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