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 /*
  51  * Bug workaround - some TPM's don't flush the most
  52  * recently changed pcr on suspend, so force the flush
  53  * with an extend to the selected _unused_ non-volatile pcr.
  54  */
  55 static int tpm_suspend_pcr;
  56 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  57 MODULE_PARM_DESC(suspend_pcr,
  58                  "PCR to use for dummy writes to faciltate flush on suspend.");
  59
  60 static LIST_HEAD(tpm_chip_list);
  61 static DEFINE_SPINLOCK(driver_lock);
  62 static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
  63
  64 /*
  65  * Array with one entry per ordinal defining the maximum amount
  66  * of time the chip could take to return the result.  The ordinal
  67  * designation of short, medium or long is defined in a table in
  68  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  69  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  70  * from the chip during initialization with a call to tpm_get_timeouts.
  71  */
  72 static const u8 tpm_protected_ordinal_duration[TPM_MAX_PROTECTED_ORDINAL] = {
  73         TPM_UNDEFINED,          /* 0 */
  74         TPM_UNDEFINED,
  75         TPM_UNDEFINED,
  76         TPM_UNDEFINED,
  77         TPM_UNDEFINED,
  78         TPM_UNDEFINED,          /* 5 */
  79         TPM_UNDEFINED,
  80         TPM_UNDEFINED,
  81         TPM_UNDEFINED,
  82         TPM_UNDEFINED,
  83         TPM_SHORT,              /* 10 */
  84         TPM_SHORT,
  85 };
  86
  87 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  88         TPM_UNDEFINED,          /* 0 */
  89         TPM_UNDEFINED,
  90         TPM_UNDEFINED,
  91         TPM_UNDEFINED,
  92         TPM_UNDEFINED,
  93         TPM_UNDEFINED,          /* 5 */
  94         TPM_UNDEFINED,
  95         TPM_UNDEFINED,
  96         TPM_UNDEFINED,
  97         TPM_UNDEFINED,
  98         TPM_SHORT,              /* 10 */
  99         TPM_SHORT,
 100         TPM_MEDIUM,
 101         TPM_LONG,
 102         TPM_LONG,
 103         TPM_MEDIUM,             /* 15 */
 104         TPM_SHORT,
 105         TPM_SHORT,
 106         TPM_MEDIUM,
 107         TPM_LONG,
 108         TPM_SHORT,              /* 20 */
 109         TPM_SHORT,
 110         TPM_MEDIUM,
 111         TPM_MEDIUM,
 112         TPM_MEDIUM,
 113         TPM_SHORT,              /* 25 */
 114         TPM_SHORT,
 115         TPM_MEDIUM,
 116         TPM_SHORT,
 117         TPM_SHORT,
 118         TPM_MEDIUM,             /* 30 */
 119         TPM_LONG,
 120         TPM_MEDIUM,
 121         TPM_SHORT,
 122         TPM_SHORT,
 123         TPM_SHORT,              /* 35 */
 124         TPM_MEDIUM,
 125         TPM_MEDIUM,
 126         TPM_UNDEFINED,
 127         TPM_UNDEFINED,
 128         TPM_MEDIUM,             /* 40 */
 129         TPM_LONG,
 130         TPM_MEDIUM,
 131         TPM_SHORT,
 132         TPM_SHORT,
 133         TPM_SHORT,              /* 45 */
 134         TPM_SHORT,
 135         TPM_SHORT,
 136         TPM_SHORT,
 137         TPM_LONG,
 138         TPM_MEDIUM,             /* 50 */
 139         TPM_MEDIUM,
 140         TPM_UNDEFINED,
 141         TPM_UNDEFINED,
 142         TPM_UNDEFINED,
 143         TPM_UNDEFINED,          /* 55 */
 144         TPM_UNDEFINED,
 145         TPM_UNDEFINED,
 146         TPM_UNDEFINED,
 147         TPM_UNDEFINED,
 148         TPM_MEDIUM,             /* 60 */
 149         TPM_MEDIUM,
 150         TPM_MEDIUM,
 151         TPM_SHORT,
 152         TPM_SHORT,
 153         TPM_MEDIUM,             /* 65 */
 154         TPM_UNDEFINED,
 155         TPM_UNDEFINED,
 156         TPM_UNDEFINED,
 157         TPM_UNDEFINED,
 158         TPM_SHORT,              /* 70 */
 159         TPM_SHORT,
 160         TPM_UNDEFINED,
 161         TPM_UNDEFINED,
 162         TPM_UNDEFINED,
 163         TPM_UNDEFINED,          /* 75 */
 164         TPM_UNDEFINED,
 165         TPM_UNDEFINED,
 166         TPM_UNDEFINED,
 167         TPM_UNDEFINED,
 168         TPM_LONG,               /* 80 */
 169         TPM_UNDEFINED,
 170         TPM_MEDIUM,
 171         TPM_LONG,
 172         TPM_SHORT,
 173         TPM_UNDEFINED,          /* 85 */
 174         TPM_UNDEFINED,
 175         TPM_UNDEFINED,
 176         TPM_UNDEFINED,
 177         TPM_UNDEFINED,
 178         TPM_SHORT,              /* 90 */
 179         TPM_SHORT,
 180         TPM_SHORT,
 181         TPM_SHORT,
 182         TPM_SHORT,
 183         TPM_UNDEFINED,          /* 95 */
 184         TPM_UNDEFINED,
 185         TPM_UNDEFINED,
 186         TPM_UNDEFINED,
 187         TPM_UNDEFINED,
 188         TPM_MEDIUM,             /* 100 */
 189         TPM_SHORT,
 190         TPM_SHORT,
 191         TPM_UNDEFINED,
 192         TPM_UNDEFINED,
 193         TPM_UNDEFINED,          /* 105 */
 194         TPM_UNDEFINED,
 195         TPM_UNDEFINED,
 196         TPM_UNDEFINED,
 197         TPM_UNDEFINED,
 198         TPM_SHORT,              /* 110 */
 199         TPM_SHORT,
 200         TPM_SHORT,
 201         TPM_SHORT,
 202         TPM_SHORT,
 203         TPM_SHORT,              /* 115 */
 204         TPM_SHORT,
 205         TPM_SHORT,
 206         TPM_UNDEFINED,
 207         TPM_UNDEFINED,
 208         TPM_LONG,               /* 120 */
 209         TPM_LONG,
 210         TPM_MEDIUM,
 211         TPM_UNDEFINED,
 212         TPM_SHORT,
 213         TPM_SHORT,              /* 125 */
 214         TPM_SHORT,
 215         TPM_LONG,
 216         TPM_SHORT,
 217         TPM_SHORT,
 218         TPM_SHORT,              /* 130 */
 219         TPM_MEDIUM,
 220         TPM_UNDEFINED,
 221         TPM_SHORT,
 222         TPM_MEDIUM,
 223         TPM_UNDEFINED,          /* 135 */
 224         TPM_UNDEFINED,
 225         TPM_UNDEFINED,
 226         TPM_UNDEFINED,
 227         TPM_UNDEFINED,
 228         TPM_SHORT,              /* 140 */
 229         TPM_SHORT,
 230         TPM_UNDEFINED,
 231         TPM_UNDEFINED,
 232         TPM_UNDEFINED,
 233         TPM_UNDEFINED,          /* 145 */
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,
 236         TPM_UNDEFINED,
 237         TPM_UNDEFINED,
 238         TPM_SHORT,              /* 150 */
 239         TPM_MEDIUM,
 240         TPM_MEDIUM,
 241         TPM_SHORT,
 242         TPM_SHORT,
 243         TPM_UNDEFINED,          /* 155 */
 244         TPM_UNDEFINED,
 245         TPM_UNDEFINED,
 246         TPM_UNDEFINED,
 247         TPM_UNDEFINED,
 248         TPM_SHORT,              /* 160 */
 249         TPM_SHORT,
 250         TPM_SHORT,
 251         TPM_SHORT,
 252         TPM_UNDEFINED,
 253         TPM_UNDEFINED,          /* 165 */
 254         TPM_UNDEFINED,
 255         TPM_UNDEFINED,
 256         TPM_UNDEFINED,
 257         TPM_UNDEFINED,
 258         TPM_LONG,               /* 170 */
 259         TPM_UNDEFINED,
 260         TPM_UNDEFINED,
 261         TPM_UNDEFINED,
 262         TPM_UNDEFINED,
 263         TPM_UNDEFINED,          /* 175 */
 264         TPM_UNDEFINED,
 265         TPM_UNDEFINED,
 266         TPM_UNDEFINED,
 267         TPM_UNDEFINED,
 268         TPM_MEDIUM,             /* 180 */
 269         TPM_SHORT,
 270         TPM_MEDIUM,
 271         TPM_MEDIUM,
 272         TPM_MEDIUM,
 273         TPM_MEDIUM,             /* 185 */
 274         TPM_SHORT,
 275         TPM_UNDEFINED,
 276         TPM_UNDEFINED,
 277         TPM_UNDEFINED,
 278         TPM_UNDEFINED,          /* 190 */
 279         TPM_UNDEFINED,
 280         TPM_UNDEFINED,
 281         TPM_UNDEFINED,
 282         TPM_UNDEFINED,
 283         TPM_UNDEFINED,          /* 195 */
 284         TPM_UNDEFINED,
 285         TPM_UNDEFINED,
 286         TPM_UNDEFINED,
 287         TPM_UNDEFINED,
 288         TPM_SHORT,              /* 200 */
 289         TPM_UNDEFINED,
 290         TPM_UNDEFINED,
 291         TPM_UNDEFINED,
 292         TPM_SHORT,
 293         TPM_SHORT,              /* 205 */
 294         TPM_SHORT,
 295         TPM_SHORT,
 296         TPM_SHORT,
 297         TPM_SHORT,
 298         TPM_MEDIUM,             /* 210 */
 299         TPM_UNDEFINED,
 300         TPM_MEDIUM,
 301         TPM_MEDIUM,
 302         TPM_MEDIUM,
 303         TPM_UNDEFINED,          /* 215 */
 304         TPM_MEDIUM,
 305         TPM_UNDEFINED,
 306         TPM_UNDEFINED,
 307         TPM_SHORT,
 308         TPM_SHORT,              /* 220 */
 309         TPM_SHORT,
 310         TPM_SHORT,
 311         TPM_SHORT,
 312         TPM_SHORT,
 313         TPM_UNDEFINED,          /* 225 */
 314         TPM_UNDEFINED,
 315         TPM_UNDEFINED,
 316         TPM_UNDEFINED,
 317         TPM_UNDEFINED,
 318         TPM_SHORT,              /* 230 */
 319         TPM_LONG,
 320         TPM_MEDIUM,
 321         TPM_UNDEFINED,
 322         TPM_UNDEFINED,
 323         TPM_UNDEFINED,          /* 235 */
 324         TPM_UNDEFINED,
 325         TPM_UNDEFINED,
 326         TPM_UNDEFINED,
 327         TPM_UNDEFINED,
 328         TPM_SHORT,              /* 240 */
 329         TPM_UNDEFINED,
 330         TPM_MEDIUM,
 331 };
 332
 333 static void user_reader_timeout(unsigned long ptr)
 334 {
 335         struct tpm_chip *chip = (struct tpm_chip *) ptr;
 336
 337         schedule_work(&chip->work);
 338 }
 339
 340 static void timeout_work(struct work_struct *work)
 341 {
 342         struct tpm_chip *chip = container_of(work, struct tpm_chip, work);
 343
 344         mutex_lock(&chip->buffer_mutex);
 345         atomic_set(&chip->data_pending, 0);
 346         memset(chip->data_buffer, 0, TPM_BUFSIZE);
 347         mutex_unlock(&chip->buffer_mutex);
 348 }
 349
 350 /*
 351  * Returns max number of jiffies to wait
 352  */
 353 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 354                                            u32 ordinal)
 355 {
 356         int duration_idx = TPM_UNDEFINED;
 357         int duration = 0;
 358
 359         if (ordinal < TPM_MAX_ORDINAL)
 360                 duration_idx = tpm_ordinal_duration[ordinal];
 361         else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
 362                  TPM_MAX_PROTECTED_ORDINAL)
 363                 duration_idx =
 364                     tpm_protected_ordinal_duration[ordinal &
 365                                                    TPM_PROTECTED_ORDINAL_MASK];
 366
 367         if (duration_idx != TPM_UNDEFINED)
 368                 duration = chip->vendor.duration[duration_idx];
 369         if (duration <= 0)
 370                 return 2 * 60 * HZ;
 371         else
 372                 return duration;
 373 }
 374 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 375
 376 /*
 377  * Internal kernel interface to transmit TPM commands
 378  */
 379 static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 380                             size_t bufsiz)
 381 {
 382         ssize_t rc;
 383         u32 count, ordinal;
 384         unsigned long stop;
 385
 386         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 387         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 388         if (count == 0)
 389                 return -ENODATA;
 390         if (count > bufsiz) {
 391                 dev_err(chip->dev,
 392                         "invalid count value %x %zx \n", count, bufsiz);
 393                 return -E2BIG;
 394         }
 395
 396         mutex_lock(&chip->tpm_mutex);
 397
 398         if ((rc = chip->vendor.send(chip, (u8 *) buf, count)) < 0) {
 399                 dev_err(chip->dev,
 400                         "tpm_transmit: tpm_send: error %zd\n", rc);
 401                 goto out;
 402         }
 403
 404         if (chip->vendor.irq)
 405                 goto out_recv;
 406
 407         stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 408         do {
 409                 u8 status = chip->vendor.status(chip);
 410                 if ((status & chip->vendor.req_complete_mask) ==
 411                     chip->vendor.req_complete_val)
 412                         goto out_recv;
 413
 414                 if ((status == chip->vendor.req_canceled)) {
 415                         dev_err(chip->dev, "Operation Canceled\n");
 416                         rc = -ECANCELED;
 417                         goto out;
 418                 }
 419
 420                 msleep(TPM_TIMEOUT);    /* CHECK */
 421                 rmb();
 422         } while (time_before(jiffies, stop));
 423
 424         chip->vendor.cancel(chip);
 425         dev_err(chip->dev, "Operation Timed out\n");
 426         rc = -ETIME;
 427         goto out;
 428
 429 out_recv:
 430         rc = chip->vendor.recv(chip, (u8 *) buf, bufsiz);
 431         if (rc < 0)
 432                 dev_err(chip->dev,
 433                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 434 out:
 435         mutex_unlock(&chip->tpm_mutex);
 436         return rc;
 437 }
 438
 439 #define TPM_DIGEST_SIZE 20
 440 #define TPM_ERROR_SIZE 10
 441 #define TPM_RET_CODE_IDX 6
 442
 443 enum tpm_capabilities {
 444         TPM_CAP_FLAG = cpu_to_be32(4),
 445         TPM_CAP_PROP = cpu_to_be32(5),
 446         CAP_VERSION_1_1 = cpu_to_be32(0x06),
 447         CAP_VERSION_1_2 = cpu_to_be32(0x1A)
 448 };
 449
 450 enum tpm_sub_capabilities {
 451         TPM_CAP_PROP_PCR = cpu_to_be32(0x101),
 452         TPM_CAP_PROP_MANUFACTURER = cpu_to_be32(0x103),
 453         TPM_CAP_FLAG_PERM = cpu_to_be32(0x108),
 454         TPM_CAP_FLAG_VOL = cpu_to_be32(0x109),
 455         TPM_CAP_PROP_OWNER = cpu_to_be32(0x111),
 456         TPM_CAP_PROP_TIS_TIMEOUT = cpu_to_be32(0x115),
 457         TPM_CAP_PROP_TIS_DURATION = cpu_to_be32(0x120),
 458
 459 };
 460
 461 static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
 462                             int len, const char *desc)
 463 {
 464         int err;
 465
 466         len = tpm_transmit(chip,(u8 *) cmd, len);
 467         if (len <  0)
 468                 return len;
 469         if (len == TPM_ERROR_SIZE) {
 470                 err = be32_to_cpu(cmd->header.out.return_code);
 471                 dev_dbg(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
 472                 return err;
 473         }
 474         return 0;
 475 }
 476
 477 #define TPM_INTERNAL_RESULT_SIZE 200
 478 #define TPM_TAG_RQU_COMMAND cpu_to_be16(193)
 479 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 480
 481 static const struct tpm_input_header tpm_getcap_header = {
 482         .tag = TPM_TAG_RQU_COMMAND,
 483         .length = cpu_to_be32(22),
 484         .ordinal = TPM_ORD_GET_CAP
 485 };
 486
 487 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
 488                    const char *desc)
 489 {
 490         struct tpm_cmd_t tpm_cmd;
 491         int rc;
 492         struct tpm_chip *chip = dev_get_drvdata(dev);
 493
 494         tpm_cmd.header.in = tpm_getcap_header;
 495         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 496                 tpm_cmd.params.getcap_in.cap = subcap_id;
 497                 /*subcap field not necessary */
 498                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 499                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 500         } else {
 501                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 502                     subcap_id == TPM_CAP_FLAG_VOL)
 503                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 504                 else
 505                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 506                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 507                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 508         }
 509         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
 510         if (!rc)
 511                 *cap = tpm_cmd.params.getcap_out.cap;
 512         return rc;
 513 }
 514
 515 void tpm_gen_interrupt(struct tpm_chip *chip)
 516 {
 517         struct  tpm_cmd_t tpm_cmd;
 518         ssize_t rc;
 519
 520         tpm_cmd.header.in = tpm_getcap_header;
 521         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 522         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 523         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 524
 525         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 526                         "attempting to determine the timeouts");
 527 }
 528 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 529
 530 void tpm_get_timeouts(struct tpm_chip *chip)
 531 {
 532         struct tpm_cmd_t tpm_cmd;
 533         struct timeout_t *timeout_cap;
 534         struct duration_t *duration_cap;
 535         ssize_t rc;
 536         u32 timeout;
 537
 538         tpm_cmd.header.in = tpm_getcap_header;
 539         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 540         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 541         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 542
 543         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 544                         "attempting to determine the timeouts");
 545         if (rc)
 546                 goto duration;
 547
 548         if (be32_to_cpu(tpm_cmd.header.out.length)
 549             != 4 * sizeof(u32))
 550                 goto duration;
 551
 552         timeout_cap = &tpm_cmd.params.getcap_out.cap.timeout;
 553         /* Don't overwrite default if value is 0 */
 554         timeout = be32_to_cpu(timeout_cap->a);
 555         if (timeout)
 556                 chip->vendor.timeout_a = usecs_to_jiffies(timeout);
 557         timeout = be32_to_cpu(timeout_cap->b);
 558         if (timeout)
 559                 chip->vendor.timeout_b = usecs_to_jiffies(timeout);
 560         timeout = be32_to_cpu(timeout_cap->c);
 561         if (timeout)
 562                 chip->vendor.timeout_c = usecs_to_jiffies(timeout);
 563         timeout = be32_to_cpu(timeout_cap->d);
 564         if (timeout)
 565                 chip->vendor.timeout_d = usecs_to_jiffies(timeout);
 566
 567 duration:
 568         tpm_cmd.header.in = tpm_getcap_header;
 569         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 570         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 571         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 572
 573         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 574                         "attempting to determine the durations");
 575         if (rc)
 576                 return;
 577
 578         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 579             be32_to_cpu(tpm_cmd.header.out.length)
 580             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 581                 return;
 582
 583         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 584         chip->vendor.duration[TPM_SHORT] =
 585             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 586         chip->vendor.duration[TPM_MEDIUM] =
 587             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 588         chip->vendor.duration[TPM_LONG] =
 589             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 590
 591         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 592          * value wrong and apparently reports msecs rather than usecs. So we
 593          * fix up the resulting too-small TPM_SHORT value to make things work.
 594          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 595          */
 596         if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
 597                 chip->vendor.duration[TPM_SHORT] = HZ;
 598                 chip->vendor.duration[TPM_MEDIUM] *= 1000;
 599                 chip->vendor.duration[TPM_LONG] *= 1000;
 600                 dev_info(chip->dev, "Adjusting TPM timeout parameters.");
 601         }
 602 }
 603 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 604
 605 void tpm_continue_selftest(struct tpm_chip *chip)
 606 {
 607         u8 data[] = {
 608                 0, 193,                 /* TPM_TAG_RQU_COMMAND */
 609                 0, 0, 0, 10,            /* length */
 610                 0, 0, 0, 83,            /* TPM_ORD_GetCapability */
 611         };
 612
 613         tpm_transmit(chip, data, sizeof(data));
 614 }
 615 EXPORT_SYMBOL_GPL(tpm_continue_selftest);
 616
 617 ssize_t tpm_show_enabled(struct device * dev, struct device_attribute * attr,
 618                         char *buf)
 619 {
 620         cap_t cap;
 621         ssize_t rc;
 622
 623         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 624                          "attempting to determine the permanent enabled state");
 625         if (rc)
 626                 return 0;
 627
 628         rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
 629         return rc;
 630 }
 631 EXPORT_SYMBOL_GPL(tpm_show_enabled);
 632
 633 ssize_t tpm_show_active(struct device * dev, struct device_attribute * attr,
 634                         char *buf)
 635 {
 636         cap_t cap;
 637         ssize_t rc;
 638
 639         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 640                          "attempting to determine the permanent active state");
 641         if (rc)
 642                 return 0;
 643
 644         rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
 645         return rc;
 646 }
 647 EXPORT_SYMBOL_GPL(tpm_show_active);
 648
 649 ssize_t tpm_show_owned(struct device * dev, struct device_attribute * attr,
 650                         char *buf)
 651 {
 652         cap_t cap;
 653         ssize_t rc;
 654
 655         rc = tpm_getcap(dev, TPM_CAP_PROP_OWNER, &cap,
 656                          "attempting to determine the owner state");
 657         if (rc)
 658                 return 0;
 659
 660         rc = sprintf(buf, "%d\n", cap.owned);
 661         return rc;
 662 }
 663 EXPORT_SYMBOL_GPL(tpm_show_owned);
 664
 665 ssize_t tpm_show_temp_deactivated(struct device * dev,
 666                                 struct device_attribute * attr, char *buf)
 667 {
 668         cap_t cap;
 669         ssize_t rc;
 670
 671         rc = tpm_getcap(dev, TPM_CAP_FLAG_VOL, &cap,
 672                          "attempting to determine the temporary state");
 673         if (rc)
 674                 return 0;
 675
 676         rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
 677         return rc;
 678 }
 679 EXPORT_SYMBOL_GPL(tpm_show_temp_deactivated);
 680
 681 /*
 682  * tpm_chip_find_get - return tpm_chip for given chip number
 683  */
 684 static struct tpm_chip *tpm_chip_find_get(int chip_num)
 685 {
 686         struct tpm_chip *pos, *chip = NULL;
 687
 688         rcu_read_lock();
 689         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
 690                 if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
 691                         continue;
 692
 693                 if (try_module_get(pos->dev->driver->owner)) {
 694                         chip = pos;
 695                         break;
 696                 }
 697         }
 698         rcu_read_unlock();
 699         return chip;
 700 }
 701
 702 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 703 #define READ_PCR_RESULT_SIZE 30
 704 static struct tpm_input_header pcrread_header = {
 705         .tag = TPM_TAG_RQU_COMMAND,
 706         .length = cpu_to_be32(14),
 707         .ordinal = TPM_ORDINAL_PCRREAD
 708 };
 709
 710 int __tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 711 {
 712         int rc;
 713         struct tpm_cmd_t cmd;
 714
 715         cmd.header.in = pcrread_header;
 716         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 717         rc = transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 718                           "attempting to read a pcr value");
 719
 720         if (rc == 0)
 721                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 722                        TPM_DIGEST_SIZE);
 723         return rc;
 724 }
 725
 726 /**
 727  * tpm_pcr_read - read a pcr value
 728  * @chip_num:   tpm idx # or ANY
 729  * @pcr_idx:    pcr idx to retrieve
 730  * @res_buf:    TPM_PCR value
 731  *              size of res_buf is 20 bytes (or NULL if you don't care)
 732  *
 733  * The TPM driver should be built-in, but for whatever reason it
 734  * isn't, protect against the chip disappearing, by incrementing
 735  * the module usage count.
 736  */
 737 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 738 {
 739         struct tpm_chip *chip;
 740         int rc;
 741
 742         chip = tpm_chip_find_get(chip_num);
 743         if (chip == NULL)
 744                 return -ENODEV;
 745         rc = __tpm_pcr_read(chip, pcr_idx, res_buf);
 746         tpm_chip_put(chip);
 747         return rc;
 748 }
 749 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 750
 751 /**
 752  * tpm_pcr_extend - extend pcr value with hash
 753  * @chip_num:   tpm idx # or AN&
 754  * @pcr_idx:    pcr idx to extend
 755  * @hash:       hash value used to extend pcr value
 756  *
 757  * The TPM driver should be built-in, but for whatever reason it
 758  * isn't, protect against the chip disappearing, by incrementing
 759  * the module usage count.
 760  */
 761 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 762 #define EXTEND_PCR_RESULT_SIZE 34
 763 static struct tpm_input_header pcrextend_header = {
 764         .tag = TPM_TAG_RQU_COMMAND,
 765         .length = cpu_to_be32(34),
 766         .ordinal = TPM_ORD_PCR_EXTEND
 767 };
 768
 769 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 770 {
 771         struct tpm_cmd_t cmd;
 772         int rc;
 773         struct tpm_chip *chip;
 774
 775         chip = tpm_chip_find_get(chip_num);
 776         if (chip == NULL)
 777                 return -ENODEV;
 778
 779         cmd.header.in = pcrextend_header;
 780         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 781         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 782         rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 783                           "attempting extend a PCR value");
 784
 785         tpm_chip_put(chip);
 786         return rc;
 787 }
 788 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 789
 790 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 791 {
 792         struct tpm_chip *chip;
 793         int rc;
 794
 795         chip = tpm_chip_find_get(chip_num);
 796         if (chip == NULL)
 797                 return -ENODEV;
 798
 799         rc = transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
 800
 801         tpm_chip_put(chip);
 802         return rc;
 803 }
 804 EXPORT_SYMBOL_GPL(tpm_send);
 805
 806 ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
 807                       char *buf)
 808 {
 809         cap_t cap;
 810         u8 digest[TPM_DIGEST_SIZE];
 811         ssize_t rc;
 812         int i, j, num_pcrs;
 813         char *str = buf;
 814         struct tpm_chip *chip = dev_get_drvdata(dev);
 815
 816         rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap,
 817                         "attempting to determine the number of PCRS");
 818         if (rc)
 819                 return 0;
 820
 821         num_pcrs = be32_to_cpu(cap.num_pcrs);
 822         for (i = 0; i < num_pcrs; i++) {
 823                 rc = __tpm_pcr_read(chip, i, digest);
 824                 if (rc)
 825                         break;
 826                 str += sprintf(str, "PCR-%02d: ", i);
 827                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
 828                         str += sprintf(str, "%02X ", digest[j]);
 829                 str += sprintf(str, "\n");
 830         }
 831         return str - buf;
 832 }
 833 EXPORT_SYMBOL_GPL(tpm_show_pcrs);
 834
 835 #define  READ_PUBEK_RESULT_SIZE 314
 836 #define TPM_ORD_READPUBEK cpu_to_be32(124)
 837 struct tpm_input_header tpm_readpubek_header = {
 838         .tag = TPM_TAG_RQU_COMMAND,
 839         .length = cpu_to_be32(30),
 840         .ordinal = TPM_ORD_READPUBEK
 841 };
 842
 843 ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
 844                        char *buf)
 845 {
 846         u8 *data;
 847         struct tpm_cmd_t tpm_cmd;
 848         ssize_t err;
 849         int i, rc;
 850         char *str = buf;
 851
 852         struct tpm_chip *chip = dev_get_drvdata(dev);
 853
 854         tpm_cmd.header.in = tpm_readpubek_header;
 855         err = transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
 856                         "attempting to read the PUBEK");
 857         if (err)
 858                 goto out;
 859
 860         /*
 861            ignore header 10 bytes
 862            algorithm 32 bits (1 == RSA )
 863            encscheme 16 bits
 864            sigscheme 16 bits
 865            parameters (RSA 12->bytes: keybit, #primes, expbit)
 866            keylenbytes 32 bits
 867            256 byte modulus
 868            ignore checksum 20 bytes
 869          */
 870         data = tpm_cmd.params.readpubek_out_buffer;
 871         str +=
 872             sprintf(str,
 873                     "Algorithm: %02X %02X %02X %02X\nEncscheme: %02X %02X\n"
 874                     "Sigscheme: %02X %02X\nParameters: %02X %02X %02X %02X"
 875                     " %02X %02X %02X %02X %02X %02X %02X %02X\n"
 876                     "Modulus length: %d\nModulus: \n",
 877                     data[10], data[11], data[12], data[13], data[14],
 878                     data[15], data[16], data[17], data[22], data[23],
 879                     data[24], data[25], data[26], data[27], data[28],
 880                     data[29], data[30], data[31], data[32], data[33],
 881                     be32_to_cpu(*((__be32 *) (data + 34))));
 882
 883         for (i = 0; i < 256; i++) {
 884                 str += sprintf(str, "%02X ", data[i + 38]);
 885                 if ((i + 1) % 16 == 0)
 886                         str += sprintf(str, "\n");
 887         }
 888 out:
 889         rc = str - buf;
 890         return rc;
 891 }
 892 EXPORT_SYMBOL_GPL(tpm_show_pubek);
 893
 894
 895 ssize_t tpm_show_caps(struct device *dev, struct device_attribute *attr,
 896                       char *buf)
 897 {
 898         cap_t cap;
 899         ssize_t rc;
 900         char *str = buf;
 901
 902         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
 903                         "attempting to determine the manufacturer");
 904         if (rc)
 905                 return 0;
 906         str += sprintf(str, "Manufacturer: 0x%x\n",
 907                        be32_to_cpu(cap.manufacturer_id));
 908
 909         rc = tpm_getcap(dev, CAP_VERSION_1_1, &cap,
 910                         "attempting to determine the 1.1 version");
 911         if (rc)
 912                 return 0;
 913         str += sprintf(str,
 914                        "TCG version: %d.%d\nFirmware version: %d.%d\n",
 915                        cap.tpm_version.Major, cap.tpm_version.Minor,
 916                        cap.tpm_version.revMajor, cap.tpm_version.revMinor);
 917         return str - buf;
 918 }
 919 EXPORT_SYMBOL_GPL(tpm_show_caps);
 920
 921 ssize_t tpm_show_caps_1_2(struct device * dev,
 922                           struct device_attribute * attr, char *buf)
 923 {
 924         cap_t cap;
 925         ssize_t rc;
 926         char *str = buf;
 927
 928         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
 929                         "attempting to determine the manufacturer");
 930         if (rc)
 931                 return 0;
 932         str += sprintf(str, "Manufacturer: 0x%x\n",
 933                        be32_to_cpu(cap.manufacturer_id));
 934         rc = tpm_getcap(dev, CAP_VERSION_1_2, &cap,
 935                          "attempting to determine the 1.2 version");
 936         if (rc)
 937                 return 0;
 938         str += sprintf(str,
 939                        "TCG version: %d.%d\nFirmware version: %d.%d\n",
 940                        cap.tpm_version_1_2.Major, cap.tpm_version_1_2.Minor,
 941                        cap.tpm_version_1_2.revMajor,
 942                        cap.tpm_version_1_2.revMinor);
 943         return str - buf;
 944 }
 945 EXPORT_SYMBOL_GPL(tpm_show_caps_1_2);
 946
 947 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
 948                         const char *buf, size_t count)
 949 {
 950         struct tpm_chip *chip = dev_get_drvdata(dev);
 951         if (chip == NULL)
 952                 return 0;
 953
 954         chip->vendor.cancel(chip);
 955         return count;
 956 }
 957 EXPORT_SYMBOL_GPL(tpm_store_cancel);
 958
 959 /*
 960  * Device file system interface to the TPM
 961  *
 962  * It's assured that the chip will be opened just once,
 963  * by the check of is_open variable, which is protected
 964  * by driver_lock.
 965  */
 966 int tpm_open(struct inode *inode, struct file *file)
 967 {
 968         int minor = iminor(inode);
 969         struct tpm_chip *chip = NULL, *pos;
 970
 971         rcu_read_lock();
 972         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
 973                 if (pos->vendor.miscdev.minor == minor) {
 974                         chip = pos;
 975                         get_device(chip->dev);
 976                         break;
 977                 }
 978         }
 979         rcu_read_unlock();
 980
 981         if (!chip)
 982                 return -ENODEV;
 983
 984         if (test_and_set_bit(0, &chip->is_open)) {
 985                 dev_dbg(chip->dev, "Another process owns this TPM\n");
 986                 put_device(chip->dev);
 987                 return -EBUSY;
 988         }
 989
 990         chip->data_buffer = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
 991         if (chip->data_buffer == NULL) {
 992                 clear_bit(0, &chip->is_open);
 993                 put_device(chip->dev);
 994                 return -ENOMEM;
 995         }
 996
 997         atomic_set(&chip->data_pending, 0);
 998
 999         file->private_data = chip;
1000         return 0;
1001 }
1002 EXPORT_SYMBOL_GPL(tpm_open);
1003
1004 /*
1005  * Called on file close
1006  */
1007 int tpm_release(struct inode *inode, struct file *file)
1008 {
1009         struct tpm_chip *chip = file->private_data;
1010
1011         del_singleshot_timer_sync(&chip->user_read_timer);
1012         flush_work_sync(&chip->work);
1013         file->private_data = NULL;
1014         atomic_set(&chip->data_pending, 0);
1015         kfree(chip->data_buffer);
1016         clear_bit(0, &chip->is_open);
1017         put_device(chip->dev);
1018         return 0;
1019 }
1020 EXPORT_SYMBOL_GPL(tpm_release);
1021
1022 ssize_t tpm_write(struct file *file, const char __user *buf,
1023                   size_t size, loff_t *off)
1024 {
1025         struct tpm_chip *chip = file->private_data;
1026         size_t in_size = size, out_size;
1027
1028         /* cannot perform a write until the read has cleared
1029            either via tpm_read or a user_read_timer timeout */
1030         while (atomic_read(&chip->data_pending) != 0)
1031                 msleep(TPM_TIMEOUT);
1032
1033         mutex_lock(&chip->buffer_mutex);
1034
1035         if (in_size > TPM_BUFSIZE)
1036                 in_size = TPM_BUFSIZE;
1037
1038         if (copy_from_user
1039             (chip->data_buffer, (void __user *) buf, in_size)) {
1040                 mutex_unlock(&chip->buffer_mutex);
1041                 return -EFAULT;
1042         }
1043
1044         /* atomic tpm command send and result receive */
1045         out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
1046
1047         atomic_set(&chip->data_pending, out_size);
1048         mutex_unlock(&chip->buffer_mutex);
1049
1050         /* Set a timeout by which the reader must come claim the result */
1051         mod_timer(&chip->user_read_timer, jiffies + (60 * HZ));
1052
1053         return in_size;
1054 }
1055 EXPORT_SYMBOL_GPL(tpm_write);
1056
1057 ssize_t tpm_read(struct file *file, char __user *buf,
1058                  size_t size, loff_t *off)
1059 {
1060         struct tpm_chip *chip = file->private_data;
1061         ssize_t ret_size;
1062
1063         del_singleshot_timer_sync(&chip->user_read_timer);
1064         flush_work_sync(&chip->work);
1065         ret_size = atomic_read(&chip->data_pending);
1066         atomic_set(&chip->data_pending, 0);
1067         if (ret_size > 0) {     /* relay data */
1068                 if (size < ret_size)
1069                         ret_size = size;
1070
1071                 mutex_lock(&chip->buffer_mutex);
1072                 if (copy_to_user(buf, chip->data_buffer, ret_size))
1073                         ret_size = -EFAULT;
1074                 mutex_unlock(&chip->buffer_mutex);
1075         }
1076
1077         return ret_size;
1078 }
1079 EXPORT_SYMBOL_GPL(tpm_read);
1080
1081 void tpm_remove_hardware(struct device *dev)
1082 {
1083         struct tpm_chip *chip = dev_get_drvdata(dev);
1084
1085         if (chip == NULL) {
1086                 dev_err(dev, "No device data found\n");
1087                 return;
1088         }
1089
1090         spin_lock(&driver_lock);
1091         list_del_rcu(&chip->list);
1092         spin_unlock(&driver_lock);
1093         synchronize_rcu();
1094
1095         misc_deregister(&chip->vendor.miscdev);
1096         sysfs_remove_group(&dev->kobj, chip->vendor.attr_group);
1097         tpm_bios_log_teardown(chip->bios_dir);
1098
1099         /* write it this way to be explicit (chip->dev == dev) */
1100         put_device(chip->dev);
1101 }
1102 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
1103
1104 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
1105 #define SAVESTATE_RESULT_SIZE 10
1106
1107 static struct tpm_input_header savestate_header = {
1108         .tag = TPM_TAG_RQU_COMMAND,
1109         .length = cpu_to_be32(10),
1110         .ordinal = TPM_ORD_SAVESTATE
1111 };
1112
1113 /*
1114  * We are about to suspend. Save the TPM state
1115  * so that it can be restored.
1116  */
1117 int tpm_pm_suspend(struct device *dev, pm_message_t pm_state)
1118 {
1119         struct tpm_chip *chip = dev_get_drvdata(dev);
1120         struct tpm_cmd_t cmd;
1121         int rc;
1122
1123         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1124
1125         if (chip == NULL)
1126                 return -ENODEV;
1127
1128         /* for buggy tpm, flush pcrs with extend to selected dummy */
1129         if (tpm_suspend_pcr) {
1130                 cmd.header.in = pcrextend_header;
1131                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
1132                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
1133                        TPM_DIGEST_SIZE);
1134                 rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
1135                                   "extending dummy pcr before suspend");
1136         }
1137
1138         /* now do the actual savestate */
1139         cmd.header.in = savestate_header;
1140         rc = transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE,
1141                           "sending savestate before suspend");
1142         return rc;
1143 }
1144 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1145
1146 /*
1147  * Resume from a power safe. The BIOS already restored
1148  * the TPM state.
1149  */
1150 int tpm_pm_resume(struct device *dev)
1151 {
1152         struct tpm_chip *chip = dev_get_drvdata(dev);
1153
1154         if (chip == NULL)
1155                 return -ENODEV;
1156
1157         return 0;
1158 }
1159 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1160
1161 /* In case vendor provided release function, call it too.*/
1162
1163 void tpm_dev_vendor_release(struct tpm_chip *chip)
1164 {
1165         if (chip->vendor.release)
1166                 chip->vendor.release(chip->dev);
1167
1168         clear_bit(chip->dev_num, dev_mask);
1169         kfree(chip->vendor.miscdev.name);
1170 }
1171 EXPORT_SYMBOL_GPL(tpm_dev_vendor_release);
1172
1173
1174 /*
1175  * Once all references to platform device are down to 0,
1176  * release all allocated structures.
1177  */
1178 void tpm_dev_release(struct device *dev)
1179 {
1180         struct tpm_chip *chip = dev_get_drvdata(dev);
1181
1182         tpm_dev_vendor_release(chip);
1183
1184         chip->release(dev);
1185         kfree(chip);
1186 }
1187 EXPORT_SYMBOL_GPL(tpm_dev_release);
1188
1189 /*
1190  * Called from tpm_<specific>.c probe function only for devices
1191  * the driver has determined it should claim.  Prior to calling
1192  * this function the specific probe function has called pci_enable_device
1193  * upon errant exit from this function specific probe function should call
1194  * pci_disable_device
1195  */
1196 struct tpm_chip *tpm_register_hardware(struct device *dev,
1197                                         const struct tpm_vendor_specific *entry)
1198 {
1199 #define DEVNAME_SIZE 7
1200
1201         char *devname;
1202         struct tpm_chip *chip;
1203
1204         /* Driver specific per-device data */
1205         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
1206         devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL);
1207
1208         if (chip == NULL || devname == NULL)
1209                 goto out_free;
1210
1211         mutex_init(&chip->buffer_mutex);
1212         mutex_init(&chip->tpm_mutex);
1213         INIT_LIST_HEAD(&chip->list);
1214
1215         INIT_WORK(&chip->work, timeout_work);
1216
1217         setup_timer(&chip->user_read_timer, user_reader_timeout,
1218                         (unsigned long)chip);
1219
1220         memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
1221
1222         chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);
1223
1224         if (chip->dev_num >= TPM_NUM_DEVICES) {
1225                 dev_err(dev, "No available tpm device numbers\n");
1226                 goto out_free;
1227         } else if (chip->dev_num == 0)
1228                 chip->vendor.miscdev.minor = TPM_MINOR;
1229         else
1230                 chip->vendor.miscdev.minor = MISC_DYNAMIC_MINOR;
1231
1232         set_bit(chip->dev_num, dev_mask);
1233
1234         scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num);
1235         chip->vendor.miscdev.name = devname;
1236
1237         chip->vendor.miscdev.parent = dev;
1238         chip->dev = get_device(dev);
1239         chip->release = dev->release;
1240         dev->release = tpm_dev_release;
1241         dev_set_drvdata(dev, chip);
1242
1243         if (misc_register(&chip->vendor.miscdev)) {
1244                 dev_err(chip->dev,
1245                         "unable to misc_register %s, minor %d\n",
1246                         chip->vendor.miscdev.name,
1247                         chip->vendor.miscdev.minor);
1248                 put_device(chip->dev);
1249                 return NULL;
1250         }
1251
1252         if (sysfs_create_group(&dev->kobj, chip->vendor.attr_group)) {
1253                 misc_deregister(&chip->vendor.miscdev);
1254                 put_device(chip->dev);
1255
1256                 return NULL;
1257         }
1258
1259         chip->bios_dir = tpm_bios_log_setup(devname);
1260
1261         /* Make chip available */
1262         spin_lock(&driver_lock);
1263         list_add_rcu(&chip->list, &tpm_chip_list);
1264         spin_unlock(&driver_lock);
1265
1266         return chip;
1267
1268 out_free:
1269         kfree(chip);
1270         kfree(devname);
1271         return NULL;
1272 }
1273 EXPORT_SYMBOL_GPL(tpm_register_hardware);
1274
1275 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1276 MODULE_DESCRIPTION("TPM Driver");
1277 MODULE_VERSION("2.0");
1278 MODULE_LICENSE("GPL");