Home Home > GIT Browse
summaryrefslogtreecommitdiff
blob: ec924deb0a323482a9d65b4520c5cbc151546644 (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
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// SPDX-License-Identifier: GPL-2.0-only
/*
 * UWB reservation management.
 *
 * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
 */
#include <linux/kernel.h>
#include <linux/uwb.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/export.h>

#include "uwb-internal.h"

static void uwb_rsv_timer(struct timer_list *t);

static const char *rsv_states[] = {
	[UWB_RSV_STATE_NONE]                 = "none            ",
	[UWB_RSV_STATE_O_INITIATED]          = "o initiated     ",
	[UWB_RSV_STATE_O_PENDING]            = "o pending       ",
	[UWB_RSV_STATE_O_MODIFIED]           = "o modified      ",
	[UWB_RSV_STATE_O_ESTABLISHED]        = "o established   ",
	[UWB_RSV_STATE_O_TO_BE_MOVED]        = "o to be moved   ",
	[UWB_RSV_STATE_O_MOVE_EXPANDING]     = "o move expanding",
	[UWB_RSV_STATE_O_MOVE_COMBINING]     = "o move combining",
	[UWB_RSV_STATE_O_MOVE_REDUCING]      = "o move reducing ",
	[UWB_RSV_STATE_T_ACCEPTED]           = "t accepted      ",
	[UWB_RSV_STATE_T_CONFLICT]           = "t conflict      ",
	[UWB_RSV_STATE_T_PENDING]            = "t pending       ",
	[UWB_RSV_STATE_T_DENIED]             = "t denied        ",
	[UWB_RSV_STATE_T_RESIZED]            = "t resized       ",
	[UWB_RSV_STATE_T_EXPANDING_ACCEPTED] = "t expanding acc ",
	[UWB_RSV_STATE_T_EXPANDING_CONFLICT] = "t expanding conf",
	[UWB_RSV_STATE_T_EXPANDING_PENDING]  = "t expanding pend",
	[UWB_RSV_STATE_T_EXPANDING_DENIED]   = "t expanding den ",
};

static const char *rsv_types[] = {
	[UWB_DRP_TYPE_ALIEN_BP] = "alien-bp",
	[UWB_DRP_TYPE_HARD]     = "hard",
	[UWB_DRP_TYPE_SOFT]     = "soft",
	[UWB_DRP_TYPE_PRIVATE]  = "private",
	[UWB_DRP_TYPE_PCA]      = "pca",
};

bool uwb_rsv_has_two_drp_ies(struct uwb_rsv *rsv)
{
	static const bool has_two_drp_ies[] = {
		[UWB_RSV_STATE_O_INITIATED]               = false,
		[UWB_RSV_STATE_O_PENDING]                 = false,
		[UWB_RSV_STATE_O_MODIFIED]                = false,
		[UWB_RSV_STATE_O_ESTABLISHED]             = false,
		[UWB_RSV_STATE_O_TO_BE_MOVED]             = false,
		[UWB_RSV_STATE_O_MOVE_COMBINING]          = false,
		[UWB_RSV_STATE_O_MOVE_REDUCING]           = false,
		[UWB_RSV_STATE_O_MOVE_EXPANDING]          = true,
		[UWB_RSV_STATE_T_ACCEPTED]                = false,
		[UWB_RSV_STATE_T_CONFLICT]                = false,
		[UWB_RSV_STATE_T_PENDING]                 = false,
		[UWB_RSV_STATE_T_DENIED]                  = false,
		[UWB_RSV_STATE_T_RESIZED]                 = false,
		[UWB_RSV_STATE_T_EXPANDING_ACCEPTED]      = true,
		[UWB_RSV_STATE_T_EXPANDING_CONFLICT]      = true,
		[UWB_RSV_STATE_T_EXPANDING_PENDING]       = true,
		[UWB_RSV_STATE_T_EXPANDING_DENIED]        = true,
	};

	return has_two_drp_ies[rsv->state];
}

/**
 * uwb_rsv_state_str - return a string for a reservation state
 * @state: the reservation state.
 */
const char *uwb_rsv_state_str(enum uwb_rsv_state state)
{
	if (state < UWB_RSV_STATE_NONE || state >= UWB_RSV_STATE_LAST)
		return "unknown";
	return rsv_states[state];
}
EXPORT_SYMBOL_GPL(uwb_rsv_state_str);

/**
 * uwb_rsv_type_str - return a string for a reservation type
 * @type: the reservation type
 */
const char *uwb_rsv_type_str(enum uwb_drp_type type)
{
	if (type < UWB_DRP_TYPE_ALIEN_BP || type > UWB_DRP_TYPE_PCA)
		return "invalid";
	return rsv_types[type];
}
EXPORT_SYMBOL_GPL(uwb_rsv_type_str);

void uwb_rsv_dump(char *text, struct uwb_rsv *rsv)
{
	struct device *dev = &rsv->rc->uwb_dev.dev;
	struct uwb_dev_addr devaddr;
	char owner[UWB_ADDR_STRSIZE], target[UWB_ADDR_STRSIZE];

	uwb_dev_addr_print(owner, sizeof(owner), &rsv->owner->dev_addr);
	if (rsv->target.type == UWB_RSV_TARGET_DEV)
		devaddr = rsv->target.dev->dev_addr;
	else
		devaddr = rsv->target.devaddr;
	uwb_dev_addr_print(target, sizeof(target), &devaddr);

	dev_dbg(dev, "rsv %s %s -> %s: %s\n",
		text, owner, target, uwb_rsv_state_str(rsv->state));
}

static void uwb_rsv_release(struct kref *kref)
{
	struct uwb_rsv *rsv = container_of(kref, struct uwb_rsv, kref);

	kfree(rsv);
}

void uwb_rsv_get(struct uwb_rsv *rsv)
{
	kref_get(&rsv->kref);
}

void uwb_rsv_put(struct uwb_rsv *rsv)
{
	kref_put(&rsv->kref, uwb_rsv_release);
}

/*
 * Get a free stream index for a reservation.
 *
 * If the target is a DevAddr (e.g., a WUSB cluster reservation) then
 * the stream is allocated from a pool of per-RC stream indexes,
 * otherwise a unique stream index for the target is selected.
 */
static int uwb_rsv_get_stream(struct uwb_rsv *rsv)
{
	struct uwb_rc *rc = rsv->rc;
	struct device *dev = &rc->uwb_dev.dev;
	unsigned long *streams_bm;
	int stream;

	switch (rsv->target.type) {
	case UWB_RSV_TARGET_DEV:
		streams_bm = rsv->target.dev->streams;
		break;
	case UWB_RSV_TARGET_DEVADDR:
		streams_bm = rc->uwb_dev.streams;
		break;
	default:
		return -EINVAL;
	}

	stream = find_first_zero_bit(streams_bm, UWB_NUM_STREAMS);
	if (stream >= UWB_NUM_STREAMS) {
		dev_err(dev, "%s: no available stream found\n", __func__);
		return -EBUSY;
	}

	rsv->stream = stream;
	set_bit(stream, streams_bm);

	dev_dbg(dev, "get stream %d\n", rsv->stream);

	return 0;
}

static void uwb_rsv_put_stream(struct uwb_rsv *rsv)
{
	struct uwb_rc *rc = rsv->rc;
	struct device *dev = &rc->uwb_dev.dev;
	unsigned long *streams_bm;

	switch (rsv->target.type) {
	case UWB_RSV_TARGET_DEV:
		streams_bm = rsv->target.dev->streams;
		break;
	case UWB_RSV_TARGET_DEVADDR:
		streams_bm = rc->uwb_dev.streams;
		break;
	default:
		return;
	}

	clear_bit(rsv->stream, streams_bm);

	dev_dbg(dev, "put stream %d\n", rsv->stream);
}

void uwb_rsv_backoff_win_timer(struct timer_list *t)
{
	struct uwb_drp_backoff_win *bow = from_timer(bow, t, timer);
	struct uwb_rc *rc = container_of(bow, struct uwb_rc, bow);
	struct device *dev = &rc->uwb_dev.dev;

	bow->can_reserve_extra_mases = true;
	if (bow->total_expired <= 4) {
		bow->total_expired++;
	} else {
		/* after 4 backoff window has expired we can exit from
		 * the backoff procedure */
		bow->total_expired = 0;
		bow->window = UWB_DRP_BACKOFF_WIN_MIN >> 1;
	}
	dev_dbg(dev, "backoff_win_timer total_expired=%d, n=%d\n", bow->total_expired, bow->n);

	/* try to relocate all the "to be moved" relocations */
	uwb_rsv_handle_drp_avail_change(rc);
}

void uwb_rsv_backoff_win_increment(struct uwb_rc *rc)
{
	struct uwb_drp_backoff_win *bow = &rc->bow;
	struct device *dev = &rc->uwb_dev.dev;
	unsigned timeout_us;

	dev_dbg(dev, "backoff_win_increment: window=%d\n", bow->window);

	bow->can_reserve_extra_mases = false;

	if((bow->window << 1) == UWB_DRP_BACKOFF_WIN_MAX)
		return;

	bow->window <<= 1;
	bow->n = prandom_u32() & (bow->window - 1);
	dev_dbg(dev, "new_window=%d, n=%d\n", bow->window, bow->n);

	/* reset the timer associated variables */
	timeout_us = bow->n * UWB_SUPERFRAME_LENGTH_US;
	bow->total_expired = 0;
	mod_timer(&bow->timer, jiffies + usecs_to_jiffies(timeout_us));
}

static void uwb_rsv_stroke_timer(struct uwb_rsv *rsv)
{
	int sframes = UWB_MAX_LOST_BEACONS;

	/*
	 * Multicast reservations can become established within 1
	 * super frame and should not be terminated if no response is
	 * received.
	 */
	if (rsv->state == UWB_RSV_STATE_NONE) {
		sframes = 0;
	} else if (rsv->is_multicast) {
		if (rsv->state == UWB_RSV_STATE_O_INITIATED
		    || rsv->state == UWB_RSV_STATE_O_MOVE_EXPANDING
		    || rsv->state == UWB_RSV_STATE_O_MOVE_COMBINING
		    || rsv->state == UWB_RSV_STATE_O_MOVE_REDUCING)
			sframes = 1;
		if (rsv->state == UWB_RSV_STATE_O_ESTABLISHED)
			sframes = 0;

	}

	if (sframes > 0) {
		/*
		 * Add an additional 2 superframes to account for the
		 * time to send the SET DRP IE command.
		 */
		unsigned timeout_us = (sframes + 2) * UWB_SUPERFRAME_LENGTH_US;
		mod_timer(&rsv->timer, jiffies + usecs_to_jiffies(timeout_us));
	} else
		del_timer(&rsv->timer);
}

/*
 * Update a reservations state, and schedule an update of the
 * transmitted DRP IEs.
 */
static void uwb_rsv_state_update(struct uwb_rsv *rsv,
				 enum uwb_rsv_state new_state)
{
	rsv->state = new_state;
	rsv->ie_valid = false;

	uwb_rsv_dump("SU", rsv);

	uwb_rsv_stroke_timer(rsv);
	uwb_rsv_sched_update(rsv->rc);
}

static void uwb_rsv_callback(struct uwb_rsv *rsv)
{
	if (rsv->callback)
		rsv->callback(rsv);
}

void uwb_rsv_set_state(struct uwb_rsv *rsv, enum uwb_rsv_state new_state)
{
	struct uwb_rsv_move *mv = &rsv->mv;

	if (rsv->state == new_state) {
		switch (rsv->state) {
		case UWB_RSV_STATE_O_ESTABLISHED:
		case UWB_RSV_STATE_O_MOVE_EXPANDING:
		case UWB_RSV_STATE_O_MOVE_COMBINING:
		case UWB_RSV_STATE_O_MOVE_REDUCING:
		case UWB_RSV_STATE_T_ACCEPTED:
		case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
		case UWB_RSV_STATE_T_RESIZED:
		case UWB_RSV_STATE_NONE:
			uwb_rsv_stroke_timer(rsv);
			break;
		default:
			/* Expecting a state transition so leave timer
			   as-is. */
			break;
		}
		return;
	}

	uwb_rsv_dump("SC", rsv);

	switch (new_state) {
	case UWB_RSV_STATE_NONE:
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_NONE);
		uwb_rsv_remove(rsv);
		uwb_rsv_callback(rsv);
		break;
	case UWB_RSV_STATE_O_INITIATED:
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_INITIATED);
		break;
	case UWB_RSV_STATE_O_PENDING:
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_PENDING);
		break;
	case UWB_RSV_STATE_O_MODIFIED:
		/* in the companion there are the MASes to drop */
		bitmap_andnot(rsv->mas.bm, rsv->mas.bm, mv->companion_mas.bm, UWB_NUM_MAS);
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MODIFIED);
		break;
	case UWB_RSV_STATE_O_ESTABLISHED:
		if (rsv->state == UWB_RSV_STATE_O_MODIFIED
		    || rsv->state == UWB_RSV_STATE_O_MOVE_REDUCING) {
			uwb_drp_avail_release(rsv->rc, &mv->companion_mas);
			rsv->needs_release_companion_mas = false;
		}
		uwb_drp_avail_reserve(rsv->rc, &rsv->mas);
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_ESTABLISHED);
		uwb_rsv_callback(rsv);
		break;
	case UWB_RSV_STATE_O_MOVE_EXPANDING:
		rsv->needs_release_companion_mas = true;
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
		break;
	case UWB_RSV_STATE_O_MOVE_COMBINING:
		rsv->needs_release_companion_mas = false;
		uwb_drp_avail_reserve(rsv->rc, &mv->companion_mas);
		bitmap_or(rsv->mas.bm, rsv->mas.bm, mv->companion_mas.bm, UWB_NUM_MAS);
		rsv->mas.safe   += mv->companion_mas.safe;
		rsv->mas.unsafe += mv->companion_mas.unsafe;
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
		break;
	case UWB_RSV_STATE_O_MOVE_REDUCING:
		bitmap_andnot(mv->companion_mas.bm, rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS);
		rsv->needs_release_companion_mas = true;
		rsv->mas.safe   = mv->final_mas.safe;
		rsv->mas.unsafe = mv->final_mas.unsafe;
		bitmap_copy(rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS);
		bitmap_copy(rsv->mas.unsafe_bm, mv->final_mas.unsafe_bm, UWB_NUM_MAS);
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
		break;
	case UWB_RSV_STATE_T_ACCEPTED:
	case UWB_RSV_STATE_T_RESIZED:
		rsv->needs_release_companion_mas = false;
		uwb_drp_avail_reserve(rsv->rc, &rsv->mas);
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_ACCEPTED);
		uwb_rsv_callback(rsv);
		break;
	case UWB_RSV_STATE_T_DENIED:
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_DENIED);
		break;
	case UWB_RSV_STATE_T_CONFLICT:
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_CONFLICT);
		break;
	case UWB_RSV_STATE_T_PENDING:
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_PENDING);
		break;
	case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
		rsv->needs_release_companion_mas = true;
		uwb_drp_avail_reserve(rsv->rc, &mv->companion_mas);
		uwb_rsv_state_update(rsv, UWB_RSV_STATE_T_EXPANDING_ACCEPTED);
		break;
	default:
		dev_err(&rsv->rc->uwb_dev.dev, "unhandled state: %s (%d)\n",
			uwb_rsv_state_str(new_state), new_state);
	}
}

static void uwb_rsv_handle_timeout_work(struct work_struct *work)
{
	struct uwb_rsv *rsv = container_of(work, struct uwb_rsv,
					   handle_timeout_work);
	struct uwb_rc *rc = rsv->rc;

	mutex_lock(&rc->rsvs_mutex);

	uwb_rsv_dump("TO", rsv);

	switch (rsv->state) {
	case UWB_RSV_STATE_O_INITIATED:
		if (rsv->is_multicast) {
			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
			goto unlock;
		}
		break;
	case UWB_RSV_STATE_O_MOVE_EXPANDING:
		if (rsv->is_multicast) {
			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_COMBINING);
			goto unlock;
		}
		break;
	case UWB_RSV_STATE_O_MOVE_COMBINING:
		if (rsv->is_multicast) {
			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_REDUCING);
			goto unlock;
		}
		break;
	case UWB_RSV_STATE_O_MOVE_REDUCING:
		if (rsv->is_multicast) {
			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_ESTABLISHED);
			goto unlock;
		}
		break;
	case UWB_RSV_STATE_O_ESTABLISHED:
		if (rsv->is_multicast)
			goto unlock;
		break;
	case UWB_RSV_STATE_T_EXPANDING_ACCEPTED:
		/*
		 * The time out could be for the main or of the
		 * companion DRP, assume it's for the companion and
		 * drop that first.  A further time out is required to
		 * drop the main.
		 */
		uwb_rsv_set_state(rsv, UWB_RSV_STATE_T_ACCEPTED);
		uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
		goto unlock;
	case UWB_RSV_STATE_NONE:
		goto unlock;
	default:
		break;
	}

	uwb_rsv_remove(rsv);

unlock:
	mutex_unlock(&rc->rsvs_mutex);
}

static struct uwb_rsv *uwb_rsv_alloc(struct uwb_rc *rc)
{
	struct uwb_rsv *rsv;

	rsv = kzalloc(sizeof(struct uwb_rsv), GFP_KERNEL);
	if (!rsv)
		return NULL;

	INIT_LIST_HEAD(&rsv->rc_node);
	INIT_LIST_HEAD(&rsv->pal_node);
	kref_init(&rsv->kref);
	timer_setup(&rsv->timer, uwb_rsv_timer, 0);

	rsv->rc = rc;
	INIT_WORK(&rsv->handle_timeout_work, uwb_rsv_handle_timeout_work);

	return rsv;
}

/**
 * uwb_rsv_create - allocate and initialize a UWB reservation structure
 * @rc: the radio controller
 * @cb: callback to use when the reservation completes or terminates
 * @pal_priv: data private to the PAL to be passed in the callback
 *
 * The callback is called when the state of the reservation changes from:
 *
 *   - pending to accepted
 *   - pending to denined
 *   - accepted to terminated
 *   - pending to terminated
 */
struct uwb_rsv *uwb_rsv_create(struct uwb_rc *rc, uwb_rsv_cb_f cb, void *pal_priv)
{
	struct uwb_rsv *rsv;

	rsv = uwb_rsv_alloc(rc);
	if (!rsv)
		return NULL;

	rsv->callback = cb;
	rsv->pal_priv = pal_priv;

	return rsv;
}
EXPORT_SYMBOL_GPL(uwb_rsv_create);

void uwb_rsv_remove(struct uwb_rsv *rsv)
{
	uwb_rsv_dump("RM", rsv);

	if (rsv->state != UWB_RSV_STATE_NONE)
		uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);

	if (rsv->needs_release_companion_mas)
		uwb_drp_avail_release(rsv->rc, &rsv->mv.companion_mas);
	uwb_drp_avail_release(rsv->rc, &rsv->mas);

	if (uwb_rsv_is_owner(rsv))
		uwb_rsv_put_stream(rsv);

	uwb_dev_put(rsv->owner);
	if (rsv->target.type == UWB_RSV_TARGET_DEV)
		uwb_dev_put(rsv->target.dev);

	list_del_init(&rsv->rc_node);
	uwb_rsv_put(rsv);
}

/**
 * uwb_rsv_destroy - free a UWB reservation structure
 * @rsv: the reservation to free
 *
 * The reservation must already be terminated.
 */
void uwb_rsv_destroy(struct uwb_rsv *rsv)
{
	uwb_rsv_put(rsv);
}
EXPORT_SYMBOL_GPL(uwb_rsv_destroy);

/**
 * usb_rsv_establish - start a reservation establishment
 * @rsv: the reservation
 *
 * The PAL should fill in @rsv's owner, target, type, max_mas,
 * min_mas, max_interval and is_multicast fields.  If the target is a
 * uwb_dev it must be referenced.
 *
 * The reservation's callback will be called when the reservation is
 * accepted, denied or times out.
 */
int uwb_rsv_establish(struct uwb_rsv *rsv)
{
	struct uwb_rc *rc = rsv->rc;
	struct uwb_mas_bm available;
	struct device *dev = &rc->uwb_dev.dev;
	int ret;

	mutex_lock(&rc->rsvs_mutex);
	ret = uwb_rsv_get_stream(rsv);
	if (ret) {
		dev_err(dev, "%s: uwb_rsv_get_stream failed: %d\n",
			__func__, ret);
		goto out;
	}

	rsv->tiebreaker = prandom_u32() & 1;
	/* get available mas bitmap */
	uwb_drp_available(rc, &available);

	ret = uwb_rsv_find_best_allocation(rsv, &available, &rsv->mas);
	if (ret == UWB_RSV_ALLOC_NOT_FOUND) {
		ret = -EBUSY;
		uwb_rsv_put_stream(rsv);
		dev_err(dev, "%s: uwb_rsv_find_best_allocation failed: %d\n",
			__func__, ret);
		goto out;
	}

	ret = uwb_drp_avail_reserve_pending(rc, &rsv->mas);
	if (ret != 0) {
		uwb_rsv_put_stream(rsv);
		dev_err(dev, "%s: uwb_drp_avail_reserve_pending failed: %d\n",
			__func__, ret);
		goto out;
	}

	uwb_rsv_get(rsv);
	list_add_tail(&rsv->rc_node, &rc->reservations);
	rsv->owner = &rc->uwb_dev;
	uwb_dev_get(rsv->owner);
	uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_INITIATED);
out:
	mutex_unlock(&rc->rsvs_mutex);
	return ret;
}
EXPORT_SYMBOL_GPL(uwb_rsv_establish);

/**
 * uwb_rsv_modify - modify an already established reservation
 * @rsv: the reservation to modify
 * @max_mas: new maximum MAS to reserve
 * @min_mas: new minimum MAS to reserve
 * @max_interval: new max_interval to use
 *
 * FIXME: implement this once there are PALs that use it.
 */
int uwb_rsv_modify(struct uwb_rsv *rsv, int max_mas, int min_mas, int max_interval)
{
	return -ENOSYS;
}
EXPORT_SYMBOL_GPL(uwb_rsv_modify);

/*
 * move an already established reservation (rc->rsvs_mutex must to be
 * taken when tis function is called)
 */
int uwb_rsv_try_move(struct uwb_rsv *rsv, struct uwb_mas_bm *available)
{
	struct uwb_rc *rc = rsv->rc;
	struct uwb_drp_backoff_win *bow = &rc->bow;
	struct device *dev = &rc->uwb_dev.dev;
	struct uwb_rsv_move *mv;
	int ret = 0;

	if (bow->can_reserve_extra_mases == false)
		return -EBUSY;

	mv = &rsv->mv;

	if (uwb_rsv_find_best_allocation(rsv, available, &mv->final_mas) == UWB_RSV_ALLOC_FOUND) {

		if (!bitmap_equal(rsv->mas.bm, mv->final_mas.bm, UWB_NUM_MAS)) {
			/* We want to move the reservation */
			bitmap_andnot(mv->companion_mas.bm, mv->final_mas.bm, rsv->mas.bm, UWB_NUM_MAS);
			uwb_drp_avail_reserve_pending(rc, &mv->companion_mas);
			uwb_rsv_set_state(rsv, UWB_RSV_STATE_O_MOVE_EXPANDING);
		}
	} else {
		dev_dbg(dev, "new allocation not found\n");
	}

	return ret;
}

/* It will try to move every reservation in state O_ESTABLISHED giving
 * to the MAS allocator algorithm an availability that is the real one
 * plus the allocation already established from the reservation. */
void uwb_rsv_handle_drp_avail_change(struct uwb_rc *rc)
{
	struct uwb_drp_backoff_win *bow = &rc->bow;
	struct uwb_rsv *rsv;
	struct uwb_mas_bm mas;

	if (bow->can_reserve_extra_mases == false)
		return;

	list_for_each_entry(rsv, &rc->reservations, rc_node) {
		if (rsv->state == UWB_RSV_STATE_O_ESTABLISHED ||
		    rsv->state == UWB_RSV_STATE_O_TO_BE_MOVED) {
			uwb_drp_available(rc, &mas);
			bitmap_or(mas.bm, mas.bm, rsv->mas.bm, UWB_NUM_MAS);
			uwb_rsv_try_move(rsv, &mas);
		}
	}

}

/**
 * uwb_rsv_terminate - terminate an established reservation
 * @rsv: the reservation to terminate
 *
 * A reservation is terminated by removing the DRP IE from the beacon,
 * the other end will consider the reservation to be terminated when
 * it does not see the DRP IE for at least mMaxLostBeacons.
 *
 * If applicable, the reference to the target uwb_dev will be released.
 */
void uwb_rsv_terminate(struct uwb_rsv *rsv)
{
	struct uwb_rc *rc = rsv->rc;

	mutex_lock(&rc->rsvs_mutex);

	if (rsv->state != UWB_RSV_STATE_NONE)
		uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);

	mutex_unlock(&rc->rsvs_mutex);
}
EXPORT_SYMBOL_GPL(uwb_rsv_terminate);

/**
 * uwb_rsv_accept - accept a new reservation from a peer
 * @rsv:      the reservation
 * @cb:       call back for reservation changes
 * @pal_priv: data to be passed in the above call back
 *
 * Reservation requests from peers are denied unless a PAL accepts it
 * by calling this function.
 *
 * The PAL call uwb_rsv_destroy() for all accepted reservations before
 * calling uwb_pal_unregister().
 */
void uwb_rsv_accept(struct uwb_rsv *rsv, uwb_rsv_cb_f cb, void *pal_priv)
{
	uwb_rsv_get(rsv);

	rsv->callback = cb;
	rsv->pal_priv = pal_priv;
	rsv->state    = UWB_RSV_STATE_T_ACCEPTED;
}
EXPORT_SYMBOL_GPL(uwb_rsv_accept);

/*
 * Is a received DRP IE for this reservation?
 */
static bool uwb_rsv_match(struct uwb_rsv *rsv, struct uwb_dev *src,
			  struct uwb_ie_drp *drp_ie)
{
	struct uwb_dev_addr *rsv_src;
	int stream;

	stream = uwb_ie_drp_stream_index(drp_ie);

	if (rsv->stream != stream)
		return false;

	switch (rsv->target.type) {
	case UWB_RSV_TARGET_DEVADDR:
		return rsv->stream == stream;
	case UWB_RSV_TARGET_DEV:
		if (uwb_ie_drp_owner(drp_ie))
			rsv_src = &rsv->owner->dev_addr;
		else
			rsv_src = &rsv->target.dev->dev_addr;
		return uwb_dev_addr_cmp(&src->dev_addr, rsv_src) == 0;
	}
	return false;
}

static struct uwb_rsv *uwb_rsv_new_target(struct uwb_rc *rc,
					  struct uwb_dev *src,
					  struct uwb_ie_drp *drp_ie)
{
	struct uwb_rsv *rsv;
	struct uwb_pal *pal;
	enum uwb_rsv_state state;

	rsv = uwb_rsv_alloc(rc);
	if (!rsv)
		return NULL;

	rsv->rc          = rc;
	rsv->owner       = src;
	uwb_dev_get(rsv->owner);
	rsv->target.type = UWB_RSV_TARGET_DEV;
	rsv->target.dev  = &rc->uwb_dev;
	uwb_dev_get(&rc->uwb_dev);
	rsv->type        = uwb_ie_drp_type(drp_ie);
	rsv->stream      = uwb_ie_drp_stream_index(drp_ie);
	uwb_drp_ie_to_bm(&rsv->mas, drp_ie);

	/*
	 * See if any PALs are interested in this reservation. If not,
	 * deny the request.
	 */
	rsv->state = UWB_RSV_STATE_T_DENIED;
	mutex_lock(&rc->uwb_dev.mutex);
	list_for_each_entry(pal, &rc->pals, node) {
		if (pal->new_rsv)
			pal->new_rsv(pal, rsv);
		if (rsv->state == UWB_RSV_STATE_T_ACCEPTED)
			break;
	}
	mutex_unlock(&rc->uwb_dev.mutex);

	list_add_tail(&rsv->rc_node, &rc->reservations);
	state = rsv->state;
	rsv->state = UWB_RSV_STATE_NONE;

	/* FIXME: do something sensible here */
	if (state == UWB_RSV_STATE_T_ACCEPTED
	    && uwb_drp_avail_reserve_pending(rc, &rsv->mas) == -EBUSY) {
		/* FIXME: do something sensible here */
	} else {
		uwb_rsv_set_state(rsv, state);
	}

	return rsv;
}

/**
 * uwb_rsv_get_usable_mas - get the bitmap of the usable MAS of a reservations
 * @rsv: the reservation.
 * @mas: returns the available MAS.
 *
 * The usable MAS of a reservation may be less than the negotiated MAS
 * if alien BPs are present.
 */
void uwb_rsv_get_usable_mas(struct uwb_rsv *rsv, struct uwb_mas_bm *mas)
{
	bitmap_zero(mas->bm, UWB_NUM_MAS);
	bitmap_andnot(mas->bm, rsv->mas.bm, rsv->rc->cnflt_alien_bitmap.bm, UWB_NUM_MAS);
}
EXPORT_SYMBOL_GPL(uwb_rsv_get_usable_mas);

/**
 * uwb_rsv_find - find a reservation for a received DRP IE.
 * @rc: the radio controller
 * @src: source of the DRP IE
 * @drp_ie: the DRP IE
 *
 * If the reservation cannot be found and the DRP IE is from a peer
 * attempting to establish a new reservation, create a new reservation
 * and add it to the list.
 */
struct uwb_rsv *uwb_rsv_find(struct uwb_rc *rc, struct uwb_dev *src,
			     struct uwb_ie_drp *drp_ie)
{
	struct uwb_rsv *rsv;

	list_for_each_entry(rsv, &rc->reservations, rc_node) {
		if (uwb_rsv_match(rsv, src, drp_ie))
			return rsv;
	}

	if (uwb_ie_drp_owner(drp_ie))
		return uwb_rsv_new_target(rc, src, drp_ie);

	return NULL;
}

/*
 * Go through all the reservations and check for timeouts and (if
 * necessary) update their DRP IEs.
 *
 * FIXME: look at building the SET_DRP_IE command here rather than
 * having to rescan the list in uwb_rc_send_all_drp_ie().
 */
static bool uwb_rsv_update_all(struct uwb_rc *rc)
{
	struct uwb_rsv *rsv, *t;
	bool ie_updated = false;

	list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
		if (!rsv->ie_valid) {
			uwb_drp_ie_update(rsv);
			ie_updated = true;
		}
	}

	return ie_updated;
}

void uwb_rsv_queue_update(struct uwb_rc *rc)
{
	unsigned long delay_us = UWB_MAS_LENGTH_US * UWB_MAS_PER_ZONE;

	queue_delayed_work(rc->rsv_workq, &rc->rsv_update_work, usecs_to_jiffies(delay_us));
}

/**
 * uwb_rsv_sched_update - schedule an update of the DRP IEs
 * @rc: the radio controller.
 *
 * To improve performance and ensure correctness with [ECMA-368] the
 * number of SET-DRP-IE commands that are done are limited.
 *
 * DRP IEs update come from two sources: DRP events from the hardware
 * which all occur at the beginning of the superframe ('syncronous'
 * events) and reservation establishment/termination requests from
 * PALs or timers ('asynchronous' events).
 *
 * A delayed work ensures that all the synchronous events result in
 * one SET-DRP-IE command.
 *
 * Additional logic (the set_drp_ie_pending and rsv_updated_postponed
 * flags) will prevent an asynchrous event starting a SET-DRP-IE
 * command if one is currently awaiting a response.
 *
 * FIXME: this does leave a window where an asynchrous event can delay
 * the SET-DRP-IE for a synchronous event by one superframe.
 */
void uwb_rsv_sched_update(struct uwb_rc *rc)
{
	spin_lock_irq(&rc->rsvs_lock);
	if (!delayed_work_pending(&rc->rsv_update_work)) {
		if (rc->set_drp_ie_pending > 0) {
			rc->set_drp_ie_pending++;
			goto unlock;
		}
		uwb_rsv_queue_update(rc);
	}
unlock:
	spin_unlock_irq(&rc->rsvs_lock);
}

/*
 * Update DRP IEs and, if necessary, the DRP Availability IE and send
 * the updated IEs to the radio controller.
 */
static void uwb_rsv_update_work(struct work_struct *work)
{
	struct uwb_rc *rc = container_of(work, struct uwb_rc,
					 rsv_update_work.work);
	bool ie_updated;

	mutex_lock(&rc->rsvs_mutex);

	ie_updated = uwb_rsv_update_all(rc);

	if (!rc->drp_avail.ie_valid) {
		uwb_drp_avail_ie_update(rc);
		ie_updated = true;
	}

	if (ie_updated && (rc->set_drp_ie_pending == 0))
		uwb_rc_send_all_drp_ie(rc);

	mutex_unlock(&rc->rsvs_mutex);
}

static void uwb_rsv_alien_bp_work(struct work_struct *work)
{
	struct uwb_rc *rc = container_of(work, struct uwb_rc,
					 rsv_alien_bp_work.work);
	struct uwb_rsv *rsv;

	mutex_lock(&rc->rsvs_mutex);

	list_for_each_entry(rsv, &rc->reservations, rc_node) {
		if (rsv->type != UWB_DRP_TYPE_ALIEN_BP) {
			uwb_rsv_callback(rsv);
		}
	}

	mutex_unlock(&rc->rsvs_mutex);
}

static void uwb_rsv_timer(struct timer_list *t)
{
	struct uwb_rsv *rsv = from_timer(rsv, t, timer);

	queue_work(rsv->rc->rsv_workq, &rsv->handle_timeout_work);
}

/**
 * uwb_rsv_remove_all - remove all reservations
 * @rc: the radio controller
 *
 * A DRP IE update is not done.
 */
void uwb_rsv_remove_all(struct uwb_rc *rc)
{
	struct uwb_rsv *rsv, *t;

	mutex_lock(&rc->rsvs_mutex);
	list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
		if (rsv->state != UWB_RSV_STATE_NONE)
			uwb_rsv_set_state(rsv, UWB_RSV_STATE_NONE);
		del_timer_sync(&rsv->timer);
	}
	/* Cancel any postponed update. */
	rc->set_drp_ie_pending = 0;
	mutex_unlock(&rc->rsvs_mutex);

	cancel_delayed_work_sync(&rc->rsv_update_work);
	flush_workqueue(rc->rsv_workq);

	mutex_lock(&rc->rsvs_mutex);
	list_for_each_entry_safe(rsv, t, &rc->reservations, rc_node) {
		uwb_rsv_remove(rsv);
	}
	mutex_unlock(&rc->rsvs_mutex);
}

void uwb_rsv_init(struct uwb_rc *rc)
{
	INIT_LIST_HEAD(&rc->reservations);
	INIT_LIST_HEAD(&rc->cnflt_alien_list);
	mutex_init(&rc->rsvs_mutex);
	spin_lock_init(&rc->rsvs_lock);
	INIT_DELAYED_WORK(&rc->rsv_update_work, uwb_rsv_update_work);
	INIT_DELAYED_WORK(&rc->rsv_alien_bp_work, uwb_rsv_alien_bp_work);
	rc->bow.can_reserve_extra_mases = true;
	rc->bow.total_expired = 0;
	rc->bow.window = UWB_DRP_BACKOFF_WIN_MIN >> 1;
	timer_setup(&rc->bow.timer, uwb_rsv_backoff_win_timer, 0);

	bitmap_complement(rc->uwb_dev.streams, rc->uwb_dev.streams, UWB_NUM_STREAMS);
}

int uwb_rsv_setup(struct uwb_rc *rc)
{
	char name[16];

	snprintf(name, sizeof(name), "%s_rsvd", dev_name(&rc->uwb_dev.dev));
	rc->rsv_workq = create_singlethread_workqueue(name);
	if (rc->rsv_workq == NULL)
		return -ENOMEM;

	return 0;
}

void uwb_rsv_cleanup(struct uwb_rc *rc)
{
	uwb_rsv_remove_all(rc);
	destroy_workqueue(rc->rsv_workq);
}