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