xref: /openbmc/linux/drivers/char/tpm/tpm-interface.c (revision bdeeed09)
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 static int tpm_request_locality(struct tpm_chip *chip)
373 {
374 	int rc;
375 
376 	if (!chip->ops->request_locality)
377 		return 0;
378 
379 	rc = chip->ops->request_locality(chip, 0);
380 	if (rc < 0)
381 		return rc;
382 
383 	chip->locality = rc;
384 
385 	return 0;
386 }
387 
388 static void tpm_relinquish_locality(struct tpm_chip *chip)
389 {
390 	int rc;
391 
392 	if (!chip->ops->relinquish_locality)
393 		return;
394 
395 	rc = chip->ops->relinquish_locality(chip, chip->locality);
396 	if (rc)
397 		dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
398 
399 	chip->locality = -1;
400 }
401 
402 static ssize_t tpm_try_transmit(struct tpm_chip *chip,
403 				struct tpm_space *space,
404 				u8 *buf, size_t bufsiz,
405 				unsigned int flags)
406 {
407 	struct tpm_output_header *header = (void *)buf;
408 	int rc;
409 	ssize_t len = 0;
410 	u32 count, ordinal;
411 	unsigned long stop;
412 	bool need_locality;
413 
414 	rc = tpm_validate_command(chip, space, buf, bufsiz);
415 	if (rc == -EINVAL)
416 		return rc;
417 	/*
418 	 * If the command is not implemented by the TPM, synthesize a
419 	 * response with a TPM2_RC_COMMAND_CODE return for user-space.
420 	 */
421 	if (rc == -EOPNOTSUPP) {
422 		header->length = cpu_to_be32(sizeof(*header));
423 		header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
424 		header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
425 						  TSS2_RESMGR_TPM_RC_LAYER);
426 		return bufsiz;
427 	}
428 
429 	if (bufsiz > TPM_BUFSIZE)
430 		bufsiz = TPM_BUFSIZE;
431 
432 	count = be32_to_cpu(*((__be32 *) (buf + 2)));
433 	ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
434 	if (count == 0)
435 		return -ENODATA;
436 	if (count > bufsiz) {
437 		dev_err(&chip->dev,
438 			"invalid count value %x %zx\n", count, bufsiz);
439 		return -E2BIG;
440 	}
441 
442 	if (!(flags & TPM_TRANSMIT_UNLOCKED))
443 		mutex_lock(&chip->tpm_mutex);
444 
445 
446 	if (chip->ops->clk_enable != NULL)
447 		chip->ops->clk_enable(chip, true);
448 
449 	/* Store the decision as chip->locality will be changed. */
450 	need_locality = chip->locality == -1;
451 
452 	if (!(flags & TPM_TRANSMIT_RAW) && need_locality) {
453 		rc = tpm_request_locality(chip);
454 		if (rc < 0)
455 			goto out_no_locality;
456 	}
457 
458 	if (chip->dev.parent)
459 		pm_runtime_get_sync(chip->dev.parent);
460 
461 	rc = tpm2_prepare_space(chip, space, ordinal, buf);
462 	if (rc)
463 		goto out;
464 
465 	rc = chip->ops->send(chip, buf, count);
466 	if (rc < 0) {
467 		if (rc != -EPIPE)
468 			dev_err(&chip->dev,
469 				"%s: tpm_send: error %d\n", __func__, rc);
470 		goto out;
471 	}
472 
473 	if (chip->flags & TPM_CHIP_FLAG_IRQ)
474 		goto out_recv;
475 
476 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
477 		stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
478 	else
479 		stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
480 	do {
481 		u8 status = chip->ops->status(chip);
482 		if ((status & chip->ops->req_complete_mask) ==
483 		    chip->ops->req_complete_val)
484 			goto out_recv;
485 
486 		if (chip->ops->req_canceled(chip, status)) {
487 			dev_err(&chip->dev, "Operation Canceled\n");
488 			rc = -ECANCELED;
489 			goto out;
490 		}
491 
492 		tpm_msleep(TPM_TIMEOUT);
493 		rmb();
494 	} while (time_before(jiffies, stop));
495 
496 	chip->ops->cancel(chip);
497 	dev_err(&chip->dev, "Operation Timed out\n");
498 	rc = -ETIME;
499 	goto out;
500 
501 out_recv:
502 	len = chip->ops->recv(chip, buf, bufsiz);
503 	if (len < 0) {
504 		rc = len;
505 		dev_err(&chip->dev,
506 			"tpm_transmit: tpm_recv: error %d\n", rc);
507 		goto out;
508 	} else if (len < TPM_HEADER_SIZE) {
509 		rc = -EFAULT;
510 		goto out;
511 	}
512 
513 	if (len != be32_to_cpu(header->length)) {
514 		rc = -EFAULT;
515 		goto out;
516 	}
517 
518 	rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
519 
520 out:
521 	if (chip->dev.parent)
522 		pm_runtime_put_sync(chip->dev.parent);
523 
524 	if (need_locality)
525 		tpm_relinquish_locality(chip);
526 
527 out_no_locality:
528 	if (chip->ops->clk_enable != NULL)
529 		chip->ops->clk_enable(chip, false);
530 
531 	if (!(flags & TPM_TRANSMIT_UNLOCKED))
532 		mutex_unlock(&chip->tpm_mutex);
533 	return rc ? rc : len;
534 }
535 
536 /**
537  * tpm_transmit - Internal kernel interface to transmit TPM commands.
538  *
539  * @chip: TPM chip to use
540  * @space: tpm space
541  * @buf: TPM command buffer
542  * @bufsiz: length of the TPM command buffer
543  * @flags: tpm transmit flags - bitmap
544  *
545  * A wrapper around tpm_try_transmit that handles TPM2_RC_RETRY
546  * returns from the TPM and retransmits the command after a delay up
547  * to a maximum wait of TPM2_DURATION_LONG.
548  *
549  * Note: TPM1 never returns TPM2_RC_RETRY so the retry logic is TPM2
550  * only
551  *
552  * Return:
553  *     the length of the return when the operation is successful.
554  *     A negative number for system errors (errno).
555  */
556 ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
557 		     u8 *buf, size_t bufsiz, unsigned int flags)
558 {
559 	struct tpm_output_header *header = (struct tpm_output_header *)buf;
560 	/* space for header and handles */
561 	u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
562 	unsigned int delay_msec = TPM2_DURATION_SHORT;
563 	u32 rc = 0;
564 	ssize_t ret;
565 	const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
566 				     bufsiz);
567 	/* the command code is where the return code will be */
568 	u32 cc = be32_to_cpu(header->return_code);
569 
570 	/*
571 	 * Subtlety here: if we have a space, the handles will be
572 	 * transformed, so when we restore the header we also have to
573 	 * restore the handles.
574 	 */
575 	memcpy(save, buf, save_size);
576 
577 	for (;;) {
578 		ret = tpm_try_transmit(chip, space, buf, bufsiz, flags);
579 		if (ret < 0)
580 			break;
581 		rc = be32_to_cpu(header->return_code);
582 		if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
583 			break;
584 		/*
585 		 * return immediately if self test returns test
586 		 * still running to shorten boot time.
587 		 */
588 		if (rc == TPM2_RC_TESTING && cc == TPM2_CC_SELF_TEST)
589 			break;
590 		delay_msec *= 2;
591 		if (delay_msec > TPM2_DURATION_LONG) {
592 			if (rc == TPM2_RC_RETRY)
593 				dev_err(&chip->dev, "in retry loop\n");
594 			else
595 				dev_err(&chip->dev,
596 					"self test is still running\n");
597 			break;
598 		}
599 		tpm_msleep(delay_msec);
600 		memcpy(buf, save, save_size);
601 	}
602 	return ret;
603 }
604 /**
605  * tpm_transmit_cmd - send a tpm command to the device
606  *    The function extracts tpm out header return code
607  *
608  * @chip: TPM chip to use
609  * @space: tpm space
610  * @buf: TPM command buffer
611  * @bufsiz: length of the buffer
612  * @min_rsp_body_length: minimum expected length of response body
613  * @flags: tpm transmit flags - bitmap
614  * @desc: command description used in the error message
615  *
616  * Return:
617  *     0 when the operation is successful.
618  *     A negative number for system errors (errno).
619  *     A positive number for a TPM error.
620  */
621 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
622 			 void *buf, size_t bufsiz,
623 			 size_t min_rsp_body_length, unsigned int flags,
624 			 const char *desc)
625 {
626 	const struct tpm_output_header *header = buf;
627 	int err;
628 	ssize_t len;
629 
630 	len = tpm_transmit(chip, space, buf, bufsiz, flags);
631 	if (len <  0)
632 		return len;
633 
634 	err = be32_to_cpu(header->return_code);
635 	if (err != 0 && desc)
636 		dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
637 			desc);
638 	if (err)
639 		return err;
640 
641 	if (len < min_rsp_body_length + TPM_HEADER_SIZE)
642 		return -EFAULT;
643 
644 	return 0;
645 }
646 EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
647 
648 #define TPM_ORD_STARTUP 153
649 #define TPM_ST_CLEAR 1
650 
651 /**
652  * tpm_startup - turn on the TPM
653  * @chip: TPM chip to use
654  *
655  * Normally the firmware should start the TPM. This function is provided as a
656  * workaround if this does not happen. A legal case for this could be for
657  * example when a TPM emulator is used.
658  *
659  * Return: same as tpm_transmit_cmd()
660  */
661 int tpm_startup(struct tpm_chip *chip)
662 {
663 	struct tpm_buf buf;
664 	int rc;
665 
666 	dev_info(&chip->dev, "starting up the TPM manually\n");
667 
668 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
669 		rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
670 		if (rc < 0)
671 			return rc;
672 
673 		tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
674 	} else {
675 		rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
676 		if (rc < 0)
677 			return rc;
678 
679 		tpm_buf_append_u16(&buf, TPM_ST_CLEAR);
680 	}
681 
682 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
683 			      "attempting to start the TPM");
684 
685 	tpm_buf_destroy(&buf);
686 	return rc;
687 }
688 
689 #define TPM_DIGEST_SIZE 20
690 #define TPM_RET_CODE_IDX 6
691 #define TPM_INTERNAL_RESULT_SIZE 200
692 #define TPM_ORD_GET_CAP 101
693 #define TPM_ORD_GET_RANDOM 70
694 
695 static const struct tpm_input_header tpm_getcap_header = {
696 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
697 	.length = cpu_to_be32(22),
698 	.ordinal = cpu_to_be32(TPM_ORD_GET_CAP)
699 };
700 
701 ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
702 		   const char *desc, size_t min_cap_length)
703 {
704 	struct tpm_buf buf;
705 	int rc;
706 
707 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
708 	if (rc)
709 		return rc;
710 
711 	if (subcap_id == TPM_CAP_VERSION_1_1 ||
712 	    subcap_id == TPM_CAP_VERSION_1_2) {
713 		tpm_buf_append_u32(&buf, subcap_id);
714 		tpm_buf_append_u32(&buf, 0);
715 	} else {
716 		if (subcap_id == TPM_CAP_FLAG_PERM ||
717 		    subcap_id == TPM_CAP_FLAG_VOL)
718 			tpm_buf_append_u32(&buf, TPM_CAP_FLAG);
719 		else
720 			tpm_buf_append_u32(&buf, TPM_CAP_PROP);
721 
722 		tpm_buf_append_u32(&buf, 4);
723 		tpm_buf_append_u32(&buf, subcap_id);
724 	}
725 	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
726 			      min_cap_length, 0, desc);
727 	if (!rc)
728 		*cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
729 
730 	tpm_buf_destroy(&buf);
731 	return rc;
732 }
733 EXPORT_SYMBOL_GPL(tpm_getcap);
734 
735 int tpm_get_timeouts(struct tpm_chip *chip)
736 {
737 	cap_t cap;
738 	unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
739 	ssize_t rc;
740 
741 	if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
742 		return 0;
743 
744 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
745 		/* Fixed timeouts for TPM2 */
746 		chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
747 		chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
748 		chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
749 		chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
750 		chip->duration[TPM_SHORT] =
751 		    msecs_to_jiffies(TPM2_DURATION_SHORT);
752 		chip->duration[TPM_MEDIUM] =
753 		    msecs_to_jiffies(TPM2_DURATION_MEDIUM);
754 		chip->duration[TPM_LONG] =
755 		    msecs_to_jiffies(TPM2_DURATION_LONG);
756 		chip->duration[TPM_LONG_LONG] =
757 		    msecs_to_jiffies(TPM2_DURATION_LONG_LONG);
758 
759 		chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
760 		return 0;
761 	}
762 
763 	rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
764 			sizeof(cap.timeout));
765 	if (rc == TPM_ERR_INVALID_POSTINIT) {
766 		if (tpm_startup(chip))
767 			return rc;
768 
769 		rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
770 				"attempting to determine the timeouts",
771 				sizeof(cap.timeout));
772 	}
773 
774 	if (rc) {
775 		dev_err(&chip->dev,
776 			"A TPM error (%zd) occurred attempting to determine the timeouts\n",
777 			rc);
778 		return rc;
779 	}
780 
781 	timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
782 	timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
783 	timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
784 	timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
785 	timeout_chip[0] = be32_to_cpu(cap.timeout.a);
786 	timeout_chip[1] = be32_to_cpu(cap.timeout.b);
787 	timeout_chip[2] = be32_to_cpu(cap.timeout.c);
788 	timeout_chip[3] = be32_to_cpu(cap.timeout.d);
789 	memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
790 
791 	/*
792 	 * Provide ability for vendor overrides of timeout values in case
793 	 * of misreporting.
794 	 */
795 	if (chip->ops->update_timeouts != NULL)
796 		chip->timeout_adjusted =
797 			chip->ops->update_timeouts(chip, timeout_eff);
798 
799 	if (!chip->timeout_adjusted) {
800 		/* Restore default if chip reported 0 */
801 		int i;
802 
803 		for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
804 			if (timeout_eff[i])
805 				continue;
806 
807 			timeout_eff[i] = timeout_old[i];
808 			chip->timeout_adjusted = true;
809 		}
810 
811 		if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
812 			/* timeouts in msec rather usec */
813 			for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
814 				timeout_eff[i] *= 1000;
815 			chip->timeout_adjusted = true;
816 		}
817 	}
818 
819 	/* Report adjusted timeouts */
820 	if (chip->timeout_adjusted) {
821 		dev_info(&chip->dev,
822 			 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
823 			 timeout_chip[0], timeout_eff[0],
824 			 timeout_chip[1], timeout_eff[1],
825 			 timeout_chip[2], timeout_eff[2],
826 			 timeout_chip[3], timeout_eff[3]);
827 	}
828 
829 	chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
830 	chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
831 	chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
832 	chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
833 
834 	rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
835 			"attempting to determine the durations",
836 			sizeof(cap.duration));
837 	if (rc)
838 		return rc;
839 
840 	chip->duration[TPM_SHORT] =
841 		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
842 	chip->duration[TPM_MEDIUM] =
843 		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
844 	chip->duration[TPM_LONG] =
845 		usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
846 	chip->duration[TPM_LONG_LONG] = 0; /* not used under 1.2 */
847 
848 	/* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
849 	 * value wrong and apparently reports msecs rather than usecs. So we
850 	 * fix up the resulting too-small TPM_SHORT value to make things work.
851 	 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
852 	 */
853 	if (chip->duration[TPM_SHORT] < (HZ / 100)) {
854 		chip->duration[TPM_SHORT] = HZ;
855 		chip->duration[TPM_MEDIUM] *= 1000;
856 		chip->duration[TPM_LONG] *= 1000;
857 		chip->duration_adjusted = true;
858 		dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
859 	}
860 
861 	chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
862 	return 0;
863 }
864 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
865 
866 #define TPM_ORD_CONTINUE_SELFTEST 83
867 #define CONTINUE_SELFTEST_RESULT_SIZE 10
868 
869 static const struct tpm_input_header continue_selftest_header = {
870 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
871 	.length = cpu_to_be32(10),
872 	.ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
873 };
874 
875 /**
876  * tpm_continue_selftest -- run TPM's selftest
877  * @chip: TPM chip to use
878  *
879  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
880  * a TPM error code.
881  */
882 static int tpm_continue_selftest(struct tpm_chip *chip)
883 {
884 	int rc;
885 	struct tpm_cmd_t cmd;
886 
887 	cmd.header.in = continue_selftest_header;
888 	rc = tpm_transmit_cmd(chip, NULL, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
889 			      0, 0, "continue selftest");
890 	return rc;
891 }
892 
893 #define TPM_ORDINAL_PCRREAD 21
894 #define READ_PCR_RESULT_SIZE 30
895 #define READ_PCR_RESULT_BODY_SIZE 20
896 static const struct tpm_input_header pcrread_header = {
897 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
898 	.length = cpu_to_be32(14),
899 	.ordinal = cpu_to_be32(TPM_ORDINAL_PCRREAD)
900 };
901 
902 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
903 {
904 	int rc;
905 	struct tpm_cmd_t cmd;
906 
907 	cmd.header.in = pcrread_header;
908 	cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
909 	rc = tpm_transmit_cmd(chip, NULL, &cmd, READ_PCR_RESULT_SIZE,
910 			      READ_PCR_RESULT_BODY_SIZE, 0,
911 			      "attempting to read a pcr value");
912 
913 	if (rc == 0)
914 		memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
915 		       TPM_DIGEST_SIZE);
916 	return rc;
917 }
918 
919 /**
920  * tpm_is_tpm2 - do we a have a TPM2 chip?
921  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
922  *
923  * Return:
924  * 1 if we have a TPM2 chip.
925  * 0 if we don't have a TPM2 chip.
926  * A negative number for system errors (errno).
927  */
928 int tpm_is_tpm2(struct tpm_chip *chip)
929 {
930 	int rc;
931 
932 	chip = tpm_chip_find_get(chip);
933 	if (!chip)
934 		return -ENODEV;
935 
936 	rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
937 
938 	tpm_put_ops(chip);
939 
940 	return rc;
941 }
942 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
943 
944 /**
945  * tpm_pcr_read - read a PCR value from SHA1 bank
946  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
947  * @pcr_idx:	the PCR to be retrieved
948  * @res_buf:	the value of the PCR
949  *
950  * Return: same as with tpm_transmit_cmd()
951  */
952 int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
953 {
954 	int rc;
955 
956 	chip = tpm_chip_find_get(chip);
957 	if (!chip)
958 		return -ENODEV;
959 	if (chip->flags & TPM_CHIP_FLAG_TPM2)
960 		rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
961 	else
962 		rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
963 	tpm_put_ops(chip);
964 	return rc;
965 }
966 EXPORT_SYMBOL_GPL(tpm_pcr_read);
967 
968 #define TPM_ORD_PCR_EXTEND 20
969 #define EXTEND_PCR_RESULT_SIZE 34
970 #define EXTEND_PCR_RESULT_BODY_SIZE 20
971 static const struct tpm_input_header pcrextend_header = {
972 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
973 	.length = cpu_to_be32(34),
974 	.ordinal = cpu_to_be32(TPM_ORD_PCR_EXTEND)
975 };
976 
977 static int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash,
978 			   char *log_msg)
979 {
980 	struct tpm_buf buf;
981 	int rc;
982 
983 	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND);
984 	if (rc)
985 		return rc;
986 
987 	tpm_buf_append_u32(&buf, pcr_idx);
988 	tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);
989 
990 	rc = tpm_transmit_cmd(chip, NULL, buf.data, EXTEND_PCR_RESULT_SIZE,
991 			      EXTEND_PCR_RESULT_BODY_SIZE, 0, log_msg);
992 	tpm_buf_destroy(&buf);
993 	return rc;
994 }
995 
996 /**
997  * tpm_pcr_extend - extend a PCR value in SHA1 bank.
998  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
999  * @pcr_idx:	the PCR to be retrieved
1000  * @hash:	the hash value used to extend the PCR value
1001  *
1002  * Note: with TPM 2.0 extends also those banks with a known digest size to the
1003  * cryto subsystem in order to prevent malicious use of those PCR banks. In the
1004  * future we should dynamically determine digest sizes.
1005  *
1006  * Return: same as with tpm_transmit_cmd()
1007  */
1008 int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
1009 {
1010 	int rc;
1011 	struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
1012 	u32 count = 0;
1013 	int i;
1014 
1015 	chip = tpm_chip_find_get(chip);
1016 	if (!chip)
1017 		return -ENODEV;
1018 
1019 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1020 		memset(digest_list, 0, sizeof(digest_list));
1021 
1022 		for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
1023 			    chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
1024 			digest_list[i].alg_id = chip->active_banks[i];
1025 			memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
1026 			count++;
1027 		}
1028 
1029 		rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);
1030 		tpm_put_ops(chip);
1031 		return rc;
1032 	}
1033 
1034 	rc = tpm1_pcr_extend(chip, pcr_idx, hash,
1035 			     "attempting extend a PCR value");
1036 	tpm_put_ops(chip);
1037 	return rc;
1038 }
1039 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
1040 
1041 /**
1042  * tpm_do_selftest - have the TPM continue its selftest and wait until it
1043  *                   can receive further commands
1044  * @chip: TPM chip to use
1045  *
1046  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
1047  * a TPM error code.
1048  */
1049 int tpm_do_selftest(struct tpm_chip *chip)
1050 {
1051 	int rc;
1052 	unsigned int loops;
1053 	unsigned int delay_msec = 100;
1054 	unsigned long duration;
1055 	u8 dummy[TPM_DIGEST_SIZE];
1056 
1057 	duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
1058 
1059 	loops = jiffies_to_msecs(duration) / delay_msec;
1060 
1061 	rc = tpm_continue_selftest(chip);
1062 	if (rc == TPM_ERR_INVALID_POSTINIT) {
1063 		chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
1064 		dev_info(&chip->dev, "TPM not ready (%d)\n", rc);
1065 	}
1066 	/* This may fail if there was no TPM driver during a suspend/resume
1067 	 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
1068 	 */
1069 	if (rc)
1070 		return rc;
1071 
1072 	do {
1073 		/* Attempt to read a PCR value */
1074 		rc = tpm_pcr_read_dev(chip, 0, dummy);
1075 
1076 		/* Some buggy TPMs will not respond to tpm_tis_ready() for
1077 		 * around 300ms while the self test is ongoing, keep trying
1078 		 * until the self test duration expires. */
1079 		if (rc == -ETIME) {
1080 			dev_info(
1081 			    &chip->dev, HW_ERR
1082 			    "TPM command timed out during continue self test");
1083 			tpm_msleep(delay_msec);
1084 			continue;
1085 		}
1086 
1087 		if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
1088 			dev_info(&chip->dev,
1089 				 "TPM is disabled/deactivated (0x%X)\n", rc);
1090 			/* TPM is disabled and/or deactivated; driver can
1091 			 * proceed and TPM does handle commands for
1092 			 * suspend/resume correctly
1093 			 */
1094 			return 0;
1095 		}
1096 		if (rc != TPM_WARN_DOING_SELFTEST)
1097 			return rc;
1098 		tpm_msleep(delay_msec);
1099 	} while (--loops > 0);
1100 
1101 	return rc;
1102 }
1103 EXPORT_SYMBOL_GPL(tpm_do_selftest);
1104 
1105 /**
1106  * tpm1_auto_startup - Perform the standard automatic TPM initialization
1107  *                     sequence
1108  * @chip: TPM chip to use
1109  *
1110  * Returns 0 on success, < 0 in case of fatal error.
1111  */
1112 int tpm1_auto_startup(struct tpm_chip *chip)
1113 {
1114 	int rc;
1115 
1116 	rc = tpm_get_timeouts(chip);
1117 	if (rc)
1118 		goto out;
1119 	rc = tpm_do_selftest(chip);
1120 	if (rc) {
1121 		dev_err(&chip->dev, "TPM self test failed\n");
1122 		goto out;
1123 	}
1124 
1125 	return rc;
1126 out:
1127 	if (rc > 0)
1128 		rc = -ENODEV;
1129 	return rc;
1130 }
1131 
1132 /**
1133  * tpm_send - send a TPM command
1134  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1135  * @cmd:	a TPM command buffer
1136  * @buflen:	the length of the TPM command buffer
1137  *
1138  * Return: same as with tpm_transmit_cmd()
1139  */
1140 int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
1141 {
1142 	int rc;
1143 
1144 	chip = tpm_chip_find_get(chip);
1145 	if (!chip)
1146 		return -ENODEV;
1147 
1148 	rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0,
1149 			      "attempting to a send a command");
1150 	tpm_put_ops(chip);
1151 	return rc;
1152 }
1153 EXPORT_SYMBOL_GPL(tpm_send);
1154 
1155 #define TPM_ORD_SAVESTATE 152
1156 #define SAVESTATE_RESULT_SIZE 10
1157 
1158 static const struct tpm_input_header savestate_header = {
1159 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1160 	.length = cpu_to_be32(10),
1161 	.ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)
1162 };
1163 
1164 /*
1165  * We are about to suspend. Save the TPM state
1166  * so that it can be restored.
1167  */
1168 int tpm_pm_suspend(struct device *dev)
1169 {
1170 	struct tpm_chip *chip = dev_get_drvdata(dev);
1171 	struct tpm_cmd_t cmd;
1172 	int rc, try;
1173 
1174 	u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1175 
1176 	if (chip == NULL)
1177 		return -ENODEV;
1178 
1179 	if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
1180 		return 0;
1181 
1182 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1183 		tpm2_shutdown(chip, TPM2_SU_STATE);
1184 		return 0;
1185 	}
1186 
1187 	/* for buggy tpm, flush pcrs with extend to selected dummy */
1188 	if (tpm_suspend_pcr)
1189 		rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
1190 				     "extending dummy pcr before suspend");
1191 
1192 	/* now do the actual savestate */
1193 	for (try = 0; try < TPM_RETRY; try++) {
1194 		cmd.header.in = savestate_header;
1195 		rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,
1196 				      0, 0, NULL);
1197 
1198 		/*
1199 		 * If the TPM indicates that it is too busy to respond to
1200 		 * this command then retry before giving up.  It can take
1201 		 * several seconds for this TPM to be ready.
1202 		 *
1203 		 * This can happen if the TPM has already been sent the
1204 		 * SaveState command before the driver has loaded.  TCG 1.2
1205 		 * specification states that any communication after SaveState
1206 		 * may cause the TPM to invalidate previously saved state.
1207 		 */
1208 		if (rc != TPM_WARN_RETRY)
1209 			break;
1210 		tpm_msleep(TPM_TIMEOUT_RETRY);
1211 	}
1212 
1213 	if (rc)
1214 		dev_err(&chip->dev,
1215 			"Error (%d) sending savestate before suspend\n", rc);
1216 	else if (try > 0)
1217 		dev_warn(&chip->dev, "TPM savestate took %dms\n",
1218 			 try * TPM_TIMEOUT_RETRY);
1219 
1220 	return rc;
1221 }
1222 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1223 
1224 /*
1225  * Resume from a power safe. The BIOS already restored
1226  * the TPM state.
1227  */
1228 int tpm_pm_resume(struct device *dev)
1229 {
1230 	struct tpm_chip *chip = dev_get_drvdata(dev);
1231 
1232 	if (chip == NULL)
1233 		return -ENODEV;
1234 
1235 	return 0;
1236 }
1237 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1238 
1239 #define TPM_GETRANDOM_RESULT_SIZE	18
1240 static const struct tpm_input_header tpm_getrandom_header = {
1241 	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1242 	.length = cpu_to_be32(14),
1243 	.ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
1244 };
1245 
1246 /**
1247  * tpm_get_random() - get random bytes from the TPM's RNG
1248  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1249  * @out:	destination buffer for the random bytes
1250  * @max:	the max number of bytes to write to @out
1251  *
1252  * Return: same as with tpm_transmit_cmd()
1253  */
1254 int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
1255 {
1256 	struct tpm_cmd_t tpm_cmd;
1257 	u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
1258 	int err, total = 0, retries = 5;
1259 	u8 *dest = out;
1260 
1261 	if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1262 		return -EINVAL;
1263 
1264 	chip = tpm_chip_find_get(chip);
1265 	if (!chip)
1266 		return -ENODEV;
1267 
1268 	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1269 		err = tpm2_get_random(chip, out, max);
1270 		tpm_put_ops(chip);
1271 		return err;
1272 	}
1273 
1274 	do {
1275 		tpm_cmd.header.in = tpm_getrandom_header;
1276 		tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1277 
1278 		err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
1279 				       TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1280 				       offsetof(struct tpm_getrandom_out,
1281 						rng_data),
1282 				       0, "attempting get random");
1283 		if (err)
1284 			break;
1285 
1286 		recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1287 		if (recd > num_bytes) {
1288 			total = -EFAULT;
1289 			break;
1290 		}
1291 
1292 		rlength = be32_to_cpu(tpm_cmd.header.out.length);
1293 		if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
1294 			      recd) {
1295 			total = -EFAULT;
1296 			break;
1297 		}
1298 		memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1299 
1300 		dest += recd;
1301 		total += recd;
1302 		num_bytes -= recd;
1303 	} while (retries-- && total < max);
1304 
1305 	tpm_put_ops(chip);
1306 	return total ? total : -EIO;
1307 }
1308 EXPORT_SYMBOL_GPL(tpm_get_random);
1309 
1310 /**
1311  * tpm_seal_trusted() - seal a trusted key payload
1312  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1313  * @options:	authentication values and other options
1314  * @payload:	the key data in clear and encrypted form
1315  *
1316  * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
1317  * the keyring subsystem.
1318  *
1319  * Return: same as with tpm_transmit_cmd()
1320  */
1321 int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload,
1322 		     struct trusted_key_options *options)
1323 {
1324 	int rc;
1325 
1326 	chip = tpm_chip_find_get(chip);
1327 	if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1328 		return -ENODEV;
1329 
1330 	rc = tpm2_seal_trusted(chip, payload, options);
1331 
1332 	tpm_put_ops(chip);
1333 	return rc;
1334 }
1335 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1336 
1337 /**
1338  * tpm_unseal_trusted() - unseal a trusted key
1339  * @chip:	a &struct tpm_chip instance, %NULL for the default chip
1340  * @options:	authentication values and other options
1341  * @payload:	the key data in clear and encrypted form
1342  *
1343  * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
1344  * the keyring subsystem.
1345  *
1346  * Return: same as with tpm_transmit_cmd()
1347  */
1348 int tpm_unseal_trusted(struct tpm_chip *chip,
1349 		       struct trusted_key_payload *payload,
1350 		       struct trusted_key_options *options)
1351 {
1352 	int rc;
1353 
1354 	chip = tpm_chip_find_get(chip);
1355 	if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1356 		return -ENODEV;
1357 
1358 	rc = tpm2_unseal_trusted(chip, payload, options);
1359 
1360 	tpm_put_ops(chip);
1361 
1362 	return rc;
1363 }
1364 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1365 
1366 static int __init tpm_init(void)
1367 {
1368 	int rc;
1369 
1370 	tpm_class = class_create(THIS_MODULE, "tpm");
1371 	if (IS_ERR(tpm_class)) {
1372 		pr_err("couldn't create tpm class\n");
1373 		return PTR_ERR(tpm_class);
1374 	}
1375 
1376 	tpmrm_class = class_create(THIS_MODULE, "tpmrm");
1377 	if (IS_ERR(tpmrm_class)) {
1378 		pr_err("couldn't create tpmrm class\n");
1379 		class_destroy(tpm_class);
1380 		return PTR_ERR(tpmrm_class);
1381 	}
1382 
1383 	rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm");
1384 	if (rc < 0) {
1385 		pr_err("tpm: failed to allocate char dev region\n");
1386 		class_destroy(tpmrm_class);
1387 		class_destroy(tpm_class);
1388 		return rc;
1389 	}
1390 
1391 	return 0;
1392 }
1393 
1394 static void __exit tpm_exit(void)
1395 {
1396 	idr_destroy(&dev_nums_idr);
1397 	class_destroy(tpm_class);
1398 	class_destroy(tpmrm_class);
1399 	unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
1400 }
1401 
1402 subsys_initcall(tpm_init);
1403 module_exit(tpm_exit);
1404 
1405 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1406 MODULE_DESCRIPTION("TPM Driver");
1407 MODULE_VERSION("2.0");
1408 MODULE_LICENSE("GPL");
1409