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>
32 #include <linux/pm_runtime.h>
35 #include "tpm_eventlog.h"
37 #define TPM_MAX_ORDINAL 243
38 #define TSC_MAX_ORDINAL 12
39 #define TPM_PROTECTED_COMMAND 0x00
40 #define TPM_CONNECTION_COMMAND 0x40
43 * Bug workaround - some TPM's don't flush the most
44 * recently changed pcr on suspend, so force the flush
45 * with an extend to the selected _unused_ non-volatile pcr.
47 static int tpm_suspend_pcr;
48 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
49 MODULE_PARM_DESC(suspend_pcr,
50 "PCR to use for dummy writes to faciltate flush on suspend.");
53 * Array with one entry per ordinal defining the maximum amount
54 * of time the chip could take to return the result. The ordinal
55 * designation of short, medium or long is defined in a table in
56 * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
57 * values of the SHORT, MEDIUM, and LONG durations are retrieved
58 * from the chip during initialization with a call to tpm_get_timeouts.
60 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
61 TPM_UNDEFINED, /* 0 */
66 TPM_UNDEFINED, /* 5 */
116 TPM_UNDEFINED, /* 55 */
136 TPM_UNDEFINED, /* 75 */
146 TPM_UNDEFINED, /* 85 */
156 TPM_UNDEFINED, /* 95 */
161 TPM_MEDIUM, /* 100 */
166 TPM_UNDEFINED, /* 105 */
196 TPM_UNDEFINED, /* 135 */
206 TPM_UNDEFINED, /* 145 */
216 TPM_UNDEFINED, /* 155 */
226 TPM_UNDEFINED, /* 165 */
236 TPM_UNDEFINED, /* 175 */
241 TPM_MEDIUM, /* 180 */
246 TPM_MEDIUM, /* 185 */
251 TPM_UNDEFINED, /* 190 */
256 TPM_UNDEFINED, /* 195 */
271 TPM_MEDIUM, /* 210 */
276 TPM_UNDEFINED, /* 215 */
286 TPM_UNDEFINED, /* 225 */
296 TPM_UNDEFINED, /* 235 */
307 * Returns max number of jiffies to wait
309 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
312 int duration_idx = TPM_UNDEFINED;
316 * We only have a duration table for protected commands, where the upper
317 * 16 bits are 0. For the few other ordinals the fallback will be used.
319 if (ordinal < TPM_MAX_ORDINAL)
320 duration_idx = tpm_ordinal_duration[ordinal];
322 if (duration_idx != TPM_UNDEFINED)
323 duration = chip->duration[duration_idx];
329 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
332 * tmp_transmit - Internal kernel interface to transmit TPM commands.
334 * @chip: TPM chip to use
335 * @buf: TPM command buffer
336 * @bufsiz: length of the TPM command buffer
337 * @flags: tpm transmit flags - bitmap
340 * 0 when the operation is successful.
341 * A negative number for system errors (errno).
343 ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
350 if (bufsiz < TPM_HEADER_SIZE)
353 if (bufsiz > TPM_BUFSIZE)
354 bufsiz = TPM_BUFSIZE;
356 count = be32_to_cpu(*((__be32 *) (buf + 2)));
357 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
360 if (count > bufsiz) {
362 "invalid count value %x %zx\n", count, bufsiz);
366 if (!(flags & TPM_TRANSMIT_UNLOCKED))
367 mutex_lock(&chip->tpm_mutex);
369 if (chip->dev.parent)
370 pm_runtime_get_sync(chip->dev.parent);
372 rc = chip->ops->send(chip, (u8 *) buf, count);
375 "tpm_transmit: tpm_send: error %zd\n", rc);
379 if (chip->flags & TPM_CHIP_FLAG_IRQ)
382 if (chip->flags & TPM_CHIP_FLAG_TPM2)
383 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
385 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
387 u8 status = chip->ops->status(chip);
388 if ((status & chip->ops->req_complete_mask) ==
389 chip->ops->req_complete_val)
392 if (chip->ops->req_canceled(chip, status)) {
393 dev_err(&chip->dev, "Operation Canceled\n");
398 msleep(TPM_TIMEOUT); /* CHECK */
400 } while (time_before(jiffies, stop));
402 chip->ops->cancel(chip);
403 dev_err(&chip->dev, "Operation Timed out\n");
408 rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
411 "tpm_transmit: tpm_recv: error %zd\n", rc);
413 if (chip->dev.parent)
414 pm_runtime_put_sync(chip->dev.parent);
416 if (!(flags & TPM_TRANSMIT_UNLOCKED))
417 mutex_unlock(&chip->tpm_mutex);
422 * tmp_transmit_cmd - send a tpm command to the device
423 * The function extracts tpm out header return code
425 * @chip: TPM chip to use
426 * @buf: TPM command buffer
427 * @bufsiz: length of the buffer
428 * @min_rsp_body_length: minimum expected length of response body
429 * @flags: tpm transmit flags - bitmap
430 * @desc: command description used in the error message
433 * 0 when the operation is successful.
434 * A negative number for system errors (errno).
435 * A positive number for a TPM error.
437 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *buf,
438 size_t bufsiz, size_t min_rsp_body_length,
439 unsigned int flags, const char *desc)
441 const struct tpm_output_header *header;
445 len = tpm_transmit(chip, (const u8 *)buf, bufsiz, flags);
448 else if (len < TPM_HEADER_SIZE)
452 if (len != be32_to_cpu(header->length))
455 err = be32_to_cpu(header->return_code);
456 if (err != 0 && desc)
457 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
462 if (len < min_rsp_body_length + TPM_HEADER_SIZE)
468 #define TPM_DIGEST_SIZE 20
469 #define TPM_RET_CODE_IDX 6
470 #define TPM_INTERNAL_RESULT_SIZE 200
471 #define TPM_ORD_GET_CAP cpu_to_be32(101)
472 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
474 static const struct tpm_input_header tpm_getcap_header = {
475 .tag = TPM_TAG_RQU_COMMAND,
476 .length = cpu_to_be32(22),
477 .ordinal = TPM_ORD_GET_CAP
480 ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
481 const char *desc, size_t min_cap_length)
483 struct tpm_cmd_t tpm_cmd;
486 tpm_cmd.header.in = tpm_getcap_header;
487 if (subcap_id == TPM_CAP_VERSION_1_1 ||
488 subcap_id == TPM_CAP_VERSION_1_2) {
489 tpm_cmd.params.getcap_in.cap = cpu_to_be32(subcap_id);
490 /*subcap field not necessary */
491 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
492 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
494 if (subcap_id == TPM_CAP_FLAG_PERM ||
495 subcap_id == TPM_CAP_FLAG_VOL)
496 tpm_cmd.params.getcap_in.cap =
497 cpu_to_be32(TPM_CAP_FLAG);
499 tpm_cmd.params.getcap_in.cap =
500 cpu_to_be32(TPM_CAP_PROP);
501 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
502 tpm_cmd.params.getcap_in.subcap = cpu_to_be32(subcap_id);
504 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
505 min_cap_length, 0, desc);
507 *cap = tpm_cmd.params.getcap_out.cap;
510 EXPORT_SYMBOL_GPL(tpm_getcap);
512 #define TPM_ORD_STARTUP cpu_to_be32(153)
513 #define TPM_ST_CLEAR cpu_to_be16(1)
514 #define TPM_ST_STATE cpu_to_be16(2)
515 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
516 static const struct tpm_input_header tpm_startup_header = {
517 .tag = TPM_TAG_RQU_COMMAND,
518 .length = cpu_to_be32(12),
519 .ordinal = TPM_ORD_STARTUP
522 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
524 struct tpm_cmd_t start_cmd;
525 start_cmd.header.in = tpm_startup_header;
527 start_cmd.params.startup_in.startup_type = startup_type;
528 return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
529 0, "attempting to start the TPM");
532 int tpm_get_timeouts(struct tpm_chip *chip)
535 unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
538 if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
541 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
542 /* Fixed timeouts for TPM2 */
543 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
544 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
545 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
546 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
547 chip->duration[TPM_SHORT] =
548 msecs_to_jiffies(TPM2_DURATION_SHORT);
549 chip->duration[TPM_MEDIUM] =
550 msecs_to_jiffies(TPM2_DURATION_MEDIUM);
551 chip->duration[TPM_LONG] =
552 msecs_to_jiffies(TPM2_DURATION_LONG);
554 chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
558 rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
559 sizeof(cap.timeout));
560 if (rc == TPM_ERR_INVALID_POSTINIT) {
561 /* The TPM is not started, we are the first to talk to it.
562 Execute a startup command. */
563 dev_info(&chip->dev, "Issuing TPM_STARTUP\n");
564 if (tpm_startup(chip, TPM_ST_CLEAR))
567 rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
568 "attempting to determine the timeouts",
569 sizeof(cap.timeout));
574 "A TPM error (%zd) occurred attempting to determine the timeouts\n",
579 timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
580 timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
581 timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
582 timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
583 timeout_chip[0] = be32_to_cpu(cap.timeout.a);
584 timeout_chip[1] = be32_to_cpu(cap.timeout.b);
585 timeout_chip[2] = be32_to_cpu(cap.timeout.c);
586 timeout_chip[3] = be32_to_cpu(cap.timeout.d);
587 memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
590 * Provide ability for vendor overrides of timeout values in case
593 if (chip->ops->update_timeouts != NULL)
594 chip->timeout_adjusted =
595 chip->ops->update_timeouts(chip, timeout_eff);
597 if (!chip->timeout_adjusted) {
598 /* Restore default if chip reported 0 */
601 for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
605 timeout_eff[i] = timeout_old[i];
606 chip->timeout_adjusted = true;
609 if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
610 /* timeouts in msec rather usec */
611 for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
612 timeout_eff[i] *= 1000;
613 chip->timeout_adjusted = true;
617 /* Report adjusted timeouts */
618 if (chip->timeout_adjusted) {
620 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
621 timeout_chip[0], timeout_eff[0],
622 timeout_chip[1], timeout_eff[1],
623 timeout_chip[2], timeout_eff[2],
624 timeout_chip[3], timeout_eff[3]);
627 chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
628 chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
629 chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
630 chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
632 rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
633 "attempting to determine the durations",
634 sizeof(cap.duration));
638 chip->duration[TPM_SHORT] =
639 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
640 chip->duration[TPM_MEDIUM] =
641 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
642 chip->duration[TPM_LONG] =
643 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
645 /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
646 * value wrong and apparently reports msecs rather than usecs. So we
647 * fix up the resulting too-small TPM_SHORT value to make things work.
648 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
650 if (chip->duration[TPM_SHORT] < (HZ / 100)) {
651 chip->duration[TPM_SHORT] = HZ;
652 chip->duration[TPM_MEDIUM] *= 1000;
653 chip->duration[TPM_LONG] *= 1000;
654 chip->duration_adjusted = true;
655 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
658 chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
661 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
663 #define TPM_ORD_CONTINUE_SELFTEST 83
664 #define CONTINUE_SELFTEST_RESULT_SIZE 10
666 static const struct tpm_input_header continue_selftest_header = {
667 .tag = TPM_TAG_RQU_COMMAND,
668 .length = cpu_to_be32(10),
669 .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
673 * tpm_continue_selftest -- run TPM's selftest
674 * @chip: TPM chip to use
676 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
679 static int tpm_continue_selftest(struct tpm_chip *chip)
682 struct tpm_cmd_t cmd;
684 cmd.header.in = continue_selftest_header;
685 rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0, 0,
686 "continue selftest");
690 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
691 #define READ_PCR_RESULT_SIZE 30
692 #define READ_PCR_RESULT_BODY_SIZE 20
693 static const struct tpm_input_header pcrread_header = {
694 .tag = TPM_TAG_RQU_COMMAND,
695 .length = cpu_to_be32(14),
696 .ordinal = TPM_ORDINAL_PCRREAD
699 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
702 struct tpm_cmd_t cmd;
704 cmd.header.in = pcrread_header;
705 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
706 rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
707 READ_PCR_RESULT_BODY_SIZE, 0,
708 "attempting to read a pcr value");
711 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
717 * tpm_is_tpm2 - is the chip a TPM2 chip?
718 * @chip_num: tpm idx # or ANY
720 * Returns < 0 on error, and 1 or 0 on success depending whether the chip
723 int tpm_is_tpm2(u32 chip_num)
725 struct tpm_chip *chip;
728 chip = tpm_chip_find_get(chip_num);
732 rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
738 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
741 * tpm_pcr_read - read a pcr value
742 * @chip_num: tpm idx # or ANY
743 * @pcr_idx: pcr idx to retrieve
744 * @res_buf: TPM_PCR value
745 * size of res_buf is 20 bytes (or NULL if you don't care)
747 * The TPM driver should be built-in, but for whatever reason it
748 * isn't, protect against the chip disappearing, by incrementing
749 * the module usage count.
751 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
753 struct tpm_chip *chip;
756 chip = tpm_chip_find_get(chip_num);
759 if (chip->flags & TPM_CHIP_FLAG_TPM2)
760 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
762 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
766 EXPORT_SYMBOL_GPL(tpm_pcr_read);
768 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
769 #define EXTEND_PCR_RESULT_SIZE 34
770 #define EXTEND_PCR_RESULT_BODY_SIZE 24
771 static const struct tpm_input_header pcrextend_header = {
772 .tag = TPM_TAG_RQU_COMMAND,
773 .length = cpu_to_be32(34),
774 .ordinal = TPM_ORD_PCR_EXTEND
778 * tpm_pcr_extend - extend pcr value with hash
779 * @chip_num: tpm idx # or AN&
780 * @pcr_idx: pcr idx to extend
781 * @hash: hash value used to extend pcr value
783 * The TPM driver should be built-in, but for whatever reason it
784 * isn't, protect against the chip disappearing, by incrementing
785 * the module usage count.
787 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
789 struct tpm_cmd_t cmd;
791 struct tpm_chip *chip;
792 struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
796 chip = tpm_chip_find_get(chip_num);
800 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
801 memset(digest_list, 0, sizeof(digest_list));
803 for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
804 chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
805 digest_list[i].alg_id = chip->active_banks[i];
806 memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
810 rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);
815 cmd.header.in = pcrextend_header;
816 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
817 memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
818 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
819 EXTEND_PCR_RESULT_BODY_SIZE, 0,
820 "attempting extend a PCR value");
825 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
828 * tpm_do_selftest - have the TPM continue its selftest and wait until it
829 * can receive further commands
830 * @chip: TPM chip to use
832 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
835 int tpm_do_selftest(struct tpm_chip *chip)
839 unsigned int delay_msec = 100;
840 unsigned long duration;
841 u8 dummy[TPM_DIGEST_SIZE];
843 duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
845 loops = jiffies_to_msecs(duration) / delay_msec;
847 rc = tpm_continue_selftest(chip);
848 /* This may fail if there was no TPM driver during a suspend/resume
849 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
855 /* Attempt to read a PCR value */
856 rc = tpm_pcr_read_dev(chip, 0, dummy);
858 /* Some buggy TPMs will not respond to tpm_tis_ready() for
859 * around 300ms while the self test is ongoing, keep trying
860 * until the self test duration expires. */
864 "TPM command timed out during continue self test");
869 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
871 "TPM is disabled/deactivated (0x%X)\n", rc);
872 /* TPM is disabled and/or deactivated; driver can
873 * proceed and TPM does handle commands for
874 * suspend/resume correctly
878 if (rc != TPM_WARN_DOING_SELFTEST)
881 } while (--loops > 0);
885 EXPORT_SYMBOL_GPL(tpm_do_selftest);
888 * tpm1_auto_startup - Perform the standard automatic TPM initialization
890 * @chip: TPM chip to use
892 * Returns 0 on success, < 0 in case of fatal error.
894 int tpm1_auto_startup(struct tpm_chip *chip)
898 rc = tpm_get_timeouts(chip);
901 rc = tpm_do_selftest(chip);
903 dev_err(&chip->dev, "TPM self test failed\n");
914 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
916 struct tpm_chip *chip;
919 chip = tpm_chip_find_get(chip_num);
923 rc = tpm_transmit_cmd(chip, cmd, buflen, 0, 0, "attempting tpm_cmd");
928 EXPORT_SYMBOL_GPL(tpm_send);
930 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
931 bool check_cancel, bool *canceled)
933 u8 status = chip->ops->status(chip);
936 if ((status & mask) == mask)
938 if (check_cancel && chip->ops->req_canceled(chip, status)) {
945 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
946 wait_queue_head_t *queue, bool check_cancel)
951 bool canceled = false;
953 /* check current status */
954 status = chip->ops->status(chip);
955 if ((status & mask) == mask)
958 stop = jiffies + timeout;
960 if (chip->flags & TPM_CHIP_FLAG_IRQ) {
962 timeout = stop - jiffies;
963 if ((long)timeout <= 0)
965 rc = wait_event_interruptible_timeout(*queue,
966 wait_for_tpm_stat_cond(chip, mask, check_cancel,
974 if (rc == -ERESTARTSYS && freezing(current)) {
975 clear_thread_flag(TIF_SIGPENDING);
981 status = chip->ops->status(chip);
982 if ((status & mask) == mask)
984 } while (time_before(jiffies, stop));
988 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
990 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
991 #define SAVESTATE_RESULT_SIZE 10
993 static const struct tpm_input_header savestate_header = {
994 .tag = TPM_TAG_RQU_COMMAND,
995 .length = cpu_to_be32(10),
996 .ordinal = TPM_ORD_SAVESTATE
1000 * We are about to suspend. Save the TPM state
1001 * so that it can be restored.
1003 int tpm_pm_suspend(struct device *dev)
1005 struct tpm_chip *chip = dev_get_drvdata(dev);
1006 struct tpm_cmd_t cmd;
1009 u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1014 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1015 tpm2_shutdown(chip, TPM2_SU_STATE);
1019 /* for buggy tpm, flush pcrs with extend to selected dummy */
1020 if (tpm_suspend_pcr) {
1021 cmd.header.in = pcrextend_header;
1022 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
1023 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
1025 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
1026 EXTEND_PCR_RESULT_BODY_SIZE, 0,
1027 "extending dummy pcr before suspend");
1030 /* now do the actual savestate */
1031 for (try = 0; try < TPM_RETRY; try++) {
1032 cmd.header.in = savestate_header;
1033 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
1037 * If the TPM indicates that it is too busy to respond to
1038 * this command then retry before giving up. It can take
1039 * several seconds for this TPM to be ready.
1041 * This can happen if the TPM has already been sent the
1042 * SaveState command before the driver has loaded. TCG 1.2
1043 * specification states that any communication after SaveState
1044 * may cause the TPM to invalidate previously saved state.
1046 if (rc != TPM_WARN_RETRY)
1048 msleep(TPM_TIMEOUT_RETRY);
1053 "Error (%d) sending savestate before suspend\n", rc);
1055 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1056 try * TPM_TIMEOUT_RETRY);
1060 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1063 * Resume from a power safe. The BIOS already restored
1066 int tpm_pm_resume(struct device *dev)
1068 struct tpm_chip *chip = dev_get_drvdata(dev);
1075 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1077 #define TPM_GETRANDOM_RESULT_SIZE 18
1078 static const struct tpm_input_header tpm_getrandom_header = {
1079 .tag = TPM_TAG_RQU_COMMAND,
1080 .length = cpu_to_be32(14),
1081 .ordinal = TPM_ORD_GET_RANDOM
1085 * tpm_get_random() - Get random bytes from the tpm's RNG
1086 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1087 * @out: destination buffer for the random bytes
1088 * @max: the max number of bytes to write to @out
1090 * Returns < 0 on error and the number of bytes read on success
1092 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1094 struct tpm_chip *chip;
1095 struct tpm_cmd_t tpm_cmd;
1096 u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
1097 int err, total = 0, retries = 5;
1100 if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1103 chip = tpm_chip_find_get(chip_num);
1107 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1108 err = tpm2_get_random(chip, out, max);
1114 tpm_cmd.header.in = tpm_getrandom_header;
1115 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1117 err = tpm_transmit_cmd(chip, &tpm_cmd,
1118 TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1119 offsetof(struct tpm_getrandom_out,
1121 0, "attempting get random");
1125 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1127 rlength = be32_to_cpu(tpm_cmd.header.out.length);
1128 if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
1133 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1138 } while (retries-- && total < max);
1141 return total ? total : -EIO;
1143 EXPORT_SYMBOL_GPL(tpm_get_random);
1146 * tpm_seal_trusted() - seal a trusted key
1147 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1148 * @options: authentication values and other options
1149 * @payload: the key data in clear and encrypted form
1151 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1154 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1155 struct trusted_key_options *options)
1157 struct tpm_chip *chip;
1160 chip = tpm_chip_find_get(chip_num);
1161 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1164 rc = tpm2_seal_trusted(chip, payload, options);
1169 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1172 * tpm_unseal_trusted() - unseal a trusted key
1173 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1174 * @options: authentication values and other options
1175 * @payload: the key data in clear and encrypted form
1177 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1180 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1181 struct trusted_key_options *options)
1183 struct tpm_chip *chip;
1186 chip = tpm_chip_find_get(chip_num);
1187 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1190 rc = tpm2_unseal_trusted(chip, payload, options);
1196 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1198 static int __init tpm_init(void)
1202 tpm_class = class_create(THIS_MODULE, "tpm");
1203 if (IS_ERR(tpm_class)) {
1204 pr_err("couldn't create tpm class\n");
1205 return PTR_ERR(tpm_class);
1208 rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1210 pr_err("tpm: failed to allocate char dev region\n");
1211 class_destroy(tpm_class);
1218 static void __exit tpm_exit(void)
1220 idr_destroy(&dev_nums_idr);
1221 class_destroy(tpm_class);
1222 unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1225 subsys_initcall(tpm_init);
1226 module_exit(tpm_exit);
1228 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1229 MODULE_DESCRIPTION("TPM Driver");
1230 MODULE_VERSION("2.0");
1231 MODULE_LICENSE("GPL");