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_HEADER_SIZE)
343 if (bufsiz > TPM_BUFSIZE)
344 bufsiz = TPM_BUFSIZE;
346 count = be32_to_cpu(*((__be32 *) (buf + 2)));
347 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
350 if (count > bufsiz) {
352 "invalid count value %x %zx\n", count, bufsiz);
356 if (!(flags & TPM_TRANSMIT_UNLOCKED))
357 mutex_lock(&chip->tpm_mutex);
359 rc = chip->ops->send(chip, (u8 *) buf, count);
362 "tpm_transmit: tpm_send: error %zd\n", rc);
366 if (chip->flags & TPM_CHIP_FLAG_IRQ)
369 if (chip->flags & TPM_CHIP_FLAG_TPM2)
370 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
372 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
374 u8 status = chip->ops->status(chip);
375 if ((status & chip->ops->req_complete_mask) ==
376 chip->ops->req_complete_val)
379 if (chip->ops->req_canceled(chip, status)) {
380 dev_err(&chip->dev, "Operation Canceled\n");
385 msleep(TPM_TIMEOUT); /* CHECK */
387 } while (time_before(jiffies, stop));
389 chip->ops->cancel(chip);
390 dev_err(&chip->dev, "Operation Timed out\n");
395 rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
398 "tpm_transmit: tpm_recv: error %zd\n", rc);
400 if (!(flags & TPM_TRANSMIT_UNLOCKED))
401 mutex_unlock(&chip->tpm_mutex);
405 #define TPM_DIGEST_SIZE 20
406 #define TPM_RET_CODE_IDX 6
408 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,
409 int len, unsigned int flags, const char *desc)
411 const struct tpm_output_header *header;
414 len = tpm_transmit(chip, (const u8 *)cmd, len, flags);
417 else if (len < TPM_HEADER_SIZE)
422 err = be32_to_cpu(header->return_code);
423 if (err != 0 && desc)
424 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
430 #define TPM_INTERNAL_RESULT_SIZE 200
431 #define TPM_ORD_GET_CAP cpu_to_be32(101)
432 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
434 static const struct tpm_input_header tpm_getcap_header = {
435 .tag = TPM_TAG_RQU_COMMAND,
436 .length = cpu_to_be32(22),
437 .ordinal = TPM_ORD_GET_CAP
440 ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap,
443 struct tpm_cmd_t tpm_cmd;
446 tpm_cmd.header.in = tpm_getcap_header;
447 if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
448 tpm_cmd.params.getcap_in.cap = subcap_id;
449 /*subcap field not necessary */
450 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
451 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
453 if (subcap_id == TPM_CAP_FLAG_PERM ||
454 subcap_id == TPM_CAP_FLAG_VOL)
455 tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
457 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
458 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
459 tpm_cmd.params.getcap_in.subcap = subcap_id;
461 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
464 *cap = tpm_cmd.params.getcap_out.cap;
467 EXPORT_SYMBOL_GPL(tpm_getcap);
469 #define TPM_ORD_STARTUP cpu_to_be32(153)
470 #define TPM_ST_CLEAR cpu_to_be16(1)
471 #define TPM_ST_STATE cpu_to_be16(2)
472 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
473 static const struct tpm_input_header tpm_startup_header = {
474 .tag = TPM_TAG_RQU_COMMAND,
475 .length = cpu_to_be32(12),
476 .ordinal = TPM_ORD_STARTUP
479 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
481 struct tpm_cmd_t start_cmd;
482 start_cmd.header.in = tpm_startup_header;
484 start_cmd.params.startup_in.startup_type = startup_type;
485 return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
486 "attempting to start the TPM");
489 int tpm_get_timeouts(struct tpm_chip *chip)
491 struct tpm_cmd_t tpm_cmd;
492 unsigned long new_timeout[4];
493 unsigned long old_timeout[4];
494 struct duration_t *duration_cap;
497 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
498 /* Fixed timeouts for TPM2 */
499 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
500 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
501 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
502 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
503 chip->duration[TPM_SHORT] =
504 msecs_to_jiffies(TPM2_DURATION_SHORT);
505 chip->duration[TPM_MEDIUM] =
506 msecs_to_jiffies(TPM2_DURATION_MEDIUM);
507 chip->duration[TPM_LONG] =
508 msecs_to_jiffies(TPM2_DURATION_LONG);
512 tpm_cmd.header.in = tpm_getcap_header;
513 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
514 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
515 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
516 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
519 if (rc == TPM_ERR_INVALID_POSTINIT) {
520 /* The TPM is not started, we are the first to talk to it.
521 Execute a startup command. */
522 dev_info(&chip->dev, "Issuing TPM_STARTUP");
523 if (tpm_startup(chip, TPM_ST_CLEAR))
526 tpm_cmd.header.in = tpm_getcap_header;
527 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
528 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
529 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
530 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
535 "A TPM error (%zd) occurred attempting to determine the timeouts\n",
540 if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
541 be32_to_cpu(tpm_cmd.header.out.length)
542 != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
545 old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
546 old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
547 old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
548 old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
549 memcpy(new_timeout, old_timeout, sizeof(new_timeout));
552 * Provide ability for vendor overrides of timeout values in case
555 if (chip->ops->update_timeouts != NULL)
556 chip->timeout_adjusted =
557 chip->ops->update_timeouts(chip, new_timeout);
559 if (!chip->timeout_adjusted) {
560 /* Don't overwrite default if value is 0 */
561 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
564 /* timeouts in msec rather usec */
565 for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
566 new_timeout[i] *= 1000;
567 chip->timeout_adjusted = true;
571 /* Report adjusted timeouts */
572 if (chip->timeout_adjusted) {
574 HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
575 old_timeout[0], new_timeout[0],
576 old_timeout[1], new_timeout[1],
577 old_timeout[2], new_timeout[2],
578 old_timeout[3], new_timeout[3]);
581 chip->timeout_a = usecs_to_jiffies(new_timeout[0]);
582 chip->timeout_b = usecs_to_jiffies(new_timeout[1]);
583 chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
584 chip->timeout_d = usecs_to_jiffies(new_timeout[3]);
587 tpm_cmd.header.in = tpm_getcap_header;
588 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
589 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
590 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
592 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
593 "attempting to determine the durations");
597 if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
598 be32_to_cpu(tpm_cmd.header.out.length)
599 != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
602 duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
603 chip->duration[TPM_SHORT] =
604 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
605 chip->duration[TPM_MEDIUM] =
606 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
607 chip->duration[TPM_LONG] =
608 usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
610 /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
611 * value wrong and apparently reports msecs rather than usecs. So we
612 * fix up the resulting too-small TPM_SHORT value to make things work.
613 * We also scale the TPM_MEDIUM and -_LONG values by 1000.
615 if (chip->duration[TPM_SHORT] < (HZ / 100)) {
616 chip->duration[TPM_SHORT] = HZ;
617 chip->duration[TPM_MEDIUM] *= 1000;
618 chip->duration[TPM_LONG] *= 1000;
619 chip->duration_adjusted = true;
620 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
624 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
626 #define TPM_ORD_CONTINUE_SELFTEST 83
627 #define CONTINUE_SELFTEST_RESULT_SIZE 10
629 static const struct tpm_input_header continue_selftest_header = {
630 .tag = TPM_TAG_RQU_COMMAND,
631 .length = cpu_to_be32(10),
632 .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
636 * tpm_continue_selftest -- run TPM's selftest
637 * @chip: TPM chip to use
639 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
642 static int tpm_continue_selftest(struct tpm_chip *chip)
645 struct tpm_cmd_t cmd;
647 cmd.header.in = continue_selftest_header;
648 rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
649 "continue selftest");
653 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
654 #define READ_PCR_RESULT_SIZE 30
655 static const struct tpm_input_header pcrread_header = {
656 .tag = TPM_TAG_RQU_COMMAND,
657 .length = cpu_to_be32(14),
658 .ordinal = TPM_ORDINAL_PCRREAD
661 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
664 struct tpm_cmd_t cmd;
666 cmd.header.in = pcrread_header;
667 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
668 rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
669 "attempting to read a pcr value");
672 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
678 * tpm_is_tpm2 - is the chip a TPM2 chip?
679 * @chip_num: tpm idx # or ANY
681 * Returns < 0 on error, and 1 or 0 on success depending whether the chip
684 int tpm_is_tpm2(u32 chip_num)
686 struct tpm_chip *chip;
689 chip = tpm_chip_find_get(chip_num);
693 rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
699 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
702 * tpm_pcr_read - read a pcr value
703 * @chip_num: tpm idx # or ANY
704 * @pcr_idx: pcr idx to retrieve
705 * @res_buf: TPM_PCR value
706 * size of res_buf is 20 bytes (or NULL if you don't care)
708 * The TPM driver should be built-in, but for whatever reason it
709 * isn't, protect against the chip disappearing, by incrementing
710 * the module usage count.
712 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
714 struct tpm_chip *chip;
717 chip = tpm_chip_find_get(chip_num);
720 if (chip->flags & TPM_CHIP_FLAG_TPM2)
721 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
723 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
727 EXPORT_SYMBOL_GPL(tpm_pcr_read);
730 * tpm_pcr_extend - extend pcr value with hash
731 * @chip_num: tpm idx # or AN&
732 * @pcr_idx: pcr idx to extend
733 * @hash: hash value used to extend pcr value
735 * The TPM driver should be built-in, but for whatever reason it
736 * isn't, protect against the chip disappearing, by incrementing
737 * the module usage count.
739 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
740 #define EXTEND_PCR_RESULT_SIZE 34
741 static const struct tpm_input_header pcrextend_header = {
742 .tag = TPM_TAG_RQU_COMMAND,
743 .length = cpu_to_be32(34),
744 .ordinal = TPM_ORD_PCR_EXTEND
747 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
749 struct tpm_cmd_t cmd;
751 struct tpm_chip *chip;
753 chip = tpm_chip_find_get(chip_num);
757 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
758 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
763 cmd.header.in = pcrextend_header;
764 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
765 memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
766 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
767 "attempting extend a PCR value");
772 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
775 * tpm_do_selftest - have the TPM continue its selftest and wait until it
776 * can receive further commands
777 * @chip: TPM chip to use
779 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
782 int tpm_do_selftest(struct tpm_chip *chip)
786 unsigned int delay_msec = 100;
787 unsigned long duration;
788 u8 dummy[TPM_DIGEST_SIZE];
790 duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
792 loops = jiffies_to_msecs(duration) / delay_msec;
794 rc = tpm_continue_selftest(chip);
795 /* This may fail if there was no TPM driver during a suspend/resume
796 * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
802 /* Attempt to read a PCR value */
803 rc = tpm_pcr_read_dev(chip, 0, dummy);
805 /* Some buggy TPMs will not respond to tpm_tis_ready() for
806 * around 300ms while the self test is ongoing, keep trying
807 * until the self test duration expires. */
811 "TPM command timed out during continue self test");
816 if (rc < TPM_HEADER_SIZE)
819 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
821 "TPM is disabled/deactivated (0x%X)\n", rc);
822 /* TPM is disabled and/or deactivated; driver can
823 * proceed and TPM does handle commands for
824 * suspend/resume correctly
828 if (rc != TPM_WARN_DOING_SELFTEST)
831 } while (--loops > 0);
835 EXPORT_SYMBOL_GPL(tpm_do_selftest);
838 * tpm1_auto_startup - Perform the standard automatic TPM initialization
840 * @chip: TPM chip to use
842 * Returns 0 on success, < 0 in case of fatal error.
844 int tpm1_auto_startup(struct tpm_chip *chip)
848 rc = tpm_get_timeouts(chip);
851 rc = tpm_do_selftest(chip);
853 dev_err(&chip->dev, "TPM self test failed\n");
864 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
866 struct tpm_chip *chip;
869 chip = tpm_chip_find_get(chip_num);
873 rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
878 EXPORT_SYMBOL_GPL(tpm_send);
880 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
881 bool check_cancel, bool *canceled)
883 u8 status = chip->ops->status(chip);
886 if ((status & mask) == mask)
888 if (check_cancel && chip->ops->req_canceled(chip, status)) {
895 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
896 wait_queue_head_t *queue, bool check_cancel)
901 bool canceled = false;
903 /* check current status */
904 status = chip->ops->status(chip);
905 if ((status & mask) == mask)
908 stop = jiffies + timeout;
910 if (chip->flags & TPM_CHIP_FLAG_IRQ) {
912 timeout = stop - jiffies;
913 if ((long)timeout <= 0)
915 rc = wait_event_interruptible_timeout(*queue,
916 wait_for_tpm_stat_cond(chip, mask, check_cancel,
924 if (rc == -ERESTARTSYS && freezing(current)) {
925 clear_thread_flag(TIF_SIGPENDING);
931 status = chip->ops->status(chip);
932 if ((status & mask) == mask)
934 } while (time_before(jiffies, stop));
938 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
940 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
941 #define SAVESTATE_RESULT_SIZE 10
943 static const struct tpm_input_header savestate_header = {
944 .tag = TPM_TAG_RQU_COMMAND,
945 .length = cpu_to_be32(10),
946 .ordinal = TPM_ORD_SAVESTATE
950 * We are about to suspend. Save the TPM state
951 * so that it can be restored.
953 int tpm_pm_suspend(struct device *dev)
955 struct tpm_chip *chip = dev_get_drvdata(dev);
956 struct tpm_cmd_t cmd;
959 u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
964 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
965 tpm2_shutdown(chip, TPM2_SU_STATE);
969 /* for buggy tpm, flush pcrs with extend to selected dummy */
970 if (tpm_suspend_pcr) {
971 cmd.header.in = pcrextend_header;
972 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
973 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
975 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
976 "extending dummy pcr before suspend");
979 /* now do the actual savestate */
980 for (try = 0; try < TPM_RETRY; try++) {
981 cmd.header.in = savestate_header;
982 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
986 * If the TPM indicates that it is too busy to respond to
987 * this command then retry before giving up. It can take
988 * several seconds for this TPM to be ready.
990 * This can happen if the TPM has already been sent the
991 * SaveState command before the driver has loaded. TCG 1.2
992 * specification states that any communication after SaveState
993 * may cause the TPM to invalidate previously saved state.
995 if (rc != TPM_WARN_RETRY)
997 msleep(TPM_TIMEOUT_RETRY);
1002 "Error (%d) sending savestate before suspend\n", rc);
1004 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1005 try * TPM_TIMEOUT_RETRY);
1009 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1012 * Resume from a power safe. The BIOS already restored
1015 int tpm_pm_resume(struct device *dev)
1017 struct tpm_chip *chip = dev_get_drvdata(dev);
1024 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1026 #define TPM_GETRANDOM_RESULT_SIZE 18
1027 static const struct tpm_input_header tpm_getrandom_header = {
1028 .tag = TPM_TAG_RQU_COMMAND,
1029 .length = cpu_to_be32(14),
1030 .ordinal = TPM_ORD_GET_RANDOM
1034 * tpm_get_random() - Get random bytes from the tpm's RNG
1035 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1036 * @out: destination buffer for the random bytes
1037 * @max: the max number of bytes to write to @out
1039 * Returns < 0 on error and the number of bytes read on success
1041 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1043 struct tpm_chip *chip;
1044 struct tpm_cmd_t tpm_cmd;
1045 u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1046 int err, total = 0, retries = 5;
1049 if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1052 chip = tpm_chip_find_get(chip_num);
1056 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1057 err = tpm2_get_random(chip, out, max);
1063 tpm_cmd.header.in = tpm_getrandom_header;
1064 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1066 err = tpm_transmit_cmd(chip, &tpm_cmd,
1067 TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1068 0, "attempting get random");
1072 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1073 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1078 } while (retries-- && total < max);
1081 return total ? total : -EIO;
1083 EXPORT_SYMBOL_GPL(tpm_get_random);
1086 * tpm_seal_trusted() - seal a trusted key
1087 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1088 * @options: authentication values and other options
1089 * @payload: the key data in clear and encrypted form
1091 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1094 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1095 struct trusted_key_options *options)
1097 struct tpm_chip *chip;
1100 chip = tpm_chip_find_get(chip_num);
1101 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1104 rc = tpm2_seal_trusted(chip, payload, options);
1109 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1112 * tpm_unseal_trusted() - unseal a trusted key
1113 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1114 * @options: authentication values and other options
1115 * @payload: the key data in clear and encrypted form
1117 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1120 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1121 struct trusted_key_options *options)
1123 struct tpm_chip *chip;
1126 chip = tpm_chip_find_get(chip_num);
1127 if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1130 rc = tpm2_unseal_trusted(chip, payload, options);
1136 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1138 static int __init tpm_init(void)
1142 tpm_class = class_create(THIS_MODULE, "tpm");
1143 if (IS_ERR(tpm_class)) {
1144 pr_err("couldn't create tpm class\n");
1145 return PTR_ERR(tpm_class);
1148 rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1150 pr_err("tpm: failed to allocate char dev region\n");
1151 class_destroy(tpm_class);
1158 static void __exit tpm_exit(void)
1160 idr_destroy(&dev_nums_idr);
1161 class_destroy(tpm_class);
1162 unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1165 subsys_initcall(tpm_init);
1166 module_exit(tpm_exit);
1168 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1169 MODULE_DESCRIPTION("TPM Driver");
1170 MODULE_VERSION("2.0");
1171 MODULE_LICENSE("GPL");