aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/usb/host/xhci-hcd.c
blob: 99911e727e0b7950e4a11dec17bb17f08151e5e4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
/*
 * xHCI host controller driver
 *
 * Copyright (C) 2008 Intel Corp.
 *
 * Author: Sarah Sharp
 * Some code borrowed from the Linux EHCI driver.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/irq.h>
#include <linux/module.h>
#include <linux/moduleparam.h>

#include "xhci.h"

#define DRIVER_AUTHOR "Sarah Sharp"
#define DRIVER_DESC "'eXtensible' Host Controller (xHC) Driver"

/* Some 0.95 hardware can't handle the chain bit on a Link TRB being cleared */
static int link_quirk;
module_param(link_quirk, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(link_quirk, "Don't clear the chain bit on a link TRB");

/* TODO: copied from ehci-hcd.c - can this be refactored? */
/*
 * handshake - spin reading hc until handshake completes or fails
 * @ptr: address of hc register to be read
 * @mask: bits to look at in result of read
 * @done: value of those bits when handshake succeeds
 * @usec: timeout in microseconds
 *
 * Returns negative errno, or zero on success
 *
 * Success happens when the "mask" bits have the specified value (hardware
 * handshake done).  There are two failure modes:  "usec" have passed (major
 * hardware flakeout), or the register reads as all-ones (hardware removed).
 */
static int handshake(struct xhci_hcd *xhci, void __iomem *ptr,
		      u32 mask, u32 done, int usec)
{
	u32	result;

	do {
		result = xhci_readl(xhci, ptr);
		if (result == ~(u32)0)		/* card removed */
			return -ENODEV;
		result &= mask;
		if (result == done)
			return 0;
		udelay(1);
		usec--;
	} while (usec > 0);
	return -ETIMEDOUT;
}

/*
 * Force HC into halt state.
 *
 * Disable any IRQs and clear the run/stop bit.
 * HC will complete any current and actively pipelined transactions, and
 * should halt within 16 microframes of the run/stop bit being cleared.
 * Read HC Halted bit in the status register to see when the HC is finished.
 * XXX: shouldn't we set HC_STATE_HALT here somewhere?
 */
int xhci_halt(struct xhci_hcd *xhci)
{
	u32 halted;
	u32 cmd;
	u32 mask;

	xhci_dbg(xhci, "// Halt the HC\n");
	/* Disable all interrupts from the host controller */
	mask = ~(XHCI_IRQS);
	halted = xhci_readl(xhci, &xhci->op_regs->status) & STS_HALT;
	if (!halted)
		mask &= ~CMD_RUN;

	cmd = xhci_readl(xhci, &xhci->op_regs->command);
	cmd &= mask;
	xhci_writel(xhci, cmd, &xhci->op_regs->command);

	return handshake(xhci, &xhci->op_regs->status,
			STS_HALT, STS_HALT, XHCI_MAX_HALT_USEC);
}

/*
 * Reset a halted HC, and set the internal HC state to HC_STATE_HALT.
 *
 * This resets pipelines, timers, counters, state machines, etc.
 * Transactions will be terminated immediately, and operational registers
 * will be set to their defaults.
 */
int xhci_reset(struct xhci_hcd *xhci)
{
	u32 command;
	u32 state;

	state = xhci_readl(xhci, &xhci->op_regs->status);
	if ((state & STS_HALT) == 0) {
		xhci_warn(xhci, "Host controller not halted, aborting reset.\n");
		return 0;
	}

	xhci_dbg(xhci, "// Reset the HC\n");
	command = xhci_readl(xhci, &xhci->op_regs->command);
	command |= CMD_RESET;
	xhci_writel(xhci, command, &xhci->op_regs->command);
	/* XXX: Why does EHCI set this here?  Shouldn't other code do this? */
	xhci_to_hcd(xhci)->state = HC_STATE_HALT;

	return handshake(xhci, &xhci->op_regs->command, CMD_RESET, 0, 250 * 1000);
}

/*
 * Stop the HC from processing the endpoint queues.
 */
static void xhci_quiesce(struct xhci_hcd *xhci)
{
	/*
	 * Queues are per endpoint, so we need to disable an endpoint or slot.
	 *
	 * To disable a slot, we need to insert a disable slot command on the
	 * command ring and ring the doorbell.  This will also free any internal
	 * resources associated with the slot (which might not be what we want).
	 *
	 * A Release Endpoint command sounds better - doesn't free internal HC
	 * memory, but removes the endpoints from the schedule and releases the
	 * bandwidth, disables the doorbells, and clears the endpoint enable
	 * flag.  Usually used prior to a set interface command.
	 *
	 * TODO: Implement after command ring code is done.
	 */
	BUG_ON(!HC_IS_RUNNING(xhci_to_hcd(xhci)->state));
	xhci_dbg(xhci, "Finished quiescing -- code not written yet\n");
}

#if 0
/* Set up MSI-X table for entry 0 (may claim other entries later) */
static int xhci_setup_msix(struct xhci_hcd *xhci)
{
	int ret;
	struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);

	xhci->msix_count = 0;
	/* XXX: did I do this right?  ixgbe does kcalloc for more than one */
	xhci->msix_entries = kmalloc(sizeof(struct msix_entry), GFP_KERNEL);
	if (!xhci->msix_entries) {
		xhci_err(xhci, "Failed to allocate MSI-X entries\n");
		return -ENOMEM;
	}
	xhci->msix_entries[0].entry = 0;

	ret = pci_enable_msix(pdev, xhci->msix_entries, xhci->msix_count);
	if (ret) {
		xhci_err(xhci, "Failed to enable MSI-X\n");
		goto free_entries;
	}

	/*
	 * Pass the xhci pointer value as the request_irq "cookie".
	 * If more irqs are added, this will need to be unique for each one.
	 */
	ret = request_irq(xhci->msix_entries[0].vector, &xhci_irq, 0,
			"xHCI", xhci_to_hcd(xhci));
	if (ret) {
		xhci_err(xhci, "Failed to allocate MSI-X interrupt\n");
		goto disable_msix;
	}
	xhci_dbg(xhci, "Finished setting up MSI-X\n");
	return 0;

disable_msix:
	pci_disable_msix(pdev);
free_entries:
	kfree(xhci->msix_entries);
	xhci->msix_entries = NULL;
	return ret;
}

/* XXX: code duplication; can xhci_setup_msix call this? */
/* Free any IRQs and disable MSI-X */
static void xhci_cleanup_msix(struct xhci_hcd *xhci)
{
	struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
	if (!xhci->msix_entries)
		return;

	free_irq(xhci->msix_entries[0].vector, xhci);
	pci_disable_msix(pdev);
	kfree(xhci->msix_entries);
	xhci->msix_entries = NULL;
	xhci_dbg(xhci, "Finished cleaning up MSI-X\n");
}
#endif

/*
 * Initialize memory for HCD and xHC (one-time init).
 *
 * Program the PAGESIZE register, initialize the device context array, create
 * device contexts (?), set up a command ring segment (or two?), create event
 * ring (one for now).
 */
int xhci_init(struct usb_hcd *hcd)
{
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
	int retval = 0;

	xhci_dbg(xhci, "xhci_init\n");
	spin_lock_init(&xhci->lock);
	if (link_quirk) {
		xhci_dbg(xhci, "QUIRK: Not clearing Link TRB chain bits.\n");
		xhci->quirks |= XHCI_LINK_TRB_QUIRK;
	} else {
		xhci_dbg(xhci, "xHCI doesn't need link TRB QUIRK\n");
	}
	retval = xhci_mem_init(xhci, GFP_KERNEL);
	xhci_dbg(xhci, "Finished xhci_init\n");

	return retval;
}

/*
 * Called in interrupt context when there might be work
 * queued on the event ring
 *
 * xhci->lock must be held by caller.
 */
static void xhci_work(struct xhci_hcd *xhci)
{
	u32 temp;
	u64 temp_64;

	/*
	 * Clear the op reg interrupt status first,
	 * so we can receive interrupts from other MSI-X interrupters.
	 * Write 1 to clear the interrupt status.
	 */
	temp = xhci_readl(xhci, &xhci->op_regs->status);
	temp |= STS_EINT;
	xhci_writel(xhci, temp, &xhci->op_regs->status);
	/* FIXME when MSI-X is supported and there are multiple vectors */
	/* Clear the MSI-X event interrupt status */

	/* Acknowledge the interrupt */
	temp = xhci_readl(xhci, &xhci->ir_set->irq_pending);
	temp |= 0x3;
	xhci_writel(xhci, temp, &xhci->ir_set->irq_pending);
	/* Flush posted writes */
	xhci_readl(xhci, &xhci->ir_set->irq_pending);

	/* FIXME this should be a delayed service routine that clears the EHB */
	xhci_handle_event(xhci);

	/* Clear the event handler busy flag (RW1C); the event ring should be empty. */
	temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
	xhci_write_64(xhci, temp_64 | ERST_EHB, &xhci->ir_set->erst_dequeue);
	/* Flush posted writes -- FIXME is this necessary? */
	xhci_readl(xhci, &xhci->ir_set->irq_pending);
}

/*-------------------------------------------------------------------------*/

/*
 * xHCI spec says we can get an interrupt, and if the HC has an error condition,
 * we might get bad data out of the event ring.  Section 4.10.2.7 has a list of
 * indicators of an event TRB error, but we check the status *first* to be safe.
 */
irqreturn_t xhci_irq(struct usb_hcd *hcd)
{
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
	u32 temp, temp2;
	union xhci_trb *trb;

	spin_lock(&xhci->lock);
	trb = xhci->event_ring->dequeue;
	/* Check if the xHC generated the interrupt, or the irq is shared */
	temp = xhci_readl(xhci, &xhci->op_regs->status);
	temp2 = xhci_readl(xhci, &xhci->ir_set->irq_pending);
	if (temp == 0xffffffff && temp2 == 0xffffffff)
		goto hw_died;

	if (!(temp & STS_EINT) && !ER_IRQ_PENDING(temp2)) {
		spin_unlock(&xhci->lock);
		return IRQ_NONE;
	}
	xhci_dbg(xhci, "op reg status = %08x\n", temp);
	xhci_dbg(xhci, "ir set irq_pending = %08x\n", temp2);
	xhci_dbg(xhci, "Event ring dequeue ptr:\n");
	xhci_dbg(xhci, "@%llx %08x %08x %08x %08x\n",
			(unsigned long long)xhci_trb_virt_to_dma(xhci->event_ring->deq_seg, trb),
			lower_32_bits(trb->link.segment_ptr),
			upper_32_bits(trb->link.segment_ptr),
			(unsigned int) trb->link.intr_target,
			(unsigned int) trb->link.control);

	if (temp & STS_FATAL) {
		xhci_warn(xhci, "WARNING: Host System Error\n");
		xhci_halt(xhci);
hw_died:
		xhci_to_hcd(xhci)->state = HC_STATE_HALT;
		spin_unlock(&xhci->lock);
		return -ESHUTDOWN;
	}

	xhci_work(xhci);
	spin_unlock(&xhci->lock);

	return IRQ_HANDLED;
}

#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
void xhci_event_ring_work(unsigned long arg)
{
	unsigned long flags;
	int temp;
	u64 temp_64;
	struct xhci_hcd *xhci = (struct xhci_hcd *) arg;
	int i, j;

	xhci_dbg(xhci, "Poll event ring: %lu\n", jiffies);

	spin_lock_irqsave(&xhci->lock, flags);
	temp = xhci_readl(xhci, &xhci->op_regs->status);
	xhci_dbg(xhci, "op reg status = 0x%x\n", temp);
	temp = xhci_readl(xhci, &xhci->ir_set->irq_pending);
	xhci_dbg(xhci, "ir_set 0 pending = 0x%x\n", temp);
	xhci_dbg(xhci, "No-op commands handled = %d\n", xhci->noops_handled);
	xhci_dbg(xhci, "HC error bitmask = 0x%x\n", xhci->error_bitmask);
	xhci->error_bitmask = 0;
	xhci_dbg(xhci, "Event ring:\n");
	xhci_debug_segment(xhci, xhci->event_ring->deq_seg);
	xhci_dbg_ring_ptrs(xhci, xhci->event_ring);
	temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
	temp_64 &= ~ERST_PTR_MASK;
	xhci_dbg(xhci, "ERST deq = 64'h%0lx\n", (long unsigned int) temp_64);
	xhci_dbg(xhci, "Command ring:\n");
	xhci_debug_segment(xhci, xhci->cmd_ring->deq_seg);
	xhci_dbg_ring_ptrs(xhci, xhci->cmd_ring);
	xhci_dbg_cmd_ptrs(xhci);
	for (i = 0; i < MAX_HC_SLOTS; ++i) {
		if (!xhci->devs[i])
			continue;
		for (j = 0; j < 31; ++j) {
			struct xhci_ring *ring = xhci->devs[i]->eps[j].ring;
			if (!ring)
				continue;
			xhci_dbg(xhci, "Dev %d endpoint ring %d:\n", i, j);
			xhci_debug_segment(xhci, ring->deq_seg);
		}
	}

	if (xhci->noops_submitted != NUM_TEST_NOOPS)
		if (xhci_setup_one_noop(xhci))
			xhci_ring_cmd_db(xhci);
	spin_unlock_irqrestore(&xhci->lock, flags);

	if (!xhci->zombie)
		mod_timer(&xhci->event_ring_timer, jiffies + POLL_TIMEOUT * HZ);
	else
		xhci_dbg(xhci, "Quit polling the event ring.\n");
}
#endif

/*
 * Start the HC after it was halted.
 *
 * This function is called by the USB core when the HC driver is added.
 * Its opposite is xhci_stop().
 *
 * xhci_init() must be called once before this function can be called.
 * Reset the HC, enable device slot contexts, program DCBAAP, and
 * set command ring pointer and event ring pointer.
 *
 * Setup MSI-X vectors and enable interrupts.
 */
int xhci_run(struct usb_hcd *hcd)
{
	u32 temp;
	u64 temp_64;
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
	void (*doorbell)(struct xhci_hcd *) = NULL;

	hcd->uses_new_polling = 1;
	hcd->poll_rh = 0;

	xhci_dbg(xhci, "xhci_run\n");
#if 0	/* FIXME: MSI not setup yet */
	/* Do this at the very last minute */
	ret = xhci_setup_msix(xhci);
	if (!ret)
		return ret;

	return -ENOSYS;
#endif
#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
	init_timer(&xhci->event_ring_timer);
	xhci->event_ring_timer.data = (unsigned long) xhci;
	xhci->event_ring_timer.function = xhci_event_ring_work;
	/* Poll the event ring */
	xhci->event_ring_timer.expires = jiffies + POLL_TIMEOUT * HZ;
	xhci->zombie = 0;
	xhci_dbg(xhci, "Setting event ring polling timer\n");
	add_timer(&xhci->event_ring_timer);
#endif

	xhci_dbg(xhci, "Command ring memory map follows:\n");
	xhci_debug_ring(xhci, xhci->cmd_ring);
	xhci_dbg_ring_ptrs(xhci, xhci->cmd_ring);
	xhci_dbg_cmd_ptrs(xhci);

	xhci_dbg(xhci, "ERST memory map follows:\n");
	xhci_dbg_erst(xhci, &xhci->erst);
	xhci_dbg(xhci, "Event ring:\n");
	xhci_debug_ring(xhci, xhci->event_ring);
	xhci_dbg_ring_ptrs(xhci, xhci->event_ring);
	temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
	temp_64 &= ~ERST_PTR_MASK;
	xhci_dbg(xhci, "ERST deq = 64'h%0lx\n", (long unsigned int) temp_64);

	xhci_dbg(xhci, "// Set the interrupt modulation register\n");
	temp = xhci_readl(xhci, &xhci->ir_set->irq_control);
	temp &= ~ER_IRQ_INTERVAL_MASK;
	temp |= (u32) 160;
	xhci_writel(xhci, temp, &xhci->ir_set->irq_control);

	/* Set the HCD state before we enable the irqs */
	hcd->state = HC_STATE_RUNNING;
	temp = xhci_readl(xhci, &xhci->op_regs->command);
	temp |= (CMD_EIE);
	xhci_dbg(xhci, "// Enable interrupts, cmd = 0x%x.\n",
			temp);
	xhci_writel(xhci, temp, &xhci->op_regs->command);

	temp = xhci_readl(xhci, &xhci->ir_set->irq_pending);
	xhci_dbg(xhci, "// Enabling event ring interrupter %p by writing 0x%x to irq_pending\n",
			xhci->ir_set, (unsigned int) ER_IRQ_ENABLE(temp));
	xhci_writel(xhci, ER_IRQ_ENABLE(temp),
			&xhci->ir_set->irq_pending);
	xhci_print_ir_set(xhci, xhci->ir_set, 0);

	if (NUM_TEST_NOOPS > 0)
		doorbell = xhci_setup_one_noop(xhci);

	temp = xhci_readl(xhci, &xhci->op_regs->command);
	temp |= (CMD_RUN);
	xhci_dbg(xhci, "// Turn on HC, cmd = 0x%x.\n",
			temp);
	xhci_writel(xhci, temp, &xhci->op_regs->command);
	/* Flush PCI posted writes */
	temp = xhci_readl(xhci, &xhci->op_regs->command);
	xhci_dbg(xhci, "// @%p = 0x%x\n", &xhci->op_regs->command, temp);
	if (doorbell)
		(*doorbell)(xhci);

	xhci_dbg(xhci, "Finished xhci_run\n");
	return 0;
}

/*
 * Stop xHCI driver.
 *
 * This function is called by the USB core when the HC driver is removed.
 * Its opposite is xhci_run().
 *
 * Disable device contexts, disable IRQs, and quiesce the HC.
 * Reset the HC, finish any completed transactions, and cleanup memory.
 */
void xhci_stop(struct usb_hcd *hcd)
{
	u32 temp;
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);

	spin_lock_irq(&xhci->lock);
	if (HC_IS_RUNNING(hcd->state))
		xhci_quiesce(xhci);
	xhci_halt(xhci);
	xhci_reset(xhci);
	spin_unlock_irq(&xhci->lock);

#if 0	/* No MSI yet */
	xhci_cleanup_msix(xhci);
#endif
#ifdef CONFIG_USB_XHCI_HCD_DEBUGGING
	/* Tell the event ring poll function not to reschedule */
	xhci->zombie = 1;
	del_timer_sync(&xhci->event_ring_timer);
#endif

	xhci_dbg(xhci, "// Disabling event ring interrupts\n");
	temp = xhci_readl(xhci, &xhci->op_regs->status);
	xhci_writel(xhci, temp & ~STS_EINT, &xhci->op_regs->status);
	temp = xhci_readl(xhci, &xhci->ir_set->irq_pending);
	xhci_writel(xhci, ER_IRQ_DISABLE(temp),
			&xhci->ir_set->irq_pending);
	xhci_print_ir_set(xhci, xhci->ir_set, 0);

	xhci_dbg(xhci, "cleaning up memory\n");
	xhci_mem_cleanup(xhci);
	xhci_dbg(xhci, "xhci_stop completed - status = %x\n",
		    xhci_readl(xhci, &xhci->op_regs->status));
}

/*
 * Shutdown HC (not bus-specific)
 *
 * This is called when the machine is rebooting or halting.  We assume that the
 * machine will be powered off, and the HC's internal state will be reset.
 * Don't bother to free memory.
 */
void xhci_shutdown(struct usb_hcd *hcd)
{
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);

	spin_lock_irq(&xhci->lock);
	xhci_halt(xhci);
	spin_unlock_irq(&xhci->lock);

#if 0
	xhci_cleanup_msix(xhci);
#endif

	xhci_dbg(xhci, "xhci_shutdown completed - status = %x\n",
		    xhci_readl(xhci, &xhci->op_regs->status));
}

/*-------------------------------------------------------------------------*/

/**
 * xhci_get_endpoint_index - Used for passing endpoint bitmasks between the core and
 * HCDs.  Find the index for an endpoint given its descriptor.  Use the return
 * value to right shift 1 for the bitmask.
 *
 * Index  = (epnum * 2) + direction - 1,
 * where direction = 0 for OUT, 1 for IN.
 * For control endpoints, the IN index is used (OUT index is unused), so
 * index = (epnum * 2) + direction - 1 = (epnum * 2) + 1 - 1 = (epnum * 2)
 */
unsigned int xhci_get_endpoint_index(struct usb_endpoint_descriptor *desc)
{
	unsigned int index;
	if (usb_endpoint_xfer_control(desc))
		index = (unsigned int) (usb_endpoint_num(desc)*2);
	else
		index = (unsigned int) (usb_endpoint_num(desc)*2) +
			(usb_endpoint_dir_in(desc) ? 1 : 0) - 1;
	return index;
}

/* Find the flag for this endpoint (for use in the control context).  Use the
 * endpoint index to create a bitmask.  The slot context is bit 0, endpoint 0 is
 * bit 1, etc.
 */
unsigned int xhci_get_endpoint_flag(struct usb_endpoint_descriptor *desc)
{
	return 1 << (xhci_get_endpoint_index(desc) + 1);
}

/* Find the flag for this endpoint (for use in the control context).  Use the
 * endpoint index to create a bitmask.  The slot context is bit 0, endpoint 0 is
 * bit 1, etc.
 */
unsigned int xhci_get_endpoint_flag_from_index(unsigned int ep_index)
{
	return 1 << (ep_index + 1);
}

/* Compute the last valid endpoint context index.  Basically, this is the
 * endpoint index plus one.  For slot contexts with more than valid endpoint,
 * we find the most significant bit set in the added contexts flags.
 * e.g. ep 1 IN (with epnum 0x81) => added_ctxs = 0b1000
 * fls(0b1000) = 4, but the endpoint context index is 3, so subtract one.
 */
unsigned int xhci_last_valid_endpoint(u32 added_ctxs)
{
	return fls(added_ctxs) - 1;
}

/* Returns 1 if the arguments are OK;
 * returns 0 this is a root hub; returns -EINVAL for NULL pointers.
 */
int xhci_check_args(struct usb_hcd *hcd, struct usb_device *udev,
		struct usb_host_endpoint *ep, int check_ep, const char *func) {
	if (!hcd || (check_ep && !ep) || !udev) {
		printk(KERN_DEBUG "xHCI %s called with invalid args\n",
				func);
		return -EINVAL;
	}
	if (!udev->parent) {
		printk(KERN_DEBUG "xHCI %s called for root hub\n",
				func);
		return 0;
	}
	if (!udev->slot_id) {
		printk(KERN_DEBUG "xHCI %s called with unaddressed device\n",
				func);
		return -EINVAL;
	}
	return 1;
}

static int xhci_configure_endpoint(struct xhci_hcd *xhci,
		struct usb_device *udev, struct xhci_command *command,
		bool ctx_change, bool must_succeed);

/*
 * Full speed devices may have a max packet size greater than 8 bytes, but the
 * USB core doesn't know that until it reads the first 8 bytes of the
 * descriptor.  If the usb_device's max packet size changes after that point,
 * we need to issue an evaluate context command and wait on it.
 */
static int xhci_check_maxpacket(struct xhci_hcd *xhci, unsigned int slot_id,
		unsigned int ep_index, struct urb *urb)
{
	struct xhci_container_ctx *in_ctx;
	struct xhci_container_ctx *out_ctx;
	struct xhci_input_control_ctx *ctrl_ctx;
	struct xhci_ep_ctx *ep_ctx;
	int max_packet_size;
	int hw_max_packet_size;
	int ret = 0;

	out_ctx = xhci->devs[slot_id]->out_ctx;
	ep_ctx = xhci_get_ep_ctx(xhci, out_ctx, ep_index);
	hw_max_packet_size = MAX_PACKET_DECODED(ep_ctx->ep_info2);
	max_packet_size = urb->dev->ep0.desc.wMaxPacketSize;
	if (hw_max_packet_size != max_packet_size) {
		xhci_dbg(xhci, "Max Packet Size for ep 0 changed.\n");
		xhci_dbg(xhci, "Max packet size in usb_device = %d\n",
				max_packet_size);
		xhci_dbg(xhci, "Max packet size in xHCI HW = %d\n",
				hw_max_packet_size);
		xhci_dbg(xhci, "Issuing evaluate context command.\n");

		/* Set up the modified control endpoint 0 */
		xhci_endpoint_copy(xhci, xhci->devs[slot_id]->in_ctx,
				xhci->devs[slot_id]->out_ctx, ep_index);
		in_ctx = xhci->devs[slot_id]->in_ctx;
		ep_ctx = xhci_get_ep_ctx(xhci, in_ctx, ep_index);
		ep_ctx->ep_info2 &= ~MAX_PACKET_MASK;
		ep_ctx->ep_info2 |= MAX_PACKET(max_packet_size);

		/* Set up the input context flags for the command */
		/* FIXME: This won't work if a non-default control endpoint
		 * changes max packet sizes.
		 */
		ctrl_ctx = xhci_get_input_control_ctx(xhci, in_ctx);
		ctrl_ctx->add_flags = EP0_FLAG;
		ctrl_ctx->drop_flags = 0;

		xhci_dbg(xhci, "Slot %d input context\n", slot_id);
		xhci_dbg_ctx(xhci, in_ctx, ep_index);
		xhci_dbg(xhci, "Slot %d output context\n", slot_id);
		xhci_dbg_ctx(xhci, out_ctx, ep_index);

		ret = xhci_configure_endpoint(xhci, urb->dev, NULL,
				true, false);

		/* Clean up the input context for later use by bandwidth
		 * functions.
		 */
		ctrl_ctx->add_flags = SLOT_FLAG;
	}
	return ret;
}

/*
 * non-error returns are a promise to giveback() the urb later
 * we drop ownership so next owner (or urb unlink) can get it
 */
int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flags)
{
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
	unsigned long flags;
	int ret = 0;
	unsigned int slot_id, ep_index;


	if (!urb || xhci_check_args(hcd, urb->dev, urb->ep, true, __func__) <= 0)
		return -EINVAL;

	slot_id = urb->dev->slot_id;
	ep_index = xhci_get_endpoint_index(&urb->ep->desc);

	if (!xhci->devs || !xhci->devs[slot_id]) {
		if (!in_interrupt())
			dev_warn(&urb->dev->dev, "WARN: urb submitted for dev with no Slot ID\n");
		ret = -EINVAL;
		goto exit;
	}
	if (!test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)) {
		if (!in_interrupt())
			xhci_dbg(xhci, "urb submitted during PCI suspend\n");
		ret = -ESHUTDOWN;
		goto exit;
	}
	if (usb_endpoint_xfer_control(&urb->ep->desc)) {
		/* Check to see if the max packet size for the default control
		 * endpoint changed during FS device enumeration
		 */
		if (urb->dev->speed == USB_SPEED_FULL) {
			ret = xhci_check_maxpacket(xhci, slot_id,
					ep_index, urb);
			if (ret < 0)
				return ret;
		}

		/* We have a spinlock and interrupts disabled, so we must pass
		 * atomic context to this function, which may allocate memory.
		 */
		spin_lock_irqsave(&xhci->lock, flags);
		ret = xhci_queue_ctrl_tx(xhci, GFP_ATOMIC, urb,
				slot_id, ep_index);
		spin_unlock_irqrestore(&xhci->lock, flags);
	} else if (usb_endpoint_xfer_bulk(&urb->ep->desc)) {
		spin_lock_irqsave(&xhci->lock, flags);
		ret = xhci_queue_bulk_tx(xhci, GFP_ATOMIC, urb,
				slot_id, ep_index);
		spin_unlock_irqrestore(&xhci->lock, flags);
	} else if (usb_endpoint_xfer_int(&urb->ep->desc)) {
		spin_lock_irqsave(&xhci->lock, flags);
		ret = xhci_queue_intr_tx(xhci, GFP_ATOMIC, urb,
				slot_id, ep_index);
		spin_unlock_irqrestore(&xhci->lock, flags);
	} else {
		ret = -EINVAL;
	}
exit:
	return ret;
}

/*
 * Remove the URB's TD from the endpoint ring.  This may cause the HC to stop
 * USB transfers, potentially stopping in the middle of a TRB buffer.  The HC
 * should pick up where it left off in the TD, unless a Set Transfer Ring
 * Dequeue Pointer is issued.
 *
 * The TRBs that make up the buffers for the canceled URB will be "removed" from
 * the ring.  Since the ring is a contiguous structure, they can't be physically
 * removed.  Instead, there are two options:
 *
 *  1) If the HC is in the middle of processing the URB to be canceled, we
 *     simply move the ring's dequeue pointer past those TRBs using the Set
 *     Transfer Ring Dequeue Pointer command.  This will be the common case,
 *     when drivers timeout on the last submitted URB and attempt to cancel.
 *
 *  2) If the HC is in the middle of a different TD, we turn the TRBs into a
 *     series of 1-TRB transfer no-op TDs.  (No-ops shouldn't be chained.)  The
 *     HC will need to invalidate the any TRBs it has cached after the stop
 *     endpoint command, as noted in the xHCI 0.95 errata.
 *
 *  3) The TD may have completed by the time the Stop Endpoint Command
 *     completes, so software needs to handle that case too.
 *
 * This function should protect against the TD enqueueing code ringing the
 * doorbell while this code is waiting for a Stop Endpoint command to complete.
 * It also needs to account for multiple cancellations on happening at the same
 * time for the same endpoint.
 *
 * Note that this function can be called in any context, or so says
 * usb_hcd_unlink_urb()
 */
int xhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
{
	unsigned long flags;
	int ret;
	struct xhci_hcd *xhci;
	struct xhci_td *td;
	unsigned int ep_index;
	struct xhci_ring *ep_ring;
	struct xhci_virt_ep *ep;

	xhci = hcd_to_xhci(hcd);
	spin_lock_irqsave(&xhci->lock, flags);
	/* Make sure the URB hasn't completed or been unlinked already */
	ret = usb_hcd_check_unlink_urb(hcd, urb, status);
	if (ret || !urb->hcpriv)
		goto done;

	xhci_dbg(xhci, "Cancel URB %p\n", urb);
	xhci_dbg(xhci, "Event ring:\n");
	xhci_debug_ring(xhci, xhci->event_ring);
	ep_index = xhci_get_endpoint_index(&urb->ep->desc);
	ep = &xhci->devs[urb->dev->slot_id]->eps[ep_index];
	ep_ring = ep->ring;
	xhci_dbg(xhci, "Endpoint ring:\n");
	xhci_debug_ring(xhci, ep_ring);
	td = (struct xhci_td *) urb->hcpriv;

	ep->cancels_pending++;
	list_add_tail(&td->cancelled_td_list, &ep->cancelled_td_list);
	/* Queue a stop endpoint command, but only if this is
	 * the first cancellation to be handled.
	 */
	if (ep->cancels_pending == 1) {
		xhci_queue_stop_endpoint(xhci, urb->dev->slot_id, ep_index);
		xhci_ring_cmd_db(xhci);
	}
done:
	spin_unlock_irqrestore(&xhci->lock, flags);
	return ret;
}

/* Drop an endpoint from a new bandwidth configuration for this device.
 * Only one call to this function is allowed per endpoint before
 * check_bandwidth() or reset_bandwidth() must be called.
 * A call to xhci_drop_endpoint() followed by a call to xhci_add_endpoint() will
 * add the endpoint to the schedule with possibly new parameters denoted by a
 * different endpoint descriptor in usb_host_endpoint.
 * A call to xhci_add_endpoint() followed by a call to xhci_drop_endpoint() is
 * not allowed.
 *
 * The USB core will not allow URBs to be queued to an endpoint that is being
 * disabled, so there's no need for mutual exclusion to protect
 * the xhci->devs[slot_id] structure.
 */
int xhci_drop_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
		struct usb_host_endpoint *ep)
{
	struct xhci_hcd *xhci;
	struct xhci_container_ctx *in_ctx, *out_ctx;
	struct xhci_input_control_ctx *ctrl_ctx;
	struct xhci_slot_ctx *slot_ctx;
	unsigned int last_ctx;
	unsigned int ep_index;
	struct xhci_ep_ctx *ep_ctx;
	u32 drop_flag;
	u32 new_add_flags, new_drop_flags, new_slot_info;
	int ret;

	ret = xhci_check_args(hcd, udev, ep, 1, __func__);
	if (ret <= 0)
		return ret;
	xhci = hcd_to_xhci(hcd);
	xhci_dbg(xhci, "%s called for udev %p\n", __func__, udev);

	drop_flag = xhci_get_endpoint_flag(&ep->desc);
	if (drop_flag == SLOT_FLAG || drop_flag == EP0_FLAG) {
		xhci_dbg(xhci, "xHCI %s - can't drop slot or ep 0 %#x\n",
				__func__, drop_flag);
		return 0;
	}

	if (!xhci->devs || !xhci->devs[udev->slot_id]) {
		xhci_warn(xhci, "xHCI %s called with unaddressed device\n",
				__func__);
		return -EINVAL;
	}

	in_ctx = xhci->devs[udev->slot_id]->in_ctx;
	out_ctx = xhci->devs[udev->slot_id]->out_ctx;
	ctrl_ctx = xhci_get_input_control_ctx(xhci, in_ctx);
	ep_index = xhci_get_endpoint_index(&ep->desc);
	ep_ctx = xhci_get_ep_ctx(xhci, out_ctx, ep_index);
	/* If the HC already knows the endpoint is disabled,
	 * or the HCD has noted it is disabled, ignore this request
	 */
	if ((ep_ctx->ep_info & EP_STATE_MASK) == EP_STATE_DISABLED ||
			ctrl_ctx->drop_flags & xhci_get_endpoint_flag(&ep->desc)) {
		xhci_warn(xhci, "xHCI %s called with disabled ep %p\n",
				__func__, ep);
		return 0;
	}

	ctrl_ctx->drop_flags |= drop_flag;
	new_drop_flags = ctrl_ctx->drop_flags;

	ctrl_ctx->add_flags = ~drop_flag;
	new_add_flags = ctrl_ctx->add_flags;

	last_ctx = xhci_last_valid_endpoint(ctrl_ctx->add_flags);
	slot_ctx = xhci_get_slot_ctx(xhci, in_ctx);
	/* Update the last valid endpoint context, if we deleted the last one */
	if ((slot_ctx->dev_info & LAST_CTX_MASK) > LAST_CTX(last_ctx)) {
		slot_ctx->dev_info &= ~LAST_CTX_MASK;
		slot_ctx->dev_info |= LAST_CTX(last_ctx);
	}
	new_slot_info = slot_ctx->dev_info;

	xhci_endpoint_zero(xhci, xhci->devs[udev->slot_id], ep);

	xhci_dbg(xhci, "drop ep 0x%x, slot id %d, new drop flags = %#x, new add flags = %#x, new slot info = %#x\n",
			(unsigned int) ep->desc.bEndpointAddress,
			udev->slot_id,
			(unsigned int) new_drop_flags,
			(unsigned int) new_add_flags,
			(unsigned int) new_slot_info);
	return 0;
}

/* Add an endpoint to a new possible bandwidth configuration for this device.
 * Only one call to this function is allowed per endpoint before
 * check_bandwidth() or reset_bandwidth() must be called.
 * A call to xhci_drop_endpoint() followed by a call to xhci_add_endpoint() will
 * add the endpoint to the schedule with possibly new parameters denoted by a
 * different endpoint descriptor in usb_host_endpoint.
 * A call to xhci_add_endpoint() followed by a call to xhci_drop_endpoint() is
 * not allowed.
 *
 * The USB core will not allow URBs to be queued to an endpoint until the
 * configuration or alt setting is installed in the device, so there's no need
 * for mutual exclusion to protect the xhci->devs[slot_id] structure.
 */
int xhci_add_endpoint(struct usb_hcd *hcd, struct usb_device *udev,
		struct usb_host_endpoint *ep)
{
	struct xhci_hcd *xhci;
	struct xhci_container_ctx *in_ctx, *out_ctx;
	unsigned int ep_index;
	struct xhci_ep_ctx *ep_ctx;
	struct xhci_slot_ctx *slot_ctx;
	struct xhci_input_control_ctx *ctrl_ctx;
	u32 added_ctxs;
	unsigned int last_ctx;
	u32 new_add_flags, new_drop_flags, new_slot_info;
	int ret = 0;

	ret = xhci_check_args(hcd, udev, ep, 1, __func__);
	if (ret <= 0) {
		/* So we won't queue a reset ep command for a root hub */
		ep->hcpriv = NULL;
		return ret;
	}
	xhci = hcd_to_xhci(hcd);

	added_ctxs = xhci_get_endpoint_flag(&ep->desc);
	last_ctx = xhci_last_valid_endpoint(added_ctxs);
	if (added_ctxs == SLOT_FLAG || added_ctxs == EP0_FLAG) {
		/* FIXME when we have to issue an evaluate endpoint command to
		 * deal with ep0 max packet size changing once we get the
		 * descriptors
		 */
		xhci_dbg(xhci, "xHCI %s - can't add slot or ep 0 %#x\n",
				__func__, added_ctxs);
		return 0;
	}

	if (!xhci->devs || !xhci->devs[udev->slot_id]) {
		xhci_warn(xhci, "xHCI %s called with unaddressed device\n",
				__func__);
		return -EINVAL;
	}

	in_ctx = xhci->devs[udev->slot_id]->in_ctx;
	out_ctx = xhci->devs[udev->slot_id]->out_ctx;
	ctrl_ctx = xhci_get_input_control_ctx(xhci, in_ctx);
	ep_index = xhci_get_endpoint_index(&ep->desc);
	ep_ctx = xhci_get_ep_ctx(xhci, out_ctx, ep_index);
	/* If the HCD has already noted the endpoint is enabled,
	 * ignore this request.
	 */
	if (ctrl_ctx->add_flags & xhci_get_endpoint_flag(&ep->desc)) {
		xhci_warn(xhci, "xHCI %s called with enabled ep %p\n",
				__func__, ep);
		return 0;
	}

	/*
	 * Configuration and alternate setting changes must be done in
	 * process context, not interrupt context (or so documenation
	 * for usb_set_interface() and usb_set_configuration() claim).
	 */
	if (xhci_endpoint_init(xhci, xhci->devs[udev->slot_id],
				udev, ep, GFP_KERNEL) < 0) {
		dev_dbg(&udev->dev, "%s - could not initialize ep %#x\n",
				__func__, ep->desc.bEndpointAddress);
		return -ENOMEM;
	}

	ctrl_ctx->add_flags |= added_ctxs;
	new_add_flags = ctrl_ctx->add_flags;

	/* If xhci_endpoint_disable() was called for this endpoint, but the
	 * xHC hasn't been notified yet through the check_bandwidth() call,
	 * this re-adds a new state for the endpoint from the new endpoint
	 * descriptors.  We must drop and re-add this endpoint, so we leave the
	 * drop flags alone.
	 */
	new_drop_flags = ctrl_ctx->drop_flags;

	slot_ctx = xhci_get_slot_ctx(xhci, in_ctx);
	/* Update the last valid endpoint context, if we just added one past */
	if ((slot_ctx->dev_info & LAST_CTX_MASK) < LAST_CTX(last_ctx)) {
		slot_ctx->dev_info &= ~LAST_CTX_MASK;
		slot_ctx->dev_info |= LAST_CTX(last_ctx);
	}
	new_slot_info = slot_ctx->dev_info;

	/* Store the usb_device pointer for later use */
	ep->hcpriv = udev;

	xhci_dbg(xhci, "add ep 0x%x, slot id %d, new drop flags = %#x, new add flags = %#x, new slot info = %#x\n",
			(unsigned int) ep->desc.bEndpointAddress,
			udev->slot_id,
			(unsigned int) new_drop_flags,
			(unsigned int) new_add_flags,
			(unsigned int) new_slot_info);
	return 0;
}

static void xhci_zero_in_ctx(struct xhci_hcd *xhci, struct xhci_virt_device *virt_dev)
{
	struct xhci_input_control_ctx *ctrl_ctx;
	struct xhci_ep_ctx *ep_ctx;
	struct xhci_slot_ctx *slot_ctx;
	int i;

	/* When a device's add flag and drop flag are zero, any subsequent
	 * configure endpoint command will leave that endpoint's state
	 * untouched.  Make sure we don't leave any old state in the input
	 * endpoint contexts.
	 */
	ctrl_ctx = xhci_get_input_control_ctx(xhci, virt_dev->in_ctx);
	ctrl_ctx->drop_flags = 0;
	ctrl_ctx->add_flags = 0;
	slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
	slot_ctx->dev_info &= ~LAST_CTX_MASK;
	/* Endpoint 0 is always valid */
	slot_ctx->dev_info |= LAST_CTX(1);
	for (i = 1; i < 31; ++i) {
		ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, i);
		ep_ctx->ep_info = 0;
		ep_ctx->ep_info2 = 0;
		ep_ctx->deq = 0;
		ep_ctx->tx_info = 0;
	}
}

static int xhci_configure_endpoint_result(struct xhci_hcd *xhci,
		struct usb_device *udev, int *cmd_status)
{
	int ret;

	switch (*cmd_status) {
	case COMP_ENOMEM:
		dev_warn(&udev->dev, "Not enough host controller resources "
				"for new device state.\n");
		ret = -ENOMEM;
		/* FIXME: can we allocate more resources for the HC? */
		break;
	case COMP_BW_ERR:
		dev_warn(&udev->dev, "Not enough bandwidth "
				"for new device state.\n");
		ret = -ENOSPC;
		/* FIXME: can we go back to the old state? */
		break;
	case COMP_TRB_ERR:
		/* the HCD set up something wrong */
		dev_warn(&udev->dev, "ERROR: Endpoint drop flag = 0, "
				"add flag = 1, "
				"and endpoint is not disabled.\n");
		ret = -EINVAL;
		break;
	case COMP_SUCCESS:
		dev_dbg(&udev->dev, "Successful Endpoint Configure command\n");
		ret = 0;
		break;
	default:
		xhci_err(xhci, "ERROR: unexpected command completion "
				"code 0x%x.\n", *cmd_status);
		ret = -EINVAL;
		break;
	}
	return ret;
}

static int xhci_evaluate_context_result(struct xhci_hcd *xhci,
		struct usb_device *udev, int *cmd_status)
{
	int ret;
	struct xhci_virt_device *virt_dev = xhci->devs[udev->slot_id];

	switch (*cmd_status) {
	case COMP_EINVAL:
		dev_warn(&udev->dev, "WARN: xHCI driver setup invalid evaluate "
				"context command.\n");
		ret = -EINVAL;
		break;
	case COMP_EBADSLT:
		dev_warn(&udev->dev, "WARN: slot not enabled for"
				"evaluate context command.\n");
	case COMP_CTX_STATE:
		dev_warn(&udev->dev, "WARN: invalid context state for "
				"evaluate context command.\n");
		xhci_dbg_ctx(xhci, virt_dev->out_ctx, 1);
		ret = -EINVAL;
		break;
	case COMP_SUCCESS:
		dev_dbg(&udev->dev, "Successful evaluate context command\n");
		ret = 0;
		break;
	default:
		xhci_err(xhci, "ERROR: unexpected command completion "
				"code 0x%x.\n", *cmd_status);
		ret = -EINVAL;
		break;
	}
	return ret;
}

/* Issue a configure endpoint command or evaluate context command
 * and wait for it to finish.
 */
static int xhci_configure_endpoint(struct xhci_hcd *xhci,
		struct usb_device *udev,
		struct xhci_command *command,
		bool ctx_change, bool must_succeed)
{
	int ret;
	int timeleft;
	unsigned long flags;
	struct xhci_container_ctx *in_ctx;
	struct completion *cmd_completion;
	int *cmd_status;
	struct xhci_virt_device *virt_dev;

	spin_lock_irqsave(&xhci->lock, flags);
	virt_dev = xhci->devs[udev->slot_id];
	if (command) {
		in_ctx = command->in_ctx;
		cmd_completion = command->completion;
		cmd_status = &command->status;
		command->command_trb = xhci->cmd_ring->enqueue;
		list_add_tail(&command->cmd_list, &virt_dev->cmd_list);
	} else {
		in_ctx = virt_dev->in_ctx;
		cmd_completion = &virt_dev->cmd_completion;
		cmd_status = &virt_dev->cmd_status;
	}

	if (!ctx_change)
		ret = xhci_queue_configure_endpoint(xhci, in_ctx->dma,
				udev->slot_id, must_succeed);
	else
		ret = xhci_queue_evaluate_context(xhci, in_ctx->dma,
				udev->slot_id);
	if (ret < 0) {
		spin_unlock_irqrestore(&xhci->lock, flags);
		xhci_dbg(xhci, "FIXME allocate a new ring segment\n");
		return -ENOMEM;
	}
	xhci_ring_cmd_db(xhci);
	spin_unlock_irqrestore(&xhci->lock, flags);

	/* Wait for the configure endpoint command to complete */
	timeleft = wait_for_completion_interruptible_timeout(
			cmd_completion,
			USB_CTRL_SET_TIMEOUT);
	if (timeleft <= 0) {
		xhci_warn(xhci, "%s while waiting for %s command\n",
				timeleft == 0 ? "Timeout" : "Signal",
				ctx_change == 0 ?
					"configure endpoint" :
					"evaluate context");
		/* FIXME cancel the configure endpoint command */
		return -ETIME;
	}

	if (!ctx_change)
		return xhci_configure_endpoint_result(xhci, udev, cmd_status);
	return xhci_evaluate_context_result(xhci, udev, cmd_status);
}

/* Called after one or more calls to xhci_add_endpoint() or
 * xhci_drop_endpoint().  If this call fails, the USB core is expected
 * to call xhci_reset_bandwidth().
 *
 * Since we are in the middle of changing either configuration or
 * installing a new alt setting, the USB core won't allow URBs to be
 * enqueued for any endpoint on the old config or interface.  Nothing
 * else should be touching the xhci->devs[slot_id] structure, so we
 * don't need to take the xhci->lock for manipulating that.
 */
int xhci_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
{
	int i;
	int ret = 0;
	struct xhci_hcd *xhci;
	struct xhci_virt_device	*virt_dev;
	struct xhci_input_control_ctx *ctrl_ctx;
	struct xhci_slot_ctx *slot_ctx;

	ret = xhci_check_args(hcd, udev, NULL, 0, __func__);
	if (ret <= 0)
		return ret;
	xhci = hcd_to_xhci(hcd);

	if (!udev->slot_id || !xhci->devs || !xhci->devs[udev->slot_id]) {
		xhci_warn(xhci, "xHCI %s called with unaddressed device\n",
				__func__);
		return -EINVAL;
	}
	xhci_dbg(xhci, "%s called for udev %p\n", __func__, udev);
	virt_dev = xhci->devs[udev->slot_id];

	/* See section 4.6.6 - A0 = 1; A1 = D0 = D1 = 0 */
	ctrl_ctx = xhci_get_input_control_ctx(xhci, virt_dev->in_ctx);
	ctrl_ctx->add_flags |= SLOT_FLAG;
	ctrl_ctx->add_flags &= ~EP0_FLAG;
	ctrl_ctx->drop_flags &= ~SLOT_FLAG;
	ctrl_ctx->drop_flags &= ~EP0_FLAG;
	xhci_dbg(xhci, "New Input Control Context:\n");
	slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
	xhci_dbg_ctx(xhci, virt_dev->in_ctx,
			LAST_CTX_TO_EP_NUM(slot_ctx->dev_info));

	ret = xhci_configure_endpoint(xhci, udev, NULL,
			false, false);
	if (ret) {
		/* Callee should call reset_bandwidth() */
		return ret;
	}

	xhci_dbg(xhci, "Output context after successful config ep cmd:\n");
	xhci_dbg_ctx(xhci, virt_dev->out_ctx,
			LAST_CTX_TO_EP_NUM(slot_ctx->dev_info));

	xhci_zero_in_ctx(xhci, virt_dev);
	/* Free any old rings */
	for (i = 1; i < 31; ++i) {
		if (virt_dev->eps[i].new_ring) {
			xhci_ring_free(xhci, virt_dev->eps[i].ring);
			virt_dev->eps[i].ring = virt_dev->eps[i].new_ring;
			virt_dev->eps[i].new_ring = NULL;
		}
	}

	return ret;
}

void xhci_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev)
{
	struct xhci_hcd *xhci;
	struct xhci_virt_device	*virt_dev;
	int i, ret;

	ret = xhci_check_args(hcd, udev, NULL, 0, __func__);
	if (ret <= 0)
		return;
	xhci = hcd_to_xhci(hcd);

	if (!xhci->devs || !xhci->devs[udev->slot_id]) {
		xhci_warn(xhci, "xHCI %s called with unaddressed device\n",
				__func__);
		return;
	}
	xhci_dbg(xhci, "%s called for udev %p\n", __func__, udev);
	virt_dev = xhci->devs[udev->slot_id];
	/* Free any rings allocated for added endpoints */
	for (i = 0; i < 31; ++i) {
		if (virt_dev->eps[i].new_ring) {
			xhci_ring_free(xhci, virt_dev->eps[i].new_ring);
			virt_dev->eps[i].new_ring = NULL;
		}
	}
	xhci_zero_in_ctx(xhci, virt_dev);
}

static void xhci_setup_input_ctx_for_config_ep(struct xhci_hcd *xhci,
		struct xhci_container_ctx *in_ctx,
		struct xhci_container_ctx *out_ctx,
		u32 add_flags, u32 drop_flags)
{
	struct xhci_input_control_ctx *ctrl_ctx;
	ctrl_ctx = xhci_get_input_control_ctx(xhci, in_ctx);
	ctrl_ctx->add_flags = add_flags;
	ctrl_ctx->drop_flags = drop_flags;
	xhci_slot_copy(xhci, in_ctx, out_ctx);
	ctrl_ctx->add_flags |= SLOT_FLAG;

	xhci_dbg(xhci, "Input Context:\n");
	xhci_dbg_ctx(xhci, in_ctx, xhci_last_valid_endpoint(add_flags));
}

void xhci_setup_input_ctx_for_quirk(struct xhci_hcd *xhci,
		unsigned int slot_id, unsigned int ep_index,
		struct xhci_dequeue_state *deq_state)
{
	struct xhci_container_ctx *in_ctx;
	struct xhci_ep_ctx *ep_ctx;
	u32 added_ctxs;
	dma_addr_t addr;

	xhci_endpoint_copy(xhci, xhci->devs[slot_id]->in_ctx,
			xhci->devs[slot_id]->out_ctx, ep_index);
	in_ctx = xhci->devs[slot_id]->in_ctx;
	ep_ctx = xhci_get_ep_ctx(xhci, in_ctx, ep_index);
	addr = xhci_trb_virt_to_dma(deq_state->new_deq_seg,
			deq_state->new_deq_ptr);
	if (addr == 0) {
		xhci_warn(xhci, "WARN Cannot submit config ep after "
				"reset ep command\n");
		xhci_warn(xhci, "WARN deq seg = %p, deq ptr = %p\n",
				deq_state->new_deq_seg,
				deq_state->new_deq_ptr);
		return;
	}
	ep_ctx->deq = addr | deq_state->new_cycle_state;

	added_ctxs = xhci_get_endpoint_flag_from_index(ep_index);
	xhci_setup_input_ctx_for_config_ep(xhci, xhci->devs[slot_id]->in_ctx,
			xhci->devs[slot_id]->out_ctx, added_ctxs, added_ctxs);
}

void xhci_cleanup_stalled_ring(struct xhci_hcd *xhci,
		struct usb_device *udev, unsigned int ep_index)
{
	struct xhci_dequeue_state deq_state;
	struct xhci_virt_ep *ep;

	xhci_dbg(xhci, "Cleaning up stalled endpoint ring\n");
	ep = &xhci->devs[udev->slot_id]->eps[ep_index];
	/* We need to move the HW's dequeue pointer past this TD,
	 * or it will attempt to resend it on the next doorbell ring.
	 */
	xhci_find_new_dequeue_state(xhci, udev->slot_id,
			ep_index, ep->stopped_td,
			&deq_state);

	/* HW with the reset endpoint quirk will use the saved dequeue state to
	 * issue a configure endpoint command later.
	 */
	if (!(xhci->quirks & XHCI_RESET_EP_QUIRK)) {
		xhci_dbg(xhci, "Queueing new dequeue state\n");
		xhci_queue_new_dequeue_state(xhci, udev->slot_id,
				ep_index, &deq_state);
	} else {
		/* Better hope no one uses the input context between now and the
		 * reset endpoint completion!
		 */
		xhci_dbg(xhci, "Setting up input context for "
				"configure endpoint command\n");
		xhci_setup_input_ctx_for_quirk(xhci, udev->slot_id,
				ep_index, &deq_state);
	}
}

/* Deal with stalled endpoints.  The core should have sent the control message
 * to clear the halt condition.  However, we need to make the xHCI hardware
 * reset its sequence number, since a device will expect a sequence number of
 * zero after the halt condition is cleared.
 * Context: in_interrupt
 */
void xhci_endpoint_reset(struct usb_hcd *hcd,
		struct usb_host_endpoint *ep)
{
	struct xhci_hcd *xhci;
	struct usb_device *udev;
	unsigned int ep_index;
	unsigned long flags;
	int ret;
	struct xhci_virt_ep *virt_ep;

	xhci = hcd_to_xhci(hcd);
	udev = (struct usb_device *) ep->hcpriv;
	/* Called with a root hub endpoint (or an endpoint that wasn't added
	 * with xhci_add_endpoint()
	 */
	if (!ep->hcpriv)
		return;
	ep_index = xhci_get_endpoint_index(&ep->desc);
	virt_ep = &xhci->devs[udev->slot_id]->eps[ep_index];
	if (!virt_ep->stopped_td) {
		xhci_dbg(xhci, "Endpoint 0x%x not halted, refusing to reset.\n",
				ep->desc.bEndpointAddress);
		return;
	}
	if (usb_endpoint_xfer_control(&ep->desc)) {
		xhci_dbg(xhci, "Control endpoint stall already handled.\n");
		return;
	}

	xhci_dbg(xhci, "Queueing reset endpoint command\n");
	spin_lock_irqsave(&xhci->lock, flags);
	ret = xhci_queue_reset_ep(xhci, udev->slot_id, ep_index);
	/*
	 * Can't change the ring dequeue pointer until it's transitioned to the
	 * stopped state, which is only upon a successful reset endpoint
	 * command.  Better hope that last command worked!
	 */
	if (!ret) {
		xhci_cleanup_stalled_ring(xhci, udev, ep_index);
		kfree(virt_ep->stopped_td);
		xhci_ring_cmd_db(xhci);
	}
	spin_unlock_irqrestore(&xhci->lock, flags);

	if (ret)
		xhci_warn(xhci, "FIXME allocate a new ring segment\n");
}

/*
 * At this point, the struct usb_device is about to go away, the device has
 * disconnected, and all traffic has been stopped and the endpoints have been
 * disabled.  Free any HC data structures associated with that device.
 */
void xhci_free_dev(struct usb_hcd *hcd, struct usb_device *udev)
{
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
	unsigned long flags;

	if (udev->slot_id == 0)
		return;

	spin_lock_irqsave(&xhci->lock, flags);
	if (xhci_queue_slot_control(xhci, TRB_DISABLE_SLOT, udev->slot_id)) {
		spin_unlock_irqrestore(&xhci->lock, flags);
		xhci_dbg(xhci, "FIXME: allocate a command ring segment\n");
		return;
	}
	xhci_ring_cmd_db(xhci);
	spin_unlock_irqrestore(&xhci->lock, flags);
	/*
	 * Event command completion handler will free any data structures
	 * associated with the slot.  XXX Can free sleep?
	 */
}

/*
 * Returns 0 if the xHC ran out of device slots, the Enable Slot command
 * timed out, or allocating memory failed.  Returns 1 on success.
 */
int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
{
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
	unsigned long flags;
	int timeleft;
	int ret;

	spin_lock_irqsave(&xhci->lock, flags);
	ret = xhci_queue_slot_control(xhci, TRB_ENABLE_SLOT, 0);
	if (ret) {
		spin_unlock_irqrestore(&xhci->lock, flags);
		xhci_dbg(xhci, "FIXME: allocate a command ring segment\n");
		return 0;
	}
	xhci_ring_cmd_db(xhci);
	spin_unlock_irqrestore(&xhci->lock, flags);

	/* XXX: how much time for xHC slot assignment? */
	timeleft = wait_for_completion_interruptible_timeout(&xhci->addr_dev,
			USB_CTRL_SET_TIMEOUT);
	if (timeleft <= 0) {
		xhci_warn(xhci, "%s while waiting for a slot\n",
				timeleft == 0 ? "Timeout" : "Signal");
		/* FIXME cancel the enable slot request */
		return 0;
	}

	if (!xhci->slot_id) {
		xhci_err(xhci, "Error while assigning device slot ID\n");
		return 0;
	}
	/* xhci_alloc_virt_device() does not touch rings; no need to lock */
	if (!xhci_alloc_virt_device(xhci, xhci->slot_id, udev, GFP_KERNEL)) {
		/* Disable slot, if we can do it without mem alloc */
		xhci_warn(xhci, "Could not allocate xHCI USB device data structures\n");
		spin_lock_irqsave(&xhci->lock, flags);
		if (!xhci_queue_slot_control(xhci, TRB_DISABLE_SLOT, udev->slot_id))
			xhci_ring_cmd_db(xhci);
		spin_unlock_irqrestore(&xhci->lock, flags);
		return 0;
	}
	udev->slot_id = xhci->slot_id;
	/* Is this a LS or FS device under a HS hub? */
	/* Hub or peripherial? */
	return 1;
}

/*
 * Issue an Address Device command (which will issue a SetAddress request to
 * the device).
 * We should be protected by the usb_address0_mutex in khubd's hub_port_init, so
 * we should only issue and wait on one address command at the same time.
 *
 * We add one to the device address issued by the hardware because the USB core
 * uses address 1 for the root hubs (even though they're not really devices).
 */
int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
{
	unsigned long flags;
	int timeleft;
	struct xhci_virt_device *virt_dev;
	int ret = 0;
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
	struct xhci_slot_ctx *slot_ctx;
	struct xhci_input_control_ctx *ctrl_ctx;
	u64 temp_64;

	if (!udev->slot_id) {
		xhci_dbg(xhci, "Bad Slot ID %d\n", udev->slot_id);
		return -EINVAL;
	}

	virt_dev = xhci->devs[udev->slot_id];

	/* If this is a Set Address to an unconfigured device, setup ep 0 */
	if (!udev->config)
		xhci_setup_addressable_virt_dev(xhci, udev);
	/* Otherwise, assume the core has the device configured how it wants */
	xhci_dbg(xhci, "Slot ID %d Input Context:\n", udev->slot_id);
	xhci_dbg_ctx(xhci, virt_dev->in_ctx, 2);

	spin_lock_irqsave(&xhci->lock, flags);
	ret = xhci_queue_address_device(xhci, virt_dev->in_ctx->dma,
					udev->slot_id);
	if (ret) {
		spin_unlock_irqrestore(&xhci->lock, flags);
		xhci_dbg(xhci, "FIXME: allocate a command ring segment\n");
		return ret;
	}
	xhci_ring_cmd_db(xhci);
	spin_unlock_irqrestore(&xhci->lock, flags);

	/* ctrl tx can take up to 5 sec; XXX: need more time for xHC? */
	timeleft = wait_for_completion_interruptible_timeout(&xhci->addr_dev,
			USB_CTRL_SET_TIMEOUT);
	/* FIXME: From section 4.3.4: "Software shall be responsible for timing
	 * the SetAddress() "recovery interval" required by USB and aborting the
	 * command on a timeout.
	 */
	if (timeleft <= 0) {
		xhci_warn(xhci, "%s while waiting for a slot\n",
				timeleft == 0 ? "Timeout" : "Signal");
		/* FIXME cancel the address device command */
		return -ETIME;
	}

	switch (virt_dev->cmd_status) {
	case COMP_CTX_STATE:
	case COMP_EBADSLT:
		xhci_err(xhci, "Setup ERROR: address device command for slot %d.\n",
				udev->slot_id);
		ret = -EINVAL;
		break;
	case COMP_TX_ERR:
		dev_warn(&udev->dev, "Device not responding to set address.\n");
		ret = -EPROTO;
		break;
	case COMP_SUCCESS:
		xhci_dbg(xhci, "Successful Address Device command\n");
		break;
	default:
		xhci_err(xhci, "ERROR: unexpected command completion "
				"code 0x%x.\n", virt_dev->cmd_status);
		xhci_dbg(xhci, "Slot ID %d Output Context:\n", udev->slot_id);
		xhci_dbg_ctx(xhci, virt_dev->out_ctx, 2);
		ret = -EINVAL;
		break;
	}
	if (ret) {
		return ret;
	}
	temp_64 = xhci_read_64(xhci, &xhci->op_regs->dcbaa_ptr);
	xhci_dbg(xhci, "Op regs DCBAA ptr = %#016llx\n", temp_64);
	xhci_dbg(xhci, "Slot ID %d dcbaa entry @%p = %#016llx\n",
			udev->slot_id,
			&xhci->dcbaa->dev_context_ptrs[udev->slot_id],
			(unsigned long long)
				xhci->dcbaa->dev_context_ptrs[udev->slot_id]);
	xhci_dbg(xhci, "Output Context DMA address = %#08llx\n",
			(unsigned long long)virt_dev->out_ctx->dma);
	xhci_dbg(xhci, "Slot ID %d Input Context:\n", udev->slot_id);
	xhci_dbg_ctx(xhci, virt_dev->in_ctx, 2);
	xhci_dbg(xhci, "Slot ID %d Output Context:\n", udev->slot_id);
	xhci_dbg_ctx(xhci, virt_dev->out_ctx, 2);
	/*
	 * USB core uses address 1 for the roothubs, so we add one to the
	 * address given back to us by the HC.
	 */
	slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->out_ctx);
	udev->devnum = (slot_ctx->dev_state & DEV_ADDR_MASK) + 1;
	/* Zero the input context control for later use */
	ctrl_ctx = xhci_get_input_control_ctx(xhci, virt_dev->in_ctx);
	ctrl_ctx->add_flags = 0;
	ctrl_ctx->drop_flags = 0;

	xhci_dbg(xhci, "Device address = %d\n", udev->devnum);
	/* XXX Meh, not sure if anyone else but choose_address uses this. */
	set_bit(udev->devnum, udev->bus->devmap.devicemap);

	return 0;
}

/* Once a hub descriptor is fetched for a device, we need to update the xHC's
 * internal data structures for the device.
 */
int xhci_update_hub_device(struct usb_hcd *hcd, struct usb_device *hdev,
			struct usb_tt *tt, gfp_t mem_flags)
{
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
	struct xhci_virt_device *vdev;
	struct xhci_command *config_cmd;
	struct xhci_input_control_ctx *ctrl_ctx;
	struct xhci_slot_ctx *slot_ctx;
	unsigned long flags;
	unsigned think_time;
	int ret;

	/* Ignore root hubs */
	if (!hdev->parent)
		return 0;

	vdev = xhci->devs[hdev->slot_id];
	if (!vdev) {
		xhci_warn(xhci, "Cannot update hub desc for unknown device.\n");
		return -EINVAL;
	}
	config_cmd = xhci_alloc_command(xhci, true, mem_flags);
	if (!config_cmd) {
		xhci_dbg(xhci, "Could not allocate xHCI command structure.\n");
		return -ENOMEM;
	}

	spin_lock_irqsave(&xhci->lock, flags);
	xhci_slot_copy(xhci, config_cmd->in_ctx, vdev->out_ctx);
	ctrl_ctx = xhci_get_input_control_ctx(xhci, config_cmd->in_ctx);
	ctrl_ctx->add_flags |= SLOT_FLAG;
	slot_ctx = xhci_get_slot_ctx(xhci, config_cmd->in_ctx);
	slot_ctx->dev_info |= DEV_HUB;
	if (tt->multi)
		slot_ctx->dev_info |= DEV_MTT;
	if (xhci->hci_version > 0x95) {
		xhci_dbg(xhci, "xHCI version %x needs hub "
				"TT think time and number of ports\n",
				(unsigned int) xhci->hci_version);
		slot_ctx->dev_info2 |= XHCI_MAX_PORTS(hdev->maxchild);
		/* Set TT think time - convert from ns to FS bit times.
		 * 0 = 8 FS bit times, 1 = 16 FS bit times,
		 * 2 = 24 FS bit times, 3 = 32 FS bit times.
		 */
		think_time = tt->think_time;
		if (think_time != 0)
			think_time = (think_time / 666) - 1;
		slot_ctx->tt_info |= TT_THINK_TIME(think_time);
	} else {
		xhci_dbg(xhci, "xHCI version %x doesn't need hub "
				"TT think time or number of ports\n",
				(unsigned int) xhci->hci_version);
	}
	slot_ctx->dev_state = 0;
	spin_unlock_irqrestore(&xhci->lock, flags);

	xhci_dbg(xhci, "Set up %s for hub device.\n",
			(xhci->hci_version > 0x95) ?
			"configure endpoint" : "evaluate context");
	xhci_dbg(xhci, "Slot %u Input Context:\n", hdev->slot_id);
	xhci_dbg_ctx(xhci, config_cmd->in_ctx, 0);

	/* Issue and wait for the configure endpoint or
	 * evaluate context command.
	 */
	if (xhci->hci_version > 0x95)
		ret = xhci_configure_endpoint(xhci, hdev, config_cmd,
				false, false);
	else
		ret = xhci_configure_endpoint(xhci, hdev, config_cmd,
				true, false);

	xhci_dbg(xhci, "Slot %u Output Context:\n", hdev->slot_id);
	xhci_dbg_ctx(xhci, vdev->out_ctx, 0);

	xhci_free_command(xhci, config_cmd);
	return ret;
}

int xhci_get_frame(struct usb_hcd *hcd)
{
	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
	/* EHCI mods by the periodic size.  Why? */
	return xhci_readl(xhci, &xhci->run_regs->microframe_index) >> 3;
}

MODULE_DESCRIPTION(DRIVER_DESC);
MODULE_AUTHOR(DRIVER_AUTHOR);
MODULE_LICENSE("GPL");

static int __init xhci_hcd_init(void)
{
#ifdef CONFIG_PCI
	int retval = 0;

	retval = xhci_register_pci();

	if (retval < 0) {
		printk(KERN_DEBUG "Problem registering PCI driver.");
		return retval;
	}
#endif
	/*
	 * Check the compiler generated sizes of structures that must be laid
	 * out in specific ways for hardware access.
	 */
	BUILD_BUG_ON(sizeof(struct xhci_doorbell_array) != 256*32/8);
	BUILD_BUG_ON(sizeof(struct xhci_slot_ctx) != 8*32/8);
	BUILD_BUG_ON(sizeof(struct xhci_ep_ctx) != 8*32/8);
	/* xhci_device_control has eight fields, and also
	 * embeds one xhci_slot_ctx and 31 xhci_ep_ctx
	 */
	BUILD_BUG_ON(sizeof(struct xhci_stream_ctx) != 4*32/8);
	BUILD_BUG_ON(sizeof(union xhci_trb) != 4*32/8);
	BUILD_BUG_ON(sizeof(struct xhci_erst_entry) != 4*32/8);
	BUILD_BUG_ON(sizeof(struct xhci_cap_regs) != 7*32/8);
	BUILD_BUG_ON(sizeof(struct xhci_intr_reg) != 8*32/8);
	/* xhci_run_regs has eight fields and embeds 128 xhci_intr_regs */
	BUILD_BUG_ON(sizeof(struct xhci_run_regs) != (8+8*128)*32/8);
	BUILD_BUG_ON(sizeof(struct xhci_doorbell_array) != 256*32/8);
	return 0;
}
module_init(xhci_hcd_init);

static void __exit xhci_hcd_cleanup(void)
{
#ifdef CONFIG_PCI
	xhci_unregister_pci();
#endif
}
module_exit(xhci_hcd_cleanup);