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 80 81 struct seg_ops segnf_ops = { 82 .dup = segnf_dup, 83 .unmap = segnf_unmap, 84 .free = segnf_free, 85 .fault = (faultcode_t (*)(struct hat *, struct seg *, caddr_t, 86 size_t, enum fault_type, enum seg_rw))segnf_nomap, 87 .faulta = (faultcode_t (*)(struct seg *, caddr_t)) segnf_nomap, 88 .setprot = segnf_setprot, 89 .checkprot = segnf_checkprot, 90 .kluster = (int (*)())segnf_badop, 91 .sync = (int (*)(struct seg *, caddr_t, size_t, int, uint_t)) 92 segnf_nop, 93 .incore = (size_t (*)(struct seg *, caddr_t, size_t, char *)) 94 segnf_nop, 95 .lockop = (int (*)(struct seg *, caddr_t, size_t, int, int, 96 ulong_t *, size_t))segnf_nop, 97 .getprot = segnf_getprot, 98 .getoffset = segnf_getoffset, 99 .gettype = segnf_gettype, 100 .getvp = segnf_getvp, 101 .advise = (int (*)(struct seg *, caddr_t, size_t, uint_t)) 102 segnf_nop, 103 .dump = segnf_dump, 104 .pagelock = segnf_pagelock, 105 }; 106 107 /* 108 * vnode and page for the page of zeros we use for the nf mappings. 109 */ 110 static kmutex_t segnf_lock; 111 static struct vnode nfvp; 112 static struct page **nfpp; 113 114 #define addr_to_vcolor(addr) \ 115 (shm_alignment) ? \ 116 ((int)(((uintptr_t)(addr) & (shm_alignment - 1)) >> PAGESHIFT)) : 0 117 118 /* 119 * We try to limit the number of Non-fault segments created. 120 * Non fault segments are created to optimize sparc V9 code which uses 121 * the sparc nonfaulting load ASI (ASI_PRIMARY_NOFAULT). 122 * 123 * There are several reasons why creating too many non-fault segments 124 * could cause problems. 125 * 126 * First, excessive allocation of kernel resources for the seg 127 * structures and the HAT data to map the zero pages. 128 * 129 * Secondly, creating nofault segments actually uses up user virtual 130 * address space. This makes it unavailable for subsequent mmap(0, ...) 131 * calls which use as_gap() to find empty va regions. Creation of too 132 * many nofault segments could thus interfere with the ability of the 133 * runtime linker to load a shared object. 134 */ 135 #define MAXSEGFORNF (10000) 136 #define MAXNFSEARCH (5) 137 138 139 /* 140 * Must be called from startup() 141 */ 142 void 143 segnf_init() 144 { 145 mutex_init(&segnf_lock, NULL, MUTEX_DEFAULT, NULL); 146 } 147 148 149 /* 150 * Create a no-fault segment. 151 * 152 * The no-fault segment is not technically necessary, as the code in 153 * nfload() in trap.c will emulate the SPARC instruction and load 154 * a value of zero in the destination register. 155 * 156 * However, this code tries to put a page of zero's at the nofault address 157 * so that subsequent non-faulting loads to the same page will not 158 * trap with a tlb miss. 159 * 160 * In order to help limit the number of segments we merge adjacent nofault 161 * segments into a single segment. If we get a large number of segments 162 * we'll also try to delete a random other nf segment. 163 */ 164 /* ARGSUSED */ 165 int 166 segnf_create(struct seg *seg, void *argsp) 167 { 168 uint_t prot; 169 pgcnt_t vacpgs; 170 u_offset_t off = 0; 171 caddr_t vaddr = NULL; 172 int i, color; 173 struct seg *s1; 174 struct seg *s2; 175 size_t size; 176 struct as *as = seg->s_as; 177 178 ASSERT(as && AS_WRITE_HELD(as, &as->a_lock)); 179 180 /* 181 * Need a page per virtual color or just 1 if no vac. 182 */ 183 mutex_enter(&segnf_lock); 184 if (nfpp == NULL) { 185 struct seg kseg; 186 187 vacpgs = 1; 188 if (shm_alignment > PAGESIZE) { 189 vacpgs = shm_alignment >> PAGESHIFT; 190 } 191 192 nfpp = kmem_alloc(sizeof (*nfpp) * vacpgs, KM_SLEEP); 193 194 kseg.s_as = &kas; 195 for (i = 0; i < vacpgs; i++, off += PAGESIZE, 196 vaddr += PAGESIZE) { 197 nfpp[i] = page_create_va(&nfvp, off, PAGESIZE, 198 PG_WAIT | PG_NORELOC, &kseg, vaddr); 199 page_io_unlock(nfpp[i]); 200 page_downgrade(nfpp[i]); 201 pagezero(nfpp[i], 0, PAGESIZE); 202 } 203 } 204 mutex_exit(&segnf_lock); 205 206 hat_map(as->a_hat, seg->s_base, seg->s_size, HAT_MAP); 207 208 /* 209 * s_data can't be NULL because of ASSERTS in the common vm code. 210 */ 211 seg->s_ops = &segnf_ops; 212 seg->s_data = seg; 213 seg->s_flags |= S_PURGE; 214 215 mutex_enter(&as->a_contents); 216 as->a_flags |= AS_NEEDSPURGE; 217 mutex_exit(&as->a_contents); 218 219 prot = PROT_READ; 220 color = addr_to_vcolor(seg->s_base); 221 if (as != &kas) 222 prot |= PROT_USER; 223 hat_memload(as->a_hat, seg->s_base, nfpp[color], 224 prot | HAT_NOFAULT, HAT_LOAD); 225 226 /* 227 * At this point see if we can concatenate a segment to 228 * a non-fault segment immediately before and/or after it. 229 */ 230 if ((s1 = AS_SEGPREV(as, seg)) != NULL && 231 s1->s_ops == &segnf_ops && 232 s1->s_base + s1->s_size == seg->s_base) { 233 size = s1->s_size; 234 seg_free(s1); 235 seg->s_base -= size; 236 seg->s_size += size; 237 } 238 239 if ((s2 = AS_SEGNEXT(as, seg)) != NULL && 240 s2->s_ops == &segnf_ops && 241 seg->s_base + seg->s_size == s2->s_base) { 242 size = s2->s_size; 243 seg_free(s2); 244 seg->s_size += size; 245 } 246 247 /* 248 * if we already have a lot of segments, try to delete some other 249 * nofault segment to reduce the probability of uncontrolled segment 250 * creation. 251 * 252 * the code looks around quickly (no more than MAXNFSEARCH segments 253 * each way) for another NF segment and then deletes it. 254 */ 255 if (avl_numnodes(&as->a_segtree) > MAXSEGFORNF) { 256 size = 0; 257 s2 = NULL; 258 s1 = AS_SEGPREV(as, seg); 259 while (size++ < MAXNFSEARCH && s1 != NULL) { 260 if (s1->s_ops == &segnf_ops) 261 s2 = s1; 262 s1 = AS_SEGPREV(s1->s_as, seg); 263 } 264 if (s2 == NULL) { 265 s1 = AS_SEGNEXT(as, seg); 266 while (size-- > 0 && s1 != NULL) { 267 if (s1->s_ops == &segnf_ops) 268 s2 = s1; 269 s1 = AS_SEGNEXT(as, seg); 270 } 271 } 272 if (s2 != NULL) 273 seg_unmap(s2); 274 } 275 276 return (0); 277 } 278 279 /* 280 * Never really need "No fault" segments, so they aren't dup'd. 281 */ 282 /* ARGSUSED */ 283 static int 284 segnf_dup(struct seg *seg, struct seg *newseg) 285 { 286 panic("segnf_dup"); 287 return (0); 288 } 289 290 /* 291 * Split a segment at addr for length len. 292 */ 293 static int 294 segnf_unmap(struct seg *seg, caddr_t addr, size_t len) 295 { 296 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock)); 297 298 /* 299 * Check for bad sizes. 300 */ 301 if (addr < seg->s_base || addr + len > seg->s_base + seg->s_size || 302 (len & PAGEOFFSET) || ((uintptr_t)addr & PAGEOFFSET)) { 303 cmn_err(CE_PANIC, "segnf_unmap: bad unmap size"); 304 } 305 306 /* 307 * Unload any hardware translations in the range to be taken out. 308 */ 309 hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD_UNMAP); 310 311 if (addr == seg->s_base && len == seg->s_size) { 312 /* 313 * Freeing entire segment. 314 */ 315 seg_free(seg); 316 } else if (addr == seg->s_base) { 317 /* 318 * Freeing the beginning of the segment. 319 */ 320 seg->s_base += len; 321 seg->s_size -= len; 322 } else if (addr + len == seg->s_base + seg->s_size) { 323 /* 324 * Freeing the end of the segment. 325 */ 326 seg->s_size -= len; 327 } else { 328 /* 329 * The section to go is in the middle of the segment, so we 330 * have to cut it into two segments. We shrink the existing 331 * "seg" at the low end, and create "nseg" for the high end. 332 */ 333 caddr_t nbase = addr + len; 334 size_t nsize = (seg->s_base + seg->s_size) - nbase; 335 struct seg *nseg; 336 337 /* 338 * Trim down "seg" before trying to stick "nseg" into the as. 339 */ 340 seg->s_size = addr - seg->s_base; 341 nseg = seg_alloc(seg->s_as, nbase, nsize); 342 if (nseg == NULL) 343 cmn_err(CE_PANIC, "segnf_unmap: seg_alloc failed"); 344 345 /* 346 * s_data can't be NULL because of ASSERTs in common VM code. 347 */ 348 nseg->s_ops = seg->s_ops; 349 nseg->s_data = nseg; 350 nseg->s_flags |= S_PURGE; 351 mutex_enter(&seg->s_as->a_contents); 352 seg->s_as->a_flags |= AS_NEEDSPURGE; 353 mutex_exit(&seg->s_as->a_contents); 354 } 355 356 return (0); 357 } 358 359 /* 360 * Free a segment. 361 */ 362 static void 363 segnf_free(struct seg *seg) 364 { 365 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock)); 366 } 367 368 /* 369 * No faults allowed on segnf. 370 */ 371 static faultcode_t 372 segnf_nomap(void) 373 { 374 return (FC_NOMAP); 375 } 376 377 /* ARGSUSED */ 378 static int 379 segnf_setprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot) 380 { 381 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 382 return (EACCES); 383 } 384 385 /* ARGSUSED */ 386 static int 387 segnf_checkprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot) 388 { 389 uint_t sprot; 390 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 391 392 sprot = seg->s_as == &kas ? PROT_READ : PROT_READ|PROT_USER; 393 return ((prot & sprot) == prot ? 0 : EACCES); 394 } 395 396 static void 397 segnf_badop(void) 398 { 399 panic("segnf_badop"); 400 /*NOTREACHED*/ 401 } 402 403 static int 404 segnf_nop(void) 405 { 406 return (0); 407 } 408 409 static int 410 segnf_getprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv) 411 { 412 size_t pgno = seg_page(seg, addr + len) - seg_page(seg, addr) + 1; 413 size_t p; 414 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 415 416 for (p = 0; p < pgno; ++p) 417 protv[p] = PROT_READ; 418 return (0); 419 } 420 421 /* ARGSUSED */ 422 static u_offset_t 423 segnf_getoffset(struct seg *seg, caddr_t addr) 424 { 425 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 426 427 return ((u_offset_t)0); 428 } 429 430 /* ARGSUSED */ 431 static int 432 segnf_gettype(struct seg *seg, caddr_t addr) 433 { 434 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 435 436 return (MAP_SHARED); 437 } 438 439 /* ARGSUSED */ 440 static int 441 segnf_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp) 442 { 443 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 444 445 *vpp = &nfvp; 446 return (0); 447 } 448 449 /* 450 * segnf pages are not dumped, so we just return 451 */ 452 /* ARGSUSED */ 453 static void 454 segnf_dump(struct seg *seg) 455 {} 456 457 /*ARGSUSED*/ 458 static int 459 segnf_pagelock(struct seg *seg, caddr_t addr, size_t len, 460 struct page ***ppp, enum lock_type type, enum seg_rw rw) 461 { 462 return (ENOTSUP); 463 }