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 */
tpm_calc_ordinal_duration(struct tpm_chip * chip,u32 ordinal)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
tpm_validate_command(struct tpm_chip * chip,struct tpm_space * space,const u8 * cmd,size_t len)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
tpm_request_locality(struct tpm_chip * chip,unsigned int flags)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
tpm_relinquish_locality(struct tpm_chip * chip,unsigned int flags)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
tpm_cmd_ready(struct tpm_chip * chip,unsigned int flags)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
tpm_go_idle(struct tpm_chip * chip,unsigned int flags)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
tpm_try_transmit(struct tpm_chip * chip,struct tpm_space * space,u8 * buf,size_t bufsiz,unsigned int flags)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 */
tpm_transmit(struct tpm_chip * chip,struct tpm_space * space,u8 * buf,size_t bufsiz,unsigned int flags)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 */
tpm_transmit_cmd(struct tpm_chip * chip,struct tpm_space * space,void * buf,size_t bufsiz,size_t min_rsp_body_length,unsigned int flags,const char * desc)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 */
tpm_startup(struct tpm_chip * chip)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
tpm_getcap(struct tpm_chip * chip,u32 subcap_id,cap_t * cap,const char * desc,size_t min_cap_length)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
tpm_get_timeouts(struct tpm_chip * chip)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 */
tpm_continue_selftest(struct tpm_chip * chip)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
tpm_pcr_read_dev(struct tpm_chip * chip,int pcr_idx,u8 * res_buf)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 */
tpm_is_tpm2(struct tpm_chip * chip)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 */
tpm_pcr_read(struct tpm_chip * chip,int pcr_idx,u8 * res_buf)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
tpm1_pcr_extend(struct tpm_chip * chip,int pcr_idx,const u8 * hash,char * log_msg)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 */
tpm_pcr_extend(struct tpm_chip * chip,int pcr_idx,const u8 * hash)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 */
tpm_do_selftest(struct tpm_chip * chip)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 */
tpm1_auto_startup(struct tpm_chip * chip)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 */
tpm_send(struct tpm_chip * chip,void * cmd,size_t buflen)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 */
tpm_pm_suspend(struct device * dev)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 */
tpm_pm_resume(struct device * dev)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 */
tpm_get_random(struct tpm_chip * chip,u8 * out,size_t max)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 */
tpm_seal_trusted(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options)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 */
tpm_unseal_trusted(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options)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
tpm_init(void)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
tpm_exit(void)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
