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 int segnf_pagelock(struct seg *seg, caddr_t addr, size_t len, 77 struct page ***ppp, enum lock_type type, enum seg_rw rw); 78 79 80 const struct seg_ops segnf_ops = { 81 .dup = segnf_dup, 82 .unmap = segnf_unmap, 83 .free = segnf_free, 84 .fault = (faultcode_t (*)(struct hat *, struct seg *, caddr_t, 85 size_t, enum fault_type, enum seg_rw))segnf_nomap, 86 .faulta = (faultcode_t (*)(struct seg *, caddr_t)) segnf_nomap, 87 .setprot = segnf_setprot, 88 .checkprot = segnf_checkprot, 89 .kluster = (int (*)())segnf_badop, 90 .sync = (int (*)(struct seg *, caddr_t, size_t, int, uint_t)) 91 segnf_nop, 92 .incore = (size_t (*)(struct seg *, caddr_t, size_t, char *)) 93 segnf_nop, 94 .lockop = (int (*)(struct seg *, caddr_t, size_t, int, int, 95 ulong_t *, size_t))segnf_nop, 96 .getprot = segnf_getprot, 97 .getoffset = segnf_getoffset, 98 .gettype = segnf_gettype, 99 .getvp = segnf_getvp, 100 .advise = (int (*)(struct seg *, caddr_t, size_t, uint_t)) 101 segnf_nop, 102 .pagelock = segnf_pagelock, 103 }; 104 105 /* 106 * vnode and page for the page of zeros we use for the nf mappings. 107 */ 108 static kmutex_t segnf_lock; 109 static struct vnode nfvp; 110 static struct page **nfpp; 111 112 #define addr_to_vcolor(addr) \ 113 (shm_alignment) ? \ 114 ((int)(((uintptr_t)(addr) & (shm_alignment - 1)) >> PAGESHIFT)) : 0 115 116 /* 117 * We try to limit the number of Non-fault segments created. 118 * Non fault segments are created to optimize sparc V9 code which uses 119 * the sparc nonfaulting load ASI (ASI_PRIMARY_NOFAULT). 120 * 121 * There are several reasons why creating too many non-fault segments 122 * could cause problems. 123 * 124 * First, excessive allocation of kernel resources for the seg 125 * structures and the HAT data to map the zero pages. 126 * 127 * Secondly, creating nofault segments actually uses up user virtual 128 * address space. This makes it unavailable for subsequent mmap(0, ...) 129 * calls which use as_gap() to find empty va regions. Creation of too 130 * many nofault segments could thus interfere with the ability of the 131 * runtime linker to load a shared object. 132 */ 133 #define MAXSEGFORNF (10000) 134 #define MAXNFSEARCH (5) 135 136 137 /* 138 * Must be called from startup() 139 */ 140 void 141 segnf_init() 142 { 143 mutex_init(&segnf_lock, NULL, MUTEX_DEFAULT, NULL); 144 } 145 146 147 /* 148 * Create a no-fault segment. 149 * 150 * The no-fault segment is not technically necessary, as the code in 151 * nfload() in trap.c will emulate the SPARC instruction and load 152 * a value of zero in the destination register. 153 * 154 * However, this code tries to put a page of zero's at the nofault address 155 * so that subsequent non-faulting loads to the same page will not 156 * trap with a tlb miss. 157 * 158 * In order to help limit the number of segments we merge adjacent nofault 159 * segments into a single segment. If we get a large number of segments 160 * we'll also try to delete a random other nf segment. 161 */ 162 /* ARGSUSED */ 163 int 164 segnf_create(struct seg *seg, void *argsp) 165 { 166 uint_t prot; 167 pgcnt_t vacpgs; 168 u_offset_t off = 0; 169 caddr_t vaddr = NULL; 170 int i, color; 171 struct seg *s1; 172 struct seg *s2; 173 size_t size; 174 struct as *as = seg->s_as; 175 176 ASSERT(as && AS_WRITE_HELD(as, &as->a_lock)); 177 178 /* 179 * Need a page per virtual color or just 1 if no vac. 180 */ 181 mutex_enter(&segnf_lock); 182 if (nfpp == NULL) { 183 struct seg kseg; 184 185 vacpgs = 1; 186 if (shm_alignment > PAGESIZE) { 187 vacpgs = shm_alignment >> PAGESHIFT; 188 } 189 190 nfpp = kmem_alloc(sizeof (*nfpp) * vacpgs, KM_SLEEP); 191 192 kseg.s_as = &kas; 193 for (i = 0; i < vacpgs; i++, off += PAGESIZE, 194 vaddr += PAGESIZE) { 195 nfpp[i] = page_create_va(&nfvp, off, PAGESIZE, 196 PG_WAIT | PG_NORELOC, &kseg, vaddr); 197 page_io_unlock(nfpp[i]); 198 page_downgrade(nfpp[i]); 199 pagezero(nfpp[i], 0, PAGESIZE); 200 } 201 } 202 mutex_exit(&segnf_lock); 203 204 hat_map(as->a_hat, seg->s_base, seg->s_size, HAT_MAP); 205 206 /* 207 * s_data can't be NULL because of ASSERTS in the common vm code. 208 */ 209 seg->s_ops = &segnf_ops; 210 seg->s_data = seg; 211 seg->s_flags |= S_PURGE; 212 213 mutex_enter(&as->a_contents); 214 as->a_flags |= AS_NEEDSPURGE; 215 mutex_exit(&as->a_contents); 216 217 prot = PROT_READ; 218 color = addr_to_vcolor(seg->s_base); 219 if (as != &kas) 220 prot |= PROT_USER; 221 hat_memload(as->a_hat, seg->s_base, nfpp[color], 222 prot | HAT_NOFAULT, HAT_LOAD); 223 224 /* 225 * At this point see if we can concatenate a segment to 226 * a non-fault segment immediately before and/or after it. 227 */ 228 if ((s1 = AS_SEGPREV(as, seg)) != NULL && 229 s1->s_ops == &segnf_ops && 230 s1->s_base + s1->s_size == seg->s_base) { 231 size = s1->s_size; 232 seg_free(s1); 233 seg->s_base -= size; 234 seg->s_size += size; 235 } 236 237 if ((s2 = AS_SEGNEXT(as, seg)) != NULL && 238 s2->s_ops == &segnf_ops && 239 seg->s_base + seg->s_size == s2->s_base) { 240 size = s2->s_size; 241 seg_free(s2); 242 seg->s_size += size; 243 } 244 245 /* 246 * if we already have a lot of segments, try to delete some other 247 * nofault segment to reduce the probability of uncontrolled segment 248 * creation. 249 * 250 * the code looks around quickly (no more than MAXNFSEARCH segments 251 * each way) for another NF segment and then deletes it. 252 */ 253 if (avl_numnodes(&as->a_segtree) > MAXSEGFORNF) { 254 size = 0; 255 s2 = NULL; 256 s1 = AS_SEGPREV(as, seg); 257 while (size++ < MAXNFSEARCH && s1 != NULL) { 258 if (s1->s_ops == &segnf_ops) 259 s2 = s1; 260 s1 = AS_SEGPREV(s1->s_as, seg); 261 } 262 if (s2 == NULL) { 263 s1 = AS_SEGNEXT(as, seg); 264 while (size-- > 0 && s1 != NULL) { 265 if (s1->s_ops == &segnf_ops) 266 s2 = s1; 267 s1 = AS_SEGNEXT(as, seg); 268 } 269 } 270 if (s2 != NULL) 271 seg_unmap(s2); 272 } 273 274 return (0); 275 } 276 277 /* 278 * Never really need "No fault" segments, so they aren't dup'd. 279 */ 280 /* ARGSUSED */ 281 static int 282 segnf_dup(struct seg *seg, struct seg *newseg) 283 { 284 panic("segnf_dup"); 285 return (0); 286 } 287 288 /* 289 * Split a segment at addr for length len. 290 */ 291 static int 292 segnf_unmap(struct seg *seg, caddr_t addr, size_t len) 293 { 294 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock)); 295 296 /* 297 * Check for bad sizes. 298 */ 299 if (addr < seg->s_base || addr + len > seg->s_base + seg->s_size || 300 (len & PAGEOFFSET) || ((uintptr_t)addr & PAGEOFFSET)) { 301 cmn_err(CE_PANIC, "segnf_unmap: bad unmap size"); 302 } 303 304 /* 305 * Unload any hardware translations in the range to be taken out. 306 */ 307 hat_unload(seg->s_as->a_hat, addr, len, HAT_UNLOAD_UNMAP); 308 309 if (addr == seg->s_base && len == seg->s_size) { 310 /* 311 * Freeing entire segment. 312 */ 313 seg_free(seg); 314 } else if (addr == seg->s_base) { 315 /* 316 * Freeing the beginning of the segment. 317 */ 318 seg->s_base += len; 319 seg->s_size -= len; 320 } else if (addr + len == seg->s_base + seg->s_size) { 321 /* 322 * Freeing the end of the segment. 323 */ 324 seg->s_size -= len; 325 } else { 326 /* 327 * The section to go is in the middle of the segment, so we 328 * have to cut it into two segments. We shrink the existing 329 * "seg" at the low end, and create "nseg" for the high end. 330 */ 331 caddr_t nbase = addr + len; 332 size_t nsize = (seg->s_base + seg->s_size) - nbase; 333 struct seg *nseg; 334 335 /* 336 * Trim down "seg" before trying to stick "nseg" into the as. 337 */ 338 seg->s_size = addr - seg->s_base; 339 nseg = seg_alloc(seg->s_as, nbase, nsize); 340 if (nseg == NULL) 341 cmn_err(CE_PANIC, "segnf_unmap: seg_alloc failed"); 342 343 /* 344 * s_data can't be NULL because of ASSERTs in common VM code. 345 */ 346 nseg->s_ops = seg->s_ops; 347 nseg->s_data = nseg; 348 nseg->s_flags |= S_PURGE; 349 mutex_enter(&seg->s_as->a_contents); 350 seg->s_as->a_flags |= AS_NEEDSPURGE; 351 mutex_exit(&seg->s_as->a_contents); 352 } 353 354 return (0); 355 } 356 357 /* 358 * Free a segment. 359 */ 360 static void 361 segnf_free(struct seg *seg) 362 { 363 ASSERT(seg->s_as && AS_WRITE_HELD(seg->s_as, &seg->s_as->a_lock)); 364 } 365 366 /* 367 * No faults allowed on segnf. 368 */ 369 static faultcode_t 370 segnf_nomap(void) 371 { 372 return (FC_NOMAP); 373 } 374 375 /* ARGSUSED */ 376 static int 377 segnf_setprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot) 378 { 379 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 380 return (EACCES); 381 } 382 383 /* ARGSUSED */ 384 static int 385 segnf_checkprot(struct seg *seg, caddr_t addr, size_t len, uint_t prot) 386 { 387 uint_t sprot; 388 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 389 390 sprot = seg->s_as == &kas ? PROT_READ : PROT_READ|PROT_USER; 391 return ((prot & sprot) == prot ? 0 : EACCES); 392 } 393 394 static void 395 segnf_badop(void) 396 { 397 panic("segnf_badop"); 398 /*NOTREACHED*/ 399 } 400 401 static int 402 segnf_nop(void) 403 { 404 return (0); 405 } 406 407 static int 408 segnf_getprot(struct seg *seg, caddr_t addr, size_t len, uint_t *protv) 409 { 410 size_t pgno = seg_page(seg, addr + len) - seg_page(seg, addr) + 1; 411 size_t p; 412 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 413 414 for (p = 0; p < pgno; ++p) 415 protv[p] = PROT_READ; 416 return (0); 417 } 418 419 /* ARGSUSED */ 420 static u_offset_t 421 segnf_getoffset(struct seg *seg, caddr_t addr) 422 { 423 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 424 425 return ((u_offset_t)0); 426 } 427 428 /* ARGSUSED */ 429 static int 430 segnf_gettype(struct seg *seg, caddr_t addr) 431 { 432 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 433 434 return (MAP_SHARED); 435 } 436 437 /* ARGSUSED */ 438 static int 439 segnf_getvp(struct seg *seg, caddr_t addr, struct vnode **vpp) 440 { 441 ASSERT(seg->s_as && AS_LOCK_HELD(seg->s_as, &seg->s_as->a_lock)); 442 443 *vpp = &nfvp; 444 return (0); 445 } 446 447 /*ARGSUSED*/ 448 static int 449 segnf_pagelock(struct seg *seg, caddr_t addr, size_t len, 450 struct page ***ppp, enum lock_type type, enum seg_rw rw) 451 { 452 return (ENOTSUP); 453 }