drivers/char/tpm/tpm.c

   1 /*
   2  * Copyright (C) 2004 IBM Corporation
   3  *
   4  * Authors:
   5  * Leendert van Doorn <leendert@watson.ibm.com>
   6  * Dave Safford <safford@watson.ibm.com>
   7  * Reiner Sailer <sailer@watson.ibm.com>
   8  * Kylene Hall <kjhall@us.ibm.com>
   9  *
  10  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  11  *
  12  * Device driver for TCG/TCPA TPM (trusted platform module).
  13  * Specifications at www.trustedcomputinggroup.org
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License as
  17  * published by the Free Software Foundation, version 2 of the
  18  * License.
  19  *
  20  * Note, the TPM chip is not interrupt driven (only polling)
  21  * and can have very long timeouts (minutes!). Hence the unusual
  22  * calls to msleep.
  23  *
  24  */
  25
  26 #include <linux/poll.h>
  27 #include <linux/slab.h>
  28 #include <linux/mutex.h>
  29 #include <linux/spinlock.h>
  30
  31 #include "tpm.h"
  32
  33 enum tpm_const {
  34         TPM_MINOR = 224,        /* officially assigned */
  35         TPM_BUFSIZE = 4096,
  36         TPM_NUM_DEVICES = 256,
  37 };
  38
  39 enum tpm_duration {
  40         TPM_SHORT = 0,
  41         TPM_MEDIUM = 1,
  42         TPM_LONG = 2,
  43         TPM_UNDEFINED,
  44 };
  45
  46 #define TPM_MAX_ORDINAL 243
  47 #define TPM_MAX_PROTECTED_ORDINAL 12
  48 #define TPM_PROTECTED_ORDINAL_MASK 0xFF
  49
  50 static LIST_HEAD(tpm_chip_list);
  51 static DEFINE_SPINLOCK(driver_lock);
  52 static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
  53
  54 /*
  55  * Array with one entry per ordinal defining the maximum amount
  56  * of time the chip could take to return the result.  The ordinal
  57  * designation of short, medium or long is defined in a table in
  58  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  59  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  60  * from the chip during initialization with a call to tpm_get_timeouts.
  61  */
  62 static const u8 tpm_protected_ordinal_duration[TPM_MAX_PROTECTED_ORDINAL] = {
  63         TPM_UNDEFINED,          /* 0 */
  64         TPM_UNDEFINED,
  65         TPM_UNDEFINED,
  66         TPM_UNDEFINED,
  67         TPM_UNDEFINED,
  68         TPM_UNDEFINED,          /* 5 */
  69         TPM_UNDEFINED,
  70         TPM_UNDEFINED,
  71         TPM_UNDEFINED,
  72         TPM_UNDEFINED,
  73         TPM_SHORT,              /* 10 */
  74         TPM_SHORT,
  75 };
  76
  77 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  78         TPM_UNDEFINED,          /* 0 */
  79         TPM_UNDEFINED,
  80         TPM_UNDEFINED,
  81         TPM_UNDEFINED,
  82         TPM_UNDEFINED,
  83         TPM_UNDEFINED,          /* 5 */
  84         TPM_UNDEFINED,
  85         TPM_UNDEFINED,
  86         TPM_UNDEFINED,
  87         TPM_UNDEFINED,
  88         TPM_SHORT,              /* 10 */
  89         TPM_SHORT,
  90         TPM_MEDIUM,
  91         TPM_LONG,
  92         TPM_LONG,
  93         TPM_MEDIUM,             /* 15 */
  94         TPM_SHORT,
  95         TPM_SHORT,
  96         TPM_MEDIUM,
  97         TPM_LONG,
  98         TPM_SHORT,              /* 20 */
  99         TPM_SHORT,
 100         TPM_MEDIUM,
 101         TPM_MEDIUM,
 102         TPM_MEDIUM,
 103         TPM_SHORT,              /* 25 */
 104         TPM_SHORT,
 105         TPM_MEDIUM,
 106         TPM_SHORT,
 107         TPM_SHORT,
 108         TPM_MEDIUM,             /* 30 */
 109         TPM_LONG,
 110         TPM_MEDIUM,
 111         TPM_SHORT,
 112         TPM_SHORT,
 113         TPM_SHORT,              /* 35 */
 114         TPM_MEDIUM,
 115         TPM_MEDIUM,
 116         TPM_UNDEFINED,
 117         TPM_UNDEFINED,
 118         TPM_MEDIUM,             /* 40 */
 119         TPM_LONG,
 120         TPM_MEDIUM,
 121         TPM_SHORT,
 122         TPM_SHORT,
 123         TPM_SHORT,              /* 45 */
 124         TPM_SHORT,
 125         TPM_SHORT,
 126         TPM_SHORT,
 127         TPM_LONG,
 128         TPM_MEDIUM,             /* 50 */
 129         TPM_MEDIUM,
 130         TPM_UNDEFINED,
 131         TPM_UNDEFINED,
 132         TPM_UNDEFINED,
 133         TPM_UNDEFINED,          /* 55 */
 134         TPM_UNDEFINED,
 135         TPM_UNDEFINED,
 136         TPM_UNDEFINED,
 137         TPM_UNDEFINED,
 138         TPM_MEDIUM,             /* 60 */
 139         TPM_MEDIUM,
 140         TPM_MEDIUM,
 141         TPM_SHORT,
 142         TPM_SHORT,
 143         TPM_MEDIUM,             /* 65 */
 144         TPM_UNDEFINED,
 145         TPM_UNDEFINED,
 146         TPM_UNDEFINED,
 147         TPM_UNDEFINED,
 148         TPM_SHORT,              /* 70 */
 149         TPM_SHORT,
 150         TPM_UNDEFINED,
 151         TPM_UNDEFINED,
 152         TPM_UNDEFINED,
 153         TPM_UNDEFINED,          /* 75 */
 154         TPM_UNDEFINED,
 155         TPM_UNDEFINED,
 156         TPM_UNDEFINED,
 157         TPM_UNDEFINED,
 158         TPM_LONG,               /* 80 */
 159         TPM_UNDEFINED,
 160         TPM_MEDIUM,
 161         TPM_LONG,
 162         TPM_SHORT,
 163         TPM_UNDEFINED,          /* 85 */
 164         TPM_UNDEFINED,
 165         TPM_UNDEFINED,
 166         TPM_UNDEFINED,
 167         TPM_UNDEFINED,
 168         TPM_SHORT,              /* 90 */
 169         TPM_SHORT,
 170         TPM_SHORT,
 171         TPM_SHORT,
 172         TPM_SHORT,
 173         TPM_UNDEFINED,          /* 95 */
 174         TPM_UNDEFINED,
 175         TPM_UNDEFINED,
 176         TPM_UNDEFINED,
 177         TPM_UNDEFINED,
 178         TPM_MEDIUM,             /* 100 */
 179         TPM_SHORT,
 180         TPM_SHORT,
 181         TPM_UNDEFINED,
 182         TPM_UNDEFINED,
 183         TPM_UNDEFINED,          /* 105 */
 184         TPM_UNDEFINED,
 185         TPM_UNDEFINED,
 186         TPM_UNDEFINED,
 187         TPM_UNDEFINED,
 188         TPM_SHORT,              /* 110 */
 189         TPM_SHORT,
 190         TPM_SHORT,
 191         TPM_SHORT,
 192         TPM_SHORT,
 193         TPM_SHORT,              /* 115 */
 194         TPM_SHORT,
 195         TPM_SHORT,
 196         TPM_UNDEFINED,
 197         TPM_UNDEFINED,
 198         TPM_LONG,               /* 120 */
 199         TPM_LONG,
 200         TPM_MEDIUM,
 201         TPM_UNDEFINED,
 202         TPM_SHORT,
 203         TPM_SHORT,              /* 125 */
 204         TPM_SHORT,
 205         TPM_LONG,
 206         TPM_SHORT,
 207         TPM_SHORT,
 208         TPM_SHORT,              /* 130 */
 209         TPM_MEDIUM,
 210         TPM_UNDEFINED,
 211         TPM_SHORT,
 212         TPM_MEDIUM,
 213         TPM_UNDEFINED,          /* 135 */
 214         TPM_UNDEFINED,
 215         TPM_UNDEFINED,
 216         TPM_UNDEFINED,
 217         TPM_UNDEFINED,
 218         TPM_SHORT,              /* 140 */
 219         TPM_SHORT,
 220         TPM_UNDEFINED,
 221         TPM_UNDEFINED,
 222         TPM_UNDEFINED,
 223         TPM_UNDEFINED,          /* 145 */
 224         TPM_UNDEFINED,
 225         TPM_UNDEFINED,
 226         TPM_UNDEFINED,
 227         TPM_UNDEFINED,
 228         TPM_SHORT,              /* 150 */
 229         TPM_MEDIUM,
 230         TPM_MEDIUM,
 231         TPM_SHORT,
 232         TPM_SHORT,
 233         TPM_UNDEFINED,          /* 155 */
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,
 236         TPM_UNDEFINED,
 237         TPM_UNDEFINED,
 238         TPM_SHORT,              /* 160 */
 239         TPM_SHORT,
 240         TPM_SHORT,
 241         TPM_SHORT,
 242         TPM_UNDEFINED,
 243         TPM_UNDEFINED,          /* 165 */
 244         TPM_UNDEFINED,
 245         TPM_UNDEFINED,
 246         TPM_UNDEFINED,
 247         TPM_UNDEFINED,
 248         TPM_LONG,               /* 170 */
 249         TPM_UNDEFINED,
 250         TPM_UNDEFINED,
 251         TPM_UNDEFINED,
 252         TPM_UNDEFINED,
 253         TPM_UNDEFINED,          /* 175 */
 254         TPM_UNDEFINED,
 255         TPM_UNDEFINED,
 256         TPM_UNDEFINED,
 257         TPM_UNDEFINED,
 258         TPM_MEDIUM,             /* 180 */
 259         TPM_SHORT,
 260         TPM_MEDIUM,
 261         TPM_MEDIUM,
 262         TPM_MEDIUM,
 263         TPM_MEDIUM,             /* 185 */
 264         TPM_SHORT,
 265         TPM_UNDEFINED,
 266         TPM_UNDEFINED,
 267         TPM_UNDEFINED,
 268         TPM_UNDEFINED,          /* 190 */
 269         TPM_UNDEFINED,
 270         TPM_UNDEFINED,
 271         TPM_UNDEFINED,
 272         TPM_UNDEFINED,
 273         TPM_UNDEFINED,          /* 195 */
 274         TPM_UNDEFINED,
 275         TPM_UNDEFINED,
 276         TPM_UNDEFINED,
 277         TPM_UNDEFINED,
 278         TPM_SHORT,              /* 200 */
 279         TPM_UNDEFINED,
 280         TPM_UNDEFINED,
 281         TPM_UNDEFINED,
 282         TPM_SHORT,
 283         TPM_SHORT,              /* 205 */
 284         TPM_SHORT,
 285         TPM_SHORT,
 286         TPM_SHORT,
 287         TPM_SHORT,
 288         TPM_MEDIUM,             /* 210 */
 289         TPM_UNDEFINED,
 290         TPM_MEDIUM,
 291         TPM_MEDIUM,
 292         TPM_MEDIUM,
 293         TPM_UNDEFINED,          /* 215 */
 294         TPM_MEDIUM,
 295         TPM_UNDEFINED,
 296         TPM_UNDEFINED,
 297         TPM_SHORT,
 298         TPM_SHORT,              /* 220 */
 299         TPM_SHORT,
 300         TPM_SHORT,
 301         TPM_SHORT,
 302         TPM_SHORT,
 303         TPM_UNDEFINED,          /* 225 */
 304         TPM_UNDEFINED,
 305         TPM_UNDEFINED,
 306         TPM_UNDEFINED,
 307         TPM_UNDEFINED,
 308         TPM_SHORT,              /* 230 */
 309         TPM_LONG,
 310         TPM_MEDIUM,
 311         TPM_UNDEFINED,
 312         TPM_UNDEFINED,
 313         TPM_UNDEFINED,          /* 235 */
 314         TPM_UNDEFINED,
 315         TPM_UNDEFINED,
 316         TPM_UNDEFINED,
 317         TPM_UNDEFINED,
 318         TPM_SHORT,              /* 240 */
 319         TPM_UNDEFINED,
 320         TPM_MEDIUM,
 321 };
 322
 323 static void user_reader_timeout(unsigned long ptr)
 324 {
 325         struct tpm_chip *chip = (struct tpm_chip *) ptr;
 326
 327         schedule_work(&chip->work);
 328 }
 329
 330 static void timeout_work(struct work_struct *work)
 331 {
 332         struct tpm_chip *chip = container_of(work, struct tpm_chip, work);
 333
 334         mutex_lock(&chip->buffer_mutex);
 335         atomic_set(&chip->data_pending, 0);
 336         memset(chip->data_buffer, 0, TPM_BUFSIZE);
 337         mutex_unlock(&chip->buffer_mutex);
 338 }
 339
 340 /*
 341  * Returns max number of jiffies to wait
 342  */
 343 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 344                                            u32 ordinal)
 345 {
 346         int duration_idx = TPM_UNDEFINED;
 347         int duration = 0;
 348
 349         if (ordinal < TPM_MAX_ORDINAL)
 350                 duration_idx = tpm_ordinal_duration[ordinal];
 351         else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
 352                  TPM_MAX_PROTECTED_ORDINAL)
 353                 duration_idx =
 354                     tpm_protected_ordinal_duration[ordinal &
 355                                                    TPM_PROTECTED_ORDINAL_MASK];
 356
 357         if (duration_idx != TPM_UNDEFINED) {
 358                 duration = chip->vendor.duration[duration_idx];
 359                 /* if duration is 0, it's because chip->vendor.duration wasn't */
 360                 /* filled yet, so we set the lowest timeout just to give enough */
 361                 /* time for tpm_get_timeouts() to succeed */
 362                 return (duration <= 0 ? HZ : duration);
 363         } else
 364                 return 2 * 60 * HZ;
 365 }
 366 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 367
 368 /*
 369  * Internal kernel interface to transmit TPM commands
 370  */
 371 static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 372                             size_t bufsiz)
 373 {
 374         ssize_t rc;
 375         u32 count, ordinal;
 376         unsigned long stop;
 377
 378         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 379         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 380         if (count == 0)
 381                 return -ENODATA;
 382         if (count > bufsiz) {
 383                 dev_err(chip->dev,
 384                         "invalid count value %x %zx \n", count, bufsiz);
 385                 return -E2BIG;
 386         }
 387
 388         mutex_lock(&chip->tpm_mutex);
 389
 390         if ((rc = chip->vendor.send(chip, (u8 *) buf, count)) < 0) {
 391                 dev_err(chip->dev,
 392                         "tpm_transmit: tpm_send: error %zd\n", rc);
 393                 goto out;
 394         }
 395
 396         if (chip->vendor.irq)
 397                 goto out_recv;
 398
 399         stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 400         do {
 401                 u8 status = chip->vendor.status(chip);
 402                 if ((status & chip->vendor.req_complete_mask) ==
 403                     chip->vendor.req_complete_val)
 404                         goto out_recv;
 405
 406                 if ((status == chip->vendor.req_canceled)) {
 407                         dev_err(chip->dev, "Operation Canceled\n");
 408                         rc = -ECANCELED;
 409                         goto out;
 410                 }
 411
 412                 msleep(TPM_TIMEOUT);    /* CHECK */
 413                 rmb();
 414         } while (time_before(jiffies, stop));
 415
 416         chip->vendor.cancel(chip);
 417         dev_err(chip->dev, "Operation Timed out\n");
 418         rc = -ETIME;
 419         goto out;
 420
 421 out_recv:
 422         rc = chip->vendor.recv(chip, (u8 *) buf, bufsiz);
 423         if (rc < 0)
 424                 dev_err(chip->dev,
 425                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 426 out:
 427         mutex_unlock(&chip->tpm_mutex);
 428         return rc;
 429 }
 430
 431 #define TPM_DIGEST_SIZE 20
 432 #define TPM_ERROR_SIZE 10
 433 #define TPM_RET_CODE_IDX 6
 434
 435 enum tpm_capabilities {
 436         TPM_CAP_FLAG = cpu_to_be32(4),
 437         TPM_CAP_PROP = cpu_to_be32(5),
 438         CAP_VERSION_1_1 = cpu_to_be32(0x06),
 439         CAP_VERSION_1_2 = cpu_to_be32(0x1A)
 440 };
 441
 442 enum tpm_sub_capabilities {
 443         TPM_CAP_PROP_PCR = cpu_to_be32(0x101),
 444         TPM_CAP_PROP_MANUFACTURER = cpu_to_be32(0x103),
 445         TPM_CAP_FLAG_PERM = cpu_to_be32(0x108),
 446         TPM_CAP_FLAG_VOL = cpu_to_be32(0x109),
 447         TPM_CAP_PROP_OWNER = cpu_to_be32(0x111),
 448         TPM_CAP_PROP_TIS_TIMEOUT = cpu_to_be32(0x115),
 449         TPM_CAP_PROP_TIS_DURATION = cpu_to_be32(0x120),
 450
 451 };
 452
 453 static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
 454                             int len, const char *desc)
 455 {
 456         int err;
 457
 458         len = tpm_transmit(chip,(u8 *) cmd, len);
 459         if (len <  0)
 460                 return len;
 461         if (len == TPM_ERROR_SIZE) {
 462                 err = be32_to_cpu(cmd->header.out.return_code);
 463                 dev_dbg(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
 464                 return err;
 465         }
 466         return 0;
 467 }
 468
 469 #define TPM_INTERNAL_RESULT_SIZE 200
 470 #define TPM_TAG_RQU_COMMAND cpu_to_be16(193)
 471 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 472
 473 static const struct tpm_input_header tpm_getcap_header = {
 474         .tag = TPM_TAG_RQU_COMMAND,
 475         .length = cpu_to_be32(22),
 476         .ordinal = TPM_ORD_GET_CAP
 477 };
 478
 479 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
 480                    const char *desc)
 481 {
 482         struct tpm_cmd_t tpm_cmd;
 483         int rc;
 484         struct tpm_chip *chip = dev_get_drvdata(dev);
 485
 486         tpm_cmd.header.in = tpm_getcap_header;
 487         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 488                 tpm_cmd.params.getcap_in.cap = subcap_id;
 489                 /*subcap field not necessary */
 490                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 491                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 492         } else {
 493                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 494                     subcap_id == TPM_CAP_FLAG_VOL)
 495                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 496                 else
 497                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 498                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 499                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 500         }
 501         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
 502         if (!rc)
 503                 *cap = tpm_cmd.params.getcap_out.cap;
 504         return rc;
 505 }
 506
 507 void tpm_gen_interrupt(struct tpm_chip *chip)
 508 {
 509         struct  tpm_cmd_t tpm_cmd;
 510         ssize_t rc;
 511
 512         tpm_cmd.header.in = tpm_getcap_header;
 513         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 514         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 515         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 516
 517         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 518                         "attempting to determine the timeouts");
 519 }
 520 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 521
 522 void tpm_get_timeouts(struct tpm_chip *chip)
 523 {
 524         struct tpm_cmd_t tpm_cmd;
 525         struct timeout_t *timeout_cap;
 526         struct duration_t *duration_cap;
 527         ssize_t rc;
 528         u32 timeout;
 529
 530         tpm_cmd.header.in = tpm_getcap_header;
 531         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 532         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 533         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 534
 535         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 536                         "attempting to determine the timeouts");
 537         if (rc)
 538                 goto duration;
 539
 540         if (be32_to_cpu(tpm_cmd.header.out.length)
 541             != 4 * sizeof(u32))
 542                 goto duration;
 543
 544         timeout_cap = &tpm_cmd.params.getcap_out.cap.timeout;
 545         /* Don't overwrite default if value is 0 */
 546         timeout = be32_to_cpu(timeout_cap->a);
 547         if (timeout)
 548                 chip->vendor.timeout_a = usecs_to_jiffies(timeout);
 549         timeout = be32_to_cpu(timeout_cap->b);
 550         if (timeout)
 551                 chip->vendor.timeout_b = usecs_to_jiffies(timeout);
 552         timeout = be32_to_cpu(timeout_cap->c);
 553         if (timeout)
 554                 chip->vendor.timeout_c = usecs_to_jiffies(timeout);
 555         timeout = be32_to_cpu(timeout_cap->d);
 556         if (timeout)
 557                 chip->vendor.timeout_d = usecs_to_jiffies(timeout);
 558
 559 duration:
 560         tpm_cmd.header.in = tpm_getcap_header;
 561         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 562         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 563         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 564
 565         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 566                         "attempting to determine the durations");
 567         if (rc)
 568                 return;
 569
 570         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 571             be32_to_cpu(tpm_cmd.header.out.length)
 572             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 573                 return;
 574
 575         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 576         chip->vendor.duration[TPM_SHORT] =
 577             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 578         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 579          * value wrong and apparently reports msecs rather than usecs. So we
 580          * fix up the resulting too-small TPM_SHORT value to make things work.
 581          */
 582         if (chip->vendor.duration[TPM_SHORT] < (HZ/100))
 583                 chip->vendor.duration[TPM_SHORT] = HZ;
 584
 585         chip->vendor.duration[TPM_MEDIUM] =
 586             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 587         chip->vendor.duration[TPM_LONG] =
 588             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 589 }
 590 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 591
 592 void tpm_continue_selftest(struct tpm_chip *chip)
 593 {
 594         u8 data[] = {
 595                 0, 193,                 /* TPM_TAG_RQU_COMMAND */
 596                 0, 0, 0, 10,            /* length */
 597                 0, 0, 0, 83,            /* TPM_ORD_GetCapability */
 598         };
 599
 600         tpm_transmit(chip, data, sizeof(data));
 601 }
 602 EXPORT_SYMBOL_GPL(tpm_continue_selftest);
 603
 604 ssize_t tpm_show_enabled(struct device * dev, struct device_attribute * attr,
 605                         char *buf)
 606 {
 607         cap_t cap;
 608         ssize_t rc;
 609
 610         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 611                          "attempting to determine the permanent enabled state");
 612         if (rc)
 613                 return 0;
 614
 615         rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
 616         return rc;
 617 }
 618 EXPORT_SYMBOL_GPL(tpm_show_enabled);
 619
 620 ssize_t tpm_show_active(struct device * dev, struct device_attribute * attr,
 621                         char *buf)
 622 {
 623         cap_t cap;
 624         ssize_t rc;
 625
 626         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 627                          "attempting to determine the permanent active state");
 628         if (rc)
 629                 return 0;
 630
 631         rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
 632         return rc;
 633 }
 634 EXPORT_SYMBOL_GPL(tpm_show_active);
 635
 636 ssize_t tpm_show_owned(struct device * dev, struct device_attribute * attr,
 637                         char *buf)
 638 {
 639         cap_t cap;
 640         ssize_t rc;
 641
 642         rc = tpm_getcap(dev, TPM_CAP_PROP_OWNER, &cap,
 643                          "attempting to determine the owner state");
 644         if (rc)
 645                 return 0;
 646
 647         rc = sprintf(buf, "%d\n", cap.owned);
 648         return rc;
 649 }
 650 EXPORT_SYMBOL_GPL(tpm_show_owned);
 651
 652 ssize_t tpm_show_temp_deactivated(struct device * dev,
 653                                 struct device_attribute * attr, char *buf)
 654 {
 655         cap_t cap;
 656         ssize_t rc;
 657
 658         rc = tpm_getcap(dev, TPM_CAP_FLAG_VOL, &cap,
 659                          "attempting to determine the temporary state");
 660         if (rc)
 661                 return 0;
 662
 663         rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
 664         return rc;
 665 }
 666 EXPORT_SYMBOL_GPL(tpm_show_temp_deactivated);
 667
 668 /*
 669  * tpm_chip_find_get - return tpm_chip for given chip number
 670  */
 671 static struct tpm_chip *tpm_chip_find_get(int chip_num)
 672 {
 673         struct tpm_chip *pos, *chip = NULL;
 674
 675         rcu_read_lock();
 676         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
 677                 if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
 678                         continue;
 679
 680                 if (try_module_get(pos->dev->driver->owner)) {
 681                         chip = pos;
 682                         break;
 683                 }
 684         }
 685         rcu_read_unlock();
 686         return chip;
 687 }
 688
 689 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 690 #define READ_PCR_RESULT_SIZE 30
 691 static struct tpm_input_header pcrread_header = {
 692         .tag = TPM_TAG_RQU_COMMAND,
 693         .length = cpu_to_be32(14),
 694         .ordinal = TPM_ORDINAL_PCRREAD
 695 };
 696
 697 int __tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 698 {
 699         int rc;
 700         struct tpm_cmd_t cmd;
 701
 702         cmd.header.in = pcrread_header;
 703         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 704         rc = transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 705                           "attempting to read a pcr value");
 706
 707         if (rc == 0)
 708                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 709                        TPM_DIGEST_SIZE);
 710         return rc;
 711 }
 712
 713 /**
 714  * tpm_pcr_read - read a pcr value
 715  * @chip_num:   tpm idx # or ANY
 716  * @pcr_idx:    pcr idx to retrieve
 717  * @res_buf:    TPM_PCR value
 718  *              size of res_buf is 20 bytes (or NULL if you don't care)
 719  *
 720  * The TPM driver should be built-in, but for whatever reason it
 721  * isn't, protect against the chip disappearing, by incrementing
 722  * the module usage count.
 723  */
 724 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 725 {
 726         struct tpm_chip *chip;
 727         int rc;
 728
 729         chip = tpm_chip_find_get(chip_num);
 730         if (chip == NULL)
 731                 return -ENODEV;
 732         rc = __tpm_pcr_read(chip, pcr_idx, res_buf);
 733         module_put(chip->dev->driver->owner);
 734         return rc;
 735 }
 736 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 737
 738 /**
 739  * tpm_pcr_extend - extend pcr value with hash
 740  * @chip_num:   tpm idx # or AN&
 741  * @pcr_idx:    pcr idx to extend
 742  * @hash:       hash value used to extend pcr value
 743  *
 744  * The TPM driver should be built-in, but for whatever reason it
 745  * isn't, protect against the chip disappearing, by incrementing
 746  * the module usage count.
 747  */
 748 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 749 #define EXTEND_PCR_RESULT_SIZE 34
 750 static struct tpm_input_header pcrextend_header = {
 751         .tag = TPM_TAG_RQU_COMMAND,
 752         .length = cpu_to_be32(34),
 753         .ordinal = TPM_ORD_PCR_EXTEND
 754 };
 755
 756 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 757 {
 758         struct tpm_cmd_t cmd;
 759         int rc;
 760         struct tpm_chip *chip;
 761
 762         chip = tpm_chip_find_get(chip_num);
 763         if (chip == NULL)
 764                 return -ENODEV;
 765
 766         cmd.header.in = pcrextend_header;
 767         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 768         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 769         rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 770                           "attempting extend a PCR value");
 771
 772         module_put(chip->dev->driver->owner);
 773         return rc;
 774 }
 775 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 776
 777 ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
 778                       char *buf)
 779 {
 780         cap_t cap;
 781         u8 digest[TPM_DIGEST_SIZE];
 782         ssize_t rc;
 783         int i, j, num_pcrs;
 784         char *str = buf;
 785         struct tpm_chip *chip = dev_get_drvdata(dev);
 786
 787         rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap,
 788                         "attempting to determine the number of PCRS");
 789         if (rc)
 790                 return 0;
 791
 792         num_pcrs = be32_to_cpu(cap.num_pcrs);
 793         for (i = 0; i < num_pcrs; i++) {
 794                 rc = __tpm_pcr_read(chip, i, digest);
 795                 if (rc)
 796                         break;
 797                 str += sprintf(str, "PCR-%02d: ", i);
 798                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
 799                         str += sprintf(str, "%02X ", digest[j]);
 800                 str += sprintf(str, "\n");
 801         }
 802         return str - buf;
 803 }
 804 EXPORT_SYMBOL_GPL(tpm_show_pcrs);
 805
 806 #define  READ_PUBEK_RESULT_SIZE 314
 807 #define TPM_ORD_READPUBEK cpu_to_be32(124)
 808 struct tpm_input_header tpm_readpubek_header = {
 809         .tag = TPM_TAG_RQU_COMMAND,
 810         .length = cpu_to_be32(30),
 811         .ordinal = TPM_ORD_READPUBEK
 812 };
 813
 814 ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
 815                        char *buf)
 816 {
 817         u8 *data;
 818         struct tpm_cmd_t tpm_cmd;
 819         ssize_t err;
 820         int i, rc;
 821         char *str = buf;
 822
 823         struct tpm_chip *chip = dev_get_drvdata(dev);
 824
 825         tpm_cmd.header.in = tpm_readpubek_header;
 826         err = transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
 827                         "attempting to read the PUBEK");
 828         if (err)
 829                 goto out;
 830
 831         /*
 832            ignore header 10 bytes
 833            algorithm 32 bits (1 == RSA )
 834            encscheme 16 bits
 835            sigscheme 16 bits
 836            parameters (RSA 12->bytes: keybit, #primes, expbit)
 837            keylenbytes 32 bits
 838            256 byte modulus
 839            ignore checksum 20 bytes
 840          */
 841         data = tpm_cmd.params.readpubek_out_buffer;
 842         str +=
 843             sprintf(str,
 844                     "Algorithm: %02X %02X %02X %02X\nEncscheme: %02X %02X\n"
 845                     "Sigscheme: %02X %02X\nParameters: %02X %02X %02X %02X"
 846                     " %02X %02X %02X %02X %02X %02X %02X %02X\n"
 847                     "Modulus length: %d\nModulus: \n",
 848                     data[10], data[11], data[12], data[13], data[14],
 849                     data[15], data[16], data[17], data[22], data[23],
 850                     data[24], data[25], data[26], data[27], data[28],
 851                     data[29], data[30], data[31], data[32], data[33],
 852                     be32_to_cpu(*((__be32 *) (data + 34))));
 853
 854         for (i = 0; i < 256; i++) {
 855                 str += sprintf(str, "%02X ", data[i + 38]);
 856                 if ((i + 1) % 16 == 0)
 857                         str += sprintf(str, "\n");
 858         }
 859 out:
 860         rc = str - buf;
 861         return rc;
 862 }
 863 EXPORT_SYMBOL_GPL(tpm_show_pubek);
 864
 865
 866 ssize_t tpm_show_caps(struct device *dev, struct device_attribute *attr,
 867                       char *buf)
 868 {
 869         cap_t cap;
 870         ssize_t rc;
 871         char *str = buf;
 872
 873         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
 874                         "attempting to determine the manufacturer");
 875         if (rc)
 876                 return 0;
 877         str += sprintf(str, "Manufacturer: 0x%x\n",
 878                        be32_to_cpu(cap.manufacturer_id));
 879
 880         rc = tpm_getcap(dev, CAP_VERSION_1_1, &cap,
 881                         "attempting to determine the 1.1 version");
 882         if (rc)
 883                 return 0;
 884         str += sprintf(str,
 885                        "TCG version: %d.%d\nFirmware version: %d.%d\n",
 886                        cap.tpm_version.Major, cap.tpm_version.Minor,
 887                        cap.tpm_version.revMajor, cap.tpm_version.revMinor);
 888         return str - buf;
 889 }
 890 EXPORT_SYMBOL_GPL(tpm_show_caps);
 891
 892 ssize_t tpm_show_caps_1_2(struct device * dev,
 893                           struct device_attribute * attr, char *buf)
 894 {
 895         cap_t cap;
 896         ssize_t rc;
 897         char *str = buf;
 898
 899         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
 900                         "attempting to determine the manufacturer");
 901         if (rc)
 902                 return 0;
 903         str += sprintf(str, "Manufacturer: 0x%x\n",
 904                        be32_to_cpu(cap.manufacturer_id));
 905         rc = tpm_getcap(dev, CAP_VERSION_1_2, &cap,
 906                          "attempting to determine the 1.2 version");
 907         if (rc)
 908                 return 0;
 909         str += sprintf(str,
 910                        "TCG version: %d.%d\nFirmware version: %d.%d\n",
 911                        cap.tpm_version_1_2.Major, cap.tpm_version_1_2.Minor,
 912                        cap.tpm_version_1_2.revMajor,
 913                        cap.tpm_version_1_2.revMinor);
 914         return str - buf;
 915 }
 916 EXPORT_SYMBOL_GPL(tpm_show_caps_1_2);
 917
 918 ssize_t tpm_show_timeouts(struct device *dev, struct device_attribute *attr,
 919                           char *buf)
 920 {
 921         struct tpm_chip *chip = dev_get_drvdata(dev);
 922
 923         return sprintf(buf, "%d %d %d\n",
 924                        jiffies_to_usecs(chip->vendor.duration[TPM_SHORT]),
 925                        jiffies_to_usecs(chip->vendor.duration[TPM_MEDIUM]),
 926                        jiffies_to_usecs(chip->vendor.duration[TPM_LONG]));
 927 }
 928 EXPORT_SYMBOL_GPL(tpm_show_timeouts);
 929
 930 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
 931                         const char *buf, size_t count)
 932 {
 933         struct tpm_chip *chip = dev_get_drvdata(dev);
 934         if (chip == NULL)
 935                 return 0;
 936
 937         chip->vendor.cancel(chip);
 938         return count;
 939 }
 940 EXPORT_SYMBOL_GPL(tpm_store_cancel);
 941
 942 /*
 943  * Device file system interface to the TPM
 944  *
 945  * It's assured that the chip will be opened just once,
 946  * by the check of is_open variable, which is protected
 947  * by driver_lock.
 948  */
 949 int tpm_open(struct inode *inode, struct file *file)
 950 {
 951         int minor = iminor(inode);
 952         struct tpm_chip *chip = NULL, *pos;
 953
 954         rcu_read_lock();
 955         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
 956                 if (pos->vendor.miscdev.minor == minor) {
 957                         chip = pos;
 958                         get_device(chip->dev);
 959                         break;
 960                 }
 961         }
 962         rcu_read_unlock();
 963
 964         if (!chip)
 965                 return -ENODEV;
 966
 967         if (test_and_set_bit(0, &chip->is_open)) {
 968                 dev_dbg(chip->dev, "Another process owns this TPM\n");
 969                 put_device(chip->dev);
 970                 return -EBUSY;
 971         }
 972
 973         chip->data_buffer = kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
 974         if (chip->data_buffer == NULL) {
 975                 clear_bit(0, &chip->is_open);
 976                 put_device(chip->dev);
 977                 return -ENOMEM;
 978         }
 979
 980         atomic_set(&chip->data_pending, 0);
 981
 982         file->private_data = chip;
 983         return 0;
 984 }
 985 EXPORT_SYMBOL_GPL(tpm_open);
 986
 987 /*
 988  * Called on file close
 989  */
 990 int tpm_release(struct inode *inode, struct file *file)
 991 {
 992         struct tpm_chip *chip = file->private_data;
 993
 994         del_singleshot_timer_sync(&chip->user_read_timer);
 995         flush_scheduled_work();
 996         file->private_data = NULL;
 997         atomic_set(&chip->data_pending, 0);
 998         kfree(chip->data_buffer);
 999         clear_bit(0, &chip->is_open);
1000         put_device(chip->dev);
1001         return 0;
1002 }
1003 EXPORT_SYMBOL_GPL(tpm_release);
1004
1005 ssize_t tpm_write(struct file *file, const char __user *buf,
1006                   size_t size, loff_t *off)
1007 {
1008         struct tpm_chip *chip = file->private_data;
1009         size_t in_size = size, out_size;
1010
1011         /* cannot perform a write until the read has cleared
1012            either via tpm_read or a user_read_timer timeout */
1013         while (atomic_read(&chip->data_pending) != 0)
1014                 msleep(TPM_TIMEOUT);
1015
1016         mutex_lock(&chip->buffer_mutex);
1017
1018         if (in_size > TPM_BUFSIZE)
1019                 in_size = TPM_BUFSIZE;
1020
1021         if (copy_from_user
1022             (chip->data_buffer, (void __user *) buf, in_size)) {
1023                 mutex_unlock(&chip->buffer_mutex);
1024                 return -EFAULT;
1025         }
1026
1027         /* atomic tpm command send and result receive */
1028         out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
1029
1030         atomic_set(&chip->data_pending, out_size);
1031         mutex_unlock(&chip->buffer_mutex);
1032
1033         /* Set a timeout by which the reader must come claim the result */
1034         mod_timer(&chip->user_read_timer, jiffies + (60 * HZ));
1035
1036         return in_size;
1037 }
1038 EXPORT_SYMBOL_GPL(tpm_write);
1039
1040 ssize_t tpm_read(struct file *file, char __user *buf,
1041                  size_t size, loff_t *off)
1042 {
1043         struct tpm_chip *chip = file->private_data;
1044         ssize_t ret_size;
1045
1046         del_singleshot_timer_sync(&chip->user_read_timer);
1047         flush_scheduled_work();
1048         ret_size = atomic_read(&chip->data_pending);
1049         atomic_set(&chip->data_pending, 0);
1050         if (ret_size > 0) {     /* relay data */
1051                 if (size < ret_size)
1052                         ret_size = size;
1053
1054                 mutex_lock(&chip->buffer_mutex);
1055                 if (copy_to_user(buf, chip->data_buffer, ret_size))
1056                         ret_size = -EFAULT;
1057                 mutex_unlock(&chip->buffer_mutex);
1058         }
1059
1060         return ret_size;
1061 }
1062 EXPORT_SYMBOL_GPL(tpm_read);
1063
1064 void tpm_remove_hardware(struct device *dev)
1065 {
1066         struct tpm_chip *chip = dev_get_drvdata(dev);
1067
1068         if (chip == NULL) {
1069                 dev_err(dev, "No device data found\n");
1070                 return;
1071         }
1072
1073         spin_lock(&driver_lock);
1074         list_del_rcu(&chip->list);
1075         spin_unlock(&driver_lock);
1076         synchronize_rcu();
1077
1078         misc_deregister(&chip->vendor.miscdev);
1079         sysfs_remove_group(&dev->kobj, chip->vendor.attr_group);
1080         tpm_bios_log_teardown(chip->bios_dir);
1081
1082         /* write it this way to be explicit (chip->dev == dev) */
1083         put_device(chip->dev);
1084 }
1085 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
1086
1087 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
1088 #define SAVESTATE_RESULT_SIZE 10
1089
1090 static struct tpm_input_header savestate_header = {
1091         .tag = TPM_TAG_RQU_COMMAND,
1092         .length = cpu_to_be32(10),
1093         .ordinal = TPM_ORD_SAVESTATE
1094 };
1095
1096 /* Bug workaround - some TPM's don't flush the most
1097  * recently changed pcr on suspend, so force the flush
1098  * with an extend to the selected _unused_ non-volatile pcr.
1099  */
1100 static int tpm_suspend_pcr;
1101 static int __init tpm_suspend_setup(char *str)
1102 {
1103         get_option(&str, &tpm_suspend_pcr);
1104         return 1;
1105 }
1106 __setup("tpm_suspend_pcr=", tpm_suspend_setup);
1107
1108 /*
1109  * We are about to suspend. Save the TPM state
1110  * so that it can be restored.
1111  */
1112 int tpm_pm_suspend(struct device *dev, pm_message_t pm_state)
1113 {
1114         struct tpm_chip *chip = dev_get_drvdata(dev);
1115         struct tpm_cmd_t cmd;
1116         int rc;
1117
1118         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1119
1120         if (chip == NULL)
1121                 return -ENODEV;
1122
1123         /* for buggy tpm, flush pcrs with extend to selected dummy */
1124         if (tpm_suspend_pcr) {
1125                 cmd.header.in = pcrextend_header;
1126                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
1127                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
1128                        TPM_DIGEST_SIZE);
1129                 rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
1130                                   "extending dummy pcr before suspend");
1131         }
1132
1133         /* now do the actual savestate */
1134         cmd.header.in = savestate_header;
1135         rc = transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE,
1136                           "sending savestate before suspend");
1137         return rc;
1138 }
1139 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1140
1141 /*
1142  * Resume from a power safe. The BIOS already restored
1143  * the TPM state.
1144  */
1145 int tpm_pm_resume(struct device *dev)
1146 {
1147         struct tpm_chip *chip = dev_get_drvdata(dev);
1148
1149         if (chip == NULL)
1150                 return -ENODEV;
1151
1152         return 0;
1153 }
1154 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1155
1156 /* In case vendor provided release function, call it too.*/
1157
1158 void tpm_dev_vendor_release(struct tpm_chip *chip)
1159 {
1160         if (chip->vendor.release)
1161                 chip->vendor.release(chip->dev);
1162
1163         clear_bit(chip->dev_num, dev_mask);
1164         kfree(chip->vendor.miscdev.name);
1165 }
1166 EXPORT_SYMBOL_GPL(tpm_dev_vendor_release);
1167
1168
1169 /*
1170  * Once all references to platform device are down to 0,
1171  * release all allocated structures.
1172  */
1173 void tpm_dev_release(struct device *dev)
1174 {
1175         struct tpm_chip *chip = dev_get_drvdata(dev);
1176
1177         tpm_dev_vendor_release(chip);
1178
1179         chip->release(dev);
1180         kfree(chip);
1181 }
1182 EXPORT_SYMBOL_GPL(tpm_dev_release);
1183
1184 /*
1185  * Called from tpm_<specific>.c probe function only for devices
1186  * the driver has determined it should claim.  Prior to calling
1187  * this function the specific probe function has called pci_enable_device
1188  * upon errant exit from this function specific probe function should call
1189  * pci_disable_device
1190  */
1191 struct tpm_chip *tpm_register_hardware(struct device *dev,
1192                                         const struct tpm_vendor_specific *entry)
1193 {
1194 #define DEVNAME_SIZE 7
1195
1196         char *devname;
1197         struct tpm_chip *chip;
1198
1199         /* Driver specific per-device data */
1200         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
1201         devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL);
1202
1203         if (chip == NULL || devname == NULL)
1204                 goto out_free;
1205
1206         mutex_init(&chip->buffer_mutex);
1207         mutex_init(&chip->tpm_mutex);
1208         INIT_LIST_HEAD(&chip->list);
1209
1210         INIT_WORK(&chip->work, timeout_work);
1211
1212         setup_timer(&chip->user_read_timer, user_reader_timeout,
1213                         (unsigned long)chip);
1214
1215         memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
1216
1217         chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);
1218
1219         if (chip->dev_num >= TPM_NUM_DEVICES) {
1220                 dev_err(dev, "No available tpm device numbers\n");
1221                 goto out_free;
1222         } else if (chip->dev_num == 0)
1223                 chip->vendor.miscdev.minor = TPM_MINOR;
1224         else
1225                 chip->vendor.miscdev.minor = MISC_DYNAMIC_MINOR;
1226
1227         set_bit(chip->dev_num, dev_mask);
1228
1229         scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num);
1230         chip->vendor.miscdev.name = devname;
1231
1232         chip->vendor.miscdev.parent = dev;
1233         chip->dev = get_device(dev);
1234         chip->release = dev->release;
1235         dev->release = tpm_dev_release;
1236         dev_set_drvdata(dev, chip);
1237
1238         if (misc_register(&chip->vendor.miscdev)) {
1239                 dev_err(chip->dev,
1240                         "unable to misc_register %s, minor %d\n",
1241                         chip->vendor.miscdev.name,
1242                         chip->vendor.miscdev.minor);
1243                 put_device(chip->dev);
1244                 return NULL;
1245         }
1246
1247         if (sysfs_create_group(&dev->kobj, chip->vendor.attr_group)) {
1248                 misc_deregister(&chip->vendor.miscdev);
1249                 put_device(chip->dev);
1250
1251                 return NULL;
1252         }
1253
1254         chip->bios_dir = tpm_bios_log_setup(devname);
1255
1256         /* Make chip available */
1257         spin_lock(&driver_lock);
1258         list_add_rcu(&chip->list, &tpm_chip_list);
1259         spin_unlock(&driver_lock);
1260
1261         return chip;
1262
1263 out_free:
1264         kfree(chip);
1265         kfree(devname);
1266         return NULL;
1267 }
1268 EXPORT_SYMBOL_GPL(tpm_register_hardware);
1269
1270 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1271 MODULE_DESCRIPTION("TPM Driver");
1272 MODULE_VERSION("2.0");
1273 MODULE_LICENSE("GPL");