summaryrefslogtreecommitdiff
path: root/drivers/char/tpm/tpm-interface.c
blob: 8de61876f6336bc2bd239ce935191b0b4c01eca4 (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
/*
 * Copyright (C) 2004 IBM Corporation
 * Copyright (C) 2014 Intel Corporation
 *
 * Authors:
 * Leendert van Doorn <leendert@watson.ibm.com>
 * Dave Safford <safford@watson.ibm.com>
 * Reiner Sailer <sailer@watson.ibm.com>
 * Kylene Hall <kjhall@us.ibm.com>
 *
 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
 *
 * Device driver for TCG/TCPA TPM (trusted platform module).
 * Specifications at www.trustedcomputinggroup.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, version 2 of the
 * License.
 *
 * Note, the TPM chip is not interrupt driven (only polling)
 * and can have very long timeouts (minutes!). Hence the unusual
 * calls to msleep.
 *
 */

#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/freezer.h>

#include "tpm.h"
#include "tpm_eventlog.h"

#define TPM_MAX_ORDINAL 243
#define TSC_MAX_ORDINAL 12
#define TPM_PROTECTED_COMMAND 0x00
#define TPM_CONNECTION_COMMAND 0x40

/*
 * Bug workaround - some TPM's don't flush the most
 * recently changed pcr on suspend, so force the flush
 * with an extend to the selected _unused_ non-volatile pcr.
 */
static int tpm_suspend_pcr;
module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
MODULE_PARM_DESC(suspend_pcr,
		 "PCR to use for dummy writes to faciltate flush on suspend.");

/*
 * Array with one entry per ordinal defining the maximum amount
 * of time the chip could take to return the result.  The ordinal
 * designation of short, medium or long is defined in a table in
 * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
 * values of the SHORT, MEDIUM, and LONG durations are retrieved
 * from the chip during initialization with a call to tpm_get_timeouts.
 */
static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
	TPM_UNDEFINED,		/* 0 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 5 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 10 */
	TPM_SHORT,
	TPM_MEDIUM,
	TPM_LONG,
	TPM_LONG,
	TPM_MEDIUM,		/* 15 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_MEDIUM,
	TPM_LONG,
	TPM_SHORT,		/* 20 */
	TPM_SHORT,
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_SHORT,		/* 25 */
	TPM_SHORT,
	TPM_MEDIUM,
	TPM_SHORT,
	TPM_SHORT,
	TPM_MEDIUM,		/* 30 */
	TPM_LONG,
	TPM_MEDIUM,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,		/* 35 */
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_MEDIUM,		/* 40 */
	TPM_LONG,
	TPM_MEDIUM,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,		/* 45 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_LONG,
	TPM_MEDIUM,		/* 50 */
	TPM_MEDIUM,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 55 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_MEDIUM,		/* 60 */
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_SHORT,
	TPM_SHORT,
	TPM_MEDIUM,		/* 65 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 70 */
	TPM_SHORT,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 75 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_LONG,		/* 80 */
	TPM_UNDEFINED,
	TPM_MEDIUM,
	TPM_LONG,
	TPM_SHORT,
	TPM_UNDEFINED,		/* 85 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 90 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_UNDEFINED,		/* 95 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_MEDIUM,		/* 100 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 105 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 110 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,		/* 115 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_LONG,		/* 120 */
	TPM_LONG,
	TPM_MEDIUM,
	TPM_UNDEFINED,
	TPM_SHORT,
	TPM_SHORT,		/* 125 */
	TPM_SHORT,
	TPM_LONG,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,		/* 130 */
	TPM_MEDIUM,
	TPM_UNDEFINED,
	TPM_SHORT,
	TPM_MEDIUM,
	TPM_UNDEFINED,		/* 135 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 140 */
	TPM_SHORT,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 145 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 150 */
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_SHORT,
	TPM_SHORT,
	TPM_UNDEFINED,		/* 155 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 160 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 165 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_LONG,		/* 170 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 175 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_MEDIUM,		/* 180 */
	TPM_SHORT,
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_MEDIUM,		/* 185 */
	TPM_SHORT,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 190 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 195 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 200 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,
	TPM_SHORT,		/* 205 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_MEDIUM,		/* 210 */
	TPM_UNDEFINED,
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_MEDIUM,
	TPM_UNDEFINED,		/* 215 */
	TPM_MEDIUM,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,
	TPM_SHORT,		/* 220 */
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_SHORT,
	TPM_UNDEFINED,		/* 225 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 230 */
	TPM_LONG,
	TPM_MEDIUM,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,		/* 235 */
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_UNDEFINED,
	TPM_SHORT,		/* 240 */
	TPM_UNDEFINED,
	TPM_MEDIUM,
};

/*
 * Returns max number of jiffies to wait
 */
unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
					   u32 ordinal)
{
	int duration_idx = TPM_UNDEFINED;
	int duration = 0;

	/*
	 * We only have a duration table for protected commands, where the upper
	 * 16 bits are 0. For the few other ordinals the fallback will be used.
	 */
	if (ordinal < TPM_MAX_ORDINAL)
		duration_idx = tpm_ordinal_duration[ordinal];

	if (duration_idx != TPM_UNDEFINED)
		duration = chip->duration[duration_idx];
	if (duration <= 0)
		return 2 * 60 * HZ;
	else
		return duration;
}
EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);

/*
 * Internal kernel interface to transmit TPM commands
 */
ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
		     unsigned int flags)
{
	ssize_t rc;
	u32 count, ordinal;
	unsigned long stop;

	if (bufsiz < TPM_HEADER_SIZE)
		return -EINVAL;

	if (bufsiz > TPM_BUFSIZE)
		bufsiz = TPM_BUFSIZE;

	count = be32_to_cpu(*((__be32 *) (buf + 2)));
	ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
	if (count == 0)
		return -ENODATA;
	if (count > bufsiz) {
		dev_err(&chip->dev,
			"invalid count value %x %zx\n", count, bufsiz);
		return -E2BIG;
	}

	if (!(flags & TPM_TRANSMIT_UNLOCKED))
		mutex_lock(&chip->tpm_mutex);

	rc = chip->ops->send(chip, (u8 *) buf, count);
	if (rc < 0) {
		dev_err(&chip->dev,
			"tpm_transmit: tpm_send: error %zd\n", rc);
		goto out;
	}

	if (chip->flags & TPM_CHIP_FLAG_IRQ)
		goto out_recv;

	if (chip->flags & TPM_CHIP_FLAG_TPM2)
		stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
	else
		stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
	do {
		u8 status = chip->ops->status(chip);
		if ((status & chip->ops->req_complete_mask) ==
		    chip->ops->req_complete_val)
			goto out_recv;

		if (chip->ops->req_canceled(chip, status)) {
			dev_err(&chip->dev, "Operation Canceled\n");
			rc = -ECANCELED;
			goto out;
		}

		msleep(TPM_TIMEOUT);	/* CHECK */
		rmb();
	} while (time_before(jiffies, stop));

	chip->ops->cancel(chip);
	dev_err(&chip->dev, "Operation Timed out\n");
	rc = -ETIME;
	goto out;

out_recv:
	rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
	if (rc < 0)
		dev_err(&chip->dev,
			"tpm_transmit: tpm_recv: error %zd\n", rc);
out:
	if (!(flags & TPM_TRANSMIT_UNLOCKED))
		mutex_unlock(&chip->tpm_mutex);
	return rc;
}

#define TPM_DIGEST_SIZE 20
#define TPM_RET_CODE_IDX 6

ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,
			 int len, unsigned int flags, const char *desc)
{
	const struct tpm_output_header *header;
	int err;

	len = tpm_transmit(chip, (const u8 *)cmd, len, flags);
	if (len <  0)
		return len;
	else if (len < TPM_HEADER_SIZE)
		return -EFAULT;

	header = cmd;

	err = be32_to_cpu(header->return_code);
	if (err != 0 && desc)
		dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
			desc);

	return err;
}

#define TPM_INTERNAL_RESULT_SIZE 200
#define TPM_ORD_GET_CAP cpu_to_be32(101)
#define TPM_ORD_GET_RANDOM cpu_to_be32(70)

static const struct tpm_input_header tpm_getcap_header = {
	.tag = TPM_TAG_RQU_COMMAND,
	.length = cpu_to_be32(22),
	.ordinal = TPM_ORD_GET_CAP
};

ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap,
		   const char *desc)
{
	struct tpm_cmd_t tpm_cmd;
	int rc;

	tpm_cmd.header.in = tpm_getcap_header;
	if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
		tpm_cmd.params.getcap_in.cap = subcap_id;
		/*subcap field not necessary */
		tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
		tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
	} else {
		if (subcap_id == TPM_CAP_FLAG_PERM ||
		    subcap_id == TPM_CAP_FLAG_VOL)
			tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
		else
			tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
		tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
		tpm_cmd.params.getcap_in.subcap = subcap_id;
	}
	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
			      desc);
	if (!rc)
		*cap = tpm_cmd.params.getcap_out.cap;
	return rc;
}
EXPORT_SYMBOL_GPL(tpm_getcap);

#define TPM_ORD_STARTUP cpu_to_be32(153)
#define TPM_ST_CLEAR cpu_to_be16(1)
#define TPM_ST_STATE cpu_to_be16(2)
#define TPM_ST_DEACTIVATED cpu_to_be16(3)
static const struct tpm_input_header tpm_startup_header = {
	.tag = TPM_TAG_RQU_COMMAND,
	.length = cpu_to_be32(12),
	.ordinal = TPM_ORD_STARTUP
};

static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
{
	struct tpm_cmd_t start_cmd;
	start_cmd.header.in = tpm_startup_header;

	start_cmd.params.startup_in.startup_type = startup_type;
	return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
				"attempting to start the TPM");
}

int tpm_get_timeouts(struct tpm_chip *chip)
{
	struct tpm_cmd_t tpm_cmd;
	unsigned long new_timeout[4];
	unsigned long old_timeout[4];
	struct duration_t *duration_cap;
	ssize_t rc;

	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
		/* Fixed timeouts for TPM2 */
		chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
		chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
		chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
		chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
		chip->duration[TPM_SHORT] =
		    msecs_to_jiffies(TPM2_DURATION_SHORT);
		chip->duration[TPM_MEDIUM] =
		    msecs_to_jiffies(TPM2_DURATION_MEDIUM);
		chip->duration[TPM_LONG] =
		    msecs_to_jiffies(TPM2_DURATION_LONG);
		return 0;
	}

	tpm_cmd.header.in = tpm_getcap_header;
	tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
			      NULL);

	if (rc == TPM_ERR_INVALID_POSTINIT) {
		/* The TPM is not started, we are the first to talk to it.
		   Execute a startup command. */
		dev_info(&chip->dev, "Issuing TPM_STARTUP");
		if (tpm_startup(chip, TPM_ST_CLEAR))
			return rc;

		tpm_cmd.header.in = tpm_getcap_header;
		tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
		tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
		tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
		rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
				      0, NULL);
	}
	if (rc) {
		dev_err(&chip->dev,
			"A TPM error (%zd) occurred attempting to determine the timeouts\n",
			rc);
		goto duration;
	}

	if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
	    be32_to_cpu(tpm_cmd.header.out.length)
	    != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
		return -EINVAL;

	old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
	old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
	old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
	old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
	memcpy(new_timeout, old_timeout, sizeof(new_timeout));

	/*
	 * Provide ability for vendor overrides of timeout values in case
	 * of misreporting.
	 */
	if (chip->ops->update_timeouts != NULL)
		chip->timeout_adjusted =
			chip->ops->update_timeouts(chip, new_timeout);

	if (!chip->timeout_adjusted) {
		/* Don't overwrite default if value is 0 */
		if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
			int i;

			/* timeouts in msec rather usec */
			for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
				new_timeout[i] *= 1000;
			chip->timeout_adjusted = true;
		}
	}

	/* Report adjusted timeouts */
	if (chip->timeout_adjusted) {
		dev_info(&chip->dev,
			 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
			 old_timeout[0], new_timeout[0],
			 old_timeout[1], new_timeout[1],
			 old_timeout[2], new_timeout[2],
			 old_timeout[3], new_timeout[3]);
	}

	chip->timeout_a = usecs_to_jiffies(new_timeout[0]);
	chip->timeout_b = usecs_to_jiffies(new_timeout[1]);
	chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
	chip->timeout_d = usecs_to_jiffies(new_timeout[3]);

duration:
	tpm_cmd.header.in = tpm_getcap_header;
	tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
	tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
	tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;

	rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
			      "attempting to determine the durations");
	if (rc)
		return rc;

	if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
	    be32_to_cpu(tpm_cmd.header.out.length)
	    != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
		return -EINVAL;

	duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
	chip->duration[TPM_SHORT] =
	    usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
	chip->duration[TPM_MEDIUM] =
	    usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
	chip->duration[TPM_LONG] =
	    usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));

	/* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
	 * value wrong and apparently reports msecs rather than usecs. So we
	 * fix up the resulting too-small TPM_SHORT value to make things work.
	 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
	 */
	if (chip->duration[TPM_SHORT] < (HZ / 100)) {
		chip->duration[TPM_SHORT] = HZ;
		chip->duration[TPM_MEDIUM] *= 1000;
		chip->duration[TPM_LONG] *= 1000;
		chip->duration_adjusted = true;
		dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
	}
	return 0;
}
EXPORT_SYMBOL_GPL(tpm_get_timeouts);

#define TPM_ORD_CONTINUE_SELFTEST 83
#define CONTINUE_SELFTEST_RESULT_SIZE 10

static const struct tpm_input_header continue_selftest_header = {
	.tag = TPM_TAG_RQU_COMMAND,
	.length = cpu_to_be32(10),
	.ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
};

/**
 * tpm_continue_selftest -- run TPM's selftest
 * @chip: TPM chip to use
 *
 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 * a TPM error code.
 */
static int tpm_continue_selftest(struct tpm_chip *chip)
{
	int rc;
	struct tpm_cmd_t cmd;

	cmd.header.in = continue_selftest_header;
	rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
			      "continue selftest");
	return rc;
}

#define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
#define READ_PCR_RESULT_SIZE 30
static const struct tpm_input_header pcrread_header = {
	.tag = TPM_TAG_RQU_COMMAND,
	.length = cpu_to_be32(14),
	.ordinal = TPM_ORDINAL_PCRREAD
};

int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
{
	int rc;
	struct tpm_cmd_t cmd;

	cmd.header.in = pcrread_header;
	cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
	rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
			      "attempting to read a pcr value");

	if (rc == 0)
		memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
		       TPM_DIGEST_SIZE);
	return rc;
}

/**
 * tpm_is_tpm2 - is the chip a TPM2 chip?
 * @chip_num:	tpm idx # or ANY
 *
 * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 * is a TPM2 chip.
 */
int tpm_is_tpm2(u32 chip_num)
{
	struct tpm_chip *chip;
	int rc;

	chip = tpm_chip_find_get(chip_num);
	if (chip == NULL)
		return -ENODEV;

	rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;

	tpm_put_ops(chip);

	return rc;
}
EXPORT_SYMBOL_GPL(tpm_is_tpm2);

/**
 * tpm_pcr_read - read a pcr value
 * @chip_num:	tpm idx # or ANY
 * @pcr_idx:	pcr idx to retrieve
 * @res_buf:	TPM_PCR value
 *		size of res_buf is 20 bytes (or NULL if you don't care)
 *
 * The TPM driver should be built-in, but for whatever reason it
 * isn't, protect against the chip disappearing, by incrementing
 * the module usage count.
 */
int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
{
	struct tpm_chip *chip;
	int rc;

	chip = tpm_chip_find_get(chip_num);
	if (chip == NULL)
		return -ENODEV;
	if (chip->flags & TPM_CHIP_FLAG_TPM2)
		rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
	else
		rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
	tpm_put_ops(chip);
	return rc;
}
EXPORT_SYMBOL_GPL(tpm_pcr_read);

/**
 * tpm_pcr_extend - extend pcr value with hash
 * @chip_num:	tpm idx # or AN&
 * @pcr_idx:	pcr idx to extend
 * @hash:	hash value used to extend pcr value
 *
 * The TPM driver should be built-in, but for whatever reason it
 * isn't, protect against the chip disappearing, by incrementing
 * the module usage count.
 */
#define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
#define EXTEND_PCR_RESULT_SIZE 34
static const struct tpm_input_header pcrextend_header = {
	.tag = TPM_TAG_RQU_COMMAND,
	.length = cpu_to_be32(34),
	.ordinal = TPM_ORD_PCR_EXTEND
};

int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
{
	struct tpm_cmd_t cmd;
	int rc;
	struct tpm_chip *chip;

	chip = tpm_chip_find_get(chip_num);
	if (chip == NULL)
		return -ENODEV;

	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
		rc = tpm2_pcr_extend(chip, pcr_idx, hash);
		tpm_put_ops(chip);
		return rc;
	}

	cmd.header.in = pcrextend_header;
	cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
	memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
	rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
			      "attempting extend a PCR value");

	tpm_put_ops(chip);
	return rc;
}
EXPORT_SYMBOL_GPL(tpm_pcr_extend);

/**
 * tpm_do_selftest - have the TPM continue its selftest and wait until it
 *                   can receive further commands
 * @chip: TPM chip to use
 *
 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 * a TPM error code.
 */
int tpm_do_selftest(struct tpm_chip *chip)
{
	int rc;
	unsigned int loops;
	unsigned int delay_msec = 100;
	unsigned long duration;
	u8 dummy[TPM_DIGEST_SIZE];

	duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);

	loops = jiffies_to_msecs(duration) / delay_msec;

	rc = tpm_continue_selftest(chip);
	/* This may fail if there was no TPM driver during a suspend/resume
	 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
	 */
	if (rc)
		return rc;

	do {
		/* Attempt to read a PCR value */
		rc = tpm_pcr_read_dev(chip, 0, dummy);

		/* Some buggy TPMs will not respond to tpm_tis_ready() for
		 * around 300ms while the self test is ongoing, keep trying
		 * until the self test duration expires. */
		if (rc == -ETIME) {
			dev_info(
			    &chip->dev, HW_ERR
			    "TPM command timed out during continue self test");
			msleep(delay_msec);
			continue;
		}

		if (rc < TPM_HEADER_SIZE)
			return -EFAULT;

		if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
			dev_info(&chip->dev,
				 "TPM is disabled/deactivated (0x%X)\n", rc);
			/* TPM is disabled and/or deactivated; driver can
			 * proceed and TPM does handle commands for
			 * suspend/resume correctly
			 */
			return 0;
		}
		if (rc != TPM_WARN_DOING_SELFTEST)
			return rc;
		msleep(delay_msec);
	} while (--loops > 0);

	return rc;
}
EXPORT_SYMBOL_GPL(tpm_do_selftest);

/**
 * tpm1_auto_startup - Perform the standard automatic TPM initialization
 *                     sequence
 * @chip: TPM chip to use
 *
 * Returns 0 on success, < 0 in case of fatal error.
 */
int tpm1_auto_startup(struct tpm_chip *chip)
{
	int rc;

	rc = tpm_get_timeouts(chip);
	if (rc)
		goto out;
	rc = tpm_do_selftest(chip);
	if (rc) {
		dev_err(&chip->dev, "TPM self test failed\n");
		goto out;
	}

	return rc;
out:
	if (rc > 0)
		rc = -ENODEV;
	return rc;
}

int tpm_send(u32 chip_num, void *cmd, size_t buflen)
{
	struct tpm_chip *chip;
	int rc;

	chip = tpm_chip_find_get(chip_num);
	if (chip == NULL)
		return -ENODEV;

	rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");

	tpm_put_ops(chip);
	return rc;
}
EXPORT_SYMBOL_GPL(tpm_send);

static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
					bool check_cancel, bool *canceled)
{
	u8 status = chip->ops->status(chip);

	*canceled = false;
	if ((status & mask) == mask)
		return true;
	if (check_cancel && chip->ops->req_canceled(chip, status)) {
		*canceled = true;
		return true;
	}
	return false;
}

int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
		      wait_queue_head_t *queue, bool check_cancel)
{
	unsigned long stop;
	long rc;
	u8 status;
	bool canceled = false;

	/* check current status */
	status = chip->ops->status(chip);
	if ((status & mask) == mask)
		return 0;

	stop = jiffies + timeout;

	if (chip->flags & TPM_CHIP_FLAG_IRQ) {
again:
		timeout = stop - jiffies;
		if ((long)timeout <= 0)
			return -ETIME;
		rc = wait_event_interruptible_timeout(*queue,
			wait_for_tpm_stat_cond(chip, mask, check_cancel,
					       &canceled),
			timeout);
		if (rc > 0) {
			if (canceled)
				return -ECANCELED;
			return 0;
		}
		if (rc == -ERESTARTSYS && freezing(current)) {
			clear_thread_flag(TIF_SIGPENDING);
			goto again;
		}
	} else {
		do {
			msleep(TPM_TIMEOUT);
			status = chip->ops->status(chip);
			if ((status & mask) == mask)
				return 0;
		} while (time_before(jiffies, stop));
	}
	return -ETIME;
}
EXPORT_SYMBOL_GPL(wait_for_tpm_stat);

#define TPM_ORD_SAVESTATE cpu_to_be32(152)
#define SAVESTATE_RESULT_SIZE 10

static const struct tpm_input_header savestate_header = {
	.tag = TPM_TAG_RQU_COMMAND,
	.length = cpu_to_be32(10),
	.ordinal = TPM_ORD_SAVESTATE
};

/*
 * We are about to suspend. Save the TPM state
 * so that it can be restored.
 */
int tpm_pm_suspend(struct device *dev)
{
	struct tpm_chip *chip = dev_get_drvdata(dev);
	struct tpm_cmd_t cmd;
	int rc, try;

	u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };

	if (chip == NULL)
		return -ENODEV;

	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
		tpm2_shutdown(chip, TPM2_SU_STATE);
		return 0;
	}

	/* for buggy tpm, flush pcrs with extend to selected dummy */
	if (tpm_suspend_pcr) {
		cmd.header.in = pcrextend_header;
		cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
		memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
		       TPM_DIGEST_SIZE);
		rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
				      "extending dummy pcr before suspend");
	}

	/* now do the actual savestate */
	for (try = 0; try < TPM_RETRY; try++) {
		cmd.header.in = savestate_header;
		rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
				      NULL);

		/*
		 * If the TPM indicates that it is too busy to respond to
		 * this command then retry before giving up.  It can take
		 * several seconds for this TPM to be ready.
		 *
		 * This can happen if the TPM has already been sent the
		 * SaveState command before the driver has loaded.  TCG 1.2
		 * specification states that any communication after SaveState
		 * may cause the TPM to invalidate previously saved state.
		 */
		if (rc != TPM_WARN_RETRY)
			break;
		msleep(TPM_TIMEOUT_RETRY);
	}

	if (rc)
		dev_err(&chip->dev,
			"Error (%d) sending savestate before suspend\n", rc);
	else if (try > 0)
		dev_warn(&chip->dev, "TPM savestate took %dms\n",
			 try * TPM_TIMEOUT_RETRY);

	return rc;
}
EXPORT_SYMBOL_GPL(tpm_pm_suspend);

/*
 * Resume from a power safe. The BIOS already restored
 * the TPM state.
 */
int tpm_pm_resume(struct device *dev)
{
	struct tpm_chip *chip = dev_get_drvdata(dev);

	if (chip == NULL)
		return -ENODEV;

	return 0;
}
EXPORT_SYMBOL_GPL(tpm_pm_resume);

#define TPM_GETRANDOM_RESULT_SIZE	18
static const struct tpm_input_header tpm_getrandom_header = {
	.tag = TPM_TAG_RQU_COMMAND,
	.length = cpu_to_be32(14),
	.ordinal = TPM_ORD_GET_RANDOM
};

/**
 * tpm_get_random() - Get random bytes from the tpm's RNG
 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
 * @out: destination buffer for the random bytes
 * @max: the max number of bytes to write to @out
 *
 * Returns < 0 on error and the number of bytes read on success
 */
int tpm_get_random(u32 chip_num, u8 *out, size_t max)
{
	struct tpm_chip *chip;
	struct tpm_cmd_t tpm_cmd;
	u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
	int err, total = 0, retries = 5;
	u8 *dest = out;

	if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
		return -EINVAL;

	chip = tpm_chip_find_get(chip_num);
	if (chip == NULL)
		return -ENODEV;

	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
		err = tpm2_get_random(chip, out, max);
		tpm_put_ops(chip);
		return err;
	}

	do {
		tpm_cmd.header.in = tpm_getrandom_header;
		tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);

		err = tpm_transmit_cmd(chip, &tpm_cmd,
				       TPM_GETRANDOM_RESULT_SIZE + num_bytes,
				       0, "attempting get random");
		if (err)
			break;

		recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
		memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);

		dest += recd;
		total += recd;
		num_bytes -= recd;
	} while (retries-- && total < max);

	tpm_put_ops(chip);
	return total ? total : -EIO;
}
EXPORT_SYMBOL_GPL(tpm_get_random);

/**
 * tpm_seal_trusted() - seal a trusted key
 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
 * @options: authentication values and other options
 * @payload: the key data in clear and encrypted form
 *
 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
 * are supported.
 */
int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
		     struct trusted_key_options *options)
{
	struct tpm_chip *chip;
	int rc;

	chip = tpm_chip_find_get(chip_num);
	if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
		return -ENODEV;

	rc = tpm2_seal_trusted(chip, payload, options);

	tpm_put_ops(chip);
	return rc;
}
EXPORT_SYMBOL_GPL(tpm_seal_trusted);

/**
 * tpm_unseal_trusted() - unseal a trusted key
 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
 * @options: authentication values and other options
 * @payload: the key data in clear and encrypted form
 *
 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
 * are supported.
 */
int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
		       struct trusted_key_options *options)
{
	struct tpm_chip *chip;
	int rc;

	chip = tpm_chip_find_get(chip_num);
	if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
		return -ENODEV;

	rc = tpm2_unseal_trusted(chip, payload, options);

	tpm_put_ops(chip);

	return rc;
}
EXPORT_SYMBOL_GPL(tpm_unseal_trusted);

static int __init tpm_init(void)
{
	int rc;

	tpm_class = class_create(THIS_MODULE, "tpm");
	if (IS_ERR(tpm_class)) {
		pr_err("couldn't create tpm class\n");
		return PTR_ERR(tpm_class);
	}

	rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
	if (rc < 0) {
		pr_err("tpm: failed to allocate char dev region\n");
		class_destroy(tpm_class);
		return rc;
	}

	return 0;
}

static void __exit tpm_exit(void)
{
	idr_destroy(&dev_nums_idr);
	class_destroy(tpm_class);
	unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
}

subsys_initcall(tpm_init);
module_exit(tpm_exit);

MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
MODULE_DESCRIPTION("TPM Driver");
MODULE_VERSION("2.0");
MODULE_LICENSE("GPL");