xref: /openbmc/linux/drivers/char/tpm/tpm1-cmd.c (revision 5e3a3f27)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2004 IBM Corporation
4  * Copyright (C) 2014 Intel Corporation
5  *
6  * Authors:
7  * Leendert van Doorn <leendert@watson.ibm.com>
8  * Dave Safford <safford@watson.ibm.com>
9  * Reiner Sailer <sailer@watson.ibm.com>
10  * Kylene Hall <kjhall@us.ibm.com>
11  *
12  * Device driver for TCG/TCPA TPM (trusted platform module).
13  * Specifications at www.trustedcomputinggroup.org
14  */
15 
16 #include <linux/poll.h>
17 #include <linux/slab.h>
18 #include <linux/mutex.h>
19 #include <linux/spinlock.h>
20 #include <linux/freezer.h>
21 #include <linux/tpm_eventlog.h>
22 
23 #include "tpm.h"
24 
25 #define TPM_MAX_ORDINAL 243
26 
27 /*
28  * Array with one entry per ordinal defining the maximum amount
29  * of time the chip could take to return the result.  The ordinal
30  * designation of short, medium or long is defined in a table in
31  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
32  * values of the SHORT, MEDIUM, and LONG durations are retrieved
33  * from the chip during initialization with a call to tpm_get_timeouts.
34  */
35 static const u8 tpm1_ordinal_duration[TPM_MAX_ORDINAL] = {
36 	TPM_UNDEFINED,		/* 0 */
37 	TPM_UNDEFINED,
38 	TPM_UNDEFINED,
39 	TPM_UNDEFINED,
40 	TPM_UNDEFINED,
41 	TPM_UNDEFINED,		/* 5 */
42 	TPM_UNDEFINED,
43 	TPM_UNDEFINED,
44 	TPM_UNDEFINED,
45 	TPM_UNDEFINED,
46 	TPM_SHORT,		/* 10 */
47 	TPM_SHORT,
48 	TPM_MEDIUM,
49 	TPM_LONG,
50 	TPM_LONG,
51 	TPM_MEDIUM,		/* 15 */
52 	TPM_SHORT,
53 	TPM_SHORT,
54 	TPM_MEDIUM,
55 	TPM_LONG,
56 	TPM_SHORT,		/* 20 */
57 	TPM_SHORT,
58 	TPM_MEDIUM,
59 	TPM_MEDIUM,
60 	TPM_MEDIUM,
61 	TPM_SHORT,		/* 25 */
62 	TPM_SHORT,
63 	TPM_MEDIUM,
64 	TPM_SHORT,
65 	TPM_SHORT,
66 	TPM_MEDIUM,		/* 30 */
67 	TPM_LONG,
68 	TPM_MEDIUM,
69 	TPM_SHORT,
70 	TPM_SHORT,
71 	TPM_SHORT,		/* 35 */
72 	TPM_MEDIUM,
73 	TPM_MEDIUM,
74 	TPM_UNDEFINED,
75 	TPM_UNDEFINED,
76 	TPM_MEDIUM,		/* 40 */
77 	TPM_LONG,
78 	TPM_MEDIUM,
79 	TPM_SHORT,
80 	TPM_SHORT,
81 	TPM_SHORT,		/* 45 */
82 	TPM_SHORT,
83 	TPM_SHORT,
84 	TPM_SHORT,
85 	TPM_LONG,
86 	TPM_MEDIUM,		/* 50 */
87 	TPM_MEDIUM,
88 	TPM_UNDEFINED,
89 	TPM_UNDEFINED,
90 	TPM_UNDEFINED,
91 	TPM_UNDEFINED,		/* 55 */
92 	TPM_UNDEFINED,
93 	TPM_UNDEFINED,
94 	TPM_UNDEFINED,
95 	TPM_UNDEFINED,
96 	TPM_MEDIUM,		/* 60 */
97 	TPM_MEDIUM,
98 	TPM_MEDIUM,
99 	TPM_SHORT,
100 	TPM_SHORT,
101 	TPM_MEDIUM,		/* 65 */
102 	TPM_UNDEFINED,
103 	TPM_UNDEFINED,
104 	TPM_UNDEFINED,
105 	TPM_UNDEFINED,
106 	TPM_SHORT,		/* 70 */
107 	TPM_SHORT,
108 	TPM_UNDEFINED,
109 	TPM_UNDEFINED,
110 	TPM_UNDEFINED,
111 	TPM_UNDEFINED,		/* 75 */
112 	TPM_UNDEFINED,
113 	TPM_UNDEFINED,
114 	TPM_UNDEFINED,
115 	TPM_UNDEFINED,
116 	TPM_LONG,		/* 80 */
117 	TPM_UNDEFINED,
118 	TPM_MEDIUM,
119 	TPM_LONG,
120 	TPM_SHORT,
121 	TPM_UNDEFINED,		/* 85 */
122 	TPM_UNDEFINED,
123 	TPM_UNDEFINED,
124 	TPM_UNDEFINED,
125 	TPM_UNDEFINED,
126 	TPM_SHORT,		/* 90 */
127 	TPM_SHORT,
128 	TPM_SHORT,
129 	TPM_SHORT,
130 	TPM_SHORT,
131 	TPM_UNDEFINED,		/* 95 */
132 	TPM_UNDEFINED,
133 	TPM_UNDEFINED,
134 	TPM_UNDEFINED,
135 	TPM_UNDEFINED,
136 	TPM_MEDIUM,		/* 100 */
137 	TPM_SHORT,
138 	TPM_SHORT,
139 	TPM_UNDEFINED,
140 	TPM_UNDEFINED,
141 	TPM_UNDEFINED,		/* 105 */
142 	TPM_UNDEFINED,
143 	TPM_UNDEFINED,
144 	TPM_UNDEFINED,
145 	TPM_UNDEFINED,
146 	TPM_SHORT,		/* 110 */
147 	TPM_SHORT,
148 	TPM_SHORT,
149 	TPM_SHORT,
150 	TPM_SHORT,
151 	TPM_SHORT,		/* 115 */
152 	TPM_SHORT,
153 	TPM_SHORT,
154 	TPM_UNDEFINED,
155 	TPM_UNDEFINED,
156 	TPM_LONG,		/* 120 */
157 	TPM_LONG,
158 	TPM_MEDIUM,
159 	TPM_UNDEFINED,
160 	TPM_SHORT,
161 	TPM_SHORT,		/* 125 */
162 	TPM_SHORT,
163 	TPM_LONG,
164 	TPM_SHORT,
165 	TPM_SHORT,
166 	TPM_SHORT,		/* 130 */
167 	TPM_MEDIUM,
168 	TPM_UNDEFINED,
169 	TPM_SHORT,
170 	TPM_MEDIUM,
171 	TPM_UNDEFINED,		/* 135 */
172 	TPM_UNDEFINED,
173 	TPM_UNDEFINED,
174 	TPM_UNDEFINED,
175 	TPM_UNDEFINED,
176 	TPM_SHORT,		/* 140 */
177 	TPM_SHORT,
178 	TPM_UNDEFINED,
179 	TPM_UNDEFINED,
180 	TPM_UNDEFINED,
181 	TPM_UNDEFINED,		/* 145 */
182 	TPM_UNDEFINED,
183 	TPM_UNDEFINED,
184 	TPM_UNDEFINED,
185 	TPM_UNDEFINED,
186 	TPM_SHORT,		/* 150 */
187 	TPM_MEDIUM,
188 	TPM_MEDIUM,
189 	TPM_SHORT,
190 	TPM_SHORT,
191 	TPM_UNDEFINED,		/* 155 */
192 	TPM_UNDEFINED,
193 	TPM_UNDEFINED,
194 	TPM_UNDEFINED,
195 	TPM_UNDEFINED,
196 	TPM_SHORT,		/* 160 */
197 	TPM_SHORT,
198 	TPM_SHORT,
199 	TPM_SHORT,
200 	TPM_UNDEFINED,
201 	TPM_UNDEFINED,		/* 165 */
202 	TPM_UNDEFINED,
203 	TPM_UNDEFINED,
204 	TPM_UNDEFINED,
205 	TPM_UNDEFINED,
206 	TPM_LONG,		/* 170 */
207 	TPM_UNDEFINED,
208 	TPM_UNDEFINED,
209 	TPM_UNDEFINED,
210 	TPM_UNDEFINED,
211 	TPM_UNDEFINED,		/* 175 */
212 	TPM_UNDEFINED,
213 	TPM_UNDEFINED,
214 	TPM_UNDEFINED,
215 	TPM_UNDEFINED,
216 	TPM_MEDIUM,		/* 180 */
217 	TPM_SHORT,
218 	TPM_MEDIUM,
219 	TPM_MEDIUM,
220 	TPM_MEDIUM,
221 	TPM_MEDIUM,		/* 185 */
222 	TPM_SHORT,
223 	TPM_UNDEFINED,
224 	TPM_UNDEFINED,
225 	TPM_UNDEFINED,
226 	TPM_UNDEFINED,		/* 190 */
227 	TPM_UNDEFINED,
228 	TPM_UNDEFINED,
229 	TPM_UNDEFINED,
230 	TPM_UNDEFINED,
231 	TPM_UNDEFINED,		/* 195 */
232 	TPM_UNDEFINED,
233 	TPM_UNDEFINED,
234 	TPM_UNDEFINED,
235 	TPM_UNDEFINED,
236 	TPM_SHORT,		/* 200 */
237 	TPM_UNDEFINED,
238 	TPM_UNDEFINED,
239 	TPM_UNDEFINED,
240 	TPM_SHORT,
241 	TPM_SHORT,		/* 205 */
242 	TPM_SHORT,
243 	TPM_SHORT,
244 	TPM_SHORT,
245 	TPM_SHORT,
246 	TPM_MEDIUM,		/* 210 */
247 	TPM_UNDEFINED,
248 	TPM_MEDIUM,
249 	TPM_MEDIUM,
250 	TPM_MEDIUM,
251 	TPM_UNDEFINED,		/* 215 */
252 	TPM_MEDIUM,
253 	TPM_UNDEFINED,
254 	TPM_UNDEFINED,
255 	TPM_SHORT,
256 	TPM_SHORT,		/* 220 */
257 	TPM_SHORT,
258 	TPM_SHORT,
259 	TPM_SHORT,
260 	TPM_SHORT,
261 	TPM_UNDEFINED,		/* 225 */
262 	TPM_UNDEFINED,
263 	TPM_UNDEFINED,
264 	TPM_UNDEFINED,
265 	TPM_UNDEFINED,
266 	TPM_SHORT,		/* 230 */
267 	TPM_LONG,
268 	TPM_MEDIUM,
269 	TPM_UNDEFINED,
270 	TPM_UNDEFINED,
271 	TPM_UNDEFINED,		/* 235 */
272 	TPM_UNDEFINED,
273 	TPM_UNDEFINED,
274 	TPM_UNDEFINED,
275 	TPM_UNDEFINED,
276 	TPM_SHORT,		/* 240 */
277 	TPM_UNDEFINED,
278 	TPM_MEDIUM,
279 };
280 
281 /**
282  * tpm1_calc_ordinal_duration() - calculate the maximum command duration
283  * @chip:    TPM chip to use.
284  * @ordinal: TPM command ordinal.
285  *
286  * The function returns the maximum amount of time the chip could take
287  * to return the result for a particular ordinal in jiffies.
288  *
289  * Return: A maximal duration time for an ordinal in jiffies.
290  */
tpm1_calc_ordinal_duration(struct tpm_chip * chip,u32 ordinal)291 unsigned long tpm1_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
292 {
293 	int duration_idx = TPM_UNDEFINED;
294 	int duration = 0;
295 
296 	/*
297 	 * We only have a duration table for protected commands, where the upper
298 	 * 16 bits are 0. For the few other ordinals the fallback will be used.
299 	 */
300 	if (ordinal < TPM_MAX_ORDINAL)
301 		duration_idx = tpm1_ordinal_duration[ordinal];
302 
303 	if (duration_idx != TPM_UNDEFINED)
304 		duration = chip->duration[duration_idx];
305 	if (duration <= 0)
306 		return 2 * 60 * HZ;
307 	else
308 		return duration;
309 }
310 
311 #define TPM_ORD_STARTUP 153
312 #define TPM_ST_CLEAR 1
313 
314 /**
315  * tpm1_startup() - turn on the TPM
316  * @chip: TPM chip to use
317  *
318  * Normally the firmware should start the TPM. This function is provided as a
319  * workaround if this does not happen. A legal case for this could be for
320  * example when a TPM emulator is used.
321  *
322  * Return: same as tpm_transmit_cmd()
323  */
tpm1_startup(struct tpm_chip * chip)324 static int tpm1_startup(struct tpm_chip *chip)
325 {
326 	struct tpm_buf buf;
327 	int rc;
328 
329 	dev_info(&chip->dev, "starting up the TPM manually\n");
330 
331 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
332 	if (rc < 0)
333 		return rc;
334 
335 	tpm_buf_append_u16(&buf, TPM_ST_CLEAR);
336 
337 	rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM");
338 	tpm_buf_destroy(&buf);
339 	return rc;
340 }
341 
tpm1_get_timeouts(struct tpm_chip * chip)342 int tpm1_get_timeouts(struct tpm_chip *chip)
343 {
344 	cap_t cap;
345 	unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
346 	unsigned long durations[3];
347 	ssize_t rc;
348 
349 	rc = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
350 			 sizeof(cap.timeout));
351 	if (rc == TPM_ERR_INVALID_POSTINIT) {
352 		if (tpm1_startup(chip))
353 			return rc;
354 
355 		rc = tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
356 				 "attempting to determine the timeouts",
357 				 sizeof(cap.timeout));
358 	}
359 
360 	if (rc) {
361 		dev_err(&chip->dev, "A TPM error (%zd) occurred attempting to determine the timeouts\n",
362 			rc);
363 		return rc;
364 	}
365 
366 	timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
367 	timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
368 	timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
369 	timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
370 	timeout_chip[0] = be32_to_cpu(cap.timeout.a);
371 	timeout_chip[1] = be32_to_cpu(cap.timeout.b);
372 	timeout_chip[2] = be32_to_cpu(cap.timeout.c);
373 	timeout_chip[3] = be32_to_cpu(cap.timeout.d);
374 	memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
375 
376 	/*
377 	 * Provide ability for vendor overrides of timeout values in case
378 	 * of misreporting.
379 	 */
380 	if (chip->ops->update_timeouts)
381 		chip->ops->update_timeouts(chip, timeout_eff);
382 
383 	if (!chip->timeout_adjusted) {
384 		/* Restore default if chip reported 0 */
385 		unsigned int i;
386 
387 		for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
388 			if (timeout_eff[i])
389 				continue;
390 
391 			timeout_eff[i] = timeout_old[i];
392 			chip->timeout_adjusted = true;
393 		}
394 
395 		if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
396 			/* timeouts in msec rather usec */
397 			for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
398 				timeout_eff[i] *= 1000;
399 			chip->timeout_adjusted = true;
400 		}
401 	}
402 
403 	/* Report adjusted timeouts */
404 	if (chip->timeout_adjusted) {
405 		dev_info(&chip->dev, HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
406 			 timeout_chip[0], timeout_eff[0],
407 			 timeout_chip[1], timeout_eff[1],
408 			 timeout_chip[2], timeout_eff[2],
409 			 timeout_chip[3], timeout_eff[3]);
410 	}
411 
412 	chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
413 	chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
414 	chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
415 	chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
416 
417 	rc = tpm1_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
418 			 "attempting to determine the durations",
419 			  sizeof(cap.duration));
420 	if (rc)
421 		return rc;
422 
423 	chip->duration[TPM_SHORT] =
424 		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
425 	chip->duration[TPM_MEDIUM] =
426 		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
427 	chip->duration[TPM_LONG] =
428 		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
429 	chip->duration[TPM_LONG_LONG] = 0; /* not used under 1.2 */
430 
431 	/*
432 	 * Provide the ability for vendor overrides of duration values in case
433 	 * of misreporting.
434 	 */
435 	if (chip->ops->update_durations)
436 		chip->ops->update_durations(chip, durations);
437 
438 	if (chip->duration_adjusted) {
439 		dev_info(&chip->dev, HW_ERR "Adjusting reported durations.");
440 		chip->duration[TPM_SHORT] = durations[0];
441 		chip->duration[TPM_MEDIUM] = durations[1];
442 		chip->duration[TPM_LONG] = durations[2];
443 	}
444 
445 	/* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
446 	 * value wrong and apparently reports msecs rather than usecs. So we
447 	 * fix up the resulting too-small TPM_SHORT value to make things work.
448 	 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
449 	 */
450 	if (chip->duration[TPM_SHORT] < (HZ / 100)) {
451 		chip->duration[TPM_SHORT] = HZ;
452 		chip->duration[TPM_MEDIUM] *= 1000;
453 		chip->duration[TPM_LONG] *= 1000;
454 		chip->duration_adjusted = true;
455 		dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
456 	}
457 
458 	chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
459 	return 0;
460 }
461 
462 #define TPM_ORD_PCR_EXTEND 20
tpm1_pcr_extend(struct tpm_chip * chip,u32 pcr_idx,const u8 * hash,const char * log_msg)463 int tpm1_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash,
464 		    const char *log_msg)
465 {
466 	struct tpm_buf buf;
467 	int rc;
468 
469 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND);
470 	if (rc)
471 		return rc;
472 
473 	tpm_buf_append_u32(&buf, pcr_idx);
474 	tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);
475 
476 	rc = tpm_transmit_cmd(chip, &buf, TPM_DIGEST_SIZE, log_msg);
477 	tpm_buf_destroy(&buf);
478 	return rc;
479 }
480 
481 #define TPM_ORD_GET_CAP 101
tpm1_getcap(struct tpm_chip * chip,u32 subcap_id,cap_t * cap,const char * desc,size_t min_cap_length)482 ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
483 		    const char *desc, size_t min_cap_length)
484 {
485 	struct tpm_buf buf;
486 	int rc;
487 
488 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
489 	if (rc)
490 		return rc;
491 
492 	if (subcap_id == TPM_CAP_VERSION_1_1 ||
493 	    subcap_id == TPM_CAP_VERSION_1_2) {
494 		tpm_buf_append_u32(&buf, subcap_id);
495 		tpm_buf_append_u32(&buf, 0);
496 	} else {
497 		if (subcap_id == TPM_CAP_FLAG_PERM ||
498 		    subcap_id == TPM_CAP_FLAG_VOL)
499 			tpm_buf_append_u32(&buf, TPM_CAP_FLAG);
500 		else
501 			tpm_buf_append_u32(&buf, TPM_CAP_PROP);
502 
503 		tpm_buf_append_u32(&buf, 4);
504 		tpm_buf_append_u32(&buf, subcap_id);
505 	}
506 	rc = tpm_transmit_cmd(chip, &buf, min_cap_length, desc);
507 	if (!rc)
508 		*cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
509 	tpm_buf_destroy(&buf);
510 	return rc;
511 }
512 EXPORT_SYMBOL_GPL(tpm1_getcap);
513 
514 #define TPM_ORD_GET_RANDOM 70
515 struct tpm1_get_random_out {
516 	__be32 rng_data_len;
517 	u8 rng_data[TPM_MAX_RNG_DATA];
518 } __packed;
519 
520 /**
521  * tpm1_get_random() - get random bytes from the TPM's RNG
522  * @chip:	a &struct tpm_chip instance
523  * @dest:	destination buffer for the random bytes
524  * @max:	the maximum number of bytes to write to @dest
525  *
526  * Return:
527  * *  number of bytes read
528  * * -errno (positive TPM return codes are masked to -EIO)
529  */
tpm1_get_random(struct tpm_chip * chip,u8 * dest,size_t max)530 int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
531 {
532 	struct tpm1_get_random_out *out;
533 	u32 num_bytes =  min_t(u32, max, TPM_MAX_RNG_DATA);
534 	struct tpm_buf buf;
535 	u32 total = 0;
536 	int retries = 5;
537 	u32 recd;
538 	int rc;
539 
540 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
541 	if (rc)
542 		return rc;
543 
544 	do {
545 		tpm_buf_append_u32(&buf, num_bytes);
546 
547 		rc = tpm_transmit_cmd(chip, &buf, sizeof(out->rng_data_len),
548 				      "attempting get random");
549 		if (rc) {
550 			if (rc > 0)
551 				rc = -EIO;
552 			goto out;
553 		}
554 
555 		out = (struct tpm1_get_random_out *)&buf.data[TPM_HEADER_SIZE];
556 
557 		recd = be32_to_cpu(out->rng_data_len);
558 		if (recd > num_bytes) {
559 			rc = -EFAULT;
560 			goto out;
561 		}
562 
563 		if (tpm_buf_length(&buf) < TPM_HEADER_SIZE +
564 					   sizeof(out->rng_data_len) + recd) {
565 			rc = -EFAULT;
566 			goto out;
567 		}
568 		memcpy(dest, out->rng_data, recd);
569 
570 		dest += recd;
571 		total += recd;
572 		num_bytes -= recd;
573 
574 		tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_RANDOM);
575 	} while (retries-- && total < max);
576 
577 	rc = total ? (int)total : -EIO;
578 out:
579 	tpm_buf_destroy(&buf);
580 	return rc;
581 }
582 
583 #define TPM_ORD_PCRREAD 21
tpm1_pcr_read(struct tpm_chip * chip,u32 pcr_idx,u8 * res_buf)584 int tpm1_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
585 {
586 	struct tpm_buf buf;
587 	int rc;
588 
589 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCRREAD);
590 	if (rc)
591 		return rc;
592 
593 	tpm_buf_append_u32(&buf, pcr_idx);
594 
595 	rc = tpm_transmit_cmd(chip, &buf, TPM_DIGEST_SIZE,
596 			      "attempting to read a pcr value");
597 	if (rc)
598 		goto out;
599 
600 	if (tpm_buf_length(&buf) < TPM_DIGEST_SIZE) {
601 		rc = -EFAULT;
602 		goto out;
603 	}
604 
605 	memcpy(res_buf, &buf.data[TPM_HEADER_SIZE], TPM_DIGEST_SIZE);
606 
607 out:
608 	tpm_buf_destroy(&buf);
609 	return rc;
610 }
611 
612 #define TPM_ORD_CONTINUE_SELFTEST 83
613 /**
614  * tpm1_continue_selftest() - run TPM's selftest
615  * @chip: TPM chip to use
616  *
617  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
618  * a TPM error code.
619  */
tpm1_continue_selftest(struct tpm_chip * chip)620 static int tpm1_continue_selftest(struct tpm_chip *chip)
621 {
622 	struct tpm_buf buf;
623 	int rc;
624 
625 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_CONTINUE_SELFTEST);
626 	if (rc)
627 		return rc;
628 
629 	rc = tpm_transmit_cmd(chip, &buf, 0, "continue selftest");
630 	tpm_buf_destroy(&buf);
631 	return rc;
632 }
633 
634 /**
635  * tpm1_do_selftest - have the TPM continue its selftest and wait until it
636  *                   can receive further commands
637  * @chip: TPM chip to use
638  *
639  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
640  * a TPM error code.
641  */
tpm1_do_selftest(struct tpm_chip * chip)642 int tpm1_do_selftest(struct tpm_chip *chip)
643 {
644 	int rc;
645 	unsigned int loops;
646 	unsigned int delay_msec = 100;
647 	unsigned long duration;
648 	u8 dummy[TPM_DIGEST_SIZE];
649 
650 	duration = tpm1_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
651 
652 	loops = jiffies_to_msecs(duration) / delay_msec;
653 
654 	rc = tpm1_continue_selftest(chip);
655 	if (rc == TPM_ERR_INVALID_POSTINIT) {
656 		chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
657 		dev_info(&chip->dev, "TPM not ready (%d)\n", rc);
658 	}
659 	/* This may fail if there was no TPM driver during a suspend/resume
660 	 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
661 	 */
662 	if (rc)
663 		return rc;
664 
665 	do {
666 		/* Attempt to read a PCR value */
667 		rc = tpm1_pcr_read(chip, 0, dummy);
668 
669 		/* Some buggy TPMs will not respond to tpm_tis_ready() for
670 		 * around 300ms while the self test is ongoing, keep trying
671 		 * until the self test duration expires.
672 		 */
673 		if (rc == -ETIME) {
674 			dev_info(&chip->dev, HW_ERR "TPM command timed out during continue self test");
675 			tpm_msleep(delay_msec);
676 			continue;
677 		}
678 
679 		if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
680 			dev_info(&chip->dev, "TPM is disabled/deactivated (0x%X)\n",
681 				 rc);
682 			/* TPM is disabled and/or deactivated; driver can
683 			 * proceed and TPM does handle commands for
684 			 * suspend/resume correctly
685 			 */
686 			return 0;
687 		}
688 		if (rc != TPM_WARN_DOING_SELFTEST)
689 			return rc;
690 		tpm_msleep(delay_msec);
691 	} while (--loops > 0);
692 
693 	return rc;
694 }
695 EXPORT_SYMBOL_GPL(tpm1_do_selftest);
696 
697 /**
698  * tpm1_auto_startup - Perform the standard automatic TPM initialization
699  *                     sequence
700  * @chip: TPM chip to use
701  *
702  * Returns 0 on success, < 0 in case of fatal error.
703  */
tpm1_auto_startup(struct tpm_chip * chip)704 int tpm1_auto_startup(struct tpm_chip *chip)
705 {
706 	int rc;
707 
708 	rc = tpm1_get_timeouts(chip);
709 	if (rc)
710 		goto out;
711 	rc = tpm1_do_selftest(chip);
712 	if (rc == TPM_ERR_FAILEDSELFTEST) {
713 		dev_warn(&chip->dev, "TPM self test failed, switching to the firmware upgrade mode\n");
714 		/* A TPM in this state possibly allows or needs a firmware upgrade */
715 		chip->flags |= TPM_CHIP_FLAG_FIRMWARE_UPGRADE;
716 		return 0;
717 	} else if (rc) {
718 		dev_err(&chip->dev, "TPM self test failed\n");
719 		goto out;
720 	}
721 
722 	return rc;
723 out:
724 	if (rc > 0)
725 		rc = -ENODEV;
726 	return rc;
727 }
728 
729 #define TPM_ORD_SAVESTATE 152
730 
731 /**
732  * tpm1_pm_suspend() - pm suspend handler
733  * @chip: TPM chip to use.
734  * @tpm_suspend_pcr: flush pcr for buggy TPM chips.
735  *
736  * The functions saves the TPM state to be restored on resume.
737  *
738  * Return:
739  * * 0 on success,
740  * * < 0 on error.
741  */
tpm1_pm_suspend(struct tpm_chip * chip,u32 tpm_suspend_pcr)742 int tpm1_pm_suspend(struct tpm_chip *chip, u32 tpm_suspend_pcr)
743 {
744 	u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
745 	struct tpm_buf buf;
746 	unsigned int try;
747 	int rc;
748 
749 
750 	/* for buggy tpm, flush pcrs with extend to selected dummy */
751 	if (tpm_suspend_pcr)
752 		rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
753 				     "extending dummy pcr before suspend");
754 
755 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_SAVESTATE);
756 	if (rc)
757 		return rc;
758 	/* now do the actual savestate */
759 	for (try = 0; try < TPM_RETRY; try++) {
760 		rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
761 		/*
762 		 * If the TPM indicates that it is too busy to respond to
763 		 * this command then retry before giving up.  It can take
764 		 * several seconds for this TPM to be ready.
765 		 *
766 		 * This can happen if the TPM has already been sent the
767 		 * SaveState command before the driver has loaded.  TCG 1.2
768 		 * specification states that any communication after SaveState
769 		 * may cause the TPM to invalidate previously saved state.
770 		 */
771 		if (rc != TPM_WARN_RETRY)
772 			break;
773 		tpm_msleep(TPM_TIMEOUT_RETRY);
774 
775 		tpm_buf_reset(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_SAVESTATE);
776 	}
777 
778 	if (rc)
779 		dev_err(&chip->dev, "Error (%d) sending savestate before suspend\n",
780 			rc);
781 	else if (try > 0)
782 		dev_warn(&chip->dev, "TPM savestate took %dms\n",
783 			 try * TPM_TIMEOUT_RETRY);
784 
785 	tpm_buf_destroy(&buf);
786 
787 	return rc;
788 }
789 
790 /**
791  * tpm1_get_pcr_allocation() - initialize the allocated bank
792  * @chip: TPM chip to use.
793  *
794  * The function initializes the SHA1 allocated bank to extend PCR
795  *
796  * Return:
797  * * 0 on success,
798  * * < 0 on error.
799  */
tpm1_get_pcr_allocation(struct tpm_chip * chip)800 int tpm1_get_pcr_allocation(struct tpm_chip *chip)
801 {
802 	chip->allocated_banks = kcalloc(1, sizeof(*chip->allocated_banks),
803 					GFP_KERNEL);
804 	if (!chip->allocated_banks)
805 		return -ENOMEM;
806 
807 	chip->allocated_banks[0].alg_id = TPM_ALG_SHA1;
808 	chip->allocated_banks[0].digest_size = hash_digest_size[HASH_ALGO_SHA1];
809 	chip->allocated_banks[0].crypto_id = HASH_ALGO_SHA1;
810 	chip->nr_allocated_banks = 1;
811 
812 	return 0;
813 }
814