1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (C) 2004 IBM Corporation
4 * Copyright (C) 2014 Intel Corporation
7 * Leendert van Doorn <leendert@watson.ibm.com>
8 * Dave Safford <safford@watson.ibm.com>
9 * Reiner Sailer <sailer@watson.ibm.com>
10 * Kylene Hall <kjhall@us.ibm.com>
12 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
14 * Device driver for TCG/TCPA TPM (trusted platform module).
15 * Specifications at www.trustedcomputinggroup.org
17 * Note, the TPM chip is not interrupt driven (only polling)
18 * and can have very long timeouts (minutes!). Hence the unusual
22 #include <linux/poll.h>
23 #include <linux/slab.h>
24 #include <linux/mutex.h>
25 #include <linux/spinlock.h>
26 #include <linux/freezer.h>
27 #include <linux/tpm_eventlog.h>
32 * Bug workaround - some TPM's don't flush the most
33 * recently changed pcr on suspend, so force the flush
34 * with an extend to the selected _unused_ non-volatile pcr.
36 static u32 tpm_suspend_pcr;
37 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
38 MODULE_PARM_DESC(suspend_pcr,
39 "PCR to use for dummy writes to facilitate flush on suspend.");
42 * tpm_calc_ordinal_duration() - calculate the maximum command duration
43 * @chip: TPM chip to use.
44 * @ordinal: TPM command ordinal.
46 * The function returns the maximum amount of time the chip could take
47 * to return the result for a particular ordinal in jiffies.
49 * Return: A maximal duration time for an ordinal in jiffies.
51 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
53 if (chip->flags & TPM_CHIP_FLAG_TPM2)
54 return tpm2_calc_ordinal_duration(chip, ordinal);
56 return tpm1_calc_ordinal_duration(chip, ordinal);
58 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
60 static ssize_t tpm_try_transmit(struct tpm_chip *chip, void *buf, size_t bufsiz)
62 struct tpm_header *header = buf;
68 if (bufsiz < TPM_HEADER_SIZE)
71 if (bufsiz > TPM_BUFSIZE)
74 count = be32_to_cpu(header->length);
75 ordinal = be32_to_cpu(header->ordinal);
80 "invalid count value %x %zx\n", count, bufsiz);
84 rc = chip->ops->send(chip, buf, count);
88 "%s: send(): error %d\n", __func__, rc);
92 /* A sanity check. send() should just return zero on success e.g.
93 * not the command length.
97 "%s: send(): invalid value %d\n", __func__, rc);
101 if (chip->flags & TPM_CHIP_FLAG_IRQ)
104 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
106 u8 status = chip->ops->status(chip);
107 if ((status & chip->ops->req_complete_mask) ==
108 chip->ops->req_complete_val)
111 if (chip->ops->req_canceled(chip, status)) {
112 dev_err(&chip->dev, "Operation Canceled\n");
116 tpm_msleep(TPM_TIMEOUT_POLL);
118 } while (time_before(jiffies, stop));
120 chip->ops->cancel(chip);
121 dev_err(&chip->dev, "Operation Timed out\n");
125 len = chip->ops->recv(chip, buf, bufsiz);
128 dev_err(&chip->dev, "tpm_transmit: tpm_recv: error %d\n", rc);
129 } else if (len < TPM_HEADER_SIZE || len != be32_to_cpu(header->length))
132 return rc ? rc : len;
136 * tpm_transmit - Internal kernel interface to transmit TPM commands.
137 * @chip: a TPM chip to use
138 * @buf: a TPM command buffer
139 * @bufsiz: length of the TPM command buffer
141 * A wrapper around tpm_try_transmit() that handles TPM2_RC_RETRY returns from
142 * the TPM and retransmits the command after a delay up to a maximum wait of
143 * TPM2_DURATION_LONG.
145 * Note that TPM 1.x never returns TPM2_RC_RETRY so the retry logic is TPM 2.0
149 * * The response length - OK
150 * * -errno - A system error
152 ssize_t tpm_transmit(struct tpm_chip *chip, u8 *buf, size_t bufsiz)
154 struct tpm_header *header = (struct tpm_header *)buf;
155 /* space for header and handles */
156 u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
157 unsigned int delay_msec = TPM2_DURATION_SHORT;
160 const size_t save_size = min(sizeof(save), bufsiz);
161 /* the command code is where the return code will be */
162 u32 cc = be32_to_cpu(header->return_code);
165 * Subtlety here: if we have a space, the handles will be
166 * transformed, so when we restore the header we also have to
167 * restore the handles.
169 memcpy(save, buf, save_size);
172 ret = tpm_try_transmit(chip, buf, bufsiz);
175 rc = be32_to_cpu(header->return_code);
176 if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
179 * return immediately if self test returns test
180 * still running to shorten boot time.
182 if (rc == TPM2_RC_TESTING && cc == TPM2_CC_SELF_TEST)
185 if (delay_msec > TPM2_DURATION_LONG) {
186 if (rc == TPM2_RC_RETRY)
187 dev_err(&chip->dev, "in retry loop\n");
190 "self test is still running\n");
193 tpm_msleep(delay_msec);
195 memcpy(buf, save, save_size);
201 * tpm_transmit_cmd - send a tpm command to the device
202 * @chip: a TPM chip to use
203 * @buf: a TPM command buffer
204 * @min_rsp_body_length: minimum expected length of response body
205 * @desc: command description used in the error message
209 * * -errno - A system error
210 * * TPM_RC - A TPM error
212 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_buf *buf,
213 size_t min_rsp_body_length, const char *desc)
215 const struct tpm_header *header = (struct tpm_header *)buf->data;
219 len = tpm_transmit(chip, buf->data, PAGE_SIZE);
223 err = be32_to_cpu(header->return_code);
224 if (err != 0 && err != TPM_ERR_DISABLED && err != TPM_ERR_DEACTIVATED
225 && err != TPM2_RC_TESTING && desc)
226 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
231 if (len < min_rsp_body_length + TPM_HEADER_SIZE)
236 EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
238 int tpm_get_timeouts(struct tpm_chip *chip)
240 if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
243 if (chip->flags & TPM_CHIP_FLAG_TPM2)
244 return tpm2_get_timeouts(chip);
246 return tpm1_get_timeouts(chip);
248 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
251 * tpm_is_tpm2 - do we a have a TPM2 chip?
252 * @chip: a &struct tpm_chip instance, %NULL for the default chip
255 * 1 if we have a TPM2 chip.
256 * 0 if we don't have a TPM2 chip.
257 * A negative number for system errors (errno).
259 int tpm_is_tpm2(struct tpm_chip *chip)
263 chip = tpm_find_get_ops(chip);
267 rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
273 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
276 * tpm_pcr_read - read a PCR value from SHA1 bank
277 * @chip: a &struct tpm_chip instance, %NULL for the default chip
278 * @pcr_idx: the PCR to be retrieved
279 * @digest: the PCR bank and buffer current PCR value is written to
281 * Return: same as with tpm_transmit_cmd()
283 int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
284 struct tpm_digest *digest)
288 chip = tpm_find_get_ops(chip);
292 if (chip->flags & TPM_CHIP_FLAG_TPM2)
293 rc = tpm2_pcr_read(chip, pcr_idx, digest, NULL);
295 rc = tpm1_pcr_read(chip, pcr_idx, digest->digest);
300 EXPORT_SYMBOL_GPL(tpm_pcr_read);
303 * tpm_pcr_extend - extend a PCR value in SHA1 bank.
304 * @chip: a &struct tpm_chip instance, %NULL for the default chip
305 * @pcr_idx: the PCR to be retrieved
306 * @digests: array of tpm_digest structures used to extend PCRs
308 * Note: callers must pass a digest for every allocated PCR bank, in the same
309 * order of the banks in chip->allocated_banks.
311 * Return: same as with tpm_transmit_cmd()
313 int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
314 struct tpm_digest *digests)
319 chip = tpm_find_get_ops(chip);
323 for (i = 0; i < chip->nr_allocated_banks; i++)
324 if (digests[i].alg_id != chip->allocated_banks[i].alg_id)
327 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
328 rc = tpm2_pcr_extend(chip, pcr_idx, digests);
333 rc = tpm1_pcr_extend(chip, pcr_idx, digests[0].digest,
334 "attempting extend a PCR value");
338 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
341 * tpm_send - send a TPM command
342 * @chip: a &struct tpm_chip instance, %NULL for the default chip
343 * @cmd: a TPM command buffer
344 * @buflen: the length of the TPM command buffer
346 * Return: same as with tpm_transmit_cmd()
348 int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
353 chip = tpm_find_get_ops(chip);
357 rc = tpm_buf_init(&buf, 0, 0);
361 memcpy(buf.data, cmd, buflen);
362 rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to a send a command");
363 tpm_buf_destroy(&buf);
368 EXPORT_SYMBOL_GPL(tpm_send);
370 int tpm_auto_startup(struct tpm_chip *chip)
374 if (!(chip->ops->flags & TPM_OPS_AUTO_STARTUP))
377 if (chip->flags & TPM_CHIP_FLAG_TPM2)
378 rc = tpm2_auto_startup(chip);
380 rc = tpm1_auto_startup(chip);
386 * We are about to suspend. Save the TPM state
387 * so that it can be restored.
389 int tpm_pm_suspend(struct device *dev)
391 struct tpm_chip *chip = dev_get_drvdata(dev);
397 if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
400 if (!tpm_chip_start(chip)) {
401 if (chip->flags & TPM_CHIP_FLAG_TPM2)
402 tpm2_shutdown(chip, TPM2_SU_STATE);
404 rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
411 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
414 * Resume from a power safe. The BIOS already restored
417 int tpm_pm_resume(struct device *dev)
419 struct tpm_chip *chip = dev_get_drvdata(dev);
426 EXPORT_SYMBOL_GPL(tpm_pm_resume);
429 * tpm_get_random() - get random bytes from the TPM's RNG
430 * @chip: a &struct tpm_chip instance, %NULL for the default chip
431 * @out: destination buffer for the random bytes
432 * @max: the max number of bytes to write to @out
434 * Return: number of random bytes read or a negative error value.
436 int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
440 if (!out || max > TPM_MAX_RNG_DATA)
443 chip = tpm_find_get_ops(chip);
447 if (chip->flags & TPM_CHIP_FLAG_TPM2)
448 rc = tpm2_get_random(chip, out, max);
450 rc = tpm1_get_random(chip, out, max);
455 EXPORT_SYMBOL_GPL(tpm_get_random);
458 * tpm_seal_trusted() - seal a trusted key payload
459 * @chip: a &struct tpm_chip instance, %NULL for the default chip
460 * @options: authentication values and other options
461 * @payload: the key data in clear and encrypted form
463 * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
464 * the keyring subsystem.
466 * Return: same as with tpm_transmit_cmd()
468 int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload,
469 struct trusted_key_options *options)
473 chip = tpm_find_get_ops(chip);
474 if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
477 rc = tpm2_seal_trusted(chip, payload, options);
482 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
485 * tpm_unseal_trusted() - unseal a trusted key
486 * @chip: a &struct tpm_chip instance, %NULL for the default chip
487 * @options: authentication values and other options
488 * @payload: the key data in clear and encrypted form
490 * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
491 * the keyring subsystem.
493 * Return: same as with tpm_transmit_cmd()
495 int tpm_unseal_trusted(struct tpm_chip *chip,
496 struct trusted_key_payload *payload,
497 struct trusted_key_options *options)
501 chip = tpm_find_get_ops(chip);
502 if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
505 rc = tpm2_unseal_trusted(chip, payload, options);
511 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
513 static int __init tpm_init(void)
517 tpm_class = class_create(THIS_MODULE, "tpm");
518 if (IS_ERR(tpm_class)) {
519 pr_err("couldn't create tpm class\n");
520 return PTR_ERR(tpm_class);
523 tpmrm_class = class_create(THIS_MODULE, "tpmrm");
524 if (IS_ERR(tpmrm_class)) {
525 pr_err("couldn't create tpmrm class\n");
526 rc = PTR_ERR(tpmrm_class);
527 goto out_destroy_tpm_class;
530 rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm");
532 pr_err("tpm: failed to allocate char dev region\n");
533 goto out_destroy_tpmrm_class;
536 rc = tpm_dev_common_init();
538 pr_err("tpm: failed to allocate char dev region\n");
539 goto out_unreg_chrdev;
545 unregister_chrdev_region(tpm_devt, 2 * TPM_NUM_DEVICES);
546 out_destroy_tpmrm_class:
547 class_destroy(tpmrm_class);
548 out_destroy_tpm_class:
549 class_destroy(tpm_class);
554 static void __exit tpm_exit(void)
556 idr_destroy(&dev_nums_idr);
557 class_destroy(tpm_class);
558 class_destroy(tpmrm_class);
559 unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
560 tpm_dev_common_exit();
563 subsys_initcall(tpm_init);
564 module_exit(tpm_exit);
566 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
567 MODULE_DESCRIPTION("TPM Driver");
568 MODULE_VERSION("2.0");
569 MODULE_LICENSE("GPL");