xref: /openbmc/linux/drivers/char/tpm/tpm2-cmd.c (revision e6e8c6c2)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014, 2015 Intel Corporation
4  *
5  * Authors:
6  * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
7  *
8  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
9  *
10  * This file contains TPM2 protocol implementations of the commands
11  * used by the kernel internally.
12  */
13 
14 #include "tpm.h"
15 #include <crypto/hash_info.h>
16 
17 static struct tpm2_hash tpm2_hash_map[] = {
18 	{HASH_ALGO_SHA1, TPM_ALG_SHA1},
19 	{HASH_ALGO_SHA256, TPM_ALG_SHA256},
20 	{HASH_ALGO_SHA384, TPM_ALG_SHA384},
21 	{HASH_ALGO_SHA512, TPM_ALG_SHA512},
22 	{HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
23 };
24 
25 int tpm2_get_timeouts(struct tpm_chip *chip)
26 {
27 	/* Fixed timeouts for TPM2 */
28 	chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
29 	chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
30 	chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
31 	chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
32 
33 	/* PTP spec timeouts */
34 	chip->duration[TPM_SHORT] = msecs_to_jiffies(TPM2_DURATION_SHORT);
35 	chip->duration[TPM_MEDIUM] = msecs_to_jiffies(TPM2_DURATION_MEDIUM);
36 	chip->duration[TPM_LONG] = msecs_to_jiffies(TPM2_DURATION_LONG);
37 
38 	/* Key creation commands long timeouts */
39 	chip->duration[TPM_LONG_LONG] =
40 		msecs_to_jiffies(TPM2_DURATION_LONG_LONG);
41 
42 	chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
43 
44 	return 0;
45 }
46 
47 /**
48  * tpm2_ordinal_duration_index() - returns an index to the chip duration table
49  * @ordinal: TPM command ordinal.
50  *
51  * The function returns an index to the chip duration table
52  * (enum tpm_duration), that describes the maximum amount of
53  * time the chip could take to return the result for a  particular ordinal.
54  *
55  * The values of the MEDIUM, and LONG durations are taken
56  * from the PC Client Profile (PTP) specification (750, 2000 msec)
57  *
58  * LONG_LONG is for commands that generates keys which empirically takes
59  * a longer time on some systems.
60  *
61  * Return:
62  * * TPM_MEDIUM
63  * * TPM_LONG
64  * * TPM_LONG_LONG
65  * * TPM_UNDEFINED
66  */
67 static u8 tpm2_ordinal_duration_index(u32 ordinal)
68 {
69 	switch (ordinal) {
70 	/* Startup */
71 	case TPM2_CC_STARTUP:                 /* 144 */
72 		return TPM_MEDIUM;
73 
74 	case TPM2_CC_SELF_TEST:               /* 143 */
75 		return TPM_LONG;
76 
77 	case TPM2_CC_GET_RANDOM:              /* 17B */
78 		return TPM_LONG;
79 
80 	case TPM2_CC_SEQUENCE_UPDATE:         /* 15C */
81 		return TPM_MEDIUM;
82 	case TPM2_CC_SEQUENCE_COMPLETE:       /* 13E */
83 		return TPM_MEDIUM;
84 	case TPM2_CC_EVENT_SEQUENCE_COMPLETE: /* 185 */
85 		return TPM_MEDIUM;
86 	case TPM2_CC_HASH_SEQUENCE_START:     /* 186 */
87 		return TPM_MEDIUM;
88 
89 	case TPM2_CC_VERIFY_SIGNATURE:        /* 177 */
90 		return TPM_LONG_LONG;
91 
92 	case TPM2_CC_PCR_EXTEND:              /* 182 */
93 		return TPM_MEDIUM;
94 
95 	case TPM2_CC_HIERARCHY_CONTROL:       /* 121 */
96 		return TPM_LONG;
97 	case TPM2_CC_HIERARCHY_CHANGE_AUTH:   /* 129 */
98 		return TPM_LONG;
99 
100 	case TPM2_CC_GET_CAPABILITY:          /* 17A */
101 		return TPM_MEDIUM;
102 
103 	case TPM2_CC_NV_READ:                 /* 14E */
104 		return TPM_LONG;
105 
106 	case TPM2_CC_CREATE_PRIMARY:          /* 131 */
107 		return TPM_LONG_LONG;
108 	case TPM2_CC_CREATE:                  /* 153 */
109 		return TPM_LONG_LONG;
110 	case TPM2_CC_CREATE_LOADED:           /* 191 */
111 		return TPM_LONG_LONG;
112 
113 	default:
114 		return TPM_UNDEFINED;
115 	}
116 }
117 
118 /**
119  * tpm2_calc_ordinal_duration() - calculate the maximum command duration
120  * @chip:    TPM chip to use.
121  * @ordinal: TPM command ordinal.
122  *
123  * The function returns the maximum amount of time the chip could take
124  * to return the result for a particular ordinal in jiffies.
125  *
126  * Return: A maximal duration time for an ordinal in jiffies.
127  */
128 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
129 {
130 	unsigned int index;
131 
132 	index = tpm2_ordinal_duration_index(ordinal);
133 
134 	if (index != TPM_UNDEFINED)
135 		return chip->duration[index];
136 	else
137 		return msecs_to_jiffies(TPM2_DURATION_DEFAULT);
138 }
139 
140 
141 struct tpm2_pcr_read_out {
142 	__be32	update_cnt;
143 	__be32	pcr_selects_cnt;
144 	__be16	hash_alg;
145 	u8	pcr_select_size;
146 	u8	pcr_select[TPM2_PCR_SELECT_MIN];
147 	__be32	digests_cnt;
148 	__be16	digest_size;
149 	u8	digest[];
150 } __packed;
151 
152 /**
153  * tpm2_pcr_read() - read a PCR value
154  * @chip:	TPM chip to use.
155  * @pcr_idx:	index of the PCR to read.
156  * @digest:	PCR bank and buffer current PCR value is written to.
157  * @digest_size_ptr:	pointer to variable that stores the digest size.
158  *
159  * Return: Same as with tpm_transmit_cmd.
160  */
161 int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
162 		  struct tpm_digest *digest, u16 *digest_size_ptr)
163 {
164 	int i;
165 	int rc;
166 	struct tpm_buf buf;
167 	struct tpm2_pcr_read_out *out;
168 	u8 pcr_select[TPM2_PCR_SELECT_MIN] = {0};
169 	u16 digest_size;
170 	u16 expected_digest_size = 0;
171 
172 	if (pcr_idx >= TPM2_PLATFORM_PCR)
173 		return -EINVAL;
174 
175 	if (!digest_size_ptr) {
176 		for (i = 0; i < chip->nr_allocated_banks &&
177 		     chip->allocated_banks[i].alg_id != digest->alg_id; i++)
178 			;
179 
180 		if (i == chip->nr_allocated_banks)
181 			return -EINVAL;
182 
183 		expected_digest_size = chip->allocated_banks[i].digest_size;
184 	}
185 
186 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_PCR_READ);
187 	if (rc)
188 		return rc;
189 
190 	pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
191 
192 	tpm_buf_append_u32(&buf, 1);
193 	tpm_buf_append_u16(&buf, digest->alg_id);
194 	tpm_buf_append_u8(&buf, TPM2_PCR_SELECT_MIN);
195 	tpm_buf_append(&buf, (const unsigned char *)pcr_select,
196 		       sizeof(pcr_select));
197 
198 	rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to read a pcr value");
199 	if (rc)
200 		goto out;
201 
202 	out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
203 	digest_size = be16_to_cpu(out->digest_size);
204 	if (digest_size > sizeof(digest->digest) ||
205 	    (!digest_size_ptr && digest_size != expected_digest_size)) {
206 		rc = -EINVAL;
207 		goto out;
208 	}
209 
210 	if (digest_size_ptr)
211 		*digest_size_ptr = digest_size;
212 
213 	memcpy(digest->digest, out->digest, digest_size);
214 out:
215 	tpm_buf_destroy(&buf);
216 	return rc;
217 }
218 
219 struct tpm2_null_auth_area {
220 	__be32  handle;
221 	__be16  nonce_size;
222 	u8  attributes;
223 	__be16  auth_size;
224 } __packed;
225 
226 /**
227  * tpm2_pcr_extend() - extend a PCR value
228  *
229  * @chip:	TPM chip to use.
230  * @pcr_idx:	index of the PCR.
231  * @digests:	list of pcr banks and corresponding digest values to extend.
232  *
233  * Return: Same as with tpm_transmit_cmd.
234  */
235 int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
236 		    struct tpm_digest *digests)
237 {
238 	struct tpm_buf buf;
239 	struct tpm2_null_auth_area auth_area;
240 	int rc;
241 	int i;
242 
243 	rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
244 	if (rc)
245 		return rc;
246 
247 	tpm_buf_append_u32(&buf, pcr_idx);
248 
249 	auth_area.handle = cpu_to_be32(TPM2_RS_PW);
250 	auth_area.nonce_size = 0;
251 	auth_area.attributes = 0;
252 	auth_area.auth_size = 0;
253 
254 	tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area));
255 	tpm_buf_append(&buf, (const unsigned char *)&auth_area,
256 		       sizeof(auth_area));
257 	tpm_buf_append_u32(&buf, chip->nr_allocated_banks);
258 
259 	for (i = 0; i < chip->nr_allocated_banks; i++) {
260 		tpm_buf_append_u16(&buf, digests[i].alg_id);
261 		tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest,
262 			       chip->allocated_banks[i].digest_size);
263 	}
264 
265 	rc = tpm_transmit_cmd(chip, &buf, 0, "attempting extend a PCR value");
266 
267 	tpm_buf_destroy(&buf);
268 
269 	return rc;
270 }
271 
272 struct tpm2_get_random_out {
273 	__be16 size;
274 	u8 buffer[TPM_MAX_RNG_DATA];
275 } __packed;
276 
277 /**
278  * tpm2_get_random() - get random bytes from the TPM RNG
279  *
280  * @chip:	a &tpm_chip instance
281  * @dest:	destination buffer
282  * @max:	the max number of random bytes to pull
283  *
284  * Return:
285  *   size of the buffer on success,
286  *   -errno otherwise (positive TPM return codes are masked to -EIO)
287  */
288 int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
289 {
290 	struct tpm2_get_random_out *out;
291 	struct tpm_buf buf;
292 	u32 recd;
293 	u32 num_bytes = max;
294 	int err;
295 	int total = 0;
296 	int retries = 5;
297 	u8 *dest_ptr = dest;
298 
299 	if (!num_bytes || max > TPM_MAX_RNG_DATA)
300 		return -EINVAL;
301 
302 	err = tpm_buf_init(&buf, 0, 0);
303 	if (err)
304 		return err;
305 
306 	do {
307 		tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM);
308 		tpm_buf_append_u16(&buf, num_bytes);
309 		err = tpm_transmit_cmd(chip, &buf,
310 				       offsetof(struct tpm2_get_random_out,
311 						buffer),
312 				       "attempting get random");
313 		if (err) {
314 			if (err > 0)
315 				err = -EIO;
316 			goto out;
317 		}
318 
319 		out = (struct tpm2_get_random_out *)
320 			&buf.data[TPM_HEADER_SIZE];
321 		recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
322 		if (tpm_buf_length(&buf) <
323 		    TPM_HEADER_SIZE +
324 		    offsetof(struct tpm2_get_random_out, buffer) +
325 		    recd) {
326 			err = -EFAULT;
327 			goto out;
328 		}
329 		memcpy(dest_ptr, out->buffer, recd);
330 
331 		dest_ptr += recd;
332 		total += recd;
333 		num_bytes -= recd;
334 	} while (retries-- && total < max);
335 
336 	tpm_buf_destroy(&buf);
337 	return total ? total : -EIO;
338 out:
339 	tpm_buf_destroy(&buf);
340 	return err;
341 }
342 
343 /**
344  * tpm2_flush_context() - execute a TPM2_FlushContext command
345  * @chip:	TPM chip to use
346  * @handle:	context handle
347  */
348 void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
349 {
350 	struct tpm_buf buf;
351 	int rc;
352 
353 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
354 	if (rc) {
355 		dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
356 			 handle);
357 		return;
358 	}
359 
360 	tpm_buf_append_u32(&buf, handle);
361 
362 	tpm_transmit_cmd(chip, &buf, 0, "flushing context");
363 	tpm_buf_destroy(&buf);
364 }
365 EXPORT_SYMBOL_GPL(tpm2_flush_context);
366 
367 struct tpm2_get_cap_out {
368 	u8 more_data;
369 	__be32 subcap_id;
370 	__be32 property_cnt;
371 	__be32 property_id;
372 	__be32 value;
373 } __packed;
374 
375 /**
376  * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
377  * @chip:		a &tpm_chip instance
378  * @property_id:	property ID.
379  * @value:		output variable.
380  * @desc:		passed to tpm_transmit_cmd()
381  *
382  * Return:
383  *   0 on success,
384  *   -errno or a TPM return code otherwise
385  */
386 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
387 			const char *desc)
388 {
389 	struct tpm2_get_cap_out *out;
390 	struct tpm_buf buf;
391 	int rc;
392 
393 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
394 	if (rc)
395 		return rc;
396 	tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
397 	tpm_buf_append_u32(&buf, property_id);
398 	tpm_buf_append_u32(&buf, 1);
399 	rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
400 	if (!rc) {
401 		out = (struct tpm2_get_cap_out *)
402 			&buf.data[TPM_HEADER_SIZE];
403 		/*
404 		 * To prevent failing boot up of some systems, Infineon TPM2.0
405 		 * returns SUCCESS on TPM2_Startup in field upgrade mode. Also
406 		 * the TPM2_Getcapability command returns a zero length list
407 		 * in field upgrade mode.
408 		 */
409 		if (be32_to_cpu(out->property_cnt) > 0)
410 			*value = be32_to_cpu(out->value);
411 		else
412 			rc = -ENODATA;
413 	}
414 	tpm_buf_destroy(&buf);
415 	return rc;
416 }
417 EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
418 
419 /**
420  * tpm2_shutdown() - send a TPM shutdown command
421  *
422  * Sends a TPM shutdown command. The shutdown command is used in call
423  * sites where the system is going down. If it fails, there is not much
424  * that can be done except print an error message.
425  *
426  * @chip:		a &tpm_chip instance
427  * @shutdown_type:	TPM_SU_CLEAR or TPM_SU_STATE.
428  */
429 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
430 {
431 	struct tpm_buf buf;
432 	int rc;
433 
434 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
435 	if (rc)
436 		return;
437 	tpm_buf_append_u16(&buf, shutdown_type);
438 	tpm_transmit_cmd(chip, &buf, 0, "stopping the TPM");
439 	tpm_buf_destroy(&buf);
440 }
441 
442 /**
443  * tpm2_do_selftest() - ensure that all self tests have passed
444  *
445  * @chip: TPM chip to use
446  *
447  * Return: Same as with tpm_transmit_cmd.
448  *
449  * The TPM can either run all self tests synchronously and then return
450  * RC_SUCCESS once all tests were successful. Or it can choose to run the tests
451  * asynchronously and return RC_TESTING immediately while the self tests still
452  * execute in the background. This function handles both cases and waits until
453  * all tests have completed.
454  */
455 static int tpm2_do_selftest(struct tpm_chip *chip)
456 {
457 	struct tpm_buf buf;
458 	int full;
459 	int rc;
460 
461 	for (full = 0; full < 2; full++) {
462 		rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST);
463 		if (rc)
464 			return rc;
465 
466 		tpm_buf_append_u8(&buf, full);
467 		rc = tpm_transmit_cmd(chip, &buf, 0,
468 				      "attempting the self test");
469 		tpm_buf_destroy(&buf);
470 
471 		if (rc == TPM2_RC_TESTING)
472 			rc = TPM2_RC_SUCCESS;
473 		if (rc == TPM2_RC_INITIALIZE || rc == TPM2_RC_SUCCESS)
474 			return rc;
475 	}
476 
477 	return rc;
478 }
479 
480 /**
481  * tpm2_probe() - probe for the TPM 2.0 protocol
482  * @chip:	a &tpm_chip instance
483  *
484  * Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the
485  * other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by
486  * this function if this is the case.
487  *
488  * Return:
489  *   0 on success,
490  *   -errno otherwise
491  */
492 int tpm2_probe(struct tpm_chip *chip)
493 {
494 	struct tpm_header *out;
495 	struct tpm_buf buf;
496 	int rc;
497 
498 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
499 	if (rc)
500 		return rc;
501 	tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
502 	tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
503 	tpm_buf_append_u32(&buf, 1);
504 	rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
505 	/* We ignore TPM return codes on purpose. */
506 	if (rc >=  0) {
507 		out = (struct tpm_header *)buf.data;
508 		if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
509 			chip->flags |= TPM_CHIP_FLAG_TPM2;
510 	}
511 	tpm_buf_destroy(&buf);
512 	return 0;
513 }
514 EXPORT_SYMBOL_GPL(tpm2_probe);
515 
516 static int tpm2_init_bank_info(struct tpm_chip *chip, u32 bank_index)
517 {
518 	struct tpm_bank_info *bank = chip->allocated_banks + bank_index;
519 	struct tpm_digest digest = { .alg_id = bank->alg_id };
520 	int i;
521 
522 	/*
523 	 * Avoid unnecessary PCR read operations to reduce overhead
524 	 * and obtain identifiers of the crypto subsystem.
525 	 */
526 	for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
527 		enum hash_algo crypto_algo = tpm2_hash_map[i].crypto_id;
528 
529 		if (bank->alg_id != tpm2_hash_map[i].tpm_id)
530 			continue;
531 
532 		bank->digest_size = hash_digest_size[crypto_algo];
533 		bank->crypto_id = crypto_algo;
534 		return 0;
535 	}
536 
537 	bank->crypto_id = HASH_ALGO__LAST;
538 
539 	return tpm2_pcr_read(chip, 0, &digest, &bank->digest_size);
540 }
541 
542 struct tpm2_pcr_selection {
543 	__be16  hash_alg;
544 	u8  size_of_select;
545 	u8  pcr_select[3];
546 } __packed;
547 
548 ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
549 {
550 	struct tpm2_pcr_selection pcr_selection;
551 	struct tpm_buf buf;
552 	void *marker;
553 	void *end;
554 	void *pcr_select_offset;
555 	u32 sizeof_pcr_selection;
556 	u32 nr_possible_banks;
557 	u32 nr_alloc_banks = 0;
558 	u16 hash_alg;
559 	u32 rsp_len;
560 	int rc;
561 	int i = 0;
562 
563 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
564 	if (rc)
565 		return rc;
566 
567 	tpm_buf_append_u32(&buf, TPM2_CAP_PCRS);
568 	tpm_buf_append_u32(&buf, 0);
569 	tpm_buf_append_u32(&buf, 1);
570 
571 	rc = tpm_transmit_cmd(chip, &buf, 9, "get tpm pcr allocation");
572 	if (rc)
573 		goto out;
574 
575 	nr_possible_banks = be32_to_cpup(
576 		(__be32 *)&buf.data[TPM_HEADER_SIZE + 5]);
577 
578 	chip->allocated_banks = kcalloc(nr_possible_banks,
579 					sizeof(*chip->allocated_banks),
580 					GFP_KERNEL);
581 	if (!chip->allocated_banks) {
582 		rc = -ENOMEM;
583 		goto out;
584 	}
585 
586 	marker = &buf.data[TPM_HEADER_SIZE + 9];
587 
588 	rsp_len = be32_to_cpup((__be32 *)&buf.data[2]);
589 	end = &buf.data[rsp_len];
590 
591 	for (i = 0; i < nr_possible_banks; i++) {
592 		pcr_select_offset = marker +
593 			offsetof(struct tpm2_pcr_selection, size_of_select);
594 		if (pcr_select_offset >= end) {
595 			rc = -EFAULT;
596 			break;
597 		}
598 
599 		memcpy(&pcr_selection, marker, sizeof(pcr_selection));
600 		hash_alg = be16_to_cpu(pcr_selection.hash_alg);
601 
602 		pcr_select_offset = memchr_inv(pcr_selection.pcr_select, 0,
603 					       pcr_selection.size_of_select);
604 		if (pcr_select_offset) {
605 			chip->allocated_banks[nr_alloc_banks].alg_id = hash_alg;
606 
607 			rc = tpm2_init_bank_info(chip, nr_alloc_banks);
608 			if (rc < 0)
609 				break;
610 
611 			nr_alloc_banks++;
612 		}
613 
614 		sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) +
615 			sizeof(pcr_selection.size_of_select) +
616 			pcr_selection.size_of_select;
617 		marker = marker + sizeof_pcr_selection;
618 	}
619 
620 	chip->nr_allocated_banks = nr_alloc_banks;
621 out:
622 	tpm_buf_destroy(&buf);
623 
624 	return rc;
625 }
626 
627 int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
628 {
629 	struct tpm_buf buf;
630 	u32 nr_commands;
631 	__be32 *attrs;
632 	u32 cc;
633 	int i;
634 	int rc;
635 
636 	rc = tpm2_get_tpm_pt(chip, TPM_PT_TOTAL_COMMANDS, &nr_commands, NULL);
637 	if (rc)
638 		goto out;
639 
640 	if (nr_commands > 0xFFFFF) {
641 		rc = -EFAULT;
642 		goto out;
643 	}
644 
645 	chip->cc_attrs_tbl = devm_kcalloc(&chip->dev, 4, nr_commands,
646 					  GFP_KERNEL);
647 	if (!chip->cc_attrs_tbl) {
648 		rc = -ENOMEM;
649 		goto out;
650 	}
651 
652 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
653 	if (rc)
654 		goto out;
655 
656 	tpm_buf_append_u32(&buf, TPM2_CAP_COMMANDS);
657 	tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
658 	tpm_buf_append_u32(&buf, nr_commands);
659 
660 	rc = tpm_transmit_cmd(chip, &buf, 9 + 4 * nr_commands, NULL);
661 	if (rc) {
662 		tpm_buf_destroy(&buf);
663 		goto out;
664 	}
665 
666 	if (nr_commands !=
667 	    be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) {
668 		rc = -EFAULT;
669 		tpm_buf_destroy(&buf);
670 		goto out;
671 	}
672 
673 	chip->nr_commands = nr_commands;
674 
675 	attrs = (__be32 *)&buf.data[TPM_HEADER_SIZE + 9];
676 	for (i = 0; i < nr_commands; i++, attrs++) {
677 		chip->cc_attrs_tbl[i] = be32_to_cpup(attrs);
678 		cc = chip->cc_attrs_tbl[i] & 0xFFFF;
679 
680 		if (cc == TPM2_CC_CONTEXT_SAVE || cc == TPM2_CC_FLUSH_CONTEXT) {
681 			chip->cc_attrs_tbl[i] &=
682 				~(GENMASK(2, 0) << TPM2_CC_ATTR_CHANDLES);
683 			chip->cc_attrs_tbl[i] |= 1 << TPM2_CC_ATTR_CHANDLES;
684 		}
685 	}
686 
687 	tpm_buf_destroy(&buf);
688 
689 out:
690 	if (rc > 0)
691 		rc = -ENODEV;
692 	return rc;
693 }
694 EXPORT_SYMBOL_GPL(tpm2_get_cc_attrs_tbl);
695 
696 /**
697  * tpm2_startup - turn on the TPM
698  * @chip: TPM chip to use
699  *
700  * Normally the firmware should start the TPM. This function is provided as a
701  * workaround if this does not happen. A legal case for this could be for
702  * example when a TPM emulator is used.
703  *
704  * Return: same as tpm_transmit_cmd()
705  */
706 
707 static int tpm2_startup(struct tpm_chip *chip)
708 {
709 	struct tpm_buf buf;
710 	int rc;
711 
712 	dev_info(&chip->dev, "starting up the TPM manually\n");
713 
714 	rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
715 	if (rc < 0)
716 		return rc;
717 
718 	tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
719 	rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM");
720 	tpm_buf_destroy(&buf);
721 
722 	return rc;
723 }
724 
725 /**
726  * tpm2_auto_startup - Perform the standard automatic TPM initialization
727  *                     sequence
728  * @chip: TPM chip to use
729  *
730  * Returns 0 on success, < 0 in case of fatal error.
731  */
732 int tpm2_auto_startup(struct tpm_chip *chip)
733 {
734 	int rc;
735 
736 	rc = tpm2_get_timeouts(chip);
737 	if (rc)
738 		goto out;
739 
740 	rc = tpm2_do_selftest(chip);
741 	if (rc && rc != TPM2_RC_INITIALIZE)
742 		goto out;
743 
744 	if (rc == TPM2_RC_INITIALIZE) {
745 		rc = tpm2_startup(chip);
746 		if (rc)
747 			goto out;
748 
749 		rc = tpm2_do_selftest(chip);
750 		if (rc)
751 			goto out;
752 	}
753 
754 	rc = tpm2_get_cc_attrs_tbl(chip);
755 	if (rc == TPM2_RC_FAILURE || (rc < 0 && rc != -ENOMEM)) {
756 		dev_info(&chip->dev,
757 			 "TPM in field failure mode, requires firmware upgrade\n");
758 		chip->flags |= TPM_CHIP_FLAG_FIRMWARE_UPGRADE;
759 		rc = 0;
760 	}
761 
762 out:
763 	/*
764 	 * Infineon TPM in field upgrade mode will return no data for the number
765 	 * of supported commands.
766 	 */
767 	if (rc == TPM2_RC_UPGRADE || rc == -ENODATA) {
768 		dev_info(&chip->dev, "TPM in field upgrade mode, requires firmware upgrade\n");
769 		chip->flags |= TPM_CHIP_FLAG_FIRMWARE_UPGRADE;
770 		rc = 0;
771 	}
772 
773 	if (rc > 0)
774 		rc = -ENODEV;
775 	return rc;
776 }
777 
778 int tpm2_find_cc(struct tpm_chip *chip, u32 cc)
779 {
780 	int i;
781 
782 	for (i = 0; i < chip->nr_commands; i++)
783 		if (cc == (chip->cc_attrs_tbl[i] & GENMASK(15, 0)))
784 			return i;
785 
786 	return -1;
787 }
788