subr_rman.c revision 265923
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: head/sys/kern/subr_rman.c 265923 2014-05-12 17:56:52Z truckman $"); 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 */ 88struct 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 102static int rman_debug = 0; 103TUNABLE_INT("debug.rman_debug", &rman_debug); 104SYSCTL_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 109static MALLOC_DEFINE(M_RMAN, "rman", "Resource manager"); 110 111struct rman_head rman_head; 112static struct mtx rman_mtx; /* mutex to protect rman_head */ 113static int int_rman_activate_resource(struct rman *rm, struct resource_i *r, 114 struct resource_i **whohas); 115static int int_rman_deactivate_resource(struct resource_i *r); 116static int int_rman_release_resource(struct rman *rm, struct resource_i *r); 117 118static __inline struct resource_i * 119int_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 130int 131rman_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 160int 161rman_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 } 233out: 234 mtx_unlock(rm->rm_mtx); 235 return rv; 236} 237 238int 239rman_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 248int 249rman_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 280int 281rman_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 298int 299rman_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. */ 317int 318rman_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 438struct resource * 439rman_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 + count - 1; 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 (start + amask < start) { 470 DPRINTF(("start+amask wrapped around\n")); 471 goto out; 472 } 473 474 /* If bound is 0, bmask will also be 0 */ 475 bmask = ~(bound - 1); 476 /* 477 * First try to find an acceptable totally-unshared region. 478 */ 479 for (s = r; s; s = TAILQ_NEXT(s, r_link)) { 480 DPRINTF(("considering [%#lx, %#lx]\n", s->r_start, s->r_end)); 481 /* 482 * The resource list is sorted, so there is no point in 483 * searching further once r_start is too large. 484 */ 485 if (s->r_start > end - (count - 1)) { 486 DPRINTF(("s->r_start (%#lx) + count - 1> end (%#lx)\n", 487 s->r_start, end)); 488 break; 489 } 490 if (s->r_start + amask < s->r_start) { 491 DPRINTF(("s->r_start (%#lx) + amask (%#lx) wrapped\n", 492 s->r_start, amask)); 493 break; 494 } 495 if (s->r_flags & RF_ALLOCATED) { 496 DPRINTF(("region is allocated\n")); 497 continue; 498 } 499 rstart = ulmax(s->r_start, start); 500 /* 501 * Try to find a region by adjusting to boundary and alignment 502 * until both conditions are satisfied. This is not an optimal 503 * algorithm, but in most cases it isn't really bad, either. 504 */ 505 do { 506 rstart = (rstart + amask) & ~amask; 507 if (((rstart ^ (rstart + count - 1)) & bmask) != 0) 508 rstart += bound - (rstart & ~bmask); 509 } while ((rstart & amask) != 0 && rstart < end && 510 rstart < s->r_end); 511 rend = ulmin(s->r_end, ulmax(rstart + count - 1, end)); 512 if (rstart > rend) { 513 DPRINTF(("adjusted start exceeds end\n")); 514 continue; 515 } 516 DPRINTF(("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n", 517 rstart, rend, (rend - rstart + 1), count)); 518 519 if ((rend - rstart + 1) >= count) { 520 DPRINTF(("candidate region: [%#lx, %#lx], size %#lx\n", 521 rstart, rend, (rend - rstart + 1))); 522 if ((s->r_end - s->r_start + 1) == count) { 523 DPRINTF(("candidate region is entire chunk\n")); 524 rv = s; 525 rv->r_flags |= RF_ALLOCATED | flags; 526 rv->r_dev = dev; 527 goto out; 528 } 529 530 /* 531 * If s->r_start < rstart and 532 * s->r_end > rstart + count - 1, then 533 * we need to split the region into three pieces 534 * (the middle one will get returned to the user). 535 * Otherwise, we are allocating at either the 536 * beginning or the end of s, so we only need to 537 * split it in two. The first case requires 538 * two new allocations; the second requires but one. 539 */ 540 rv = int_alloc_resource(M_NOWAIT); 541 if (rv == NULL) 542 goto out; 543 rv->r_start = rstart; 544 rv->r_end = rstart + count - 1; 545 rv->r_flags = flags | RF_ALLOCATED; 546 rv->r_dev = dev; 547 rv->r_rm = rm; 548 549 if (s->r_start < rv->r_start && s->r_end > rv->r_end) { 550 DPRINTF(("splitting region in three parts: " 551 "[%#lx, %#lx]; [%#lx, %#lx]; [%#lx, %#lx]\n", 552 s->r_start, rv->r_start - 1, 553 rv->r_start, rv->r_end, 554 rv->r_end + 1, s->r_end)); 555 /* 556 * We are allocating in the middle. 557 */ 558 r = int_alloc_resource(M_NOWAIT); 559 if (r == NULL) { 560 free(rv, M_RMAN); 561 rv = NULL; 562 goto out; 563 } 564 r->r_start = rv->r_end + 1; 565 r->r_end = s->r_end; 566 r->r_flags = s->r_flags; 567 r->r_rm = rm; 568 s->r_end = rv->r_start - 1; 569 TAILQ_INSERT_AFTER(&rm->rm_list, s, rv, 570 r_link); 571 TAILQ_INSERT_AFTER(&rm->rm_list, rv, r, 572 r_link); 573 } else if (s->r_start == rv->r_start) { 574 DPRINTF(("allocating from the beginning\n")); 575 /* 576 * We are allocating at the beginning. 577 */ 578 s->r_start = rv->r_end + 1; 579 TAILQ_INSERT_BEFORE(s, rv, r_link); 580 } else { 581 DPRINTF(("allocating at the end\n")); 582 /* 583 * We are allocating at the end. 584 */ 585 s->r_end = rv->r_start - 1; 586 TAILQ_INSERT_AFTER(&rm->rm_list, s, rv, 587 r_link); 588 } 589 goto out; 590 } 591 } 592 593 /* 594 * Now find an acceptable shared region, if the client's requirements 595 * allow sharing. By our implementation restriction, a candidate 596 * region must match exactly by both size and sharing type in order 597 * to be considered compatible with the client's request. (The 598 * former restriction could probably be lifted without too much 599 * additional work, but this does not seem warranted.) 600 */ 601 DPRINTF(("no unshared regions found\n")); 602 if ((flags & (RF_SHAREABLE | RF_TIMESHARE)) == 0) 603 goto out; 604 605 for (s = r; s; s = TAILQ_NEXT(s, r_link)) { 606 if (s->r_start > end) 607 break; 608 if ((s->r_flags & flags) != flags) 609 continue; 610 if (s->r_start >= start && s->r_end <= end 611 && (s->r_end - s->r_start + 1) == count && 612 (s->r_start & amask) == 0 && 613 ((s->r_start ^ s->r_end) & bmask) == 0) { 614 rv = int_alloc_resource(M_NOWAIT); 615 if (rv == NULL) 616 goto out; 617 rv->r_start = s->r_start; 618 rv->r_end = s->r_end; 619 rv->r_flags = s->r_flags & 620 (RF_ALLOCATED | RF_SHAREABLE | RF_TIMESHARE); 621 rv->r_dev = dev; 622 rv->r_rm = rm; 623 if (s->r_sharehead == NULL) { 624 s->r_sharehead = malloc(sizeof *s->r_sharehead, 625 M_RMAN, M_NOWAIT | M_ZERO); 626 if (s->r_sharehead == NULL) { 627 free(rv, M_RMAN); 628 rv = NULL; 629 goto out; 630 } 631 LIST_INIT(s->r_sharehead); 632 LIST_INSERT_HEAD(s->r_sharehead, s, 633 r_sharelink); 634 s->r_flags |= RF_FIRSTSHARE; 635 } 636 rv->r_sharehead = s->r_sharehead; 637 LIST_INSERT_HEAD(s->r_sharehead, rv, r_sharelink); 638 goto out; 639 } 640 } 641 642 /* 643 * We couldn't find anything. 644 */ 645out: 646 /* 647 * If the user specified RF_ACTIVE in the initial flags, 648 * which is reflected in `want_activate', we attempt to atomically 649 * activate the resource. If this fails, we release the resource 650 * and indicate overall failure. (This behavior probably doesn't 651 * make sense for RF_TIMESHARE-type resources.) 652 */ 653 if (rv && want_activate) { 654 struct resource_i *whohas; 655 if (int_rman_activate_resource(rm, rv, &whohas)) { 656 int_rman_release_resource(rm, rv); 657 rv = NULL; 658 } 659 } 660 661 mtx_unlock(rm->rm_mtx); 662 return (rv == NULL ? NULL : &rv->r_r); 663} 664 665struct resource * 666rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count, 667 u_int flags, struct device *dev) 668{ 669 670 return (rman_reserve_resource_bound(rm, start, end, count, 0, flags, 671 dev)); 672} 673 674static int 675int_rman_activate_resource(struct rman *rm, struct resource_i *r, 676 struct resource_i **whohas) 677{ 678 struct resource_i *s; 679 int ok; 680 681 /* 682 * If we are not timesharing, then there is nothing much to do. 683 * If we already have the resource, then there is nothing at all to do. 684 * If we are not on a sharing list with anybody else, then there is 685 * little to do. 686 */ 687 if ((r->r_flags & RF_TIMESHARE) == 0 688 || (r->r_flags & RF_ACTIVE) != 0 689 || r->r_sharehead == NULL) { 690 r->r_flags |= RF_ACTIVE; 691 return 0; 692 } 693 694 ok = 1; 695 for (s = LIST_FIRST(r->r_sharehead); s && ok; 696 s = LIST_NEXT(s, r_sharelink)) { 697 if ((s->r_flags & RF_ACTIVE) != 0) { 698 ok = 0; 699 *whohas = s; 700 } 701 } 702 if (ok) { 703 r->r_flags |= RF_ACTIVE; 704 return 0; 705 } 706 return EBUSY; 707} 708 709int 710rman_activate_resource(struct resource *re) 711{ 712 int rv; 713 struct resource_i *r, *whohas; 714 struct rman *rm; 715 716 r = re->__r_i; 717 rm = r->r_rm; 718 mtx_lock(rm->rm_mtx); 719 rv = int_rman_activate_resource(rm, r, &whohas); 720 mtx_unlock(rm->rm_mtx); 721 return rv; 722} 723 724int 725rman_await_resource(struct resource *re, int pri, int timo) 726{ 727 int rv; 728 struct resource_i *r, *whohas; 729 struct rman *rm; 730 731 r = re->__r_i; 732 rm = r->r_rm; 733 mtx_lock(rm->rm_mtx); 734 for (;;) { 735 rv = int_rman_activate_resource(rm, r, &whohas); 736 if (rv != EBUSY) 737 return (rv); /* returns with mutex held */ 738 739 if (r->r_sharehead == NULL) 740 panic("rman_await_resource"); 741 whohas->r_flags |= RF_WANTED; 742 rv = msleep(r->r_sharehead, rm->rm_mtx, pri, "rmwait", timo); 743 if (rv) { 744 mtx_unlock(rm->rm_mtx); 745 return (rv); 746 } 747 } 748} 749 750static int 751int_rman_deactivate_resource(struct resource_i *r) 752{ 753 754 r->r_flags &= ~RF_ACTIVE; 755 if (r->r_flags & RF_WANTED) { 756 r->r_flags &= ~RF_WANTED; 757 wakeup(r->r_sharehead); 758 } 759 return 0; 760} 761 762int 763rman_deactivate_resource(struct resource *r) 764{ 765 struct rman *rm; 766 767 rm = r->__r_i->r_rm; 768 mtx_lock(rm->rm_mtx); 769 int_rman_deactivate_resource(r->__r_i); 770 mtx_unlock(rm->rm_mtx); 771 return 0; 772} 773 774static int 775int_rman_release_resource(struct rman *rm, struct resource_i *r) 776{ 777 struct resource_i *s, *t; 778 779 if (r->r_flags & RF_ACTIVE) 780 int_rman_deactivate_resource(r); 781 782 /* 783 * Check for a sharing list first. If there is one, then we don't 784 * have to think as hard. 785 */ 786 if (r->r_sharehead) { 787 /* 788 * If a sharing list exists, then we know there are at 789 * least two sharers. 790 * 791 * If we are in the main circleq, appoint someone else. 792 */ 793 LIST_REMOVE(r, r_sharelink); 794 s = LIST_FIRST(r->r_sharehead); 795 if (r->r_flags & RF_FIRSTSHARE) { 796 s->r_flags |= RF_FIRSTSHARE; 797 TAILQ_INSERT_BEFORE(r, s, r_link); 798 TAILQ_REMOVE(&rm->rm_list, r, r_link); 799 } 800 801 /* 802 * Make sure that the sharing list goes away completely 803 * if the resource is no longer being shared at all. 804 */ 805 if (LIST_NEXT(s, r_sharelink) == NULL) { 806 free(s->r_sharehead, M_RMAN); 807 s->r_sharehead = NULL; 808 s->r_flags &= ~RF_FIRSTSHARE; 809 } 810 goto out; 811 } 812 813 /* 814 * Look at the adjacent resources in the list and see if our 815 * segment can be merged with any of them. If either of the 816 * resources is allocated or is not exactly adjacent then they 817 * cannot be merged with our segment. 818 */ 819 s = TAILQ_PREV(r, resource_head, r_link); 820 if (s != NULL && ((s->r_flags & RF_ALLOCATED) != 0 || 821 s->r_end + 1 != r->r_start)) 822 s = NULL; 823 t = TAILQ_NEXT(r, r_link); 824 if (t != NULL && ((t->r_flags & RF_ALLOCATED) != 0 || 825 r->r_end + 1 != t->r_start)) 826 t = NULL; 827 828 if (s != NULL && t != NULL) { 829 /* 830 * Merge all three segments. 831 */ 832 s->r_end = t->r_end; 833 TAILQ_REMOVE(&rm->rm_list, r, r_link); 834 TAILQ_REMOVE(&rm->rm_list, t, r_link); 835 free(t, M_RMAN); 836 } else if (s != NULL) { 837 /* 838 * Merge previous segment with ours. 839 */ 840 s->r_end = r->r_end; 841 TAILQ_REMOVE(&rm->rm_list, r, r_link); 842 } else if (t != NULL) { 843 /* 844 * Merge next segment with ours. 845 */ 846 t->r_start = r->r_start; 847 TAILQ_REMOVE(&rm->rm_list, r, r_link); 848 } else { 849 /* 850 * At this point, we know there is nothing we 851 * can potentially merge with, because on each 852 * side, there is either nothing there or what is 853 * there is still allocated. In that case, we don't 854 * want to remove r from the list; we simply want to 855 * change it to an unallocated region and return 856 * without freeing anything. 857 */ 858 r->r_flags &= ~RF_ALLOCATED; 859 r->r_dev = NULL; 860 return 0; 861 } 862 863out: 864 free(r, M_RMAN); 865 return 0; 866} 867 868int 869rman_release_resource(struct resource *re) 870{ 871 int rv; 872 struct resource_i *r; 873 struct rman *rm; 874 875 r = re->__r_i; 876 rm = r->r_rm; 877 mtx_lock(rm->rm_mtx); 878 rv = int_rman_release_resource(rm, r); 879 mtx_unlock(rm->rm_mtx); 880 return (rv); 881} 882 883uint32_t 884rman_make_alignment_flags(uint32_t size) 885{ 886 int i; 887 888 /* 889 * Find the hightest bit set, and add one if more than one bit 890 * set. We're effectively computing the ceil(log2(size)) here. 891 */ 892 for (i = 31; i > 0; i--) 893 if ((1 << i) & size) 894 break; 895 if (~(1 << i) & size) 896 i++; 897 898 return(RF_ALIGNMENT_LOG2(i)); 899} 900 901void 902rman_set_start(struct resource *r, u_long start) 903{ 904 r->__r_i->r_start = start; 905} 906 907u_long 908rman_get_start(struct resource *r) 909{ 910 return (r->__r_i->r_start); 911} 912 913void 914rman_set_end(struct resource *r, u_long end) 915{ 916 r->__r_i->r_end = end; 917} 918 919u_long 920rman_get_end(struct resource *r) 921{ 922 return (r->__r_i->r_end); 923} 924 925u_long 926rman_get_size(struct resource *r) 927{ 928 return (r->__r_i->r_end - r->__r_i->r_start + 1); 929} 930 931u_int 932rman_get_flags(struct resource *r) 933{ 934 return (r->__r_i->r_flags); 935} 936 937void 938rman_set_virtual(struct resource *r, void *v) 939{ 940 r->__r_i->r_virtual = v; 941} 942 943void * 944rman_get_virtual(struct resource *r) 945{ 946 return (r->__r_i->r_virtual); 947} 948 949void 950rman_set_bustag(struct resource *r, bus_space_tag_t t) 951{ 952 r->r_bustag = t; 953} 954 955bus_space_tag_t 956rman_get_bustag(struct resource *r) 957{ 958 return (r->r_bustag); 959} 960 961void 962rman_set_bushandle(struct resource *r, bus_space_handle_t h) 963{ 964 r->r_bushandle = h; 965} 966 967bus_space_handle_t 968rman_get_bushandle(struct resource *r) 969{ 970 return (r->r_bushandle); 971} 972 973void 974rman_set_rid(struct resource *r, int rid) 975{ 976 r->__r_i->r_rid = rid; 977} 978 979int 980rman_get_rid(struct resource *r) 981{ 982 return (r->__r_i->r_rid); 983} 984 985void 986rman_set_device(struct resource *r, struct device *dev) 987{ 988 r->__r_i->r_dev = dev; 989} 990 991struct device * 992rman_get_device(struct resource *r) 993{ 994 return (r->__r_i->r_dev); 995} 996 997int 998rman_is_region_manager(struct resource *r, struct rman *rm) 999{ 1000 1001 return (r->__r_i->r_rm == rm); 1002} 1003 1004/* 1005 * Sysctl interface for scanning the resource lists. 1006 * 1007 * We take two input parameters; the index into the list of resource 1008 * managers, and the resource offset into the list. 1009 */ 1010static int 1011sysctl_rman(SYSCTL_HANDLER_ARGS) 1012{ 1013 int *name = (int *)arg1; 1014 u_int namelen = arg2; 1015 int rman_idx, res_idx; 1016 struct rman *rm; 1017 struct resource_i *res; 1018 struct resource_i *sres; 1019 struct u_rman urm; 1020 struct u_resource ures; 1021 int error; 1022 1023 if (namelen != 3) 1024 return (EINVAL); 1025 1026 if (bus_data_generation_check(name[0])) 1027 return (EINVAL); 1028 rman_idx = name[1]; 1029 res_idx = name[2]; 1030 1031 /* 1032 * Find the indexed resource manager 1033 */ 1034 mtx_lock(&rman_mtx); 1035 TAILQ_FOREACH(rm, &rman_head, rm_link) { 1036 if (rman_idx-- == 0) 1037 break; 1038 } 1039 mtx_unlock(&rman_mtx); 1040 if (rm == NULL) 1041 return (ENOENT); 1042 1043 /* 1044 * If the resource index is -1, we want details on the 1045 * resource manager. 1046 */ 1047 if (res_idx == -1) { 1048 bzero(&urm, sizeof(urm)); 1049 urm.rm_handle = (uintptr_t)rm; 1050 if (rm->rm_descr != NULL) 1051 strlcpy(urm.rm_descr, rm->rm_descr, RM_TEXTLEN); 1052 urm.rm_start = rm->rm_start; 1053 urm.rm_size = rm->rm_end - rm->rm_start + 1; 1054 urm.rm_type = rm->rm_type; 1055 1056 error = SYSCTL_OUT(req, &urm, sizeof(urm)); 1057 return (error); 1058 } 1059 1060 /* 1061 * Find the indexed resource and return it. 1062 */ 1063 mtx_lock(rm->rm_mtx); 1064 TAILQ_FOREACH(res, &rm->rm_list, r_link) { 1065 if (res->r_sharehead != NULL) { 1066 LIST_FOREACH(sres, res->r_sharehead, r_sharelink) 1067 if (res_idx-- == 0) { 1068 res = sres; 1069 goto found; 1070 } 1071 } 1072 else if (res_idx-- == 0) 1073 goto found; 1074 } 1075 mtx_unlock(rm->rm_mtx); 1076 return (ENOENT); 1077 1078found: 1079 bzero(&ures, sizeof(ures)); 1080 ures.r_handle = (uintptr_t)res; 1081 ures.r_parent = (uintptr_t)res->r_rm; 1082 ures.r_device = (uintptr_t)res->r_dev; 1083 if (res->r_dev != NULL) { 1084 if (device_get_name(res->r_dev) != NULL) { 1085 snprintf(ures.r_devname, RM_TEXTLEN, 1086 "%s%d", 1087 device_get_name(res->r_dev), 1088 device_get_unit(res->r_dev)); 1089 } else { 1090 strlcpy(ures.r_devname, "nomatch", 1091 RM_TEXTLEN); 1092 } 1093 } else { 1094 ures.r_devname[0] = '\0'; 1095 } 1096 ures.r_start = res->r_start; 1097 ures.r_size = res->r_end - res->r_start + 1; 1098 ures.r_flags = res->r_flags; 1099 1100 mtx_unlock(rm->rm_mtx); 1101 error = SYSCTL_OUT(req, &ures, sizeof(ures)); 1102 return (error); 1103} 1104 1105static SYSCTL_NODE(_hw_bus, OID_AUTO, rman, CTLFLAG_RD, sysctl_rman, 1106 "kernel resource manager"); 1107 1108#ifdef DDB 1109static void 1110dump_rman_header(struct rman *rm) 1111{ 1112 1113 if (db_pager_quit) 1114 return; 1115 db_printf("rman %p: %s (0x%lx-0x%lx full range)\n", 1116 rm, rm->rm_descr, rm->rm_start, rm->rm_end); 1117} 1118 1119static void 1120dump_rman(struct rman *rm) 1121{ 1122 struct resource_i *r; 1123 const char *devname; 1124 1125 if (db_pager_quit) 1126 return; 1127 TAILQ_FOREACH(r, &rm->rm_list, r_link) { 1128 if (r->r_dev != NULL) { 1129 devname = device_get_nameunit(r->r_dev); 1130 if (devname == NULL) 1131 devname = "nomatch"; 1132 } else 1133 devname = NULL; 1134 db_printf(" 0x%lx-0x%lx ", r->r_start, r->r_end); 1135 if (devname != NULL) 1136 db_printf("(%s)\n", devname); 1137 else 1138 db_printf("----\n"); 1139 if (db_pager_quit) 1140 return; 1141 } 1142} 1143 1144DB_SHOW_COMMAND(rman, db_show_rman) 1145{ 1146 1147 if (have_addr) { 1148 dump_rman_header((struct rman *)addr); 1149 dump_rman((struct rman *)addr); 1150 } 1151} 1152 1153DB_SHOW_COMMAND(rmans, db_show_rmans) 1154{ 1155 struct rman *rm; 1156 1157 TAILQ_FOREACH(rm, &rman_head, rm_link) { 1158 dump_rman_header(rm); 1159 } 1160} 1161 1162DB_SHOW_ALL_COMMAND(rman, db_show_all_rman) 1163{ 1164 struct rman *rm; 1165 1166 TAILQ_FOREACH(rm, &rman_head, rm_link) { 1167 dump_rman_header(rm); 1168 dump_rman(rm); 1169 } 1170} 1171DB_SHOW_ALIAS(allrman, db_show_all_rman); 1172#endif 1173