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 #include <linux/pm_runtime.h>
  33
  34 #include "tpm.h"
  35 #include "tpm_eventlog.h"
  36
  37 #define TPM_MAX_ORDINAL 243
  38 #define TSC_MAX_ORDINAL 12
  39 #define TPM_PROTECTED_COMMAND 0x00
  40 #define TPM_CONNECTION_COMMAND 0x40
  41
  42 /*
  43  * Bug workaround - some TPM's don't flush the most
  44  * recently changed pcr on suspend, so force the flush
  45  * with an extend to the selected _unused_ non-volatile pcr.
  46  */
  47 static int tpm_suspend_pcr;
  48 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  49 MODULE_PARM_DESC(suspend_pcr,
  50                  "PCR to use for dummy writes to faciltate flush on suspend.");
  51
  52 /*
  53  * Array with one entry per ordinal defining the maximum amount
  54  * of time the chip could take to return the result.  The ordinal
  55  * designation of short, medium or long is defined in a table in
  56  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  57  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  58  * from the chip during initialization with a call to tpm_get_timeouts.
  59  */
  60 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  61         TPM_UNDEFINED,          /* 0 */
  62         TPM_UNDEFINED,
  63         TPM_UNDEFINED,
  64         TPM_UNDEFINED,
  65         TPM_UNDEFINED,
  66         TPM_UNDEFINED,          /* 5 */
  67         TPM_UNDEFINED,
  68         TPM_UNDEFINED,
  69         TPM_UNDEFINED,
  70         TPM_UNDEFINED,
  71         TPM_SHORT,              /* 10 */
  72         TPM_SHORT,
  73         TPM_MEDIUM,
  74         TPM_LONG,
  75         TPM_LONG,
  76         TPM_MEDIUM,             /* 15 */
  77         TPM_SHORT,
  78         TPM_SHORT,
  79         TPM_MEDIUM,
  80         TPM_LONG,
  81         TPM_SHORT,              /* 20 */
  82         TPM_SHORT,
  83         TPM_MEDIUM,
  84         TPM_MEDIUM,
  85         TPM_MEDIUM,
  86         TPM_SHORT,              /* 25 */
  87         TPM_SHORT,
  88         TPM_MEDIUM,
  89         TPM_SHORT,
  90         TPM_SHORT,
  91         TPM_MEDIUM,             /* 30 */
  92         TPM_LONG,
  93         TPM_MEDIUM,
  94         TPM_SHORT,
  95         TPM_SHORT,
  96         TPM_SHORT,              /* 35 */
  97         TPM_MEDIUM,
  98         TPM_MEDIUM,
  99         TPM_UNDEFINED,
 100         TPM_UNDEFINED,
 101         TPM_MEDIUM,             /* 40 */
 102         TPM_LONG,
 103         TPM_MEDIUM,
 104         TPM_SHORT,
 105         TPM_SHORT,
 106         TPM_SHORT,              /* 45 */
 107         TPM_SHORT,
 108         TPM_SHORT,
 109         TPM_SHORT,
 110         TPM_LONG,
 111         TPM_MEDIUM,             /* 50 */
 112         TPM_MEDIUM,
 113         TPM_UNDEFINED,
 114         TPM_UNDEFINED,
 115         TPM_UNDEFINED,
 116         TPM_UNDEFINED,          /* 55 */
 117         TPM_UNDEFINED,
 118         TPM_UNDEFINED,
 119         TPM_UNDEFINED,
 120         TPM_UNDEFINED,
 121         TPM_MEDIUM,             /* 60 */
 122         TPM_MEDIUM,
 123         TPM_MEDIUM,
 124         TPM_SHORT,
 125         TPM_SHORT,
 126         TPM_MEDIUM,             /* 65 */
 127         TPM_UNDEFINED,
 128         TPM_UNDEFINED,
 129         TPM_UNDEFINED,
 130         TPM_UNDEFINED,
 131         TPM_SHORT,              /* 70 */
 132         TPM_SHORT,
 133         TPM_UNDEFINED,
 134         TPM_UNDEFINED,
 135         TPM_UNDEFINED,
 136         TPM_UNDEFINED,          /* 75 */
 137         TPM_UNDEFINED,
 138         TPM_UNDEFINED,
 139         TPM_UNDEFINED,
 140         TPM_UNDEFINED,
 141         TPM_LONG,               /* 80 */
 142         TPM_UNDEFINED,
 143         TPM_MEDIUM,
 144         TPM_LONG,
 145         TPM_SHORT,
 146         TPM_UNDEFINED,          /* 85 */
 147         TPM_UNDEFINED,
 148         TPM_UNDEFINED,
 149         TPM_UNDEFINED,
 150         TPM_UNDEFINED,
 151         TPM_SHORT,              /* 90 */
 152         TPM_SHORT,
 153         TPM_SHORT,
 154         TPM_SHORT,
 155         TPM_SHORT,
 156         TPM_UNDEFINED,          /* 95 */
 157         TPM_UNDEFINED,
 158         TPM_UNDEFINED,
 159         TPM_UNDEFINED,
 160         TPM_UNDEFINED,
 161         TPM_MEDIUM,             /* 100 */
 162         TPM_SHORT,
 163         TPM_SHORT,
 164         TPM_UNDEFINED,
 165         TPM_UNDEFINED,
 166         TPM_UNDEFINED,          /* 105 */
 167         TPM_UNDEFINED,
 168         TPM_UNDEFINED,
 169         TPM_UNDEFINED,
 170         TPM_UNDEFINED,
 171         TPM_SHORT,              /* 110 */
 172         TPM_SHORT,
 173         TPM_SHORT,
 174         TPM_SHORT,
 175         TPM_SHORT,
 176         TPM_SHORT,              /* 115 */
 177         TPM_SHORT,
 178         TPM_SHORT,
 179         TPM_UNDEFINED,
 180         TPM_UNDEFINED,
 181         TPM_LONG,               /* 120 */
 182         TPM_LONG,
 183         TPM_MEDIUM,
 184         TPM_UNDEFINED,
 185         TPM_SHORT,
 186         TPM_SHORT,              /* 125 */
 187         TPM_SHORT,
 188         TPM_LONG,
 189         TPM_SHORT,
 190         TPM_SHORT,
 191         TPM_SHORT,              /* 130 */
 192         TPM_MEDIUM,
 193         TPM_UNDEFINED,
 194         TPM_SHORT,
 195         TPM_MEDIUM,
 196         TPM_UNDEFINED,          /* 135 */
 197         TPM_UNDEFINED,
 198         TPM_UNDEFINED,
 199         TPM_UNDEFINED,
 200         TPM_UNDEFINED,
 201         TPM_SHORT,              /* 140 */
 202         TPM_SHORT,
 203         TPM_UNDEFINED,
 204         TPM_UNDEFINED,
 205         TPM_UNDEFINED,
 206         TPM_UNDEFINED,          /* 145 */
 207         TPM_UNDEFINED,
 208         TPM_UNDEFINED,
 209         TPM_UNDEFINED,
 210         TPM_UNDEFINED,
 211         TPM_SHORT,              /* 150 */
 212         TPM_MEDIUM,
 213         TPM_MEDIUM,
 214         TPM_SHORT,
 215         TPM_SHORT,
 216         TPM_UNDEFINED,          /* 155 */
 217         TPM_UNDEFINED,
 218         TPM_UNDEFINED,
 219         TPM_UNDEFINED,
 220         TPM_UNDEFINED,
 221         TPM_SHORT,              /* 160 */
 222         TPM_SHORT,
 223         TPM_SHORT,
 224         TPM_SHORT,
 225         TPM_UNDEFINED,
 226         TPM_UNDEFINED,          /* 165 */
 227         TPM_UNDEFINED,
 228         TPM_UNDEFINED,
 229         TPM_UNDEFINED,
 230         TPM_UNDEFINED,
 231         TPM_LONG,               /* 170 */
 232         TPM_UNDEFINED,
 233         TPM_UNDEFINED,
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,
 236         TPM_UNDEFINED,          /* 175 */
 237         TPM_UNDEFINED,
 238         TPM_UNDEFINED,
 239         TPM_UNDEFINED,
 240         TPM_UNDEFINED,
 241         TPM_MEDIUM,             /* 180 */
 242         TPM_SHORT,
 243         TPM_MEDIUM,
 244         TPM_MEDIUM,
 245         TPM_MEDIUM,
 246         TPM_MEDIUM,             /* 185 */
 247         TPM_SHORT,
 248         TPM_UNDEFINED,
 249         TPM_UNDEFINED,
 250         TPM_UNDEFINED,
 251         TPM_UNDEFINED,          /* 190 */
 252         TPM_UNDEFINED,
 253         TPM_UNDEFINED,
 254         TPM_UNDEFINED,
 255         TPM_UNDEFINED,
 256         TPM_UNDEFINED,          /* 195 */
 257         TPM_UNDEFINED,
 258         TPM_UNDEFINED,
 259         TPM_UNDEFINED,
 260         TPM_UNDEFINED,
 261         TPM_SHORT,              /* 200 */
 262         TPM_UNDEFINED,
 263         TPM_UNDEFINED,
 264         TPM_UNDEFINED,
 265         TPM_SHORT,
 266         TPM_SHORT,              /* 205 */
 267         TPM_SHORT,
 268         TPM_SHORT,
 269         TPM_SHORT,
 270         TPM_SHORT,
 271         TPM_MEDIUM,             /* 210 */
 272         TPM_UNDEFINED,
 273         TPM_MEDIUM,
 274         TPM_MEDIUM,
 275         TPM_MEDIUM,
 276         TPM_UNDEFINED,          /* 215 */
 277         TPM_MEDIUM,
 278         TPM_UNDEFINED,
 279         TPM_UNDEFINED,
 280         TPM_SHORT,
 281         TPM_SHORT,              /* 220 */
 282         TPM_SHORT,
 283         TPM_SHORT,
 284         TPM_SHORT,
 285         TPM_SHORT,
 286         TPM_UNDEFINED,          /* 225 */
 287         TPM_UNDEFINED,
 288         TPM_UNDEFINED,
 289         TPM_UNDEFINED,
 290         TPM_UNDEFINED,
 291         TPM_SHORT,              /* 230 */
 292         TPM_LONG,
 293         TPM_MEDIUM,
 294         TPM_UNDEFINED,
 295         TPM_UNDEFINED,
 296         TPM_UNDEFINED,          /* 235 */
 297         TPM_UNDEFINED,
 298         TPM_UNDEFINED,
 299         TPM_UNDEFINED,
 300         TPM_UNDEFINED,
 301         TPM_SHORT,              /* 240 */
 302         TPM_UNDEFINED,
 303         TPM_MEDIUM,
 304 };
 305
 306 /*
 307  * Returns max number of jiffies to wait
 308  */
 309 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 310                                            u32 ordinal)
 311 {
 312         int duration_idx = TPM_UNDEFINED;
 313         int duration = 0;
 314
 315         /*
 316          * We only have a duration table for protected commands, where the upper
 317          * 16 bits are 0. For the few other ordinals the fallback will be used.
 318          */
 319         if (ordinal < TPM_MAX_ORDINAL)
 320                 duration_idx = tpm_ordinal_duration[ordinal];
 321
 322         if (duration_idx != TPM_UNDEFINED)
 323                 duration = chip->duration[duration_idx];
 324         if (duration <= 0)
 325                 return 2 * 60 * HZ;
 326         else
 327                 return duration;
 328 }
 329 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 330
 331 /*
 332  * Internal kernel interface to transmit TPM commands
 333  */
 334 ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
 335                      unsigned int flags)
 336 {
 337         ssize_t rc;
 338         u32 count, ordinal;
 339         unsigned long stop;
 340
 341         if (bufsiz < TPM_HEADER_SIZE)
 342                 return -EINVAL;
 343
 344         if (bufsiz > TPM_BUFSIZE)
 345                 bufsiz = TPM_BUFSIZE;
 346
 347         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 348         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 349         if (count == 0)
 350                 return -ENODATA;
 351         if (count > bufsiz) {
 352                 dev_err(&chip->dev,
 353                         "invalid count value %x %zx\n", count, bufsiz);
 354                 return -E2BIG;
 355         }
 356
 357         if (!(flags & TPM_TRANSMIT_UNLOCKED))
 358                 mutex_lock(&chip->tpm_mutex);
 359
 360         if (chip->dev.parent)
 361                 pm_runtime_get_sync(chip->dev.parent);
 362
 363         rc = chip->ops->send(chip, (u8 *) buf, count);
 364         if (rc < 0) {
 365                 dev_err(&chip->dev,
 366                         "tpm_transmit: tpm_send: error %zd\n", rc);
 367                 goto out;
 368         }
 369
 370         if (chip->flags & TPM_CHIP_FLAG_IRQ)
 371                 goto out_recv;
 372
 373         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 374                 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
 375         else
 376                 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 377         do {
 378                 u8 status = chip->ops->status(chip);
 379                 if ((status & chip->ops->req_complete_mask) ==
 380                     chip->ops->req_complete_val)
 381                         goto out_recv;
 382
 383                 if (chip->ops->req_canceled(chip, status)) {
 384                         dev_err(&chip->dev, "Operation Canceled\n");
 385                         rc = -ECANCELED;
 386                         goto out;
 387                 }
 388
 389                 msleep(TPM_TIMEOUT);    /* CHECK */
 390                 rmb();
 391         } while (time_before(jiffies, stop));
 392
 393         chip->ops->cancel(chip);
 394         dev_err(&chip->dev, "Operation Timed out\n");
 395         rc = -ETIME;
 396         goto out;
 397
 398 out_recv:
 399         rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
 400         if (rc < 0)
 401                 dev_err(&chip->dev,
 402                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 403 out:
 404         if (chip->dev.parent)
 405                 pm_runtime_put_sync(chip->dev.parent);
 406
 407         if (!(flags & TPM_TRANSMIT_UNLOCKED))
 408                 mutex_unlock(&chip->tpm_mutex);
 409         return rc;
 410 }
 411
 412 #define TPM_DIGEST_SIZE 20
 413 #define TPM_RET_CODE_IDX 6
 414
 415 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,
 416                          int len, unsigned int flags, const char *desc)
 417 {
 418         const struct tpm_output_header *header;
 419         int err;
 420
 421         len = tpm_transmit(chip, (const u8 *)cmd, len, flags);
 422         if (len <  0)
 423                 return len;
 424         else if (len < TPM_HEADER_SIZE)
 425                 return -EFAULT;
 426
 427         header = cmd;
 428
 429         err = be32_to_cpu(header->return_code);
 430         if (err != 0 && desc)
 431                 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
 432                         desc);
 433
 434         return err;
 435 }
 436
 437 #define TPM_INTERNAL_RESULT_SIZE 200
 438 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 439 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 440
 441 static const struct tpm_input_header tpm_getcap_header = {
 442         .tag = TPM_TAG_RQU_COMMAND,
 443         .length = cpu_to_be32(22),
 444         .ordinal = TPM_ORD_GET_CAP
 445 };
 446
 447 ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
 448                    const char *desc)
 449 {
 450         struct tpm_cmd_t tpm_cmd;
 451         int rc;
 452
 453         tpm_cmd.header.in = tpm_getcap_header;
 454         if (subcap_id == TPM_CAP_VERSION_1_1 ||
 455             subcap_id == TPM_CAP_VERSION_1_2) {
 456                 tpm_cmd.params.getcap_in.cap = cpu_to_be32(subcap_id);
 457                 /*subcap field not necessary */
 458                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 459                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 460         } else {
 461                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 462                     subcap_id == TPM_CAP_FLAG_VOL)
 463                         tpm_cmd.params.getcap_in.cap =
 464                                 cpu_to_be32(TPM_CAP_FLAG);
 465                 else
 466                         tpm_cmd.params.getcap_in.cap =
 467                                 cpu_to_be32(TPM_CAP_PROP);
 468                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 469                 tpm_cmd.params.getcap_in.subcap = cpu_to_be32(subcap_id);
 470         }
 471         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 472                               desc);
 473         if (!rc)
 474                 *cap = tpm_cmd.params.getcap_out.cap;
 475         return rc;
 476 }
 477 EXPORT_SYMBOL_GPL(tpm_getcap);
 478
 479 #define TPM_ORD_STARTUP cpu_to_be32(153)
 480 #define TPM_ST_CLEAR cpu_to_be16(1)
 481 #define TPM_ST_STATE cpu_to_be16(2)
 482 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 483 static const struct tpm_input_header tpm_startup_header = {
 484         .tag = TPM_TAG_RQU_COMMAND,
 485         .length = cpu_to_be32(12),
 486         .ordinal = TPM_ORD_STARTUP
 487 };
 488
 489 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 490 {
 491         struct tpm_cmd_t start_cmd;
 492         start_cmd.header.in = tpm_startup_header;
 493
 494         start_cmd.params.startup_in.startup_type = startup_type;
 495         return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 496                                 "attempting to start the TPM");
 497 }
 498
 499 int tpm_get_timeouts(struct tpm_chip *chip)
 500 {
 501         cap_t cap;
 502         unsigned long new_timeout[4];
 503         unsigned long old_timeout[4];
 504         ssize_t rc;
 505
 506         if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
 507                 return 0;
 508
 509         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 510                 /* Fixed timeouts for TPM2 */
 511                 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
 512                 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
 513                 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
 514                 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
 515                 chip->duration[TPM_SHORT] =
 516                     msecs_to_jiffies(TPM2_DURATION_SHORT);
 517                 chip->duration[TPM_MEDIUM] =
 518                     msecs_to_jiffies(TPM2_DURATION_MEDIUM);
 519                 chip->duration[TPM_LONG] =
 520                     msecs_to_jiffies(TPM2_DURATION_LONG);
 521
 522                 chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
 523                 return 0;
 524         }
 525
 526         rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
 527                         "attempting to determine the timeouts");
 528         if (rc == TPM_ERR_INVALID_POSTINIT) {
 529                 /* The TPM is not started, we are the first to talk to it.
 530                    Execute a startup command. */
 531                 dev_info(&chip->dev, "Issuing TPM_STARTUP\n");
 532                 if (tpm_startup(chip, TPM_ST_CLEAR))
 533                         return rc;
 534
 535                 rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
 536                                 "attempting to determine the timeouts");
 537         }
 538         if (rc)
 539                 return rc;
 540
 541         old_timeout[0] = be32_to_cpu(cap.timeout.a);
 542         old_timeout[1] = be32_to_cpu(cap.timeout.b);
 543         old_timeout[2] = be32_to_cpu(cap.timeout.c);
 544         old_timeout[3] = be32_to_cpu(cap.timeout.d);
 545         memcpy(new_timeout, old_timeout, sizeof(new_timeout));
 546
 547         /*
 548          * Provide ability for vendor overrides of timeout values in case
 549          * of misreporting.
 550          */
 551         if (chip->ops->update_timeouts != NULL)
 552                 chip->timeout_adjusted =
 553                         chip->ops->update_timeouts(chip, new_timeout);
 554
 555         if (!chip->timeout_adjusted) {
 556                 /* Don't overwrite default if value is 0 */
 557                 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
 558                         int i;
 559
 560                         /* timeouts in msec rather usec */
 561                         for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
 562                                 new_timeout[i] *= 1000;
 563                         chip->timeout_adjusted = true;
 564                 }
 565         }
 566
 567         /* Report adjusted timeouts */
 568         if (chip->timeout_adjusted) {
 569                 dev_info(&chip->dev,
 570                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 571                          old_timeout[0], new_timeout[0],
 572                          old_timeout[1], new_timeout[1],
 573                          old_timeout[2], new_timeout[2],
 574                          old_timeout[3], new_timeout[3]);
 575         }
 576
 577         chip->timeout_a = usecs_to_jiffies(new_timeout[0]);
 578         chip->timeout_b = usecs_to_jiffies(new_timeout[1]);
 579         chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
 580         chip->timeout_d = usecs_to_jiffies(new_timeout[3]);
 581
 582         rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
 583                         "attempting to determine the durations");
 584         if (rc)
 585                 return rc;
 586
 587         chip->duration[TPM_SHORT] =
 588                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
 589         chip->duration[TPM_MEDIUM] =
 590                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
 591         chip->duration[TPM_LONG] =
 592                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
 593
 594         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 595          * value wrong and apparently reports msecs rather than usecs. So we
 596          * fix up the resulting too-small TPM_SHORT value to make things work.
 597          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 598          */
 599         if (chip->duration[TPM_SHORT] < (HZ / 100)) {
 600                 chip->duration[TPM_SHORT] = HZ;
 601                 chip->duration[TPM_MEDIUM] *= 1000;
 602                 chip->duration[TPM_LONG] *= 1000;
 603                 chip->duration_adjusted = true;
 604                 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 605         }
 606
 607         chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
 608         return 0;
 609 }
 610 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 611
 612 #define TPM_ORD_CONTINUE_SELFTEST 83
 613 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 614
 615 static const struct tpm_input_header continue_selftest_header = {
 616         .tag = TPM_TAG_RQU_COMMAND,
 617         .length = cpu_to_be32(10),
 618         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 619 };
 620
 621 /**
 622  * tpm_continue_selftest -- run TPM's selftest
 623  * @chip: TPM chip to use
 624  *
 625  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 626  * a TPM error code.
 627  */
 628 static int tpm_continue_selftest(struct tpm_chip *chip)
 629 {
 630         int rc;
 631         struct tpm_cmd_t cmd;
 632
 633         cmd.header.in = continue_selftest_header;
 634         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
 635                               "continue selftest");
 636         return rc;
 637 }
 638
 639 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 640 #define READ_PCR_RESULT_SIZE 30
 641 static const struct tpm_input_header pcrread_header = {
 642         .tag = TPM_TAG_RQU_COMMAND,
 643         .length = cpu_to_be32(14),
 644         .ordinal = TPM_ORDINAL_PCRREAD
 645 };
 646
 647 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 648 {
 649         int rc;
 650         struct tpm_cmd_t cmd;
 651
 652         cmd.header.in = pcrread_header;
 653         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 654         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
 655                               "attempting to read a pcr value");
 656
 657         if (rc == 0)
 658                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 659                        TPM_DIGEST_SIZE);
 660         return rc;
 661 }
 662
 663 /**
 664  * tpm_is_tpm2 - is the chip a TPM2 chip?
 665  * @chip_num:   tpm idx # or ANY
 666  *
 667  * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 668  * is a TPM2 chip.
 669  */
 670 int tpm_is_tpm2(u32 chip_num)
 671 {
 672         struct tpm_chip *chip;
 673         int rc;
 674
 675         chip = tpm_chip_find_get(chip_num);
 676         if (chip == NULL)
 677                 return -ENODEV;
 678
 679         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 680
 681         tpm_put_ops(chip);
 682
 683         return rc;
 684 }
 685 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 686
 687 /**
 688  * tpm_pcr_read - read a pcr value
 689  * @chip_num:   tpm idx # or ANY
 690  * @pcr_idx:    pcr idx to retrieve
 691  * @res_buf:    TPM_PCR value
 692  *              size of res_buf is 20 bytes (or NULL if you don't care)
 693  *
 694  * The TPM driver should be built-in, but for whatever reason it
 695  * isn't, protect against the chip disappearing, by incrementing
 696  * the module usage count.
 697  */
 698 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 699 {
 700         struct tpm_chip *chip;
 701         int rc;
 702
 703         chip = tpm_chip_find_get(chip_num);
 704         if (chip == NULL)
 705                 return -ENODEV;
 706         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 707                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 708         else
 709                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 710         tpm_put_ops(chip);
 711         return rc;
 712 }
 713 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 714
 715 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 716 #define EXTEND_PCR_RESULT_SIZE 34
 717 static const struct tpm_input_header pcrextend_header = {
 718         .tag = TPM_TAG_RQU_COMMAND,
 719         .length = cpu_to_be32(34),
 720         .ordinal = TPM_ORD_PCR_EXTEND
 721 };
 722
 723 /**
 724  * tpm_pcr_extend - extend pcr value with hash
 725  * @chip_num:   tpm idx # or AN&
 726  * @pcr_idx:    pcr idx to extend
 727  * @hash:       hash value used to extend pcr value
 728  *
 729  * The TPM driver should be built-in, but for whatever reason it
 730  * isn't, protect against the chip disappearing, by incrementing
 731  * the module usage count.
 732  */
 733 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 734 {
 735         struct tpm_cmd_t cmd;
 736         int rc;
 737         struct tpm_chip *chip;
 738
 739         chip = tpm_chip_find_get(chip_num);
 740         if (chip == NULL)
 741                 return -ENODEV;
 742
 743         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 744                 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
 745                 tpm_put_ops(chip);
 746                 return rc;
 747         }
 748
 749         cmd.header.in = pcrextend_header;
 750         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 751         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 752         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 753                               "attempting extend a PCR value");
 754
 755         tpm_put_ops(chip);
 756         return rc;
 757 }
 758 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 759
 760 /**
 761  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 762  *                   can receive further commands
 763  * @chip: TPM chip to use
 764  *
 765  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 766  * a TPM error code.
 767  */
 768 int tpm_do_selftest(struct tpm_chip *chip)
 769 {
 770         int rc;
 771         unsigned int loops;
 772         unsigned int delay_msec = 100;
 773         unsigned long duration;
 774         u8 dummy[TPM_DIGEST_SIZE];
 775
 776         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 777
 778         loops = jiffies_to_msecs(duration) / delay_msec;
 779
 780         rc = tpm_continue_selftest(chip);
 781         /* This may fail if there was no TPM driver during a suspend/resume
 782          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 783          */
 784         if (rc)
 785                 return rc;
 786
 787         do {
 788                 /* Attempt to read a PCR value */
 789                 rc = tpm_pcr_read_dev(chip, 0, dummy);
 790
 791                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 792                  * around 300ms while the self test is ongoing, keep trying
 793                  * until the self test duration expires. */
 794                 if (rc == -ETIME) {
 795                         dev_info(
 796                             &chip->dev, HW_ERR
 797                             "TPM command timed out during continue self test");
 798                         msleep(delay_msec);
 799                         continue;
 800                 }
 801
 802                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 803                         dev_info(&chip->dev,
 804                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 805                         /* TPM is disabled and/or deactivated; driver can
 806                          * proceed and TPM does handle commands for
 807                          * suspend/resume correctly
 808                          */
 809                         return 0;
 810                 }
 811                 if (rc != TPM_WARN_DOING_SELFTEST)
 812                         return rc;
 813                 msleep(delay_msec);
 814         } while (--loops > 0);
 815
 816         return rc;
 817 }
 818 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 819
 820 /**
 821  * tpm1_auto_startup - Perform the standard automatic TPM initialization
 822  *                     sequence
 823  * @chip: TPM chip to use
 824  *
 825  * Returns 0 on success, < 0 in case of fatal error.
 826  */
 827 int tpm1_auto_startup(struct tpm_chip *chip)
 828 {
 829         int rc;
 830
 831         rc = tpm_get_timeouts(chip);
 832         if (rc)
 833                 goto out;
 834         rc = tpm_do_selftest(chip);
 835         if (rc) {
 836                 dev_err(&chip->dev, "TPM self test failed\n");
 837                 goto out;
 838         }
 839
 840         return rc;
 841 out:
 842         if (rc > 0)
 843                 rc = -ENODEV;
 844         return rc;
 845 }
 846
 847 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 848 {
 849         struct tpm_chip *chip;
 850         int rc;
 851
 852         chip = tpm_chip_find_get(chip_num);
 853         if (chip == NULL)
 854                 return -ENODEV;
 855
 856         rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
 857
 858         tpm_put_ops(chip);
 859         return rc;
 860 }
 861 EXPORT_SYMBOL_GPL(tpm_send);
 862
 863 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 864                                         bool check_cancel, bool *canceled)
 865 {
 866         u8 status = chip->ops->status(chip);
 867
 868         *canceled = false;
 869         if ((status & mask) == mask)
 870                 return true;
 871         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 872                 *canceled = true;
 873                 return true;
 874         }
 875         return false;
 876 }
 877
 878 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 879                       wait_queue_head_t *queue, bool check_cancel)
 880 {
 881         unsigned long stop;
 882         long rc;
 883         u8 status;
 884         bool canceled = false;
 885
 886         /* check current status */
 887         status = chip->ops->status(chip);
 888         if ((status & mask) == mask)
 889                 return 0;
 890
 891         stop = jiffies + timeout;
 892
 893         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
 894 again:
 895                 timeout = stop - jiffies;
 896                 if ((long)timeout <= 0)
 897                         return -ETIME;
 898                 rc = wait_event_interruptible_timeout(*queue,
 899                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 900                                                &canceled),
 901                         timeout);
 902                 if (rc > 0) {
 903                         if (canceled)
 904                                 return -ECANCELED;
 905                         return 0;
 906                 }
 907                 if (rc == -ERESTARTSYS && freezing(current)) {
 908                         clear_thread_flag(TIF_SIGPENDING);
 909                         goto again;
 910                 }
 911         } else {
 912                 do {
 913                         msleep(TPM_TIMEOUT);
 914                         status = chip->ops->status(chip);
 915                         if ((status & mask) == mask)
 916                                 return 0;
 917                 } while (time_before(jiffies, stop));
 918         }
 919         return -ETIME;
 920 }
 921 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 922
 923 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 924 #define SAVESTATE_RESULT_SIZE 10
 925
 926 static const struct tpm_input_header savestate_header = {
 927         .tag = TPM_TAG_RQU_COMMAND,
 928         .length = cpu_to_be32(10),
 929         .ordinal = TPM_ORD_SAVESTATE
 930 };
 931
 932 /*
 933  * We are about to suspend. Save the TPM state
 934  * so that it can be restored.
 935  */
 936 int tpm_pm_suspend(struct device *dev)
 937 {
 938         struct tpm_chip *chip = dev_get_drvdata(dev);
 939         struct tpm_cmd_t cmd;
 940         int rc, try;
 941
 942         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 943
 944         if (chip == NULL)
 945                 return -ENODEV;
 946
 947         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 948                 tpm2_shutdown(chip, TPM2_SU_STATE);
 949                 return 0;
 950         }
 951
 952         /* for buggy tpm, flush pcrs with extend to selected dummy */
 953         if (tpm_suspend_pcr) {
 954                 cmd.header.in = pcrextend_header;
 955                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 956                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 957                        TPM_DIGEST_SIZE);
 958                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 959                                       "extending dummy pcr before suspend");
 960         }
 961
 962         /* now do the actual savestate */
 963         for (try = 0; try < TPM_RETRY; try++) {
 964                 cmd.header.in = savestate_header;
 965                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
 966                                       NULL);
 967
 968                 /*
 969                  * If the TPM indicates that it is too busy to respond to
 970                  * this command then retry before giving up.  It can take
 971                  * several seconds for this TPM to be ready.
 972                  *
 973                  * This can happen if the TPM has already been sent the
 974                  * SaveState command before the driver has loaded.  TCG 1.2
 975                  * specification states that any communication after SaveState
 976                  * may cause the TPM to invalidate previously saved state.
 977                  */
 978                 if (rc != TPM_WARN_RETRY)
 979                         break;
 980                 msleep(TPM_TIMEOUT_RETRY);
 981         }
 982
 983         if (rc)
 984                 dev_err(&chip->dev,
 985                         "Error (%d) sending savestate before suspend\n", rc);
 986         else if (try > 0)
 987                 dev_warn(&chip->dev, "TPM savestate took %dms\n",
 988                          try * TPM_TIMEOUT_RETRY);
 989
 990         return rc;
 991 }
 992 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
 993
 994 /*
 995  * Resume from a power safe. The BIOS already restored
 996  * the TPM state.
 997  */
 998 int tpm_pm_resume(struct device *dev)
 999 {
1000         struct tpm_chip *chip = dev_get_drvdata(dev);
1001
1002         if (chip == NULL)
1003                 return -ENODEV;
1004
1005         return 0;
1006 }
1007 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1008
1009 #define TPM_GETRANDOM_RESULT_SIZE       18
1010 static const struct tpm_input_header tpm_getrandom_header = {
1011         .tag = TPM_TAG_RQU_COMMAND,
1012         .length = cpu_to_be32(14),
1013         .ordinal = TPM_ORD_GET_RANDOM
1014 };
1015
1016 /**
1017  * tpm_get_random() - Get random bytes from the tpm's RNG
1018  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1019  * @out: destination buffer for the random bytes
1020  * @max: the max number of bytes to write to @out
1021  *
1022  * Returns < 0 on error and the number of bytes read on success
1023  */
1024 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1025 {
1026         struct tpm_chip *chip;
1027         struct tpm_cmd_t tpm_cmd;
1028         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1029         int err, total = 0, retries = 5;
1030         u8 *dest = out;
1031
1032         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1033                 return -EINVAL;
1034
1035         chip = tpm_chip_find_get(chip_num);
1036         if (chip == NULL)
1037                 return -ENODEV;
1038
1039         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1040                 err = tpm2_get_random(chip, out, max);
1041                 tpm_put_ops(chip);
1042                 return err;
1043         }
1044
1045         do {
1046                 tpm_cmd.header.in = tpm_getrandom_header;
1047                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1048
1049                 err = tpm_transmit_cmd(chip, &tpm_cmd,
1050                                        TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1051                                        0, "attempting get random");
1052                 if (err)
1053                         break;
1054
1055                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1056                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1057
1058                 dest += recd;
1059                 total += recd;
1060                 num_bytes -= recd;
1061         } while (retries-- && total < max);
1062
1063         tpm_put_ops(chip);
1064         return total ? total : -EIO;
1065 }
1066 EXPORT_SYMBOL_GPL(tpm_get_random);
1067
1068 /**
1069  * tpm_seal_trusted() - seal a trusted key
1070  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1071  * @options: authentication values and other options
1072  * @payload: the key data in clear and encrypted form
1073  *
1074  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1075  * are supported.
1076  */
1077 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1078                      struct trusted_key_options *options)
1079 {
1080         struct tpm_chip *chip;
1081         int rc;
1082
1083         chip = tpm_chip_find_get(chip_num);
1084         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1085                 return -ENODEV;
1086
1087         rc = tpm2_seal_trusted(chip, payload, options);
1088
1089         tpm_put_ops(chip);
1090         return rc;
1091 }
1092 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1093
1094 /**
1095  * tpm_unseal_trusted() - unseal a trusted key
1096  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1097  * @options: authentication values and other options
1098  * @payload: the key data in clear and encrypted form
1099  *
1100  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1101  * are supported.
1102  */
1103 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1104                        struct trusted_key_options *options)
1105 {
1106         struct tpm_chip *chip;
1107         int rc;
1108
1109         chip = tpm_chip_find_get(chip_num);
1110         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1111                 return -ENODEV;
1112
1113         rc = tpm2_unseal_trusted(chip, payload, options);
1114
1115         tpm_put_ops(chip);
1116
1117         return rc;
1118 }
1119 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1120
1121 static int __init tpm_init(void)
1122 {
1123         int rc;
1124
1125         tpm_class = class_create(THIS_MODULE, "tpm");
1126         if (IS_ERR(tpm_class)) {
1127                 pr_err("couldn't create tpm class\n");
1128                 return PTR_ERR(tpm_class);
1129         }
1130
1131         rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1132         if (rc < 0) {
1133                 pr_err("tpm: failed to allocate char dev region\n");
1134                 class_destroy(tpm_class);
1135                 return rc;
1136         }
1137
1138         return 0;
1139 }
1140
1141 static void __exit tpm_exit(void)
1142 {
1143         idr_destroy(&dev_nums_idr);
1144         class_destroy(tpm_class);
1145         unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1146 }
1147
1148 subsys_initcall(tpm_init);
1149 module_exit(tpm_exit);
1150
1151 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1152 MODULE_DESCRIPTION("TPM Driver");
1153 MODULE_VERSION("2.0");
1154 MODULE_LICENSE("GPL");