xref: /openbmc/linux/drivers/char/tpm/tpm-interface.c (revision bc05aa6e)
1 /*
2  * Copyright (C) 2004 IBM Corporation
3  * Copyright (C) 2014 Intel Corporation
4  *
5  * Authors:
6  * Leendert van Doorn <leendert@watson.ibm.com>
7  * Dave Safford <safford@watson.ibm.com>
8  * Reiner Sailer <sailer@watson.ibm.com>
9  * Kylene Hall <kjhall@us.ibm.com>
10  *
11  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
12  *
13  * Device driver for TCG/TCPA TPM (trusted platform module).
14  * Specifications at www.trustedcomputinggroup.org
15  *
16  * This program is free software; you can redistribute it and/or
17  * modify it under the terms of the GNU General Public License as
18  * published by the Free Software Foundation, version 2 of the
19  * License.
20  *
21  * Note, the TPM chip is not interrupt driven (only polling)
22  * and can have very long timeouts (minutes!). Hence the unusual
23  * calls to msleep.
24  *
25  */
26 
27 #include <linux/poll.h>
28 #include <linux/slab.h>
29 #include <linux/mutex.h>
30 #include <linux/spinlock.h>
31 #include <linux/freezer.h>
32 #include <linux/pm_runtime.h>
33 #include <linux/tpm_eventlog.h>
34 
35 #include "tpm.h"
36 
37 #define TPM_MAX_ORDINAL 243
38 #define TSC_MAX_ORDINAL 12
39 #define TPM_PROTECTED_COMMAND 0x00
40 #define TPM_CONNECTION_COMMAND 0x40
41 
42 /*
43  * Bug workaround - some TPM's don't flush the most
44  * recently changed pcr on suspend, so force the flush
45  * with an extend to the selected _unused_ non-volatile pcr.
46  */
47 static int tpm_suspend_pcr;
48 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
49 MODULE_PARM_DESC(suspend_pcr,
50 		 "PCR to use for dummy writes to facilitate flush on suspend.");
51 
52 /*
53  * Array with one entry per ordinal defining the maximum amount
54  * of time the chip could take to return the result.  The ordinal
55  * designation of short, medium or long is defined in a table in
56  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
57  * values of the SHORT, MEDIUM, and LONG durations are retrieved
58  * from the chip during initialization with a call to tpm_get_timeouts.
59  */
60 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
61 	TPM_UNDEFINED,		/* 0 */
62 	TPM_UNDEFINED,
63 	TPM_UNDEFINED,
64 	TPM_UNDEFINED,
65 	TPM_UNDEFINED,
66 	TPM_UNDEFINED,		/* 5 */
67 	TPM_UNDEFINED,
68 	TPM_UNDEFINED,
69 	TPM_UNDEFINED,
70 	TPM_UNDEFINED,
71 	TPM_SHORT,		/* 10 */
72 	TPM_SHORT,
73 	TPM_MEDIUM,
74 	TPM_LONG,
75 	TPM_LONG,
76 	TPM_MEDIUM,		/* 15 */
77 	TPM_SHORT,
78 	TPM_SHORT,
79 	TPM_MEDIUM,
80 	TPM_LONG,
81 	TPM_SHORT,		/* 20 */
82 	TPM_SHORT,
83 	TPM_MEDIUM,
84 	TPM_MEDIUM,
85 	TPM_MEDIUM,
86 	TPM_SHORT,		/* 25 */
87 	TPM_SHORT,
88 	TPM_MEDIUM,
89 	TPM_SHORT,
90 	TPM_SHORT,
91 	TPM_MEDIUM,		/* 30 */
92 	TPM_LONG,
93 	TPM_MEDIUM,
94 	TPM_SHORT,
95 	TPM_SHORT,
96 	TPM_SHORT,		/* 35 */
97 	TPM_MEDIUM,
98 	TPM_MEDIUM,
99 	TPM_UNDEFINED,
100 	TPM_UNDEFINED,
101 	TPM_MEDIUM,		/* 40 */
102 	TPM_LONG,
103 	TPM_MEDIUM,
104 	TPM_SHORT,
105 	TPM_SHORT,
106 	TPM_SHORT,		/* 45 */
107 	TPM_SHORT,
108 	TPM_SHORT,
109 	TPM_SHORT,
110 	TPM_LONG,
111 	TPM_MEDIUM,		/* 50 */
112 	TPM_MEDIUM,
113 	TPM_UNDEFINED,
114 	TPM_UNDEFINED,
115 	TPM_UNDEFINED,
116 	TPM_UNDEFINED,		/* 55 */
117 	TPM_UNDEFINED,
118 	TPM_UNDEFINED,
119 	TPM_UNDEFINED,
120 	TPM_UNDEFINED,
121 	TPM_MEDIUM,		/* 60 */
122 	TPM_MEDIUM,
123 	TPM_MEDIUM,
124 	TPM_SHORT,
125 	TPM_SHORT,
126 	TPM_MEDIUM,		/* 65 */
127 	TPM_UNDEFINED,
128 	TPM_UNDEFINED,
129 	TPM_UNDEFINED,
130 	TPM_UNDEFINED,
131 	TPM_SHORT,		/* 70 */
132 	TPM_SHORT,
133 	TPM_UNDEFINED,
134 	TPM_UNDEFINED,
135 	TPM_UNDEFINED,
136 	TPM_UNDEFINED,		/* 75 */
137 	TPM_UNDEFINED,
138 	TPM_UNDEFINED,
139 	TPM_UNDEFINED,
140 	TPM_UNDEFINED,
141 	TPM_LONG,		/* 80 */
142 	TPM_UNDEFINED,
143 	TPM_MEDIUM,
144 	TPM_LONG,
145 	TPM_SHORT,
146 	TPM_UNDEFINED,		/* 85 */
147 	TPM_UNDEFINED,
148 	TPM_UNDEFINED,
149 	TPM_UNDEFINED,
150 	TPM_UNDEFINED,
151 	TPM_SHORT,		/* 90 */
152 	TPM_SHORT,
153 	TPM_SHORT,
154 	TPM_SHORT,
155 	TPM_SHORT,
156 	TPM_UNDEFINED,		/* 95 */
157 	TPM_UNDEFINED,
158 	TPM_UNDEFINED,
159 	TPM_UNDEFINED,
160 	TPM_UNDEFINED,
161 	TPM_MEDIUM,		/* 100 */
162 	TPM_SHORT,
163 	TPM_SHORT,
164 	TPM_UNDEFINED,
165 	TPM_UNDEFINED,
166 	TPM_UNDEFINED,		/* 105 */
167 	TPM_UNDEFINED,
168 	TPM_UNDEFINED,
169 	TPM_UNDEFINED,
170 	TPM_UNDEFINED,
171 	TPM_SHORT,		/* 110 */
172 	TPM_SHORT,
173 	TPM_SHORT,
174 	TPM_SHORT,
175 	TPM_SHORT,
176 	TPM_SHORT,		/* 115 */
177 	TPM_SHORT,
178 	TPM_SHORT,
179 	TPM_UNDEFINED,
180 	TPM_UNDEFINED,
181 	TPM_LONG,		/* 120 */
182 	TPM_LONG,
183 	TPM_MEDIUM,
184 	TPM_UNDEFINED,
185 	TPM_SHORT,
186 	TPM_SHORT,		/* 125 */
187 	TPM_SHORT,
188 	TPM_LONG,
189 	TPM_SHORT,
190 	TPM_SHORT,
191 	TPM_SHORT,		/* 130 */
192 	TPM_MEDIUM,
193 	TPM_UNDEFINED,
194 	TPM_SHORT,
195 	TPM_MEDIUM,
196 	TPM_UNDEFINED,		/* 135 */
197 	TPM_UNDEFINED,
198 	TPM_UNDEFINED,
199 	TPM_UNDEFINED,
200 	TPM_UNDEFINED,
201 	TPM_SHORT,		/* 140 */
202 	TPM_SHORT,
203 	TPM_UNDEFINED,
204 	TPM_UNDEFINED,
205 	TPM_UNDEFINED,
206 	TPM_UNDEFINED,		/* 145 */
207 	TPM_UNDEFINED,
208 	TPM_UNDEFINED,
209 	TPM_UNDEFINED,
210 	TPM_UNDEFINED,
211 	TPM_SHORT,		/* 150 */
212 	TPM_MEDIUM,
213 	TPM_MEDIUM,
214 	TPM_SHORT,
215 	TPM_SHORT,
216 	TPM_UNDEFINED,		/* 155 */
217 	TPM_UNDEFINED,
218 	TPM_UNDEFINED,
219 	TPM_UNDEFINED,
220 	TPM_UNDEFINED,
221 	TPM_SHORT,		/* 160 */
222 	TPM_SHORT,
223 	TPM_SHORT,
224 	TPM_SHORT,
225 	TPM_UNDEFINED,
226 	TPM_UNDEFINED,		/* 165 */
227 	TPM_UNDEFINED,
228 	TPM_UNDEFINED,
229 	TPM_UNDEFINED,
230 	TPM_UNDEFINED,
231 	TPM_LONG,		/* 170 */
232 	TPM_UNDEFINED,
233 	TPM_UNDEFINED,
234 	TPM_UNDEFINED,
235 	TPM_UNDEFINED,
236 	TPM_UNDEFINED,		/* 175 */
237 	TPM_UNDEFINED,
238 	TPM_UNDEFINED,
239 	TPM_UNDEFINED,
240 	TPM_UNDEFINED,
241 	TPM_MEDIUM,		/* 180 */
242 	TPM_SHORT,
243 	TPM_MEDIUM,
244 	TPM_MEDIUM,
245 	TPM_MEDIUM,
246 	TPM_MEDIUM,		/* 185 */
247 	TPM_SHORT,
248 	TPM_UNDEFINED,
249 	TPM_UNDEFINED,
250 	TPM_UNDEFINED,
251 	TPM_UNDEFINED,		/* 190 */
252 	TPM_UNDEFINED,
253 	TPM_UNDEFINED,
254 	TPM_UNDEFINED,
255 	TPM_UNDEFINED,
256 	TPM_UNDEFINED,		/* 195 */
257 	TPM_UNDEFINED,
258 	TPM_UNDEFINED,
259 	TPM_UNDEFINED,
260 	TPM_UNDEFINED,
261 	TPM_SHORT,		/* 200 */
262 	TPM_UNDEFINED,
263 	TPM_UNDEFINED,
264 	TPM_UNDEFINED,
265 	TPM_SHORT,
266 	TPM_SHORT,		/* 205 */
267 	TPM_SHORT,
268 	TPM_SHORT,
269 	TPM_SHORT,
270 	TPM_SHORT,
271 	TPM_MEDIUM,		/* 210 */
272 	TPM_UNDEFINED,
273 	TPM_MEDIUM,
274 	TPM_MEDIUM,
275 	TPM_MEDIUM,
276 	TPM_UNDEFINED,		/* 215 */
277 	TPM_MEDIUM,
278 	TPM_UNDEFINED,
279 	TPM_UNDEFINED,
280 	TPM_SHORT,
281 	TPM_SHORT,		/* 220 */
282 	TPM_SHORT,
283 	TPM_SHORT,
284 	TPM_SHORT,
285 	TPM_SHORT,
286 	TPM_UNDEFINED,		/* 225 */
287 	TPM_UNDEFINED,
288 	TPM_UNDEFINED,
289 	TPM_UNDEFINED,
290 	TPM_UNDEFINED,
291 	TPM_SHORT,		/* 230 */
292 	TPM_LONG,
293 	TPM_MEDIUM,
294 	TPM_UNDEFINED,
295 	TPM_UNDEFINED,
296 	TPM_UNDEFINED,		/* 235 */
297 	TPM_UNDEFINED,
298 	TPM_UNDEFINED,
299 	TPM_UNDEFINED,
300 	TPM_UNDEFINED,
301 	TPM_SHORT,		/* 240 */
302 	TPM_UNDEFINED,
303 	TPM_MEDIUM,
304 };
305 
306 /*
307  * Returns max number of jiffies to wait
308  */
309 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
310 					   u32 ordinal)
311 {
312 	int duration_idx = TPM_UNDEFINED;
313 	int duration = 0;
314 
315 	/*
316 	 * We only have a duration table for protected commands, where the upper
317 	 * 16 bits are 0. For the few other ordinals the fallback will be used.
318 	 */
319 	if (ordinal < TPM_MAX_ORDINAL)
320 		duration_idx = tpm_ordinal_duration[ordinal];
321 
322 	if (duration_idx != TPM_UNDEFINED)
323 		duration = chip->duration[duration_idx];
324 	if (duration <= 0)
325 		return 2 * 60 * HZ;
326 	else
327 		return duration;
328 }
329 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
330 
331 static int tpm_validate_command(struct tpm_chip *chip,
332 				 struct tpm_space *space,
333 				 const u8 *cmd,
334 				 size_t len)
335 {
336 	const struct tpm_input_header *header = (const void *)cmd;
337 	int i;
338 	u32 cc;
339 	u32 attrs;
340 	unsigned int nr_handles;
341 
342 	if (len < TPM_HEADER_SIZE)
343 		return -EINVAL;
344 
345 	if (!space)
346 		return 0;
347 
348 	if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
349 		cc = be32_to_cpu(header->ordinal);
350 
351 		i = tpm2_find_cc(chip, cc);
352 		if (i < 0) {
353 			dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
354 				cc);
355 			return -EOPNOTSUPP;
356 		}
357 
358 		attrs = chip->cc_attrs_tbl[i];
359 		nr_handles =
360 			4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
361 		if (len < TPM_HEADER_SIZE + 4 * nr_handles)
362 			goto err_len;
363 	}
364 
365 	return 0;
366 err_len:
367 	dev_dbg(&chip->dev,
368 		"%s: insufficient command length %zu", __func__, len);
369 	return -EINVAL;
370 }
371 
372 /**
373  * tmp_transmit - Internal kernel interface to transmit TPM commands.
374  *
375  * @chip: TPM chip to use
376  * @buf: TPM command buffer
377  * @bufsiz: length of the TPM command buffer
378  * @flags: tpm transmit flags - bitmap
379  *
380  * Return:
381  *     0 when the operation is successful.
382  *     A negative number for system errors (errno).
383  */
384 ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
385 		     u8 *buf, size_t bufsiz, unsigned int flags)
386 {
387 	struct tpm_output_header *header = (void *)buf;
388 	int rc;
389 	ssize_t len = 0;
390 	u32 count, ordinal;
391 	unsigned long stop;
392 	bool need_locality;
393 
394 	rc = tpm_validate_command(chip, space, buf, bufsiz);
395 	if (rc == -EINVAL)
396 		return rc;
397 	/*
398 	 * If the command is not implemented by the TPM, synthesize a
399 	 * response with a TPM2_RC_COMMAND_CODE return for user-space.
400 	 */
401 	if (rc == -EOPNOTSUPP) {
402 		header->length = cpu_to_be32(sizeof(*header));
403 		header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
404 		header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
405 						  TSS2_RESMGR_TPM_RC_LAYER);
406 		return bufsiz;
407 	}
408 
409 	if (bufsiz > TPM_BUFSIZE)
410 		bufsiz = TPM_BUFSIZE;
411 
412 	count = be32_to_cpu(*((__be32 *) (buf + 2)));
413 	ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
414 	if (count == 0)
415 		return -ENODATA;
416 	if (count > bufsiz) {
417 		dev_err(&chip->dev,
418 			"invalid count value %x %zx\n", count, bufsiz);
419 		return -E2BIG;
420 	}
421 
422 	if (!(flags & TPM_TRANSMIT_UNLOCKED))
423 		mutex_lock(&chip->tpm_mutex);
424 
425 	if (chip->dev.parent)
426 		pm_runtime_get_sync(chip->dev.parent);
427 
428 	if (chip->ops->clk_enable != NULL)
429 		chip->ops->clk_enable(chip, true);
430 
431 	/* Store the decision as chip->locality will be changed. */
432 	need_locality = chip->locality == -1;
433 
434 	if (!(flags & TPM_TRANSMIT_RAW) &&
435 	    need_locality && chip->ops->request_locality)  {
436 		rc = chip->ops->request_locality(chip, 0);
437 		if (rc < 0)
438 			goto out_no_locality;
439 		chip->locality = rc;
440 	}
441 
442 	rc = tpm2_prepare_space(chip, space, ordinal, buf);
443 	if (rc)
444 		goto out;
445 
446 	rc = chip->ops->send(chip, (u8 *) buf, count);
447 	if (rc < 0) {
448 		if (rc != -EPIPE)
449 			dev_err(&chip->dev,
450 				"%s: tpm_send: error %d\n", __func__, rc);
451 		goto out;
452 	}
453 
454 	if (chip->flags & TPM_CHIP_FLAG_IRQ)
455 		goto out_recv;
456 
457 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
458 		stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
459 	else
460 		stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
461 	do {
462 		u8 status = chip->ops->status(chip);
463 		if ((status & chip->ops->req_complete_mask) ==
464 		    chip->ops->req_complete_val)
465 			goto out_recv;
466 
467 		if (chip->ops->req_canceled(chip, status)) {
468 			dev_err(&chip->dev, "Operation Canceled\n");
469 			rc = -ECANCELED;
470 			goto out;
471 		}
472 
473 		tpm_msleep(TPM_TIMEOUT);
474 		rmb();
475 	} while (time_before(jiffies, stop));
476 
477 	chip->ops->cancel(chip);
478 	dev_err(&chip->dev, "Operation Timed out\n");
479 	rc = -ETIME;
480 	goto out;
481 
482 out_recv:
483 	len = chip->ops->recv(chip, (u8 *) buf, bufsiz);
484 	if (len < 0) {
485 		rc = len;
486 		dev_err(&chip->dev,
487 			"tpm_transmit: tpm_recv: error %d\n", rc);
488 		goto out;
489 	} else if (len < TPM_HEADER_SIZE) {
490 		rc = -EFAULT;
491 		goto out;
492 	}
493 
494 	if (len != be32_to_cpu(header->length)) {
495 		rc = -EFAULT;
496 		goto out;
497 	}
498 
499 	rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
500 
501 out:
502 	if (need_locality && chip->ops->relinquish_locality) {
503 		chip->ops->relinquish_locality(chip, chip->locality);
504 		chip->locality = -1;
505 	}
506 out_no_locality:
507 	if (chip->ops->clk_enable != NULL)
508 		chip->ops->clk_enable(chip, false);
509 
510 	if (chip->dev.parent)
511 		pm_runtime_put_sync(chip->dev.parent);
512 
513 	if (!(flags & TPM_TRANSMIT_UNLOCKED))
514 		mutex_unlock(&chip->tpm_mutex);
515 	return rc ? rc : len;
516 }
517 
518 /**
519  * tmp_transmit_cmd - send a tpm command to the device
520  *    The function extracts tpm out header return code
521  *
522  * @chip: TPM chip to use
523  * @buf: TPM command buffer
524  * @bufsiz: length of the buffer
525  * @min_rsp_body_length: minimum expected length of response body
526  * @flags: tpm transmit flags - bitmap
527  * @desc: command description used in the error message
528  *
529  * Return:
530  *     0 when the operation is successful.
531  *     A negative number for system errors (errno).
532  *     A positive number for a TPM error.
533  */
534 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
535 			 const void *buf, size_t bufsiz,
536 			 size_t min_rsp_body_length, unsigned int flags,
537 			 const char *desc)
538 {
539 	const struct tpm_output_header *header = buf;
540 	int err;
541 	ssize_t len;
542 
543 	len = tpm_transmit(chip, space, (u8 *)buf, bufsiz, flags);
544 	if (len <  0)
545 		return len;
546 
547 	err = be32_to_cpu(header->return_code);
548 	if (err != 0 && desc)
549 		dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
550 			desc);
551 	if (err)
552 		return err;
553 
554 	if (len < min_rsp_body_length + TPM_HEADER_SIZE)
555 		return -EFAULT;
556 
557 	return 0;
558 }
559 EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
560 
561 #define TPM_ORD_STARTUP 153
562 #define TPM_ST_CLEAR 1
563 
564 /**
565  * tpm_startup - turn on the TPM
566  * @chip: TPM chip to use
567  *
568  * Normally the firmware should start the TPM. This function is provided as a
569  * workaround if this does not happen. A legal case for this could be for
570  * example when a TPM emulator is used.
571  *
572  * Return: same as tpm_transmit_cmd()
573  */
574 int tpm_startup(struct tpm_chip *chip)
575 {
576 	struct tpm_buf buf;
577 	int rc;
578 
579 	dev_info(&chip->dev, "starting up the TPM manually\n");
580 
581 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
582 		rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
583 		if (rc < 0)
584 			return rc;
585 
586 		tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
587 	} else {
588 		rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
589 		if (rc < 0)
590 			return rc;
591 
592 		tpm_buf_append_u16(&buf, TPM_ST_CLEAR);
593 	}
594 
595 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
596 			      "attempting to start the TPM");
597 
598 	tpm_buf_destroy(&buf);
599 	return rc;
600 }
601 
602 #define TPM_DIGEST_SIZE 20
603 #define TPM_RET_CODE_IDX 6
604 #define TPM_INTERNAL_RESULT_SIZE 200
605 #define TPM_ORD_GET_CAP 101
606 #define TPM_ORD_GET_RANDOM 70
607 
608 static const struct tpm_input_header tpm_getcap_header = {
609 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
610 	.length = cpu_to_be32(22),
611 	.ordinal = cpu_to_be32(TPM_ORD_GET_CAP)
612 };
613 
614 ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
615 		   const char *desc, size_t min_cap_length)
616 {
617 	struct tpm_buf buf;
618 	int rc;
619 
620 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
621 	if (rc)
622 		return rc;
623 
624 	if (subcap_id == TPM_CAP_VERSION_1_1 ||
625 	    subcap_id == TPM_CAP_VERSION_1_2) {
626 		tpm_buf_append_u32(&buf, subcap_id);
627 		tpm_buf_append_u32(&buf, 0);
628 	} else {
629 		if (subcap_id == TPM_CAP_FLAG_PERM ||
630 		    subcap_id == TPM_CAP_FLAG_VOL)
631 			tpm_buf_append_u32(&buf, TPM_CAP_FLAG);
632 		else
633 			tpm_buf_append_u32(&buf, TPM_CAP_PROP);
634 
635 		tpm_buf_append_u32(&buf, 4);
636 		tpm_buf_append_u32(&buf, subcap_id);
637 	}
638 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
639 			      min_cap_length, 0, desc);
640 	if (!rc)
641 		*cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
642 
643 	tpm_buf_destroy(&buf);
644 	return rc;
645 }
646 EXPORT_SYMBOL_GPL(tpm_getcap);
647 
648 int tpm_get_timeouts(struct tpm_chip *chip)
649 {
650 	cap_t cap;
651 	unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
652 	ssize_t rc;
653 
654 	if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
655 		return 0;
656 
657 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
658 		/* Fixed timeouts for TPM2 */
659 		chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
660 		chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
661 		chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
662 		chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
663 		chip->duration[TPM_SHORT] =
664 		    msecs_to_jiffies(TPM2_DURATION_SHORT);
665 		chip->duration[TPM_MEDIUM] =
666 		    msecs_to_jiffies(TPM2_DURATION_MEDIUM);
667 		chip->duration[TPM_LONG] =
668 		    msecs_to_jiffies(TPM2_DURATION_LONG);
669 
670 		chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
671 		return 0;
672 	}
673 
674 	rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
675 			sizeof(cap.timeout));
676 	if (rc == TPM_ERR_INVALID_POSTINIT) {
677 		if (tpm_startup(chip))
678 			return rc;
679 
680 		rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
681 				"attempting to determine the timeouts",
682 				sizeof(cap.timeout));
683 	}
684 
685 	if (rc) {
686 		dev_err(&chip->dev,
687 			"A TPM error (%zd) occurred attempting to determine the timeouts\n",
688 			rc);
689 		return rc;
690 	}
691 
692 	timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
693 	timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
694 	timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
695 	timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
696 	timeout_chip[0] = be32_to_cpu(cap.timeout.a);
697 	timeout_chip[1] = be32_to_cpu(cap.timeout.b);
698 	timeout_chip[2] = be32_to_cpu(cap.timeout.c);
699 	timeout_chip[3] = be32_to_cpu(cap.timeout.d);
700 	memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
701 
702 	/*
703 	 * Provide ability for vendor overrides of timeout values in case
704 	 * of misreporting.
705 	 */
706 	if (chip->ops->update_timeouts != NULL)
707 		chip->timeout_adjusted =
708 			chip->ops->update_timeouts(chip, timeout_eff);
709 
710 	if (!chip->timeout_adjusted) {
711 		/* Restore default if chip reported 0 */
712 		int i;
713 
714 		for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
715 			if (timeout_eff[i])
716 				continue;
717 
718 			timeout_eff[i] = timeout_old[i];
719 			chip->timeout_adjusted = true;
720 		}
721 
722 		if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
723 			/* timeouts in msec rather usec */
724 			for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
725 				timeout_eff[i] *= 1000;
726 			chip->timeout_adjusted = true;
727 		}
728 	}
729 
730 	/* Report adjusted timeouts */
731 	if (chip->timeout_adjusted) {
732 		dev_info(&chip->dev,
733 			 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
734 			 timeout_chip[0], timeout_eff[0],
735 			 timeout_chip[1], timeout_eff[1],
736 			 timeout_chip[2], timeout_eff[2],
737 			 timeout_chip[3], timeout_eff[3]);
738 	}
739 
740 	chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
741 	chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
742 	chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
743 	chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
744 
745 	rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
746 			"attempting to determine the durations",
747 			sizeof(cap.duration));
748 	if (rc)
749 		return rc;
750 
751 	chip->duration[TPM_SHORT] =
752 		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
753 	chip->duration[TPM_MEDIUM] =
754 		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
755 	chip->duration[TPM_LONG] =
756 		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
757 
758 	/* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
759 	 * value wrong and apparently reports msecs rather than usecs. So we
760 	 * fix up the resulting too-small TPM_SHORT value to make things work.
761 	 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
762 	 */
763 	if (chip->duration[TPM_SHORT] < (HZ / 100)) {
764 		chip->duration[TPM_SHORT] = HZ;
765 		chip->duration[TPM_MEDIUM] *= 1000;
766 		chip->duration[TPM_LONG] *= 1000;
767 		chip->duration_adjusted = true;
768 		dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
769 	}
770 
771 	chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
772 	return 0;
773 }
774 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
775 
776 #define TPM_ORD_CONTINUE_SELFTEST 83
777 #define CONTINUE_SELFTEST_RESULT_SIZE 10
778 
779 static const struct tpm_input_header continue_selftest_header = {
780 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
781 	.length = cpu_to_be32(10),
782 	.ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
783 };
784 
785 /**
786  * tpm_continue_selftest -- run TPM's selftest
787  * @chip: TPM chip to use
788  *
789  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
790  * a TPM error code.
791  */
792 static int tpm_continue_selftest(struct tpm_chip *chip)
793 {
794 	int rc;
795 	struct tpm_cmd_t cmd;
796 
797 	cmd.header.in = continue_selftest_header;
798 	rc = tpm_transmit_cmd(chip, NULL, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
799 			      0, 0, "continue selftest");
800 	return rc;
801 }
802 
803 #define TPM_ORDINAL_PCRREAD 21
804 #define READ_PCR_RESULT_SIZE 30
805 #define READ_PCR_RESULT_BODY_SIZE 20
806 static const struct tpm_input_header pcrread_header = {
807 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
808 	.length = cpu_to_be32(14),
809 	.ordinal = cpu_to_be32(TPM_ORDINAL_PCRREAD)
810 };
811 
812 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
813 {
814 	int rc;
815 	struct tpm_cmd_t cmd;
816 
817 	cmd.header.in = pcrread_header;
818 	cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
819 	rc = tpm_transmit_cmd(chip, NULL, &cmd, READ_PCR_RESULT_SIZE,
820 			      READ_PCR_RESULT_BODY_SIZE, 0,
821 			      "attempting to read a pcr value");
822 
823 	if (rc == 0)
824 		memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
825 		       TPM_DIGEST_SIZE);
826 	return rc;
827 }
828 
829 /**
830  * tpm_is_tpm2 - do we a have a TPM2 chip?
831  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
832  *
833  * Return:
834  * 1 if we have a TPM2 chip.
835  * 0 if we don't have a TPM2 chip.
836  * A negative number for system errors (errno).
837  */
838 int tpm_is_tpm2(struct tpm_chip *chip)
839 {
840 	int rc;
841 
842 	chip = tpm_chip_find_get(chip);
843 	if (!chip)
844 		return -ENODEV;
845 
846 	rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
847 
848 	tpm_put_ops(chip);
849 
850 	return rc;
851 }
852 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
853 
854 /**
855  * tpm_pcr_read - read a PCR value from SHA1 bank
856  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
857  * @pcr_idx:	the PCR to be retrieved
858  * @res_buf:	the value of the PCR
859  *
860  * Return: same as with tpm_transmit_cmd()
861  */
862 int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
863 {
864 	int rc;
865 
866 	chip = tpm_chip_find_get(chip);
867 	if (!chip)
868 		return -ENODEV;
869 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
870 		rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
871 	else
872 		rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
873 	tpm_put_ops(chip);
874 	return rc;
875 }
876 EXPORT_SYMBOL_GPL(tpm_pcr_read);
877 
878 #define TPM_ORD_PCR_EXTEND 20
879 #define EXTEND_PCR_RESULT_SIZE 34
880 #define EXTEND_PCR_RESULT_BODY_SIZE 20
881 static const struct tpm_input_header pcrextend_header = {
882 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
883 	.length = cpu_to_be32(34),
884 	.ordinal = cpu_to_be32(TPM_ORD_PCR_EXTEND)
885 };
886 
887 static int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash,
888 			   char *log_msg)
889 {
890 	struct tpm_buf buf;
891 	int rc;
892 
893 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND);
894 	if (rc)
895 		return rc;
896 
897 	tpm_buf_append_u32(&buf, pcr_idx);
898 	tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);
899 
900 	rc = tpm_transmit_cmd(chip, NULL, buf.data, EXTEND_PCR_RESULT_SIZE,
901 			      EXTEND_PCR_RESULT_BODY_SIZE, 0, log_msg);
902 	tpm_buf_destroy(&buf);
903 	return rc;
904 }
905 
906 /**
907  * tpm_pcr_extend - extend a PCR value in SHA1 bank.
908  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
909  * @pcr_idx:	the PCR to be retrieved
910  * @hash:	the hash value used to extend the PCR value
911  *
912  * Note: with TPM 2.0 extends also those banks with a known digest size to the
913  * cryto subsystem in order to prevent malicious use of those PCR banks. In the
914  * future we should dynamically determine digest sizes.
915  *
916  * Return: same as with tpm_transmit_cmd()
917  */
918 int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
919 {
920 	int rc;
921 	struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
922 	u32 count = 0;
923 	int i;
924 
925 	chip = tpm_chip_find_get(chip);
926 	if (!chip)
927 		return -ENODEV;
928 
929 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
930 		memset(digest_list, 0, sizeof(digest_list));
931 
932 		for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
933 			    chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
934 			digest_list[i].alg_id = chip->active_banks[i];
935 			memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
936 			count++;
937 		}
938 
939 		rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);
940 		tpm_put_ops(chip);
941 		return rc;
942 	}
943 
944 	rc = tpm1_pcr_extend(chip, pcr_idx, hash,
945 			     "attempting extend a PCR value");
946 	tpm_put_ops(chip);
947 	return rc;
948 }
949 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
950 
951 /**
952  * tpm_do_selftest - have the TPM continue its selftest and wait until it
953  *                   can receive further commands
954  * @chip: TPM chip to use
955  *
956  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
957  * a TPM error code.
958  */
959 int tpm_do_selftest(struct tpm_chip *chip)
960 {
961 	int rc;
962 	unsigned int loops;
963 	unsigned int delay_msec = 100;
964 	unsigned long duration;
965 	u8 dummy[TPM_DIGEST_SIZE];
966 
967 	duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
968 
969 	loops = jiffies_to_msecs(duration) / delay_msec;
970 
971 	rc = tpm_continue_selftest(chip);
972 	/* This may fail if there was no TPM driver during a suspend/resume
973 	 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
974 	 */
975 	if (rc)
976 		return rc;
977 
978 	do {
979 		/* Attempt to read a PCR value */
980 		rc = tpm_pcr_read_dev(chip, 0, dummy);
981 
982 		/* Some buggy TPMs will not respond to tpm_tis_ready() for
983 		 * around 300ms while the self test is ongoing, keep trying
984 		 * until the self test duration expires. */
985 		if (rc == -ETIME) {
986 			dev_info(
987 			    &chip->dev, HW_ERR
988 			    "TPM command timed out during continue self test");
989 			tpm_msleep(delay_msec);
990 			continue;
991 		}
992 
993 		if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
994 			dev_info(&chip->dev,
995 				 "TPM is disabled/deactivated (0x%X)\n", rc);
996 			/* TPM is disabled and/or deactivated; driver can
997 			 * proceed and TPM does handle commands for
998 			 * suspend/resume correctly
999 			 */
1000 			return 0;
1001 		}
1002 		if (rc != TPM_WARN_DOING_SELFTEST)
1003 			return rc;
1004 		tpm_msleep(delay_msec);
1005 	} while (--loops > 0);
1006 
1007 	return rc;
1008 }
1009 EXPORT_SYMBOL_GPL(tpm_do_selftest);
1010 
1011 /**
1012  * tpm1_auto_startup - Perform the standard automatic TPM initialization
1013  *                     sequence
1014  * @chip: TPM chip to use
1015  *
1016  * Returns 0 on success, < 0 in case of fatal error.
1017  */
1018 int tpm1_auto_startup(struct tpm_chip *chip)
1019 {
1020 	int rc;
1021 
1022 	rc = tpm_get_timeouts(chip);
1023 	if (rc)
1024 		goto out;
1025 	rc = tpm_do_selftest(chip);
1026 	if (rc) {
1027 		dev_err(&chip->dev, "TPM self test failed\n");
1028 		goto out;
1029 	}
1030 
1031 	return rc;
1032 out:
1033 	if (rc > 0)
1034 		rc = -ENODEV;
1035 	return rc;
1036 }
1037 
1038 /**
1039  * tpm_send - send a TPM command
1040  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1041  * @cmd:	a TPM command buffer
1042  * @buflen:	the length of the TPM command buffer
1043  *
1044  * Return: same as with tpm_transmit_cmd()
1045  */
1046 int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
1047 {
1048 	int rc;
1049 
1050 	chip = tpm_chip_find_get(chip);
1051 	if (!chip)
1052 		return -ENODEV;
1053 
1054 	rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0,
1055 			      "attempting to a send a command");
1056 	tpm_put_ops(chip);
1057 	return rc;
1058 }
1059 EXPORT_SYMBOL_GPL(tpm_send);
1060 
1061 #define TPM_ORD_SAVESTATE 152
1062 #define SAVESTATE_RESULT_SIZE 10
1063 
1064 static const struct tpm_input_header savestate_header = {
1065 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1066 	.length = cpu_to_be32(10),
1067 	.ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)
1068 };
1069 
1070 /*
1071  * We are about to suspend. Save the TPM state
1072  * so that it can be restored.
1073  */
1074 int tpm_pm_suspend(struct device *dev)
1075 {
1076 	struct tpm_chip *chip = dev_get_drvdata(dev);
1077 	struct tpm_cmd_t cmd;
1078 	int rc, try;
1079 
1080 	u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1081 
1082 	if (chip == NULL)
1083 		return -ENODEV;
1084 
1085 	if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
1086 		return 0;
1087 
1088 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1089 		tpm2_shutdown(chip, TPM2_SU_STATE);
1090 		return 0;
1091 	}
1092 
1093 	/* for buggy tpm, flush pcrs with extend to selected dummy */
1094 	if (tpm_suspend_pcr)
1095 		rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
1096 				     "extending dummy pcr before suspend");
1097 
1098 	/* now do the actual savestate */
1099 	for (try = 0; try < TPM_RETRY; try++) {
1100 		cmd.header.in = savestate_header;
1101 		rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,
1102 				      0, 0, NULL);
1103 
1104 		/*
1105 		 * If the TPM indicates that it is too busy to respond to
1106 		 * this command then retry before giving up.  It can take
1107 		 * several seconds for this TPM to be ready.
1108 		 *
1109 		 * This can happen if the TPM has already been sent the
1110 		 * SaveState command before the driver has loaded.  TCG 1.2
1111 		 * specification states that any communication after SaveState
1112 		 * may cause the TPM to invalidate previously saved state.
1113 		 */
1114 		if (rc != TPM_WARN_RETRY)
1115 			break;
1116 		tpm_msleep(TPM_TIMEOUT_RETRY);
1117 	}
1118 
1119 	if (rc)
1120 		dev_err(&chip->dev,
1121 			"Error (%d) sending savestate before suspend\n", rc);
1122 	else if (try > 0)
1123 		dev_warn(&chip->dev, "TPM savestate took %dms\n",
1124 			 try * TPM_TIMEOUT_RETRY);
1125 
1126 	return rc;
1127 }
1128 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1129 
1130 /*
1131  * Resume from a power safe. The BIOS already restored
1132  * the TPM state.
1133  */
1134 int tpm_pm_resume(struct device *dev)
1135 {
1136 	struct tpm_chip *chip = dev_get_drvdata(dev);
1137 
1138 	if (chip == NULL)
1139 		return -ENODEV;
1140 
1141 	return 0;
1142 }
1143 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1144 
1145 #define TPM_GETRANDOM_RESULT_SIZE	18
1146 static const struct tpm_input_header tpm_getrandom_header = {
1147 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1148 	.length = cpu_to_be32(14),
1149 	.ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
1150 };
1151 
1152 /**
1153  * tpm_get_random() - get random bytes from the TPM's RNG
1154  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1155  * @out:	destination buffer for the random bytes
1156  * @max:	the max number of bytes to write to @out
1157  *
1158  * Return: same as with tpm_transmit_cmd()
1159  */
1160 int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
1161 {
1162 	struct tpm_cmd_t tpm_cmd;
1163 	u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
1164 	int err, total = 0, retries = 5;
1165 	u8 *dest = out;
1166 
1167 	if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1168 		return -EINVAL;
1169 
1170 	chip = tpm_chip_find_get(chip);
1171 	if (!chip)
1172 		return -ENODEV;
1173 
1174 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1175 		err = tpm2_get_random(chip, out, max);
1176 		tpm_put_ops(chip);
1177 		return err;
1178 	}
1179 
1180 	do {
1181 		tpm_cmd.header.in = tpm_getrandom_header;
1182 		tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1183 
1184 		err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
1185 				       TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1186 				       offsetof(struct tpm_getrandom_out,
1187 						rng_data),
1188 				       0, "attempting get random");
1189 		if (err)
1190 			break;
1191 
1192 		recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1193 		if (recd > num_bytes) {
1194 			total = -EFAULT;
1195 			break;
1196 		}
1197 
1198 		rlength = be32_to_cpu(tpm_cmd.header.out.length);
1199 		if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
1200 			      recd) {
1201 			total = -EFAULT;
1202 			break;
1203 		}
1204 		memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1205 
1206 		dest += recd;
1207 		total += recd;
1208 		num_bytes -= recd;
1209 	} while (retries-- && total < max);
1210 
1211 	tpm_put_ops(chip);
1212 	return total ? total : -EIO;
1213 }
1214 EXPORT_SYMBOL_GPL(tpm_get_random);
1215 
1216 /**
1217  * tpm_seal_trusted() - seal a trusted key payload
1218  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1219  * @options:	authentication values and other options
1220  * @payload:	the key data in clear and encrypted form
1221  *
1222  * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
1223  * the keyring subsystem.
1224  *
1225  * Return: same as with tpm_transmit_cmd()
1226  */
1227 int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload,
1228 		     struct trusted_key_options *options)
1229 {
1230 	int rc;
1231 
1232 	chip = tpm_chip_find_get(chip);
1233 	if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1234 		return -ENODEV;
1235 
1236 	rc = tpm2_seal_trusted(chip, payload, options);
1237 
1238 	tpm_put_ops(chip);
1239 	return rc;
1240 }
1241 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1242 
1243 /**
1244  * tpm_unseal_trusted() - unseal a trusted key
1245  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1246  * @options:	authentication values and other options
1247  * @payload:	the key data in clear and encrypted form
1248  *
1249  * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
1250  * the keyring subsystem.
1251  *
1252  * Return: same as with tpm_transmit_cmd()
1253  */
1254 int tpm_unseal_trusted(struct tpm_chip *chip,
1255 		       struct trusted_key_payload *payload,
1256 		       struct trusted_key_options *options)
1257 {
1258 	int rc;
1259 
1260 	chip = tpm_chip_find_get(chip);
1261 	if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1262 		return -ENODEV;
1263 
1264 	rc = tpm2_unseal_trusted(chip, payload, options);
1265 
1266 	tpm_put_ops(chip);
1267 
1268 	return rc;
1269 }
1270 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1271 
1272 static int __init tpm_init(void)
1273 {
1274 	int rc;
1275 
1276 	tpm_class = class_create(THIS_MODULE, "tpm");
1277 	if (IS_ERR(tpm_class)) {
1278 		pr_err("couldn't create tpm class\n");
1279 		return PTR_ERR(tpm_class);
1280 	}
1281 
1282 	tpmrm_class = class_create(THIS_MODULE, "tpmrm");
1283 	if (IS_ERR(tpmrm_class)) {
1284 		pr_err("couldn't create tpmrm class\n");
1285 		class_destroy(tpm_class);
1286 		return PTR_ERR(tpmrm_class);
1287 	}
1288 
1289 	rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm");
1290 	if (rc < 0) {
1291 		pr_err("tpm: failed to allocate char dev region\n");
1292 		class_destroy(tpmrm_class);
1293 		class_destroy(tpm_class);
1294 		return rc;
1295 	}
1296 
1297 	return 0;
1298 }
1299 
1300 static void __exit tpm_exit(void)
1301 {
1302 	idr_destroy(&dev_nums_idr);
1303 	class_destroy(tpm_class);
1304 	class_destroy(tpmrm_class);
1305 	unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
1306 }
1307 
1308 subsys_initcall(tpm_init);
1309 module_exit(tpm_exit);
1310 
1311 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1312 MODULE_DESCRIPTION("TPM Driver");
1313 MODULE_VERSION("2.0");
1314 MODULE_LICENSE("GPL");
1315