sys/kern/subr_rman.c

   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  * $DragonFly: src/sys/kern/subr_rman.c,v 1.2 2003/06/17 04:28:41 dillon Exp $
  31  */
  32
  33 /*
  34  * The kernel resource manager.  This code is responsible for keeping track
  35  * of hardware resources which are apportioned out to various drivers.
  36  * It does not actually assign those resources, and it is not expected
  37  * that end-device drivers will call into this code directly.  Rather,
  38  * the code which implements the buses that those devices are attached to,
  39  * and the code which manages CPU resources, will call this code, and the
  40  * end-device drivers will make upcalls to that code to actually perform
  41  * the allocation.
  42  *
  43  * There are two sorts of resources managed by this code.  The first is
  44  * the more familiar array (RMAN_ARRAY) type; resources in this class
  45  * consist of a sequence of individually-allocatable objects which have
  46  * been numbered in some well-defined order.  Most of the resources
  47  * are of this type, as it is the most familiar.  The second type is
  48  * called a gauge (RMAN_GAUGE), and models fungible resources (i.e.,
  49  * resources in which each instance is indistinguishable from every
  50  * other instance).  The principal anticipated application of gauges
  51  * is in the context of power consumption, where a bus may have a specific
  52  * power budget which all attached devices share.  RMAN_GAUGE is not
  53  * implemented yet.
  54  *
  55  * For array resources, we make one simplifying assumption: two clients
  56  * sharing the same resource must use the same range of indices.  That
  57  * is to say, sharing of overlapping-but-not-identical regions is not
  58  * permitted.
  59  */
  60
  61 #include <sys/param.h>
  62 #include <sys/systm.h>
  63 #include <sys/kernel.h>
  64 #include <sys/lock.h>
  65 #include <sys/malloc.h>
  66 #include <sys/bus.h>            /* XXX debugging */
  67 #include <machine/bus.h>
  68 #include <sys/rman.h>
  69
  70 static MALLOC_DEFINE(M_RMAN, "rman", "Resource manager");
  71
  72 struct  rman_head rman_head;
  73 #ifndef NULL_SIMPLELOCKS
  74 static  struct simplelock rman_lock; /* mutex to protect rman_head */
  75 #endif
  76 static  int int_rman_activate_resource(struct rman *rm, struct resource *r,
  77                                        struct resource **whohas);
  78 static  int int_rman_deactivate_resource(struct resource *r);
  79 static  int int_rman_release_resource(struct rman *rm, struct resource *r);
  80
  81 #define CIRCLEQ_TERMCOND(var, head)     (var == (void *)&(head))
  82
  83 int
  84 rman_init(struct rman *rm)
  85 {
  86         static int once;
  87
  88         if (once == 0) {
  89                 once = 1;
  90                 TAILQ_INIT(&rman_head);
  91                 simple_lock_init(&rman_lock);
  92         }
  93
  94         if (rm->rm_type == RMAN_UNINIT)
  95                 panic("rman_init");
  96         if (rm->rm_type == RMAN_GAUGE)
  97                 panic("implement RMAN_GAUGE");
  98
  99         CIRCLEQ_INIT(&rm->rm_list);
 100         rm->rm_slock = malloc(sizeof *rm->rm_slock, M_RMAN, M_NOWAIT);
 101         if (rm->rm_slock == 0)
 102                 return ENOMEM;
 103         simple_lock_init(rm->rm_slock);
 104
 105         simple_lock(&rman_lock);
 106         TAILQ_INSERT_TAIL(&rman_head, rm, rm_link);
 107         simple_unlock(&rman_lock);
 108         return 0;
 109 }
 110
 111 /*
 112  * NB: this interface is not robust against programming errors which
 113  * add multiple copies of the same region.
 114  */
 115 int
 116 rman_manage_region(struct rman *rm, u_long start, u_long end)
 117 {
 118         struct resource *r, *s;
 119
 120         r = malloc(sizeof *r, M_RMAN, M_NOWAIT);
 121         if (r == 0)
 122                 return ENOMEM;
 123         bzero(r, sizeof *r);
 124         r->r_sharehead = 0;
 125         r->r_start = start;
 126         r->r_end = end;
 127         r->r_flags = 0;
 128         r->r_dev = 0;
 129         r->r_rm = rm;
 130
 131         simple_lock(rm->rm_slock);
 132         for (s = CIRCLEQ_FIRST(&rm->rm_list);
 133              !CIRCLEQ_TERMCOND(s, rm->rm_list) && s->r_end < r->r_start;
 134              s = CIRCLEQ_NEXT(s, r_link))
 135                 ;
 136
 137         if (CIRCLEQ_TERMCOND(s, rm->rm_list)) {
 138                 CIRCLEQ_INSERT_TAIL(&rm->rm_list, r, r_link);
 139         } else {
 140                 CIRCLEQ_INSERT_BEFORE(&rm->rm_list, s, r, r_link);
 141         }
 142
 143         simple_unlock(rm->rm_slock);
 144         return 0;
 145 }
 146
 147 int
 148 rman_fini(struct rman *rm)
 149 {
 150         struct resource *r;
 151
 152         simple_lock(rm->rm_slock);
 153         CIRCLEQ_FOREACH(r, &rm->rm_list, r_link) {
 154                 if (r->r_flags & RF_ALLOCATED) {
 155                         simple_unlock(rm->rm_slock);
 156                         return EBUSY;
 157                 }
 158         }
 159
 160         /*
 161          * There really should only be one of these if we are in this
 162          * state and the code is working properly, but it can't hurt.
 163          */
 164         while (!CIRCLEQ_EMPTY(&rm->rm_list)) {
 165                 r = CIRCLEQ_FIRST(&rm->rm_list);
 166                 CIRCLEQ_REMOVE(&rm->rm_list, r, r_link);
 167                 free(r, M_RMAN);
 168         }
 169         simple_unlock(rm->rm_slock);
 170         simple_lock(&rman_lock);
 171         TAILQ_REMOVE(&rman_head, rm, rm_link);
 172         simple_unlock(&rman_lock);
 173         free(rm->rm_slock, M_RMAN);
 174
 175         return 0;
 176 }
 177
 178 struct resource *
 179 rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
 180                       u_int flags, struct device *dev)
 181 {
 182         u_int   want_activate;
 183         struct  resource *r, *s, *rv;
 184         u_long  rstart, rend;
 185
 186         rv = 0;
 187
 188 #ifdef RMAN_DEBUG
 189         printf("rman_reserve_resource: <%s> request: [%#lx, %#lx], length "
 190                "%#lx, flags %u, device %s%d\n", rm->rm_descr, start, end,
 191                count, flags, device_get_name(dev), device_get_unit(dev));
 192 #endif /* RMAN_DEBUG */
 193         want_activate = (flags & RF_ACTIVE);
 194         flags &= ~RF_ACTIVE;
 195
 196         simple_lock(rm->rm_slock);
 197
 198         for (r = CIRCLEQ_FIRST(&rm->rm_list);
 199              !CIRCLEQ_TERMCOND(r, rm->rm_list) && r->r_end < start;
 200              r = CIRCLEQ_NEXT(r, r_link))
 201                 ;
 202
 203         if (CIRCLEQ_TERMCOND(r, rm->rm_list)) {
 204 #ifdef RMAN_DEBUG
 205                 printf("could not find a region\n");
 206 #endif RMAN_DEBUG
 207                 goto out;
 208         }
 209
 210         /*
 211          * First try to find an acceptable totally-unshared region.
 212          */
 213         for (s = r; !CIRCLEQ_TERMCOND(s, rm->rm_list);
 214              s = CIRCLEQ_NEXT(s, r_link)) {
 215 #ifdef RMAN_DEBUG
 216                 printf("considering [%#lx, %#lx]\n", s->r_start, s->r_end);
 217 #endif /* RMAN_DEBUG */
 218                 if (s->r_start > end) {
 219 #ifdef RMAN_DEBUG
 220                         printf("s->r_start (%#lx) > end (%#lx)\n", s->r_start, end);
 221 #endif /* RMAN_DEBUG */
 222                         break;
 223                 }
 224                 if (s->r_flags & RF_ALLOCATED) {
 225 #ifdef RMAN_DEBUG
 226                         printf("region is allocated\n");
 227 #endif /* RMAN_DEBUG */
 228                         continue;
 229                 }
 230                 rstart = max(s->r_start, start);
 231                 rstart = (rstart + ((1ul << RF_ALIGNMENT(flags))) - 1) &
 232                     ~((1ul << RF_ALIGNMENT(flags)) - 1);
 233                 rend = min(s->r_end, max(start + count, end));
 234 #ifdef RMAN_DEBUG
 235                 printf("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n",
 236                        rstart, rend, (rend - rstart + 1), count);
 237 #endif /* RMAN_DEBUG */
 238
 239                 if ((rend - rstart + 1) >= count) {
 240 #ifdef RMAN_DEBUG
 241                         printf("candidate region: [%#lx, %#lx], size %#lx\n",
 242                                rend, rstart, (rend - rstart + 1));
 243 #endif /* RMAN_DEBUG */
 244                         if ((s->r_end - s->r_start + 1) == count) {
 245 #ifdef RMAN_DEBUG
 246                                 printf("candidate region is entire chunk\n");
 247 #endif /* RMAN_DEBUG */
 248                                 rv = s;
 249                                 rv->r_flags |= RF_ALLOCATED | flags;
 250                                 rv->r_dev = dev;
 251                                 goto out;
 252                         }
 253
 254                         /*
 255                          * If s->r_start < rstart and
 256                          *    s->r_end > rstart + count - 1, then
 257                          * we need to split the region into three pieces
 258                          * (the middle one will get returned to the user).
 259                          * Otherwise, we are allocating at either the
 260                          * beginning or the end of s, so we only need to
 261                          * split it in two.  The first case requires
 262                          * two new allocations; the second requires but one.
 263                          */
 264                         rv = malloc(sizeof *rv, M_RMAN, M_NOWAIT);
 265                         if (rv == 0)
 266                                 goto out;
 267                         bzero(rv, sizeof *rv);
 268                         rv->r_start = rstart;
 269                         rv->r_end = rstart + count - 1;
 270                         rv->r_flags = flags | RF_ALLOCATED;
 271                         rv->r_dev = dev;
 272                         rv->r_sharehead = 0;
 273                         rv->r_rm = rm;
 274
 275                         if (s->r_start < rv->r_start && s->r_end > rv->r_end) {
 276 #ifdef RMAN_DEBUG
 277                                 printf("splitting region in three parts: "
 278                                        "[%#lx, %#lx]; [%#lx, %#lx]; [%#lx, %#lx]\n",
 279                                        s->r_start, rv->r_start - 1,
 280                                        rv->r_start, rv->r_end,
 281                                        rv->r_end + 1, s->r_end);
 282 #endif /* RMAN_DEBUG */
 283                                 /*
 284                                  * We are allocating in the middle.
 285                                  */
 286                                 r = malloc(sizeof *r, M_RMAN, M_NOWAIT);
 287                                 if (r == 0) {
 288                                         free(rv, M_RMAN);
 289                                         rv = 0;
 290                                         goto out;
 291                                 }
 292                                 bzero(r, sizeof *r);
 293                                 r->r_start = rv->r_end + 1;
 294                                 r->r_end = s->r_end;
 295                                 r->r_flags = s->r_flags;
 296                                 r->r_dev = 0;
 297                                 r->r_sharehead = 0;
 298                                 r->r_rm = rm;
 299                                 s->r_end = rv->r_start - 1;
 300                                 CIRCLEQ_INSERT_AFTER(&rm->rm_list, s, rv,
 301                                                      r_link);
 302                                 CIRCLEQ_INSERT_AFTER(&rm->rm_list, rv, r,
 303                                                      r_link);
 304                         } else if (s->r_start == rv->r_start) {
 305 #ifdef RMAN_DEBUG
 306                                 printf("allocating from the beginning\n");
 307 #endif /* RMAN_DEBUG */
 308                                 /*
 309                                  * We are allocating at the beginning.
 310                                  */
 311                                 s->r_start = rv->r_end + 1;
 312                                 CIRCLEQ_INSERT_BEFORE(&rm->rm_list, s, rv,
 313                                                       r_link);
 314                         } else {
 315 #ifdef RMAN_DEBUG
 316                                 printf("allocating at the end\n");
 317 #endif /* RMAN_DEBUG */
 318                                 /*
 319                                  * We are allocating at the end.
 320                                  */
 321                                 s->r_end = rv->r_start - 1;
 322                                 CIRCLEQ_INSERT_AFTER(&rm->rm_list, s, rv,
 323                                                      r_link);
 324                         }
 325                         goto out;
 326                 }
 327         }
 328
 329         /*
 330          * Now find an acceptable shared region, if the client's requirements
 331          * allow sharing.  By our implementation restriction, a candidate
 332          * region must match exactly by both size and sharing type in order
 333          * to be considered compatible with the client's request.  (The
 334          * former restriction could probably be lifted without too much
 335          * additional work, but this does not seem warranted.)
 336          */
 337 #ifdef RMAN_DEBUG
 338         printf("no unshared regions found\n");
 339 #endif /* RMAN_DEBUG */
 340         if ((flags & (RF_SHAREABLE | RF_TIMESHARE)) == 0)
 341                 goto out;
 342
 343         for (s = r; !CIRCLEQ_TERMCOND(s, rm->rm_list);
 344              s = CIRCLEQ_NEXT(s, r_link)) {
 345                 if (s->r_start > end)
 346                         break;
 347                 if ((s->r_flags & flags) != flags)
 348                         continue;
 349                 rstart = max(s->r_start, start);
 350                 rend = min(s->r_end, max(start + count, end));
 351                 if (s->r_start >= start && s->r_end <= end
 352                     && (s->r_end - s->r_start + 1) == count) {
 353                         rv = malloc(sizeof *rv, M_RMAN, M_NOWAIT);
 354                         if (rv == 0)
 355                                 goto out;
 356                         bzero(rv, sizeof *rv);
 357                         rv->r_start = s->r_start;
 358                         rv->r_end = s->r_end;
 359                         rv->r_flags = s->r_flags &
 360                                 (RF_ALLOCATED | RF_SHAREABLE | RF_TIMESHARE);
 361                         rv->r_dev = dev;
 362                         rv->r_rm = rm;
 363                         if (s->r_sharehead == 0) {
 364                                 s->r_sharehead = malloc(sizeof *s->r_sharehead,
 365                                                         M_RMAN, M_NOWAIT);
 366                                 if (s->r_sharehead == 0) {
 367                                         free(rv, M_RMAN);
 368                                         rv = 0;
 369                                         goto out;
 370                                 }
 371                                 bzero(s->r_sharehead, sizeof *s->r_sharehead);
 372                                 LIST_INIT(s->r_sharehead);
 373                                 LIST_INSERT_HEAD(s->r_sharehead, s,
 374                                                  r_sharelink);
 375                                 s->r_flags |= RF_FIRSTSHARE;
 376                         }
 377                         rv->r_sharehead = s->r_sharehead;
 378                         LIST_INSERT_HEAD(s->r_sharehead, rv, r_sharelink);
 379                         goto out;
 380                 }
 381         }
 382
 383         /*
 384          * We couldn't find anything.
 385          */
 386 out:
 387         /*
 388          * If the user specified RF_ACTIVE in the initial flags,
 389          * which is reflected in `want_activate', we attempt to atomically
 390          * activate the resource.  If this fails, we release the resource
 391          * and indicate overall failure.  (This behavior probably doesn't
 392          * make sense for RF_TIMESHARE-type resources.)
 393          */
 394         if (rv && want_activate) {
 395                 struct resource *whohas;
 396                 if (int_rman_activate_resource(rm, rv, &whohas)) {
 397                         int_rman_release_resource(rm, rv);
 398                         rv = 0;
 399                 }
 400         }
 401
 402         simple_unlock(rm->rm_slock);
 403         return (rv);
 404 }
 405
 406 static int
 407 int_rman_activate_resource(struct rman *rm, struct resource *r,
 408                            struct resource **whohas)
 409 {
 410         struct resource *s;
 411         int ok;
 412
 413         /*
 414          * If we are not timesharing, then there is nothing much to do.
 415          * If we already have the resource, then there is nothing at all to do.
 416          * If we are not on a sharing list with anybody else, then there is
 417          * little to do.
 418          */
 419         if ((r->r_flags & RF_TIMESHARE) == 0
 420             || (r->r_flags & RF_ACTIVE) != 0
 421             || r->r_sharehead == 0) {
 422                 r->r_flags |= RF_ACTIVE;
 423                 return 0;
 424         }
 425
 426         ok = 1;
 427         for (s = LIST_FIRST(r->r_sharehead); s && ok;
 428              s = LIST_NEXT(s, r_sharelink)) {
 429                 if ((s->r_flags & RF_ACTIVE) != 0) {
 430                         ok = 0;
 431                         *whohas = s;
 432                 }
 433         }
 434         if (ok) {
 435                 r->r_flags |= RF_ACTIVE;
 436                 return 0;
 437         }
 438         return EBUSY;
 439 }
 440
 441 int
 442 rman_activate_resource(struct resource *r)
 443 {
 444         int rv;
 445         struct resource *whohas;
 446         struct rman *rm;
 447
 448         rm = r->r_rm;
 449         simple_lock(rm->rm_slock);
 450         rv = int_rman_activate_resource(rm, r, &whohas);
 451         simple_unlock(rm->rm_slock);
 452         return rv;
 453 }
 454
 455 int
 456 rman_await_resource(struct resource *r, int pri, int timo)
 457 {
 458         int     rv, s;
 459         struct  resource *whohas;
 460         struct  rman *rm;
 461
 462         rm = r->r_rm;
 463         for (;;) {
 464                 simple_lock(rm->rm_slock);
 465                 rv = int_rman_activate_resource(rm, r, &whohas);
 466                 if (rv != EBUSY)
 467                         return (rv);    /* returns with simplelock */
 468
 469                 if (r->r_sharehead == 0)
 470                         panic("rman_await_resource");
 471                 /*
 472                  * splhigh hopefully will prevent a race between
 473                  * simple_unlock and tsleep where a process
 474                  * could conceivably get in and release the resource
 475                  * before we have a chance to sleep on it.
 476                  */
 477                 s = splhigh();
 478                 whohas->r_flags |= RF_WANTED;
 479                 simple_unlock(rm->rm_slock);
 480                 rv = tsleep(r->r_sharehead, pri, "rmwait", timo);
 481                 if (rv) {
 482                         splx(s);
 483                         return rv;
 484                 }
 485                 simple_lock(rm->rm_slock);
 486                 splx(s);
 487         }
 488 }
 489
 490 static int
 491 int_rman_deactivate_resource(struct resource *r)
 492 {
 493         struct  rman *rm;
 494
 495         rm = r->r_rm;
 496         r->r_flags &= ~RF_ACTIVE;
 497         if (r->r_flags & RF_WANTED) {
 498                 r->r_flags &= ~RF_WANTED;
 499                 wakeup(r->r_sharehead);
 500         }
 501         return 0;
 502 }
 503
 504 int
 505 rman_deactivate_resource(struct resource *r)
 506 {
 507         struct  rman *rm;
 508
 509         rm = r->r_rm;
 510         simple_lock(rm->rm_slock);
 511         int_rman_deactivate_resource(r);
 512         simple_unlock(rm->rm_slock);
 513         return 0;
 514 }
 515
 516 static int
 517 int_rman_release_resource(struct rman *rm, struct resource *r)
 518 {
 519         struct  resource *s, *t;
 520
 521         if (r->r_flags & RF_ACTIVE)
 522                 int_rman_deactivate_resource(r);
 523
 524         /*
 525          * Check for a sharing list first.  If there is one, then we don't
 526          * have to think as hard.
 527          */
 528         if (r->r_sharehead) {
 529                 /*
 530                  * If a sharing list exists, then we know there are at
 531                  * least two sharers.
 532                  *
 533                  * If we are in the main circleq, appoint someone else.
 534                  */
 535                 LIST_REMOVE(r, r_sharelink);
 536                 s = LIST_FIRST(r->r_sharehead);
 537                 if (r->r_flags & RF_FIRSTSHARE) {
 538                         s->r_flags |= RF_FIRSTSHARE;
 539                         CIRCLEQ_INSERT_BEFORE(&rm->rm_list, r, s, r_link);
 540                         CIRCLEQ_REMOVE(&rm->rm_list, r, r_link);
 541                 }
 542
 543                 /*
 544                  * Make sure that the sharing list goes away completely
 545                  * if the resource is no longer being shared at all.
 546                  */
 547                 if (LIST_NEXT(s, r_sharelink) == 0) {
 548                         free(s->r_sharehead, M_RMAN);
 549                         s->r_sharehead = 0;
 550                         s->r_flags &= ~RF_FIRSTSHARE;
 551                 }
 552                 goto out;
 553         }
 554
 555         /*
 556          * Look at the adjacent resources in the list and see if our
 557          * segment can be merged with any of them.
 558          */
 559         s = CIRCLEQ_PREV(r, r_link);
 560         t = CIRCLEQ_NEXT(r, r_link);
 561
 562         if (s != (void *)&rm->rm_list && (s->r_flags & RF_ALLOCATED) == 0
 563             && t != (void *)&rm->rm_list && (t->r_flags & RF_ALLOCATED) == 0) {
 564                 /*
 565                  * Merge all three segments.
 566                  */
 567                 s->r_end = t->r_end;
 568                 CIRCLEQ_REMOVE(&rm->rm_list, r, r_link);
 569                 CIRCLEQ_REMOVE(&rm->rm_list, t, r_link);
 570                 free(t, M_RMAN);
 571         } else if (s != (void *)&rm->rm_list
 572                    && (s->r_flags & RF_ALLOCATED) == 0) {
 573                 /*
 574                  * Merge previous segment with ours.
 575                  */
 576                 s->r_end = r->r_end;
 577                 CIRCLEQ_REMOVE(&rm->rm_list, r, r_link);
 578         } else if (t != (void *)&rm->rm_list
 579                    && (t->r_flags & RF_ALLOCATED) == 0) {
 580                 /*
 581                  * Merge next segment with ours.
 582                  */
 583                 t->r_start = r->r_start;
 584                 CIRCLEQ_REMOVE(&rm->rm_list, r, r_link);
 585         } else {
 586                 /*
 587                  * At this point, we know there is nothing we
 588                  * can potentially merge with, because on each
 589                  * side, there is either nothing there or what is
 590                  * there is still allocated.  In that case, we don't
 591                  * want to remove r from the list; we simply want to
 592                  * change it to an unallocated region and return
 593                  * without freeing anything.
 594                  */
 595                 r->r_flags &= ~RF_ALLOCATED;
 596                 return 0;
 597         }
 598
 599 out:
 600         free(r, M_RMAN);
 601         return 0;
 602 }
 603
 604 int
 605 rman_release_resource(struct resource *r)
 606 {
 607         int     rv;
 608         struct  rman *rm = r->r_rm;
 609
 610         simple_lock(rm->rm_slock);
 611         rv = int_rman_release_resource(rm, r);
 612         simple_unlock(rm->rm_slock);
 613         return (rv);
 614 }
 615
 616 uint32_t
 617 rman_make_alignment_flags(uint32_t size)
 618 {
 619         int     i;
 620
 621         /*
 622          * Find the hightest bit set, and add one if more than one bit
 623          * set.  We're effectively computing the ceil(log2(size)) here.
 624          */
 625         for (i = 32; i > 0; i--)
 626                 if ((1 << i) & size)
 627                         break;
 628         if (~(1 << i) & size)
 629                 i++;
 630
 631         return(RF_ALIGNMENT_LOG2(i));
 632 }