1 /* 2 * (MPSAFE) 3 * 4 * Copyright (c) 1991 Regents of the University of California. 5 * Copyright (c) 1994 John S. Dyson 6 * Copyright (c) 1994 David Greenman 7 * Copyright (c) 2003 Peter Wemm 8 * Copyright (c) 2005-2008 Alan L. Cox <alc@cs.rice.edu> 9 * Copyright (c) 2008, 2009 The DragonFly Project. 10 * Copyright (c) 2008, 2009 Jordan Gordeev. 11 * All rights reserved. 12 * 13 * This code is derived from software contributed to Berkeley by 14 * the Systems Programming Group of the University of Utah Computer 15 * Science Department and William Jolitz of UUNET Technologies Inc. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 3. All advertising materials mentioning features or use of this software 26 * must display the following acknowledgement: 27 * This product includes software developed by the University of 28 * California, Berkeley and its contributors. 29 * 4. Neither the name of the University nor the names of its contributors 30 * may be used to endorse or promote products derived from this software 31 * without specific prior written permission. 32 * 33 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 34 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 35 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 36 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 37 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 38 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 39 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 41 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 42 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 43 * SUCH DAMAGE. 44 * 45 * from: @(#)pmap.c 7.7 (Berkeley) 5/12/91 46 * $FreeBSD: src/sys/i386/i386/pmap.c,v 1.250.2.18 2002/03/06 22:48:53 silby Exp $ 47 */ 48 49 /* 50 * Manages physical address maps. 51 * 52 * In most cases the vm_token must be held when manipulating a user pmap 53 * or elements within a vm_page, and the kvm_token must be held when 54 * manipulating the kernel pmap. Operations on user pmaps may require 55 * additional synchronization. 56 * 57 * In some cases the caller may hold the required tokens to prevent pmap 58 * functions from blocking on those same tokens. This typically only works 59 * for lookup-style operations. 60 */ 61 62 #if JG 63 #include "opt_pmap.h" 64 #endif 65 #include "opt_msgbuf.h" 66 67 #include <sys/param.h> 68 #include <sys/systm.h> 69 #include <sys/kernel.h> 70 #include <sys/proc.h> 71 #include <sys/msgbuf.h> 72 #include <sys/vmmeter.h> 73 #include <sys/mman.h> 74 #include <sys/vmspace.h> 75 76 #include <vm/vm.h> 77 #include <vm/vm_param.h> 78 #include <sys/sysctl.h> 79 #include <sys/lock.h> 80 #include <vm/vm_kern.h> 81 #include <vm/vm_page.h> 82 #include <vm/vm_map.h> 83 #include <vm/vm_object.h> 84 #include <vm/vm_extern.h> 85 #include <vm/vm_pageout.h> 86 #include <vm/vm_pager.h> 87 #include <vm/vm_zone.h> 88 89 #include <sys/user.h> 90 #include <sys/thread2.h> 91 #include <sys/sysref2.h> 92 93 #include <machine/cputypes.h> 94 #include <machine/md_var.h> 95 #include <machine/specialreg.h> 96 #include <machine/smp.h> 97 #include <machine/globaldata.h> 98 #include <machine/pmap.h> 99 #include <machine/pmap_inval.h> 100 101 #include <ddb/ddb.h> 102 103 #include <stdio.h> 104 #include <assert.h> 105 #include <stdlib.h> 106 107 #define PMAP_KEEP_PDIRS 108 #ifndef PMAP_SHPGPERPROC 109 #define PMAP_SHPGPERPROC 200 110 #endif 111 112 #if defined(DIAGNOSTIC) 113 #define PMAP_DIAGNOSTIC 114 #endif 115 116 #define MINPV 2048 117 118 #if !defined(PMAP_DIAGNOSTIC) 119 #define PMAP_INLINE __inline 120 #else 121 #define PMAP_INLINE 122 #endif 123 124 /* 125 * Get PDEs and PTEs for user/kernel address space 126 */ 127 static pd_entry_t *pmap_pde(pmap_t pmap, vm_offset_t va); 128 #define pdir_pde(m, v) (m[(vm_offset_t)(v) >> PDRSHIFT]) 129 130 #define pmap_pde_v(pte) ((*(pd_entry_t *)pte & VPTE_V) != 0) 131 #define pmap_pte_w(pte) ((*(pt_entry_t *)pte & VPTE_WIRED) != 0) 132 #define pmap_pte_m(pte) ((*(pt_entry_t *)pte & VPTE_M) != 0) 133 #define pmap_pte_u(pte) ((*(pt_entry_t *)pte & VPTE_A) != 0) 134 #define pmap_pte_v(pte) ((*(pt_entry_t *)pte & VPTE_V) != 0) 135 136 /* 137 * Given a map and a machine independent protection code, 138 * convert to a vax protection code. 139 */ 140 #define pte_prot(m, p) \ 141 (protection_codes[p & (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)]) 142 static int protection_codes[8]; 143 144 struct pmap kernel_pmap; 145 static TAILQ_HEAD(,pmap) pmap_list = TAILQ_HEAD_INITIALIZER(pmap_list); 146 147 static boolean_t pmap_initialized = FALSE; /* Has pmap_init completed? */ 148 149 static vm_object_t kptobj; 150 151 static int nkpt; 152 153 static uint64_t KPDphys; /* phys addr of kernel level 2 */ 154 uint64_t KPDPphys; /* phys addr of kernel level 3 */ 155 uint64_t KPML4phys; /* phys addr of kernel level 4 */ 156 157 158 /* 159 * Data for the pv entry allocation mechanism 160 */ 161 static vm_zone_t pvzone; 162 static struct vm_zone pvzone_store; 163 static struct vm_object pvzone_obj; 164 static int pv_entry_count=0, pv_entry_max=0, pv_entry_high_water=0; 165 static int pmap_pagedaemon_waken = 0; 166 static struct pv_entry *pvinit; 167 168 /* 169 * All those kernel PT submaps that BSD is so fond of 170 */ 171 pt_entry_t *CMAP1 = 0, *ptmmap; 172 caddr_t CADDR1 = 0; 173 static pt_entry_t *msgbufmap; 174 175 uint64_t KPTphys; 176 177 static PMAP_INLINE void free_pv_entry (pv_entry_t pv); 178 static pv_entry_t get_pv_entry (void); 179 static void i386_protection_init (void); 180 static __inline void pmap_clearbit (vm_page_t m, int bit); 181 182 static void pmap_remove_all (vm_page_t m); 183 static int pmap_remove_pte (struct pmap *pmap, pt_entry_t *ptq, 184 vm_offset_t sva); 185 static void pmap_remove_page (struct pmap *pmap, vm_offset_t va); 186 static int pmap_remove_entry (struct pmap *pmap, vm_page_t m, 187 vm_offset_t va); 188 static boolean_t pmap_testbit (vm_page_t m, int bit); 189 static void pmap_insert_entry (pmap_t pmap, vm_offset_t va, 190 vm_page_t mpte, vm_page_t m); 191 192 static vm_page_t pmap_allocpte (pmap_t pmap, vm_offset_t va); 193 194 static int pmap_release_free_page (pmap_t pmap, vm_page_t p); 195 static vm_page_t _pmap_allocpte (pmap_t pmap, vm_pindex_t ptepindex); 196 #if JGPMAP32 197 static pt_entry_t * pmap_pte_quick (pmap_t pmap, vm_offset_t va); 198 #endif 199 static vm_page_t pmap_page_lookup (vm_object_t object, vm_pindex_t pindex); 200 static int pmap_unuse_pt (pmap_t, vm_offset_t, vm_page_t); 201 202 /* 203 * pmap_pte_quick: 204 * 205 * Super fast pmap_pte routine best used when scanning the pv lists. 206 * This eliminates many course-grained invltlb calls. Note that many of 207 * the pv list scans are across different pmaps and it is very wasteful 208 * to do an entire invltlb when checking a single mapping. 209 * 210 * Should only be called while in a critical section. 211 */ 212 #if JGPMAP32 213 static __inline pt_entry_t *pmap_pte(pmap_t pmap, vm_offset_t va); 214 215 static pt_entry_t * 216 pmap_pte_quick(pmap_t pmap, vm_offset_t va) 217 { 218 return pmap_pte(pmap, va); 219 } 220 #endif 221 222 /* Return a non-clipped PD index for a given VA */ 223 static __inline vm_pindex_t 224 pmap_pde_pindex(vm_offset_t va) 225 { 226 return va >> PDRSHIFT; 227 } 228 229 /* Return various clipped indexes for a given VA */ 230 static __inline vm_pindex_t 231 pmap_pte_index(vm_offset_t va) 232 { 233 234 return ((va >> PAGE_SHIFT) & ((1ul << NPTEPGSHIFT) - 1)); 235 } 236 237 static __inline vm_pindex_t 238 pmap_pde_index(vm_offset_t va) 239 { 240 241 return ((va >> PDRSHIFT) & ((1ul << NPDEPGSHIFT) - 1)); 242 } 243 244 static __inline vm_pindex_t 245 pmap_pdpe_index(vm_offset_t va) 246 { 247 248 return ((va >> PDPSHIFT) & ((1ul << NPDPEPGSHIFT) - 1)); 249 } 250 251 static __inline vm_pindex_t 252 pmap_pml4e_index(vm_offset_t va) 253 { 254 255 return ((va >> PML4SHIFT) & ((1ul << NPML4EPGSHIFT) - 1)); 256 } 257 258 /* Return a pointer to the PML4 slot that corresponds to a VA */ 259 static __inline pml4_entry_t * 260 pmap_pml4e(pmap_t pmap, vm_offset_t va) 261 { 262 263 return (&pmap->pm_pml4[pmap_pml4e_index(va)]); 264 } 265 266 /* Return a pointer to the PDP slot that corresponds to a VA */ 267 static __inline pdp_entry_t * 268 pmap_pml4e_to_pdpe(pml4_entry_t *pml4e, vm_offset_t va) 269 { 270 pdp_entry_t *pdpe; 271 272 pdpe = (pdp_entry_t *)PHYS_TO_DMAP(*pml4e & VPTE_FRAME); 273 return (&pdpe[pmap_pdpe_index(va)]); 274 } 275 276 /* Return a pointer to the PDP slot that corresponds to a VA */ 277 static __inline pdp_entry_t * 278 pmap_pdpe(pmap_t pmap, vm_offset_t va) 279 { 280 pml4_entry_t *pml4e; 281 282 pml4e = pmap_pml4e(pmap, va); 283 if ((*pml4e & VPTE_V) == 0) 284 return NULL; 285 return (pmap_pml4e_to_pdpe(pml4e, va)); 286 } 287 288 /* Return a pointer to the PD slot that corresponds to a VA */ 289 static __inline pd_entry_t * 290 pmap_pdpe_to_pde(pdp_entry_t *pdpe, vm_offset_t va) 291 { 292 pd_entry_t *pde; 293 294 pde = (pd_entry_t *)PHYS_TO_DMAP(*pdpe & VPTE_FRAME); 295 return (&pde[pmap_pde_index(va)]); 296 } 297 298 /* Return a pointer to the PD slot that corresponds to a VA */ 299 static __inline pd_entry_t * 300 pmap_pde(pmap_t pmap, vm_offset_t va) 301 { 302 pdp_entry_t *pdpe; 303 304 pdpe = pmap_pdpe(pmap, va); 305 if (pdpe == NULL || (*pdpe & VPTE_V) == 0) 306 return NULL; 307 return (pmap_pdpe_to_pde(pdpe, va)); 308 } 309 310 /* Return a pointer to the PT slot that corresponds to a VA */ 311 static __inline pt_entry_t * 312 pmap_pde_to_pte(pd_entry_t *pde, vm_offset_t va) 313 { 314 pt_entry_t *pte; 315 316 pte = (pt_entry_t *)PHYS_TO_DMAP(*pde & VPTE_FRAME); 317 return (&pte[pmap_pte_index(va)]); 318 } 319 320 /* Return a pointer to the PT slot that corresponds to a VA */ 321 static __inline pt_entry_t * 322 pmap_pte(pmap_t pmap, vm_offset_t va) 323 { 324 pd_entry_t *pde; 325 326 pde = pmap_pde(pmap, va); 327 if (pde == NULL || (*pde & VPTE_V) == 0) 328 return NULL; 329 if ((*pde & VPTE_PS) != 0) /* compat with i386 pmap_pte() */ 330 return ((pt_entry_t *)pde); 331 return (pmap_pde_to_pte(pde, va)); 332 } 333 334 335 #if JGV 336 PMAP_INLINE pt_entry_t * 337 vtopte(vm_offset_t va) 338 { 339 uint64_t mask = ((1ul << (NPTEPGSHIFT + NPDEPGSHIFT + NPDPEPGSHIFT + NPML4EPGSHIFT)) - 1); 340 341 return (PTmap + ((va >> PAGE_SHIFT) & mask)); 342 } 343 344 static __inline pd_entry_t * 345 vtopde(vm_offset_t va) 346 { 347 uint64_t mask = ((1ul << (NPDEPGSHIFT + NPDPEPGSHIFT + NPML4EPGSHIFT)) - 1); 348 349 return (PDmap + ((va >> PDRSHIFT) & mask)); 350 } 351 #else 352 static PMAP_INLINE pt_entry_t * 353 vtopte(vm_offset_t va) 354 { 355 pt_entry_t *x; 356 x = pmap_pte(&kernel_pmap, va); 357 assert(x != NULL); 358 return x; 359 } 360 361 static __inline pd_entry_t * 362 vtopde(vm_offset_t va) 363 { 364 pd_entry_t *x; 365 x = pmap_pde(&kernel_pmap, va); 366 assert(x != NULL); 367 return x; 368 } 369 #endif 370 371 static uint64_t 372 allocpages(vm_paddr_t *firstaddr, int n) 373 { 374 uint64_t ret; 375 376 ret = *firstaddr; 377 #if JGV 378 bzero((void *)ret, n * PAGE_SIZE); 379 #endif 380 *firstaddr += n * PAGE_SIZE; 381 return (ret); 382 } 383 384 static void 385 create_pagetables(vm_paddr_t *firstaddr, int64_t ptov_offset) 386 { 387 int i; 388 pml4_entry_t *KPML4virt; 389 pdp_entry_t *KPDPvirt; 390 pd_entry_t *KPDvirt; 391 pt_entry_t *KPTvirt; 392 int kpml4i = pmap_pml4e_index(ptov_offset); 393 int kpdpi = pmap_pdpe_index(ptov_offset); 394 395 396 /* Allocate pages */ 397 KPML4phys = allocpages(firstaddr, 1); 398 KPDPphys = allocpages(firstaddr, NKPML4E); 399 KPDphys = allocpages(firstaddr, NKPDPE); 400 KPTphys = allocpages(firstaddr, NKPT); 401 402 KPML4virt = (pml4_entry_t *)PHYS_TO_DMAP(KPML4phys); 403 KPDPvirt = (pdp_entry_t *)PHYS_TO_DMAP(KPDPphys); 404 KPDvirt = (pd_entry_t *)PHYS_TO_DMAP(KPDphys); 405 KPTvirt = (pt_entry_t *)PHYS_TO_DMAP(KPTphys); 406 407 bzero(KPML4virt, 1 * PAGE_SIZE); 408 bzero(KPDPvirt, NKPML4E * PAGE_SIZE); 409 bzero(KPDvirt, NKPDPE * PAGE_SIZE); 410 bzero(KPTvirt, NKPT * PAGE_SIZE); 411 412 /* Now map the page tables at their location within PTmap */ 413 for (i = 0; i < NKPT; i++) { 414 KPDvirt[i] = KPTphys + (i << PAGE_SHIFT); 415 KPDvirt[i] |= VPTE_R | VPTE_W | VPTE_V; 416 } 417 418 /* And connect up the PD to the PDP */ 419 for (i = 0; i < NKPDPE; i++) { 420 KPDPvirt[i + kpdpi] = KPDphys + (i << PAGE_SHIFT); 421 KPDPvirt[i + kpdpi] |= VPTE_R | VPTE_W | VPTE_V; 422 } 423 424 /* And recursively map PML4 to itself in order to get PTmap */ 425 KPML4virt[PML4PML4I] = KPML4phys; 426 KPML4virt[PML4PML4I] |= VPTE_R | VPTE_W | VPTE_V; 427 428 /* Connect the KVA slot up to the PML4 */ 429 KPML4virt[kpml4i] = KPDPphys; 430 KPML4virt[kpml4i] |= VPTE_R | VPTE_W | VPTE_V; 431 } 432 433 /* 434 * Bootstrap the system enough to run with virtual memory. 435 * 436 * On the i386 this is called after mapping has already been enabled 437 * and just syncs the pmap module with what has already been done. 438 * [We can't call it easily with mapping off since the kernel is not 439 * mapped with PA == VA, hence we would have to relocate every address 440 * from the linked base (virtual) address "KERNBASE" to the actual 441 * (physical) address starting relative to 0] 442 */ 443 void 444 pmap_bootstrap(vm_paddr_t *firstaddr, int64_t ptov_offset) 445 { 446 vm_offset_t va; 447 pt_entry_t *pte; 448 449 /* 450 * Create an initial set of page tables to run the kernel in. 451 */ 452 create_pagetables(firstaddr, ptov_offset); 453 454 virtual_start = KvaStart + *firstaddr; 455 virtual_end = KvaEnd; 456 457 /* 458 * Initialize protection array. 459 */ 460 i386_protection_init(); 461 462 /* 463 * The kernel's pmap is statically allocated so we don't have to use 464 * pmap_create, which is unlikely to work correctly at this part of 465 * the boot sequence (XXX and which no longer exists). 466 */ 467 kernel_pmap.pm_pml4 = (pml4_entry_t *)PHYS_TO_DMAP(KPML4phys); 468 kernel_pmap.pm_count = 1; 469 kernel_pmap.pm_active = (cpumask_t)-1; /* don't allow deactivation */ 470 TAILQ_INIT(&kernel_pmap.pm_pvlist); 471 nkpt = NKPT; 472 473 /* 474 * Reserve some special page table entries/VA space for temporary 475 * mapping of pages. 476 */ 477 #define SYSMAP(c, p, v, n) \ 478 v = (c)va; va += ((n)*PAGE_SIZE); p = pte; pte += (n); 479 480 va = virtual_start; 481 pte = pmap_pte(&kernel_pmap, va); 482 483 /* 484 * CMAP1/CMAP2 are used for zeroing and copying pages. 485 */ 486 SYSMAP(caddr_t, CMAP1, CADDR1, 1) 487 488 #if JGV 489 /* 490 * Crashdump maps. 491 */ 492 SYSMAP(caddr_t, pt_crashdumpmap, crashdumpmap, MAXDUMPPGS); 493 #endif 494 495 /* 496 * ptvmmap is used for reading arbitrary physical pages via 497 * /dev/mem. 498 */ 499 SYSMAP(caddr_t, ptmmap, ptvmmap, 1) 500 501 /* 502 * msgbufp is used to map the system message buffer. 503 * XXX msgbufmap is not used. 504 */ 505 SYSMAP(struct msgbuf *, msgbufmap, msgbufp, 506 atop(round_page(MSGBUF_SIZE))) 507 508 virtual_start = va; 509 510 *CMAP1 = 0; 511 512 cpu_invltlb(); 513 } 514 515 /* 516 * Initialize the pmap module. 517 * Called by vm_init, to initialize any structures that the pmap 518 * system needs to map virtual memory. 519 * pmap_init has been enhanced to support in a fairly consistant 520 * way, discontiguous physical memory. 521 */ 522 void 523 pmap_init(void) 524 { 525 int i; 526 int initial_pvs; 527 528 /* 529 * object for kernel page table pages 530 */ 531 /* JG I think the number can be arbitrary */ 532 kptobj = vm_object_allocate(OBJT_DEFAULT, 5); 533 534 /* 535 * Allocate memory for random pmap data structures. Includes the 536 * pv_head_table. 537 */ 538 539 for(i = 0; i < vm_page_array_size; i++) { 540 vm_page_t m; 541 542 m = &vm_page_array[i]; 543 TAILQ_INIT(&m->md.pv_list); 544 m->md.pv_list_count = 0; 545 } 546 547 /* 548 * init the pv free list 549 */ 550 initial_pvs = vm_page_array_size; 551 if (initial_pvs < MINPV) 552 initial_pvs = MINPV; 553 pvzone = &pvzone_store; 554 pvinit = (struct pv_entry *) kmem_alloc(&kernel_map, 555 initial_pvs * sizeof (struct pv_entry)); 556 zbootinit(pvzone, "PV ENTRY", sizeof (struct pv_entry), pvinit, 557 initial_pvs); 558 559 /* 560 * Now it is safe to enable pv_table recording. 561 */ 562 pmap_initialized = TRUE; 563 } 564 565 /* 566 * Initialize the address space (zone) for the pv_entries. Set a 567 * high water mark so that the system can recover from excessive 568 * numbers of pv entries. 569 */ 570 void 571 pmap_init2(void) 572 { 573 int shpgperproc = PMAP_SHPGPERPROC; 574 575 TUNABLE_INT_FETCH("vm.pmap.shpgperproc", &shpgperproc); 576 pv_entry_max = shpgperproc * maxproc + vm_page_array_size; 577 TUNABLE_INT_FETCH("vm.pmap.pv_entries", &pv_entry_max); 578 pv_entry_high_water = 9 * (pv_entry_max / 10); 579 zinitna(pvzone, &pvzone_obj, NULL, 0, pv_entry_max, ZONE_INTERRUPT, 1); 580 } 581 582 583 /*************************************************** 584 * Low level helper routines..... 585 ***************************************************/ 586 587 /* 588 * The modification bit is not tracked for any pages in this range. XXX 589 * such pages in this maps should always use pmap_k*() functions and not 590 * be managed anyhow. 591 * 592 * XXX User and kernel address spaces are independant for virtual kernels, 593 * this function only applies to the kernel pmap. 594 */ 595 static int 596 pmap_track_modified(pmap_t pmap, vm_offset_t va) 597 { 598 if (pmap != &kernel_pmap) 599 return 1; 600 if ((va < clean_sva) || (va >= clean_eva)) 601 return 1; 602 else 603 return 0; 604 } 605 606 /* 607 * Extract the physical page address associated with the map/VA pair. 608 * 609 * No requirements. 610 */ 611 vm_paddr_t 612 pmap_extract(pmap_t pmap, vm_offset_t va) 613 { 614 vm_paddr_t rtval; 615 pt_entry_t *pte; 616 pd_entry_t pde, *pdep; 617 618 lwkt_gettoken(&vm_token); 619 rtval = 0; 620 pdep = pmap_pde(pmap, va); 621 if (pdep != NULL) { 622 pde = *pdep; 623 if (pde) { 624 if ((pde & VPTE_PS) != 0) { 625 /* JGV */ 626 rtval = (pde & PG_PS_FRAME) | (va & PDRMASK); 627 } else { 628 pte = pmap_pde_to_pte(pdep, va); 629 rtval = (*pte & VPTE_FRAME) | (va & PAGE_MASK); 630 } 631 } 632 } 633 lwkt_reltoken(&vm_token); 634 return rtval; 635 } 636 637 /* 638 * Routine: pmap_kextract 639 * Function: 640 * Extract the physical page address associated 641 * kernel virtual address. 642 */ 643 vm_paddr_t 644 pmap_kextract(vm_offset_t va) 645 { 646 pd_entry_t pde; 647 vm_paddr_t pa; 648 649 KKASSERT(va >= KvaStart && va < KvaEnd); 650 651 /* 652 * The DMAP region is not included in [KvaStart, KvaEnd) 653 */ 654 #if 0 655 if (va >= DMAP_MIN_ADDRESS && va < DMAP_MAX_ADDRESS) { 656 pa = DMAP_TO_PHYS(va); 657 } else { 658 #endif 659 pde = *vtopde(va); 660 if (pde & VPTE_PS) { 661 /* JGV */ 662 pa = (pde & PG_PS_FRAME) | (va & PDRMASK); 663 } else { 664 /* 665 * Beware of a concurrent promotion that changes the 666 * PDE at this point! For example, vtopte() must not 667 * be used to access the PTE because it would use the 668 * new PDE. It is, however, safe to use the old PDE 669 * because the page table page is preserved by the 670 * promotion. 671 */ 672 pa = *pmap_pde_to_pte(&pde, va); 673 pa = (pa & VPTE_FRAME) | (va & PAGE_MASK); 674 } 675 #if 0 676 } 677 #endif 678 return pa; 679 } 680 681 /*************************************************** 682 * Low level mapping routines..... 683 ***************************************************/ 684 685 /* 686 * Enter a mapping into kernel_pmap. Mappings created in this fashion 687 * are not managed. Mappings must be immediately accessible on all cpus. 688 * 689 * Call pmap_inval_pte() to invalidate the virtual pte and clean out the 690 * real pmap and handle related races before storing the new vpte. 691 */ 692 void 693 pmap_kenter(vm_offset_t va, vm_paddr_t pa) 694 { 695 pt_entry_t *pte; 696 pt_entry_t npte; 697 698 KKASSERT(va >= KvaStart && va < KvaEnd); 699 npte = pa | VPTE_R | VPTE_W | VPTE_V; 700 pte = vtopte(va); 701 if (*pte & VPTE_V) 702 pmap_inval_pte(pte, &kernel_pmap, va); 703 *pte = npte; 704 } 705 706 /* 707 * Enter an unmanaged KVA mapping for the private use of the current 708 * cpu only. pmap_kenter_sync() may be called to make the mapping usable 709 * by other cpus. 710 * 711 * It is illegal for the mapping to be accessed by other cpus unleess 712 * pmap_kenter_sync*() is called. 713 */ 714 void 715 pmap_kenter_quick(vm_offset_t va, vm_paddr_t pa) 716 { 717 pt_entry_t *pte; 718 pt_entry_t npte; 719 720 KKASSERT(va >= KvaStart && va < KvaEnd); 721 722 npte = (vpte_t)pa | VPTE_R | VPTE_W | VPTE_V; 723 pte = vtopte(va); 724 if (*pte & VPTE_V) 725 pmap_inval_pte_quick(pte, &kernel_pmap, va); 726 *pte = npte; 727 //cpu_invlpg((void *)va); 728 } 729 730 /* 731 * Synchronize a kvm mapping originally made for the private use on 732 * some other cpu so it can be used on all cpus. 733 * 734 * XXX add MADV_RESYNC to improve performance. 735 */ 736 void 737 pmap_kenter_sync(vm_offset_t va) 738 { 739 madvise((void *)va, PAGE_SIZE, MADV_INVAL); 740 } 741 742 /* 743 * Synchronize a kvm mapping originally made for the private use on 744 * some other cpu so it can be used on our cpu. Turns out to be the 745 * same madvise() call, because we have to sync the real pmaps anyway. 746 * 747 * XXX add MADV_RESYNC to improve performance. 748 */ 749 void 750 pmap_kenter_sync_quick(vm_offset_t va) 751 { 752 madvise((void *)va, PAGE_SIZE, MADV_INVAL); 753 } 754 755 /* 756 * Remove an unmanaged mapping created with pmap_kenter*(). 757 */ 758 void 759 pmap_kremove(vm_offset_t va) 760 { 761 pt_entry_t *pte; 762 763 KKASSERT(va >= KvaStart && va < KvaEnd); 764 765 pte = vtopte(va); 766 if (*pte & VPTE_V) 767 pmap_inval_pte(pte, &kernel_pmap, va); 768 *pte = 0; 769 } 770 771 /* 772 * Remove an unmanaged mapping created with pmap_kenter*() but synchronize 773 * only with this cpu. 774 * 775 * Unfortunately because we optimize new entries by testing VPTE_V later 776 * on, we actually still have to synchronize with all the cpus. XXX maybe 777 * store a junk value and test against 0 in the other places instead? 778 */ 779 void 780 pmap_kremove_quick(vm_offset_t va) 781 { 782 pt_entry_t *pte; 783 784 KKASSERT(va >= KvaStart && va < KvaEnd); 785 786 pte = vtopte(va); 787 if (*pte & VPTE_V) 788 pmap_inval_pte(pte, &kernel_pmap, va); /* NOT _quick */ 789 *pte = 0; 790 } 791 792 /* 793 * Used to map a range of physical addresses into kernel 794 * virtual address space. 795 * 796 * For now, VM is already on, we only need to map the 797 * specified memory. 798 */ 799 vm_offset_t 800 pmap_map(vm_offset_t *virtp, vm_paddr_t start, vm_paddr_t end, int prot) 801 { 802 return PHYS_TO_DMAP(start); 803 } 804 805 806 /* 807 * Map a set of unmanaged VM pages into KVM. 808 */ 809 void 810 pmap_qenter(vm_offset_t va, vm_page_t *m, int count) 811 { 812 vm_offset_t end_va; 813 814 end_va = va + count * PAGE_SIZE; 815 KKASSERT(va >= KvaStart && end_va < KvaEnd); 816 817 while (va < end_va) { 818 pt_entry_t *pte; 819 820 pte = vtopte(va); 821 if (*pte & VPTE_V) 822 pmap_inval_pte(pte, &kernel_pmap, va); 823 *pte = VM_PAGE_TO_PHYS(*m) | VPTE_R | VPTE_W | VPTE_V; 824 va += PAGE_SIZE; 825 m++; 826 } 827 } 828 829 /* 830 * Undo the effects of pmap_qenter*(). 831 */ 832 void 833 pmap_qremove(vm_offset_t va, int count) 834 { 835 vm_offset_t end_va; 836 837 end_va = va + count * PAGE_SIZE; 838 KKASSERT(va >= KvaStart && end_va < KvaEnd); 839 840 while (va < end_va) { 841 pt_entry_t *pte; 842 843 pte = vtopte(va); 844 if (*pte & VPTE_V) 845 pmap_inval_pte(pte, &kernel_pmap, va); 846 *pte = 0; 847 va += PAGE_SIZE; 848 } 849 } 850 851 /* 852 * This routine works like vm_page_lookup() but also blocks as long as the 853 * page is busy. This routine does not busy the page it returns. 854 * 855 * Unless the caller is managing objects whos pages are in a known state, 856 * the call should be made with a critical section held so the page's object 857 * association remains valid on return. 858 */ 859 static vm_page_t 860 pmap_page_lookup(vm_object_t object, vm_pindex_t pindex) 861 { 862 vm_page_t m; 863 864 do { 865 m = vm_page_lookup(object, pindex); 866 } while (m && vm_page_sleep_busy(m, FALSE, "pplookp")); 867 868 return(m); 869 } 870 871 /* 872 * Create a new thread and optionally associate it with a (new) process. 873 * NOTE! the new thread's cpu may not equal the current cpu. 874 */ 875 void 876 pmap_init_thread(thread_t td) 877 { 878 /* enforce pcb placement */ 879 td->td_pcb = (struct pcb *)(td->td_kstack + td->td_kstack_size) - 1; 880 td->td_savefpu = &td->td_pcb->pcb_save; 881 td->td_sp = (char *)td->td_pcb - 16; /* JG is -16 needed on x86_64? */ 882 } 883 884 /* 885 * This routine directly affects the fork perf for a process. 886 */ 887 void 888 pmap_init_proc(struct proc *p) 889 { 890 } 891 892 /* 893 * Dispose the UPAGES for a process that has exited. 894 * This routine directly impacts the exit perf of a process. 895 */ 896 void 897 pmap_dispose_proc(struct proc *p) 898 { 899 KASSERT(p->p_lock == 0, ("attempt to dispose referenced proc! %p", p)); 900 } 901 902 /*************************************************** 903 * Page table page management routines..... 904 ***************************************************/ 905 906 static __inline int pmap_unwire_pte_hold(pmap_t pmap, vm_offset_t va, 907 vm_page_t m); 908 909 /* 910 * This routine unholds page table pages, and if the hold count 911 * drops to zero, then it decrements the wire count. 912 * 913 * We must recheck that this is the last hold reference after busy-sleeping 914 * on the page. 915 */ 916 static int 917 _pmap_unwire_pte_hold(pmap_t pmap, vm_offset_t va, vm_page_t m) 918 { 919 while (vm_page_sleep_busy(m, FALSE, "pmuwpt")) 920 ; 921 KASSERT(m->queue == PQ_NONE, 922 ("_pmap_unwire_pte_hold: %p->queue != PQ_NONE", m)); 923 924 if (m->hold_count == 1) { 925 /* 926 * Unmap the page table page. 927 */ 928 //abort(); /* JG */ 929 vm_page_busy(m); 930 /* pmap_inval_add(info, pmap, -1); */ 931 932 if (m->pindex >= (NUPDE + NUPDPE)) { 933 /* PDP page */ 934 pml4_entry_t *pml4; 935 pml4 = pmap_pml4e(pmap, va); 936 *pml4 = 0; 937 } else if (m->pindex >= NUPDE) { 938 /* PD page */ 939 pdp_entry_t *pdp; 940 pdp = pmap_pdpe(pmap, va); 941 *pdp = 0; 942 } else { 943 /* PT page */ 944 pd_entry_t *pd; 945 pd = pmap_pde(pmap, va); 946 *pd = 0; 947 } 948 949 KKASSERT(pmap->pm_stats.resident_count > 0); 950 --pmap->pm_stats.resident_count; 951 952 if (pmap->pm_ptphint == m) 953 pmap->pm_ptphint = NULL; 954 955 if (m->pindex < NUPDE) { 956 /* We just released a PT, unhold the matching PD */ 957 vm_page_t pdpg; 958 959 pdpg = PHYS_TO_VM_PAGE(*pmap_pdpe(pmap, va) & VPTE_FRAME); 960 pmap_unwire_pte_hold(pmap, va, pdpg); 961 } 962 if (m->pindex >= NUPDE && m->pindex < (NUPDE + NUPDPE)) { 963 /* We just released a PD, unhold the matching PDP */ 964 vm_page_t pdppg; 965 966 pdppg = PHYS_TO_VM_PAGE(*pmap_pml4e(pmap, va) & VPTE_FRAME); 967 pmap_unwire_pte_hold(pmap, va, pdppg); 968 } 969 970 /* 971 * This was our last hold, the page had better be unwired 972 * after we decrement wire_count. 973 * 974 * FUTURE NOTE: shared page directory page could result in 975 * multiple wire counts. 976 */ 977 vm_page_unhold(m); 978 --m->wire_count; 979 KKASSERT(m->wire_count == 0); 980 --vmstats.v_wire_count; 981 vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE); 982 vm_page_flash(m); 983 vm_page_free_zero(m); 984 return 1; 985 } else { 986 KKASSERT(m->hold_count > 1); 987 vm_page_unhold(m); 988 return 0; 989 } 990 } 991 992 static __inline int 993 pmap_unwire_pte_hold(pmap_t pmap, vm_offset_t va, vm_page_t m) 994 { 995 KKASSERT(m->hold_count > 0); 996 if (m->hold_count > 1) { 997 vm_page_unhold(m); 998 return 0; 999 } else { 1000 return _pmap_unwire_pte_hold(pmap, va, m); 1001 } 1002 } 1003 1004 /* 1005 * After removing a page table entry, this routine is used to 1006 * conditionally free the page, and manage the hold/wire counts. 1007 */ 1008 static int 1009 pmap_unuse_pt(pmap_t pmap, vm_offset_t va, vm_page_t mpte) 1010 { 1011 /* JG Use FreeBSD/amd64 or FreeBSD/i386 ptepde approaches? */ 1012 vm_pindex_t ptepindex; 1013 1014 if (mpte == NULL) { 1015 /* 1016 * page table pages in the kernel_pmap are not managed. 1017 */ 1018 if (pmap == &kernel_pmap) 1019 return(0); 1020 ptepindex = pmap_pde_pindex(va); 1021 if (pmap->pm_ptphint && 1022 (pmap->pm_ptphint->pindex == ptepindex)) { 1023 mpte = pmap->pm_ptphint; 1024 } else { 1025 mpte = pmap_page_lookup(pmap->pm_pteobj, ptepindex); 1026 pmap->pm_ptphint = mpte; 1027 } 1028 } 1029 1030 return pmap_unwire_pte_hold(pmap, va, mpte); 1031 } 1032 1033 /* 1034 * Initialize pmap0/vmspace0 . Since process 0 never enters user mode we 1035 * just dummy it up so it works well enough for fork(). 1036 * 1037 * In DragonFly, process pmaps may only be used to manipulate user address 1038 * space, never kernel address space. 1039 */ 1040 void 1041 pmap_pinit0(struct pmap *pmap) 1042 { 1043 pmap_pinit(pmap); 1044 } 1045 1046 /* 1047 * Initialize a preallocated and zeroed pmap structure, 1048 * such as one in a vmspace structure. 1049 */ 1050 void 1051 pmap_pinit(struct pmap *pmap) 1052 { 1053 vm_page_t ptdpg; 1054 1055 /* 1056 * No need to allocate page table space yet but we do need a valid 1057 * page directory table. 1058 */ 1059 if (pmap->pm_pml4 == NULL) { 1060 pmap->pm_pml4 = 1061 (pml4_entry_t *)kmem_alloc_pageable(&kernel_map, PAGE_SIZE); 1062 } 1063 1064 /* 1065 * Allocate an object for the ptes 1066 */ 1067 if (pmap->pm_pteobj == NULL) 1068 pmap->pm_pteobj = vm_object_allocate(OBJT_DEFAULT, NUPDE + NUPDPE + PML4PML4I + 1); 1069 1070 /* 1071 * Allocate the page directory page, unless we already have 1072 * one cached. If we used the cached page the wire_count will 1073 * already be set appropriately. 1074 */ 1075 if ((ptdpg = pmap->pm_pdirm) == NULL) { 1076 ptdpg = vm_page_grab(pmap->pm_pteobj, NUPDE + NUPDPE + PML4PML4I, 1077 VM_ALLOC_NORMAL | VM_ALLOC_RETRY); 1078 pmap->pm_pdirm = ptdpg; 1079 vm_page_flag_clear(ptdpg, PG_MAPPED | PG_BUSY); 1080 ptdpg->valid = VM_PAGE_BITS_ALL; 1081 if (ptdpg->wire_count == 0) 1082 ++vmstats.v_wire_count; 1083 ptdpg->wire_count = 1; 1084 pmap_kenter((vm_offset_t)pmap->pm_pml4, VM_PAGE_TO_PHYS(ptdpg)); 1085 } 1086 if ((ptdpg->flags & PG_ZERO) == 0) 1087 bzero(pmap->pm_pml4, PAGE_SIZE); 1088 1089 pmap->pm_count = 1; 1090 pmap->pm_active = 0; 1091 pmap->pm_ptphint = NULL; 1092 TAILQ_INIT(&pmap->pm_pvlist); 1093 bzero(&pmap->pm_stats, sizeof pmap->pm_stats); 1094 pmap->pm_stats.resident_count = 1; 1095 } 1096 1097 /* 1098 * Clean up a pmap structure so it can be physically freed. This routine 1099 * is called by the vmspace dtor function. A great deal of pmap data is 1100 * left passively mapped to improve vmspace management so we have a bit 1101 * of cleanup work to do here. 1102 * 1103 * No requirements. 1104 */ 1105 void 1106 pmap_puninit(pmap_t pmap) 1107 { 1108 vm_page_t p; 1109 1110 KKASSERT(pmap->pm_active == 0); 1111 lwkt_gettoken(&vm_token); 1112 if ((p = pmap->pm_pdirm) != NULL) { 1113 KKASSERT(pmap->pm_pml4 != NULL); 1114 pmap_kremove((vm_offset_t)pmap->pm_pml4); 1115 p->wire_count--; 1116 vmstats.v_wire_count--; 1117 KKASSERT((p->flags & PG_BUSY) == 0); 1118 vm_page_busy(p); 1119 vm_page_free_zero(p); 1120 pmap->pm_pdirm = NULL; 1121 } 1122 lwkt_reltoken(&vm_token); 1123 if (pmap->pm_pml4) { 1124 kmem_free(&kernel_map, (vm_offset_t)pmap->pm_pml4, PAGE_SIZE); 1125 pmap->pm_pml4 = NULL; 1126 } 1127 if (pmap->pm_pteobj) { 1128 vm_object_deallocate(pmap->pm_pteobj); 1129 pmap->pm_pteobj = NULL; 1130 } 1131 } 1132 1133 /* 1134 * Wire in kernel global address entries. To avoid a race condition 1135 * between pmap initialization and pmap_growkernel, this procedure 1136 * adds the pmap to the master list (which growkernel scans to update), 1137 * then copies the template. 1138 * 1139 * In a virtual kernel there are no kernel global address entries. 1140 * 1141 * No requirements. 1142 */ 1143 void 1144 pmap_pinit2(struct pmap *pmap) 1145 { 1146 crit_enter(); 1147 lwkt_gettoken(&vm_token); 1148 TAILQ_INSERT_TAIL(&pmap_list, pmap, pm_pmnode); 1149 lwkt_reltoken(&vm_token); 1150 crit_exit(); 1151 } 1152 1153 /* 1154 * Attempt to release and free a vm_page in a pmap. Returns 1 on success, 1155 * 0 on failure (if the procedure had to sleep). 1156 * 1157 * When asked to remove the page directory page itself, we actually just 1158 * leave it cached so we do not have to incur the SMP inval overhead of 1159 * removing the kernel mapping. pmap_puninit() will take care of it. 1160 */ 1161 static int 1162 pmap_release_free_page(struct pmap *pmap, vm_page_t p) 1163 { 1164 /* 1165 * This code optimizes the case of freeing non-busy 1166 * page-table pages. Those pages are zero now, and 1167 * might as well be placed directly into the zero queue. 1168 */ 1169 if (vm_page_sleep_busy(p, FALSE, "pmaprl")) 1170 return 0; 1171 1172 vm_page_busy(p); 1173 1174 /* 1175 * Remove the page table page from the processes address space. 1176 */ 1177 if (p->pindex == NUPDE + NUPDPE + PML4PML4I) { 1178 /* 1179 * We are the pml4 table itself. 1180 */ 1181 /* XXX anything to do here? */ 1182 } else if (p->pindex >= (NUPDE + NUPDPE)) { 1183 /* 1184 * We are a PDP page. 1185 * We look for the PML4 entry that points to us. 1186 */ 1187 vm_page_t m4 = vm_page_lookup(pmap->pm_pteobj, NUPDE + NUPDPE + PML4PML4I); 1188 KKASSERT(m4 != NULL); 1189 pml4_entry_t *pml4 = (pml4_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m4)); 1190 int idx = (p->pindex - (NUPDE + NUPDPE)) % NPML4EPG; 1191 KKASSERT(pml4[idx] != 0); 1192 pml4[idx] = 0; 1193 m4->hold_count--; 1194 /* JG What about wire_count? */ 1195 } else if (p->pindex >= NUPDE) { 1196 /* 1197 * We are a PD page. 1198 * We look for the PDP entry that points to us. 1199 */ 1200 vm_page_t m3 = vm_page_lookup(pmap->pm_pteobj, NUPDE + NUPDPE + (p->pindex - NUPDE) / NPDPEPG); 1201 KKASSERT(m3 != NULL); 1202 pdp_entry_t *pdp = (pdp_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m3)); 1203 int idx = (p->pindex - NUPDE) % NPDPEPG; 1204 KKASSERT(pdp[idx] != 0); 1205 pdp[idx] = 0; 1206 m3->hold_count--; 1207 /* JG What about wire_count? */ 1208 } else { 1209 /* We are a PT page. 1210 * We look for the PD entry that points to us. 1211 */ 1212 vm_page_t m2 = vm_page_lookup(pmap->pm_pteobj, NUPDE + p->pindex / NPDEPG); 1213 KKASSERT(m2 != NULL); 1214 pd_entry_t *pd = (pd_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m2)); 1215 int idx = p->pindex % NPDEPG; 1216 pd[idx] = 0; 1217 m2->hold_count--; 1218 /* JG What about wire_count? */ 1219 } 1220 KKASSERT(pmap->pm_stats.resident_count > 0); 1221 --pmap->pm_stats.resident_count; 1222 1223 if (p->hold_count) { 1224 panic("pmap_release: freeing held page table page"); 1225 } 1226 if (pmap->pm_ptphint && (pmap->pm_ptphint->pindex == p->pindex)) 1227 pmap->pm_ptphint = NULL; 1228 1229 /* 1230 * We leave the top-level page table page cached, wired, and mapped in 1231 * the pmap until the dtor function (pmap_puninit()) gets called. 1232 * However, still clean it up so we can set PG_ZERO. 1233 */ 1234 if (p->pindex == NUPDE + NUPDPE + PML4PML4I) { 1235 bzero(pmap->pm_pml4, PAGE_SIZE); 1236 vm_page_flag_set(p, PG_ZERO); 1237 vm_page_wakeup(p); 1238 } else { 1239 abort(); 1240 p->wire_count--; 1241 vmstats.v_wire_count--; 1242 /* JG eventually revert to using vm_page_free_zero() */ 1243 vm_page_free(p); 1244 } 1245 return 1; 1246 } 1247 1248 /* 1249 * this routine is called if the page table page is not 1250 * mapped correctly. 1251 */ 1252 static vm_page_t 1253 _pmap_allocpte(pmap_t pmap, vm_pindex_t ptepindex) 1254 { 1255 vm_page_t m, pdppg, pdpg; 1256 1257 /* 1258 * Find or fabricate a new pagetable page 1259 */ 1260 m = vm_page_grab(pmap->pm_pteobj, ptepindex, 1261 VM_ALLOC_NORMAL | VM_ALLOC_ZERO | VM_ALLOC_RETRY); 1262 1263 if ((m->flags & PG_ZERO) == 0) { 1264 pmap_zero_page(VM_PAGE_TO_PHYS(m)); 1265 } 1266 1267 KASSERT(m->queue == PQ_NONE, 1268 ("_pmap_allocpte: %p->queue != PQ_NONE", m)); 1269 1270 /* 1271 * Increment the hold count for the page we will be returning to 1272 * the caller. 1273 */ 1274 m->hold_count++; 1275 1276 if (m->wire_count == 0) 1277 vmstats.v_wire_count++; 1278 m->wire_count++; 1279 1280 /* 1281 * Map the pagetable page into the process address space, if 1282 * it isn't already there. 1283 */ 1284 1285 ++pmap->pm_stats.resident_count; 1286 1287 if (ptepindex >= (NUPDE + NUPDPE)) { 1288 pml4_entry_t *pml4; 1289 vm_pindex_t pml4index; 1290 1291 /* Wire up a new PDP page */ 1292 pml4index = ptepindex - (NUPDE + NUPDPE); 1293 pml4 = &pmap->pm_pml4[pml4index]; 1294 *pml4 = VM_PAGE_TO_PHYS(m) | VPTE_R | VPTE_W | VPTE_V | 1295 VPTE_A | VPTE_M; 1296 } else if (ptepindex >= NUPDE) { 1297 vm_pindex_t pml4index; 1298 vm_pindex_t pdpindex; 1299 pml4_entry_t *pml4; 1300 pdp_entry_t *pdp; 1301 1302 /* Wire up a new PD page */ 1303 pdpindex = ptepindex - NUPDE; 1304 pml4index = pdpindex >> NPML4EPGSHIFT; 1305 1306 pml4 = &pmap->pm_pml4[pml4index]; 1307 if ((*pml4 & VPTE_V) == 0) { 1308 /* Have to allocate a new PDP page, recurse */ 1309 if (_pmap_allocpte(pmap, NUPDE + NUPDPE + pml4index) 1310 == NULL) { 1311 --m->wire_count; 1312 vm_page_free(m); 1313 return (NULL); 1314 } 1315 } else { 1316 /* Add reference to the PDP page */ 1317 pdppg = PHYS_TO_VM_PAGE(*pml4 & VPTE_FRAME); 1318 pdppg->hold_count++; 1319 } 1320 pdp = (pdp_entry_t *)PHYS_TO_DMAP(*pml4 & VPTE_FRAME); 1321 1322 /* Now find the pdp page */ 1323 pdp = &pdp[pdpindex & ((1ul << NPDPEPGSHIFT) - 1)]; 1324 KKASSERT(*pdp == 0); /* JG DEBUG64 */ 1325 *pdp = VM_PAGE_TO_PHYS(m) | VPTE_R | VPTE_W | VPTE_V | 1326 VPTE_A | VPTE_M; 1327 } else { 1328 vm_pindex_t pml4index; 1329 vm_pindex_t pdpindex; 1330 pml4_entry_t *pml4; 1331 pdp_entry_t *pdp; 1332 pd_entry_t *pd; 1333 1334 /* Wire up a new PT page */ 1335 pdpindex = ptepindex >> NPDPEPGSHIFT; 1336 pml4index = pdpindex >> NPML4EPGSHIFT; 1337 1338 /* First, find the pdp and check that its valid. */ 1339 pml4 = &pmap->pm_pml4[pml4index]; 1340 if ((*pml4 & VPTE_V) == 0) { 1341 /* We miss a PDP page. We ultimately need a PD page. 1342 * Recursively allocating a PD page will allocate 1343 * the missing PDP page and will also allocate 1344 * the PD page we need. 1345 */ 1346 /* Have to allocate a new PD page, recurse */ 1347 if (_pmap_allocpte(pmap, NUPDE + pdpindex) 1348 == NULL) { 1349 --m->wire_count; 1350 vm_page_free(m); 1351 return (NULL); 1352 } 1353 pdp = (pdp_entry_t *)PHYS_TO_DMAP(*pml4 & VPTE_FRAME); 1354 pdp = &pdp[pdpindex & ((1ul << NPDPEPGSHIFT) - 1)]; 1355 } else { 1356 pdp = (pdp_entry_t *)PHYS_TO_DMAP(*pml4 & VPTE_FRAME); 1357 pdp = &pdp[pdpindex & ((1ul << NPDPEPGSHIFT) - 1)]; 1358 if ((*pdp & VPTE_V) == 0) { 1359 /* Have to allocate a new PD page, recurse */ 1360 if (_pmap_allocpte(pmap, NUPDE + pdpindex) 1361 == NULL) { 1362 --m->wire_count; 1363 vm_page_free(m); 1364 return (NULL); 1365 } 1366 } else { 1367 /* Add reference to the PD page */ 1368 pdpg = PHYS_TO_VM_PAGE(*pdp & VPTE_FRAME); 1369 pdpg->hold_count++; 1370 } 1371 } 1372 pd = (pd_entry_t *)PHYS_TO_DMAP(*pdp & VPTE_FRAME); 1373 1374 /* Now we know where the page directory page is */ 1375 pd = &pd[ptepindex & ((1ul << NPDEPGSHIFT) - 1)]; 1376 KKASSERT(*pd == 0); /* JG DEBUG64 */ 1377 *pd = VM_PAGE_TO_PHYS(m) | VPTE_R | VPTE_W | VPTE_V | 1378 VPTE_A | VPTE_M; 1379 } 1380 1381 /* 1382 * Set the page table hint 1383 */ 1384 pmap->pm_ptphint = m; 1385 1386 m->valid = VM_PAGE_BITS_ALL; 1387 vm_page_flag_clear(m, PG_ZERO); 1388 vm_page_flag_set(m, PG_MAPPED); 1389 vm_page_wakeup(m); 1390 1391 return m; 1392 } 1393 1394 /* 1395 * Determine the page table page required to access the VA in the pmap 1396 * and allocate it if necessary. Return a held vm_page_t for the page. 1397 * 1398 * Only used with user pmaps. 1399 */ 1400 static vm_page_t 1401 pmap_allocpte(pmap_t pmap, vm_offset_t va) 1402 { 1403 vm_pindex_t ptepindex; 1404 pd_entry_t *pd; 1405 vm_page_t m; 1406 1407 /* 1408 * Calculate pagetable page index 1409 */ 1410 ptepindex = pmap_pde_pindex(va); 1411 1412 /* 1413 * Get the page directory entry 1414 */ 1415 pd = pmap_pde(pmap, va); 1416 1417 /* 1418 * This supports switching from a 2MB page to a 1419 * normal 4K page. 1420 */ 1421 if (pd != NULL && (*pd & (VPTE_PS | VPTE_V)) == (VPTE_PS | VPTE_V)) { 1422 panic("no promotion/demotion yet"); 1423 *pd = 0; 1424 pd = NULL; 1425 /*cpu_invltlb();*/ 1426 /*smp_invltlb();*/ 1427 } 1428 1429 /* 1430 * If the page table page is mapped, we just increment the 1431 * hold count, and activate it. 1432 */ 1433 if (pd != NULL && (*pd & VPTE_V) != 0) { 1434 /* YYY hint is used here on i386 */ 1435 m = pmap_page_lookup( pmap->pm_pteobj, ptepindex); 1436 pmap->pm_ptphint = m; 1437 m->hold_count++; 1438 return m; 1439 } 1440 /* 1441 * Here if the pte page isn't mapped, or if it has been deallocated. 1442 */ 1443 return _pmap_allocpte(pmap, ptepindex); 1444 } 1445 1446 1447 /*************************************************** 1448 * Pmap allocation/deallocation routines. 1449 ***************************************************/ 1450 1451 /* 1452 * Release any resources held by the given physical map. 1453 * Called when a pmap initialized by pmap_pinit is being released. 1454 * Should only be called if the map contains no valid mappings. 1455 * 1456 * No requirements. 1457 */ 1458 static int pmap_release_callback(struct vm_page *p, void *data); 1459 1460 void 1461 pmap_release(struct pmap *pmap) 1462 { 1463 vm_object_t object = pmap->pm_pteobj; 1464 struct rb_vm_page_scan_info info; 1465 1466 KKASSERT(pmap != &kernel_pmap); 1467 1468 #if defined(DIAGNOSTIC) 1469 if (object->ref_count != 1) 1470 panic("pmap_release: pteobj reference count != 1"); 1471 #endif 1472 1473 info.pmap = pmap; 1474 info.object = object; 1475 crit_enter(); 1476 lwkt_gettoken(&vm_token); 1477 TAILQ_REMOVE(&pmap_list, pmap, pm_pmnode); 1478 crit_exit(); 1479 1480 do { 1481 crit_enter(); 1482 info.error = 0; 1483 info.mpte = NULL; 1484 info.limit = object->generation; 1485 1486 vm_page_rb_tree_RB_SCAN(&object->rb_memq, NULL, 1487 pmap_release_callback, &info); 1488 if (info.error == 0 && info.mpte) { 1489 if (!pmap_release_free_page(pmap, info.mpte)) 1490 info.error = 1; 1491 } 1492 crit_exit(); 1493 } while (info.error); 1494 lwkt_reltoken(&vm_token); 1495 } 1496 1497 static int 1498 pmap_release_callback(struct vm_page *p, void *data) 1499 { 1500 struct rb_vm_page_scan_info *info = data; 1501 1502 if (p->pindex == NUPDE + NUPDPE + PML4PML4I) { 1503 info->mpte = p; 1504 return(0); 1505 } 1506 if (!pmap_release_free_page(info->pmap, p)) { 1507 info->error = 1; 1508 return(-1); 1509 } 1510 if (info->object->generation != info->limit) { 1511 info->error = 1; 1512 return(-1); 1513 } 1514 return(0); 1515 } 1516 1517 /* 1518 * Grow the number of kernel page table entries, if needed. 1519 * 1520 * No requirements. 1521 */ 1522 void 1523 pmap_growkernel(vm_offset_t addr) 1524 { 1525 vm_paddr_t paddr; 1526 vm_offset_t ptppaddr; 1527 vm_page_t nkpg; 1528 pd_entry_t *pde, newpdir; 1529 pdp_entry_t newpdp; 1530 1531 crit_enter(); 1532 lwkt_gettoken(&vm_token); 1533 if (kernel_vm_end == 0) { 1534 kernel_vm_end = KvaStart; 1535 nkpt = 0; 1536 while ((*pmap_pde(&kernel_pmap, kernel_vm_end) & VPTE_V) != 0) { 1537 kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1); 1538 nkpt++; 1539 if (kernel_vm_end - 1 >= kernel_map.max_offset) { 1540 kernel_vm_end = kernel_map.max_offset; 1541 break; 1542 } 1543 } 1544 } 1545 addr = roundup2(addr, PAGE_SIZE * NPTEPG); 1546 if (addr - 1 >= kernel_map.max_offset) 1547 addr = kernel_map.max_offset; 1548 while (kernel_vm_end < addr) { 1549 pde = pmap_pde(&kernel_pmap, kernel_vm_end); 1550 if (pde == NULL) { 1551 /* We need a new PDP entry */ 1552 nkpg = vm_page_alloc(kptobj, nkpt, 1553 VM_ALLOC_NORMAL | VM_ALLOC_SYSTEM 1554 | VM_ALLOC_INTERRUPT); 1555 if (nkpg == NULL) 1556 panic("pmap_growkernel: no memory to grow kernel"); 1557 paddr = VM_PAGE_TO_PHYS(nkpg); 1558 if ((nkpg->flags & PG_ZERO) == 0) 1559 pmap_zero_page(paddr); 1560 vm_page_flag_clear(nkpg, PG_ZERO); 1561 newpdp = (pdp_entry_t) 1562 (paddr | VPTE_V | VPTE_R | VPTE_W | VPTE_A | VPTE_M); 1563 *pmap_pdpe(&kernel_pmap, kernel_vm_end) = newpdp; 1564 nkpt++; 1565 continue; /* try again */ 1566 } 1567 if ((*pde & VPTE_V) != 0) { 1568 kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1); 1569 if (kernel_vm_end - 1 >= kernel_map.max_offset) { 1570 kernel_vm_end = kernel_map.max_offset; 1571 break; 1572 } 1573 continue; 1574 } 1575 1576 /* 1577 * This index is bogus, but out of the way 1578 */ 1579 nkpg = vm_page_alloc(kptobj, nkpt, 1580 VM_ALLOC_NORMAL | VM_ALLOC_SYSTEM | VM_ALLOC_INTERRUPT); 1581 if (nkpg == NULL) 1582 panic("pmap_growkernel: no memory to grow kernel"); 1583 1584 vm_page_wire(nkpg); 1585 ptppaddr = VM_PAGE_TO_PHYS(nkpg); 1586 pmap_zero_page(ptppaddr); 1587 vm_page_flag_clear(nkpg, PG_ZERO); 1588 newpdir = (pd_entry_t) (ptppaddr | VPTE_V | VPTE_R | VPTE_W | VPTE_A | VPTE_M); 1589 *pmap_pde(&kernel_pmap, kernel_vm_end) = newpdir; 1590 nkpt++; 1591 1592 kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1); 1593 if (kernel_vm_end - 1 >= kernel_map.max_offset) { 1594 kernel_vm_end = kernel_map.max_offset; 1595 break; 1596 } 1597 } 1598 lwkt_reltoken(&vm_token); 1599 crit_exit(); 1600 } 1601 1602 /* 1603 * Retire the given physical map from service. Should only be called 1604 * if the map contains no valid mappings. 1605 * 1606 * No requirements. 1607 */ 1608 void 1609 pmap_destroy(pmap_t pmap) 1610 { 1611 if (pmap == NULL) 1612 return; 1613 1614 lwkt_gettoken(&vm_token); 1615 if (--pmap->pm_count == 0) { 1616 pmap_release(pmap); 1617 panic("destroying a pmap is not yet implemented"); 1618 } 1619 lwkt_reltoken(&vm_token); 1620 } 1621 1622 /* 1623 * Add a reference to the specified pmap. 1624 * 1625 * No requirements. 1626 */ 1627 void 1628 pmap_reference(pmap_t pmap) 1629 { 1630 if (pmap) { 1631 lwkt_gettoken(&vm_token); 1632 ++pmap->pm_count; 1633 lwkt_reltoken(&vm_token); 1634 } 1635 } 1636 1637 /************************************************************************ 1638 * VMSPACE MANAGEMENT * 1639 ************************************************************************ 1640 * 1641 * The VMSPACE management we do in our virtual kernel must be reflected 1642 * in the real kernel. This is accomplished by making vmspace system 1643 * calls to the real kernel. 1644 */ 1645 void 1646 cpu_vmspace_alloc(struct vmspace *vm) 1647 { 1648 int r; 1649 void *rp; 1650 vpte_t vpte; 1651 1652 #define USER_SIZE (VM_MAX_USER_ADDRESS - VM_MIN_USER_ADDRESS) 1653 1654 if (vmspace_create(&vm->vm_pmap, 0, NULL) < 0) 1655 panic("vmspace_create() failed"); 1656 1657 rp = vmspace_mmap(&vm->vm_pmap, VM_MIN_USER_ADDRESS, USER_SIZE, 1658 PROT_READ|PROT_WRITE, 1659 MAP_FILE|MAP_SHARED|MAP_VPAGETABLE|MAP_FIXED, 1660 MemImageFd, 0); 1661 if (rp == MAP_FAILED) 1662 panic("vmspace_mmap: failed"); 1663 vmspace_mcontrol(&vm->vm_pmap, VM_MIN_USER_ADDRESS, USER_SIZE, 1664 MADV_NOSYNC, 0); 1665 vpte = VM_PAGE_TO_PHYS(vmspace_pmap(vm)->pm_pdirm) | VPTE_R | VPTE_W | VPTE_V; 1666 r = vmspace_mcontrol(&vm->vm_pmap, VM_MIN_USER_ADDRESS, USER_SIZE, 1667 MADV_SETMAP, vpte); 1668 if (r < 0) 1669 panic("vmspace_mcontrol: failed"); 1670 } 1671 1672 void 1673 cpu_vmspace_free(struct vmspace *vm) 1674 { 1675 if (vmspace_destroy(&vm->vm_pmap) < 0) 1676 panic("vmspace_destroy() failed"); 1677 } 1678 1679 /*************************************************** 1680 * page management routines. 1681 ***************************************************/ 1682 1683 /* 1684 * free the pv_entry back to the free list. This function may be 1685 * called from an interrupt. 1686 */ 1687 static __inline void 1688 free_pv_entry(pv_entry_t pv) 1689 { 1690 pv_entry_count--; 1691 KKASSERT(pv_entry_count >= 0); 1692 zfree(pvzone, pv); 1693 } 1694 1695 /* 1696 * get a new pv_entry, allocating a block from the system 1697 * when needed. This function may be called from an interrupt. 1698 */ 1699 static pv_entry_t 1700 get_pv_entry(void) 1701 { 1702 pv_entry_count++; 1703 if (pv_entry_high_water && 1704 (pv_entry_count > pv_entry_high_water) && 1705 (pmap_pagedaemon_waken == 0)) { 1706 pmap_pagedaemon_waken = 1; 1707 wakeup(&vm_pages_needed); 1708 } 1709 return zalloc(pvzone); 1710 } 1711 1712 /* 1713 * This routine is very drastic, but can save the system 1714 * in a pinch. 1715 * 1716 * No requirements. 1717 */ 1718 void 1719 pmap_collect(void) 1720 { 1721 int i; 1722 vm_page_t m; 1723 static int warningdone=0; 1724 1725 if (pmap_pagedaemon_waken == 0) 1726 return; 1727 lwkt_gettoken(&vm_token); 1728 pmap_pagedaemon_waken = 0; 1729 1730 if (warningdone < 5) { 1731 kprintf("pmap_collect: collecting pv entries -- suggest increasing PMAP_SHPGPERPROC\n"); 1732 warningdone++; 1733 } 1734 1735 for(i = 0; i < vm_page_array_size; i++) { 1736 m = &vm_page_array[i]; 1737 if (m->wire_count || m->hold_count || m->busy || 1738 (m->flags & PG_BUSY)) 1739 continue; 1740 pmap_remove_all(m); 1741 } 1742 lwkt_reltoken(&vm_token); 1743 } 1744 1745 1746 /* 1747 * If it is the first entry on the list, it is actually 1748 * in the header and we must copy the following entry up 1749 * to the header. Otherwise we must search the list for 1750 * the entry. In either case we free the now unused entry. 1751 */ 1752 static int 1753 pmap_remove_entry(struct pmap *pmap, vm_page_t m, vm_offset_t va) 1754 { 1755 pv_entry_t pv; 1756 int rtval; 1757 1758 crit_enter(); 1759 if (m->md.pv_list_count < pmap->pm_stats.resident_count) { 1760 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { 1761 if (pmap == pv->pv_pmap && va == pv->pv_va) 1762 break; 1763 } 1764 } else { 1765 TAILQ_FOREACH(pv, &pmap->pm_pvlist, pv_plist) { 1766 if (va == pv->pv_va) 1767 break; 1768 } 1769 } 1770 1771 /* 1772 * Note that pv_ptem is NULL if the page table page itself is not 1773 * managed, even if the page being removed IS managed. 1774 */ 1775 rtval = 0; 1776 /* JGXXX When can 'pv' be NULL? */ 1777 if (pv) { 1778 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); 1779 m->md.pv_list_count--; 1780 KKASSERT(m->md.pv_list_count >= 0); 1781 if (TAILQ_EMPTY(&m->md.pv_list)) 1782 vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE); 1783 TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist); 1784 ++pmap->pm_generation; 1785 rtval = pmap_unuse_pt(pmap, va, pv->pv_ptem); 1786 free_pv_entry(pv); 1787 } 1788 crit_exit(); 1789 return rtval; 1790 } 1791 1792 /* 1793 * Create a pv entry for page at pa for (pmap, va). If the page table page 1794 * holding the VA is managed, mpte will be non-NULL. 1795 */ 1796 static void 1797 pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t mpte, vm_page_t m) 1798 { 1799 pv_entry_t pv; 1800 1801 crit_enter(); 1802 pv = get_pv_entry(); 1803 pv->pv_va = va; 1804 pv->pv_pmap = pmap; 1805 pv->pv_ptem = mpte; 1806 1807 TAILQ_INSERT_TAIL(&pmap->pm_pvlist, pv, pv_plist); 1808 TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list); 1809 m->md.pv_list_count++; 1810 1811 crit_exit(); 1812 } 1813 1814 /* 1815 * pmap_remove_pte: do the things to unmap a page in a process 1816 */ 1817 static int 1818 pmap_remove_pte(struct pmap *pmap, pt_entry_t *ptq, vm_offset_t va) 1819 { 1820 pt_entry_t oldpte; 1821 vm_page_t m; 1822 1823 oldpte = pmap_inval_loadandclear(ptq, pmap, va); 1824 if (oldpte & VPTE_WIRED) 1825 --pmap->pm_stats.wired_count; 1826 KKASSERT(pmap->pm_stats.wired_count >= 0); 1827 1828 #if 0 1829 /* 1830 * Machines that don't support invlpg, also don't support 1831 * PG_G. XXX PG_G is disabled for SMP so don't worry about 1832 * the SMP case. 1833 */ 1834 if (oldpte & PG_G) 1835 cpu_invlpg((void *)va); 1836 #endif 1837 KKASSERT(pmap->pm_stats.resident_count > 0); 1838 --pmap->pm_stats.resident_count; 1839 if (oldpte & VPTE_MANAGED) { 1840 m = PHYS_TO_VM_PAGE(oldpte); 1841 if (oldpte & VPTE_M) { 1842 #if defined(PMAP_DIAGNOSTIC) 1843 if (pmap_nw_modified((pt_entry_t) oldpte)) { 1844 kprintf( 1845 "pmap_remove: modified page not writable: va: 0x%lx, pte: 0x%lx\n", 1846 va, oldpte); 1847 } 1848 #endif 1849 if (pmap_track_modified(pmap, va)) 1850 vm_page_dirty(m); 1851 } 1852 if (oldpte & VPTE_A) 1853 vm_page_flag_set(m, PG_REFERENCED); 1854 return pmap_remove_entry(pmap, m, va); 1855 } else { 1856 return pmap_unuse_pt(pmap, va, NULL); 1857 } 1858 1859 return 0; 1860 } 1861 1862 /* 1863 * pmap_remove_page: 1864 * 1865 * Remove a single page from a process address space. 1866 * 1867 * This function may not be called from an interrupt if the pmap is 1868 * not kernel_pmap. 1869 */ 1870 static void 1871 pmap_remove_page(struct pmap *pmap, vm_offset_t va) 1872 { 1873 pt_entry_t *pte; 1874 1875 pte = pmap_pte(pmap, va); 1876 if (pte == NULL) 1877 return; 1878 if ((*pte & VPTE_V) == 0) 1879 return; 1880 pmap_remove_pte(pmap, pte, va); 1881 } 1882 1883 /* 1884 * Remove the given range of addresses from the specified map. 1885 * 1886 * It is assumed that the start and end are properly rounded to 1887 * the page size. 1888 * 1889 * This function may not be called from an interrupt if the pmap is 1890 * not kernel_pmap. 1891 * 1892 * No requirements. 1893 */ 1894 void 1895 pmap_remove(struct pmap *pmap, vm_offset_t sva, vm_offset_t eva) 1896 { 1897 vm_offset_t va_next; 1898 pml4_entry_t *pml4e; 1899 pdp_entry_t *pdpe; 1900 pd_entry_t ptpaddr, *pde; 1901 pt_entry_t *pte; 1902 1903 if (pmap == NULL) 1904 return; 1905 1906 lwkt_gettoken(&vm_token); 1907 KKASSERT(pmap->pm_stats.resident_count >= 0); 1908 if (pmap->pm_stats.resident_count == 0) { 1909 lwkt_reltoken(&vm_token); 1910 return; 1911 } 1912 1913 /* 1914 * special handling of removing one page. a very 1915 * common operation and easy to short circuit some 1916 * code. 1917 */ 1918 if (sva + PAGE_SIZE == eva) { 1919 pde = pmap_pde(pmap, sva); 1920 if (pde && (*pde & VPTE_PS) == 0) { 1921 pmap_remove_page(pmap, sva); 1922 lwkt_reltoken(&vm_token); 1923 return; 1924 } 1925 } 1926 1927 for (; sva < eva; sva = va_next) { 1928 pml4e = pmap_pml4e(pmap, sva); 1929 if ((*pml4e & VPTE_V) == 0) { 1930 va_next = (sva + NBPML4) & ~PML4MASK; 1931 if (va_next < sva) 1932 va_next = eva; 1933 continue; 1934 } 1935 1936 pdpe = pmap_pml4e_to_pdpe(pml4e, sva); 1937 if ((*pdpe & VPTE_V) == 0) { 1938 va_next = (sva + NBPDP) & ~PDPMASK; 1939 if (va_next < sva) 1940 va_next = eva; 1941 continue; 1942 } 1943 1944 /* 1945 * Calculate index for next page table. 1946 */ 1947 va_next = (sva + NBPDR) & ~PDRMASK; 1948 if (va_next < sva) 1949 va_next = eva; 1950 1951 pde = pmap_pdpe_to_pde(pdpe, sva); 1952 ptpaddr = *pde; 1953 1954 /* 1955 * Weed out invalid mappings. 1956 */ 1957 if (ptpaddr == 0) 1958 continue; 1959 1960 /* 1961 * Check for large page. 1962 */ 1963 if ((ptpaddr & VPTE_PS) != 0) { 1964 /* JG FreeBSD has more complex treatment here */ 1965 KKASSERT(*pde != 0); 1966 pmap_inval_pde(pde, pmap, sva); 1967 pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE; 1968 continue; 1969 } 1970 1971 /* 1972 * Limit our scan to either the end of the va represented 1973 * by the current page table page, or to the end of the 1974 * range being removed. 1975 */ 1976 if (va_next > eva) 1977 va_next = eva; 1978 1979 /* 1980 * NOTE: pmap_remove_pte() can block. 1981 */ 1982 for (pte = pmap_pde_to_pte(pde, sva); sva != va_next; pte++, 1983 sva += PAGE_SIZE) { 1984 if (*pte == 0) 1985 continue; 1986 if (pmap_remove_pte(pmap, pte, sva)) 1987 break; 1988 } 1989 } 1990 lwkt_reltoken(&vm_token); 1991 } 1992 1993 /* 1994 * Removes this physical page from all physical maps in which it resides. 1995 * Reflects back modify bits to the pager. 1996 * 1997 * This routine may not be called from an interrupt. 1998 * 1999 * No requirements. 2000 */ 2001 2002 static void 2003 pmap_remove_all(vm_page_t m) 2004 { 2005 pt_entry_t *pte, tpte; 2006 pv_entry_t pv; 2007 2008 #if defined(PMAP_DIAGNOSTIC) 2009 /* 2010 * XXX this makes pmap_page_protect(NONE) illegal for non-managed 2011 * pages! 2012 */ 2013 if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) { 2014 panic("pmap_page_protect: illegal for unmanaged page, va: 0x%08llx", (long long)VM_PAGE_TO_PHYS(m)); 2015 } 2016 #endif 2017 2018 crit_enter(); 2019 lwkt_gettoken(&vm_token); 2020 while ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) { 2021 KKASSERT(pv->pv_pmap->pm_stats.resident_count > 0); 2022 --pv->pv_pmap->pm_stats.resident_count; 2023 2024 pte = pmap_pte(pv->pv_pmap, pv->pv_va); 2025 KKASSERT(pte != NULL); 2026 2027 tpte = pmap_inval_loadandclear(pte, pv->pv_pmap, pv->pv_va); 2028 if (tpte & VPTE_WIRED) 2029 pv->pv_pmap->pm_stats.wired_count--; 2030 KKASSERT(pv->pv_pmap->pm_stats.wired_count >= 0); 2031 2032 if (tpte & VPTE_A) 2033 vm_page_flag_set(m, PG_REFERENCED); 2034 2035 /* 2036 * Update the vm_page_t clean and reference bits. 2037 */ 2038 if (tpte & VPTE_M) { 2039 #if defined(PMAP_DIAGNOSTIC) 2040 if (pmap_nw_modified(tpte)) { 2041 kprintf( 2042 "pmap_remove_all: modified page not writable: va: 0x%lx, pte: 0x%lx\n", 2043 pv->pv_va, tpte); 2044 } 2045 #endif 2046 if (pmap_track_modified(pv->pv_pmap, pv->pv_va)) 2047 vm_page_dirty(m); 2048 } 2049 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); 2050 TAILQ_REMOVE(&pv->pv_pmap->pm_pvlist, pv, pv_plist); 2051 ++pv->pv_pmap->pm_generation; 2052 m->md.pv_list_count--; 2053 KKASSERT(m->md.pv_list_count >= 0); 2054 if (TAILQ_EMPTY(&m->md.pv_list)) 2055 vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE); 2056 pmap_unuse_pt(pv->pv_pmap, pv->pv_va, pv->pv_ptem); 2057 free_pv_entry(pv); 2058 } 2059 KKASSERT((m->flags & (PG_MAPPED|PG_WRITEABLE)) == 0); 2060 lwkt_reltoken(&vm_token); 2061 crit_exit(); 2062 } 2063 2064 /* 2065 * Set the physical protection on the specified range of this map 2066 * as requested. 2067 * 2068 * This function may not be called from an interrupt if the map is 2069 * not the kernel_pmap. 2070 * 2071 * No requirements. 2072 */ 2073 void 2074 pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot) 2075 { 2076 vm_offset_t va_next; 2077 pml4_entry_t *pml4e; 2078 pdp_entry_t *pdpe; 2079 pd_entry_t ptpaddr, *pde; 2080 pt_entry_t *pte; 2081 2082 /* JG review for NX */ 2083 2084 if (pmap == NULL) 2085 return; 2086 2087 if ((prot & VM_PROT_READ) == VM_PROT_NONE) { 2088 pmap_remove(pmap, sva, eva); 2089 return; 2090 } 2091 2092 if (prot & VM_PROT_WRITE) 2093 return; 2094 2095 lwkt_gettoken(&vm_token); 2096 2097 for (; sva < eva; sva = va_next) { 2098 2099 pml4e = pmap_pml4e(pmap, sva); 2100 if ((*pml4e & VPTE_V) == 0) { 2101 va_next = (sva + NBPML4) & ~PML4MASK; 2102 if (va_next < sva) 2103 va_next = eva; 2104 continue; 2105 } 2106 2107 pdpe = pmap_pml4e_to_pdpe(pml4e, sva); 2108 if ((*pdpe & VPTE_V) == 0) { 2109 va_next = (sva + NBPDP) & ~PDPMASK; 2110 if (va_next < sva) 2111 va_next = eva; 2112 continue; 2113 } 2114 2115 va_next = (sva + NBPDR) & ~PDRMASK; 2116 if (va_next < sva) 2117 va_next = eva; 2118 2119 pde = pmap_pdpe_to_pde(pdpe, sva); 2120 ptpaddr = *pde; 2121 2122 /* 2123 * Check for large page. 2124 */ 2125 if ((ptpaddr & VPTE_PS) != 0) { 2126 /* JG correct? */ 2127 pmap_clean_pde(pde, pmap, sva); 2128 pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE; 2129 continue; 2130 } 2131 2132 /* 2133 * Weed out invalid mappings. Note: we assume that the page 2134 * directory table is always allocated, and in kernel virtual. 2135 */ 2136 if (ptpaddr == 0) 2137 continue; 2138 2139 if (va_next > eva) 2140 va_next = eva; 2141 2142 for (pte = pmap_pde_to_pte(pde, sva); sva != va_next; pte++, 2143 sva += PAGE_SIZE) { 2144 pt_entry_t pbits; 2145 vm_page_t m; 2146 2147 /* 2148 * Clean managed pages and also check the accessed 2149 * bit. Just remove write perms for unmanaged 2150 * pages. Be careful of races, turning off write 2151 * access will force a fault rather then setting 2152 * the modified bit at an unexpected time. 2153 */ 2154 if (*pte & VPTE_MANAGED) { 2155 pbits = pmap_clean_pte(pte, pmap, sva); 2156 m = NULL; 2157 if (pbits & VPTE_A) { 2158 m = PHYS_TO_VM_PAGE(pbits & VPTE_FRAME); 2159 vm_page_flag_set(m, PG_REFERENCED); 2160 atomic_clear_long(pte, VPTE_A); 2161 } 2162 if (pbits & VPTE_M) { 2163 if (pmap_track_modified(pmap, sva)) { 2164 if (m == NULL) 2165 m = PHYS_TO_VM_PAGE(pbits & VPTE_FRAME); 2166 vm_page_dirty(m); 2167 } 2168 } 2169 } else { 2170 pbits = pmap_setro_pte(pte, pmap, sva); 2171 } 2172 } 2173 } 2174 lwkt_reltoken(&vm_token); 2175 } 2176 2177 /* 2178 * Enter a managed page into a pmap. If the page is not wired related pmap 2179 * data can be destroyed at any time for later demand-operation. 2180 * 2181 * Insert the vm_page (m) at virtual address (v) in (pmap), with the 2182 * specified protection, and wire the mapping if requested. 2183 * 2184 * NOTE: This routine may not lazy-evaluate or lose information. The 2185 * page must actually be inserted into the given map NOW. 2186 * 2187 * NOTE: When entering a page at a KVA address, the pmap must be the 2188 * kernel_pmap. 2189 * 2190 * No requirements. 2191 */ 2192 void 2193 pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot, 2194 boolean_t wired) 2195 { 2196 vm_paddr_t pa; 2197 pd_entry_t *pde; 2198 pt_entry_t *pte; 2199 vm_paddr_t opa; 2200 pt_entry_t origpte, newpte; 2201 vm_page_t mpte; 2202 2203 if (pmap == NULL) 2204 return; 2205 2206 va = trunc_page(va); 2207 2208 lwkt_gettoken(&vm_token); 2209 2210 /* 2211 * Get the page table page. The kernel_pmap's page table pages 2212 * are preallocated and have no associated vm_page_t. 2213 */ 2214 if (pmap == &kernel_pmap) 2215 mpte = NULL; 2216 else 2217 mpte = pmap_allocpte(pmap, va); 2218 2219 pde = pmap_pde(pmap, va); 2220 if (pde != NULL && (*pde & VPTE_V) != 0) { 2221 if ((*pde & VPTE_PS) != 0) 2222 panic("pmap_enter: attempted pmap_enter on 2MB page"); 2223 pte = pmap_pde_to_pte(pde, va); 2224 } else { 2225 panic("pmap_enter: invalid page directory va=%#lx", va); 2226 } 2227 2228 KKASSERT(pte != NULL); 2229 /* 2230 * Deal with races on the original mapping (though don't worry 2231 * about VPTE_A races) by cleaning it. This will force a fault 2232 * if an attempt is made to write to the page. 2233 */ 2234 pa = VM_PAGE_TO_PHYS(m); 2235 origpte = pmap_clean_pte(pte, pmap, va); 2236 opa = origpte & VPTE_FRAME; 2237 2238 if (origpte & VPTE_PS) 2239 panic("pmap_enter: attempted pmap_enter on 2MB page"); 2240 2241 /* 2242 * Mapping has not changed, must be protection or wiring change. 2243 */ 2244 if (origpte && (opa == pa)) { 2245 /* 2246 * Wiring change, just update stats. We don't worry about 2247 * wiring PT pages as they remain resident as long as there 2248 * are valid mappings in them. Hence, if a user page is wired, 2249 * the PT page will be also. 2250 */ 2251 if (wired && ((origpte & VPTE_WIRED) == 0)) 2252 ++pmap->pm_stats.wired_count; 2253 else if (!wired && (origpte & VPTE_WIRED)) 2254 --pmap->pm_stats.wired_count; 2255 2256 /* 2257 * Remove the extra pte reference. Note that we cannot 2258 * optimize the RO->RW case because we have adjusted the 2259 * wiring count above and may need to adjust the wiring 2260 * bits below. 2261 */ 2262 if (mpte) 2263 mpte->hold_count--; 2264 2265 /* 2266 * We might be turning off write access to the page, 2267 * so we go ahead and sense modify status. 2268 */ 2269 if (origpte & VPTE_MANAGED) { 2270 if ((origpte & VPTE_M) && 2271 pmap_track_modified(pmap, va)) { 2272 vm_page_t om; 2273 om = PHYS_TO_VM_PAGE(opa); 2274 vm_page_dirty(om); 2275 } 2276 pa |= VPTE_MANAGED; 2277 KKASSERT(m->flags & PG_MAPPED); 2278 } 2279 goto validate; 2280 } 2281 /* 2282 * Mapping has changed, invalidate old range and fall through to 2283 * handle validating new mapping. 2284 */ 2285 if (opa) { 2286 int err; 2287 err = pmap_remove_pte(pmap, pte, va); 2288 if (err) 2289 panic("pmap_enter: pte vanished, va: 0x%lx", va); 2290 } 2291 2292 /* 2293 * Enter on the PV list if part of our managed memory. Note that we 2294 * raise IPL while manipulating pv_table since pmap_enter can be 2295 * called at interrupt time. 2296 */ 2297 if (pmap_initialized && 2298 (m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) { 2299 pmap_insert_entry(pmap, va, mpte, m); 2300 pa |= VPTE_MANAGED; 2301 vm_page_flag_set(m, PG_MAPPED); 2302 } 2303 2304 /* 2305 * Increment counters 2306 */ 2307 ++pmap->pm_stats.resident_count; 2308 if (wired) 2309 pmap->pm_stats.wired_count++; 2310 2311 validate: 2312 /* 2313 * Now validate mapping with desired protection/wiring. 2314 */ 2315 newpte = (pt_entry_t) (pa | pte_prot(pmap, prot) | VPTE_V); 2316 2317 if (wired) 2318 newpte |= VPTE_WIRED; 2319 if (pmap != &kernel_pmap) 2320 newpte |= VPTE_U; 2321 2322 /* 2323 * If the mapping or permission bits are different from the 2324 * (now cleaned) original pte, an update is needed. We've 2325 * already downgraded or invalidated the page so all we have 2326 * to do now is update the bits. 2327 * 2328 * XXX should we synchronize RO->RW changes to avoid another 2329 * fault? 2330 */ 2331 if ((origpte & ~(VPTE_W|VPTE_M|VPTE_A)) != newpte) { 2332 *pte = newpte | VPTE_A; 2333 if (newpte & VPTE_W) 2334 vm_page_flag_set(m, PG_WRITEABLE); 2335 } 2336 KKASSERT((newpte & VPTE_MANAGED) == 0 || (m->flags & PG_MAPPED)); 2337 lwkt_reltoken(&vm_token); 2338 } 2339 2340 /* 2341 * This code works like pmap_enter() but assumes VM_PROT_READ and not-wired. 2342 * 2343 * Currently this routine may only be used on user pmaps, not kernel_pmap. 2344 * 2345 * No requirements. 2346 */ 2347 void 2348 pmap_enter_quick(pmap_t pmap, vm_offset_t va, vm_page_t m) 2349 { 2350 pt_entry_t *pte; 2351 vm_paddr_t pa; 2352 vm_page_t mpte; 2353 vm_pindex_t ptepindex; 2354 pd_entry_t *ptepa; 2355 2356 KKASSERT(pmap != &kernel_pmap); 2357 2358 KKASSERT(va >= VM_MIN_USER_ADDRESS && va < VM_MAX_USER_ADDRESS); 2359 2360 /* 2361 * Calculate pagetable page index 2362 */ 2363 ptepindex = pmap_pde_pindex(va); 2364 2365 lwkt_gettoken(&vm_token); 2366 2367 do { 2368 /* 2369 * Get the page directory entry 2370 */ 2371 ptepa = pmap_pde(pmap, va); 2372 2373 /* 2374 * If the page table page is mapped, we just increment 2375 * the hold count, and activate it. 2376 */ 2377 if (ptepa && (*ptepa & VPTE_V) != 0) { 2378 if (*ptepa & VPTE_PS) 2379 panic("pmap_enter_quick: unexpected mapping into 2MB page"); 2380 if (pmap->pm_ptphint && 2381 (pmap->pm_ptphint->pindex == ptepindex)) { 2382 mpte = pmap->pm_ptphint; 2383 } else { 2384 mpte = pmap_page_lookup( pmap->pm_pteobj, ptepindex); 2385 pmap->pm_ptphint = mpte; 2386 } 2387 if (mpte) 2388 mpte->hold_count++; 2389 } else { 2390 mpte = _pmap_allocpte(pmap, ptepindex); 2391 } 2392 } while (mpte == NULL); 2393 2394 /* 2395 * Ok, now that the page table page has been validated, get the pte. 2396 * If the pte is already mapped undo mpte's hold_count and 2397 * just return. 2398 */ 2399 pte = pmap_pte(pmap, va); 2400 if (*pte & VPTE_V) { 2401 KKASSERT(mpte != NULL); 2402 pmap_unwire_pte_hold(pmap, va, mpte); 2403 pa = VM_PAGE_TO_PHYS(m); 2404 KKASSERT(((*pte ^ pa) & VPTE_FRAME) == 0); 2405 lwkt_reltoken(&vm_token); 2406 return; 2407 } 2408 2409 /* 2410 * Enter on the PV list if part of our managed memory 2411 */ 2412 if ((m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) == 0) { 2413 pmap_insert_entry(pmap, va, mpte, m); 2414 vm_page_flag_set(m, PG_MAPPED); 2415 } 2416 2417 /* 2418 * Increment counters 2419 */ 2420 ++pmap->pm_stats.resident_count; 2421 2422 pa = VM_PAGE_TO_PHYS(m); 2423 2424 /* 2425 * Now validate mapping with RO protection 2426 */ 2427 if (m->flags & (PG_FICTITIOUS|PG_UNMANAGED)) 2428 *pte = (vpte_t)pa | VPTE_V | VPTE_U; 2429 else 2430 *pte = (vpte_t)pa | VPTE_V | VPTE_U | VPTE_MANAGED; 2431 /*pmap_inval_add(&info, pmap, va); shouldn't be needed 0->valid */ 2432 /*pmap_inval_flush(&info); don't need for vkernel */ 2433 lwkt_reltoken(&vm_token); 2434 } 2435 2436 /* 2437 * Make a temporary mapping for a physical address. This is only intended 2438 * to be used for panic dumps. 2439 */ 2440 void * 2441 pmap_kenter_temporary(vm_paddr_t pa, int i) 2442 { 2443 pmap_kenter(crashdumpmap + (i * PAGE_SIZE), pa); 2444 return ((void *)crashdumpmap); 2445 } 2446 2447 #define MAX_INIT_PT (96) 2448 2449 /* 2450 * This routine preloads the ptes for a given object into the specified pmap. 2451 * This eliminates the blast of soft faults on process startup and 2452 * immediately after an mmap. 2453 * 2454 * No requirements. 2455 */ 2456 static int pmap_object_init_pt_callback(vm_page_t p, void *data); 2457 2458 void 2459 pmap_object_init_pt(pmap_t pmap, vm_offset_t addr, vm_prot_t prot, 2460 vm_object_t object, vm_pindex_t pindex, 2461 vm_size_t size, int limit) 2462 { 2463 struct rb_vm_page_scan_info info; 2464 struct lwp *lp; 2465 vm_size_t psize; 2466 2467 /* 2468 * We can't preinit if read access isn't set or there is no pmap 2469 * or object. 2470 */ 2471 if ((prot & VM_PROT_READ) == 0 || pmap == NULL || object == NULL) 2472 return; 2473 2474 /* 2475 * We can't preinit if the pmap is not the current pmap 2476 */ 2477 lp = curthread->td_lwp; 2478 if (lp == NULL || pmap != vmspace_pmap(lp->lwp_vmspace)) 2479 return; 2480 2481 psize = x86_64_btop(size); 2482 2483 if ((object->type != OBJT_VNODE) || 2484 ((limit & MAP_PREFAULT_PARTIAL) && (psize > MAX_INIT_PT) && 2485 (object->resident_page_count > MAX_INIT_PT))) { 2486 return; 2487 } 2488 2489 if (psize + pindex > object->size) { 2490 if (object->size < pindex) 2491 return; 2492 psize = object->size - pindex; 2493 } 2494 2495 if (psize == 0) 2496 return; 2497 2498 /* 2499 * Use a red-black scan to traverse the requested range and load 2500 * any valid pages found into the pmap. 2501 * 2502 * We cannot safely scan the object's memq unless we are in a 2503 * critical section since interrupts can remove pages from objects. 2504 */ 2505 info.start_pindex = pindex; 2506 info.end_pindex = pindex + psize - 1; 2507 info.limit = limit; 2508 info.mpte = NULL; 2509 info.addr = addr; 2510 info.pmap = pmap; 2511 2512 crit_enter(); 2513 lwkt_gettoken(&vm_token); 2514 vm_page_rb_tree_RB_SCAN(&object->rb_memq, rb_vm_page_scancmp, 2515 pmap_object_init_pt_callback, &info); 2516 lwkt_reltoken(&vm_token); 2517 crit_exit(); 2518 } 2519 2520 static 2521 int 2522 pmap_object_init_pt_callback(vm_page_t p, void *data) 2523 { 2524 struct rb_vm_page_scan_info *info = data; 2525 vm_pindex_t rel_index; 2526 /* 2527 * don't allow an madvise to blow away our really 2528 * free pages allocating pv entries. 2529 */ 2530 if ((info->limit & MAP_PREFAULT_MADVISE) && 2531 vmstats.v_free_count < vmstats.v_free_reserved) { 2532 return(-1); 2533 } 2534 if (((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) && 2535 (p->busy == 0) && (p->flags & (PG_BUSY | PG_FICTITIOUS)) == 0) { 2536 if ((p->queue - p->pc) == PQ_CACHE) 2537 vm_page_deactivate(p); 2538 vm_page_busy(p); 2539 rel_index = p->pindex - info->start_pindex; 2540 pmap_enter_quick(info->pmap, 2541 info->addr + x86_64_ptob(rel_index), p); 2542 vm_page_wakeup(p); 2543 } 2544 return(0); 2545 } 2546 2547 /* 2548 * Return TRUE if the pmap is in shape to trivially 2549 * pre-fault the specified address. 2550 * 2551 * Returns FALSE if it would be non-trivial or if a 2552 * pte is already loaded into the slot. 2553 * 2554 * No requirements. 2555 */ 2556 int 2557 pmap_prefault_ok(pmap_t pmap, vm_offset_t addr) 2558 { 2559 pt_entry_t *pte; 2560 pd_entry_t *pde; 2561 int ret; 2562 2563 lwkt_gettoken(&vm_token); 2564 pde = pmap_pde(pmap, addr); 2565 if (pde == NULL || *pde == 0) { 2566 ret = 0; 2567 } else { 2568 pte = pmap_pde_to_pte(pde, addr); 2569 ret = (*pte) ? 0 : 1; 2570 } 2571 lwkt_reltoken(&vm_token); 2572 return (ret); 2573 } 2574 2575 /* 2576 * Change the wiring attribute for a map/virtual-address pair. 2577 * 2578 * The mapping must already exist in the pmap. 2579 * No other requirements. 2580 */ 2581 void 2582 pmap_change_wiring(pmap_t pmap, vm_offset_t va, boolean_t wired) 2583 { 2584 pt_entry_t *pte; 2585 2586 if (pmap == NULL) 2587 return; 2588 2589 lwkt_gettoken(&vm_token); 2590 pte = pmap_pte(pmap, va); 2591 2592 if (wired && !pmap_pte_w(pte)) 2593 pmap->pm_stats.wired_count++; 2594 else if (!wired && pmap_pte_w(pte)) 2595 pmap->pm_stats.wired_count--; 2596 2597 /* 2598 * Wiring is not a hardware characteristic so there is no need to 2599 * invalidate TLB. However, in an SMP environment we must use 2600 * a locked bus cycle to update the pte (if we are not using 2601 * the pmap_inval_*() API that is)... it's ok to do this for simple 2602 * wiring changes. 2603 */ 2604 if (wired) 2605 atomic_set_long(pte, VPTE_WIRED); 2606 else 2607 atomic_clear_long(pte, VPTE_WIRED); 2608 lwkt_reltoken(&vm_token); 2609 } 2610 2611 /* 2612 * Copy the range specified by src_addr/len 2613 * from the source map to the range dst_addr/len 2614 * in the destination map. 2615 * 2616 * This routine is only advisory and need not do anything. 2617 */ 2618 void 2619 pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr, 2620 vm_size_t len, vm_offset_t src_addr) 2621 { 2622 /* 2623 * XXX BUGGY. Amoung other things srcmpte is assumed to remain 2624 * valid through blocking calls, and that's just not going to 2625 * be the case. 2626 * 2627 * FIXME! 2628 */ 2629 return; 2630 } 2631 2632 /* 2633 * pmap_zero_page: 2634 * 2635 * Zero the specified physical page. 2636 * 2637 * This function may be called from an interrupt and no locking is 2638 * required. 2639 */ 2640 void 2641 pmap_zero_page(vm_paddr_t phys) 2642 { 2643 vm_offset_t va = PHYS_TO_DMAP(phys); 2644 2645 bzero((void *)va, PAGE_SIZE); 2646 } 2647 2648 /* 2649 * pmap_page_assertzero: 2650 * 2651 * Assert that a page is empty, panic if it isn't. 2652 */ 2653 void 2654 pmap_page_assertzero(vm_paddr_t phys) 2655 { 2656 int i; 2657 2658 crit_enter(); 2659 vm_offset_t virt = PHYS_TO_DMAP(phys); 2660 2661 for (i = 0; i < PAGE_SIZE; i += sizeof(int)) { 2662 if (*(int *)((char *)virt + i) != 0) { 2663 panic("pmap_page_assertzero() @ %p not zero!\n", 2664 (void *)virt); 2665 } 2666 } 2667 crit_exit(); 2668 } 2669 2670 /* 2671 * pmap_zero_page: 2672 * 2673 * Zero part of a physical page by mapping it into memory and clearing 2674 * its contents with bzero. 2675 * 2676 * off and size may not cover an area beyond a single hardware page. 2677 */ 2678 void 2679 pmap_zero_page_area(vm_paddr_t phys, int off, int size) 2680 { 2681 crit_enter(); 2682 vm_offset_t virt = PHYS_TO_DMAP(phys); 2683 bzero((char *)virt + off, size); 2684 crit_exit(); 2685 } 2686 2687 /* 2688 * pmap_copy_page: 2689 * 2690 * Copy the physical page from the source PA to the target PA. 2691 * This function may be called from an interrupt. No locking 2692 * is required. 2693 */ 2694 void 2695 pmap_copy_page(vm_paddr_t src, vm_paddr_t dst) 2696 { 2697 vm_offset_t src_virt, dst_virt; 2698 2699 crit_enter(); 2700 src_virt = PHYS_TO_DMAP(src); 2701 dst_virt = PHYS_TO_DMAP(dst); 2702 bcopy((void *)src_virt, (void *)dst_virt, PAGE_SIZE); 2703 crit_exit(); 2704 } 2705 2706 /* 2707 * pmap_copy_page_frag: 2708 * 2709 * Copy the physical page from the source PA to the target PA. 2710 * This function may be called from an interrupt. No locking 2711 * is required. 2712 */ 2713 void 2714 pmap_copy_page_frag(vm_paddr_t src, vm_paddr_t dst, size_t bytes) 2715 { 2716 vm_offset_t src_virt, dst_virt; 2717 2718 crit_enter(); 2719 src_virt = PHYS_TO_DMAP(src); 2720 dst_virt = PHYS_TO_DMAP(dst); 2721 bcopy((char *)src_virt + (src & PAGE_MASK), 2722 (char *)dst_virt + (dst & PAGE_MASK), 2723 bytes); 2724 crit_exit(); 2725 } 2726 2727 /* 2728 * Returns true if the pmap's pv is one of the first 16 pvs linked to 2729 * from this page. This count may be changed upwards or downwards 2730 * in the future; it is only necessary that true be returned for a small 2731 * subset of pmaps for proper page aging. 2732 * 2733 * No other requirements. 2734 */ 2735 boolean_t 2736 pmap_page_exists_quick(pmap_t pmap, vm_page_t m) 2737 { 2738 pv_entry_t pv; 2739 int loops = 0; 2740 2741 if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) 2742 return FALSE; 2743 2744 crit_enter(); 2745 lwkt_gettoken(&vm_token); 2746 2747 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { 2748 if (pv->pv_pmap == pmap) { 2749 lwkt_reltoken(&vm_token); 2750 crit_exit(); 2751 return TRUE; 2752 } 2753 loops++; 2754 if (loops >= 16) 2755 break; 2756 } 2757 lwkt_reltoken(&vm_token); 2758 crit_exit(); 2759 return (FALSE); 2760 } 2761 2762 /* 2763 * Remove all pages from specified address space this aids process 2764 * exit speeds. Also, this code is special cased for current 2765 * process only, but can have the more generic (and slightly slower) 2766 * mode enabled. This is much faster than pmap_remove in the case 2767 * of running down an entire address space. 2768 * 2769 * No other requirements. 2770 */ 2771 void 2772 pmap_remove_pages(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) 2773 { 2774 pt_entry_t *pte, tpte; 2775 pv_entry_t pv, npv; 2776 vm_page_t m; 2777 int save_generation; 2778 2779 crit_enter(); 2780 lwkt_gettoken(&vm_token); 2781 for (pv = TAILQ_FIRST(&pmap->pm_pvlist); pv; pv = npv) { 2782 if (pv->pv_va >= eva || pv->pv_va < sva) { 2783 npv = TAILQ_NEXT(pv, pv_plist); 2784 continue; 2785 } 2786 2787 KKASSERT(pmap == pv->pv_pmap); 2788 2789 pte = pmap_pte(pmap, pv->pv_va); 2790 2791 /* 2792 * We cannot remove wired pages from a process' mapping 2793 * at this time 2794 */ 2795 if (*pte & VPTE_WIRED) { 2796 npv = TAILQ_NEXT(pv, pv_plist); 2797 continue; 2798 } 2799 tpte = pmap_inval_loadandclear(pte, pmap, pv->pv_va); 2800 2801 m = PHYS_TO_VM_PAGE(tpte & VPTE_FRAME); 2802 2803 KASSERT(m < &vm_page_array[vm_page_array_size], 2804 ("pmap_remove_pages: bad tpte %lx", tpte)); 2805 2806 KKASSERT(pmap->pm_stats.resident_count > 0); 2807 --pmap->pm_stats.resident_count; 2808 2809 /* 2810 * Update the vm_page_t clean and reference bits. 2811 */ 2812 if (tpte & VPTE_M) { 2813 vm_page_dirty(m); 2814 } 2815 2816 npv = TAILQ_NEXT(pv, pv_plist); 2817 TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist); 2818 save_generation = ++pmap->pm_generation; 2819 2820 m->md.pv_list_count--; 2821 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); 2822 if (TAILQ_EMPTY(&m->md.pv_list)) 2823 vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE); 2824 2825 pmap_unuse_pt(pmap, pv->pv_va, pv->pv_ptem); 2826 free_pv_entry(pv); 2827 2828 /* 2829 * Restart the scan if we blocked during the unuse or free 2830 * calls and other removals were made. 2831 */ 2832 if (save_generation != pmap->pm_generation) { 2833 kprintf("Warning: pmap_remove_pages race-A avoided\n"); 2834 npv = TAILQ_FIRST(&pmap->pm_pvlist); 2835 } 2836 } 2837 lwkt_reltoken(&vm_token); 2838 crit_exit(); 2839 } 2840 2841 /* 2842 * pmap_testbit tests bits in active mappings of a VM page. 2843 */ 2844 static boolean_t 2845 pmap_testbit(vm_page_t m, int bit) 2846 { 2847 pv_entry_t pv; 2848 pt_entry_t *pte; 2849 2850 if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) 2851 return FALSE; 2852 2853 if (TAILQ_FIRST(&m->md.pv_list) == NULL) 2854 return FALSE; 2855 2856 crit_enter(); 2857 2858 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { 2859 /* 2860 * if the bit being tested is the modified bit, then 2861 * mark clean_map and ptes as never 2862 * modified. 2863 */ 2864 if (bit & (VPTE_A|VPTE_M)) { 2865 if (!pmap_track_modified(pv->pv_pmap, pv->pv_va)) 2866 continue; 2867 } 2868 2869 #if defined(PMAP_DIAGNOSTIC) 2870 if (pv->pv_pmap == NULL) { 2871 kprintf("Null pmap (tb) at va: 0x%lx\n", pv->pv_va); 2872 continue; 2873 } 2874 #endif 2875 pte = pmap_pte(pv->pv_pmap, pv->pv_va); 2876 if (*pte & bit) { 2877 crit_exit(); 2878 return TRUE; 2879 } 2880 } 2881 crit_exit(); 2882 return (FALSE); 2883 } 2884 2885 /* 2886 * This routine is used to clear bits in ptes. Certain bits require special 2887 * handling, in particular (on virtual kernels) the VPTE_M (modify) bit. 2888 * 2889 * This routine is only called with certain VPTE_* bit combinations. 2890 */ 2891 static __inline void 2892 pmap_clearbit(vm_page_t m, int bit) 2893 { 2894 pv_entry_t pv; 2895 pt_entry_t *pte; 2896 pt_entry_t pbits; 2897 2898 if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) 2899 return; 2900 2901 crit_enter(); 2902 2903 /* 2904 * Loop over all current mappings setting/clearing as appropos If 2905 * setting RO do we need to clear the VAC? 2906 */ 2907 TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) { 2908 /* 2909 * don't write protect pager mappings 2910 */ 2911 if (bit == VPTE_W) { 2912 if (!pmap_track_modified(pv->pv_pmap, pv->pv_va)) 2913 continue; 2914 } 2915 2916 #if defined(PMAP_DIAGNOSTIC) 2917 if (pv->pv_pmap == NULL) { 2918 kprintf("Null pmap (cb) at va: 0x%lx\n", pv->pv_va); 2919 continue; 2920 } 2921 #endif 2922 2923 /* 2924 * Careful here. We can use a locked bus instruction to 2925 * clear VPTE_A or VPTE_M safely but we need to synchronize 2926 * with the target cpus when we mess with VPTE_W. 2927 * 2928 * On virtual kernels we must force a new fault-on-write 2929 * in the real kernel if we clear the Modify bit ourselves, 2930 * otherwise the real kernel will not get a new fault and 2931 * will never set our Modify bit again. 2932 */ 2933 pte = pmap_pte(pv->pv_pmap, pv->pv_va); 2934 if (*pte & bit) { 2935 if (bit == VPTE_W) { 2936 /* 2937 * We must also clear VPTE_M when clearing 2938 * VPTE_W 2939 */ 2940 pbits = pmap_clean_pte(pte, pv->pv_pmap, 2941 pv->pv_va); 2942 if (pbits & VPTE_M) 2943 vm_page_dirty(m); 2944 } else if (bit == VPTE_M) { 2945 /* 2946 * We do not have to make the page read-only 2947 * when clearing the Modify bit. The real 2948 * kernel will make the real PTE read-only 2949 * or otherwise detect the write and set 2950 * our VPTE_M again simply by us invalidating 2951 * the real kernel VA for the pmap (as we did 2952 * above). This allows the real kernel to 2953 * handle the write fault without forwarding 2954 * the fault to us. 2955 */ 2956 atomic_clear_long(pte, VPTE_M); 2957 } else if ((bit & (VPTE_W|VPTE_M)) == (VPTE_W|VPTE_M)) { 2958 /* 2959 * We've been asked to clear W & M, I guess 2960 * the caller doesn't want us to update 2961 * the dirty status of the VM page. 2962 */ 2963 pmap_clean_pte(pte, pv->pv_pmap, pv->pv_va); 2964 } else { 2965 /* 2966 * We've been asked to clear bits that do 2967 * not interact with hardware. 2968 */ 2969 atomic_clear_long(pte, bit); 2970 } 2971 } 2972 } 2973 crit_exit(); 2974 } 2975 2976 /* 2977 * Lower the permission for all mappings to a given page. 2978 * 2979 * No other requirements. 2980 */ 2981 void 2982 pmap_page_protect(vm_page_t m, vm_prot_t prot) 2983 { 2984 /* JG NX support? */ 2985 if ((prot & VM_PROT_WRITE) == 0) { 2986 lwkt_gettoken(&vm_token); 2987 if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) { 2988 pmap_clearbit(m, VPTE_W); 2989 vm_page_flag_clear(m, PG_WRITEABLE); 2990 } else { 2991 pmap_remove_all(m); 2992 } 2993 lwkt_reltoken(&vm_token); 2994 } 2995 } 2996 2997 vm_paddr_t 2998 pmap_phys_address(vm_pindex_t ppn) 2999 { 3000 return (x86_64_ptob(ppn)); 3001 } 3002 3003 /* 3004 * Return a count of reference bits for a page, clearing those bits. 3005 * It is not necessary for every reference bit to be cleared, but it 3006 * is necessary that 0 only be returned when there are truly no 3007 * reference bits set. 3008 * 3009 * XXX: The exact number of bits to check and clear is a matter that 3010 * should be tested and standardized at some point in the future for 3011 * optimal aging of shared pages. 3012 * 3013 * No other requirements. 3014 */ 3015 int 3016 pmap_ts_referenced(vm_page_t m) 3017 { 3018 pv_entry_t pv, pvf, pvn; 3019 pt_entry_t *pte; 3020 int rtval = 0; 3021 3022 if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) 3023 return (rtval); 3024 3025 crit_enter(); 3026 lwkt_gettoken(&vm_token); 3027 3028 if ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) { 3029 3030 pvf = pv; 3031 3032 do { 3033 pvn = TAILQ_NEXT(pv, pv_list); 3034 3035 TAILQ_REMOVE(&m->md.pv_list, pv, pv_list); 3036 3037 TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list); 3038 3039 if (!pmap_track_modified(pv->pv_pmap, pv->pv_va)) 3040 continue; 3041 3042 pte = pmap_pte(pv->pv_pmap, pv->pv_va); 3043 3044 if (pte && (*pte & VPTE_A)) { 3045 #ifdef SMP 3046 atomic_clear_long(pte, VPTE_A); 3047 #else 3048 atomic_clear_long_nonlocked(pte, VPTE_A); 3049 #endif 3050 rtval++; 3051 if (rtval > 4) { 3052 break; 3053 } 3054 } 3055 } while ((pv = pvn) != NULL && pv != pvf); 3056 } 3057 lwkt_reltoken(&vm_token); 3058 crit_exit(); 3059 3060 return (rtval); 3061 } 3062 3063 /* 3064 * Return whether or not the specified physical page was modified 3065 * in any physical maps. 3066 * 3067 * No other requirements. 3068 */ 3069 boolean_t 3070 pmap_is_modified(vm_page_t m) 3071 { 3072 boolean_t res; 3073 3074 lwkt_gettoken(&vm_token); 3075 res = pmap_testbit(m, VPTE_M); 3076 lwkt_reltoken(&vm_token); 3077 return (res); 3078 } 3079 3080 /* 3081 * Clear the modify bits on the specified physical page. 3082 * 3083 * No other requirements. 3084 */ 3085 void 3086 pmap_clear_modify(vm_page_t m) 3087 { 3088 lwkt_gettoken(&vm_token); 3089 pmap_clearbit(m, VPTE_M); 3090 lwkt_reltoken(&vm_token); 3091 } 3092 3093 /* 3094 * Clear the reference bit on the specified physical page. 3095 * 3096 * No other requirements. 3097 */ 3098 void 3099 pmap_clear_reference(vm_page_t m) 3100 { 3101 lwkt_gettoken(&vm_token); 3102 pmap_clearbit(m, VPTE_A); 3103 lwkt_reltoken(&vm_token); 3104 } 3105 3106 /* 3107 * Miscellaneous support routines follow 3108 */ 3109 3110 static void 3111 i386_protection_init(void) 3112 { 3113 int *kp, prot; 3114 3115 kp = protection_codes; 3116 for (prot = 0; prot < 8; prot++) { 3117 if (prot & VM_PROT_READ) 3118 *kp |= VPTE_R; 3119 if (prot & VM_PROT_WRITE) 3120 *kp |= VPTE_W; 3121 if (prot & VM_PROT_EXECUTE) 3122 *kp |= VPTE_X; 3123 ++kp; 3124 } 3125 } 3126 3127 /* 3128 * Perform the pmap work for mincore 3129 * 3130 * No other requirements. 3131 */ 3132 int 3133 pmap_mincore(pmap_t pmap, vm_offset_t addr) 3134 { 3135 pt_entry_t *ptep, pte; 3136 vm_page_t m; 3137 int val = 0; 3138 3139 lwkt_gettoken(&vm_token); 3140 ptep = pmap_pte(pmap, addr); 3141 3142 if (ptep && (pte = *ptep) != 0) { 3143 vm_paddr_t pa; 3144 3145 val = MINCORE_INCORE; 3146 if ((pte & VPTE_MANAGED) == 0) 3147 goto done; 3148 3149 pa = pte & VPTE_FRAME; 3150 3151 m = PHYS_TO_VM_PAGE(pa); 3152 3153 /* 3154 * Modified by us 3155 */ 3156 if (pte & VPTE_M) 3157 val |= MINCORE_MODIFIED|MINCORE_MODIFIED_OTHER; 3158 /* 3159 * Modified by someone 3160 */ 3161 else if (m->dirty || pmap_is_modified(m)) 3162 val |= MINCORE_MODIFIED_OTHER; 3163 /* 3164 * Referenced by us 3165 */ 3166 if (pte & VPTE_A) 3167 val |= MINCORE_REFERENCED|MINCORE_REFERENCED_OTHER; 3168 3169 /* 3170 * Referenced by someone 3171 */ 3172 else if ((m->flags & PG_REFERENCED) || pmap_ts_referenced(m)) { 3173 val |= MINCORE_REFERENCED_OTHER; 3174 vm_page_flag_set(m, PG_REFERENCED); 3175 } 3176 } 3177 done: 3178 lwkt_reltoken(&vm_token); 3179 return val; 3180 } 3181 3182 /* 3183 * Replace p->p_vmspace with a new one. If adjrefs is non-zero the new 3184 * vmspace will be ref'd and the old one will be deref'd. 3185 */ 3186 void 3187 pmap_replacevm(struct proc *p, struct vmspace *newvm, int adjrefs) 3188 { 3189 struct vmspace *oldvm; 3190 struct lwp *lp; 3191 3192 crit_enter(); 3193 oldvm = p->p_vmspace; 3194 if (oldvm != newvm) { 3195 p->p_vmspace = newvm; 3196 KKASSERT(p->p_nthreads == 1); 3197 lp = RB_ROOT(&p->p_lwp_tree); 3198 pmap_setlwpvm(lp, newvm); 3199 if (adjrefs) { 3200 sysref_get(&newvm->vm_sysref); 3201 sysref_put(&oldvm->vm_sysref); 3202 } 3203 } 3204 crit_exit(); 3205 } 3206 3207 /* 3208 * Set the vmspace for a LWP. The vmspace is almost universally set the 3209 * same as the process vmspace, but virtual kernels need to swap out contexts 3210 * on a per-lwp basis. 3211 */ 3212 void 3213 pmap_setlwpvm(struct lwp *lp, struct vmspace *newvm) 3214 { 3215 struct vmspace *oldvm; 3216 struct pmap *pmap; 3217 3218 crit_enter(); 3219 oldvm = lp->lwp_vmspace; 3220 3221 if (oldvm != newvm) { 3222 lp->lwp_vmspace = newvm; 3223 if (curthread->td_lwp == lp) { 3224 pmap = vmspace_pmap(newvm); 3225 #if defined(SMP) 3226 atomic_set_int(&pmap->pm_active, 1 << mycpu->gd_cpuid); 3227 #else 3228 pmap->pm_active |= 1; 3229 #endif 3230 #if defined(SWTCH_OPTIM_STATS) 3231 tlb_flush_count++; 3232 #endif 3233 pmap = vmspace_pmap(oldvm); 3234 #if defined(SMP) 3235 atomic_clear_int(&pmap->pm_active, 3236 1 << mycpu->gd_cpuid); 3237 #else 3238 pmap->pm_active &= ~1; 3239 #endif 3240 } 3241 } 3242 crit_exit(); 3243 } 3244 3245 vm_offset_t 3246 pmap_addr_hint(vm_object_t obj, vm_offset_t addr, vm_size_t size) 3247 { 3248 3249 if ((obj == NULL) || (size < NBPDR) || (obj->type != OBJT_DEVICE)) { 3250 return addr; 3251 } 3252 3253 addr = (addr + (NBPDR - 1)) & ~(NBPDR - 1); 3254 return addr; 3255 } 3256