1 /* $NetBSD: uvm_bio.c,v 1.24 2002/02/15 17:45:05 simonb Exp $ */ 2 3 /* 4 * Copyright (c) 1998 Chuck Silvers. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 23 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 25 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 26 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 */ 31 32 /* 33 * uvm_bio.c: buffered i/o vnode mapping cache 34 */ 35 36 #include <sys/cdefs.h> 37 __KERNEL_RCSID(0, "$NetBSD: uvm_bio.c,v 1.24 2002/02/15 17:45:05 simonb Exp $"); 38 39 #include "opt_uvmhist.h" 40 41 #include <sys/param.h> 42 #include <sys/systm.h> 43 #include <sys/malloc.h> 44 #include <sys/kernel.h> 45 #include <sys/vnode.h> 46 #include <sys/proc.h> 47 48 #include <uvm/uvm.h> 49 50 /* 51 * global data structures 52 */ 53 54 /* 55 * local functions 56 */ 57 58 int ubc_fault __P((struct uvm_faultinfo *, vaddr_t, struct vm_page **, int, 59 int, vm_fault_t, vm_prot_t, int)); 60 struct ubc_map *ubc_find_mapping __P((struct uvm_object *, voff_t)); 61 62 /* 63 * local data structues 64 */ 65 66 #define UBC_HASH(uobj, offset) \ 67 (((((u_long)(uobj)) >> 8) + (((u_long)(offset)) >> PAGE_SHIFT)) & \ 68 ubc_object.hashmask) 69 70 #define UBC_QUEUE(offset) \ 71 (&ubc_object.inactive[(((u_long)(offset)) >> ubc_winshift) & \ 72 (UBC_NQUEUES - 1)]) 73 74 #define UBC_UMAP_ADDR(u) \ 75 (vaddr_t)(ubc_object.kva + (((u) - ubc_object.umap) << ubc_winshift)) 76 77 78 #define UMAP_PAGES_LOCKED 0x0001 79 #define UMAP_MAPPING_CACHED 0x0002 80 81 struct ubc_map 82 { 83 struct uvm_object * uobj; /* mapped object */ 84 voff_t offset; /* offset into uobj */ 85 voff_t writeoff; /* overwrite offset */ 86 vsize_t writelen; /* overwrite len */ 87 int refcount; /* refcount on mapping */ 88 int flags; /* extra state */ 89 90 LIST_ENTRY(ubc_map) hash; /* hash table */ 91 TAILQ_ENTRY(ubc_map) inactive; /* inactive queue */ 92 }; 93 94 static struct ubc_object 95 { 96 struct uvm_object uobj; /* glue for uvm_map() */ 97 char *kva; /* where ubc_object is mapped */ 98 struct ubc_map *umap; /* array of ubc_map's */ 99 100 LIST_HEAD(, ubc_map) *hash; /* hashtable for cached ubc_map's */ 101 u_long hashmask; /* mask for hashtable */ 102 103 TAILQ_HEAD(ubc_inactive_head, ubc_map) *inactive; 104 /* inactive queues for ubc_map's */ 105 106 } ubc_object; 107 108 struct uvm_pagerops ubc_pager = 109 { 110 NULL, /* init */ 111 NULL, /* reference */ 112 NULL, /* detach */ 113 ubc_fault, /* fault */ 114 /* ... rest are NULL */ 115 }; 116 117 int ubc_nwins = UBC_NWINS; 118 int ubc_winshift = UBC_WINSHIFT; 119 int ubc_winsize; 120 #ifdef PMAP_PREFER 121 int ubc_nqueues; 122 boolean_t ubc_release_unmap = FALSE; 123 #define UBC_NQUEUES ubc_nqueues 124 #define UBC_RELEASE_UNMAP ubc_release_unmap 125 #else 126 #define UBC_NQUEUES 1 127 #define UBC_RELEASE_UNMAP FALSE 128 #endif 129 130 /* 131 * ubc_init 132 * 133 * init pager private data structures. 134 */ 135 136 void 137 ubc_init(void) 138 { 139 struct ubc_map *umap; 140 vaddr_t va; 141 int i; 142 143 /* 144 * Make sure ubc_winshift is sane. 145 */ 146 if (ubc_winshift < PAGE_SHIFT) 147 ubc_winshift = PAGE_SHIFT; 148 149 /* 150 * init ubc_object. 151 * alloc and init ubc_map's. 152 * init inactive queues. 153 * alloc and init hashtable. 154 * map in ubc_object. 155 */ 156 157 simple_lock_init(&ubc_object.uobj.vmobjlock); 158 ubc_object.uobj.pgops = &ubc_pager; 159 TAILQ_INIT(&ubc_object.uobj.memq); 160 ubc_object.uobj.uo_npages = 0; 161 ubc_object.uobj.uo_refs = UVM_OBJ_KERN; 162 163 ubc_object.umap = malloc(ubc_nwins * sizeof(struct ubc_map), 164 M_TEMP, M_NOWAIT); 165 if (ubc_object.umap == NULL) 166 panic("ubc_init: failed to allocate ubc_map"); 167 memset(ubc_object.umap, 0, ubc_nwins * sizeof(struct ubc_map)); 168 169 if (ubc_winshift < PAGE_SHIFT) { 170 ubc_winshift = PAGE_SHIFT; 171 } 172 va = (vaddr_t)1L; 173 #ifdef PMAP_PREFER 174 PMAP_PREFER(0, &va); 175 ubc_nqueues = va >> ubc_winshift; 176 if (ubc_nqueues == 0) { 177 ubc_nqueues = 1; 178 } 179 if (ubc_nqueues != 1) { 180 ubc_release_unmap = TRUE; 181 } 182 #endif 183 ubc_winsize = 1 << ubc_winshift; 184 ubc_object.inactive = malloc(UBC_NQUEUES * 185 sizeof(struct ubc_inactive_head), M_TEMP, M_NOWAIT); 186 if (ubc_object.inactive == NULL) 187 panic("ubc_init: failed to allocate inactive queue heads"); 188 for (i = 0; i < UBC_NQUEUES; i++) { 189 TAILQ_INIT(&ubc_object.inactive[i]); 190 } 191 for (i = 0; i < ubc_nwins; i++) { 192 umap = &ubc_object.umap[i]; 193 TAILQ_INSERT_TAIL(&ubc_object.inactive[i & (UBC_NQUEUES - 1)], 194 umap, inactive); 195 } 196 197 ubc_object.hash = hashinit(ubc_nwins, HASH_LIST, M_TEMP, M_NOWAIT, 198 &ubc_object.hashmask); 199 for (i = 0; i <= ubc_object.hashmask; i++) { 200 LIST_INIT(&ubc_object.hash[i]); 201 } 202 203 if (uvm_map(kernel_map, (vaddr_t *)&ubc_object.kva, 204 ubc_nwins << ubc_winshift, &ubc_object.uobj, 0, (vsize_t)va, 205 UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, UVM_INH_NONE, 206 UVM_ADV_RANDOM, UVM_FLAG_NOMERGE)) != 0) { 207 panic("ubc_init: failed to map ubc_object\n"); 208 } 209 UVMHIST_INIT(ubchist, 300); 210 } 211 212 /* 213 * ubc_fault: fault routine for ubc mapping 214 */ 215 216 int 217 ubc_fault(ufi, ign1, ign2, ign3, ign4, fault_type, access_type, flags) 218 struct uvm_faultinfo *ufi; 219 vaddr_t ign1; 220 struct vm_page **ign2; 221 int ign3, ign4; 222 vm_fault_t fault_type; 223 vm_prot_t access_type; 224 int flags; 225 { 226 struct uvm_object *uobj; 227 struct vnode *vp; 228 struct ubc_map *umap; 229 vaddr_t va, eva, ubc_offset, slot_offset; 230 int i, error, npages; 231 struct vm_page *pgs[ubc_winsize >> PAGE_SHIFT], *pg; 232 vm_prot_t prot; 233 UVMHIST_FUNC("ubc_fault"); UVMHIST_CALLED(ubchist); 234 235 /* 236 * no need to try with PGO_LOCKED... 237 * we don't need to have the map locked since we know that 238 * no one will mess with it until our reference is released. 239 */ 240 241 if (flags & PGO_LOCKED) { 242 uvmfault_unlockall(ufi, NULL, &ubc_object.uobj, NULL); 243 flags &= ~PGO_LOCKED; 244 } 245 246 va = ufi->orig_rvaddr; 247 ubc_offset = va - (vaddr_t)ubc_object.kva; 248 249 UVMHIST_LOG(ubchist, "va 0x%lx ubc_offset 0x%lx at %d", 250 va, ubc_offset, access_type, 0); 251 252 umap = &ubc_object.umap[ubc_offset >> ubc_winshift]; 253 KASSERT(umap->refcount != 0); 254 slot_offset = ubc_offset & (ubc_winsize - 1); 255 256 /* no umap locking needed since we have a ref on the umap */ 257 uobj = umap->uobj; 258 vp = (struct vnode *)uobj; 259 KASSERT(vp != NULL); 260 261 npages = MIN(ubc_winsize - slot_offset, 262 (round_page(MAX(vp->v_size, umap->offset + 263 umap->writeoff + umap->writelen)) - 264 umap->offset)) >> PAGE_SHIFT; 265 266 again: 267 memset(pgs, 0, sizeof (pgs)); 268 simple_lock(&uobj->vmobjlock); 269 270 UVMHIST_LOG(ubchist, "slot_offset 0x%x writeoff 0x%x writelen 0x%x " 271 "v_size 0x%x", slot_offset, umap->writeoff, umap->writelen, 272 vp->v_size); 273 UVMHIST_LOG(ubchist, "getpages vp %p offset 0x%x npages %d", 274 uobj, umap->offset + slot_offset, npages, 0); 275 276 flags |= PGO_PASTEOF; 277 error = VOP_GETPAGES(vp, umap->offset + slot_offset, pgs, &npages, 0, 278 access_type, 0, flags); 279 UVMHIST_LOG(ubchist, "getpages error %d npages %d", error, npages, 0, 280 0); 281 282 if (error == EAGAIN) { 283 tsleep(&lbolt, PVM, "ubc_fault", 0); 284 goto again; 285 } 286 if (error) { 287 return error; 288 } 289 290 va = ufi->orig_rvaddr; 291 eva = ufi->orig_rvaddr + (npages << PAGE_SHIFT); 292 293 /* 294 * for virtually-indexed, virtually-tagged caches we should avoid 295 * creating writable mappings when we don't absolutely need them, 296 * since the "compatible alias" trick doesn't work on such caches. 297 * otherwise, we can always map the pages writable. 298 */ 299 300 #ifdef PMAP_CACHE_VIVT 301 prot = VM_PROT_READ | access_type; 302 #else 303 prot = VM_PROT_READ | VM_PROT_WRITE; 304 #endif 305 UVMHIST_LOG(ubchist, "va 0x%lx eva 0x%lx", va, eva, 0, 0); 306 simple_lock(&uobj->vmobjlock); 307 uvm_lock_pageq(); 308 for (i = 0; va < eva; i++, va += PAGE_SIZE) { 309 UVMHIST_LOG(ubchist, "pgs[%d] = %p", i, pgs[i], 0, 0); 310 pg = pgs[i]; 311 312 if (pg == NULL || pg == PGO_DONTCARE) { 313 continue; 314 } 315 if (pg->flags & PG_WANTED) { 316 wakeup(pg); 317 } 318 KASSERT((pg->flags & PG_FAKE) == 0); 319 if (pg->flags & PG_RELEASED) { 320 uvm_pagefree(pg); 321 continue; 322 } 323 KASSERT(access_type == VM_PROT_READ || 324 (pg->flags & PG_RDONLY) == 0); 325 pmap_enter(ufi->orig_map->pmap, va, VM_PAGE_TO_PHYS(pg), 326 prot, access_type); 327 uvm_pageactivate(pg); 328 pg->flags &= ~(PG_BUSY); 329 UVM_PAGE_OWN(pg, NULL); 330 } 331 uvm_unlock_pageq(); 332 simple_unlock(&uobj->vmobjlock); 333 pmap_update(ufi->orig_map->pmap); 334 return 0; 335 } 336 337 /* 338 * local functions 339 */ 340 341 struct ubc_map * 342 ubc_find_mapping(uobj, offset) 343 struct uvm_object *uobj; 344 voff_t offset; 345 { 346 struct ubc_map *umap; 347 348 LIST_FOREACH(umap, &ubc_object.hash[UBC_HASH(uobj, offset)], hash) { 349 if (umap->uobj == uobj && umap->offset == offset) { 350 return umap; 351 } 352 } 353 return NULL; 354 } 355 356 357 /* 358 * ubc interface functions 359 */ 360 361 /* 362 * ubc_alloc: allocate a file mapping window 363 */ 364 365 void * 366 ubc_alloc(uobj, offset, lenp, flags) 367 struct uvm_object *uobj; 368 voff_t offset; 369 vsize_t *lenp; 370 int flags; 371 { 372 struct vnode *vp = (struct vnode *)uobj; 373 vaddr_t slot_offset, va; 374 struct ubc_map *umap; 375 voff_t umap_offset; 376 int error; 377 UVMHIST_FUNC("ubc_alloc"); UVMHIST_CALLED(ubchist); 378 379 UVMHIST_LOG(ubchist, "uobj %p offset 0x%lx len 0x%lx filesize 0x%x", 380 uobj, offset, *lenp, vp->v_size); 381 382 umap_offset = (offset & ~((voff_t)ubc_winsize - 1)); 383 slot_offset = (vaddr_t)(offset & ((voff_t)ubc_winsize - 1)); 384 *lenp = MIN(*lenp, ubc_winsize - slot_offset); 385 386 /* 387 * the vnode is always locked here, so we don't need to add a ref. 388 */ 389 390 again: 391 simple_lock(&ubc_object.uobj.vmobjlock); 392 umap = ubc_find_mapping(uobj, umap_offset); 393 if (umap == NULL) { 394 umap = TAILQ_FIRST(UBC_QUEUE(offset)); 395 if (umap == NULL) { 396 simple_unlock(&ubc_object.uobj.vmobjlock); 397 tsleep(&lbolt, PVM, "ubc_alloc", 0); 398 goto again; 399 } 400 401 /* 402 * remove from old hash (if any), add to new hash. 403 */ 404 405 if (umap->uobj != NULL) { 406 LIST_REMOVE(umap, hash); 407 } 408 umap->uobj = uobj; 409 umap->offset = umap_offset; 410 LIST_INSERT_HEAD(&ubc_object.hash[UBC_HASH(uobj, umap_offset)], 411 umap, hash); 412 va = UBC_UMAP_ADDR(umap); 413 if (umap->flags & UMAP_MAPPING_CACHED) { 414 umap->flags &= ~UMAP_MAPPING_CACHED; 415 pmap_remove(pmap_kernel(), va, va + ubc_winsize); 416 pmap_update(pmap_kernel()); 417 } 418 } else { 419 va = UBC_UMAP_ADDR(umap); 420 } 421 422 if (umap->refcount == 0) { 423 TAILQ_REMOVE(UBC_QUEUE(offset), umap, inactive); 424 } 425 426 #ifdef DIAGNOSTIC 427 if ((flags & UBC_WRITE) && (umap->writeoff || umap->writelen)) { 428 panic("ubc_fault: concurrent writes vp %p", uobj); 429 } 430 #endif 431 if (flags & UBC_WRITE) { 432 umap->writeoff = slot_offset; 433 umap->writelen = *lenp; 434 } 435 436 umap->refcount++; 437 simple_unlock(&ubc_object.uobj.vmobjlock); 438 UVMHIST_LOG(ubchist, "umap %p refs %d va %p flags 0x%x", 439 umap, umap->refcount, va, flags); 440 441 if (flags & UBC_FAULTBUSY) { 442 int npages = (*lenp + PAGE_SIZE - 1) >> PAGE_SHIFT; 443 struct vm_page *pgs[npages]; 444 int gpflags = PGO_SYNCIO|PGO_OVERWRITE|PGO_PASTEOF; 445 int i; 446 447 if (umap->flags & UMAP_MAPPING_CACHED) { 448 umap->flags &= ~UMAP_MAPPING_CACHED; 449 pmap_remove(pmap_kernel(), va, va + ubc_winsize); 450 } 451 memset(pgs, 0, sizeof(pgs)); 452 simple_lock(&uobj->vmobjlock); 453 error = VOP_GETPAGES(vp, trunc_page(offset), pgs, &npages, 0, 454 VM_PROT_READ|VM_PROT_WRITE, 0, gpflags); 455 UVMHIST_LOG(ubchist, "faultbusy getpages %d", error, 0, 0, 0); 456 if (error) { 457 goto out; 458 } 459 for (i = 0; i < npages; i++) { 460 pmap_kenter_pa(va + slot_offset + (i << PAGE_SHIFT), 461 VM_PAGE_TO_PHYS(pgs[i]), 462 VM_PROT_READ | VM_PROT_WRITE); 463 } 464 pmap_update(pmap_kernel()); 465 umap->flags |= UMAP_PAGES_LOCKED; 466 } 467 468 out: 469 return (void *)(va + slot_offset); 470 } 471 472 /* 473 * ubc_release: free a file mapping window. 474 */ 475 476 void 477 ubc_release(va, flags) 478 void *va; 479 int flags; 480 { 481 struct ubc_map *umap; 482 struct uvm_object *uobj; 483 vaddr_t umapva; 484 boolean_t unmapped; 485 UVMHIST_FUNC("ubc_release"); UVMHIST_CALLED(ubchist); 486 487 UVMHIST_LOG(ubchist, "va %p", va, 0, 0, 0); 488 umap = &ubc_object.umap[((char *)va - ubc_object.kva) >> ubc_winshift]; 489 umapva = UBC_UMAP_ADDR(umap); 490 uobj = umap->uobj; 491 KASSERT(uobj != NULL); 492 493 if (umap->flags & UMAP_PAGES_LOCKED) { 494 int slot_offset = umap->writeoff; 495 int endoff = umap->writeoff + umap->writelen; 496 int zerolen = round_page(endoff) - endoff; 497 int npages = (int)(round_page(umap->writeoff + umap->writelen) 498 - trunc_page(umap->writeoff)) >> PAGE_SHIFT; 499 struct vm_page *pgs[npages]; 500 paddr_t pa; 501 int i; 502 boolean_t rv; 503 504 if (zerolen) { 505 memset((char *)umapva + endoff, 0, zerolen); 506 } 507 umap->flags &= ~UMAP_PAGES_LOCKED; 508 uvm_lock_pageq(); 509 for (i = 0; i < npages; i++) { 510 rv = pmap_extract(pmap_kernel(), 511 umapva + slot_offset + (i << PAGE_SHIFT), &pa); 512 KASSERT(rv); 513 pgs[i] = PHYS_TO_VM_PAGE(pa); 514 pgs[i]->flags &= ~(PG_FAKE|PG_CLEAN); 515 uvm_pageactivate(pgs[i]); 516 } 517 uvm_unlock_pageq(); 518 pmap_kremove(umapva, ubc_winsize); 519 pmap_update(pmap_kernel()); 520 uvm_page_unbusy(pgs, npages); 521 unmapped = TRUE; 522 } else { 523 unmapped = FALSE; 524 } 525 526 simple_lock(&ubc_object.uobj.vmobjlock); 527 umap->writeoff = 0; 528 umap->writelen = 0; 529 umap->refcount--; 530 if (umap->refcount == 0) { 531 if (UBC_RELEASE_UNMAP && 532 (((struct vnode *)uobj)->v_flag & VTEXT)) { 533 534 /* 535 * if this file is the executable image of 536 * some process, that process will likely have 537 * the file mapped at an alignment other than 538 * what PMAP_PREFER() would like. we'd like 539 * to have process text be able to use the 540 * cache even if someone is also reading the 541 * file, so invalidate mappings of such files 542 * as soon as possible. 543 */ 544 545 pmap_remove(pmap_kernel(), umapva, 546 umapva + ubc_winsize); 547 umap->flags &= ~UMAP_MAPPING_CACHED; 548 pmap_update(pmap_kernel()); 549 LIST_REMOVE(umap, hash); 550 umap->uobj = NULL; 551 TAILQ_INSERT_HEAD(UBC_QUEUE(umap->offset), umap, 552 inactive); 553 } else { 554 if (!unmapped) { 555 umap->flags |= UMAP_MAPPING_CACHED; 556 } 557 TAILQ_INSERT_TAIL(UBC_QUEUE(umap->offset), umap, 558 inactive); 559 } 560 } 561 UVMHIST_LOG(ubchist, "umap %p refs %d", umap, umap->refcount, 0, 0); 562 simple_unlock(&ubc_object.uobj.vmobjlock); 563 } 564 565 566 /* 567 * removing a range of mappings from the ubc mapping cache. 568 */ 569 570 void 571 ubc_flush(uobj, start, end) 572 struct uvm_object *uobj; 573 voff_t start, end; 574 { 575 struct ubc_map *umap; 576 vaddr_t va; 577 UVMHIST_FUNC("ubc_flush"); UVMHIST_CALLED(ubchist); 578 579 UVMHIST_LOG(ubchist, "uobj %p start 0x%lx end 0x%lx", 580 uobj, start, end, 0); 581 582 simple_lock(&ubc_object.uobj.vmobjlock); 583 for (umap = ubc_object.umap; 584 umap < &ubc_object.umap[ubc_nwins]; 585 umap++) { 586 587 if (umap->uobj != uobj || umap->offset < start || 588 (umap->offset >= end && end != 0) || 589 umap->refcount > 0) { 590 continue; 591 } 592 593 /* 594 * remove from hash, 595 * move to head of inactive queue. 596 */ 597 598 va = (vaddr_t)(ubc_object.kva + 599 ((umap - ubc_object.umap) << ubc_winshift)); 600 pmap_remove(pmap_kernel(), va, va + ubc_winsize); 601 602 LIST_REMOVE(umap, hash); 603 umap->uobj = NULL; 604 TAILQ_REMOVE(UBC_QUEUE(umap->offset), umap, inactive); 605 TAILQ_INSERT_HEAD(UBC_QUEUE(umap->offset), umap, inactive); 606 } 607 pmap_update(pmap_kernel()); 608 simple_unlock(&ubc_object.uobj.vmobjlock); 609 } 610