summaryrefslogtreecommitdiffstats
path: root/drivers/thunderbolt/xdomain.c
blob: 4eb51a123a6fd22f2ed5b2d0acd83b1db14c4b4b (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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
/*
 * Thunderbolt XDomain discovery protocol support
 *
 * Copyright (C) 2017, Intel Corporation
 * Authors: Michael Jamet <michael.jamet@intel.com>
 *          Mika Westerberg <mika.westerberg@linux.intel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/device.h>
#include <linux/kmod.h>
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/utsname.h>
#include <linux/uuid.h>
#include <linux/workqueue.h>

#include "tb.h"

#define XDOMAIN_DEFAULT_TIMEOUT			5000 /* ms */
#define XDOMAIN_PROPERTIES_RETRIES		60
#define XDOMAIN_PROPERTIES_CHANGED_RETRIES	10

struct xdomain_request_work {
	struct work_struct work;
	struct tb_xdp_header *pkg;
	struct tb *tb;
};

/* Serializes access to the properties and protocol handlers below */
static DEFINE_MUTEX(xdomain_lock);

/* Properties exposed to the remote domains */
static struct tb_property_dir *xdomain_property_dir;
static u32 *xdomain_property_block;
static u32 xdomain_property_block_len;
static u32 xdomain_property_block_gen;

/* Additional protocol handlers */
static LIST_HEAD(protocol_handlers);

/* UUID for XDomain discovery protocol: b638d70e-42ff-40bb-97c2-90e2c0b2ff07 */
static const uuid_t tb_xdp_uuid =
	UUID_INIT(0xb638d70e, 0x42ff, 0x40bb,
		  0x97, 0xc2, 0x90, 0xe2, 0xc0, 0xb2, 0xff, 0x07);

static bool tb_xdomain_match(const struct tb_cfg_request *req,
			     const struct ctl_pkg *pkg)
{
	switch (pkg->frame.eof) {
	case TB_CFG_PKG_ERROR:
		return true;

	case TB_CFG_PKG_XDOMAIN_RESP: {
		const struct tb_xdp_header *res_hdr = pkg->buffer;
		const struct tb_xdp_header *req_hdr = req->request;

		if (pkg->frame.size < req->response_size / 4)
			return false;

		/* Make sure route matches */
		if ((res_hdr->xd_hdr.route_hi & ~BIT(31)) !=
		     req_hdr->xd_hdr.route_hi)
			return false;
		if ((res_hdr->xd_hdr.route_lo) != req_hdr->xd_hdr.route_lo)
			return false;

		/* Check that the XDomain protocol matches */
		if (!uuid_equal(&res_hdr->uuid, &req_hdr->uuid))
			return false;

		return true;
	}

	default:
		return false;
	}
}

static bool tb_xdomain_copy(struct tb_cfg_request *req,
			    const struct ctl_pkg *pkg)
{
	memcpy(req->response, pkg->buffer, req->response_size);
	req->result.err = 0;
	return true;
}

static void response_ready(void *data)
{
	tb_cfg_request_put(data);
}

static int __tb_xdomain_response(struct tb_ctl *ctl, const void *response,
				 size_t size, enum tb_cfg_pkg_type type)
{
	struct tb_cfg_request *req;

	req = tb_cfg_request_alloc();
	if (!req)
		return -ENOMEM;

	req->match = tb_xdomain_match;
	req->copy = tb_xdomain_copy;
	req->request = response;
	req->request_size = size;
	req->request_type = type;

	return tb_cfg_request(ctl, req, response_ready, req);
}

/**
 * tb_xdomain_response() - Send a XDomain response message
 * @xd: XDomain to send the message
 * @response: Response to send
 * @size: Size of the response
 * @type: PDF type of the response
 *
 * This can be used to send a XDomain response message to the other
 * domain. No response for the message is expected.
 *
 * Return: %0 in case of success and negative errno in case of failure
 */
int tb_xdomain_response(struct tb_xdomain *xd, const void *response,
			size_t size, enum tb_cfg_pkg_type type)
{
	return __tb_xdomain_response(xd->tb->ctl, response, size, type);
}
EXPORT_SYMBOL_GPL(tb_xdomain_response);

static int __tb_xdomain_request(struct tb_ctl *ctl, const void *request,
	size_t request_size, enum tb_cfg_pkg_type request_type, void *response,
	size_t response_size, enum tb_cfg_pkg_type response_type,
	unsigned int timeout_msec)
{
	struct tb_cfg_request *req;
	struct tb_cfg_result res;

	req = tb_cfg_request_alloc();
	if (!req)
		return -ENOMEM;

	req->match = tb_xdomain_match;
	req->copy = tb_xdomain_copy;
	req->request = request;
	req->request_size = request_size;
	req->request_type = request_type;
	req->response = response;
	req->response_size = response_size;
	req->response_type = response_type;

	res = tb_cfg_request_sync(ctl, req, timeout_msec);

	tb_cfg_request_put(req);

	return res.err == 1 ? -EIO : res.err;
}

/**
 * tb_xdomain_request() - Send a XDomain request
 * @xd: XDomain to send the request
 * @request: Request to send
 * @request_size: Size of the request in bytes
 * @request_type: PDF type of the request
 * @response: Response is copied here
 * @response_size: Expected size of the response in bytes
 * @response_type: Expected PDF type of the response
 * @timeout_msec: Timeout in milliseconds to wait for the response
 *
 * This function can be used to send XDomain control channel messages to
 * the other domain. The function waits until the response is received
 * or when timeout triggers. Whichever comes first.
 *
 * Return: %0 in case of success and negative errno in case of failure
 */
int tb_xdomain_request(struct tb_xdomain *xd, const void *request,
	size_t request_size, enum tb_cfg_pkg_type request_type,
	void *response, size_t response_size,
	enum tb_cfg_pkg_type response_type, unsigned int timeout_msec)
{
	return __tb_xdomain_request(xd->tb->ctl, request, request_size,
				    request_type, response, response_size,
				    response_type, timeout_msec);
}
EXPORT_SYMBOL_GPL(tb_xdomain_request);

static inline void tb_xdp_fill_header(struct tb_xdp_header *hdr, u64 route,
	u8 sequence, enum tb_xdp_type type, size_t size)
{
	u32 length_sn;

	length_sn = (size - sizeof(hdr->xd_hdr)) / 4;
	length_sn |= (sequence << TB_XDOMAIN_SN_SHIFT) & TB_XDOMAIN_SN_MASK;

	hdr->xd_hdr.route_hi = upper_32_bits(route);
	hdr->xd_hdr.route_lo = lower_32_bits(route);
	hdr->xd_hdr.length_sn = length_sn;
	hdr->type = type;
	memcpy(&hdr->uuid, &tb_xdp_uuid, sizeof(tb_xdp_uuid));
}

static int tb_xdp_handle_error(const struct tb_xdp_header *hdr)
{
	const struct tb_xdp_error_response *error;

	if (hdr->type != ERROR_RESPONSE)
		return 0;

	error = (const struct tb_xdp_error_response *)hdr;

	switch (error->error) {
	case ERROR_UNKNOWN_PACKET:
	case ERROR_UNKNOWN_DOMAIN:
		return -EIO;
	case ERROR_NOT_SUPPORTED:
		return -ENOTSUPP;
	case ERROR_NOT_READY:
		return -EAGAIN;
	default:
		break;
	}

	return 0;
}

static int tb_xdp_error_response(struct tb_ctl *ctl, u64 route, u8 sequence,
				 enum tb_xdp_error error)
{
	struct tb_xdp_error_response res;

	memset(&res, 0, sizeof(res));
	tb_xdp_fill_header(&res.hdr, route, sequence, ERROR_RESPONSE,
			   sizeof(res));
	res.error = error;

	return __tb_xdomain_response(ctl, &res, sizeof(res),
				     TB_CFG_PKG_XDOMAIN_RESP);
}

static int tb_xdp_properties_request(struct tb_ctl *ctl, u64 route,
	const uuid_t *src_uuid, const uuid_t *dst_uuid, int retry,
	u32 **block, u32 *generation)
{
	struct tb_xdp_properties_response *res;
	struct tb_xdp_properties req;
	u16 data_len, len;
	size_t total_size;
	u32 *data = NULL;
	int ret;

	total_size = sizeof(*res) + TB_XDP_PROPERTIES_MAX_DATA_LENGTH * 4;
	res = kzalloc(total_size, GFP_KERNEL);
	if (!res)
		return -ENOMEM;

	memset(&req, 0, sizeof(req));
	tb_xdp_fill_header(&req.hdr, route, retry % 4, PROPERTIES_REQUEST,
			   sizeof(req));
	memcpy(&req.src_uuid, src_uuid, sizeof(*src_uuid));
	memcpy(&req.dst_uuid, dst_uuid, sizeof(*dst_uuid));

	len = 0;
	data_len = 0;

	do {
		ret = __tb_xdomain_request(ctl, &req, sizeof(req),
					   TB_CFG_PKG_XDOMAIN_REQ, res,
					   total_size, TB_CFG_PKG_XDOMAIN_RESP,
					   XDOMAIN_DEFAULT_TIMEOUT);
		if (ret)
			goto err;

		ret = tb_xdp_handle_error(&res->hdr);
		if (ret)
			goto err;

		/*
		 * Package length includes the whole payload without the
		 * XDomain header. Validate first that the package is at
		 * least size of the response structure.
		 */
		len = res->hdr.xd_hdr.length_sn & TB_XDOMAIN_LENGTH_MASK;
		if (len < sizeof(*res) / 4) {
			ret = -EINVAL;
			goto err;
		}

		len += sizeof(res->hdr.xd_hdr) / 4;
		len -= sizeof(*res) / 4;

		if (res->offset != req.offset) {
			ret = -EINVAL;
			goto err;
		}

		/*
		 * First time allocate block that has enough space for
		 * the whole properties block.
		 */
		if (!data) {
			data_len = res->data_length;
			if (data_len > TB_XDP_PROPERTIES_MAX_LENGTH) {
				ret = -E2BIG;
				goto err;
			}

			data = kcalloc(data_len, sizeof(u32), GFP_KERNEL);
			if (!data) {
				ret = -ENOMEM;
				goto err;
			}
		}

		memcpy(data + req.offset, res->data, len * 4);
		req.offset += len;
	} while (!data_len || req.offset < data_len);

	*block = data;
	*generation = res->generation;

	kfree(res);

	return data_len;

err:
	kfree(data);
	kfree(res);

	return ret;
}

static int tb_xdp_properties_response(struct tb *tb, struct tb_ctl *ctl,
	u64 route, u8 sequence, const uuid_t *src_uuid,
	const struct tb_xdp_properties *req)
{
	struct tb_xdp_properties_response *res;
	size_t total_size;
	u16 len;
	int ret;

	/*
	 * Currently we expect all requests to be directed to us. The
	 * protocol supports forwarding, though which we might add
	 * support later on.
	 */
	if (!uuid_equal(src_uuid, &req->dst_uuid)) {
		tb_xdp_error_response(ctl, route, sequence,
				      ERROR_UNKNOWN_DOMAIN);
		return 0;
	}

	mutex_lock(&xdomain_lock);

	if (req->offset >= xdomain_property_block_len) {
		mutex_unlock(&xdomain_lock);
		return -EINVAL;
	}

	len = xdomain_property_block_len - req->offset;
	len = min_t(u16, len, TB_XDP_PROPERTIES_MAX_DATA_LENGTH);
	total_size = sizeof(*res) + len * 4;

	res = kzalloc(total_size, GFP_KERNEL);
	if (!res) {
		mutex_unlock(&xdomain_lock);
		return -ENOMEM;
	}

	tb_xdp_fill_header(&res->hdr, route, sequence, PROPERTIES_RESPONSE,
			   total_size);
	res->generation = xdomain_property_block_gen;
	res->data_length = xdomain_property_block_len;
	res->offset = req->offset;
	uuid_copy(&res->src_uuid, src_uuid);
	uuid_copy(&res->dst_uuid, &req->src_uuid);
	memcpy(res->data, &xdomain_property_block[req->offset], len * 4);

	mutex_unlock(&xdomain_lock);

	ret = __tb_xdomain_response(ctl, res, total_size,
				    TB_CFG_PKG_XDOMAIN_RESP);

	kfree(res);
	return ret;
}

static int tb_xdp_properties_changed_request(struct tb_ctl *ctl, u64 route,
					     int retry, const uuid_t *uuid)
{
	struct tb_xdp_properties_changed_response res;
	struct tb_xdp_properties_changed req;
	int ret;

	memset(&req, 0, sizeof(req));
	tb_xdp_fill_header(&req.hdr, route, retry % 4,
			   PROPERTIES_CHANGED_REQUEST, sizeof(req));
	uuid_copy(&req.src_uuid, uuid);

	memset(&res, 0, sizeof(res));
	ret = __tb_xdomain_request(ctl, &req, sizeof(req),
				   TB_CFG_PKG_XDOMAIN_REQ, &res, sizeof(res),
				   TB_CFG_PKG_XDOMAIN_RESP,
				   XDOMAIN_DEFAULT_TIMEOUT);
	if (ret)
		return ret;

	return tb_xdp_handle_error(&res.hdr);
}

static int
tb_xdp_properties_changed_response(struct tb_ctl *ctl, u64 route, u8 sequence)
{
	struct tb_xdp_properties_changed_response res;

	memset(&res, 0, sizeof(res));
	tb_xdp_fill_header(&res.hdr, route, sequence,
			   PROPERTIES_CHANGED_RESPONSE, sizeof(res));
	return __tb_xdomain_response(ctl, &res, sizeof(res),
				     TB_CFG_PKG_XDOMAIN_RESP);
}

/**
 * tb_register_protocol_handler() - Register protocol handler
 * @handler: Handler to register
 *
 * This allows XDomain service drivers to hook into incoming XDomain
 * messages. After this function is called the service driver needs to
 * be able to handle calls to callback whenever a package with the
 * registered protocol is received.
 */
int tb_register_protocol_handler(struct tb_protocol_handler *handler)
{
	if (!handler->uuid || !handler->callback)
		return -EINVAL;
	if (uuid_equal(handler->uuid, &tb_xdp_uuid))
		return -EINVAL;

	mutex_lock(&xdomain_lock);
	list_add_tail(&handler->list, &protocol_handlers);
	mutex_unlock(&xdomain_lock);

	return 0;
}
EXPORT_SYMBOL_GPL(tb_register_protocol_handler);

/**
 * tb_unregister_protocol_handler() - Unregister protocol handler
 * @handler: Handler to unregister
 *
 * Removes the previously registered protocol handler.
 */
void tb_unregister_protocol_handler(struct tb_protocol_handler *handler)
{
	mutex_lock(&xdomain_lock);
	list_del_init(&handler->list);
	mutex_unlock(&xdomain_lock);
}
EXPORT_SYMBOL_GPL(tb_unregister_protocol_handler);

static void tb_xdp_handle_request(struct work_struct *work)
{
	struct xdomain_request_work *xw = container_of(work, typeof(*xw), work);
	const struct tb_xdp_header *pkg = xw->pkg;
	const struct tb_xdomain_header *xhdr = &pkg->xd_hdr;
	struct tb *tb = xw->tb;
	struct tb_ctl *ctl = tb->ctl;
	const uuid_t *uuid;
	int ret = 0;
	u32 sequence;
	u64 route;

	route = ((u64)xhdr->route_hi << 32 | xhdr->route_lo) & ~BIT_ULL(63);
	sequence = xhdr->length_sn & TB_XDOMAIN_SN_MASK;
	sequence >>= TB_XDOMAIN_SN_SHIFT;

	mutex_lock(&tb->lock);
	if (tb->root_switch)
		uuid = tb->root_switch->uuid;
	else
		uuid = NULL;
	mutex_unlock(&tb->lock);

	if (!uuid) {
		tb_xdp_error_response(ctl, route, sequence, ERROR_NOT_READY);
		goto out;
	}

	switch (pkg->type) {
	case PROPERTIES_REQUEST:
		ret = tb_xdp_properties_response(tb, ctl, route, sequence, uuid,
			(const struct tb_xdp_properties *)pkg);
		break;

	case PROPERTIES_CHANGED_REQUEST: {
		const struct tb_xdp_properties_changed *xchg =
			(const struct tb_xdp_properties_changed *)pkg;
		struct tb_xdomain *xd;

		ret = tb_xdp_properties_changed_response(ctl, route, sequence);

		/*
		 * Since the properties have been changed, let's update
		 * the xdomain related to this connection as well in
		 * case there is a change in services it offers.
		 */
		xd = tb_xdomain_find_by_uuid_locked(tb, &xchg->src_uuid);
		if (xd) {
			queue_delayed_work(tb->wq, &xd->get_properties_work,
					   msecs_to_jiffies(50));
			tb_xdomain_put(xd);
		}

		break;
	}

	default:
		break;
	}

	if (ret) {
		tb_warn(tb, "failed to send XDomain response for %#x\n",
			pkg->type);
	}

out:
	kfree(xw->pkg);
	kfree(xw);
}

static void
tb_xdp_schedule_request(struct tb *tb, const struct tb_xdp_header *hdr,
			size_t size)
{
	struct xdomain_request_work *xw;

	xw = kmalloc(sizeof(*xw), GFP_KERNEL);
	if (!xw)
		return;

	INIT_WORK(&xw->work, tb_xdp_handle_request);
	xw->pkg = kmemdup(hdr, size, GFP_KERNEL);
	xw->tb = tb;

	queue_work(tb->wq, &xw->work);
}

/**
 * tb_register_service_driver() - Register XDomain service driver
 * @drv: Driver to register
 *
 * Registers new service driver from @drv to the bus.
 */
int tb_register_service_driver(struct tb_service_driver *drv)
{
	drv->driver.bus = &tb_bus_type;
	return driver_register(&drv->driver);
}
EXPORT_SYMBOL_GPL(tb_register_service_driver);

/**
 * tb_unregister_service_driver() - Unregister XDomain service driver
 * @xdrv: Driver to unregister
 *
 * Unregisters XDomain service driver from the bus.
 */
void tb_unregister_service_driver(struct tb_service_driver *drv)
{
	driver_unregister(&drv->driver);
}
EXPORT_SYMBOL_GPL(tb_unregister_service_driver);

static ssize_t key_show(struct device *dev, struct device_attribute *attr,
			char *buf)
{
	struct tb_service *svc = container_of(dev, struct tb_service, dev);

	/*
	 * It should be null terminated but anything else is pretty much
	 * allowed.
	 */
	return sprintf(buf, "%*pEp\n", (int)strlen(svc->key), svc->key);
}
static DEVICE_ATTR_RO(key);

static int get_modalias(struct tb_service *svc, char *buf, size_t size)
{
	return snprintf(buf, size, "tbsvc:k%sp%08Xv%08Xr%08X", svc->key,
			svc->prtcid, svc->prtcvers, svc->prtcrevs);
}

static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct tb_service *svc = container_of(dev, struct tb_service, dev);

	/* Full buffer size except new line and null termination */
	get_modalias(svc, buf, PAGE_SIZE - 2);
	return sprintf(buf, "%s\n", buf);
}
static DEVICE_ATTR_RO(modalias);

static ssize_t prtcid_show(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct tb_service *svc = container_of(dev, struct tb_service, dev);

	return sprintf(buf, "%u\n", svc->prtcid);
}
static DEVICE_ATTR_RO(prtcid);

static ssize_t prtcvers_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct tb_service *svc = container_of(dev, struct tb_service, dev);

	return sprintf(buf, "%u\n", svc->prtcvers);
}
static DEVICE_ATTR_RO(prtcvers);

static ssize_t prtcrevs_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct tb_service *svc = container_of(dev, struct tb_service, dev);

	return sprintf(buf, "%u\n", svc->prtcrevs);
}
static DEVICE_ATTR_RO(prtcrevs);

static ssize_t prtcstns_show(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct tb_service *svc = container_of(dev, struct tb_service, dev);

	return sprintf(buf, "0x%08x\n", svc->prtcstns);
}
static DEVICE_ATTR_RO(prtcstns);

static struct attribute *tb_service_attrs[] = {
	&dev_attr_key.attr,
	&dev_attr_modalias.attr,
	&dev_attr_prtcid.attr,
	&dev_attr_prtcvers.attr,
	&dev_attr_prtcrevs.attr,
	&dev_attr_prtcstns.attr,
	NULL,
};

static struct attribute_group tb_service_attr_group = {
	.attrs = tb_service_attrs,
};

static const struct attribute_group *tb_service_attr_groups[] = {
	&tb_service_attr_group,
	NULL,
};

static int tb_service_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	struct tb_service *svc = container_of(dev, struct tb_service, dev);
	char modalias[64];

	get_modalias(svc, modalias, sizeof(modalias));
	return add_uevent_var(env, "MODALIAS=%s", modalias);
}

static void tb_service_release(struct device *dev)
{
	struct tb_service *svc = container_of(dev, struct tb_service, dev);
	struct tb_xdomain *xd = tb_service_parent(svc);

	ida_simple_remove(&xd->service_ids, svc->id);
	kfree(svc->key);
	kfree(svc);
}

struct device_type tb_service_type = {
	.name = "thunderbolt_service",
	.groups = tb_service_attr_groups,
	.uevent = tb_service_uevent,
	.release = tb_service_release,
};
EXPORT_SYMBOL_GPL(tb_service_type);

static int remove_missing_service(struct device *dev, void *data)
{
	struct tb_xdomain *xd = data;
	struct tb_service *svc;

	svc = tb_to_service(dev);
	if (!svc)
		return 0;

	if (!tb_property_find(xd->properties, svc->key,
			      TB_PROPERTY_TYPE_DIRECTORY))
		device_unregister(dev);

	return 0;
}

static int find_service(struct device *dev, void *data)
{
	const struct tb_property *p = data;
	struct tb_service *svc;

	svc = tb_to_service(dev);
	if (!svc)
		return 0;

	return !strcmp(svc->key, p->key);
}

static int populate_service(struct tb_service *svc,
			    struct tb_property *property)
{
	struct tb_property_dir *dir = property->value.dir;
	struct tb_property *p;

	/* Fill in standard properties */
	p = tb_property_find(dir, "prtcid", TB_PROPERTY_TYPE_VALUE);
	if (p)
		svc->prtcid = p->value.immediate;
	p = tb_property_find(dir, "prtcvers", TB_PROPERTY_TYPE_VALUE);
	if (p)
		svc->prtcvers = p->value.immediate;
	p = tb_property_find(dir, "prtcrevs", TB_PROPERTY_TYPE_VALUE);
	if (p)
		svc->prtcrevs = p->value.immediate;
	p = tb_property_find(dir, "prtcstns", TB_PROPERTY_TYPE_VALUE);
	if (p)
		svc->prtcstns = p->value.immediate;

	svc->key = kstrdup(property->key, GFP_KERNEL);
	if (!svc->key)
		return -ENOMEM;

	return 0;
}

static void enumerate_services(struct tb_xdomain *xd)
{
	struct tb_service *svc;
	struct tb_property *p;
	struct device *dev;
	int id;

	/*
	 * First remove all services that are not available anymore in
	 * the updated property block.
	 */
	device_for_each_child_reverse(&xd->dev, xd, remove_missing_service);

	/* Then re-enumerate properties creating new services as we go */
	tb_property_for_each(xd->properties, p) {
		if (p->type != TB_PROPERTY_TYPE_DIRECTORY)
			continue;

		/* If the service exists already we are fine */
		dev = device_find_child(&xd->dev, p, find_service);
		if (dev) {
			put_device(dev);
			continue;
		}

		svc = kzalloc(sizeof(*svc), GFP_KERNEL);
		if (!svc)
			break;

		if (populate_service(svc, p)) {
			kfree(svc);
			break;
		}

		id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
		if (id < 0) {
			kfree(svc->key);
			kfree(svc);
			break;
		}
		svc->id = id;
		svc->dev.bus = &tb_bus_type;
		svc->dev.type = &tb_service_type;
		svc->dev.parent = &xd->dev;
		dev_set_name(&svc->dev, "%s.%d", dev_name(&xd->dev), svc->id);

		if (device_register(&svc->dev)) {
			put_device(&svc->dev);
			break;
		}
	}
}

static int populate_properties(struct tb_xdomain *xd,
			       struct tb_property_dir *dir)
{
	const struct tb_property *p;

	/* Required properties */
	p = tb_property_find(dir, "deviceid", TB_PROPERTY_TYPE_VALUE);
	if (!p)
		return -EINVAL;
	xd->device = p->value.immediate;

	p = tb_property_find(dir, "vendorid", TB_PROPERTY_TYPE_VALUE);
	if (!p)
		return -EINVAL;
	xd->vendor = p->value.immediate;

	kfree(xd->device_name);
	xd->device_name = NULL;
	kfree(xd->vendor_name);
	xd->vendor_name = NULL;

	/* Optional properties */
	p = tb_property_find(dir, "deviceid", TB_PROPERTY_TYPE_TEXT);
	if (p)
		xd->device_name = kstrdup(p->value.text, GFP_KERNEL);
	p = tb_property_find(dir, "vendorid", TB_PROPERTY_TYPE_TEXT);
	if (p)
		xd->vendor_name = kstrdup(p->value.text, GFP_KERNEL);

	return 0;
}

/* Called with @xd->lock held */
static void tb_xdomain_restore_paths(struct tb_xdomain *xd)
{
	if (!xd->resume)
		return;

	xd->resume = false;
	if (xd->transmit_path) {
		dev_dbg(&xd->dev, "re-establishing DMA path\n");
		tb_domain_approve_xdomain_paths(xd->tb, xd);
	}
}

static void tb_xdomain_get_properties(struct work_struct *work)
{
	struct tb_xdomain *xd = container_of(work, typeof(*xd),
					     get_properties_work.work);
	struct tb_property_dir *dir;
	struct tb *tb = xd->tb;
	bool update = false;
	u32 *block = NULL;
	u32 gen = 0;
	int ret;

	ret = tb_xdp_properties_request(tb->ctl, xd->route, xd->local_uuid,
					xd->remote_uuid, xd->properties_retries,
					&block, &gen);
	if (ret < 0) {
		if (xd->properties_retries-- > 0) {
			queue_delayed_work(xd->tb->wq, &xd->get_properties_work,
					   msecs_to_jiffies(1000));
		} else {
			/* Give up now */
			dev_err(&xd->dev,
				"failed read XDomain properties from %pUb\n",
				xd->remote_uuid);
		}
		return;
	}

	xd->properties_retries = XDOMAIN_PROPERTIES_RETRIES;

	mutex_lock(&xd->lock);

	/* Only accept newer generation properties */
	if (xd->properties && gen <= xd->property_block_gen) {
		/*
		 * On resume it is likely that the properties block is
		 * not changed (unless the other end added or removed
		 * services). However, we need to make sure the existing
		 * DMA paths are restored properly.
		 */
		tb_xdomain_restore_paths(xd);
		goto err_free_block;
	}

	dir = tb_property_parse_dir(block, ret);
	if (!dir) {
		dev_err(&xd->dev, "failed to parse XDomain properties\n");
		goto err_free_block;
	}

	ret = populate_properties(xd, dir);
	if (ret) {
		dev_err(&xd->dev, "missing XDomain properties in response\n");
		goto err_free_dir;
	}

	/* Release the existing one */
	if (xd->properties) {
		tb_property_free_dir(xd->properties);
		update = true;
	}

	xd->properties = dir;
	xd->property_block_gen = gen;

	tb_xdomain_restore_paths(xd);

	mutex_unlock(&xd->lock);

	kfree(block);

	/*
	 * Now the device should be ready enough so we can add it to the
	 * bus and let userspace know about it. If the device is already
	 * registered, we notify the userspace that it has changed.
	 */
	if (!update) {
		if (device_add(&xd->dev)) {
			dev_err(&xd->dev, "failed to add XDomain device\n");
			return;
		}
	} else {
		kobject_uevent(&xd->dev.kobj, KOBJ_CHANGE);
	}

	enumerate_services(xd);
	return;

err_free_dir:
	tb_property_free_dir(dir);
err_free_block:
	kfree(block);
	mutex_unlock(&xd->lock);
}

static void tb_xdomain_properties_changed(struct work_struct *work)
{
	struct tb_xdomain *xd = container_of(work, typeof(*xd),
					     properties_changed_work.work);
	int ret;

	ret = tb_xdp_properties_changed_request(xd->tb->ctl, xd->route,
				xd->properties_changed_retries, xd->local_uuid);
	if (ret) {
		if (xd->properties_changed_retries-- > 0)
			queue_delayed_work(xd->tb->wq,
					   &xd->properties_changed_work,
					   msecs_to_jiffies(1000));
		return;
	}

	xd->properties_changed_retries = XDOMAIN_PROPERTIES_CHANGED_RETRIES;
}

static ssize_t device_show(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);

	return sprintf(buf, "%#x\n", xd->device);
}
static DEVICE_ATTR_RO(device);

static ssize_t
device_name_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);
	int ret;

	if (mutex_lock_interruptible(&xd->lock))
		return -ERESTARTSYS;
	ret = sprintf(buf, "%s\n", xd->device_name ? xd->device_name : "");
	mutex_unlock(&xd->lock);

	return ret;
}
static DEVICE_ATTR_RO(device_name);

static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
			   char *buf)
{
	struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);

	return sprintf(buf, "%#x\n", xd->vendor);
}
static DEVICE_ATTR_RO(vendor);

static ssize_t
vendor_name_show(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);
	int ret;

	if (mutex_lock_interruptible(&xd->lock))
		return -ERESTARTSYS;
	ret = sprintf(buf, "%s\n", xd->vendor_name ? xd->vendor_name : "");
	mutex_unlock(&xd->lock);

	return ret;
}
static DEVICE_ATTR_RO(vendor_name);

static ssize_t unique_id_show(struct device *dev, struct device_attribute *attr,
			      char *buf)
{
	struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);

	return sprintf(buf, "%pUb\n", xd->remote_uuid);
}
static DEVICE_ATTR_RO(unique_id);

static struct attribute *xdomain_attrs[] = {
	&dev_attr_device.attr,
	&dev_attr_device_name.attr,
	&dev_attr_unique_id.attr,
	&dev_attr_vendor.attr,
	&dev_attr_vendor_name.attr,
	NULL,
};

static struct attribute_group xdomain_attr_group = {
	.attrs = xdomain_attrs,
};

static const struct attribute_group *xdomain_attr_groups[] = {
	&xdomain_attr_group,
	NULL,
};

static void tb_xdomain_release(struct device *dev)
{
	struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);

	put_device(xd->dev.parent);

	tb_property_free_dir(xd->properties);
	ida_destroy(&xd->service_ids);

	kfree(xd->local_uuid);
	kfree(xd->remote_uuid);
	kfree(xd->device_name);
	kfree(xd->vendor_name);
	kfree(xd);
}

static void start_handshake(struct tb_xdomain *xd)
{
	xd->properties_retries = XDOMAIN_PROPERTIES_RETRIES;
	xd->properties_changed_retries = XDOMAIN_PROPERTIES_CHANGED_RETRIES;

	/* Start exchanging properties with the other host */
	queue_delayed_work(xd->tb->wq, &xd->properties_changed_work,
			   msecs_to_jiffies(100));
	queue_delayed_work(xd->tb->wq, &xd->get_properties_work,
			   msecs_to_jiffies(1000));
}

static void stop_handshake(struct tb_xdomain *xd)
{
	xd->properties_retries = 0;
	xd->properties_changed_retries = 0;

	cancel_delayed_work_sync(&xd->get_properties_work);
	cancel_delayed_work_sync(&xd->properties_changed_work);
}

static int __maybe_unused tb_xdomain_suspend(struct device *dev)
{
	stop_handshake(tb_to_xdomain(dev));
	return 0;
}

static int __maybe_unused tb_xdomain_resume(struct device *dev)
{
	struct tb_xdomain *xd = tb_to_xdomain(dev);

	/*
	 * Ask tb_xdomain_get_properties() restore any existing DMA
	 * paths after properties are re-read.
	 */
	xd->resume = true;
	start_handshake(xd);

	return 0;
}

static const struct dev_pm_ops tb_xdomain_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(tb_xdomain_suspend, tb_xdomain_resume)
};

struct device_type tb_xdomain_type = {
	.name = "thunderbolt_xdomain",
	.release = tb_xdomain_release,
	.pm = &tb_xdomain_pm_ops,
};
EXPORT_SYMBOL_GPL(tb_xdomain_type);

/**
 * tb_xdomain_alloc() - Allocate new XDomain object
 * @tb: Domain where the XDomain belongs
 * @parent: Parent device (the switch through the connection to the
 *	    other domain is reached).
 * @route: Route string used to reach the other domain
 * @local_uuid: Our local domain UUID
 * @remote_uuid: UUID of the other domain
 *
 * Allocates new XDomain structure and returns pointer to that. The
 * object must be released by calling tb_xdomain_put().
 */
struct tb_xdomain *tb_xdomain_alloc(struct tb *tb, struct device *parent,
				    u64 route, const uuid_t *local_uuid,
				    const uuid_t *remote_uuid)
{
	struct tb_xdomain *xd;

	xd = kzalloc(sizeof(*xd), GFP_KERNEL);
	if (!xd)
		return NULL;

	xd->tb = tb;
	xd->route = route;
	ida_init(&xd->service_ids);
	mutex_init(&xd->lock);
	INIT_DELAYED_WORK(&xd->get_properties_work, tb_xdomain_get_properties);
	INIT_DELAYED_WORK(&xd->properties_changed_work,
			  tb_xdomain_properties_changed);

	xd->local_uuid = kmemdup(local_uuid, sizeof(uuid_t), GFP_KERNEL);
	if (!xd->local_uuid)
		goto err_free;

	xd->remote_uuid = kmemdup(remote_uuid, sizeof(uuid_t), GFP_KERNEL);
	if (!xd->remote_uuid)
		goto err_free_local_uuid;

	device_initialize(&xd->dev);
	xd->dev.parent = get_device(parent);
	xd->dev.bus = &tb_bus_type;
	xd->dev.type = &tb_xdomain_type;
	xd->dev.groups = xdomain_attr_groups;
	dev_set_name(&xd->dev, "%u-%llx", tb->index, route);

	/*
	 * This keeps the DMA powered on as long as we have active
	 * connection to another host.
	 */
	pm_runtime_set_active(&xd->dev);
	pm_runtime_get_noresume(&xd->dev);
	pm_runtime_enable(&xd->dev);

	return xd;

err_free_local_uuid:
	kfree(xd->local_uuid);
err_free:
	kfree(xd);

	return NULL;
}

/**
 * tb_xdomain_add() - Add XDomain to the bus
 * @xd: XDomain to add
 *
 * This function starts XDomain discovery protocol handshake and
 * eventually adds the XDomain to the bus. After calling this function
 * the caller needs to call tb_xdomain_remove() in order to remove and
 * release the object regardless whether the handshake succeeded or not.
 */
void tb_xdomain_add(struct tb_xdomain *xd)
{
	/* Start exchanging properties with the other host */
	start_handshake(xd);
}

static int unregister_service(struct device *dev, void *data)
{
	device_unregister(dev);
	return 0;
}

/**
 * tb_xdomain_remove() - Remove XDomain from the bus
 * @xd: XDomain to remove
 *
 * This will stop all ongoing configuration work and remove the XDomain
 * along with any services from the bus. When the last reference to @xd
 * is released the object will be released as well.
 */
void tb_xdomain_remove(struct tb_xdomain *xd)
{
	stop_handshake(xd);

	device_for_each_child_reverse(&xd->dev, xd, unregister_service);

	/*
	 * Undo runtime PM here explicitly because it is possible that
	 * the XDomain was never added to the bus and thus device_del()
	 * is not called for it (device_del() would handle this otherwise).
	 */
	pm_runtime_disable(&xd->dev);
	pm_runtime_put_noidle(&xd->dev);
	pm_runtime_set_suspended(&xd->dev);

	if (!device_is_registered(&xd->dev))
		put_device(&xd->dev);
	else
		device_unregister(&xd->dev);
}

/**
 * tb_xdomain_enable_paths() - Enable DMA paths for XDomain connection
 * @xd: XDomain connection
 * @transmit_path: HopID of the transmit path the other end is using to
 *		   send packets
 * @transmit_ring: DMA ring used to receive packets from the other end
 * @receive_path: HopID of the receive path the other end is using to
 *		  receive packets
 * @receive_ring: DMA ring used to send packets to the other end
 *
 * The function enables DMA paths accordingly so that after successful
 * return the caller can send and receive packets using high-speed DMA
 * path.
 *
 * Return: %0 in case of success and negative errno in case of error
 */
int tb_xdomain_enable_paths(struct tb_xdomain *xd, u16 transmit_path,
			    u16 transmit_ring, u16 receive_path,
			    u16 receive_ring)
{
	int ret;

	mutex_lock(&xd->lock);

	if (xd->transmit_path) {
		ret = xd->transmit_path == transmit_path ? 0 : -EBUSY;
		goto exit_unlock;
	}

	xd->transmit_path = transmit_path;
	xd->transmit_ring = transmit_ring;
	xd->receive_path = receive_path;
	xd->receive_ring = receive_ring;

	ret = tb_domain_approve_xdomain_paths(xd->tb, xd);

exit_unlock:
	mutex_unlock(&xd->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(tb_xdomain_enable_paths);

/**
 * tb_xdomain_disable_paths() - Disable DMA paths for XDomain connection
 * @xd: XDomain connection
 *
 * This does the opposite of tb_xdomain_enable_paths(). After call to
 * this the caller is not expected to use the rings anymore.
 *
 * Return: %0 in case of success and negative errno in case of error
 */
int tb_xdomain_disable_paths(struct tb_xdomain *xd)
{
	int ret = 0;

	mutex_lock(&xd->lock);
	if (xd->transmit_path) {
		xd->transmit_path = 0;
		xd->transmit_ring = 0;
		xd->receive_path = 0;
		xd->receive_ring = 0;

		ret = tb_domain_disconnect_xdomain_paths(xd->tb, xd);
	}
	mutex_unlock(&xd->lock);

	return ret;
}
EXPORT_SYMBOL_GPL(tb_xdomain_disable_paths);

struct tb_xdomain_lookup {
	const uuid_t *uuid;
	u8 link;
	u8 depth;
	u64 route;
};

static struct tb_xdomain *switch_find_xdomain(struct tb_switch *sw,
	const struct tb_xdomain_lookup *lookup)
{
	int i;

	for (i = 1; i <= sw->config.max_port_number; i++) {
		struct tb_port *port = &sw->ports[i];
		struct tb_xdomain *xd;

		if (tb_is_upstream_port(port))
			continue;

		if (port->xdomain) {
			xd = port->xdomain;

			if (lookup->uuid) {
				if (uuid_equal(xd->remote_uuid, lookup->uuid))
					return xd;
			} else if (lookup->link &&
				   lookup->link == xd->link &&
				   lookup->depth == xd->depth) {
				return xd;
			} else if (lookup->route &&
				   lookup->route == xd->route) {
				return xd;
			}
		} else if (port->remote) {
			xd = switch_find_xdomain(port->remote->sw, lookup);
			if (xd)
				return xd;
		}
	}

	return NULL;
}

/**
 * tb_xdomain_find_by_uuid() - Find an XDomain by UUID
 * @tb: Domain where the XDomain belongs to
 * @uuid: UUID to look for
 *
 * Finds XDomain by walking through the Thunderbolt topology below @tb.
 * The returned XDomain will have its reference count increased so the
 * caller needs to call tb_xdomain_put() when it is done with the
 * object.
 *
 * This will find all XDomains including the ones that are not yet added
 * to the bus (handshake is still in progress).
 *
 * The caller needs to hold @tb->lock.
 */
struct tb_xdomain *tb_xdomain_find_by_uuid(struct tb *tb, const uuid_t *uuid)
{
	struct tb_xdomain_lookup lookup;
	struct tb_xdomain *xd;

	memset(&lookup, 0, sizeof(lookup));
	lookup.uuid = uuid;

	xd = switch_find_xdomain(tb->root_switch, &lookup);
	return tb_xdomain_get(xd);
}
EXPORT_SYMBOL_GPL(tb_xdomain_find_by_uuid);

/**
 * tb_xdomain_find_by_link_depth() - Find an XDomain by link and depth
 * @tb: Domain where the XDomain belongs to
 * @link: Root switch link number
 * @depth: Depth in the link
 *
 * Finds XDomain by walking through the Thunderbolt topology below @tb.
 * The returned XDomain will have its reference count increased so the
 * caller needs to call tb_xdomain_put() when it is done with the
 * object.
 *
 * This will find all XDomains including the ones that are not yet added
 * to the bus (handshake is still in progress).
 *
 * The caller needs to hold @tb->lock.
 */
struct tb_xdomain *tb_xdomain_find_by_link_depth(struct tb *tb, u8 link,
						 u8 depth)
{
	struct tb_xdomain_lookup lookup;
	struct tb_xdomain *xd;

	memset(&lookup, 0, sizeof(lookup));
	lookup.link = link;
	lookup.depth = depth;

	xd = switch_find_xdomain(tb->root_switch, &lookup);
	return tb_xdomain_get(xd);
}

/**
 * tb_xdomain_find_by_route() - Find an XDomain by route string
 * @tb: Domain where the XDomain belongs to
 * @route: XDomain route string
 *
 * Finds XDomain by walking through the Thunderbolt topology below @tb.
 * The returned XDomain will have its reference count increased so the
 * caller needs to call tb_xdomain_put() when it is done with the
 * object.
 *
 * This will find all XDomains including the ones that are not yet added
 * to the bus (handshake is still in progress).
 *
 * The caller needs to hold @tb->lock.
 */
struct tb_xdomain *tb_xdomain_find_by_route(struct tb *tb, u64 route)
{
	struct tb_xdomain_lookup lookup;
	struct tb_xdomain *xd;

	memset(&lookup, 0, sizeof(lookup));
	lookup.route = route;

	xd = switch_find_xdomain(tb->root_switch, &lookup);
	return tb_xdomain_get(xd);
}
EXPORT_SYMBOL_GPL(tb_xdomain_find_by_route);

bool tb_xdomain_handle_request(struct tb *tb, enum tb_cfg_pkg_type type,
			       const void *buf, size_t size)
{
	const struct tb_protocol_handler *handler, *tmp;
	const struct tb_xdp_header *hdr = buf;
	unsigned int length;
	int ret = 0;

	/* We expect the packet is at least size of the header */
	length = hdr->xd_hdr.length_sn & TB_XDOMAIN_LENGTH_MASK;
	if (length != size / 4 - sizeof(hdr->xd_hdr) / 4)
		return true;
	if (length < sizeof(*hdr) / 4 - sizeof(hdr->xd_hdr) / 4)
		return true;

	/*
	 * Handle XDomain discovery protocol packets directly here. For
	 * other protocols (based on their UUID) we call registered
	 * handlers in turn.
	 */
	if (uuid_equal(&hdr->uuid, &tb_xdp_uuid)) {
		if (type == TB_CFG_PKG_XDOMAIN_REQ) {
			tb_xdp_schedule_request(tb, hdr, size);
			return true;
		}
		return false;
	}

	mutex_lock(&xdomain_lock);
	list_for_each_entry_safe(handler, tmp, &protocol_handlers, list) {
		if (!uuid_equal(&hdr->uuid, handler->uuid))
			continue;

		mutex_unlock(&xdomain_lock);
		ret = handler->callback(buf, size, handler->data);
		mutex_lock(&xdomain_lock);

		if (ret)
			break;
	}
	mutex_unlock(&xdomain_lock);

	return ret > 0;
}

static int rebuild_property_block(void)
{
	u32 *block, len;
	int ret;

	ret = tb_property_format_dir(xdomain_property_dir, NULL, 0);
	if (ret < 0)
		return ret;

	len = ret;

	block = kcalloc(len, sizeof(u32), GFP_KERNEL);
	if (!block)
		return -ENOMEM;

	ret = tb_property_format_dir(xdomain_property_dir, block, len);
	if (ret) {
		kfree(block);
		return ret;
	}

	kfree(xdomain_property_block);
	xdomain_property_block = block;
	xdomain_property_block_len = len;
	xdomain_property_block_gen++;

	return 0;
}

static int update_xdomain(struct device *dev, void *data)
{
	struct tb_xdomain *xd;

	xd = tb_to_xdomain(dev);
	if (xd) {
		queue_delayed_work(xd->tb->wq, &xd->properties_changed_work,
				   msecs_to_jiffies(50));
	}

	return 0;
}

static void update_all_xdomains(void)
{
	bus_for_each_dev(&tb_bus_type, NULL, NULL, update_xdomain);
}

static bool remove_directory(const char *key, const struct tb_property_dir *dir)
{
	struct tb_property *p;

	p = tb_property_find(xdomain_property_dir, key,
			     TB_PROPERTY_TYPE_DIRECTORY);
	if (p && p->value.dir == dir) {
		tb_property_remove(p);
		return true;
	}
	return false;
}

/**
 * tb_register_property_dir() - Register property directory to the host
 * @key: Key (name) of the directory to add
 * @dir: Directory to add
 *
 * Service drivers can use this function to add new property directory
 * to the host available properties. The other connected hosts are
 * notified so they can re-read properties of this host if they are
 * interested.
 *
 * Return: %0 on success and negative errno on failure
 */
int tb_register_property_dir(const char *key, struct tb_property_dir *dir)
{
	int ret;

	if (WARN_ON(!xdomain_property_dir))
		return -EAGAIN;

	if (!key || strlen(key) > 8)
		return -EINVAL;

	mutex_lock(&xdomain_lock);
	if (tb_property_find(xdomain_property_dir, key,
			     TB_PROPERTY_TYPE_DIRECTORY)) {
		ret = -EEXIST;
		goto err_unlock;
	}

	ret = tb_property_add_dir(xdomain_property_dir, key, dir);
	if (ret)
		goto err_unlock;

	ret = rebuild_property_block();
	if (ret) {
		remove_directory(key, dir);
		goto err_unlock;
	}

	mutex_unlock(&xdomain_lock);
	update_all_xdomains();
	return 0;

err_unlock:
	mutex_unlock(&xdomain_lock);
	return ret;
}
EXPORT_SYMBOL_GPL(tb_register_property_dir);

/**
 * tb_unregister_property_dir() - Removes property directory from host
 * @key: Key (name) of the directory
 * @dir: Directory to remove
 *
 * This will remove the existing directory from this host and notify the
 * connected hosts about the change.
 */
void tb_unregister_property_dir(const char *key, struct tb_property_dir *dir)
{
	int ret = 0;

	mutex_lock(&xdomain_lock);
	if (remove_directory(key, dir))
		ret = rebuild_property_block();
	mutex_unlock(&xdomain_lock);

	if (!ret)
		update_all_xdomains();
}
EXPORT_SYMBOL_GPL(tb_unregister_property_dir);

int tb_xdomain_init(void)
{
	int ret;

	xdomain_property_dir = tb_property_create_dir(NULL);
	if (!xdomain_property_dir)
		return -ENOMEM;

	/*
	 * Initialize standard set of properties without any service
	 * directories. Those will be added by service drivers
	 * themselves when they are loaded.
	 */
	tb_property_add_immediate(xdomain_property_dir, "vendorid",
				  PCI_VENDOR_ID_INTEL);
	tb_property_add_text(xdomain_property_dir, "vendorid", "Intel Corp.");
	tb_property_add_immediate(xdomain_property_dir, "deviceid", 0x1);
	tb_property_add_text(xdomain_property_dir, "deviceid",
			     utsname()->nodename);
	tb_property_add_immediate(xdomain_property_dir, "devicerv", 0x80000100);

	ret = rebuild_property_block();
	if (ret) {
		tb_property_free_dir(xdomain_property_dir);
		xdomain_property_dir = NULL;
	}

	return ret;
}

void tb_xdomain_exit(void)
{
	kfree(xdomain_property_block);
	tb_property_free_dir(xdomain_property_dir);
}