2 * Copyright (C) 2004 IBM Corporation
3 * Copyright (C) 2014 Intel Corporation
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>
11 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
13 * Device driver for TCG/TCPA TPM (trusted platform module).
14 * Specifications at www.trustedcomputinggroup.org
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
21 * Note, the TPM chip is not interrupt driven (only polling)
22 * and can have very long timeouts (minutes!). Hence the unusual
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>
34 #include "tpm_eventlog.h"
36 #define TPM_MAX_ORDINAL 243
37 #define TSC_MAX_ORDINAL 12
38 #define TPM_PROTECTED_COMMAND 0x00
39 #define TPM_CONNECTION_COMMAND 0x40
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.
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 faciltate flush on suspend.");
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.
59 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
60 TPM_UNDEFINED, /* 0 */
65 TPM_UNDEFINED, /* 5 */
115 TPM_UNDEFINED, /* 55 */
135 TPM_UNDEFINED, /* 75 */
145 TPM_UNDEFINED, /* 85 */
155 TPM_UNDEFINED, /* 95 */
160 TPM_MEDIUM, /* 100 */
165 TPM_UNDEFINED, /* 105 */
195 TPM_UNDEFINED, /* 135 */
205 TPM_UNDEFINED, /* 145 */
215 TPM_UNDEFINED, /* 155 */
225 TPM_UNDEFINED, /* 165 */
235 TPM_UNDEFINED, /* 175 */
240 TPM_MEDIUM, /* 180 */
245 TPM_MEDIUM, /* 185 */
250 TPM_UNDEFINED, /* 190 */
255 TPM_UNDEFINED, /* 195 */
270 TPM_MEDIUM, /* 210 */
275 TPM_UNDEFINED, /* 215 */
285 TPM_UNDEFINED, /* 225 */
295 TPM_UNDEFINED, /* 235 */
306 * Returns max number of jiffies to wait
308 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
311 int duration_idx = TPM_UNDEFINED;
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.
318 if (ordinal < TPM_MAX_ORDINAL)
319 duration_idx = tpm_ordinal_duration[ordinal];
321 if (duration_idx != TPM_UNDEFINED)
322 duration = chip->duration[duration_idx];
328 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
331 * Internal kernel interface to transmit TPM commands
333 ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
340 if (bufsiz > TPM_BUFSIZE)
341 bufsiz = TPM_BUFSIZE;
343 count = be32_to_cpu(*((__be32 *) (buf + 2)));
344 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
347 if (count > bufsiz) {
349 "invalid count value %x %zx\n", count, bufsiz);
353 if (!(flags & TPM_TRANSMIT_UNLOCKED))
354 mutex_lock(&chip->tpm_mutex);
356 rc = chip->ops->send(chip, (u8 *) buf, count);
359 "tpm_transmit: tpm_send: error %zd\n", rc);
363 if (chip->flags & TPM_CHIP_FLAG_IRQ)
366 if (chip->flags & TPM_CHIP_FLAG_TPM2)
367 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
369 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
371 u8 status = chip->ops->status(chip);
372 if ((status & chip->ops->req_complete_mask) ==
373 chip->ops->req_complete_val)
376 if (chip->ops->req_canceled(chip, status)) {
377 dev_err(&chip->dev, "Operation Canceled\n");
382 msleep(TPM_TIMEOUT); /* CHECK */
384 } while (time_before(jiffies, stop));
386 chip->ops->cancel(chip);
387 dev_err(&chip->dev, "Operation Timed out\n");
392 rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
395 "tpm_transmit: tpm_recv: error %zd\n", rc);
397 if (!(flags & TPM_TRANSMIT_UNLOCKED))
398 mutex_unlock(&chip->tpm_mutex);
402 #define TPM_DIGEST_SIZE 20
403 #define TPM_RET_CODE_IDX 6
405 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,
406 int len, unsigned int flags, const char *desc)
408 const struct tpm_output_header *header;
411 len = tpm_transmit(chip, (const u8 *)cmd, len, flags);
414 else if (len < TPM_HEADER_SIZE)
419 err = be32_to_cpu(header->return_code);
420 if (err != 0 && desc)
421 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
427 #define TPM_INTERNAL_RESULT_SIZE 200
428 #define TPM_ORD_GET_CAP cpu_to_be32(101)
429 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
431 static const struct tpm_input_header tpm_getcap_header = {
432 .tag = TPM_TAG_RQU_COMMAND,
433 .length = cpu_to_be32(22),
434 .ordinal = TPM_ORD_GET_CAP
437 ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap,
440 struct tpm_cmd_t tpm_cmd;
443 tpm_cmd.header.in = tpm_getcap_header;
444 if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
445 tpm_cmd.params.getcap_in.cap = subcap_id;
446 /*subcap field not necessary */
447 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
448 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
450 if (subcap_id == TPM_CAP_FLAG_PERM ||
451 subcap_id == TPM_CAP_FLAG_VOL)
452 tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
454 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
455 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
456 tpm_cmd.params.getcap_in.subcap = subcap_id;
458 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
461 *cap = tpm_cmd.params.getcap_out.cap;
464 EXPORT_SYMBOL_GPL(tpm_getcap);
466 #define TPM_ORD_STARTUP cpu_to_be32(153)
467 #define TPM_ST_CLEAR cpu_to_be16(1)
468 #define TPM_ST_STATE cpu_to_be16(2)
469 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
470 static const struct tpm_input_header tpm_startup_header = {
471 .tag = TPM_TAG_RQU_COMMAND,
472 .length = cpu_to_be32(12),
473 .ordinal = TPM_ORD_STARTUP
476 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
478 struct tpm_cmd_t start_cmd;
479 start_cmd.header.in = tpm_startup_header;
481 start_cmd.params.startup_in.startup_type = startup_type;
482 return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
483 "attempting to start the TPM");
486 int tpm_get_timeouts(struct tpm_chip *chip)
488 struct tpm_cmd_t tpm_cmd;
489 unsigned long new_timeout[4];
490 unsigned long old_timeout[4];
491 struct duration_t *duration_cap;
494 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
495 /* Fixed timeouts for TPM2 */
496 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
497 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
498 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
499 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
500 chip->duration[TPM_SHORT] =
501 msecs_to_jiffies(TPM2_DURATION_SHORT);
502 chip->duration[TPM_MEDIUM] =
503 msecs_to_jiffies(TPM2_DURATION_MEDIUM);
504 chip->duration[TPM_LONG] =
505 msecs_to_jiffies(TPM2_DURATION_LONG);
509 tpm_cmd.header.in = tpm_getcap_header;
510 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
511 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
512 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
513 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
516 if (rc == TPM_ERR_INVALID_POSTINIT) {
517 /* The TPM is not started, we are the first to talk to it.
518 Execute a startup command. */
519 dev_info(&chip->dev, "Issuing TPM_STARTUP");
520 if (tpm_startup(chip, TPM_ST_CLEAR))
523 tpm_cmd.header.in = tpm_getcap_header;
524 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
525 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
526 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
527 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
532 "A TPM error (%zd) occurred attempting to determine the timeouts\n",
537 if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
538 be32_to_cpu(tpm_cmd.header.out.length)
539 != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
542 old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
543 old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
544 old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
545 old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
546 memcpy(new_timeout, old_timeout, sizeof(new_timeout));
549 * Provide ability for vendor overrides of timeout values in case
552 if (chip->ops->update_timeouts != NULL)
553 chip->timeout_adjusted =
554 chip->ops->update_timeouts(chip, new_timeout);
556 if (!chip->timeout_adjusted) {
557 /* Don't overwrite default if value is 0 */
558 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
561 /* timeouts in msec rather usec */
562 for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
563 new_timeout[i] *= 1000;
564 chip->timeout_adjusted = true;
568 /* Report adjusted timeouts */
569 if (chip->timeout_adjusted) {
571 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
572 old_timeout[0], new_timeout[0],
573 old_timeout[1], new_timeout[1],
574 old_timeout[2], new_timeout[2],
575 old_timeout[3], new_timeout[3]);
578 chip->timeout_a = usecs_to_jiffies(new_timeout[0]);
579 chip->timeout_b = usecs_to_jiffies(new_timeout[1]);
580 chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
581 chip->timeout_d = usecs_to_jiffies(new_timeout[3]);
584 tpm_cmd.header.in = tpm_getcap_header;
585 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
586 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
587 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
589 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
590 "attempting to determine the durations");
594 if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
595 be32_to_cpu(tpm_cmd.header.out.length)
596 != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
599 duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
600 chip->duration[TPM_SHORT] =
601 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
602 chip->duration[TPM_MEDIUM] =
603 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
604 chip->duration[TPM_LONG] =
605 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
607 /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
608 * value wrong and apparently reports msecs rather than usecs. So we
609 * fix up the resulting too-small TPM_SHORT value to make things work.
610 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
612 if (chip->duration[TPM_SHORT] < (HZ / 100)) {
613 chip->duration[TPM_SHORT] = HZ;
614 chip->duration[TPM_MEDIUM] *= 1000;
615 chip->duration[TPM_LONG] *= 1000;
616 chip->duration_adjusted = true;
617 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
621 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
623 #define TPM_ORD_CONTINUE_SELFTEST 83
624 #define CONTINUE_SELFTEST_RESULT_SIZE 10
626 static struct tpm_input_header continue_selftest_header = {
627 .tag = TPM_TAG_RQU_COMMAND,
628 .length = cpu_to_be32(10),
629 .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
633 * tpm_continue_selftest -- run TPM's selftest
634 * @chip: TPM chip to use
636 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
639 static int tpm_continue_selftest(struct tpm_chip *chip)
642 struct tpm_cmd_t cmd;
644 cmd.header.in = continue_selftest_header;
645 rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
646 "continue selftest");
650 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
651 #define READ_PCR_RESULT_SIZE 30
652 static struct tpm_input_header pcrread_header = {
653 .tag = TPM_TAG_RQU_COMMAND,
654 .length = cpu_to_be32(14),
655 .ordinal = TPM_ORDINAL_PCRREAD
658 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
661 struct tpm_cmd_t cmd;
663 cmd.header.in = pcrread_header;
664 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
665 rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
666 "attempting to read a pcr value");
669 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
675 * tpm_is_tpm2 - is the chip a TPM2 chip?
676 * @chip_num: tpm idx # or ANY
678 * Returns < 0 on error, and 1 or 0 on success depending whether the chip
681 int tpm_is_tpm2(u32 chip_num)
683 struct tpm_chip *chip;
686 chip = tpm_chip_find_get(chip_num);
690 rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
696 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
699 * tpm_pcr_read - read a pcr value
700 * @chip_num: tpm idx # or ANY
701 * @pcr_idx: pcr idx to retrieve
702 * @res_buf: TPM_PCR value
703 * size of res_buf is 20 bytes (or NULL if you don't care)
705 * The TPM driver should be built-in, but for whatever reason it
706 * isn't, protect against the chip disappearing, by incrementing
707 * the module usage count.
709 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
711 struct tpm_chip *chip;
714 chip = tpm_chip_find_get(chip_num);
717 if (chip->flags & TPM_CHIP_FLAG_TPM2)
718 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
720 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
724 EXPORT_SYMBOL_GPL(tpm_pcr_read);
727 * tpm_pcr_extend - extend pcr value with hash
728 * @chip_num: tpm idx # or AN&
729 * @pcr_idx: pcr idx to extend
730 * @hash: hash value used to extend pcr value
732 * The TPM driver should be built-in, but for whatever reason it
733 * isn't, protect against the chip disappearing, by incrementing
734 * the module usage count.
736 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
737 #define EXTEND_PCR_RESULT_SIZE 34
738 static struct tpm_input_header pcrextend_header = {
739 .tag = TPM_TAG_RQU_COMMAND,
740 .length = cpu_to_be32(34),
741 .ordinal = TPM_ORD_PCR_EXTEND
744 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
746 struct tpm_cmd_t cmd;
748 struct tpm_chip *chip;
750 chip = tpm_chip_find_get(chip_num);
754 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
755 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
760 cmd.header.in = pcrextend_header;
761 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
762 memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
763 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
764 "attempting extend a PCR value");
769 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
772 * tpm_do_selftest - have the TPM continue its selftest and wait until it
773 * can receive further commands
774 * @chip: TPM chip to use
776 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
779 int tpm_do_selftest(struct tpm_chip *chip)
783 unsigned int delay_msec = 100;
784 unsigned long duration;
785 u8 dummy[TPM_DIGEST_SIZE];
787 duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
789 loops = jiffies_to_msecs(duration) / delay_msec;
791 rc = tpm_continue_selftest(chip);
792 /* This may fail if there was no TPM driver during a suspend/resume
793 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
799 /* Attempt to read a PCR value */
800 rc = tpm_pcr_read_dev(chip, 0, dummy);
802 /* Some buggy TPMs will not respond to tpm_tis_ready() for
803 * around 300ms while the self test is ongoing, keep trying
804 * until the self test duration expires. */
808 "TPM command timed out during continue self test");
813 if (rc < TPM_HEADER_SIZE)
816 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
818 "TPM is disabled/deactivated (0x%X)\n", rc);
819 /* TPM is disabled and/or deactivated; driver can
820 * proceed and TPM does handle commands for
821 * suspend/resume correctly
825 if (rc != TPM_WARN_DOING_SELFTEST)
828 } while (--loops > 0);
832 EXPORT_SYMBOL_GPL(tpm_do_selftest);
835 * tpm1_auto_startup - Perform the standard automatic TPM initialization
837 * @chip: TPM chip to use
839 * Returns 0 on success, < 0 in case of fatal error.
841 int tpm1_auto_startup(struct tpm_chip *chip)
845 rc = tpm_get_timeouts(chip);
848 rc = tpm_do_selftest(chip);
850 dev_err(&chip->dev, "TPM self test failed\n");
861 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
863 struct tpm_chip *chip;
866 chip = tpm_chip_find_get(chip_num);
870 rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
875 EXPORT_SYMBOL_GPL(tpm_send);
877 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
878 bool check_cancel, bool *canceled)
880 u8 status = chip->ops->status(chip);
883 if ((status & mask) == mask)
885 if (check_cancel && chip->ops->req_canceled(chip, status)) {
892 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
893 wait_queue_head_t *queue, bool check_cancel)
898 bool canceled = false;
900 /* check current status */
901 status = chip->ops->status(chip);
902 if ((status & mask) == mask)
905 stop = jiffies + timeout;
907 if (chip->flags & TPM_CHIP_FLAG_IRQ) {
909 timeout = stop - jiffies;
910 if ((long)timeout <= 0)
912 rc = wait_event_interruptible_timeout(*queue,
913 wait_for_tpm_stat_cond(chip, mask, check_cancel,
921 if (rc == -ERESTARTSYS && freezing(current)) {
922 clear_thread_flag(TIF_SIGPENDING);
928 status = chip->ops->status(chip);
929 if ((status & mask) == mask)
931 } while (time_before(jiffies, stop));
935 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
937 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
938 #define SAVESTATE_RESULT_SIZE 10
940 static struct tpm_input_header savestate_header = {
941 .tag = TPM_TAG_RQU_COMMAND,
942 .length = cpu_to_be32(10),
943 .ordinal = TPM_ORD_SAVESTATE
947 * We are about to suspend. Save the TPM state
948 * so that it can be restored.
950 int tpm_pm_suspend(struct device *dev)
952 struct tpm_chip *chip = dev_get_drvdata(dev);
953 struct tpm_cmd_t cmd;
956 u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
961 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
962 tpm2_shutdown(chip, TPM2_SU_STATE);
966 /* for buggy tpm, flush pcrs with extend to selected dummy */
967 if (tpm_suspend_pcr) {
968 cmd.header.in = pcrextend_header;
969 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
970 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
972 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
973 "extending dummy pcr before suspend");
976 /* now do the actual savestate */
977 for (try = 0; try < TPM_RETRY; try++) {
978 cmd.header.in = savestate_header;
979 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
983 * If the TPM indicates that it is too busy to respond to
984 * this command then retry before giving up. It can take
985 * several seconds for this TPM to be ready.
987 * This can happen if the TPM has already been sent the
988 * SaveState command before the driver has loaded. TCG 1.2
989 * specification states that any communication after SaveState
990 * may cause the TPM to invalidate previously saved state.
992 if (rc != TPM_WARN_RETRY)
994 msleep(TPM_TIMEOUT_RETRY);
999 "Error (%d) sending savestate before suspend\n", rc);
1001 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1002 try * TPM_TIMEOUT_RETRY);
1006 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1009 * Resume from a power safe. The BIOS already restored
1012 int tpm_pm_resume(struct device *dev)
1014 struct tpm_chip *chip = dev_get_drvdata(dev);
1021 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1023 #define TPM_GETRANDOM_RESULT_SIZE 18
1024 static struct tpm_input_header tpm_getrandom_header = {
1025 .tag = TPM_TAG_RQU_COMMAND,
1026 .length = cpu_to_be32(14),
1027 .ordinal = TPM_ORD_GET_RANDOM
1031 * tpm_get_random() - Get random bytes from the tpm's RNG
1032 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1033 * @out: destination buffer for the random bytes
1034 * @max: the max number of bytes to write to @out
1036 * Returns < 0 on error and the number of bytes read on success
1038 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1040 struct tpm_chip *chip;
1041 struct tpm_cmd_t tpm_cmd;
1042 u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1043 int err, total = 0, retries = 5;
1046 if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1049 chip = tpm_chip_find_get(chip_num);
1053 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1054 err = tpm2_get_random(chip, out, max);
1060 tpm_cmd.header.in = tpm_getrandom_header;
1061 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1063 err = tpm_transmit_cmd(chip, &tpm_cmd,
1064 TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1065 0, "attempting get random");
1069 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1070 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1075 } while (retries-- && total < max);
1078 return total ? total : -EIO;
1080 EXPORT_SYMBOL_GPL(tpm_get_random);
1083 * tpm_seal_trusted() - seal a trusted key
1084 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1085 * @options: authentication values and other options
1086 * @payload: the key data in clear and encrypted form
1088 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1091 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1092 struct trusted_key_options *options)
1094 struct tpm_chip *chip;
1097 chip = tpm_chip_find_get(chip_num);
1098 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1101 rc = tpm2_seal_trusted(chip, payload, options);
1106 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1109 * tpm_unseal_trusted() - unseal a trusted key
1110 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1111 * @options: authentication values and other options
1112 * @payload: the key data in clear and encrypted form
1114 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1117 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1118 struct trusted_key_options *options)
1120 struct tpm_chip *chip;
1123 chip = tpm_chip_find_get(chip_num);
1124 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1127 rc = tpm2_unseal_trusted(chip, payload, options);
1133 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1135 static int __init tpm_init(void)
1139 tpm_class = class_create(THIS_MODULE, "tpm");
1140 if (IS_ERR(tpm_class)) {
1141 pr_err("couldn't create tpm class\n");
1142 return PTR_ERR(tpm_class);
1145 rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1147 pr_err("tpm: failed to allocate char dev region\n");
1148 class_destroy(tpm_class);
1155 static void __exit tpm_exit(void)
1157 idr_destroy(&dev_nums_idr);
1158 class_destroy(tpm_class);
1159 unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1162 subsys_initcall(tpm_init);
1163 module_exit(tpm_exit);
1165 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1166 MODULE_DESCRIPTION("TPM Driver");
1167 MODULE_VERSION("2.0");
1168 MODULE_LICENSE("GPL");