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 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->flags & TPM_CHIP_FLAG_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 tpm_chip *chip, __be32 subcap_id, cap_t *cap,
 436                    const char *desc)
 437 {
 438         struct tpm_cmd_t tpm_cmd;
 439         int rc;
 440
 441         tpm_cmd.header.in = tpm_getcap_header;
 442         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 443                 tpm_cmd.params.getcap_in.cap = subcap_id;
 444                 /*subcap field not necessary */
 445                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 446                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 447         } else {
 448                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 449                     subcap_id == TPM_CAP_FLAG_VOL)
 450                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 451                 else
 452                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 453                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 454                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 455         }
 456         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
 457         if (!rc)
 458                 *cap = tpm_cmd.params.getcap_out.cap;
 459         return rc;
 460 }
 461
 462 void tpm_gen_interrupt(struct tpm_chip *chip)
 463 {
 464         struct  tpm_cmd_t tpm_cmd;
 465         ssize_t rc;
 466
 467         tpm_cmd.header.in = tpm_getcap_header;
 468         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 469         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 470         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 471
 472         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 473                               "attempting to determine the timeouts");
 474 }
 475 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 476
 477 #define TPM_ORD_STARTUP cpu_to_be32(153)
 478 #define TPM_ST_CLEAR cpu_to_be16(1)
 479 #define TPM_ST_STATE cpu_to_be16(2)
 480 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 481 static const struct tpm_input_header tpm_startup_header = {
 482         .tag = TPM_TAG_RQU_COMMAND,
 483         .length = cpu_to_be32(12),
 484         .ordinal = TPM_ORD_STARTUP
 485 };
 486
 487 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 488 {
 489         struct tpm_cmd_t start_cmd;
 490         start_cmd.header.in = tpm_startup_header;
 491
 492         start_cmd.params.startup_in.startup_type = startup_type;
 493         return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
 494                                 "attempting to start the TPM");
 495 }
 496
 497 int tpm_get_timeouts(struct tpm_chip *chip)
 498 {
 499         struct tpm_cmd_t tpm_cmd;
 500         unsigned long new_timeout[4];
 501         unsigned long old_timeout[4];
 502         struct duration_t *duration_cap;
 503         ssize_t rc;
 504
 505         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 506                 /* Fixed timeouts for TPM2 */
 507                 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
 508                 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
 509                 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
 510                 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
 511                 chip->duration[TPM_SHORT] =
 512                     msecs_to_jiffies(TPM2_DURATION_SHORT);
 513                 chip->duration[TPM_MEDIUM] =
 514                     msecs_to_jiffies(TPM2_DURATION_MEDIUM);
 515                 chip->duration[TPM_LONG] =
 516                     msecs_to_jiffies(TPM2_DURATION_LONG);
 517                 return 0;
 518         }
 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         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
 525
 526         if (rc == TPM_ERR_INVALID_POSTINIT) {
 527                 /* The TPM is not started, we are the first to talk to it.
 528                    Execute a startup command. */
 529                 dev_info(&chip->dev, "Issuing TPM_STARTUP");
 530                 if (tpm_startup(chip, TPM_ST_CLEAR))
 531                         return rc;
 532
 533                 tpm_cmd.header.in = tpm_getcap_header;
 534                 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 535                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 536                 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 537                 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 538                                   NULL);
 539         }
 540         if (rc) {
 541                 dev_err(&chip->dev,
 542                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 543                         rc);
 544                 goto duration;
 545         }
 546
 547         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 548             be32_to_cpu(tpm_cmd.header.out.length)
 549             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 550                 return -EINVAL;
 551
 552         old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
 553         old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
 554         old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
 555         old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
 556         memcpy(new_timeout, old_timeout, sizeof(new_timeout));
 557
 558         /*
 559          * Provide ability for vendor overrides of timeout values in case
 560          * of misreporting.
 561          */
 562         if (chip->ops->update_timeouts != NULL)
 563                 chip->timeout_adjusted =
 564                         chip->ops->update_timeouts(chip, new_timeout);
 565
 566         if (!chip->timeout_adjusted) {
 567                 /* Don't overwrite default if value is 0 */
 568                 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
 569                         int i;
 570
 571                         /* timeouts in msec rather usec */
 572                         for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
 573                                 new_timeout[i] *= 1000;
 574                         chip->timeout_adjusted = true;
 575                 }
 576         }
 577
 578         /* Report adjusted timeouts */
 579         if (chip->timeout_adjusted) {
 580                 dev_info(&chip->dev,
 581                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 582                          old_timeout[0], new_timeout[0],
 583                          old_timeout[1], new_timeout[1],
 584                          old_timeout[2], new_timeout[2],
 585                          old_timeout[3], new_timeout[3]);
 586         }
 587
 588         chip->timeout_a = usecs_to_jiffies(new_timeout[0]);
 589         chip->timeout_b = usecs_to_jiffies(new_timeout[1]);
 590         chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
 591         chip->timeout_d = usecs_to_jiffies(new_timeout[3]);
 592
 593 duration:
 594         tpm_cmd.header.in = tpm_getcap_header;
 595         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 596         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 597         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 598
 599         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 600                               "attempting to determine the durations");
 601         if (rc)
 602                 return rc;
 603
 604         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 605             be32_to_cpu(tpm_cmd.header.out.length)
 606             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 607                 return -EINVAL;
 608
 609         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 610         chip->duration[TPM_SHORT] =
 611             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 612         chip->duration[TPM_MEDIUM] =
 613             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 614         chip->duration[TPM_LONG] =
 615             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 616
 617         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 618          * value wrong and apparently reports msecs rather than usecs. So we
 619          * fix up the resulting too-small TPM_SHORT value to make things work.
 620          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 621          */
 622         if (chip->duration[TPM_SHORT] < (HZ / 100)) {
 623                 chip->duration[TPM_SHORT] = HZ;
 624                 chip->duration[TPM_MEDIUM] *= 1000;
 625                 chip->duration[TPM_LONG] *= 1000;
 626                 chip->duration_adjusted = true;
 627                 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 628         }
 629         return 0;
 630 }
 631 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 632
 633 #define TPM_ORD_CONTINUE_SELFTEST 83
 634 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 635
 636 static struct tpm_input_header continue_selftest_header = {
 637         .tag = TPM_TAG_RQU_COMMAND,
 638         .length = cpu_to_be32(10),
 639         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 640 };
 641
 642 /**
 643  * tpm_continue_selftest -- run TPM's selftest
 644  * @chip: TPM chip to use
 645  *
 646  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 647  * a TPM error code.
 648  */
 649 static int tpm_continue_selftest(struct tpm_chip *chip)
 650 {
 651         int rc;
 652         struct tpm_cmd_t cmd;
 653
 654         cmd.header.in = continue_selftest_header;
 655         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 656                               "continue selftest");
 657         return rc;
 658 }
 659
 660 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 661 #define READ_PCR_RESULT_SIZE 30
 662 static struct tpm_input_header pcrread_header = {
 663         .tag = TPM_TAG_RQU_COMMAND,
 664         .length = cpu_to_be32(14),
 665         .ordinal = TPM_ORDINAL_PCRREAD
 666 };
 667
 668 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 669 {
 670         int rc;
 671         struct tpm_cmd_t cmd;
 672
 673         cmd.header.in = pcrread_header;
 674         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 675         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 676                               "attempting to read a pcr value");
 677
 678         if (rc == 0)
 679                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 680                        TPM_DIGEST_SIZE);
 681         return rc;
 682 }
 683
 684 /**
 685  * tpm_is_tpm2 - is the chip a TPM2 chip?
 686  * @chip_num:   tpm idx # or ANY
 687  *
 688  * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 689  * is a TPM2 chip.
 690  */
 691 int tpm_is_tpm2(u32 chip_num)
 692 {
 693         struct tpm_chip *chip;
 694         int rc;
 695
 696         chip = tpm_chip_find_get(chip_num);
 697         if (chip == NULL)
 698                 return -ENODEV;
 699
 700         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 701
 702         tpm_put_ops(chip);
 703
 704         return rc;
 705 }
 706 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 707
 708 /**
 709  * tpm_pcr_read - read a pcr value
 710  * @chip_num:   tpm idx # or ANY
 711  * @pcr_idx:    pcr idx to retrieve
 712  * @res_buf:    TPM_PCR value
 713  *              size of res_buf is 20 bytes (or NULL if you don't care)
 714  *
 715  * The TPM driver should be built-in, but for whatever reason it
 716  * isn't, protect against the chip disappearing, by incrementing
 717  * the module usage count.
 718  */
 719 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 720 {
 721         struct tpm_chip *chip;
 722         int rc;
 723
 724         chip = tpm_chip_find_get(chip_num);
 725         if (chip == NULL)
 726                 return -ENODEV;
 727         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 728                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 729         else
 730                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 731         tpm_put_ops(chip);
 732         return rc;
 733 }
 734 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 735
 736 /**
 737  * tpm_pcr_extend - extend pcr value with hash
 738  * @chip_num:   tpm idx # or AN&
 739  * @pcr_idx:    pcr idx to extend
 740  * @hash:       hash value used to extend pcr value
 741  *
 742  * The TPM driver should be built-in, but for whatever reason it
 743  * isn't, protect against the chip disappearing, by incrementing
 744  * the module usage count.
 745  */
 746 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 747 #define EXTEND_PCR_RESULT_SIZE 34
 748 static struct tpm_input_header pcrextend_header = {
 749         .tag = TPM_TAG_RQU_COMMAND,
 750         .length = cpu_to_be32(34),
 751         .ordinal = TPM_ORD_PCR_EXTEND
 752 };
 753
 754 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 755 {
 756         struct tpm_cmd_t cmd;
 757         int rc;
 758         struct tpm_chip *chip;
 759
 760         chip = tpm_chip_find_get(chip_num);
 761         if (chip == NULL)
 762                 return -ENODEV;
 763
 764         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 765                 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
 766                 tpm_put_ops(chip);
 767                 return rc;
 768         }
 769
 770         cmd.header.in = pcrextend_header;
 771         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 772         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 773         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 774                               "attempting extend a PCR value");
 775
 776         tpm_put_ops(chip);
 777         return rc;
 778 }
 779 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 780
 781 /**
 782  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 783  *                   can receive further commands
 784  * @chip: TPM chip to use
 785  *
 786  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 787  * a TPM error code.
 788  */
 789 int tpm_do_selftest(struct tpm_chip *chip)
 790 {
 791         int rc;
 792         unsigned int loops;
 793         unsigned int delay_msec = 100;
 794         unsigned long duration;
 795         struct tpm_cmd_t cmd;
 796
 797         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 798
 799         loops = jiffies_to_msecs(duration) / delay_msec;
 800
 801         rc = tpm_continue_selftest(chip);
 802         /* This may fail if there was no TPM driver during a suspend/resume
 803          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 804          */
 805         if (rc)
 806                 return rc;
 807
 808         do {
 809                 /* Attempt to read a PCR value */
 810                 cmd.header.in = pcrread_header;
 811                 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
 812                 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
 813                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 814                  * around 300ms while the self test is ongoing, keep trying
 815                  * until the self test duration expires. */
 816                 if (rc == -ETIME) {
 817                         dev_info(
 818                             &chip->dev, HW_ERR
 819                             "TPM command timed out during continue self test");
 820                         msleep(delay_msec);
 821                         continue;
 822                 }
 823
 824                 if (rc < TPM_HEADER_SIZE)
 825                         return -EFAULT;
 826
 827                 rc = be32_to_cpu(cmd.header.out.return_code);
 828                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 829                         dev_info(&chip->dev,
 830                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 831                         /* TPM is disabled and/or deactivated; driver can
 832                          * proceed and TPM does handle commands for
 833                          * suspend/resume correctly
 834                          */
 835                         return 0;
 836                 }
 837                 if (rc != TPM_WARN_DOING_SELFTEST)
 838                         return rc;
 839                 msleep(delay_msec);
 840         } while (--loops > 0);
 841
 842         return rc;
 843 }
 844 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 845
 846 /**
 847  * tpm1_auto_startup - Perform the standard automatic TPM initialization
 848  *                     sequence
 849  * @chip: TPM chip to use
 850  *
 851  * Returns 0 on success, < 0 in case of fatal error.
 852  */
 853 int tpm1_auto_startup(struct tpm_chip *chip)
 854 {
 855         int rc;
 856
 857         rc = tpm_get_timeouts(chip);
 858         if (rc)
 859                 goto out;
 860         rc = tpm_do_selftest(chip);
 861         if (rc) {
 862                 dev_err(&chip->dev, "TPM self test failed\n");
 863                 goto out;
 864         }
 865
 866         return rc;
 867 out:
 868         if (rc > 0)
 869                 rc = -ENODEV;
 870         return rc;
 871 }
 872
 873 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 874 {
 875         struct tpm_chip *chip;
 876         int rc;
 877
 878         chip = tpm_chip_find_get(chip_num);
 879         if (chip == NULL)
 880                 return -ENODEV;
 881
 882         rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
 883
 884         tpm_put_ops(chip);
 885         return rc;
 886 }
 887 EXPORT_SYMBOL_GPL(tpm_send);
 888
 889 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 890                                         bool check_cancel, bool *canceled)
 891 {
 892         u8 status = chip->ops->status(chip);
 893
 894         *canceled = false;
 895         if ((status & mask) == mask)
 896                 return true;
 897         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 898                 *canceled = true;
 899                 return true;
 900         }
 901         return false;
 902 }
 903
 904 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 905                       wait_queue_head_t *queue, bool check_cancel)
 906 {
 907         unsigned long stop;
 908         long rc;
 909         u8 status;
 910         bool canceled = false;
 911
 912         /* check current status */
 913         status = chip->ops->status(chip);
 914         if ((status & mask) == mask)
 915                 return 0;
 916
 917         stop = jiffies + timeout;
 918
 919         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
 920 again:
 921                 timeout = stop - jiffies;
 922                 if ((long)timeout <= 0)
 923                         return -ETIME;
 924                 rc = wait_event_interruptible_timeout(*queue,
 925                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 926                                                &canceled),
 927                         timeout);
 928                 if (rc > 0) {
 929                         if (canceled)
 930                                 return -ECANCELED;
 931                         return 0;
 932                 }
 933                 if (rc == -ERESTARTSYS && freezing(current)) {
 934                         clear_thread_flag(TIF_SIGPENDING);
 935                         goto again;
 936                 }
 937         } else {
 938                 do {
 939                         msleep(TPM_TIMEOUT);
 940                         status = chip->ops->status(chip);
 941                         if ((status & mask) == mask)
 942                                 return 0;
 943                 } while (time_before(jiffies, stop));
 944         }
 945         return -ETIME;
 946 }
 947 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 948
 949 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 950 #define SAVESTATE_RESULT_SIZE 10
 951
 952 static struct tpm_input_header savestate_header = {
 953         .tag = TPM_TAG_RQU_COMMAND,
 954         .length = cpu_to_be32(10),
 955         .ordinal = TPM_ORD_SAVESTATE
 956 };
 957
 958 /*
 959  * We are about to suspend. Save the TPM state
 960  * so that it can be restored.
 961  */
 962 int tpm_pm_suspend(struct device *dev)
 963 {
 964         struct tpm_chip *chip = dev_get_drvdata(dev);
 965         struct tpm_cmd_t cmd;
 966         int rc, try;
 967
 968         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 969
 970         if (chip == NULL)
 971                 return -ENODEV;
 972
 973         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 974                 tpm2_shutdown(chip, TPM2_SU_STATE);
 975                 return 0;
 976         }
 977
 978         /* for buggy tpm, flush pcrs with extend to selected dummy */
 979         if (tpm_suspend_pcr) {
 980                 cmd.header.in = pcrextend_header;
 981                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 982                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 983                        TPM_DIGEST_SIZE);
 984                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 985                                       "extending dummy pcr before suspend");
 986         }
 987
 988         /* now do the actual savestate */
 989         for (try = 0; try < TPM_RETRY; try++) {
 990                 cmd.header.in = savestate_header;
 991                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
 992
 993                 /*
 994                  * If the TPM indicates that it is too busy to respond to
 995                  * this command then retry before giving up.  It can take
 996                  * several seconds for this TPM to be ready.
 997                  *
 998                  * This can happen if the TPM has already been sent the
 999                  * SaveState command before the driver has loaded.  TCG 1.2
1000                  * specification states that any communication after SaveState
1001                  * may cause the TPM to invalidate previously saved state.
1002                  */
1003                 if (rc != TPM_WARN_RETRY)
1004                         break;
1005                 msleep(TPM_TIMEOUT_RETRY);
1006         }
1007
1008         if (rc)
1009                 dev_err(&chip->dev,
1010                         "Error (%d) sending savestate before suspend\n", rc);
1011         else if (try > 0)
1012                 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1013                          try * TPM_TIMEOUT_RETRY);
1014
1015         return rc;
1016 }
1017 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1018
1019 /*
1020  * Resume from a power safe. The BIOS already restored
1021  * the TPM state.
1022  */
1023 int tpm_pm_resume(struct device *dev)
1024 {
1025         struct tpm_chip *chip = dev_get_drvdata(dev);
1026
1027         if (chip == NULL)
1028                 return -ENODEV;
1029
1030         return 0;
1031 }
1032 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1033
1034 #define TPM_GETRANDOM_RESULT_SIZE       18
1035 static struct tpm_input_header tpm_getrandom_header = {
1036         .tag = TPM_TAG_RQU_COMMAND,
1037         .length = cpu_to_be32(14),
1038         .ordinal = TPM_ORD_GET_RANDOM
1039 };
1040
1041 /**
1042  * tpm_get_random() - Get random bytes from the tpm's RNG
1043  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1044  * @out: destination buffer for the random bytes
1045  * @max: the max number of bytes to write to @out
1046  *
1047  * Returns < 0 on error and the number of bytes read on success
1048  */
1049 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1050 {
1051         struct tpm_chip *chip;
1052         struct tpm_cmd_t tpm_cmd;
1053         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1054         int err, total = 0, retries = 5;
1055         u8 *dest = out;
1056
1057         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1058                 return -EINVAL;
1059
1060         chip = tpm_chip_find_get(chip_num);
1061         if (chip == NULL)
1062                 return -ENODEV;
1063
1064         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1065                 err = tpm2_get_random(chip, out, max);
1066                 tpm_put_ops(chip);
1067                 return err;
1068         }
1069
1070         do {
1071                 tpm_cmd.header.in = tpm_getrandom_header;
1072                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1073
1074                 err = tpm_transmit_cmd(chip, &tpm_cmd,
1075                                    TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1076                                    "attempting get random");
1077                 if (err)
1078                         break;
1079
1080                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1081                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1082
1083                 dest += recd;
1084                 total += recd;
1085                 num_bytes -= recd;
1086         } while (retries-- && total < max);
1087
1088         tpm_put_ops(chip);
1089         return total ? total : -EIO;
1090 }
1091 EXPORT_SYMBOL_GPL(tpm_get_random);
1092
1093 /**
1094  * tpm_seal_trusted() - seal 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_seal_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_seal_trusted(chip, payload, options);
1113
1114         tpm_put_ops(chip);
1115         return rc;
1116 }
1117 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1118
1119 /**
1120  * tpm_unseal_trusted() - unseal a trusted key
1121  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1122  * @options: authentication values and other options
1123  * @payload: the key data in clear and encrypted form
1124  *
1125  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1126  * are supported.
1127  */
1128 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1129                        struct trusted_key_options *options)
1130 {
1131         struct tpm_chip *chip;
1132         int rc;
1133
1134         chip = tpm_chip_find_get(chip_num);
1135         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1136                 return -ENODEV;
1137
1138         rc = tpm2_unseal_trusted(chip, payload, options);
1139
1140         tpm_put_ops(chip);
1141
1142         return rc;
1143 }
1144 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1145
1146 static int __init tpm_init(void)
1147 {
1148         int rc;
1149
1150         tpm_class = class_create(THIS_MODULE, "tpm");
1151         if (IS_ERR(tpm_class)) {
1152                 pr_err("couldn't create tpm class\n");
1153                 return PTR_ERR(tpm_class);
1154         }
1155
1156         rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1157         if (rc < 0) {
1158                 pr_err("tpm: failed to allocate char dev region\n");
1159                 class_destroy(tpm_class);
1160                 return rc;
1161         }
1162
1163         return 0;
1164 }
1165
1166 static void __exit tpm_exit(void)
1167 {
1168         idr_destroy(&dev_nums_idr);
1169         class_destroy(tpm_class);
1170         unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1171 }
1172
1173 subsys_initcall(tpm_init);
1174 module_exit(tpm_exit);
1175
1176 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1177 MODULE_DESCRIPTION("TPM Driver");
1178 MODULE_VERSION("2.0");
1179 MODULE_LICENSE("GPL");