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 need_locality = false;
482 goto out_locality;
483 }
484 }
485
486 rc = tpm_cmd_ready(chip, flags);
487 if (rc)
488 goto out_locality;
489
490 rc = tpm2_prepare_space(chip, space, ordinal, buf);
491 if (rc)
492 goto out;
493
494 rc = chip->ops->send(chip, buf, count);
495 if (rc < 0) {
496 if (rc != -EPIPE)
497 dev_err(&chip->dev,
498 "%s: send(): error %d\n", __func__, rc);
499 goto out;
500 }
501
502 /* A sanity check. send() should just return zero on success e.g.
503 * not the command length.
504 */
505 if (rc > 0) {
506 dev_warn(&chip->dev,
507 "%s: send(): invalid value %d\n", __func__, rc);
508 rc = 0;
509 }
510
511 if (chip->flags & TPM_CHIP_FLAG_IRQ)
512 goto out_recv;
513
514 if (chip->flags & TPM_CHIP_FLAG_TPM2)
515 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
516 else
517 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
518 do {
519 u8 status = chip->ops->status(chip);
520 if ((status & chip->ops->req_complete_mask) ==
521 chip->ops->req_complete_val)
522 goto out_recv;
523
524 if (chip->ops->req_canceled(chip, status)) {
525 dev_err(&chip->dev, "Operation Canceled\n");
526 rc = -ECANCELED;
527 goto out;
528 }
529
530 tpm_msleep(TPM_TIMEOUT_POLL);
531 rmb();
532 } while (time_before(jiffies, stop));
533
534 chip->ops->cancel(chip);
535 dev_err(&chip->dev, "Operation Timed out\n");
536 rc = -ETIME;
537 goto out;
538
539 out_recv:
540 len = chip->ops->recv(chip, buf, bufsiz);
541 if (len < 0) {
542 rc = len;
543 dev_err(&chip->dev,
544 "tpm_transmit: tpm_recv: error %d\n", rc);
545 goto out;
546 } else if (len < TPM_HEADER_SIZE) {
547 rc = -EFAULT;
548 goto out;
549 }
550
551 if (len != be32_to_cpu(header->length)) {
552 rc = -EFAULT;
553 goto out;
554 }
555
556 rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
557 if (rc)
558 dev_err(&chip->dev, "tpm2_commit_space: error %d\n", rc);
559
560 out:
561 /* may fail but do not override previous error value in rc */
562 tpm_go_idle(chip, flags);
563
564 out_locality:
565 if (need_locality)
566 tpm_relinquish_locality(chip, flags);
567
568 if (chip->ops->clk_enable != NULL)
569 chip->ops->clk_enable(chip, false);
570
571 if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
572 mutex_unlock(&chip->tpm_mutex);
573 return rc ? rc : len;
574 }
575
576 /**
577 * tpm_transmit - Internal kernel interface to transmit TPM commands.
578 *
579 * @chip: TPM chip to use
580 * @space: tpm space
581 * @buf: TPM command buffer
582 * @bufsiz: length of the TPM command buffer
583 * @flags: tpm transmit flags - bitmap
584 *
585 * A wrapper around tpm_try_transmit that handles TPM2_RC_RETRY
586 * returns from the TPM and retransmits the command after a delay up
587 * to a maximum wait of TPM2_DURATION_LONG.
588 *
589 * Note: TPM1 never returns TPM2_RC_RETRY so the retry logic is TPM2
590 * only
591 *
592 * Return:
593 * the length of the return when the operation is successful.
594 * A negative number for system errors (errno).
595 */
tpm_transmit(struct tpm_chip * chip,struct tpm_space * space,u8 * buf,size_t bufsiz,unsigned int flags)596 ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
597 u8 *buf, size_t bufsiz, unsigned int flags)
598 {
599 struct tpm_output_header *header = (struct tpm_output_header *)buf;
600 /* space for header and handles */
601 u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
602 unsigned int delay_msec = TPM2_DURATION_SHORT;
603 u32 rc = 0;
604 ssize_t ret;
605 const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
606 bufsiz);
607 /* the command code is where the return code will be */
608 u32 cc = be32_to_cpu(header->return_code);
609
610 /*
611 * Subtlety here: if we have a space, the handles will be
612 * transformed, so when we restore the header we also have to
613 * restore the handles.
614 */
615 memcpy(save, buf, save_size);
616
617 for (;;) {
618 ret = tpm_try_transmit(chip, space, buf, bufsiz, flags);
619 if (ret < 0)
620 break;
621 rc = be32_to_cpu(header->return_code);
622 if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
623 break;
624 /*
625 * return immediately if self test returns test
626 * still running to shorten boot time.
627 */
628 if (rc == TPM2_RC_TESTING && cc == TPM2_CC_SELF_TEST)
629 break;
630
631 if (delay_msec > TPM2_DURATION_LONG) {
632 if (rc == TPM2_RC_RETRY)
633 dev_err(&chip->dev, "in retry loop\n");
634 else
635 dev_err(&chip->dev,
636 "self test is still running\n");
637 break;
638 }
639 tpm_msleep(delay_msec);
640 delay_msec *= 2;
641 memcpy(buf, save, save_size);
642 }
643 return ret;
644 }
645 /**
646 * tpm_transmit_cmd - send a tpm command to the device
647 * The function extracts tpm out header return code
648 *
649 * @chip: TPM chip to use
650 * @space: tpm space
651 * @buf: TPM command buffer
652 * @bufsiz: length of the buffer
653 * @min_rsp_body_length: minimum expected length of response body
654 * @flags: tpm transmit flags - bitmap
655 * @desc: command description used in the error message
656 *
657 * Return:
658 * 0 when the operation is successful.
659 * A negative number for system errors (errno).
660 * A positive number for a TPM error.
661 */
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)662 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
663 void *buf, size_t bufsiz,
664 size_t min_rsp_body_length, unsigned int flags,
665 const char *desc)
666 {
667 const struct tpm_output_header *header = buf;
668 int err;
669 ssize_t len;
670
671 len = tpm_transmit(chip, space, buf, bufsiz, flags);
672 if (len < 0)
673 return len;
674
675 err = be32_to_cpu(header->return_code);
676 if (err != 0 && err != TPM_ERR_DISABLED && err != TPM_ERR_DEACTIVATED
677 && desc)
678 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
679 desc);
680 if (err)
681 return err;
682
683 if (len < min_rsp_body_length + TPM_HEADER_SIZE)
684 return -EFAULT;
685
686 return 0;
687 }
688 EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
689
690 #define TPM_ORD_STARTUP 153
691 #define TPM_ST_CLEAR 1
692
693 /**
694 * tpm_startup - turn on the TPM
695 * @chip: TPM chip to use
696 *
697 * Normally the firmware should start the TPM. This function is provided as a
698 * workaround if this does not happen. A legal case for this could be for
699 * example when a TPM emulator is used.
700 *
701 * Return: same as tpm_transmit_cmd()
702 */
tpm_startup(struct tpm_chip * chip)703 int tpm_startup(struct tpm_chip *chip)
704 {
705 struct tpm_buf buf;
706 int rc;
707
708 dev_info(&chip->dev, "starting up the TPM manually\n");
709
710 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
711 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
712 if (rc < 0)
713 return rc;
714
715 tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
716 } else {
717 rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
718 if (rc < 0)
719 return rc;
720
721 tpm_buf_append_u16(&buf, TPM_ST_CLEAR);
722 }
723
724 rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
725 "attempting to start the TPM");
726
727 tpm_buf_destroy(&buf);
728 return rc;
729 }
730
731 #define TPM_DIGEST_SIZE 20
732 #define TPM_RET_CODE_IDX 6
733 #define TPM_INTERNAL_RESULT_SIZE 200
734 #define TPM_ORD_GET_CAP 101
735 #define TPM_ORD_GET_RANDOM 70
736
737 static const struct tpm_input_header tpm_getcap_header = {
738 .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
739 .length = cpu_to_be32(22),
740 .ordinal = cpu_to_be32(TPM_ORD_GET_CAP)
741 };
742
tpm_getcap(struct tpm_chip * chip,u32 subcap_id,cap_t * cap,const char * desc,size_t min_cap_length)743 ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
744 const char *desc, size_t min_cap_length)
745 {
746 struct tpm_buf buf;
747 int rc;
748
749 rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
750 if (rc)
751 return rc;
752
753 if (subcap_id == TPM_CAP_VERSION_1_1 ||
754 subcap_id == TPM_CAP_VERSION_1_2) {
755 tpm_buf_append_u32(&buf, subcap_id);
756 tpm_buf_append_u32(&buf, 0);
757 } else {
758 if (subcap_id == TPM_CAP_FLAG_PERM ||
759 subcap_id == TPM_CAP_FLAG_VOL)
760 tpm_buf_append_u32(&buf, TPM_CAP_FLAG);
761 else
762 tpm_buf_append_u32(&buf, TPM_CAP_PROP);
763
764 tpm_buf_append_u32(&buf, 4);
765 tpm_buf_append_u32(&buf, subcap_id);
766 }
767 rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
768 min_cap_length, 0, desc);
769 if (!rc)
770 *cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
771
772 tpm_buf_destroy(&buf);
773 return rc;
774 }
775 EXPORT_SYMBOL_GPL(tpm_getcap);
776
tpm_get_timeouts(struct tpm_chip * chip)777 int tpm_get_timeouts(struct tpm_chip *chip)
778 {
779 cap_t cap;
780 unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
781 ssize_t rc;
782
783 if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
784 return 0;
785
786 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
787 /* Fixed timeouts for TPM2 */
788 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
789 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
790 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
791 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
792 chip->duration[TPM_SHORT] =
793 msecs_to_jiffies(TPM2_DURATION_SHORT);
794 chip->duration[TPM_MEDIUM] =
795 msecs_to_jiffies(TPM2_DURATION_MEDIUM);
796 chip->duration[TPM_LONG] =
797 msecs_to_jiffies(TPM2_DURATION_LONG);
798 chip->duration[TPM_LONG_LONG] =
799 msecs_to_jiffies(TPM2_DURATION_LONG_LONG);
800
801 chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
802 return 0;
803 }
804
805 rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
806 sizeof(cap.timeout));
807 if (rc == TPM_ERR_INVALID_POSTINIT) {
808 if (tpm_startup(chip))
809 return rc;
810
811 rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
812 "attempting to determine the timeouts",
813 sizeof(cap.timeout));
814 }
815
816 if (rc) {
817 dev_err(&chip->dev,
818 "A TPM error (%zd) occurred attempting to determine the timeouts\n",
819 rc);
820 return rc;
821 }
822
823 timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
824 timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
825 timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
826 timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
827 timeout_chip[0] = be32_to_cpu(cap.timeout.a);
828 timeout_chip[1] = be32_to_cpu(cap.timeout.b);
829 timeout_chip[2] = be32_to_cpu(cap.timeout.c);
830 timeout_chip[3] = be32_to_cpu(cap.timeout.d);
831 memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
832
833 /*
834 * Provide ability for vendor overrides of timeout values in case
835 * of misreporting.
836 */
837 if (chip->ops->update_timeouts != NULL)
838 chip->timeout_adjusted =
839 chip->ops->update_timeouts(chip, timeout_eff);
840
841 if (!chip->timeout_adjusted) {
842 /* Restore default if chip reported 0 */
843 int i;
844
845 for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
846 if (timeout_eff[i])
847 continue;
848
849 timeout_eff[i] = timeout_old[i];
850 chip->timeout_adjusted = true;
851 }
852
853 if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
854 /* timeouts in msec rather usec */
855 for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
856 timeout_eff[i] *= 1000;
857 chip->timeout_adjusted = true;
858 }
859 }
860
861 /* Report adjusted timeouts */
862 if (chip->timeout_adjusted) {
863 dev_info(&chip->dev,
864 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
865 timeout_chip[0], timeout_eff[0],
866 timeout_chip[1], timeout_eff[1],
867 timeout_chip[2], timeout_eff[2],
868 timeout_chip[3], timeout_eff[3]);
869 }
870
871 chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
872 chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
873 chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
874 chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
875
876 rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
877 "attempting to determine the durations",
878 sizeof(cap.duration));
879 if (rc)
880 return rc;
881
882 chip->duration[TPM_SHORT] =
883 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
884 chip->duration[TPM_MEDIUM] =
885 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
886 chip->duration[TPM_LONG] =
887 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
888 chip->duration[TPM_LONG_LONG] = 0; /* not used under 1.2 */
889
890 /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
891 * value wrong and apparently reports msecs rather than usecs. So we
892 * fix up the resulting too-small TPM_SHORT value to make things work.
893 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
894 */
895 if (chip->duration[TPM_SHORT] < (HZ / 100)) {
896 chip->duration[TPM_SHORT] = HZ;
897 chip->duration[TPM_MEDIUM] *= 1000;
898 chip->duration[TPM_LONG] *= 1000;
899 chip->duration_adjusted = true;
900 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
901 }
902
903 chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
904 return 0;
905 }
906 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
907
908 #define TPM_ORD_CONTINUE_SELFTEST 83
909 #define CONTINUE_SELFTEST_RESULT_SIZE 10
910
911 static const struct tpm_input_header continue_selftest_header = {
912 .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
913 .length = cpu_to_be32(10),
914 .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
915 };
916
917 /**
918 * tpm_continue_selftest -- run TPM's selftest
919 * @chip: TPM chip to use
920 *
921 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
922 * a TPM error code.
923 */
tpm_continue_selftest(struct tpm_chip * chip)924 static int tpm_continue_selftest(struct tpm_chip *chip)
925 {
926 int rc;
927 struct tpm_cmd_t cmd;
928
929 cmd.header.in = continue_selftest_header;
930 rc = tpm_transmit_cmd(chip, NULL, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
931 0, 0, "continue selftest");
932 return rc;
933 }
934
935 #define TPM_ORDINAL_PCRREAD 21
936 #define READ_PCR_RESULT_SIZE 30
937 #define READ_PCR_RESULT_BODY_SIZE 20
938 static const struct tpm_input_header pcrread_header = {
939 .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
940 .length = cpu_to_be32(14),
941 .ordinal = cpu_to_be32(TPM_ORDINAL_PCRREAD)
942 };
943
tpm_pcr_read_dev(struct tpm_chip * chip,int pcr_idx,u8 * res_buf)944 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
945 {
946 int rc;
947 struct tpm_cmd_t cmd;
948
949 cmd.header.in = pcrread_header;
950 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
951 rc = tpm_transmit_cmd(chip, NULL, &cmd, READ_PCR_RESULT_SIZE,
952 READ_PCR_RESULT_BODY_SIZE, 0,
953 "attempting to read a pcr value");
954
955 if (rc == 0)
956 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
957 TPM_DIGEST_SIZE);
958 return rc;
959 }
960
961 /**
962 * tpm_is_tpm2 - do we a have a TPM2 chip?
963 * @chip: a &struct tpm_chip instance, %NULL for the default chip
964 *
965 * Return:
966 * 1 if we have a TPM2 chip.
967 * 0 if we don't have a TPM2 chip.
968 * A negative number for system errors (errno).
969 */
tpm_is_tpm2(struct tpm_chip * chip)970 int tpm_is_tpm2(struct tpm_chip *chip)
971 {
972 int rc;
973
974 chip = tpm_find_get_ops(chip);
975 if (!chip)
976 return -ENODEV;
977
978 rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
979
980 tpm_put_ops(chip);
981
982 return rc;
983 }
984 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
985
986 /**
987 * tpm_pcr_read - read a PCR value from SHA1 bank
988 * @chip: a &struct tpm_chip instance, %NULL for the default chip
989 * @pcr_idx: the PCR to be retrieved
990 * @res_buf: the value of the PCR
991 *
992 * Return: same as with tpm_transmit_cmd()
993 */
tpm_pcr_read(struct tpm_chip * chip,int pcr_idx,u8 * res_buf)994 int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
995 {
996 int rc;
997
998 chip = tpm_find_get_ops(chip);
999 if (!chip)
1000 return -ENODEV;
1001 if (chip->flags & TPM_CHIP_FLAG_TPM2)
1002 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
1003 else
1004 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
1005 tpm_put_ops(chip);
1006 return rc;
1007 }
1008 EXPORT_SYMBOL_GPL(tpm_pcr_read);
1009
1010 #define TPM_ORD_PCR_EXTEND 20
1011 #define EXTEND_PCR_RESULT_SIZE 34
1012 #define EXTEND_PCR_RESULT_BODY_SIZE 20
1013 static const struct tpm_input_header pcrextend_header = {
1014 .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1015 .length = cpu_to_be32(34),
1016 .ordinal = cpu_to_be32(TPM_ORD_PCR_EXTEND)
1017 };
1018
tpm1_pcr_extend(struct tpm_chip * chip,int pcr_idx,const u8 * hash,char * log_msg)1019 static int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash,
1020 char *log_msg)
1021 {
1022 struct tpm_buf buf;
1023 int rc;
1024
1025 rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND);
1026 if (rc)
1027 return rc;
1028
1029 tpm_buf_append_u32(&buf, pcr_idx);
1030 tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);
1031
1032 rc = tpm_transmit_cmd(chip, NULL, buf.data, EXTEND_PCR_RESULT_SIZE,
1033 EXTEND_PCR_RESULT_BODY_SIZE, 0, log_msg);
1034 tpm_buf_destroy(&buf);
1035 return rc;
1036 }
1037
1038 /**
1039 * tpm_pcr_extend - extend a PCR value in SHA1 bank.
1040 * @chip: a &struct tpm_chip instance, %NULL for the default chip
1041 * @pcr_idx: the PCR to be retrieved
1042 * @hash: the hash value used to extend the PCR value
1043 *
1044 * Note: with TPM 2.0 extends also those banks with a known digest size to the
1045 * cryto subsystem in order to prevent malicious use of those PCR banks. In the
1046 * future we should dynamically determine digest sizes.
1047 *
1048 * Return: same as with tpm_transmit_cmd()
1049 */
tpm_pcr_extend(struct tpm_chip * chip,int pcr_idx,const u8 * hash)1050 int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
1051 {
1052 int rc;
1053 struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
1054 u32 count = 0;
1055 int i;
1056
1057 chip = tpm_find_get_ops(chip);
1058 if (!chip)
1059 return -ENODEV;
1060
1061 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1062 memset(digest_list, 0, sizeof(digest_list));
1063
1064 for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
1065 chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
1066 digest_list[i].alg_id = chip->active_banks[i];
1067 memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
1068 count++;
1069 }
1070
1071 rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);
1072 tpm_put_ops(chip);
1073 return rc;
1074 }
1075
1076 rc = tpm1_pcr_extend(chip, pcr_idx, hash,
1077 "attempting extend a PCR value");
1078 tpm_put_ops(chip);
1079 return rc;
1080 }
1081 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
1082
1083 /**
1084 * tpm_do_selftest - have the TPM continue its selftest and wait until it
1085 * can receive further commands
1086 * @chip: TPM chip to use
1087 *
1088 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
1089 * a TPM error code.
1090 */
tpm_do_selftest(struct tpm_chip * chip)1091 int tpm_do_selftest(struct tpm_chip *chip)
1092 {
1093 int rc;
1094 unsigned int loops;
1095 unsigned int delay_msec = 100;
1096 unsigned long duration;
1097 u8 dummy[TPM_DIGEST_SIZE];
1098
1099 duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
1100
1101 loops = jiffies_to_msecs(duration) / delay_msec;
1102
1103 rc = tpm_continue_selftest(chip);
1104 if (rc == TPM_ERR_INVALID_POSTINIT) {
1105 chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
1106 dev_info(&chip->dev, "TPM not ready (%d)\n", rc);
1107 }
1108 /* This may fail if there was no TPM driver during a suspend/resume
1109 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
1110 */
1111 if (rc)
1112 return rc;
1113
1114 do {
1115 /* Attempt to read a PCR value */
1116 rc = tpm_pcr_read_dev(chip, 0, dummy);
1117
1118 /* Some buggy TPMs will not respond to tpm_tis_ready() for
1119 * around 300ms while the self test is ongoing, keep trying
1120 * until the self test duration expires. */
1121 if (rc == -ETIME) {
1122 dev_info(
1123 &chip->dev, HW_ERR
1124 "TPM command timed out during continue self test");
1125 tpm_msleep(delay_msec);
1126 continue;
1127 }
1128
1129 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
1130 dev_info(&chip->dev,
1131 "TPM is disabled/deactivated (0x%X)\n", rc);
1132 /* TPM is disabled and/or deactivated; driver can
1133 * proceed and TPM does handle commands for
1134 * suspend/resume correctly
1135 */
1136 return 0;
1137 }
1138 if (rc != TPM_WARN_DOING_SELFTEST)
1139 return rc;
1140 tpm_msleep(delay_msec);
1141 } while (--loops > 0);
1142
1143 return rc;
1144 }
1145 EXPORT_SYMBOL_GPL(tpm_do_selftest);
1146
1147 /**
1148 * tpm1_auto_startup - Perform the standard automatic TPM initialization
1149 * sequence
1150 * @chip: TPM chip to use
1151 *
1152 * Returns 0 on success, < 0 in case of fatal error.
1153 */
tpm1_auto_startup(struct tpm_chip * chip)1154 int tpm1_auto_startup(struct tpm_chip *chip)
1155 {
1156 int rc;
1157
1158 rc = tpm_get_timeouts(chip);
1159 if (rc)
1160 goto out;
1161 rc = tpm_do_selftest(chip);
1162 if (rc) {
1163 dev_err(&chip->dev, "TPM self test failed\n");
1164 goto out;
1165 }
1166
1167 return rc;
1168 out:
1169 if (rc > 0)
1170 rc = -ENODEV;
1171 return rc;
1172 }
1173
1174 /**
1175 * tpm_send - send a TPM command
1176 * @chip: a &struct tpm_chip instance, %NULL for the default chip
1177 * @cmd: a TPM command buffer
1178 * @buflen: the length of the TPM command buffer
1179 *
1180 * Return: same as with tpm_transmit_cmd()
1181 */
tpm_send(struct tpm_chip * chip,void * cmd,size_t buflen)1182 int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
1183 {
1184 int rc;
1185
1186 chip = tpm_find_get_ops(chip);
1187 if (!chip)
1188 return -ENODEV;
1189
1190 rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0,
1191 "attempting to a send a command");
1192 tpm_put_ops(chip);
1193 return rc;
1194 }
1195 EXPORT_SYMBOL_GPL(tpm_send);
1196
1197 #define TPM_ORD_SAVESTATE 152
1198 #define SAVESTATE_RESULT_SIZE 10
1199
1200 static const struct tpm_input_header savestate_header = {
1201 .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1202 .length = cpu_to_be32(10),
1203 .ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)
1204 };
1205
1206 /*
1207 * We are about to suspend. Save the TPM state
1208 * so that it can be restored.
1209 */
tpm_pm_suspend(struct device * dev)1210 int tpm_pm_suspend(struct device *dev)
1211 {
1212 struct tpm_chip *chip = dev_get_drvdata(dev);
1213 struct tpm_cmd_t cmd;
1214 int rc, try;
1215
1216 u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1217
1218 if (chip == NULL)
1219 return -ENODEV;
1220
1221 if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
1222 return 0;
1223
1224 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1225 tpm2_shutdown(chip, TPM2_SU_STATE);
1226 return 0;
1227 }
1228
1229 /* for buggy tpm, flush pcrs with extend to selected dummy */
1230 if (tpm_suspend_pcr)
1231 rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
1232 "extending dummy pcr before suspend");
1233
1234 /* now do the actual savestate */
1235 for (try = 0; try < TPM_RETRY; try++) {
1236 cmd.header.in = savestate_header;
1237 rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,
1238 0, 0, NULL);
1239
1240 /*
1241 * If the TPM indicates that it is too busy to respond to
1242 * this command then retry before giving up. It can take
1243 * several seconds for this TPM to be ready.
1244 *
1245 * This can happen if the TPM has already been sent the
1246 * SaveState command before the driver has loaded. TCG 1.2
1247 * specification states that any communication after SaveState
1248 * may cause the TPM to invalidate previously saved state.
1249 */
1250 if (rc != TPM_WARN_RETRY)
1251 break;
1252 tpm_msleep(TPM_TIMEOUT_RETRY);
1253 }
1254
1255 if (rc)
1256 dev_err(&chip->dev,
1257 "Error (%d) sending savestate before suspend\n", rc);
1258 else if (try > 0)
1259 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1260 try * TPM_TIMEOUT_RETRY);
1261
1262 return rc;
1263 }
1264 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1265
1266 /*
1267 * Resume from a power safe. The BIOS already restored
1268 * the TPM state.
1269 */
tpm_pm_resume(struct device * dev)1270 int tpm_pm_resume(struct device *dev)
1271 {
1272 struct tpm_chip *chip = dev_get_drvdata(dev);
1273
1274 if (chip == NULL)
1275 return -ENODEV;
1276
1277 return 0;
1278 }
1279 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1280
1281 #define TPM_GETRANDOM_RESULT_SIZE 18
1282 static const struct tpm_input_header tpm_getrandom_header = {
1283 .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1284 .length = cpu_to_be32(14),
1285 .ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
1286 };
1287
1288 /**
1289 * tpm_get_random() - get random bytes from the TPM's RNG
1290 * @chip: a &struct tpm_chip instance, %NULL for the default chip
1291 * @out: destination buffer for the random bytes
1292 * @max: the max number of bytes to write to @out
1293 *
1294 * Return: same as with tpm_transmit_cmd()
1295 */
tpm_get_random(struct tpm_chip * chip,u8 * out,size_t max)1296 int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
1297 {
1298 struct tpm_cmd_t tpm_cmd;
1299 u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
1300 int err, total = 0, retries = 5;
1301 u8 *dest = out;
1302
1303 if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1304 return -EINVAL;
1305
1306 chip = tpm_find_get_ops(chip);
1307 if (!chip)
1308 return -ENODEV;
1309
1310 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1311 err = tpm2_get_random(chip, out, max);
1312 tpm_put_ops(chip);
1313 return err;
1314 }
1315
1316 do {
1317 tpm_cmd.header.in = tpm_getrandom_header;
1318 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1319
1320 err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
1321 TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1322 offsetof(struct tpm_getrandom_out,
1323 rng_data),
1324 0, "attempting get random");
1325 if (err)
1326 break;
1327
1328 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1329 if (recd > num_bytes) {
1330 total = -EFAULT;
1331 break;
1332 }
1333
1334 rlength = be32_to_cpu(tpm_cmd.header.out.length);
1335 if (rlength < TPM_HEADER_SIZE +
1336 offsetof(struct tpm_getrandom_out, rng_data) +
1337 recd) {
1338 total = -EFAULT;
1339 break;
1340 }
1341 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1342
1343 dest += recd;
1344 total += recd;
1345 num_bytes -= recd;
1346 } while (retries-- && total < max);
1347
1348 tpm_put_ops(chip);
1349 return total ? total : -EIO;
1350 }
1351 EXPORT_SYMBOL_GPL(tpm_get_random);
1352
1353 /**
1354 * tpm_seal_trusted() - seal a trusted key payload
1355 * @chip: a &struct tpm_chip instance, %NULL for the default chip
1356 * @options: authentication values and other options
1357 * @payload: the key data in clear and encrypted form
1358 *
1359 * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
1360 * the keyring subsystem.
1361 *
1362 * Return: same as with tpm_transmit_cmd()
1363 */
tpm_seal_trusted(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options)1364 int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload,
1365 struct trusted_key_options *options)
1366 {
1367 int rc;
1368
1369 chip = tpm_find_get_ops(chip);
1370 if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1371 return -ENODEV;
1372
1373 rc = tpm2_seal_trusted(chip, payload, options);
1374
1375 tpm_put_ops(chip);
1376 return rc;
1377 }
1378 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1379
1380 /**
1381 * tpm_unseal_trusted() - unseal a trusted key
1382 * @chip: a &struct tpm_chip instance, %NULL for the default chip
1383 * @options: authentication values and other options
1384 * @payload: the key data in clear and encrypted form
1385 *
1386 * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
1387 * the keyring subsystem.
1388 *
1389 * Return: same as with tpm_transmit_cmd()
1390 */
tpm_unseal_trusted(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options)1391 int tpm_unseal_trusted(struct tpm_chip *chip,
1392 struct trusted_key_payload *payload,
1393 struct trusted_key_options *options)
1394 {
1395 int rc;
1396
1397 chip = tpm_find_get_ops(chip);
1398 if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1399 return -ENODEV;
1400
1401 rc = tpm2_unseal_trusted(chip, payload, options);
1402
1403 tpm_put_ops(chip);
1404
1405 return rc;
1406 }
1407 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1408
tpm_init(void)1409 static int __init tpm_init(void)
1410 {
1411 int rc;
1412
1413 tpm_class = class_create(THIS_MODULE, "tpm");
1414 if (IS_ERR(tpm_class)) {
1415 pr_err("couldn't create tpm class\n");
1416 return PTR_ERR(tpm_class);
1417 }
1418
1419 tpmrm_class = class_create(THIS_MODULE, "tpmrm");
1420 if (IS_ERR(tpmrm_class)) {
1421 pr_err("couldn't create tpmrm class\n");
1422 class_destroy(tpm_class);
1423 return PTR_ERR(tpmrm_class);
1424 }
1425
1426 rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm");
1427 if (rc < 0) {
1428 pr_err("tpm: failed to allocate char dev region\n");
1429 class_destroy(tpmrm_class);
1430 class_destroy(tpm_class);
1431 return rc;
1432 }
1433
1434 return 0;
1435 }
1436
tpm_exit(void)1437 static void __exit tpm_exit(void)
1438 {
1439 idr_destroy(&dev_nums_idr);
1440 class_destroy(tpm_class);
1441 class_destroy(tpmrm_class);
1442 unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
1443 }
1444
1445 subsys_initcall(tpm_init);
1446 module_exit(tpm_exit);
1447
1448 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1449 MODULE_DESCRIPTION("TPM Driver");
1450 MODULE_VERSION("2.0");
1451 MODULE_LICENSE("GPL");
1452