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,
66 struct tpm_space *space,
70 const struct tpm_input_header *header = (const void *)cmd;
74 unsigned int nr_handles;
76 if (len < TPM_HEADER_SIZE)
82 if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
83 cc = be32_to_cpu(header->ordinal);
85 i = tpm2_find_cc(chip, cc);
87 dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
92 attrs = chip->cc_attrs_tbl[i];
94 4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
95 if (len < TPM_HEADER_SIZE + 4 * nr_handles)
102 "%s: insufficient command length %zu", __func__, len);
106 static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
110 if (flags & TPM_TRANSMIT_NESTED)
113 if (!chip->ops->request_locality)
116 rc = chip->ops->request_locality(chip, 0);
125 static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
129 if (flags & TPM_TRANSMIT_NESTED)
132 if (!chip->ops->relinquish_locality)
135 rc = chip->ops->relinquish_locality(chip, chip->locality);
137 dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
142 static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
144 if (flags & TPM_TRANSMIT_NESTED)
147 if (!chip->ops->cmd_ready)
150 return chip->ops->cmd_ready(chip);
153 static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
155 if (flags & TPM_TRANSMIT_NESTED)
158 if (!chip->ops->go_idle)
161 return chip->ops->go_idle(chip);
164 static ssize_t tpm_try_transmit(struct tpm_chip *chip,
165 struct tpm_space *space,
166 u8 *buf, size_t bufsiz,
169 struct tpm_output_header *header = (void *)buf;
176 rc = tpm_validate_command(chip, space, buf, bufsiz);
180 * If the command is not implemented by the TPM, synthesize a
181 * response with a TPM2_RC_COMMAND_CODE return for user-space.
183 if (rc == -EOPNOTSUPP) {
184 header->length = cpu_to_be32(sizeof(*header));
185 header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
186 header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
187 TSS2_RESMGR_TPM_RC_LAYER);
188 return sizeof(*header);
191 if (bufsiz > TPM_BUFSIZE)
192 bufsiz = TPM_BUFSIZE;
194 count = be32_to_cpu(*((__be32 *) (buf + 2)));
195 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
198 if (count > bufsiz) {
200 "invalid count value %x %zx\n", count, bufsiz);
204 if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
205 mutex_lock(&chip->tpm_mutex);
207 if (chip->ops->clk_enable != NULL)
208 chip->ops->clk_enable(chip, true);
210 /* Store the decision as chip->locality will be changed. */
211 need_locality = chip->locality == -1;
214 rc = tpm_request_locality(chip, flags);
216 need_locality = false;
221 rc = tpm_cmd_ready(chip, flags);
225 rc = tpm2_prepare_space(chip, space, ordinal, buf);
229 rc = chip->ops->send(chip, buf, count);
233 "%s: tpm_send: error %d\n", __func__, rc);
237 if (chip->flags & TPM_CHIP_FLAG_IRQ)
240 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
242 u8 status = chip->ops->status(chip);
243 if ((status & chip->ops->req_complete_mask) ==
244 chip->ops->req_complete_val)
247 if (chip->ops->req_canceled(chip, status)) {
248 dev_err(&chip->dev, "Operation Canceled\n");
253 tpm_msleep(TPM_TIMEOUT_POLL);
255 } while (time_before(jiffies, stop));
257 chip->ops->cancel(chip);
258 dev_err(&chip->dev, "Operation Timed out\n");
263 len = chip->ops->recv(chip, buf, bufsiz);
267 "tpm_transmit: tpm_recv: error %d\n", rc);
269 } else if (len < TPM_HEADER_SIZE) {
274 if (len != be32_to_cpu(header->length)) {
279 rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
281 dev_err(&chip->dev, "tpm2_commit_space: error %d\n", rc);
284 /* may fail but do not override previous error value in rc */
285 tpm_go_idle(chip, flags);
289 tpm_relinquish_locality(chip, flags);
291 if (chip->ops->clk_enable != NULL)
292 chip->ops->clk_enable(chip, false);
294 if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
295 mutex_unlock(&chip->tpm_mutex);
296 return rc ? rc : len;
300 * tpm_transmit - Internal kernel interface to transmit TPM commands.
302 * @chip: TPM chip to use
304 * @buf: TPM command buffer
305 * @bufsiz: length of the TPM command buffer
306 * @flags: tpm transmit flags - bitmap
308 * A wrapper around tpm_try_transmit that handles TPM2_RC_RETRY
309 * returns from the TPM and retransmits the command after a delay up
310 * to a maximum wait of TPM2_DURATION_LONG.
312 * Note: TPM1 never returns TPM2_RC_RETRY so the retry logic is TPM2
316 * the length of the return when the operation is successful.
317 * A negative number for system errors (errno).
319 ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
320 u8 *buf, size_t bufsiz, unsigned int flags)
322 struct tpm_output_header *header = (struct tpm_output_header *)buf;
323 /* space for header and handles */
324 u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
325 unsigned int delay_msec = TPM2_DURATION_SHORT;
328 const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
330 /* the command code is where the return code will be */
331 u32 cc = be32_to_cpu(header->return_code);
334 * Subtlety here: if we have a space, the handles will be
335 * transformed, so when we restore the header we also have to
336 * restore the handles.
338 memcpy(save, buf, save_size);
341 ret = tpm_try_transmit(chip, space, buf, bufsiz, flags);
344 rc = be32_to_cpu(header->return_code);
345 if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
348 * return immediately if self test returns test
349 * still running to shorten boot time.
351 if (rc == TPM2_RC_TESTING && cc == TPM2_CC_SELF_TEST)
354 if (delay_msec > TPM2_DURATION_LONG) {
355 if (rc == TPM2_RC_RETRY)
356 dev_err(&chip->dev, "in retry loop\n");
359 "self test is still running\n");
362 tpm_msleep(delay_msec);
364 memcpy(buf, save, save_size);
369 * tpm_transmit_cmd - send a tpm command to the device
370 * The function extracts tpm out header return code
372 * @chip: TPM chip to use
374 * @buf: TPM command buffer
375 * @bufsiz: length of the buffer
376 * @min_rsp_body_length: minimum expected length of response body
377 * @flags: tpm transmit flags - bitmap
378 * @desc: command description used in the error message
381 * 0 when the operation is successful.
382 * A negative number for system errors (errno).
383 * A positive number for a TPM error.
385 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
386 void *buf, size_t bufsiz,
387 size_t min_rsp_body_length, unsigned int flags,
390 const struct tpm_output_header *header = buf;
394 len = tpm_transmit(chip, space, buf, bufsiz, flags);
398 err = be32_to_cpu(header->return_code);
399 if (err != 0 && err != TPM_ERR_DISABLED && err != TPM_ERR_DEACTIVATED
401 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
406 if (len < min_rsp_body_length + TPM_HEADER_SIZE)
411 EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
413 int tpm_get_timeouts(struct tpm_chip *chip)
415 if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
418 if (chip->flags & TPM_CHIP_FLAG_TPM2)
419 return tpm2_get_timeouts(chip);
421 return tpm1_get_timeouts(chip);
423 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
426 * tpm_is_tpm2 - do we a have a TPM2 chip?
427 * @chip: a &struct tpm_chip instance, %NULL for the default chip
430 * 1 if we have a TPM2 chip.
431 * 0 if we don't have a TPM2 chip.
432 * A negative number for system errors (errno).
434 int tpm_is_tpm2(struct tpm_chip *chip)
438 chip = tpm_find_get_ops(chip);
442 rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
448 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
451 * tpm_pcr_read - read a PCR value from SHA1 bank
452 * @chip: a &struct tpm_chip instance, %NULL for the default chip
453 * @pcr_idx: the PCR to be retrieved
454 * @res_buf: the value of the PCR
456 * Return: same as with tpm_transmit_cmd()
458 int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
462 chip = tpm_find_get_ops(chip);
466 if (chip->flags & TPM_CHIP_FLAG_TPM2)
467 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
469 rc = tpm1_pcr_read(chip, pcr_idx, res_buf);
474 EXPORT_SYMBOL_GPL(tpm_pcr_read);
477 * tpm_pcr_extend - extend a PCR value in SHA1 bank.
478 * @chip: a &struct tpm_chip instance, %NULL for the default chip
479 * @pcr_idx: the PCR to be retrieved
480 * @hash: the hash value used to extend the PCR value
482 * Note: with TPM 2.0 extends also those banks with a known digest size to the
483 * cryto subsystem in order to prevent malicious use of those PCR banks. In the
484 * future we should dynamically determine digest sizes.
486 * Return: same as with tpm_transmit_cmd()
488 int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, const u8 *hash)
491 struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
495 chip = tpm_find_get_ops(chip);
499 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
500 memset(digest_list, 0, sizeof(digest_list));
502 for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
503 chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
504 digest_list[i].alg_id = chip->active_banks[i];
505 memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
509 rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);
514 rc = tpm1_pcr_extend(chip, pcr_idx, hash,
515 "attempting extend a PCR value");
519 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
522 * tpm_send - send a TPM command
523 * @chip: a &struct tpm_chip instance, %NULL for the default chip
524 * @cmd: a TPM command buffer
525 * @buflen: the length of the TPM command buffer
527 * Return: same as with tpm_transmit_cmd()
529 int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
533 chip = tpm_find_get_ops(chip);
537 rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0,
538 "attempting to a send a command");
542 EXPORT_SYMBOL_GPL(tpm_send);
544 int tpm_auto_startup(struct tpm_chip *chip)
548 if (!(chip->ops->flags & TPM_OPS_AUTO_STARTUP))
551 if (chip->flags & TPM_CHIP_FLAG_TPM2)
552 rc = tpm2_auto_startup(chip);
554 rc = tpm1_auto_startup(chip);
560 * We are about to suspend. Save the TPM state
561 * so that it can be restored.
563 int tpm_pm_suspend(struct device *dev)
565 struct tpm_chip *chip = dev_get_drvdata(dev);
571 if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
574 if (chip->flags & TPM_CHIP_FLAG_TPM2)
575 tpm2_shutdown(chip, TPM2_SU_STATE);
577 rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
581 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
584 * Resume from a power safe. The BIOS already restored
587 int tpm_pm_resume(struct device *dev)
589 struct tpm_chip *chip = dev_get_drvdata(dev);
596 EXPORT_SYMBOL_GPL(tpm_pm_resume);
599 * tpm_get_random() - get random bytes from the TPM's RNG
600 * @chip: a &struct tpm_chip instance, %NULL for the default chip
601 * @out: destination buffer for the random bytes
602 * @max: the max number of bytes to write to @out
604 * Return: number of random bytes read or a negative error value.
606 int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
610 if (!out || max > TPM_MAX_RNG_DATA)
613 chip = tpm_find_get_ops(chip);
617 if (chip->flags & TPM_CHIP_FLAG_TPM2)
618 rc = tpm2_get_random(chip, out, max);
620 rc = tpm1_get_random(chip, out, max);
625 EXPORT_SYMBOL_GPL(tpm_get_random);
628 * tpm_seal_trusted() - seal a trusted key payload
629 * @chip: a &struct tpm_chip instance, %NULL for the default chip
630 * @options: authentication values and other options
631 * @payload: the key data in clear and encrypted form
633 * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
634 * the keyring subsystem.
636 * Return: same as with tpm_transmit_cmd()
638 int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload,
639 struct trusted_key_options *options)
643 chip = tpm_find_get_ops(chip);
644 if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
647 rc = tpm2_seal_trusted(chip, payload, options);
652 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
655 * tpm_unseal_trusted() - unseal a trusted key
656 * @chip: a &struct tpm_chip instance, %NULL for the default chip
657 * @options: authentication values and other options
658 * @payload: the key data in clear and encrypted form
660 * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
661 * the keyring subsystem.
663 * Return: same as with tpm_transmit_cmd()
665 int tpm_unseal_trusted(struct tpm_chip *chip,
666 struct trusted_key_payload *payload,
667 struct trusted_key_options *options)
671 chip = tpm_find_get_ops(chip);
672 if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
675 rc = tpm2_unseal_trusted(chip, payload, options);
681 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
683 static int __init tpm_init(void)
687 tpm_class = class_create(THIS_MODULE, "tpm");
688 if (IS_ERR(tpm_class)) {
689 pr_err("couldn't create tpm class\n");
690 return PTR_ERR(tpm_class);
693 tpmrm_class = class_create(THIS_MODULE, "tpmrm");
694 if (IS_ERR(tpmrm_class)) {
695 pr_err("couldn't create tpmrm class\n");
696 rc = PTR_ERR(tpmrm_class);
697 goto out_destroy_tpm_class;
700 rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm");
702 pr_err("tpm: failed to allocate char dev region\n");
703 goto out_destroy_tpmrm_class;
706 rc = tpm_dev_common_init();
708 pr_err("tpm: failed to allocate char dev region\n");
709 goto out_unreg_chrdev;
715 unregister_chrdev_region(tpm_devt, 2 * TPM_NUM_DEVICES);
716 out_destroy_tpmrm_class:
717 class_destroy(tpmrm_class);
718 out_destroy_tpm_class:
719 class_destroy(tpm_class);
724 static void __exit tpm_exit(void)
726 idr_destroy(&dev_nums_idr);
727 class_destroy(tpm_class);
728 class_destroy(tpmrm_class);
729 unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
730 tpm_dev_common_exit();
733 subsys_initcall(tpm_init);
734 module_exit(tpm_exit);
736 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
737 MODULE_DESCRIPTION("TPM Driver");
738 MODULE_VERSION("2.0");
739 MODULE_LICENSE("GPL");