xref: /freebsd/sys/kern/subr_rman.c (revision 28bd1fdc0be889d5b7d7f36f014709ccd0a112a4)
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("$FreeBSD$");
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_i *r,
85 				       struct resource_i **whohas);
86 static	int int_rman_deactivate_resource(struct resource_i *r);
87 static	int int_rman_release_resource(struct rman *rm, struct resource_i *r);
88 
89 static __inline struct resource_i *
90 int_alloc_resource(int malloc_flag)
91 {
92 	struct resource_i *r;
93 
94 	r = malloc(sizeof *r, M_RMAN, malloc_flag | M_ZERO);
95 	if (r != NULL) {
96 		r->r_r.__r_i = r;
97 	}
98 	return (r);
99 }
100 
101 /*
102  * XXX: puc.c is a big hack.
103  * XXX: it should be rewritten to act like a bridge and offer
104  * XXX: its own resource manager.
105  * XXX: until somebody has time, help it out with these two functions
106  */
107 
108 struct resource *
109 rman_secret_puc_alloc_resource(int malloc_flag)
110 {
111 	struct resource_i *r;
112 
113 	r = int_alloc_resource(malloc_flag);
114 	if (r)
115 		return (&r->r_r);
116 	return (NULL);
117 }
118 
119 void
120 rman_secret_puc_free_resource(struct resource *r)
121 {
122 
123 	free(r->__r_i, M_RMAN);
124 }
125 
126 int
127 rman_init(struct rman *rm)
128 {
129 	static int once;
130 
131 	if (once == 0) {
132 		once = 1;
133 		TAILQ_INIT(&rman_head);
134 		mtx_init(&rman_mtx, "rman head", NULL, MTX_DEF);
135 	}
136 
137 	if (rm->rm_type == RMAN_UNINIT)
138 		panic("rman_init");
139 	if (rm->rm_type == RMAN_GAUGE)
140 		panic("implement RMAN_GAUGE");
141 
142 	TAILQ_INIT(&rm->rm_list);
143 	rm->rm_mtx = malloc(sizeof *rm->rm_mtx, M_RMAN, M_NOWAIT | M_ZERO);
144 	if (rm->rm_mtx == 0)
145 		return ENOMEM;
146 	mtx_init(rm->rm_mtx, "rman", NULL, MTX_DEF);
147 
148 	mtx_lock(&rman_mtx);
149 	TAILQ_INSERT_TAIL(&rman_head, rm, rm_link);
150 	mtx_unlock(&rman_mtx);
151 	return 0;
152 }
153 
154 /*
155  * NB: this interface is not robust against programming errors which
156  * add multiple copies of the same region.
157  */
158 int
159 rman_manage_region(struct rman *rm, u_long start, u_long end)
160 {
161 	struct resource_i *r, *s;
162 
163 	DPRINTF(("rman_manage_region: <%s> request: start %#lx, end %#lx\n",
164 	    rm->rm_descr, start, end));
165 	r = int_alloc_resource(M_NOWAIT);
166 	if (r == 0)
167 		return ENOMEM;
168 	r->r_start = start;
169 	r->r_end = end;
170 	r->r_rm = rm;
171 
172 	mtx_lock(rm->rm_mtx);
173 	for (s = TAILQ_FIRST(&rm->rm_list);
174 	     s && s->r_end < r->r_start;
175 	     s = TAILQ_NEXT(s, r_link))
176 		;
177 
178 	if (s == NULL) {
179 		TAILQ_INSERT_TAIL(&rm->rm_list, r, r_link);
180 	} else {
181 		TAILQ_INSERT_BEFORE(s, r, r_link);
182 	}
183 
184 	mtx_unlock(rm->rm_mtx);
185 	return 0;
186 }
187 
188 int
189 rman_fini(struct rman *rm)
190 {
191 	struct resource_i *r;
192 
193 	mtx_lock(rm->rm_mtx);
194 	TAILQ_FOREACH(r, &rm->rm_list, r_link) {
195 		if (r->r_flags & RF_ALLOCATED) {
196 			mtx_unlock(rm->rm_mtx);
197 			return EBUSY;
198 		}
199 	}
200 
201 	/*
202 	 * There really should only be one of these if we are in this
203 	 * state and the code is working properly, but it can't hurt.
204 	 */
205 	while (!TAILQ_EMPTY(&rm->rm_list)) {
206 		r = TAILQ_FIRST(&rm->rm_list);
207 		TAILQ_REMOVE(&rm->rm_list, r, r_link);
208 		free(r, M_RMAN);
209 	}
210 	mtx_unlock(rm->rm_mtx);
211 	mtx_lock(&rman_mtx);
212 	TAILQ_REMOVE(&rman_head, rm, rm_link);
213 	mtx_unlock(&rman_mtx);
214 	mtx_destroy(rm->rm_mtx);
215 	free(rm->rm_mtx, M_RMAN);
216 
217 	return 0;
218 }
219 
220 struct resource *
221 rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end,
222 		      u_long count, u_long bound,  u_int flags,
223 		      struct device *dev)
224 {
225 	u_int	want_activate;
226 	struct	resource_i *r, *s, *rv;
227 	u_long	rstart, rend, amask, bmask;
228 
229 	rv = 0;
230 
231 	DPRINTF(("rman_reserve_resource: <%s> request: [%#lx, %#lx], length "
232 	       "%#lx, flags %u, device %s\n", rm->rm_descr, start, end, count,
233 	       flags, dev == NULL ? "<null>" : device_get_nameunit(dev)));
234 	want_activate = (flags & RF_ACTIVE);
235 	flags &= ~RF_ACTIVE;
236 
237 	mtx_lock(rm->rm_mtx);
238 
239 	for (r = TAILQ_FIRST(&rm->rm_list);
240 	     r && r->r_end < start;
241 	     r = TAILQ_NEXT(r, r_link))
242 		;
243 
244 	if (r == NULL) {
245 		DPRINTF(("could not find a region\n"));
246 		goto out;
247 	}
248 
249 	amask = (1ul << RF_ALIGNMENT(flags)) - 1;
250 	/* If bound is 0, bmask will also be 0 */
251 	bmask = ~(bound - 1);
252 	/*
253 	 * First try to find an acceptable totally-unshared region.
254 	 */
255 	for (s = r; s; s = TAILQ_NEXT(s, r_link)) {
256 		DPRINTF(("considering [%#lx, %#lx]\n", s->r_start, s->r_end));
257 		if (s->r_start + count - 1 > end) {
258 			DPRINTF(("s->r_start (%#lx) + count - 1> end (%#lx)\n",
259 			    s->r_start, end));
260 			break;
261 		}
262 		if (s->r_flags & RF_ALLOCATED) {
263 			DPRINTF(("region is allocated\n"));
264 			continue;
265 		}
266 		rstart = ulmax(s->r_start, start);
267 		/*
268 		 * Try to find a region by adjusting to boundary and alignment
269 		 * until both conditions are satisfied. This is not an optimal
270 		 * algorithm, but in most cases it isn't really bad, either.
271 		 */
272 		do {
273 			rstart = (rstart + amask) & ~amask;
274 			if (((rstart ^ (rstart + count - 1)) & bmask) != 0)
275 				rstart += bound - (rstart & ~bmask);
276 		} while ((rstart & amask) != 0 && rstart < end &&
277 		    rstart < s->r_end);
278 		rend = ulmin(s->r_end, ulmax(rstart + count - 1, end));
279 		if (rstart > rend) {
280 			DPRINTF(("adjusted start exceeds end\n"));
281 			continue;
282 		}
283 		DPRINTF(("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n",
284 		       rstart, rend, (rend - rstart + 1), count));
285 
286 		if ((rend - rstart + 1) >= count) {
287 			DPRINTF(("candidate region: [%#lx, %#lx], size %#lx\n",
288 			       rstart, rend, (rend - rstart + 1)));
289 			if ((s->r_end - s->r_start + 1) == count) {
290 				DPRINTF(("candidate region is entire chunk\n"));
291 				rv = s;
292 				rv->r_flags |= RF_ALLOCATED | flags;
293 				rv->r_dev = dev;
294 				goto out;
295 			}
296 
297 			/*
298 			 * If s->r_start < rstart and
299 			 *    s->r_end > rstart + count - 1, then
300 			 * we need to split the region into three pieces
301 			 * (the middle one will get returned to the user).
302 			 * Otherwise, we are allocating at either the
303 			 * beginning or the end of s, so we only need to
304 			 * split it in two.  The first case requires
305 			 * two new allocations; the second requires but one.
306 			 */
307 			rv = int_alloc_resource(M_NOWAIT);
308 			if (rv == 0)
309 				goto out;
310 			rv->r_start = rstart;
311 			rv->r_end = rstart + count - 1;
312 			rv->r_flags = flags | RF_ALLOCATED;
313 			rv->r_dev = dev;
314 			rv->r_rm = rm;
315 
316 			if (s->r_start < rv->r_start && s->r_end > rv->r_end) {
317 				DPRINTF(("splitting region in three parts: "
318 				       "[%#lx, %#lx]; [%#lx, %#lx]; [%#lx, %#lx]\n",
319 				       s->r_start, rv->r_start - 1,
320 				       rv->r_start, rv->r_end,
321 				       rv->r_end + 1, s->r_end));
322 				/*
323 				 * We are allocating in the middle.
324 				 */
325 				r = int_alloc_resource(M_NOWAIT);
326 				if (r == 0) {
327 					free(rv, M_RMAN);
328 					rv = 0;
329 					goto out;
330 				}
331 				r->r_start = rv->r_end + 1;
332 				r->r_end = s->r_end;
333 				r->r_flags = s->r_flags;
334 				r->r_rm = rm;
335 				s->r_end = rv->r_start - 1;
336 				TAILQ_INSERT_AFTER(&rm->rm_list, s, rv,
337 						     r_link);
338 				TAILQ_INSERT_AFTER(&rm->rm_list, rv, r,
339 						     r_link);
340 			} else if (s->r_start == rv->r_start) {
341 				DPRINTF(("allocating from the beginning\n"));
342 				/*
343 				 * We are allocating at the beginning.
344 				 */
345 				s->r_start = rv->r_end + 1;
346 				TAILQ_INSERT_BEFORE(s, rv, r_link);
347 			} else {
348 				DPRINTF(("allocating at the end\n"));
349 				/*
350 				 * We are allocating at the end.
351 				 */
352 				s->r_end = rv->r_start - 1;
353 				TAILQ_INSERT_AFTER(&rm->rm_list, s, rv,
354 						     r_link);
355 			}
356 			goto out;
357 		}
358 	}
359 
360 	/*
361 	 * Now find an acceptable shared region, if the client's requirements
362 	 * allow sharing.  By our implementation restriction, a candidate
363 	 * region must match exactly by both size and sharing type in order
364 	 * to be considered compatible with the client's request.  (The
365 	 * former restriction could probably be lifted without too much
366 	 * additional work, but this does not seem warranted.)
367 	 */
368 	DPRINTF(("no unshared regions found\n"));
369 	if ((flags & (RF_SHAREABLE | RF_TIMESHARE)) == 0)
370 		goto out;
371 
372 	for (s = r; s; s = TAILQ_NEXT(s, r_link)) {
373 		if (s->r_start > end)
374 			break;
375 		if ((s->r_flags & flags) != flags)
376 			continue;
377 		rstart = ulmax(s->r_start, start);
378 		rend = ulmin(s->r_end, ulmax(start + count - 1, end));
379 		if (s->r_start >= start && s->r_end <= end
380 		    && (s->r_end - s->r_start + 1) == count &&
381 		    (s->r_start & amask) == 0 &&
382 		    ((s->r_start ^ s->r_end) & bmask) == 0) {
383 			rv = int_alloc_resource(M_NOWAIT);
384 			if (rv == 0)
385 				goto out;
386 			rv->r_start = s->r_start;
387 			rv->r_end = s->r_end;
388 			rv->r_flags = s->r_flags &
389 				(RF_ALLOCATED | RF_SHAREABLE | RF_TIMESHARE);
390 			rv->r_dev = dev;
391 			rv->r_rm = rm;
392 			if (s->r_sharehead == 0) {
393 				s->r_sharehead = malloc(sizeof *s->r_sharehead,
394 						M_RMAN, M_NOWAIT | M_ZERO);
395 				if (s->r_sharehead == 0) {
396 					free(rv, M_RMAN);
397 					rv = 0;
398 					goto out;
399 				}
400 				LIST_INIT(s->r_sharehead);
401 				LIST_INSERT_HEAD(s->r_sharehead, s,
402 						 r_sharelink);
403 				s->r_flags |= RF_FIRSTSHARE;
404 			}
405 			rv->r_sharehead = s->r_sharehead;
406 			LIST_INSERT_HEAD(s->r_sharehead, rv, r_sharelink);
407 			goto out;
408 		}
409 	}
410 
411 	/*
412 	 * We couldn't find anything.
413 	 */
414 out:
415 	/*
416 	 * If the user specified RF_ACTIVE in the initial flags,
417 	 * which is reflected in `want_activate', we attempt to atomically
418 	 * activate the resource.  If this fails, we release the resource
419 	 * and indicate overall failure.  (This behavior probably doesn't
420 	 * make sense for RF_TIMESHARE-type resources.)
421 	 */
422 	if (rv && want_activate) {
423 		struct resource_i *whohas;
424 		if (int_rman_activate_resource(rm, rv, &whohas)) {
425 			int_rman_release_resource(rm, rv);
426 			rv = 0;
427 		}
428 	}
429 
430 	mtx_unlock(rm->rm_mtx);
431 	return (&rv->r_r);
432 }
433 
434 struct resource *
435 rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
436 		      u_int flags, struct device *dev)
437 {
438 
439 	return (rman_reserve_resource_bound(rm, start, end, count, 0, flags,
440 	    dev));
441 }
442 
443 static int
444 int_rman_activate_resource(struct rman *rm, struct resource_i *r,
445 			   struct resource_i **whohas)
446 {
447 	struct resource_i *s;
448 	int ok;
449 
450 	/*
451 	 * If we are not timesharing, then there is nothing much to do.
452 	 * If we already have the resource, then there is nothing at all to do.
453 	 * If we are not on a sharing list with anybody else, then there is
454 	 * little to do.
455 	 */
456 	if ((r->r_flags & RF_TIMESHARE) == 0
457 	    || (r->r_flags & RF_ACTIVE) != 0
458 	    || r->r_sharehead == 0) {
459 		r->r_flags |= RF_ACTIVE;
460 		return 0;
461 	}
462 
463 	ok = 1;
464 	for (s = LIST_FIRST(r->r_sharehead); s && ok;
465 	     s = LIST_NEXT(s, r_sharelink)) {
466 		if ((s->r_flags & RF_ACTIVE) != 0) {
467 			ok = 0;
468 			*whohas = s;
469 		}
470 	}
471 	if (ok) {
472 		r->r_flags |= RF_ACTIVE;
473 		return 0;
474 	}
475 	return EBUSY;
476 }
477 
478 int
479 rman_activate_resource(struct resource *re)
480 {
481 	int rv;
482 	struct resource_i *r, *whohas;
483 	struct rman *rm;
484 
485 	r = re->__r_i;
486 	rm = r->r_rm;
487 	mtx_lock(rm->rm_mtx);
488 	rv = int_rman_activate_resource(rm, r, &whohas);
489 	mtx_unlock(rm->rm_mtx);
490 	return rv;
491 }
492 
493 int
494 rman_await_resource(struct resource *re, int pri, int timo)
495 {
496 	int	rv;
497 	struct	resource_i *r, *whohas;
498 	struct	rman *rm;
499 
500 	r = re->__r_i;
501 	rm = r->r_rm;
502 	mtx_lock(rm->rm_mtx);
503 	for (;;) {
504 		rv = int_rman_activate_resource(rm, r, &whohas);
505 		if (rv != EBUSY)
506 			return (rv);	/* returns with mutex held */
507 
508 		if (r->r_sharehead == 0)
509 			panic("rman_await_resource");
510 		whohas->r_flags |= RF_WANTED;
511 		rv = msleep(r->r_sharehead, rm->rm_mtx, pri, "rmwait", timo);
512 		if (rv) {
513 			mtx_unlock(rm->rm_mtx);
514 			return (rv);
515 		}
516 	}
517 }
518 
519 static int
520 int_rman_deactivate_resource(struct resource_i *r)
521 {
522 
523 	r->r_flags &= ~RF_ACTIVE;
524 	if (r->r_flags & RF_WANTED) {
525 		r->r_flags &= ~RF_WANTED;
526 		wakeup(r->r_sharehead);
527 	}
528 	return 0;
529 }
530 
531 int
532 rman_deactivate_resource(struct resource *r)
533 {
534 	struct	rman *rm;
535 
536 	rm = r->__r_i->r_rm;
537 	mtx_lock(rm->rm_mtx);
538 	int_rman_deactivate_resource(r->__r_i);
539 	mtx_unlock(rm->rm_mtx);
540 	return 0;
541 }
542 
543 static int
544 int_rman_release_resource(struct rman *rm, struct resource_i *r)
545 {
546 	struct	resource_i *s, *t;
547 
548 	if (r->r_flags & RF_ACTIVE)
549 		int_rman_deactivate_resource(r);
550 
551 	/*
552 	 * Check for a sharing list first.  If there is one, then we don't
553 	 * have to think as hard.
554 	 */
555 	if (r->r_sharehead) {
556 		/*
557 		 * If a sharing list exists, then we know there are at
558 		 * least two sharers.
559 		 *
560 		 * If we are in the main circleq, appoint someone else.
561 		 */
562 		LIST_REMOVE(r, r_sharelink);
563 		s = LIST_FIRST(r->r_sharehead);
564 		if (r->r_flags & RF_FIRSTSHARE) {
565 			s->r_flags |= RF_FIRSTSHARE;
566 			TAILQ_INSERT_BEFORE(r, s, r_link);
567 			TAILQ_REMOVE(&rm->rm_list, r, r_link);
568 		}
569 
570 		/*
571 		 * Make sure that the sharing list goes away completely
572 		 * if the resource is no longer being shared at all.
573 		 */
574 		if (LIST_NEXT(s, r_sharelink) == 0) {
575 			free(s->r_sharehead, M_RMAN);
576 			s->r_sharehead = 0;
577 			s->r_flags &= ~RF_FIRSTSHARE;
578 		}
579 		goto out;
580 	}
581 
582 	/*
583 	 * Look at the adjacent resources in the list and see if our
584 	 * segment can be merged with any of them.  If either of the
585 	 * resources is allocated or is not exactly adjacent then they
586 	 * cannot be merged with our segment.
587 	 */
588 	s = TAILQ_PREV(r, resource_head, r_link);
589 	if (s != NULL && ((s->r_flags & RF_ALLOCATED) != 0 ||
590 	    s->r_end + 1 != r->r_start))
591 		s = NULL;
592 	t = TAILQ_NEXT(r, r_link);
593 	if (t != NULL && ((t->r_flags & RF_ALLOCATED) != 0 ||
594 	    r->r_end + 1 != t->r_start))
595 		t = NULL;
596 
597 	if (s != NULL && t != NULL) {
598 		/*
599 		 * Merge all three segments.
600 		 */
601 		s->r_end = t->r_end;
602 		TAILQ_REMOVE(&rm->rm_list, r, r_link);
603 		TAILQ_REMOVE(&rm->rm_list, t, r_link);
604 		free(t, M_RMAN);
605 	} else if (s != NULL) {
606 		/*
607 		 * Merge previous segment with ours.
608 		 */
609 		s->r_end = r->r_end;
610 		TAILQ_REMOVE(&rm->rm_list, r, r_link);
611 	} else if (t != NULL) {
612 		/*
613 		 * Merge next segment with ours.
614 		 */
615 		t->r_start = r->r_start;
616 		TAILQ_REMOVE(&rm->rm_list, r, r_link);
617 	} else {
618 		/*
619 		 * At this point, we know there is nothing we
620 		 * can potentially merge with, because on each
621 		 * side, there is either nothing there or what is
622 		 * there is still allocated.  In that case, we don't
623 		 * want to remove r from the list; we simply want to
624 		 * change it to an unallocated region and return
625 		 * without freeing anything.
626 		 */
627 		r->r_flags &= ~RF_ALLOCATED;
628 		return 0;
629 	}
630 
631 out:
632 	free(r, M_RMAN);
633 	return 0;
634 }
635 
636 int
637 rman_release_resource(struct resource *re)
638 {
639 	int	rv;
640 	struct	resource_i *r;
641 	struct	rman *rm;
642 
643 	r = re->__r_i;
644 	rm = r->r_rm;
645 	mtx_lock(rm->rm_mtx);
646 	rv = int_rman_release_resource(rm, r);
647 	mtx_unlock(rm->rm_mtx);
648 	return (rv);
649 }
650 
651 uint32_t
652 rman_make_alignment_flags(uint32_t size)
653 {
654 	int	i;
655 
656 	/*
657 	 * Find the hightest bit set, and add one if more than one bit
658 	 * set.  We're effectively computing the ceil(log2(size)) here.
659 	 */
660 	for (i = 31; i > 0; i--)
661 		if ((1 << i) & size)
662 			break;
663 	if (~(1 << i) & size)
664 		i++;
665 
666 	return(RF_ALIGNMENT_LOG2(i));
667 }
668 
669 u_long
670 rman_get_start(struct resource *r)
671 {
672 	return (r->__r_i->r_start);
673 }
674 
675 u_long
676 rman_get_end(struct resource *r)
677 {
678 	return (r->__r_i->r_end);
679 }
680 
681 u_long
682 rman_get_size(struct resource *r)
683 {
684 	return (r->__r_i->r_end - r->__r_i->r_start + 1);
685 }
686 
687 u_int
688 rman_get_flags(struct resource *r)
689 {
690 	return (r->__r_i->r_flags);
691 }
692 
693 void
694 rman_set_virtual(struct resource *r, void *v)
695 {
696 	r->__r_i->r_virtual = v;
697 }
698 
699 void *
700 rman_get_virtual(struct resource *r)
701 {
702 	return (r->__r_i->r_virtual);
703 }
704 
705 void
706 rman_set_bustag(struct resource *r, bus_space_tag_t t)
707 {
708 	r->r_bustag = t;
709 }
710 
711 bus_space_tag_t
712 rman_get_bustag(struct resource *r)
713 {
714 	return (r->r_bustag);
715 }
716 
717 void
718 rman_set_bushandle(struct resource *r, bus_space_handle_t h)
719 {
720 	r->r_bushandle = h;
721 }
722 
723 bus_space_handle_t
724 rman_get_bushandle(struct resource *r)
725 {
726 	return (r->r_bushandle);
727 }
728 
729 void
730 rman_set_rid(struct resource *r, int rid)
731 {
732 	r->__r_i->r_rid = rid;
733 }
734 
735 void
736 rman_set_start(struct resource *r, u_long start)
737 {
738 	r->__r_i->r_start = start;
739 }
740 
741 void
742 rman_set_end(struct resource *r, u_long end)
743 {
744 	r->__r_i->r_end = end;
745 }
746 
747 int
748 rman_get_rid(struct resource *r)
749 {
750 	return (r->__r_i->r_rid);
751 }
752 
753 struct device *
754 rman_get_device(struct resource *r)
755 {
756 	return (r->__r_i->r_dev);
757 }
758 
759 void
760 rman_set_device(struct resource *r, struct device *dev)
761 {
762 	r->__r_i->r_dev = dev;
763 }
764 
765 int
766 rman_is_region_manager(struct resource *r, struct rman *rm)
767 {
768 
769 	return (r->__r_i->r_rm == rm);
770 }
771 
772 /*
773  * Sysctl interface for scanning the resource lists.
774  *
775  * We take two input parameters; the index into the list of resource
776  * managers, and the resource offset into the list.
777  */
778 static int
779 sysctl_rman(SYSCTL_HANDLER_ARGS)
780 {
781 	int			*name = (int *)arg1;
782 	u_int			namelen = arg2;
783 	int			rman_idx, res_idx;
784 	struct rman		*rm;
785 	struct resource_i	*res;
786 	struct u_rman		urm;
787 	struct u_resource	ures;
788 	int			error;
789 
790 	if (namelen != 3)
791 		return (EINVAL);
792 
793 	if (bus_data_generation_check(name[0]))
794 		return (EINVAL);
795 	rman_idx = name[1];
796 	res_idx = name[2];
797 
798 	/*
799 	 * Find the indexed resource manager
800 	 */
801 	TAILQ_FOREACH(rm, &rman_head, rm_link) {
802 		if (rman_idx-- == 0)
803 			break;
804 	}
805 	if (rm == NULL)
806 		return (ENOENT);
807 
808 	/*
809 	 * If the resource index is -1, we want details on the
810 	 * resource manager.
811 	 */
812 	if (res_idx == -1) {
813 		bzero(&urm, sizeof(urm));
814 		urm.rm_handle = (uintptr_t)rm;
815 		strlcpy(urm.rm_descr, rm->rm_descr, RM_TEXTLEN);
816 		urm.rm_start = rm->rm_start;
817 		urm.rm_size = rm->rm_end - rm->rm_start + 1;
818 		urm.rm_type = rm->rm_type;
819 
820 		error = SYSCTL_OUT(req, &urm, sizeof(urm));
821 		return (error);
822 	}
823 
824 	/*
825 	 * Find the indexed resource and return it.
826 	 */
827 	TAILQ_FOREACH(res, &rm->rm_list, r_link) {
828 		if (res_idx-- == 0) {
829 			bzero(&ures, sizeof(ures));
830 			ures.r_handle = (uintptr_t)res;
831 			ures.r_parent = (uintptr_t)res->r_rm;
832 			ures.r_device = (uintptr_t)res->r_dev;
833 			if (res->r_dev != NULL) {
834 				if (device_get_name(res->r_dev) != NULL) {
835 					snprintf(ures.r_devname, RM_TEXTLEN,
836 					    "%s%d",
837 					    device_get_name(res->r_dev),
838 					    device_get_unit(res->r_dev));
839 				} else {
840 					strlcpy(ures.r_devname, "nomatch",
841 					    RM_TEXTLEN);
842 				}
843 			} else {
844 				ures.r_devname[0] = '\0';
845 			}
846 			ures.r_start = res->r_start;
847 			ures.r_size = res->r_end - res->r_start + 1;
848 			ures.r_flags = res->r_flags;
849 
850 			error = SYSCTL_OUT(req, &ures, sizeof(ures));
851 			return (error);
852 		}
853 	}
854 	return (ENOENT);
855 }
856 
857 SYSCTL_NODE(_hw_bus, OID_AUTO, rman, CTLFLAG_RD, sysctl_rman,
858     "kernel resource manager");
859 
860