drivers/char/tpm/tpm-interface.c

   1 /*
   2  * Copyright (C) 2004 IBM Corporation
   3  * Copyright (C) 2014 Intel Corporation
   4  *
   5  * Authors:
   6  * Leendert van Doorn <leendert@watson.ibm.com>
   7  * Dave Safford <safford@watson.ibm.com>
   8  * Reiner Sailer <sailer@watson.ibm.com>
   9  * Kylene Hall <kjhall@us.ibm.com>
  10  *
  11  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  12  *
  13  * Device driver for TCG/TCPA TPM (trusted platform module).
  14  * Specifications at www.trustedcomputinggroup.org
  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  * Note, the TPM chip is not interrupt driven (only polling)
  22  * and can have very long timeouts (minutes!). Hence the unusual
  23  * calls to msleep.
  24  *
  25  */
  26
  27 #include <linux/poll.h>
  28 #include <linux/slab.h>
  29 #include <linux/mutex.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/freezer.h>
  32
  33 #include "tpm.h"
  34 #include "tpm_eventlog.h"
  35
  36 #define TPM_MAX_ORDINAL 243
  37 #define TSC_MAX_ORDINAL 12
  38 #define TPM_PROTECTED_COMMAND 0x00
  39 #define TPM_CONNECTION_COMMAND 0x40
  40
  41 /*
  42  * Bug workaround - some TPM's don't flush the most
  43  * recently changed pcr on suspend, so force the flush
  44  * with an extend to the selected _unused_ non-volatile pcr.
  45  */
  46 static int tpm_suspend_pcr;
  47 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  48 MODULE_PARM_DESC(suspend_pcr,
  49                  "PCR to use for dummy writes to faciltate flush on suspend.");
  50
  51 /*
  52  * Array with one entry per ordinal defining the maximum amount
  53  * of time the chip could take to return the result.  The ordinal
  54  * designation of short, medium or long is defined in a table in
  55  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  56  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  57  * from the chip during initialization with a call to tpm_get_timeouts.
  58  */
  59 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  60         TPM_UNDEFINED,          /* 0 */
  61         TPM_UNDEFINED,
  62         TPM_UNDEFINED,
  63         TPM_UNDEFINED,
  64         TPM_UNDEFINED,
  65         TPM_UNDEFINED,          /* 5 */
  66         TPM_UNDEFINED,
  67         TPM_UNDEFINED,
  68         TPM_UNDEFINED,
  69         TPM_UNDEFINED,
  70         TPM_SHORT,              /* 10 */
  71         TPM_SHORT,
  72         TPM_MEDIUM,
  73         TPM_LONG,
  74         TPM_LONG,
  75         TPM_MEDIUM,             /* 15 */
  76         TPM_SHORT,
  77         TPM_SHORT,
  78         TPM_MEDIUM,
  79         TPM_LONG,
  80         TPM_SHORT,              /* 20 */
  81         TPM_SHORT,
  82         TPM_MEDIUM,
  83         TPM_MEDIUM,
  84         TPM_MEDIUM,
  85         TPM_SHORT,              /* 25 */
  86         TPM_SHORT,
  87         TPM_MEDIUM,
  88         TPM_SHORT,
  89         TPM_SHORT,
  90         TPM_MEDIUM,             /* 30 */
  91         TPM_LONG,
  92         TPM_MEDIUM,
  93         TPM_SHORT,
  94         TPM_SHORT,
  95         TPM_SHORT,              /* 35 */
  96         TPM_MEDIUM,
  97         TPM_MEDIUM,
  98         TPM_UNDEFINED,
  99         TPM_UNDEFINED,
 100         TPM_MEDIUM,             /* 40 */
 101         TPM_LONG,
 102         TPM_MEDIUM,
 103         TPM_SHORT,
 104         TPM_SHORT,
 105         TPM_SHORT,              /* 45 */
 106         TPM_SHORT,
 107         TPM_SHORT,
 108         TPM_SHORT,
 109         TPM_LONG,
 110         TPM_MEDIUM,             /* 50 */
 111         TPM_MEDIUM,
 112         TPM_UNDEFINED,
 113         TPM_UNDEFINED,
 114         TPM_UNDEFINED,
 115         TPM_UNDEFINED,          /* 55 */
 116         TPM_UNDEFINED,
 117         TPM_UNDEFINED,
 118         TPM_UNDEFINED,
 119         TPM_UNDEFINED,
 120         TPM_MEDIUM,             /* 60 */
 121         TPM_MEDIUM,
 122         TPM_MEDIUM,
 123         TPM_SHORT,
 124         TPM_SHORT,
 125         TPM_MEDIUM,             /* 65 */
 126         TPM_UNDEFINED,
 127         TPM_UNDEFINED,
 128         TPM_UNDEFINED,
 129         TPM_UNDEFINED,
 130         TPM_SHORT,              /* 70 */
 131         TPM_SHORT,
 132         TPM_UNDEFINED,
 133         TPM_UNDEFINED,
 134         TPM_UNDEFINED,
 135         TPM_UNDEFINED,          /* 75 */
 136         TPM_UNDEFINED,
 137         TPM_UNDEFINED,
 138         TPM_UNDEFINED,
 139         TPM_UNDEFINED,
 140         TPM_LONG,               /* 80 */
 141         TPM_UNDEFINED,
 142         TPM_MEDIUM,
 143         TPM_LONG,
 144         TPM_SHORT,
 145         TPM_UNDEFINED,          /* 85 */
 146         TPM_UNDEFINED,
 147         TPM_UNDEFINED,
 148         TPM_UNDEFINED,
 149         TPM_UNDEFINED,
 150         TPM_SHORT,              /* 90 */
 151         TPM_SHORT,
 152         TPM_SHORT,
 153         TPM_SHORT,
 154         TPM_SHORT,
 155         TPM_UNDEFINED,          /* 95 */
 156         TPM_UNDEFINED,
 157         TPM_UNDEFINED,
 158         TPM_UNDEFINED,
 159         TPM_UNDEFINED,
 160         TPM_MEDIUM,             /* 100 */
 161         TPM_SHORT,
 162         TPM_SHORT,
 163         TPM_UNDEFINED,
 164         TPM_UNDEFINED,
 165         TPM_UNDEFINED,          /* 105 */
 166         TPM_UNDEFINED,
 167         TPM_UNDEFINED,
 168         TPM_UNDEFINED,
 169         TPM_UNDEFINED,
 170         TPM_SHORT,              /* 110 */
 171         TPM_SHORT,
 172         TPM_SHORT,
 173         TPM_SHORT,
 174         TPM_SHORT,
 175         TPM_SHORT,              /* 115 */
 176         TPM_SHORT,
 177         TPM_SHORT,
 178         TPM_UNDEFINED,
 179         TPM_UNDEFINED,
 180         TPM_LONG,               /* 120 */
 181         TPM_LONG,
 182         TPM_MEDIUM,
 183         TPM_UNDEFINED,
 184         TPM_SHORT,
 185         TPM_SHORT,              /* 125 */
 186         TPM_SHORT,
 187         TPM_LONG,
 188         TPM_SHORT,
 189         TPM_SHORT,
 190         TPM_SHORT,              /* 130 */
 191         TPM_MEDIUM,
 192         TPM_UNDEFINED,
 193         TPM_SHORT,
 194         TPM_MEDIUM,
 195         TPM_UNDEFINED,          /* 135 */
 196         TPM_UNDEFINED,
 197         TPM_UNDEFINED,
 198         TPM_UNDEFINED,
 199         TPM_UNDEFINED,
 200         TPM_SHORT,              /* 140 */
 201         TPM_SHORT,
 202         TPM_UNDEFINED,
 203         TPM_UNDEFINED,
 204         TPM_UNDEFINED,
 205         TPM_UNDEFINED,          /* 145 */
 206         TPM_UNDEFINED,
 207         TPM_UNDEFINED,
 208         TPM_UNDEFINED,
 209         TPM_UNDEFINED,
 210         TPM_SHORT,              /* 150 */
 211         TPM_MEDIUM,
 212         TPM_MEDIUM,
 213         TPM_SHORT,
 214         TPM_SHORT,
 215         TPM_UNDEFINED,          /* 155 */
 216         TPM_UNDEFINED,
 217         TPM_UNDEFINED,
 218         TPM_UNDEFINED,
 219         TPM_UNDEFINED,
 220         TPM_SHORT,              /* 160 */
 221         TPM_SHORT,
 222         TPM_SHORT,
 223         TPM_SHORT,
 224         TPM_UNDEFINED,
 225         TPM_UNDEFINED,          /* 165 */
 226         TPM_UNDEFINED,
 227         TPM_UNDEFINED,
 228         TPM_UNDEFINED,
 229         TPM_UNDEFINED,
 230         TPM_LONG,               /* 170 */
 231         TPM_UNDEFINED,
 232         TPM_UNDEFINED,
 233         TPM_UNDEFINED,
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,          /* 175 */
 236         TPM_UNDEFINED,
 237         TPM_UNDEFINED,
 238         TPM_UNDEFINED,
 239         TPM_UNDEFINED,
 240         TPM_MEDIUM,             /* 180 */
 241         TPM_SHORT,
 242         TPM_MEDIUM,
 243         TPM_MEDIUM,
 244         TPM_MEDIUM,
 245         TPM_MEDIUM,             /* 185 */
 246         TPM_SHORT,
 247         TPM_UNDEFINED,
 248         TPM_UNDEFINED,
 249         TPM_UNDEFINED,
 250         TPM_UNDEFINED,          /* 190 */
 251         TPM_UNDEFINED,
 252         TPM_UNDEFINED,
 253         TPM_UNDEFINED,
 254         TPM_UNDEFINED,
 255         TPM_UNDEFINED,          /* 195 */
 256         TPM_UNDEFINED,
 257         TPM_UNDEFINED,
 258         TPM_UNDEFINED,
 259         TPM_UNDEFINED,
 260         TPM_SHORT,              /* 200 */
 261         TPM_UNDEFINED,
 262         TPM_UNDEFINED,
 263         TPM_UNDEFINED,
 264         TPM_SHORT,
 265         TPM_SHORT,              /* 205 */
 266         TPM_SHORT,
 267         TPM_SHORT,
 268         TPM_SHORT,
 269         TPM_SHORT,
 270         TPM_MEDIUM,             /* 210 */
 271         TPM_UNDEFINED,
 272         TPM_MEDIUM,
 273         TPM_MEDIUM,
 274         TPM_MEDIUM,
 275         TPM_UNDEFINED,          /* 215 */
 276         TPM_MEDIUM,
 277         TPM_UNDEFINED,
 278         TPM_UNDEFINED,
 279         TPM_SHORT,
 280         TPM_SHORT,              /* 220 */
 281         TPM_SHORT,
 282         TPM_SHORT,
 283         TPM_SHORT,
 284         TPM_SHORT,
 285         TPM_UNDEFINED,          /* 225 */
 286         TPM_UNDEFINED,
 287         TPM_UNDEFINED,
 288         TPM_UNDEFINED,
 289         TPM_UNDEFINED,
 290         TPM_SHORT,              /* 230 */
 291         TPM_LONG,
 292         TPM_MEDIUM,
 293         TPM_UNDEFINED,
 294         TPM_UNDEFINED,
 295         TPM_UNDEFINED,          /* 235 */
 296         TPM_UNDEFINED,
 297         TPM_UNDEFINED,
 298         TPM_UNDEFINED,
 299         TPM_UNDEFINED,
 300         TPM_SHORT,              /* 240 */
 301         TPM_UNDEFINED,
 302         TPM_MEDIUM,
 303 };
 304
 305 /*
 306  * Returns max number of jiffies to wait
 307  */
 308 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 309                                            u32 ordinal)
 310 {
 311         int duration_idx = TPM_UNDEFINED;
 312         int duration = 0;
 313
 314         /*
 315          * We only have a duration table for protected commands, where the upper
 316          * 16 bits are 0. For the few other ordinals the fallback will be used.
 317          */
 318         if (ordinal < TPM_MAX_ORDINAL)
 319                 duration_idx = tpm_ordinal_duration[ordinal];
 320
 321         if (duration_idx != TPM_UNDEFINED)
 322                 duration = chip->vendor.duration[duration_idx];
 323         if (duration <= 0)
 324                 return 2 * 60 * HZ;
 325         else
 326                 return duration;
 327 }
 328 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 329
 330 /*
 331  * Internal kernel interface to transmit TPM commands
 332  */
 333 ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 334                      size_t bufsiz)
 335 {
 336         ssize_t rc;
 337         u32 count, ordinal;
 338         unsigned long stop;
 339
 340         if (bufsiz > TPM_BUFSIZE)
 341                 bufsiz = TPM_BUFSIZE;
 342
 343         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 344         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 345         if (count == 0)
 346                 return -ENODATA;
 347         if (count > bufsiz) {
 348                 dev_err(&chip->dev,
 349                         "invalid count value %x %zx\n", count, bufsiz);
 350                 return -E2BIG;
 351         }
 352
 353         mutex_lock(&chip->tpm_mutex);
 354
 355         rc = chip->ops->send(chip, (u8 *) buf, count);
 356         if (rc < 0) {
 357                 dev_err(&chip->dev,
 358                         "tpm_transmit: tpm_send: error %zd\n", rc);
 359                 goto out;
 360         }
 361
 362         if (chip->vendor.irq)
 363                 goto out_recv;
 364
 365         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 366                 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
 367         else
 368                 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 369         do {
 370                 u8 status = chip->ops->status(chip);
 371                 if ((status & chip->ops->req_complete_mask) ==
 372                     chip->ops->req_complete_val)
 373                         goto out_recv;
 374
 375                 if (chip->ops->req_canceled(chip, status)) {
 376                         dev_err(&chip->dev, "Operation Canceled\n");
 377                         rc = -ECANCELED;
 378                         goto out;
 379                 }
 380
 381                 msleep(TPM_TIMEOUT);    /* CHECK */
 382                 rmb();
 383         } while (time_before(jiffies, stop));
 384
 385         chip->ops->cancel(chip);
 386         dev_err(&chip->dev, "Operation Timed out\n");
 387         rc = -ETIME;
 388         goto out;
 389
 390 out_recv:
 391         rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
 392         if (rc < 0)
 393                 dev_err(&chip->dev,
 394                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 395 out:
 396         mutex_unlock(&chip->tpm_mutex);
 397         return rc;
 398 }
 399
 400 #define TPM_DIGEST_SIZE 20
 401 #define TPM_RET_CODE_IDX 6
 402
 403 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd,
 404                          int len, const char *desc)
 405 {
 406         struct tpm_output_header *header;
 407         int err;
 408
 409         len = tpm_transmit(chip, (u8 *) cmd, len);
 410         if (len <  0)
 411                 return len;
 412         else if (len < TPM_HEADER_SIZE)
 413                 return -EFAULT;
 414
 415         header = cmd;
 416
 417         err = be32_to_cpu(header->return_code);
 418         if (err != 0 && desc)
 419                 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
 420                         desc);
 421
 422         return err;
 423 }
 424
 425 #define TPM_INTERNAL_RESULT_SIZE 200
 426 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 427 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 428
 429 static const struct tpm_input_header tpm_getcap_header = {
 430         .tag = TPM_TAG_RQU_COMMAND,
 431         .length = cpu_to_be32(22),
 432         .ordinal = TPM_ORD_GET_CAP
 433 };
 434
 435 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
 436                    const char *desc)
 437 {
 438         struct tpm_cmd_t tpm_cmd;
 439         int rc;
 440         struct tpm_chip *chip = dev_get_drvdata(dev);
 441
 442         tpm_cmd.header.in = tpm_getcap_header;
 443         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 444                 tpm_cmd.params.getcap_in.cap = subcap_id;
 445                 /*subcap field not necessary */
 446                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 447                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 448         } else {
 449                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 450                     subcap_id == TPM_CAP_FLAG_VOL)
 451                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 452                 else
 453                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 454                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 455                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 456         }
 457         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
 458         if (!rc)
 459                 *cap = tpm_cmd.params.getcap_out.cap;
 460         return rc;
 461 }
 462
 463 void tpm_gen_interrupt(struct tpm_chip *chip)
 464 {
 465         struct  tpm_cmd_t tpm_cmd;
 466         ssize_t rc;
 467
 468         tpm_cmd.header.in = tpm_getcap_header;
 469         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 470         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 471         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 472
 473         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 474                               "attempting to determine the timeouts");
 475 }
 476 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 477
 478 #define TPM_ORD_STARTUP cpu_to_be32(153)
 479 #define TPM_ST_CLEAR cpu_to_be16(1)
 480 #define TPM_ST_STATE cpu_to_be16(2)
 481 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 482 static const struct tpm_input_header tpm_startup_header = {
 483         .tag = TPM_TAG_RQU_COMMAND,
 484         .length = cpu_to_be32(12),
 485         .ordinal = TPM_ORD_STARTUP
 486 };
 487
 488 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 489 {
 490         struct tpm_cmd_t start_cmd;
 491         start_cmd.header.in = tpm_startup_header;
 492
 493         start_cmd.params.startup_in.startup_type = startup_type;
 494         return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
 495                                 "attempting to start the TPM");
 496 }
 497
 498 int tpm_get_timeouts(struct tpm_chip *chip)
 499 {
 500         struct tpm_cmd_t tpm_cmd;
 501         unsigned long new_timeout[4];
 502         unsigned long old_timeout[4];
 503         struct duration_t *duration_cap;
 504         ssize_t rc;
 505
 506         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 507                 /* Fixed timeouts for TPM2 */
 508                 chip->vendor.timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
 509                 chip->vendor.timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
 510                 chip->vendor.timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
 511                 chip->vendor.timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
 512                 chip->vendor.duration[TPM_SHORT] =
 513                     msecs_to_jiffies(TPM2_DURATION_SHORT);
 514                 chip->vendor.duration[TPM_MEDIUM] =
 515                     msecs_to_jiffies(TPM2_DURATION_MEDIUM);
 516                 chip->vendor.duration[TPM_LONG] =
 517                     msecs_to_jiffies(TPM2_DURATION_LONG);
 518                 return 0;
 519         }
 520
 521         tpm_cmd.header.in = tpm_getcap_header;
 522         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 523         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 524         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 525         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
 526
 527         if (rc == TPM_ERR_INVALID_POSTINIT) {
 528                 /* The TPM is not started, we are the first to talk to it.
 529                    Execute a startup command. */
 530                 dev_info(&chip->dev, "Issuing TPM_STARTUP");
 531                 if (tpm_startup(chip, TPM_ST_CLEAR))
 532                         return rc;
 533
 534                 tpm_cmd.header.in = tpm_getcap_header;
 535                 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 536                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 537                 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 538                 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 539                                   NULL);
 540         }
 541         if (rc) {
 542                 dev_err(&chip->dev,
 543                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 544                         rc);
 545                 goto duration;
 546         }
 547
 548         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 549             be32_to_cpu(tpm_cmd.header.out.length)
 550             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 551                 return -EINVAL;
 552
 553         old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
 554         old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
 555         old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
 556         old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
 557         memcpy(new_timeout, old_timeout, sizeof(new_timeout));
 558
 559         /*
 560          * Provide ability for vendor overrides of timeout values in case
 561          * of misreporting.
 562          */
 563         if (chip->ops->update_timeouts != NULL)
 564                 chip->vendor.timeout_adjusted =
 565                         chip->ops->update_timeouts(chip, new_timeout);
 566
 567         if (!chip->vendor.timeout_adjusted) {
 568                 /* Don't overwrite default if value is 0 */
 569                 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
 570                         int i;
 571
 572                         /* timeouts in msec rather usec */
 573                         for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
 574                                 new_timeout[i] *= 1000;
 575                         chip->vendor.timeout_adjusted = true;
 576                 }
 577         }
 578
 579         /* Report adjusted timeouts */
 580         if (chip->vendor.timeout_adjusted) {
 581                 dev_info(&chip->dev,
 582                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 583                          old_timeout[0], new_timeout[0],
 584                          old_timeout[1], new_timeout[1],
 585                          old_timeout[2], new_timeout[2],
 586                          old_timeout[3], new_timeout[3]);
 587         }
 588
 589         chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
 590         chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
 591         chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
 592         chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
 593
 594 duration:
 595         tpm_cmd.header.in = tpm_getcap_header;
 596         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 597         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 598         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 599
 600         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 601                               "attempting to determine the durations");
 602         if (rc)
 603                 return rc;
 604
 605         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 606             be32_to_cpu(tpm_cmd.header.out.length)
 607             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 608                 return -EINVAL;
 609
 610         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 611         chip->vendor.duration[TPM_SHORT] =
 612             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 613         chip->vendor.duration[TPM_MEDIUM] =
 614             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 615         chip->vendor.duration[TPM_LONG] =
 616             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 617
 618         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 619          * value wrong and apparently reports msecs rather than usecs. So we
 620          * fix up the resulting too-small TPM_SHORT value to make things work.
 621          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 622          */
 623         if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
 624                 chip->vendor.duration[TPM_SHORT] = HZ;
 625                 chip->vendor.duration[TPM_MEDIUM] *= 1000;
 626                 chip->vendor.duration[TPM_LONG] *= 1000;
 627                 chip->vendor.duration_adjusted = true;
 628                 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 629         }
 630         return 0;
 631 }
 632 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 633
 634 #define TPM_ORD_CONTINUE_SELFTEST 83
 635 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 636
 637 static struct tpm_input_header continue_selftest_header = {
 638         .tag = TPM_TAG_RQU_COMMAND,
 639         .length = cpu_to_be32(10),
 640         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 641 };
 642
 643 /**
 644  * tpm_continue_selftest -- run TPM's selftest
 645  * @chip: TPM chip to use
 646  *
 647  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 648  * a TPM error code.
 649  */
 650 static int tpm_continue_selftest(struct tpm_chip *chip)
 651 {
 652         int rc;
 653         struct tpm_cmd_t cmd;
 654
 655         cmd.header.in = continue_selftest_header;
 656         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 657                               "continue selftest");
 658         return rc;
 659 }
 660
 661 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 662 #define READ_PCR_RESULT_SIZE 30
 663 static struct tpm_input_header pcrread_header = {
 664         .tag = TPM_TAG_RQU_COMMAND,
 665         .length = cpu_to_be32(14),
 666         .ordinal = TPM_ORDINAL_PCRREAD
 667 };
 668
 669 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 670 {
 671         int rc;
 672         struct tpm_cmd_t cmd;
 673
 674         cmd.header.in = pcrread_header;
 675         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 676         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 677                               "attempting to read a pcr value");
 678
 679         if (rc == 0)
 680                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 681                        TPM_DIGEST_SIZE);
 682         return rc;
 683 }
 684
 685 /**
 686  * tpm_is_tpm2 - is the chip a TPM2 chip?
 687  * @chip_num:   tpm idx # or ANY
 688  *
 689  * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 690  * is a TPM2 chip.
 691  */
 692 int tpm_is_tpm2(u32 chip_num)
 693 {
 694         struct tpm_chip *chip;
 695         int rc;
 696
 697         chip = tpm_chip_find_get(chip_num);
 698         if (chip == NULL)
 699                 return -ENODEV;
 700
 701         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 702
 703         tpm_chip_put(chip);
 704
 705         return rc;
 706 }
 707 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 708
 709 /**
 710  * tpm_pcr_read - read a pcr value
 711  * @chip_num:   tpm idx # or ANY
 712  * @pcr_idx:    pcr idx to retrieve
 713  * @res_buf:    TPM_PCR value
 714  *              size of res_buf is 20 bytes (or NULL if you don't care)
 715  *
 716  * The TPM driver should be built-in, but for whatever reason it
 717  * isn't, protect against the chip disappearing, by incrementing
 718  * the module usage count.
 719  */
 720 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 721 {
 722         struct tpm_chip *chip;
 723         int rc;
 724
 725         chip = tpm_chip_find_get(chip_num);
 726         if (chip == NULL)
 727                 return -ENODEV;
 728         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 729                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 730         else
 731                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 732         tpm_chip_put(chip);
 733         return rc;
 734 }
 735 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 736
 737 /**
 738  * tpm_pcr_extend - extend pcr value with hash
 739  * @chip_num:   tpm idx # or AN&
 740  * @pcr_idx:    pcr idx to extend
 741  * @hash:       hash value used to extend pcr value
 742  *
 743  * The TPM driver should be built-in, but for whatever reason it
 744  * isn't, protect against the chip disappearing, by incrementing
 745  * the module usage count.
 746  */
 747 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 748 #define EXTEND_PCR_RESULT_SIZE 34
 749 static struct tpm_input_header pcrextend_header = {
 750         .tag = TPM_TAG_RQU_COMMAND,
 751         .length = cpu_to_be32(34),
 752         .ordinal = TPM_ORD_PCR_EXTEND
 753 };
 754
 755 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 756 {
 757         struct tpm_cmd_t cmd;
 758         int rc;
 759         struct tpm_chip *chip;
 760
 761         chip = tpm_chip_find_get(chip_num);
 762         if (chip == NULL)
 763                 return -ENODEV;
 764
 765         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 766                 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
 767                 tpm_chip_put(chip);
 768                 return rc;
 769         }
 770
 771         cmd.header.in = pcrextend_header;
 772         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 773         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 774         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 775                               "attempting extend a PCR value");
 776
 777         tpm_chip_put(chip);
 778         return rc;
 779 }
 780 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 781
 782 /**
 783  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 784  *                   can receive further commands
 785  * @chip: TPM chip to use
 786  *
 787  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 788  * a TPM error code.
 789  */
 790 int tpm_do_selftest(struct tpm_chip *chip)
 791 {
 792         int rc;
 793         unsigned int loops;
 794         unsigned int delay_msec = 100;
 795         unsigned long duration;
 796         struct tpm_cmd_t cmd;
 797
 798         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 799
 800         loops = jiffies_to_msecs(duration) / delay_msec;
 801
 802         rc = tpm_continue_selftest(chip);
 803         /* This may fail if there was no TPM driver during a suspend/resume
 804          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 805          */
 806         if (rc)
 807                 return rc;
 808
 809         do {
 810                 /* Attempt to read a PCR value */
 811                 cmd.header.in = pcrread_header;
 812                 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
 813                 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
 814                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 815                  * around 300ms while the self test is ongoing, keep trying
 816                  * until the self test duration expires. */
 817                 if (rc == -ETIME) {
 818                         dev_info(
 819                             &chip->dev, HW_ERR
 820                             "TPM command timed out during continue self test");
 821                         msleep(delay_msec);
 822                         continue;
 823                 }
 824
 825                 if (rc < TPM_HEADER_SIZE)
 826                         return -EFAULT;
 827
 828                 rc = be32_to_cpu(cmd.header.out.return_code);
 829                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 830                         dev_info(&chip->dev,
 831                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 832                         /* TPM is disabled and/or deactivated; driver can
 833                          * proceed and TPM does handle commands for
 834                          * suspend/resume correctly
 835                          */
 836                         return 0;
 837                 }
 838                 if (rc != TPM_WARN_DOING_SELFTEST)
 839                         return rc;
 840                 msleep(delay_msec);
 841         } while (--loops > 0);
 842
 843         return rc;
 844 }
 845 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 846
 847 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 848 {
 849         struct tpm_chip *chip;
 850         int rc;
 851
 852         chip = tpm_chip_find_get(chip_num);
 853         if (chip == NULL)
 854                 return -ENODEV;
 855
 856         rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
 857
 858         tpm_chip_put(chip);
 859         return rc;
 860 }
 861 EXPORT_SYMBOL_GPL(tpm_send);
 862
 863 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 864                                         bool check_cancel, bool *canceled)
 865 {
 866         u8 status = chip->ops->status(chip);
 867
 868         *canceled = false;
 869         if ((status & mask) == mask)
 870                 return true;
 871         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 872                 *canceled = true;
 873                 return true;
 874         }
 875         return false;
 876 }
 877
 878 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 879                       wait_queue_head_t *queue, bool check_cancel)
 880 {
 881         unsigned long stop;
 882         long rc;
 883         u8 status;
 884         bool canceled = false;
 885
 886         /* check current status */
 887         status = chip->ops->status(chip);
 888         if ((status & mask) == mask)
 889                 return 0;
 890
 891         stop = jiffies + timeout;
 892
 893         if (chip->vendor.irq) {
 894 again:
 895                 timeout = stop - jiffies;
 896                 if ((long)timeout <= 0)
 897                         return -ETIME;
 898                 rc = wait_event_interruptible_timeout(*queue,
 899                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 900                                                &canceled),
 901                         timeout);
 902                 if (rc > 0) {
 903                         if (canceled)
 904                                 return -ECANCELED;
 905                         return 0;
 906                 }
 907                 if (rc == -ERESTARTSYS && freezing(current)) {
 908                         clear_thread_flag(TIF_SIGPENDING);
 909                         goto again;
 910                 }
 911         } else {
 912                 do {
 913                         msleep(TPM_TIMEOUT);
 914                         status = chip->ops->status(chip);
 915                         if ((status & mask) == mask)
 916                                 return 0;
 917                 } while (time_before(jiffies, stop));
 918         }
 919         return -ETIME;
 920 }
 921 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 922
 923 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 924 #define SAVESTATE_RESULT_SIZE 10
 925
 926 static struct tpm_input_header savestate_header = {
 927         .tag = TPM_TAG_RQU_COMMAND,
 928         .length = cpu_to_be32(10),
 929         .ordinal = TPM_ORD_SAVESTATE
 930 };
 931
 932 /*
 933  * We are about to suspend. Save the TPM state
 934  * so that it can be restored.
 935  */
 936 int tpm_pm_suspend(struct device *dev)
 937 {
 938         struct tpm_chip *chip = dev_get_drvdata(dev);
 939         struct tpm_cmd_t cmd;
 940         int rc, try;
 941
 942         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 943
 944         if (chip == NULL)
 945                 return -ENODEV;
 946
 947         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 948                 tpm2_shutdown(chip, TPM2_SU_STATE);
 949                 return 0;
 950         }
 951
 952         /* for buggy tpm, flush pcrs with extend to selected dummy */
 953         if (tpm_suspend_pcr) {
 954                 cmd.header.in = pcrextend_header;
 955                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 956                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 957                        TPM_DIGEST_SIZE);
 958                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 959                                       "extending dummy pcr before suspend");
 960         }
 961
 962         /* now do the actual savestate */
 963         for (try = 0; try < TPM_RETRY; try++) {
 964                 cmd.header.in = savestate_header;
 965                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
 966
 967                 /*
 968                  * If the TPM indicates that it is too busy to respond to
 969                  * this command then retry before giving up.  It can take
 970                  * several seconds for this TPM to be ready.
 971                  *
 972                  * This can happen if the TPM has already been sent the
 973                  * SaveState command before the driver has loaded.  TCG 1.2
 974                  * specification states that any communication after SaveState
 975                  * may cause the TPM to invalidate previously saved state.
 976                  */
 977                 if (rc != TPM_WARN_RETRY)
 978                         break;
 979                 msleep(TPM_TIMEOUT_RETRY);
 980         }
 981
 982         if (rc)
 983                 dev_err(&chip->dev,
 984                         "Error (%d) sending savestate before suspend\n", rc);
 985         else if (try > 0)
 986                 dev_warn(&chip->dev, "TPM savestate took %dms\n",
 987                          try * TPM_TIMEOUT_RETRY);
 988
 989         return rc;
 990 }
 991 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
 992
 993 /*
 994  * Resume from a power safe. The BIOS already restored
 995  * the TPM state.
 996  */
 997 int tpm_pm_resume(struct device *dev)
 998 {
 999         struct tpm_chip *chip = dev_get_drvdata(dev);
1000
1001         if (chip == NULL)
1002                 return -ENODEV;
1003
1004         return 0;
1005 }
1006 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1007
1008 #define TPM_GETRANDOM_RESULT_SIZE       18
1009 static struct tpm_input_header tpm_getrandom_header = {
1010         .tag = TPM_TAG_RQU_COMMAND,
1011         .length = cpu_to_be32(14),
1012         .ordinal = TPM_ORD_GET_RANDOM
1013 };
1014
1015 /**
1016  * tpm_get_random() - Get random bytes from the tpm's RNG
1017  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1018  * @out: destination buffer for the random bytes
1019  * @max: the max number of bytes to write to @out
1020  *
1021  * Returns < 0 on error and the number of bytes read on success
1022  */
1023 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1024 {
1025         struct tpm_chip *chip;
1026         struct tpm_cmd_t tpm_cmd;
1027         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1028         int err, total = 0, retries = 5;
1029         u8 *dest = out;
1030
1031         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1032                 return -EINVAL;
1033
1034         chip = tpm_chip_find_get(chip_num);
1035         if (chip == NULL)
1036                 return -ENODEV;
1037
1038         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1039                 err = tpm2_get_random(chip, out, max);
1040                 tpm_chip_put(chip);
1041                 return err;
1042         }
1043
1044         do {
1045                 tpm_cmd.header.in = tpm_getrandom_header;
1046                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1047
1048                 err = tpm_transmit_cmd(chip, &tpm_cmd,
1049                                    TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1050                                    "attempting get random");
1051                 if (err)
1052                         break;
1053
1054                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1055                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1056
1057                 dest += recd;
1058                 total += recd;
1059                 num_bytes -= recd;
1060         } while (retries-- && total < max);
1061
1062         tpm_chip_put(chip);
1063         return total ? total : -EIO;
1064 }
1065 EXPORT_SYMBOL_GPL(tpm_get_random);
1066
1067 /**
1068  * tpm_seal_trusted() - seal a trusted key
1069  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1070  * @options: authentication values and other options
1071  * @payload: the key data in clear and encrypted form
1072  *
1073  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1074  * are supported.
1075  */
1076 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1077                      struct trusted_key_options *options)
1078 {
1079         struct tpm_chip *chip;
1080         int rc;
1081
1082         chip = tpm_chip_find_get(chip_num);
1083         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1084                 return -ENODEV;
1085
1086         rc = tpm2_seal_trusted(chip, payload, options);
1087
1088         tpm_chip_put(chip);
1089         return rc;
1090 }
1091 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1092
1093 /**
1094  * tpm_unseal_trusted() - unseal a trusted key
1095  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1096  * @options: authentication values and other options
1097  * @payload: the key data in clear and encrypted form
1098  *
1099  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1100  * are supported.
1101  */
1102 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1103                        struct trusted_key_options *options)
1104 {
1105         struct tpm_chip *chip;
1106         int rc;
1107
1108         chip = tpm_chip_find_get(chip_num);
1109         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1110                 return -ENODEV;
1111
1112         rc = tpm2_unseal_trusted(chip, payload, options);
1113
1114         tpm_chip_put(chip);
1115         return rc;
1116 }
1117 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1118
1119 static int __init tpm_init(void)
1120 {
1121         int rc;
1122
1123         tpm_class = class_create(THIS_MODULE, "tpm");
1124         if (IS_ERR(tpm_class)) {
1125                 pr_err("couldn't create tpm class\n");
1126                 return PTR_ERR(tpm_class);
1127         }
1128
1129         rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1130         if (rc < 0) {
1131                 pr_err("tpm: failed to allocate char dev region\n");
1132                 class_destroy(tpm_class);
1133                 return rc;
1134         }
1135
1136         return 0;
1137 }
1138
1139 static void __exit tpm_exit(void)
1140 {
1141         class_destroy(tpm_class);
1142         unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1143 }
1144
1145 subsys_initcall(tpm_init);
1146 module_exit(tpm_exit);
1147
1148 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1149 MODULE_DESCRIPTION("TPM Driver");
1150 MODULE_VERSION("2.0");
1151 MODULE_LICENSE("GPL");