subr_rman.c revision 221218
1/*-
2 * Copyright 1998 Massachusetts Institute of Technology
3 *
4 * Permission to use, copy, modify, and distribute this software and
5 * its documentation for any purpose and without fee is hereby
6 * granted, provided that both the above copyright notice and this
7 * permission notice appear in all copies, that both the above
8 * copyright notice and this permission notice appear in all
9 * supporting documentation, and that the name of M.I.T. not be used
10 * in advertising or publicity pertaining to distribution of the
11 * software without specific, written prior permission.  M.I.T. makes
12 * no representations about the suitability of this software for any
13 * purpose.  It is provided "as is" without express or implied
14 * warranty.
15 *
16 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
17 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
20 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
23 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30/*
31 * The kernel resource manager.  This code is responsible for keeping track
32 * of hardware resources which are apportioned out to various drivers.
33 * It does not actually assign those resources, and it is not expected
34 * that end-device drivers will call into this code directly.  Rather,
35 * the code which implements the buses that those devices are attached to,
36 * and the code which manages CPU resources, will call this code, and the
37 * end-device drivers will make upcalls to that code to actually perform
38 * the allocation.
39 *
40 * There are two sorts of resources managed by this code.  The first is
41 * the more familiar array (RMAN_ARRAY) type; resources in this class
42 * consist of a sequence of individually-allocatable objects which have
43 * been numbered in some well-defined order.  Most of the resources
44 * are of this type, as it is the most familiar.  The second type is
45 * called a gauge (RMAN_GAUGE), and models fungible resources (i.e.,
46 * resources in which each instance is indistinguishable from every
47 * other instance).  The principal anticipated application of gauges
48 * is in the context of power consumption, where a bus may have a specific
49 * power budget which all attached devices share.  RMAN_GAUGE is not
50 * implemented yet.
51 *
52 * For array resources, we make one simplifying assumption: two clients
53 * sharing the same resource must use the same range of indices.  That
54 * is to say, sharing of overlapping-but-not-identical regions is not
55 * permitted.
56 */
57
58#include "opt_ddb.h"
59
60#include <sys/cdefs.h>
61__FBSDID("$FreeBSD: head/sys/kern/subr_rman.c 221218 2011-04-29 18:41:21Z jhb $");
62
63#include <sys/param.h>
64#include <sys/systm.h>
65#include <sys/kernel.h>
66#include <sys/limits.h>
67#include <sys/lock.h>
68#include <sys/malloc.h>
69#include <sys/mutex.h>
70#include <sys/bus.h>		/* XXX debugging */
71#include <machine/bus.h>
72#include <sys/rman.h>
73#include <sys/sysctl.h>
74
75#ifdef DDB
76#include <ddb/ddb.h>
77#endif
78
79/*
80 * We use a linked list rather than a bitmap because we need to be able to
81 * represent potentially huge objects (like all of a processor's physical
82 * address space).  That is also why the indices are defined to have type
83 * `unsigned long' -- that being the largest integral type in ISO C (1990).
84 * The 1999 version of C allows `long long'; we may need to switch to that
85 * at some point in the future, particularly if we want to support 36-bit
86 * addresses on IA32 hardware.
87 */
88struct resource_i {
89	struct resource		r_r;
90	TAILQ_ENTRY(resource_i)	r_link;
91	LIST_ENTRY(resource_i)	r_sharelink;
92	LIST_HEAD(, resource_i)	*r_sharehead;
93	u_long	r_start;	/* index of the first entry in this resource */
94	u_long	r_end;		/* index of the last entry (inclusive) */
95	u_int	r_flags;
96	void	*r_virtual;	/* virtual address of this resource */
97	struct	device *r_dev;	/* device which has allocated this resource */
98	struct	rman *r_rm;	/* resource manager from whence this came */
99	int	r_rid;		/* optional rid for this resource. */
100};
101
102static int     rman_debug = 0;
103TUNABLE_INT("debug.rman_debug", &rman_debug);
104SYSCTL_INT(_debug, OID_AUTO, rman_debug, CTLFLAG_RW,
105    &rman_debug, 0, "rman debug");
106
107#define DPRINTF(params) if (rman_debug) printf params
108
109static MALLOC_DEFINE(M_RMAN, "rman", "Resource manager");
110
111struct	rman_head rman_head;
112static	struct mtx rman_mtx; /* mutex to protect rman_head */
113static	int int_rman_activate_resource(struct rman *rm, struct resource_i *r,
114				       struct resource_i **whohas);
115static	int int_rman_deactivate_resource(struct resource_i *r);
116static	int int_rman_release_resource(struct rman *rm, struct resource_i *r);
117
118static __inline struct resource_i *
119int_alloc_resource(int malloc_flag)
120{
121	struct resource_i *r;
122
123	r = malloc(sizeof *r, M_RMAN, malloc_flag | M_ZERO);
124	if (r != NULL) {
125		r->r_r.__r_i = r;
126	}
127	return (r);
128}
129
130int
131rman_init(struct rman *rm)
132{
133	static int once = 0;
134
135	if (once == 0) {
136		once = 1;
137		TAILQ_INIT(&rman_head);
138		mtx_init(&rman_mtx, "rman head", NULL, MTX_DEF);
139	}
140
141	if (rm->rm_start == 0 && rm->rm_end == 0)
142		rm->rm_end = ~0ul;
143	if (rm->rm_type == RMAN_UNINIT)
144		panic("rman_init");
145	if (rm->rm_type == RMAN_GAUGE)
146		panic("implement RMAN_GAUGE");
147
148	TAILQ_INIT(&rm->rm_list);
149	rm->rm_mtx = malloc(sizeof *rm->rm_mtx, M_RMAN, M_NOWAIT | M_ZERO);
150	if (rm->rm_mtx == NULL)
151		return ENOMEM;
152	mtx_init(rm->rm_mtx, "rman", NULL, MTX_DEF);
153
154	mtx_lock(&rman_mtx);
155	TAILQ_INSERT_TAIL(&rman_head, rm, rm_link);
156	mtx_unlock(&rman_mtx);
157	return 0;
158}
159
160int
161rman_manage_region(struct rman *rm, u_long start, u_long end)
162{
163	struct resource_i *r, *s, *t;
164
165	DPRINTF(("rman_manage_region: <%s> request: start %#lx, end %#lx\n",
166	    rm->rm_descr, start, end));
167	if (start < rm->rm_start || end > rm->rm_end)
168		return EINVAL;
169	r = int_alloc_resource(M_NOWAIT);
170	if (r == NULL)
171		return ENOMEM;
172	r->r_start = start;
173	r->r_end = end;
174	r->r_rm = rm;
175
176	mtx_lock(rm->rm_mtx);
177
178	/* Skip entries before us. */
179	TAILQ_FOREACH(s, &rm->rm_list, r_link) {
180		if (s->r_end == ULONG_MAX)
181			break;
182		if (s->r_end + 1 >= r->r_start)
183			break;
184	}
185
186	/* If we ran off the end of the list, insert at the tail. */
187	if (s == NULL) {
188		TAILQ_INSERT_TAIL(&rm->rm_list, r, r_link);
189	} else {
190		/* Check for any overlap with the current region. */
191		if (r->r_start <= s->r_end && r->r_end >= s->r_start)
192			return EBUSY;
193
194		/* Check for any overlap with the next region. */
195		t = TAILQ_NEXT(s, r_link);
196		if (t && r->r_start <= t->r_end && r->r_end >= t->r_start)
197			return EBUSY;
198
199		/*
200		 * See if this region can be merged with the next region.  If
201		 * not, clear the pointer.
202		 */
203		if (t && (r->r_end + 1 != t->r_start || t->r_flags != 0))
204			t = NULL;
205
206		/* See if we can merge with the current region. */
207		if (s->r_end + 1 == r->r_start && s->r_flags == 0) {
208			/* Can we merge all 3 regions? */
209			if (t != NULL) {
210				s->r_end = t->r_end;
211				TAILQ_REMOVE(&rm->rm_list, t, r_link);
212				free(r, M_RMAN);
213				free(t, M_RMAN);
214			} else {
215				s->r_end = r->r_end;
216				free(r, M_RMAN);
217			}
218		} else if (t != NULL) {
219			/* Can we merge with just the next region? */
220			t->r_start = r->r_start;
221			free(r, M_RMAN);
222		} else if (s->r_end < r->r_start) {
223			TAILQ_INSERT_AFTER(&rm->rm_list, s, r, r_link);
224		} else {
225			TAILQ_INSERT_BEFORE(s, r, r_link);
226		}
227	}
228
229	mtx_unlock(rm->rm_mtx);
230	return 0;
231}
232
233int
234rman_init_from_resource(struct rman *rm, struct resource *r)
235{
236	int rv;
237
238	if ((rv = rman_init(rm)) != 0)
239		return (rv);
240	return (rman_manage_region(rm, r->__r_i->r_start, r->__r_i->r_end));
241}
242
243int
244rman_fini(struct rman *rm)
245{
246	struct resource_i *r;
247
248	mtx_lock(rm->rm_mtx);
249	TAILQ_FOREACH(r, &rm->rm_list, r_link) {
250		if (r->r_flags & RF_ALLOCATED) {
251			mtx_unlock(rm->rm_mtx);
252			return EBUSY;
253		}
254	}
255
256	/*
257	 * There really should only be one of these if we are in this
258	 * state and the code is working properly, but it can't hurt.
259	 */
260	while (!TAILQ_EMPTY(&rm->rm_list)) {
261		r = TAILQ_FIRST(&rm->rm_list);
262		TAILQ_REMOVE(&rm->rm_list, r, r_link);
263		free(r, M_RMAN);
264	}
265	mtx_unlock(rm->rm_mtx);
266	mtx_lock(&rman_mtx);
267	TAILQ_REMOVE(&rman_head, rm, rm_link);
268	mtx_unlock(&rman_mtx);
269	mtx_destroy(rm->rm_mtx);
270	free(rm->rm_mtx, M_RMAN);
271
272	return 0;
273}
274
275struct resource *
276rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end,
277		      u_long count, u_long bound,  u_int flags,
278		      struct device *dev)
279{
280	u_int	want_activate;
281	struct	resource_i *r, *s, *rv;
282	u_long	rstart, rend, amask, bmask;
283
284	rv = NULL;
285
286	DPRINTF(("rman_reserve_resource_bound: <%s> request: [%#lx, %#lx], "
287	       "length %#lx, flags %u, device %s\n", rm->rm_descr, start, end,
288	       count, flags,
289	       dev == NULL ? "<null>" : device_get_nameunit(dev)));
290	want_activate = (flags & RF_ACTIVE);
291	flags &= ~RF_ACTIVE;
292
293	mtx_lock(rm->rm_mtx);
294
295	for (r = TAILQ_FIRST(&rm->rm_list);
296	     r && r->r_end < start;
297	     r = TAILQ_NEXT(r, r_link))
298		;
299
300	if (r == NULL) {
301		DPRINTF(("could not find a region\n"));
302		goto out;
303	}
304
305	amask = (1ul << RF_ALIGNMENT(flags)) - 1;
306	/* If bound is 0, bmask will also be 0 */
307	bmask = ~(bound - 1);
308	/*
309	 * First try to find an acceptable totally-unshared region.
310	 */
311	for (s = r; s; s = TAILQ_NEXT(s, r_link)) {
312		DPRINTF(("considering [%#lx, %#lx]\n", s->r_start, s->r_end));
313		if (s->r_start + count - 1 > end) {
314			DPRINTF(("s->r_start (%#lx) + count - 1> end (%#lx)\n",
315			    s->r_start, end));
316			break;
317		}
318		if (s->r_flags & RF_ALLOCATED) {
319			DPRINTF(("region is allocated\n"));
320			continue;
321		}
322		rstart = ulmax(s->r_start, start);
323		/*
324		 * Try to find a region by adjusting to boundary and alignment
325		 * until both conditions are satisfied. This is not an optimal
326		 * algorithm, but in most cases it isn't really bad, either.
327		 */
328		do {
329			rstart = (rstart + amask) & ~amask;
330			if (((rstart ^ (rstart + count - 1)) & bmask) != 0)
331				rstart += bound - (rstart & ~bmask);
332		} while ((rstart & amask) != 0 && rstart < end &&
333		    rstart < s->r_end);
334		rend = ulmin(s->r_end, ulmax(rstart + count - 1, end));
335		if (rstart > rend) {
336			DPRINTF(("adjusted start exceeds end\n"));
337			continue;
338		}
339		DPRINTF(("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n",
340		       rstart, rend, (rend - rstart + 1), count));
341
342		if ((rend - rstart + 1) >= count) {
343			DPRINTF(("candidate region: [%#lx, %#lx], size %#lx\n",
344			       rstart, rend, (rend - rstart + 1)));
345			if ((s->r_end - s->r_start + 1) == count) {
346				DPRINTF(("candidate region is entire chunk\n"));
347				rv = s;
348				rv->r_flags |= RF_ALLOCATED | flags;
349				rv->r_dev = dev;
350				goto out;
351			}
352
353			/*
354			 * If s->r_start < rstart and
355			 *    s->r_end > rstart + count - 1, then
356			 * we need to split the region into three pieces
357			 * (the middle one will get returned to the user).
358			 * Otherwise, we are allocating at either the
359			 * beginning or the end of s, so we only need to
360			 * split it in two.  The first case requires
361			 * two new allocations; the second requires but one.
362			 */
363			rv = int_alloc_resource(M_NOWAIT);
364			if (rv == NULL)
365				goto out;
366			rv->r_start = rstart;
367			rv->r_end = rstart + count - 1;
368			rv->r_flags = flags | RF_ALLOCATED;
369			rv->r_dev = dev;
370			rv->r_rm = rm;
371
372			if (s->r_start < rv->r_start && s->r_end > rv->r_end) {
373				DPRINTF(("splitting region in three parts: "
374				       "[%#lx, %#lx]; [%#lx, %#lx]; [%#lx, %#lx]\n",
375				       s->r_start, rv->r_start - 1,
376				       rv->r_start, rv->r_end,
377				       rv->r_end + 1, s->r_end));
378				/*
379				 * We are allocating in the middle.
380				 */
381				r = int_alloc_resource(M_NOWAIT);
382				if (r == NULL) {
383					free(rv, M_RMAN);
384					rv = NULL;
385					goto out;
386				}
387				r->r_start = rv->r_end + 1;
388				r->r_end = s->r_end;
389				r->r_flags = s->r_flags;
390				r->r_rm = rm;
391				s->r_end = rv->r_start - 1;
392				TAILQ_INSERT_AFTER(&rm->rm_list, s, rv,
393						     r_link);
394				TAILQ_INSERT_AFTER(&rm->rm_list, rv, r,
395						     r_link);
396			} else if (s->r_start == rv->r_start) {
397				DPRINTF(("allocating from the beginning\n"));
398				/*
399				 * We are allocating at the beginning.
400				 */
401				s->r_start = rv->r_end + 1;
402				TAILQ_INSERT_BEFORE(s, rv, r_link);
403			} else {
404				DPRINTF(("allocating at the end\n"));
405				/*
406				 * We are allocating at the end.
407				 */
408				s->r_end = rv->r_start - 1;
409				TAILQ_INSERT_AFTER(&rm->rm_list, s, rv,
410						     r_link);
411			}
412			goto out;
413		}
414	}
415
416	/*
417	 * Now find an acceptable shared region, if the client's requirements
418	 * allow sharing.  By our implementation restriction, a candidate
419	 * region must match exactly by both size and sharing type in order
420	 * to be considered compatible with the client's request.  (The
421	 * former restriction could probably be lifted without too much
422	 * additional work, but this does not seem warranted.)
423	 */
424	DPRINTF(("no unshared regions found\n"));
425	if ((flags & (RF_SHAREABLE | RF_TIMESHARE)) == 0)
426		goto out;
427
428	for (s = r; s; s = TAILQ_NEXT(s, r_link)) {
429		if (s->r_start > end)
430			break;
431		if ((s->r_flags & flags) != flags)
432			continue;
433		rstart = ulmax(s->r_start, start);
434		rend = ulmin(s->r_end, ulmax(start + count - 1, end));
435		if (s->r_start >= start && s->r_end <= end
436		    && (s->r_end - s->r_start + 1) == count &&
437		    (s->r_start & amask) == 0 &&
438		    ((s->r_start ^ s->r_end) & bmask) == 0) {
439			rv = int_alloc_resource(M_NOWAIT);
440			if (rv == NULL)
441				goto out;
442			rv->r_start = s->r_start;
443			rv->r_end = s->r_end;
444			rv->r_flags = s->r_flags &
445				(RF_ALLOCATED | RF_SHAREABLE | RF_TIMESHARE);
446			rv->r_dev = dev;
447			rv->r_rm = rm;
448			if (s->r_sharehead == NULL) {
449				s->r_sharehead = malloc(sizeof *s->r_sharehead,
450						M_RMAN, M_NOWAIT | M_ZERO);
451				if (s->r_sharehead == NULL) {
452					free(rv, M_RMAN);
453					rv = NULL;
454					goto out;
455				}
456				LIST_INIT(s->r_sharehead);
457				LIST_INSERT_HEAD(s->r_sharehead, s,
458						 r_sharelink);
459				s->r_flags |= RF_FIRSTSHARE;
460			}
461			rv->r_sharehead = s->r_sharehead;
462			LIST_INSERT_HEAD(s->r_sharehead, rv, r_sharelink);
463			goto out;
464		}
465	}
466
467	/*
468	 * We couldn't find anything.
469	 */
470out:
471	/*
472	 * If the user specified RF_ACTIVE in the initial flags,
473	 * which is reflected in `want_activate', we attempt to atomically
474	 * activate the resource.  If this fails, we release the resource
475	 * and indicate overall failure.  (This behavior probably doesn't
476	 * make sense for RF_TIMESHARE-type resources.)
477	 */
478	if (rv && want_activate) {
479		struct resource_i *whohas;
480		if (int_rman_activate_resource(rm, rv, &whohas)) {
481			int_rman_release_resource(rm, rv);
482			rv = NULL;
483		}
484	}
485
486	mtx_unlock(rm->rm_mtx);
487	return (rv == NULL ? NULL : &rv->r_r);
488}
489
490struct resource *
491rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
492		      u_int flags, struct device *dev)
493{
494
495	return (rman_reserve_resource_bound(rm, start, end, count, 0, flags,
496	    dev));
497}
498
499static int
500int_rman_activate_resource(struct rman *rm, struct resource_i *r,
501			   struct resource_i **whohas)
502{
503	struct resource_i *s;
504	int ok;
505
506	/*
507	 * If we are not timesharing, then there is nothing much to do.
508	 * If we already have the resource, then there is nothing at all to do.
509	 * If we are not on a sharing list with anybody else, then there is
510	 * little to do.
511	 */
512	if ((r->r_flags & RF_TIMESHARE) == 0
513	    || (r->r_flags & RF_ACTIVE) != 0
514	    || r->r_sharehead == NULL) {
515		r->r_flags |= RF_ACTIVE;
516		return 0;
517	}
518
519	ok = 1;
520	for (s = LIST_FIRST(r->r_sharehead); s && ok;
521	     s = LIST_NEXT(s, r_sharelink)) {
522		if ((s->r_flags & RF_ACTIVE) != 0) {
523			ok = 0;
524			*whohas = s;
525		}
526	}
527	if (ok) {
528		r->r_flags |= RF_ACTIVE;
529		return 0;
530	}
531	return EBUSY;
532}
533
534int
535rman_activate_resource(struct resource *re)
536{
537	int rv;
538	struct resource_i *r, *whohas;
539	struct rman *rm;
540
541	r = re->__r_i;
542	rm = r->r_rm;
543	mtx_lock(rm->rm_mtx);
544	rv = int_rman_activate_resource(rm, r, &whohas);
545	mtx_unlock(rm->rm_mtx);
546	return rv;
547}
548
549int
550rman_await_resource(struct resource *re, int pri, int timo)
551{
552	int	rv;
553	struct	resource_i *r, *whohas;
554	struct	rman *rm;
555
556	r = re->__r_i;
557	rm = r->r_rm;
558	mtx_lock(rm->rm_mtx);
559	for (;;) {
560		rv = int_rman_activate_resource(rm, r, &whohas);
561		if (rv != EBUSY)
562			return (rv);	/* returns with mutex held */
563
564		if (r->r_sharehead == NULL)
565			panic("rman_await_resource");
566		whohas->r_flags |= RF_WANTED;
567		rv = msleep(r->r_sharehead, rm->rm_mtx, pri, "rmwait", timo);
568		if (rv) {
569			mtx_unlock(rm->rm_mtx);
570			return (rv);
571		}
572	}
573}
574
575static int
576int_rman_deactivate_resource(struct resource_i *r)
577{
578
579	r->r_flags &= ~RF_ACTIVE;
580	if (r->r_flags & RF_WANTED) {
581		r->r_flags &= ~RF_WANTED;
582		wakeup(r->r_sharehead);
583	}
584	return 0;
585}
586
587int
588rman_deactivate_resource(struct resource *r)
589{
590	struct	rman *rm;
591
592	rm = r->__r_i->r_rm;
593	mtx_lock(rm->rm_mtx);
594	int_rman_deactivate_resource(r->__r_i);
595	mtx_unlock(rm->rm_mtx);
596	return 0;
597}
598
599static int
600int_rman_release_resource(struct rman *rm, struct resource_i *r)
601{
602	struct	resource_i *s, *t;
603
604	if (r->r_flags & RF_ACTIVE)
605		int_rman_deactivate_resource(r);
606
607	/*
608	 * Check for a sharing list first.  If there is one, then we don't
609	 * have to think as hard.
610	 */
611	if (r->r_sharehead) {
612		/*
613		 * If a sharing list exists, then we know there are at
614		 * least two sharers.
615		 *
616		 * If we are in the main circleq, appoint someone else.
617		 */
618		LIST_REMOVE(r, r_sharelink);
619		s = LIST_FIRST(r->r_sharehead);
620		if (r->r_flags & RF_FIRSTSHARE) {
621			s->r_flags |= RF_FIRSTSHARE;
622			TAILQ_INSERT_BEFORE(r, s, r_link);
623			TAILQ_REMOVE(&rm->rm_list, r, r_link);
624		}
625
626		/*
627		 * Make sure that the sharing list goes away completely
628		 * if the resource is no longer being shared at all.
629		 */
630		if (LIST_NEXT(s, r_sharelink) == NULL) {
631			free(s->r_sharehead, M_RMAN);
632			s->r_sharehead = NULL;
633			s->r_flags &= ~RF_FIRSTSHARE;
634		}
635		goto out;
636	}
637
638	/*
639	 * Look at the adjacent resources in the list and see if our
640	 * segment can be merged with any of them.  If either of the
641	 * resources is allocated or is not exactly adjacent then they
642	 * cannot be merged with our segment.
643	 */
644	s = TAILQ_PREV(r, resource_head, r_link);
645	if (s != NULL && ((s->r_flags & RF_ALLOCATED) != 0 ||
646	    s->r_end + 1 != r->r_start))
647		s = NULL;
648	t = TAILQ_NEXT(r, r_link);
649	if (t != NULL && ((t->r_flags & RF_ALLOCATED) != 0 ||
650	    r->r_end + 1 != t->r_start))
651		t = NULL;
652
653	if (s != NULL && t != NULL) {
654		/*
655		 * Merge all three segments.
656		 */
657		s->r_end = t->r_end;
658		TAILQ_REMOVE(&rm->rm_list, r, r_link);
659		TAILQ_REMOVE(&rm->rm_list, t, r_link);
660		free(t, M_RMAN);
661	} else if (s != NULL) {
662		/*
663		 * Merge previous segment with ours.
664		 */
665		s->r_end = r->r_end;
666		TAILQ_REMOVE(&rm->rm_list, r, r_link);
667	} else if (t != NULL) {
668		/*
669		 * Merge next segment with ours.
670		 */
671		t->r_start = r->r_start;
672		TAILQ_REMOVE(&rm->rm_list, r, r_link);
673	} else {
674		/*
675		 * At this point, we know there is nothing we
676		 * can potentially merge with, because on each
677		 * side, there is either nothing there or what is
678		 * there is still allocated.  In that case, we don't
679		 * want to remove r from the list; we simply want to
680		 * change it to an unallocated region and return
681		 * without freeing anything.
682		 */
683		r->r_flags &= ~RF_ALLOCATED;
684		return 0;
685	}
686
687out:
688	free(r, M_RMAN);
689	return 0;
690}
691
692int
693rman_release_resource(struct resource *re)
694{
695	int	rv;
696	struct	resource_i *r;
697	struct	rman *rm;
698
699	r = re->__r_i;
700	rm = r->r_rm;
701	mtx_lock(rm->rm_mtx);
702	rv = int_rman_release_resource(rm, r);
703	mtx_unlock(rm->rm_mtx);
704	return (rv);
705}
706
707uint32_t
708rman_make_alignment_flags(uint32_t size)
709{
710	int	i;
711
712	/*
713	 * Find the hightest bit set, and add one if more than one bit
714	 * set.  We're effectively computing the ceil(log2(size)) here.
715	 */
716	for (i = 31; i > 0; i--)
717		if ((1 << i) & size)
718			break;
719	if (~(1 << i) & size)
720		i++;
721
722	return(RF_ALIGNMENT_LOG2(i));
723}
724
725void
726rman_set_start(struct resource *r, u_long start)
727{
728	r->__r_i->r_start = start;
729}
730
731u_long
732rman_get_start(struct resource *r)
733{
734	return (r->__r_i->r_start);
735}
736
737void
738rman_set_end(struct resource *r, u_long end)
739{
740	r->__r_i->r_end = end;
741}
742
743u_long
744rman_get_end(struct resource *r)
745{
746	return (r->__r_i->r_end);
747}
748
749u_long
750rman_get_size(struct resource *r)
751{
752	return (r->__r_i->r_end - r->__r_i->r_start + 1);
753}
754
755u_int
756rman_get_flags(struct resource *r)
757{
758	return (r->__r_i->r_flags);
759}
760
761void
762rman_set_virtual(struct resource *r, void *v)
763{
764	r->__r_i->r_virtual = v;
765}
766
767void *
768rman_get_virtual(struct resource *r)
769{
770	return (r->__r_i->r_virtual);
771}
772
773void
774rman_set_bustag(struct resource *r, bus_space_tag_t t)
775{
776	r->r_bustag = t;
777}
778
779bus_space_tag_t
780rman_get_bustag(struct resource *r)
781{
782	return (r->r_bustag);
783}
784
785void
786rman_set_bushandle(struct resource *r, bus_space_handle_t h)
787{
788	r->r_bushandle = h;
789}
790
791bus_space_handle_t
792rman_get_bushandle(struct resource *r)
793{
794	return (r->r_bushandle);
795}
796
797void
798rman_set_rid(struct resource *r, int rid)
799{
800	r->__r_i->r_rid = rid;
801}
802
803int
804rman_get_rid(struct resource *r)
805{
806	return (r->__r_i->r_rid);
807}
808
809void
810rman_set_device(struct resource *r, struct device *dev)
811{
812	r->__r_i->r_dev = dev;
813}
814
815struct device *
816rman_get_device(struct resource *r)
817{
818	return (r->__r_i->r_dev);
819}
820
821int
822rman_is_region_manager(struct resource *r, struct rman *rm)
823{
824
825	return (r->__r_i->r_rm == rm);
826}
827
828/*
829 * Sysctl interface for scanning the resource lists.
830 *
831 * We take two input parameters; the index into the list of resource
832 * managers, and the resource offset into the list.
833 */
834static int
835sysctl_rman(SYSCTL_HANDLER_ARGS)
836{
837	int			*name = (int *)arg1;
838	u_int			namelen = arg2;
839	int			rman_idx, res_idx;
840	struct rman		*rm;
841	struct resource_i	*res;
842	struct resource_i	*sres;
843	struct u_rman		urm;
844	struct u_resource	ures;
845	int			error;
846
847	if (namelen != 3)
848		return (EINVAL);
849
850	if (bus_data_generation_check(name[0]))
851		return (EINVAL);
852	rman_idx = name[1];
853	res_idx = name[2];
854
855	/*
856	 * Find the indexed resource manager
857	 */
858	mtx_lock(&rman_mtx);
859	TAILQ_FOREACH(rm, &rman_head, rm_link) {
860		if (rman_idx-- == 0)
861			break;
862	}
863	mtx_unlock(&rman_mtx);
864	if (rm == NULL)
865		return (ENOENT);
866
867	/*
868	 * If the resource index is -1, we want details on the
869	 * resource manager.
870	 */
871	if (res_idx == -1) {
872		bzero(&urm, sizeof(urm));
873		urm.rm_handle = (uintptr_t)rm;
874		if (rm->rm_descr != NULL)
875			strlcpy(urm.rm_descr, rm->rm_descr, RM_TEXTLEN);
876		urm.rm_start = rm->rm_start;
877		urm.rm_size = rm->rm_end - rm->rm_start + 1;
878		urm.rm_type = rm->rm_type;
879
880		error = SYSCTL_OUT(req, &urm, sizeof(urm));
881		return (error);
882	}
883
884	/*
885	 * Find the indexed resource and return it.
886	 */
887	mtx_lock(rm->rm_mtx);
888	TAILQ_FOREACH(res, &rm->rm_list, r_link) {
889		if (res->r_sharehead != NULL) {
890			LIST_FOREACH(sres, res->r_sharehead, r_sharelink)
891				if (res_idx-- == 0) {
892					res = sres;
893					goto found;
894				}
895		}
896		else if (res_idx-- == 0)
897				goto found;
898	}
899	mtx_unlock(rm->rm_mtx);
900	return (ENOENT);
901
902found:
903	bzero(&ures, sizeof(ures));
904	ures.r_handle = (uintptr_t)res;
905	ures.r_parent = (uintptr_t)res->r_rm;
906	ures.r_device = (uintptr_t)res->r_dev;
907	if (res->r_dev != NULL) {
908		if (device_get_name(res->r_dev) != NULL) {
909			snprintf(ures.r_devname, RM_TEXTLEN,
910			    "%s%d",
911			    device_get_name(res->r_dev),
912			    device_get_unit(res->r_dev));
913		} else {
914			strlcpy(ures.r_devname, "nomatch",
915			    RM_TEXTLEN);
916		}
917	} else {
918		ures.r_devname[0] = '\0';
919	}
920	ures.r_start = res->r_start;
921	ures.r_size = res->r_end - res->r_start + 1;
922	ures.r_flags = res->r_flags;
923
924	mtx_unlock(rm->rm_mtx);
925	error = SYSCTL_OUT(req, &ures, sizeof(ures));
926	return (error);
927}
928
929SYSCTL_NODE(_hw_bus, OID_AUTO, rman, CTLFLAG_RD, sysctl_rman,
930    "kernel resource manager");
931
932#ifdef DDB
933static void
934dump_rman_header(struct rman *rm)
935{
936
937	if (db_pager_quit)
938		return;
939	db_printf("rman %p: %s (0x%lx-0x%lx full range)\n",
940	    rm, rm->rm_descr, rm->rm_start, rm->rm_end);
941}
942
943static void
944dump_rman(struct rman *rm)
945{
946	struct resource_i *r;
947	const char *devname;
948
949	if (db_pager_quit)
950		return;
951	TAILQ_FOREACH(r, &rm->rm_list, r_link) {
952		if (r->r_dev != NULL) {
953			devname = device_get_nameunit(r->r_dev);
954			if (devname == NULL)
955				devname = "nomatch";
956		} else
957			devname = NULL;
958		db_printf("    0x%lx-0x%lx ", r->r_start, r->r_end);
959		if (devname != NULL)
960			db_printf("(%s)\n", devname);
961		else
962			db_printf("----\n");
963		if (db_pager_quit)
964			return;
965	}
966}
967
968DB_SHOW_COMMAND(rman, db_show_rman)
969{
970
971	if (have_addr) {
972		dump_rman_header((struct rman *)addr);
973		dump_rman((struct rman *)addr);
974	}
975}
976
977DB_SHOW_COMMAND(rmans, db_show_rmans)
978{
979	struct rman *rm;
980
981	TAILQ_FOREACH(rm, &rman_head, rm_link) {
982		dump_rman_header(rm);
983	}
984}
985
986DB_SHOW_ALL_COMMAND(rman, db_show_all_rman)
987{
988	struct rman *rm;
989
990	TAILQ_FOREACH(rm, &rman_head, rm_link) {
991		dump_rman_header(rm);
992		dump_rman(rm);
993	}
994}
995DB_SHOW_ALIAS(allrman, db_show_all_rman);
996#endif
997