summaryrefslogtreecommitdiff
path: root/include/linux/ntb.h
blob: 56a92e3ae3ae5f0785c74eabcb56ae90a4a10b93 (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
/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 *   redistributing this file, you may do so under either license.
 *
 *   GPL LICENSE SUMMARY
 *
 *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
 *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of version 2 of the GNU General Public License as
 *   published by the Free Software Foundation.
 *
 *   This program is distributed in the hope that it will be useful, but
 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *   General Public License for more details.
 *
 *   BSD LICENSE
 *
 *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
 *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copy
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS 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.
 *
 * PCIe NTB Linux driver
 *
 * Contact Information:
 * Allen Hubbe <Allen.Hubbe@emc.com>
 */

#ifndef _NTB_H_
#define _NTB_H_

#include <linux/completion.h>
#include <linux/device.h>

struct ntb_client;
struct ntb_dev;
struct pci_dev;

/**
 * enum ntb_topo - NTB connection topology
 * @NTB_TOPO_NONE:	Topology is unknown or invalid.
 * @NTB_TOPO_PRI:	On primary side of local ntb.
 * @NTB_TOPO_SEC:	On secondary side of remote ntb.
 * @NTB_TOPO_B2B_USD:	On primary side of local ntb upstream of remote ntb.
 * @NTB_TOPO_B2B_DSD:	On primary side of local ntb downstream of remote ntb.
 * @NTB_TOPO_SWITCH:	Connected via a switch which supports ntb.
 * @NTB_TOPO_CROSSLINK: Connected via two symmetric switchecs
 */
enum ntb_topo {
	NTB_TOPO_NONE = -1,
	NTB_TOPO_PRI,
	NTB_TOPO_SEC,
	NTB_TOPO_B2B_USD,
	NTB_TOPO_B2B_DSD,
	NTB_TOPO_SWITCH,
	NTB_TOPO_CROSSLINK,
};

static inline int ntb_topo_is_b2b(enum ntb_topo topo)
{
	switch ((int)topo) {
	case NTB_TOPO_B2B_USD:
	case NTB_TOPO_B2B_DSD:
		return 1;
	}
	return 0;
}

static inline char *ntb_topo_string(enum ntb_topo topo)
{
	switch (topo) {
	case NTB_TOPO_NONE:		return "NTB_TOPO_NONE";
	case NTB_TOPO_PRI:		return "NTB_TOPO_PRI";
	case NTB_TOPO_SEC:		return "NTB_TOPO_SEC";
	case NTB_TOPO_B2B_USD:		return "NTB_TOPO_B2B_USD";
	case NTB_TOPO_B2B_DSD:		return "NTB_TOPO_B2B_DSD";
	case NTB_TOPO_SWITCH:		return "NTB_TOPO_SWITCH";
	case NTB_TOPO_CROSSLINK:	return "NTB_TOPO_CROSSLINK";
	}
	return "NTB_TOPO_INVALID";
}

/**
 * enum ntb_speed - NTB link training speed
 * @NTB_SPEED_AUTO:	Request the max supported speed.
 * @NTB_SPEED_NONE:	Link is not trained to any speed.
 * @NTB_SPEED_GEN1:	Link is trained to gen1 speed.
 * @NTB_SPEED_GEN2:	Link is trained to gen2 speed.
 * @NTB_SPEED_GEN3:	Link is trained to gen3 speed.
 * @NTB_SPEED_GEN4:	Link is trained to gen4 speed.
 */
enum ntb_speed {
	NTB_SPEED_AUTO = -1,
	NTB_SPEED_NONE = 0,
	NTB_SPEED_GEN1 = 1,
	NTB_SPEED_GEN2 = 2,
	NTB_SPEED_GEN3 = 3,
	NTB_SPEED_GEN4 = 4
};

/**
 * enum ntb_width - NTB link training width
 * @NTB_WIDTH_AUTO:	Request the max supported width.
 * @NTB_WIDTH_NONE:	Link is not trained to any width.
 * @NTB_WIDTH_1:	Link is trained to 1 lane width.
 * @NTB_WIDTH_2:	Link is trained to 2 lane width.
 * @NTB_WIDTH_4:	Link is trained to 4 lane width.
 * @NTB_WIDTH_8:	Link is trained to 8 lane width.
 * @NTB_WIDTH_12:	Link is trained to 12 lane width.
 * @NTB_WIDTH_16:	Link is trained to 16 lane width.
 * @NTB_WIDTH_32:	Link is trained to 32 lane width.
 */
enum ntb_width {
	NTB_WIDTH_AUTO = -1,
	NTB_WIDTH_NONE = 0,
	NTB_WIDTH_1 = 1,
	NTB_WIDTH_2 = 2,
	NTB_WIDTH_4 = 4,
	NTB_WIDTH_8 = 8,
	NTB_WIDTH_12 = 12,
	NTB_WIDTH_16 = 16,
	NTB_WIDTH_32 = 32,
};

/**
 * enum ntb_default_port - NTB default port number
 * @NTB_PORT_PRI_USD:	Default port of the NTB_TOPO_PRI/NTB_TOPO_B2B_USD
 *			topologies
 * @NTB_PORT_SEC_DSD:	Default port of the NTB_TOPO_SEC/NTB_TOPO_B2B_DSD
 *			topologies
 */
enum ntb_default_port {
	NTB_PORT_PRI_USD,
	NTB_PORT_SEC_DSD
};
#define NTB_DEF_PEER_CNT	(1)
#define NTB_DEF_PEER_IDX	(0)

/**
 * struct ntb_client_ops - ntb client operations
 * @probe:		Notify client of a new device.
 * @remove:		Notify client to remove a device.
 */
struct ntb_client_ops {
	int (*probe)(struct ntb_client *client, struct ntb_dev *ntb);
	void (*remove)(struct ntb_client *client, struct ntb_dev *ntb);
};

static inline int ntb_client_ops_is_valid(const struct ntb_client_ops *ops)
{
	/* commented callbacks are not required: */
	return
		ops->probe			&&
		ops->remove			&&
		1;
}

/**
 * struct ntb_ctx_ops - ntb driver context operations
 * @link_event:		See ntb_link_event().
 * @db_event:		See ntb_db_event().
 * @msg_event:		See ntb_msg_event().
 */
struct ntb_ctx_ops {
	void (*link_event)(void *ctx);
	void (*db_event)(void *ctx, int db_vector);
	void (*msg_event)(void *ctx);
};

static inline int ntb_ctx_ops_is_valid(const struct ntb_ctx_ops *ops)
{
	/* commented callbacks are not required: */
	return
		/* ops->link_event		&& */
		/* ops->db_event		&& */
		/* ops->msg_event		&& */
		1;
}

/**
 * struct ntb_ctx_ops - ntb device operations
 * @port_number:	See ntb_port_number().
 * @peer_port_count:	See ntb_peer_port_count().
 * @peer_port_number:	See ntb_peer_port_number().
 * @peer_port_idx:	See ntb_peer_port_idx().
 * @link_is_up:		See ntb_link_is_up().
 * @link_enable:	See ntb_link_enable().
 * @link_disable:	See ntb_link_disable().
 * @mw_count:		See ntb_mw_count().
 * @mw_get_align:	See ntb_mw_get_align().
 * @mw_set_trans:	See ntb_mw_set_trans().
 * @mw_clear_trans:	See ntb_mw_clear_trans().
 * @peer_mw_count:	See ntb_peer_mw_count().
 * @peer_mw_get_addr:	See ntb_peer_mw_get_addr().
 * @peer_mw_set_trans:	See ntb_peer_mw_set_trans().
 * @peer_mw_clear_trans:See ntb_peer_mw_clear_trans().
 * @db_is_unsafe:	See ntb_db_is_unsafe().
 * @db_valid_mask:	See ntb_db_valid_mask().
 * @db_vector_count:	See ntb_db_vector_count().
 * @db_vector_mask:	See ntb_db_vector_mask().
 * @db_read:		See ntb_db_read().
 * @db_set:		See ntb_db_set().
 * @db_clear:		See ntb_db_clear().
 * @db_read_mask:	See ntb_db_read_mask().
 * @db_set_mask:	See ntb_db_set_mask().
 * @db_clear_mask:	See ntb_db_clear_mask().
 * @peer_db_addr:	See ntb_peer_db_addr().
 * @peer_db_read:	See ntb_peer_db_read().
 * @peer_db_set:	See ntb_peer_db_set().
 * @peer_db_clear:	See ntb_peer_db_clear().
 * @peer_db_read_mask:	See ntb_peer_db_read_mask().
 * @peer_db_set_mask:	See ntb_peer_db_set_mask().
 * @peer_db_clear_mask:	See ntb_peer_db_clear_mask().
 * @spad_is_unsafe:	See ntb_spad_is_unsafe().
 * @spad_count:		See ntb_spad_count().
 * @spad_read:		See ntb_spad_read().
 * @spad_write:		See ntb_spad_write().
 * @peer_spad_addr:	See ntb_peer_spad_addr().
 * @peer_spad_read:	See ntb_peer_spad_read().
 * @peer_spad_write:	See ntb_peer_spad_write().
 * @msg_count:		See ntb_msg_count().
 * @msg_inbits:		See ntb_msg_inbits().
 * @msg_outbits:	See ntb_msg_outbits().
 * @msg_read_sts:	See ntb_msg_read_sts().
 * @msg_clear_sts:	See ntb_msg_clear_sts().
 * @msg_set_mask:	See ntb_msg_set_mask().
 * @msg_clear_mask:	See ntb_msg_clear_mask().
 * @msg_read:		See ntb_msg_read().
 * @peer_msg_write:	See ntb_peer_msg_write().
 */
struct ntb_dev_ops {
	int (*port_number)(struct ntb_dev *ntb);
	int (*peer_port_count)(struct ntb_dev *ntb);
	int (*peer_port_number)(struct ntb_dev *ntb, int pidx);
	int (*peer_port_idx)(struct ntb_dev *ntb, int port);

	u64 (*link_is_up)(struct ntb_dev *ntb,
			  enum ntb_speed *speed, enum ntb_width *width);
	int (*link_enable)(struct ntb_dev *ntb,
			   enum ntb_speed max_speed, enum ntb_width max_width);
	int (*link_disable)(struct ntb_dev *ntb);

	int (*mw_count)(struct ntb_dev *ntb, int pidx);
	int (*mw_get_align)(struct ntb_dev *ntb, int pidx, int widx,
			    resource_size_t *addr_align,
			    resource_size_t *size_align,
			    resource_size_t *size_max);
	int (*mw_set_trans)(struct ntb_dev *ntb, int pidx, int widx,
			    dma_addr_t addr, resource_size_t size);
	int (*mw_clear_trans)(struct ntb_dev *ntb, int pidx, int widx);
	int (*peer_mw_count)(struct ntb_dev *ntb);
	int (*peer_mw_get_addr)(struct ntb_dev *ntb, int widx,
				phys_addr_t *base, resource_size_t *size);
	int (*peer_mw_set_trans)(struct ntb_dev *ntb, int pidx, int widx,
				 u64 addr, resource_size_t size);
	int (*peer_mw_clear_trans)(struct ntb_dev *ntb, int pidx, int widx);

	int (*db_is_unsafe)(struct ntb_dev *ntb);
	u64 (*db_valid_mask)(struct ntb_dev *ntb);
	int (*db_vector_count)(struct ntb_dev *ntb);
	u64 (*db_vector_mask)(struct ntb_dev *ntb, int db_vector);

	u64 (*db_read)(struct ntb_dev *ntb);
	int (*db_set)(struct ntb_dev *ntb, u64 db_bits);
	int (*db_clear)(struct ntb_dev *ntb, u64 db_bits);

	u64 (*db_read_mask)(struct ntb_dev *ntb);
	int (*db_set_mask)(struct ntb_dev *ntb, u64 db_bits);
	int (*db_clear_mask)(struct ntb_dev *ntb, u64 db_bits);

	int (*peer_db_addr)(struct ntb_dev *ntb,
			    phys_addr_t *db_addr, resource_size_t *db_size,
				u64 *db_data, int db_bit);
	u64 (*peer_db_read)(struct ntb_dev *ntb);
	int (*peer_db_set)(struct ntb_dev *ntb, u64 db_bits);
	int (*peer_db_clear)(struct ntb_dev *ntb, u64 db_bits);

	u64 (*peer_db_read_mask)(struct ntb_dev *ntb);
	int (*peer_db_set_mask)(struct ntb_dev *ntb, u64 db_bits);
	int (*peer_db_clear_mask)(struct ntb_dev *ntb, u64 db_bits);

	int (*spad_is_unsafe)(struct ntb_dev *ntb);
	int (*spad_count)(struct ntb_dev *ntb);

	u32 (*spad_read)(struct ntb_dev *ntb, int sidx);
	int (*spad_write)(struct ntb_dev *ntb, int sidx, u32 val);

	int (*peer_spad_addr)(struct ntb_dev *ntb, int pidx, int sidx,
			      phys_addr_t *spad_addr);
	u32 (*peer_spad_read)(struct ntb_dev *ntb, int pidx, int sidx);
	int (*peer_spad_write)(struct ntb_dev *ntb, int pidx, int sidx,
			       u32 val);

	int (*msg_count)(struct ntb_dev *ntb);
	u64 (*msg_inbits)(struct ntb_dev *ntb);
	u64 (*msg_outbits)(struct ntb_dev *ntb);
	u64 (*msg_read_sts)(struct ntb_dev *ntb);
	int (*msg_clear_sts)(struct ntb_dev *ntb, u64 sts_bits);
	int (*msg_set_mask)(struct ntb_dev *ntb, u64 mask_bits);
	int (*msg_clear_mask)(struct ntb_dev *ntb, u64 mask_bits);
	u32 (*msg_read)(struct ntb_dev *ntb, int *pidx, int midx);
	int (*peer_msg_write)(struct ntb_dev *ntb, int pidx, int midx, u32 msg);
};

static inline int ntb_dev_ops_is_valid(const struct ntb_dev_ops *ops)
{
	/* commented callbacks are not required: */
	return
		/* Port operations are required for multiport devices */
		!ops->peer_port_count == !ops->port_number	&&
		!ops->peer_port_number == !ops->port_number	&&
		!ops->peer_port_idx == !ops->port_number	&&

		/* Link operations are required */
		ops->link_is_up				&&
		ops->link_enable			&&
		ops->link_disable			&&

		/* One or both MW interfaces should be developed */
		ops->mw_count				&&
		ops->mw_get_align			&&
		(ops->mw_set_trans			||
		 ops->peer_mw_set_trans)		&&
		/* ops->mw_clear_trans			&& */
		ops->peer_mw_count			&&
		ops->peer_mw_get_addr			&&
		/* ops->peer_mw_clear_trans		&& */

		/* Doorbell operations are mostly required */
		/* ops->db_is_unsafe			&& */
		ops->db_valid_mask			&&
		/* both set, or both unset */
		(!ops->db_vector_count == !ops->db_vector_mask)	&&
		ops->db_read				&&
		/* ops->db_set				&& */
		ops->db_clear				&&
		/* ops->db_read_mask			&& */
		ops->db_set_mask			&&
		ops->db_clear_mask			&&
		/* ops->peer_db_addr			&& */
		/* ops->peer_db_read			&& */
		ops->peer_db_set			&&
		/* ops->peer_db_clear			&& */
		/* ops->peer_db_read_mask		&& */
		/* ops->peer_db_set_mask		&& */
		/* ops->peer_db_clear_mask		&& */

		/* Scrachpads interface is optional */
		/* !ops->spad_is_unsafe == !ops->spad_count	&& */
		!ops->spad_read == !ops->spad_count		&&
		!ops->spad_write == !ops->spad_count		&&
		/* !ops->peer_spad_addr == !ops->spad_count	&& */
		/* !ops->peer_spad_read == !ops->spad_count	&& */
		!ops->peer_spad_write == !ops->spad_count	&&

		/* Messaging interface is optional */
		!ops->msg_inbits == !ops->msg_count		&&
		!ops->msg_outbits == !ops->msg_count		&&
		!ops->msg_read_sts == !ops->msg_count		&&
		!ops->msg_clear_sts == !ops->msg_count		&&
		/* !ops->msg_set_mask == !ops->msg_count	&& */
		/* !ops->msg_clear_mask == !ops->msg_count	&& */
		!ops->msg_read == !ops->msg_count		&&
		!ops->peer_msg_write == !ops->msg_count		&&
		1;
}

/**
 * struct ntb_client - client interested in ntb devices
 * @drv:		Linux driver object.
 * @ops:		See &ntb_client_ops.
 */
struct ntb_client {
	struct device_driver		drv;
	const struct ntb_client_ops	ops;
};
#define drv_ntb_client(__drv) container_of((__drv), struct ntb_client, drv)

/**
 * struct ntb_device - ntb device
 * @dev:		Linux device object.
 * @pdev:		PCI device entry of the ntb.
 * @topo:		Detected topology of the ntb.
 * @ops:		See &ntb_dev_ops.
 * @ctx:		See &ntb_ctx_ops.
 * @ctx_ops:		See &ntb_ctx_ops.
 */
struct ntb_dev {
	struct device			dev;
	struct pci_dev			*pdev;
	enum ntb_topo			topo;
	const struct ntb_dev_ops	*ops;
	void				*ctx;
	const struct ntb_ctx_ops	*ctx_ops;

	/* private: */

	/* synchronize setting, clearing, and calling ctx_ops */
	spinlock_t			ctx_lock;
	/* block unregister until device is fully released */
	struct completion		released;
};
#define dev_ntb(__dev) container_of((__dev), struct ntb_dev, dev)

/**
 * ntb_register_client() - register a client for interest in ntb devices
 * @client:	Client context.
 *
 * The client will be added to the list of clients interested in ntb devices.
 * The client will be notified of any ntb devices that are not already
 * associated with a client, or if ntb devices are registered later.
 *
 * Return: Zero if the client is registered, otherwise an error number.
 */
#define ntb_register_client(client) \
	__ntb_register_client((client), THIS_MODULE, KBUILD_MODNAME)

int __ntb_register_client(struct ntb_client *client, struct module *mod,
			  const char *mod_name);

/**
 * ntb_unregister_client() - unregister a client for interest in ntb devices
 * @client:	Client context.
 *
 * The client will be removed from the list of clients interested in ntb
 * devices.  If any ntb devices are associated with the client, the client will
 * be notified to remove those devices.
 */
void ntb_unregister_client(struct ntb_client *client);

#define module_ntb_client(__ntb_client) \
	module_driver(__ntb_client, ntb_register_client, \
			ntb_unregister_client)

/**
 * ntb_register_device() - register a ntb device
 * @ntb:	NTB device context.
 *
 * The device will be added to the list of ntb devices.  If any clients are
 * interested in ntb devices, each client will be notified of the ntb device,
 * until at most one client accepts the device.
 *
 * Return: Zero if the device is registered, otherwise an error number.
 */
int ntb_register_device(struct ntb_dev *ntb);

/**
 * ntb_register_device() - unregister a ntb device
 * @ntb:	NTB device context.
 *
 * The device will be removed from the list of ntb devices.  If the ntb device
 * is associated with a client, the client will be notified to remove the
 * device.
 */
void ntb_unregister_device(struct ntb_dev *ntb);

/**
 * ntb_set_ctx() - associate a driver context with an ntb device
 * @ntb:	NTB device context.
 * @ctx:	Driver context.
 * @ctx_ops:	Driver context operations.
 *
 * Associate a driver context and operations with a ntb device.  The context is
 * provided by the client driver, and the driver may associate a different
 * context with each ntb device.
 *
 * Return: Zero if the context is associated, otherwise an error number.
 */
int ntb_set_ctx(struct ntb_dev *ntb, void *ctx,
		const struct ntb_ctx_ops *ctx_ops);

/**
 * ntb_clear_ctx() - disassociate any driver context from an ntb device
 * @ntb:	NTB device context.
 *
 * Clear any association that may exist between a driver context and the ntb
 * device.
 */
void ntb_clear_ctx(struct ntb_dev *ntb);

/**
 * ntb_link_event() - notify driver context of a change in link status
 * @ntb:	NTB device context.
 *
 * Notify the driver context that the link status may have changed.  The driver
 * should call ntb_link_is_up() to get the current status.
 */
void ntb_link_event(struct ntb_dev *ntb);

/**
 * ntb_db_event() - notify driver context of a doorbell event
 * @ntb:	NTB device context.
 * @vector:	Interrupt vector number.
 *
 * Notify the driver context of a doorbell event.  If hardware supports
 * multiple interrupt vectors for doorbells, the vector number indicates which
 * vector received the interrupt.  The vector number is relative to the first
 * vector used for doorbells, starting at zero, and must be less than
 * ntb_db_vector_count().  The driver may call ntb_db_read() to check which
 * doorbell bits need service, and ntb_db_vector_mask() to determine which of
 * those bits are associated with the vector number.
 */
void ntb_db_event(struct ntb_dev *ntb, int vector);

/**
 * ntb_msg_event() - notify driver context of a message event
 * @ntb:	NTB device context.
 *
 * Notify the driver context of a message event.  If hardware supports
 * message registers, this event indicates, that a new message arrived in
 * some incoming message register or last sent message couldn't be delivered.
 * The events can be masked/unmasked by the methods ntb_msg_set_mask() and
 * ntb_msg_clear_mask().
 */
void ntb_msg_event(struct ntb_dev *ntb);

/**
 * ntb_default_port_number() - get the default local port number
 * @ntb:	NTB device context.
 *
 * If hardware driver doesn't specify port_number() callback method, the NTB
 * is considered with just two ports. So this method returns default local
 * port number in compliance with topology.
 *
 * NOTE Don't call this method directly. The ntb_port_number() function should
 * be used instead.
 *
 * Return: the default local port number
 */
int ntb_default_port_number(struct ntb_dev *ntb);

/**
 * ntb_default_port_count() - get the default number of peer device ports
 * @ntb:	NTB device context.
 *
 * By default hardware driver supports just one peer device.
 *
 * NOTE Don't call this method directly. The ntb_peer_port_count() function
 * should be used instead.
 *
 * Return: the default number of peer ports
 */
int ntb_default_peer_port_count(struct ntb_dev *ntb);

/**
 * ntb_default_peer_port_number() - get the default peer port by given index
 * @ntb:	NTB device context.
 * @idx:	Peer port index (should not differ from zero).
 *
 * By default hardware driver supports just one peer device, so this method
 * shall return the corresponding value from enum ntb_default_port.
 *
 * NOTE Don't call this method directly. The ntb_peer_port_number() function
 * should be used instead.
 *
 * Return: the peer device port or negative value indicating an error
 */
int ntb_default_peer_port_number(struct ntb_dev *ntb, int pidx);

/**
 * ntb_default_peer_port_idx() - get the default peer device port index by
 *				 given port number
 * @ntb:	NTB device context.
 * @port:	Peer port number (should be one of enum ntb_default_port).
 *
 * By default hardware driver supports just one peer device, so while
 * specified port-argument indicates peer port from enum ntb_default_port,
 * the return value shall be zero.
 *
 * NOTE Don't call this method directly. The ntb_peer_port_idx() function
 * should be used instead.
 *
 * Return: the peer port index or negative value indicating an error
 */
int ntb_default_peer_port_idx(struct ntb_dev *ntb, int port);

/**
 * ntb_port_number() - get the local port number
 * @ntb:	NTB device context.
 *
 * Hardware must support at least simple two-ports ntb connection
 *
 * Return: the local port number
 */
static inline int ntb_port_number(struct ntb_dev *ntb)
{
	if (!ntb->ops->port_number)
		return ntb_default_port_number(ntb);

	return ntb->ops->port_number(ntb);
}

/**
 * ntb_peer_port_count() - get the number of peer device ports
 * @ntb:	NTB device context.
 *
 * Hardware may support an access to memory of several remote domains
 * over multi-port NTB devices. This method returns the number of peers,
 * local device can have shared memory with.
 *
 * Return: the number of peer ports
 */
static inline int ntb_peer_port_count(struct ntb_dev *ntb)
{
	if (!ntb->ops->peer_port_count)
		return ntb_default_peer_port_count(ntb);

	return ntb->ops->peer_port_count(ntb);
}

/**
 * ntb_peer_port_number() - get the peer port by given index
 * @ntb:	NTB device context.
 * @pidx:	Peer port index.
 *
 * Peer ports are continuously enumerated by NTB API logic, so this method
 * lets to retrieve port real number by its index.
 *
 * Return: the peer device port or negative value indicating an error
 */
static inline int ntb_peer_port_number(struct ntb_dev *ntb, int pidx)
{
	if (!ntb->ops->peer_port_number)
		return ntb_default_peer_port_number(ntb, pidx);

	return ntb->ops->peer_port_number(ntb, pidx);
}

/**
 * ntb_peer_port_idx() - get the peer device port index by given port number
 * @ntb:	NTB device context.
 * @port:	Peer port number.
 *
 * Inverse operation of ntb_peer_port_number(), so one can get port index
 * by specified port number.
 *
 * Return: the peer port index or negative value indicating an error
 */
static inline int ntb_peer_port_idx(struct ntb_dev *ntb, int port)
{
	if (!ntb->ops->peer_port_idx)
		return ntb_default_peer_port_idx(ntb, port);

	return ntb->ops->peer_port_idx(ntb, port);
}

/**
 * ntb_link_is_up() - get the current ntb link state
 * @ntb:	NTB device context.
 * @speed:	OUT - The link speed expressed as PCIe generation number.
 * @width:	OUT - The link width expressed as the number of PCIe lanes.
 *
 * Get the current state of the ntb link.  It is recommended to query the link
 * state once after every link event.  It is safe to query the link state in
 * the context of the link event callback.
 *
 * Return: bitfield of indexed ports link state: bit is set/cleared if the
 *         link is up/down respectively.
 */
static inline u64 ntb_link_is_up(struct ntb_dev *ntb,
				 enum ntb_speed *speed, enum ntb_width *width)
{
	return ntb->ops->link_is_up(ntb, speed, width);
}

/**
 * ntb_link_enable() - enable the local port ntb connection
 * @ntb:	NTB device context.
 * @max_speed:	The maximum link speed expressed as PCIe generation number.
 * @max_width:	The maximum link width expressed as the number of PCIe lanes.
 *
 * Enable the NTB/PCIe link on the local or remote (for bridge-to-bridge
 * topology) side of the bridge. If it's supported the ntb device should train
 * the link to its maximum speed and width, or the requested speed and width,
 * whichever is smaller. Some hardware doesn't support PCIe link training, so
 * the last two arguments will be ignored then.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_link_enable(struct ntb_dev *ntb,
				  enum ntb_speed max_speed,
				  enum ntb_width max_width)
{
	return ntb->ops->link_enable(ntb, max_speed, max_width);
}

/**
 * ntb_link_disable() - disable the local port ntb connection
 * @ntb:	NTB device context.
 *
 * Disable the link on the local or remote (for b2b topology) of the ntb.
 * The ntb device should disable the link.  Returning from this call must
 * indicate that a barrier has passed, though with no more writes may pass in
 * either direction across the link, except if this call returns an error
 * number.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_link_disable(struct ntb_dev *ntb)
{
	return ntb->ops->link_disable(ntb);
}

/**
 * ntb_mw_count() - get the number of inbound memory windows, which could
 *                  be created for a specified peer device
 * @ntb:	NTB device context.
 * @pidx:	Port index of peer device.
 *
 * Hardware and topology may support a different number of memory windows.
 * Moreover different peer devices can support different number of memory
 * windows. Simply speaking this method returns the number of possible inbound
 * memory windows to share with specified peer device. Note: this may return
 * zero if the link is not up yet.
 *
 * Return: the number of memory windows.
 */
static inline int ntb_mw_count(struct ntb_dev *ntb, int pidx)
{
	return ntb->ops->mw_count(ntb, pidx);
}

/**
 * ntb_mw_get_align() - get the restriction parameters of inbound memory window
 * @ntb:	NTB device context.
 * @pidx:	Port index of peer device.
 * @widx:	Memory window index.
 * @addr_align:	OUT - the base alignment for translating the memory window
 * @size_align:	OUT - the size alignment for translating the memory window
 * @size_max:	OUT - the maximum size of the memory window
 *
 * Get the alignments of an inbound memory window with specified index.
 * NULL may be given for any output parameter if the value is not needed.
 * The alignment and size parameters may be used for allocation of proper
 * shared memory. Note: this must only be called when the link is up.
 *
 * Return: Zero on success, otherwise a negative error number.
 */
static inline int ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int widx,
				   resource_size_t *addr_align,
				   resource_size_t *size_align,
				   resource_size_t *size_max)
{
	if (!(ntb_link_is_up(ntb, NULL, NULL) & BIT_ULL(pidx)))
		return -ENOTCONN;

	return ntb->ops->mw_get_align(ntb, pidx, widx, addr_align, size_align,
				      size_max);
}

/**
 * ntb_mw_set_trans() - set the translation of an inbound memory window
 * @ntb:	NTB device context.
 * @pidx:	Port index of peer device.
 * @widx:	Memory window index.
 * @addr:	The dma address of local memory to expose to the peer.
 * @size:	The size of the local memory to expose to the peer.
 *
 * Set the translation of a memory window.  The peer may access local memory
 * through the window starting at the address, up to the size.  The address
 * and size must be aligned in compliance with restrictions of
 * ntb_mw_get_align(). The region size should not exceed the size_max parameter
 * of that method.
 *
 * This method may not be implemented due to the hardware specific memory
 * windows interface.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
				   dma_addr_t addr, resource_size_t size)
{
	if (!ntb->ops->mw_set_trans)
		return 0;

	return ntb->ops->mw_set_trans(ntb, pidx, widx, addr, size);
}

/**
 * ntb_mw_clear_trans() - clear the translation address of an inbound memory
 *                        window
 * @ntb:	NTB device context.
 * @pidx:	Port index of peer device.
 * @widx:	Memory window index.
 *
 * Clear the translation of an inbound memory window.  The peer may no longer
 * access local memory through the window.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_mw_clear_trans(struct ntb_dev *ntb, int pidx, int widx)
{
	if (!ntb->ops->mw_clear_trans)
		return ntb_mw_set_trans(ntb, pidx, widx, 0, 0);

	return ntb->ops->mw_clear_trans(ntb, pidx, widx);
}

/**
 * ntb_peer_mw_count() - get the number of outbound memory windows, which could
 *                       be mapped to access a shared memory
 * @ntb:	NTB device context.
 *
 * Hardware and topology may support a different number of memory windows.
 * This method returns the number of outbound memory windows supported by
 * local device.
 *
 * Return: the number of memory windows.
 */
static inline int ntb_peer_mw_count(struct ntb_dev *ntb)
{
	return ntb->ops->peer_mw_count(ntb);
}

/**
 * ntb_peer_mw_get_addr() - get map address of an outbound memory window
 * @ntb:	NTB device context.
 * @widx:	Memory window index (within ntb_peer_mw_count() return value).
 * @base:	OUT - the base address of mapping region.
 * @size:	OUT - the size of mapping region.
 *
 * Get base and size of memory region to map.  NULL may be given for any output
 * parameter if the value is not needed.  The base and size may be used for
 * mapping the memory window, to access the peer memory.
 *
 * Return: Zero on success, otherwise a negative error number.
 */
static inline int ntb_peer_mw_get_addr(struct ntb_dev *ntb, int widx,
				      phys_addr_t *base, resource_size_t *size)
{
	return ntb->ops->peer_mw_get_addr(ntb, widx, base, size);
}

/**
 * ntb_peer_mw_set_trans() - set a translation address of a memory window
 *                           retrieved from a peer device
 * @ntb:	NTB device context.
 * @pidx:	Port index of peer device the translation address received from.
 * @widx:	Memory window index.
 * @addr:	The dma address of the shared memory to access.
 * @size:	The size of the shared memory to access.
 *
 * Set the translation of an outbound memory window.  The local device may
 * access shared memory allocated by a peer device sent the address.
 *
 * This method may not be implemented due to the hardware specific memory
 * windows interface, so a translation address can be only set on the side,
 * where shared memory (inbound memory windows) is allocated.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_peer_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
					u64 addr, resource_size_t size)
{
	if (!ntb->ops->peer_mw_set_trans)
		return 0;

	return ntb->ops->peer_mw_set_trans(ntb, pidx, widx, addr, size);
}

/**
 * ntb_peer_mw_clear_trans() - clear the translation address of an outbound
 *                             memory window
 * @ntb:	NTB device context.
 * @pidx:	Port index of peer device.
 * @widx:	Memory window index.
 *
 * Clear the translation of a outbound memory window.  The local device may no
 * longer access a shared memory through the window.
 *
 * This method may not be implemented due to the hardware specific memory
 * windows interface.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_peer_mw_clear_trans(struct ntb_dev *ntb, int pidx,
					  int widx)
{
	if (!ntb->ops->peer_mw_clear_trans)
		return ntb_peer_mw_set_trans(ntb, pidx, widx, 0, 0);

	return ntb->ops->peer_mw_clear_trans(ntb, pidx, widx);
}

/**
 * ntb_db_is_unsafe() - check if it is safe to use hardware doorbell
 * @ntb:	NTB device context.
 *
 * It is possible for some ntb hardware to be affected by errata.  Hardware
 * drivers can advise clients to avoid using doorbells.  Clients may ignore
 * this advice, though caution is recommended.
 *
 * Return: Zero if it is safe to use doorbells, or One if it is not safe.
 */
static inline int ntb_db_is_unsafe(struct ntb_dev *ntb)
{
	if (!ntb->ops->db_is_unsafe)
		return 0;

	return ntb->ops->db_is_unsafe(ntb);
}

/**
 * ntb_db_valid_mask() - get a mask of doorbell bits supported by the ntb
 * @ntb:	NTB device context.
 *
 * Hardware may support different number or arrangement of doorbell bits.
 *
 * Return: A mask of doorbell bits supported by the ntb.
 */
static inline u64 ntb_db_valid_mask(struct ntb_dev *ntb)
{
	return ntb->ops->db_valid_mask(ntb);
}

/**
 * ntb_db_vector_count() - get the number of doorbell interrupt vectors
 * @ntb:	NTB device context.
 *
 * Hardware may support different number of interrupt vectors.
 *
 * Return: The number of doorbell interrupt vectors.
 */
static inline int ntb_db_vector_count(struct ntb_dev *ntb)
{
	if (!ntb->ops->db_vector_count)
		return 1;

	return ntb->ops->db_vector_count(ntb);
}

/**
 * ntb_db_vector_mask() - get a mask of doorbell bits serviced by a vector
 * @ntb:	NTB device context.
 * @vector:	Doorbell vector number.
 *
 * Each interrupt vector may have a different number or arrangement of bits.
 *
 * Return: A mask of doorbell bits serviced by a vector.
 */
static inline u64 ntb_db_vector_mask(struct ntb_dev *ntb, int vector)
{
	if (!ntb->ops->db_vector_mask)
		return ntb_db_valid_mask(ntb);

	return ntb->ops->db_vector_mask(ntb, vector);
}

/**
 * ntb_db_read() - read the local doorbell register
 * @ntb:	NTB device context.
 *
 * Read the local doorbell register, and return the bits that are set.
 *
 * Return: The bits currently set in the local doorbell register.
 */
static inline u64 ntb_db_read(struct ntb_dev *ntb)
{
	return ntb->ops->db_read(ntb);
}

/**
 * ntb_db_set() - set bits in the local doorbell register
 * @ntb:	NTB device context.
 * @db_bits:	Doorbell bits to set.
 *
 * Set bits in the local doorbell register, which may generate a local doorbell
 * interrupt.  Bits that were already set must remain set.
 *
 * This is unusual, and hardware may not support it.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_db_set(struct ntb_dev *ntb, u64 db_bits)
{
	if (!ntb->ops->db_set)
		return -EINVAL;

	return ntb->ops->db_set(ntb, db_bits);
}

/**
 * ntb_db_clear() - clear bits in the local doorbell register
 * @ntb:	NTB device context.
 * @db_bits:	Doorbell bits to clear.
 *
 * Clear bits in the local doorbell register, arming the bits for the next
 * doorbell.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
{
	return ntb->ops->db_clear(ntb, db_bits);
}

/**
 * ntb_db_read_mask() - read the local doorbell mask
 * @ntb:	NTB device context.
 *
 * Read the local doorbell mask register, and return the bits that are set.
 *
 * This is unusual, though hardware is likely to support it.
 *
 * Return: The bits currently set in the local doorbell mask register.
 */
static inline u64 ntb_db_read_mask(struct ntb_dev *ntb)
{
	if (!ntb->ops->db_read_mask)
		return 0;

	return ntb->ops->db_read_mask(ntb);
}

/**
 * ntb_db_set_mask() - set bits in the local doorbell mask
 * @ntb:	NTB device context.
 * @db_bits:	Doorbell mask bits to set.
 *
 * Set bits in the local doorbell mask register, preventing doorbell interrupts
 * from being generated for those doorbell bits.  Bits that were already set
 * must remain set.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
{
	return ntb->ops->db_set_mask(ntb, db_bits);
}

/**
 * ntb_db_clear_mask() - clear bits in the local doorbell mask
 * @ntb:	NTB device context.
 * @db_bits:	Doorbell bits to clear.
 *
 * Clear bits in the local doorbell mask register, allowing doorbell interrupts
 * from being generated for those doorbell bits.  If a doorbell bit is already
 * set at the time the mask is cleared, and the corresponding mask bit is
 * changed from set to clear, then the ntb driver must ensure that
 * ntb_db_event() is called.  If the hardware does not generate the interrupt
 * on clearing the mask bit, then the driver must call ntb_db_event() anyway.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
{
	return ntb->ops->db_clear_mask(ntb, db_bits);
}

/**
 * ntb_peer_db_addr() - address and size of the peer doorbell register
 * @ntb:	NTB device context.
 * @db_addr:	OUT - The address of the peer doorbell register.
 * @db_size:	OUT - The number of bytes to write the peer doorbell register.
 * @db_data:	OUT - The data of peer doorbell register
 * @db_bit:		door bell bit number
 *
 * Return the address of the peer doorbell register.  This may be used, for
 * example, by drivers that offload memory copy operations to a dma engine.
 * The drivers may wish to ring the peer doorbell at the completion of memory
 * copy operations.  For efficiency, and to simplify ordering of operations
 * between the dma memory copies and the ringing doorbell, the driver may
 * append one additional dma memory copy with the doorbell register as the
 * destination, after the memory copy operations.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_peer_db_addr(struct ntb_dev *ntb,
				   phys_addr_t *db_addr,
				   resource_size_t *db_size,
				   u64 *db_data, int db_bit)
{
	if (!ntb->ops->peer_db_addr)
		return -EINVAL;

	return ntb->ops->peer_db_addr(ntb, db_addr, db_size, db_data, db_bit);
}

/**
 * ntb_peer_db_read() - read the peer doorbell register
 * @ntb:	NTB device context.
 *
 * Read the peer doorbell register, and return the bits that are set.
 *
 * This is unusual, and hardware may not support it.
 *
 * Return: The bits currently set in the peer doorbell register.
 */
static inline u64 ntb_peer_db_read(struct ntb_dev *ntb)
{
	if (!ntb->ops->peer_db_read)
		return 0;

	return ntb->ops->peer_db_read(ntb);
}

/**
 * ntb_peer_db_set() - set bits in the peer doorbell register
 * @ntb:	NTB device context.
 * @db_bits:	Doorbell bits to set.
 *
 * Set bits in the peer doorbell register, which may generate a peer doorbell
 * interrupt.  Bits that were already set must remain set.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
{
	return ntb->ops->peer_db_set(ntb, db_bits);
}

/**
 * ntb_peer_db_clear() - clear bits in the peer doorbell register
 * @ntb:	NTB device context.
 * @db_bits:	Doorbell bits to clear.
 *
 * Clear bits in the peer doorbell register, arming the bits for the next
 * doorbell.
 *
 * This is unusual, and hardware may not support it.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_peer_db_clear(struct ntb_dev *ntb, u64 db_bits)
{
	if (!ntb->ops->db_clear)
		return -EINVAL;

	return ntb->ops->peer_db_clear(ntb, db_bits);
}

/**
 * ntb_peer_db_read_mask() - read the peer doorbell mask
 * @ntb:	NTB device context.
 *
 * Read the peer doorbell mask register, and return the bits that are set.
 *
 * This is unusual, and hardware may not support it.
 *
 * Return: The bits currently set in the peer doorbell mask register.
 */
static inline u64 ntb_peer_db_read_mask(struct ntb_dev *ntb)
{
	if (!ntb->ops->db_read_mask)
		return 0;

	return ntb->ops->peer_db_read_mask(ntb);
}

/**
 * ntb_peer_db_set_mask() - set bits in the peer doorbell mask
 * @ntb:	NTB device context.
 * @db_bits:	Doorbell mask bits to set.
 *
 * Set bits in the peer doorbell mask register, preventing doorbell interrupts
 * from being generated for those doorbell bits.  Bits that were already set
 * must remain set.
 *
 * This is unusual, and hardware may not support it.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_peer_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
{
	if (!ntb->ops->db_set_mask)
		return -EINVAL;

	return ntb->ops->peer_db_set_mask(ntb, db_bits);
}

/**
 * ntb_peer_db_clear_mask() - clear bits in the peer doorbell mask
 * @ntb:	NTB device context.
 * @db_bits:	Doorbell bits to clear.
 *
 * Clear bits in the peer doorbell mask register, allowing doorbell interrupts
 * from being generated for those doorbell bits.  If the hardware does not
 * generate the interrupt on clearing the mask bit, then the driver should not
 * implement this function!
 *
 * This is unusual, and hardware may not support it.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_peer_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
{
	if (!ntb->ops->db_clear_mask)
		return -EINVAL;

	return ntb->ops->peer_db_clear_mask(ntb, db_bits);
}

/**
 * ntb_spad_is_unsafe() - check if it is safe to use the hardware scratchpads
 * @ntb:	NTB device context.
 *
 * It is possible for some ntb hardware to be affected by errata.  Hardware
 * drivers can advise clients to avoid using scratchpads.  Clients may ignore
 * this advice, though caution is recommended.
 *
 * Return: Zero if it is safe to use scratchpads, or One if it is not safe.
 */
static inline int ntb_spad_is_unsafe(struct ntb_dev *ntb)
{
	if (!ntb->ops->spad_is_unsafe)
		return 0;

	return ntb->ops->spad_is_unsafe(ntb);
}

/**
 * ntb_spad_count() - get the number of scratchpads
 * @ntb:	NTB device context.
 *
 * Hardware and topology may support a different number of scratchpads.
 * Although it must be the same for all ports per NTB device.
 *
 * Return: the number of scratchpads.
 */
static inline int ntb_spad_count(struct ntb_dev *ntb)
{
	if (!ntb->ops->spad_count)
		return 0;

	return ntb->ops->spad_count(ntb);
}

/**
 * ntb_spad_read() - read the local scratchpad register
 * @ntb:	NTB device context.
 * @sidx:	Scratchpad index.
 *
 * Read the local scratchpad register, and return the value.
 *
 * Return: The value of the local scratchpad register.
 */
static inline u32 ntb_spad_read(struct ntb_dev *ntb, int sidx)
{
	if (!ntb->ops->spad_read)
		return ~(u32)0;

	return ntb->ops->spad_read(ntb, sidx);
}

/**
 * ntb_spad_write() - write the local scratchpad register
 * @ntb:	NTB device context.
 * @sidx:	Scratchpad index.
 * @val:	Scratchpad value.
 *
 * Write the value to the local scratchpad register.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_spad_write(struct ntb_dev *ntb, int sidx, u32 val)
{
	if (!ntb->ops->spad_write)
		return -EINVAL;

	return ntb->ops->spad_write(ntb, sidx, val);
}

/**
 * ntb_peer_spad_addr() - address of the peer scratchpad register
 * @ntb:	NTB device context.
 * @pidx:	Port index of peer device.
 * @sidx:	Scratchpad index.
 * @spad_addr:	OUT - The address of the peer scratchpad register.
 *
 * Return the address of the peer doorbell register.  This may be used, for
 * example, by drivers that offload memory copy operations to a dma engine.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_peer_spad_addr(struct ntb_dev *ntb, int pidx, int sidx,
				     phys_addr_t *spad_addr)
{
	if (!ntb->ops->peer_spad_addr)
		return -EINVAL;

	return ntb->ops->peer_spad_addr(ntb, pidx, sidx, spad_addr);
}

/**
 * ntb_peer_spad_read() - read the peer scratchpad register
 * @ntb:	NTB device context.
 * @pidx:	Port index of peer device.
 * @sidx:	Scratchpad index.
 *
 * Read the peer scratchpad register, and return the value.
 *
 * Return: The value of the local scratchpad register.
 */
static inline u32 ntb_peer_spad_read(struct ntb_dev *ntb, int pidx, int sidx)
{
	if (!ntb->ops->peer_spad_read)
		return ~(u32)0;

	return ntb->ops->peer_spad_read(ntb, pidx, sidx);
}

/**
 * ntb_peer_spad_write() - write the peer scratchpad register
 * @ntb:	NTB device context.
 * @pidx:	Port index of peer device.
 * @sidx:	Scratchpad index.
 * @val:	Scratchpad value.
 *
 * Write the value to the peer scratchpad register.
 *
 * Return: Zero on success, otherwise an error number.
 */
static inline int ntb_peer_spad_write(struct ntb_dev *ntb, int pidx, int sidx,
				      u32 val)
{
	if (!ntb->ops->peer_spad_write)
		return -EINVAL;

	return ntb->ops->peer_spad_write(ntb, pidx, sidx, val);
}

/**
 * ntb_msg_count() - get the number of message registers
 * @ntb:	NTB device context.
 *
 * Hardware may support a different number of message registers.
 *
 * Return: the number of message registers.
 */
static inline int ntb_msg_count(struct ntb_dev *ntb)
{
	if (!ntb->ops->msg_count)
		return 0;

	return ntb->ops->msg_count(ntb);
}

/**
 * ntb_msg_inbits() - get a bitfield of inbound message registers status
 * @ntb:	NTB device context.
 *
 * The method returns the bitfield of status and mask registers, which related
 * to inbound message registers.
 *
 * Return: bitfield of inbound message registers.
 */
static inline u64 ntb_msg_inbits(struct ntb_dev *ntb)
{
	if (!ntb->ops->msg_inbits)
		return 0;

	return ntb->ops->msg_inbits(ntb);
}

/**
 * ntb_msg_outbits() - get a bitfield of outbound message registers status
 * @ntb:	NTB device context.
 *
 * The method returns the bitfield of status and mask registers, which related
 * to outbound message registers.
 *
 * Return: bitfield of outbound message registers.
 */
static inline u64 ntb_msg_outbits(struct ntb_dev *ntb)
{
	if (!ntb->ops->msg_outbits)
		return 0;

	return ntb->ops->msg_outbits(ntb);
}

/**
 * ntb_msg_read_sts() - read the message registers status
 * @ntb:	NTB device context.
 *
 * Read the status of message register. Inbound and outbound message registers
 * related bits can be filtered by masks retrieved from ntb_msg_inbits() and
 * ntb_msg_outbits().
 *
 * Return: status bits of message registers
 */
static inline u64 ntb_msg_read_sts(struct ntb_dev *ntb)
{
	if (!ntb->ops->msg_read_sts)
		return 0;

	return ntb->ops->msg_read_sts(ntb);
}

/**
 * ntb_msg_clear_sts() - clear status bits of message registers
 * @ntb:	NTB device context.
 * @sts_bits:	Status bits to clear.
 *
 * Clear bits in the status register.
 *
 * Return: Zero on success, otherwise a negative error number.
 */
static inline int ntb_msg_clear_sts(struct ntb_dev *ntb, u64 sts_bits)
{
	if (!ntb->ops->msg_clear_sts)
		return -EINVAL;

	return ntb->ops->msg_clear_sts(ntb, sts_bits);
}

/**
 * ntb_msg_set_mask() - set mask of message register status bits
 * @ntb:	NTB device context.
 * @mask_bits:	Mask bits.
 *
 * Mask the message registers status bits from raising the message event.
 *
 * Return: Zero on success, otherwise a negative error number.
 */
static inline int ntb_msg_set_mask(struct ntb_dev *ntb, u64 mask_bits)
{
	if (!ntb->ops->msg_set_mask)
		return -EINVAL;

	return ntb->ops->msg_set_mask(ntb, mask_bits);
}

/**
 * ntb_msg_clear_mask() - clear message registers mask
 * @ntb:	NTB device context.
 * @mask_bits:	Mask bits to clear.
 *
 * Clear bits in the message events mask register.
 *
 * Return: Zero on success, otherwise a negative error number.
 */
static inline int ntb_msg_clear_mask(struct ntb_dev *ntb, u64 mask_bits)
{
	if (!ntb->ops->msg_clear_mask)
		return -EINVAL;

	return ntb->ops->msg_clear_mask(ntb, mask_bits);
}

/**
 * ntb_msg_read() - read inbound message register with specified index
 * @ntb:	NTB device context.
 * @pidx:	OUT - Port index of peer device a message retrieved from
 * @midx:	Message register index
 *
 * Read data from the specified message register. Source port index of a
 * message is retrieved as well.
 *
 * Return: The value of the inbound message register.
 */
static inline u32 ntb_msg_read(struct ntb_dev *ntb, int *pidx, int midx)
{
	if (!ntb->ops->msg_read)
		return ~(u32)0;

	return ntb->ops->msg_read(ntb, pidx, midx);
}

/**
 * ntb_peer_msg_write() - write data to the specified peer message register
 * @ntb:	NTB device context.
 * @pidx:	Port index of peer device a message being sent to
 * @midx:	Message register index
 * @msg:	Data to send
 *
 * Send data to a specified peer device using the defined message register.
 * Message event can be raised if the midx registers isn't empty while
 * calling this method and the corresponding interrupt isn't masked.
 *
 * Return: Zero on success, otherwise a negative error number.
 */
static inline int ntb_peer_msg_write(struct ntb_dev *ntb, int pidx, int midx,
				     u32 msg)
{
	if (!ntb->ops->peer_msg_write)
		return -EINVAL;

	return ntb->ops->peer_msg_write(ntb, pidx, midx, msg);
}

#endif