| 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 | |
| 28 | DEFINE_IDR(dev_nums_idr); |
| 29 | static DEFINE_MUTEX(idr_lock); |
| 30 | |
| 31 | struct class *tpm_class; |
| 32 | struct class *tpmrm_class; |
| 33 | dev_t tpm_devt; |
| 34 | |
| 35 | static 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 | |
| 50 | static 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 | |
| 64 | static 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 | |
| 72 | static 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 | |
| 80 | static void tpm_clk_enable(struct tpm_chip *chip) |
| 81 | { |
| 82 | if (chip->ops->clk_enable) |
| 83 | chip->ops->clk_enable(chip, true); |
| 84 | } |
| 85 | |
| 86 | static 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 | */ |
| 100 | int 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 | } |
| 123 | EXPORT_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 | */ |
| 133 | void tpm_chip_stop(struct tpm_chip *chip) |
| 134 | { |
| 135 | tpm_go_idle(chip); |
| 136 | tpm_relinquish_locality(chip); |
| 137 | tpm_clk_disable(chip); |
| 138 | } |
| 139 | EXPORT_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 | */ |
| 152 | int 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; |
| 168 | out_lock: |
| 169 | mutex_unlock(&chip->tpm_mutex); |
| 170 | out_ops: |
| 171 | up_read(&chip->ops_sem); |
| 172 | put_device(&chip->dev); |
| 173 | return rc; |
| 174 | } |
| 175 | EXPORT_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 | */ |
| 184 | void 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 | } |
| 191 | EXPORT_SYMBOL_GPL(tpm_put_ops); |
| 192 | |
| 193 | /** |
| 194 | * tpm_default_chip() - find a TPM chip and get a reference to it |
| 195 | */ |
| 196 | struct 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 | } |
| 218 | EXPORT_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 | */ |
| 235 | struct 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 | */ |
| 262 | static 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 | static void tpm_devs_release(struct device *dev) |
| 278 | { |
| 279 | struct tpm_chip *chip = container_of(dev, struct tpm_chip, devs); |
| 280 | |
| 281 | /* release the master device reference */ |
| 282 | put_device(&chip->dev); |
| 283 | } |
| 284 | |
| 285 | /** |
| 286 | * tpm_class_shutdown() - prepare the TPM device for loss of power. |
| 287 | * @dev: device to which the chip is associated. |
| 288 | * |
| 289 | * Issues a TPM2_Shutdown command prior to loss of power, as required by the |
| 290 | * TPM 2.0 spec. |
| 291 | * Then, calls bus- and device- specific shutdown code. |
| 292 | * |
| 293 | * XXX: This codepath relies on the fact that sysfs is not enabled for |
| 294 | * TPM2: sysfs uses an implicit lock on chip->ops, so this could race if TPM2 |
| 295 | * has sysfs support enabled before TPM sysfs's implicit locking is fixed. |
| 296 | */ |
| 297 | static int tpm_class_shutdown(struct device *dev) |
| 298 | { |
| 299 | struct tpm_chip *chip = container_of(dev, struct tpm_chip, dev); |
| 300 | |
| 301 | down_write(&chip->ops_sem); |
| 302 | if (chip->flags & TPM_CHIP_FLAG_TPM2) { |
| 303 | if (!tpm_chip_start(chip)) { |
| 304 | tpm2_shutdown(chip, TPM2_SU_CLEAR); |
| 305 | tpm_chip_stop(chip); |
| 306 | } |
| 307 | } |
| 308 | chip->ops = NULL; |
| 309 | up_write(&chip->ops_sem); |
| 310 | |
| 311 | return 0; |
| 312 | } |
| 313 | |
| 314 | /** |
| 315 | * tpm_chip_alloc() - allocate a new struct tpm_chip instance |
| 316 | * @pdev: device to which the chip is associated |
| 317 | * At this point pdev mst be initialized, but does not have to |
| 318 | * be registered |
| 319 | * @ops: struct tpm_class_ops instance |
| 320 | * |
| 321 | * Allocates a new struct tpm_chip instance and assigns a free |
| 322 | * device number for it. Must be paired with put_device(&chip->dev). |
| 323 | */ |
| 324 | struct tpm_chip *tpm_chip_alloc(struct device *pdev, |
| 325 | const struct tpm_class_ops *ops) |
| 326 | { |
| 327 | struct tpm_chip *chip; |
| 328 | int rc; |
| 329 | |
| 330 | chip = kzalloc(sizeof(*chip), GFP_KERNEL); |
| 331 | if (chip == NULL) |
| 332 | return ERR_PTR(-ENOMEM); |
| 333 | |
| 334 | mutex_init(&chip->tpm_mutex); |
| 335 | init_rwsem(&chip->ops_sem); |
| 336 | |
| 337 | chip->ops = ops; |
| 338 | |
| 339 | mutex_lock(&idr_lock); |
| 340 | rc = idr_alloc(&dev_nums_idr, NULL, 0, TPM_NUM_DEVICES, GFP_KERNEL); |
| 341 | mutex_unlock(&idr_lock); |
| 342 | if (rc < 0) { |
| 343 | dev_err(pdev, "No available tpm device numbers\n"); |
| 344 | kfree(chip); |
| 345 | return ERR_PTR(rc); |
| 346 | } |
| 347 | chip->dev_num = rc; |
| 348 | |
| 349 | device_initialize(&chip->dev); |
| 350 | device_initialize(&chip->devs); |
| 351 | |
| 352 | chip->dev.class = tpm_class; |
| 353 | chip->dev.class->shutdown_pre = tpm_class_shutdown; |
| 354 | chip->dev.release = tpm_dev_release; |
| 355 | chip->dev.parent = pdev; |
| 356 | chip->dev.groups = chip->groups; |
| 357 | |
| 358 | chip->devs.parent = pdev; |
| 359 | chip->devs.class = tpmrm_class; |
| 360 | chip->devs.release = tpm_devs_release; |
| 361 | /* get extra reference on main device to hold on |
| 362 | * behalf of devs. This holds the chip structure |
| 363 | * while cdevs is in use. The corresponding put |
| 364 | * is in the tpm_devs_release (TPM2 only) |
| 365 | */ |
| 366 | if (chip->flags & TPM_CHIP_FLAG_TPM2) |
| 367 | get_device(&chip->dev); |
| 368 | |
| 369 | if (chip->dev_num == 0) |
| 370 | chip->dev.devt = MKDEV(MISC_MAJOR, TPM_MINOR); |
| 371 | else |
| 372 | chip->dev.devt = MKDEV(MAJOR(tpm_devt), chip->dev_num); |
| 373 | |
| 374 | chip->devs.devt = |
| 375 | MKDEV(MAJOR(tpm_devt), chip->dev_num + TPM_NUM_DEVICES); |
| 376 | |
| 377 | rc = dev_set_name(&chip->dev, "tpm%d", chip->dev_num); |
| 378 | if (rc) |
| 379 | goto out; |
| 380 | rc = dev_set_name(&chip->devs, "tpmrm%d", chip->dev_num); |
| 381 | if (rc) |
| 382 | goto out; |
| 383 | |
| 384 | if (!pdev) |
| 385 | chip->flags |= TPM_CHIP_FLAG_VIRTUAL; |
| 386 | |
| 387 | cdev_init(&chip->cdev, &tpm_fops); |
| 388 | cdev_init(&chip->cdevs, &tpmrm_fops); |
| 389 | chip->cdev.owner = THIS_MODULE; |
| 390 | chip->cdevs.owner = THIS_MODULE; |
| 391 | |
| 392 | chip->work_space.context_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); |
| 393 | if (!chip->work_space.context_buf) { |
| 394 | rc = -ENOMEM; |
| 395 | goto out; |
| 396 | } |
| 397 | chip->work_space.session_buf = kzalloc(PAGE_SIZE, GFP_KERNEL); |
| 398 | if (!chip->work_space.session_buf) { |
| 399 | rc = -ENOMEM; |
| 400 | goto out; |
| 401 | } |
| 402 | |
| 403 | chip->locality = -1; |
| 404 | return chip; |
| 405 | |
| 406 | out: |
| 407 | put_device(&chip->devs); |
| 408 | put_device(&chip->dev); |
| 409 | return ERR_PTR(rc); |
| 410 | } |
| 411 | EXPORT_SYMBOL_GPL(tpm_chip_alloc); |
| 412 | |
| 413 | /** |
| 414 | * tpmm_chip_alloc() - allocate a new struct tpm_chip instance |
| 415 | * @pdev: parent device to which the chip is associated |
| 416 | * @ops: struct tpm_class_ops instance |
| 417 | * |
| 418 | * Same as tpm_chip_alloc except devm is used to do the put_device |
| 419 | */ |
| 420 | struct tpm_chip *tpmm_chip_alloc(struct device *pdev, |
| 421 | const struct tpm_class_ops *ops) |
| 422 | { |
| 423 | struct tpm_chip *chip; |
| 424 | int rc; |
| 425 | |
| 426 | chip = tpm_chip_alloc(pdev, ops); |
| 427 | if (IS_ERR(chip)) |
| 428 | return chip; |
| 429 | |
| 430 | rc = devm_add_action_or_reset(pdev, |
| 431 | (void (*)(void *)) put_device, |
| 432 | &chip->dev); |
| 433 | if (rc) |
| 434 | return ERR_PTR(rc); |
| 435 | |
| 436 | dev_set_drvdata(pdev, chip); |
| 437 | |
| 438 | return chip; |
| 439 | } |
| 440 | EXPORT_SYMBOL_GPL(tpmm_chip_alloc); |
| 441 | |
| 442 | static int tpm_add_char_device(struct tpm_chip *chip) |
| 443 | { |
| 444 | int rc; |
| 445 | |
| 446 | rc = cdev_device_add(&chip->cdev, &chip->dev); |
| 447 | if (rc) { |
| 448 | dev_err(&chip->dev, |
| 449 | "unable to cdev_device_add() %s, major %d, minor %d, err=%d\n", |
| 450 | dev_name(&chip->dev), MAJOR(chip->dev.devt), |
| 451 | MINOR(chip->dev.devt), rc); |
| 452 | return rc; |
| 453 | } |
| 454 | |
| 455 | if (chip->flags & TPM_CHIP_FLAG_TPM2) { |
| 456 | rc = cdev_device_add(&chip->cdevs, &chip->devs); |
| 457 | if (rc) { |
| 458 | dev_err(&chip->devs, |
| 459 | "unable to cdev_device_add() %s, major %d, minor %d, err=%d\n", |
| 460 | dev_name(&chip->devs), MAJOR(chip->devs.devt), |
| 461 | MINOR(chip->devs.devt), rc); |
| 462 | return rc; |
| 463 | } |
| 464 | } |
| 465 | |
| 466 | /* Make the chip available. */ |
| 467 | mutex_lock(&idr_lock); |
| 468 | idr_replace(&dev_nums_idr, chip, chip->dev_num); |
| 469 | mutex_unlock(&idr_lock); |
| 470 | |
| 471 | return rc; |
| 472 | } |
| 473 | |
| 474 | static void tpm_del_char_device(struct tpm_chip *chip) |
| 475 | { |
| 476 | cdev_device_del(&chip->cdev, &chip->dev); |
| 477 | |
| 478 | /* Make the chip unavailable. */ |
| 479 | mutex_lock(&idr_lock); |
| 480 | idr_replace(&dev_nums_idr, NULL, chip->dev_num); |
| 481 | mutex_unlock(&idr_lock); |
| 482 | |
| 483 | /* Make the driver uncallable. */ |
| 484 | down_write(&chip->ops_sem); |
| 485 | if (chip->flags & TPM_CHIP_FLAG_TPM2) { |
| 486 | if (!tpm_chip_start(chip)) { |
| 487 | tpm2_shutdown(chip, TPM2_SU_CLEAR); |
| 488 | tpm_chip_stop(chip); |
| 489 | } |
| 490 | } |
| 491 | chip->ops = NULL; |
| 492 | up_write(&chip->ops_sem); |
| 493 | } |
| 494 | |
| 495 | static void tpm_del_legacy_sysfs(struct tpm_chip *chip) |
| 496 | { |
| 497 | struct attribute **i; |
| 498 | |
| 499 | if (chip->flags & (TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_VIRTUAL)) |
| 500 | return; |
| 501 | |
| 502 | sysfs_remove_link(&chip->dev.parent->kobj, "ppi"); |
| 503 | |
| 504 | for (i = chip->groups[0]->attrs; *i != NULL; ++i) |
| 505 | sysfs_remove_link(&chip->dev.parent->kobj, (*i)->name); |
| 506 | } |
| 507 | |
| 508 | /* For compatibility with legacy sysfs paths we provide symlinks from the |
| 509 | * parent dev directory to selected names within the tpm chip directory. Old |
| 510 | * kernel versions created these files directly under the parent. |
| 511 | */ |
| 512 | static int tpm_add_legacy_sysfs(struct tpm_chip *chip) |
| 513 | { |
| 514 | struct attribute **i; |
| 515 | int rc; |
| 516 | |
| 517 | if (chip->flags & (TPM_CHIP_FLAG_TPM2 | TPM_CHIP_FLAG_VIRTUAL)) |
| 518 | return 0; |
| 519 | |
| 520 | rc = __compat_only_sysfs_link_entry_to_kobj( |
| 521 | &chip->dev.parent->kobj, &chip->dev.kobj, "ppi"); |
| 522 | if (rc && rc != -ENOENT) |
| 523 | return rc; |
| 524 | |
| 525 | /* All the names from tpm-sysfs */ |
| 526 | for (i = chip->groups[0]->attrs; *i != NULL; ++i) { |
| 527 | rc = __compat_only_sysfs_link_entry_to_kobj( |
| 528 | &chip->dev.parent->kobj, &chip->dev.kobj, (*i)->name); |
| 529 | if (rc) { |
| 530 | tpm_del_legacy_sysfs(chip); |
| 531 | return rc; |
| 532 | } |
| 533 | } |
| 534 | |
| 535 | return 0; |
| 536 | } |
| 537 | |
| 538 | static int tpm_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait) |
| 539 | { |
| 540 | struct tpm_chip *chip = container_of(rng, struct tpm_chip, hwrng); |
| 541 | |
| 542 | return tpm_get_random(chip, data, max); |
| 543 | } |
| 544 | |
| 545 | static int tpm_add_hwrng(struct tpm_chip *chip) |
| 546 | { |
| 547 | if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM)) |
| 548 | return 0; |
| 549 | |
| 550 | snprintf(chip->hwrng_name, sizeof(chip->hwrng_name), |
| 551 | "tpm-rng-%d", chip->dev_num); |
| 552 | chip->hwrng.name = chip->hwrng_name; |
| 553 | chip->hwrng.read = tpm_hwrng_read; |
| 554 | return hwrng_register(&chip->hwrng); |
| 555 | } |
| 556 | |
| 557 | /* |
| 558 | * tpm_chip_register() - create a character device for the TPM chip |
| 559 | * @chip: TPM chip to use. |
| 560 | * |
| 561 | * Creates a character device for the TPM chip and adds sysfs attributes for |
| 562 | * the device. As the last step this function adds the chip to the list of TPM |
| 563 | * chips available for in-kernel use. |
| 564 | * |
| 565 | * This function should be only called after the chip initialization is |
| 566 | * complete. |
| 567 | */ |
| 568 | int tpm_chip_register(struct tpm_chip *chip) |
| 569 | { |
| 570 | int rc; |
| 571 | |
| 572 | rc = tpm_chip_start(chip); |
| 573 | if (rc) |
| 574 | return rc; |
| 575 | rc = tpm_auto_startup(chip); |
| 576 | tpm_chip_stop(chip); |
| 577 | if (rc) |
| 578 | return rc; |
| 579 | |
| 580 | tpm_sysfs_add_device(chip); |
| 581 | |
| 582 | rc = tpm_bios_log_setup(chip); |
| 583 | if (rc != 0 && rc != -ENODEV) |
| 584 | return rc; |
| 585 | |
| 586 | tpm_add_ppi(chip); |
| 587 | |
| 588 | rc = tpm_add_hwrng(chip); |
| 589 | if (rc) |
| 590 | goto out_ppi; |
| 591 | |
| 592 | rc = tpm_add_char_device(chip); |
| 593 | if (rc) |
| 594 | goto out_hwrng; |
| 595 | |
| 596 | rc = tpm_add_legacy_sysfs(chip); |
| 597 | if (rc) { |
| 598 | tpm_chip_unregister(chip); |
| 599 | return rc; |
| 600 | } |
| 601 | |
| 602 | return 0; |
| 603 | |
| 604 | out_hwrng: |
| 605 | if (IS_ENABLED(CONFIG_HW_RANDOM_TPM)) |
| 606 | hwrng_unregister(&chip->hwrng); |
| 607 | out_ppi: |
| 608 | tpm_bios_log_teardown(chip); |
| 609 | |
| 610 | return rc; |
| 611 | } |
| 612 | EXPORT_SYMBOL_GPL(tpm_chip_register); |
| 613 | |
| 614 | /* |
| 615 | * tpm_chip_unregister() - release the TPM driver |
| 616 | * @chip: TPM chip to use. |
| 617 | * |
| 618 | * Takes the chip first away from the list of available TPM chips and then |
| 619 | * cleans up all the resources reserved by tpm_chip_register(). |
| 620 | * |
| 621 | * Once this function returns the driver call backs in 'op's will not be |
| 622 | * running and will no longer start. |
| 623 | * |
| 624 | * NOTE: This function should be only called before deinitializing chip |
| 625 | * resources. |
| 626 | */ |
| 627 | void tpm_chip_unregister(struct tpm_chip *chip) |
| 628 | { |
| 629 | tpm_del_legacy_sysfs(chip); |
| 630 | if (IS_ENABLED(CONFIG_HW_RANDOM_TPM)) |
| 631 | hwrng_unregister(&chip->hwrng); |
| 632 | tpm_bios_log_teardown(chip); |
| 633 | if (chip->flags & TPM_CHIP_FLAG_TPM2) |
| 634 | cdev_device_del(&chip->cdevs, &chip->devs); |
| 635 | tpm_del_char_device(chip); |
| 636 | } |
| 637 | EXPORT_SYMBOL_GPL(tpm_chip_unregister); |