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 char *buf,
 332                      size_t bufsiz)
 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         mutex_lock(&chip->tpm_mutex);
 352
 353         rc = chip->ops->send(chip, (u8 *) buf, count);
 354         if (rc < 0) {
 355                 dev_err(chip->pdev,
 356                         "tpm_transmit: tpm_send: error %zd\n", rc);
 357                 goto out;
 358         }
 359
 360         if (chip->vendor.irq)
 361                 goto out_recv;
 362
 363         stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 364         do {
 365                 u8 status = chip->ops->status(chip);
 366                 if ((status & chip->ops->req_complete_mask) ==
 367                     chip->ops->req_complete_val)
 368                         goto out_recv;
 369
 370                 if (chip->ops->req_canceled(chip, status)) {
 371                         dev_err(chip->pdev, "Operation Canceled\n");
 372                         rc = -ECANCELED;
 373                         goto out;
 374                 }
 375
 376                 msleep(TPM_TIMEOUT);    /* CHECK */
 377                 rmb();
 378         } while (time_before(jiffies, stop));
 379
 380         chip->ops->cancel(chip);
 381         dev_err(chip->pdev, "Operation Timed out\n");
 382         rc = -ETIME;
 383         goto out;
 384
 385 out_recv:
 386         rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
 387         if (rc < 0)
 388                 dev_err(chip->pdev,
 389                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 390 out:
 391         mutex_unlock(&chip->tpm_mutex);
 392         return rc;
 393 }
 394
 395 #define TPM_DIGEST_SIZE 20
 396 #define TPM_RET_CODE_IDX 6
 397
 398 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd,
 399                          int len, const char *desc)
 400 {
 401         struct tpm_output_header *header;
 402         int err;
 403
 404         len = tpm_transmit(chip, (u8 *) cmd, len);
 405         if (len <  0)
 406                 return len;
 407         else if (len < TPM_HEADER_SIZE)
 408                 return -EFAULT;
 409
 410         header = cmd;
 411
 412         err = be32_to_cpu(header->return_code);
 413         if (err != 0 && desc)
 414                 dev_err(chip->pdev, "A TPM error (%d) occurred %s\n", err,
 415                         desc);
 416
 417         return err;
 418 }
 419
 420 #define TPM_INTERNAL_RESULT_SIZE 200
 421 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 422 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 423
 424 static const struct tpm_input_header tpm_getcap_header = {
 425         .tag = TPM_TAG_RQU_COMMAND,
 426         .length = cpu_to_be32(22),
 427         .ordinal = TPM_ORD_GET_CAP
 428 };
 429
 430 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
 431                    const char *desc)
 432 {
 433         struct tpm_cmd_t tpm_cmd;
 434         int rc;
 435         struct tpm_chip *chip = dev_get_drvdata(dev);
 436
 437         tpm_cmd.header.in = tpm_getcap_header;
 438         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 439                 tpm_cmd.params.getcap_in.cap = subcap_id;
 440                 /*subcap field not necessary */
 441                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 442                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 443         } else {
 444                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 445                     subcap_id == TPM_CAP_FLAG_VOL)
 446                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 447                 else
 448                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 449                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 450                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 451         }
 452         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
 453         if (!rc)
 454                 *cap = tpm_cmd.params.getcap_out.cap;
 455         return rc;
 456 }
 457
 458 void tpm_gen_interrupt(struct tpm_chip *chip)
 459 {
 460         struct  tpm_cmd_t tpm_cmd;
 461         ssize_t rc;
 462
 463         tpm_cmd.header.in = tpm_getcap_header;
 464         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 465         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 466         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 467
 468         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 469                               "attempting to determine the timeouts");
 470 }
 471 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 472
 473 #define TPM_ORD_STARTUP cpu_to_be32(153)
 474 #define TPM_ST_CLEAR cpu_to_be16(1)
 475 #define TPM_ST_STATE cpu_to_be16(2)
 476 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 477 static const struct tpm_input_header tpm_startup_header = {
 478         .tag = TPM_TAG_RQU_COMMAND,
 479         .length = cpu_to_be32(12),
 480         .ordinal = TPM_ORD_STARTUP
 481 };
 482
 483 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 484 {
 485         struct tpm_cmd_t start_cmd;
 486         start_cmd.header.in = tpm_startup_header;
 487         start_cmd.params.startup_in.startup_type = startup_type;
 488         return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
 489                                 "attempting to start the TPM");
 490 }
 491
 492 int tpm_get_timeouts(struct tpm_chip *chip)
 493 {
 494         struct tpm_cmd_t tpm_cmd;
 495         unsigned long new_timeout[4];
 496         unsigned long old_timeout[4];
 497         struct duration_t *duration_cap;
 498         ssize_t rc;
 499
 500         tpm_cmd.header.in = tpm_getcap_header;
 501         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 502         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 503         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 504         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
 505
 506         if (rc == TPM_ERR_INVALID_POSTINIT) {
 507                 /* The TPM is not started, we are the first to talk to it.
 508                    Execute a startup command. */
 509                 dev_info(chip->pdev, "Issuing TPM_STARTUP");
 510                 if (tpm_startup(chip, TPM_ST_CLEAR))
 511                         return rc;
 512
 513                 tpm_cmd.header.in = tpm_getcap_header;
 514                 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 515                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 516                 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 517                 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 518                                   NULL);
 519         }
 520         if (rc) {
 521                 dev_err(chip->pdev,
 522                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 523                         rc);
 524                 goto duration;
 525         }
 526
 527         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 528             be32_to_cpu(tpm_cmd.header.out.length)
 529             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 530                 return -EINVAL;
 531
 532         old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
 533         old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
 534         old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
 535         old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
 536         memcpy(new_timeout, old_timeout, sizeof(new_timeout));
 537
 538         /*
 539          * Provide ability for vendor overrides of timeout values in case
 540          * of misreporting.
 541          */
 542         if (chip->ops->update_timeouts != NULL)
 543                 chip->vendor.timeout_adjusted =
 544                         chip->ops->update_timeouts(chip, new_timeout);
 545
 546         if (!chip->vendor.timeout_adjusted) {
 547                 /* Don't overwrite default if value is 0 */
 548                 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
 549                         int i;
 550
 551                         /* timeouts in msec rather usec */
 552                         for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
 553                                 new_timeout[i] *= 1000;
 554                         chip->vendor.timeout_adjusted = true;
 555                 }
 556         }
 557
 558         /* Report adjusted timeouts */
 559         if (chip->vendor.timeout_adjusted) {
 560                 dev_info(chip->pdev,
 561                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 562                          old_timeout[0], new_timeout[0],
 563                          old_timeout[1], new_timeout[1],
 564                          old_timeout[2], new_timeout[2],
 565                          old_timeout[3], new_timeout[3]);
 566         }
 567
 568         chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
 569         chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
 570         chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
 571         chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
 572
 573 duration:
 574         tpm_cmd.header.in = tpm_getcap_header;
 575         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 576         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 577         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 578
 579         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 580                               "attempting to determine the durations");
 581         if (rc)
 582                 return rc;
 583
 584         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 585             be32_to_cpu(tpm_cmd.header.out.length)
 586             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 587                 return -EINVAL;
 588
 589         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 590         chip->vendor.duration[TPM_SHORT] =
 591             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 592         chip->vendor.duration[TPM_MEDIUM] =
 593             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 594         chip->vendor.duration[TPM_LONG] =
 595             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 596
 597         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 598          * value wrong and apparently reports msecs rather than usecs. So we
 599          * fix up the resulting too-small TPM_SHORT value to make things work.
 600          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 601          */
 602         if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
 603                 chip->vendor.duration[TPM_SHORT] = HZ;
 604                 chip->vendor.duration[TPM_MEDIUM] *= 1000;
 605                 chip->vendor.duration[TPM_LONG] *= 1000;
 606                 chip->vendor.duration_adjusted = true;
 607                 dev_info(chip->pdev, "Adjusting TPM timeout parameters.");
 608         }
 609         return 0;
 610 }
 611 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 612
 613 #define TPM_ORD_CONTINUE_SELFTEST 83
 614 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 615
 616 static struct tpm_input_header continue_selftest_header = {
 617         .tag = TPM_TAG_RQU_COMMAND,
 618         .length = cpu_to_be32(10),
 619         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 620 };
 621
 622 /**
 623  * tpm_continue_selftest -- run TPM's selftest
 624  * @chip: TPM chip to use
 625  *
 626  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 627  * a TPM error code.
 628  */
 629 static int tpm_continue_selftest(struct tpm_chip *chip)
 630 {
 631         int rc;
 632         struct tpm_cmd_t cmd;
 633
 634         cmd.header.in = continue_selftest_header;
 635         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 636                               "continue selftest");
 637         return rc;
 638 }
 639
 640 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 641 #define READ_PCR_RESULT_SIZE 30
 642 static struct tpm_input_header pcrread_header = {
 643         .tag = TPM_TAG_RQU_COMMAND,
 644         .length = cpu_to_be32(14),
 645         .ordinal = TPM_ORDINAL_PCRREAD
 646 };
 647
 648 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 649 {
 650         int rc;
 651         struct tpm_cmd_t cmd;
 652
 653         cmd.header.in = pcrread_header;
 654         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 655         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 656                               "attempting to read a pcr value");
 657
 658         if (rc == 0)
 659                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 660                        TPM_DIGEST_SIZE);
 661         return rc;
 662 }
 663
 664 /**
 665  * tpm_pcr_read - read a pcr value
 666  * @chip_num:   tpm idx # or ANY
 667  * @pcr_idx:    pcr idx to retrieve
 668  * @res_buf:    TPM_PCR value
 669  *              size of res_buf is 20 bytes (or NULL if you don't care)
 670  *
 671  * The TPM driver should be built-in, but for whatever reason it
 672  * isn't, protect against the chip disappearing, by incrementing
 673  * the module usage count.
 674  */
 675 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 676 {
 677         struct tpm_chip *chip;
 678         int rc;
 679
 680         chip = tpm_chip_find_get(chip_num);
 681         if (chip == NULL)
 682                 return -ENODEV;
 683         rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 684         tpm_chip_put(chip);
 685         return rc;
 686 }
 687 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 688
 689 /**
 690  * tpm_pcr_extend - extend pcr value with hash
 691  * @chip_num:   tpm idx # or AN&
 692  * @pcr_idx:    pcr idx to extend
 693  * @hash:       hash value used to extend pcr value
 694  *
 695  * The TPM driver should be built-in, but for whatever reason it
 696  * isn't, protect against the chip disappearing, by incrementing
 697  * the module usage count.
 698  */
 699 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 700 #define EXTEND_PCR_RESULT_SIZE 34
 701 static struct tpm_input_header pcrextend_header = {
 702         .tag = TPM_TAG_RQU_COMMAND,
 703         .length = cpu_to_be32(34),
 704         .ordinal = TPM_ORD_PCR_EXTEND
 705 };
 706
 707 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 708 {
 709         struct tpm_cmd_t cmd;
 710         int rc;
 711         struct tpm_chip *chip;
 712
 713         chip = tpm_chip_find_get(chip_num);
 714         if (chip == NULL)
 715                 return -ENODEV;
 716
 717         cmd.header.in = pcrextend_header;
 718         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 719         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 720         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 721                               "attempting extend a PCR value");
 722
 723         tpm_chip_put(chip);
 724         return rc;
 725 }
 726 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 727
 728 /**
 729  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 730  *                   can receive further commands
 731  * @chip: TPM chip to use
 732  *
 733  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 734  * a TPM error code.
 735  */
 736 int tpm_do_selftest(struct tpm_chip *chip)
 737 {
 738         int rc;
 739         unsigned int loops;
 740         unsigned int delay_msec = 100;
 741         unsigned long duration;
 742         struct tpm_cmd_t cmd;
 743
 744         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 745
 746         loops = jiffies_to_msecs(duration) / delay_msec;
 747
 748         rc = tpm_continue_selftest(chip);
 749         /* This may fail if there was no TPM driver during a suspend/resume
 750          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 751          */
 752         if (rc)
 753                 return rc;
 754
 755         do {
 756                 /* Attempt to read a PCR value */
 757                 cmd.header.in = pcrread_header;
 758                 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
 759                 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
 760                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 761                  * around 300ms while the self test is ongoing, keep trying
 762                  * until the self test duration expires. */
 763                 if (rc == -ETIME) {
 764                         dev_info(chip->pdev, HW_ERR "TPM command timed out during continue self test");
 765                         msleep(delay_msec);
 766                         continue;
 767                 }
 768
 769                 if (rc < TPM_HEADER_SIZE)
 770                         return -EFAULT;
 771
 772                 rc = be32_to_cpu(cmd.header.out.return_code);
 773                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 774                         dev_info(chip->pdev,
 775                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 776                         /* TPM is disabled and/or deactivated; driver can
 777                          * proceed and TPM does handle commands for
 778                          * suspend/resume correctly
 779                          */
 780                         return 0;
 781                 }
 782                 if (rc != TPM_WARN_DOING_SELFTEST)
 783                         return rc;
 784                 msleep(delay_msec);
 785         } while (--loops > 0);
 786
 787         return rc;
 788 }
 789 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 790
 791 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 792 {
 793         struct tpm_chip *chip;
 794         int rc;
 795
 796         chip = tpm_chip_find_get(chip_num);
 797         if (chip == NULL)
 798                 return -ENODEV;
 799
 800         rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
 801
 802         tpm_chip_put(chip);
 803         return rc;
 804 }
 805 EXPORT_SYMBOL_GPL(tpm_send);
 806
 807 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 808                                         bool check_cancel, bool *canceled)
 809 {
 810         u8 status = chip->ops->status(chip);
 811
 812         *canceled = false;
 813         if ((status & mask) == mask)
 814                 return true;
 815         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 816                 *canceled = true;
 817                 return true;
 818         }
 819         return false;
 820 }
 821
 822 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 823                       wait_queue_head_t *queue, bool check_cancel)
 824 {
 825         unsigned long stop;
 826         long rc;
 827         u8 status;
 828         bool canceled = false;
 829
 830         /* check current status */
 831         status = chip->ops->status(chip);
 832         if ((status & mask) == mask)
 833                 return 0;
 834
 835         stop = jiffies + timeout;
 836
 837         if (chip->vendor.irq) {
 838 again:
 839                 timeout = stop - jiffies;
 840                 if ((long)timeout <= 0)
 841                         return -ETIME;
 842                 rc = wait_event_interruptible_timeout(*queue,
 843                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 844                                                &canceled),
 845                         timeout);
 846                 if (rc > 0) {
 847                         if (canceled)
 848                                 return -ECANCELED;
 849                         return 0;
 850                 }
 851                 if (rc == -ERESTARTSYS && freezing(current)) {
 852                         clear_thread_flag(TIF_SIGPENDING);
 853                         goto again;
 854                 }
 855         } else {
 856                 do {
 857                         msleep(TPM_TIMEOUT);
 858                         status = chip->ops->status(chip);
 859                         if ((status & mask) == mask)
 860                                 return 0;
 861                 } while (time_before(jiffies, stop));
 862         }
 863         return -ETIME;
 864 }
 865 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 866
 867 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 868 #define SAVESTATE_RESULT_SIZE 10
 869
 870 static struct tpm_input_header savestate_header = {
 871         .tag = TPM_TAG_RQU_COMMAND,
 872         .length = cpu_to_be32(10),
 873         .ordinal = TPM_ORD_SAVESTATE
 874 };
 875
 876 /*
 877  * We are about to suspend. Save the TPM state
 878  * so that it can be restored.
 879  */
 880 int tpm_pm_suspend(struct device *dev)
 881 {
 882         struct tpm_chip *chip = dev_get_drvdata(dev);
 883         struct tpm_cmd_t cmd;
 884         int rc, try;
 885
 886         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 887
 888         if (chip == NULL)
 889                 return -ENODEV;
 890
 891         /* for buggy tpm, flush pcrs with extend to selected dummy */
 892         if (tpm_suspend_pcr) {
 893                 cmd.header.in = pcrextend_header;
 894                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 895                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 896                        TPM_DIGEST_SIZE);
 897                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 898                                       "extending dummy pcr before suspend");
 899         }
 900
 901         /* now do the actual savestate */
 902         for (try = 0; try < TPM_RETRY; try++) {
 903                 cmd.header.in = savestate_header;
 904                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
 905
 906                 /*
 907                  * If the TPM indicates that it is too busy to respond to
 908                  * this command then retry before giving up.  It can take
 909                  * several seconds for this TPM to be ready.
 910                  *
 911                  * This can happen if the TPM has already been sent the
 912                  * SaveState command before the driver has loaded.  TCG 1.2
 913                  * specification states that any communication after SaveState
 914                  * may cause the TPM to invalidate previously saved state.
 915                  */
 916                 if (rc != TPM_WARN_RETRY)
 917                         break;
 918                 msleep(TPM_TIMEOUT_RETRY);
 919         }
 920
 921         if (rc)
 922                 dev_err(chip->pdev,
 923                         "Error (%d) sending savestate before suspend\n", rc);
 924         else if (try > 0)
 925                 dev_warn(chip->pdev, "TPM savestate took %dms\n",
 926                          try * TPM_TIMEOUT_RETRY);
 927
 928         return rc;
 929 }
 930 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
 931
 932 /*
 933  * Resume from a power safe. The BIOS already restored
 934  * the TPM state.
 935  */
 936 int tpm_pm_resume(struct device *dev)
 937 {
 938         struct tpm_chip *chip = dev_get_drvdata(dev);
 939
 940         if (chip == NULL)
 941                 return -ENODEV;
 942
 943         return 0;
 944 }
 945 EXPORT_SYMBOL_GPL(tpm_pm_resume);
 946
 947 #define TPM_GETRANDOM_RESULT_SIZE       18
 948 static struct tpm_input_header tpm_getrandom_header = {
 949         .tag = TPM_TAG_RQU_COMMAND,
 950         .length = cpu_to_be32(14),
 951         .ordinal = TPM_ORD_GET_RANDOM
 952 };
 953
 954 /**
 955  * tpm_get_random() - Get random bytes from the tpm's RNG
 956  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
 957  * @out: destination buffer for the random bytes
 958  * @max: the max number of bytes to write to @out
 959  *
 960  * Returns < 0 on error and the number of bytes read on success
 961  */
 962 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
 963 {
 964         struct tpm_chip *chip;
 965         struct tpm_cmd_t tpm_cmd;
 966         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
 967         int err, total = 0, retries = 5;
 968         u8 *dest = out;
 969
 970         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
 971                 return -EINVAL;
 972
 973         chip = tpm_chip_find_get(chip_num);
 974         if (chip == NULL)
 975                 return -ENODEV;
 976
 977         do {
 978                 tpm_cmd.header.in = tpm_getrandom_header;
 979                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
 980
 981                 err = tpm_transmit_cmd(chip, &tpm_cmd,
 982                                    TPM_GETRANDOM_RESULT_SIZE + num_bytes,
 983                                    "attempting get random");
 984                 if (err)
 985                         break;
 986
 987                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
 988                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
 989
 990                 dest += recd;
 991                 total += recd;
 992                 num_bytes -= recd;
 993         } while (retries-- && total < max);
 994
 995         tpm_chip_put(chip);
 996         return total ? total : -EIO;
 997 }
 998 EXPORT_SYMBOL_GPL(tpm_get_random);
 999
1000 static int __init tpm_init(void)
1001 {
1002         int rc;
1003
1004         tpm_class = class_create(THIS_MODULE, "tpm");
1005         if (IS_ERR(tpm_class)) {
1006                 pr_err("couldn't create tpm class\n");
1007                 return PTR_ERR(tpm_class);
1008         }
1009
1010         rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1011         if (rc < 0) {
1012                 pr_err("tpm: failed to allocate char dev region\n");
1013                 class_destroy(tpm_class);
1014                 return rc;
1015         }
1016
1017         return 0;
1018 }
1019
1020 static void __exit tpm_exit(void)
1021 {
1022         class_destroy(tpm_class);
1023         unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1024 }
1025
1026 subsys_initcall(tpm_init);
1027 module_exit(tpm_exit);
1028
1029 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1030 MODULE_DESCRIPTION("TPM Driver");
1031 MODULE_VERSION("2.0");
1032 MODULE_LICENSE("GPL");