drivers/char/tpm/tpm-interface.c

   1 /*
   2  * Copyright (C) 2004 IBM Corporation
   3  * Copyright (C) 2014 Intel Corporation
   4  *
   5  * Authors:
   6  * Leendert van Doorn <leendert@watson.ibm.com>
   7  * Dave Safford <safford@watson.ibm.com>
   8  * Reiner Sailer <sailer@watson.ibm.com>
   9  * Kylene Hall <kjhall@us.ibm.com>
  10  *
  11  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  12  *
  13  * Device driver for TCG/TCPA TPM (trusted platform module).
  14  * Specifications at www.trustedcomputinggroup.org
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License as
  18  * published by the Free Software Foundation, version 2 of the
  19  * License.
  20  *
  21  * Note, the TPM chip is not interrupt driven (only polling)
  22  * and can have very long timeouts (minutes!). Hence the unusual
  23  * calls to msleep.
  24  *
  25  */
  26
  27 #include <linux/poll.h>
  28 #include <linux/slab.h>
  29 #include <linux/mutex.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/freezer.h>
  32
  33 #include "tpm.h"
  34 #include "tpm_eventlog.h"
  35
  36 #define TPM_MAX_ORDINAL 243
  37 #define TSC_MAX_ORDINAL 12
  38 #define TPM_PROTECTED_COMMAND 0x00
  39 #define TPM_CONNECTION_COMMAND 0x40
  40
  41 /*
  42  * Bug workaround - some TPM's don't flush the most
  43  * recently changed pcr on suspend, so force the flush
  44  * with an extend to the selected _unused_ non-volatile pcr.
  45  */
  46 static int tpm_suspend_pcr;
  47 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  48 MODULE_PARM_DESC(suspend_pcr,
  49                  "PCR to use for dummy writes to faciltate flush on suspend.");
  50
  51 /*
  52  * Array with one entry per ordinal defining the maximum amount
  53  * of time the chip could take to return the result.  The ordinal
  54  * designation of short, medium or long is defined in a table in
  55  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  56  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  57  * from the chip during initialization with a call to tpm_get_timeouts.
  58  */
  59 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  60         TPM_UNDEFINED,          /* 0 */
  61         TPM_UNDEFINED,
  62         TPM_UNDEFINED,
  63         TPM_UNDEFINED,
  64         TPM_UNDEFINED,
  65         TPM_UNDEFINED,          /* 5 */
  66         TPM_UNDEFINED,
  67         TPM_UNDEFINED,
  68         TPM_UNDEFINED,
  69         TPM_UNDEFINED,
  70         TPM_SHORT,              /* 10 */
  71         TPM_SHORT,
  72         TPM_MEDIUM,
  73         TPM_LONG,
  74         TPM_LONG,
  75         TPM_MEDIUM,             /* 15 */
  76         TPM_SHORT,
  77         TPM_SHORT,
  78         TPM_MEDIUM,
  79         TPM_LONG,
  80         TPM_SHORT,              /* 20 */
  81         TPM_SHORT,
  82         TPM_MEDIUM,
  83         TPM_MEDIUM,
  84         TPM_MEDIUM,
  85         TPM_SHORT,              /* 25 */
  86         TPM_SHORT,
  87         TPM_MEDIUM,
  88         TPM_SHORT,
  89         TPM_SHORT,
  90         TPM_MEDIUM,             /* 30 */
  91         TPM_LONG,
  92         TPM_MEDIUM,
  93         TPM_SHORT,
  94         TPM_SHORT,
  95         TPM_SHORT,              /* 35 */
  96         TPM_MEDIUM,
  97         TPM_MEDIUM,
  98         TPM_UNDEFINED,
  99         TPM_UNDEFINED,
 100         TPM_MEDIUM,             /* 40 */
 101         TPM_LONG,
 102         TPM_MEDIUM,
 103         TPM_SHORT,
 104         TPM_SHORT,
 105         TPM_SHORT,              /* 45 */
 106         TPM_SHORT,
 107         TPM_SHORT,
 108         TPM_SHORT,
 109         TPM_LONG,
 110         TPM_MEDIUM,             /* 50 */
 111         TPM_MEDIUM,
 112         TPM_UNDEFINED,
 113         TPM_UNDEFINED,
 114         TPM_UNDEFINED,
 115         TPM_UNDEFINED,          /* 55 */
 116         TPM_UNDEFINED,
 117         TPM_UNDEFINED,
 118         TPM_UNDEFINED,
 119         TPM_UNDEFINED,
 120         TPM_MEDIUM,             /* 60 */
 121         TPM_MEDIUM,
 122         TPM_MEDIUM,
 123         TPM_SHORT,
 124         TPM_SHORT,
 125         TPM_MEDIUM,             /* 65 */
 126         TPM_UNDEFINED,
 127         TPM_UNDEFINED,
 128         TPM_UNDEFINED,
 129         TPM_UNDEFINED,
 130         TPM_SHORT,              /* 70 */
 131         TPM_SHORT,
 132         TPM_UNDEFINED,
 133         TPM_UNDEFINED,
 134         TPM_UNDEFINED,
 135         TPM_UNDEFINED,          /* 75 */
 136         TPM_UNDEFINED,
 137         TPM_UNDEFINED,
 138         TPM_UNDEFINED,
 139         TPM_UNDEFINED,
 140         TPM_LONG,               /* 80 */
 141         TPM_UNDEFINED,
 142         TPM_MEDIUM,
 143         TPM_LONG,
 144         TPM_SHORT,
 145         TPM_UNDEFINED,          /* 85 */
 146         TPM_UNDEFINED,
 147         TPM_UNDEFINED,
 148         TPM_UNDEFINED,
 149         TPM_UNDEFINED,
 150         TPM_SHORT,              /* 90 */
 151         TPM_SHORT,
 152         TPM_SHORT,
 153         TPM_SHORT,
 154         TPM_SHORT,
 155         TPM_UNDEFINED,          /* 95 */
 156         TPM_UNDEFINED,
 157         TPM_UNDEFINED,
 158         TPM_UNDEFINED,
 159         TPM_UNDEFINED,
 160         TPM_MEDIUM,             /* 100 */
 161         TPM_SHORT,
 162         TPM_SHORT,
 163         TPM_UNDEFINED,
 164         TPM_UNDEFINED,
 165         TPM_UNDEFINED,          /* 105 */
 166         TPM_UNDEFINED,
 167         TPM_UNDEFINED,
 168         TPM_UNDEFINED,
 169         TPM_UNDEFINED,
 170         TPM_SHORT,              /* 110 */
 171         TPM_SHORT,
 172         TPM_SHORT,
 173         TPM_SHORT,
 174         TPM_SHORT,
 175         TPM_SHORT,              /* 115 */
 176         TPM_SHORT,
 177         TPM_SHORT,
 178         TPM_UNDEFINED,
 179         TPM_UNDEFINED,
 180         TPM_LONG,               /* 120 */
 181         TPM_LONG,
 182         TPM_MEDIUM,
 183         TPM_UNDEFINED,
 184         TPM_SHORT,
 185         TPM_SHORT,              /* 125 */
 186         TPM_SHORT,
 187         TPM_LONG,
 188         TPM_SHORT,
 189         TPM_SHORT,
 190         TPM_SHORT,              /* 130 */
 191         TPM_MEDIUM,
 192         TPM_UNDEFINED,
 193         TPM_SHORT,
 194         TPM_MEDIUM,
 195         TPM_UNDEFINED,          /* 135 */
 196         TPM_UNDEFINED,
 197         TPM_UNDEFINED,
 198         TPM_UNDEFINED,
 199         TPM_UNDEFINED,
 200         TPM_SHORT,              /* 140 */
 201         TPM_SHORT,
 202         TPM_UNDEFINED,
 203         TPM_UNDEFINED,
 204         TPM_UNDEFINED,
 205         TPM_UNDEFINED,          /* 145 */
 206         TPM_UNDEFINED,
 207         TPM_UNDEFINED,
 208         TPM_UNDEFINED,
 209         TPM_UNDEFINED,
 210         TPM_SHORT,              /* 150 */
 211         TPM_MEDIUM,
 212         TPM_MEDIUM,
 213         TPM_SHORT,
 214         TPM_SHORT,
 215         TPM_UNDEFINED,          /* 155 */
 216         TPM_UNDEFINED,
 217         TPM_UNDEFINED,
 218         TPM_UNDEFINED,
 219         TPM_UNDEFINED,
 220         TPM_SHORT,              /* 160 */
 221         TPM_SHORT,
 222         TPM_SHORT,
 223         TPM_SHORT,
 224         TPM_UNDEFINED,
 225         TPM_UNDEFINED,          /* 165 */
 226         TPM_UNDEFINED,
 227         TPM_UNDEFINED,
 228         TPM_UNDEFINED,
 229         TPM_UNDEFINED,
 230         TPM_LONG,               /* 170 */
 231         TPM_UNDEFINED,
 232         TPM_UNDEFINED,
 233         TPM_UNDEFINED,
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,          /* 175 */
 236         TPM_UNDEFINED,
 237         TPM_UNDEFINED,
 238         TPM_UNDEFINED,
 239         TPM_UNDEFINED,
 240         TPM_MEDIUM,             /* 180 */
 241         TPM_SHORT,
 242         TPM_MEDIUM,
 243         TPM_MEDIUM,
 244         TPM_MEDIUM,
 245         TPM_MEDIUM,             /* 185 */
 246         TPM_SHORT,
 247         TPM_UNDEFINED,
 248         TPM_UNDEFINED,
 249         TPM_UNDEFINED,
 250         TPM_UNDEFINED,          /* 190 */
 251         TPM_UNDEFINED,
 252         TPM_UNDEFINED,
 253         TPM_UNDEFINED,
 254         TPM_UNDEFINED,
 255         TPM_UNDEFINED,          /* 195 */
 256         TPM_UNDEFINED,
 257         TPM_UNDEFINED,
 258         TPM_UNDEFINED,
 259         TPM_UNDEFINED,
 260         TPM_SHORT,              /* 200 */
 261         TPM_UNDEFINED,
 262         TPM_UNDEFINED,
 263         TPM_UNDEFINED,
 264         TPM_SHORT,
 265         TPM_SHORT,              /* 205 */
 266         TPM_SHORT,
 267         TPM_SHORT,
 268         TPM_SHORT,
 269         TPM_SHORT,
 270         TPM_MEDIUM,             /* 210 */
 271         TPM_UNDEFINED,
 272         TPM_MEDIUM,
 273         TPM_MEDIUM,
 274         TPM_MEDIUM,
 275         TPM_UNDEFINED,          /* 215 */
 276         TPM_MEDIUM,
 277         TPM_UNDEFINED,
 278         TPM_UNDEFINED,
 279         TPM_SHORT,
 280         TPM_SHORT,              /* 220 */
 281         TPM_SHORT,
 282         TPM_SHORT,
 283         TPM_SHORT,
 284         TPM_SHORT,
 285         TPM_UNDEFINED,          /* 225 */
 286         TPM_UNDEFINED,
 287         TPM_UNDEFINED,
 288         TPM_UNDEFINED,
 289         TPM_UNDEFINED,
 290         TPM_SHORT,              /* 230 */
 291         TPM_LONG,
 292         TPM_MEDIUM,
 293         TPM_UNDEFINED,
 294         TPM_UNDEFINED,
 295         TPM_UNDEFINED,          /* 235 */
 296         TPM_UNDEFINED,
 297         TPM_UNDEFINED,
 298         TPM_UNDEFINED,
 299         TPM_UNDEFINED,
 300         TPM_SHORT,              /* 240 */
 301         TPM_UNDEFINED,
 302         TPM_MEDIUM,
 303 };
 304
 305 /*
 306  * Returns max number of jiffies to wait
 307  */
 308 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 309                                            u32 ordinal)
 310 {
 311         int duration_idx = TPM_UNDEFINED;
 312         int duration = 0;
 313
 314         /*
 315          * We only have a duration table for protected commands, where the upper
 316          * 16 bits are 0. For the few other ordinals the fallback will be used.
 317          */
 318         if (ordinal < TPM_MAX_ORDINAL)
 319                 duration_idx = tpm_ordinal_duration[ordinal];
 320
 321         if (duration_idx != TPM_UNDEFINED)
 322                 duration = chip->vendor.duration[duration_idx];
 323         if (duration <= 0)
 324                 return 2 * 60 * HZ;
 325         else
 326                 return duration;
 327 }
 328 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 329
 330 /*
 331  * Internal kernel interface to transmit TPM commands
 332  */
 333 ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 334                      size_t bufsiz)
 335 {
 336         ssize_t rc;
 337         u32 count, ordinal;
 338         unsigned long stop;
 339
 340         if (bufsiz > TPM_BUFSIZE)
 341                 bufsiz = TPM_BUFSIZE;
 342
 343         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 344         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 345         if (count == 0)
 346                 return -ENODATA;
 347         if (count > bufsiz) {
 348                 dev_err(chip->pdev,
 349                         "invalid count value %x %zx\n", count, bufsiz);
 350                 return -E2BIG;
 351         }
 352
 353         mutex_lock(&chip->tpm_mutex);
 354
 355         rc = chip->ops->send(chip, (u8 *) buf, count);
 356         if (rc < 0) {
 357                 dev_err(chip->pdev,
 358                         "tpm_transmit: tpm_send: error %zd\n", rc);
 359                 goto out;
 360         }
 361
 362         if (chip->vendor.irq)
 363                 goto out_recv;
 364
 365         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 366                 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
 367         else
 368                 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 369         do {
 370                 u8 status = chip->ops->status(chip);
 371                 if ((status & chip->ops->req_complete_mask) ==
 372                     chip->ops->req_complete_val)
 373                         goto out_recv;
 374
 375                 if (chip->ops->req_canceled(chip, status)) {
 376                         dev_err(chip->pdev, "Operation Canceled\n");
 377                         rc = -ECANCELED;
 378                         goto out;
 379                 }
 380
 381                 msleep(TPM_TIMEOUT);    /* CHECK */
 382                 rmb();
 383         } while (time_before(jiffies, stop));
 384
 385         chip->ops->cancel(chip);
 386         dev_err(chip->pdev, "Operation Timed out\n");
 387         rc = -ETIME;
 388         goto out;
 389
 390 out_recv:
 391         rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
 392         if (rc < 0)
 393                 dev_err(chip->pdev,
 394                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 395 out:
 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, void *cmd,
 404                          int len, const char *desc)
 405 {
 406         struct tpm_output_header *header;
 407         int err;
 408
 409         len = tpm_transmit(chip, (u8 *) cmd, len);
 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, desc);
 458         if (!rc)
 459                 *cap = tpm_cmd.params.getcap_out.cap;
 460         return rc;
 461 }
 462
 463 void tpm_gen_interrupt(struct tpm_chip *chip)
 464 {
 465         struct  tpm_cmd_t tpm_cmd;
 466         ssize_t rc;
 467
 468         tpm_cmd.header.in = tpm_getcap_header;
 469         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 470         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 471         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 472
 473         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 474                               "attempting to determine the timeouts");
 475 }
 476 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 477
 478 #define TPM_ORD_STARTUP cpu_to_be32(153)
 479 #define TPM_ST_CLEAR cpu_to_be16(1)
 480 #define TPM_ST_STATE cpu_to_be16(2)
 481 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 482 static const struct tpm_input_header tpm_startup_header = {
 483         .tag = TPM_TAG_RQU_COMMAND,
 484         .length = cpu_to_be32(12),
 485         .ordinal = TPM_ORD_STARTUP
 486 };
 487
 488 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 489 {
 490         struct tpm_cmd_t start_cmd;
 491         start_cmd.header.in = tpm_startup_header;
 492
 493         start_cmd.params.startup_in.startup_type = startup_type;
 494         return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
 495                                 "attempting to start the TPM");
 496 }
 497
 498 int tpm_get_timeouts(struct tpm_chip *chip)
 499 {
 500         struct tpm_cmd_t tpm_cmd;
 501         unsigned long new_timeout[4];
 502         unsigned long old_timeout[4];
 503         struct duration_t *duration_cap;
 504         ssize_t rc;
 505
 506         tpm_cmd.header.in = tpm_getcap_header;
 507         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 508         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 509         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 510         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
 511
 512         if (rc == TPM_ERR_INVALID_POSTINIT) {
 513                 /* The TPM is not started, we are the first to talk to it.
 514                    Execute a startup command. */
 515                 dev_info(chip->pdev, "Issuing TPM_STARTUP");
 516                 if (tpm_startup(chip, TPM_ST_CLEAR))
 517                         return rc;
 518
 519                 tpm_cmd.header.in = tpm_getcap_header;
 520                 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 521                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 522                 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 523                 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 524                                   NULL);
 525         }
 526         if (rc) {
 527                 dev_err(chip->pdev,
 528                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 529                         rc);
 530                 goto duration;
 531         }
 532
 533         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 534             be32_to_cpu(tpm_cmd.header.out.length)
 535             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 536                 return -EINVAL;
 537
 538         old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
 539         old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
 540         old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
 541         old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
 542         memcpy(new_timeout, old_timeout, sizeof(new_timeout));
 543
 544         /*
 545          * Provide ability for vendor overrides of timeout values in case
 546          * of misreporting.
 547          */
 548         if (chip->ops->update_timeouts != NULL)
 549                 chip->vendor.timeout_adjusted =
 550                         chip->ops->update_timeouts(chip, new_timeout);
 551
 552         if (!chip->vendor.timeout_adjusted) {
 553                 /* Don't overwrite default if value is 0 */
 554                 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
 555                         int i;
 556
 557                         /* timeouts in msec rather usec */
 558                         for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
 559                                 new_timeout[i] *= 1000;
 560                         chip->vendor.timeout_adjusted = true;
 561                 }
 562         }
 563
 564         /* Report adjusted timeouts */
 565         if (chip->vendor.timeout_adjusted) {
 566                 dev_info(chip->pdev,
 567                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 568                          old_timeout[0], new_timeout[0],
 569                          old_timeout[1], new_timeout[1],
 570                          old_timeout[2], new_timeout[2],
 571                          old_timeout[3], new_timeout[3]);
 572         }
 573
 574         chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
 575         chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
 576         chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
 577         chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
 578
 579 duration:
 580         tpm_cmd.header.in = tpm_getcap_header;
 581         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 582         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 583         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 584
 585         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 586                               "attempting to determine the durations");
 587         if (rc)
 588                 return rc;
 589
 590         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 591             be32_to_cpu(tpm_cmd.header.out.length)
 592             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 593                 return -EINVAL;
 594
 595         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 596         chip->vendor.duration[TPM_SHORT] =
 597             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 598         chip->vendor.duration[TPM_MEDIUM] =
 599             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 600         chip->vendor.duration[TPM_LONG] =
 601             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 602
 603         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 604          * value wrong and apparently reports msecs rather than usecs. So we
 605          * fix up the resulting too-small TPM_SHORT value to make things work.
 606          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 607          */
 608         if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
 609                 chip->vendor.duration[TPM_SHORT] = HZ;
 610                 chip->vendor.duration[TPM_MEDIUM] *= 1000;
 611                 chip->vendor.duration[TPM_LONG] *= 1000;
 612                 chip->vendor.duration_adjusted = true;
 613                 dev_info(chip->pdev, "Adjusting TPM timeout parameters.");
 614         }
 615         return 0;
 616 }
 617 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 618
 619 #define TPM_ORD_CONTINUE_SELFTEST 83
 620 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 621
 622 static struct tpm_input_header continue_selftest_header = {
 623         .tag = TPM_TAG_RQU_COMMAND,
 624         .length = cpu_to_be32(10),
 625         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 626 };
 627
 628 /**
 629  * tpm_continue_selftest -- run TPM's selftest
 630  * @chip: TPM chip to use
 631  *
 632  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 633  * a TPM error code.
 634  */
 635 static int tpm_continue_selftest(struct tpm_chip *chip)
 636 {
 637         int rc;
 638         struct tpm_cmd_t cmd;
 639
 640         cmd.header.in = continue_selftest_header;
 641         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 642                               "continue selftest");
 643         return rc;
 644 }
 645
 646 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 647 #define READ_PCR_RESULT_SIZE 30
 648 static struct tpm_input_header pcrread_header = {
 649         .tag = TPM_TAG_RQU_COMMAND,
 650         .length = cpu_to_be32(14),
 651         .ordinal = TPM_ORDINAL_PCRREAD
 652 };
 653
 654 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 655 {
 656         int rc;
 657         struct tpm_cmd_t cmd;
 658
 659         cmd.header.in = pcrread_header;
 660         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 661         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 662                               "attempting to read a pcr value");
 663
 664         if (rc == 0)
 665                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 666                        TPM_DIGEST_SIZE);
 667         return rc;
 668 }
 669
 670 /**
 671  * tpm_is_tpm2 - is the chip a TPM2 chip?
 672  * @chip_num:   tpm idx # or ANY
 673  *
 674  * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 675  * is a TPM2 chip.
 676  */
 677 int tpm_is_tpm2(u32 chip_num)
 678 {
 679         struct tpm_chip *chip;
 680         int rc;
 681
 682         chip = tpm_chip_find_get(chip_num);
 683         if (chip == NULL)
 684                 return -ENODEV;
 685
 686         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 687
 688         tpm_chip_put(chip);
 689
 690         return rc;
 691 }
 692 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 693
 694 /**
 695  * tpm_pcr_read - read a pcr value
 696  * @chip_num:   tpm idx # or ANY
 697  * @pcr_idx:    pcr idx to retrieve
 698  * @res_buf:    TPM_PCR value
 699  *              size of res_buf is 20 bytes (or NULL if you don't care)
 700  *
 701  * The TPM driver should be built-in, but for whatever reason it
 702  * isn't, protect against the chip disappearing, by incrementing
 703  * the module usage count.
 704  */
 705 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 706 {
 707         struct tpm_chip *chip;
 708         int rc;
 709
 710         chip = tpm_chip_find_get(chip_num);
 711         if (chip == NULL)
 712                 return -ENODEV;
 713         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 714                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 715         else
 716                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 717         tpm_chip_put(chip);
 718         return rc;
 719 }
 720 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 721
 722 /**
 723  * tpm_pcr_extend - extend pcr value with hash
 724  * @chip_num:   tpm idx # or AN&
 725  * @pcr_idx:    pcr idx to extend
 726  * @hash:       hash value used to extend pcr value
 727  *
 728  * The TPM driver should be built-in, but for whatever reason it
 729  * isn't, protect against the chip disappearing, by incrementing
 730  * the module usage count.
 731  */
 732 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 733 #define EXTEND_PCR_RESULT_SIZE 34
 734 static struct tpm_input_header pcrextend_header = {
 735         .tag = TPM_TAG_RQU_COMMAND,
 736         .length = cpu_to_be32(34),
 737         .ordinal = TPM_ORD_PCR_EXTEND
 738 };
 739
 740 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 741 {
 742         struct tpm_cmd_t cmd;
 743         int rc;
 744         struct tpm_chip *chip;
 745
 746         chip = tpm_chip_find_get(chip_num);
 747         if (chip == NULL)
 748                 return -ENODEV;
 749
 750         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 751                 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
 752                 tpm_chip_put(chip);
 753                 return rc;
 754         }
 755
 756         cmd.header.in = pcrextend_header;
 757         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 758         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 759         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 760                               "attempting extend a PCR value");
 761
 762         tpm_chip_put(chip);
 763         return rc;
 764 }
 765 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 766
 767 /**
 768  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 769  *                   can receive further commands
 770  * @chip: TPM chip to use
 771  *
 772  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 773  * a TPM error code.
 774  */
 775 int tpm_do_selftest(struct tpm_chip *chip)
 776 {
 777         int rc;
 778         unsigned int loops;
 779         unsigned int delay_msec = 100;
 780         unsigned long duration;
 781         struct tpm_cmd_t cmd;
 782
 783         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 784
 785         loops = jiffies_to_msecs(duration) / delay_msec;
 786
 787         rc = tpm_continue_selftest(chip);
 788         /* This may fail if there was no TPM driver during a suspend/resume
 789          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 790          */
 791         if (rc)
 792                 return rc;
 793
 794         do {
 795                 /* Attempt to read a PCR value */
 796                 cmd.header.in = pcrread_header;
 797                 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
 798                 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
 799                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 800                  * around 300ms while the self test is ongoing, keep trying
 801                  * until the self test duration expires. */
 802                 if (rc == -ETIME) {
 803                         dev_info(chip->pdev, HW_ERR "TPM command timed out during continue self test");
 804                         msleep(delay_msec);
 805                         continue;
 806                 }
 807
 808                 if (rc < TPM_HEADER_SIZE)
 809                         return -EFAULT;
 810
 811                 rc = be32_to_cpu(cmd.header.out.return_code);
 812                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 813                         dev_info(chip->pdev,
 814                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 815                         /* TPM is disabled and/or deactivated; driver can
 816                          * proceed and TPM does handle commands for
 817                          * suspend/resume correctly
 818                          */
 819                         return 0;
 820                 }
 821                 if (rc != TPM_WARN_DOING_SELFTEST)
 822                         return rc;
 823                 msleep(delay_msec);
 824         } while (--loops > 0);
 825
 826         return rc;
 827 }
 828 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 829
 830 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 831 {
 832         struct tpm_chip *chip;
 833         int rc;
 834
 835         chip = tpm_chip_find_get(chip_num);
 836         if (chip == NULL)
 837                 return -ENODEV;
 838
 839         rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
 840
 841         tpm_chip_put(chip);
 842         return rc;
 843 }
 844 EXPORT_SYMBOL_GPL(tpm_send);
 845
 846 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 847                                         bool check_cancel, bool *canceled)
 848 {
 849         u8 status = chip->ops->status(chip);
 850
 851         *canceled = false;
 852         if ((status & mask) == mask)
 853                 return true;
 854         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 855                 *canceled = true;
 856                 return true;
 857         }
 858         return false;
 859 }
 860
 861 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 862                       wait_queue_head_t *queue, bool check_cancel)
 863 {
 864         unsigned long stop;
 865         long rc;
 866         u8 status;
 867         bool canceled = false;
 868
 869         /* check current status */
 870         status = chip->ops->status(chip);
 871         if ((status & mask) == mask)
 872                 return 0;
 873
 874         stop = jiffies + timeout;
 875
 876         if (chip->vendor.irq) {
 877 again:
 878                 timeout = stop - jiffies;
 879                 if ((long)timeout <= 0)
 880                         return -ETIME;
 881                 rc = wait_event_interruptible_timeout(*queue,
 882                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 883                                                &canceled),
 884                         timeout);
 885                 if (rc > 0) {
 886                         if (canceled)
 887                                 return -ECANCELED;
 888                         return 0;
 889                 }
 890                 if (rc == -ERESTARTSYS && freezing(current)) {
 891                         clear_thread_flag(TIF_SIGPENDING);
 892                         goto again;
 893                 }
 894         } else {
 895                 do {
 896                         msleep(TPM_TIMEOUT);
 897                         status = chip->ops->status(chip);
 898                         if ((status & mask) == mask)
 899                                 return 0;
 900                 } while (time_before(jiffies, stop));
 901         }
 902         return -ETIME;
 903 }
 904 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 905
 906 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 907 #define SAVESTATE_RESULT_SIZE 10
 908
 909 static struct tpm_input_header savestate_header = {
 910         .tag = TPM_TAG_RQU_COMMAND,
 911         .length = cpu_to_be32(10),
 912         .ordinal = TPM_ORD_SAVESTATE
 913 };
 914
 915 /*
 916  * We are about to suspend. Save the TPM state
 917  * so that it can be restored.
 918  */
 919 int tpm_pm_suspend(struct device *dev)
 920 {
 921         struct tpm_chip *chip = dev_get_drvdata(dev);
 922         struct tpm_cmd_t cmd;
 923         int rc, try;
 924
 925         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 926
 927         if (chip == NULL)
 928                 return -ENODEV;
 929
 930         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 931                 tpm2_shutdown(chip, TPM2_SU_STATE);
 932                 return 0;
 933         }
 934
 935         /* for buggy tpm, flush pcrs with extend to selected dummy */
 936         if (tpm_suspend_pcr) {
 937                 cmd.header.in = pcrextend_header;
 938                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 939                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 940                        TPM_DIGEST_SIZE);
 941                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 942                                       "extending dummy pcr before suspend");
 943         }
 944
 945         /* now do the actual savestate */
 946         for (try = 0; try < TPM_RETRY; try++) {
 947                 cmd.header.in = savestate_header;
 948                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
 949
 950                 /*
 951                  * If the TPM indicates that it is too busy to respond to
 952                  * this command then retry before giving up.  It can take
 953                  * several seconds for this TPM to be ready.
 954                  *
 955                  * This can happen if the TPM has already been sent the
 956                  * SaveState command before the driver has loaded.  TCG 1.2
 957                  * specification states that any communication after SaveState
 958                  * may cause the TPM to invalidate previously saved state.
 959                  */
 960                 if (rc != TPM_WARN_RETRY)
 961                         break;
 962                 msleep(TPM_TIMEOUT_RETRY);
 963         }
 964
 965         if (rc)
 966                 dev_err(chip->pdev,
 967                         "Error (%d) sending savestate before suspend\n", rc);
 968         else if (try > 0)
 969                 dev_warn(chip->pdev, "TPM savestate took %dms\n",
 970                          try * TPM_TIMEOUT_RETRY);
 971
 972         return rc;
 973 }
 974 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
 975
 976 /*
 977  * Resume from a power safe. The BIOS already restored
 978  * the TPM state.
 979  */
 980 int tpm_pm_resume(struct device *dev)
 981 {
 982         struct tpm_chip *chip = dev_get_drvdata(dev);
 983
 984         if (chip == NULL)
 985                 return -ENODEV;
 986
 987         return 0;
 988 }
 989 EXPORT_SYMBOL_GPL(tpm_pm_resume);
 990
 991 #define TPM_GETRANDOM_RESULT_SIZE       18
 992 static struct tpm_input_header tpm_getrandom_header = {
 993         .tag = TPM_TAG_RQU_COMMAND,
 994         .length = cpu_to_be32(14),
 995         .ordinal = TPM_ORD_GET_RANDOM
 996 };
 997
 998 /**
 999  * tpm_get_random() - Get random bytes from the tpm's RNG
1000  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1001  * @out: destination buffer for the random bytes
1002  * @max: the max number of bytes to write to @out
1003  *
1004  * Returns < 0 on error and the number of bytes read on success
1005  */
1006 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1007 {
1008         struct tpm_chip *chip;
1009         struct tpm_cmd_t tpm_cmd;
1010         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1011         int err, total = 0, retries = 5;
1012         u8 *dest = out;
1013
1014         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1015                 return -EINVAL;
1016
1017         chip = tpm_chip_find_get(chip_num);
1018         if (chip == NULL)
1019                 return -ENODEV;
1020
1021         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1022                 err = tpm2_get_random(chip, out, max);
1023                 tpm_chip_put(chip);
1024                 return err;
1025         }
1026
1027         do {
1028                 tpm_cmd.header.in = tpm_getrandom_header;
1029                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1030
1031                 err = tpm_transmit_cmd(chip, &tpm_cmd,
1032                                    TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1033                                    "attempting get random");
1034                 if (err)
1035                         break;
1036
1037                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1038                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1039
1040                 dest += recd;
1041                 total += recd;
1042                 num_bytes -= recd;
1043         } while (retries-- && total < max);
1044
1045         tpm_chip_put(chip);
1046         return total ? total : -EIO;
1047 }
1048 EXPORT_SYMBOL_GPL(tpm_get_random);
1049
1050 /**
1051  * tpm_seal_trusted() - seal a trusted key
1052  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1053  * @options: authentication values and other options
1054  * @payload: the key data in clear and encrypted form
1055  *
1056  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1057  * are supported.
1058  */
1059 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1060                      struct trusted_key_options *options)
1061 {
1062         struct tpm_chip *chip;
1063         int rc;
1064
1065         chip = tpm_chip_find_get(chip_num);
1066         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1067                 return -ENODEV;
1068
1069         rc = tpm2_seal_trusted(chip, payload, options);
1070
1071         tpm_chip_put(chip);
1072         return rc;
1073 }
1074 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1075
1076 /**
1077  * tpm_unseal_trusted() - unseal a trusted key
1078  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1079  * @options: authentication values and other options
1080  * @payload: the key data in clear and encrypted form
1081  *
1082  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1083  * are supported.
1084  */
1085 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1086                        struct trusted_key_options *options)
1087 {
1088         struct tpm_chip *chip;
1089         int rc;
1090
1091         chip = tpm_chip_find_get(chip_num);
1092         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1093                 return -ENODEV;
1094
1095         rc = tpm2_unseal_trusted(chip, payload, options);
1096
1097         tpm_chip_put(chip);
1098         return rc;
1099 }
1100 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1101
1102 static int __init tpm_init(void)
1103 {
1104         int rc;
1105
1106         tpm_class = class_create(THIS_MODULE, "tpm");
1107         if (IS_ERR(tpm_class)) {
1108                 pr_err("couldn't create tpm class\n");
1109                 return PTR_ERR(tpm_class);
1110         }
1111
1112         rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1113         if (rc < 0) {
1114                 pr_err("tpm: failed to allocate char dev region\n");
1115                 class_destroy(tpm_class);
1116                 return rc;
1117         }
1118
1119         return 0;
1120 }
1121
1122 static void __exit tpm_exit(void)
1123 {
1124         class_destroy(tpm_class);
1125         unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1126 }
1127
1128 subsys_initcall(tpm_init);
1129 module_exit(tpm_exit);
1130
1131 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1132 MODULE_DESCRIPTION("TPM Driver");
1133 MODULE_VERSION("2.0");
1134 MODULE_LICENSE("GPL");