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FreeBSD/Linux Kernel Cross Reference
sys/kern/subr_rman.c
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1 /*- 2 * Copyright 1998 Massachusetts Institute of Technology 3 * 4 * Permission to use, copy, modify, and distribute this software and 5 * its documentation for any purpose and without fee is hereby 6 * granted, provided that both the above copyright notice and this 7 * permission notice appear in all copies, that both the above 8 * copyright notice and this permission notice appear in all 9 * supporting documentation, and that the name of M.I.T. not be used 10 * in advertising or publicity pertaining to distribution of the 11 * software without specific, written prior permission. M.I.T. makes 12 * no representations about the suitability of this software for any 13 * purpose. It is provided "as is" without express or implied 14 * warranty. 15 * 16 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS 17 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE, 18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT 20 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 23 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 /* 31 * The kernel resource manager. This code is responsible for keeping track 32 * of hardware resources which are apportioned out to various drivers. 33 * It does not actually assign those resources, and it is not expected 34 * that end-device drivers will call into this code directly. Rather, 35 * the code which implements the buses that those devices are attached to, 36 * and the code which manages CPU resources, will call this code, and the 37 * end-device drivers will make upcalls to that code to actually perform 38 * the allocation. 39 * 40 * There are two sorts of resources managed by this code. The first is 41 * the more familiar array (RMAN_ARRAY) type; resources in this class 42 * consist of a sequence of individually-allocatable objects which have 43 * been numbered in some well-defined order. Most of the resources 44 * are of this type, as it is the most familiar. The second type is 45 * called a gauge (RMAN_GAUGE), and models fungible resources (i.e., 46 * resources in which each instance is indistinguishable from every 47 * other instance). The principal anticipated application of gauges 48 * is in the context of power consumption, where a bus may have a specific 49 * power budget which all attached devices share. RMAN_GAUGE is not 50 * implemented yet. 51 * 52 * For array resources, we make one simplifying assumption: two clients 53 * sharing the same resource must use the same range of indices. That 54 * is to say, sharing of overlapping-but-not-identical regions is not 55 * permitted. 56 */ 57 58 #include "opt_ddb.h" 59 60 #include <sys/cdefs.h> 61 __FBSDID("$FreeBSD: releng/10.0/sys/kern/subr_rman.c 236359 2012-05-31 17:27:05Z imp $"); 62 63 #include <sys/param.h> 64 #include <sys/systm.h> 65 #include <sys/kernel.h> 66 #include <sys/limits.h> 67 #include <sys/lock.h> 68 #include <sys/malloc.h> 69 #include <sys/mutex.h> 70 #include <sys/bus.h> /* XXX debugging */ 71 #include <machine/bus.h> 72 #include <sys/rman.h> 73 #include <sys/sysctl.h> 74 75 #ifdef DDB 76 #include <ddb/ddb.h> 77 #endif 78 79 /* 80 * We use a linked list rather than a bitmap because we need to be able to 81 * represent potentially huge objects (like all of a processor's physical 82 * address space). That is also why the indices are defined to have type 83 * `unsigned long' -- that being the largest integral type in ISO C (1990). 84 * The 1999 version of C allows `long long'; we may need to switch to that 85 * at some point in the future, particularly if we want to support 36-bit 86 * addresses on IA32 hardware. 87 */ 88 struct resource_i { 89 struct resource r_r; 90 TAILQ_ENTRY(resource_i) r_link; 91 LIST_ENTRY(resource_i) r_sharelink; 92 LIST_HEAD(, resource_i) *r_sharehead; 93 u_long r_start; /* index of the first entry in this resource */ 94 u_long r_end; /* index of the last entry (inclusive) */ 95 u_int r_flags; 96 void *r_virtual; /* virtual address of this resource */ 97 struct device *r_dev; /* device which has allocated this resource */ 98 struct rman *r_rm; /* resource manager from whence this came */ 99 int r_rid; /* optional rid for this resource. */ 100 }; 101 102 static int rman_debug = 0; 103 TUNABLE_INT("debug.rman_debug", &rman_debug); 104 SYSCTL_INT(_debug, OID_AUTO, rman_debug, CTLFLAG_RW, 105 &rman_debug, 0, "rman debug"); 106 107 #define DPRINTF(params) if (rman_debug) printf params 108 109 static MALLOC_DEFINE(M_RMAN, "rman", "Resource manager"); 110 111 struct rman_head rman_head; 112 static struct mtx rman_mtx; /* mutex to protect rman_head */ 113 static int int_rman_activate_resource(struct rman *rm, struct resource_i *r, 114 struct resource_i **whohas); 115 static int int_rman_deactivate_resource(struct resource_i *r); 116 static int int_rman_release_resource(struct rman *rm, struct resource_i *r); 117 118 static __inline struct resource_i * 119 int_alloc_resource(int malloc_flag) 120 { 121 struct resource_i *r; 122 123 r = malloc(sizeof *r, M_RMAN, malloc_flag | M_ZERO); 124 if (r != NULL) { 125 r->r_r.__r_i = r; 126 } 127 return (r); 128 } 129 130 int 131 rman_init(struct rman *rm) 132 { 133 static int once = 0; 134 135 if (once == 0) { 136 once = 1; 137 TAILQ_INIT(&rman_head); 138 mtx_init(&rman_mtx, "rman head", NULL, MTX_DEF); 139 } 140 141 if (rm->rm_start == 0 && rm->rm_end == 0) 142 rm->rm_end = ~0ul; 143 if (rm->rm_type == RMAN_UNINIT) 144 panic("rman_init"); 145 if (rm->rm_type == RMAN_GAUGE) 146 panic("implement RMAN_GAUGE"); 147 148 TAILQ_INIT(&rm->rm_list); 149 rm->rm_mtx = malloc(sizeof *rm->rm_mtx, M_RMAN, M_NOWAIT | M_ZERO); 150 if (rm->rm_mtx == NULL) 151 return ENOMEM; 152 mtx_init(rm->rm_mtx, "rman", NULL, MTX_DEF); 153 154 mtx_lock(&rman_mtx); 155 TAILQ_INSERT_TAIL(&rman_head, rm, rm_link); 156 mtx_unlock(&rman_mtx); 157 return 0; 158 } 159 160 int 161 rman_manage_region(struct rman *rm, u_long start, u_long end) 162 { 163 struct resource_i *r, *s, *t; 164 int rv = 0; 165 166 DPRINTF(("rman_manage_region: <%s> request: start %#lx, end %#lx\n", 167 rm->rm_descr, start, end)); 168 if (start < rm->rm_start || end > rm->rm_end) 169 return EINVAL; 170 r = int_alloc_resource(M_NOWAIT); 171 if (r == NULL) 172 return ENOMEM; 173 r->r_start = start; 174 r->r_end = end; 175 r->r_rm = rm; 176 177 mtx_lock(rm->rm_mtx); 178 179 /* Skip entries before us. */ 180 TAILQ_FOREACH(s, &rm->rm_list, r_link) { 181 if (s->r_end == ULONG_MAX) 182 break; 183 if (s->r_end + 1 >= r->r_start) 184 break; 185 } 186 187 /* If we ran off the end of the list, insert at the tail. */ 188 if (s == NULL) { 189 TAILQ_INSERT_TAIL(&rm->rm_list, r, r_link); 190 } else { 191 /* Check for any overlap with the current region. */ 192 if (r->r_start <= s->r_end && r->r_end >= s->r_start) { 193 rv = EBUSY; 194 goto out; 195 } 196 197 /* Check for any overlap with the next region. */ 198 t = TAILQ_NEXT(s, r_link); 199 if (t && r->r_start <= t->r_end && r->r_end >= t->r_start) { 200 rv = EBUSY; 201 goto out; 202 } 203 204 /* 205 * See if this region can be merged with the next region. If 206 * not, clear the pointer. 207 */ 208 if (t && (r->r_end + 1 != t->r_start || t->r_flags != 0)) 209 t = NULL; 210 211 /* See if we can merge with the current region. */ 212 if (s->r_end + 1 == r->r_start && s->r_flags == 0) { 213 /* Can we merge all 3 regions? */ 214 if (t != NULL) { 215 s->r_end = t->r_end; 216 TAILQ_REMOVE(&rm->rm_list, t, r_link); 217 free(r, M_RMAN); 218 free(t, M_RMAN); 219 } else { 220 s->r_end = r->r_end; 221 free(r, M_RMAN); 222 } 223 } else if (t != NULL) { 224 /* Can we merge with just the next region? */ 225 t->r_start = r->r_start; 226 free(r, M_RMAN); 227 } else if (s->r_end < r->r_start) { 228 TAILQ_INSERT_AFTER(&rm->rm_list, s, r, r_link); 229 } else { 230 TAILQ_INSERT_BEFORE(s, r, r_link); 231 } 232 } 233 out: 234 mtx_unlock(rm->rm_mtx); 235 return rv; 236 } 237 238 int 239 rman_init_from_resource(struct rman *rm, struct resource *r) 240 { 241 int rv; 242 243 if ((rv = rman_init(rm)) != 0) 244 return (rv); 245 return (rman_manage_region(rm, r->__r_i->r_start, r->__r_i->r_end)); 246 } 247 248 int 249 rman_fini(struct rman *rm) 250 { 251 struct resource_i *r; 252 253 mtx_lock(rm->rm_mtx); 254 TAILQ_FOREACH(r, &rm->rm_list, r_link) { 255 if (r->r_flags & RF_ALLOCATED) { 256 mtx_unlock(rm->rm_mtx); 257 return EBUSY; 258 } 259 } 260 261 /* 262 * There really should only be one of these if we are in this 263 * state and the code is working properly, but it can't hurt. 264 */ 265 while (!TAILQ_EMPTY(&rm->rm_list)) { 266 r = TAILQ_FIRST(&rm->rm_list); 267 TAILQ_REMOVE(&rm->rm_list, r, r_link); 268 free(r, M_RMAN); 269 } 270 mtx_unlock(rm->rm_mtx); 271 mtx_lock(&rman_mtx); 272 TAILQ_REMOVE(&rman_head, rm, rm_link); 273 mtx_unlock(&rman_mtx); 274 mtx_destroy(rm->rm_mtx); 275 free(rm->rm_mtx, M_RMAN); 276 277 return 0; 278 } 279 280 int 281 rman_first_free_region(struct rman *rm, u_long *start, u_long *end) 282 { 283 struct resource_i *r; 284 285 mtx_lock(rm->rm_mtx); 286 TAILQ_FOREACH(r, &rm->rm_list, r_link) { 287 if (!(r->r_flags & RF_ALLOCATED)) { 288 *start = r->r_start; 289 *end = r->r_end; 290 mtx_unlock(rm->rm_mtx); 291 return (0); 292 } 293 } 294 mtx_unlock(rm->rm_mtx); 295 return (ENOENT); 296 } 297 298 int 299 rman_last_free_region(struct rman *rm, u_long *start, u_long *end) 300 { 301 struct resource_i *r; 302 303 mtx_lock(rm->rm_mtx); 304 TAILQ_FOREACH_REVERSE(r, &rm->rm_list, resource_head, r_link) { 305 if (!(r->r_flags & RF_ALLOCATED)) { 306 *start = r->r_start; 307 *end = r->r_end; 308 mtx_unlock(rm->rm_mtx); 309 return (0); 310 } 311 } 312 mtx_unlock(rm->rm_mtx); 313 return (ENOENT); 314 } 315 316 /* Shrink or extend one or both ends of an allocated resource. */ 317 int 318 rman_adjust_resource(struct resource *rr, u_long start, u_long end) 319 { 320 struct resource_i *r, *s, *t, *new; 321 struct rman *rm; 322 323 /* Not supported for shared resources. */ 324 r = rr->__r_i; 325 if (r->r_flags & (RF_TIMESHARE | RF_SHAREABLE)) 326 return (EINVAL); 327 328 /* 329 * This does not support wholesale moving of a resource. At 330 * least part of the desired new range must overlap with the 331 * existing resource. 332 */ 333 if (end < r->r_start || r->r_end < start) 334 return (EINVAL); 335 336 /* 337 * Find the two resource regions immediately adjacent to the 338 * allocated resource. 339 */ 340 rm = r->r_rm; 341 mtx_lock(rm->rm_mtx); 342 #ifdef INVARIANTS 343 TAILQ_FOREACH(s, &rm->rm_list, r_link) { 344 if (s == r) 345 break; 346 } 347 if (s == NULL) 348 panic("resource not in list"); 349 #endif 350 s = TAILQ_PREV(r, resource_head, r_link); 351 t = TAILQ_NEXT(r, r_link); 352 KASSERT(s == NULL || s->r_end + 1 == r->r_start, 353 ("prev resource mismatch")); 354 KASSERT(t == NULL || r->r_end + 1 == t->r_start, 355 ("next resource mismatch")); 356 357 /* 358 * See if the changes are permitted. Shrinking is always allowed, 359 * but growing requires sufficient room in the adjacent region. 360 */ 361 if (start < r->r_start && (s == NULL || (s->r_flags & RF_ALLOCATED) || 362 s->r_start > start)) { 363 mtx_unlock(rm->rm_mtx); 364 return (EBUSY); 365 } 366 if (end > r->r_end && (t == NULL || (t->r_flags & RF_ALLOCATED) || 367 t->r_end < end)) { 368 mtx_unlock(rm->rm_mtx); 369 return (EBUSY); 370 } 371 372 /* 373 * While holding the lock, grow either end of the resource as 374 * needed and shrink either end if the shrinking does not require 375 * allocating a new resource. We can safely drop the lock and then 376 * insert a new range to handle the shrinking case afterwards. 377 */ 378 if (start < r->r_start || 379 (start > r->r_start && s != NULL && !(s->r_flags & RF_ALLOCATED))) { 380 KASSERT(s->r_flags == 0, ("prev is busy")); 381 r->r_start = start; 382 if (s->r_start == start) { 383 TAILQ_REMOVE(&rm->rm_list, s, r_link); 384 free(s, M_RMAN); 385 } else 386 s->r_end = start - 1; 387 } 388 if (end > r->r_end || 389 (end < r->r_end && t != NULL && !(t->r_flags & RF_ALLOCATED))) { 390 KASSERT(t->r_flags == 0, ("next is busy")); 391 r->r_end = end; 392 if (t->r_end == end) { 393 TAILQ_REMOVE(&rm->rm_list, t, r_link); 394 free(t, M_RMAN); 395 } else 396 t->r_start = end + 1; 397 } 398 mtx_unlock(rm->rm_mtx); 399 400 /* 401 * Handle the shrinking cases that require allocating a new 402 * resource to hold the newly-free region. We have to recheck 403 * if we still need this new region after acquiring the lock. 404 */ 405 if (start > r->r_start) { 406 new = int_alloc_resource(M_WAITOK); 407 new->r_start = r->r_start; 408 new->r_end = start - 1; 409 new->r_rm = rm; 410 mtx_lock(rm->rm_mtx); 411 r->r_start = start; 412 s = TAILQ_PREV(r, resource_head, r_link); 413 if (s != NULL && !(s->r_flags & RF_ALLOCATED)) { 414 s->r_end = start - 1; 415 free(new, M_RMAN); 416 } else 417 TAILQ_INSERT_BEFORE(r, new, r_link); 418 mtx_unlock(rm->rm_mtx); 419 } 420 if (end < r->r_end) { 421 new = int_alloc_resource(M_WAITOK); 422 new->r_start = end + 1; 423 new->r_end = r->r_end; 424 new->r_rm = rm; 425 mtx_lock(rm->rm_mtx); 426 r->r_end = end; 427 t = TAILQ_NEXT(r, r_link); 428 if (t != NULL && !(t->r_flags & RF_ALLOCATED)) { 429 t->r_start = end + 1; 430 free(new, M_RMAN); 431 } else 432 TAILQ_INSERT_AFTER(&rm->rm_list, r, new, r_link); 433 mtx_unlock(rm->rm_mtx); 434 } 435 return (0); 436 } 437 438 struct resource * 439 rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end, 440 u_long count, u_long bound, u_int flags, 441 struct device *dev) 442 { 443 u_int want_activate; 444 struct resource_i *r, *s, *rv; 445 u_long rstart, rend, amask, bmask; 446 447 rv = NULL; 448 449 DPRINTF(("rman_reserve_resource_bound: <%s> request: [%#lx, %#lx], " 450 "length %#lx, flags %u, device %s\n", rm->rm_descr, start, end, 451 count, flags, 452 dev == NULL ? "<null>" : device_get_nameunit(dev))); 453 want_activate = (flags & RF_ACTIVE); 454 flags &= ~RF_ACTIVE; 455 456 mtx_lock(rm->rm_mtx); 457 458 for (r = TAILQ_FIRST(&rm->rm_list); 459 r && r->r_end < start; 460 r = TAILQ_NEXT(r, r_link)) 461 ; 462 463 if (r == NULL) { 464 DPRINTF(("could not find a region\n")); 465 goto out; 466 } 467 468 amask = (1ul << RF_ALIGNMENT(flags)) - 1; 469 /* If bound is 0, bmask will also be 0 */ 470 bmask = ~(bound - 1); 471 /* 472 * First try to find an acceptable totally-unshared region. 473 */ 474 for (s = r; s; s = TAILQ_NEXT(s, r_link)) { 475 DPRINTF(("considering [%#lx, %#lx]\n", s->r_start, s->r_end)); 476 if (s->r_start + count - 1 > end) { 477 DPRINTF(("s->r_start (%#lx) + count - 1> end (%#lx)\n", 478 s->r_start, end)); 479 break; 480 } 481 if (s->r_flags & RF_ALLOCATED) { 482 DPRINTF(("region is allocated\n")); 483 continue; 484 } 485 rstart = ulmax(s->r_start, start); 486 /* 487 * Try to find a region by adjusting to boundary and alignment 488 * until both conditions are satisfied. This is not an optimal 489 * algorithm, but in most cases it isn't really bad, either. 490 */ 491 do { 492 rstart = (rstart + amask) & ~amask; 493 if (((rstart ^ (rstart + count - 1)) & bmask) != 0) 494 rstart += bound - (rstart & ~bmask); 495 } while ((rstart & amask) != 0 && rstart < end && 496 rstart < s->r_end); 497 rend = ulmin(s->r_end, ulmax(rstart + count - 1, end)); 498 if (rstart > rend) { 499 DPRINTF(("adjusted start exceeds end\n")); 500 continue; 501 } 502 DPRINTF(("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n", 503 rstart, rend, (rend - rstart + 1), count)); 504 505 if ((rend - rstart + 1) >= count) { 506 DPRINTF(("candidate region: [%#lx, %#lx], size %#lx\n", 507 rstart, rend, (rend - rstart + 1))); 508 if ((s->r_end - s->r_start + 1) == count) { 509 DPRINTF(("candidate region is entire chunk\n")); 510 rv = s; 511 rv->r_flags |= RF_ALLOCATED | flags; 512 rv->r_dev = dev; 513 goto out; 514 } 515 516 /* 517 * If s->r_start < rstart and 518 * s->r_end > rstart + count - 1, then 519 * we need to split the region into three pieces 520 * (the middle one will get returned to the user). 521 * Otherwise, we are allocating at either the 522 * beginning or the end of s, so we only need to 523 * split it in two. The first case requires 524 * two new allocations; the second requires but one. 525 */ 526 rv = int_alloc_resource(M_NOWAIT); 527 if (rv == NULL) 528 goto out; 529 rv->r_start = rstart; 530 rv->r_end = rstart + count - 1; 531 rv->r_flags = flags | RF_ALLOCATED; 532 rv->r_dev = dev; 533 rv->r_rm = rm; 534 535 if (s->r_start < rv->r_start && s->r_end > rv->r_end) { 536 DPRINTF(("splitting region in three parts: " 537 "[%#lx, %#lx]; [%#lx, %#lx]; [%#lx, %#lx]\n", 538 s->r_start, rv->r_start - 1, 539 rv->r_start, rv->r_end, 540 rv->r_end + 1, s->r_end)); 541 /* 542 * We are allocating in the middle. 543 */ 544 r = int_alloc_resource(M_NOWAIT); 545 if (r == NULL) { 546 free(rv, M_RMAN); 547 rv = NULL; 548 goto out; 549 } 550 r->r_start = rv->r_end + 1; 551 r->r_end = s->r_end; 552 r->r_flags = s->r_flags; 553 r->r_rm = rm; 554 s->r_end = rv->r_start - 1; 555 TAILQ_INSERT_AFTER(&rm->rm_list, s, rv, 556 r_link); 557 TAILQ_INSERT_AFTER(&rm->rm_list, rv, r, 558 r_link); 559 } else if (s->r_start == rv->r_start) { 560 DPRINTF(("allocating from the beginning\n")); 561 /* 562 * We are allocating at the beginning. 563 */ 564 s->r_start = rv->r_end + 1; 565 TAILQ_INSERT_BEFORE(s, rv, r_link); 566 } else { 567 DPRINTF(("allocating at the end\n")); 568 /* 569 * We are allocating at the end. 570 */ 571 s->r_end = rv->r_start - 1; 572 TAILQ_INSERT_AFTER(&rm->rm_list, s, rv, 573 r_link); 574 } 575 goto out; 576 } 577 } 578 579 /* 580 * Now find an acceptable shared region, if the client's requirements 581 * allow sharing. By our implementation restriction, a candidate 582 * region must match exactly by both size and sharing type in order 583 * to be considered compatible with the client's request. (The 584 * former restriction could probably be lifted without too much 585 * additional work, but this does not seem warranted.) 586 */ 587 DPRINTF(("no unshared regions found\n")); 588 if ((flags & (RF_SHAREABLE | RF_TIMESHARE)) == 0) 589 goto out; 590 591 for (s = r; s; s = TAILQ_NEXT(s, r_link)) { 592 if (s->r_start > end) 593 break; 594 if ((s->r_flags & flags) != flags) 595 continue; 596 rstart = ulmax(s->r_start, start); 597 rend = ulmin(s->r_end, ulmax(start + count - 1, end)); 598 if (s->r_start >= start && s->r_end <= end 599 && (s->r_end - s->r_start + 1) == count && 600 (s->r_start & amask) == 0 && 601 ((s->r_start ^ s->r_end) & bmask) == 0) { 602 rv = int_alloc_resource(M_NOWAIT); 603 if (rv == NULL) 604 goto out; 605 rv->r_start = s->r_start; 606 rv->r_end = s->r_end; 607 rv->r_flags = s->r_flags & 608 (RF_ALLOCATED | RF_SHAREABLE | RF_TIMESHARE); 609 rv->r_dev = dev; 610 rv->r_rm = rm; 611 if (s->r_sharehead == NULL) { 612 s->r_sharehead = malloc(sizeof *s->r_sharehead, 613 M_RMAN, M_NOWAIT | M_ZERO); 614 if (s->r_sharehead == NULL) { 615 free(rv, M_RMAN); 616 rv = NULL; 617 goto out; 618 } 619 LIST_INIT(s->r_sharehead); 620 LIST_INSERT_HEAD(s->r_sharehead, s, 621 r_sharelink); 622 s->r_flags |= RF_FIRSTSHARE; 623 } 624 rv->r_sharehead = s->r_sharehead; 625 LIST_INSERT_HEAD(s->r_sharehead, rv, r_sharelink); 626 goto out; 627 } 628 } 629 630 /* 631 * We couldn't find anything. 632 */ 633 out: 634 /* 635 * If the user specified RF_ACTIVE in the initial flags, 636 * which is reflected in `want_activate', we attempt to atomically 637 * activate the resource. If this fails, we release the resource 638 * and indicate overall failure. (This behavior probably doesn't 639 * make sense for RF_TIMESHARE-type resources.) 640 */ 641 if (rv && want_activate) { 642 struct resource_i *whohas; 643 if (int_rman_activate_resource(rm, rv, &whohas)) { 644 int_rman_release_resource(rm, rv); 645 rv = NULL; 646 } 647 } 648 649 mtx_unlock(rm->rm_mtx); 650 return (rv == NULL ? NULL : &rv->r_r); 651 } 652 653 struct resource * 654 rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count, 655 u_int flags, struct device *dev) 656 { 657 658 return (rman_reserve_resource_bound(rm, start, end, count, 0, flags, 659 dev)); 660 } 661 662 static int 663 int_rman_activate_resource(struct rman *rm, struct resource_i *r, 664 struct resource_i **whohas) 665 { 666 struct resource_i *s; 667 int ok; 668 669 /* 670 * If we are not timesharing, then there is nothing much to do. 671 * If we already have the resource, then there is nothing at all to do. 672 * If we are not on a sharing list with anybody else, then there is 673 * little to do. 674 */ 675 if ((r->r_flags & RF_TIMESHARE) == 0 676 || (r->r_flags & RF_ACTIVE) != 0 677 || r->r_sharehead == NULL) { 678 r->r_flags |= RF_ACTIVE; 679 return 0; 680 } 681 682 ok = 1; 683 for (s = LIST_FIRST(r->r_sharehead); s && ok; 684 s = LIST_NEXT(s, r_sharelink)) { 685 if ((s->r_flags & RF_ACTIVE) != 0) { 686 ok = 0; 687 *whohas = s; 688 } 689 } 690 if (ok) { 691 r->r_flags |= RF_ACTIVE; 692 return 0; 693 } 694 return EBUSY; 695 } 696 697 int 698 rman_activate_resource(struct resource *re) 699 { 700 int rv; 701 struct resource_i *r, *whohas; 702 struct rman *rm; 703 704 r = re->__r_i; 705 rm = r->r_rm; 706 mtx_lock(rm->rm_mtx); 707 rv = int_rman_activate_resource(rm, r, &whohas); 708 mtx_unlock(rm->rm_mtx); 709 return rv; 710 } 711 712 int 713 rman_await_resource(struct resource *re, int pri, int timo) 714 { 715 int rv; 716 struct resource_i *r, *whohas; 717 struct rman *rm; 718 719 r = re->__r_i; 720 rm = r->r_rm; 721 mtx_lock(rm->rm_mtx); 722 for (;;) { 723 rv = int_rman_activate_resource(rm, r, &whohas); 724 if (rv != EBUSY) 725 return (rv); /* returns with mutex held */ 726 727 if (r->r_sharehead == NULL) 728 panic("rman_await_resource"); 729 whohas->r_flags |= RF_WANTED; 730 rv = msleep(r->r_sharehead, rm->rm_mtx, pri, "rmwait", timo); 731 if (rv) { 732 mtx_unlock(rm->rm_mtx); 733 return (rv); 734 } 735 } 736 } 737 738 static int 739 int_rman_deactivate_resource(struct resource_i *r) 740 { 741 742 r->r_flags &= ~RF_ACTIVE; 743 if (r->r_flags & RF_WANTED) { 744 r->r_flags &= ~RF_WANTED; 745 wakeup(r->r_sharehead); 746 } 747 return 0; 748 } 749 750 int 751 rman_deactivate_resource(struct resource *r) 752 { 753 struct rman *rm; 754 755 rm = r->__r_i->r_rm; 756 mtx_lock(rm->rm_mtx); 757 int_rman_deactivate_resource(r->__r_i); 758 mtx_unlock(rm->rm_mtx); 759 return 0; 760 } 761 762 static int 763 int_rman_release_resource(struct rman *rm, struct resource_i *r) 764 { 765 struct resource_i *s, *t; 766 767 if (r->r_flags & RF_ACTIVE) 768 int_rman_deactivate_resource(r); 769 770 /* 771 * Check for a sharing list first. If there is one, then we don't 772 * have to think as hard. 773 */ 774 if (r->r_sharehead) { 775 /* 776 * If a sharing list exists, then we know there are at 777 * least two sharers. 778 * 779 * If we are in the main circleq, appoint someone else. 780 */ 781 LIST_REMOVE(r, r_sharelink); 782 s = LIST_FIRST(r->r_sharehead); 783 if (r->r_flags & RF_FIRSTSHARE) { 784 s->r_flags |= RF_FIRSTSHARE; 785 TAILQ_INSERT_BEFORE(r, s, r_link); 786 TAILQ_REMOVE(&rm->rm_list, r, r_link); 787 } 788 789 /* 790 * Make sure that the sharing list goes away completely 791 * if the resource is no longer being shared at all. 792 */ 793 if (LIST_NEXT(s, r_sharelink) == NULL) { 794 free(s->r_sharehead, M_RMAN); 795 s->r_sharehead = NULL; 796 s->r_flags &= ~RF_FIRSTSHARE; 797 } 798 goto out; 799 } 800 801 /* 802 * Look at the adjacent resources in the list and see if our 803 * segment can be merged with any of them. If either of the 804 * resources is allocated or is not exactly adjacent then they 805 * cannot be merged with our segment. 806 */ 807 s = TAILQ_PREV(r, resource_head, r_link); 808 if (s != NULL && ((s->r_flags & RF_ALLOCATED) != 0 || 809 s->r_end + 1 != r->r_start)) 810 s = NULL; 811 t = TAILQ_NEXT(r, r_link); 812 if (t != NULL && ((t->r_flags & RF_ALLOCATED) != 0 || 813 r->r_end + 1 != t->r_start)) 814 t = NULL; 815 816 if (s != NULL && t != NULL) { 817 /* 818 * Merge all three segments. 819 */ 820 s->r_end = t->r_end; 821 TAILQ_REMOVE(&rm->rm_list, r, r_link); 822 TAILQ_REMOVE(&rm->rm_list, t, r_link); 823 free(t, M_RMAN); 824 } else if (s != NULL) { 825 /* 826 * Merge previous segment with ours. 827 */ 828 s->r_end = r->r_end; 829 TAILQ_REMOVE(&rm->rm_list, r, r_link); 830 } else if (t != NULL) { 831 /* 832 * Merge next segment with ours. 833 */ 834 t->r_start = r->r_start; 835 TAILQ_REMOVE(&rm->rm_list, r, r_link); 836 } else { 837 /* 838 * At this point, we know there is nothing we 839 * can potentially merge with, because on each 840 * side, there is either nothing there or what is 841 * there is still allocated. In that case, we don't 842 * want to remove r from the list; we simply want to 843 * change it to an unallocated region and return 844 * without freeing anything. 845 */ 846 r->r_flags &= ~RF_ALLOCATED; 847 r->r_dev = NULL; 848 return 0; 849 } 850 851 out: 852 free(r, M_RMAN); 853 return 0; 854 } 855 856 int 857 rman_release_resource(struct resource *re) 858 { 859 int rv; 860 struct resource_i *r; 861 struct rman *rm; 862 863 r = re->__r_i; 864 rm = r->r_rm; 865 mtx_lock(rm->rm_mtx); 866 rv = int_rman_release_resource(rm, r); 867 mtx_unlock(rm->rm_mtx); 868 return (rv); 869 } 870 871 uint32_t 872 rman_make_alignment_flags(uint32_t size) 873 { 874 int i; 875 876 /* 877 * Find the hightest bit set, and add one if more than one bit 878 * set. We're effectively computing the ceil(log2(size)) here. 879 */ 880 for (i = 31; i > 0; i--) 881 if ((1 << i) & size) 882 break; 883 if (~(1 << i) & size) 884 i++; 885 886 return(RF_ALIGNMENT_LOG2(i)); 887 } 888 889 void 890 rman_set_start(struct resource *r, u_long start) 891 { 892 r->__r_i->r_start = start; 893 } 894 895 u_long 896 rman_get_start(struct resource *r) 897 { 898 return (r->__r_i->r_start); 899 } 900 901 void 902 rman_set_end(struct resource *r, u_long end) 903 { 904 r->__r_i->r_end = end; 905 } 906 907 u_long 908 rman_get_end(struct resource *r) 909 { 910 return (r->__r_i->r_end); 911 } 912 913 u_long 914 rman_get_size(struct resource *r) 915 { 916 return (r->__r_i->r_end - r->__r_i->r_start + 1); 917 } 918 919 u_int 920 rman_get_flags(struct resource *r) 921 { 922 return (r->__r_i->r_flags); 923 } 924 925 void 926 rman_set_virtual(struct resource *r, void *v) 927 { 928 r->__r_i->r_virtual = v; 929 } 930 931 void * 932 rman_get_virtual(struct resource *r) 933 { 934 return (r->__r_i->r_virtual); 935 } 936 937 void 938 rman_set_bustag(struct resource *r, bus_space_tag_t t) 939 { 940 r->r_bustag = t; 941 } 942 943 bus_space_tag_t 944 rman_get_bustag(struct resource *r) 945 { 946 return (r->r_bustag); 947 } 948 949 void 950 rman_set_bushandle(struct resource *r, bus_space_handle_t h) 951 { 952 r->r_bushandle = h; 953 } 954 955 bus_space_handle_t 956 rman_get_bushandle(struct resource *r) 957 { 958 return (r->r_bushandle); 959 } 960 961 void 962 rman_set_rid(struct resource *r, int rid) 963 { 964 r->__r_i->r_rid = rid; 965 } 966 967 int 968 rman_get_rid(struct resource *r) 969 { 970 return (r->__r_i->r_rid); 971 } 972 973 void 974 rman_set_device(struct resource *r, struct device *dev) 975 { 976 r->__r_i->r_dev = dev; 977 } 978 979 struct device * 980 rman_get_device(struct resource *r) 981 { 982 return (r->__r_i->r_dev); 983 } 984 985 int 986 rman_is_region_manager(struct resource *r, struct rman *rm) 987 { 988 989 return (r->__r_i->r_rm == rm); 990 } 991 992 /* 993 * Sysctl interface for scanning the resource lists. 994 * 995 * We take two input parameters; the index into the list of resource 996 * managers, and the resource offset into the list. 997 */ 998 static int 999 sysctl_rman(SYSCTL_HANDLER_ARGS) 1000 { 1001 int *name = (int *)arg1; 1002 u_int namelen = arg2; 1003 int rman_idx, res_idx; 1004 struct rman *rm; 1005 struct resource_i *res; 1006 struct resource_i *sres; 1007 struct u_rman urm; 1008 struct u_resource ures; 1009 int error; 1010 1011 if (namelen != 3) 1012 return (EINVAL); 1013 1014 if (bus_data_generation_check(name[0])) 1015 return (EINVAL); 1016 rman_idx = name[1]; 1017 res_idx = name[2]; 1018 1019 /* 1020 * Find the indexed resource manager 1021 */ 1022 mtx_lock(&rman_mtx); 1023 TAILQ_FOREACH(rm, &rman_head, rm_link) { 1024 if (rman_idx-- == 0) 1025 break; 1026 } 1027 mtx_unlock(&rman_mtx); 1028 if (rm == NULL) 1029 return (ENOENT); 1030 1031 /* 1032 * If the resource index is -1, we want details on the 1033 * resource manager. 1034 */ 1035 if (res_idx == -1) { 1036 bzero(&urm, sizeof(urm)); 1037 urm.rm_handle = (uintptr_t)rm; 1038 if (rm->rm_descr != NULL) 1039 strlcpy(urm.rm_descr, rm->rm_descr, RM_TEXTLEN); 1040 urm.rm_start = rm->rm_start; 1041 urm.rm_size = rm->rm_end - rm->rm_start + 1; 1042 urm.rm_type = rm->rm_type; 1043 1044 error = SYSCTL_OUT(req, &urm, sizeof(urm)); 1045 return (error); 1046 } 1047 1048 /* 1049 * Find the indexed resource and return it. 1050 */ 1051 mtx_lock(rm->rm_mtx); 1052 TAILQ_FOREACH(res, &rm->rm_list, r_link) { 1053 if (res->r_sharehead != NULL) { 1054 LIST_FOREACH(sres, res->r_sharehead, r_sharelink) 1055 if (res_idx-- == 0) { 1056 res = sres; 1057 goto found; 1058 } 1059 } 1060 else if (res_idx-- == 0) 1061 goto found; 1062 } 1063 mtx_unlock(rm->rm_mtx); 1064 return (ENOENT); 1065 1066 found: 1067 bzero(&ures, sizeof(ures)); 1068 ures.r_handle = (uintptr_t)res; 1069 ures.r_parent = (uintptr_t)res->r_rm; 1070 ures.r_device = (uintptr_t)res->r_dev; 1071 if (res->r_dev != NULL) { 1072 if (device_get_name(res->r_dev) != NULL) { 1073 snprintf(ures.r_devname, RM_TEXTLEN, 1074 "%s%d", 1075 device_get_name(res->r_dev), 1076 device_get_unit(res->r_dev)); 1077 } else { 1078 strlcpy(ures.r_devname, "nomatch", 1079 RM_TEXTLEN); 1080 } 1081 } else { 1082 ures.r_devname[0] = '\0'; 1083 } 1084 ures.r_start = res->r_start; 1085 ures.r_size = res->r_end - res->r_start + 1; 1086 ures.r_flags = res->r_flags; 1087 1088 mtx_unlock(rm->rm_mtx); 1089 error = SYSCTL_OUT(req, &ures, sizeof(ures)); 1090 return (error); 1091 } 1092 1093 static SYSCTL_NODE(_hw_bus, OID_AUTO, rman, CTLFLAG_RD, sysctl_rman, 1094 "kernel resource manager"); 1095 1096 #ifdef DDB 1097 static void 1098 dump_rman_header(struct rman *rm) 1099 { 1100 1101 if (db_pager_quit) 1102 return; 1103 db_printf("rman %p: %s (0x%lx-0x%lx full range)\n", 1104 rm, rm->rm_descr, rm->rm_start, rm->rm_end); 1105 } 1106 1107 static void 1108 dump_rman(struct rman *rm) 1109 { 1110 struct resource_i *r; 1111 const char *devname; 1112 1113 if (db_pager_quit) 1114 return; 1115 TAILQ_FOREACH(r, &rm->rm_list, r_link) { 1116 if (r->r_dev != NULL) { 1117 devname = device_get_nameunit(r->r_dev); 1118 if (devname == NULL) 1119 devname = "nomatch"; 1120 } else 1121 devname = NULL; 1122 db_printf(" 0x%lx-0x%lx ", r->r_start, r->r_end); 1123 if (devname != NULL) 1124 db_printf("(%s)\n", devname); 1125 else 1126 db_printf("----\n"); 1127 if (db_pager_quit) 1128 return; 1129 } 1130 } 1131 1132 DB_SHOW_COMMAND(rman, db_show_rman) 1133 { 1134 1135 if (have_addr) { 1136 dump_rman_header((struct rman *)addr); 1137 dump_rman((struct rman *)addr); 1138 } 1139 } 1140 1141 DB_SHOW_COMMAND(rmans, db_show_rmans) 1142 { 1143 struct rman *rm; 1144 1145 TAILQ_FOREACH(rm, &rman_head, rm_link) { 1146 dump_rman_header(rm); 1147 } 1148 } 1149 1150 DB_SHOW_ALL_COMMAND(rman, db_show_all_rman) 1151 { 1152 struct rman *rm; 1153 1154 TAILQ_FOREACH(rm, &rman_head, rm_link) { 1155 dump_rman_header(rm); 1156 dump_rman(rm); 1157 } 1158 } 1159 DB_SHOW_ALIAS(allrman, db_show_all_rman); 1160 #endif
Cache object: 43d646c50fac95d3ed406560c7c9bb42
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