summaryrefslogtreecommitdiffstats
path: root/drivers/ntb/hw/mscc/ntb_hw_switchtec.c
blob: f4959458d90967621919b6274814ef3c1befc244 (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
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Microsemi Switchtec(tm) PCIe Management Driver
 * Copyright (c) 2017, Microsemi Corporation
 */

#include <linux/interrupt.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/ntb.h>
#include <linux/pci.h>
#include <linux/switchtec.h>

MODULE_DESCRIPTION("Microsemi Switchtec(tm) NTB Driver");
MODULE_VERSION("0.1");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Microsemi Corporation");

static ulong max_mw_size = SZ_2M;
module_param(max_mw_size, ulong, 0644);
MODULE_PARM_DESC(max_mw_size,
	"Max memory window size reported to the upper layer");

static bool use_lut_mws;
module_param(use_lut_mws, bool, 0644);
MODULE_PARM_DESC(use_lut_mws,
		 "Enable the use of the LUT based memory windows");

#define SWITCHTEC_NTB_MAGIC 0x45CC0001
#define MAX_MWS     128

struct shared_mw {
	u32 magic;
	u32 link_sta;
	u32 partition_id;
	u64 mw_sizes[MAX_MWS];
	u32 spad[128];
};

#define MAX_DIRECT_MW ARRAY_SIZE(((struct ntb_ctrl_regs *)(0))->bar_entry)
#define LUT_SIZE SZ_64K

struct switchtec_ntb {
	struct ntb_dev ntb;
	struct switchtec_dev *stdev;

	int self_partition;
	int peer_partition;

	int doorbell_irq;
	int message_irq;

	struct ntb_info_regs __iomem *mmio_ntb;
	struct ntb_ctrl_regs __iomem *mmio_ctrl;
	struct ntb_dbmsg_regs __iomem *mmio_dbmsg;
	struct ntb_ctrl_regs __iomem *mmio_self_ctrl;
	struct ntb_ctrl_regs __iomem *mmio_peer_ctrl;
	struct ntb_dbmsg_regs __iomem *mmio_self_dbmsg;
	struct ntb_dbmsg_regs __iomem *mmio_peer_dbmsg;

	void __iomem *mmio_xlink_win;

	struct shared_mw *self_shared;
	struct shared_mw __iomem *peer_shared;
	dma_addr_t self_shared_dma;

	u64 db_mask;
	u64 db_valid_mask;
	int db_shift;
	int db_peer_shift;

	/* synchronize rmw access of db_mask and hw reg */
	spinlock_t db_mask_lock;

	int nr_direct_mw;
	int nr_lut_mw;
	int nr_rsvd_luts;
	int direct_mw_to_bar[MAX_DIRECT_MW];

	int peer_nr_direct_mw;
	int peer_nr_lut_mw;
	int peer_direct_mw_to_bar[MAX_DIRECT_MW];

	bool link_is_up;
	enum ntb_speed link_speed;
	enum ntb_width link_width;
	struct work_struct check_link_status_work;
	bool link_force_down;
};

static struct switchtec_ntb *ntb_sndev(struct ntb_dev *ntb)
{
	return container_of(ntb, struct switchtec_ntb, ntb);
}

static int switchtec_ntb_part_op(struct switchtec_ntb *sndev,
				 struct ntb_ctrl_regs __iomem *ctl,
				 u32 op, int wait_status)
{
	static const char * const op_text[] = {
		[NTB_CTRL_PART_OP_LOCK] = "lock",
		[NTB_CTRL_PART_OP_CFG] = "configure",
		[NTB_CTRL_PART_OP_RESET] = "reset",
	};

	int i;
	u32 ps;
	int status;

	switch (op) {
	case NTB_CTRL_PART_OP_LOCK:
		status = NTB_CTRL_PART_STATUS_LOCKING;
		break;
	case NTB_CTRL_PART_OP_CFG:
		status = NTB_CTRL_PART_STATUS_CONFIGURING;
		break;
	case NTB_CTRL_PART_OP_RESET:
		status = NTB_CTRL_PART_STATUS_RESETTING;
		break;
	default:
		return -EINVAL;
	}

	iowrite32(op, &ctl->partition_op);

	for (i = 0; i < 1000; i++) {
		if (msleep_interruptible(50) != 0) {
			iowrite32(NTB_CTRL_PART_OP_RESET, &ctl->partition_op);
			return -EINTR;
		}

		ps = ioread32(&ctl->partition_status) & 0xFFFF;

		if (ps != status)
			break;
	}

	if (ps == wait_status)
		return 0;

	if (ps == status) {
		dev_err(&sndev->stdev->dev,
			"Timed out while performing %s (%d). (%08x)\n",
			op_text[op], op,
			ioread32(&ctl->partition_status));

		return -ETIMEDOUT;
	}

	return -EIO;
}

static int switchtec_ntb_send_msg(struct switchtec_ntb *sndev, int idx,
				  u32 val)
{
	if (idx < 0 || idx >= ARRAY_SIZE(sndev->mmio_peer_dbmsg->omsg))
		return -EINVAL;

	iowrite32(val, &sndev->mmio_peer_dbmsg->omsg[idx].msg);

	return 0;
}

static int switchtec_ntb_mw_count(struct ntb_dev *ntb, int pidx)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);
	int nr_direct_mw = sndev->peer_nr_direct_mw;
	int nr_lut_mw = sndev->peer_nr_lut_mw - sndev->nr_rsvd_luts;

	if (pidx != NTB_DEF_PEER_IDX)
		return -EINVAL;

	if (!use_lut_mws)
		nr_lut_mw = 0;

	return nr_direct_mw + nr_lut_mw;
}

static int lut_index(struct switchtec_ntb *sndev, int mw_idx)
{
	return mw_idx - sndev->nr_direct_mw + sndev->nr_rsvd_luts;
}

static int peer_lut_index(struct switchtec_ntb *sndev, int mw_idx)
{
	return mw_idx - sndev->peer_nr_direct_mw + sndev->nr_rsvd_luts;
}

static int switchtec_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)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);
	int lut;
	resource_size_t size;

	if (pidx != NTB_DEF_PEER_IDX)
		return -EINVAL;

	lut = widx >= sndev->peer_nr_direct_mw;
	size = ioread64(&sndev->peer_shared->mw_sizes[widx]);

	if (size == 0)
		return -EINVAL;

	if (addr_align)
		*addr_align = lut ? size : SZ_4K;

	if (size_align)
		*size_align = lut ? size : SZ_4K;

	if (size_max)
		*size_max = size;

	return 0;
}

static void switchtec_ntb_mw_clr_direct(struct switchtec_ntb *sndev, int idx)
{
	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
	int bar = sndev->peer_direct_mw_to_bar[idx];
	u32 ctl_val;

	ctl_val = ioread32(&ctl->bar_entry[bar].ctl);
	ctl_val &= ~NTB_CTRL_BAR_DIR_WIN_EN;
	iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
	iowrite32(0, &ctl->bar_entry[bar].win_size);
	iowrite32(0, &ctl->bar_ext_entry[bar].win_size);
	iowrite64(sndev->self_partition, &ctl->bar_entry[bar].xlate_addr);
}

static void switchtec_ntb_mw_clr_lut(struct switchtec_ntb *sndev, int idx)
{
	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;

	iowrite64(0, &ctl->lut_entry[peer_lut_index(sndev, idx)]);
}

static void switchtec_ntb_mw_set_direct(struct switchtec_ntb *sndev, int idx,
					dma_addr_t addr, resource_size_t size)
{
	int xlate_pos = ilog2(size);
	int bar = sndev->peer_direct_mw_to_bar[idx];
	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
	u32 ctl_val;

	ctl_val = ioread32(&ctl->bar_entry[bar].ctl);
	ctl_val |= NTB_CTRL_BAR_DIR_WIN_EN;

	iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
	iowrite32(xlate_pos | (lower_32_bits(size) & 0xFFFFF000),
		  &ctl->bar_entry[bar].win_size);
	iowrite32(upper_32_bits(size), &ctl->bar_ext_entry[bar].win_size);
	iowrite64(sndev->self_partition | addr,
		  &ctl->bar_entry[bar].xlate_addr);
}

static void switchtec_ntb_mw_set_lut(struct switchtec_ntb *sndev, int idx,
				     dma_addr_t addr, resource_size_t size)
{
	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;

	iowrite64((NTB_CTRL_LUT_EN | (sndev->self_partition << 1) | addr),
		  &ctl->lut_entry[peer_lut_index(sndev, idx)]);
}

static int switchtec_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int widx,
				      dma_addr_t addr, resource_size_t size)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);
	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_peer_ctrl;
	int xlate_pos = ilog2(size);
	int nr_direct_mw = sndev->peer_nr_direct_mw;
	int rc;

	if (pidx != NTB_DEF_PEER_IDX)
		return -EINVAL;

	dev_dbg(&sndev->stdev->dev, "MW %d: part %d addr %pad size %pap\n",
		widx, pidx, &addr, &size);

	if (widx >= switchtec_ntb_mw_count(ntb, pidx))
		return -EINVAL;

	if (xlate_pos < 12)
		return -EINVAL;

	if (!IS_ALIGNED(addr, BIT_ULL(xlate_pos))) {
		/*
		 * In certain circumstances we can get a buffer that is
		 * not aligned to its size. (Most of the time
		 * dma_alloc_coherent ensures this). This can happen when
		 * using large buffers allocated by the CMA
		 * (see CMA_CONFIG_ALIGNMENT)
		 */
		dev_err(&sndev->stdev->dev,
			"ERROR: Memory window address is not aligned to it's size!\n");
		return -EINVAL;
	}

	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
				   NTB_CTRL_PART_STATUS_LOCKED);
	if (rc)
		return rc;

	if (addr == 0 || size == 0) {
		if (widx < nr_direct_mw)
			switchtec_ntb_mw_clr_direct(sndev, widx);
		else
			switchtec_ntb_mw_clr_lut(sndev, widx);
	} else {
		if (widx < nr_direct_mw)
			switchtec_ntb_mw_set_direct(sndev, widx, addr, size);
		else
			switchtec_ntb_mw_set_lut(sndev, widx, addr, size);
	}

	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
				   NTB_CTRL_PART_STATUS_NORMAL);

	if (rc == -EIO) {
		dev_err(&sndev->stdev->dev,
			"Hardware reported an error configuring mw %d: %08x\n",
			widx, ioread32(&ctl->bar_error));

		if (widx < nr_direct_mw)
			switchtec_ntb_mw_clr_direct(sndev, widx);
		else
			switchtec_ntb_mw_clr_lut(sndev, widx);

		switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
				      NTB_CTRL_PART_STATUS_NORMAL);
	}

	return rc;
}

static int switchtec_ntb_peer_mw_count(struct ntb_dev *ntb)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);
	int nr_lut_mw = sndev->nr_lut_mw - sndev->nr_rsvd_luts;

	return sndev->nr_direct_mw + (use_lut_mws ? nr_lut_mw : 0);
}

static int switchtec_ntb_direct_get_addr(struct switchtec_ntb *sndev,
					 int idx, phys_addr_t *base,
					 resource_size_t *size)
{
	int bar = sndev->direct_mw_to_bar[idx];
	size_t offset = 0;

	if (bar < 0)
		return -EINVAL;

	if (idx == 0) {
		/*
		 * This is the direct BAR shared with the LUTs
		 * which means the actual window will be offset
		 * by the size of all the LUT entries.
		 */

		offset = LUT_SIZE * sndev->nr_lut_mw;
	}

	if (base)
		*base = pci_resource_start(sndev->ntb.pdev, bar) + offset;

	if (size) {
		*size = pci_resource_len(sndev->ntb.pdev, bar) - offset;
		if (offset && *size > offset)
			*size = offset;

		if (*size > max_mw_size)
			*size = max_mw_size;
	}

	return 0;
}

static int switchtec_ntb_lut_get_addr(struct switchtec_ntb *sndev,
				      int idx, phys_addr_t *base,
				      resource_size_t *size)
{
	int bar = sndev->direct_mw_to_bar[0];
	int offset;

	offset = LUT_SIZE * lut_index(sndev, idx);

	if (base)
		*base = pci_resource_start(sndev->ntb.pdev, bar) + offset;

	if (size)
		*size = LUT_SIZE;

	return 0;
}

static int switchtec_ntb_peer_mw_get_addr(struct ntb_dev *ntb, int idx,
					  phys_addr_t *base,
					  resource_size_t *size)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	if (idx < sndev->nr_direct_mw)
		return switchtec_ntb_direct_get_addr(sndev, idx, base, size);
	else if (idx < switchtec_ntb_peer_mw_count(ntb))
		return switchtec_ntb_lut_get_addr(sndev, idx, base, size);
	else
		return -EINVAL;
}

static void switchtec_ntb_part_link_speed(struct switchtec_ntb *sndev,
					  int partition,
					  enum ntb_speed *speed,
					  enum ntb_width *width)
{
	struct switchtec_dev *stdev = sndev->stdev;

	u32 pff = ioread32(&stdev->mmio_part_cfg[partition].vep_pff_inst_id);
	u32 linksta = ioread32(&stdev->mmio_pff_csr[pff].pci_cap_region[13]);

	if (speed)
		*speed = (linksta >> 16) & 0xF;

	if (width)
		*width = (linksta >> 20) & 0x3F;
}

static void switchtec_ntb_set_link_speed(struct switchtec_ntb *sndev)
{
	enum ntb_speed self_speed, peer_speed;
	enum ntb_width self_width, peer_width;

	if (!sndev->link_is_up) {
		sndev->link_speed = NTB_SPEED_NONE;
		sndev->link_width = NTB_WIDTH_NONE;
		return;
	}

	switchtec_ntb_part_link_speed(sndev, sndev->self_partition,
				      &self_speed, &self_width);
	switchtec_ntb_part_link_speed(sndev, sndev->peer_partition,
				      &peer_speed, &peer_width);

	sndev->link_speed = min(self_speed, peer_speed);
	sndev->link_width = min(self_width, peer_width);
}

static int crosslink_is_enabled(struct switchtec_ntb *sndev)
{
	struct ntb_info_regs __iomem *inf = sndev->mmio_ntb;

	return ioread8(&inf->ntp_info[sndev->peer_partition].xlink_enabled);
}

static void crosslink_init_dbmsgs(struct switchtec_ntb *sndev)
{
	int i;
	u32 msg_map = 0;

	if (!crosslink_is_enabled(sndev))
		return;

	for (i = 0; i < ARRAY_SIZE(sndev->mmio_peer_dbmsg->imsg); i++) {
		int m = i | sndev->self_partition << 2;

		msg_map |= m << i * 8;
	}

	iowrite32(msg_map, &sndev->mmio_peer_dbmsg->msg_map);
	iowrite64(sndev->db_valid_mask << sndev->db_peer_shift,
		  &sndev->mmio_peer_dbmsg->odb_mask);
}

enum switchtec_msg {
	LINK_MESSAGE = 0,
	MSG_LINK_UP = 1,
	MSG_LINK_DOWN = 2,
	MSG_CHECK_LINK = 3,
	MSG_LINK_FORCE_DOWN = 4,
};

static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev);

static void switchtec_ntb_link_status_update(struct switchtec_ntb *sndev)
{
	int link_sta;
	int old = sndev->link_is_up;

	link_sta = sndev->self_shared->link_sta;
	if (link_sta) {
		u64 peer = ioread64(&sndev->peer_shared->magic);

		if ((peer & 0xFFFFFFFF) == SWITCHTEC_NTB_MAGIC)
			link_sta = peer >> 32;
		else
			link_sta = 0;
	}

	sndev->link_is_up = link_sta;
	switchtec_ntb_set_link_speed(sndev);

	if (link_sta != old) {
		switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_CHECK_LINK);
		ntb_link_event(&sndev->ntb);
		dev_info(&sndev->stdev->dev, "ntb link %s\n",
			 link_sta ? "up" : "down");

		if (link_sta)
			crosslink_init_dbmsgs(sndev);
	}
}

static void check_link_status_work(struct work_struct *work)
{
	struct switchtec_ntb *sndev;

	sndev = container_of(work, struct switchtec_ntb,
			     check_link_status_work);

	if (sndev->link_force_down) {
		sndev->link_force_down = false;
		switchtec_ntb_reinit_peer(sndev);

		if (sndev->link_is_up) {
			sndev->link_is_up = 0;
			ntb_link_event(&sndev->ntb);
			dev_info(&sndev->stdev->dev, "ntb link forced down\n");
		}

		return;
	}

	switchtec_ntb_link_status_update(sndev);
}

static void switchtec_ntb_check_link(struct switchtec_ntb *sndev,
				      enum switchtec_msg msg)
{
	if (msg == MSG_LINK_FORCE_DOWN)
		sndev->link_force_down = true;

	schedule_work(&sndev->check_link_status_work);
}

static void switchtec_ntb_link_notification(struct switchtec_dev *stdev)
{
	struct switchtec_ntb *sndev = stdev->sndev;

	switchtec_ntb_check_link(sndev, MSG_CHECK_LINK);
}

static u64 switchtec_ntb_link_is_up(struct ntb_dev *ntb,
				    enum ntb_speed *speed,
				    enum ntb_width *width)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	if (speed)
		*speed = sndev->link_speed;
	if (width)
		*width = sndev->link_width;

	return sndev->link_is_up;
}

static int switchtec_ntb_link_enable(struct ntb_dev *ntb,
				     enum ntb_speed max_speed,
				     enum ntb_width max_width)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	dev_dbg(&sndev->stdev->dev, "enabling link\n");

	sndev->self_shared->link_sta = 1;
	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_UP);

	switchtec_ntb_link_status_update(sndev);

	return 0;
}

static int switchtec_ntb_link_disable(struct ntb_dev *ntb)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	dev_dbg(&sndev->stdev->dev, "disabling link\n");

	sndev->self_shared->link_sta = 0;
	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_DOWN);

	switchtec_ntb_link_status_update(sndev);

	return 0;
}

static u64 switchtec_ntb_db_valid_mask(struct ntb_dev *ntb)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	return sndev->db_valid_mask;
}

static int switchtec_ntb_db_vector_count(struct ntb_dev *ntb)
{
	return 1;
}

static u64 switchtec_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	if (db_vector < 0 || db_vector > 1)
		return 0;

	return sndev->db_valid_mask;
}

static u64 switchtec_ntb_db_read(struct ntb_dev *ntb)
{
	u64 ret;
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	ret = ioread64(&sndev->mmio_self_dbmsg->idb) >> sndev->db_shift;

	return ret & sndev->db_valid_mask;
}

static int switchtec_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	iowrite64(db_bits << sndev->db_shift, &sndev->mmio_self_dbmsg->idb);

	return 0;
}

static int switchtec_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
{
	unsigned long irqflags;
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	if (db_bits & ~sndev->db_valid_mask)
		return -EINVAL;

	spin_lock_irqsave(&sndev->db_mask_lock, irqflags);

	sndev->db_mask |= db_bits << sndev->db_shift;
	iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask);

	spin_unlock_irqrestore(&sndev->db_mask_lock, irqflags);

	return 0;
}

static int switchtec_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
{
	unsigned long irqflags;
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	if (db_bits & ~sndev->db_valid_mask)
		return -EINVAL;

	spin_lock_irqsave(&sndev->db_mask_lock, irqflags);

	sndev->db_mask &= ~(db_bits << sndev->db_shift);
	iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask);

	spin_unlock_irqrestore(&sndev->db_mask_lock, irqflags);

	return 0;
}

static u64 switchtec_ntb_db_read_mask(struct ntb_dev *ntb)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	return (sndev->db_mask >> sndev->db_shift) & sndev->db_valid_mask;
}

static int switchtec_ntb_peer_db_addr(struct ntb_dev *ntb,
				      phys_addr_t *db_addr,
				      resource_size_t *db_size,
				      u64 *db_data,
				      int db_bit)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);
	unsigned long offset;

	if (unlikely(db_bit >= BITS_PER_LONG_LONG))
		return -EINVAL;

	offset = (unsigned long)sndev->mmio_peer_dbmsg->odb -
		(unsigned long)sndev->stdev->mmio;

	offset += sndev->db_shift / 8;

	if (db_addr)
		*db_addr = pci_resource_start(ntb->pdev, 0) + offset;
	if (db_size)
		*db_size = sizeof(u32);
	if (db_data)
		*db_data = BIT_ULL(db_bit) << sndev->db_peer_shift;

	return 0;
}

static int switchtec_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	iowrite64(db_bits << sndev->db_peer_shift,
		  &sndev->mmio_peer_dbmsg->odb);

	return 0;
}

static int switchtec_ntb_spad_count(struct ntb_dev *ntb)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	return ARRAY_SIZE(sndev->self_shared->spad);
}

static u32 switchtec_ntb_spad_read(struct ntb_dev *ntb, int idx)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	if (idx < 0 || idx >= ARRAY_SIZE(sndev->self_shared->spad))
		return 0;

	if (!sndev->self_shared)
		return 0;

	return sndev->self_shared->spad[idx];
}

static int switchtec_ntb_spad_write(struct ntb_dev *ntb, int idx, u32 val)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	if (idx < 0 || idx >= ARRAY_SIZE(sndev->self_shared->spad))
		return -EINVAL;

	if (!sndev->self_shared)
		return -EIO;

	sndev->self_shared->spad[idx] = val;

	return 0;
}

static u32 switchtec_ntb_peer_spad_read(struct ntb_dev *ntb, int pidx,
					int sidx)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	if (pidx != NTB_DEF_PEER_IDX)
		return -EINVAL;

	if (sidx < 0 || sidx >= ARRAY_SIZE(sndev->peer_shared->spad))
		return 0;

	if (!sndev->peer_shared)
		return 0;

	return ioread32(&sndev->peer_shared->spad[sidx]);
}

static int switchtec_ntb_peer_spad_write(struct ntb_dev *ntb, int pidx,
					 int sidx, u32 val)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);

	if (pidx != NTB_DEF_PEER_IDX)
		return -EINVAL;

	if (sidx < 0 || sidx >= ARRAY_SIZE(sndev->peer_shared->spad))
		return -EINVAL;

	if (!sndev->peer_shared)
		return -EIO;

	iowrite32(val, &sndev->peer_shared->spad[sidx]);

	return 0;
}

static int switchtec_ntb_peer_spad_addr(struct ntb_dev *ntb, int pidx,
					int sidx, phys_addr_t *spad_addr)
{
	struct switchtec_ntb *sndev = ntb_sndev(ntb);
	unsigned long offset;

	if (pidx != NTB_DEF_PEER_IDX)
		return -EINVAL;

	offset = (unsigned long)&sndev->peer_shared->spad[sidx] -
		(unsigned long)sndev->stdev->mmio;

	if (spad_addr)
		*spad_addr = pci_resource_start(ntb->pdev, 0) + offset;

	return 0;
}

static const struct ntb_dev_ops switchtec_ntb_ops = {
	.mw_count		= switchtec_ntb_mw_count,
	.mw_get_align		= switchtec_ntb_mw_get_align,
	.mw_set_trans		= switchtec_ntb_mw_set_trans,
	.peer_mw_count		= switchtec_ntb_peer_mw_count,
	.peer_mw_get_addr	= switchtec_ntb_peer_mw_get_addr,
	.link_is_up		= switchtec_ntb_link_is_up,
	.link_enable		= switchtec_ntb_link_enable,
	.link_disable		= switchtec_ntb_link_disable,
	.db_valid_mask		= switchtec_ntb_db_valid_mask,
	.db_vector_count	= switchtec_ntb_db_vector_count,
	.db_vector_mask		= switchtec_ntb_db_vector_mask,
	.db_read		= switchtec_ntb_db_read,
	.db_clear		= switchtec_ntb_db_clear,
	.db_set_mask		= switchtec_ntb_db_set_mask,
	.db_clear_mask		= switchtec_ntb_db_clear_mask,
	.db_read_mask		= switchtec_ntb_db_read_mask,
	.peer_db_addr		= switchtec_ntb_peer_db_addr,
	.peer_db_set		= switchtec_ntb_peer_db_set,
	.spad_count		= switchtec_ntb_spad_count,
	.spad_read		= switchtec_ntb_spad_read,
	.spad_write		= switchtec_ntb_spad_write,
	.peer_spad_read		= switchtec_ntb_peer_spad_read,
	.peer_spad_write	= switchtec_ntb_peer_spad_write,
	.peer_spad_addr		= switchtec_ntb_peer_spad_addr,
};

static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)
{
	u64 tpart_vec;
	int self;
	u64 part_map;
	int bit;

	sndev->ntb.pdev = sndev->stdev->pdev;
	sndev->ntb.topo = NTB_TOPO_SWITCH;
	sndev->ntb.ops = &switchtec_ntb_ops;

	INIT_WORK(&sndev->check_link_status_work, check_link_status_work);
	sndev->link_force_down = false;

	sndev->self_partition = sndev->stdev->partition;

	sndev->mmio_ntb = sndev->stdev->mmio_ntb;

	self = sndev->self_partition;
	tpart_vec = ioread32(&sndev->mmio_ntb->ntp_info[self].target_part_high);
	tpart_vec <<= 32;
	tpart_vec |= ioread32(&sndev->mmio_ntb->ntp_info[self].target_part_low);

	part_map = ioread64(&sndev->mmio_ntb->ep_map);
	part_map &= ~(1 << sndev->self_partition);

	if (!ffs(tpart_vec)) {
		if (sndev->stdev->partition_count != 2) {
			dev_err(&sndev->stdev->dev,
				"ntb target partition not defined\n");
			return -ENODEV;
		}

		bit = ffs(part_map);
		if (!bit) {
			dev_err(&sndev->stdev->dev,
				"peer partition is not NT partition\n");
			return -ENODEV;
		}

		sndev->peer_partition = bit - 1;
	} else {
		if (ffs(tpart_vec) != fls(tpart_vec)) {
			dev_err(&sndev->stdev->dev,
				"ntb driver only supports 1 pair of 1-1 ntb mapping\n");
			return -ENODEV;
		}

		sndev->peer_partition = ffs(tpart_vec) - 1;
		if (!(part_map & (1ULL << sndev->peer_partition))) {
			dev_err(&sndev->stdev->dev,
				"ntb target partition is not NT partition\n");
			return -ENODEV;
		}
	}

	dev_dbg(&sndev->stdev->dev, "Partition ID %d of %d\n",
		sndev->self_partition, sndev->stdev->partition_count);

	sndev->mmio_ctrl = (void * __iomem)sndev->mmio_ntb +
		SWITCHTEC_NTB_REG_CTRL_OFFSET;
	sndev->mmio_dbmsg = (void * __iomem)sndev->mmio_ntb +
		SWITCHTEC_NTB_REG_DBMSG_OFFSET;

	sndev->mmio_self_ctrl = &sndev->mmio_ctrl[sndev->self_partition];
	sndev->mmio_peer_ctrl = &sndev->mmio_ctrl[sndev->peer_partition];
	sndev->mmio_self_dbmsg = &sndev->mmio_dbmsg[sndev->self_partition];
	sndev->mmio_peer_dbmsg = sndev->mmio_self_dbmsg;

	return 0;
}

static int config_rsvd_lut_win(struct switchtec_ntb *sndev,
			       struct ntb_ctrl_regs __iomem *ctl,
			       int lut_idx, int partition, u64 addr)
{
	int peer_bar = sndev->peer_direct_mw_to_bar[0];
	u32 ctl_val;
	int rc;

	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
				   NTB_CTRL_PART_STATUS_LOCKED);
	if (rc)
		return rc;

	ctl_val = ioread32(&ctl->bar_entry[peer_bar].ctl);
	ctl_val &= 0xFF;
	ctl_val |= NTB_CTRL_BAR_LUT_WIN_EN;
	ctl_val |= ilog2(LUT_SIZE) << 8;
	ctl_val |= (sndev->nr_lut_mw - 1) << 14;
	iowrite32(ctl_val, &ctl->bar_entry[peer_bar].ctl);

	iowrite64((NTB_CTRL_LUT_EN | (partition << 1) | addr),
		  &ctl->lut_entry[lut_idx]);

	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
				   NTB_CTRL_PART_STATUS_NORMAL);
	if (rc) {
		u32 bar_error, lut_error;

		bar_error = ioread32(&ctl->bar_error);
		lut_error = ioread32(&ctl->lut_error);
		dev_err(&sndev->stdev->dev,
			"Error setting up reserved lut window: %08x / %08x\n",
			bar_error, lut_error);
		return rc;
	}

	return 0;
}

static int config_req_id_table(struct switchtec_ntb *sndev,
			       struct ntb_ctrl_regs __iomem *mmio_ctrl,
			       int *req_ids, int count)
{
	int i, rc = 0;
	u32 error;
	u32 proxy_id;

	if (ioread32(&mmio_ctrl->req_id_table_size) < count) {
		dev_err(&sndev->stdev->dev,
			"Not enough requester IDs available.\n");
		return -EFAULT;
	}

	rc = switchtec_ntb_part_op(sndev, mmio_ctrl,
				   NTB_CTRL_PART_OP_LOCK,
				   NTB_CTRL_PART_STATUS_LOCKED);
	if (rc)
		return rc;

	iowrite32(NTB_PART_CTRL_ID_PROT_DIS,
		  &mmio_ctrl->partition_ctrl);

	for (i = 0; i < count; i++) {
		iowrite32(req_ids[i] << 16 | NTB_CTRL_REQ_ID_EN,
			  &mmio_ctrl->req_id_table[i]);

		proxy_id = ioread32(&mmio_ctrl->req_id_table[i]);
		dev_dbg(&sndev->stdev->dev,
			"Requester ID %02X:%02X.%X -> BB:%02X.%X\n",
			req_ids[i] >> 8, (req_ids[i] >> 3) & 0x1F,
			req_ids[i] & 0x7, (proxy_id >> 4) & 0x1F,
			(proxy_id >> 1) & 0x7);
	}

	rc = switchtec_ntb_part_op(sndev, mmio_ctrl,
				   NTB_CTRL_PART_OP_CFG,
				   NTB_CTRL_PART_STATUS_NORMAL);

	if (rc == -EIO) {
		error = ioread32(&mmio_ctrl->req_id_error);
		dev_err(&sndev->stdev->dev,
			"Error setting up the requester ID table: %08x\n",
			error);
	}

	return 0;
}

static int crosslink_setup_mws(struct switchtec_ntb *sndev, int ntb_lut_idx,
			       u64 *mw_addrs, int mw_count)
{
	int rc, i;
	struct ntb_ctrl_regs __iomem *ctl = sndev->mmio_self_ctrl;
	u64 addr;
	size_t size, offset;
	int bar;
	int xlate_pos;
	u32 ctl_val;

	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_LOCK,
				   NTB_CTRL_PART_STATUS_LOCKED);
	if (rc)
		return rc;

	for (i = 0; i < sndev->nr_lut_mw; i++) {
		if (i == ntb_lut_idx)
			continue;

		addr = mw_addrs[0] + LUT_SIZE * i;

		iowrite64((NTB_CTRL_LUT_EN | (sndev->peer_partition << 1) |
			   addr),
			  &ctl->lut_entry[i]);
	}

	sndev->nr_direct_mw = min_t(int, sndev->nr_direct_mw, mw_count);

	for (i = 0; i < sndev->nr_direct_mw; i++) {
		bar = sndev->direct_mw_to_bar[i];
		offset = (i == 0) ? LUT_SIZE * sndev->nr_lut_mw : 0;
		addr = mw_addrs[i] + offset;
		size = pci_resource_len(sndev->ntb.pdev, bar) - offset;
		xlate_pos = ilog2(size);

		if (offset && size > offset)
			size = offset;

		ctl_val = ioread32(&ctl->bar_entry[bar].ctl);
		ctl_val |= NTB_CTRL_BAR_DIR_WIN_EN;

		iowrite32(ctl_val, &ctl->bar_entry[bar].ctl);
		iowrite32(xlate_pos | (lower_32_bits(size) & 0xFFFFF000),
			  &ctl->bar_entry[bar].win_size);
		iowrite32(upper_32_bits(size), &ctl->bar_ext_entry[bar].win_size);
		iowrite64(sndev->peer_partition | addr,
			  &ctl->bar_entry[bar].xlate_addr);
	}

	rc = switchtec_ntb_part_op(sndev, ctl, NTB_CTRL_PART_OP_CFG,
				   NTB_CTRL_PART_STATUS_NORMAL);
	if (rc) {
		u32 bar_error, lut_error;

		bar_error = ioread32(&ctl->bar_error);
		lut_error = ioread32(&ctl->lut_error);
		dev_err(&sndev->stdev->dev,
			"Error setting up cross link windows: %08x / %08x\n",
			bar_error, lut_error);
		return rc;
	}

	return 0;
}

static int crosslink_setup_req_ids(struct switchtec_ntb *sndev,
	struct ntb_ctrl_regs __iomem *mmio_ctrl)
{
	int req_ids[16];
	int i;
	u32 proxy_id;

	for (i = 0; i < ARRAY_SIZE(req_ids); i++) {
		proxy_id = ioread32(&sndev->mmio_self_ctrl->req_id_table[i]);

		if (!(proxy_id & NTB_CTRL_REQ_ID_EN))
			break;

		req_ids[i] = ((proxy_id >> 1) & 0xFF);
	}

	return config_req_id_table(sndev, mmio_ctrl, req_ids, i);
}

/*
 * In crosslink configuration there is a virtual partition in the
 * middle of the two switches. The BARs in this partition have to be
 * enumerated and assigned addresses.
 */
static int crosslink_enum_partition(struct switchtec_ntb *sndev,
				    u64 *bar_addrs)
{
	struct part_cfg_regs __iomem *part_cfg =
		&sndev->stdev->mmio_part_cfg_all[sndev->peer_partition];
	u32 pff = ioread32(&part_cfg->vep_pff_inst_id);
	struct pff_csr_regs __iomem *mmio_pff =
		&sndev->stdev->mmio_pff_csr[pff];
	const u64 bar_space = 0x1000000000LL;
	u64 bar_addr;
	int bar_cnt = 0;
	int i;

	iowrite16(0x6, &mmio_pff->pcicmd);

	for (i = 0; i < ARRAY_SIZE(mmio_pff->pci_bar64); i++) {
		iowrite64(bar_space * i, &mmio_pff->pci_bar64[i]);
		bar_addr = ioread64(&mmio_pff->pci_bar64[i]);
		bar_addr &= ~0xf;

		dev_dbg(&sndev->stdev->dev,
			"Crosslink BAR%d addr: %llx\n",
			i*2, bar_addr);

		if (bar_addr != bar_space * i)
			continue;

		bar_addrs[bar_cnt++] = bar_addr;
	}

	return bar_cnt;
}

static int switchtec_ntb_init_crosslink(struct switchtec_ntb *sndev)
{
	int rc;
	int bar = sndev->direct_mw_to_bar[0];
	const int ntb_lut_idx = 1;
	u64 bar_addrs[6];
	u64 addr;
	int offset;
	int bar_cnt;

	if (!crosslink_is_enabled(sndev))
		return 0;

	dev_info(&sndev->stdev->dev, "Using crosslink configuration\n");
	sndev->ntb.topo = NTB_TOPO_CROSSLINK;

	bar_cnt = crosslink_enum_partition(sndev, bar_addrs);
	if (bar_cnt < sndev->nr_direct_mw + 1) {
		dev_err(&sndev->stdev->dev,
			"Error enumerating crosslink partition\n");
		return -EINVAL;
	}

	addr = (bar_addrs[0] + SWITCHTEC_GAS_NTB_OFFSET +
		SWITCHTEC_NTB_REG_DBMSG_OFFSET +
		sizeof(struct ntb_dbmsg_regs) * sndev->peer_partition);

	offset = addr & (LUT_SIZE - 1);
	addr -= offset;

	rc = config_rsvd_lut_win(sndev, sndev->mmio_self_ctrl, ntb_lut_idx,
				 sndev->peer_partition, addr);
	if (rc)
		return rc;

	rc = crosslink_setup_mws(sndev, ntb_lut_idx, &bar_addrs[1],
				 bar_cnt - 1);
	if (rc)
		return rc;

	rc = crosslink_setup_req_ids(sndev, sndev->mmio_peer_ctrl);
	if (rc)
		return rc;

	sndev->mmio_xlink_win = pci_iomap_range(sndev->stdev->pdev, bar,
						LUT_SIZE, LUT_SIZE);
	if (!sndev->mmio_xlink_win) {
		rc = -ENOMEM;
		return rc;
	}

	sndev->mmio_peer_dbmsg = sndev->mmio_xlink_win + offset;
	sndev->nr_rsvd_luts++;

	crosslink_init_dbmsgs(sndev);

	return 0;
}

static void switchtec_ntb_deinit_crosslink(struct switchtec_ntb *sndev)
{
	if (sndev->mmio_xlink_win)
		pci_iounmap(sndev->stdev->pdev, sndev->mmio_xlink_win);
}

static int map_bars(int *map, struct ntb_ctrl_regs __iomem *ctrl)
{
	int i;
	int cnt = 0;

	for (i = 0; i < ARRAY_SIZE(ctrl->bar_entry); i++) {
		u32 r = ioread32(&ctrl->bar_entry[i].ctl);

		if (r & NTB_CTRL_BAR_VALID)
			map[cnt++] = i;
	}

	return cnt;
}

static void switchtec_ntb_init_mw(struct switchtec_ntb *sndev)
{
	sndev->nr_direct_mw = map_bars(sndev->direct_mw_to_bar,
				       sndev->mmio_self_ctrl);

	sndev->nr_lut_mw = ioread16(&sndev->mmio_self_ctrl->lut_table_entries);
	sndev->nr_lut_mw = rounddown_pow_of_two(sndev->nr_lut_mw);

	dev_dbg(&sndev->stdev->dev, "MWs: %d direct, %d lut\n",
		sndev->nr_direct_mw, sndev->nr_lut_mw);

	sndev->peer_nr_direct_mw = map_bars(sndev->peer_direct_mw_to_bar,
					    sndev->mmio_peer_ctrl);

	sndev->peer_nr_lut_mw =
		ioread16(&sndev->mmio_peer_ctrl->lut_table_entries);
	sndev->peer_nr_lut_mw = rounddown_pow_of_two(sndev->peer_nr_lut_mw);

	dev_dbg(&sndev->stdev->dev, "Peer MWs: %d direct, %d lut\n",
		sndev->peer_nr_direct_mw, sndev->peer_nr_lut_mw);

}

/*
 * There are 64 doorbells in the switch hardware but this is
 * shared among all partitions. So we must split them in half
 * (32 for each partition). However, the message interrupts are
 * also shared with the top 4 doorbells so we just limit this to
 * 28 doorbells per partition.
 *
 * In crosslink mode, each side has it's own dbmsg register so
 * they can each use all 60 of the available doorbells.
 */
static void switchtec_ntb_init_db(struct switchtec_ntb *sndev)
{
	sndev->db_mask = 0x0FFFFFFFFFFFFFFFULL;

	if (sndev->mmio_peer_dbmsg != sndev->mmio_self_dbmsg) {
		sndev->db_shift = 0;
		sndev->db_peer_shift = 0;
		sndev->db_valid_mask = sndev->db_mask;
	} else if (sndev->self_partition < sndev->peer_partition) {
		sndev->db_shift = 0;
		sndev->db_peer_shift = 32;
		sndev->db_valid_mask = 0x0FFFFFFF;
	} else {
		sndev->db_shift = 32;
		sndev->db_peer_shift = 0;
		sndev->db_valid_mask = 0x0FFFFFFF;
	}

	iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask);
	iowrite64(sndev->db_valid_mask << sndev->db_peer_shift,
		  &sndev->mmio_peer_dbmsg->odb_mask);

	dev_dbg(&sndev->stdev->dev, "dbs: shift %d/%d, mask %016llx\n",
		sndev->db_shift, sndev->db_peer_shift, sndev->db_valid_mask);
}

static void switchtec_ntb_init_msgs(struct switchtec_ntb *sndev)
{
	int i;
	u32 msg_map = 0;

	for (i = 0; i < ARRAY_SIZE(sndev->mmio_self_dbmsg->imsg); i++) {
		int m = i | sndev->peer_partition << 2;

		msg_map |= m << i * 8;
	}

	iowrite32(msg_map, &sndev->mmio_self_dbmsg->msg_map);

	for (i = 0; i < ARRAY_SIZE(sndev->mmio_self_dbmsg->imsg); i++)
		iowrite64(NTB_DBMSG_IMSG_STATUS | NTB_DBMSG_IMSG_MASK,
			  &sndev->mmio_self_dbmsg->imsg[i]);
}

static int
switchtec_ntb_init_req_id_table(struct switchtec_ntb *sndev)
{
	int req_ids[2];

	/*
	 * Root Complex Requester ID (which is 0:00.0)
	 */
	req_ids[0] = 0;

	/*
	 * Host Bridge Requester ID (as read from the mmap address)
	 */
	req_ids[1] = ioread16(&sndev->mmio_ntb->requester_id);

	return config_req_id_table(sndev, sndev->mmio_self_ctrl, req_ids,
				   ARRAY_SIZE(req_ids));
}

static void switchtec_ntb_init_shared(struct switchtec_ntb *sndev)
{
	int i;

	memset(sndev->self_shared, 0, LUT_SIZE);
	sndev->self_shared->magic = SWITCHTEC_NTB_MAGIC;
	sndev->self_shared->partition_id = sndev->stdev->partition;

	for (i = 0; i < sndev->nr_direct_mw; i++) {
		int bar = sndev->direct_mw_to_bar[i];
		resource_size_t sz = pci_resource_len(sndev->stdev->pdev, bar);

		if (i == 0)
			sz = min_t(resource_size_t, sz,
				   LUT_SIZE * sndev->nr_lut_mw);

		sndev->self_shared->mw_sizes[i] = sz;
	}

	for (i = 0; i < sndev->nr_lut_mw; i++) {
		int idx = sndev->nr_direct_mw + i;

		sndev->self_shared->mw_sizes[idx] = LUT_SIZE;
	}
}

static int switchtec_ntb_init_shared_mw(struct switchtec_ntb *sndev)
{
	int self_bar = sndev->direct_mw_to_bar[0];
	int rc;

	sndev->nr_rsvd_luts++;
	sndev->self_shared = dma_alloc_coherent(&sndev->stdev->pdev->dev,
						LUT_SIZE,
						&sndev->self_shared_dma,
						GFP_KERNEL);
	if (!sndev->self_shared) {
		dev_err(&sndev->stdev->dev,
			"unable to allocate memory for shared mw\n");
		return -ENOMEM;
	}

	switchtec_ntb_init_shared(sndev);

	rc = config_rsvd_lut_win(sndev, sndev->mmio_peer_ctrl, 0,
				 sndev->self_partition,
				 sndev->self_shared_dma);
	if (rc)
		goto unalloc_and_exit;

	sndev->peer_shared = pci_iomap(sndev->stdev->pdev, self_bar, LUT_SIZE);
	if (!sndev->peer_shared) {
		rc = -ENOMEM;
		goto unalloc_and_exit;
	}

	dev_dbg(&sndev->stdev->dev, "Shared MW Ready\n");
	return 0;

unalloc_and_exit:
	dma_free_coherent(&sndev->stdev->pdev->dev, LUT_SIZE,
			  sndev->self_shared, sndev->self_shared_dma);

	return rc;
}

static void switchtec_ntb_deinit_shared_mw(struct switchtec_ntb *sndev)
{
	if (sndev->peer_shared)
		pci_iounmap(sndev->stdev->pdev, sndev->peer_shared);

	if (sndev->self_shared)
		dma_free_coherent(&sndev->stdev->pdev->dev, LUT_SIZE,
				  sndev->self_shared,
				  sndev->self_shared_dma);
	sndev->nr_rsvd_luts--;
}

static irqreturn_t switchtec_ntb_doorbell_isr(int irq, void *dev)
{
	struct switchtec_ntb *sndev = dev;

	dev_dbg(&sndev->stdev->dev, "doorbell\n");

	ntb_db_event(&sndev->ntb, 0);

	return IRQ_HANDLED;
}

static irqreturn_t switchtec_ntb_message_isr(int irq, void *dev)
{
	int i;
	struct switchtec_ntb *sndev = dev;

	for (i = 0; i < ARRAY_SIZE(sndev->mmio_self_dbmsg->imsg); i++) {
		u64 msg = ioread64(&sndev->mmio_self_dbmsg->imsg[i]);

		if (msg & NTB_DBMSG_IMSG_STATUS) {
			dev_dbg(&sndev->stdev->dev, "message: %d %08x\n",
				i, (u32)msg);
			iowrite8(1, &sndev->mmio_self_dbmsg->imsg[i].status);

			if (i == LINK_MESSAGE)
				switchtec_ntb_check_link(sndev, msg);
		}
	}

	return IRQ_HANDLED;
}

static int switchtec_ntb_init_db_msg_irq(struct switchtec_ntb *sndev)
{
	int i;
	int rc;
	int doorbell_irq = 0;
	int message_irq = 0;
	int event_irq;
	int idb_vecs = sizeof(sndev->mmio_self_dbmsg->idb_vec_map);

	event_irq = ioread32(&sndev->stdev->mmio_part_cfg->vep_vector_number);

	while (doorbell_irq == event_irq)
		doorbell_irq++;
	while (message_irq == doorbell_irq ||
	       message_irq == event_irq)
		message_irq++;

	dev_dbg(&sndev->stdev->dev, "irqs - event: %d, db: %d, msgs: %d\n",
		event_irq, doorbell_irq, message_irq);

	for (i = 0; i < idb_vecs - 4; i++)
		iowrite8(doorbell_irq,
			 &sndev->mmio_self_dbmsg->idb_vec_map[i]);

	for (; i < idb_vecs; i++)
		iowrite8(message_irq,
			 &sndev->mmio_self_dbmsg->idb_vec_map[i]);

	sndev->doorbell_irq = pci_irq_vector(sndev->stdev->pdev, doorbell_irq);
	sndev->message_irq = pci_irq_vector(sndev->stdev->pdev, message_irq);

	rc = request_irq(sndev->doorbell_irq,
			 switchtec_ntb_doorbell_isr, 0,
			 "switchtec_ntb_doorbell", sndev);
	if (rc)
		return rc;

	rc = request_irq(sndev->message_irq,
			 switchtec_ntb_message_isr, 0,
			 "switchtec_ntb_message", sndev);
	if (rc) {
		free_irq(sndev->doorbell_irq, sndev);
		return rc;
	}

	return 0;
}

static void switchtec_ntb_deinit_db_msg_irq(struct switchtec_ntb *sndev)
{
	free_irq(sndev->doorbell_irq, sndev);
	free_irq(sndev->message_irq, sndev);
}

static int switchtec_ntb_reinit_peer(struct switchtec_ntb *sndev)
{
	int rc;

	if (crosslink_is_enabled(sndev))
		return 0;

	dev_info(&sndev->stdev->dev, "reinitialize shared memory window\n");
	rc = config_rsvd_lut_win(sndev, sndev->mmio_peer_ctrl, 0,
				 sndev->self_partition,
				 sndev->self_shared_dma);
	return rc;
}

static int switchtec_ntb_add(struct device *dev,
			     struct class_interface *class_intf)
{
	struct switchtec_dev *stdev = to_stdev(dev);
	struct switchtec_ntb *sndev;
	int rc;

	stdev->sndev = NULL;

	if (stdev->pdev->class != (PCI_CLASS_BRIDGE_OTHER << 8))
		return -ENODEV;

	sndev = kzalloc_node(sizeof(*sndev), GFP_KERNEL, dev_to_node(dev));
	if (!sndev)
		return -ENOMEM;

	sndev->stdev = stdev;
	rc = switchtec_ntb_init_sndev(sndev);
	if (rc)
		goto free_and_exit;

	switchtec_ntb_init_mw(sndev);

	rc = switchtec_ntb_init_req_id_table(sndev);
	if (rc)
		goto free_and_exit;

	rc = switchtec_ntb_init_crosslink(sndev);
	if (rc)
		goto free_and_exit;

	switchtec_ntb_init_db(sndev);
	switchtec_ntb_init_msgs(sndev);

	rc = switchtec_ntb_init_shared_mw(sndev);
	if (rc)
		goto deinit_crosslink;

	rc = switchtec_ntb_init_db_msg_irq(sndev);
	if (rc)
		goto deinit_shared_and_exit;

	/*
	 * If this host crashed, the other host may think the link is
	 * still up. Tell them to force it down (it will go back up
	 * once we register the ntb device).
	 */
	switchtec_ntb_send_msg(sndev, LINK_MESSAGE, MSG_LINK_FORCE_DOWN);

	rc = ntb_register_device(&sndev->ntb);
	if (rc)
		goto deinit_and_exit;

	stdev->sndev = sndev;
	stdev->link_notifier = switchtec_ntb_link_notification;
	dev_info(dev, "NTB device registered\n");

	return 0;

deinit_and_exit:
	switchtec_ntb_deinit_db_msg_irq(sndev);
deinit_shared_and_exit:
	switchtec_ntb_deinit_shared_mw(sndev);
deinit_crosslink:
	switchtec_ntb_deinit_crosslink(sndev);
free_and_exit:
	kfree(sndev);
	dev_err(dev, "failed to register ntb device: %d\n", rc);
	return rc;
}

static void switchtec_ntb_remove(struct device *dev,
				 struct class_interface *class_intf)
{
	struct switchtec_dev *stdev = to_stdev(dev);
	struct switchtec_ntb *sndev = stdev->sndev;

	if (!sndev)
		return;

	stdev->link_notifier = NULL;
	stdev->sndev = NULL;
	ntb_unregister_device(&sndev->ntb);
	switchtec_ntb_deinit_db_msg_irq(sndev);
	switchtec_ntb_deinit_shared_mw(sndev);
	switchtec_ntb_deinit_crosslink(sndev);
	kfree(sndev);
	dev_info(dev, "ntb device unregistered\n");
}

static struct class_interface switchtec_interface  = {
	.add_dev = switchtec_ntb_add,
	.remove_dev = switchtec_ntb_remove,
};

static int __init switchtec_ntb_init(void)
{
	switchtec_interface.class = switchtec_class;
	return class_interface_register(&switchtec_interface);
}
module_init(switchtec_ntb_init);

static void __exit switchtec_ntb_exit(void)
{
	class_interface_unregister(&switchtec_interface);
}
module_exit(switchtec_ntb_exit);