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;
313 u8 category = (ordinal >> 24) & 0xFF;
315 if ((category == TPM_PROTECTED_COMMAND && ordinal < TPM_MAX_ORDINAL) ||
316 (category == TPM_CONNECTION_COMMAND && ordinal < TSC_MAX_ORDINAL))
317 duration_idx = tpm_ordinal_duration[ordinal];
319 if (duration_idx != TPM_UNDEFINED)
320 duration = chip->vendor.duration[duration_idx];
326 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
329 * Internal kernel interface to transmit TPM commands
331 ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
338 if (bufsiz > TPM_BUFSIZE)
339 bufsiz = TPM_BUFSIZE;
341 count = be32_to_cpu(*((__be32 *) (buf + 2)));
342 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
345 if (count > bufsiz) {
347 "invalid count value %x %zx\n", count, bufsiz);
351 mutex_lock(&chip->tpm_mutex);
353 rc = chip->ops->send(chip, (u8 *) buf, count);
356 "tpm_transmit: tpm_send: error %zd\n", rc);
360 if (chip->vendor.irq)
363 if (chip->flags & TPM_CHIP_FLAG_TPM2)
364 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
366 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
368 u8 status = chip->ops->status(chip);
369 if ((status & chip->ops->req_complete_mask) ==
370 chip->ops->req_complete_val)
373 if (chip->ops->req_canceled(chip, status)) {
374 dev_err(chip->pdev, "Operation Canceled\n");
379 msleep(TPM_TIMEOUT); /* CHECK */
381 } while (time_before(jiffies, stop));
383 chip->ops->cancel(chip);
384 dev_err(chip->pdev, "Operation Timed out\n");
389 rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
392 "tpm_transmit: tpm_recv: error %zd\n", rc);
394 mutex_unlock(&chip->tpm_mutex);
398 #define TPM_DIGEST_SIZE 20
399 #define TPM_RET_CODE_IDX 6
401 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd,
402 int len, const char *desc)
404 struct tpm_output_header *header;
407 len = tpm_transmit(chip, (u8 *) cmd, len);
410 else if (len < TPM_HEADER_SIZE)
415 err = be32_to_cpu(header->return_code);
416 if (err != 0 && desc)
417 dev_err(chip->pdev, "A TPM error (%d) occurred %s\n", err,
423 #define TPM_INTERNAL_RESULT_SIZE 200
424 #define TPM_ORD_GET_CAP cpu_to_be32(101)
425 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
427 static const struct tpm_input_header tpm_getcap_header = {
428 .tag = TPM_TAG_RQU_COMMAND,
429 .length = cpu_to_be32(22),
430 .ordinal = TPM_ORD_GET_CAP
433 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
436 struct tpm_cmd_t tpm_cmd;
438 struct tpm_chip *chip = dev_get_drvdata(dev);
440 tpm_cmd.header.in = tpm_getcap_header;
441 if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
442 tpm_cmd.params.getcap_in.cap = subcap_id;
443 /*subcap field not necessary */
444 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
445 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
447 if (subcap_id == TPM_CAP_FLAG_PERM ||
448 subcap_id == TPM_CAP_FLAG_VOL)
449 tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
451 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
452 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
453 tpm_cmd.params.getcap_in.subcap = subcap_id;
455 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
457 *cap = tpm_cmd.params.getcap_out.cap;
461 void tpm_gen_interrupt(struct tpm_chip *chip)
463 struct tpm_cmd_t tpm_cmd;
466 tpm_cmd.header.in = tpm_getcap_header;
467 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
468 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
469 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
471 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
472 "attempting to determine the timeouts");
474 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
476 #define TPM_ORD_STARTUP cpu_to_be32(153)
477 #define TPM_ST_CLEAR cpu_to_be16(1)
478 #define TPM_ST_STATE cpu_to_be16(2)
479 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
480 static const struct tpm_input_header tpm_startup_header = {
481 .tag = TPM_TAG_RQU_COMMAND,
482 .length = cpu_to_be32(12),
483 .ordinal = TPM_ORD_STARTUP
486 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
488 struct tpm_cmd_t start_cmd;
489 start_cmd.header.in = tpm_startup_header;
491 start_cmd.params.startup_in.startup_type = startup_type;
492 return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
493 "attempting to start the TPM");
496 int tpm_get_timeouts(struct tpm_chip *chip)
498 struct tpm_cmd_t tpm_cmd;
499 unsigned long new_timeout[4];
500 unsigned long old_timeout[4];
501 struct duration_t *duration_cap;
504 tpm_cmd.header.in = tpm_getcap_header;
505 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
506 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
507 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
508 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
510 if (rc == TPM_ERR_INVALID_POSTINIT) {
511 /* The TPM is not started, we are the first to talk to it.
512 Execute a startup command. */
513 dev_info(chip->pdev, "Issuing TPM_STARTUP");
514 if (tpm_startup(chip, TPM_ST_CLEAR))
517 tpm_cmd.header.in = tpm_getcap_header;
518 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
519 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
520 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
521 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
526 "A TPM error (%zd) occurred attempting to determine the timeouts\n",
531 if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
532 be32_to_cpu(tpm_cmd.header.out.length)
533 != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
536 old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
537 old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
538 old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
539 old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
540 memcpy(new_timeout, old_timeout, sizeof(new_timeout));
543 * Provide ability for vendor overrides of timeout values in case
546 if (chip->ops->update_timeouts != NULL)
547 chip->vendor.timeout_adjusted =
548 chip->ops->update_timeouts(chip, new_timeout);
550 if (!chip->vendor.timeout_adjusted) {
551 /* Don't overwrite default if value is 0 */
552 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
555 /* timeouts in msec rather usec */
556 for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
557 new_timeout[i] *= 1000;
558 chip->vendor.timeout_adjusted = true;
562 /* Report adjusted timeouts */
563 if (chip->vendor.timeout_adjusted) {
565 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
566 old_timeout[0], new_timeout[0],
567 old_timeout[1], new_timeout[1],
568 old_timeout[2], new_timeout[2],
569 old_timeout[3], new_timeout[3]);
572 chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
573 chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
574 chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
575 chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
578 tpm_cmd.header.in = tpm_getcap_header;
579 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
580 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
581 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
583 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
584 "attempting to determine the durations");
588 if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
589 be32_to_cpu(tpm_cmd.header.out.length)
590 != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
593 duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
594 chip->vendor.duration[TPM_SHORT] =
595 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
596 chip->vendor.duration[TPM_MEDIUM] =
597 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
598 chip->vendor.duration[TPM_LONG] =
599 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
601 /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
602 * value wrong and apparently reports msecs rather than usecs. So we
603 * fix up the resulting too-small TPM_SHORT value to make things work.
604 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
606 if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
607 chip->vendor.duration[TPM_SHORT] = HZ;
608 chip->vendor.duration[TPM_MEDIUM] *= 1000;
609 chip->vendor.duration[TPM_LONG] *= 1000;
610 chip->vendor.duration_adjusted = true;
611 dev_info(chip->pdev, "Adjusting TPM timeout parameters.");
615 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
617 #define TPM_ORD_CONTINUE_SELFTEST 83
618 #define CONTINUE_SELFTEST_RESULT_SIZE 10
620 static struct tpm_input_header continue_selftest_header = {
621 .tag = TPM_TAG_RQU_COMMAND,
622 .length = cpu_to_be32(10),
623 .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
627 * tpm_continue_selftest -- run TPM's selftest
628 * @chip: TPM chip to use
630 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
633 static int tpm_continue_selftest(struct tpm_chip *chip)
636 struct tpm_cmd_t cmd;
638 cmd.header.in = continue_selftest_header;
639 rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
640 "continue selftest");
644 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
645 #define READ_PCR_RESULT_SIZE 30
646 static struct tpm_input_header pcrread_header = {
647 .tag = TPM_TAG_RQU_COMMAND,
648 .length = cpu_to_be32(14),
649 .ordinal = TPM_ORDINAL_PCRREAD
652 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
655 struct tpm_cmd_t cmd;
657 cmd.header.in = pcrread_header;
658 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
659 rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
660 "attempting to read a pcr value");
663 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
669 * tpm_is_tpm2 - is the chip a TPM2 chip?
670 * @chip_num: tpm idx # or ANY
672 * Returns < 0 on error, and 1 or 0 on success depending whether the chip
675 int tpm_is_tpm2(u32 chip_num)
677 struct tpm_chip *chip;
680 chip = tpm_chip_find_get(chip_num);
684 rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
690 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
693 * tpm_pcr_read - read a pcr value
694 * @chip_num: tpm idx # or ANY
695 * @pcr_idx: pcr idx to retrieve
696 * @res_buf: TPM_PCR value
697 * size of res_buf is 20 bytes (or NULL if you don't care)
699 * The TPM driver should be built-in, but for whatever reason it
700 * isn't, protect against the chip disappearing, by incrementing
701 * the module usage count.
703 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
705 struct tpm_chip *chip;
708 chip = tpm_chip_find_get(chip_num);
711 if (chip->flags & TPM_CHIP_FLAG_TPM2)
712 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
714 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
718 EXPORT_SYMBOL_GPL(tpm_pcr_read);
721 * tpm_pcr_extend - extend pcr value with hash
722 * @chip_num: tpm idx # or AN&
723 * @pcr_idx: pcr idx to extend
724 * @hash: hash value used to extend pcr value
726 * The TPM driver should be built-in, but for whatever reason it
727 * isn't, protect against the chip disappearing, by incrementing
728 * the module usage count.
730 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
731 #define EXTEND_PCR_RESULT_SIZE 34
732 static struct tpm_input_header pcrextend_header = {
733 .tag = TPM_TAG_RQU_COMMAND,
734 .length = cpu_to_be32(34),
735 .ordinal = TPM_ORD_PCR_EXTEND
738 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
740 struct tpm_cmd_t cmd;
742 struct tpm_chip *chip;
744 chip = tpm_chip_find_get(chip_num);
748 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
749 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
754 cmd.header.in = pcrextend_header;
755 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
756 memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
757 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
758 "attempting extend a PCR value");
763 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
766 * tpm_do_selftest - have the TPM continue its selftest and wait until it
767 * can receive further commands
768 * @chip: TPM chip to use
770 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
773 int tpm_do_selftest(struct tpm_chip *chip)
777 unsigned int delay_msec = 100;
778 unsigned long duration;
779 struct tpm_cmd_t cmd;
781 duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
783 loops = jiffies_to_msecs(duration) / delay_msec;
785 rc = tpm_continue_selftest(chip);
786 /* This may fail if there was no TPM driver during a suspend/resume
787 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
793 /* Attempt to read a PCR value */
794 cmd.header.in = pcrread_header;
795 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
796 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
797 /* Some buggy TPMs will not respond to tpm_tis_ready() for
798 * around 300ms while the self test is ongoing, keep trying
799 * until the self test duration expires. */
801 dev_info(chip->pdev, HW_ERR "TPM command timed out during continue self test");
806 if (rc < TPM_HEADER_SIZE)
809 rc = be32_to_cpu(cmd.header.out.return_code);
810 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
812 "TPM is disabled/deactivated (0x%X)\n", rc);
813 /* TPM is disabled and/or deactivated; driver can
814 * proceed and TPM does handle commands for
815 * suspend/resume correctly
819 if (rc != TPM_WARN_DOING_SELFTEST)
822 } while (--loops > 0);
826 EXPORT_SYMBOL_GPL(tpm_do_selftest);
828 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
830 struct tpm_chip *chip;
833 chip = tpm_chip_find_get(chip_num);
837 rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
842 EXPORT_SYMBOL_GPL(tpm_send);
844 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
845 bool check_cancel, bool *canceled)
847 u8 status = chip->ops->status(chip);
850 if ((status & mask) == mask)
852 if (check_cancel && chip->ops->req_canceled(chip, status)) {
859 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
860 wait_queue_head_t *queue, bool check_cancel)
865 bool canceled = false;
867 /* check current status */
868 status = chip->ops->status(chip);
869 if ((status & mask) == mask)
872 stop = jiffies + timeout;
874 if (chip->vendor.irq) {
876 timeout = stop - jiffies;
877 if ((long)timeout <= 0)
879 rc = wait_event_interruptible_timeout(*queue,
880 wait_for_tpm_stat_cond(chip, mask, check_cancel,
888 if (rc == -ERESTARTSYS && freezing(current)) {
889 clear_thread_flag(TIF_SIGPENDING);
895 status = chip->ops->status(chip);
896 if ((status & mask) == mask)
898 } while (time_before(jiffies, stop));
902 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
904 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
905 #define SAVESTATE_RESULT_SIZE 10
907 static struct tpm_input_header savestate_header = {
908 .tag = TPM_TAG_RQU_COMMAND,
909 .length = cpu_to_be32(10),
910 .ordinal = TPM_ORD_SAVESTATE
914 * We are about to suspend. Save the TPM state
915 * so that it can be restored.
917 int tpm_pm_suspend(struct device *dev)
919 struct tpm_chip *chip = dev_get_drvdata(dev);
920 struct tpm_cmd_t cmd;
923 u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
928 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
929 tpm2_shutdown(chip, TPM2_SU_STATE);
933 /* for buggy tpm, flush pcrs with extend to selected dummy */
934 if (tpm_suspend_pcr) {
935 cmd.header.in = pcrextend_header;
936 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
937 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
939 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
940 "extending dummy pcr before suspend");
943 /* now do the actual savestate */
944 for (try = 0; try < TPM_RETRY; try++) {
945 cmd.header.in = savestate_header;
946 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
949 * If the TPM indicates that it is too busy to respond to
950 * this command then retry before giving up. It can take
951 * several seconds for this TPM to be ready.
953 * This can happen if the TPM has already been sent the
954 * SaveState command before the driver has loaded. TCG 1.2
955 * specification states that any communication after SaveState
956 * may cause the TPM to invalidate previously saved state.
958 if (rc != TPM_WARN_RETRY)
960 msleep(TPM_TIMEOUT_RETRY);
965 "Error (%d) sending savestate before suspend\n", rc);
967 dev_warn(chip->pdev, "TPM savestate took %dms\n",
968 try * TPM_TIMEOUT_RETRY);
972 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
975 * Resume from a power safe. The BIOS already restored
978 int tpm_pm_resume(struct device *dev)
980 struct tpm_chip *chip = dev_get_drvdata(dev);
987 EXPORT_SYMBOL_GPL(tpm_pm_resume);
989 #define TPM_GETRANDOM_RESULT_SIZE 18
990 static struct tpm_input_header tpm_getrandom_header = {
991 .tag = TPM_TAG_RQU_COMMAND,
992 .length = cpu_to_be32(14),
993 .ordinal = TPM_ORD_GET_RANDOM
997 * tpm_get_random() - Get random bytes from the tpm's RNG
998 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
999 * @out: destination buffer for the random bytes
1000 * @max: the max number of bytes to write to @out
1002 * Returns < 0 on error and the number of bytes read on success
1004 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1006 struct tpm_chip *chip;
1007 struct tpm_cmd_t tpm_cmd;
1008 u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1009 int err, total = 0, retries = 5;
1012 if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1015 chip = tpm_chip_find_get(chip_num);
1019 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1020 err = tpm2_get_random(chip, out, max);
1026 tpm_cmd.header.in = tpm_getrandom_header;
1027 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1029 err = tpm_transmit_cmd(chip, &tpm_cmd,
1030 TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1031 "attempting get random");
1035 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1036 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1041 } while (retries-- && total < max);
1044 return total ? total : -EIO;
1046 EXPORT_SYMBOL_GPL(tpm_get_random);
1049 * tpm_seal_trusted() - seal a trusted key
1050 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1051 * @options: authentication values and other options
1052 * @payload: the key data in clear and encrypted form
1054 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1057 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1058 struct trusted_key_options *options)
1060 struct tpm_chip *chip;
1063 chip = tpm_chip_find_get(chip_num);
1064 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1067 rc = tpm2_seal_trusted(chip, payload, options);
1072 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1075 * tpm_unseal_trusted() - unseal a trusted key
1076 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1077 * @options: authentication values and other options
1078 * @payload: the key data in clear and encrypted form
1080 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1083 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1084 struct trusted_key_options *options)
1086 struct tpm_chip *chip;
1089 chip = tpm_chip_find_get(chip_num);
1090 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1093 rc = tpm2_unseal_trusted(chip, payload, options);
1098 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1100 static int __init tpm_init(void)
1104 tpm_class = class_create(THIS_MODULE, "tpm");
1105 if (IS_ERR(tpm_class)) {
1106 pr_err("couldn't create tpm class\n");
1107 return PTR_ERR(tpm_class);
1110 rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1112 pr_err("tpm: failed to allocate char dev region\n");
1113 class_destroy(tpm_class);
1120 static void __exit tpm_exit(void)
1122 class_destroy(tpm_class);
1123 unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1126 subsys_initcall(tpm_init);
1127 module_exit(tpm_exit);
1129 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1130 MODULE_DESCRIPTION("TPM Driver");
1131 MODULE_VERSION("2.0");
1132 MODULE_LICENSE("GPL");