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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2004 IBM Corporation
4 * Copyright (C) 2014 Intel Corporation
5 *
6 * Authors:
7 * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
8 * Leendert van Doorn <leendert@watson.ibm.com>
9 * Dave Safford <safford@watson.ibm.com>
10 * Reiner Sailer <sailer@watson.ibm.com>
11 * Kylene Hall <kjhall@us.ibm.com>
12 *
13 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
14 *
15 * TPM chip management routines.
16 */
17
18#include <linux/poll.h>
19#include <linux/slab.h>
20#include <linux/mutex.h>
21#include <linux/spinlock.h>
22#include <linux/freezer.h>
23#include <linux/major.h>
24#include <linux/tpm_eventlog.h>
25#include <linux/hw_random.h>
26#include "tpm.h"
27
28DEFINE_IDR(dev_nums_idr);
29static DEFINE_MUTEX(idr_lock);
30
31const struct class tpm_class = {
32 .name = "tpm",
33 .shutdown_pre = tpm_class_shutdown,
34};
35const struct class tpmrm_class = {
36 .name = "tpmrm",
37};
38dev_t tpm_devt;
39
40static int tpm_request_locality(struct tpm_chip *chip)
41{
42 int rc;
43
44 if (!chip->ops->request_locality)
45 return 0;
46
47 rc = chip->ops->request_locality(chip, 0);
48 if (rc < 0)
49 return rc;
50
51 chip->locality = rc;
52 return 0;
53}
54
55static void tpm_relinquish_locality(struct tpm_chip *chip)
56{
57 int rc;
58
59 if (!chip->ops->relinquish_locality)
60 return;
61
62 rc = chip->ops->relinquish_locality(chip, chip->locality);
63 if (rc)
64 dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
65
66 chip->locality = -1;
67}
68
69static int tpm_cmd_ready(struct tpm_chip *chip)
70{
71 if (!chip->ops->cmd_ready)
72 return 0;
73
74 return chip->ops->cmd_ready(chip);
75}
76
77static int tpm_go_idle(struct tpm_chip *chip)
78{
79 if (!chip->ops->go_idle)
80 return 0;
81
82 return chip->ops->go_idle(chip);
83}
84
85static void tpm_clk_enable(struct tpm_chip *chip)
86{
87 if (chip->ops->clk_enable)
88 chip->ops->clk_enable(chip, true);
89}
90
91static void tpm_clk_disable(struct tpm_chip *chip)
92{
93 if (chip->ops->clk_enable)
94 chip->ops->clk_enable(chip, false);
95}
96
97/**
98 * tpm_chip_start() - power on the TPM
99 * @chip: a TPM chip to use
100 *
101 * Return:
102 * * The response length - OK
103 * * -errno - A system error
104 */
105int tpm_chip_start(struct tpm_chip *chip)
106{
107 int ret;
108
109 tpm_clk_enable(chip);
110
111 if (chip->locality == -1) {
112 ret = tpm_request_locality(chip);
113 if (ret) {
114 tpm_clk_disable(chip);
115 return ret;
116 }
117 }
118
119 ret = tpm_cmd_ready(chip);
120 if (ret) {
121 tpm_relinquish_locality(chip);
122 tpm_clk_disable(chip);
123 return ret;
124 }
125
126 return 0;
127}
128EXPORT_SYMBOL_GPL(tpm_chip_start);
129
130/**
131 * tpm_chip_stop() - power off the TPM
132 * @chip: a TPM chip to use
133 *
134 * Return:
135 * * The response length - OK
136 * * -errno - A system error
137 */
138void tpm_chip_stop(struct tpm_chip *chip)
139{
140 tpm_go_idle(chip);
141 tpm_relinquish_locality(chip);
142 tpm_clk_disable(chip);
143}
144EXPORT_SYMBOL_GPL(tpm_chip_stop);
145
146/**
147 * tpm_try_get_ops() - Get a ref to the tpm_chip
148 * @chip: Chip to ref
149 *
150 * The caller must already have some kind of locking to ensure that chip is
151 * valid. This function will lock the chip so that the ops member can be
152 * accessed safely. The locking prevents tpm_chip_unregister from
153 * completing, so it should not be held for long periods.
154 *
155 * Returns -ERRNO if the chip could not be got.
156 */
157int tpm_try_get_ops(struct tpm_chip *chip)
158{
159 int rc = -EIO;
160
161 get_device(&chip->dev);
162
163 down_read(&chip->ops_sem);
164 if (!chip->ops)
165 goto out_ops;
166
167 mutex_lock(&chip->tpm_mutex);
168 rc = tpm_chip_start(chip);
169 if (rc)
170 goto out_lock;
171
172 return 0;
173out_lock:
174 mutex_unlock(&chip->tpm_mutex);
175out_ops:
176 up_read(&chip->ops_sem);
177 put_device(&chip->dev);
178 return rc;
179}
180EXPORT_SYMBOL_GPL(tpm_try_get_ops);
181
182/**
183 * tpm_put_ops() - Release a ref to the tpm_chip
184 * @chip: Chip to put
185 *
186 * This is the opposite pair to tpm_try_get_ops(). After this returns chip may
187 * be kfree'd.
188 */
189void tpm_put_ops(struct tpm_chip *chip)
190{
191 tpm_chip_stop(chip);
192 mutex_unlock(&chip->tpm_mutex);
193 up_read(&chip->ops_sem);
194 put_device(&chip->dev);
195}
196EXPORT_SYMBOL_GPL(tpm_put_ops);
197
198/**
199 * tpm_default_chip() - find a TPM chip and get a reference to it
200 */
201struct tpm_chip *tpm_default_chip(void)
202{
203 struct tpm_chip *chip, *res = NULL;
204 int chip_num = 0;
205 int chip_prev;
206
207 mutex_lock(&idr_lock);
208
209 do {
210 chip_prev = chip_num;
211 chip = idr_get_next(&dev_nums_idr, &chip_num);
212 if (chip) {
213 get_device(&chip->dev);
214 res = chip;
215 break;
216 }
217 } while (chip_prev != chip_num);
218
219 mutex_unlock(&idr_lock);
220
221 return res;
222}
223EXPORT_SYMBOL_GPL(tpm_default_chip);
224
225/**
226 * tpm_find_get_ops() - find and reserve a TPM chip
227 * @chip: a &struct tpm_chip instance, %NULL for the default chip
228 *
229 * Finds a TPM chip and reserves its class device and operations. The chip must
230 * be released with tpm_put_ops() after use.
231 * This function is for internal use only. It supports existing TPM callers
232 * by accepting NULL, but those callers should be converted to pass in a chip
233 * directly.
234 *
235 * Return:
236 * A reserved &struct tpm_chip instance.
237 * %NULL if a chip is not found.
238 * %NULL if the chip is not available.
239 */
240struct tpm_chip *tpm_find_get_ops(struct tpm_chip *chip)
241{
242 int rc;
243
244 if (chip) {
245 if (!tpm_try_get_ops(chip))
246 return chip;
247 return NULL;
248 }
249
250 chip = tpm_default_chip();
251 if (!chip)
252 return NULL;
253 rc = tpm_try_get_ops(chip);
254 /* release additional reference we got from tpm_default_chip() */
255 put_device(&chip->dev);
256 if (rc)
257 return NULL;
258 return chip;
259}
260
261/**
262 * tpm_dev_release() - free chip memory and the device number
263 * @dev: the character device for the TPM chip
264 *
265 * This is used as the release function for the character device.
266 */
267static void tpm_dev_release(struct device *dev)
268{
269 struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
270
271 mutex_lock(&idr_lock);
272 idr_remove(&dev_nums_idr, chip->dev_num);
273 mutex_unlock(&idr_lock);
274
275 kfree(chip->work_space.context_buf);
276 kfree(chip->work_space.session_buf);
277 kfree(chip->allocated_banks);
278 kfree(chip);
279}
280
281/**
282 * tpm_class_shutdown() - prepare the TPM device for loss of power.
283 * @dev: device to which the chip is associated.
284 *
285 * Issues a TPM2_Shutdown command prior to loss of power, as required by the
286 * TPM 2.0 spec. Then, calls bus- and device- specific shutdown code.
287 *
288 * Return: always 0 (i.e. success)
289 */
290int tpm_class_shutdown(struct device *dev)
291{
292 struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
293
294 down_write(&chip->ops_sem);
295 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
296 if (!tpm_chip_start(chip)) {
297 tpm2_shutdown(chip, TPM2_SU_CLEAR);
298 tpm_chip_stop(chip);
299 }
300 }
301 chip->ops = NULL;
302 up_write(&chip->ops_sem);
303
304 return 0;
305}
306
307/**
308 * tpm_chip_alloc() - allocate a new struct tpm_chip instance
309 * @pdev: device to which the chip is associated
310 * At this point pdev mst be initialized, but does not have to
311 * be registered
312 * @ops: struct tpm_class_ops instance
313 *
314 * Allocates a new struct tpm_chip instance and assigns a free
315 * device number for it. Must be paired with put_device(&chip->dev).
316 */
317struct tpm_chip *tpm_chip_alloc(struct device *pdev,
318 const struct tpm_class_ops *ops)
319{
320 struct tpm_chip *chip;
321 int rc;
322
323 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
324 if (chip == NULL)
325 return ERR_PTR(-ENOMEM);
326
327 mutex_init(&chip->tpm_mutex);
328 init_rwsem(&chip->ops_sem);
329
330 chip->ops = ops;
331
332 mutex_lock(&idr_lock);
333 rc = idr_alloc(&dev_nums_idr, NULL, 0, TPM_NUM_DEVICES, GFP_KERNEL);
334 mutex_unlock(&idr_lock);
335 if (rc < 0) {
336 dev_err(pdev, "No available tpm device numbers\n");
337 kfree(chip);
338 return ERR_PTR(rc);
339 }
340 chip->dev_num = rc;
341
342 device_initialize(&chip->dev);
343
344 chip->dev.class = &tpm_class;
345 chip->dev.release = tpm_dev_release;
346 chip->dev.parent = pdev;
347 chip->dev.groups = chip->groups;
348
349 if (chip->dev_num == 0)
350 chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR);
351 else
352 chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num);
353
354 rc = dev_set_name(&chip->dev, "tpm%d", chip->dev_num);
355 if (rc)
356 goto out;
357
358 if (!pdev)
359 chip->flags |= TPM_CHIP_FLAG_VIRTUAL;
360
361 cdev_init(&chip->cdev, &tpm_fops);
362 chip->cdev.owner = THIS_MODULE;
363
364 rc = tpm2_init_space(&chip->work_space, TPM2_SPACE_BUFFER_SIZE);
365 if (rc) {
366 rc = -ENOMEM;
367 goto out;
368 }
369
370 chip->locality = -1;
371 return chip;
372
373out:
374 put_device(&chip->dev);
375 return ERR_PTR(rc);
376}
377EXPORT_SYMBOL_GPL(tpm_chip_alloc);
378
379static void tpm_put_device(void *dev)
380{
381 put_device(dev);
382}
383
384/**
385 * tpmm_chip_alloc() - allocate a new struct tpm_chip instance
386 * @pdev: parent device to which the chip is associated
387 * @ops: struct tpm_class_ops instance
388 *
389 * Same as tpm_chip_alloc except devm is used to do the put_device
390 */
391struct tpm_chip *tpmm_chip_alloc(struct device *pdev,
392 const struct tpm_class_ops *ops)
393{
394 struct tpm_chip *chip;
395 int rc;
396
397 chip = tpm_chip_alloc(pdev, ops);
398 if (IS_ERR(chip))
399 return chip;
400
401 rc = devm_add_action_or_reset(pdev,
402 tpm_put_device,
403 &chip->dev);
404 if (rc)
405 return ERR_PTR(rc);
406
407 dev_set_drvdata(pdev, chip);
408
409 return chip;
410}
411EXPORT_SYMBOL_GPL(tpmm_chip_alloc);
412
413static int tpm_add_char_device(struct tpm_chip *chip)
414{
415 int rc;
416
417 rc = cdev_device_add(&chip->cdev, &chip->dev);
418 if (rc) {
419 dev_err(&chip->dev,
420 "unable to cdev_device_add() %s, major %d, minor %d, err=%d\n",
421 dev_name(&chip->dev), MAJOR(chip->dev.devt),
422 MINOR(chip->dev.devt), rc);
423 return rc;
424 }
425
426 if (chip->flags & TPM_CHIP_FLAG_TPM2 && !tpm_is_firmware_upgrade(chip)) {
427 rc = tpm_devs_add(chip);
428 if (rc)
429 goto err_del_cdev;
430 }
431
432 /* Make the chip available. */
433 mutex_lock(&idr_lock);
434 idr_replace(&dev_nums_idr, chip, chip->dev_num);
435 mutex_unlock(&idr_lock);
436
437 return 0;
438
439err_del_cdev:
440 cdev_device_del(&chip->cdev, &chip->dev);
441 return rc;
442}
443
444static void tpm_del_char_device(struct tpm_chip *chip)
445{
446 cdev_device_del(&chip->cdev, &chip->dev);
447
448 /* Make the chip unavailable. */
449 mutex_lock(&idr_lock);
450 idr_replace(&dev_nums_idr, NULL, chip->dev_num);
451 mutex_unlock(&idr_lock);
452
453 /* Make the driver uncallable. */
454 down_write(&chip->ops_sem);
455
456 /*
457 * Check if chip->ops is still valid: In case that the controller
458 * drivers shutdown handler unregisters the controller in its
459 * shutdown handler we are called twice and chip->ops to NULL.
460 */
461 if (chip->ops) {
462 if (chip->flags & TPM_CHIP_FLAG_TPM2) {
463 if (!tpm_chip_start(chip)) {
464 tpm2_shutdown(chip, TPM2_SU_CLEAR);
465 tpm_chip_stop(chip);
466 }
467 }
468 chip->ops = NULL;
469 }
470 up_write(&chip->ops_sem);
471}
472
473static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
474{
475 struct attribute **i;
476
477 if (chip->flags & (TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_VIRTUAL) ||
478 tpm_is_firmware_upgrade(chip))
479 return;
480
481 sysfs_remove_link(&chip->dev.parent->kobj, "ppi");
482
483 for (i = chip->groups[0]->attrs; *i != NULL; ++i)
484 sysfs_remove_link(&chip->dev.parent->kobj, (*i)->name);
485}
486
487/* For compatibility with legacy sysfs paths we provide symlinks from the
488 * parent dev directory to selected names within the tpm chip directory. Old
489 * kernel versions created these files directly under the parent.
490 */
491static int tpm_add_legacy_sysfs(struct tpm_chip *chip)
492{
493 struct attribute **i;
494 int rc;
495
496 if (chip->flags & (TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_VIRTUAL) ||
497 tpm_is_firmware_upgrade(chip))
498 return 0;
499
500 rc = compat_only_sysfs_link_entry_to_kobj(
501 &chip->dev.parent->kobj, &chip->dev.kobj, "ppi", NULL);
502 if (rc && rc != -ENOENT)
503 return rc;
504
505 /* All the names from tpm-sysfs */
506 for (i = chip->groups[0]->attrs; *i != NULL; ++i) {
507 rc = compat_only_sysfs_link_entry_to_kobj(
508 &chip->dev.parent->kobj, &chip->dev.kobj, (*i)->name, NULL);
509 if (rc) {
510 tpm_del_legacy_sysfs(chip);
511 return rc;
512 }
513 }
514
515 return 0;
516}
517
518static int tpm_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait)
519{
520 struct tpm_chip *chip = container_of(rng, struct tpm_chip, hwrng);
521
522 /* Give back zero bytes, as TPM chip has not yet fully resumed: */
523 if (chip->flags & TPM_CHIP_FLAG_SUSPENDED)
524 return 0;
525
526 return tpm_get_random(chip, data, max);
527}
528
529static bool tpm_is_hwrng_enabled(struct tpm_chip *chip)
530{
531 if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM))
532 return false;
533 if (tpm_is_firmware_upgrade(chip))
534 return false;
535 if (chip->flags & TPM_CHIP_FLAG_HWRNG_DISABLED)
536 return false;
537 return true;
538}
539
540static int tpm_add_hwrng(struct tpm_chip *chip)
541{
542 if (!tpm_is_hwrng_enabled(chip))
543 return 0;
544
545 snprintf(chip->hwrng_name, sizeof(chip->hwrng_name),
546 "tpm-rng-%d", chip->dev_num);
547 chip->hwrng.name = chip->hwrng_name;
548 chip->hwrng.read = tpm_hwrng_read;
549 return hwrng_register(&chip->hwrng);
550}
551
552static int tpm_get_pcr_allocation(struct tpm_chip *chip)
553{
554 int rc;
555
556 if (tpm_is_firmware_upgrade(chip))
557 return 0;
558
559 rc = (chip->flags & TPM_CHIP_FLAG_TPM2) ?
560 tpm2_get_pcr_allocation(chip) :
561 tpm1_get_pcr_allocation(chip);
562
563 if (rc > 0)
564 return -ENODEV;
565
566 return rc;
567}
568
569/*
570 * tpm_chip_bootstrap() - Boostrap TPM chip after power on
571 * @chip: TPM chip to use.
572 *
573 * Initialize TPM chip after power on. This a one-shot function: subsequent
574 * calls will have no effect.
575 */
576int tpm_chip_bootstrap(struct tpm_chip *chip)
577{
578 int rc;
579
580 if (chip->flags & TPM_CHIP_FLAG_BOOTSTRAPPED)
581 return 0;
582
583 rc = tpm_chip_start(chip);
584 if (rc)
585 return rc;
586
587 rc = tpm_auto_startup(chip);
588 if (rc)
589 goto stop;
590
591 rc = tpm_get_pcr_allocation(chip);
592stop:
593 tpm_chip_stop(chip);
594
595 /*
596 * Unconditionally set, as driver initialization should cease, when the
597 * boostrapping process fails.
598 */
599 chip->flags |= TPM_CHIP_FLAG_BOOTSTRAPPED;
600
601 return rc;
602}
603EXPORT_SYMBOL_GPL(tpm_chip_bootstrap);
604
605/*
606 * tpm_chip_register() - create a character device for the TPM chip
607 * @chip: TPM chip to use.
608 *
609 * Creates a character device for the TPM chip and adds sysfs attributes for
610 * the device. As the last step this function adds the chip to the list of TPM
611 * chips available for in-kernel use.
612 *
613 * This function should be only called after the chip initialization is
614 * complete.
615 */
616int tpm_chip_register(struct tpm_chip *chip)
617{
618 int rc;
619
620 rc = tpm_chip_bootstrap(chip);
621 if (rc)
622 return rc;
623
624 tpm_sysfs_add_device(chip);
625
626 tpm_bios_log_setup(chip);
627
628 tpm_add_ppi(chip);
629
630 rc = tpm_add_hwrng(chip);
631 if (rc)
632 goto out_ppi;
633
634 rc = tpm_add_char_device(chip);
635 if (rc)
636 goto out_hwrng;
637
638 rc = tpm_add_legacy_sysfs(chip);
639 if (rc) {
640 tpm_chip_unregister(chip);
641 return rc;
642 }
643
644 return 0;
645
646out_hwrng:
647 if (tpm_is_hwrng_enabled(chip))
648 hwrng_unregister(&chip->hwrng);
649out_ppi:
650 tpm_bios_log_teardown(chip);
651
652 return rc;
653}
654EXPORT_SYMBOL_GPL(tpm_chip_register);
655
656/*
657 * tpm_chip_unregister() - release the TPM driver
658 * @chip: TPM chip to use.
659 *
660 * Takes the chip first away from the list of available TPM chips and then
661 * cleans up all the resources reserved by tpm_chip_register().
662 *
663 * Once this function returns the driver call backs in 'op's will not be
664 * running and will no longer start.
665 *
666 * NOTE: This function should be only called before deinitializing chip
667 * resources.
668 */
669void tpm_chip_unregister(struct tpm_chip *chip)
670{
671 tpm_del_legacy_sysfs(chip);
672 if (tpm_is_hwrng_enabled(chip))
673 hwrng_unregister(&chip->hwrng);
674 tpm_bios_log_teardown(chip);
675 if (chip->flags & TPM_CHIP_FLAG_TPM2 && !tpm_is_firmware_upgrade(chip))
676 tpm_devs_remove(chip);
677 tpm_del_char_device(chip);
678}
679EXPORT_SYMBOL_GPL(tpm_chip_unregister);
1/*
2 * Copyright (C) 2004 IBM Corporation
3 * Copyright (C) 2014 Intel Corporation
4 *
5 * Authors:
6 * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
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>
11 *
12 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
13 *
14 * TPM chip management routines.
15 *
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
19 * License.
20 *
21 */
22
23#include <linux/poll.h>
24#include <linux/slab.h>
25#include <linux/mutex.h>
26#include <linux/spinlock.h>
27#include <linux/freezer.h>
28#include <linux/major.h>
29#include "tpm.h"
30#include "tpm_eventlog.h"
31
32DEFINE_IDR(dev_nums_idr);
33static DEFINE_MUTEX(idr_lock);
34
35struct class *tpm_class;
36dev_t tpm_devt;
37
38/**
39 * tpm_try_get_ops() - Get a ref to the tpm_chip
40 * @chip: Chip to ref
41 *
42 * The caller must already have some kind of locking to ensure that chip is
43 * valid. This function will lock the chip so that the ops member can be
44 * accessed safely. The locking prevents tpm_chip_unregister from
45 * completing, so it should not be held for long periods.
46 *
47 * Returns -ERRNO if the chip could not be got.
48 */
49int tpm_try_get_ops(struct tpm_chip *chip)
50{
51 int rc = -EIO;
52
53 get_device(&chip->dev);
54
55 down_read(&chip->ops_sem);
56 if (!chip->ops)
57 goto out_lock;
58
59 return 0;
60out_lock:
61 up_read(&chip->ops_sem);
62 put_device(&chip->dev);
63 return rc;
64}
65EXPORT_SYMBOL_GPL(tpm_try_get_ops);
66
67/**
68 * tpm_put_ops() - Release a ref to the tpm_chip
69 * @chip: Chip to put
70 *
71 * This is the opposite pair to tpm_try_get_ops(). After this returns chip may
72 * be kfree'd.
73 */
74void tpm_put_ops(struct tpm_chip *chip)
75{
76 up_read(&chip->ops_sem);
77 put_device(&chip->dev);
78}
79EXPORT_SYMBOL_GPL(tpm_put_ops);
80
81/**
82 * tpm_chip_find_get() - return tpm_chip for a given chip number
83 * @chip_num: id to find
84 *
85 * The return'd chip has been tpm_try_get_ops'd and must be released via
86 * tpm_put_ops
87 */
88struct tpm_chip *tpm_chip_find_get(int chip_num)
89{
90 struct tpm_chip *chip, *res = NULL;
91 int chip_prev;
92
93 mutex_lock(&idr_lock);
94
95 if (chip_num == TPM_ANY_NUM) {
96 chip_num = 0;
97 do {
98 chip_prev = chip_num;
99 chip = idr_get_next(&dev_nums_idr, &chip_num);
100 if (chip && !tpm_try_get_ops(chip)) {
101 res = chip;
102 break;
103 }
104 } while (chip_prev != chip_num);
105 } else {
106 chip = idr_find(&dev_nums_idr, chip_num);
107 if (chip && !tpm_try_get_ops(chip))
108 res = chip;
109 }
110
111 mutex_unlock(&idr_lock);
112
113 return res;
114}
115
116/**
117 * tpm_dev_release() - free chip memory and the device number
118 * @dev: the character device for the TPM chip
119 *
120 * This is used as the release function for the character device.
121 */
122static void tpm_dev_release(struct device *dev)
123{
124 struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev);
125
126 mutex_lock(&idr_lock);
127 idr_remove(&dev_nums_idr, chip->dev_num);
128 mutex_unlock(&idr_lock);
129
130 kfree(chip->log.bios_event_log);
131 kfree(chip);
132}
133
134/**
135 * tpm_chip_alloc() - allocate a new struct tpm_chip instance
136 * @pdev: device to which the chip is associated
137 * At this point pdev mst be initialized, but does not have to
138 * be registered
139 * @ops: struct tpm_class_ops instance
140 *
141 * Allocates a new struct tpm_chip instance and assigns a free
142 * device number for it. Must be paired with put_device(&chip->dev).
143 */
144struct tpm_chip *tpm_chip_alloc(struct device *dev,
145 const struct tpm_class_ops *ops)
146{
147 struct tpm_chip *chip;
148 int rc;
149
150 chip = kzalloc(sizeof(*chip), GFP_KERNEL);
151 if (chip == NULL)
152 return ERR_PTR(-ENOMEM);
153
154 mutex_init(&chip->tpm_mutex);
155 init_rwsem(&chip->ops_sem);
156
157 chip->ops = ops;
158
159 mutex_lock(&idr_lock);
160 rc = idr_alloc(&dev_nums_idr, NULL, 0, TPM_NUM_DEVICES, GFP_KERNEL);
161 mutex_unlock(&idr_lock);
162 if (rc < 0) {
163 dev_err(dev, "No available tpm device numbers\n");
164 kfree(chip);
165 return ERR_PTR(rc);
166 }
167 chip->dev_num = rc;
168
169 device_initialize(&chip->dev);
170
171 chip->dev.class = tpm_class;
172 chip->dev.release = tpm_dev_release;
173 chip->dev.parent = dev;
174 chip->dev.groups = chip->groups;
175
176 if (chip->dev_num == 0)
177 chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR);
178 else
179 chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num);
180
181 rc = dev_set_name(&chip->dev, "tpm%d", chip->dev_num);
182 if (rc)
183 goto out;
184
185 if (!dev)
186 chip->flags |= TPM_CHIP_FLAG_VIRTUAL;
187
188 cdev_init(&chip->cdev, &tpm_fops);
189 chip->cdev.owner = THIS_MODULE;
190 chip->cdev.kobj.parent = &chip->dev.kobj;
191
192 return chip;
193
194out:
195 put_device(&chip->dev);
196 return ERR_PTR(rc);
197}
198EXPORT_SYMBOL_GPL(tpm_chip_alloc);
199
200/**
201 * tpmm_chip_alloc() - allocate a new struct tpm_chip instance
202 * @pdev: parent device to which the chip is associated
203 * @ops: struct tpm_class_ops instance
204 *
205 * Same as tpm_chip_alloc except devm is used to do the put_device
206 */
207struct tpm_chip *tpmm_chip_alloc(struct device *pdev,
208 const struct tpm_class_ops *ops)
209{
210 struct tpm_chip *chip;
211 int rc;
212
213 chip = tpm_chip_alloc(pdev, ops);
214 if (IS_ERR(chip))
215 return chip;
216
217 rc = devm_add_action_or_reset(pdev,
218 (void (*)(void *)) put_device,
219 &chip->dev);
220 if (rc)
221 return ERR_PTR(rc);
222
223 dev_set_drvdata(pdev, chip);
224
225 return chip;
226}
227EXPORT_SYMBOL_GPL(tpmm_chip_alloc);
228
229static int tpm_add_char_device(struct tpm_chip *chip)
230{
231 int rc;
232
233 rc = cdev_add(&chip->cdev, chip->dev.devt, 1);
234 if (rc) {
235 dev_err(&chip->dev,
236 "unable to cdev_add() %s, major %d, minor %d, err=%d\n",
237 dev_name(&chip->dev), MAJOR(chip->dev.devt),
238 MINOR(chip->dev.devt), rc);
239
240 return rc;
241 }
242
243 rc = device_add(&chip->dev);
244 if (rc) {
245 dev_err(&chip->dev,
246 "unable to device_register() %s, major %d, minor %d, err=%d\n",
247 dev_name(&chip->dev), MAJOR(chip->dev.devt),
248 MINOR(chip->dev.devt), rc);
249
250 cdev_del(&chip->cdev);
251 return rc;
252 }
253
254 /* Make the chip available. */
255 mutex_lock(&idr_lock);
256 idr_replace(&dev_nums_idr, chip, chip->dev_num);
257 mutex_unlock(&idr_lock);
258
259 return rc;
260}
261
262static void tpm_del_char_device(struct tpm_chip *chip)
263{
264 cdev_del(&chip->cdev);
265 device_del(&chip->dev);
266
267 /* Make the chip unavailable. */
268 mutex_lock(&idr_lock);
269 idr_replace(&dev_nums_idr, NULL, chip->dev_num);
270 mutex_unlock(&idr_lock);
271
272 /* Make the driver uncallable. */
273 down_write(&chip->ops_sem);
274 if (chip->flags & TPM_CHIP_FLAG_TPM2)
275 tpm2_shutdown(chip, TPM2_SU_CLEAR);
276 chip->ops = NULL;
277 up_write(&chip->ops_sem);
278}
279
280static void tpm_del_legacy_sysfs(struct tpm_chip *chip)
281{
282 struct attribute **i;
283
284 if (chip->flags & (TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_VIRTUAL))
285 return;
286
287 sysfs_remove_link(&chip->dev.parent->kobj, "ppi");
288
289 for (i = chip->groups[0]->attrs; *i != NULL; ++i)
290 sysfs_remove_link(&chip->dev.parent->kobj, (*i)->name);
291}
292
293/* For compatibility with legacy sysfs paths we provide symlinks from the
294 * parent dev directory to selected names within the tpm chip directory. Old
295 * kernel versions created these files directly under the parent.
296 */
297static int tpm_add_legacy_sysfs(struct tpm_chip *chip)
298{
299 struct attribute **i;
300 int rc;
301
302 if (chip->flags & (TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_VIRTUAL))
303 return 0;
304
305 rc = __compat_only_sysfs_link_entry_to_kobj(
306 &chip->dev.parent->kobj, &chip->dev.kobj, "ppi");
307 if (rc && rc != -ENOENT)
308 return rc;
309
310 /* All the names from tpm-sysfs */
311 for (i = chip->groups[0]->attrs; *i != NULL; ++i) {
312 rc = __compat_only_sysfs_link_entry_to_kobj(
313 &chip->dev.parent->kobj, &chip->dev.kobj, (*i)->name);
314 if (rc) {
315 tpm_del_legacy_sysfs(chip);
316 return rc;
317 }
318 }
319
320 return 0;
321}
322/*
323 * tpm_chip_register() - create a character device for the TPM chip
324 * @chip: TPM chip to use.
325 *
326 * Creates a character device for the TPM chip and adds sysfs attributes for
327 * the device. As the last step this function adds the chip to the list of TPM
328 * chips available for in-kernel use.
329 *
330 * This function should be only called after the chip initialization is
331 * complete.
332 */
333int tpm_chip_register(struct tpm_chip *chip)
334{
335 int rc;
336
337 if (chip->ops->flags & TPM_OPS_AUTO_STARTUP) {
338 if (chip->flags & TPM_CHIP_FLAG_TPM2)
339 rc = tpm2_auto_startup(chip);
340 else
341 rc = tpm1_auto_startup(chip);
342 if (rc)
343 return rc;
344 }
345
346 tpm_sysfs_add_device(chip);
347
348 rc = tpm_bios_log_setup(chip);
349 if (rc != 0 && rc != -ENODEV)
350 return rc;
351
352 tpm_add_ppi(chip);
353
354 rc = tpm_add_char_device(chip);
355 if (rc) {
356 tpm_bios_log_teardown(chip);
357 return rc;
358 }
359
360 rc = tpm_add_legacy_sysfs(chip);
361 if (rc) {
362 tpm_chip_unregister(chip);
363 return rc;
364 }
365
366 return 0;
367}
368EXPORT_SYMBOL_GPL(tpm_chip_register);
369
370/*
371 * tpm_chip_unregister() - release the TPM driver
372 * @chip: TPM chip to use.
373 *
374 * Takes the chip first away from the list of available TPM chips and then
375 * cleans up all the resources reserved by tpm_chip_register().
376 *
377 * Once this function returns the driver call backs in 'op's will not be
378 * running and will no longer start.
379 *
380 * NOTE: This function should be only called before deinitializing chip
381 * resources.
382 */
383void tpm_chip_unregister(struct tpm_chip *chip)
384{
385 tpm_del_legacy_sysfs(chip);
386 tpm_bios_log_teardown(chip);
387 tpm_del_char_device(chip);
388}
389EXPORT_SYMBOL_GPL(tpm_chip_unregister);