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->dev,
 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->dev,
 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->dev, "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->dev, "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->dev,
 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 && err != TPM_ERR_DISABLED && err != TPM_ERR_DEACTIVATED
 419             && desc)
 420                 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
 421                         desc);
 422
 423         return err;
 424 }
 425
 426 #define TPM_INTERNAL_RESULT_SIZE 200
 427 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 428 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 429
 430 static const struct tpm_input_header tpm_getcap_header = {
 431         .tag = TPM_TAG_RQU_COMMAND,
 432         .length = cpu_to_be32(22),
 433         .ordinal = TPM_ORD_GET_CAP
 434 };
 435
 436 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
 437                    const char *desc)
 438 {
 439         struct tpm_cmd_t tpm_cmd;
 440         int rc;
 441         struct tpm_chip *chip = dev_get_drvdata(dev);
 442
 443         tpm_cmd.header.in = tpm_getcap_header;
 444         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 445                 tpm_cmd.params.getcap_in.cap = subcap_id;
 446                 /*subcap field not necessary */
 447                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 448                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 449         } else {
 450                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 451                     subcap_id == TPM_CAP_FLAG_VOL)
 452                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 453                 else
 454                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 455                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 456                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 457         }
 458         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 459                               desc);
 460         if (!rc)
 461                 *cap = tpm_cmd.params.getcap_out.cap;
 462         return rc;
 463 }
 464
 465 void tpm_gen_interrupt(struct tpm_chip *chip)
 466 {
 467         struct  tpm_cmd_t tpm_cmd;
 468         ssize_t rc;
 469
 470         tpm_cmd.header.in = tpm_getcap_header;
 471         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 472         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 473         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 474
 475         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 476                               "attempting to determine the timeouts");
 477 }
 478 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 479
 480 #define TPM_ORD_STARTUP cpu_to_be32(153)
 481 #define TPM_ST_CLEAR cpu_to_be16(1)
 482 #define TPM_ST_STATE cpu_to_be16(2)
 483 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 484 static const struct tpm_input_header tpm_startup_header = {
 485         .tag = TPM_TAG_RQU_COMMAND,
 486         .length = cpu_to_be32(12),
 487         .ordinal = TPM_ORD_STARTUP
 488 };
 489
 490 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 491 {
 492         struct tpm_cmd_t start_cmd;
 493         start_cmd.header.in = tpm_startup_header;
 494
 495         start_cmd.params.startup_in.startup_type = startup_type;
 496         return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 497                                 "attempting to start the TPM");
 498 }
 499
 500 int tpm_get_timeouts(struct tpm_chip *chip)
 501 {
 502         struct tpm_cmd_t tpm_cmd;
 503         unsigned long new_timeout[4];
 504         unsigned long old_timeout[4];
 505         struct duration_t *duration_cap;
 506         ssize_t rc;
 507
 508         tpm_cmd.header.in = tpm_getcap_header;
 509         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 510         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 511         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 512         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 513                               NULL);
 514
 515         if (rc == TPM_ERR_INVALID_POSTINIT) {
 516                 /* The TPM is not started, we are the first to talk to it.
 517                    Execute a startup command. */
 518                 dev_info(&chip->dev, "Issuing TPM_STARTUP");
 519                 if (tpm_startup(chip, TPM_ST_CLEAR))
 520                         return rc;
 521
 522                 tpm_cmd.header.in = tpm_getcap_header;
 523                 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 524                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 525                 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 526                 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 527                                       0, NULL);
 528         }
 529         if (rc) {
 530                 dev_err(&chip->dev,
 531                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 532                         rc);
 533                 goto duration;
 534         }
 535
 536         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 537             be32_to_cpu(tpm_cmd.header.out.length)
 538             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 539                 return -EINVAL;
 540
 541         old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
 542         old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
 543         old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
 544         old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.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->vendor.timeout_adjusted =
 553                         chip->ops->update_timeouts(chip, new_timeout);
 554
 555         if (!chip->vendor.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->vendor.timeout_adjusted = true;
 564                 }
 565         }
 566
 567         /* Report adjusted timeouts */
 568         if (chip->vendor.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->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
 578         chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
 579         chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
 580         chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
 581
 582 duration:
 583         tpm_cmd.header.in = tpm_getcap_header;
 584         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 585         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 586         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 587
 588         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 589                               "attempting to determine the durations");
 590         if (rc)
 591                 return rc;
 592
 593         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 594             be32_to_cpu(tpm_cmd.header.out.length)
 595             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 596                 return -EINVAL;
 597
 598         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 599         chip->vendor.duration[TPM_SHORT] =
 600             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 601         chip->vendor.duration[TPM_MEDIUM] =
 602             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 603         chip->vendor.duration[TPM_LONG] =
 604             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 605
 606         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 607          * value wrong and apparently reports msecs rather than usecs. So we
 608          * fix up the resulting too-small TPM_SHORT value to make things work.
 609          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 610          */
 611         if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
 612                 chip->vendor.duration[TPM_SHORT] = HZ;
 613                 chip->vendor.duration[TPM_MEDIUM] *= 1000;
 614                 chip->vendor.duration[TPM_LONG] *= 1000;
 615                 chip->vendor.duration_adjusted = true;
 616                 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 617         }
 618         return 0;
 619 }
 620 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 621
 622 #define TPM_ORD_CONTINUE_SELFTEST 83
 623 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 624
 625 static struct tpm_input_header continue_selftest_header = {
 626         .tag = TPM_TAG_RQU_COMMAND,
 627         .length = cpu_to_be32(10),
 628         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 629 };
 630
 631 /**
 632  * tpm_continue_selftest -- run TPM's selftest
 633  * @chip: TPM chip to use
 634  *
 635  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 636  * a TPM error code.
 637  */
 638 static int tpm_continue_selftest(struct tpm_chip *chip)
 639 {
 640         int rc;
 641         struct tpm_cmd_t cmd;
 642
 643         cmd.header.in = continue_selftest_header;
 644         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
 645                               "continue selftest");
 646         return rc;
 647 }
 648
 649 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 650 #define READ_PCR_RESULT_SIZE 30
 651 static struct tpm_input_header pcrread_header = {
 652         .tag = TPM_TAG_RQU_COMMAND,
 653         .length = cpu_to_be32(14),
 654         .ordinal = TPM_ORDINAL_PCRREAD
 655 };
 656
 657 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 658 {
 659         int rc;
 660         struct tpm_cmd_t cmd;
 661
 662         cmd.header.in = pcrread_header;
 663         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 664         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
 665                               "attempting to read a pcr value");
 666
 667         if (rc == 0)
 668                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 669                        TPM_DIGEST_SIZE);
 670         return rc;
 671 }
 672
 673 /**
 674  * tpm_is_tpm2 - is the chip a TPM2 chip?
 675  * @chip_num:   tpm idx # or ANY
 676  *
 677  * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 678  * is a TPM2 chip.
 679  */
 680 int tpm_is_tpm2(u32 chip_num)
 681 {
 682         struct tpm_chip *chip;
 683         int rc;
 684
 685         chip = tpm_chip_find_get(chip_num);
 686         if (chip == NULL)
 687                 return -ENODEV;
 688
 689         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 690
 691         tpm_put_ops(chip);
 692
 693         return rc;
 694 }
 695 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 696
 697 /**
 698  * tpm_pcr_read - read a pcr value
 699  * @chip_num:   tpm idx # or ANY
 700  * @pcr_idx:    pcr idx to retrieve
 701  * @res_buf:    TPM_PCR value
 702  *              size of res_buf is 20 bytes (or NULL if you don't care)
 703  *
 704  * The TPM driver should be built-in, but for whatever reason it
 705  * isn't, protect against the chip disappearing, by incrementing
 706  * the module usage count.
 707  */
 708 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 709 {
 710         struct tpm_chip *chip;
 711         int rc;
 712
 713         chip = tpm_chip_find_get(chip_num);
 714         if (chip == NULL)
 715                 return -ENODEV;
 716         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 717                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 718         else
 719                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 720         tpm_put_ops(chip);
 721         return rc;
 722 }
 723 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 724
 725 /**
 726  * tpm_pcr_extend - extend pcr value with hash
 727  * @chip_num:   tpm idx # or AN&
 728  * @pcr_idx:    pcr idx to extend
 729  * @hash:       hash value used to extend pcr value
 730  *
 731  * The TPM driver should be built-in, but for whatever reason it
 732  * isn't, protect against the chip disappearing, by incrementing
 733  * the module usage count.
 734  */
 735 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 736 #define EXTEND_PCR_RESULT_SIZE 34
 737 static struct tpm_input_header pcrextend_header = {
 738         .tag = TPM_TAG_RQU_COMMAND,
 739         .length = cpu_to_be32(34),
 740         .ordinal = TPM_ORD_PCR_EXTEND
 741 };
 742
 743 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 744 {
 745         struct tpm_cmd_t cmd;
 746         int rc;
 747         struct tpm_chip *chip;
 748
 749         chip = tpm_chip_find_get(chip_num);
 750         if (chip == NULL)
 751                 return -ENODEV;
 752
 753         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 754                 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
 755                 tpm_put_ops(chip);
 756                 return rc;
 757         }
 758
 759         cmd.header.in = pcrextend_header;
 760         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 761         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 762         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 763                               "attempting extend a PCR value");
 764
 765         tpm_put_ops(chip);
 766         return rc;
 767 }
 768 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 769
 770 /**
 771  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 772  *                   can receive further commands
 773  * @chip: TPM chip to use
 774  *
 775  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 776  * a TPM error code.
 777  */
 778 int tpm_do_selftest(struct tpm_chip *chip)
 779 {
 780         int rc;
 781         unsigned int loops;
 782         unsigned int delay_msec = 100;
 783         unsigned long duration;
 784         struct tpm_cmd_t cmd;
 785
 786         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 787
 788         loops = jiffies_to_msecs(duration) / delay_msec;
 789
 790         rc = tpm_continue_selftest(chip);
 791         if (rc == TPM_ERR_INVALID_POSTINIT) {
 792                 chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
 793                 dev_info(&chip->dev, "TPM not ready (%d)\n", rc);
 794         }
 795         /* This may fail if there was no TPM driver during a suspend/resume
 796          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 797          */
 798         if (rc)
 799                 return rc;
 800
 801         do {
 802                 /* Attempt to read a PCR value */
 803                 cmd.header.in = pcrread_header;
 804                 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
 805                 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE, 0);
 806                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 807                  * around 300ms while the self test is ongoing, keep trying
 808                  * until the self test duration expires. */
 809                 if (rc == -ETIME) {
 810                         dev_info(
 811                             &chip->dev, HW_ERR
 812                             "TPM command timed out during continue self test");
 813                         msleep(delay_msec);
 814                         continue;
 815                 }
 816
 817                 if (rc < TPM_HEADER_SIZE)
 818                         return -EFAULT;
 819
 820                 rc = be32_to_cpu(cmd.header.out.return_code);
 821                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 822                         dev_info(&chip->dev,
 823                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 824                         /* TPM is disabled and/or deactivated; driver can
 825                          * proceed and TPM does handle commands for
 826                          * suspend/resume correctly
 827                          */
 828                         return 0;
 829                 }
 830                 if (rc != TPM_WARN_DOING_SELFTEST)
 831                         return rc;
 832                 msleep(delay_msec);
 833         } while (--loops > 0);
 834
 835         return rc;
 836 }
 837 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 838
 839 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 840 {
 841         struct tpm_chip *chip;
 842         int rc;
 843
 844         chip = tpm_chip_find_get(chip_num);
 845         if (chip == NULL)
 846                 return -ENODEV;
 847
 848         rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
 849
 850         tpm_put_ops(chip);
 851         return rc;
 852 }
 853 EXPORT_SYMBOL_GPL(tpm_send);
 854
 855 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 856                                         bool check_cancel, bool *canceled)
 857 {
 858         u8 status = chip->ops->status(chip);
 859
 860         *canceled = false;
 861         if ((status & mask) == mask)
 862                 return true;
 863         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 864                 *canceled = true;
 865                 return true;
 866         }
 867         return false;
 868 }
 869
 870 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 871                       wait_queue_head_t *queue, bool check_cancel)
 872 {
 873         unsigned long stop;
 874         long rc;
 875         u8 status;
 876         bool canceled = false;
 877
 878         /* check current status */
 879         status = chip->ops->status(chip);
 880         if ((status & mask) == mask)
 881                 return 0;
 882
 883         stop = jiffies + timeout;
 884
 885         if (chip->vendor.irq) {
 886 again:
 887                 timeout = stop - jiffies;
 888                 if ((long)timeout <= 0)
 889                         return -ETIME;
 890                 rc = wait_event_interruptible_timeout(*queue,
 891                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 892                                                &canceled),
 893                         timeout);
 894                 if (rc > 0) {
 895                         if (canceled)
 896                                 return -ECANCELED;
 897                         return 0;
 898                 }
 899                 if (rc == -ERESTARTSYS && freezing(current)) {
 900                         clear_thread_flag(TIF_SIGPENDING);
 901                         goto again;
 902                 }
 903         } else {
 904                 do {
 905                         msleep(TPM_TIMEOUT);
 906                         status = chip->ops->status(chip);
 907                         if ((status & mask) == mask)
 908                                 return 0;
 909                 } while (time_before(jiffies, stop));
 910         }
 911         return -ETIME;
 912 }
 913 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 914
 915 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 916 #define SAVESTATE_RESULT_SIZE 10
 917
 918 static struct tpm_input_header savestate_header = {
 919         .tag = TPM_TAG_RQU_COMMAND,
 920         .length = cpu_to_be32(10),
 921         .ordinal = TPM_ORD_SAVESTATE
 922 };
 923
 924 /*
 925  * We are about to suspend. Save the TPM state
 926  * so that it can be restored.
 927  */
 928 int tpm_pm_suspend(struct device *dev)
 929 {
 930         struct tpm_chip *chip = dev_get_drvdata(dev);
 931         struct tpm_cmd_t cmd;
 932         int rc, try;
 933
 934         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 935
 936         if (chip == NULL)
 937                 return -ENODEV;
 938
 939         if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
 940                 return 0;
 941
 942         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 943                 tpm2_shutdown(chip, TPM2_SU_STATE);
 944                 return 0;
 945         }
 946
 947         /* for buggy tpm, flush pcrs with extend to selected dummy */
 948         if (tpm_suspend_pcr) {
 949                 cmd.header.in = pcrextend_header;
 950                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 951                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 952                        TPM_DIGEST_SIZE);
 953                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 954                                       "extending dummy pcr before suspend");
 955         }
 956
 957         /* now do the actual savestate */
 958         for (try = 0; try < TPM_RETRY; try++) {
 959                 cmd.header.in = savestate_header;
 960                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
 961                                       NULL);
 962
 963                 /*
 964                  * If the TPM indicates that it is too busy to respond to
 965                  * this command then retry before giving up.  It can take
 966                  * several seconds for this TPM to be ready.
 967                  *
 968                  * This can happen if the TPM has already been sent the
 969                  * SaveState command before the driver has loaded.  TCG 1.2
 970                  * specification states that any communication after SaveState
 971                  * may cause the TPM to invalidate previously saved state.
 972                  */
 973                 if (rc != TPM_WARN_RETRY)
 974                         break;
 975                 msleep(TPM_TIMEOUT_RETRY);
 976         }
 977
 978         if (rc)
 979                 dev_err(&chip->dev,
 980                         "Error (%d) sending savestate before suspend\n", rc);
 981         else if (try > 0)
 982                 dev_warn(&chip->dev, "TPM savestate took %dms\n",
 983                          try * TPM_TIMEOUT_RETRY);
 984
 985         return rc;
 986 }
 987 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
 988
 989 /*
 990  * Resume from a power safe. The BIOS already restored
 991  * the TPM state.
 992  */
 993 int tpm_pm_resume(struct device *dev)
 994 {
 995         struct tpm_chip *chip = dev_get_drvdata(dev);
 996
 997         if (chip == NULL)
 998                 return -ENODEV;
 999
1000         return 0;
1001 }
1002 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1003
1004 #define TPM_GETRANDOM_RESULT_SIZE       18
1005 static struct tpm_input_header tpm_getrandom_header = {
1006         .tag = TPM_TAG_RQU_COMMAND,
1007         .length = cpu_to_be32(14),
1008         .ordinal = TPM_ORD_GET_RANDOM
1009 };
1010
1011 /**
1012  * tpm_get_random() - Get random bytes from the tpm's RNG
1013  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1014  * @out: destination buffer for the random bytes
1015  * @max: the max number of bytes to write to @out
1016  *
1017  * Returns < 0 on error and the number of bytes read on success
1018  */
1019 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1020 {
1021         struct tpm_chip *chip;
1022         struct tpm_cmd_t tpm_cmd;
1023         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1024         int err, total = 0, retries = 5;
1025         u8 *dest = out;
1026
1027         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1028                 return -EINVAL;
1029
1030         chip = tpm_chip_find_get(chip_num);
1031         if (chip == NULL)
1032                 return -ENODEV;
1033
1034         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1035                 err = tpm2_get_random(chip, out, max);
1036                 tpm_put_ops(chip);
1037                 return err;
1038         }
1039
1040         do {
1041                 tpm_cmd.header.in = tpm_getrandom_header;
1042                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1043
1044                 err = tpm_transmit_cmd(chip, &tpm_cmd,
1045                                        TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1046                                        0, "attempting get random");
1047                 if (err)
1048                         break;
1049
1050                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1051                 if (recd > num_bytes) {
1052                         total = -EFAULT;
1053                         break;
1054                 }
1055
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");