kernel/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         u8 category = (ordinal >> 24) & 0xFF;
 314
 315         if ((category == TPM_PROTECTED_COMMAND && ordinal < TPM_MAX_ORDINAL) ||
 316             (category == TPM_CONNECTION_COMMAND && ordinal < TSC_MAX_ORDINAL))
 317                 duration_idx = tpm_ordinal_duration[ordinal];
 318
 319         if (duration_idx != TPM_UNDEFINED)
 320                 duration = chip->vendor.duration[duration_idx];
 321         if (duration <= 0)
 322                 return 2 * 60 * HZ;
 323         else
 324                 return duration;
 325 }
 326 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 327
 328 /*
 329  * Internal kernel interface to transmit TPM commands
 330  */
 331 ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
 332                      unsigned int flags)
 333 {
 334         ssize_t rc;
 335         u32 count, ordinal;
 336         unsigned long stop;
 337
 338         if (bufsiz > TPM_BUFSIZE)
 339                 bufsiz = TPM_BUFSIZE;
 340
 341         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 342         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 343         if (count == 0)
 344                 return -ENODATA;
 345         if (count > bufsiz) {
 346                 dev_err(chip->pdev,
 347                         "invalid count value %x %zx\n", count, bufsiz);
 348                 return -E2BIG;
 349         }
 350
 351         if (!(flags & TPM_TRANSMIT_UNLOCKED))
 352                 mutex_lock(&chip->tpm_mutex);
 353
 354         rc = chip->ops->send(chip, (u8 *) buf, count);
 355         if (rc < 0) {
 356                 dev_err(chip->pdev,
 357                         "tpm_transmit: tpm_send: error %zd\n", rc);
 358                 goto out;
 359         }
 360
 361         if (chip->vendor.irq)
 362                 goto out_recv;
 363
 364         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 365                 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
 366         else
 367                 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 368         do {
 369                 u8 status = chip->ops->status(chip);
 370                 if ((status & chip->ops->req_complete_mask) ==
 371                     chip->ops->req_complete_val)
 372                         goto out_recv;
 373
 374                 if (chip->ops->req_canceled(chip, status)) {
 375                         dev_err(chip->pdev, "Operation Canceled\n");
 376                         rc = -ECANCELED;
 377                         goto out;
 378                 }
 379
 380                 msleep(TPM_TIMEOUT);    /* CHECK */
 381                 rmb();
 382         } while (time_before(jiffies, stop));
 383
 384         chip->ops->cancel(chip);
 385         dev_err(chip->pdev, "Operation Timed out\n");
 386         rc = -ETIME;
 387         goto out;
 388
 389 out_recv:
 390         rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
 391         if (rc < 0)
 392                 dev_err(chip->pdev,
 393                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 394 out:
 395         if (!(flags & TPM_TRANSMIT_UNLOCKED))
 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, const void *cmd,
 404                          int len, unsigned int flags, const char *desc)
 405 {
 406         const struct tpm_output_header *header;
 407         int err;
 408
 409         len = tpm_transmit(chip, (const u8 *)cmd, len, flags);
 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->pdev, "A TPM error (%d) occurred %s\n", err,
 420                         desc);
 421
 422         return err;
 423 }
 424
 425 #define TPM_INTERNAL_RESULT_SIZE 200
 426 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 427 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 428
 429 static const struct tpm_input_header tpm_getcap_header = {
 430         .tag = TPM_TAG_RQU_COMMAND,
 431         .length = cpu_to_be32(22),
 432         .ordinal = TPM_ORD_GET_CAP
 433 };
 434
 435 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
 436                    const char *desc)
 437 {
 438         struct tpm_cmd_t tpm_cmd;
 439         int rc;
 440         struct tpm_chip *chip = dev_get_drvdata(dev);
 441
 442         tpm_cmd.header.in = tpm_getcap_header;
 443         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 444                 tpm_cmd.params.getcap_in.cap = subcap_id;
 445                 /*subcap field not necessary */
 446                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 447                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 448         } else {
 449                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 450                     subcap_id == TPM_CAP_FLAG_VOL)
 451                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 452                 else
 453                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 454                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 455                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 456         }
 457         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 458                               desc);
 459         if (!rc)
 460                 *cap = tpm_cmd.params.getcap_out.cap;
 461         return rc;
 462 }
 463
 464 void tpm_gen_interrupt(struct tpm_chip *chip)
 465 {
 466         struct  tpm_cmd_t tpm_cmd;
 467         ssize_t rc;
 468
 469         tpm_cmd.header.in = tpm_getcap_header;
 470         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 471         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 472         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 473
 474         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 475                               "attempting to determine the timeouts");
 476 }
 477 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 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         struct tpm_cmd_t tpm_cmd;
 502         unsigned long new_timeout[4];
 503         unsigned long old_timeout[4];
 504         struct duration_t *duration_cap;
 505         ssize_t rc;
 506
 507         tpm_cmd.header.in = tpm_getcap_header;
 508         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 509         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 510         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 511         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 512                               NULL);
 513
 514         if (rc == TPM_ERR_INVALID_POSTINIT) {
 515                 /* The TPM is not started, we are the first to talk to it.
 516                    Execute a startup command. */
 517                 dev_info(chip->pdev, "Issuing TPM_STARTUP");
 518                 if (tpm_startup(chip, TPM_ST_CLEAR))
 519                         return rc;
 520
 521                 tpm_cmd.header.in = tpm_getcap_header;
 522                 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 523                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 524                 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 525                 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 526                                       0, NULL);
 527         }
 528         if (rc) {
 529                 dev_err(chip->pdev,
 530                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 531                         rc);
 532                 goto duration;
 533         }
 534
 535         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 536             be32_to_cpu(tpm_cmd.header.out.length)
 537             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 538                 return -EINVAL;
 539
 540         old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
 541         old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
 542         old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
 543         old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
 544         memcpy(new_timeout, old_timeout, sizeof(new_timeout));
 545
 546         /*
 547          * Provide ability for vendor overrides of timeout values in case
 548          * of misreporting.
 549          */
 550         if (chip->ops->update_timeouts != NULL)
 551                 chip->vendor.timeout_adjusted =
 552                         chip->ops->update_timeouts(chip, new_timeout);
 553
 554         if (!chip->vendor.timeout_adjusted) {
 555                 /* Don't overwrite default if value is 0 */
 556                 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
 557                         int i;
 558
 559                         /* timeouts in msec rather usec */
 560                         for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
 561                                 new_timeout[i] *= 1000;
 562                         chip->vendor.timeout_adjusted = true;
 563                 }
 564         }
 565
 566         /* Report adjusted timeouts */
 567         if (chip->vendor.timeout_adjusted) {
 568                 dev_info(chip->pdev,
 569                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 570                          old_timeout[0], new_timeout[0],
 571                          old_timeout[1], new_timeout[1],
 572                          old_timeout[2], new_timeout[2],
 573                          old_timeout[3], new_timeout[3]);
 574         }
 575
 576         chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
 577         chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
 578         chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
 579         chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
 580
 581 duration:
 582         tpm_cmd.header.in = tpm_getcap_header;
 583         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 584         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 585         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 586
 587         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 588                               "attempting to determine the durations");
 589         if (rc)
 590                 return rc;
 591
 592         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 593             be32_to_cpu(tpm_cmd.header.out.length)
 594             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 595                 return -EINVAL;
 596
 597         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 598         chip->vendor.duration[TPM_SHORT] =
 599             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 600         chip->vendor.duration[TPM_MEDIUM] =
 601             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 602         chip->vendor.duration[TPM_LONG] =
 603             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 604
 605         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 606          * value wrong and apparently reports msecs rather than usecs. So we
 607          * fix up the resulting too-small TPM_SHORT value to make things work.
 608          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 609          */
 610         if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
 611                 chip->vendor.duration[TPM_SHORT] = HZ;
 612                 chip->vendor.duration[TPM_MEDIUM] *= 1000;
 613                 chip->vendor.duration[TPM_LONG] *= 1000;
 614                 chip->vendor.duration_adjusted = true;
 615                 dev_info(chip->pdev, "Adjusting TPM timeout parameters.");
 616         }
 617         return 0;
 618 }
 619 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 620
 621 #define TPM_ORD_CONTINUE_SELFTEST 83
 622 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 623
 624 static struct tpm_input_header continue_selftest_header = {
 625         .tag = TPM_TAG_RQU_COMMAND,
 626         .length = cpu_to_be32(10),
 627         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 628 };
 629
 630 /**
 631  * tpm_continue_selftest -- run TPM's selftest
 632  * @chip: TPM chip to use
 633  *
 634  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 635  * a TPM error code.
 636  */
 637 static int tpm_continue_selftest(struct tpm_chip *chip)
 638 {
 639         int rc;
 640         struct tpm_cmd_t cmd;
 641
 642         cmd.header.in = continue_selftest_header;
 643         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
 644                               "continue selftest");
 645         return rc;
 646 }
 647
 648 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 649 #define READ_PCR_RESULT_SIZE 30
 650 static struct tpm_input_header pcrread_header = {
 651         .tag = TPM_TAG_RQU_COMMAND,
 652         .length = cpu_to_be32(14),
 653         .ordinal = TPM_ORDINAL_PCRREAD
 654 };
 655
 656 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 657 {
 658         int rc;
 659         struct tpm_cmd_t cmd;
 660
 661         cmd.header.in = pcrread_header;
 662         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 663         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
 664                               "attempting to read a pcr value");
 665
 666         if (rc == 0)
 667                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 668                        TPM_DIGEST_SIZE);
 669         return rc;
 670 }
 671
 672 /**
 673  * tpm_is_tpm2 - is the chip a TPM2 chip?
 674  * @chip_num:   tpm idx # or ANY
 675  *
 676  * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 677  * is a TPM2 chip.
 678  */
 679 int tpm_is_tpm2(u32 chip_num)
 680 {
 681         struct tpm_chip *chip;
 682         int rc;
 683
 684         chip = tpm_chip_find_get(chip_num);
 685         if (chip == NULL)
 686                 return -ENODEV;
 687
 688         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 689
 690         tpm_chip_put(chip);
 691
 692         return rc;
 693 }
 694 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 695
 696 /**
 697  * tpm_pcr_read - read a pcr value
 698  * @chip_num:   tpm idx # or ANY
 699  * @pcr_idx:    pcr idx to retrieve
 700  * @res_buf:    TPM_PCR value
 701  *              size of res_buf is 20 bytes (or NULL if you don't care)
 702  *
 703  * The TPM driver should be built-in, but for whatever reason it
 704  * isn't, protect against the chip disappearing, by incrementing
 705  * the module usage count.
 706  */
 707 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 708 {
 709         struct tpm_chip *chip;
 710         int rc;
 711
 712         chip = tpm_chip_find_get(chip_num);
 713         if (chip == NULL)
 714                 return -ENODEV;
 715         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 716                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 717         else
 718                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 719         tpm_chip_put(chip);
 720         return rc;
 721 }
 722 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 723
 724 /**
 725  * tpm_pcr_extend - extend pcr value with hash
 726  * @chip_num:   tpm idx # or AN&
 727  * @pcr_idx:    pcr idx to extend
 728  * @hash:       hash value used to extend pcr value
 729  *
 730  * The TPM driver should be built-in, but for whatever reason it
 731  * isn't, protect against the chip disappearing, by incrementing
 732  * the module usage count.
 733  */
 734 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 735 #define EXTEND_PCR_RESULT_SIZE 34
 736 static struct tpm_input_header pcrextend_header = {
 737         .tag = TPM_TAG_RQU_COMMAND,
 738         .length = cpu_to_be32(34),
 739         .ordinal = TPM_ORD_PCR_EXTEND
 740 };
 741
 742 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 743 {
 744         struct tpm_cmd_t cmd;
 745         int rc;
 746         struct tpm_chip *chip;
 747
 748         chip = tpm_chip_find_get(chip_num);
 749         if (chip == NULL)
 750                 return -ENODEV;
 751
 752         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 753                 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
 754                 tpm_chip_put(chip);
 755                 return rc;
 756         }
 757
 758         cmd.header.in = pcrextend_header;
 759         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 760         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 761         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 762                               "attempting extend a PCR value");
 763
 764         tpm_chip_put(chip);
 765         return rc;
 766 }
 767 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 768
 769 /**
 770  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 771  *                   can receive further commands
 772  * @chip: TPM chip to use
 773  *
 774  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 775  * a TPM error code.
 776  */
 777 int tpm_do_selftest(struct tpm_chip *chip)
 778 {
 779         int rc;
 780         unsigned int loops;
 781         unsigned int delay_msec = 100;
 782         unsigned long duration;
 783         struct tpm_cmd_t cmd;
 784
 785         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 786
 787         loops = jiffies_to_msecs(duration) / delay_msec;
 788
 789         rc = tpm_continue_selftest(chip);
 790         /* This may fail if there was no TPM driver during a suspend/resume
 791          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 792          */
 793         if (rc)
 794                 return rc;
 795
 796         do {
 797                 /* Attempt to read a PCR value */
 798                 cmd.header.in = pcrread_header;
 799                 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
 800                 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE, 0);
 801                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 802                  * around 300ms while the self test is ongoing, keep trying
 803                  * until the self test duration expires. */
 804                 if (rc == -ETIME) {
 805                         dev_info(chip->pdev, HW_ERR "TPM command timed out during continue self test");
 806                         msleep(delay_msec);
 807                         continue;
 808                 }
 809
 810                 if (rc < TPM_HEADER_SIZE)
 811                         return -EFAULT;
 812
 813                 rc = be32_to_cpu(cmd.header.out.return_code);
 814                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 815                         dev_info(chip->pdev,
 816                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 817                         /* TPM is disabled and/or deactivated; driver can
 818                          * proceed and TPM does handle commands for
 819                          * suspend/resume correctly
 820                          */
 821                         return 0;
 822                 }
 823                 if (rc != TPM_WARN_DOING_SELFTEST)
 824                         return rc;
 825                 msleep(delay_msec);
 826         } while (--loops > 0);
 827
 828         return rc;
 829 }
 830 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 831
 832 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 833 {
 834         struct tpm_chip *chip;
 835         int rc;
 836
 837         chip = tpm_chip_find_get(chip_num);
 838         if (chip == NULL)
 839                 return -ENODEV;
 840
 841         rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
 842
 843         tpm_chip_put(chip);
 844         return rc;
 845 }
 846 EXPORT_SYMBOL_GPL(tpm_send);
 847
 848 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 849                                         bool check_cancel, bool *canceled)
 850 {
 851         u8 status = chip->ops->status(chip);
 852
 853         *canceled = false;
 854         if ((status & mask) == mask)
 855                 return true;
 856         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 857                 *canceled = true;
 858                 return true;
 859         }
 860         return false;
 861 }
 862
 863 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 864                       wait_queue_head_t *queue, bool check_cancel)
 865 {
 866         unsigned long stop;
 867         long rc;
 868         u8 status;
 869         bool canceled = false;
 870
 871         /* check current status */
 872         status = chip->ops->status(chip);
 873         if ((status & mask) == mask)
 874                 return 0;
 875
 876         stop = jiffies + timeout;
 877
 878         if (chip->vendor.irq) {
 879 again:
 880                 timeout = stop - jiffies;
 881                 if ((long)timeout <= 0)
 882                         return -ETIME;
 883                 rc = wait_event_interruptible_timeout(*queue,
 884                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 885                                                &canceled),
 886                         timeout);
 887                 if (rc > 0) {
 888                         if (canceled)
 889                                 return -ECANCELED;
 890                         return 0;
 891                 }
 892                 if (rc == -ERESTARTSYS && freezing(current)) {
 893                         clear_thread_flag(TIF_SIGPENDING);
 894                         goto again;
 895                 }
 896         } else {
 897                 do {
 898                         msleep(TPM_TIMEOUT);
 899                         status = chip->ops->status(chip);
 900                         if ((status & mask) == mask)
 901                                 return 0;
 902                 } while (time_before(jiffies, stop));
 903         }
 904         return -ETIME;
 905 }
 906 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 907
 908 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 909 #define SAVESTATE_RESULT_SIZE 10
 910
 911 static struct tpm_input_header savestate_header = {
 912         .tag = TPM_TAG_RQU_COMMAND,
 913         .length = cpu_to_be32(10),
 914         .ordinal = TPM_ORD_SAVESTATE
 915 };
 916
 917 /*
 918  * We are about to suspend. Save the TPM state
 919  * so that it can be restored.
 920  */
 921 int tpm_pm_suspend(struct device *dev)
 922 {
 923         struct tpm_chip *chip = dev_get_drvdata(dev);
 924         struct tpm_cmd_t cmd;
 925         int rc, try;
 926
 927         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 928
 929         if (chip == NULL)
 930                 return -ENODEV;
 931
 932         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 933                 tpm2_shutdown(chip, TPM2_SU_STATE);
 934                 return 0;
 935         }
 936
 937         /* for buggy tpm, flush pcrs with extend to selected dummy */
 938         if (tpm_suspend_pcr) {
 939                 cmd.header.in = pcrextend_header;
 940                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 941                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 942                        TPM_DIGEST_SIZE);
 943                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 944                                       "extending dummy pcr before suspend");
 945         }
 946
 947         /* now do the actual savestate */
 948         for (try = 0; try < TPM_RETRY; try++) {
 949                 cmd.header.in = savestate_header;
 950                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
 951                                       NULL);
 952
 953                 /*
 954                  * If the TPM indicates that it is too busy to respond to
 955                  * this command then retry before giving up.  It can take
 956                  * several seconds for this TPM to be ready.
 957                  *
 958                  * This can happen if the TPM has already been sent the
 959                  * SaveState command before the driver has loaded.  TCG 1.2
 960                  * specification states that any communication after SaveState
 961                  * may cause the TPM to invalidate previously saved state.
 962                  */
 963                 if (rc != TPM_WARN_RETRY)
 964                         break;
 965                 msleep(TPM_TIMEOUT_RETRY);
 966         }
 967
 968         if (rc)
 969                 dev_err(chip->pdev,
 970                         "Error (%d) sending savestate before suspend\n", rc);
 971         else if (try > 0)
 972                 dev_warn(chip->pdev, "TPM savestate took %dms\n",
 973                          try * TPM_TIMEOUT_RETRY);
 974
 975         return rc;
 976 }
 977 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
 978
 979 /*
 980  * Resume from a power safe. The BIOS already restored
 981  * the TPM state.
 982  */
 983 int tpm_pm_resume(struct device *dev)
 984 {
 985         struct tpm_chip *chip = dev_get_drvdata(dev);
 986
 987         if (chip == NULL)
 988                 return -ENODEV;
 989
 990         return 0;
 991 }
 992 EXPORT_SYMBOL_GPL(tpm_pm_resume);
 993
 994 #define TPM_GETRANDOM_RESULT_SIZE       18
 995 static struct tpm_input_header tpm_getrandom_header = {
 996         .tag = TPM_TAG_RQU_COMMAND,
 997         .length = cpu_to_be32(14),
 998         .ordinal = TPM_ORD_GET_RANDOM
 999 };
1000
1001 /**
1002  * tpm_get_random() - Get random bytes from the tpm's RNG
1003  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1004  * @out: destination buffer for the random bytes
1005  * @max: the max number of bytes to write to @out
1006  *
1007  * Returns < 0 on error and the number of bytes read on success
1008  */
1009 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1010 {
1011         struct tpm_chip *chip;
1012         struct tpm_cmd_t tpm_cmd;
1013         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1014         int err, total = 0, retries = 5;
1015         u8 *dest = out;
1016
1017         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1018                 return -EINVAL;
1019
1020         chip = tpm_chip_find_get(chip_num);
1021         if (chip == NULL)
1022                 return -ENODEV;
1023
1024         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1025                 err = tpm2_get_random(chip, out, max);
1026                 tpm_chip_put(chip);
1027                 return err;
1028         }
1029
1030         do {
1031                 tpm_cmd.header.in = tpm_getrandom_header;
1032                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1033
1034                 err = tpm_transmit_cmd(chip, &tpm_cmd,
1035                                        TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1036                                        0, "attempting get random");
1037                 if (err)
1038                         break;
1039
1040                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1041                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1042
1043                 dest += recd;
1044                 total += recd;
1045                 num_bytes -= recd;
1046         } while (retries-- && total < max);
1047
1048         tpm_chip_put(chip);
1049         return total ? total : -EIO;
1050 }
1051 EXPORT_SYMBOL_GPL(tpm_get_random);
1052
1053 /**
1054  * tpm_seal_trusted() - seal a trusted key
1055  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1056  * @options: authentication values and other options
1057  * @payload: the key data in clear and encrypted form
1058  *
1059  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1060  * are supported.
1061  */
1062 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1063                      struct trusted_key_options *options)
1064 {
1065         struct tpm_chip *chip;
1066         int rc;
1067
1068         chip = tpm_chip_find_get(chip_num);
1069         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1070                 return -ENODEV;
1071
1072         rc = tpm2_seal_trusted(chip, payload, options);
1073
1074         tpm_chip_put(chip);
1075         return rc;
1076 }
1077 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1078
1079 /**
1080  * tpm_unseal_trusted() - unseal a trusted key
1081  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1082  * @options: authentication values and other options
1083  * @payload: the key data in clear and encrypted form
1084  *
1085  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1086  * are supported.
1087  */
1088 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1089                        struct trusted_key_options *options)
1090 {
1091         struct tpm_chip *chip;
1092         int rc;
1093
1094         chip = tpm_chip_find_get(chip_num);
1095         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1096                 return -ENODEV;
1097
1098         rc = tpm2_unseal_trusted(chip, payload, options);
1099
1100         tpm_chip_put(chip);
1101         return rc;
1102 }
1103 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1104
1105 static int __init tpm_init(void)
1106 {
1107         int rc;
1108
1109         tpm_class = class_create(THIS_MODULE, "tpm");
1110         if (IS_ERR(tpm_class)) {
1111                 pr_err("couldn't create tpm class\n");
1112                 return PTR_ERR(tpm_class);
1113         }
1114
1115         rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1116         if (rc < 0) {
1117                 pr_err("tpm: failed to allocate char dev region\n");
1118                 class_destroy(tpm_class);
1119                 return rc;
1120         }
1121
1122         return 0;
1123 }
1124
1125 static void __exit tpm_exit(void)
1126 {
1127         class_destroy(tpm_class);
1128         unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1129 }
1130
1131 subsys_initcall(tpm_init);
1132 module_exit(tpm_exit);
1133
1134 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1135 MODULE_DESCRIPTION("TPM Driver");
1136 MODULE_VERSION("2.0");
1137 MODULE_LICENSE("GPL");