1 /* $NetBSD: uvm_page.c,v 1.39 2000/06/27 17:29:31 mrg Exp $ */ 2 3 /* 4 * Copyright (c) 1997 Charles D. Cranor and Washington University. 5 * Copyright (c) 1991, 1993, The Regents of the University of California. 6 * 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * The Mach Operating System project at Carnegie-Mellon University. 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by Charles D. Cranor, 23 * Washington University, the University of California, Berkeley and 24 * 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 * @(#)vm_page.c 8.3 (Berkeley) 3/21/94 42 * from: Id: uvm_page.c,v 1.1.2.18 1998/02/06 05:24:42 chs Exp 43 * 44 * 45 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 46 * All rights reserved. 47 * 48 * Permission to use, copy, modify and distribute this software and 49 * its documentation is hereby granted, provided that both the copyright 50 * notice and this permission notice appear in all copies of the 51 * software, derivative works or modified versions, and any portions 52 * thereof, and that both notices appear in supporting documentation. 53 * 54 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 55 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 56 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 57 * 58 * Carnegie Mellon requests users of this software to return to 59 * 60 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 61 * School of Computer Science 62 * Carnegie Mellon University 63 * Pittsburgh PA 15213-3890 64 * 65 * any improvements or extensions that they make and grant Carnegie the 66 * rights to redistribute these changes. 67 */ 68 69 /* 70 * uvm_page.c: page ops. 71 */ 72 73 #include <sys/param.h> 74 #include <sys/systm.h> 75 #include <sys/malloc.h> 76 #include <sys/sched.h> 77 78 #define UVM_PAGE /* pull in uvm_page.h functions */ 79 #include <uvm/uvm.h> 80 81 /* 82 * global vars... XXXCDC: move to uvm. structure. 83 */ 84 85 /* 86 * physical memory config is stored in vm_physmem. 87 */ 88 89 struct vm_physseg vm_physmem[VM_PHYSSEG_MAX]; /* XXXCDC: uvm.physmem */ 90 int vm_nphysseg = 0; /* XXXCDC: uvm.nphysseg */ 91 92 /* 93 * Some supported CPUs in a given architecture don't support all 94 * of the things necessary to do idle page zero'ing efficiently. 95 * We therefore provide a way to disable it from machdep code here. 96 */ 97 98 boolean_t vm_page_zero_enable = TRUE; 99 100 /* 101 * local variables 102 */ 103 104 /* 105 * these variables record the values returned by vm_page_bootstrap, 106 * for debugging purposes. The implementation of uvm_pageboot_alloc 107 * and pmap_startup here also uses them internally. 108 */ 109 110 static vaddr_t virtual_space_start; 111 static vaddr_t virtual_space_end; 112 113 /* 114 * we use a hash table with only one bucket during bootup. we will 115 * later rehash (resize) the hash table once the allocator is ready. 116 * we static allocate the one bootstrap bucket below... 117 */ 118 119 static struct pglist uvm_bootbucket; 120 121 /* 122 * local prototypes 123 */ 124 125 static void uvm_pageinsert __P((struct vm_page *)); 126 127 128 /* 129 * inline functions 130 */ 131 132 /* 133 * uvm_pageinsert: insert a page in the object and the hash table 134 * 135 * => caller must lock object 136 * => caller must lock page queues 137 * => call should have already set pg's object and offset pointers 138 * and bumped the version counter 139 */ 140 141 __inline static void 142 uvm_pageinsert(pg) 143 struct vm_page *pg; 144 { 145 struct pglist *buck; 146 int s; 147 148 #ifdef DIAGNOSTIC 149 if (pg->flags & PG_TABLED) 150 panic("uvm_pageinsert: already inserted"); 151 #endif 152 153 buck = &uvm.page_hash[uvm_pagehash(pg->uobject,pg->offset)]; 154 s = splimp(); 155 simple_lock(&uvm.hashlock); 156 TAILQ_INSERT_TAIL(buck, pg, hashq); /* put in hash */ 157 simple_unlock(&uvm.hashlock); 158 splx(s); 159 160 TAILQ_INSERT_TAIL(&pg->uobject->memq, pg, listq); /* put in object */ 161 pg->flags |= PG_TABLED; 162 pg->uobject->uo_npages++; 163 164 } 165 166 /* 167 * uvm_page_remove: remove page from object and hash 168 * 169 * => caller must lock object 170 * => caller must lock page queues 171 */ 172 173 void __inline 174 uvm_pageremove(pg) 175 struct vm_page *pg; 176 { 177 struct pglist *buck; 178 int s; 179 180 #ifdef DIAGNOSTIC 181 if ((pg->flags & (PG_FAULTING)) != 0) 182 panic("uvm_pageremove: page is faulting"); 183 #endif 184 185 if ((pg->flags & PG_TABLED) == 0) 186 return; /* XXX: log */ 187 188 buck = &uvm.page_hash[uvm_pagehash(pg->uobject,pg->offset)]; 189 s = splimp(); 190 simple_lock(&uvm.hashlock); 191 TAILQ_REMOVE(buck, pg, hashq); 192 simple_unlock(&uvm.hashlock); 193 splx(s); 194 195 /* object should be locked */ 196 TAILQ_REMOVE(&pg->uobject->memq, pg, listq); 197 198 pg->flags &= ~PG_TABLED; 199 pg->uobject->uo_npages--; 200 pg->uobject = NULL; 201 pg->version++; 202 203 } 204 205 /* 206 * uvm_page_init: init the page system. called from uvm_init(). 207 * 208 * => we return the range of kernel virtual memory in kvm_startp/kvm_endp 209 */ 210 211 void 212 uvm_page_init(kvm_startp, kvm_endp) 213 vaddr_t *kvm_startp, *kvm_endp; 214 { 215 vsize_t freepages, pagecount, n; 216 vm_page_t pagearray; 217 int lcv, i; 218 paddr_t paddr; 219 220 221 /* 222 * step 1: init the page queues and page queue locks 223 */ 224 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 225 for (i = 0; i < PGFL_NQUEUES; i++) 226 TAILQ_INIT(&uvm.page_free[lcv].pgfl_queues[i]); 227 } 228 TAILQ_INIT(&uvm.page_active); 229 TAILQ_INIT(&uvm.page_inactive_swp); 230 TAILQ_INIT(&uvm.page_inactive_obj); 231 simple_lock_init(&uvm.pageqlock); 232 simple_lock_init(&uvm.fpageqlock); 233 234 /* 235 * step 2: init the <obj,offset> => <page> hash table. for now 236 * we just have one bucket (the bootstrap bucket). later on we 237 * will allocate new buckets as we dynamically resize the hash table. 238 */ 239 240 uvm.page_nhash = 1; /* 1 bucket */ 241 uvm.page_hashmask = 0; /* mask for hash function */ 242 uvm.page_hash = &uvm_bootbucket; /* install bootstrap bucket */ 243 TAILQ_INIT(uvm.page_hash); /* init hash table */ 244 simple_lock_init(&uvm.hashlock); /* init hash table lock */ 245 246 /* 247 * step 3: allocate vm_page structures. 248 */ 249 250 /* 251 * sanity check: 252 * before calling this function the MD code is expected to register 253 * some free RAM with the uvm_page_physload() function. our job 254 * now is to allocate vm_page structures for this memory. 255 */ 256 257 if (vm_nphysseg == 0) 258 panic("vm_page_bootstrap: no memory pre-allocated"); 259 260 /* 261 * first calculate the number of free pages... 262 * 263 * note that we use start/end rather than avail_start/avail_end. 264 * this allows us to allocate extra vm_page structures in case we 265 * want to return some memory to the pool after booting. 266 */ 267 268 freepages = 0; 269 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 270 freepages += (vm_physmem[lcv].end - vm_physmem[lcv].start); 271 272 /* 273 * we now know we have (PAGE_SIZE * freepages) bytes of memory we can 274 * use. for each page of memory we use we need a vm_page structure. 275 * thus, the total number of pages we can use is the total size of 276 * the memory divided by the PAGE_SIZE plus the size of the vm_page 277 * structure. we add one to freepages as a fudge factor to avoid 278 * truncation errors (since we can only allocate in terms of whole 279 * pages). 280 */ 281 282 pagecount = ((freepages + 1) << PAGE_SHIFT) / 283 (PAGE_SIZE + sizeof(struct vm_page)); 284 pagearray = (vm_page_t)uvm_pageboot_alloc(pagecount * 285 sizeof(struct vm_page)); 286 memset(pagearray, 0, pagecount * sizeof(struct vm_page)); 287 288 /* 289 * step 4: init the vm_page structures and put them in the correct 290 * place... 291 */ 292 293 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 294 295 n = vm_physmem[lcv].end - vm_physmem[lcv].start; 296 if (n > pagecount) { 297 printf("uvm_page_init: lost %ld page(s) in init\n", 298 (long)(n - pagecount)); 299 panic("uvm_page_init"); /* XXXCDC: shouldn't happen? */ 300 /* n = pagecount; */ 301 } 302 /* set up page array pointers */ 303 vm_physmem[lcv].pgs = pagearray; 304 pagearray += n; 305 pagecount -= n; 306 vm_physmem[lcv].lastpg = vm_physmem[lcv].pgs + (n - 1); 307 308 /* init and free vm_pages (we've already zeroed them) */ 309 paddr = ptoa(vm_physmem[lcv].start); 310 for (i = 0 ; i < n ; i++, paddr += PAGE_SIZE) { 311 vm_physmem[lcv].pgs[i].phys_addr = paddr; 312 if (atop(paddr) >= vm_physmem[lcv].avail_start && 313 atop(paddr) <= vm_physmem[lcv].avail_end) { 314 uvmexp.npages++; 315 /* add page to free pool */ 316 uvm_pagefree(&vm_physmem[lcv].pgs[i]); 317 } 318 } 319 } 320 /* 321 * step 5: pass up the values of virtual_space_start and 322 * virtual_space_end (obtained by uvm_pageboot_alloc) to the upper 323 * layers of the VM. 324 */ 325 326 *kvm_startp = round_page(virtual_space_start); 327 *kvm_endp = trunc_page(virtual_space_end); 328 329 /* 330 * step 6: init pagedaemon lock 331 */ 332 333 simple_lock_init(&uvm.pagedaemon_lock); 334 335 /* 336 * step 7: init reserve thresholds 337 * XXXCDC - values may need adjusting 338 */ 339 uvmexp.reserve_pagedaemon = 1; 340 uvmexp.reserve_kernel = 5; 341 342 /* 343 * step 8: determine if we should zero pages in the idle 344 * loop. 345 * 346 * XXXJRT - might consider zero'ing up to the target *now*, 347 * but that could take an awfully long time if you 348 * have a lot of memory. 349 */ 350 uvm.page_idle_zero = vm_page_zero_enable; 351 352 /* 353 * done! 354 */ 355 356 uvm.page_init_done = TRUE; 357 } 358 359 /* 360 * uvm_setpagesize: set the page size 361 * 362 * => sets page_shift and page_mask from uvmexp.pagesize. 363 * => XXXCDC: move global vars. 364 */ 365 366 void 367 uvm_setpagesize() 368 { 369 if (uvmexp.pagesize == 0) 370 uvmexp.pagesize = DEFAULT_PAGE_SIZE; 371 uvmexp.pagemask = uvmexp.pagesize - 1; 372 if ((uvmexp.pagemask & uvmexp.pagesize) != 0) 373 panic("uvm_setpagesize: page size not a power of two"); 374 for (uvmexp.pageshift = 0; ; uvmexp.pageshift++) 375 if ((1 << uvmexp.pageshift) == uvmexp.pagesize) 376 break; 377 } 378 379 /* 380 * uvm_pageboot_alloc: steal memory from physmem for bootstrapping 381 */ 382 383 vaddr_t 384 uvm_pageboot_alloc(size) 385 vsize_t size; 386 { 387 #if defined(PMAP_STEAL_MEMORY) 388 vaddr_t addr; 389 390 /* 391 * defer bootstrap allocation to MD code (it may want to allocate 392 * from a direct-mapped segment). pmap_steal_memory should round 393 * off virtual_space_start/virtual_space_end. 394 */ 395 396 addr = pmap_steal_memory(size, &virtual_space_start, 397 &virtual_space_end); 398 399 return(addr); 400 401 #else /* !PMAP_STEAL_MEMORY */ 402 403 static boolean_t initialized = FALSE; 404 vaddr_t addr, vaddr; 405 paddr_t paddr; 406 407 /* round to page size */ 408 size = round_page(size); 409 410 /* 411 * on first call to this function, initialize ourselves. 412 */ 413 if (initialized == FALSE) { 414 pmap_virtual_space(&virtual_space_start, &virtual_space_end); 415 416 /* round it the way we like it */ 417 virtual_space_start = round_page(virtual_space_start); 418 virtual_space_end = trunc_page(virtual_space_end); 419 420 initialized = TRUE; 421 } 422 423 /* 424 * allocate virtual memory for this request 425 */ 426 if (virtual_space_start == virtual_space_end || 427 (virtual_space_end - virtual_space_start) < size) 428 panic("uvm_pageboot_alloc: out of virtual space"); 429 430 addr = virtual_space_start; 431 432 #ifdef PMAP_GROWKERNEL 433 /* 434 * If the kernel pmap can't map the requested space, 435 * then allocate more resources for it. 436 */ 437 if (uvm_maxkaddr < (addr + size)) { 438 uvm_maxkaddr = pmap_growkernel(addr + size); 439 if (uvm_maxkaddr < (addr + size)) 440 panic("uvm_pageboot_alloc: pmap_growkernel() failed"); 441 } 442 #endif 443 444 virtual_space_start += size; 445 446 /* 447 * allocate and mapin physical pages to back new virtual pages 448 */ 449 450 for (vaddr = round_page(addr) ; vaddr < addr + size ; 451 vaddr += PAGE_SIZE) { 452 453 if (!uvm_page_physget(&paddr)) 454 panic("uvm_pageboot_alloc: out of memory"); 455 456 /* 457 * Note this memory is no longer managed, so using 458 * pmap_kenter is safe. 459 */ 460 pmap_kenter_pa(vaddr, paddr, VM_PROT_READ|VM_PROT_WRITE); 461 } 462 return(addr); 463 #endif /* PMAP_STEAL_MEMORY */ 464 } 465 466 #if !defined(PMAP_STEAL_MEMORY) 467 /* 468 * uvm_page_physget: "steal" one page from the vm_physmem structure. 469 * 470 * => attempt to allocate it off the end of a segment in which the "avail" 471 * values match the start/end values. if we can't do that, then we 472 * will advance both values (making them equal, and removing some 473 * vm_page structures from the non-avail area). 474 * => return false if out of memory. 475 */ 476 477 /* subroutine: try to allocate from memory chunks on the specified freelist */ 478 static boolean_t uvm_page_physget_freelist __P((paddr_t *, int)); 479 480 static boolean_t 481 uvm_page_physget_freelist(paddrp, freelist) 482 paddr_t *paddrp; 483 int freelist; 484 { 485 int lcv, x; 486 487 /* pass 1: try allocating from a matching end */ 488 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 489 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 490 #else 491 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 492 #endif 493 { 494 495 if (uvm.page_init_done == TRUE) 496 panic("vm_page_physget: called _after_ bootstrap"); 497 498 if (vm_physmem[lcv].free_list != freelist) 499 continue; 500 501 /* try from front */ 502 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].start && 503 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 504 *paddrp = ptoa(vm_physmem[lcv].avail_start); 505 vm_physmem[lcv].avail_start++; 506 vm_physmem[lcv].start++; 507 /* nothing left? nuke it */ 508 if (vm_physmem[lcv].avail_start == 509 vm_physmem[lcv].end) { 510 if (vm_nphysseg == 1) 511 panic("vm_page_physget: out of memory!"); 512 vm_nphysseg--; 513 for (x = lcv ; x < vm_nphysseg ; x++) 514 /* structure copy */ 515 vm_physmem[x] = vm_physmem[x+1]; 516 } 517 return (TRUE); 518 } 519 520 /* try from rear */ 521 if (vm_physmem[lcv].avail_end == vm_physmem[lcv].end && 522 vm_physmem[lcv].avail_start < vm_physmem[lcv].avail_end) { 523 *paddrp = ptoa(vm_physmem[lcv].avail_end - 1); 524 vm_physmem[lcv].avail_end--; 525 vm_physmem[lcv].end--; 526 /* nothing left? nuke it */ 527 if (vm_physmem[lcv].avail_end == 528 vm_physmem[lcv].start) { 529 if (vm_nphysseg == 1) 530 panic("vm_page_physget: out of memory!"); 531 vm_nphysseg--; 532 for (x = lcv ; x < vm_nphysseg ; x++) 533 /* structure copy */ 534 vm_physmem[x] = vm_physmem[x+1]; 535 } 536 return (TRUE); 537 } 538 } 539 540 /* pass2: forget about matching ends, just allocate something */ 541 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 542 for (lcv = vm_nphysseg - 1 ; lcv >= 0 ; lcv--) 543 #else 544 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 545 #endif 546 { 547 548 /* any room in this bank? */ 549 if (vm_physmem[lcv].avail_start >= vm_physmem[lcv].avail_end) 550 continue; /* nope */ 551 552 *paddrp = ptoa(vm_physmem[lcv].avail_start); 553 vm_physmem[lcv].avail_start++; 554 /* truncate! */ 555 vm_physmem[lcv].start = vm_physmem[lcv].avail_start; 556 557 /* nothing left? nuke it */ 558 if (vm_physmem[lcv].avail_start == vm_physmem[lcv].end) { 559 if (vm_nphysseg == 1) 560 panic("vm_page_physget: out of memory!"); 561 vm_nphysseg--; 562 for (x = lcv ; x < vm_nphysseg ; x++) 563 /* structure copy */ 564 vm_physmem[x] = vm_physmem[x+1]; 565 } 566 return (TRUE); 567 } 568 569 return (FALSE); /* whoops! */ 570 } 571 572 boolean_t 573 uvm_page_physget(paddrp) 574 paddr_t *paddrp; 575 { 576 int i; 577 578 /* try in the order of freelist preference */ 579 for (i = 0; i < VM_NFREELIST; i++) 580 if (uvm_page_physget_freelist(paddrp, i) == TRUE) 581 return (TRUE); 582 return (FALSE); 583 } 584 #endif /* PMAP_STEAL_MEMORY */ 585 586 /* 587 * uvm_page_physload: load physical memory into VM system 588 * 589 * => all args are PFs 590 * => all pages in start/end get vm_page structures 591 * => areas marked by avail_start/avail_end get added to the free page pool 592 * => we are limited to VM_PHYSSEG_MAX physical memory segments 593 */ 594 595 void 596 uvm_page_physload(start, end, avail_start, avail_end, free_list) 597 paddr_t start, end, avail_start, avail_end; 598 int free_list; 599 { 600 int preload, lcv; 601 psize_t npages; 602 struct vm_page *pgs; 603 struct vm_physseg *ps; 604 605 if (uvmexp.pagesize == 0) 606 panic("vm_page_physload: page size not set!"); 607 608 if (free_list >= VM_NFREELIST || free_list < VM_FREELIST_DEFAULT) 609 panic("uvm_page_physload: bad free list %d\n", free_list); 610 611 if (start >= end) 612 panic("uvm_page_physload: start >= end"); 613 614 /* 615 * do we have room? 616 */ 617 if (vm_nphysseg == VM_PHYSSEG_MAX) { 618 printf("vm_page_physload: unable to load physical memory " 619 "segment\n"); 620 printf("\t%d segments allocated, ignoring 0x%llx -> 0x%llx\n", 621 VM_PHYSSEG_MAX, (long long)start, (long long)end); 622 return; 623 } 624 625 /* 626 * check to see if this is a "preload" (i.e. uvm_mem_init hasn't been 627 * called yet, so malloc is not available). 628 */ 629 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) { 630 if (vm_physmem[lcv].pgs) 631 break; 632 } 633 preload = (lcv == vm_nphysseg); 634 635 /* 636 * if VM is already running, attempt to malloc() vm_page structures 637 */ 638 if (!preload) { 639 #if defined(VM_PHYSSEG_NOADD) 640 panic("vm_page_physload: tried to add RAM after vm_mem_init"); 641 #else 642 /* XXXCDC: need some sort of lockout for this case */ 643 paddr_t paddr; 644 npages = end - start; /* # of pages */ 645 MALLOC(pgs, struct vm_page *, sizeof(struct vm_page) * npages, 646 M_VMPAGE, M_NOWAIT); 647 if (pgs == NULL) { 648 printf("vm_page_physload: can not malloc vm_page " 649 "structs for segment\n"); 650 printf("\tignoring 0x%lx -> 0x%lx\n", start, end); 651 return; 652 } 653 /* zero data, init phys_addr and free_list, and free pages */ 654 memset(pgs, 0, sizeof(struct vm_page) * npages); 655 for (lcv = 0, paddr = ptoa(start) ; 656 lcv < npages ; lcv++, paddr += PAGE_SIZE) { 657 pgs[lcv].phys_addr = paddr; 658 pgs[lcv].free_list = free_list; 659 if (atop(paddr) >= avail_start && 660 atop(paddr) <= avail_end) 661 uvm_pagefree(&pgs[lcv]); 662 } 663 /* XXXCDC: incomplete: need to update uvmexp.free, what else? */ 664 /* XXXCDC: need hook to tell pmap to rebuild pv_list, etc... */ 665 #endif 666 } else { 667 668 /* gcc complains if these don't get init'd */ 669 pgs = NULL; 670 npages = 0; 671 672 } 673 674 /* 675 * now insert us in the proper place in vm_physmem[] 676 */ 677 678 #if (VM_PHYSSEG_STRAT == VM_PSTRAT_RANDOM) 679 680 /* random: put it at the end (easy!) */ 681 ps = &vm_physmem[vm_nphysseg]; 682 683 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BSEARCH) 684 685 { 686 int x; 687 /* sort by address for binary search */ 688 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 689 if (start < vm_physmem[lcv].start) 690 break; 691 ps = &vm_physmem[lcv]; 692 /* move back other entries, if necessary ... */ 693 for (x = vm_nphysseg ; x > lcv ; x--) 694 /* structure copy */ 695 vm_physmem[x] = vm_physmem[x - 1]; 696 } 697 698 #elif (VM_PHYSSEG_STRAT == VM_PSTRAT_BIGFIRST) 699 700 { 701 int x; 702 /* sort by largest segment first */ 703 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 704 if ((end - start) > 705 (vm_physmem[lcv].end - vm_physmem[lcv].start)) 706 break; 707 ps = &vm_physmem[lcv]; 708 /* move back other entries, if necessary ... */ 709 for (x = vm_nphysseg ; x > lcv ; x--) 710 /* structure copy */ 711 vm_physmem[x] = vm_physmem[x - 1]; 712 } 713 714 #else 715 716 panic("vm_page_physload: unknown physseg strategy selected!"); 717 718 #endif 719 720 ps->start = start; 721 ps->end = end; 722 ps->avail_start = avail_start; 723 ps->avail_end = avail_end; 724 if (preload) { 725 ps->pgs = NULL; 726 } else { 727 ps->pgs = pgs; 728 ps->lastpg = pgs + npages - 1; 729 } 730 ps->free_list = free_list; 731 vm_nphysseg++; 732 733 /* 734 * done! 735 */ 736 737 if (!preload) 738 uvm_page_rehash(); 739 740 return; 741 } 742 743 /* 744 * uvm_page_rehash: reallocate hash table based on number of free pages. 745 */ 746 747 void 748 uvm_page_rehash() 749 { 750 int freepages, lcv, bucketcount, s, oldcount; 751 struct pglist *newbuckets, *oldbuckets; 752 struct vm_page *pg; 753 size_t newsize, oldsize; 754 755 /* 756 * compute number of pages that can go in the free pool 757 */ 758 759 freepages = 0; 760 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 761 freepages += 762 (vm_physmem[lcv].avail_end - vm_physmem[lcv].avail_start); 763 764 /* 765 * compute number of buckets needed for this number of pages 766 */ 767 768 bucketcount = 1; 769 while (bucketcount < freepages) 770 bucketcount = bucketcount * 2; 771 772 /* 773 * compute the size of the current table and new table. 774 */ 775 776 oldbuckets = uvm.page_hash; 777 oldcount = uvm.page_nhash; 778 oldsize = round_page(sizeof(struct pglist) * oldcount); 779 newsize = round_page(sizeof(struct pglist) * bucketcount); 780 781 /* 782 * allocate the new buckets 783 */ 784 785 newbuckets = (struct pglist *) uvm_km_alloc(kernel_map, newsize); 786 if (newbuckets == NULL) { 787 printf("uvm_page_physrehash: WARNING: could not grow page " 788 "hash table\n"); 789 return; 790 } 791 for (lcv = 0 ; lcv < bucketcount ; lcv++) 792 TAILQ_INIT(&newbuckets[lcv]); 793 794 /* 795 * now replace the old buckets with the new ones and rehash everything 796 */ 797 798 s = splimp(); 799 simple_lock(&uvm.hashlock); 800 uvm.page_hash = newbuckets; 801 uvm.page_nhash = bucketcount; 802 uvm.page_hashmask = bucketcount - 1; /* power of 2 */ 803 804 /* ... and rehash */ 805 for (lcv = 0 ; lcv < oldcount ; lcv++) { 806 while ((pg = oldbuckets[lcv].tqh_first) != NULL) { 807 TAILQ_REMOVE(&oldbuckets[lcv], pg, hashq); 808 TAILQ_INSERT_TAIL( 809 &uvm.page_hash[uvm_pagehash(pg->uobject, pg->offset)], 810 pg, hashq); 811 } 812 } 813 simple_unlock(&uvm.hashlock); 814 splx(s); 815 816 /* 817 * free old bucket array if is not the boot-time table 818 */ 819 820 if (oldbuckets != &uvm_bootbucket) 821 uvm_km_free(kernel_map, (vaddr_t) oldbuckets, oldsize); 822 823 /* 824 * done 825 */ 826 return; 827 } 828 829 830 #if 1 /* XXXCDC: TMP TMP TMP DEBUG DEBUG DEBUG */ 831 832 void uvm_page_physdump __P((void)); /* SHUT UP GCC */ 833 834 /* call from DDB */ 835 void 836 uvm_page_physdump() 837 { 838 int lcv; 839 840 printf("rehash: physical memory config [segs=%d of %d]:\n", 841 vm_nphysseg, VM_PHYSSEG_MAX); 842 for (lcv = 0 ; lcv < vm_nphysseg ; lcv++) 843 printf("0x%llx->0x%llx [0x%llx->0x%llx]\n", 844 (long long)vm_physmem[lcv].start, 845 (long long)vm_physmem[lcv].end, 846 (long long)vm_physmem[lcv].avail_start, 847 (long long)vm_physmem[lcv].avail_end); 848 printf("STRATEGY = "); 849 switch (VM_PHYSSEG_STRAT) { 850 case VM_PSTRAT_RANDOM: printf("RANDOM\n"); break; 851 case VM_PSTRAT_BSEARCH: printf("BSEARCH\n"); break; 852 case VM_PSTRAT_BIGFIRST: printf("BIGFIRST\n"); break; 853 default: printf("<<UNKNOWN>>!!!!\n"); 854 } 855 printf("number of buckets = %d\n", uvm.page_nhash); 856 } 857 #endif 858 859 /* 860 * uvm_pagealloc_strat: allocate vm_page from a particular free list. 861 * 862 * => return null if no pages free 863 * => wake up pagedaemon if number of free pages drops below low water mark 864 * => if obj != NULL, obj must be locked (to put in hash) 865 * => if anon != NULL, anon must be locked (to put in anon) 866 * => only one of obj or anon can be non-null 867 * => caller must activate/deactivate page if it is not wired. 868 * => free_list is ignored if strat == UVM_PGA_STRAT_NORMAL. 869 * => policy decision: it is more important to pull a page off of the 870 * appropriate priority free list than it is to get a zero'd or 871 * unknown contents page. This is because we live with the 872 * consequences of a bad free list decision for the entire 873 * lifetime of the page, e.g. if the page comes from memory that 874 * is slower to access. 875 */ 876 877 struct vm_page * 878 uvm_pagealloc_strat(obj, off, anon, flags, strat, free_list) 879 struct uvm_object *obj; 880 voff_t off; 881 int flags; 882 struct vm_anon *anon; 883 int strat, free_list; 884 { 885 int lcv, try1, try2, s, zeroit = 0; 886 struct vm_page *pg; 887 struct pglist *freeq; 888 struct pgfreelist *pgfl; 889 boolean_t use_reserve; 890 891 #ifdef DIAGNOSTIC 892 /* sanity check */ 893 if (obj && anon) 894 panic("uvm_pagealloc: obj and anon != NULL"); 895 #endif 896 897 s = uvm_lock_fpageq(); /* lock free page queue */ 898 899 /* 900 * check to see if we need to generate some free pages waking 901 * the pagedaemon. 902 */ 903 904 if (uvmexp.free < uvmexp.freemin || (uvmexp.free < uvmexp.freetarg && 905 uvmexp.inactive < uvmexp.inactarg)) 906 wakeup(&uvm.pagedaemon); 907 908 /* 909 * fail if any of these conditions is true: 910 * [1] there really are no free pages, or 911 * [2] only kernel "reserved" pages remain and 912 * the page isn't being allocated to a kernel object. 913 * [3] only pagedaemon "reserved" pages remain and 914 * the requestor isn't the pagedaemon. 915 */ 916 917 use_reserve = (flags & UVM_PGA_USERESERVE) || 918 (obj && UVM_OBJ_IS_KERN_OBJECT(obj)); 919 if ((uvmexp.free <= uvmexp.reserve_kernel && !use_reserve) || 920 (uvmexp.free <= uvmexp.reserve_pagedaemon && 921 !(use_reserve && curproc == uvm.pagedaemon_proc))) 922 goto fail; 923 924 #if PGFL_NQUEUES != 2 925 #error uvm_pagealloc_strat needs to be updated 926 #endif 927 928 /* 929 * If we want a zero'd page, try the ZEROS queue first, otherwise 930 * we try the UNKNOWN queue first. 931 */ 932 if (flags & UVM_PGA_ZERO) { 933 try1 = PGFL_ZEROS; 934 try2 = PGFL_UNKNOWN; 935 } else { 936 try1 = PGFL_UNKNOWN; 937 try2 = PGFL_ZEROS; 938 } 939 940 again: 941 switch (strat) { 942 case UVM_PGA_STRAT_NORMAL: 943 /* Check all freelists in descending priority order. */ 944 for (lcv = 0; lcv < VM_NFREELIST; lcv++) { 945 pgfl = &uvm.page_free[lcv]; 946 if ((pg = TAILQ_FIRST((freeq = 947 &pgfl->pgfl_queues[try1]))) != NULL || 948 (pg = TAILQ_FIRST((freeq = 949 &pgfl->pgfl_queues[try2]))) != NULL) 950 goto gotit; 951 } 952 953 /* No pages free! */ 954 goto fail; 955 956 case UVM_PGA_STRAT_ONLY: 957 case UVM_PGA_STRAT_FALLBACK: 958 /* Attempt to allocate from the specified free list. */ 959 #ifdef DIAGNOSTIC 960 if (free_list >= VM_NFREELIST || free_list < 0) 961 panic("uvm_pagealloc_strat: bad free list %d", 962 free_list); 963 #endif 964 pgfl = &uvm.page_free[free_list]; 965 if ((pg = TAILQ_FIRST((freeq = 966 &pgfl->pgfl_queues[try1]))) != NULL || 967 (pg = TAILQ_FIRST((freeq = 968 &pgfl->pgfl_queues[try2]))) != NULL) 969 goto gotit; 970 971 /* Fall back, if possible. */ 972 if (strat == UVM_PGA_STRAT_FALLBACK) { 973 strat = UVM_PGA_STRAT_NORMAL; 974 goto again; 975 } 976 977 /* No pages free! */ 978 goto fail; 979 980 default: 981 panic("uvm_pagealloc_strat: bad strat %d", strat); 982 /* NOTREACHED */ 983 } 984 985 gotit: 986 TAILQ_REMOVE(freeq, pg, pageq); 987 uvmexp.free--; 988 989 /* update zero'd page count */ 990 if (pg->flags & PG_ZERO) 991 uvmexp.zeropages--; 992 993 /* 994 * update allocation statistics and remember if we have to 995 * zero the page 996 */ 997 if (flags & UVM_PGA_ZERO) { 998 if (pg->flags & PG_ZERO) { 999 uvmexp.pga_zerohit++; 1000 zeroit = 0; 1001 } else { 1002 uvmexp.pga_zeromiss++; 1003 zeroit = 1; 1004 } 1005 } 1006 1007 uvm_unlock_fpageq(s); /* unlock free page queue */ 1008 1009 pg->offset = off; 1010 pg->uobject = obj; 1011 pg->uanon = anon; 1012 pg->flags = PG_BUSY|PG_CLEAN|PG_FAKE; 1013 pg->version++; 1014 pg->wire_count = 0; 1015 pg->loan_count = 0; 1016 if (anon) { 1017 anon->u.an_page = pg; 1018 pg->pqflags = PQ_ANON; 1019 } else { 1020 if (obj) 1021 uvm_pageinsert(pg); 1022 pg->pqflags = 0; 1023 } 1024 #if defined(UVM_PAGE_TRKOWN) 1025 pg->owner_tag = NULL; 1026 #endif 1027 UVM_PAGE_OWN(pg, "new alloc"); 1028 1029 if (flags & UVM_PGA_ZERO) { 1030 /* 1031 * A zero'd page is not clean. If we got a page not already 1032 * zero'd, then we have to zero it ourselves. 1033 */ 1034 pg->flags &= ~PG_CLEAN; 1035 if (zeroit) 1036 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1037 } 1038 1039 return(pg); 1040 1041 fail: 1042 uvm_unlock_fpageq(s); 1043 return (NULL); 1044 } 1045 1046 /* 1047 * uvm_pagerealloc: reallocate a page from one object to another 1048 * 1049 * => both objects must be locked 1050 */ 1051 1052 void 1053 uvm_pagerealloc(pg, newobj, newoff) 1054 struct vm_page *pg; 1055 struct uvm_object *newobj; 1056 voff_t newoff; 1057 { 1058 /* 1059 * remove it from the old object 1060 */ 1061 1062 if (pg->uobject) { 1063 uvm_pageremove(pg); 1064 } 1065 1066 /* 1067 * put it in the new object 1068 */ 1069 1070 if (newobj) { 1071 pg->uobject = newobj; 1072 pg->offset = newoff; 1073 pg->version++; 1074 uvm_pageinsert(pg); 1075 } 1076 1077 return; 1078 } 1079 1080 1081 /* 1082 * uvm_pagefree: free page 1083 * 1084 * => erase page's identity (i.e. remove from hash/object) 1085 * => put page on free list 1086 * => caller must lock owning object (either anon or uvm_object) 1087 * => caller must lock page queues 1088 * => assumes all valid mappings of pg are gone 1089 */ 1090 1091 void uvm_pagefree(pg) 1092 1093 struct vm_page *pg; 1094 1095 { 1096 int s; 1097 int saved_loan_count = pg->loan_count; 1098 1099 /* 1100 * if the page was an object page (and thus "TABLED"), remove it 1101 * from the object. 1102 */ 1103 1104 if (pg->flags & PG_TABLED) { 1105 1106 /* 1107 * if the object page is on loan we are going to drop ownership. 1108 * it is possible that an anon will take over as owner for this 1109 * page later on. the anon will want a !PG_CLEAN page so that 1110 * it knows it needs to allocate swap if it wants to page the 1111 * page out. 1112 */ 1113 1114 if (saved_loan_count) 1115 pg->flags &= ~PG_CLEAN; /* in case an anon takes over */ 1116 1117 uvm_pageremove(pg); 1118 1119 /* 1120 * if our page was on loan, then we just lost control over it 1121 * (in fact, if it was loaned to an anon, the anon may have 1122 * already taken over ownership of the page by now and thus 1123 * changed the loan_count [e.g. in uvmfault_anonget()]) we just 1124 * return (when the last loan is dropped, then the page can be 1125 * freed by whatever was holding the last loan). 1126 */ 1127 if (saved_loan_count) 1128 return; 1129 1130 } else if (saved_loan_count && (pg->pqflags & PQ_ANON)) { 1131 1132 /* 1133 * if our page is owned by an anon and is loaned out to the 1134 * kernel then we just want to drop ownership and return. 1135 * the kernel must free the page when all its loans clear ... 1136 * note that the kernel can't change the loan status of our 1137 * page as long as we are holding PQ lock. 1138 */ 1139 pg->pqflags &= ~PQ_ANON; 1140 pg->uanon = NULL; 1141 return; 1142 } 1143 1144 #ifdef DIAGNOSTIC 1145 if (saved_loan_count) { 1146 printf("uvm_pagefree: warning: freeing page with a loan " 1147 "count of %d\n", saved_loan_count); 1148 panic("uvm_pagefree: loan count"); 1149 } 1150 #endif 1151 1152 1153 /* 1154 * now remove the page from the queues 1155 */ 1156 1157 if (pg->pqflags & PQ_ACTIVE) { 1158 TAILQ_REMOVE(&uvm.page_active, pg, pageq); 1159 pg->pqflags &= ~PQ_ACTIVE; 1160 uvmexp.active--; 1161 } 1162 if (pg->pqflags & PQ_INACTIVE) { 1163 if (pg->pqflags & PQ_SWAPBACKED) 1164 TAILQ_REMOVE(&uvm.page_inactive_swp, pg, pageq); 1165 else 1166 TAILQ_REMOVE(&uvm.page_inactive_obj, pg, pageq); 1167 pg->pqflags &= ~PQ_INACTIVE; 1168 uvmexp.inactive--; 1169 } 1170 1171 /* 1172 * if the page was wired, unwire it now. 1173 */ 1174 if (pg->wire_count) { 1175 pg->wire_count = 0; 1176 uvmexp.wired--; 1177 } 1178 1179 /* 1180 * and put on free queue 1181 */ 1182 1183 pg->flags &= ~PG_ZERO; 1184 1185 s = uvm_lock_fpageq(); 1186 TAILQ_INSERT_TAIL(&uvm.page_free[ 1187 uvm_page_lookup_freelist(pg)].pgfl_queues[PGFL_UNKNOWN], pg, pageq); 1188 pg->pqflags = PQ_FREE; 1189 #ifdef DEBUG 1190 pg->uobject = (void *)0xdeadbeef; 1191 pg->offset = 0xdeadbeef; 1192 pg->uanon = (void *)0xdeadbeef; 1193 #endif 1194 uvmexp.free++; 1195 1196 if (uvmexp.zeropages < UVM_PAGEZERO_TARGET) 1197 uvm.page_idle_zero = vm_page_zero_enable; 1198 1199 uvm_unlock_fpageq(s); 1200 } 1201 1202 #if defined(UVM_PAGE_TRKOWN) 1203 /* 1204 * uvm_page_own: set or release page ownership 1205 * 1206 * => this is a debugging function that keeps track of who sets PG_BUSY 1207 * and where they do it. it can be used to track down problems 1208 * such a process setting "PG_BUSY" and never releasing it. 1209 * => page's object [if any] must be locked 1210 * => if "tag" is NULL then we are releasing page ownership 1211 */ 1212 void 1213 uvm_page_own(pg, tag) 1214 struct vm_page *pg; 1215 char *tag; 1216 { 1217 /* gain ownership? */ 1218 if (tag) { 1219 if (pg->owner_tag) { 1220 printf("uvm_page_own: page %p already owned " 1221 "by proc %d [%s]\n", pg, 1222 pg->owner, pg->owner_tag); 1223 panic("uvm_page_own"); 1224 } 1225 pg->owner = (curproc) ? curproc->p_pid : (pid_t) -1; 1226 pg->owner_tag = tag; 1227 return; 1228 } 1229 1230 /* drop ownership */ 1231 if (pg->owner_tag == NULL) { 1232 printf("uvm_page_own: dropping ownership of an non-owned " 1233 "page (%p)\n", pg); 1234 panic("uvm_page_own"); 1235 } 1236 pg->owner_tag = NULL; 1237 return; 1238 } 1239 #endif 1240 1241 /* 1242 * uvm_pageidlezero: zero free pages while the system is idle. 1243 * 1244 * => we do at least one iteration per call, if we are below the target. 1245 * => we loop until we either reach the target or whichqs indicates that 1246 * there is a process ready to run. 1247 */ 1248 void 1249 uvm_pageidlezero() 1250 { 1251 struct vm_page *pg; 1252 struct pgfreelist *pgfl; 1253 int free_list, s; 1254 1255 do { 1256 s = uvm_lock_fpageq(); 1257 1258 if (uvmexp.zeropages >= UVM_PAGEZERO_TARGET) { 1259 uvm.page_idle_zero = FALSE; 1260 uvm_unlock_fpageq(s); 1261 return; 1262 } 1263 1264 for (free_list = 0; free_list < VM_NFREELIST; free_list++) { 1265 pgfl = &uvm.page_free[free_list]; 1266 if ((pg = TAILQ_FIRST(&pgfl->pgfl_queues[ 1267 PGFL_UNKNOWN])) != NULL) 1268 break; 1269 } 1270 1271 if (pg == NULL) { 1272 /* 1273 * No non-zero'd pages; don't bother trying again 1274 * until we know we have non-zero'd pages free. 1275 */ 1276 uvm.page_idle_zero = FALSE; 1277 uvm_unlock_fpageq(s); 1278 return; 1279 } 1280 1281 TAILQ_REMOVE(&pgfl->pgfl_queues[PGFL_UNKNOWN], pg, pageq); 1282 uvmexp.free--; 1283 uvm_unlock_fpageq(s); 1284 1285 #ifdef PMAP_PAGEIDLEZERO 1286 PMAP_PAGEIDLEZERO(VM_PAGE_TO_PHYS(pg)); 1287 #else 1288 /* 1289 * XXX This will toast the cache unless the pmap_zero_page() 1290 * XXX implementation does uncached access. 1291 */ 1292 pmap_zero_page(VM_PAGE_TO_PHYS(pg)); 1293 #endif 1294 pg->flags |= PG_ZERO; 1295 1296 s = uvm_lock_fpageq(); 1297 TAILQ_INSERT_HEAD(&pgfl->pgfl_queues[PGFL_ZEROS], pg, pageq); 1298 uvmexp.free++; 1299 uvmexp.zeropages++; 1300 uvm_unlock_fpageq(s); 1301 } while (sched_whichqs == 0); 1302 } 1303