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 83 84 struct seg_ops segnf_ops = { 85 .dup = segnf_dup, 86 .unmap = segnf_unmap, 87 .free = segnf_free, 88 .fault = (faultcode_t (*)(struct hat *, struct seg *, caddr_t, 89 size_t, enum fault_type, enum seg_rw))segnf_nomap, 90 .faulta = (faultcode_t (*)(struct seg *, caddr_t)) segnf_nomap, 91 .setprot = segnf_setprot, 92 .checkprot = segnf_checkprot, 93 .kluster = (int (*)())segnf_badop, 94 .sync = (int (*)(struct seg *, caddr_t, size_t, int, uint_t)) 95 segnf_nop, 96 .incore = (size_t (*)(struct seg *, caddr_t, size_t, char *)) 97 segnf_nop, 98 .lockop = (int (*)(struct seg *, caddr_t, size_t, int, int, 99 ulong_t *, size_t))segnf_nop, 100 .getprot = segnf_getprot, 101 .getoffset = segnf_getoffset, 102 .gettype = segnf_gettype, 103 .getvp = segnf_getvp, 104 .advise = (int (*)(struct seg *, caddr_t, size_t, uint_t)) 105 segnf_nop, 106 .dump = segnf_dump, 107 .pagelock = segnf_pagelock, 108 .setpagesize = segnf_setpagesize, 109 .getmemid = segnf_getmemid, 110 }; 111 112 /* 113 * vnode and page for the page of zeros we use for the nf mappings. 114 */ 115 static kmutex_t segnf_lock; 116 static struct vnode nfvp; 117 static struct page **nfpp; 118 119 #define addr_to_vcolor(addr) \ 120 (shm_alignment) ? \ 121 ((int)(((uintptr_t)(addr) & (shm_alignment - 1)) >> PAGESHIFT)) : 0 122 123 /* 124 * We try to limit the number of Non-fault segments created. 125 * Non fault segments are created to optimize sparc V9 code which uses 126 * the sparc nonfaulting load ASI (ASI_PRIMARY_NOFAULT). 127 * 128 * There are several reasons why creating too many non-fault segments 129 * could cause problems. 130 * 131 * First, excessive allocation of kernel resources for the seg 132 * structures and the HAT data to map the zero pages. 133 * 134 * Secondly, creating nofault segments actually uses up user virtual 135 * address space. This makes it unavailable for subsequent mmap(0, ...) 136 * calls which use as_gap() to find empty va regions. Creation of too 137 * many nofault segments could thus interfere with the ability of the 138 * runtime linker to load a shared object. 139 */ 140 #define MAXSEGFORNF (10000) 141 #define MAXNFSEARCH (5) 142 143 144 /* 145 * Must be called from startup() 146 */ 147 void 148 segnf_init() 149 { 150 mutex_init(&segnf_lock, NULL, MUTEX_DEFAULT, NULL); 151 } 152 153 154 /* 155 * Create a no-fault segment. 156 * 157 * The no-fault segment is not technically necessary, as the code in 158 * nfload() in trap.c will emulate the SPARC instruction and load 159 * a value of zero in the destination register. 160 * 161 * However, this code tries to put a page of zero's at the nofault address 162 * so that subsequent non-faulting loads to the same page will not 163 * trap with a tlb miss. 164 * 165 * In order to help limit the number of segments we merge adjacent nofault 166 * segments into a single segment. If we get a large number of segments 167 * we'll also try to delete a random other nf segment. 168 */ 169 /* ARGSUSED */ 170 int 171 segnf_create(struct seg *seg, void *argsp) 172 { 173 uint_t prot; 174 pgcnt_t vacpgs; 175 u_offset_t off = 0; 176 caddr_t vaddr = NULL; 177 int i, color; 178 struct seg *s1; 179 struct seg *s2; 180 size_t size; 181 struct as *as = seg->s_as; 182 183 ASSERT(as && AS_WRITE_HELD(as, &as->a_lock)); 184 185 /* 186 * Need a page per virtual color or just 1 if no vac. 187 */ 188 mutex_enter(&segnf_lock); 189 if (nfpp == NULL) { 190 struct seg kseg; 191 192 vacpgs = 1; 193 if (shm_alignment > PAGESIZE) { 194 vacpgs = shm_alignment >> PAGESHIFT; 195 } 196 197 nfpp = kmem_alloc(sizeof (*nfpp) * vacpgs, KM_SLEEP); 198 199 kseg.s_as = &kas; 200 for (i = 0; i < vacpgs; i++, off += PAGESIZE, 201 vaddr += PAGESIZE) { 202 nfpp[i] = page_create_va(&nfvp, off, PAGESIZE, 203 PG_WAIT | PG_NORELOC, &kseg, vaddr); 204 page_io_unlock(nfpp[i]); 205 page_downgrade(nfpp[i]); 206 pagezero(nfpp[i], 0, PAGESIZE); 207 } 208 } 209 mutex_exit(&segnf_lock); 210 211 hat_map(as->a_hat, seg->s_base, seg->s_size, HAT_MAP); 212 213 /* 214 * s_data can't be NULL because of ASSERTS in the common vm code. 215 */ 216 seg->s_ops = &segnf_ops; 217 seg->s_data = seg; 218 seg->s_flags |= S_PURGE; 219 220 mutex_enter(&as->a_contents); 221 as->a_flags |= AS_NEEDSPURGE; 222 mutex_exit(&as->a_contents); 223 224 prot = PROT_READ; 225 color = addr_to_vcolor(seg->s_base); 226 if (as != &kas) 227 prot |= PROT_USER; 228 hat_memload(as->a_hat, seg->s_base, nfpp[color], 229 prot | HAT_NOFAULT, HAT_LOAD); 230 231 /* 232 * At this point see if we can concatenate a segment to 233 * a non-fault segment immediately before and/or after it. 234 */ 235 if ((s1 = AS_SEGPREV(as, seg)) != NULL && 236 s1->s_ops == &segnf_ops && 237 s1->s_base + s1->s_size == seg->s_base) { 238 size = s1->s_size; 239 seg_free(s1); 240 seg->s_base -= size; 241 seg->s_size += size; 242 } 243 244 if ((s2 = AS_SEGNEXT(as, seg)) != NULL && 245 s2->s_ops == &segnf_ops && 246 seg->s_base + seg->s_size == s2->s_base) { 247 size = s2->s_size; 248 seg_free(s2); 249 seg->s_size += size; 250 } 251 252 /* 253 * if we already have a lot of segments, try to delete some other 254 * nofault segment to reduce the probability of uncontrolled segment 255 * creation. 256 * 257 * the code looks around quickly (no more than MAXNFSEARCH segments 258 * each way) for another NF segment and then deletes it. 259 */ 260 if (avl_numnodes(&as->a_segtree) > MAXSEGFORNF) { 261 size = 0; 262 s2 = NULL; 263 s1 = AS_SEGPREV(as, seg); 264 while (size++ < MAXNFSEARCH && s1 != NULL) { 265 if (s1->s_ops == &segnf_ops) 266 s2 = s1; 267 s1 = AS_SEGPREV(s1->s_as, seg); 268 } 269 if (s2 == NULL) { 270 s1 = AS_SEGNEXT(as, seg); 271 while (size-- > 0 && s1 != NULL) { 272 if (s1->s_ops == &segnf_ops) 273 s2 = s1; 274 s1 = AS_SEGNEXT(as, seg); 275 } 276 } 277 if (s2 != NULL) 278 seg_unmap(s2); 279 } 280 281 return (0); 282 } 283 284 /* 285 * Never really need "No fault" segments, so they aren't dup'd. 286 */ 287 /* ARGSUSED */ 288 static int 289 segnf_dup(struct seg *seg, struct seg *newseg) 290 { 291 panic("segnf_dup"); 292 return (0); 293 } 294 295 /* 296 * Split a segment at addr for length len. 297 */ 298 static int 299 segnf_unmap(struct seg *seg, caddr_t addr, size_t len) 300 { 301 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock)); 302 303 /* 304 * Check for bad sizes. 305 */ 306 if (addr < seg->s_base || addr + len > seg->s_base + seg->s_size || 307 (len & PAGEOFFSET) || ((uintptr_t)addr & PAGEOFFSET)) { 308 cmn_err(CE_PANIC, "segnf_unmap: bad unmap size"); 309 } 310 311 /* 312 * Unload any hardware translations in the range to be taken out. 313 */ 314 hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD_UNMAP); 315 316 if (addr == seg->s_base && len == seg->s_size) { 317 /* 318 * Freeing entire segment. 319 */ 320 seg_free(seg); 321 } else if (addr == seg->s_base) { 322 /* 323 * Freeing the beginning of the segment. 324 */ 325 seg->s_base += len; 326 seg->s_size -= len; 327 } else if (addr + len == seg->s_base + seg->s_size) { 328 /* 329 * Freeing the end of the segment. 330 */ 331 seg->s_size -= len; 332 } else { 333 /* 334 * The section to go is in the middle of the segment, so we 335 * have to cut it into two segments. We shrink the existing 336 * "seg" at the low end, and create "nseg" for the high end. 337 */ 338 caddr_t nbase = addr + len; 339 size_t nsize = (seg->s_base + seg->s_size) - nbase; 340 struct seg *nseg; 341 342 /* 343 * Trim down "seg" before trying to stick "nseg" into the as. 344 */ 345 seg->s_size = addr - seg->s_base; 346 nseg = seg_alloc(seg->s_as, nbase, nsize); 347 if (nseg == NULL) 348 cmn_err(CE_PANIC, "segnf_unmap: seg_alloc failed"); 349 350 /* 351 * s_data can't be NULL because of ASSERTs in common VM code. 352 */ 353 nseg->s_ops = seg->s_ops; 354 nseg->s_data = nseg; 355 nseg->s_flags |= S_PURGE; 356 mutex_enter(&seg->s_as->a_contents); 357 seg->s_as->a_flags |= AS_NEEDSPURGE; 358 mutex_exit(&seg->s_as->a_contents); 359 } 360 361 return (0); 362 } 363 364 /* 365 * Free a segment. 366 */ 367 static void 368 segnf_free(struct seg *seg) 369 { 370 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock)); 371 } 372 373 /* 374 * No faults allowed on segnf. 375 */ 376 static faultcode_t 377 segnf_nomap(void) 378 { 379 return (FC_NOMAP); 380 } 381 382 /* ARGSUSED */ 383 static int 384 segnf_setprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot) 385 { 386 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 387 return (EACCES); 388 } 389 390 /* ARGSUSED */ 391 static int 392 segnf_checkprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot) 393 { 394 uint_t sprot; 395 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 396 397 sprot = seg->s_as == &kas ? PROT_READ : PROT_READ|PROT_USER; 398 return ((prot & sprot) == prot ? 0 : EACCES); 399 } 400 401 static void 402 segnf_badop(void) 403 { 404 panic("segnf_badop"); 405 /*NOTREACHED*/ 406 } 407 408 static int 409 segnf_nop(void) 410 { 411 return (0); 412 } 413 414 static int 415 segnf_getprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv) 416 { 417 size_t pgno = seg_page(seg, addr + len) - seg_page(seg, addr) + 1; 418 size_t p; 419 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 420 421 for (p = 0; p < pgno; ++p) 422 protv[p] = PROT_READ; 423 return (0); 424 } 425 426 /* ARGSUSED */ 427 static u_offset_t 428 segnf_getoffset(struct seg *seg, caddr_t addr) 429 { 430 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 431 432 return ((u_offset_t)0); 433 } 434 435 /* ARGSUSED */ 436 static int 437 segnf_gettype(struct seg *seg, caddr_t addr) 438 { 439 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 440 441 return (MAP_SHARED); 442 } 443 444 /* ARGSUSED */ 445 static int 446 segnf_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp) 447 { 448 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 449 450 *vpp = &nfvp; 451 return (0); 452 } 453 454 /* 455 * segnf pages are not dumped, so we just return 456 */ 457 /* ARGSUSED */ 458 static void 459 segnf_dump(struct seg *seg) 460 {} 461 462 /*ARGSUSED*/ 463 static int 464 segnf_pagelock(struct seg *seg, caddr_t addr, size_t len, 465 struct page ***ppp, enum lock_type type, enum seg_rw rw) 466 { 467 return (ENOTSUP); 468 } 469 470 /*ARGSUSED*/ 471 static int 472 segnf_setpagesize(struct seg *seg, caddr_t addr, size_t len, 473 uint_t szc) 474 { 475 return (ENOTSUP); 476 } 477 478 /*ARGSUSED*/ 479 static int 480 segnf_getmemid(struct seg *seg, caddr_t addr, memid_t *memidp) 481 { 482 return (ENODEV); 483 }