drivers/char/tpm/tpm-interface.c

   1 /*
   2  * Copyright (C) 2004 IBM Corporation
   3  * Copyright (C) 2014 Intel Corporation
   4  *
   5  * Authors:
   6  * Leendert van Doorn <leendert@watson.ibm.com>
   7  * Dave Safford <safford@watson.ibm.com>
   8  * Reiner Sailer <sailer@watson.ibm.com>
   9  * Kylene Hall <kjhall@us.ibm.com>
  10  *
  11  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  12  *
  13  * Device driver for TCG/TCPA TPM (trusted platform module).
  14  * Specifications at www.trustedcomputinggroup.org
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License as
  18  * published by the Free Software Foundation, version 2 of the
  19  * License.
  20  *
  21  * Note, the TPM chip is not interrupt driven (only polling)
  22  * and can have very long timeouts (minutes!). Hence the unusual
  23  * calls to msleep.
  24  *
  25  */
  26
  27 #include <linux/poll.h>
  28 #include <linux/slab.h>
  29 #include <linux/mutex.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/freezer.h>
  32 #include <linux/pm_runtime.h>
  33
  34 #include "tpm.h"
  35 #include "tpm_eventlog.h"
  36
  37 #define TPM_MAX_ORDINAL 243
  38 #define TSC_MAX_ORDINAL 12
  39 #define TPM_PROTECTED_COMMAND 0x00
  40 #define TPM_CONNECTION_COMMAND 0x40
  41
  42 /*
  43  * Bug workaround - some TPM's don't flush the most
  44  * recently changed pcr on suspend, so force the flush
  45  * with an extend to the selected _unused_ non-volatile pcr.
  46  */
  47 static int tpm_suspend_pcr;
  48 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  49 MODULE_PARM_DESC(suspend_pcr,
  50                  "PCR to use for dummy writes to faciltate flush on suspend.");
  51
  52 /*
  53  * Array with one entry per ordinal defining the maximum amount
  54  * of time the chip could take to return the result.  The ordinal
  55  * designation of short, medium or long is defined in a table in
  56  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  57  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  58  * from the chip during initialization with a call to tpm_get_timeouts.
  59  */
  60 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  61         TPM_UNDEFINED,          /* 0 */
  62         TPM_UNDEFINED,
  63         TPM_UNDEFINED,
  64         TPM_UNDEFINED,
  65         TPM_UNDEFINED,
  66         TPM_UNDEFINED,          /* 5 */
  67         TPM_UNDEFINED,
  68         TPM_UNDEFINED,
  69         TPM_UNDEFINED,
  70         TPM_UNDEFINED,
  71         TPM_SHORT,              /* 10 */
  72         TPM_SHORT,
  73         TPM_MEDIUM,
  74         TPM_LONG,
  75         TPM_LONG,
  76         TPM_MEDIUM,             /* 15 */
  77         TPM_SHORT,
  78         TPM_SHORT,
  79         TPM_MEDIUM,
  80         TPM_LONG,
  81         TPM_SHORT,              /* 20 */
  82         TPM_SHORT,
  83         TPM_MEDIUM,
  84         TPM_MEDIUM,
  85         TPM_MEDIUM,
  86         TPM_SHORT,              /* 25 */
  87         TPM_SHORT,
  88         TPM_MEDIUM,
  89         TPM_SHORT,
  90         TPM_SHORT,
  91         TPM_MEDIUM,             /* 30 */
  92         TPM_LONG,
  93         TPM_MEDIUM,
  94         TPM_SHORT,
  95         TPM_SHORT,
  96         TPM_SHORT,              /* 35 */
  97         TPM_MEDIUM,
  98         TPM_MEDIUM,
  99         TPM_UNDEFINED,
 100         TPM_UNDEFINED,
 101         TPM_MEDIUM,             /* 40 */
 102         TPM_LONG,
 103         TPM_MEDIUM,
 104         TPM_SHORT,
 105         TPM_SHORT,
 106         TPM_SHORT,              /* 45 */
 107         TPM_SHORT,
 108         TPM_SHORT,
 109         TPM_SHORT,
 110         TPM_LONG,
 111         TPM_MEDIUM,             /* 50 */
 112         TPM_MEDIUM,
 113         TPM_UNDEFINED,
 114         TPM_UNDEFINED,
 115         TPM_UNDEFINED,
 116         TPM_UNDEFINED,          /* 55 */
 117         TPM_UNDEFINED,
 118         TPM_UNDEFINED,
 119         TPM_UNDEFINED,
 120         TPM_UNDEFINED,
 121         TPM_MEDIUM,             /* 60 */
 122         TPM_MEDIUM,
 123         TPM_MEDIUM,
 124         TPM_SHORT,
 125         TPM_SHORT,
 126         TPM_MEDIUM,             /* 65 */
 127         TPM_UNDEFINED,
 128         TPM_UNDEFINED,
 129         TPM_UNDEFINED,
 130         TPM_UNDEFINED,
 131         TPM_SHORT,              /* 70 */
 132         TPM_SHORT,
 133         TPM_UNDEFINED,
 134         TPM_UNDEFINED,
 135         TPM_UNDEFINED,
 136         TPM_UNDEFINED,          /* 75 */
 137         TPM_UNDEFINED,
 138         TPM_UNDEFINED,
 139         TPM_UNDEFINED,
 140         TPM_UNDEFINED,
 141         TPM_LONG,               /* 80 */
 142         TPM_UNDEFINED,
 143         TPM_MEDIUM,
 144         TPM_LONG,
 145         TPM_SHORT,
 146         TPM_UNDEFINED,          /* 85 */
 147         TPM_UNDEFINED,
 148         TPM_UNDEFINED,
 149         TPM_UNDEFINED,
 150         TPM_UNDEFINED,
 151         TPM_SHORT,              /* 90 */
 152         TPM_SHORT,
 153         TPM_SHORT,
 154         TPM_SHORT,
 155         TPM_SHORT,
 156         TPM_UNDEFINED,          /* 95 */
 157         TPM_UNDEFINED,
 158         TPM_UNDEFINED,
 159         TPM_UNDEFINED,
 160         TPM_UNDEFINED,
 161         TPM_MEDIUM,             /* 100 */
 162         TPM_SHORT,
 163         TPM_SHORT,
 164         TPM_UNDEFINED,
 165         TPM_UNDEFINED,
 166         TPM_UNDEFINED,          /* 105 */
 167         TPM_UNDEFINED,
 168         TPM_UNDEFINED,
 169         TPM_UNDEFINED,
 170         TPM_UNDEFINED,
 171         TPM_SHORT,              /* 110 */
 172         TPM_SHORT,
 173         TPM_SHORT,
 174         TPM_SHORT,
 175         TPM_SHORT,
 176         TPM_SHORT,              /* 115 */
 177         TPM_SHORT,
 178         TPM_SHORT,
 179         TPM_UNDEFINED,
 180         TPM_UNDEFINED,
 181         TPM_LONG,               /* 120 */
 182         TPM_LONG,
 183         TPM_MEDIUM,
 184         TPM_UNDEFINED,
 185         TPM_SHORT,
 186         TPM_SHORT,              /* 125 */
 187         TPM_SHORT,
 188         TPM_LONG,
 189         TPM_SHORT,
 190         TPM_SHORT,
 191         TPM_SHORT,              /* 130 */
 192         TPM_MEDIUM,
 193         TPM_UNDEFINED,
 194         TPM_SHORT,
 195         TPM_MEDIUM,
 196         TPM_UNDEFINED,          /* 135 */
 197         TPM_UNDEFINED,
 198         TPM_UNDEFINED,
 199         TPM_UNDEFINED,
 200         TPM_UNDEFINED,
 201         TPM_SHORT,              /* 140 */
 202         TPM_SHORT,
 203         TPM_UNDEFINED,
 204         TPM_UNDEFINED,
 205         TPM_UNDEFINED,
 206         TPM_UNDEFINED,          /* 145 */
 207         TPM_UNDEFINED,
 208         TPM_UNDEFINED,
 209         TPM_UNDEFINED,
 210         TPM_UNDEFINED,
 211         TPM_SHORT,              /* 150 */
 212         TPM_MEDIUM,
 213         TPM_MEDIUM,
 214         TPM_SHORT,
 215         TPM_SHORT,
 216         TPM_UNDEFINED,          /* 155 */
 217         TPM_UNDEFINED,
 218         TPM_UNDEFINED,
 219         TPM_UNDEFINED,
 220         TPM_UNDEFINED,
 221         TPM_SHORT,              /* 160 */
 222         TPM_SHORT,
 223         TPM_SHORT,
 224         TPM_SHORT,
 225         TPM_UNDEFINED,
 226         TPM_UNDEFINED,          /* 165 */
 227         TPM_UNDEFINED,
 228         TPM_UNDEFINED,
 229         TPM_UNDEFINED,
 230         TPM_UNDEFINED,
 231         TPM_LONG,               /* 170 */
 232         TPM_UNDEFINED,
 233         TPM_UNDEFINED,
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,
 236         TPM_UNDEFINED,          /* 175 */
 237         TPM_UNDEFINED,
 238         TPM_UNDEFINED,
 239         TPM_UNDEFINED,
 240         TPM_UNDEFINED,
 241         TPM_MEDIUM,             /* 180 */
 242         TPM_SHORT,
 243         TPM_MEDIUM,
 244         TPM_MEDIUM,
 245         TPM_MEDIUM,
 246         TPM_MEDIUM,             /* 185 */
 247         TPM_SHORT,
 248         TPM_UNDEFINED,
 249         TPM_UNDEFINED,
 250         TPM_UNDEFINED,
 251         TPM_UNDEFINED,          /* 190 */
 252         TPM_UNDEFINED,
 253         TPM_UNDEFINED,
 254         TPM_UNDEFINED,
 255         TPM_UNDEFINED,
 256         TPM_UNDEFINED,          /* 195 */
 257         TPM_UNDEFINED,
 258         TPM_UNDEFINED,
 259         TPM_UNDEFINED,
 260         TPM_UNDEFINED,
 261         TPM_SHORT,              /* 200 */
 262         TPM_UNDEFINED,
 263         TPM_UNDEFINED,
 264         TPM_UNDEFINED,
 265         TPM_SHORT,
 266         TPM_SHORT,              /* 205 */
 267         TPM_SHORT,
 268         TPM_SHORT,
 269         TPM_SHORT,
 270         TPM_SHORT,
 271         TPM_MEDIUM,             /* 210 */
 272         TPM_UNDEFINED,
 273         TPM_MEDIUM,
 274         TPM_MEDIUM,
 275         TPM_MEDIUM,
 276         TPM_UNDEFINED,          /* 215 */
 277         TPM_MEDIUM,
 278         TPM_UNDEFINED,
 279         TPM_UNDEFINED,
 280         TPM_SHORT,
 281         TPM_SHORT,              /* 220 */
 282         TPM_SHORT,
 283         TPM_SHORT,
 284         TPM_SHORT,
 285         TPM_SHORT,
 286         TPM_UNDEFINED,          /* 225 */
 287         TPM_UNDEFINED,
 288         TPM_UNDEFINED,
 289         TPM_UNDEFINED,
 290         TPM_UNDEFINED,
 291         TPM_SHORT,              /* 230 */
 292         TPM_LONG,
 293         TPM_MEDIUM,
 294         TPM_UNDEFINED,
 295         TPM_UNDEFINED,
 296         TPM_UNDEFINED,          /* 235 */
 297         TPM_UNDEFINED,
 298         TPM_UNDEFINED,
 299         TPM_UNDEFINED,
 300         TPM_UNDEFINED,
 301         TPM_SHORT,              /* 240 */
 302         TPM_UNDEFINED,
 303         TPM_MEDIUM,
 304 };
 305
 306 /*
 307  * Returns max number of jiffies to wait
 308  */
 309 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 310                                            u32 ordinal)
 311 {
 312         int duration_idx = TPM_UNDEFINED;
 313         int duration = 0;
 314
 315         /*
 316          * We only have a duration table for protected commands, where the upper
 317          * 16 bits are 0. For the few other ordinals the fallback will be used.
 318          */
 319         if (ordinal < TPM_MAX_ORDINAL)
 320                 duration_idx = tpm_ordinal_duration[ordinal];
 321
 322         if (duration_idx != TPM_UNDEFINED)
 323                 duration = chip->duration[duration_idx];
 324         if (duration <= 0)
 325                 return 2 * 60 * HZ;
 326         else
 327                 return duration;
 328 }
 329 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 330
 331 /**
 332  * tmp_transmit - Internal kernel interface to transmit TPM commands.
 333  *
 334  * @chip: TPM chip to use
 335  * @buf: TPM command buffer
 336  * @bufsiz: length of the TPM command buffer
 337  * @flags: tpm transmit flags - bitmap
 338  *
 339  * Return:
 340  *     0 when the operation is successful.
 341  *     A negative number for system errors (errno).
 342  */
 343 ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
 344                      unsigned int flags)
 345 {
 346         ssize_t rc;
 347         u32 count, ordinal;
 348         unsigned long stop;
 349
 350         if (bufsiz < TPM_HEADER_SIZE)
 351                 return -EINVAL;
 352
 353         if (bufsiz > TPM_BUFSIZE)
 354                 bufsiz = TPM_BUFSIZE;
 355
 356         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 357         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 358         if (count == 0)
 359                 return -ENODATA;
 360         if (count > bufsiz) {
 361                 dev_err(&chip->dev,
 362                         "invalid count value %x %zx\n", count, bufsiz);
 363                 return -E2BIG;
 364         }
 365
 366         if (!(flags & TPM_TRANSMIT_UNLOCKED))
 367                 mutex_lock(&chip->tpm_mutex);
 368
 369         if (chip->dev.parent)
 370                 pm_runtime_get_sync(chip->dev.parent);
 371
 372         rc = chip->ops->send(chip, (u8 *) buf, count);
 373         if (rc < 0) {
 374                 dev_err(&chip->dev,
 375                         "tpm_transmit: tpm_send: error %zd\n", rc);
 376                 goto out;
 377         }
 378
 379         if (chip->flags & TPM_CHIP_FLAG_IRQ)
 380                 goto out_recv;
 381
 382         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 383                 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
 384         else
 385                 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 386         do {
 387                 u8 status = chip->ops->status(chip);
 388                 if ((status & chip->ops->req_complete_mask) ==
 389                     chip->ops->req_complete_val)
 390                         goto out_recv;
 391
 392                 if (chip->ops->req_canceled(chip, status)) {
 393                         dev_err(&chip->dev, "Operation Canceled\n");
 394                         rc = -ECANCELED;
 395                         goto out;
 396                 }
 397
 398                 msleep(TPM_TIMEOUT);    /* CHECK */
 399                 rmb();
 400         } while (time_before(jiffies, stop));
 401
 402         chip->ops->cancel(chip);
 403         dev_err(&chip->dev, "Operation Timed out\n");
 404         rc = -ETIME;
 405         goto out;
 406
 407 out_recv:
 408         rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
 409         if (rc < 0)
 410                 dev_err(&chip->dev,
 411                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 412 out:
 413         if (chip->dev.parent)
 414                 pm_runtime_put_sync(chip->dev.parent);
 415
 416         if (!(flags & TPM_TRANSMIT_UNLOCKED))
 417                 mutex_unlock(&chip->tpm_mutex);
 418         return rc;
 419 }
 420
 421 /**
 422  * tmp_transmit_cmd - send a tpm command to the device
 423  *    The function extracts tpm out header return code
 424  *
 425  * @chip: TPM chip to use
 426  * @cmd: TPM command buffer
 427  * @len: length of the TPM command
 428  * @flags: tpm transmit flags - bitmap
 429  * @desc: command description used in the error message
 430  *
 431  * Return:
 432  *     0 when the operation is successful.
 433  *     A negative number for system errors (errno).
 434  *     A positive number for a TPM error.
 435  */
 436 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,
 437                          int len, unsigned int flags, const char *desc)
 438 {
 439         const struct tpm_output_header *header;
 440         int err;
 441
 442         len = tpm_transmit(chip, (const u8 *)cmd, len, flags);
 443         if (len <  0)
 444                 return len;
 445         else if (len < TPM_HEADER_SIZE)
 446                 return -EFAULT;
 447
 448         header = cmd;
 449
 450         err = be32_to_cpu(header->return_code);
 451         if (err != 0 && desc)
 452                 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
 453                         desc);
 454
 455         return err;
 456 }
 457
 458 #define TPM_DIGEST_SIZE 20
 459 #define TPM_RET_CODE_IDX 6
 460 #define TPM_INTERNAL_RESULT_SIZE 200
 461 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 462 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 463
 464 static const struct tpm_input_header tpm_getcap_header = {
 465         .tag = TPM_TAG_RQU_COMMAND,
 466         .length = cpu_to_be32(22),
 467         .ordinal = TPM_ORD_GET_CAP
 468 };
 469
 470 ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
 471                    const char *desc)
 472 {
 473         struct tpm_cmd_t tpm_cmd;
 474         int rc;
 475
 476         tpm_cmd.header.in = tpm_getcap_header;
 477         if (subcap_id == TPM_CAP_VERSION_1_1 ||
 478             subcap_id == TPM_CAP_VERSION_1_2) {
 479                 tpm_cmd.params.getcap_in.cap = cpu_to_be32(subcap_id);
 480                 /*subcap field not necessary */
 481                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 482                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 483         } else {
 484                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 485                     subcap_id == TPM_CAP_FLAG_VOL)
 486                         tpm_cmd.params.getcap_in.cap =
 487                                 cpu_to_be32(TPM_CAP_FLAG);
 488                 else
 489                         tpm_cmd.params.getcap_in.cap =
 490                                 cpu_to_be32(TPM_CAP_PROP);
 491                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 492                 tpm_cmd.params.getcap_in.subcap = cpu_to_be32(subcap_id);
 493         }
 494         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 495                               desc);
 496         if (!rc)
 497                 *cap = tpm_cmd.params.getcap_out.cap;
 498         return rc;
 499 }
 500 EXPORT_SYMBOL_GPL(tpm_getcap);
 501
 502 #define TPM_ORD_STARTUP cpu_to_be32(153)
 503 #define TPM_ST_CLEAR cpu_to_be16(1)
 504 #define TPM_ST_STATE cpu_to_be16(2)
 505 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 506 static const struct tpm_input_header tpm_startup_header = {
 507         .tag = TPM_TAG_RQU_COMMAND,
 508         .length = cpu_to_be32(12),
 509         .ordinal = TPM_ORD_STARTUP
 510 };
 511
 512 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 513 {
 514         struct tpm_cmd_t start_cmd;
 515         start_cmd.header.in = tpm_startup_header;
 516
 517         start_cmd.params.startup_in.startup_type = startup_type;
 518         return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 519                                 "attempting to start the TPM");
 520 }
 521
 522 int tpm_get_timeouts(struct tpm_chip *chip)
 523 {
 524         cap_t cap;
 525         unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
 526         ssize_t rc;
 527
 528         if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
 529                 return 0;
 530
 531         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 532                 /* Fixed timeouts for TPM2 */
 533                 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
 534                 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
 535                 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
 536                 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
 537                 chip->duration[TPM_SHORT] =
 538                     msecs_to_jiffies(TPM2_DURATION_SHORT);
 539                 chip->duration[TPM_MEDIUM] =
 540                     msecs_to_jiffies(TPM2_DURATION_MEDIUM);
 541                 chip->duration[TPM_LONG] =
 542                     msecs_to_jiffies(TPM2_DURATION_LONG);
 543
 544                 chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
 545                 return 0;
 546         }
 547
 548         rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL);
 549         if (rc == TPM_ERR_INVALID_POSTINIT) {
 550                 /* The TPM is not started, we are the first to talk to it.
 551                    Execute a startup command. */
 552                 dev_info(&chip->dev, "Issuing TPM_STARTUP\n");
 553                 if (tpm_startup(chip, TPM_ST_CLEAR))
 554                         return rc;
 555
 556                 rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
 557                                 "attempting to determine the timeouts");
 558         }
 559         if (rc) {
 560                 dev_err(&chip->dev,
 561                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 562                         rc);
 563                 return rc;
 564         }
 565
 566         timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
 567         timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
 568         timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
 569         timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
 570         timeout_chip[0] = be32_to_cpu(cap.timeout.a);
 571         timeout_chip[1] = be32_to_cpu(cap.timeout.b);
 572         timeout_chip[2] = be32_to_cpu(cap.timeout.c);
 573         timeout_chip[3] = be32_to_cpu(cap.timeout.d);
 574         memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
 575
 576         /*
 577          * Provide ability for vendor overrides of timeout values in case
 578          * of misreporting.
 579          */
 580         if (chip->ops->update_timeouts != NULL)
 581                 chip->timeout_adjusted =
 582                         chip->ops->update_timeouts(chip, timeout_eff);
 583
 584         if (!chip->timeout_adjusted) {
 585                 /* Restore default if chip reported 0 */
 586                 int i;
 587
 588                 for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
 589                         if (timeout_eff[i])
 590                                 continue;
 591
 592                         timeout_eff[i] = timeout_old[i];
 593                         chip->timeout_adjusted = true;
 594                 }
 595
 596                 if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
 597                         /* timeouts in msec rather usec */
 598                         for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
 599                                 timeout_eff[i] *= 1000;
 600                         chip->timeout_adjusted = true;
 601                 }
 602         }
 603
 604         /* Report adjusted timeouts */
 605         if (chip->timeout_adjusted) {
 606                 dev_info(&chip->dev,
 607                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 608                          timeout_chip[0], timeout_eff[0],
 609                          timeout_chip[1], timeout_eff[1],
 610                          timeout_chip[2], timeout_eff[2],
 611                          timeout_chip[3], timeout_eff[3]);
 612         }
 613
 614         chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
 615         chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
 616         chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
 617         chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
 618
 619         rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
 620                         "attempting to determine the durations");
 621         if (rc)
 622                 return rc;
 623
 624         chip->duration[TPM_SHORT] =
 625                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
 626         chip->duration[TPM_MEDIUM] =
 627                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
 628         chip->duration[TPM_LONG] =
 629                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
 630
 631         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 632          * value wrong and apparently reports msecs rather than usecs. So we
 633          * fix up the resulting too-small TPM_SHORT value to make things work.
 634          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 635          */
 636         if (chip->duration[TPM_SHORT] < (HZ / 100)) {
 637                 chip->duration[TPM_SHORT] = HZ;
 638                 chip->duration[TPM_MEDIUM] *= 1000;
 639                 chip->duration[TPM_LONG] *= 1000;
 640                 chip->duration_adjusted = true;
 641                 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 642         }
 643
 644         chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
 645         return 0;
 646 }
 647 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 648
 649 #define TPM_ORD_CONTINUE_SELFTEST 83
 650 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 651
 652 static const struct tpm_input_header continue_selftest_header = {
 653         .tag = TPM_TAG_RQU_COMMAND,
 654         .length = cpu_to_be32(10),
 655         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 656 };
 657
 658 /**
 659  * tpm_continue_selftest -- run TPM's selftest
 660  * @chip: TPM chip to use
 661  *
 662  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 663  * a TPM error code.
 664  */
 665 static int tpm_continue_selftest(struct tpm_chip *chip)
 666 {
 667         int rc;
 668         struct tpm_cmd_t cmd;
 669
 670         cmd.header.in = continue_selftest_header;
 671         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
 672                               "continue selftest");
 673         return rc;
 674 }
 675
 676 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 677 #define READ_PCR_RESULT_SIZE 30
 678 static const struct tpm_input_header pcrread_header = {
 679         .tag = TPM_TAG_RQU_COMMAND,
 680         .length = cpu_to_be32(14),
 681         .ordinal = TPM_ORDINAL_PCRREAD
 682 };
 683
 684 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 685 {
 686         int rc;
 687         struct tpm_cmd_t cmd;
 688
 689         cmd.header.in = pcrread_header;
 690         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 691         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
 692                               "attempting to read a pcr value");
 693
 694         if (rc == 0)
 695                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 696                        TPM_DIGEST_SIZE);
 697         return rc;
 698 }
 699
 700 /**
 701  * tpm_is_tpm2 - is the chip a TPM2 chip?
 702  * @chip_num:   tpm idx # or ANY
 703  *
 704  * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 705  * is a TPM2 chip.
 706  */
 707 int tpm_is_tpm2(u32 chip_num)
 708 {
 709         struct tpm_chip *chip;
 710         int rc;
 711
 712         chip = tpm_chip_find_get(chip_num);
 713         if (chip == NULL)
 714                 return -ENODEV;
 715
 716         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 717
 718         tpm_put_ops(chip);
 719
 720         return rc;
 721 }
 722 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 723
 724 /**
 725  * tpm_pcr_read - read a pcr value
 726  * @chip_num:   tpm idx # or ANY
 727  * @pcr_idx:    pcr idx to retrieve
 728  * @res_buf:    TPM_PCR value
 729  *              size of res_buf is 20 bytes (or NULL if you don't care)
 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 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 736 {
 737         struct tpm_chip *chip;
 738         int rc;
 739
 740         chip = tpm_chip_find_get(chip_num);
 741         if (chip == NULL)
 742                 return -ENODEV;
 743         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 744                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 745         else
 746                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 747         tpm_put_ops(chip);
 748         return rc;
 749 }
 750 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 751
 752 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 753 #define EXTEND_PCR_RESULT_SIZE 34
 754 static const struct tpm_input_header pcrextend_header = {
 755         .tag = TPM_TAG_RQU_COMMAND,
 756         .length = cpu_to_be32(34),
 757         .ordinal = TPM_ORD_PCR_EXTEND
 758 };
 759
 760 /**
 761  * tpm_pcr_extend - extend pcr value with hash
 762  * @chip_num:   tpm idx # or AN&
 763  * @pcr_idx:    pcr idx to extend
 764  * @hash:       hash value used to extend pcr value
 765  *
 766  * The TPM driver should be built-in, but for whatever reason it
 767  * isn't, protect against the chip disappearing, by incrementing
 768  * the module usage count.
 769  */
 770 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 771 {
 772         struct tpm_cmd_t cmd;
 773         int rc;
 774         struct tpm_chip *chip;
 775
 776         chip = tpm_chip_find_get(chip_num);
 777         if (chip == NULL)
 778                 return -ENODEV;
 779
 780         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 781                 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
 782                 tpm_put_ops(chip);
 783                 return rc;
 784         }
 785
 786         cmd.header.in = pcrextend_header;
 787         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 788         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 789         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 790                               "attempting extend a PCR value");
 791
 792         tpm_put_ops(chip);
 793         return rc;
 794 }
 795 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 796
 797 /**
 798  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 799  *                   can receive further commands
 800  * @chip: TPM chip to use
 801  *
 802  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 803  * a TPM error code.
 804  */
 805 int tpm_do_selftest(struct tpm_chip *chip)
 806 {
 807         int rc;
 808         unsigned int loops;
 809         unsigned int delay_msec = 100;
 810         unsigned long duration;
 811         u8 dummy[TPM_DIGEST_SIZE];
 812
 813         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 814
 815         loops = jiffies_to_msecs(duration) / delay_msec;
 816
 817         rc = tpm_continue_selftest(chip);
 818         /* This may fail if there was no TPM driver during a suspend/resume
 819          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 820          */
 821         if (rc)
 822                 return rc;
 823
 824         do {
 825                 /* Attempt to read a PCR value */
 826                 rc = tpm_pcr_read_dev(chip, 0, dummy);
 827
 828                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 829                  * around 300ms while the self test is ongoing, keep trying
 830                  * until the self test duration expires. */
 831                 if (rc == -ETIME) {
 832                         dev_info(
 833                             &chip->dev, HW_ERR
 834                             "TPM command timed out during continue self test");
 835                         msleep(delay_msec);
 836                         continue;
 837                 }
 838
 839                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 840                         dev_info(&chip->dev,
 841                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 842                         /* TPM is disabled and/or deactivated; driver can
 843                          * proceed and TPM does handle commands for
 844                          * suspend/resume correctly
 845                          */
 846                         return 0;
 847                 }
 848                 if (rc != TPM_WARN_DOING_SELFTEST)
 849                         return rc;
 850                 msleep(delay_msec);
 851         } while (--loops > 0);
 852
 853         return rc;
 854 }
 855 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 856
 857 /**
 858  * tpm1_auto_startup - Perform the standard automatic TPM initialization
 859  *                     sequence
 860  * @chip: TPM chip to use
 861  *
 862  * Returns 0 on success, < 0 in case of fatal error.
 863  */
 864 int tpm1_auto_startup(struct tpm_chip *chip)
 865 {
 866         int rc;
 867
 868         rc = tpm_get_timeouts(chip);
 869         if (rc)
 870                 goto out;
 871         rc = tpm_do_selftest(chip);
 872         if (rc) {
 873                 dev_err(&chip->dev, "TPM self test failed\n");
 874                 goto out;
 875         }
 876
 877         return rc;
 878 out:
 879         if (rc > 0)
 880                 rc = -ENODEV;
 881         return rc;
 882 }
 883
 884 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 885 {
 886         struct tpm_chip *chip;
 887         int rc;
 888
 889         chip = tpm_chip_find_get(chip_num);
 890         if (chip == NULL)
 891                 return -ENODEV;
 892
 893         rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
 894
 895         tpm_put_ops(chip);
 896         return rc;
 897 }
 898 EXPORT_SYMBOL_GPL(tpm_send);
 899
 900 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 901                                         bool check_cancel, bool *canceled)
 902 {
 903         u8 status = chip->ops->status(chip);
 904
 905         *canceled = false;
 906         if ((status & mask) == mask)
 907                 return true;
 908         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 909                 *canceled = true;
 910                 return true;
 911         }
 912         return false;
 913 }
 914
 915 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 916                       wait_queue_head_t *queue, bool check_cancel)
 917 {
 918         unsigned long stop;
 919         long rc;
 920         u8 status;
 921         bool canceled = false;
 922
 923         /* check current status */
 924         status = chip->ops->status(chip);
 925         if ((status & mask) == mask)
 926                 return 0;
 927
 928         stop = jiffies + timeout;
 929
 930         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
 931 again:
 932                 timeout = stop - jiffies;
 933                 if ((long)timeout <= 0)
 934                         return -ETIME;
 935                 rc = wait_event_interruptible_timeout(*queue,
 936                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 937                                                &canceled),
 938                         timeout);
 939                 if (rc > 0) {
 940                         if (canceled)
 941                                 return -ECANCELED;
 942                         return 0;
 943                 }
 944                 if (rc == -ERESTARTSYS && freezing(current)) {
 945                         clear_thread_flag(TIF_SIGPENDING);
 946                         goto again;
 947                 }
 948         } else {
 949                 do {
 950                         msleep(TPM_TIMEOUT);
 951                         status = chip->ops->status(chip);
 952                         if ((status & mask) == mask)
 953                                 return 0;
 954                 } while (time_before(jiffies, stop));
 955         }
 956         return -ETIME;
 957 }
 958 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 959
 960 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 961 #define SAVESTATE_RESULT_SIZE 10
 962
 963 static const struct tpm_input_header savestate_header = {
 964         .tag = TPM_TAG_RQU_COMMAND,
 965         .length = cpu_to_be32(10),
 966         .ordinal = TPM_ORD_SAVESTATE
 967 };
 968
 969 /*
 970  * We are about to suspend. Save the TPM state
 971  * so that it can be restored.
 972  */
 973 int tpm_pm_suspend(struct device *dev)
 974 {
 975         struct tpm_chip *chip = dev_get_drvdata(dev);
 976         struct tpm_cmd_t cmd;
 977         int rc, try;
 978
 979         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 980
 981         if (chip == NULL)
 982                 return -ENODEV;
 983
 984         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 985                 tpm2_shutdown(chip, TPM2_SU_STATE);
 986                 return 0;
 987         }
 988
 989         /* for buggy tpm, flush pcrs with extend to selected dummy */
 990         if (tpm_suspend_pcr) {
 991                 cmd.header.in = pcrextend_header;
 992                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 993                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 994                        TPM_DIGEST_SIZE);
 995                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 996                                       "extending dummy pcr before suspend");
 997         }
 998
 999         /* now do the actual savestate */
1000         for (try = 0; try < TPM_RETRY; try++) {
1001                 cmd.header.in = savestate_header;
1002                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
1003                                       NULL);
1004
1005                 /*
1006                  * If the TPM indicates that it is too busy to respond to
1007                  * this command then retry before giving up.  It can take
1008                  * several seconds for this TPM to be ready.
1009                  *
1010                  * This can happen if the TPM has already been sent the
1011                  * SaveState command before the driver has loaded.  TCG 1.2
1012                  * specification states that any communication after SaveState
1013                  * may cause the TPM to invalidate previously saved state.
1014                  */
1015                 if (rc != TPM_WARN_RETRY)
1016                         break;
1017                 msleep(TPM_TIMEOUT_RETRY);
1018         }
1019
1020         if (rc)
1021                 dev_err(&chip->dev,
1022                         "Error (%d) sending savestate before suspend\n", rc);
1023         else if (try > 0)
1024                 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1025                          try * TPM_TIMEOUT_RETRY);
1026
1027         return rc;
1028 }
1029 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1030
1031 /*
1032  * Resume from a power safe. The BIOS already restored
1033  * the TPM state.
1034  */
1035 int tpm_pm_resume(struct device *dev)
1036 {
1037         struct tpm_chip *chip = dev_get_drvdata(dev);
1038
1039         if (chip == NULL)
1040                 return -ENODEV;
1041
1042         return 0;
1043 }
1044 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1045
1046 #define TPM_GETRANDOM_RESULT_SIZE       18
1047 static const struct tpm_input_header tpm_getrandom_header = {
1048         .tag = TPM_TAG_RQU_COMMAND,
1049         .length = cpu_to_be32(14),
1050         .ordinal = TPM_ORD_GET_RANDOM
1051 };
1052
1053 /**
1054  * tpm_get_random() - Get random bytes from the tpm's RNG
1055  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1056  * @out: destination buffer for the random bytes
1057  * @max: the max number of bytes to write to @out
1058  *
1059  * Returns < 0 on error and the number of bytes read on success
1060  */
1061 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1062 {
1063         struct tpm_chip *chip;
1064         struct tpm_cmd_t tpm_cmd;
1065         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1066         int err, total = 0, retries = 5;
1067         u8 *dest = out;
1068
1069         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1070                 return -EINVAL;
1071
1072         chip = tpm_chip_find_get(chip_num);
1073         if (chip == NULL)
1074                 return -ENODEV;
1075
1076         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1077                 err = tpm2_get_random(chip, out, max);
1078                 tpm_put_ops(chip);
1079                 return err;
1080         }
1081
1082         do {
1083                 tpm_cmd.header.in = tpm_getrandom_header;
1084                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1085
1086                 err = tpm_transmit_cmd(chip, &tpm_cmd,
1087                                        TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1088                                        0, "attempting get random");
1089                 if (err)
1090                         break;
1091
1092                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1093                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1094
1095                 dest += recd;
1096                 total += recd;
1097                 num_bytes -= recd;
1098         } while (retries-- && total < max);
1099
1100         tpm_put_ops(chip);
1101         return total ? total : -EIO;
1102 }
1103 EXPORT_SYMBOL_GPL(tpm_get_random);
1104
1105 /**
1106  * tpm_seal_trusted() - seal a trusted key
1107  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1108  * @options: authentication values and other options
1109  * @payload: the key data in clear and encrypted form
1110  *
1111  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1112  * are supported.
1113  */
1114 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1115                      struct trusted_key_options *options)
1116 {
1117         struct tpm_chip *chip;
1118         int rc;
1119
1120         chip = tpm_chip_find_get(chip_num);
1121         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1122                 return -ENODEV;
1123
1124         rc = tpm2_seal_trusted(chip, payload, options);
1125
1126         tpm_put_ops(chip);
1127         return rc;
1128 }
1129 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1130
1131 /**
1132  * tpm_unseal_trusted() - unseal a trusted key
1133  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1134  * @options: authentication values and other options
1135  * @payload: the key data in clear and encrypted form
1136  *
1137  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1138  * are supported.
1139  */
1140 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1141                        struct trusted_key_options *options)
1142 {
1143         struct tpm_chip *chip;
1144         int rc;
1145
1146         chip = tpm_chip_find_get(chip_num);
1147         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1148                 return -ENODEV;
1149
1150         rc = tpm2_unseal_trusted(chip, payload, options);
1151
1152         tpm_put_ops(chip);
1153
1154         return rc;
1155 }
1156 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1157
1158 static int __init tpm_init(void)
1159 {
1160         int rc;
1161
1162         tpm_class = class_create(THIS_MODULE, "tpm");
1163         if (IS_ERR(tpm_class)) {
1164                 pr_err("couldn't create tpm class\n");
1165                 return PTR_ERR(tpm_class);
1166         }
1167
1168         rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1169         if (rc < 0) {
1170                 pr_err("tpm: failed to allocate char dev region\n");
1171                 class_destroy(tpm_class);
1172                 return rc;
1173         }
1174
1175         return 0;
1176 }
1177
1178 static void __exit tpm_exit(void)
1179 {
1180         idr_destroy(&dev_nums_idr);
1181         class_destroy(tpm_class);
1182         unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1183 }
1184
1185 subsys_initcall(tpm_init);
1186 module_exit(tpm_exit);
1187
1188 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1189 MODULE_DESCRIPTION("TPM Driver");
1190 MODULE_VERSION("2.0");
1191 MODULE_LICENSE("GPL");