions: 1642 * The mapping must already exist in the pmap. 1643 */ 1644void 1645pmap_change_wiring(pmap, va, wired) 1646 register pmap_t pmap; 1647 vm_offset_t va; 1648 boolean_t wired; 1649{ 1650 register pt_entry_t *pte; 1651 1652 if (pmap == NULL) 1653 return; 1654 1655 pte = pmap_pte(pmap, va); 1656 1657 if (wired && !pmap_pte_w(pte)) 1658 pmap->pm_stats.wired_count++; 1659 else if (!wired && pmap_pte_w(pte)) 1660 pmap->pm_stats.wired_count--; 1661 1662 /* 1663 * Wiring is not a hardware characteristic so there is no need to 1664 * invalidate TLB. 1665 */ 1666 pmap_pte_set_w(pte, wired); 1667 /* 1668 * When unwiring, set the modified bit in the pte -- could have been 1669 * changed by the kernel 1670 */ 1671 if (!wired) 1672 (int) *pte |= PG_M; 1673} 1674 1675 1676 1677/* 1678 * Copy the range specified by src_addr/len 1679 * from the source map to the range dst_addr/len 1680 * in the destination map. 1681 * 1682 * This routine is only advisory and need not do anything. 1683 */ 1684void 1685pmap_copy(dst_pmap, src_pmap, dst_addr, len, src_addr) 1686 pmap_t dst_pmap, src_pmap; 1687 vm_offset_t dst_addr; 1688 vm_size_t len; 1689 vm_offset_t src_addr; 1690{ 1691} 1692 1693/* 1694 * Routine: pmap_kernel 1695 * Function: 1696 * Returns the physical map handle for the kernel. 1697 */ 1698pmap_t 1699pmap_kernel() 1700{ 1701 return (kernel_pmap); 1702} 1703 1704/* 1705 * pmap_zero_page zeros the specified (machine independent) 1706 * page by mapping the page into virtual memory and using 1707 * bzero to clear its contents, one machine dependent page 1708 * at a time. 1709 */ 1710void 1711pmap_zero_page(phys) 1712 vm_offset_t phys; 1713{ 1714 if (*(int *) CMAP2) 1715 panic("pmap_zero_page: CMAP busy"); 1716 1717 *(int *) CMAP2 = PG_V | PG_KW | i386_trunc_page(phys); 1718 bzero(CADDR2, NBPG); 1719 1720 *(int *) CMAP2 = 0; 1721 pmap_update(); 1722} 1723 1724/* 1725 * pmap_copy_page copies the specified (machine independent) 1726 * page by mapping the page into virtual memory and using 1727 * bcopy to copy the page, one machine dependent page at a 1728 * time. 1729 */ 1730void 1731pmap_copy_page(src, dst) 1732 vm_offset_t src; 1733 vm_offset_t dst; 1734{ 1735 if (*(int *) CMAP1 || *(int *) CMAP2) 1736 panic("pmap_copy_page: CMAP busy"); 1737 1738 *(int *) CMAP1 = PG_V | PG_KW | i386_trunc_page(src); 1739 *(int *) CMAP2 = PG_V | PG_KW | i386_trunc_page(dst); 1740 1741#if __GNUC__ > 1 1742 memcpy(CADDR2, CADDR1, NBPG); 1743#else 1744 bcopy(CADDR1, CADDR2, NBPG); 1745#endif 1746 *(int *) CMAP1 = 0; 1747 *(int *) CMAP2 = 0; 1748 pmap_update(); 1749} 1750 1751 1752/* 1753 * Routine: pmap_pageable 1754 * Function: 1755 * Make the specified pages (by pmap, offset) 1756 * pageable (or not) as requested. 1757 * 1758 * A page which is not pageable may not take 1759 * a fault; therefore, its page table entry 1760 * must remain valid for the duration. 1761 * 1762 * This routine is merely advisory; pmap_enter 1763 * will specify that these pages are to be wired 1764 * down (or not) as appropriate. 1765 */ 1766void 1767pmap_pageable(pmap, sva, eva, pageable) 1768 pmap_t pmap; 1769 vm_offset_t sva, eva; 1770 boolean_t pageable; 1771{ 1772} 1773 1774/* 1775 * this routine returns true if a physical page resides 1776 * in the given pmap. 1777 */ 1778boolean_t 1779pmap_page_exists(pmap, pa) 1780 pmap_t pmap; 1781 vm_offset_t pa; 1782{ 1783 register pv_entry_t pv; 1784 int s; 1785 1786 if (!pmap_is_managed(pa)) 1787 return FALSE; 1788 1789 pv = pa_to_pvh(pa); 1790 s = splhigh(); 1791 1792 /* 1793 * Not found, check current mappings returning immediately if found. 1794 */ 1795 if (pv->pv_pmap != NULL) { 1796 for (; pv; pv = pv->pv_next) { 1797 if (pv->pv_pmap == pmap) { 1798 splx(s); 1799 return TRUE; 1800 } 1801 } 1802 } 1803 splx(s); 1804 return (FALSE); 1805} 1806 1807/* 1808 * pmap_testbit tests bits in pte's 1809 * note that the testbit/changebit routines are inline, 1810 * and a lot of things compile-time evaluate. 1811 */ 1812__inline boolean_t 1813pmap_testbit(pa, bit) 1814 register vm_offset_t pa; 1815 int bit; 1816{ 1817 register pv_entry_t pv; 1818 pt_entry_t *pte; 1819 int s; 1820 1821 if (!pmap_is_managed(pa)) 1822 return FALSE; 1823 1824 pv = pa_to_pvh(pa); 1825 s = splhigh(); 1826 1827 /* 1828 * Not found, check current mappings returning immediately if found. 1829 */ 1830 if (pv->pv_pmap != NULL) { 1831 for (; pv; pv = pv->pv_next) { 1832 /* 1833 * if the bit being tested is the modified bit, then 1834 * mark UPAGES as always modified, and ptes as never 1835 * modified. 1836 */ 1837 if (bit & PG_U) { 1838 if ((pv->pv_va >= clean_sva) && (pv->pv_va < clean_eva)) { 1839 continue; 1840 } 1841 } 1842 if (bit & PG_M) { 1843 if (pv->pv_va >= USRSTACK) { 1844 if (pv->pv_va >= clean_sva && pv->pv_va < clean_eva) { 1845 continue; 1846 } 1847 if (pv->pv_va < USRSTACK + (UPAGES * NBPG)) { 1848 splx(s); 1849 return TRUE; 1850 } else if (pv->pv_va < UPT_MAX_ADDRESS) { 1851 splx(s); 1852 return FALSE; 1853 } 1854 } 1855 } 1856 if (!pv->pv_pmap) { 1857 printf("Null pmap (tb) at va: 0x%lx\n", pv->pv_va); 1858 continue; 1859 } 1860 pte = pmap_pte(pv->pv_pmap, pv->pv_va); 1861 if ((int) *pte & bit) { 1862 splx(s); 1863 return TRUE; 1864 } 1865 } 1866 } 1867 splx(s); 1868 return (FALSE); 1869} 1870 1871/* 1872 * this routine is used to modify bits in ptes 1873 */ 1874__inline void 1875pmap_changebit(pa, bit, setem) 1876 vm_offset_t pa; 1877 int bit; 1878 boolean_t setem; 1879{ 1880 register pv_entry_t pv; 1881 register pt_entry_t *pte, npte; 1882 vm_offset_t va; 1883 int s; 1884 1885 if (!pmap_is_managed(pa)) 1886 return; 1887 1888 pv = pa_to_pvh(pa); 1889 s = splhigh(); 1890 1891 /* 1892 * Loop over all current mappings setting/clearing as appropos If 1893 * setting RO do we need to clear the VAC? 1894 */ 1895 if (pv->pv_pmap != NULL) { 1896 for (; pv; pv = pv->pv_next) { 1897 va = pv->pv_va; 1898 1899 /* 1900 * don't write protect pager mappings 1901 */ 1902 if (!setem && (bit == PG_RW)) { 1903 if (va >= clean_sva && va < clean_eva) 1904 continue; 1905 } 1906 if (!pv->pv_pmap) { 1907 printf("Null pmap (cb) at va: 0x%lx\n", va); 1908 continue; 1909 } 1910 pte = pmap_pte(pv->pv_pmap, va); 1911 if (setem) 1912 (int) npte = (int) *pte | bit; 1913 else 1914 (int) npte = (int) *pte & ~bit; 1915 *pte = npte; 1916 } 1917 } 1918 splx(s); 1919 pmap_update(); 1920} 1921 1922/* 1923 * pmap_page_protect: 1924 * 1925 * Lower the permission for all mappings to a given page. 1926 */ 1927void 1928pmap_page_protect(phys, prot) 1929 vm_offset_t phys; 1930 vm_prot_t prot; 1931{ 1932 if ((prot & VM_PROT_WRITE) == 0) { 1933 if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) 1934 pmap_changebit(phys, PG_RW, FALSE); 1935 else 1936 pmap_remove_all(phys); 1937 } 1938} 1939 1940vm_offset_t 1941pmap_phys_address(ppn) 1942 int ppn; 1943{ 1944 return (i386_ptob(ppn)); 1945} 1946 1947/* 1948 * pmap_is_referenced: 1949 * 1950 * Return whether or not the specified physical page was referenced 1951 * by any physical maps. 1952 */ 1953boolean_t 1954pmap_is_referenced(vm_offset_t pa) 1955{ 1956 return pmap_testbit((pa), PG_U); 1957} 1958 1959/* 1960 * pmap_is_modified: 1961 * 1962 * Return whether or not the specified physical page was modified 1963 * in any physical maps. 1964 */ 1965boolean_t 1966pmap_is_modified(vm_offset_t pa) 1967{ 1968 return pmap_testbit((pa), PG_M); 1969} 1970 1971/* 1972 * Clear the modify bits on the specified physical page. 1973 */ 1974void 1975pmap_clear_modify(vm_offset_t pa) 1976{ 1977 pmap_changebit((pa), PG_M, FALSE); 1978} 1979 1980/* 1981 * pmap_clear_reference: 1982 * 1983 * Clear the reference bit on the specified physical page. 1984 */ 1985void 1986pmap_clear_reference(vm_offset_t pa) 1987{ 1988 pmap_changebit((pa), PG_U, FALSE); 1989} 1990 1991/* 1992 * Routine: pmap_copy_on_write 1993 * Function: 1994 * Remove write privileges from all 1995 * physical maps for this physical page. 1996 */ 1997void 1998pmap_copy_on_write(vm_offset_t pa) 1999{ 2000 pmap_changebit((pa), PG_RW, FALSE); 2001} 2002 2003/* 2004 * Miscellaneous support routines follow 2005 */ 2006 2007void 2008i386_protection_init() 2009{ 2010 register int *kp, prot; 2011 2012 kp = protection_codes; 2013 for (prot = 0; prot < 8; prot++) { 2014 switch (prot) { 2015 case VM_PROT_NONE | VM_PROT_NONE | VM_PROT_NONE: 2016 /* 2017 * Read access is also 0. There isn't any execute bit, 2018 * so just make it readable. 2019 */ 2020 case VM_PROT_READ | VM_PROT_NONE | VM_PROT_NONE: 2021 case VM_PROT_READ | VM_PROT_NONE | VM_PROT_EXECUTE: 2022 case VM_PROT_NONE | VM_PROT_NONE | VM_PROT_EXECUTE: 2023 *kp++ = 0; 2024 break; 2025 case VM_PROT_NONE | VM_PROT_WRITE | VM_PROT_NONE: 2026 case VM_PROT_NONE | VM_PROT_WRITE | VM_PROT_EXECUTE: 2027 case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_NONE: 2028 case VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE: 2029 *kp++ = PG_RW; 2030 break; 2031 } 2032 } 2033} 2034 2035/* 2036 * Map a set of physical memory pages into the kernel virtual 2037 * address space. Return a pointer to where it is mapped. This 2038 * routine is intended to be used for mapping device memory, 2039 * NOT real memory. The non-cacheable bits are set on each 2040 * mapped page. 2041 */ 2042void * 2043pmap_mapdev(pa, size) 2044 vm_offset_t pa; 2045 vm_size_t size; 2046{ 2047 vm_offset_t va, tmpva; 2048 pt_entry_t *pte; 2049 2050 pa = trunc_page(pa); 2051 size = roundup(size, PAGE_SIZE); 2052 2053 va = kmem_alloc_pageable(kernel_map, size); 2054 if (!va) 2055 panic("pmap_mapdev: Couldn't alloc kernel virtual memory"); 2056 2057 for (tmpva = va; size > 0;) { 2058 pte = vtopte(tmpva); 2059 *pte = (pt_entry_t) ((int) (pa | PG_RW | PG_V | PG_N)); 2060 size -= PAGE_SIZE; 2061 tmpva += PAGE_SIZE; 2062 pa += PAGE_SIZE; 2063 } 2064 pmap_update(); 2065 2066 return ((void *) va); 2067} 2068 2069#ifdef DEBUG 2070/* print address space of pmap*/ 2071void 2072pads(pm) 2073 pmap_t pm; 2074{ 2075 unsigned va, i, j; 2076 pt_entry_t *ptep; 2077 2078 if (pm == kernel_pmap) 2079 return; 2080 for (i = 0; i < 1024; i++) 2081 if (pm->pm_pdir[i]) 2082 for (j = 0; j < 1024; j++) { 2083 va = (i << PD_SHIFT) + (j << PG_SHIFT); 2084 if (pm == kernel_pmap && va < KERNBASE) 2085 continue; 2086 if (pm != kernel_pmap && va > UPT_MAX_ADDRESS) 2087 continue; 2088 ptep = pmap_pte(pm, va); 2089 if (pmap_pte_v(ptep)) 2090 printf("%x:%x ", va, *(int *) ptep); 2091 }; 2092 2093} 2094 2095void 2096pmap_pvdump(pa) 2097 vm_offset_t pa; 2098{ 2099 register pv_entry_t pv; 2100 2101 printf("pa %x", pa); 2102 for (pv = pa_to_pvh(pa); pv; pv = pv->pv_next) { 2103#ifdef used_to_be 2104 printf(" -> pmap %x, va %x, flags %x", 2105 pv->pv_pmap, pv->pv_va, pv->pv_flags); 2106#endif 2107 printf(" -> pmap %x, va %x", 2108 pv->pv_pmap, pv->pv_va); 2109 pads(pv->pv_pmap); 2110 } 2111 printf(" "); 2112} 2113#endif 2114