The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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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 <sys/cdefs.h>
   59 __FBSDID("$FreeBSD: releng/6.0/sys/kern/subr_rman.c 145953 2005-05-06 02:50:00Z cperciva $");
   60 
   61 #define __RMAN_RESOURCE_VISIBLE
   62 #include <sys/param.h>
   63 #include <sys/systm.h>
   64 #include <sys/kernel.h>
   65 #include <sys/lock.h>
   66 #include <sys/malloc.h>
   67 #include <sys/mutex.h>
   68 #include <sys/bus.h>            /* XXX debugging */
   69 #include <machine/bus.h>
   70 #include <sys/rman.h>
   71 #include <sys/sysctl.h>
   72 
   73 int     rman_debug = 0;
   74 TUNABLE_INT("debug.rman_debug", &rman_debug);
   75 SYSCTL_INT(_debug, OID_AUTO, rman_debug, CTLFLAG_RW,
   76     &rman_debug, 0, "rman debug");
   77 
   78 #define DPRINTF(params) if (rman_debug) printf params
   79 
   80 static MALLOC_DEFINE(M_RMAN, "rman", "Resource manager");
   81 
   82 struct  rman_head rman_head;
   83 static  struct mtx rman_mtx; /* mutex to protect rman_head */
   84 static  int int_rman_activate_resource(struct rman *rm, struct resource *r,
   85                                        struct resource **whohas);
   86 static  int int_rman_deactivate_resource(struct resource *r);
   87 static  int int_rman_release_resource(struct rman *rm, struct resource *r);
   88 
   89 int
   90 rman_init(struct rman *rm)
   91 {
   92         static int once;
   93 
   94         if (once == 0) {
   95                 once = 1;
   96                 TAILQ_INIT(&rman_head);
   97                 mtx_init(&rman_mtx, "rman head", NULL, MTX_DEF);
   98         }
   99 
  100         if (rm->rm_type == RMAN_UNINIT)
  101                 panic("rman_init");
  102         if (rm->rm_type == RMAN_GAUGE)
  103                 panic("implement RMAN_GAUGE");
  104 
  105         TAILQ_INIT(&rm->rm_list);
  106         rm->rm_mtx = malloc(sizeof *rm->rm_mtx, M_RMAN, M_NOWAIT | M_ZERO);
  107         if (rm->rm_mtx == 0)
  108                 return ENOMEM;
  109         mtx_init(rm->rm_mtx, "rman", NULL, MTX_DEF);
  110 
  111         mtx_lock(&rman_mtx);
  112         TAILQ_INSERT_TAIL(&rman_head, rm, rm_link);
  113         mtx_unlock(&rman_mtx);
  114         return 0;
  115 }
  116 
  117 /*
  118  * NB: this interface is not robust against programming errors which
  119  * add multiple copies of the same region.
  120  */
  121 int
  122 rman_manage_region(struct rman *rm, u_long start, u_long end)
  123 {
  124         struct resource *r, *s;
  125 
  126         DPRINTF(("rman_manage_region: <%s> request: start %#lx, end %#lx\n",
  127             rm->rm_descr, start, end));
  128         r = malloc(sizeof *r, M_RMAN, M_NOWAIT | M_ZERO);
  129         if (r == 0)
  130                 return ENOMEM;
  131         r->r_start = start;
  132         r->r_end = end;
  133         r->r_rm = rm;
  134 
  135         mtx_lock(rm->rm_mtx);
  136         for (s = TAILQ_FIRST(&rm->rm_list);     
  137              s && s->r_end < r->r_start;
  138              s = TAILQ_NEXT(s, r_link))
  139                 ;
  140 
  141         if (s == NULL) {
  142                 TAILQ_INSERT_TAIL(&rm->rm_list, r, r_link);
  143         } else {
  144                 TAILQ_INSERT_BEFORE(s, r, r_link);
  145         }
  146 
  147         mtx_unlock(rm->rm_mtx);
  148         return 0;
  149 }
  150 
  151 int
  152 rman_fini(struct rman *rm)
  153 {
  154         struct resource *r;
  155 
  156         mtx_lock(rm->rm_mtx);
  157         TAILQ_FOREACH(r, &rm->rm_list, r_link) {
  158                 if (r->r_flags & RF_ALLOCATED) {
  159                         mtx_unlock(rm->rm_mtx);
  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                 free(r, M_RMAN);
  172         }
  173         mtx_unlock(rm->rm_mtx);
  174         mtx_lock(&rman_mtx);
  175         TAILQ_REMOVE(&rman_head, rm, rm_link);
  176         mtx_unlock(&rman_mtx);
  177         mtx_destroy(rm->rm_mtx);
  178         free(rm->rm_mtx, M_RMAN);
  179 
  180         return 0;
  181 }
  182 
  183 struct resource *
  184 rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end,
  185                       u_long count, u_long bound,  u_int flags,
  186                       struct device *dev)
  187 {
  188         u_int   want_activate;
  189         struct  resource *r, *s, *rv;
  190         u_long  rstart, rend, amask, bmask;
  191 
  192         rv = 0;
  193 
  194         DPRINTF(("rman_reserve_resource: <%s> request: [%#lx, %#lx], length "
  195                "%#lx, flags %u, device %s\n", rm->rm_descr, start, end, count,
  196                flags, dev == NULL ? "<null>" : device_get_nameunit(dev)));
  197         want_activate = (flags & RF_ACTIVE);
  198         flags &= ~RF_ACTIVE;
  199 
  200         mtx_lock(rm->rm_mtx);
  201 
  202         for (r = TAILQ_FIRST(&rm->rm_list); 
  203              r && r->r_end < start;
  204              r = TAILQ_NEXT(r, r_link))
  205                 ;
  206 
  207         if (r == NULL) {
  208                 DPRINTF(("could not find a region\n"));
  209                 goto out;
  210         }
  211 
  212         amask = (1ul << RF_ALIGNMENT(flags)) - 1;
  213         /* If bound is 0, bmask will also be 0 */
  214         bmask = ~(bound - 1);
  215         /*
  216          * First try to find an acceptable totally-unshared region.
  217          */
  218         for (s = r; s; s = TAILQ_NEXT(s, r_link)) {
  219                 DPRINTF(("considering [%#lx, %#lx]\n", s->r_start, s->r_end));
  220                 if (s->r_start + count - 1 > end) {
  221                         DPRINTF(("s->r_start (%#lx) + count - 1> end (%#lx)\n",
  222                             s->r_start, end));
  223                         break;
  224                 }
  225                 if (s->r_flags & RF_ALLOCATED) {
  226                         DPRINTF(("region is allocated\n"));
  227                         continue;
  228                 }
  229                 rstart = ulmax(s->r_start, start);
  230                 /*
  231                  * Try to find a region by adjusting to boundary and alignment
  232                  * until both conditions are satisfied. This is not an optimal
  233                  * algorithm, but in most cases it isn't really bad, either.
  234                  */
  235                 do {
  236                         rstart = (rstart + amask) & ~amask;
  237                         if (((rstart ^ (rstart + count - 1)) & bmask) != 0)
  238                                 rstart += bound - (rstart & ~bmask);
  239                 } while ((rstart & amask) != 0 && rstart < end &&
  240                     rstart < s->r_end);
  241                 rend = ulmin(s->r_end, ulmax(rstart + count - 1, end));
  242                 if (rstart > rend) {
  243                         DPRINTF(("adjusted start exceeds end\n"));
  244                         continue;
  245                 }
  246                 DPRINTF(("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n",
  247                        rstart, rend, (rend - rstart + 1), count));
  248 
  249                 if ((rend - rstart + 1) >= count) {
  250                         DPRINTF(("candidate region: [%#lx, %#lx], size %#lx\n",
  251                                rstart, rend, (rend - rstart + 1)));
  252                         if ((s->r_end - s->r_start + 1) == count) {
  253                                 DPRINTF(("candidate region is entire chunk\n"));
  254                                 rv = s;
  255                                 rv->r_flags |= RF_ALLOCATED | flags;
  256                                 rv->r_dev = dev;
  257                                 goto out;
  258                         }
  259 
  260                         /*
  261                          * If s->r_start < rstart and
  262                          *    s->r_end > rstart + count - 1, then
  263                          * we need to split the region into three pieces
  264                          * (the middle one will get returned to the user).
  265                          * Otherwise, we are allocating at either the
  266                          * beginning or the end of s, so we only need to
  267                          * split it in two.  The first case requires
  268                          * two new allocations; the second requires but one.
  269                          */
  270                         rv = malloc(sizeof *rv, M_RMAN, M_NOWAIT | M_ZERO);
  271                         if (rv == 0)
  272                                 goto out;
  273                         rv->r_start = rstart;
  274                         rv->r_end = rstart + count - 1;
  275                         rv->r_flags = flags | RF_ALLOCATED;
  276                         rv->r_dev = dev;
  277                         rv->r_rm = rm;
  278                         
  279                         if (s->r_start < rv->r_start && s->r_end > rv->r_end) {
  280                                 DPRINTF(("splitting region in three parts: "
  281                                        "[%#lx, %#lx]; [%#lx, %#lx]; [%#lx, %#lx]\n",
  282                                        s->r_start, rv->r_start - 1,
  283                                        rv->r_start, rv->r_end,
  284                                        rv->r_end + 1, s->r_end));
  285                                 /*
  286                                  * We are allocating in the middle.
  287                                  */
  288                                 r = malloc(sizeof *r, M_RMAN, M_NOWAIT|M_ZERO);
  289                                 if (r == 0) {
  290                                         free(rv, M_RMAN);
  291                                         rv = 0;
  292                                         goto out;
  293                                 }
  294                                 r->r_start = rv->r_end + 1;
  295                                 r->r_end = s->r_end;
  296                                 r->r_flags = s->r_flags;
  297                                 r->r_rm = rm;
  298                                 s->r_end = rv->r_start - 1;
  299                                 TAILQ_INSERT_AFTER(&rm->rm_list, s, rv,
  300                                                      r_link);
  301                                 TAILQ_INSERT_AFTER(&rm->rm_list, rv, r,
  302                                                      r_link);
  303                         } else if (s->r_start == rv->r_start) {
  304                                 DPRINTF(("allocating from the beginning\n"));
  305                                 /*
  306                                  * We are allocating at the beginning.
  307                                  */
  308                                 s->r_start = rv->r_end + 1;
  309                                 TAILQ_INSERT_BEFORE(s, rv, r_link);
  310                         } else {
  311                                 DPRINTF(("allocating at the end\n"));
  312                                 /*
  313                                  * We are allocating at the end.
  314                                  */
  315                                 s->r_end = rv->r_start - 1;
  316                                 TAILQ_INSERT_AFTER(&rm->rm_list, s, rv,
  317                                                      r_link);
  318                         }
  319                         goto out;
  320                 }
  321         }
  322 
  323         /*
  324          * Now find an acceptable shared region, if the client's requirements
  325          * allow sharing.  By our implementation restriction, a candidate
  326          * region must match exactly by both size and sharing type in order
  327          * to be considered compatible with the client's request.  (The
  328          * former restriction could probably be lifted without too much
  329          * additional work, but this does not seem warranted.)
  330          */
  331         DPRINTF(("no unshared regions found\n"));
  332         if ((flags & (RF_SHAREABLE | RF_TIMESHARE)) == 0)
  333                 goto out;
  334 
  335         for (s = r; s; s = TAILQ_NEXT(s, r_link)) {
  336                 if (s->r_start > end)
  337                         break;
  338                 if ((s->r_flags & flags) != flags)
  339                         continue;
  340                 rstart = ulmax(s->r_start, start);
  341                 rend = ulmin(s->r_end, ulmax(start + count - 1, end));
  342                 if (s->r_start >= start && s->r_end <= end
  343                     && (s->r_end - s->r_start + 1) == count &&
  344                     (s->r_start & amask) == 0 &&
  345                     ((s->r_start ^ s->r_end) & bmask) == 0) {
  346                         rv = malloc(sizeof *rv, M_RMAN, M_NOWAIT | M_ZERO);
  347                         if (rv == 0)
  348                                 goto out;
  349                         rv->r_start = s->r_start;
  350                         rv->r_end = s->r_end;
  351                         rv->r_flags = s->r_flags & 
  352                                 (RF_ALLOCATED | RF_SHAREABLE | RF_TIMESHARE);
  353                         rv->r_dev = dev;
  354                         rv->r_rm = rm;
  355                         if (s->r_sharehead == 0) {
  356                                 s->r_sharehead = malloc(sizeof *s->r_sharehead,
  357                                                 M_RMAN, M_NOWAIT | M_ZERO);
  358                                 if (s->r_sharehead == 0) {
  359                                         free(rv, M_RMAN);
  360                                         rv = 0;
  361                                         goto out;
  362                                 }
  363                                 LIST_INIT(s->r_sharehead);
  364                                 LIST_INSERT_HEAD(s->r_sharehead, s, 
  365                                                  r_sharelink);
  366                                 s->r_flags |= RF_FIRSTSHARE;
  367                         }
  368                         rv->r_sharehead = s->r_sharehead;
  369                         LIST_INSERT_HEAD(s->r_sharehead, rv, r_sharelink);
  370                         goto out;
  371                 }
  372         }
  373 
  374         /*
  375          * We couldn't find anything.
  376          */
  377 out:
  378         /*
  379          * If the user specified RF_ACTIVE in the initial flags,
  380          * which is reflected in `want_activate', we attempt to atomically
  381          * activate the resource.  If this fails, we release the resource
  382          * and indicate overall failure.  (This behavior probably doesn't
  383          * make sense for RF_TIMESHARE-type resources.)
  384          */
  385         if (rv && want_activate) {
  386                 struct resource *whohas;
  387                 if (int_rman_activate_resource(rm, rv, &whohas)) {
  388                         int_rman_release_resource(rm, rv);
  389                         rv = 0;
  390                 }
  391         }
  392                         
  393         mtx_unlock(rm->rm_mtx);
  394         return (rv);
  395 }
  396 
  397 struct resource *
  398 rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
  399                       u_int flags, struct device *dev)
  400 {
  401 
  402         return (rman_reserve_resource_bound(rm, start, end, count, 0, flags,
  403             dev));
  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         mtx_lock(rm->rm_mtx);
  450         rv = int_rman_activate_resource(rm, r, &whohas);
  451         mtx_unlock(rm->rm_mtx);
  452         return rv;
  453 }
  454 
  455 int
  456 rman_await_resource(struct resource *r, int pri, int timo)
  457 {
  458         int     rv;
  459         struct  resource *whohas;
  460         struct  rman *rm;
  461 
  462         rm = r->r_rm;
  463         mtx_lock(rm->rm_mtx);
  464         for (;;) {
  465                 rv = int_rman_activate_resource(rm, r, &whohas);
  466                 if (rv != EBUSY)
  467                         return (rv);    /* returns with mutex held */
  468 
  469                 if (r->r_sharehead == 0)
  470                         panic("rman_await_resource");
  471                 whohas->r_flags |= RF_WANTED;
  472                 rv = msleep(r->r_sharehead, rm->rm_mtx, pri, "rmwait", timo);
  473                 if (rv) {
  474                         mtx_unlock(rm->rm_mtx);
  475                         return (rv);
  476                 }
  477         }
  478 }
  479 
  480 static int
  481 int_rman_deactivate_resource(struct resource *r)
  482 {
  483 
  484         r->r_flags &= ~RF_ACTIVE;
  485         if (r->r_flags & RF_WANTED) {
  486                 r->r_flags &= ~RF_WANTED;
  487                 wakeup(r->r_sharehead);
  488         }
  489         return 0;
  490 }
  491 
  492 int
  493 rman_deactivate_resource(struct resource *r)
  494 {
  495         struct  rman *rm;
  496 
  497         rm = r->r_rm;
  498         mtx_lock(rm->rm_mtx);
  499         int_rman_deactivate_resource(r);
  500         mtx_unlock(rm->rm_mtx);
  501         return 0;
  502 }
  503 
  504 static int
  505 int_rman_release_resource(struct rman *rm, struct resource *r)
  506 {
  507         struct  resource *s, *t;
  508 
  509         if (r->r_flags & RF_ACTIVE)
  510                 int_rman_deactivate_resource(r);
  511 
  512         /*
  513          * Check for a sharing list first.  If there is one, then we don't
  514          * have to think as hard.
  515          */
  516         if (r->r_sharehead) {
  517                 /*
  518                  * If a sharing list exists, then we know there are at
  519                  * least two sharers.
  520                  *
  521                  * If we are in the main circleq, appoint someone else.
  522                  */
  523                 LIST_REMOVE(r, r_sharelink);
  524                 s = LIST_FIRST(r->r_sharehead);
  525                 if (r->r_flags & RF_FIRSTSHARE) {
  526                         s->r_flags |= RF_FIRSTSHARE;
  527                         TAILQ_INSERT_BEFORE(r, s, r_link);
  528                         TAILQ_REMOVE(&rm->rm_list, r, r_link);
  529                 }
  530 
  531                 /*
  532                  * Make sure that the sharing list goes away completely
  533                  * if the resource is no longer being shared at all.
  534                  */
  535                 if (LIST_NEXT(s, r_sharelink) == 0) {
  536                         free(s->r_sharehead, M_RMAN);
  537                         s->r_sharehead = 0;
  538                         s->r_flags &= ~RF_FIRSTSHARE;
  539                 }
  540                 goto out;
  541         }
  542 
  543         /*
  544          * Look at the adjacent resources in the list and see if our
  545          * segment can be merged with any of them.  If either of the
  546          * resources is allocated or is not exactly adjacent then they
  547          * cannot be merged with our segment.
  548          */
  549         s = TAILQ_PREV(r, resource_head, r_link);
  550         if (s != NULL && ((s->r_flags & RF_ALLOCATED) != 0 ||
  551             s->r_end + 1 != r->r_start))
  552                 s = NULL;
  553         t = TAILQ_NEXT(r, r_link);
  554         if (t != NULL && ((t->r_flags & RF_ALLOCATED) != 0 ||
  555             r->r_end + 1 != t->r_start))
  556                 t = NULL;
  557 
  558         if (s != NULL && t != NULL) {
  559                 /*
  560                  * Merge all three segments.
  561                  */
  562                 s->r_end = t->r_end;
  563                 TAILQ_REMOVE(&rm->rm_list, r, r_link);
  564                 TAILQ_REMOVE(&rm->rm_list, t, r_link);
  565                 free(t, M_RMAN);
  566         } else if (s != NULL) {
  567                 /*
  568                  * Merge previous segment with ours.
  569                  */
  570                 s->r_end = r->r_end;
  571                 TAILQ_REMOVE(&rm->rm_list, r, r_link);
  572         } else if (t != NULL) {
  573                 /*
  574                  * Merge next segment with ours.
  575                  */
  576                 t->r_start = r->r_start;
  577                 TAILQ_REMOVE(&rm->rm_list, r, r_link);
  578         } else {
  579                 /*
  580                  * At this point, we know there is nothing we
  581                  * can potentially merge with, because on each
  582                  * side, there is either nothing there or what is
  583                  * there is still allocated.  In that case, we don't
  584                  * want to remove r from the list; we simply want to
  585                  * change it to an unallocated region and return
  586                  * without freeing anything.
  587                  */
  588                 r->r_flags &= ~RF_ALLOCATED;
  589                 return 0;
  590         }
  591 
  592 out:
  593         free(r, M_RMAN);
  594         return 0;
  595 }
  596 
  597 int
  598 rman_release_resource(struct resource *r)
  599 {
  600         int     rv;
  601         struct  rman *rm = r->r_rm;
  602 
  603         mtx_lock(rm->rm_mtx);
  604         rv = int_rman_release_resource(rm, r);
  605         mtx_unlock(rm->rm_mtx);
  606         return (rv);
  607 }
  608 
  609 uint32_t
  610 rman_make_alignment_flags(uint32_t size)
  611 {
  612         int     i;
  613 
  614         /*
  615          * Find the hightest bit set, and add one if more than one bit
  616          * set.  We're effectively computing the ceil(log2(size)) here.
  617          */
  618         for (i = 31; i > 0; i--)
  619                 if ((1 << i) & size)
  620                         break;
  621         if (~(1 << i) & size)
  622                 i++;
  623 
  624         return(RF_ALIGNMENT_LOG2(i));
  625 }
  626 
  627 u_long
  628 rman_get_start(struct resource *r)
  629 {
  630         return (r->r_start);
  631 }
  632 
  633 u_long
  634 rman_get_end(struct resource *r)
  635 {
  636         return (r->r_end);
  637 }
  638 
  639 u_long
  640 rman_get_size(struct resource *r)
  641 {
  642         return (r->r_end - r->r_start + 1);
  643 }
  644 
  645 u_int
  646 rman_get_flags(struct resource *r)
  647 {
  648         return (r->r_flags);
  649 }
  650 
  651 void
  652 rman_set_virtual(struct resource *r, void *v)
  653 {
  654         r->r_virtual = v;
  655 }
  656 
  657 void *
  658 rman_get_virtual(struct resource *r)
  659 {
  660         return (r->r_virtual);
  661 }
  662 
  663 void
  664 rman_set_bustag(struct resource *r, bus_space_tag_t t)
  665 {
  666         r->r_bustag = t;
  667 }
  668 
  669 bus_space_tag_t
  670 rman_get_bustag(struct resource *r)
  671 {
  672         return (r->r_bustag);
  673 }
  674 
  675 void
  676 rman_set_bushandle(struct resource *r, bus_space_handle_t h)
  677 {
  678         r->r_bushandle = h;
  679 }
  680 
  681 bus_space_handle_t
  682 rman_get_bushandle(struct resource *r)
  683 {
  684         return (r->r_bushandle);
  685 }
  686 
  687 void
  688 rman_set_rid(struct resource *r, int rid)
  689 {
  690         r->r_rid = rid;
  691 }
  692 
  693 void
  694 rman_set_start(struct resource *r, u_long start)
  695 {
  696         r->r_start = start;
  697 }
  698 
  699 void
  700 rman_set_end(struct resource *r, u_long end)
  701 {
  702         r->r_end = end;
  703 }
  704 
  705 int
  706 rman_get_rid(struct resource *r)
  707 {
  708         return (r->r_rid);
  709 }
  710 
  711 struct device *
  712 rman_get_device(struct resource *r)
  713 {
  714         return (r->r_dev);
  715 }
  716 
  717 void
  718 rman_set_device(struct resource *r, struct device *dev)
  719 {
  720         r->r_dev = dev;
  721 }
  722 
  723 /*
  724  * Sysctl interface for scanning the resource lists.
  725  *
  726  * We take two input parameters; the index into the list of resource
  727  * managers, and the resource offset into the list.
  728  */
  729 static int
  730 sysctl_rman(SYSCTL_HANDLER_ARGS)
  731 {
  732         int                     *name = (int *)arg1;
  733         u_int                   namelen = arg2;
  734         int                     rman_idx, res_idx;
  735         struct rman             *rm;
  736         struct resource         *res;
  737         struct u_rman           urm;
  738         struct u_resource       ures;
  739         int                     error;
  740 
  741         if (namelen != 3)
  742                 return (EINVAL);
  743 
  744         if (bus_data_generation_check(name[0]))
  745                 return (EINVAL);
  746         rman_idx = name[1];
  747         res_idx = name[2];
  748 
  749         /*
  750          * Find the indexed resource manager
  751          */
  752         TAILQ_FOREACH(rm, &rman_head, rm_link) {
  753                 if (rman_idx-- == 0)
  754                         break;
  755         }
  756         if (rm == NULL)
  757                 return (ENOENT);
  758 
  759         /*
  760          * If the resource index is -1, we want details on the
  761          * resource manager.
  762          */
  763         if (res_idx == -1) {
  764                 bzero(&urm, sizeof(urm));
  765                 urm.rm_handle = (uintptr_t)rm;
  766                 strlcpy(urm.rm_descr, rm->rm_descr, RM_TEXTLEN);
  767                 urm.rm_start = rm->rm_start;
  768                 urm.rm_size = rm->rm_end - rm->rm_start + 1;
  769                 urm.rm_type = rm->rm_type;
  770 
  771                 error = SYSCTL_OUT(req, &urm, sizeof(urm));
  772                 return (error);
  773         }
  774 
  775         /*
  776          * Find the indexed resource and return it.
  777          */
  778         TAILQ_FOREACH(res, &rm->rm_list, r_link) {
  779                 if (res_idx-- == 0) {
  780                         bzero(&ures, sizeof(ures));
  781                         ures.r_handle = (uintptr_t)res;
  782                         ures.r_parent = (uintptr_t)res->r_rm;
  783                         ures.r_device = (uintptr_t)res->r_dev;
  784                         if (res->r_dev != NULL) {
  785                                 if (device_get_name(res->r_dev) != NULL) {
  786                                         snprintf(ures.r_devname, RM_TEXTLEN,
  787                                             "%s%d",
  788                                             device_get_name(res->r_dev),
  789                                             device_get_unit(res->r_dev));
  790                                 } else {
  791                                         strlcpy(ures.r_devname, "nomatch",
  792                                             RM_TEXTLEN);
  793                                 }
  794                         } else {
  795                                 ures.r_devname[0] = '\0';
  796                         }
  797                         ures.r_start = res->r_start;
  798                         ures.r_size = res->r_end - res->r_start + 1;
  799                         ures.r_flags = res->r_flags;
  800 
  801                         error = SYSCTL_OUT(req, &ures, sizeof(ures));
  802                         return (error);
  803                 }
  804         }
  805         return (ENOENT);
  806 }
  807 
  808 SYSCTL_NODE(_hw_bus, OID_AUTO, rman, CTLFLAG_RD, sysctl_rman,
  809     "kernel resource manager");
  810 

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