summaryrefslogtreecommitdiffstats
path: root/sys/kern/subr_rman.c
blob: cdac3ef3fd6aaa3d6142d79a689b0ae0d9aa5d8b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
/*-
 * Copyright 1998 Massachusetts Institute of Technology
 *
 * Permission to use, copy, modify, and distribute this software and
 * its documentation for any purpose and without fee is hereby
 * granted, provided that both the above copyright notice and this
 * permission notice appear in all copies, that both the above
 * copyright notice and this permission notice appear in all
 * supporting documentation, and that the name of M.I.T. not be used
 * in advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.  M.I.T. makes
 * no representations about the suitability of this software for any
 * purpose.  It is provided "as is" without express or implied
 * warranty.
 *
 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''.  M.I.T. DISCLAIMS
 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * The kernel resource manager.  This code is responsible for keeping track
 * of hardware resources which are apportioned out to various drivers.
 * It does not actually assign those resources, and it is not expected
 * that end-device drivers will call into this code directly.  Rather,
 * the code which implements the buses that those devices are attached to,
 * and the code which manages CPU resources, will call this code, and the
 * end-device drivers will make upcalls to that code to actually perform
 * the allocation.
 *
 * There are two sorts of resources managed by this code.  The first is
 * the more familiar array (RMAN_ARRAY) type; resources in this class
 * consist of a sequence of individually-allocatable objects which have
 * been numbered in some well-defined order.  Most of the resources
 * are of this type, as it is the most familiar.  The second type is
 * called a gauge (RMAN_GAUGE), and models fungible resources (i.e.,
 * resources in which each instance is indistinguishable from every
 * other instance).  The principal anticipated application of gauges
 * is in the context of power consumption, where a bus may have a specific
 * power budget which all attached devices share.  RMAN_GAUGE is not
 * implemented yet.
 *
 * For array resources, we make one simplifying assumption: two clients
 * sharing the same resource must use the same range of indices.  That
 * is to say, sharing of overlapping-but-not-identical regions is not
 * permitted.
 */

#include "opt_ddb.h"

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/bus.h>		/* XXX debugging */
#include <machine/bus.h>
#include <sys/rman.h>
#include <sys/sysctl.h>

#ifdef DDB
#include <ddb/ddb.h>
#endif

/*
 * We use a linked list rather than a bitmap because we need to be able to
 * represent potentially huge objects (like all of a processor's physical
 * address space).  That is also why the indices are defined to have type
 * `unsigned long' -- that being the largest integral type in ISO C (1990).
 * The 1999 version of C allows `long long'; we may need to switch to that
 * at some point in the future, particularly if we want to support 36-bit
 * addresses on IA32 hardware.
 */
struct resource_i {
	struct resource		r_r;
	TAILQ_ENTRY(resource_i)	r_link;
	LIST_ENTRY(resource_i)	r_sharelink;
	LIST_HEAD(, resource_i)	*r_sharehead;
	u_long	r_start;	/* index of the first entry in this resource */
	u_long	r_end;		/* index of the last entry (inclusive) */
	u_int	r_flags;
	void	*r_virtual;	/* virtual address of this resource */
	struct	device *r_dev;	/* device which has allocated this resource */
	struct	rman *r_rm;	/* resource manager from whence this came */
	int	r_rid;		/* optional rid for this resource. */
};

int     rman_debug = 0;
TUNABLE_INT("debug.rman_debug", &rman_debug);
SYSCTL_INT(_debug, OID_AUTO, rman_debug, CTLFLAG_RW,
    &rman_debug, 0, "rman debug");

#define DPRINTF(params) if (rman_debug) printf params

static MALLOC_DEFINE(M_RMAN, "rman", "Resource manager");

struct	rman_head rman_head;
static	struct mtx rman_mtx; /* mutex to protect rman_head */
static	int int_rman_activate_resource(struct rman *rm, struct resource_i *r,
				       struct resource_i **whohas);
static	int int_rman_deactivate_resource(struct resource_i *r);
static	int int_rman_release_resource(struct rman *rm, struct resource_i *r);

static __inline struct resource_i *
int_alloc_resource(int malloc_flag)
{
	struct resource_i *r;

	r = malloc(sizeof *r, M_RMAN, malloc_flag | M_ZERO);
	if (r != NULL) {
		r->r_r.__r_i = r;
	}
	return (r);
}

int
rman_init(struct rman *rm)
{
	static int once = 0;

	if (once == 0) {
		once = 1;
		TAILQ_INIT(&rman_head);
		mtx_init(&rman_mtx, "rman head", NULL, MTX_DEF);
	}

	if (rm->rm_type == RMAN_UNINIT)
		panic("rman_init");
	if (rm->rm_type == RMAN_GAUGE)
		panic("implement RMAN_GAUGE");

	TAILQ_INIT(&rm->rm_list);
	rm->rm_mtx = malloc(sizeof *rm->rm_mtx, M_RMAN, M_NOWAIT | M_ZERO);
	if (rm->rm_mtx == NULL)
		return ENOMEM;
	mtx_init(rm->rm_mtx, "rman", NULL, MTX_DEF);

	mtx_lock(&rman_mtx);
	TAILQ_INSERT_TAIL(&rman_head, rm, rm_link);
	mtx_unlock(&rman_mtx);
	return 0;
}

int
rman_manage_region(struct rman *rm, u_long start, u_long end)
{
	struct resource_i *r, *s, *t;

	DPRINTF(("rman_manage_region: <%s> request: start %#lx, end %#lx\n",
	    rm->rm_descr, start, end));
	r = int_alloc_resource(M_NOWAIT);
	if (r == NULL)
		return ENOMEM;
	r->r_start = start;
	r->r_end = end;
	r->r_rm = rm;

	mtx_lock(rm->rm_mtx);

	/* Skip entries before us. */
	TAILQ_FOREACH(s, &rm->rm_list, r_link) {
		if (s->r_end == ULONG_MAX)
			break;
		if (s->r_end + 1 >= r->r_start)
			break;
	}

	/* If we ran off the end of the list, insert at the tail. */
	if (s == NULL) {
		TAILQ_INSERT_TAIL(&rm->rm_list, r, r_link);
	} else {
		/* Check for any overlap with the current region. */
		if (r->r_start <= s->r_end && r->r_end >= s->r_start)
			return EBUSY;

		/* Check for any overlap with the next region. */
		t = TAILQ_NEXT(s, r_link);
		if (t && r->r_start <= t->r_end && r->r_end >= t->r_start)
			return EBUSY;

		/*
		 * See if this region can be merged with the next region.  If
		 * not, clear the pointer.
		 */
		if (t && (r->r_end + 1 != t->r_start || t->r_flags != 0))
			t = NULL;

		/* See if we can merge with the current region. */
		if (s->r_end + 1 == r->r_start && s->r_flags == 0) {
			/* Can we merge all 3 regions? */
			if (t != NULL) {
				s->r_end = t->r_end;
				TAILQ_REMOVE(&rm->rm_list, t, r_link);
				free(r, M_RMAN);
				free(t, M_RMAN);
			} else {
				s->r_end = r->r_end;
				free(r, M_RMAN);
			}
		} else if (t != NULL) {
			/* Can we merge with just the next region? */
			t->r_start = r->r_start;
			free(r, M_RMAN);
		} else if (s->r_end < r->r_start) {
			TAILQ_INSERT_AFTER(&rm->rm_list, s, r, r_link);
		} else {
			TAILQ_INSERT_BEFORE(s, r, r_link);
		}
	}

	mtx_unlock(rm->rm_mtx);
	return 0;
}

int
rman_init_from_resource(struct rman *rm, struct resource *r)
{
	int rv;

	if ((rv = rman_init(rm)) != 0)
		return (rv);
	return (rman_manage_region(rm, r->__r_i->r_start, r->__r_i->r_end));
}

int
rman_fini(struct rman *rm)
{
	struct resource_i *r;

	mtx_lock(rm->rm_mtx);
	TAILQ_FOREACH(r, &rm->rm_list, r_link) {
		if (r->r_flags & RF_ALLOCATED) {
			mtx_unlock(rm->rm_mtx);
			return EBUSY;
		}
	}

	/*
	 * There really should only be one of these if we are in this
	 * state and the code is working properly, but it can't hurt.
	 */
	while (!TAILQ_EMPTY(&rm->rm_list)) {
		r = TAILQ_FIRST(&rm->rm_list);
		TAILQ_REMOVE(&rm->rm_list, r, r_link);
		free(r, M_RMAN);
	}
	mtx_unlock(rm->rm_mtx);
	mtx_lock(&rman_mtx);
	TAILQ_REMOVE(&rman_head, rm, rm_link);
	mtx_unlock(&rman_mtx);
	mtx_destroy(rm->rm_mtx);
	free(rm->rm_mtx, M_RMAN);

	return 0;
}

struct resource *
rman_reserve_resource_bound(struct rman *rm, u_long start, u_long end,
		      u_long count, u_long bound,  u_int flags,
		      struct device *dev)
{
	u_int	want_activate;
	struct	resource_i *r, *s, *rv;
	u_long	rstart, rend, amask, bmask;

	rv = NULL;

	DPRINTF(("rman_reserve_resource_bound: <%s> request: [%#lx, %#lx], "
	       "length %#lx, flags %u, device %s\n", rm->rm_descr, start, end,
	       count, flags,
	       dev == NULL ? "<null>" : device_get_nameunit(dev)));
	want_activate = (flags & RF_ACTIVE);
	flags &= ~RF_ACTIVE;

	mtx_lock(rm->rm_mtx);

	for (r = TAILQ_FIRST(&rm->rm_list);
	     r && r->r_end < start;
	     r = TAILQ_NEXT(r, r_link))
		;

	if (r == NULL) {
		DPRINTF(("could not find a region\n"));
		goto out;
	}

	amask = (1ul << RF_ALIGNMENT(flags)) - 1;
	/* If bound is 0, bmask will also be 0 */
	bmask = ~(bound - 1);
	/*
	 * First try to find an acceptable totally-unshared region.
	 */
	for (s = r; s; s = TAILQ_NEXT(s, r_link)) {
		DPRINTF(("considering [%#lx, %#lx]\n", s->r_start, s->r_end));
		if (s->r_start + count - 1 > end) {
			DPRINTF(("s->r_start (%#lx) + count - 1> end (%#lx)\n",
			    s->r_start, end));
			break;
		}
		if (s->r_flags & RF_ALLOCATED) {
			DPRINTF(("region is allocated\n"));
			continue;
		}
		rstart = ulmax(s->r_start, start);
		/*
		 * Try to find a region by adjusting to boundary and alignment
		 * until both conditions are satisfied. This is not an optimal
		 * algorithm, but in most cases it isn't really bad, either.
		 */
		do {
			rstart = (rstart + amask) & ~amask;
			if (((rstart ^ (rstart + count - 1)) & bmask) != 0)
				rstart += bound - (rstart & ~bmask);
		} while ((rstart & amask) != 0 && rstart < end &&
		    rstart < s->r_end);
		rend = ulmin(s->r_end, ulmax(rstart + count - 1, end));
		if (rstart > rend) {
			DPRINTF(("adjusted start exceeds end\n"));
			continue;
		}
		DPRINTF(("truncated region: [%#lx, %#lx]; size %#lx (requested %#lx)\n",
		       rstart, rend, (rend - rstart + 1), count));

		if ((rend - rstart + 1) >= count) {
			DPRINTF(("candidate region: [%#lx, %#lx], size %#lx\n",
			       rstart, rend, (rend - rstart + 1)));
			if ((s->r_end - s->r_start + 1) == count) {
				DPRINTF(("candidate region is entire chunk\n"));
				rv = s;
				rv->r_flags |= RF_ALLOCATED | flags;
				rv->r_dev = dev;
				goto out;
			}

			/*
			 * If s->r_start < rstart and
			 *    s->r_end > rstart + count - 1, then
			 * we need to split the region into three pieces
			 * (the middle one will get returned to the user).
			 * Otherwise, we are allocating at either the
			 * beginning or the end of s, so we only need to
			 * split it in two.  The first case requires
			 * two new allocations; the second requires but one.
			 */
			rv = int_alloc_resource(M_NOWAIT);
			if (rv == NULL)
				goto out;
			rv->r_start = rstart;
			rv->r_end = rstart + count - 1;
			rv->r_flags = flags | RF_ALLOCATED;
			rv->r_dev = dev;
			rv->r_rm = rm;

			if (s->r_start < rv->r_start && s->r_end > rv->r_end) {
				DPRINTF(("splitting region in three parts: "
				       "[%#lx, %#lx]; [%#lx, %#lx]; [%#lx, %#lx]\n",
				       s->r_start, rv->r_start - 1,
				       rv->r_start, rv->r_end,
				       rv->r_end + 1, s->r_end));
				/*
				 * We are allocating in the middle.
				 */
				r = int_alloc_resource(M_NOWAIT);
				if (r == NULL) {
					free(rv, M_RMAN);
					rv = NULL;
					goto out;
				}
				r->r_start = rv->r_end + 1;
				r->r_end = s->r_end;
				r->r_flags = s->r_flags;
				r->r_rm = rm;
				s->r_end = rv->r_start - 1;
				TAILQ_INSERT_AFTER(&rm->rm_list, s, rv,
						     r_link);
				TAILQ_INSERT_AFTER(&rm->rm_list, rv, r,
						     r_link);
			} else if (s->r_start == rv->r_start) {
				DPRINTF(("allocating from the beginning\n"));
				/*
				 * We are allocating at the beginning.
				 */
				s->r_start = rv->r_end + 1;
				TAILQ_INSERT_BEFORE(s, rv, r_link);
			} else {
				DPRINTF(("allocating at the end\n"));
				/*
				 * We are allocating at the end.
				 */
				s->r_end = rv->r_start - 1;
				TAILQ_INSERT_AFTER(&rm->rm_list, s, rv,
						     r_link);
			}
			goto out;
		}
	}

	/*
	 * Now find an acceptable shared region, if the client's requirements
	 * allow sharing.  By our implementation restriction, a candidate
	 * region must match exactly by both size and sharing type in order
	 * to be considered compatible with the client's request.  (The
	 * former restriction could probably be lifted without too much
	 * additional work, but this does not seem warranted.)
	 */
	DPRINTF(("no unshared regions found\n"));
	if ((flags & (RF_SHAREABLE | RF_TIMESHARE)) == 0)
		goto out;

	for (s = r; s; s = TAILQ_NEXT(s, r_link)) {
		if (s->r_start > end)
			break;
		if ((s->r_flags & flags) != flags)
			continue;
		rstart = ulmax(s->r_start, start);
		rend = ulmin(s->r_end, ulmax(start + count - 1, end));
		if (s->r_start >= start && s->r_end <= end
		    && (s->r_end - s->r_start + 1) == count &&
		    (s->r_start & amask) == 0 &&
		    ((s->r_start ^ s->r_end) & bmask) == 0) {
			rv = int_alloc_resource(M_NOWAIT);
			if (rv == NULL)
				goto out;
			rv->r_start = s->r_start;
			rv->r_end = s->r_end;
			rv->r_flags = s->r_flags &
				(RF_ALLOCATED | RF_SHAREABLE | RF_TIMESHARE);
			rv->r_dev = dev;
			rv->r_rm = rm;
			if (s->r_sharehead == NULL) {
				s->r_sharehead = malloc(sizeof *s->r_sharehead,
						M_RMAN, M_NOWAIT | M_ZERO);
				if (s->r_sharehead == NULL) {
					free(rv, M_RMAN);
					rv = NULL;
					goto out;
				}
				LIST_INIT(s->r_sharehead);
				LIST_INSERT_HEAD(s->r_sharehead, s,
						 r_sharelink);
				s->r_flags |= RF_FIRSTSHARE;
			}
			rv->r_sharehead = s->r_sharehead;
			LIST_INSERT_HEAD(s->r_sharehead, rv, r_sharelink);
			goto out;
		}
	}

	/*
	 * We couldn't find anything.
	 */
out:
	/*
	 * If the user specified RF_ACTIVE in the initial flags,
	 * which is reflected in `want_activate', we attempt to atomically
	 * activate the resource.  If this fails, we release the resource
	 * and indicate overall failure.  (This behavior probably doesn't
	 * make sense for RF_TIMESHARE-type resources.)
	 */
	if (rv && want_activate) {
		struct resource_i *whohas;
		if (int_rman_activate_resource(rm, rv, &whohas)) {
			int_rman_release_resource(rm, rv);
			rv = NULL;
		}
	}

	mtx_unlock(rm->rm_mtx);
	return (rv == NULL ? NULL : &rv->r_r);
}

struct resource *
rman_reserve_resource(struct rman *rm, u_long start, u_long end, u_long count,
		      u_int flags, struct device *dev)
{

	return (rman_reserve_resource_bound(rm, start, end, count, 0, flags,
	    dev));
}

static int
int_rman_activate_resource(struct rman *rm, struct resource_i *r,
			   struct resource_i **whohas)
{
	struct resource_i *s;
	int ok;

	/*
	 * If we are not timesharing, then there is nothing much to do.
	 * If we already have the resource, then there is nothing at all to do.
	 * If we are not on a sharing list with anybody else, then there is
	 * little to do.
	 */
	if ((r->r_flags & RF_TIMESHARE) == 0
	    || (r->r_flags & RF_ACTIVE) != 0
	    || r->r_sharehead == NULL) {
		r->r_flags |= RF_ACTIVE;
		return 0;
	}

	ok = 1;
	for (s = LIST_FIRST(r->r_sharehead); s && ok;
	     s = LIST_NEXT(s, r_sharelink)) {
		if ((s->r_flags & RF_ACTIVE) != 0) {
			ok = 0;
			*whohas = s;
		}
	}
	if (ok) {
		r->r_flags |= RF_ACTIVE;
		return 0;
	}
	return EBUSY;
}

int
rman_activate_resource(struct resource *re)
{
	int rv;
	struct resource_i *r, *whohas;
	struct rman *rm;

	r = re->__r_i;
	rm = r->r_rm;
	mtx_lock(rm->rm_mtx);
	rv = int_rman_activate_resource(rm, r, &whohas);
	mtx_unlock(rm->rm_mtx);
	return rv;
}

int
rman_await_resource(struct resource *re, int pri, int timo)
{
	int	rv;
	struct	resource_i *r, *whohas;
	struct	rman *rm;

	r = re->__r_i;
	rm = r->r_rm;
	mtx_lock(rm->rm_mtx);
	for (;;) {
		rv = int_rman_activate_resource(rm, r, &whohas);
		if (rv != EBUSY)
			return (rv);	/* returns with mutex held */

		if (r->r_sharehead == NULL)
			panic("rman_await_resource");
		whohas->r_flags |= RF_WANTED;
		rv = msleep(r->r_sharehead, rm->rm_mtx, pri, "rmwait", timo);
		if (rv) {
			mtx_unlock(rm->rm_mtx);
			return (rv);
		}
	}
}

static int
int_rman_deactivate_resource(struct resource_i *r)
{

	r->r_flags &= ~RF_ACTIVE;
	if (r->r_flags & RF_WANTED) {
		r->r_flags &= ~RF_WANTED;
		wakeup(r->r_sharehead);
	}
	return 0;
}

int
rman_deactivate_resource(struct resource *r)
{
	struct	rman *rm;

	rm = r->__r_i->r_rm;
	mtx_lock(rm->rm_mtx);
	int_rman_deactivate_resource(r->__r_i);
	mtx_unlock(rm->rm_mtx);
	return 0;
}

static int
int_rman_release_resource(struct rman *rm, struct resource_i *r)
{
	struct	resource_i *s, *t;

	if (r->r_flags & RF_ACTIVE)
		int_rman_deactivate_resource(r);

	/*
	 * Check for a sharing list first.  If there is one, then we don't
	 * have to think as hard.
	 */
	if (r->r_sharehead) {
		/*
		 * If a sharing list exists, then we know there are at
		 * least two sharers.
		 *
		 * If we are in the main circleq, appoint someone else.
		 */
		LIST_REMOVE(r, r_sharelink);
		s = LIST_FIRST(r->r_sharehead);
		if (r->r_flags & RF_FIRSTSHARE) {
			s->r_flags |= RF_FIRSTSHARE;
			TAILQ_INSERT_BEFORE(r, s, r_link);
			TAILQ_REMOVE(&rm->rm_list, r, r_link);
		}

		/*
		 * Make sure that the sharing list goes away completely
		 * if the resource is no longer being shared at all.
		 */
		if (LIST_NEXT(s, r_sharelink) == NULL) {
			free(s->r_sharehead, M_RMAN);
			s->r_sharehead = NULL;
			s->r_flags &= ~RF_FIRSTSHARE;
		}
		goto out;
	}

	/*
	 * Look at the adjacent resources in the list and see if our
	 * segment can be merged with any of them.  If either of the
	 * resources is allocated or is not exactly adjacent then they
	 * cannot be merged with our segment.
	 */
	s = TAILQ_PREV(r, resource_head, r_link);
	if (s != NULL && ((s->r_flags & RF_ALLOCATED) != 0 ||
	    s->r_end + 1 != r->r_start))
		s = NULL;
	t = TAILQ_NEXT(r, r_link);
	if (t != NULL && ((t->r_flags & RF_ALLOCATED) != 0 ||
	    r->r_end + 1 != t->r_start))
		t = NULL;

	if (s != NULL && t != NULL) {
		/*
		 * Merge all three segments.
		 */
		s->r_end = t->r_end;
		TAILQ_REMOVE(&rm->rm_list, r, r_link);
		TAILQ_REMOVE(&rm->rm_list, t, r_link);
		free(t, M_RMAN);
	} else if (s != NULL) {
		/*
		 * Merge previous segment with ours.
		 */
		s->r_end = r->r_end;
		TAILQ_REMOVE(&rm->rm_list, r, r_link);
	} else if (t != NULL) {
		/*
		 * Merge next segment with ours.
		 */
		t->r_start = r->r_start;
		TAILQ_REMOVE(&rm->rm_list, r, r_link);
	} else {
		/*
		 * At this point, we know there is nothing we
		 * can potentially merge with, because on each
		 * side, there is either nothing there or what is
		 * there is still allocated.  In that case, we don't
		 * want to remove r from the list; we simply want to
		 * change it to an unallocated region and return
		 * without freeing anything.
		 */
		r->r_flags &= ~RF_ALLOCATED;
		return 0;
	}

out:
	free(r, M_RMAN);
	return 0;
}

int
rman_release_resource(struct resource *re)
{
	int	rv;
	struct	resource_i *r;
	struct	rman *rm;

	r = re->__r_i;
	rm = r->r_rm;
	mtx_lock(rm->rm_mtx);
	rv = int_rman_release_resource(rm, r);
	mtx_unlock(rm->rm_mtx);
	return (rv);
}

uint32_t
rman_make_alignment_flags(uint32_t size)
{
	int	i;

	/*
	 * Find the hightest bit set, and add one if more than one bit
	 * set.  We're effectively computing the ceil(log2(size)) here.
	 */
	for (i = 31; i > 0; i--)
		if ((1 << i) & size)
			break;
	if (~(1 << i) & size)
		i++;

	return(RF_ALIGNMENT_LOG2(i));
}

u_long
rman_get_start(struct resource *r)
{
	return (r->__r_i->r_start);
}

u_long
rman_get_end(struct resource *r)
{
	return (r->__r_i->r_end);
}

u_long
rman_get_size(struct resource *r)
{
	return (r->__r_i->r_end - r->__r_i->r_start + 1);
}

u_int
rman_get_flags(struct resource *r)
{
	return (r->__r_i->r_flags);
}

void
rman_set_virtual(struct resource *r, void *v)
{
	r->__r_i->r_virtual = v;
}

void *
rman_get_virtual(struct resource *r)
{
	return (r->__r_i->r_virtual);
}

void
rman_set_bustag(struct resource *r, bus_space_tag_t t)
{
	r->r_bustag = t;
}

bus_space_tag_t
rman_get_bustag(struct resource *r)
{
	return (r->r_bustag);
}

void
rman_set_bushandle(struct resource *r, bus_space_handle_t h)
{
	r->r_bushandle = h;
}

bus_space_handle_t
rman_get_bushandle(struct resource *r)
{
	return (r->r_bushandle);
}

void
rman_set_rid(struct resource *r, int rid)
{
	r->__r_i->r_rid = rid;
}

void
rman_set_start(struct resource *r, u_long start)
{
	r->__r_i->r_start = start;
}

void
rman_set_end(struct resource *r, u_long end)
{
	r->__r_i->r_end = end;
}

int
rman_get_rid(struct resource *r)
{
	return (r->__r_i->r_rid);
}

struct device *
rman_get_device(struct resource *r)
{
	return (r->__r_i->r_dev);
}

void
rman_set_device(struct resource *r, struct device *dev)
{
	r->__r_i->r_dev = dev;
}

int
rman_is_region_manager(struct resource *r, struct rman *rm)
{

	return (r->__r_i->r_rm == rm);
}

/*
 * Sysctl interface for scanning the resource lists.
 *
 * We take two input parameters; the index into the list of resource
 * managers, and the resource offset into the list.
 */
static int
sysctl_rman(SYSCTL_HANDLER_ARGS)
{
	int			*name = (int *)arg1;
	u_int			namelen = arg2;
	int			rman_idx, res_idx;
	struct rman		*rm;
	struct resource_i	*res;
	struct u_rman		urm;
	struct u_resource	ures;
	int			error;

	if (namelen != 3)
		return (EINVAL);

	if (bus_data_generation_check(name[0]))
		return (EINVAL);
	rman_idx = name[1];
	res_idx = name[2];

	/*
	 * Find the indexed resource manager
	 */
	mtx_lock(&rman_mtx);
	TAILQ_FOREACH(rm, &rman_head, rm_link) {
		if (rman_idx-- == 0)
			break;
	}
	mtx_unlock(&rman_mtx);
	if (rm == NULL)
		return (ENOENT);

	/*
	 * If the resource index is -1, we want details on the
	 * resource manager.
	 */
	if (res_idx == -1) {
		bzero(&urm, sizeof(urm));
		urm.rm_handle = (uintptr_t)rm;
		strlcpy(urm.rm_descr, rm->rm_descr, RM_TEXTLEN);
		urm.rm_start = rm->rm_start;
		urm.rm_size = rm->rm_end - rm->rm_start + 1;
		urm.rm_type = rm->rm_type;

		error = SYSCTL_OUT(req, &urm, sizeof(urm));
		return (error);
	}

	/*
	 * Find the indexed resource and return it.
	 */
	mtx_lock(rm->rm_mtx);
	TAILQ_FOREACH(res, &rm->rm_list, r_link) {
		if (res_idx-- == 0) {
			bzero(&ures, sizeof(ures));
			ures.r_handle = (uintptr_t)res;
			ures.r_parent = (uintptr_t)res->r_rm;
			ures.r_device = (uintptr_t)res->r_dev;
			if (res->r_dev != NULL) {
				if (device_get_name(res->r_dev) != NULL) {
					snprintf(ures.r_devname, RM_TEXTLEN,
					    "%s%d",
					    device_get_name(res->r_dev),
					    device_get_unit(res->r_dev));
				} else {
					strlcpy(ures.r_devname, "nomatch",
					    RM_TEXTLEN);
				}
			} else {
				ures.r_devname[0] = '\0';
			}
			ures.r_start = res->r_start;
			ures.r_size = res->r_end - res->r_start + 1;
			ures.r_flags = res->r_flags;

			mtx_unlock(rm->rm_mtx);
			error = SYSCTL_OUT(req, &ures, sizeof(ures));
			return (error);
		}
	}
	mtx_unlock(rm->rm_mtx);
	return (ENOENT);
}

SYSCTL_NODE(_hw_bus, OID_AUTO, rman, CTLFLAG_RD, sysctl_rman,
    "kernel resource manager");

#ifdef DDB
static void
dump_rman(struct rman *rm)
{
	struct resource_i *r;
	const char *devname;

	if (db_pager_quit)
		return;
	db_printf("rman: %s\n", rm->rm_descr);
	db_printf("    0x%lx-0x%lx (full range)\n", rm->rm_start, rm->rm_end);
	TAILQ_FOREACH(r, &rm->rm_list, r_link) {
		if (r->r_dev != NULL) {
			devname = device_get_nameunit(r->r_dev);
			if (devname == NULL)
				devname = "nomatch";
		} else
			devname = NULL;
		db_printf("    0x%lx-0x%lx ", r->r_start, r->r_end);
		if (devname != NULL)
			db_printf("(%s)\n", devname);
		else
			db_printf("----\n");
		if (db_pager_quit)
			return;
	}
}

DB_SHOW_COMMAND(rman, db_show_rman)
{

	if (have_addr)
		dump_rman((struct rman *)addr);
}

DB_SHOW_COMMAND(allrman, db_show_all_rman)
{
	struct rman *rm;

	TAILQ_FOREACH(rm, &rman_head, rm_link)
		dump_rman(rm);
}
#endif
OpenPOWER on IntegriCloud