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/tpm_eventlog.h>
37 * Bug workaround - some TPM's don't flush the most
38 * recently changed pcr on suspend, so force the flush
39 * with an extend to the selected _unused_ non-volatile pcr.
41 static u32 tpm_suspend_pcr;
42 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
43 MODULE_PARM_DESC(suspend_pcr,
44 "PCR to use for dummy writes to facilitate flush on suspend.");
47 * tpm_calc_ordinal_duration() - calculate the maximum command duration
48 * @chip: TPM chip to use.
49 * @ordinal: TPM command ordinal.
51 * The function returns the maximum amount of time the chip could take
52 * to return the result for a particular ordinal in jiffies.
54 * Return: A maximal duration time for an ordinal in jiffies.
56 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
58 if (chip->flags & TPM_CHIP_FLAG_TPM2)
59 return tpm2_calc_ordinal_duration(chip, ordinal);
61 return tpm1_calc_ordinal_duration(chip, ordinal);
63 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
65 static int tpm_validate_command(struct tpm_chip *chip, struct tpm_space *space,
66 const void *cmd, size_t len)
68 const struct tpm_header *header = cmd;
72 unsigned int nr_handles;
74 if (len < TPM_HEADER_SIZE)
80 if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
81 cc = be32_to_cpu(header->ordinal);
83 i = tpm2_find_cc(chip, cc);
85 dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
90 attrs = chip->cc_attrs_tbl[i];
92 4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
93 if (len < TPM_HEADER_SIZE + 4 * nr_handles)
100 "%s: insufficient command length %zu", __func__, len);
104 static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
108 if (flags & TPM_TRANSMIT_NESTED)
111 if (!chip->ops->request_locality)
114 rc = chip->ops->request_locality(chip, 0);
123 static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
127 if (flags & TPM_TRANSMIT_NESTED)
130 if (!chip->ops->relinquish_locality)
133 rc = chip->ops->relinquish_locality(chip, chip->locality);
135 dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
140 static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
142 if (flags & TPM_TRANSMIT_NESTED)
145 if (!chip->ops->cmd_ready)
148 return chip->ops->cmd_ready(chip);
151 static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
153 if (flags & TPM_TRANSMIT_NESTED)
156 if (!chip->ops->go_idle)
159 return chip->ops->go_idle(chip);
162 static ssize_t tpm_try_transmit(struct tpm_chip *chip, struct tpm_space *space,
163 void *buf, size_t bufsiz, unsigned int flags)
165 struct tpm_header *header = buf;
172 rc = tpm_validate_command(chip, space, buf, bufsiz);
176 * If the command is not implemented by the TPM, synthesize a
177 * response with a TPM2_RC_COMMAND_CODE return for user-space.
179 if (rc == -EOPNOTSUPP) {
180 header->length = cpu_to_be32(sizeof(*header));
181 header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
182 header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
183 TSS2_RESMGR_TPM_RC_LAYER);
184 return sizeof(*header);
187 if (bufsiz > TPM_BUFSIZE)
188 bufsiz = TPM_BUFSIZE;
190 count = be32_to_cpu(header->length);
191 ordinal = be32_to_cpu(header->ordinal);
194 if (count > bufsiz) {
196 "invalid count value %x %zx\n", count, bufsiz);
200 if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
201 mutex_lock(&chip->tpm_mutex);
203 if (chip->ops->clk_enable != NULL)
204 chip->ops->clk_enable(chip, true);
206 /* Store the decision as chip->locality will be changed. */
207 need_locality = chip->locality == -1;
210 rc = tpm_request_locality(chip, flags);
212 need_locality = false;
217 rc = tpm_cmd_ready(chip, flags);
221 rc = tpm2_prepare_space(chip, space, ordinal, buf);
225 rc = chip->ops->send(chip, buf, count);
229 "%s: send(): error %d\n", __func__, rc);
233 /* A sanity check. send() should just return zero on success e.g.
234 * not the command length.
238 "%s: send(): invalid value %d\n", __func__, rc);
242 if (chip->flags & TPM_CHIP_FLAG_IRQ)
245 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
247 u8 status = chip->ops->status(chip);
248 if ((status & chip->ops->req_complete_mask) ==
249 chip->ops->req_complete_val)
252 if (chip->ops->req_canceled(chip, status)) {
253 dev_err(&chip->dev, "Operation Canceled\n");
258 tpm_msleep(TPM_TIMEOUT_POLL);
260 } while (time_before(jiffies, stop));
262 chip->ops->cancel(chip);
263 dev_err(&chip->dev, "Operation Timed out\n");
268 len = chip->ops->recv(chip, buf, bufsiz);
272 "tpm_transmit: tpm_recv: error %d\n", rc);
274 } else if (len < TPM_HEADER_SIZE) {
279 if (len != be32_to_cpu(header->length)) {
284 rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
287 /* may fail but do not override previous error value in rc */
288 tpm_go_idle(chip, flags);
292 tpm_relinquish_locality(chip, flags);
294 if (chip->ops->clk_enable != NULL)
295 chip->ops->clk_enable(chip, false);
297 if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
298 mutex_unlock(&chip->tpm_mutex);
299 return rc ? rc : len;
303 * tpm_transmit - Internal kernel interface to transmit TPM commands.
304 * @chip: a TPM chip to use
305 * @space: a TPM space
306 * @buf: a TPM command buffer
307 * @bufsiz: length of the TPM command buffer
308 * @flags: TPM transmit flags
310 * A wrapper around tpm_try_transmit() that handles TPM2_RC_RETRY returns from
311 * the TPM and retransmits the command after a delay up to a maximum wait of
312 * TPM2_DURATION_LONG.
314 * Note that TPM 1.x never returns TPM2_RC_RETRY so the retry logic is TPM 2.0
318 * * The response length - OK
319 * * -errno - A system error
321 ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
322 u8 *buf, size_t bufsiz, unsigned int flags)
324 struct tpm_header *header = (struct tpm_header *)buf;
325 /* space for header and handles */
326 u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
327 unsigned int delay_msec = TPM2_DURATION_SHORT;
330 const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
332 /* the command code is where the return code will be */
333 u32 cc = be32_to_cpu(header->return_code);
336 * Subtlety here: if we have a space, the handles will be
337 * transformed, so when we restore the header we also have to
338 * restore the handles.
340 memcpy(save, buf, save_size);
343 ret = tpm_try_transmit(chip, space, buf, bufsiz, flags);
346 rc = be32_to_cpu(header->return_code);
347 if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
350 * return immediately if self test returns test
351 * still running to shorten boot time.
353 if (rc == TPM2_RC_TESTING && cc == TPM2_CC_SELF_TEST)
356 if (delay_msec > TPM2_DURATION_LONG) {
357 if (rc == TPM2_RC_RETRY)
358 dev_err(&chip->dev, "in retry loop\n");
361 "self test is still running\n");
364 tpm_msleep(delay_msec);
366 memcpy(buf, save, save_size);
372 * tpm_transmit_cmd - send a tpm command to the device
373 * @chip: a TPM chip to use
374 * @space: a TPM space
375 * @buf: a TPM command buffer
376 * @min_rsp_body_length: minimum expected length of response body
377 * @flags: TPM transmit flags
378 * @desc: command description used in the error message
382 * * -errno - A system error
383 * * TPM_RC - A TPM error
385 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
386 struct tpm_buf *buf, size_t min_rsp_body_length,
387 unsigned int flags, const char *desc)
389 const struct tpm_header *header = (struct tpm_header *)buf->data;
393 len = tpm_transmit(chip, space, buf->data, PAGE_SIZE, flags);
397 err = be32_to_cpu(header->return_code);
398 if (err != 0 && err != TPM_ERR_DISABLED && err != TPM_ERR_DEACTIVATED
399 && err != TPM2_RC_TESTING && desc)
400 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
405 if (len < min_rsp_body_length + TPM_HEADER_SIZE)
410 EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
412 int tpm_get_timeouts(struct tpm_chip *chip)
414 if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
417 if (chip->flags & TPM_CHIP_FLAG_TPM2)
418 return tpm2_get_timeouts(chip);
420 return tpm1_get_timeouts(chip);
422 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
425 * tpm_is_tpm2 - do we a have a TPM2 chip?
426 * @chip: a &struct tpm_chip instance, %NULL for the default chip
429 * 1 if we have a TPM2 chip.
430 * 0 if we don't have a TPM2 chip.
431 * A negative number for system errors (errno).
433 int tpm_is_tpm2(struct tpm_chip *chip)
437 chip = tpm_find_get_ops(chip);
441 rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
447 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
450 * tpm_pcr_read - read a PCR value from SHA1 bank
451 * @chip: a &struct tpm_chip instance, %NULL for the default chip
452 * @pcr_idx: the PCR to be retrieved
453 * @res_buf: the value of the PCR
455 * Return: same as with tpm_transmit_cmd()
457 int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
461 chip = tpm_find_get_ops(chip);
465 if (chip->flags & TPM_CHIP_FLAG_TPM2)
466 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
468 rc = tpm1_pcr_read(chip, pcr_idx, res_buf);
473 EXPORT_SYMBOL_GPL(tpm_pcr_read);
476 * tpm_pcr_extend - extend a PCR value in SHA1 bank.
477 * @chip: a &struct tpm_chip instance, %NULL for the default chip
478 * @pcr_idx: the PCR to be retrieved
479 * @hash: the hash value used to extend the PCR value
481 * Note: with TPM 2.0 extends also those banks with a known digest size to the
482 * cryto subsystem in order to prevent malicious use of those PCR banks. In the
483 * future we should dynamically determine digest sizes.
485 * Return: same as with tpm_transmit_cmd()
487 int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash)
490 struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
494 chip = tpm_find_get_ops(chip);
498 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
499 memset(digest_list, 0, sizeof(digest_list));
501 for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
502 chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
503 digest_list[i].alg_id = chip->active_banks[i];
504 memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
508 rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);
513 rc = tpm1_pcr_extend(chip, pcr_idx, hash,
514 "attempting extend a PCR value");
518 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
521 * tpm_send - send a TPM command
522 * @chip: a &struct tpm_chip instance, %NULL for the default chip
523 * @cmd: a TPM command buffer
524 * @buflen: the length of the TPM command buffer
526 * Return: same as with tpm_transmit_cmd()
528 int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
533 chip = tpm_find_get_ops(chip);
537 rc = tpm_buf_init(&buf, 0, 0);
541 memcpy(buf.data, cmd, buflen);
542 rc = tpm_transmit_cmd(chip, NULL, &buf, 0, 0,
543 "attempting to a send a command");
544 tpm_buf_destroy(&buf);
549 EXPORT_SYMBOL_GPL(tpm_send);
551 int tpm_auto_startup(struct tpm_chip *chip)
555 if (!(chip->ops->flags & TPM_OPS_AUTO_STARTUP))
558 if (chip->flags & TPM_CHIP_FLAG_TPM2)
559 rc = tpm2_auto_startup(chip);
561 rc = tpm1_auto_startup(chip);
567 * We are about to suspend. Save the TPM state
568 * so that it can be restored.
570 int tpm_pm_suspend(struct device *dev)
572 struct tpm_chip *chip = dev_get_drvdata(dev);
578 if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
581 if (chip->flags & TPM_CHIP_FLAG_TPM2)
582 tpm2_shutdown(chip, TPM2_SU_STATE);
584 rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
588 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
591 * Resume from a power safe. The BIOS already restored
594 int tpm_pm_resume(struct device *dev)
596 struct tpm_chip *chip = dev_get_drvdata(dev);
603 EXPORT_SYMBOL_GPL(tpm_pm_resume);
606 * tpm_get_random() - get random bytes from the TPM's RNG
607 * @chip: a &struct tpm_chip instance, %NULL for the default chip
608 * @out: destination buffer for the random bytes
609 * @max: the max number of bytes to write to @out
611 * Return: number of random bytes read or a negative error value.
613 int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
617 if (!out || max > TPM_MAX_RNG_DATA)
620 chip = tpm_find_get_ops(chip);
624 if (chip->flags & TPM_CHIP_FLAG_TPM2)
625 rc = tpm2_get_random(chip, out, max);
627 rc = tpm1_get_random(chip, out, max);
632 EXPORT_SYMBOL_GPL(tpm_get_random);
635 * tpm_seal_trusted() - seal a trusted key payload
636 * @chip: a &struct tpm_chip instance, %NULL for the default chip
637 * @options: authentication values and other options
638 * @payload: the key data in clear and encrypted form
640 * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
641 * the keyring subsystem.
643 * Return: same as with tpm_transmit_cmd()
645 int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload,
646 struct trusted_key_options *options)
650 chip = tpm_find_get_ops(chip);
651 if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
654 rc = tpm2_seal_trusted(chip, payload, options);
659 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
662 * tpm_unseal_trusted() - unseal a trusted key
663 * @chip: a &struct tpm_chip instance, %NULL for the default chip
664 * @options: authentication values and other options
665 * @payload: the key data in clear and encrypted form
667 * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
668 * the keyring subsystem.
670 * Return: same as with tpm_transmit_cmd()
672 int tpm_unseal_trusted(struct tpm_chip *chip,
673 struct trusted_key_payload *payload,
674 struct trusted_key_options *options)
678 chip = tpm_find_get_ops(chip);
679 if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
682 rc = tpm2_unseal_trusted(chip, payload, options);
688 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
690 static int __init tpm_init(void)
694 tpm_class = class_create(THIS_MODULE, "tpm");
695 if (IS_ERR(tpm_class)) {
696 pr_err("couldn't create tpm class\n");
697 return PTR_ERR(tpm_class);
700 tpmrm_class = class_create(THIS_MODULE, "tpmrm");
701 if (IS_ERR(tpmrm_class)) {
702 pr_err("couldn't create tpmrm class\n");
703 rc = PTR_ERR(tpmrm_class);
704 goto out_destroy_tpm_class;
707 rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm");
709 pr_err("tpm: failed to allocate char dev region\n");
710 goto out_destroy_tpmrm_class;
713 rc = tpm_dev_common_init();
715 pr_err("tpm: failed to allocate char dev region\n");
716 goto out_unreg_chrdev;
722 unregister_chrdev_region(tpm_devt, 2 * TPM_NUM_DEVICES);
723 out_destroy_tpmrm_class:
724 class_destroy(tpmrm_class);
725 out_destroy_tpm_class:
726 class_destroy(tpm_class);
731 static void __exit tpm_exit(void)
733 idr_destroy(&dev_nums_idr);
734 class_destroy(tpm_class);
735 class_destroy(tpmrm_class);
736 unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
737 tpm_dev_common_exit();
740 subsys_initcall(tpm_init);
741 module_exit(tpm_exit);
743 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
744 MODULE_DESCRIPTION("TPM Driver");
745 MODULE_VERSION("2.0");
746 MODULE_LICENSE("GPL");