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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("$FreeBSD$"); 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; 164 165 DPRINTF(("rman_manage_region: <%s> request: start %#lx, end %#lx\n", 166 rm->rm_descr, start, end)); 167 if (start < rm->rm_start || end > rm->rm_end) 168 return EINVAL; 169 r = int_alloc_resource(M_NOWAIT); 170 if (r == NULL) 171 return ENOMEM; 172 r->r_start = start; 173 r->r_end = end; 174 r->r_rm = rm; 175 176 mtx_lock(rm->rm_mtx); 177 178 /* Skip entries before us. */ 179 TAILQ_FOREACH(s, &rm->rm_list, r_link) { 180 if (s->r_end == ULONG_MAX) 181 break; 182 if (s->r_end + 1 >= r->r_start) 183 break; 184 } 185 186 /* If we ran off the end of the list, insert at the tail. */ 187 if (s == NULL) { 188 TAILQ_INSERT_TAIL(&rm->rm_list, r, r_link); 189 } else { 190 /* Check for any overlap with the current region. */ 191 if (r->r_start <= s->r_end && r->r_end >= s->r_start) 192 return EBUSY; 193 194 /* Check for any overlap with the next region. */ 195 t = TAILQ_NEXT(s, r_link); 196 if (t && r->r_start <= t->r_end && r->r_end >= t->r_start) 197 return EBUSY; 198 199 /* 200 * See if this region can be merged with the next region. If 201 * not, clear the pointer. 202 */ 203 if (t && (r->r_end + 1 != t->r_start || t->r_flags != 0)) 204 t = NULL; 205 206 /* See if we can merge with the current region. */ 207 if (s->r_end + 1 == r->r_start && s->r_flags == 0) { 208 /* Can we merge all 3 regions? */ 209 if (t != NULL) { 210 s->r_end = t->r_end; 211 TAILQ_REMOVE(&rm->rm_list, t, r_link); 212 free(r, M_RMAN); 213 free(t, M_RMAN); 214 } else { 215 s->r_end = r->r_end; 216 free(r, M_RMAN); 217 } 218 } else if (t != NULL) { 219 /* Can we merge with just the next region? */ 220 t->r_start = r->r_start; 221 free(r, M_RMAN); 222 } else if (s->r_end < r->r_start) { 223 TAILQ_INSERT_AFTER(&rm->rm_list, s, r, r_link); 224 } else { 225 TAILQ_INSERT_BEFORE(s, r, r_link); 226 } 227 } 228 229 mtx_unlock(rm->rm_mtx); 230 return 0; 231 } 232 233 int 234 rman_init_from_resource(struct rman *rm, struct resource *r) 235 { 236 int rv; 237 238 if ((rv = rman_init(rm)) != 0) 239 return (rv); 240 return (rman_manage_region(rm, r->__r_i->r_start, r->__r_i->r_end)); 241 } 242 243 int 244 rman_fini(struct rman *rm) 245 { 246 struct resource_i *r; 247 248 mtx_lock(rm->rm_mtx); 249 TAILQ_FOREACH(r, &rm->rm_list, r_link) { 250 if (r->r_flags & RF_ALLOCATED) { 251 mtx_unlock(rm->rm_mtx); 252 return EBUSY; 253 } 254 } 255 256 /* 257 * There really should only be one of these if we are in this 258 * state and the code is working properly, but it can't hurt. 259 */ 260 while (!TAILQ_EMPTY(&rm->rm_list)) { 261 r = TAILQ_FIRST(&rm->rm_list); 262 TAILQ_REMOVE(&rm->rm_list, r, r_link); 263 free(r, M_RMAN); 264 } 265 mtx_unlock(rm->rm_mtx); 266 mtx_lock(&rman_mtx); 267 TAILQ_REMOVE(&rman_head, rm, rm_link); 268 mtx_unlock(&rman_mtx); 269 mtx_destroy(rm->rm_mtx); 270 free(rm->rm_mtx, M_RMAN); 271 272 return 0; 273 } 274 275 int 276 rman_first_free_region(struct rman *rm, u_long *start, u_long *end) 277 { 278 struct resource_i *r; 279 280 mtx_lock(rm->rm_mtx); 281 TAILQ_FOREACH(r, &rm->rm_list, r_link) { 282 if (!(r->r_flags & RF_ALLOCATED)) { 283 *start = r->r_start; 284 *end = r->r_end; 285 mtx_unlock(rm->rm_mtx); 286 return (0); 287 } 288 } 289 mtx_unlock(rm->rm_mtx); 290 return (ENOENT); 291 } 292 293 int 294 rman_last_free_region(struct rman *rm, u_long *start, u_long *end) 295 { 296 struct resource_i *r; 297 298 mtx_lock(rm->rm_mtx); 299 TAILQ_FOREACH_REVERSE(r, &rm->rm_list, resource_head, r_link) { 300 if (!(r->r_flags & RF_ALLOCATED)) { 301 *start = r->r_start; 302 *end = r->r_end; 303 mtx_unlock(rm->rm_mtx); 304 return (0); 305 } 306 } 307 mtx_unlock(rm->rm_mtx); 308 return (ENOENT); 309 } 310 311 /* Shrink or extend one or both ends of an allocated resource. */ 312 int 313 rman_adjust_resource(struct resource *rr, u_long start, u_long end) 314 { 315 struct resource_i *r, *s, *t, *new; 316 struct rman *rm; 317 318 /* Not supported for shared resources. */ 319 r = rr->__r_i; 320 if (r->r_flags & (RF_TIMESHARE | RF_SHAREABLE)) 321 return (EINVAL); 322 323 /* 324 * This does not support wholesale moving of a resource. At 325 * least part of the desired new range must overlap with the 326 * existing resource. 327 */ 328 if (end < r->r_start || r->r_end < start) 329 return (EINVAL); 330 331 /* 332 * Find the two resource regions immediately adjacent to the 333 * allocated resource. 334 */ 335 rm = r->r_rm; 336 mtx_lock(rm->rm_mtx); 337 #ifdef INVARIANTS 338 TAILQ_FOREACH(s, &rm->rm_list, r_link) { 339 if (s == r) 340 break; 341 } 342 if (s == NULL) 343 panic("resource not in list"); 344 #endif 345 s = TAILQ_PREV(r, resource_head, r_link); 346 t = TAILQ_NEXT(r, r_link); 347 KASSERT(s == NULL || s->r_end + 1 == r->r_start, 348 ("prev resource mismatch")); 349 KASSERT(t == NULL || r->r_end + 1 == t->r_start, 350 ("next resource mismatch")); 351 352 /* 353 * See if the changes are permitted. Shrinking is always allowed, 354 * but growing requires sufficient room in the adjacent region. 355 */ 356 if (start < r->r_start && (s == NULL || (s->r_flags & RF_ALLOCATED) || 357 s->r_start > start)) { 358 mtx_unlock(rm->rm_mtx); 359 return (EBUSY); 360 } 361 if (end > r->r_end && (t == NULL || (t->r_flags & RF_ALLOCATED) || 362 t->r_end < end)) { 363 mtx_unlock(rm->rm_mtx); 364 return (EBUSY); 365 } 366 367 /* 368 * While holding the lock, grow either end of the resource as 369 * needed and shrink either end if the shrinking does not require 370 * allocating a new resource. We can safely drop the lock and then 371 * insert a new range to handle the shrinking case afterwards. 372 */ 373 if (start < r->r_start || 374 (start > r->r_start && s != NULL && !(s->r_flags & RF_ALLOCATED))) { 375 KASSERT(s->r_flags == 0, ("prev is busy")); 376 r->r_start = start; 377 if (s->r_start == start) { 378 TAILQ_REMOVE(&rm->rm_list, s, r_link); 379 free(s, M_RMAN); 380 } else 381 s->r_end = start - 1; 382 } 383 if (end > r->r_end || 384 (end < r->r_end && t != NULL && !(t->r_flags & RF_ALLOCATED))) { 385 KASSERT(t->r_flags == 0, ("next is busy")); 386 r->r_end = end; 387 if (t->r_end == end) { 388 TAILQ_REMOVE(&rm->rm_list, t, r_link); 389 free(t, M_RMAN); 390 } else 391 t->r_start = end + 1; 392 } 393 mtx_unlock(rm->rm_mtx); 394 395 /* 396 * Handle the shrinking cases that require allocating a new 397 * resource to hold the newly-free region. We have to recheck 398 * if we still need this new region after acquiring the lock. 399 */ 400 if (start > r->r_start) { 401 new = int_alloc_resource(M_WAITOK); 402 new->r_start = r->r_start; 403 new->r_end = start - 1; 404 new->r_rm = rm; 405 mtx_lock(rm->rm_mtx); 406 r->r_start = start; 407 s = TAILQ_PREV(r, resource_head, r_link); 408 if (s != NULL && !(s->r_flags & RF_ALLOCATED)) { 409 s->r_end = start - 1; 410 free(new, M_RMAN); 411 } else 412 TAILQ_INSERT_BEFORE(r, new, r_link); 413 mtx_unlock(rm->rm_mtx); 414 } 415 if (end < r->r_end) { 416 new = int_alloc_resource(M_WAITOK); 417 new->r_start = end + 1; 418 new->r_end = r->r_end; 419 new->r_rm = rm; 420 mtx_lock(rm->rm_mtx); 421 r->r_end = end; 422 t = TAILQ_NEXT(r, r_link); 423 if (t != NULL && !(t->r_flags & RF_ALLOCATED)) { 424 t->r_start = end + 1; 425 free(new, M_RMAN); 426 } else 427 TAILQ_INSERT_AFTER(&rm->rm_list, r, new, r_link); 428 mtx_unlock(rm->rm_mtx); 429 } 430 return (0); 431 } 432 433 #define SHARE_TYPE(f) (f & (RF_SHAREABLE | RF_TIMESHARE | RF_PREFETCHABLE)) 434 435 struct resource * 436 rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end, 437 u_long count, u_long bound, u_int flags, 438 struct device *dev) 439 { 440 u_int new_rflags; 441 struct resource_i *r, *s, *rv; 442 u_long rstart, rend, amask, bmask; 443 444 rv = NULL; 445 446 DPRINTF(("rman_reserve_resource_bound: <%s> request: [%#lx, %#lx], " 447 "length %#lx, flags %u, device %s\n", rm->rm_descr, start, end, 448 count, flags, 449 dev == NULL ? "<null>" : device_get_nameunit(dev))); 450 KASSERT((flags & (RF_WANTED | RF_FIRSTSHARE)) == 0, 451 ("invalid flags %#x", flags)); 452 new_rflags = (flags & ~(RF_ACTIVE | RF_WANTED | RF_FIRSTSHARE)) | 453 RF_ALLOCATED; 454 455 mtx_lock(rm->rm_mtx); 456 457 for (r = TAILQ_FIRST(&rm->rm_list); 458 r && r->r_end < start + count - 1; 459 r = TAILQ_NEXT(r, r_link)) 460 ; 461 462 if (r == NULL) { 463 DPRINTF(("could not find a region\n")); 464 goto out; 465 } 466 467 amask = (1ul << RF_ALIGNMENT(flags)) - 1; 468 KASSERT(start <= ULONG_MAX - amask, 469 ("start (%#lx) + amask (%#lx) would wrap around", start, amask)); 470 471 /* If bound is 0, bmask will also be 0 */ 472 bmask = ~(bound - 1); 473 /* 474 * First try to find an acceptable totally-unshared region. 475 */ 476 for (s = r; s; s = TAILQ_NEXT(s, r_link)) { 477 DPRINTF(("considering [%#lx, %#lx]\n", s->r_start, s->r_end)); 478 /* 479 * The resource list is sorted, so there is no point in 480 * searching further once r_start is too large. 481 */ 482 if (s->r_start > end - (count - 1)) { 483 DPRINTF(("s->r_start (%#lx) + count - 1> end (%#lx)\n", 484 s->r_start, end)); 485 break; 486 } 487 if (s->r_start > ULONG_MAX - amask) { 488 DPRINTF(("s->r_start (%#lx) + amask (%#lx) too large\n", 489 s->r_start, amask)); 490 break; 491 } 492 if (s->r_flags & RF_ALLOCATED) { 493 DPRINTF(("region is allocated\n")); 494 continue; 495 } 496 rstart = ulmax(s->r_start, start); 497 /* 498 * Try to find a region by adjusting to boundary and alignment 499 * until both conditions are satisfied. This is not an optimal 500 * algorithm, but in most cases it isn't really bad, either. 501 */ 502 do { 503 rstart = (rstart + amask) & ~amask; 504 if (((rstart ^ (rstart + count - 1)) & bmask) != 0) 505 rstart += bound - (rstart & ~bmask); 506 } while ((rstart & amask) != 0 && rstart < end && 507 rstart < s->r_end); 508 rend = ulmin(s->r_end, ulmax(rstart + count - 1, end)); 509 if (rstart > rend) { 510 DPRINTF(("adjusted start exceeds end\n")); 511 continue; 512 } 513 DPRINTF(("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n", 514 rstart, rend, (rend - rstart + 1), count)); 515 516 if ((rend - rstart + 1) >= count) { 517 DPRINTF(("candidate region: [%#lx, %#lx], size %#lx\n", 518 rstart, rend, (rend - rstart + 1))); 519 if ((s->r_end - s->r_start + 1) == count) { 520 DPRINTF(("candidate region is entire chunk\n")); 521 rv = s; 522 rv->r_flags = new_rflags; 523 rv->r_dev = dev; 524 goto out; 525 } 526 527 /* 528 * If s->r_start < rstart and 529 * s->r_end > rstart + count - 1, then 530 * we need to split the region into three pieces 531 * (the middle one will get returned to the user). 532 * Otherwise, we are allocating at either the 533 * beginning or the end of s, so we only need to 534 * split it in two. The first case requires 535 * two new allocations; the second requires but one. 536 */ 537 rv = int_alloc_resource(M_NOWAIT); 538 if (rv == NULL) 539 goto out; 540 rv->r_start = rstart; 541 rv->r_end = rstart + count - 1; 542 rv->r_flags = new_rflags; 543 rv->r_dev = dev; 544 rv->r_rm = rm; 545 546 if (s->r_start < rv->r_start && s->r_end > rv->r_end) { 547 DPRINTF(("splitting region in three parts: " 548 "[%#lx, %#lx]; [%#lx, %#lx]; [%#lx, %#lx]\n", 549 s->r_start, rv->r_start - 1, 550 rv->r_start, rv->r_end, 551 rv->r_end + 1, s->r_end)); 552 /* 553 * We are allocating in the middle. 554 */ 555 r = int_alloc_resource(M_NOWAIT); 556 if (r == NULL) { 557 free(rv, M_RMAN); 558 rv = NULL; 559 goto out; 560 } 561 r->r_start = rv->r_end + 1; 562 r->r_end = s->r_end; 563 r->r_flags = s->r_flags; 564 r->r_rm = rm; 565 s->r_end = rv->r_start - 1; 566 TAILQ_INSERT_AFTER(&rm->rm_list, s, rv, 567 r_link); 568 TAILQ_INSERT_AFTER(&rm->rm_list, rv, r, 569 r_link); 570 } else if (s->r_start == rv->r_start) { 571 DPRINTF(("allocating from the beginning\n")); 572 /* 573 * We are allocating at the beginning. 574 */ 575 s->r_start = rv->r_end + 1; 576 TAILQ_INSERT_BEFORE(s, rv, r_link); 577 } else { 578 DPRINTF(("allocating at the end\n")); 579 /* 580 * We are allocating at the end. 581 */ 582 s->r_end = rv->r_start - 1; 583 TAILQ_INSERT_AFTER(&rm->rm_list, s, rv, 584 r_link); 585 } 586 goto out; 587 } 588 } 589 590 /* 591 * Now find an acceptable shared region, if the client's requirements 592 * allow sharing. By our implementation restriction, a candidate 593 * region must match exactly by both size and sharing type in order 594 * to be considered compatible with the client's request. (The 595 * former restriction could probably be lifted without too much 596 * additional work, but this does not seem warranted.) 597 */ 598 DPRINTF(("no unshared regions found\n")); 599 if ((flags & (RF_SHAREABLE | RF_TIMESHARE)) == 0) 600 goto out; 601 602 for (s = r; s && s->r_end <= end; s = TAILQ_NEXT(s, r_link)) { 603 if (SHARE_TYPE(s->r_flags) == SHARE_TYPE(flags) && 604 s->r_start >= start && 605 (s->r_end - s->r_start + 1) == count && 606 (s->r_start & amask) == 0 && 607 ((s->r_start ^ s->r_end) & bmask) == 0) { 608 rv = int_alloc_resource(M_NOWAIT); 609 if (rv == NULL) 610 goto out; 611 rv->r_start = s->r_start; 612 rv->r_end = s->r_end; 613 rv->r_flags = new_rflags; 614 rv->r_dev = dev; 615 rv->r_rm = rm; 616 if (s->r_sharehead == NULL) { 617 s->r_sharehead = malloc(sizeof *s->r_sharehead, 618 M_RMAN, M_NOWAIT | M_ZERO); 619 if (s->r_sharehead == NULL) { 620 free(rv, M_RMAN); 621 rv = NULL; 622 goto out; 623 } 624 LIST_INIT(s->r_sharehead); 625 LIST_INSERT_HEAD(s->r_sharehead, s, 626 r_sharelink); 627 s->r_flags |= RF_FIRSTSHARE; 628 } 629 rv->r_sharehead = s->r_sharehead; 630 LIST_INSERT_HEAD(s->r_sharehead, rv, r_sharelink); 631 goto out; 632 } 633 } 634 635 /* 636 * We couldn't find anything. 637 */ 638 out: 639 /* 640 * If the user specified RF_ACTIVE in flags, we attempt to atomically 641 * activate the resource. If this fails, we release the resource 642 * and indicate overall failure. (This behavior probably doesn't 643 * make sense for RF_TIMESHARE-type resources.) 644 */ 645 if (rv && (flags & RF_ACTIVE) != 0) { 646 struct resource_i *whohas; 647 if (int_rman_activate_resource(rm, rv, &whohas)) { 648 int_rman_release_resource(rm, rv); 649 rv = NULL; 650 } 651 } 652 653 mtx_unlock(rm->rm_mtx); 654 return (rv == NULL ? NULL : &rv->r_r); 655 } 656 657 struct resource * 658 rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count, 659 u_int flags, struct device *dev) 660 { 661 662 return (rman_reserve_resource_bound(rm, start, end, count, 0, flags, 663 dev)); 664 } 665 666 static int 667 int_rman_activate_resource(struct rman *rm, struct resource_i *r, 668 struct resource_i **whohas) 669 { 670 struct resource_i *s; 671 int ok; 672 673 /* 674 * If we are not timesharing, then there is nothing much to do. 675 * If we already have the resource, then there is nothing at all to do. 676 * If we are not on a sharing list with anybody else, then there is 677 * little to do. 678 */ 679 if ((r->r_flags & RF_TIMESHARE) == 0 680 || (r->r_flags & RF_ACTIVE) != 0 681 || r->r_sharehead == NULL) { 682 r->r_flags |= RF_ACTIVE; 683 return 0; 684 } 685 686 ok = 1; 687 for (s = LIST_FIRST(r->r_sharehead); s && ok; 688 s = LIST_NEXT(s, r_sharelink)) { 689 if ((s->r_flags & RF_ACTIVE) != 0) { 690 ok = 0; 691 *whohas = s; 692 } 693 } 694 if (ok) { 695 r->r_flags |= RF_ACTIVE; 696 return 0; 697 } 698 return EBUSY; 699 } 700 701 int 702 rman_activate_resource(struct resource *re) 703 { 704 int rv; 705 struct resource_i *r, *whohas; 706 struct rman *rm; 707 708 r = re->__r_i; 709 rm = r->r_rm; 710 mtx_lock(rm->rm_mtx); 711 rv = int_rman_activate_resource(rm, r, &whohas); 712 mtx_unlock(rm->rm_mtx); 713 return rv; 714 } 715 716 int 717 rman_await_resource(struct resource *re, int pri, int timo) 718 { 719 int rv; 720 struct resource_i *r, *whohas; 721 struct rman *rm; 722 723 r = re->__r_i; 724 rm = r->r_rm; 725 mtx_lock(rm->rm_mtx); 726 for (;;) { 727 rv = int_rman_activate_resource(rm, r, &whohas); 728 if (rv != EBUSY) 729 return (rv); /* returns with mutex held */ 730 731 if (r->r_sharehead == NULL) 732 panic("rman_await_resource"); 733 whohas->r_flags |= RF_WANTED; 734 rv = msleep(r->r_sharehead, rm->rm_mtx, pri, "rmwait", timo); 735 if (rv) { 736 mtx_unlock(rm->rm_mtx); 737 return (rv); 738 } 739 } 740 } 741 742 static int 743 int_rman_deactivate_resource(struct resource_i *r) 744 { 745 746 r->r_flags &= ~RF_ACTIVE; 747 if (r->r_flags & RF_WANTED) { 748 r->r_flags &= ~RF_WANTED; 749 wakeup(r->r_sharehead); 750 } 751 return 0; 752 } 753 754 int 755 rman_deactivate_resource(struct resource *r) 756 { 757 struct rman *rm; 758 759 rm = r->__r_i->r_rm; 760 mtx_lock(rm->rm_mtx); 761 int_rman_deactivate_resource(r->__r_i); 762 mtx_unlock(rm->rm_mtx); 763 return 0; 764 } 765 766 static int 767 int_rman_release_resource(struct rman *rm, struct resource_i *r) 768 { 769 struct resource_i *s, *t; 770 771 if (r->r_flags & RF_ACTIVE) 772 int_rman_deactivate_resource(r); 773 774 /* 775 * Check for a sharing list first. If there is one, then we don't 776 * have to think as hard. 777 */ 778 if (r->r_sharehead) { 779 /* 780 * If a sharing list exists, then we know there are at 781 * least two sharers. 782 * 783 * If we are in the main circleq, appoint someone else. 784 */ 785 LIST_REMOVE(r, r_sharelink); 786 s = LIST_FIRST(r->r_sharehead); 787 if (r->r_flags & RF_FIRSTSHARE) { 788 s->r_flags |= RF_FIRSTSHARE; 789 TAILQ_INSERT_BEFORE(r, s, r_link); 790 TAILQ_REMOVE(&rm->rm_list, r, r_link); 791 } 792 793 /* 794 * Make sure that the sharing list goes away completely 795 * if the resource is no longer being shared at all. 796 */ 797 if (LIST_NEXT(s, r_sharelink) == NULL) { 798 free(s->r_sharehead, M_RMAN); 799 s->r_sharehead = NULL; 800 s->r_flags &= ~RF_FIRSTSHARE; 801 } 802 goto out; 803 } 804 805 /* 806 * Look at the adjacent resources in the list and see if our 807 * segment can be merged with any of them. If either of the 808 * resources is allocated or is not exactly adjacent then they 809 * cannot be merged with our segment. 810 */ 811 s = TAILQ_PREV(r, resource_head, r_link); 812 if (s != NULL && ((s->r_flags & RF_ALLOCATED) != 0 || 813 s->r_end + 1 != r->r_start)) 814 s = NULL; 815 t = TAILQ_NEXT(r, r_link); 816 if (t != NULL && ((t->r_flags & RF_ALLOCATED) != 0 || 817 r->r_end + 1 != t->r_start)) 818 t = NULL; 819 820 if (s != NULL && t != NULL) { 821 /* 822 * Merge all three segments. 823 */ 824 s->r_end = t->r_end; 825 TAILQ_REMOVE(&rm->rm_list, r, r_link); 826 TAILQ_REMOVE(&rm->rm_list, t, r_link); 827 free(t, M_RMAN); 828 } else if (s != NULL) { 829 /* 830 * Merge previous segment with ours. 831 */ 832 s->r_end = r->r_end; 833 TAILQ_REMOVE(&rm->rm_list, r, r_link); 834 } else if (t != NULL) { 835 /* 836 * Merge next segment with ours. 837 */ 838 t->r_start = r->r_start; 839 TAILQ_REMOVE(&rm->rm_list, r, r_link); 840 } else { 841 /* 842 * At this point, we know there is nothing we 843 * can potentially merge with, because on each 844 * side, there is either nothing there or what is 845 * there is still allocated. In that case, we don't 846 * want to remove r from the list; we simply want to 847 * change it to an unallocated region and return 848 * without freeing anything. 849 */ 850 r->r_flags &= ~RF_ALLOCATED; 851 r->r_dev = NULL; 852 return 0; 853 } 854 855 out: 856 free(r, M_RMAN); 857 return 0; 858 } 859 860 int 861 rman_release_resource(struct resource *re) 862 { 863 int rv; 864 struct resource_i *r; 865 struct rman *rm; 866 867 r = re->__r_i; 868 rm = r->r_rm; 869 mtx_lock(rm->rm_mtx); 870 rv = int_rman_release_resource(rm, r); 871 mtx_unlock(rm->rm_mtx); 872 return (rv); 873 } 874 875 uint32_t 876 rman_make_alignment_flags(uint32_t size) 877 { 878 int i; 879 880 /* 881 * Find the hightest bit set, and add one if more than one bit 882 * set. We're effectively computing the ceil(log2(size)) here. 883 */ 884 for (i = 31; i > 0; i--) 885 if ((1 << i) & size) 886 break; 887 if (~(1 << i) & size) 888 i++; 889 890 return(RF_ALIGNMENT_LOG2(i)); 891 } 892 893 void 894 rman_set_start(struct resource *r, u_long start) 895 { 896 897 r->__r_i->r_start = start; 898 } 899 900 u_long 901 rman_get_start(struct resource *r) 902 { 903 904 return (r->__r_i->r_start); 905 } 906 907 void 908 rman_set_end(struct resource *r, u_long end) 909 { 910 911 r->__r_i->r_end = end; 912 } 913 914 u_long 915 rman_get_end(struct resource *r) 916 { 917 918 return (r->__r_i->r_end); 919 } 920 921 u_long 922 rman_get_size(struct resource *r) 923 { 924 925 return (r->__r_i->r_end - r->__r_i->r_start + 1); 926 } 927 928 u_int 929 rman_get_flags(struct resource *r) 930 { 931 932 return (r->__r_i->r_flags); 933 } 934 935 void 936 rman_set_virtual(struct resource *r, void *v) 937 { 938 939 r->__r_i->r_virtual = v; 940 } 941 942 void * 943 rman_get_virtual(struct resource *r) 944 { 945 946 return (r->__r_i->r_virtual); 947 } 948 949 void 950 rman_set_bustag(struct resource *r, bus_space_tag_t t) 951 { 952 953 r->r_bustag = t; 954 } 955 956 bus_space_tag_t 957 rman_get_bustag(struct resource *r) 958 { 959 960 return (r->r_bustag); 961 } 962 963 void 964 rman_set_bushandle(struct resource *r, bus_space_handle_t h) 965 { 966 967 r->r_bushandle = h; 968 } 969 970 bus_space_handle_t 971 rman_get_bushandle(struct resource *r) 972 { 973 974 return (r->r_bushandle); 975 } 976 977 void 978 rman_set_rid(struct resource *r, int rid) 979 { 980 981 r->__r_i->r_rid = rid; 982 } 983 984 int 985 rman_get_rid(struct resource *r) 986 { 987 988 return (r->__r_i->r_rid); 989 } 990 991 void 992 rman_set_device(struct resource *r, struct device *dev) 993 { 994 995 r->__r_i->r_dev = dev; 996 } 997 998 struct device * 999 rman_get_device(struct resource *r) 1000 { 1001 1002 return (r->__r_i->r_dev); 1003 } 1004 1005 int 1006 rman_is_region_manager(struct resource *r, struct rman *rm) 1007 { 1008 1009 return (r->__r_i->r_rm == rm); 1010 } 1011 1012 /* 1013 * Sysctl interface for scanning the resource lists. 1014 * 1015 * We take two input parameters; the index into the list of resource 1016 * managers, and the resource offset into the list. 1017 */ 1018 static int 1019 sysctl_rman(SYSCTL_HANDLER_ARGS) 1020 { 1021 int *name = (int *)arg1; 1022 u_int namelen = arg2; 1023 int rman_idx, res_idx; 1024 struct rman *rm; 1025 struct resource_i *res; 1026 struct resource_i *sres; 1027 struct u_rman urm; 1028 struct u_resource ures; 1029 int error; 1030 1031 if (namelen != 3) 1032 return (EINVAL); 1033 1034 if (bus_data_generation_check(name[0])) 1035 return (EINVAL); 1036 rman_idx = name[1]; 1037 res_idx = name[2]; 1038 1039 /* 1040 * Find the indexed resource manager 1041 */ 1042 mtx_lock(&rman_mtx); 1043 TAILQ_FOREACH(rm, &rman_head, rm_link) { 1044 if (rman_idx-- == 0) 1045 break; 1046 } 1047 mtx_unlock(&rman_mtx); 1048 if (rm == NULL) 1049 return (ENOENT); 1050 1051 /* 1052 * If the resource index is -1, we want details on the 1053 * resource manager. 1054 */ 1055 if (res_idx == -1) { 1056 bzero(&urm, sizeof(urm)); 1057 urm.rm_handle = (uintptr_t)rm; 1058 if (rm->rm_descr != NULL) 1059 strlcpy(urm.rm_descr, rm->rm_descr, RM_TEXTLEN); 1060 urm.rm_start = rm->rm_start; 1061 urm.rm_size = rm->rm_end - rm->rm_start + 1; 1062 urm.rm_type = rm->rm_type; 1063 1064 error = SYSCTL_OUT(req, &urm, sizeof(urm)); 1065 return (error); 1066 } 1067 1068 /* 1069 * Find the indexed resource and return it. 1070 */ 1071 mtx_lock(rm->rm_mtx); 1072 TAILQ_FOREACH(res, &rm->rm_list, r_link) { 1073 if (res->r_sharehead != NULL) { 1074 LIST_FOREACH(sres, res->r_sharehead, r_sharelink) 1075 if (res_idx-- == 0) { 1076 res = sres; 1077 goto found; 1078 } 1079 } 1080 else if (res_idx-- == 0) 1081 goto found; 1082 } 1083 mtx_unlock(rm->rm_mtx); 1084 return (ENOENT); 1085 1086 found: 1087 bzero(&ures, sizeof(ures)); 1088 ures.r_handle = (uintptr_t)res; 1089 ures.r_parent = (uintptr_t)res->r_rm; 1090 ures.r_device = (uintptr_t)res->r_dev; 1091 if (res->r_dev != NULL) { 1092 if (device_get_name(res->r_dev) != NULL) { 1093 snprintf(ures.r_devname, RM_TEXTLEN, 1094 "%s%d", 1095 device_get_name(res->r_dev), 1096 device_get_unit(res->r_dev)); 1097 } else { 1098 strlcpy(ures.r_devname, "nomatch", 1099 RM_TEXTLEN); 1100 } 1101 } else { 1102 ures.r_devname[0] = '\0'; 1103 } 1104 ures.r_start = res->r_start; 1105 ures.r_size = res->r_end - res->r_start + 1; 1106 ures.r_flags = res->r_flags; 1107 1108 mtx_unlock(rm->rm_mtx); 1109 error = SYSCTL_OUT(req, &ures, sizeof(ures)); 1110 return (error); 1111 } 1112 1113 SYSCTL_NODE(_hw_bus, OID_AUTO, rman, CTLFLAG_RD, sysctl_rman, 1114 "kernel resource manager"); 1115 1116 #ifdef DDB 1117 static void 1118 dump_rman(struct rman *rm) 1119 { 1120 struct resource_i *r; 1121 const char *devname; 1122 1123 if (db_pager_quit) 1124 return; 1125 db_printf("rman: %s\n", rm->rm_descr); 1126 db_printf(" 0x%lx-0x%lx (full range)\n", rm->rm_start, rm->rm_end); 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 1144 DB_SHOW_COMMAND(rman, db_show_rman) 1145 { 1146 1147 if (have_addr) 1148 dump_rman((struct rman *)addr); 1149 } 1150 1151 DB_SHOW_ALL_COMMAND(rman, db_show_all_rman) 1152 { 1153 struct rman *rm; 1154 1155 TAILQ_FOREACH(rm, &rman_head, rm_link) 1156 dump_rman(rm); 1157 } 1158 DB_SHOW_ALIAS(allrman, db_show_all_rman); 1159 #endif
Cache object: 5cdac0cd09d8d9d81aec26b0d3b8c01d
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