Commit | Line | Data |
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afb5abc2 JS |
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> | |
313d21ee | 28 | #include <linux/major.h> |
fd3ec366 | 29 | #include <linux/tpm_eventlog.h> |
6e592a06 | 30 | #include <linux/hw_random.h> |
afb5abc2 | 31 | #include "tpm.h" |
afb5abc2 | 32 | |
15516788 SB |
33 | DEFINE_IDR(dev_nums_idr); |
34 | static DEFINE_MUTEX(idr_lock); | |
afb5abc2 | 35 | |
313d21ee | 36 | struct class *tpm_class; |
fdc915f7 | 37 | struct class *tpmrm_class; |
313d21ee JS |
38 | dev_t tpm_devt; |
39 | ||
4e26195f JG |
40 | /** |
41 | * tpm_try_get_ops() - Get a ref to the tpm_chip | |
42 | * @chip: Chip to ref | |
43 | * | |
44 | * The caller must already have some kind of locking to ensure that chip is | |
45 | * valid. This function will lock the chip so that the ops member can be | |
46 | * accessed safely. The locking prevents tpm_chip_unregister from | |
47 | * completing, so it should not be held for long periods. | |
48 | * | |
49 | * Returns -ERRNO if the chip could not be got. | |
afb5abc2 | 50 | */ |
4e26195f JG |
51 | int tpm_try_get_ops(struct tpm_chip *chip) |
52 | { | |
53 | int rc = -EIO; | |
54 | ||
55 | get_device(&chip->dev); | |
56 | ||
57 | down_read(&chip->ops_sem); | |
58 | if (!chip->ops) | |
59 | goto out_lock; | |
60 | ||
4e26195f JG |
61 | return 0; |
62 | out_lock: | |
63 | up_read(&chip->ops_sem); | |
64 | put_device(&chip->dev); | |
65 | return rc; | |
66 | } | |
67 | EXPORT_SYMBOL_GPL(tpm_try_get_ops); | |
68 | ||
69 | /** | |
70 | * tpm_put_ops() - Release a ref to the tpm_chip | |
71 | * @chip: Chip to put | |
72 | * | |
73 | * This is the opposite pair to tpm_try_get_ops(). After this returns chip may | |
74 | * be kfree'd. | |
75 | */ | |
76 | void tpm_put_ops(struct tpm_chip *chip) | |
77 | { | |
4e26195f JG |
78 | up_read(&chip->ops_sem); |
79 | put_device(&chip->dev); | |
80 | } | |
81 | EXPORT_SYMBOL_GPL(tpm_put_ops); | |
82 | ||
83 | /** | |
aad887f6 JS |
84 | * tpm_chip_find_get() - find and reserve a TPM chip |
85 | * @chip: a &struct tpm_chip instance, %NULL for the default chip | |
4e26195f | 86 | * |
aad887f6 JS |
87 | * Finds a TPM chip and reserves its class device and operations. The chip must |
88 | * be released with tpm_chip_put_ops() after use. | |
89 | * | |
90 | * Return: | |
91 | * A reserved &struct tpm_chip instance. | |
92 | * %NULL if a chip is not found. | |
93 | * %NULL if the chip is not available. | |
37f4915f | 94 | */ |
aad887f6 | 95 | struct tpm_chip *tpm_chip_find_get(struct tpm_chip *chip) |
afb5abc2 | 96 | { |
aad887f6 JS |
97 | struct tpm_chip *res = NULL; |
98 | int chip_num = 0; | |
15516788 SB |
99 | int chip_prev; |
100 | ||
101 | mutex_lock(&idr_lock); | |
102 | ||
aad887f6 | 103 | if (!chip) { |
15516788 SB |
104 | do { |
105 | chip_prev = chip_num; | |
106 | chip = idr_get_next(&dev_nums_idr, &chip_num); | |
107 | if (chip && !tpm_try_get_ops(chip)) { | |
108 | res = chip; | |
109 | break; | |
110 | } | |
111 | } while (chip_prev != chip_num); | |
112 | } else { | |
aad887f6 | 113 | if (!tpm_try_get_ops(chip)) |
15516788 SB |
114 | res = chip; |
115 | } | |
afb5abc2 | 116 | |
15516788 | 117 | mutex_unlock(&idr_lock); |
afb5abc2 | 118 | |
15516788 | 119 | return res; |
afb5abc2 JS |
120 | } |
121 | ||
122 | /** | |
313d21ee JS |
123 | * tpm_dev_release() - free chip memory and the device number |
124 | * @dev: the character device for the TPM chip | |
afb5abc2 | 125 | * |
313d21ee | 126 | * This is used as the release function for the character device. |
afb5abc2 | 127 | */ |
313d21ee | 128 | static void tpm_dev_release(struct device *dev) |
afb5abc2 | 129 | { |
313d21ee | 130 | struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev); |
afb5abc2 | 131 | |
15516788 SB |
132 | mutex_lock(&idr_lock); |
133 | idr_remove(&dev_nums_idr, chip->dev_num); | |
134 | mutex_unlock(&idr_lock); | |
135 | ||
748935ee | 136 | kfree(chip->log.bios_event_log); |
745b361e | 137 | kfree(chip->work_space.context_buf); |
4d57856a | 138 | kfree(chip->work_space.session_buf); |
afb5abc2 JS |
139 | kfree(chip); |
140 | } | |
141 | ||
fdc915f7 JB |
142 | static void tpm_devs_release(struct device *dev) |
143 | { | |
144 | struct tpm_chip *chip = container_of(dev, struct tpm_chip, devs); | |
145 | ||
146 | /* release the master device reference */ | |
147 | put_device(&chip->dev); | |
148 | } | |
149 | ||
d1bd4a79 JZ |
150 | /** |
151 | * tpm_class_shutdown() - prepare the TPM device for loss of power. | |
152 | * @dev: device to which the chip is associated. | |
153 | * | |
154 | * Issues a TPM2_Shutdown command prior to loss of power, as required by the | |
155 | * TPM 2.0 spec. | |
156 | * Then, calls bus- and device- specific shutdown code. | |
157 | * | |
158 | * XXX: This codepath relies on the fact that sysfs is not enabled for | |
159 | * TPM2: sysfs uses an implicit lock on chip->ops, so this could race if TPM2 | |
160 | * has sysfs support enabled before TPM sysfs's implicit locking is fixed. | |
161 | */ | |
162 | static int tpm_class_shutdown(struct device *dev) | |
163 | { | |
164 | struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev); | |
165 | ||
166 | if (chip->flags & TPM_CHIP_FLAG_TPM2) { | |
167 | down_write(&chip->ops_sem); | |
168 | tpm2_shutdown(chip, TPM2_SU_CLEAR); | |
169 | chip->ops = NULL; | |
170 | up_write(&chip->ops_sem); | |
171 | } | |
7521621e | 172 | |
d1bd4a79 JZ |
173 | return 0; |
174 | } | |
175 | ||
afb5abc2 | 176 | /** |
3897cd9c JG |
177 | * tpm_chip_alloc() - allocate a new struct tpm_chip instance |
178 | * @pdev: device to which the chip is associated | |
179 | * At this point pdev mst be initialized, but does not have to | |
180 | * be registered | |
afb5abc2 JS |
181 | * @ops: struct tpm_class_ops instance |
182 | * | |
183 | * Allocates a new struct tpm_chip instance and assigns a free | |
3897cd9c | 184 | * device number for it. Must be paired with put_device(&chip->dev). |
afb5abc2 | 185 | */ |
2998b02b | 186 | struct tpm_chip *tpm_chip_alloc(struct device *pdev, |
3897cd9c | 187 | const struct tpm_class_ops *ops) |
afb5abc2 JS |
188 | { |
189 | struct tpm_chip *chip; | |
4f3b193d | 190 | int rc; |
afb5abc2 JS |
191 | |
192 | chip = kzalloc(sizeof(*chip), GFP_KERNEL); | |
193 | if (chip == NULL) | |
194 | return ERR_PTR(-ENOMEM); | |
195 | ||
196 | mutex_init(&chip->tpm_mutex); | |
4e26195f | 197 | init_rwsem(&chip->ops_sem); |
afb5abc2 JS |
198 | |
199 | chip->ops = ops; | |
200 | ||
15516788 SB |
201 | mutex_lock(&idr_lock); |
202 | rc = idr_alloc(&dev_nums_idr, NULL, 0, TPM_NUM_DEVICES, GFP_KERNEL); | |
203 | mutex_unlock(&idr_lock); | |
204 | if (rc < 0) { | |
2998b02b | 205 | dev_err(pdev, "No available tpm device numbers\n"); |
afb5abc2 | 206 | kfree(chip); |
15516788 | 207 | return ERR_PTR(rc); |
afb5abc2 | 208 | } |
15516788 | 209 | chip->dev_num = rc; |
afb5abc2 | 210 | |
3635e2ec | 211 | device_initialize(&chip->dev); |
fdc915f7 | 212 | device_initialize(&chip->devs); |
afb5abc2 | 213 | |
313d21ee | 214 | chip->dev.class = tpm_class; |
7521621e | 215 | chip->dev.class->shutdown_pre = tpm_class_shutdown; |
313d21ee | 216 | chip->dev.release = tpm_dev_release; |
2998b02b | 217 | chip->dev.parent = pdev; |
9b774d5c | 218 | chip->dev.groups = chip->groups; |
313d21ee | 219 | |
fdc915f7 JB |
220 | chip->devs.parent = pdev; |
221 | chip->devs.class = tpmrm_class; | |
222 | chip->devs.release = tpm_devs_release; | |
223 | /* get extra reference on main device to hold on | |
224 | * behalf of devs. This holds the chip structure | |
225 | * while cdevs is in use. The corresponding put | |
8979b02a | 226 | * is in the tpm_devs_release (TPM2 only) |
fdc915f7 | 227 | */ |
8979b02a SB |
228 | if (chip->flags & TPM_CHIP_FLAG_TPM2) |
229 | get_device(&chip->dev); | |
fdc915f7 | 230 | |
313d21ee JS |
231 | if (chip->dev_num == 0) |
232 | chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR); | |
233 | else | |
234 | chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num); | |
235 | ||
fdc915f7 JB |
236 | chip->devs.devt = |
237 | MKDEV(MAJOR(tpm_devt), chip->dev_num + TPM_NUM_DEVICES); | |
238 | ||
3635e2ec | 239 | rc = dev_set_name(&chip->dev, "tpm%d", chip->dev_num); |
fdc915f7 JB |
240 | if (rc) |
241 | goto out; | |
242 | rc = dev_set_name(&chip->devs, "tpmrm%d", chip->dev_num); | |
3635e2ec JG |
243 | if (rc) |
244 | goto out; | |
313d21ee | 245 | |
2998b02b | 246 | if (!pdev) |
2f9f5377 SB |
247 | chip->flags |= TPM_CHIP_FLAG_VIRTUAL; |
248 | ||
313d21ee | 249 | cdev_init(&chip->cdev, &tpm_fops); |
fdc915f7 | 250 | cdev_init(&chip->cdevs, &tpmrm_fops); |
2072df40 | 251 | chip->cdev.owner = THIS_MODULE; |
fdc915f7 | 252 | chip->cdevs.owner = THIS_MODULE; |
313d21ee | 253 | |
745b361e JS |
254 | chip->work_space.context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); |
255 | if (!chip->work_space.context_buf) { | |
256 | rc = -ENOMEM; | |
257 | goto out; | |
258 | } | |
4d57856a JB |
259 | chip->work_space.session_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); |
260 | if (!chip->work_space.session_buf) { | |
261 | rc = -ENOMEM; | |
262 | goto out; | |
263 | } | |
745b361e | 264 | |
877c57d0 | 265 | chip->locality = -1; |
3897cd9c JG |
266 | return chip; |
267 | ||
268 | out: | |
fdc915f7 | 269 | put_device(&chip->devs); |
3897cd9c JG |
270 | put_device(&chip->dev); |
271 | return ERR_PTR(rc); | |
272 | } | |
273 | EXPORT_SYMBOL_GPL(tpm_chip_alloc); | |
274 | ||
275 | /** | |
276 | * tpmm_chip_alloc() - allocate a new struct tpm_chip instance | |
277 | * @pdev: parent device to which the chip is associated | |
278 | * @ops: struct tpm_class_ops instance | |
279 | * | |
280 | * Same as tpm_chip_alloc except devm is used to do the put_device | |
281 | */ | |
282 | struct tpm_chip *tpmm_chip_alloc(struct device *pdev, | |
283 | const struct tpm_class_ops *ops) | |
284 | { | |
285 | struct tpm_chip *chip; | |
286 | int rc; | |
287 | ||
288 | chip = tpm_chip_alloc(pdev, ops); | |
289 | if (IS_ERR(chip)) | |
290 | return chip; | |
291 | ||
2b88cd96 SM |
292 | rc = devm_add_action_or_reset(pdev, |
293 | (void (*)(void *)) put_device, | |
294 | &chip->dev); | |
295 | if (rc) | |
4f3b193d | 296 | return ERR_PTR(rc); |
8e0ee3c9 | 297 | |
3897cd9c | 298 | dev_set_drvdata(pdev, chip); |
3635e2ec | 299 | |
3897cd9c | 300 | return chip; |
afb5abc2 JS |
301 | } |
302 | EXPORT_SYMBOL_GPL(tpmm_chip_alloc); | |
303 | ||
72c91ce8 | 304 | static int tpm_add_char_device(struct tpm_chip *chip) |
313d21ee JS |
305 | { |
306 | int rc; | |
307 | ||
8dbbf582 | 308 | rc = cdev_device_add(&chip->cdev, &chip->dev); |
313d21ee JS |
309 | if (rc) { |
310 | dev_err(&chip->dev, | |
8dbbf582 | 311 | "unable to cdev_device_add() %s, major %d, minor %d, err=%d\n", |
3635e2ec | 312 | dev_name(&chip->dev), MAJOR(chip->dev.devt), |
313d21ee | 313 | MINOR(chip->dev.devt), rc); |
313d21ee JS |
314 | return rc; |
315 | } | |
316 | ||
af82455f LT |
317 | if (chip->flags & TPM_CHIP_FLAG_TPM2) { |
318 | rc = cdev_device_add(&chip->cdevs, &chip->devs); | |
319 | if (rc) { | |
320 | dev_err(&chip->devs, | |
321 | "unable to cdev_device_add() %s, major %d, minor %d, err=%d\n", | |
322 | dev_name(&chip->devs), MAJOR(chip->devs.devt), | |
323 | MINOR(chip->devs.devt), rc); | |
324 | return rc; | |
325 | } | |
fdc915f7 JB |
326 | } |
327 | ||
15516788 SB |
328 | /* Make the chip available. */ |
329 | mutex_lock(&idr_lock); | |
330 | idr_replace(&dev_nums_idr, chip, chip->dev_num); | |
331 | mutex_unlock(&idr_lock); | |
332 | ||
313d21ee JS |
333 | return rc; |
334 | } | |
335 | ||
72c91ce8 | 336 | static void tpm_del_char_device(struct tpm_chip *chip) |
313d21ee | 337 | { |
8dbbf582 | 338 | cdev_device_del(&chip->cdev, &chip->dev); |
15516788 SB |
339 | |
340 | /* Make the chip unavailable. */ | |
341 | mutex_lock(&idr_lock); | |
342 | idr_replace(&dev_nums_idr, NULL, chip->dev_num); | |
343 | mutex_unlock(&idr_lock); | |
4e26195f JG |
344 | |
345 | /* Make the driver uncallable. */ | |
346 | down_write(&chip->ops_sem); | |
c0dff1f4 JS |
347 | if (chip->flags & TPM_CHIP_FLAG_TPM2) |
348 | tpm2_shutdown(chip, TPM2_SU_CLEAR); | |
4e26195f JG |
349 | chip->ops = NULL; |
350 | up_write(&chip->ops_sem); | |
313d21ee JS |
351 | } |
352 | ||
062807f2 JG |
353 | static void tpm_del_legacy_sysfs(struct tpm_chip *chip) |
354 | { | |
355 | struct attribute **i; | |
356 | ||
2f9f5377 | 357 | if (chip->flags & (TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_VIRTUAL)) |
062807f2 | 358 | return; |
34d47b63 | 359 | |
062807f2 JG |
360 | sysfs_remove_link(&chip->dev.parent->kobj, "ppi"); |
361 | ||
362 | for (i = chip->groups[0]->attrs; *i != NULL; ++i) | |
363 | sysfs_remove_link(&chip->dev.parent->kobj, (*i)->name); | |
34d47b63 JS |
364 | } |
365 | ||
062807f2 JG |
366 | /* For compatibility with legacy sysfs paths we provide symlinks from the |
367 | * parent dev directory to selected names within the tpm chip directory. Old | |
368 | * kernel versions created these files directly under the parent. | |
369 | */ | |
370 | static int tpm_add_legacy_sysfs(struct tpm_chip *chip) | |
371 | { | |
372 | struct attribute **i; | |
373 | int rc; | |
374 | ||
2f9f5377 | 375 | if (chip->flags & (TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_VIRTUAL)) |
062807f2 JG |
376 | return 0; |
377 | ||
378 | rc = __compat_only_sysfs_link_entry_to_kobj( | |
379 | &chip->dev.parent->kobj, &chip->dev.kobj, "ppi"); | |
380 | if (rc && rc != -ENOENT) | |
381 | return rc; | |
382 | ||
383 | /* All the names from tpm-sysfs */ | |
384 | for (i = chip->groups[0]->attrs; *i != NULL; ++i) { | |
385 | rc = __compat_only_sysfs_link_entry_to_kobj( | |
386 | &chip->dev.parent->kobj, &chip->dev.kobj, (*i)->name); | |
387 | if (rc) { | |
388 | tpm_del_legacy_sysfs(chip); | |
389 | return rc; | |
390 | } | |
391 | } | |
392 | ||
393 | return 0; | |
394 | } | |
6e592a06 JG |
395 | |
396 | static int tpm_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait) | |
397 | { | |
398 | struct tpm_chip *chip = container_of(rng, struct tpm_chip, hwrng); | |
399 | ||
400 | return tpm_get_random(chip, data, max); | |
401 | } | |
402 | ||
403 | static int tpm_add_hwrng(struct tpm_chip *chip) | |
404 | { | |
405 | if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM)) | |
406 | return 0; | |
407 | ||
408 | snprintf(chip->hwrng_name, sizeof(chip->hwrng_name), | |
409 | "tpm-rng-%d", chip->dev_num); | |
410 | chip->hwrng.name = chip->hwrng_name; | |
411 | chip->hwrng.read = tpm_hwrng_read; | |
412 | return hwrng_register(&chip->hwrng); | |
413 | } | |
414 | ||
afb5abc2 | 415 | /* |
313d21ee | 416 | * tpm_chip_register() - create a character device for the TPM chip |
afb5abc2 JS |
417 | * @chip: TPM chip to use. |
418 | * | |
d972b052 JS |
419 | * Creates a character device for the TPM chip and adds sysfs attributes for |
420 | * the device. As the last step this function adds the chip to the list of TPM | |
421 | * chips available for in-kernel use. | |
afb5abc2 | 422 | * |
d972b052 JS |
423 | * This function should be only called after the chip initialization is |
424 | * complete. | |
afb5abc2 JS |
425 | */ |
426 | int tpm_chip_register(struct tpm_chip *chip) | |
427 | { | |
428 | int rc; | |
429 | ||
cae8b441 JG |
430 | if (chip->ops->flags & TPM_OPS_AUTO_STARTUP) { |
431 | if (chip->flags & TPM_CHIP_FLAG_TPM2) | |
432 | rc = tpm2_auto_startup(chip); | |
433 | else | |
434 | rc = tpm1_auto_startup(chip); | |
435 | if (rc) | |
436 | return rc; | |
437 | } | |
438 | ||
7518a21a JS |
439 | tpm_sysfs_add_device(chip); |
440 | ||
441 | rc = tpm_bios_log_setup(chip); | |
0cf577a0 | 442 | if (rc != 0 && rc != -ENODEV) |
34d47b63 | 443 | return rc; |
afb5abc2 | 444 | |
9b774d5c JS |
445 | tpm_add_ppi(chip); |
446 | ||
6e592a06 JG |
447 | rc = tpm_add_hwrng(chip); |
448 | if (rc) | |
449 | goto out_ppi; | |
450 | ||
72c91ce8 | 451 | rc = tpm_add_char_device(chip); |
6e592a06 JG |
452 | if (rc) |
453 | goto out_hwrng; | |
d972b052 | 454 | |
062807f2 JG |
455 | rc = tpm_add_legacy_sysfs(chip); |
456 | if (rc) { | |
457 | tpm_chip_unregister(chip); | |
458 | return rc; | |
d56e4f75 JS |
459 | } |
460 | ||
afb5abc2 | 461 | return 0; |
6e592a06 JG |
462 | |
463 | out_hwrng: | |
464 | if (IS_ENABLED(CONFIG_HW_RANDOM_TPM)) | |
465 | hwrng_unregister(&chip->hwrng); | |
466 | out_ppi: | |
467 | tpm_bios_log_teardown(chip); | |
468 | ||
469 | return rc; | |
afb5abc2 JS |
470 | } |
471 | EXPORT_SYMBOL_GPL(tpm_chip_register); | |
472 | ||
473 | /* | |
474 | * tpm_chip_unregister() - release the TPM driver | |
475 | * @chip: TPM chip to use. | |
476 | * | |
477 | * Takes the chip first away from the list of available TPM chips and then | |
478 | * cleans up all the resources reserved by tpm_chip_register(). | |
479 | * | |
4e26195f JG |
480 | * Once this function returns the driver call backs in 'op's will not be |
481 | * running and will no longer start. | |
482 | * | |
afb5abc2 JS |
483 | * NOTE: This function should be only called before deinitializing chip |
484 | * resources. | |
485 | */ | |
486 | void tpm_chip_unregister(struct tpm_chip *chip) | |
487 | { | |
062807f2 | 488 | tpm_del_legacy_sysfs(chip); |
6e592a06 JG |
489 | if (IS_ENABLED(CONFIG_HW_RANDOM_TPM)) |
490 | hwrng_unregister(&chip->hwrng); | |
7518a21a | 491 | tpm_bios_log_teardown(chip); |
af82455f LT |
492 | if (chip->flags & TPM_CHIP_FLAG_TPM2) |
493 | cdev_device_del(&chip->cdevs, &chip->devs); | |
72c91ce8 | 494 | tpm_del_char_device(chip); |
afb5abc2 JS |
495 | } |
496 | EXPORT_SYMBOL_GPL(tpm_chip_unregister); |