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 * $FreeBSD: src/sys/kern/subr_rman.c,v 1.10.2.1 2001/06/05 08:06:08 imp Exp $ 30 */ 31 32 /* 33 * The kernel resource manager. This code is responsible for keeping track 34 * of hardware resources which are apportioned out to various drivers. 35 * It does not actually assign those resources, and it is not expected 36 * that end-device drivers will call into this code directly. Rather, 37 * the code which implements the buses that those devices are attached to, 38 * and the code which manages CPU resources, will call this code, and the 39 * end-device drivers will make upcalls to that code to actually perform 40 * the allocation. 41 * 42 * There are two sorts of resources managed by this code. The first is 43 * the more familiar array (RMAN_ARRAY) type; resources in this class 44 * consist of a sequence of individually-allocatable objects which have 45 * been numbered in some well-defined order. Most of the resources 46 * are of this type, as it is the most familiar. The second type is 47 * called a gauge (RMAN_GAUGE), and models fungible resources (i.e., 48 * resources in which each instance is indistinguishable from every 49 * other instance). The principal anticipated application of gauges 50 * is in the context of power consumption, where a bus may have a specific 51 * power budget which all attached devices share. RMAN_GAUGE is not 52 * implemented yet. 53 * 54 * For array resources, we make one simplifying assumption: two clients 55 * sharing the same resource must use the same range of indices. That 56 * is to say, sharing of overlapping-but-not-identical regions is not 57 * permitted. 58 */ 59 60 #include <sys/param.h> 61 #include <sys/systm.h> 62 #include <sys/kernel.h> 63 #include <sys/lock.h> 64 #include <sys/malloc.h> 65 #include <sys/bus.h> /* XXX debugging */ 66 #include <sys/rman.h> 67 #include <sys/sysctl.h> 68 69 int rman_debug = 0; 70 TUNABLE_INT("debug.rman_debug", &rman_debug); 71 SYSCTL_INT(_debug, OID_AUTO, rman_debug, CTLFLAG_RW, 72 &rman_debug, 0, "rman debug"); 73 74 #define DPRINTF(params) if (rman_debug) kprintf params 75 76 static MALLOC_DEFINE(M_RMAN, "rman", "Resource manager"); 77 78 struct rman_head rman_head; 79 static struct lwkt_token rman_tok; /* mutex to protect rman_head */ 80 static int int_rman_activate_resource(struct rman *rm, struct resource *r, 81 struct resource **whohas); 82 static int int_rman_deactivate_resource(struct resource *r); 83 static int int_rman_release_resource(struct rman *rm, struct resource *r); 84 85 int 86 rman_init(struct rman *rm, int cpuid) 87 { 88 static int once; 89 90 if (once == 0) { 91 once = 1; 92 TAILQ_INIT(&rman_head); 93 lwkt_token_init(&rman_tok, "rman"); 94 } 95 96 if (rm->rm_type == RMAN_UNINIT) 97 panic("rman_init"); 98 if (rm->rm_type == RMAN_GAUGE) 99 panic("implement RMAN_GAUGE"); 100 101 TAILQ_INIT(&rm->rm_list); 102 rm->rm_slock = kmalloc(sizeof *rm->rm_slock, M_RMAN, M_NOWAIT); 103 if (rm->rm_slock == NULL) 104 return ENOMEM; 105 lwkt_token_init(rm->rm_slock, "rmanslock"); 106 107 rm->rm_cpuid = cpuid; 108 109 lwkt_gettoken(&rman_tok); 110 TAILQ_INSERT_TAIL(&rman_head, rm, rm_link); 111 lwkt_reltoken(&rman_tok); 112 return 0; 113 } 114 115 /* 116 * NB: this interface is not robust against programming errors which 117 * add multiple copies of the same region. 118 */ 119 int 120 rman_manage_region(struct rman *rm, u_long start, u_long end) 121 { 122 struct resource *r, *s; 123 124 DPRINTF(("rman_manage_region: <%s> request: start %#lx, end %#lx\n", 125 rm->rm_descr, start, end)); 126 r = kmalloc(sizeof *r, M_RMAN, M_NOWAIT | M_ZERO); 127 if (r == NULL) 128 return ENOMEM; 129 r->r_sharehead = 0; 130 r->r_start = start; 131 r->r_end = end; 132 r->r_flags = 0; 133 r->r_dev = 0; 134 r->r_rm = rm; 135 136 lwkt_gettoken(rm->rm_slock); 137 for (s = TAILQ_FIRST(&rm->rm_list); 138 s && s->r_end < r->r_start; 139 s = TAILQ_NEXT(s, r_link)) 140 ; 141 142 if (s == NULL) 143 TAILQ_INSERT_TAIL(&rm->rm_list, r, r_link); 144 else 145 TAILQ_INSERT_BEFORE(s, r, r_link); 146 147 lwkt_reltoken(rm->rm_slock); 148 return 0; 149 } 150 151 int 152 rman_fini(struct rman *rm) 153 { 154 struct resource *r; 155 156 lwkt_gettoken(rm->rm_slock); 157 TAILQ_FOREACH(r, &rm->rm_list, r_link) { 158 if (r->r_flags & RF_ALLOCATED) { 159 lwkt_reltoken(rm->rm_slock); 160 return EBUSY; 161 } 162 } 163 164 /* 165 * There really should only be one of these if we are in this 166 * state and the code is working properly, but it can't hurt. 167 */ 168 while (!TAILQ_EMPTY(&rm->rm_list)) { 169 r = TAILQ_FIRST(&rm->rm_list); 170 TAILQ_REMOVE(&rm->rm_list, r, r_link); 171 kfree(r, M_RMAN); 172 } 173 lwkt_reltoken(rm->rm_slock); 174 175 /* XXX what's the point of this if we are going to free the struct? */ 176 lwkt_gettoken(&rman_tok); 177 TAILQ_REMOVE(&rman_head, rm, rm_link); 178 lwkt_reltoken(&rman_tok); 179 kfree(rm->rm_slock, M_RMAN); 180 181 return 0; 182 } 183 184 struct resource * 185 rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count, 186 u_int flags, struct device *dev) 187 { 188 u_int want_activate; 189 struct resource *r, *s, *rv; 190 u_long rstart, rend; 191 192 rv = NULL; 193 194 DPRINTF(("rman_reserve_resource: <%s> request: [%#lx, %#lx], length " 195 "%#lx, flags %u, device %s\n", rm->rm_descr, start, end, 196 count, flags, 197 dev == NULL ? "<null>" : device_get_nameunit(dev))); 198 want_activate = (flags & RF_ACTIVE); 199 flags &= ~RF_ACTIVE; 200 201 lwkt_gettoken(rm->rm_slock); 202 203 for (r = TAILQ_FIRST(&rm->rm_list); 204 r && r->r_end < start; 205 r = TAILQ_NEXT(r, r_link)) 206 ; 207 208 if (r == NULL) { 209 DPRINTF(("could not find a region\n")); 210 goto out; 211 } 212 213 /* 214 * First try to find an acceptable totally-unshared region. 215 */ 216 for (s = r; s; s = TAILQ_NEXT(s, r_link)) { 217 DPRINTF(("considering [%#lx, %#lx]\n", s->r_start, s->r_end)); 218 if (s->r_start > end) { 219 DPRINTF(("s->r_start (%#lx) > end (%#lx)\n", 220 s->r_start, end)); 221 break; 222 } 223 if (s->r_flags & RF_ALLOCATED) { 224 DPRINTF(("region is allocated\n")); 225 continue; 226 } 227 rstart = max(s->r_start, start); 228 rstart = (rstart + ((1ul << RF_ALIGNMENT(flags))) - 1) & 229 ~((1ul << RF_ALIGNMENT(flags)) - 1); 230 rend = min(s->r_end, max(start + count, end)); 231 DPRINTF(("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n", 232 rstart, rend, (rend - rstart + 1), count)); 233 234 if ((rend - rstart + 1) >= count) { 235 DPRINTF(("candidate region: [%#lx, %#lx], size %#lx\n", 236 rstart, rend, (rend - rstart + 1))); 237 if ((s->r_end - s->r_start + 1) == count) { 238 DPRINTF(("candidate region is entire chunk\n")); 239 rv = s; 240 rv->r_flags |= RF_ALLOCATED | flags; 241 rv->r_dev = dev; 242 goto out; 243 } 244 245 /* 246 * If s->r_start < rstart and 247 * s->r_end > rstart + count - 1, then 248 * we need to split the region into three pieces 249 * (the middle one will get returned to the user). 250 * Otherwise, we are allocating at either the 251 * beginning or the end of s, so we only need to 252 * split it in two. The first case requires 253 * two new allocations; the second requires but one. 254 */ 255 rv = kmalloc(sizeof *rv, M_RMAN, M_NOWAIT | M_ZERO); 256 if (rv == NULL) 257 goto out; 258 rv->r_start = rstart; 259 rv->r_end = rstart + count - 1; 260 rv->r_flags = flags | RF_ALLOCATED; 261 rv->r_dev = dev; 262 rv->r_sharehead = 0; 263 rv->r_rm = rm; 264 265 if (s->r_start < rv->r_start && s->r_end > rv->r_end) { 266 DPRINTF(("splitting region in three parts: " 267 "[%#lx, %#lx]; [%#lx, %#lx]; [%#lx, %#lx]\n", 268 s->r_start, rv->r_start - 1, 269 rv->r_start, rv->r_end, 270 rv->r_end + 1, s->r_end)); 271 /* 272 * We are allocating in the middle. 273 */ 274 r = kmalloc(sizeof *r, M_RMAN, 275 M_NOWAIT | M_ZERO); 276 if (r == NULL) { 277 kfree(rv, M_RMAN); 278 rv = NULL; 279 goto out; 280 } 281 r->r_start = rv->r_end + 1; 282 r->r_end = s->r_end; 283 r->r_flags = s->r_flags; 284 r->r_dev = 0; 285 r->r_sharehead = 0; 286 r->r_rm = rm; 287 s->r_end = rv->r_start - 1; 288 TAILQ_INSERT_AFTER(&rm->rm_list, s, rv, 289 r_link); 290 TAILQ_INSERT_AFTER(&rm->rm_list, rv, r, 291 r_link); 292 } else if (s->r_start == rv->r_start) { 293 DPRINTF(("allocating from the beginning\n")); 294 /* 295 * We are allocating at the beginning. 296 */ 297 s->r_start = rv->r_end + 1; 298 TAILQ_INSERT_BEFORE(s, rv, r_link); 299 } else { 300 DPRINTF(("allocating at the end\n")); 301 /* 302 * We are allocating at the end. 303 */ 304 s->r_end = rv->r_start - 1; 305 TAILQ_INSERT_AFTER(&rm->rm_list, s, rv, 306 r_link); 307 } 308 goto out; 309 } 310 } 311 312 /* 313 * Now find an acceptable shared region, if the client's requirements 314 * allow sharing. By our implementation restriction, a candidate 315 * region must match exactly by both size and sharing type in order 316 * to be considered compatible with the client's request. (The 317 * former restriction could probably be lifted without too much 318 * additional work, but this does not seem warranted.) 319 */ 320 DPRINTF(("no unshared regions found\n")); 321 if ((flags & (RF_SHAREABLE | RF_TIMESHARE)) == 0) 322 goto out; 323 324 for (s = r; s; s = TAILQ_NEXT(s, r_link)) { 325 if (s->r_start > end) 326 break; 327 if ((s->r_flags & flags) != flags) 328 continue; 329 rstart = max(s->r_start, start); 330 rend = min(s->r_end, max(start + count, end)); 331 if (s->r_start >= start && s->r_end <= end 332 && (s->r_end - s->r_start + 1) == count) { 333 rv = kmalloc(sizeof *rv, M_RMAN, M_NOWAIT | M_ZERO); 334 if (rv == NULL) 335 goto out; 336 rv->r_start = s->r_start; 337 rv->r_end = s->r_end; 338 rv->r_flags = s->r_flags & 339 (RF_ALLOCATED | RF_SHAREABLE | RF_TIMESHARE); 340 rv->r_dev = dev; 341 rv->r_rm = rm; 342 if (s->r_sharehead == 0) { 343 s->r_sharehead = kmalloc(sizeof *s->r_sharehead, 344 M_RMAN, 345 M_NOWAIT | M_ZERO); 346 if (s->r_sharehead == 0) { 347 kfree(rv, M_RMAN); 348 rv = NULL; 349 goto out; 350 } 351 LIST_INIT(s->r_sharehead); 352 LIST_INSERT_HEAD(s->r_sharehead, s, 353 r_sharelink); 354 s->r_flags |= RF_FIRSTSHARE; 355 } 356 rv->r_sharehead = s->r_sharehead; 357 LIST_INSERT_HEAD(s->r_sharehead, rv, r_sharelink); 358 goto out; 359 } 360 } 361 362 /* 363 * We couldn't find anything. 364 */ 365 out: 366 /* 367 * If the user specified RF_ACTIVE in the initial flags, 368 * which is reflected in `want_activate', we attempt to atomically 369 * activate the resource. If this fails, we release the resource 370 * and indicate overall failure. (This behavior probably doesn't 371 * make sense for RF_TIMESHARE-type resources.) 372 */ 373 if (rv && want_activate) { 374 struct resource *whohas; 375 if (int_rman_activate_resource(rm, rv, &whohas)) { 376 int_rman_release_resource(rm, rv); 377 rv = NULL; 378 } 379 } 380 lwkt_reltoken(rm->rm_slock); 381 return (rv); 382 } 383 384 static int 385 int_rman_activate_resource(struct rman *rm, struct resource *r, 386 struct resource **whohas) 387 { 388 struct resource *s; 389 int ok; 390 391 /* 392 * If we are not timesharing, then there is nothing much to do. 393 * If we already have the resource, then there is nothing at all to do. 394 * If we are not on a sharing list with anybody else, then there is 395 * little to do. 396 */ 397 if ((r->r_flags & RF_TIMESHARE) == 0 398 || (r->r_flags & RF_ACTIVE) != 0 399 || r->r_sharehead == 0) { 400 r->r_flags |= RF_ACTIVE; 401 return 0; 402 } 403 404 ok = 1; 405 for (s = LIST_FIRST(r->r_sharehead); s && ok; 406 s = LIST_NEXT(s, r_sharelink)) { 407 if ((s->r_flags & RF_ACTIVE) != 0) { 408 ok = 0; 409 *whohas = s; 410 } 411 } 412 if (ok) { 413 r->r_flags |= RF_ACTIVE; 414 return 0; 415 } 416 return EBUSY; 417 } 418 419 int 420 rman_activate_resource(struct resource *r) 421 { 422 int rv; 423 struct resource *whohas; 424 struct rman *rm; 425 426 rm = r->r_rm; 427 lwkt_gettoken(rm->rm_slock); 428 rv = int_rman_activate_resource(rm, r, &whohas); 429 lwkt_reltoken(rm->rm_slock); 430 return rv; 431 } 432 433 #if 0 434 435 /* XXX */ 436 int 437 rman_await_resource(struct resource *r, int slpflags, int timo) 438 { 439 int rv; 440 struct resource *whohas; 441 struct rman *rm; 442 443 rm = r->r_rm; 444 for (;;) { 445 lwkt_gettoken(rm->rm_slock); 446 rv = int_rman_activate_resource(rm, r, &whohas); 447 if (rv != EBUSY) 448 return (rv); /* returns with ilock held */ 449 450 if (r->r_sharehead == 0) 451 panic("rman_await_resource"); 452 /* 453 * A critical section will hopefully will prevent a race 454 * between lwkt_reltoken and tsleep where a process 455 * could conceivably get in and release the resource 456 * before we have a chance to sleep on it. YYY 457 */ 458 crit_enter(); 459 whohas->r_flags |= RF_WANTED; 460 rv = tsleep(r->r_sharehead, slpflags, "rmwait", timo); 461 if (rv) { 462 lwkt_reltoken(rm->rm_slock); 463 crit_exit(); 464 return rv; 465 } 466 crit_exit(); 467 } 468 } 469 470 #endif 471 472 static int 473 int_rman_deactivate_resource(struct resource *r) 474 { 475 r->r_flags &= ~RF_ACTIVE; 476 if (r->r_flags & RF_WANTED) { 477 r->r_flags &= ~RF_WANTED; 478 wakeup(r->r_sharehead); 479 } 480 return 0; 481 } 482 483 int 484 rman_deactivate_resource(struct resource *r) 485 { 486 struct rman *rm; 487 488 rm = r->r_rm; 489 lwkt_gettoken(rm->rm_slock); 490 int_rman_deactivate_resource(r); 491 lwkt_reltoken(rm->rm_slock); 492 return 0; 493 } 494 495 static int 496 int_rman_release_resource(struct rman *rm, struct resource *r) 497 { 498 struct resource *s, *t; 499 500 if (r->r_flags & RF_ACTIVE) 501 int_rman_deactivate_resource(r); 502 503 /* 504 * Check for a sharing list first. If there is one, then we don't 505 * have to think as hard. 506 */ 507 if (r->r_sharehead) { 508 /* 509 * If a sharing list exists, then we know there are at 510 * least two sharers. 511 * 512 * If we are in the main circleq, appoint someone else. 513 */ 514 LIST_REMOVE(r, r_sharelink); 515 s = LIST_FIRST(r->r_sharehead); 516 if (r->r_flags & RF_FIRSTSHARE) { 517 s->r_flags |= RF_FIRSTSHARE; 518 TAILQ_INSERT_BEFORE(r, s, r_link); 519 TAILQ_REMOVE(&rm->rm_list, r, r_link); 520 } 521 522 /* 523 * Make sure that the sharing list goes away completely 524 * if the resource is no longer being shared at all. 525 */ 526 if (LIST_NEXT(s, r_sharelink) == 0) { 527 kfree(s->r_sharehead, M_RMAN); 528 s->r_sharehead = 0; 529 s->r_flags &= ~RF_FIRSTSHARE; 530 } 531 goto out; 532 } 533 534 /* 535 * Look at the adjacent resources in the list and see if our 536 * segment can be merged with any of them. 537 */ 538 s = TAILQ_PREV(r, resource_head, r_link); 539 t = TAILQ_NEXT(r, r_link); 540 541 if (s != NULL && (s->r_flags & RF_ALLOCATED) == 0 542 && t != NULL && (t->r_flags & RF_ALLOCATED) == 0) { 543 /* 544 * Merge all three segments. 545 */ 546 s->r_end = t->r_end; 547 TAILQ_REMOVE(&rm->rm_list, r, r_link); 548 TAILQ_REMOVE(&rm->rm_list, t, r_link); 549 kfree(t, M_RMAN); 550 } else if (s != NULL && (s->r_flags & RF_ALLOCATED) == 0) { 551 /* 552 * Merge previous segment with ours. 553 */ 554 s->r_end = r->r_end; 555 TAILQ_REMOVE(&rm->rm_list, r, r_link); 556 } else if (t != NULL && (t->r_flags & RF_ALLOCATED) == 0) { 557 /* 558 * Merge next segment with ours. 559 */ 560 t->r_start = r->r_start; 561 TAILQ_REMOVE(&rm->rm_list, r, r_link); 562 } else { 563 /* 564 * At this point, we know there is nothing we 565 * can potentially merge with, because on each 566 * side, there is either nothing there or what is 567 * there is still allocated. In that case, we don't 568 * want to remove r from the list; we simply want to 569 * change it to an unallocated region and return 570 * without freeing anything. 571 */ 572 r->r_flags &= ~RF_ALLOCATED; 573 return 0; 574 } 575 576 out: 577 kfree(r, M_RMAN); 578 return 0; 579 } 580 581 int 582 rman_release_resource(struct resource *r) 583 { 584 struct rman *rm = r->r_rm; 585 int rv; 586 587 lwkt_gettoken(rm->rm_slock); 588 rv = int_rman_release_resource(rm, r); 589 lwkt_reltoken(rm->rm_slock); 590 return (rv); 591 } 592 593 uint32_t 594 rman_make_alignment_flags(uint32_t size) 595 { 596 int i; 597 598 /* 599 * Find the hightest bit set, and add one if more than one bit 600 * set. We're effectively computing the ceil(log2(size)) here. 601 */ 602 for (i = 32; i > 0; i--) 603 if ((1 << i) & size) 604 break; 605 if (~(1 << i) & size) 606 i++; 607 608 return(RF_ALIGNMENT_LOG2(i)); 609 } 610 611 /* 612 * Sysctl interface for scanning the resource lists. 613 * 614 * We take two input parameters; the index into the list of resource 615 * managers, and the resource offset into the list. 616 */ 617 static int 618 sysctl_rman(SYSCTL_HANDLER_ARGS) 619 { 620 int *name = (int *)arg1; 621 u_int namelen = arg2; 622 int rman_idx, res_idx; 623 struct rman *rm; 624 struct resource *res; 625 struct u_rman urm; 626 struct u_resource ures; 627 int error; 628 629 if (namelen != 3) 630 return (EINVAL); 631 632 if (bus_data_generation_check(name[0])) 633 return (EINVAL); 634 rman_idx = name[1]; 635 res_idx = name[2]; 636 637 /* 638 * Find the indexed resource manager 639 */ 640 TAILQ_FOREACH(rm, &rman_head, rm_link) { 641 if (rman_idx-- == 0) 642 break; 643 } 644 if (rm == NULL) 645 return (ENOENT); 646 647 /* 648 * If the resource index is -1, we want details on the 649 * resource manager. 650 */ 651 if (res_idx == -1) { 652 urm.rm_handle = (uintptr_t)rm; 653 strlcpy(urm.rm_descr, rm->rm_descr, RM_TEXTLEN); 654 urm.rm_start = rm->rm_start; 655 urm.rm_size = rm->rm_end - rm->rm_start + 1; 656 urm.rm_type = rm->rm_type; 657 658 error = SYSCTL_OUT(req, &urm, sizeof(urm)); 659 return (error); 660 } 661 662 /* 663 * Find the indexed resource and return it. 664 */ 665 TAILQ_FOREACH(res, &rm->rm_list, r_link) { 666 if (res_idx-- == 0) { 667 ures.r_handle = (uintptr_t)res; 668 ures.r_parent = (uintptr_t)res->r_rm; 669 ures.r_device = (uintptr_t)res->r_dev; 670 if (res->r_dev != NULL) { 671 if (device_get_name(res->r_dev) != NULL) { 672 ksnprintf(ures.r_devname, RM_TEXTLEN, 673 "%s%d", 674 device_get_name(res->r_dev), 675 device_get_unit(res->r_dev)); 676 } else { 677 strlcpy(ures.r_devname, "nomatch", 678 RM_TEXTLEN); 679 } 680 } else { 681 ures.r_devname[0] = '\0'; 682 } 683 ures.r_start = res->r_start; 684 ures.r_size = res->r_end - res->r_start + 1; 685 ures.r_flags = res->r_flags; 686 687 error = SYSCTL_OUT(req, &ures, sizeof(ures)); 688 return (error); 689 } 690 } 691 return (ENOENT); 692 } 693 694 SYSCTL_NODE(_hw_bus, OID_AUTO, rman, CTLFLAG_RD, sysctl_rman, 695 "kernel resource manager"); 696