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 char *buf,
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 mutex_lock(&chip->tpm_mutex);
355 rc = chip->ops->send(chip, (u8 *) buf, count);
358 "tpm_transmit: tpm_send: error %zd\n", rc);
362 if (chip->flags & TPM_CHIP_FLAG_IRQ)
365 if (chip->flags & TPM_CHIP_FLAG_TPM2)
366 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
368 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
370 u8 status = chip->ops->status(chip);
371 if ((status & chip->ops->req_complete_mask) ==
372 chip->ops->req_complete_val)
375 if (chip->ops->req_canceled(chip, status)) {
376 dev_err(&chip->dev, "Operation Canceled\n");
381 msleep(TPM_TIMEOUT); /* CHECK */
383 } while (time_before(jiffies, stop));
385 chip->ops->cancel(chip);
386 dev_err(&chip->dev, "Operation Timed out\n");
391 rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
394 "tpm_transmit: tpm_recv: error %zd\n", rc);
396 mutex_unlock(&chip->tpm_mutex);
400 #define TPM_DIGEST_SIZE 20
401 #define TPM_RET_CODE_IDX 6
403 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd,
404 int len, const char *desc)
406 struct tpm_output_header *header;
409 len = tpm_transmit(chip, (u8 *) cmd, len);
412 else if (len < TPM_HEADER_SIZE)
417 err = be32_to_cpu(header->return_code);
418 if (err != 0 && desc)
419 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
425 #define TPM_INTERNAL_RESULT_SIZE 200
426 #define TPM_ORD_GET_CAP cpu_to_be32(101)
427 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
429 static const struct tpm_input_header tpm_getcap_header = {
430 .tag = TPM_TAG_RQU_COMMAND,
431 .length = cpu_to_be32(22),
432 .ordinal = TPM_ORD_GET_CAP
435 ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap,
438 struct tpm_cmd_t tpm_cmd;
441 tpm_cmd.header.in = tpm_getcap_header;
442 if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
443 tpm_cmd.params.getcap_in.cap = subcap_id;
444 /*subcap field not necessary */
445 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
446 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
448 if (subcap_id == TPM_CAP_FLAG_PERM ||
449 subcap_id == TPM_CAP_FLAG_VOL)
450 tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
452 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
453 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
454 tpm_cmd.params.getcap_in.subcap = subcap_id;
456 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
458 *cap = tpm_cmd.params.getcap_out.cap;
462 void tpm_gen_interrupt(struct tpm_chip *chip)
464 struct tpm_cmd_t tpm_cmd;
467 tpm_cmd.header.in = tpm_getcap_header;
468 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
469 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
470 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
472 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
473 "attempting to determine the timeouts");
475 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
477 #define TPM_ORD_STARTUP cpu_to_be32(153)
478 #define TPM_ST_CLEAR cpu_to_be16(1)
479 #define TPM_ST_STATE cpu_to_be16(2)
480 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
481 static const struct tpm_input_header tpm_startup_header = {
482 .tag = TPM_TAG_RQU_COMMAND,
483 .length = cpu_to_be32(12),
484 .ordinal = TPM_ORD_STARTUP
487 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
489 struct tpm_cmd_t start_cmd;
490 start_cmd.header.in = tpm_startup_header;
492 start_cmd.params.startup_in.startup_type = startup_type;
493 return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
494 "attempting to start the TPM");
497 int tpm_get_timeouts(struct tpm_chip *chip)
499 struct tpm_cmd_t tpm_cmd;
500 unsigned long new_timeout[4];
501 unsigned long old_timeout[4];
502 struct duration_t *duration_cap;
505 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
506 /* Fixed timeouts for TPM2 */
507 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
508 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
509 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
510 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
511 chip->duration[TPM_SHORT] =
512 msecs_to_jiffies(TPM2_DURATION_SHORT);
513 chip->duration[TPM_MEDIUM] =
514 msecs_to_jiffies(TPM2_DURATION_MEDIUM);
515 chip->duration[TPM_LONG] =
516 msecs_to_jiffies(TPM2_DURATION_LONG);
520 tpm_cmd.header.in = tpm_getcap_header;
521 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
522 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
523 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
524 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
526 if (rc == TPM_ERR_INVALID_POSTINIT) {
527 /* The TPM is not started, we are the first to talk to it.
528 Execute a startup command. */
529 dev_info(&chip->dev, "Issuing TPM_STARTUP");
530 if (tpm_startup(chip, TPM_ST_CLEAR))
533 tpm_cmd.header.in = tpm_getcap_header;
534 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
535 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
536 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
537 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
542 "A TPM error (%zd) occurred attempting to determine the timeouts\n",
547 if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
548 be32_to_cpu(tpm_cmd.header.out.length)
549 != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
552 old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
553 old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
554 old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
555 old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
556 memcpy(new_timeout, old_timeout, sizeof(new_timeout));
559 * Provide ability for vendor overrides of timeout values in case
562 if (chip->ops->update_timeouts != NULL)
563 chip->timeout_adjusted =
564 chip->ops->update_timeouts(chip, new_timeout);
566 if (!chip->timeout_adjusted) {
567 /* Don't overwrite default if value is 0 */
568 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
571 /* timeouts in msec rather usec */
572 for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
573 new_timeout[i] *= 1000;
574 chip->timeout_adjusted = true;
578 /* Report adjusted timeouts */
579 if (chip->timeout_adjusted) {
581 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
582 old_timeout[0], new_timeout[0],
583 old_timeout[1], new_timeout[1],
584 old_timeout[2], new_timeout[2],
585 old_timeout[3], new_timeout[3]);
588 chip->timeout_a = usecs_to_jiffies(new_timeout[0]);
589 chip->timeout_b = usecs_to_jiffies(new_timeout[1]);
590 chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
591 chip->timeout_d = usecs_to_jiffies(new_timeout[3]);
594 tpm_cmd.header.in = tpm_getcap_header;
595 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
596 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
597 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
599 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
600 "attempting to determine the durations");
604 if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
605 be32_to_cpu(tpm_cmd.header.out.length)
606 != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
609 duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
610 chip->duration[TPM_SHORT] =
611 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
612 chip->duration[TPM_MEDIUM] =
613 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
614 chip->duration[TPM_LONG] =
615 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
617 /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
618 * value wrong and apparently reports msecs rather than usecs. So we
619 * fix up the resulting too-small TPM_SHORT value to make things work.
620 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
622 if (chip->duration[TPM_SHORT] < (HZ / 100)) {
623 chip->duration[TPM_SHORT] = HZ;
624 chip->duration[TPM_MEDIUM] *= 1000;
625 chip->duration[TPM_LONG] *= 1000;
626 chip->duration_adjusted = true;
627 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
631 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
633 #define TPM_ORD_CONTINUE_SELFTEST 83
634 #define CONTINUE_SELFTEST_RESULT_SIZE 10
636 static struct tpm_input_header continue_selftest_header = {
637 .tag = TPM_TAG_RQU_COMMAND,
638 .length = cpu_to_be32(10),
639 .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
643 * tpm_continue_selftest -- run TPM's selftest
644 * @chip: TPM chip to use
646 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
649 static int tpm_continue_selftest(struct tpm_chip *chip)
652 struct tpm_cmd_t cmd;
654 cmd.header.in = continue_selftest_header;
655 rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
656 "continue selftest");
660 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
661 #define READ_PCR_RESULT_SIZE 30
662 static struct tpm_input_header pcrread_header = {
663 .tag = TPM_TAG_RQU_COMMAND,
664 .length = cpu_to_be32(14),
665 .ordinal = TPM_ORDINAL_PCRREAD
668 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
671 struct tpm_cmd_t cmd;
673 cmd.header.in = pcrread_header;
674 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
675 rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
676 "attempting to read a pcr value");
679 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
685 * tpm_is_tpm2 - is the chip a TPM2 chip?
686 * @chip_num: tpm idx # or ANY
688 * Returns < 0 on error, and 1 or 0 on success depending whether the chip
691 int tpm_is_tpm2(u32 chip_num)
693 struct tpm_chip *chip;
696 chip = tpm_chip_find_get(chip_num);
700 rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
706 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
709 * tpm_pcr_read - read a pcr value
710 * @chip_num: tpm idx # or ANY
711 * @pcr_idx: pcr idx to retrieve
712 * @res_buf: TPM_PCR value
713 * size of res_buf is 20 bytes (or NULL if you don't care)
715 * The TPM driver should be built-in, but for whatever reason it
716 * isn't, protect against the chip disappearing, by incrementing
717 * the module usage count.
719 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
721 struct tpm_chip *chip;
724 chip = tpm_chip_find_get(chip_num);
727 if (chip->flags & TPM_CHIP_FLAG_TPM2)
728 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
730 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
734 EXPORT_SYMBOL_GPL(tpm_pcr_read);
737 * tpm_pcr_extend - extend pcr value with hash
738 * @chip_num: tpm idx # or AN&
739 * @pcr_idx: pcr idx to extend
740 * @hash: hash value used to extend pcr value
742 * The TPM driver should be built-in, but for whatever reason it
743 * isn't, protect against the chip disappearing, by incrementing
744 * the module usage count.
746 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
747 #define EXTEND_PCR_RESULT_SIZE 34
748 static struct tpm_input_header pcrextend_header = {
749 .tag = TPM_TAG_RQU_COMMAND,
750 .length = cpu_to_be32(34),
751 .ordinal = TPM_ORD_PCR_EXTEND
754 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
756 struct tpm_cmd_t cmd;
758 struct tpm_chip *chip;
760 chip = tpm_chip_find_get(chip_num);
764 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
765 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
770 cmd.header.in = pcrextend_header;
771 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
772 memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
773 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
774 "attempting extend a PCR value");
779 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
782 * tpm_do_selftest - have the TPM continue its selftest and wait until it
783 * can receive further commands
784 * @chip: TPM chip to use
786 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
789 int tpm_do_selftest(struct tpm_chip *chip)
793 unsigned int delay_msec = 100;
794 unsigned long duration;
795 struct tpm_cmd_t cmd;
797 duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
799 loops = jiffies_to_msecs(duration) / delay_msec;
801 rc = tpm_continue_selftest(chip);
802 /* This may fail if there was no TPM driver during a suspend/resume
803 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
809 /* Attempt to read a PCR value */
810 cmd.header.in = pcrread_header;
811 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
812 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
813 /* Some buggy TPMs will not respond to tpm_tis_ready() for
814 * around 300ms while the self test is ongoing, keep trying
815 * until the self test duration expires. */
819 "TPM command timed out during continue self test");
824 if (rc < TPM_HEADER_SIZE)
827 rc = be32_to_cpu(cmd.header.out.return_code);
828 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
830 "TPM is disabled/deactivated (0x%X)\n", rc);
831 /* TPM is disabled and/or deactivated; driver can
832 * proceed and TPM does handle commands for
833 * suspend/resume correctly
837 if (rc != TPM_WARN_DOING_SELFTEST)
840 } while (--loops > 0);
844 EXPORT_SYMBOL_GPL(tpm_do_selftest);
847 * tpm1_auto_startup - Perform the standard automatic TPM initialization
849 * @chip: TPM chip to use
851 * Returns 0 on success, < 0 in case of fatal error.
853 int tpm1_auto_startup(struct tpm_chip *chip)
857 rc = tpm_get_timeouts(chip);
860 rc = tpm_do_selftest(chip);
862 dev_err(&chip->dev, "TPM self test failed\n");
873 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
875 struct tpm_chip *chip;
878 chip = tpm_chip_find_get(chip_num);
882 rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
887 EXPORT_SYMBOL_GPL(tpm_send);
889 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
890 bool check_cancel, bool *canceled)
892 u8 status = chip->ops->status(chip);
895 if ((status & mask) == mask)
897 if (check_cancel && chip->ops->req_canceled(chip, status)) {
904 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
905 wait_queue_head_t *queue, bool check_cancel)
910 bool canceled = false;
912 /* check current status */
913 status = chip->ops->status(chip);
914 if ((status & mask) == mask)
917 stop = jiffies + timeout;
919 if (chip->flags & TPM_CHIP_FLAG_IRQ) {
921 timeout = stop - jiffies;
922 if ((long)timeout <= 0)
924 rc = wait_event_interruptible_timeout(*queue,
925 wait_for_tpm_stat_cond(chip, mask, check_cancel,
933 if (rc == -ERESTARTSYS && freezing(current)) {
934 clear_thread_flag(TIF_SIGPENDING);
940 status = chip->ops->status(chip);
941 if ((status & mask) == mask)
943 } while (time_before(jiffies, stop));
947 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
949 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
950 #define SAVESTATE_RESULT_SIZE 10
952 static struct tpm_input_header savestate_header = {
953 .tag = TPM_TAG_RQU_COMMAND,
954 .length = cpu_to_be32(10),
955 .ordinal = TPM_ORD_SAVESTATE
959 * We are about to suspend. Save the TPM state
960 * so that it can be restored.
962 int tpm_pm_suspend(struct device *dev)
964 struct tpm_chip *chip = dev_get_drvdata(dev);
965 struct tpm_cmd_t cmd;
968 u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
973 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
974 tpm2_shutdown(chip, TPM2_SU_STATE);
978 /* for buggy tpm, flush pcrs with extend to selected dummy */
979 if (tpm_suspend_pcr) {
980 cmd.header.in = pcrextend_header;
981 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
982 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
984 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
985 "extending dummy pcr before suspend");
988 /* now do the actual savestate */
989 for (try = 0; try < TPM_RETRY; try++) {
990 cmd.header.in = savestate_header;
991 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
994 * If the TPM indicates that it is too busy to respond to
995 * this command then retry before giving up. It can take
996 * several seconds for this TPM to be ready.
998 * This can happen if the TPM has already been sent the
999 * SaveState command before the driver has loaded. TCG 1.2
1000 * specification states that any communication after SaveState
1001 * may cause the TPM to invalidate previously saved state.
1003 if (rc != TPM_WARN_RETRY)
1005 msleep(TPM_TIMEOUT_RETRY);
1010 "Error (%d) sending savestate before suspend\n", rc);
1012 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1013 try * TPM_TIMEOUT_RETRY);
1017 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1020 * Resume from a power safe. The BIOS already restored
1023 int tpm_pm_resume(struct device *dev)
1025 struct tpm_chip *chip = dev_get_drvdata(dev);
1032 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1034 #define TPM_GETRANDOM_RESULT_SIZE 18
1035 static struct tpm_input_header tpm_getrandom_header = {
1036 .tag = TPM_TAG_RQU_COMMAND,
1037 .length = cpu_to_be32(14),
1038 .ordinal = TPM_ORD_GET_RANDOM
1042 * tpm_get_random() - Get random bytes from the tpm's RNG
1043 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1044 * @out: destination buffer for the random bytes
1045 * @max: the max number of bytes to write to @out
1047 * Returns < 0 on error and the number of bytes read on success
1049 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1051 struct tpm_chip *chip;
1052 struct tpm_cmd_t tpm_cmd;
1053 u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1054 int err, total = 0, retries = 5;
1057 if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1060 chip = tpm_chip_find_get(chip_num);
1064 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1065 err = tpm2_get_random(chip, out, max);
1071 tpm_cmd.header.in = tpm_getrandom_header;
1072 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1074 err = tpm_transmit_cmd(chip, &tpm_cmd,
1075 TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1076 "attempting get random");
1080 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1081 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1086 } while (retries-- && total < max);
1089 return total ? total : -EIO;
1091 EXPORT_SYMBOL_GPL(tpm_get_random);
1094 * tpm_seal_trusted() - seal a trusted key
1095 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1096 * @options: authentication values and other options
1097 * @payload: the key data in clear and encrypted form
1099 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1102 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1103 struct trusted_key_options *options)
1105 struct tpm_chip *chip;
1108 chip = tpm_chip_find_get(chip_num);
1109 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1112 rc = tpm2_seal_trusted(chip, payload, options);
1117 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1120 * tpm_unseal_trusted() - unseal a trusted key
1121 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1122 * @options: authentication values and other options
1123 * @payload: the key data in clear and encrypted form
1125 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1128 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1129 struct trusted_key_options *options)
1131 struct tpm_chip *chip;
1134 chip = tpm_chip_find_get(chip_num);
1135 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1138 rc = tpm2_unseal_trusted(chip, payload, options);
1144 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1146 static int __init tpm_init(void)
1150 tpm_class = class_create(THIS_MODULE, "tpm");
1151 if (IS_ERR(tpm_class)) {
1152 pr_err("couldn't create tpm class\n");
1153 return PTR_ERR(tpm_class);
1156 rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1158 pr_err("tpm: failed to allocate char dev region\n");
1159 class_destroy(tpm_class);
1166 static void __exit tpm_exit(void)
1168 idr_destroy(&dev_nums_idr);
1169 class_destroy(tpm_class);
1170 unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1173 subsys_initcall(tpm_init);
1174 module_exit(tpm_exit);
1176 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1177 MODULE_DESCRIPTION("TPM Driver");
1178 MODULE_VERSION("2.0");
1179 MODULE_LICENSE("GPL");