1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */ 27 /* All Rights Reserved */ 28 29 /* 30 * Portions of this source code were derived from Berkeley 4.3 BSD 31 * under license from the Regents of the University of California. 32 */ 33 34 /* 35 * VM - segment for non-faulting loads. 36 */ 37 38 #include <sys/types.h> 39 #include <sys/t_lock.h> 40 #include <sys/param.h> 41 #include <sys/mman.h> 42 #include <sys/errno.h> 43 #include <sys/kmem.h> 44 #include <sys/cmn_err.h> 45 #include <sys/vnode.h> 46 #include <sys/proc.h> 47 #include <sys/conf.h> 48 #include <sys/debug.h> 49 #include <sys/archsystm.h> 50 #include <sys/lgrp.h> 51 52 #include <vm/page.h> 53 #include <vm/hat.h> 54 #include <vm/as.h> 55 #include <vm/seg.h> 56 #include <vm/vpage.h> 57 58 /* 59 * Private seg op routines. 60 */ 61 static int segnf_dup(struct seg *seg, struct seg *newseg); 62 static int segnf_unmap(struct seg *seg, caddr_t addr, size_t len); 63 static void segnf_free(struct seg *seg); 64 static faultcode_t segnf_nomap(void); 65 static int segnf_setprot(struct seg *seg, caddr_t addr, 66 size_t len, uint_t prot); 67 static int segnf_checkprot(struct seg *seg, caddr_t addr, 68 size_t len, uint_t prot); 69 static void segnf_badop(void); 70 static int segnf_nop(void); 71 static int segnf_getprot(struct seg *seg, caddr_t addr, 72 size_t len, uint_t *protv); 73 static u_offset_t segnf_getoffset(struct seg *seg, caddr_t addr); 74 static int segnf_gettype(struct seg *seg, caddr_t addr); 75 static int segnf_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp); 76 static void segnf_dump(struct seg *seg); 77 static int segnf_pagelock(struct seg *seg, caddr_t addr, size_t len, 78 struct page ***ppp, enum lock_type type, enum seg_rw rw); 79 static int segnf_setpagesize(struct seg *seg, caddr_t addr, size_t len, 80 uint_t szc); 81 static int segnf_getmemid(struct seg *seg, caddr_t addr, memid_t *memidp); 82 static lgrp_mem_policy_info_t *segnf_getpolicy(struct seg *seg, 83 caddr_t addr); 84 85 86 struct seg_ops segnf_ops = { 87 segnf_dup, 88 segnf_unmap, 89 segnf_free, 90 (faultcode_t (*)(struct hat *, struct seg *, caddr_t, size_t, 91 enum fault_type, enum seg_rw)) 92 segnf_nomap, /* fault */ 93 (faultcode_t (*)(struct seg *, caddr_t)) 94 segnf_nomap, /* faulta */ 95 segnf_setprot, 96 segnf_checkprot, 97 (int (*)())segnf_badop, /* kluster */ 98 (int (*)(struct seg *, caddr_t, size_t, int, uint_t)) 99 segnf_nop, /* sync */ 100 (size_t (*)(struct seg *, caddr_t, size_t, char *)) 101 segnf_nop, /* incore */ 102 (int (*)(struct seg *, caddr_t, size_t, int, int, ulong_t *, size_t)) 103 segnf_nop, /* lockop */ 104 segnf_getprot, 105 segnf_getoffset, 106 segnf_gettype, 107 segnf_getvp, 108 (int (*)(struct seg *, caddr_t, size_t, uint_t)) 109 segnf_nop, /* advise */ 110 segnf_dump, 111 segnf_pagelock, 112 segnf_setpagesize, 113 segnf_getmemid, 114 segnf_getpolicy, 115 }; 116 117 /* 118 * vnode and page for the page of zeros we use for the nf mappings. 119 */ 120 static kmutex_t segnf_lock; 121 static struct vnode nfvp; 122 static struct page **nfpp; 123 124 #define addr_to_vcolor(addr) \ 125 (shm_alignment) ? \ 126 ((int)(((uintptr_t)(addr) & (shm_alignment - 1)) >> PAGESHIFT)) : 0 127 128 /* 129 * We try to limit the number of Non-fault segments created. 130 * Non fault segments are created to optimize sparc V9 code which uses 131 * the sparc nonfaulting load ASI (ASI_PRIMARY_NOFAULT). 132 * 133 * There are several reasons why creating too many non-fault segments 134 * could cause problems. 135 * 136 * First, excessive allocation of kernel resources for the seg 137 * structures and the HAT data to map the zero pages. 138 * 139 * Secondly, creating nofault segments actually uses up user virtual 140 * address space. This makes it unavailable for subsequent mmap(0, ...) 141 * calls which use as_gap() to find empty va regions. Creation of too 142 * many nofault segments could thus interfere with the ability of the 143 * runtime linker to load a shared object. 144 */ 145 #define MAXSEGFORNF (10000) 146 #define MAXNFSEARCH (5) 147 148 149 /* 150 * Must be called from startup() 151 */ 152 void 153 segnf_init() 154 { 155 mutex_init(&segnf_lock, NULL, MUTEX_DEFAULT, NULL); 156 } 157 158 159 /* 160 * Create a no-fault segment. 161 * 162 * The no-fault segment is not technically necessary, as the code in 163 * nfload() in trap.c will emulate the SPARC instruction and load 164 * a value of zero in the destination register. 165 * 166 * However, this code tries to put a page of zero's at the nofault address 167 * so that subsequent non-faulting loads to the same page will not 168 * trap with a tlb miss. 169 * 170 * In order to help limit the number of segments we merge adjacent nofault 171 * segments into a single segment. If we get a large number of segments 172 * we'll also try to delete a random other nf segment. 173 */ 174 /* ARGSUSED */ 175 int 176 segnf_create(struct seg *seg, void *argsp) 177 { 178 uint_t prot; 179 pgcnt_t vacpgs; 180 u_offset_t off = 0; 181 caddr_t vaddr = NULL; 182 int i, color; 183 struct seg *s1; 184 struct seg *s2; 185 size_t size; 186 struct as *as = seg->s_as; 187 188 ASSERT(as && AS_WRITE_HELD(as)); 189 190 /* 191 * Need a page per virtual color or just 1 if no vac. 192 */ 193 mutex_enter(&segnf_lock); 194 if (nfpp == NULL) { 195 struct seg kseg; 196 197 vacpgs = 1; 198 if (shm_alignment > PAGESIZE) { 199 vacpgs = shm_alignment >> PAGESHIFT; 200 } 201 202 nfpp = kmem_alloc(sizeof (*nfpp) * vacpgs, KM_SLEEP); 203 204 kseg.s_as = &kas; 205 for (i = 0; i < vacpgs; i++, off += PAGESIZE, 206 vaddr += PAGESIZE) { 207 nfpp[i] = page_create_va(&nfvp, off, PAGESIZE, 208 PG_WAIT | PG_NORELOC, &kseg, vaddr); 209 page_io_unlock(nfpp[i]); 210 page_downgrade(nfpp[i]); 211 pagezero(nfpp[i], 0, PAGESIZE); 212 } 213 } 214 mutex_exit(&segnf_lock); 215 216 hat_map(as->a_hat, seg->s_base, seg->s_size, HAT_MAP); 217 218 /* 219 * s_data can't be NULL because of ASSERTS in the common vm code. 220 */ 221 seg->s_ops = &segnf_ops; 222 seg->s_data = seg; 223 seg->s_flags |= S_PURGE; 224 225 mutex_enter(&as->a_contents); 226 as->a_flags |= AS_NEEDSPURGE; 227 mutex_exit(&as->a_contents); 228 229 prot = PROT_READ; 230 color = addr_to_vcolor(seg->s_base); 231 if (as != &kas) 232 prot |= PROT_USER; 233 hat_memload(as->a_hat, seg->s_base, nfpp[color], 234 prot | HAT_NOFAULT, HAT_LOAD); 235 236 /* 237 * At this point see if we can concatenate a segment to 238 * a non-fault segment immediately before and/or after it. 239 */ 240 if ((s1 = AS_SEGPREV(as, seg)) != NULL && 241 s1->s_ops == &segnf_ops && 242 s1->s_base + s1->s_size == seg->s_base) { 243 size = s1->s_size; 244 seg_free(s1); 245 seg->s_base -= size; 246 seg->s_size += size; 247 } 248 249 if ((s2 = AS_SEGNEXT(as, seg)) != NULL && 250 s2->s_ops == &segnf_ops && 251 seg->s_base + seg->s_size == s2->s_base) { 252 size = s2->s_size; 253 seg_free(s2); 254 seg->s_size += size; 255 } 256 257 /* 258 * if we already have a lot of segments, try to delete some other 259 * nofault segment to reduce the probability of uncontrolled segment 260 * creation. 261 * 262 * the code looks around quickly (no more than MAXNFSEARCH segments 263 * each way) for another NF segment and then deletes it. 264 */ 265 if (avl_numnodes(&as->a_segtree) > MAXSEGFORNF) { 266 size = 0; 267 s2 = NULL; 268 s1 = AS_SEGPREV(as, seg); 269 while (size++ < MAXNFSEARCH && s1 != NULL) { 270 if (s1->s_ops == &segnf_ops) 271 s2 = s1; 272 s1 = AS_SEGPREV(s1->s_as, seg); 273 } 274 if (s2 == NULL) { 275 s1 = AS_SEGNEXT(as, seg); 276 while (size-- > 0 && s1 != NULL) { 277 if (s1->s_ops == &segnf_ops) 278 s2 = s1; 279 s1 = AS_SEGNEXT(as, seg); 280 } 281 } 282 if (s2 != NULL) 283 seg_unmap(s2); 284 } 285 286 return (0); 287 } 288 289 /* 290 * Never really need "No fault" segments, so they aren't dup'd. 291 */ 292 /* ARGSUSED */ 293 static int 294 segnf_dup(struct seg *seg, struct seg *newseg) 295 { 296 panic("segnf_dup"); 297 return (0); 298 } 299 300 /* 301 * Split a segment at addr for length len. 302 */ 303 static int 304 segnf_unmap(struct seg *seg, caddr_t addr, size_t len) 305 { 306 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as)); 307 308 /* 309 * Check for bad sizes. 310 */ 311 if (addr < seg->s_base || addr + len > seg->s_base + seg->s_size || 312 (len & PAGEOFFSET) || ((uintptr_t)addr & PAGEOFFSET)) { 313 cmn_err(CE_PANIC, "segnf_unmap: bad unmap size"); 314 } 315 316 /* 317 * Unload any hardware translations in the range to be taken out. 318 */ 319 hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD_UNMAP); 320 321 if (addr == seg->s_base && len == seg->s_size) { 322 /* 323 * Freeing entire segment. 324 */ 325 seg_free(seg); 326 } else if (addr == seg->s_base) { 327 /* 328 * Freeing the beginning of the segment. 329 */ 330 seg->s_base += len; 331 seg->s_size -= len; 332 } else if (addr + len == seg->s_base + seg->s_size) { 333 /* 334 * Freeing the end of the segment. 335 */ 336 seg->s_size -= len; 337 } else { 338 /* 339 * The section to go is in the middle of the segment, so we 340 * have to cut it into two segments. We shrink the existing 341 * "seg" at the low end, and create "nseg" for the high end. 342 */ 343 caddr_t nbase = addr + len; 344 size_t nsize = (seg->s_base + seg->s_size) - nbase; 345 struct seg *nseg; 346 347 /* 348 * Trim down "seg" before trying to stick "nseg" into the as. 349 */ 350 seg->s_size = addr - seg->s_base; 351 nseg = seg_alloc(seg->s_as, nbase, nsize); 352 if (nseg == NULL) 353 cmn_err(CE_PANIC, "segnf_unmap: seg_alloc failed"); 354 355 /* 356 * s_data can't be NULL because of ASSERTs in common VM code. 357 */ 358 nseg->s_ops = seg->s_ops; 359 nseg->s_data = nseg; 360 nseg->s_flags |= S_PURGE; 361 mutex_enter(&seg->s_as->a_contents); 362 seg->s_as->a_flags |= AS_NEEDSPURGE; 363 mutex_exit(&seg->s_as->a_contents); 364 } 365 366 return (0); 367 } 368 369 /* 370 * Free a segment. 371 */ 372 static void 373 segnf_free(struct seg *seg) 374 { 375 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as)); 376 } 377 378 /* 379 * No faults allowed on segnf. 380 */ 381 static faultcode_t 382 segnf_nomap(void) 383 { 384 return (FC_NOMAP); 385 } 386 387 /* ARGSUSED */ 388 static int 389 segnf_setprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot) 390 { 391 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as)); 392 return (EACCES); 393 } 394 395 /* ARGSUSED */ 396 static int 397 segnf_checkprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot) 398 { 399 uint_t sprot; 400 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as)); 401 402 sprot = seg->s_as == &kas ? PROT_READ : PROT_READ|PROT_USER; 403 return ((prot & sprot) == prot ? 0 : EACCES); 404 } 405 406 static void 407 segnf_badop(void) 408 { 409 panic("segnf_badop"); 410 /*NOTREACHED*/ 411 } 412 413 static int 414 segnf_nop(void) 415 { 416 return (0); 417 } 418 419 static int 420 segnf_getprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv) 421 { 422 size_t pgno = seg_page(seg, addr + len) - seg_page(seg, addr) + 1; 423 size_t p; 424 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as)); 425 426 for (p = 0; p < pgno; ++p) 427 protv[p] = PROT_READ; 428 return (0); 429 } 430 431 /* ARGSUSED */ 432 static u_offset_t 433 segnf_getoffset(struct seg *seg, caddr_t addr) 434 { 435 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as)); 436 437 return ((u_offset_t)0); 438 } 439 440 /* ARGSUSED */ 441 static int 442 segnf_gettype(struct seg *seg, caddr_t addr) 443 { 444 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as)); 445 446 return (MAP_SHARED); 447 } 448 449 /* ARGSUSED */ 450 static int 451 segnf_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp) 452 { 453 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as)); 454 455 *vpp = &nfvp; 456 return (0); 457 } 458 459 /* 460 * segnf pages are not dumped, so we just return 461 */ 462 /* ARGSUSED */ 463 static void 464 segnf_dump(struct seg *seg) 465 {} 466 467 /*ARGSUSED*/ 468 static int 469 segnf_pagelock(struct seg *seg, caddr_t addr, size_t len, 470 struct page ***ppp, enum lock_type type, enum seg_rw rw) 471 { 472 return (ENOTSUP); 473 } 474 475 /*ARGSUSED*/ 476 static int 477 segnf_setpagesize(struct seg *seg, caddr_t addr, size_t len, 478 uint_t szc) 479 { 480 return (ENOTSUP); 481 } 482 483 /*ARGSUSED*/ 484 static int 485 segnf_getmemid(struct seg *seg, caddr_t addr, memid_t *memidp) 486 { 487 return (ENODEV); 488 } 489 490 /*ARGSUSED*/ 491 static lgrp_mem_policy_info_t * 492 segnf_getpolicy(struct seg *seg, caddr_t addr) 493 { 494 return (NULL); 495 }