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 && err != TPM_ERR_DISABLED && err != TPM_ERR_DEACTIVATED
 424             && desc)
 425                 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
 426                         desc);
 427
 428         return err;
 429 }
 430
 431 #define TPM_INTERNAL_RESULT_SIZE 200
 432 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 433 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 434
 435 static const struct tpm_input_header tpm_getcap_header = {
 436         .tag = TPM_TAG_RQU_COMMAND,
 437         .length = cpu_to_be32(22),
 438         .ordinal = TPM_ORD_GET_CAP
 439 };
 440
 441 ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap,
 442                    const char *desc)
 443 {
 444         struct tpm_cmd_t tpm_cmd;
 445         int rc;
 446
 447         tpm_cmd.header.in = tpm_getcap_header;
 448         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 449                 tpm_cmd.params.getcap_in.cap = subcap_id;
 450                 /*subcap field not necessary */
 451                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 452                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 453         } else {
 454                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 455                     subcap_id == TPM_CAP_FLAG_VOL)
 456                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 457                 else
 458                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 459                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 460                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 461         }
 462         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 463                               desc);
 464         if (!rc)
 465                 *cap = tpm_cmd.params.getcap_out.cap;
 466         return rc;
 467 }
 468 EXPORT_SYMBOL_GPL(tpm_getcap);
 469
 470 #define TPM_ORD_STARTUP cpu_to_be32(153)
 471 #define TPM_ST_CLEAR cpu_to_be16(1)
 472 #define TPM_ST_STATE cpu_to_be16(2)
 473 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 474 static const struct tpm_input_header tpm_startup_header = {
 475         .tag = TPM_TAG_RQU_COMMAND,
 476         .length = cpu_to_be32(12),
 477         .ordinal = TPM_ORD_STARTUP
 478 };
 479
 480 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 481 {
 482         struct tpm_cmd_t start_cmd;
 483         start_cmd.header.in = tpm_startup_header;
 484
 485         start_cmd.params.startup_in.startup_type = startup_type;
 486         return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 487                                 "attempting to start the TPM");
 488 }
 489
 490 int tpm_get_timeouts(struct tpm_chip *chip)
 491 {
 492         struct tpm_cmd_t tpm_cmd;
 493         unsigned long timeout_old[4], timeout_chip[4], timeout_eff[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         timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
 546         timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
 547         timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
 548         timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
 549         timeout_chip[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
 550         timeout_chip[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
 551         timeout_chip[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
 552         timeout_chip[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
 553         memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
 554
 555         /*
 556          * Provide ability for vendor overrides of timeout values in case
 557          * of misreporting.
 558          */
 559         if (chip->ops->update_timeouts != NULL)
 560                 chip->timeout_adjusted =
 561                         chip->ops->update_timeouts(chip, timeout_eff);
 562
 563         if (!chip->timeout_adjusted) {
 564                 /* Restore default if chip reported 0 */
 565                 int i;
 566
 567                 for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
 568                         if (timeout_eff[i])
 569                                 continue;
 570
 571                         timeout_eff[i] = timeout_old[i];
 572                         chip->timeout_adjusted = true;
 573                 }
 574
 575                 if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
 576                         /* timeouts in msec rather usec */
 577                         for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
 578                                 timeout_eff[i] *= 1000;
 579                         chip->timeout_adjusted = true;
 580                 }
 581         }
 582
 583         /* Report adjusted timeouts */
 584         if (chip->timeout_adjusted) {
 585                 dev_info(&chip->dev,
 586                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 587                          timeout_chip[0], timeout_eff[0],
 588                          timeout_chip[1], timeout_eff[1],
 589                          timeout_chip[2], timeout_eff[2],
 590                          timeout_chip[3], timeout_eff[3]);
 591         }
 592
 593         chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
 594         chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
 595         chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
 596         chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
 597
 598 duration:
 599         tpm_cmd.header.in = tpm_getcap_header;
 600         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 601         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 602         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 603
 604         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 605                               "attempting to determine the durations");
 606         if (rc)
 607                 return rc;
 608
 609         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 610             be32_to_cpu(tpm_cmd.header.out.length)
 611             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 612                 return -EINVAL;
 613
 614         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 615         chip->duration[TPM_SHORT] =
 616             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 617         chip->duration[TPM_MEDIUM] =
 618             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 619         chip->duration[TPM_LONG] =
 620             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 621
 622         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 623          * value wrong and apparently reports msecs rather than usecs. So we
 624          * fix up the resulting too-small TPM_SHORT value to make things work.
 625          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 626          */
 627         if (chip->duration[TPM_SHORT] < (HZ / 100)) {
 628                 chip->duration[TPM_SHORT] = HZ;
 629                 chip->duration[TPM_MEDIUM] *= 1000;
 630                 chip->duration[TPM_LONG] *= 1000;
 631                 chip->duration_adjusted = true;
 632                 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 633         }
 634         return 0;
 635 }
 636 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 637
 638 #define TPM_ORD_CONTINUE_SELFTEST 83
 639 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 640
 641 static const struct tpm_input_header continue_selftest_header = {
 642         .tag = TPM_TAG_RQU_COMMAND,
 643         .length = cpu_to_be32(10),
 644         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 645 };
 646
 647 /**
 648  * tpm_continue_selftest -- run TPM's selftest
 649  * @chip: TPM chip to use
 650  *
 651  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 652  * a TPM error code.
 653  */
 654 static int tpm_continue_selftest(struct tpm_chip *chip)
 655 {
 656         int rc;
 657         struct tpm_cmd_t cmd;
 658
 659         cmd.header.in = continue_selftest_header;
 660         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
 661                               "continue selftest");
 662         return rc;
 663 }
 664
 665 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 666 #define READ_PCR_RESULT_SIZE 30
 667 static const struct tpm_input_header pcrread_header = {
 668         .tag = TPM_TAG_RQU_COMMAND,
 669         .length = cpu_to_be32(14),
 670         .ordinal = TPM_ORDINAL_PCRREAD
 671 };
 672
 673 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 674 {
 675         int rc;
 676         struct tpm_cmd_t cmd;
 677
 678         cmd.header.in = pcrread_header;
 679         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 680         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
 681                               "attempting to read a pcr value");
 682
 683         if (rc == 0)
 684                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 685                        TPM_DIGEST_SIZE);
 686         return rc;
 687 }
 688
 689 /**
 690  * tpm_is_tpm2 - is the chip a TPM2 chip?
 691  * @chip_num:   tpm idx # or ANY
 692  *
 693  * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 694  * is a TPM2 chip.
 695  */
 696 int tpm_is_tpm2(u32 chip_num)
 697 {
 698         struct tpm_chip *chip;
 699         int rc;
 700
 701         chip = tpm_chip_find_get(chip_num);
 702         if (chip == NULL)
 703                 return -ENODEV;
 704
 705         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 706
 707         tpm_put_ops(chip);
 708
 709         return rc;
 710 }
 711 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 712
 713 /**
 714  * tpm_pcr_read - read a pcr value
 715  * @chip_num:   tpm idx # or ANY
 716  * @pcr_idx:    pcr idx to retrieve
 717  * @res_buf:    TPM_PCR value
 718  *              size of res_buf is 20 bytes (or NULL if you don't care)
 719  *
 720  * The TPM driver should be built-in, but for whatever reason it
 721  * isn't, protect against the chip disappearing, by incrementing
 722  * the module usage count.
 723  */
 724 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 725 {
 726         struct tpm_chip *chip;
 727         int rc;
 728
 729         chip = tpm_chip_find_get(chip_num);
 730         if (chip == NULL)
 731                 return -ENODEV;
 732         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 733                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 734         else
 735                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 736         tpm_put_ops(chip);
 737         return rc;
 738 }
 739 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 740
 741 /**
 742  * tpm_pcr_extend - extend pcr value with hash
 743  * @chip_num:   tpm idx # or AN&
 744  * @pcr_idx:    pcr idx to extend
 745  * @hash:       hash value used to extend pcr value
 746  *
 747  * The TPM driver should be built-in, but for whatever reason it
 748  * isn't, protect against the chip disappearing, by incrementing
 749  * the module usage count.
 750  */
 751 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 752 #define EXTEND_PCR_RESULT_SIZE 34
 753 static const struct tpm_input_header pcrextend_header = {
 754         .tag = TPM_TAG_RQU_COMMAND,
 755         .length = cpu_to_be32(34),
 756         .ordinal = TPM_ORD_PCR_EXTEND
 757 };
 758
 759 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 760 {
 761         struct tpm_cmd_t cmd;
 762         int rc;
 763         struct tpm_chip *chip;
 764
 765         chip = tpm_chip_find_get(chip_num);
 766         if (chip == NULL)
 767                 return -ENODEV;
 768
 769         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 770                 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
 771                 tpm_put_ops(chip);
 772                 return rc;
 773         }
 774
 775         cmd.header.in = pcrextend_header;
 776         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 777         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 778         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 779                               "attempting extend a PCR value");
 780
 781         tpm_put_ops(chip);
 782         return rc;
 783 }
 784 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 785
 786 /**
 787  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 788  *                   can receive further commands
 789  * @chip: TPM chip to use
 790  *
 791  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 792  * a TPM error code.
 793  */
 794 int tpm_do_selftest(struct tpm_chip *chip)
 795 {
 796         int rc;
 797         unsigned int loops;
 798         unsigned int delay_msec = 100;
 799         unsigned long duration;
 800         u8 dummy[TPM_DIGEST_SIZE];
 801
 802         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 803
 804         loops = jiffies_to_msecs(duration) / delay_msec;
 805
 806         rc = tpm_continue_selftest(chip);
 807         if (rc == TPM_ERR_INVALID_POSTINIT) {
 808                 chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
 809                 dev_info(&chip->dev, "TPM not ready (%d)\n", rc);
 810         }
 811         /* This may fail if there was no TPM driver during a suspend/resume
 812          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 813          */
 814         if (rc)
 815                 return rc;
 816
 817         do {
 818                 /* Attempt to read a PCR value */
 819                 rc = tpm_pcr_read_dev(chip, 0, dummy);
 820
 821                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 822                  * around 300ms while the self test is ongoing, keep trying
 823                  * until the self test duration expires. */
 824                 if (rc == -ETIME) {
 825                         dev_info(
 826                             &chip->dev, HW_ERR
 827                             "TPM command timed out during continue self test");
 828                         msleep(delay_msec);
 829                         continue;
 830                 }
 831
 832                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 833                         dev_info(&chip->dev,
 834                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 835                         /* TPM is disabled and/or deactivated; driver can
 836                          * proceed and TPM does handle commands for
 837                          * suspend/resume correctly
 838                          */
 839                         return 0;
 840                 }
 841                 if (rc != TPM_WARN_DOING_SELFTEST)
 842                         return rc;
 843                 msleep(delay_msec);
 844         } while (--loops > 0);
 845
 846         return rc;
 847 }
 848 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 849
 850 /**
 851  * tpm1_auto_startup - Perform the standard automatic TPM initialization
 852  *                     sequence
 853  * @chip: TPM chip to use
 854  *
 855  * Returns 0 on success, < 0 in case of fatal error.
 856  */
 857 int tpm1_auto_startup(struct tpm_chip *chip)
 858 {
 859         int rc;
 860
 861         rc = tpm_get_timeouts(chip);
 862         if (rc)
 863                 goto out;
 864         rc = tpm_do_selftest(chip);
 865         if (rc) {
 866                 dev_err(&chip->dev, "TPM self test failed\n");
 867                 goto out;
 868         }
 869
 870         return rc;
 871 out:
 872         if (rc > 0)
 873                 rc = -ENODEV;
 874         return rc;
 875 }
 876
 877 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 878 {
 879         struct tpm_chip *chip;
 880         int rc;
 881
 882         chip = tpm_chip_find_get(chip_num);
 883         if (chip == NULL)
 884                 return -ENODEV;
 885
 886         rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
 887
 888         tpm_put_ops(chip);
 889         return rc;
 890 }
 891 EXPORT_SYMBOL_GPL(tpm_send);
 892
 893 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 894                                         bool check_cancel, bool *canceled)
 895 {
 896         u8 status = chip->ops->status(chip);
 897
 898         *canceled = false;
 899         if ((status & mask) == mask)
 900                 return true;
 901         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 902                 *canceled = true;
 903                 return true;
 904         }
 905         return false;
 906 }
 907
 908 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 909                       wait_queue_head_t *queue, bool check_cancel)
 910 {
 911         unsigned long stop;
 912         long rc;
 913         u8 status;
 914         bool canceled = false;
 915
 916         /* check current status */
 917         status = chip->ops->status(chip);
 918         if ((status & mask) == mask)
 919                 return 0;
 920
 921         stop = jiffies + timeout;
 922
 923         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
 924 again:
 925                 timeout = stop - jiffies;
 926                 if ((long)timeout <= 0)
 927                         return -ETIME;
 928                 rc = wait_event_interruptible_timeout(*queue,
 929                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 930                                                &canceled),
 931                         timeout);
 932                 if (rc > 0) {
 933                         if (canceled)
 934                                 return -ECANCELED;
 935                         return 0;
 936                 }
 937                 if (rc == -ERESTARTSYS && freezing(current)) {
 938                         clear_thread_flag(TIF_SIGPENDING);
 939                         goto again;
 940                 }
 941         } else {
 942                 do {
 943                         msleep(TPM_TIMEOUT);
 944                         status = chip->ops->status(chip);
 945                         if ((status & mask) == mask)
 946                                 return 0;
 947                 } while (time_before(jiffies, stop));
 948         }
 949         return -ETIME;
 950 }
 951 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 952
 953 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 954 #define SAVESTATE_RESULT_SIZE 10
 955
 956 static const struct tpm_input_header savestate_header = {
 957         .tag = TPM_TAG_RQU_COMMAND,
 958         .length = cpu_to_be32(10),
 959         .ordinal = TPM_ORD_SAVESTATE
 960 };
 961
 962 /*
 963  * We are about to suspend. Save the TPM state
 964  * so that it can be restored.
 965  */
 966 int tpm_pm_suspend(struct device *dev)
 967 {
 968         struct tpm_chip *chip = dev_get_drvdata(dev);
 969         struct tpm_cmd_t cmd;
 970         int rc, try;
 971
 972         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 973
 974         if (chip == NULL)
 975                 return -ENODEV;
 976
 977         if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
 978                 return 0;
 979
 980         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 981                 tpm2_shutdown(chip, TPM2_SU_STATE);
 982                 return 0;
 983         }
 984
 985         /* for buggy tpm, flush pcrs with extend to selected dummy */
 986         if (tpm_suspend_pcr) {
 987                 cmd.header.in = pcrextend_header;
 988                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 989                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 990                        TPM_DIGEST_SIZE);
 991                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 992                                       "extending dummy pcr before suspend");
 993         }
 994
 995         /* now do the actual savestate */
 996         for (try = 0; try < TPM_RETRY; try++) {
 997                 cmd.header.in = savestate_header;
 998                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
 999                                       NULL);
1000
1001                 /*
1002                  * If the TPM indicates that it is too busy to respond to
1003                  * this command then retry before giving up.  It can take
1004                  * several seconds for this TPM to be ready.
1005                  *
1006                  * This can happen if the TPM has already been sent the
1007                  * SaveState command before the driver has loaded.  TCG 1.2
1008                  * specification states that any communication after SaveState
1009                  * may cause the TPM to invalidate previously saved state.
1010                  */
1011                 if (rc != TPM_WARN_RETRY)
1012                         break;
1013                 msleep(TPM_TIMEOUT_RETRY);
1014         }
1015
1016         if (rc)
1017                 dev_err(&chip->dev,
1018                         "Error (%d) sending savestate before suspend\n", rc);
1019         else if (try > 0)
1020                 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1021                          try * TPM_TIMEOUT_RETRY);
1022
1023         return rc;
1024 }
1025 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1026
1027 /*
1028  * Resume from a power safe. The BIOS already restored
1029  * the TPM state.
1030  */
1031 int tpm_pm_resume(struct device *dev)
1032 {
1033         struct tpm_chip *chip = dev_get_drvdata(dev);
1034
1035         if (chip == NULL)
1036                 return -ENODEV;
1037
1038         return 0;
1039 }
1040 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1041
1042 #define TPM_GETRANDOM_RESULT_SIZE       18
1043 static const struct tpm_input_header tpm_getrandom_header = {
1044         .tag = TPM_TAG_RQU_COMMAND,
1045         .length = cpu_to_be32(14),
1046         .ordinal = TPM_ORD_GET_RANDOM
1047 };
1048
1049 /**
1050  * tpm_get_random() - Get random bytes from the tpm's RNG
1051  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1052  * @out: destination buffer for the random bytes
1053  * @max: the max number of bytes to write to @out
1054  *
1055  * Returns < 0 on error and the number of bytes read on success
1056  */
1057 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1058 {
1059         struct tpm_chip *chip;
1060         struct tpm_cmd_t tpm_cmd;
1061         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1062         int err, total = 0, retries = 5;
1063         u8 *dest = out;
1064
1065         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1066                 return -EINVAL;
1067
1068         chip = tpm_chip_find_get(chip_num);
1069         if (chip == NULL)
1070                 return -ENODEV;
1071
1072         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1073                 err = tpm2_get_random(chip, out, max);
1074                 tpm_put_ops(chip);
1075                 return err;
1076         }
1077
1078         do {
1079                 tpm_cmd.header.in = tpm_getrandom_header;
1080                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1081
1082                 err = tpm_transmit_cmd(chip, &tpm_cmd,
1083                                        TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1084                                        0, "attempting get random");
1085                 if (err)
1086                         break;
1087
1088                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1089                 if (recd > num_bytes) {
1090                         total = -EFAULT;
1091                         break;
1092                 }
1093
1094                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1095
1096                 dest += recd;
1097                 total += recd;
1098                 num_bytes -= recd;
1099         } while (retries-- && total < max);
1100
1101         tpm_put_ops(chip);
1102         return total ? total : -EIO;
1103 }
1104 EXPORT_SYMBOL_GPL(tpm_get_random);
1105
1106 /**
1107  * tpm_seal_trusted() - seal a trusted key
1108  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1109  * @options: authentication values and other options
1110  * @payload: the key data in clear and encrypted form
1111  *
1112  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1113  * are supported.
1114  */
1115 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1116                      struct trusted_key_options *options)
1117 {
1118         struct tpm_chip *chip;
1119         int rc;
1120
1121         chip = tpm_chip_find_get(chip_num);
1122         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1123                 return -ENODEV;
1124
1125         rc = tpm2_seal_trusted(chip, payload, options);
1126
1127         tpm_put_ops(chip);
1128         return rc;
1129 }
1130 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1131
1132 /**
1133  * tpm_unseal_trusted() - unseal a trusted key
1134  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1135  * @options: authentication values and other options
1136  * @payload: the key data in clear and encrypted form
1137  *
1138  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1139  * are supported.
1140  */
1141 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1142                        struct trusted_key_options *options)
1143 {
1144         struct tpm_chip *chip;
1145         int rc;
1146
1147         chip = tpm_chip_find_get(chip_num);
1148         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1149                 return -ENODEV;
1150
1151         rc = tpm2_unseal_trusted(chip, payload, options);
1152
1153         tpm_put_ops(chip);
1154
1155         return rc;
1156 }
1157 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1158
1159 static int __init tpm_init(void)
1160 {
1161         int rc;
1162
1163         tpm_class = class_create(THIS_MODULE, "tpm");
1164         if (IS_ERR(tpm_class)) {
1165                 pr_err("couldn't create tpm class\n");
1166                 return PTR_ERR(tpm_class);
1167         }
1168
1169         rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1170         if (rc < 0) {
1171                 pr_err("tpm: failed to allocate char dev region\n");
1172                 class_destroy(tpm_class);
1173                 return rc;
1174         }
1175
1176         return 0;
1177 }
1178
1179 static void __exit tpm_exit(void)
1180 {
1181         idr_destroy(&dev_nums_idr);
1182         class_destroy(tpm_class);
1183         unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1184 }
1185
1186 subsys_initcall(tpm_init);
1187 module_exit(tpm_exit);
1188
1189 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1190 MODULE_DESCRIPTION("TPM Driver");
1191 MODULE_VERSION("2.0");
1192 MODULE_LICENSE("GPL");