xref: /openbmc/linux/drivers/char/tpm/tpm-interface.c (revision 96de2506)
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/tpm_eventlog.h>
33 
34 #include "tpm.h"
35 
36 #define TPM_MAX_ORDINAL 243
37 #define TSC_MAX_ORDINAL 12
38 #define TPM_PROTECTED_COMMAND 0x00
39 #define TPM_CONNECTION_COMMAND 0x40
40 
41 /*
42  * Bug workaround - some TPM's don't flush the most
43  * recently changed pcr on suspend, so force the flush
44  * with an extend to the selected _unused_ non-volatile pcr.
45  */
46 static int tpm_suspend_pcr;
47 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
48 MODULE_PARM_DESC(suspend_pcr,
49 		 "PCR to use for dummy writes to facilitate flush on suspend.");
50 
51 /*
52  * Array with one entry per ordinal defining the maximum amount
53  * of time the chip could take to return the result.  The ordinal
54  * designation of short, medium or long is defined in a table in
55  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
56  * values of the SHORT, MEDIUM, and LONG durations are retrieved
57  * from the chip during initialization with a call to tpm_get_timeouts.
58  */
59 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
60 	TPM_UNDEFINED,		/* 0 */
61 	TPM_UNDEFINED,
62 	TPM_UNDEFINED,
63 	TPM_UNDEFINED,
64 	TPM_UNDEFINED,
65 	TPM_UNDEFINED,		/* 5 */
66 	TPM_UNDEFINED,
67 	TPM_UNDEFINED,
68 	TPM_UNDEFINED,
69 	TPM_UNDEFINED,
70 	TPM_SHORT,		/* 10 */
71 	TPM_SHORT,
72 	TPM_MEDIUM,
73 	TPM_LONG,
74 	TPM_LONG,
75 	TPM_MEDIUM,		/* 15 */
76 	TPM_SHORT,
77 	TPM_SHORT,
78 	TPM_MEDIUM,
79 	TPM_LONG,
80 	TPM_SHORT,		/* 20 */
81 	TPM_SHORT,
82 	TPM_MEDIUM,
83 	TPM_MEDIUM,
84 	TPM_MEDIUM,
85 	TPM_SHORT,		/* 25 */
86 	TPM_SHORT,
87 	TPM_MEDIUM,
88 	TPM_SHORT,
89 	TPM_SHORT,
90 	TPM_MEDIUM,		/* 30 */
91 	TPM_LONG,
92 	TPM_MEDIUM,
93 	TPM_SHORT,
94 	TPM_SHORT,
95 	TPM_SHORT,		/* 35 */
96 	TPM_MEDIUM,
97 	TPM_MEDIUM,
98 	TPM_UNDEFINED,
99 	TPM_UNDEFINED,
100 	TPM_MEDIUM,		/* 40 */
101 	TPM_LONG,
102 	TPM_MEDIUM,
103 	TPM_SHORT,
104 	TPM_SHORT,
105 	TPM_SHORT,		/* 45 */
106 	TPM_SHORT,
107 	TPM_SHORT,
108 	TPM_SHORT,
109 	TPM_LONG,
110 	TPM_MEDIUM,		/* 50 */
111 	TPM_MEDIUM,
112 	TPM_UNDEFINED,
113 	TPM_UNDEFINED,
114 	TPM_UNDEFINED,
115 	TPM_UNDEFINED,		/* 55 */
116 	TPM_UNDEFINED,
117 	TPM_UNDEFINED,
118 	TPM_UNDEFINED,
119 	TPM_UNDEFINED,
120 	TPM_MEDIUM,		/* 60 */
121 	TPM_MEDIUM,
122 	TPM_MEDIUM,
123 	TPM_SHORT,
124 	TPM_SHORT,
125 	TPM_MEDIUM,		/* 65 */
126 	TPM_UNDEFINED,
127 	TPM_UNDEFINED,
128 	TPM_UNDEFINED,
129 	TPM_UNDEFINED,
130 	TPM_SHORT,		/* 70 */
131 	TPM_SHORT,
132 	TPM_UNDEFINED,
133 	TPM_UNDEFINED,
134 	TPM_UNDEFINED,
135 	TPM_UNDEFINED,		/* 75 */
136 	TPM_UNDEFINED,
137 	TPM_UNDEFINED,
138 	TPM_UNDEFINED,
139 	TPM_UNDEFINED,
140 	TPM_LONG,		/* 80 */
141 	TPM_UNDEFINED,
142 	TPM_MEDIUM,
143 	TPM_LONG,
144 	TPM_SHORT,
145 	TPM_UNDEFINED,		/* 85 */
146 	TPM_UNDEFINED,
147 	TPM_UNDEFINED,
148 	TPM_UNDEFINED,
149 	TPM_UNDEFINED,
150 	TPM_SHORT,		/* 90 */
151 	TPM_SHORT,
152 	TPM_SHORT,
153 	TPM_SHORT,
154 	TPM_SHORT,
155 	TPM_UNDEFINED,		/* 95 */
156 	TPM_UNDEFINED,
157 	TPM_UNDEFINED,
158 	TPM_UNDEFINED,
159 	TPM_UNDEFINED,
160 	TPM_MEDIUM,		/* 100 */
161 	TPM_SHORT,
162 	TPM_SHORT,
163 	TPM_UNDEFINED,
164 	TPM_UNDEFINED,
165 	TPM_UNDEFINED,		/* 105 */
166 	TPM_UNDEFINED,
167 	TPM_UNDEFINED,
168 	TPM_UNDEFINED,
169 	TPM_UNDEFINED,
170 	TPM_SHORT,		/* 110 */
171 	TPM_SHORT,
172 	TPM_SHORT,
173 	TPM_SHORT,
174 	TPM_SHORT,
175 	TPM_SHORT,		/* 115 */
176 	TPM_SHORT,
177 	TPM_SHORT,
178 	TPM_UNDEFINED,
179 	TPM_UNDEFINED,
180 	TPM_LONG,		/* 120 */
181 	TPM_LONG,
182 	TPM_MEDIUM,
183 	TPM_UNDEFINED,
184 	TPM_SHORT,
185 	TPM_SHORT,		/* 125 */
186 	TPM_SHORT,
187 	TPM_LONG,
188 	TPM_SHORT,
189 	TPM_SHORT,
190 	TPM_SHORT,		/* 130 */
191 	TPM_MEDIUM,
192 	TPM_UNDEFINED,
193 	TPM_SHORT,
194 	TPM_MEDIUM,
195 	TPM_UNDEFINED,		/* 135 */
196 	TPM_UNDEFINED,
197 	TPM_UNDEFINED,
198 	TPM_UNDEFINED,
199 	TPM_UNDEFINED,
200 	TPM_SHORT,		/* 140 */
201 	TPM_SHORT,
202 	TPM_UNDEFINED,
203 	TPM_UNDEFINED,
204 	TPM_UNDEFINED,
205 	TPM_UNDEFINED,		/* 145 */
206 	TPM_UNDEFINED,
207 	TPM_UNDEFINED,
208 	TPM_UNDEFINED,
209 	TPM_UNDEFINED,
210 	TPM_SHORT,		/* 150 */
211 	TPM_MEDIUM,
212 	TPM_MEDIUM,
213 	TPM_SHORT,
214 	TPM_SHORT,
215 	TPM_UNDEFINED,		/* 155 */
216 	TPM_UNDEFINED,
217 	TPM_UNDEFINED,
218 	TPM_UNDEFINED,
219 	TPM_UNDEFINED,
220 	TPM_SHORT,		/* 160 */
221 	TPM_SHORT,
222 	TPM_SHORT,
223 	TPM_SHORT,
224 	TPM_UNDEFINED,
225 	TPM_UNDEFINED,		/* 165 */
226 	TPM_UNDEFINED,
227 	TPM_UNDEFINED,
228 	TPM_UNDEFINED,
229 	TPM_UNDEFINED,
230 	TPM_LONG,		/* 170 */
231 	TPM_UNDEFINED,
232 	TPM_UNDEFINED,
233 	TPM_UNDEFINED,
234 	TPM_UNDEFINED,
235 	TPM_UNDEFINED,		/* 175 */
236 	TPM_UNDEFINED,
237 	TPM_UNDEFINED,
238 	TPM_UNDEFINED,
239 	TPM_UNDEFINED,
240 	TPM_MEDIUM,		/* 180 */
241 	TPM_SHORT,
242 	TPM_MEDIUM,
243 	TPM_MEDIUM,
244 	TPM_MEDIUM,
245 	TPM_MEDIUM,		/* 185 */
246 	TPM_SHORT,
247 	TPM_UNDEFINED,
248 	TPM_UNDEFINED,
249 	TPM_UNDEFINED,
250 	TPM_UNDEFINED,		/* 190 */
251 	TPM_UNDEFINED,
252 	TPM_UNDEFINED,
253 	TPM_UNDEFINED,
254 	TPM_UNDEFINED,
255 	TPM_UNDEFINED,		/* 195 */
256 	TPM_UNDEFINED,
257 	TPM_UNDEFINED,
258 	TPM_UNDEFINED,
259 	TPM_UNDEFINED,
260 	TPM_SHORT,		/* 200 */
261 	TPM_UNDEFINED,
262 	TPM_UNDEFINED,
263 	TPM_UNDEFINED,
264 	TPM_SHORT,
265 	TPM_SHORT,		/* 205 */
266 	TPM_SHORT,
267 	TPM_SHORT,
268 	TPM_SHORT,
269 	TPM_SHORT,
270 	TPM_MEDIUM,		/* 210 */
271 	TPM_UNDEFINED,
272 	TPM_MEDIUM,
273 	TPM_MEDIUM,
274 	TPM_MEDIUM,
275 	TPM_UNDEFINED,		/* 215 */
276 	TPM_MEDIUM,
277 	TPM_UNDEFINED,
278 	TPM_UNDEFINED,
279 	TPM_SHORT,
280 	TPM_SHORT,		/* 220 */
281 	TPM_SHORT,
282 	TPM_SHORT,
283 	TPM_SHORT,
284 	TPM_SHORT,
285 	TPM_UNDEFINED,		/* 225 */
286 	TPM_UNDEFINED,
287 	TPM_UNDEFINED,
288 	TPM_UNDEFINED,
289 	TPM_UNDEFINED,
290 	TPM_SHORT,		/* 230 */
291 	TPM_LONG,
292 	TPM_MEDIUM,
293 	TPM_UNDEFINED,
294 	TPM_UNDEFINED,
295 	TPM_UNDEFINED,		/* 235 */
296 	TPM_UNDEFINED,
297 	TPM_UNDEFINED,
298 	TPM_UNDEFINED,
299 	TPM_UNDEFINED,
300 	TPM_SHORT,		/* 240 */
301 	TPM_UNDEFINED,
302 	TPM_MEDIUM,
303 };
304 
305 /*
306  * Returns max number of jiffies to wait
307  */
308 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
309 					   u32 ordinal)
310 {
311 	int duration_idx = TPM_UNDEFINED;
312 	int duration = 0;
313 
314 	/*
315 	 * We only have a duration table for protected commands, where the upper
316 	 * 16 bits are 0. For the few other ordinals the fallback will be used.
317 	 */
318 	if (ordinal < TPM_MAX_ORDINAL)
319 		duration_idx = tpm_ordinal_duration[ordinal];
320 
321 	if (duration_idx != TPM_UNDEFINED)
322 		duration = chip->duration[duration_idx];
323 	if (duration <= 0)
324 		return 2 * 60 * HZ;
325 	else
326 		return duration;
327 }
328 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
329 
330 static int tpm_validate_command(struct tpm_chip *chip,
331 				 struct tpm_space *space,
332 				 const u8 *cmd,
333 				 size_t len)
334 {
335 	const struct tpm_input_header *header = (const void *)cmd;
336 	int i;
337 	u32 cc;
338 	u32 attrs;
339 	unsigned int nr_handles;
340 
341 	if (len < TPM_HEADER_SIZE)
342 		return -EINVAL;
343 
344 	if (!space)
345 		return 0;
346 
347 	if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
348 		cc = be32_to_cpu(header->ordinal);
349 
350 		i = tpm2_find_cc(chip, cc);
351 		if (i < 0) {
352 			dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
353 				cc);
354 			return -EOPNOTSUPP;
355 		}
356 
357 		attrs = chip->cc_attrs_tbl[i];
358 		nr_handles =
359 			4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
360 		if (len < TPM_HEADER_SIZE + 4 * nr_handles)
361 			goto err_len;
362 	}
363 
364 	return 0;
365 err_len:
366 	dev_dbg(&chip->dev,
367 		"%s: insufficient command length %zu", __func__, len);
368 	return -EINVAL;
369 }
370 
371 static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
372 {
373 	int rc;
374 
375 	if (flags & TPM_TRANSMIT_NESTED)
376 		return 0;
377 
378 	if (!chip->ops->request_locality)
379 		return 0;
380 
381 	rc = chip->ops->request_locality(chip, 0);
382 	if (rc < 0)
383 		return rc;
384 
385 	chip->locality = rc;
386 
387 	return 0;
388 }
389 
390 static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
391 {
392 	int rc;
393 
394 	if (flags & TPM_TRANSMIT_NESTED)
395 		return;
396 
397 	if (!chip->ops->relinquish_locality)
398 		return;
399 
400 	rc = chip->ops->relinquish_locality(chip, chip->locality);
401 	if (rc)
402 		dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
403 
404 	chip->locality = -1;
405 }
406 
407 static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
408 {
409 	if (flags & TPM_TRANSMIT_NESTED)
410 		return 0;
411 
412 	if (!chip->ops->cmd_ready)
413 		return 0;
414 
415 	return chip->ops->cmd_ready(chip);
416 }
417 
418 static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
419 {
420 	if (flags & TPM_TRANSMIT_NESTED)
421 		return 0;
422 
423 	if (!chip->ops->go_idle)
424 		return 0;
425 
426 	return chip->ops->go_idle(chip);
427 }
428 
429 static ssize_t tpm_try_transmit(struct tpm_chip *chip,
430 				struct tpm_space *space,
431 				u8 *buf, size_t bufsiz,
432 				unsigned int flags)
433 {
434 	struct tpm_output_header *header = (void *)buf;
435 	int rc;
436 	ssize_t len = 0;
437 	u32 count, ordinal;
438 	unsigned long stop;
439 	bool need_locality;
440 
441 	rc = tpm_validate_command(chip, space, buf, bufsiz);
442 	if (rc == -EINVAL)
443 		return rc;
444 	/*
445 	 * If the command is not implemented by the TPM, synthesize a
446 	 * response with a TPM2_RC_COMMAND_CODE return for user-space.
447 	 */
448 	if (rc == -EOPNOTSUPP) {
449 		header->length = cpu_to_be32(sizeof(*header));
450 		header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
451 		header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
452 						  TSS2_RESMGR_TPM_RC_LAYER);
453 		return sizeof(*header);
454 	}
455 
456 	if (bufsiz > TPM_BUFSIZE)
457 		bufsiz = TPM_BUFSIZE;
458 
459 	count = be32_to_cpu(*((__be32 *) (buf + 2)));
460 	ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
461 	if (count == 0)
462 		return -ENODATA;
463 	if (count > bufsiz) {
464 		dev_err(&chip->dev,
465 			"invalid count value %x %zx\n", count, bufsiz);
466 		return -E2BIG;
467 	}
468 
469 	if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
470 		mutex_lock(&chip->tpm_mutex);
471 
472 	if (chip->ops->clk_enable != NULL)
473 		chip->ops->clk_enable(chip, true);
474 
475 	/* Store the decision as chip->locality will be changed. */
476 	need_locality = chip->locality == -1;
477 
478 	if (need_locality) {
479 		rc = tpm_request_locality(chip, flags);
480 		if (rc < 0)
481 			goto out_no_locality;
482 	}
483 
484 	rc = tpm_cmd_ready(chip, flags);
485 	if (rc)
486 		goto out;
487 
488 	rc = tpm2_prepare_space(chip, space, ordinal, buf);
489 	if (rc)
490 		goto out;
491 
492 	rc = chip->ops->send(chip, buf, count);
493 	if (rc < 0) {
494 		if (rc != -EPIPE)
495 			dev_err(&chip->dev,
496 				"%s: tpm_send: error %d\n", __func__, rc);
497 		goto out;
498 	}
499 
500 	if (chip->flags & TPM_CHIP_FLAG_IRQ)
501 		goto out_recv;
502 
503 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
504 		stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
505 	else
506 		stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
507 	do {
508 		u8 status = chip->ops->status(chip);
509 		if ((status & chip->ops->req_complete_mask) ==
510 		    chip->ops->req_complete_val)
511 			goto out_recv;
512 
513 		if (chip->ops->req_canceled(chip, status)) {
514 			dev_err(&chip->dev, "Operation Canceled\n");
515 			rc = -ECANCELED;
516 			goto out;
517 		}
518 
519 		tpm_msleep(TPM_TIMEOUT_POLL);
520 		rmb();
521 	} while (time_before(jiffies, stop));
522 
523 	chip->ops->cancel(chip);
524 	dev_err(&chip->dev, "Operation Timed out\n");
525 	rc = -ETIME;
526 	goto out;
527 
528 out_recv:
529 	len = chip->ops->recv(chip, buf, bufsiz);
530 	if (len < 0) {
531 		rc = len;
532 		dev_err(&chip->dev,
533 			"tpm_transmit: tpm_recv: error %d\n", rc);
534 		goto out;
535 	} else if (len < TPM_HEADER_SIZE) {
536 		rc = -EFAULT;
537 		goto out;
538 	}
539 
540 	if (len != be32_to_cpu(header->length)) {
541 		rc = -EFAULT;
542 		goto out;
543 	}
544 
545 	rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
546 	if (rc)
547 		dev_err(&chip->dev, "tpm2_commit_space: error %d\n", rc);
548 
549 out:
550 	rc = tpm_go_idle(chip, flags);
551 	if (rc)
552 		goto out;
553 
554 	if (need_locality)
555 		tpm_relinquish_locality(chip, flags);
556 
557 out_no_locality:
558 	if (chip->ops->clk_enable != NULL)
559 		chip->ops->clk_enable(chip, false);
560 
561 	if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
562 		mutex_unlock(&chip->tpm_mutex);
563 	return rc ? rc : len;
564 }
565 
566 /**
567  * tpm_transmit - Internal kernel interface to transmit TPM commands.
568  *
569  * @chip: TPM chip to use
570  * @space: tpm space
571  * @buf: TPM command buffer
572  * @bufsiz: length of the TPM command buffer
573  * @flags: tpm transmit flags - bitmap
574  *
575  * A wrapper around tpm_try_transmit that handles TPM2_RC_RETRY
576  * returns from the TPM and retransmits the command after a delay up
577  * to a maximum wait of TPM2_DURATION_LONG.
578  *
579  * Note: TPM1 never returns TPM2_RC_RETRY so the retry logic is TPM2
580  * only
581  *
582  * Return:
583  *     the length of the return when the operation is successful.
584  *     A negative number for system errors (errno).
585  */
586 ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
587 		     u8 *buf, size_t bufsiz, unsigned int flags)
588 {
589 	struct tpm_output_header *header = (struct tpm_output_header *)buf;
590 	/* space for header and handles */
591 	u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
592 	unsigned int delay_msec = TPM2_DURATION_SHORT;
593 	u32 rc = 0;
594 	ssize_t ret;
595 	const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
596 				     bufsiz);
597 	/* the command code is where the return code will be */
598 	u32 cc = be32_to_cpu(header->return_code);
599 
600 	/*
601 	 * Subtlety here: if we have a space, the handles will be
602 	 * transformed, so when we restore the header we also have to
603 	 * restore the handles.
604 	 */
605 	memcpy(save, buf, save_size);
606 
607 	for (;;) {
608 		ret = tpm_try_transmit(chip, space, buf, bufsiz, flags);
609 		if (ret < 0)
610 			break;
611 		rc = be32_to_cpu(header->return_code);
612 		if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
613 			break;
614 		/*
615 		 * return immediately if self test returns test
616 		 * still running to shorten boot time.
617 		 */
618 		if (rc == TPM2_RC_TESTING && cc == TPM2_CC_SELF_TEST)
619 			break;
620 
621 		if (delay_msec > TPM2_DURATION_LONG) {
622 			if (rc == TPM2_RC_RETRY)
623 				dev_err(&chip->dev, "in retry loop\n");
624 			else
625 				dev_err(&chip->dev,
626 					"self test is still running\n");
627 			break;
628 		}
629 		tpm_msleep(delay_msec);
630 		delay_msec *= 2;
631 		memcpy(buf, save, save_size);
632 	}
633 	return ret;
634 }
635 /**
636  * tpm_transmit_cmd - send a tpm command to the device
637  *    The function extracts tpm out header return code
638  *
639  * @chip: TPM chip to use
640  * @space: tpm space
641  * @buf: TPM command buffer
642  * @bufsiz: length of the buffer
643  * @min_rsp_body_length: minimum expected length of response body
644  * @flags: tpm transmit flags - bitmap
645  * @desc: command description used in the error message
646  *
647  * Return:
648  *     0 when the operation is successful.
649  *     A negative number for system errors (errno).
650  *     A positive number for a TPM error.
651  */
652 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
653 			 void *buf, size_t bufsiz,
654 			 size_t min_rsp_body_length, unsigned int flags,
655 			 const char *desc)
656 {
657 	const struct tpm_output_header *header = buf;
658 	int err;
659 	ssize_t len;
660 
661 	len = tpm_transmit(chip, space, buf, bufsiz, flags);
662 	if (len <  0)
663 		return len;
664 
665 	err = be32_to_cpu(header->return_code);
666 	if (err != 0 && desc)
667 		dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
668 			desc);
669 	if (err)
670 		return err;
671 
672 	if (len < min_rsp_body_length + TPM_HEADER_SIZE)
673 		return -EFAULT;
674 
675 	return 0;
676 }
677 EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
678 
679 #define TPM_ORD_STARTUP 153
680 #define TPM_ST_CLEAR 1
681 
682 /**
683  * tpm_startup - turn on the TPM
684  * @chip: TPM chip to use
685  *
686  * Normally the firmware should start the TPM. This function is provided as a
687  * workaround if this does not happen. A legal case for this could be for
688  * example when a TPM emulator is used.
689  *
690  * Return: same as tpm_transmit_cmd()
691  */
692 int tpm_startup(struct tpm_chip *chip)
693 {
694 	struct tpm_buf buf;
695 	int rc;
696 
697 	dev_info(&chip->dev, "starting up the TPM manually\n");
698 
699 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
700 		rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
701 		if (rc < 0)
702 			return rc;
703 
704 		tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
705 	} else {
706 		rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
707 		if (rc < 0)
708 			return rc;
709 
710 		tpm_buf_append_u16(&buf, TPM_ST_CLEAR);
711 	}
712 
713 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
714 			      "attempting to start the TPM");
715 
716 	tpm_buf_destroy(&buf);
717 	return rc;
718 }
719 
720 #define TPM_DIGEST_SIZE 20
721 #define TPM_RET_CODE_IDX 6
722 #define TPM_INTERNAL_RESULT_SIZE 200
723 #define TPM_ORD_GET_CAP 101
724 #define TPM_ORD_GET_RANDOM 70
725 
726 static const struct tpm_input_header tpm_getcap_header = {
727 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
728 	.length = cpu_to_be32(22),
729 	.ordinal = cpu_to_be32(TPM_ORD_GET_CAP)
730 };
731 
732 ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
733 		   const char *desc, size_t min_cap_length)
734 {
735 	struct tpm_buf buf;
736 	int rc;
737 
738 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
739 	if (rc)
740 		return rc;
741 
742 	if (subcap_id == TPM_CAP_VERSION_1_1 ||
743 	    subcap_id == TPM_CAP_VERSION_1_2) {
744 		tpm_buf_append_u32(&buf, subcap_id);
745 		tpm_buf_append_u32(&buf, 0);
746 	} else {
747 		if (subcap_id == TPM_CAP_FLAG_PERM ||
748 		    subcap_id == TPM_CAP_FLAG_VOL)
749 			tpm_buf_append_u32(&buf, TPM_CAP_FLAG);
750 		else
751 			tpm_buf_append_u32(&buf, TPM_CAP_PROP);
752 
753 		tpm_buf_append_u32(&buf, 4);
754 		tpm_buf_append_u32(&buf, subcap_id);
755 	}
756 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
757 			      min_cap_length, 0, desc);
758 	if (!rc)
759 		*cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
760 
761 	tpm_buf_destroy(&buf);
762 	return rc;
763 }
764 EXPORT_SYMBOL_GPL(tpm_getcap);
765 
766 int tpm_get_timeouts(struct tpm_chip *chip)
767 {
768 	cap_t cap;
769 	unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
770 	ssize_t rc;
771 
772 	if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
773 		return 0;
774 
775 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
776 		/* Fixed timeouts for TPM2 */
777 		chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
778 		chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
779 		chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
780 		chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
781 		chip->duration[TPM_SHORT] =
782 		    msecs_to_jiffies(TPM2_DURATION_SHORT);
783 		chip->duration[TPM_MEDIUM] =
784 		    msecs_to_jiffies(TPM2_DURATION_MEDIUM);
785 		chip->duration[TPM_LONG] =
786 		    msecs_to_jiffies(TPM2_DURATION_LONG);
787 		chip->duration[TPM_LONG_LONG] =
788 		    msecs_to_jiffies(TPM2_DURATION_LONG_LONG);
789 
790 		chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
791 		return 0;
792 	}
793 
794 	rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
795 			sizeof(cap.timeout));
796 	if (rc == TPM_ERR_INVALID_POSTINIT) {
797 		if (tpm_startup(chip))
798 			return rc;
799 
800 		rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
801 				"attempting to determine the timeouts",
802 				sizeof(cap.timeout));
803 	}
804 
805 	if (rc) {
806 		dev_err(&chip->dev,
807 			"A TPM error (%zd) occurred attempting to determine the timeouts\n",
808 			rc);
809 		return rc;
810 	}
811 
812 	timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
813 	timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
814 	timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
815 	timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
816 	timeout_chip[0] = be32_to_cpu(cap.timeout.a);
817 	timeout_chip[1] = be32_to_cpu(cap.timeout.b);
818 	timeout_chip[2] = be32_to_cpu(cap.timeout.c);
819 	timeout_chip[3] = be32_to_cpu(cap.timeout.d);
820 	memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
821 
822 	/*
823 	 * Provide ability for vendor overrides of timeout values in case
824 	 * of misreporting.
825 	 */
826 	if (chip->ops->update_timeouts != NULL)
827 		chip->timeout_adjusted =
828 			chip->ops->update_timeouts(chip, timeout_eff);
829 
830 	if (!chip->timeout_adjusted) {
831 		/* Restore default if chip reported 0 */
832 		int i;
833 
834 		for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
835 			if (timeout_eff[i])
836 				continue;
837 
838 			timeout_eff[i] = timeout_old[i];
839 			chip->timeout_adjusted = true;
840 		}
841 
842 		if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
843 			/* timeouts in msec rather usec */
844 			for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
845 				timeout_eff[i] *= 1000;
846 			chip->timeout_adjusted = true;
847 		}
848 	}
849 
850 	/* Report adjusted timeouts */
851 	if (chip->timeout_adjusted) {
852 		dev_info(&chip->dev,
853 			 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
854 			 timeout_chip[0], timeout_eff[0],
855 			 timeout_chip[1], timeout_eff[1],
856 			 timeout_chip[2], timeout_eff[2],
857 			 timeout_chip[3], timeout_eff[3]);
858 	}
859 
860 	chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
861 	chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
862 	chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
863 	chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
864 
865 	rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
866 			"attempting to determine the durations",
867 			sizeof(cap.duration));
868 	if (rc)
869 		return rc;
870 
871 	chip->duration[TPM_SHORT] =
872 		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
873 	chip->duration[TPM_MEDIUM] =
874 		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
875 	chip->duration[TPM_LONG] =
876 		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
877 	chip->duration[TPM_LONG_LONG] = 0; /* not used under 1.2 */
878 
879 	/* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
880 	 * value wrong and apparently reports msecs rather than usecs. So we
881 	 * fix up the resulting too-small TPM_SHORT value to make things work.
882 	 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
883 	 */
884 	if (chip->duration[TPM_SHORT] < (HZ / 100)) {
885 		chip->duration[TPM_SHORT] = HZ;
886 		chip->duration[TPM_MEDIUM] *= 1000;
887 		chip->duration[TPM_LONG] *= 1000;
888 		chip->duration_adjusted = true;
889 		dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
890 	}
891 
892 	chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
893 	return 0;
894 }
895 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
896 
897 #define TPM_ORD_CONTINUE_SELFTEST 83
898 #define CONTINUE_SELFTEST_RESULT_SIZE 10
899 
900 static const struct tpm_input_header continue_selftest_header = {
901 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
902 	.length = cpu_to_be32(10),
903 	.ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
904 };
905 
906 /**
907  * tpm_continue_selftest -- run TPM's selftest
908  * @chip: TPM chip to use
909  *
910  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
911  * a TPM error code.
912  */
913 static int tpm_continue_selftest(struct tpm_chip *chip)
914 {
915 	int rc;
916 	struct tpm_cmd_t cmd;
917 
918 	cmd.header.in = continue_selftest_header;
919 	rc = tpm_transmit_cmd(chip, NULL, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
920 			      0, 0, "continue selftest");
921 	return rc;
922 }
923 
924 #define TPM_ORDINAL_PCRREAD 21
925 #define READ_PCR_RESULT_SIZE 30
926 #define READ_PCR_RESULT_BODY_SIZE 20
927 static const struct tpm_input_header pcrread_header = {
928 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
929 	.length = cpu_to_be32(14),
930 	.ordinal = cpu_to_be32(TPM_ORDINAL_PCRREAD)
931 };
932 
933 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
934 {
935 	int rc;
936 	struct tpm_cmd_t cmd;
937 
938 	cmd.header.in = pcrread_header;
939 	cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
940 	rc = tpm_transmit_cmd(chip, NULL, &cmd, READ_PCR_RESULT_SIZE,
941 			      READ_PCR_RESULT_BODY_SIZE, 0,
942 			      "attempting to read a pcr value");
943 
944 	if (rc == 0)
945 		memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
946 		       TPM_DIGEST_SIZE);
947 	return rc;
948 }
949 
950 /**
951  * tpm_is_tpm2 - do we a have a TPM2 chip?
952  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
953  *
954  * Return:
955  * 1 if we have a TPM2 chip.
956  * 0 if we don't have a TPM2 chip.
957  * A negative number for system errors (errno).
958  */
959 int tpm_is_tpm2(struct tpm_chip *chip)
960 {
961 	int rc;
962 
963 	chip = tpm_find_get_ops(chip);
964 	if (!chip)
965 		return -ENODEV;
966 
967 	rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
968 
969 	tpm_put_ops(chip);
970 
971 	return rc;
972 }
973 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
974 
975 /**
976  * tpm_pcr_read - read a PCR value from SHA1 bank
977  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
978  * @pcr_idx:	the PCR to be retrieved
979  * @res_buf:	the value of the PCR
980  *
981  * Return: same as with tpm_transmit_cmd()
982  */
983 int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
984 {
985 	int rc;
986 
987 	chip = tpm_find_get_ops(chip);
988 	if (!chip)
989 		return -ENODEV;
990 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
991 		rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
992 	else
993 		rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
994 	tpm_put_ops(chip);
995 	return rc;
996 }
997 EXPORT_SYMBOL_GPL(tpm_pcr_read);
998 
999 #define TPM_ORD_PCR_EXTEND 20
1000 #define EXTEND_PCR_RESULT_SIZE 34
1001 #define EXTEND_PCR_RESULT_BODY_SIZE 20
1002 static const struct tpm_input_header pcrextend_header = {
1003 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1004 	.length = cpu_to_be32(34),
1005 	.ordinal = cpu_to_be32(TPM_ORD_PCR_EXTEND)
1006 };
1007 
1008 static int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash,
1009 			   char *log_msg)
1010 {
1011 	struct tpm_buf buf;
1012 	int rc;
1013 
1014 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND);
1015 	if (rc)
1016 		return rc;
1017 
1018 	tpm_buf_append_u32(&buf, pcr_idx);
1019 	tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);
1020 
1021 	rc = tpm_transmit_cmd(chip, NULL, buf.data, EXTEND_PCR_RESULT_SIZE,
1022 			      EXTEND_PCR_RESULT_BODY_SIZE, 0, log_msg);
1023 	tpm_buf_destroy(&buf);
1024 	return rc;
1025 }
1026 
1027 /**
1028  * tpm_pcr_extend - extend a PCR value in SHA1 bank.
1029  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1030  * @pcr_idx:	the PCR to be retrieved
1031  * @hash:	the hash value used to extend the PCR value
1032  *
1033  * Note: with TPM 2.0 extends also those banks with a known digest size to the
1034  * cryto subsystem in order to prevent malicious use of those PCR banks. In the
1035  * future we should dynamically determine digest sizes.
1036  *
1037  * Return: same as with tpm_transmit_cmd()
1038  */
1039 int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
1040 {
1041 	int rc;
1042 	struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
1043 	u32 count = 0;
1044 	int i;
1045 
1046 	chip = tpm_find_get_ops(chip);
1047 	if (!chip)
1048 		return -ENODEV;
1049 
1050 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1051 		memset(digest_list, 0, sizeof(digest_list));
1052 
1053 		for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
1054 			    chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
1055 			digest_list[i].alg_id = chip->active_banks[i];
1056 			memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
1057 			count++;
1058 		}
1059 
1060 		rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);
1061 		tpm_put_ops(chip);
1062 		return rc;
1063 	}
1064 
1065 	rc = tpm1_pcr_extend(chip, pcr_idx, hash,
1066 			     "attempting extend a PCR value");
1067 	tpm_put_ops(chip);
1068 	return rc;
1069 }
1070 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
1071 
1072 /**
1073  * tpm_do_selftest - have the TPM continue its selftest and wait until it
1074  *                   can receive further commands
1075  * @chip: TPM chip to use
1076  *
1077  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
1078  * a TPM error code.
1079  */
1080 int tpm_do_selftest(struct tpm_chip *chip)
1081 {
1082 	int rc;
1083 	unsigned int loops;
1084 	unsigned int delay_msec = 100;
1085 	unsigned long duration;
1086 	u8 dummy[TPM_DIGEST_SIZE];
1087 
1088 	duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
1089 
1090 	loops = jiffies_to_msecs(duration) / delay_msec;
1091 
1092 	rc = tpm_continue_selftest(chip);
1093 	if (rc == TPM_ERR_INVALID_POSTINIT) {
1094 		chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
1095 		dev_info(&chip->dev, "TPM not ready (%d)\n", rc);
1096 	}
1097 	/* This may fail if there was no TPM driver during a suspend/resume
1098 	 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
1099 	 */
1100 	if (rc)
1101 		return rc;
1102 
1103 	do {
1104 		/* Attempt to read a PCR value */
1105 		rc = tpm_pcr_read_dev(chip, 0, dummy);
1106 
1107 		/* Some buggy TPMs will not respond to tpm_tis_ready() for
1108 		 * around 300ms while the self test is ongoing, keep trying
1109 		 * until the self test duration expires. */
1110 		if (rc == -ETIME) {
1111 			dev_info(
1112 			    &chip->dev, HW_ERR
1113 			    "TPM command timed out during continue self test");
1114 			tpm_msleep(delay_msec);
1115 			continue;
1116 		}
1117 
1118 		if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
1119 			dev_info(&chip->dev,
1120 				 "TPM is disabled/deactivated (0x%X)\n", rc);
1121 			/* TPM is disabled and/or deactivated; driver can
1122 			 * proceed and TPM does handle commands for
1123 			 * suspend/resume correctly
1124 			 */
1125 			return 0;
1126 		}
1127 		if (rc != TPM_WARN_DOING_SELFTEST)
1128 			return rc;
1129 		tpm_msleep(delay_msec);
1130 	} while (--loops > 0);
1131 
1132 	return rc;
1133 }
1134 EXPORT_SYMBOL_GPL(tpm_do_selftest);
1135 
1136 /**
1137  * tpm1_auto_startup - Perform the standard automatic TPM initialization
1138  *                     sequence
1139  * @chip: TPM chip to use
1140  *
1141  * Returns 0 on success, < 0 in case of fatal error.
1142  */
1143 int tpm1_auto_startup(struct tpm_chip *chip)
1144 {
1145 	int rc;
1146 
1147 	rc = tpm_get_timeouts(chip);
1148 	if (rc)
1149 		goto out;
1150 	rc = tpm_do_selftest(chip);
1151 	if (rc) {
1152 		dev_err(&chip->dev, "TPM self test failed\n");
1153 		goto out;
1154 	}
1155 
1156 	return rc;
1157 out:
1158 	if (rc > 0)
1159 		rc = -ENODEV;
1160 	return rc;
1161 }
1162 
1163 /**
1164  * tpm_send - send a TPM command
1165  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1166  * @cmd:	a TPM command buffer
1167  * @buflen:	the length of the TPM command buffer
1168  *
1169  * Return: same as with tpm_transmit_cmd()
1170  */
1171 int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
1172 {
1173 	int rc;
1174 
1175 	chip = tpm_find_get_ops(chip);
1176 	if (!chip)
1177 		return -ENODEV;
1178 
1179 	rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0,
1180 			      "attempting to a send a command");
1181 	tpm_put_ops(chip);
1182 	return rc;
1183 }
1184 EXPORT_SYMBOL_GPL(tpm_send);
1185 
1186 #define TPM_ORD_SAVESTATE 152
1187 #define SAVESTATE_RESULT_SIZE 10
1188 
1189 static const struct tpm_input_header savestate_header = {
1190 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1191 	.length = cpu_to_be32(10),
1192 	.ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)
1193 };
1194 
1195 /*
1196  * We are about to suspend. Save the TPM state
1197  * so that it can be restored.
1198  */
1199 int tpm_pm_suspend(struct device *dev)
1200 {
1201 	struct tpm_chip *chip = dev_get_drvdata(dev);
1202 	struct tpm_cmd_t cmd;
1203 	int rc, try;
1204 
1205 	u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1206 
1207 	if (chip == NULL)
1208 		return -ENODEV;
1209 
1210 	if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
1211 		return 0;
1212 
1213 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1214 		tpm2_shutdown(chip, TPM2_SU_STATE);
1215 		return 0;
1216 	}
1217 
1218 	/* for buggy tpm, flush pcrs with extend to selected dummy */
1219 	if (tpm_suspend_pcr)
1220 		rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
1221 				     "extending dummy pcr before suspend");
1222 
1223 	/* now do the actual savestate */
1224 	for (try = 0; try < TPM_RETRY; try++) {
1225 		cmd.header.in = savestate_header;
1226 		rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,
1227 				      0, 0, NULL);
1228 
1229 		/*
1230 		 * If the TPM indicates that it is too busy to respond to
1231 		 * this command then retry before giving up.  It can take
1232 		 * several seconds for this TPM to be ready.
1233 		 *
1234 		 * This can happen if the TPM has already been sent the
1235 		 * SaveState command before the driver has loaded.  TCG 1.2
1236 		 * specification states that any communication after SaveState
1237 		 * may cause the TPM to invalidate previously saved state.
1238 		 */
1239 		if (rc != TPM_WARN_RETRY)
1240 			break;
1241 		tpm_msleep(TPM_TIMEOUT_RETRY);
1242 	}
1243 
1244 	if (rc)
1245 		dev_err(&chip->dev,
1246 			"Error (%d) sending savestate before suspend\n", rc);
1247 	else if (try > 0)
1248 		dev_warn(&chip->dev, "TPM savestate took %dms\n",
1249 			 try * TPM_TIMEOUT_RETRY);
1250 
1251 	return rc;
1252 }
1253 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1254 
1255 /*
1256  * Resume from a power safe. The BIOS already restored
1257  * the TPM state.
1258  */
1259 int tpm_pm_resume(struct device *dev)
1260 {
1261 	struct tpm_chip *chip = dev_get_drvdata(dev);
1262 
1263 	if (chip == NULL)
1264 		return -ENODEV;
1265 
1266 	return 0;
1267 }
1268 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1269 
1270 #define TPM_GETRANDOM_RESULT_SIZE	18
1271 static const struct tpm_input_header tpm_getrandom_header = {
1272 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1273 	.length = cpu_to_be32(14),
1274 	.ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
1275 };
1276 
1277 /**
1278  * tpm_get_random() - get random bytes from the TPM's RNG
1279  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1280  * @out:	destination buffer for the random bytes
1281  * @max:	the max number of bytes to write to @out
1282  *
1283  * Return: same as with tpm_transmit_cmd()
1284  */
1285 int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
1286 {
1287 	struct tpm_cmd_t tpm_cmd;
1288 	u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
1289 	int err, total = 0, retries = 5;
1290 	u8 *dest = out;
1291 
1292 	if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1293 		return -EINVAL;
1294 
1295 	chip = tpm_find_get_ops(chip);
1296 	if (!chip)
1297 		return -ENODEV;
1298 
1299 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1300 		err = tpm2_get_random(chip, out, max);
1301 		tpm_put_ops(chip);
1302 		return err;
1303 	}
1304 
1305 	do {
1306 		tpm_cmd.header.in = tpm_getrandom_header;
1307 		tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1308 
1309 		err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
1310 				       TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1311 				       offsetof(struct tpm_getrandom_out,
1312 						rng_data),
1313 				       0, "attempting get random");
1314 		if (err)
1315 			break;
1316 
1317 		recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1318 		if (recd > num_bytes) {
1319 			total = -EFAULT;
1320 			break;
1321 		}
1322 
1323 		rlength = be32_to_cpu(tpm_cmd.header.out.length);
1324 		if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
1325 			      recd) {
1326 			total = -EFAULT;
1327 			break;
1328 		}
1329 		memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1330 
1331 		dest += recd;
1332 		total += recd;
1333 		num_bytes -= recd;
1334 	} while (retries-- && total < max);
1335 
1336 	tpm_put_ops(chip);
1337 	return total ? total : -EIO;
1338 }
1339 EXPORT_SYMBOL_GPL(tpm_get_random);
1340 
1341 /**
1342  * tpm_seal_trusted() - seal a trusted key payload
1343  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1344  * @options:	authentication values and other options
1345  * @payload:	the key data in clear and encrypted form
1346  *
1347  * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
1348  * the keyring subsystem.
1349  *
1350  * Return: same as with tpm_transmit_cmd()
1351  */
1352 int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload,
1353 		     struct trusted_key_options *options)
1354 {
1355 	int rc;
1356 
1357 	chip = tpm_find_get_ops(chip);
1358 	if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1359 		return -ENODEV;
1360 
1361 	rc = tpm2_seal_trusted(chip, payload, options);
1362 
1363 	tpm_put_ops(chip);
1364 	return rc;
1365 }
1366 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1367 
1368 /**
1369  * tpm_unseal_trusted() - unseal a trusted key
1370  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1371  * @options:	authentication values and other options
1372  * @payload:	the key data in clear and encrypted form
1373  *
1374  * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
1375  * the keyring subsystem.
1376  *
1377  * Return: same as with tpm_transmit_cmd()
1378  */
1379 int tpm_unseal_trusted(struct tpm_chip *chip,
1380 		       struct trusted_key_payload *payload,
1381 		       struct trusted_key_options *options)
1382 {
1383 	int rc;
1384 
1385 	chip = tpm_find_get_ops(chip);
1386 	if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1387 		return -ENODEV;
1388 
1389 	rc = tpm2_unseal_trusted(chip, payload, options);
1390 
1391 	tpm_put_ops(chip);
1392 
1393 	return rc;
1394 }
1395 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1396 
1397 static int __init tpm_init(void)
1398 {
1399 	int rc;
1400 
1401 	tpm_class = class_create(THIS_MODULE, "tpm");
1402 	if (IS_ERR(tpm_class)) {
1403 		pr_err("couldn't create tpm class\n");
1404 		return PTR_ERR(tpm_class);
1405 	}
1406 
1407 	tpmrm_class = class_create(THIS_MODULE, "tpmrm");
1408 	if (IS_ERR(tpmrm_class)) {
1409 		pr_err("couldn't create tpmrm class\n");
1410 		class_destroy(tpm_class);
1411 		return PTR_ERR(tpmrm_class);
1412 	}
1413 
1414 	rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm");
1415 	if (rc < 0) {
1416 		pr_err("tpm: failed to allocate char dev region\n");
1417 		class_destroy(tpmrm_class);
1418 		class_destroy(tpm_class);
1419 		return rc;
1420 	}
1421 
1422 	return 0;
1423 }
1424 
1425 static void __exit tpm_exit(void)
1426 {
1427 	idr_destroy(&dev_nums_idr);
1428 	class_destroy(tpm_class);
1429 	class_destroy(tpmrm_class);
1430 	unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
1431 }
1432 
1433 subsys_initcall(tpm_init);
1434 module_exit(tpm_exit);
1435 
1436 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1437 MODULE_DESCRIPTION("TPM Driver");
1438 MODULE_VERSION("2.0");
1439 MODULE_LICENSE("GPL");
1440