summaryrefslogtreecommitdiffstats
path: root/drivers/char/tpm/tpm1-cmd.c
blob: faacbe1ffa1a9016798cb8ab00c5a1ca4879471b (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
// SPDX-License-Identifier: GPL-2.0
/*
 * 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>
 *
 * Device driver for TCG/TCPA TPM (trusted platform module).
 * Specifications at www.trustedcomputinggroup.org
 */

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

#include "tpm.h"

#define TPM_MAX_ORDINAL 243

/*
 * 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 tpm1_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,
};

/**
 * tpm1_calc_ordinal_duration() - calculate the maximum command duration
 * @chip:    TPM chip to use.
 * @ordinal: TPM command ordinal.
 *
 * The function returns the maximum amount of time the chip could take
 * to return the result for a particular ordinal in jiffies.
 *
 * Return: A maximal duration time for an ordinal in jiffies.
 */
unsigned long tpm1_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 = tpm1_ordinal_duration[ordinal];

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

#define TPM_ORD_STARTUP 153
#define TPM_ST_CLEAR 1

/**
 * tpm_startup() - turn on the TPM
 * @chip: TPM chip to use
 *
 * Normally the firmware should start the TPM. This function is provided as a
 * workaround if this does not happen. A legal case for this could be for
 * example when a TPM emulator is used.
 *
 * Return: same as tpm_transmit_cmd()
 */
static int tpm1_startup(struct tpm_chip *chip)
{
	struct tpm_buf buf;
	int rc;

	dev_info(&chip->dev, "starting up the TPM manually\n");

	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
	if (rc < 0)
		return rc;

	tpm_buf_append_u16(&buf, TPM_ST_CLEAR);

	rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM");
	tpm_buf_destroy(&buf);
	return rc;
}

int tpm1_get_timeouts(struct tpm_chip *chip)
{
	cap_t cap;
	unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
	ssize_t rc;

	rc = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
			 sizeof(cap.timeout));
	if (rc == TPM_ERR_INVALID_POSTINIT) {
		if (tpm1_startup(chip))
			return rc;

		rc = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
				 "attempting to determine the timeouts",
				 sizeof(cap.timeout));
	}

	if (rc) {
		dev_err(&chip->dev, "A TPM error (%zd) occurred attempting to determine the timeouts\n",
			rc);
		return rc;
	}

	timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
	timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
	timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
	timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
	timeout_chip[0] = be32_to_cpu(cap.timeout.a);
	timeout_chip[1] = be32_to_cpu(cap.timeout.b);
	timeout_chip[2] = be32_to_cpu(cap.timeout.c);
	timeout_chip[3] = be32_to_cpu(cap.timeout.d);
	memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));

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

	if (!chip->timeout_adjusted) {
		/* Restore default if chip reported 0 */
		unsigned int i;

		for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
			if (timeout_eff[i])
				continue;

			timeout_eff[i] = timeout_old[i];
			chip->timeout_adjusted = true;
		}

		if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
			/* timeouts in msec rather usec */
			for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
				timeout_eff[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",
			 timeout_chip[0], timeout_eff[0],
			 timeout_chip[1], timeout_eff[1],
			 timeout_chip[2], timeout_eff[2],
			 timeout_chip[3], timeout_eff[3]);
	}

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

	rc = tpm1_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
			 "attempting to determine the durations",
			  sizeof(cap.duration));
	if (rc)
		return rc;

	chip->duration[TPM_SHORT] =
		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
	chip->duration[TPM_MEDIUM] =
		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
	chip->duration[TPM_LONG] =
		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
	chip->duration[TPM_LONG_LONG] = 0; /* not used under 1.2 */

	/* 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.");
	}

	chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
	return 0;
}

#define TPM_ORD_PCR_EXTEND 20
int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash,
		    const char *log_msg)
{
	struct tpm_buf buf;
	int rc;

	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND);
	if (rc)
		return rc;

	tpm_buf_append_u32(&buf, pcr_idx);
	tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);

	rc = tpm_transmit_cmd(chip, &buf, TPM_DIGEST_SIZE, log_msg);
	tpm_buf_destroy(&buf);
	return rc;
}

#define TPM_ORD_GET_CAP 101
ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
		    const char *desc, size_t min_cap_length)
{
	struct tpm_buf buf;
	int rc;

	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
	if (rc)
		return rc;

	if (subcap_id == TPM_CAP_VERSION_1_1 ||
	    subcap_id == TPM_CAP_VERSION_1_2) {
		tpm_buf_append_u32(&buf, subcap_id);
		tpm_buf_append_u32(&buf, 0);
	} else {
		if (subcap_id == TPM_CAP_FLAG_PERM ||
		    subcap_id == TPM_CAP_FLAG_VOL)
			tpm_buf_append_u32(&buf, TPM_CAP_FLAG);
		else
			tpm_buf_append_u32(&buf, TPM_CAP_PROP);

		tpm_buf_append_u32(&buf, 4);
		tpm_buf_append_u32(&buf, subcap_id);
	}
	rc = tpm_transmit_cmd(chip, &buf, min_cap_length, desc);
	if (!rc)
		*cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
	tpm_buf_destroy(&buf);
	return rc;
}
EXPORT_SYMBOL_GPL(tpm1_getcap);

#define TPM_ORD_GET_RANDOM 70
struct tpm1_get_random_out {
	__be32 rng_data_len;
	u8 rng_data[TPM_MAX_RNG_DATA];
} __packed;

/**
 * tpm1_get_random() - get random bytes from the TPM's RNG
 * @chip:	a &struct tpm_chip instance
 * @dest:	destination buffer for the random bytes
 * @max:	the maximum number of bytes to write to @dest
 *
 * Return:
 * *  number of bytes read
 * * -errno (positive TPM return codes are masked to -EIO)
 */
int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
{
	struct tpm1_get_random_out *out;
	u32 num_bytes =  min_t(u32, max, TPM_MAX_RNG_DATA);
	struct tpm_buf buf;
	u32 total = 0;
	int retries = 5;
	u32 recd;
	int rc;

	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
	if (rc)
		return rc;

	do {
		tpm_buf_append_u32(&buf, num_bytes);

		rc = tpm_transmit_cmd(chip, &buf, sizeof(out->rng_data_len),
				      "attempting get random");
		if (rc) {
			if (rc > 0)
				rc = -EIO;
			goto out;
		}

		out = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE];

		recd = be32_to_cpu(out->rng_data_len);
		if (recd > num_bytes) {
			rc = -EFAULT;
			goto out;
		}

		if (tpm_buf_length(&buf) < TPM_HEADER_SIZE +
					   sizeof(out->rng_data_len) + recd) {
			rc = -EFAULT;
			goto out;
		}
		memcpy(dest, out->rng_data, recd);

		dest += recd;
		total += recd;
		num_bytes -= recd;

		tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
	} while (retries-- && total < max);

	rc = total ? (int)total : -EIO;
out:
	tpm_buf_destroy(&buf);
	return rc;
}

#define TPM_ORD_PCRREAD 21
int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
{
	struct tpm_buf buf;
	int rc;

	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCRREAD);
	if (rc)
		return rc;

	tpm_buf_append_u32(&buf, pcr_idx);

	rc = tpm_transmit_cmd(chip, &buf, TPM_DIGEST_SIZE,
			      "attempting to read a pcr value");
	if (rc)
		goto out;

	if (tpm_buf_length(&buf) < TPM_DIGEST_SIZE) {
		rc = -EFAULT;
		goto out;
	}

	memcpy(res_buf, &buf.data[TPM_HEADER_SIZE], TPM_DIGEST_SIZE);

out:
	tpm_buf_destroy(&buf);
	return rc;
}

#define TPM_ORD_CONTINUE_SELFTEST 83
/**
 * 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 tpm1_continue_selftest(struct tpm_chip *chip)
{
	struct tpm_buf buf;
	int rc;

	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_CONTINUE_SELFTEST);
	if (rc)
		return rc;

	rc = tpm_transmit_cmd(chip, &buf, 0, "continue selftest");
	tpm_buf_destroy(&buf);
	return rc;
}

/**
 * tpm1_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 tpm1_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 = tpm1_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);

	loops = jiffies_to_msecs(duration) / delay_msec;

	rc = tpm1_continue_selftest(chip);
	if (rc == TPM_ERR_INVALID_POSTINIT) {
		chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
		dev_info(&chip->dev, "TPM not ready (%d)\n", rc);
	}
	/* 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 = tpm1_pcr_read(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");
			tpm_msleep(delay_msec);
			continue;
		}

		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;
		tpm_msleep(delay_msec);
	} while (--loops > 0);

	return rc;
}
EXPORT_SYMBOL_GPL(tpm1_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 = tpm1_get_timeouts(chip);
	if (rc)
		goto out;
	rc = tpm1_do_selftest(chip);
	if (rc) {
		dev_err(&chip->dev, "TPM self test failed\n");
		goto out;
	}

	chip->allocated_banks = kcalloc(1, sizeof(*chip->allocated_banks),
					GFP_KERNEL);
	if (!chip->allocated_banks) {
		rc = -ENOMEM;
		goto out;
	}

	chip->allocated_banks[0].alg_id = TPM_ALG_SHA1;
	chip->allocated_banks[0].digest_size = hash_digest_size[HASH_ALGO_SHA1];
	chip->allocated_banks[0].crypto_id = HASH_ALGO_SHA1;
	chip->nr_allocated_banks = 1;

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

#define TPM_ORD_SAVESTATE 152

/**
 * tpm1_pm_suspend() - pm suspend handler
 * @chip: TPM chip to use.
 * @tpm_suspend_pcr: flush pcr for buggy TPM chips.
 *
 * The functions saves the TPM state to be restored on resume.
 *
 * Return:
 * * 0 on success,
 * * < 0 on error.
 */
int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_suspend_pcr)
{
	u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
	struct tpm_buf buf;
	unsigned int try;
	int rc;


	/* for buggy tpm, flush pcrs with extend to selected dummy */
	if (tpm_suspend_pcr)
		rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
				     "extending dummy pcr before suspend");

	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_SAVESTATE);
	if (rc)
		return rc;
	/* now do the actual savestate */
	for (try = 0; try < TPM_RETRY; try++) {
		rc = tpm_transmit_cmd(chip, &buf, 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;
		tpm_msleep(TPM_TIMEOUT_RETRY);

		tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_SAVESTATE);
	}

	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);

	tpm_buf_destroy(&buf);

	return rc;
}