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->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 u8 *buf, size_t bufsiz,
 334                      unsigned int flags)
 335 {
 336         ssize_t rc;
 337         u32 count, ordinal;
 338         unsigned long stop;
 339
 340         if (bufsiz < TPM_HEADER_SIZE)
 341                 return -EINVAL;
 342
 343         if (bufsiz > TPM_BUFSIZE)
 344                 bufsiz = TPM_BUFSIZE;
 345
 346         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 347         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 348         if (count == 0)
 349                 return -ENODATA;
 350         if (count > bufsiz) {
 351                 dev_err(&chip->dev,
 352                         "invalid count value %x %zx\n", count, bufsiz);
 353                 return -E2BIG;
 354         }
 355
 356         if (!(flags & TPM_TRANSMIT_UNLOCKED))
 357                 mutex_lock(&chip->tpm_mutex);
 358
 359         rc = chip->ops->send(chip, (u8 *) buf, count);
 360         if (rc < 0) {
 361                 dev_err(&chip->dev,
 362                         "tpm_transmit: tpm_send: error %zd\n", rc);
 363                 goto out;
 364         }
 365
 366         if (chip->flags & TPM_CHIP_FLAG_IRQ)
 367                 goto out_recv;
 368
 369         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 370                 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
 371         else
 372                 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 373         do {
 374                 u8 status = chip->ops->status(chip);
 375                 if ((status & chip->ops->req_complete_mask) ==
 376                     chip->ops->req_complete_val)
 377                         goto out_recv;
 378
 379                 if (chip->ops->req_canceled(chip, status)) {
 380                         dev_err(&chip->dev, "Operation Canceled\n");
 381                         rc = -ECANCELED;
 382                         goto out;
 383                 }
 384
 385                 msleep(TPM_TIMEOUT);    /* CHECK */
 386                 rmb();
 387         } while (time_before(jiffies, stop));
 388
 389         chip->ops->cancel(chip);
 390         dev_err(&chip->dev, "Operation Timed out\n");
 391         rc = -ETIME;
 392         goto out;
 393
 394 out_recv:
 395         rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
 396         if (rc < 0)
 397                 dev_err(&chip->dev,
 398                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 399 out:
 400         if (!(flags & TPM_TRANSMIT_UNLOCKED))
 401                 mutex_unlock(&chip->tpm_mutex);
 402         return rc;
 403 }
 404
 405 #define TPM_DIGEST_SIZE 20
 406 #define TPM_RET_CODE_IDX 6
 407
 408 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,
 409                          int len, unsigned int flags, const char *desc)
 410 {
 411         const struct tpm_output_header *header;
 412         int err;
 413
 414         len = tpm_transmit(chip, (const u8 *)cmd, len, flags);
 415         if (len <  0)
 416                 return len;
 417         else if (len < TPM_HEADER_SIZE)
 418                 return -EFAULT;
 419
 420         header = cmd;
 421
 422         err = be32_to_cpu(header->return_code);
 423         if (err != 0 && desc)
 424                 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
 425                         desc);
 426
 427         return err;
 428 }
 429
 430 #define TPM_INTERNAL_RESULT_SIZE 200
 431 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 432 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 433
 434 static const struct tpm_input_header tpm_getcap_header = {
 435         .tag = TPM_TAG_RQU_COMMAND,
 436         .length = cpu_to_be32(22),
 437         .ordinal = TPM_ORD_GET_CAP
 438 };
 439
 440 ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap,
 441                    const char *desc)
 442 {
 443         struct tpm_cmd_t tpm_cmd;
 444         int rc;
 445
 446         tpm_cmd.header.in = tpm_getcap_header;
 447         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 448                 tpm_cmd.params.getcap_in.cap = subcap_id;
 449                 /*subcap field not necessary */
 450                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 451                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 452         } else {
 453                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 454                     subcap_id == TPM_CAP_FLAG_VOL)
 455                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 456                 else
 457                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 458                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 459                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 460         }
 461         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 462                               desc);
 463         if (!rc)
 464                 *cap = tpm_cmd.params.getcap_out.cap;
 465         return rc;
 466 }
 467 EXPORT_SYMBOL_GPL(tpm_getcap);
 468
 469 #define TPM_ORD_STARTUP cpu_to_be32(153)
 470 #define TPM_ST_CLEAR cpu_to_be16(1)
 471 #define TPM_ST_STATE cpu_to_be16(2)
 472 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 473 static const struct tpm_input_header tpm_startup_header = {
 474         .tag = TPM_TAG_RQU_COMMAND,
 475         .length = cpu_to_be32(12),
 476         .ordinal = TPM_ORD_STARTUP
 477 };
 478
 479 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 480 {
 481         struct tpm_cmd_t start_cmd;
 482         start_cmd.header.in = tpm_startup_header;
 483
 484         start_cmd.params.startup_in.startup_type = startup_type;
 485         return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 486                                 "attempting to start the TPM");
 487 }
 488
 489 int tpm_get_timeouts(struct tpm_chip *chip)
 490 {
 491         struct tpm_cmd_t tpm_cmd;
 492         unsigned long new_timeout[4];
 493         unsigned long old_timeout[4];
 494         struct duration_t *duration_cap;
 495         ssize_t rc;
 496
 497         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 498                 /* Fixed timeouts for TPM2 */
 499                 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
 500                 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
 501                 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
 502                 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
 503                 chip->duration[TPM_SHORT] =
 504                     msecs_to_jiffies(TPM2_DURATION_SHORT);
 505                 chip->duration[TPM_MEDIUM] =
 506                     msecs_to_jiffies(TPM2_DURATION_MEDIUM);
 507                 chip->duration[TPM_LONG] =
 508                     msecs_to_jiffies(TPM2_DURATION_LONG);
 509                 return 0;
 510         }
 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         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 517                               NULL);
 518
 519         if (rc == TPM_ERR_INVALID_POSTINIT) {
 520                 /* The TPM is not started, we are the first to talk to it.
 521                    Execute a startup command. */
 522                 dev_info(&chip->dev, "Issuing TPM_STARTUP");
 523                 if (tpm_startup(chip, TPM_ST_CLEAR))
 524                         return rc;
 525
 526                 tpm_cmd.header.in = tpm_getcap_header;
 527                 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 528                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 529                 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 530                 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 531                                       0, NULL);
 532         }
 533         if (rc) {
 534                 dev_err(&chip->dev,
 535                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 536                         rc);
 537                 goto duration;
 538         }
 539
 540         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 541             be32_to_cpu(tpm_cmd.header.out.length)
 542             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 543                 return -EINVAL;
 544
 545         old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
 546         old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
 547         old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
 548         old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
 549         memcpy(new_timeout, old_timeout, sizeof(new_timeout));
 550
 551         /*
 552          * Provide ability for vendor overrides of timeout values in case
 553          * of misreporting.
 554          */
 555         if (chip->ops->update_timeouts != NULL)
 556                 chip->timeout_adjusted =
 557                         chip->ops->update_timeouts(chip, new_timeout);
 558
 559         if (!chip->timeout_adjusted) {
 560                 /* Don't overwrite default if value is 0 */
 561                 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
 562                         int i;
 563
 564                         /* timeouts in msec rather usec */
 565                         for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
 566                                 new_timeout[i] *= 1000;
 567                         chip->timeout_adjusted = true;
 568                 }
 569         }
 570
 571         /* Report adjusted timeouts */
 572         if (chip->timeout_adjusted) {
 573                 dev_info(&chip->dev,
 574                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 575                          old_timeout[0], new_timeout[0],
 576                          old_timeout[1], new_timeout[1],
 577                          old_timeout[2], new_timeout[2],
 578                          old_timeout[3], new_timeout[3]);
 579         }
 580
 581         chip->timeout_a = usecs_to_jiffies(new_timeout[0]);
 582         chip->timeout_b = usecs_to_jiffies(new_timeout[1]);
 583         chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
 584         chip->timeout_d = usecs_to_jiffies(new_timeout[3]);
 585
 586 duration:
 587         tpm_cmd.header.in = tpm_getcap_header;
 588         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 589         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 590         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 591
 592         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 593                               "attempting to determine the durations");
 594         if (rc)
 595                 return rc;
 596
 597         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 598             be32_to_cpu(tpm_cmd.header.out.length)
 599             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 600                 return -EINVAL;
 601
 602         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 603         chip->duration[TPM_SHORT] =
 604             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 605         chip->duration[TPM_MEDIUM] =
 606             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 607         chip->duration[TPM_LONG] =
 608             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 609
 610         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 611          * value wrong and apparently reports msecs rather than usecs. So we
 612          * fix up the resulting too-small TPM_SHORT value to make things work.
 613          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 614          */
 615         if (chip->duration[TPM_SHORT] < (HZ / 100)) {
 616                 chip->duration[TPM_SHORT] = HZ;
 617                 chip->duration[TPM_MEDIUM] *= 1000;
 618                 chip->duration[TPM_LONG] *= 1000;
 619                 chip->duration_adjusted = true;
 620                 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 621         }
 622         return 0;
 623 }
 624 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 625
 626 #define TPM_ORD_CONTINUE_SELFTEST 83
 627 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 628
 629 static const struct tpm_input_header continue_selftest_header = {
 630         .tag = TPM_TAG_RQU_COMMAND,
 631         .length = cpu_to_be32(10),
 632         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 633 };
 634
 635 /**
 636  * tpm_continue_selftest -- run TPM's selftest
 637  * @chip: TPM chip to use
 638  *
 639  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 640  * a TPM error code.
 641  */
 642 static int tpm_continue_selftest(struct tpm_chip *chip)
 643 {
 644         int rc;
 645         struct tpm_cmd_t cmd;
 646
 647         cmd.header.in = continue_selftest_header;
 648         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
 649                               "continue selftest");
 650         return rc;
 651 }
 652
 653 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 654 #define READ_PCR_RESULT_SIZE 30
 655 static const struct tpm_input_header pcrread_header = {
 656         .tag = TPM_TAG_RQU_COMMAND,
 657         .length = cpu_to_be32(14),
 658         .ordinal = TPM_ORDINAL_PCRREAD
 659 };
 660
 661 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 662 {
 663         int rc;
 664         struct tpm_cmd_t cmd;
 665
 666         cmd.header.in = pcrread_header;
 667         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 668         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
 669                               "attempting to read a pcr value");
 670
 671         if (rc == 0)
 672                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 673                        TPM_DIGEST_SIZE);
 674         return rc;
 675 }
 676
 677 /**
 678  * tpm_is_tpm2 - is the chip a TPM2 chip?
 679  * @chip_num:   tpm idx # or ANY
 680  *
 681  * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 682  * is a TPM2 chip.
 683  */
 684 int tpm_is_tpm2(u32 chip_num)
 685 {
 686         struct tpm_chip *chip;
 687         int rc;
 688
 689         chip = tpm_chip_find_get(chip_num);
 690         if (chip == NULL)
 691                 return -ENODEV;
 692
 693         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 694
 695         tpm_put_ops(chip);
 696
 697         return rc;
 698 }
 699 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 700
 701 /**
 702  * tpm_pcr_read - read a pcr value
 703  * @chip_num:   tpm idx # or ANY
 704  * @pcr_idx:    pcr idx to retrieve
 705  * @res_buf:    TPM_PCR value
 706  *              size of res_buf is 20 bytes (or NULL if you don't care)
 707  *
 708  * The TPM driver should be built-in, but for whatever reason it
 709  * isn't, protect against the chip disappearing, by incrementing
 710  * the module usage count.
 711  */
 712 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 713 {
 714         struct tpm_chip *chip;
 715         int rc;
 716
 717         chip = tpm_chip_find_get(chip_num);
 718         if (chip == NULL)
 719                 return -ENODEV;
 720         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 721                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 722         else
 723                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 724         tpm_put_ops(chip);
 725         return rc;
 726 }
 727 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 728
 729 /**
 730  * tpm_pcr_extend - extend pcr value with hash
 731  * @chip_num:   tpm idx # or AN&
 732  * @pcr_idx:    pcr idx to extend
 733  * @hash:       hash value used to extend pcr value
 734  *
 735  * The TPM driver should be built-in, but for whatever reason it
 736  * isn't, protect against the chip disappearing, by incrementing
 737  * the module usage count.
 738  */
 739 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 740 #define EXTEND_PCR_RESULT_SIZE 34
 741 static const struct tpm_input_header pcrextend_header = {
 742         .tag = TPM_TAG_RQU_COMMAND,
 743         .length = cpu_to_be32(34),
 744         .ordinal = TPM_ORD_PCR_EXTEND
 745 };
 746
 747 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 748 {
 749         struct tpm_cmd_t cmd;
 750         int rc;
 751         struct tpm_chip *chip;
 752
 753         chip = tpm_chip_find_get(chip_num);
 754         if (chip == NULL)
 755                 return -ENODEV;
 756
 757         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 758                 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
 759                 tpm_put_ops(chip);
 760                 return rc;
 761         }
 762
 763         cmd.header.in = pcrextend_header;
 764         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 765         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 766         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 767                               "attempting extend a PCR value");
 768
 769         tpm_put_ops(chip);
 770         return rc;
 771 }
 772 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 773
 774 /**
 775  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 776  *                   can receive further commands
 777  * @chip: TPM chip to use
 778  *
 779  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 780  * a TPM error code.
 781  */
 782 int tpm_do_selftest(struct tpm_chip *chip)
 783 {
 784         int rc;
 785         unsigned int loops;
 786         unsigned int delay_msec = 100;
 787         unsigned long duration;
 788         u8 dummy[TPM_DIGEST_SIZE];
 789
 790         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 791
 792         loops = jiffies_to_msecs(duration) / delay_msec;
 793
 794         rc = tpm_continue_selftest(chip);
 795         /* This may fail if there was no TPM driver during a suspend/resume
 796          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 797          */
 798         if (rc)
 799                 return rc;
 800
 801         do {
 802                 /* Attempt to read a PCR value */
 803                 rc = tpm_pcr_read_dev(chip, 0, dummy);
 804
 805                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 806                  * around 300ms while the self test is ongoing, keep trying
 807                  * until the self test duration expires. */
 808                 if (rc == -ETIME) {
 809                         dev_info(
 810                             &chip->dev, HW_ERR
 811                             "TPM command timed out during continue self test");
 812                         msleep(delay_msec);
 813                         continue;
 814                 }
 815
 816                 if (rc < TPM_HEADER_SIZE)
 817                         return -EFAULT;
 818
 819                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 820                         dev_info(&chip->dev,
 821                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 822                         /* TPM is disabled and/or deactivated; driver can
 823                          * proceed and TPM does handle commands for
 824                          * suspend/resume correctly
 825                          */
 826                         return 0;
 827                 }
 828                 if (rc != TPM_WARN_DOING_SELFTEST)
 829                         return rc;
 830                 msleep(delay_msec);
 831         } while (--loops > 0);
 832
 833         return rc;
 834 }
 835 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 836
 837 /**
 838  * tpm1_auto_startup - Perform the standard automatic TPM initialization
 839  *                     sequence
 840  * @chip: TPM chip to use
 841  *
 842  * Returns 0 on success, < 0 in case of fatal error.
 843  */
 844 int tpm1_auto_startup(struct tpm_chip *chip)
 845 {
 846         int rc;
 847
 848         rc = tpm_get_timeouts(chip);
 849         if (rc)
 850                 goto out;
 851         rc = tpm_do_selftest(chip);
 852         if (rc) {
 853                 dev_err(&chip->dev, "TPM self test failed\n");
 854                 goto out;
 855         }
 856
 857         return rc;
 858 out:
 859         if (rc > 0)
 860                 rc = -ENODEV;
 861         return rc;
 862 }
 863
 864 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 865 {
 866         struct tpm_chip *chip;
 867         int rc;
 868
 869         chip = tpm_chip_find_get(chip_num);
 870         if (chip == NULL)
 871                 return -ENODEV;
 872
 873         rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
 874
 875         tpm_put_ops(chip);
 876         return rc;
 877 }
 878 EXPORT_SYMBOL_GPL(tpm_send);
 879
 880 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 881                                         bool check_cancel, bool *canceled)
 882 {
 883         u8 status = chip->ops->status(chip);
 884
 885         *canceled = false;
 886         if ((status & mask) == mask)
 887                 return true;
 888         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 889                 *canceled = true;
 890                 return true;
 891         }
 892         return false;
 893 }
 894
 895 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 896                       wait_queue_head_t *queue, bool check_cancel)
 897 {
 898         unsigned long stop;
 899         long rc;
 900         u8 status;
 901         bool canceled = false;
 902
 903         /* check current status */
 904         status = chip->ops->status(chip);
 905         if ((status & mask) == mask)
 906                 return 0;
 907
 908         stop = jiffies + timeout;
 909
 910         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
 911 again:
 912                 timeout = stop - jiffies;
 913                 if ((long)timeout <= 0)
 914                         return -ETIME;
 915                 rc = wait_event_interruptible_timeout(*queue,
 916                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 917                                                &canceled),
 918                         timeout);
 919                 if (rc > 0) {
 920                         if (canceled)
 921                                 return -ECANCELED;
 922                         return 0;
 923                 }
 924                 if (rc == -ERESTARTSYS && freezing(current)) {
 925                         clear_thread_flag(TIF_SIGPENDING);
 926                         goto again;
 927                 }
 928         } else {
 929                 do {
 930                         msleep(TPM_TIMEOUT);
 931                         status = chip->ops->status(chip);
 932                         if ((status & mask) == mask)
 933                                 return 0;
 934                 } while (time_before(jiffies, stop));
 935         }
 936         return -ETIME;
 937 }
 938 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 939
 940 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 941 #define SAVESTATE_RESULT_SIZE 10
 942
 943 static const struct tpm_input_header savestate_header = {
 944         .tag = TPM_TAG_RQU_COMMAND,
 945         .length = cpu_to_be32(10),
 946         .ordinal = TPM_ORD_SAVESTATE
 947 };
 948
 949 /*
 950  * We are about to suspend. Save the TPM state
 951  * so that it can be restored.
 952  */
 953 int tpm_pm_suspend(struct device *dev)
 954 {
 955         struct tpm_chip *chip = dev_get_drvdata(dev);
 956         struct tpm_cmd_t cmd;
 957         int rc, try;
 958
 959         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 960
 961         if (chip == NULL)
 962                 return -ENODEV;
 963
 964         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 965                 tpm2_shutdown(chip, TPM2_SU_STATE);
 966                 return 0;
 967         }
 968
 969         /* for buggy tpm, flush pcrs with extend to selected dummy */
 970         if (tpm_suspend_pcr) {
 971                 cmd.header.in = pcrextend_header;
 972                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 973                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 974                        TPM_DIGEST_SIZE);
 975                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 976                                       "extending dummy pcr before suspend");
 977         }
 978
 979         /* now do the actual savestate */
 980         for (try = 0; try < TPM_RETRY; try++) {
 981                 cmd.header.in = savestate_header;
 982                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
 983                                       NULL);
 984
 985                 /*
 986                  * If the TPM indicates that it is too busy to respond to
 987                  * this command then retry before giving up.  It can take
 988                  * several seconds for this TPM to be ready.
 989                  *
 990                  * This can happen if the TPM has already been sent the
 991                  * SaveState command before the driver has loaded.  TCG 1.2
 992                  * specification states that any communication after SaveState
 993                  * may cause the TPM to invalidate previously saved state.
 994                  */
 995                 if (rc != TPM_WARN_RETRY)
 996                         break;
 997                 msleep(TPM_TIMEOUT_RETRY);
 998         }
 999
1000         if (rc)
1001                 dev_err(&chip->dev,
1002                         "Error (%d) sending savestate before suspend\n", rc);
1003         else if (try > 0)
1004                 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1005                          try * TPM_TIMEOUT_RETRY);
1006
1007         return rc;
1008 }
1009 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1010
1011 /*
1012  * Resume from a power safe. The BIOS already restored
1013  * the TPM state.
1014  */
1015 int tpm_pm_resume(struct device *dev)
1016 {
1017         struct tpm_chip *chip = dev_get_drvdata(dev);
1018
1019         if (chip == NULL)
1020                 return -ENODEV;
1021
1022         return 0;
1023 }
1024 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1025
1026 #define TPM_GETRANDOM_RESULT_SIZE       18
1027 static const struct tpm_input_header tpm_getrandom_header = {
1028         .tag = TPM_TAG_RQU_COMMAND,
1029         .length = cpu_to_be32(14),
1030         .ordinal = TPM_ORD_GET_RANDOM
1031 };
1032
1033 /**
1034  * tpm_get_random() - Get random bytes from the tpm's RNG
1035  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1036  * @out: destination buffer for the random bytes
1037  * @max: the max number of bytes to write to @out
1038  *
1039  * Returns < 0 on error and the number of bytes read on success
1040  */
1041 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1042 {
1043         struct tpm_chip *chip;
1044         struct tpm_cmd_t tpm_cmd;
1045         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1046         int err, total = 0, retries = 5;
1047         u8 *dest = out;
1048
1049         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1050                 return -EINVAL;
1051
1052         chip = tpm_chip_find_get(chip_num);
1053         if (chip == NULL)
1054                 return -ENODEV;
1055
1056         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1057                 err = tpm2_get_random(chip, out, max);
1058                 tpm_put_ops(chip);
1059                 return err;
1060         }
1061
1062         do {
1063                 tpm_cmd.header.in = tpm_getrandom_header;
1064                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1065
1066                 err = tpm_transmit_cmd(chip, &tpm_cmd,
1067                                        TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1068                                        0, "attempting get random");
1069                 if (err)
1070                         break;
1071
1072                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1073                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1074
1075                 dest += recd;
1076                 total += recd;
1077                 num_bytes -= recd;
1078         } while (retries-- && total < max);
1079
1080         tpm_put_ops(chip);
1081         return total ? total : -EIO;
1082 }
1083 EXPORT_SYMBOL_GPL(tpm_get_random);
1084
1085 /**
1086  * tpm_seal_trusted() - seal a trusted key
1087  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1088  * @options: authentication values and other options
1089  * @payload: the key data in clear and encrypted form
1090  *
1091  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1092  * are supported.
1093  */
1094 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1095                      struct trusted_key_options *options)
1096 {
1097         struct tpm_chip *chip;
1098         int rc;
1099
1100         chip = tpm_chip_find_get(chip_num);
1101         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1102                 return -ENODEV;
1103
1104         rc = tpm2_seal_trusted(chip, payload, options);
1105
1106         tpm_put_ops(chip);
1107         return rc;
1108 }
1109 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1110
1111 /**
1112  * tpm_unseal_trusted() - unseal a trusted key
1113  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1114  * @options: authentication values and other options
1115  * @payload: the key data in clear and encrypted form
1116  *
1117  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1118  * are supported.
1119  */
1120 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1121                        struct trusted_key_options *options)
1122 {
1123         struct tpm_chip *chip;
1124         int rc;
1125
1126         chip = tpm_chip_find_get(chip_num);
1127         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1128                 return -ENODEV;
1129
1130         rc = tpm2_unseal_trusted(chip, payload, options);
1131
1132         tpm_put_ops(chip);
1133
1134         return rc;
1135 }
1136 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1137
1138 static int __init tpm_init(void)
1139 {
1140         int rc;
1141
1142         tpm_class = class_create(THIS_MODULE, "tpm");
1143         if (IS_ERR(tpm_class)) {
1144                 pr_err("couldn't create tpm class\n");
1145                 return PTR_ERR(tpm_class);
1146         }
1147
1148         rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1149         if (rc < 0) {
1150                 pr_err("tpm: failed to allocate char dev region\n");
1151                 class_destroy(tpm_class);
1152                 return rc;
1153         }
1154
1155         return 0;
1156 }
1157
1158 static void __exit tpm_exit(void)
1159 {
1160         idr_destroy(&dev_nums_idr);
1161         class_destroy(tpm_class);
1162         unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1163 }
1164
1165 subsys_initcall(tpm_init);
1166 module_exit(tpm_exit);
1167
1168 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1169 MODULE_DESCRIPTION("TPM Driver");
1170 MODULE_VERSION("2.0");
1171 MODULE_LICENSE("GPL");