kernel/drivers/char/tpm/tpm-interface.c

   1 /*
   2  * Copyright (C) 2004 IBM Corporation
   3  * Copyright (C) 2014 Intel Corporation
   4  *
   5  * Authors:
   6  * Leendert van Doorn <leendert@watson.ibm.com>
   7  * Dave Safford <safford@watson.ibm.com>
   8  * Reiner Sailer <sailer@watson.ibm.com>
   9  * Kylene Hall <kjhall@us.ibm.com>
  10  *
  11  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  12  *
  13  * Device driver for TCG/TCPA TPM (trusted platform module).
  14  * Specifications at www.trustedcomputinggroup.org
  15  *
  16  * This program is free software; you can redistribute it and/or
  17  * modify it under the terms of the GNU General Public License as
  18  * published by the Free Software Foundation, version 2 of the
  19  * License.
  20  *
  21  * Note, the TPM chip is not interrupt driven (only polling)
  22  * and can have very long timeouts (minutes!). Hence the unusual
  23  * calls to msleep.
  24  *
  25  */
  26
  27 #include <linux/poll.h>
  28 #include <linux/slab.h>
  29 #include <linux/mutex.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/freezer.h>
  32
  33 #include "tpm.h"
  34 #include "tpm_eventlog.h"
  35
  36 #define TPM_MAX_ORDINAL 243
  37 #define TSC_MAX_ORDINAL 12
  38 #define TPM_PROTECTED_COMMAND 0x00
  39 #define TPM_CONNECTION_COMMAND 0x40
  40
  41 /*
  42  * Bug workaround - some TPM's don't flush the most
  43  * recently changed pcr on suspend, so force the flush
  44  * with an extend to the selected _unused_ non-volatile pcr.
  45  */
  46 static int tpm_suspend_pcr;
  47 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  48 MODULE_PARM_DESC(suspend_pcr,
  49                  "PCR to use for dummy writes to faciltate flush on suspend.");
  50
  51 /*
  52  * Array with one entry per ordinal defining the maximum amount
  53  * of time the chip could take to return the result.  The ordinal
  54  * designation of short, medium or long is defined in a table in
  55  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  56  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  57  * from the chip during initialization with a call to tpm_get_timeouts.
  58  */
  59 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  60         TPM_UNDEFINED,          /* 0 */
  61         TPM_UNDEFINED,
  62         TPM_UNDEFINED,
  63         TPM_UNDEFINED,
  64         TPM_UNDEFINED,
  65         TPM_UNDEFINED,          /* 5 */
  66         TPM_UNDEFINED,
  67         TPM_UNDEFINED,
  68         TPM_UNDEFINED,
  69         TPM_UNDEFINED,
  70         TPM_SHORT,              /* 10 */
  71         TPM_SHORT,
  72         TPM_MEDIUM,
  73         TPM_LONG,
  74         TPM_LONG,
  75         TPM_MEDIUM,             /* 15 */
  76         TPM_SHORT,
  77         TPM_SHORT,
  78         TPM_MEDIUM,
  79         TPM_LONG,
  80         TPM_SHORT,              /* 20 */
  81         TPM_SHORT,
  82         TPM_MEDIUM,
  83         TPM_MEDIUM,
  84         TPM_MEDIUM,
  85         TPM_SHORT,              /* 25 */
  86         TPM_SHORT,
  87         TPM_MEDIUM,
  88         TPM_SHORT,
  89         TPM_SHORT,
  90         TPM_MEDIUM,             /* 30 */
  91         TPM_LONG,
  92         TPM_MEDIUM,
  93         TPM_SHORT,
  94         TPM_SHORT,
  95         TPM_SHORT,              /* 35 */
  96         TPM_MEDIUM,
  97         TPM_MEDIUM,
  98         TPM_UNDEFINED,
  99         TPM_UNDEFINED,
 100         TPM_MEDIUM,             /* 40 */
 101         TPM_LONG,
 102         TPM_MEDIUM,
 103         TPM_SHORT,
 104         TPM_SHORT,
 105         TPM_SHORT,              /* 45 */
 106         TPM_SHORT,
 107         TPM_SHORT,
 108         TPM_SHORT,
 109         TPM_LONG,
 110         TPM_MEDIUM,             /* 50 */
 111         TPM_MEDIUM,
 112         TPM_UNDEFINED,
 113         TPM_UNDEFINED,
 114         TPM_UNDEFINED,
 115         TPM_UNDEFINED,          /* 55 */
 116         TPM_UNDEFINED,
 117         TPM_UNDEFINED,
 118         TPM_UNDEFINED,
 119         TPM_UNDEFINED,
 120         TPM_MEDIUM,             /* 60 */
 121         TPM_MEDIUM,
 122         TPM_MEDIUM,
 123         TPM_SHORT,
 124         TPM_SHORT,
 125         TPM_MEDIUM,             /* 65 */
 126         TPM_UNDEFINED,
 127         TPM_UNDEFINED,
 128         TPM_UNDEFINED,
 129         TPM_UNDEFINED,
 130         TPM_SHORT,              /* 70 */
 131         TPM_SHORT,
 132         TPM_UNDEFINED,
 133         TPM_UNDEFINED,
 134         TPM_UNDEFINED,
 135         TPM_UNDEFINED,          /* 75 */
 136         TPM_UNDEFINED,
 137         TPM_UNDEFINED,
 138         TPM_UNDEFINED,
 139         TPM_UNDEFINED,
 140         TPM_LONG,               /* 80 */
 141         TPM_UNDEFINED,
 142         TPM_MEDIUM,
 143         TPM_LONG,
 144         TPM_SHORT,
 145         TPM_UNDEFINED,          /* 85 */
 146         TPM_UNDEFINED,
 147         TPM_UNDEFINED,
 148         TPM_UNDEFINED,
 149         TPM_UNDEFINED,
 150         TPM_SHORT,              /* 90 */
 151         TPM_SHORT,
 152         TPM_SHORT,
 153         TPM_SHORT,
 154         TPM_SHORT,
 155         TPM_UNDEFINED,          /* 95 */
 156         TPM_UNDEFINED,
 157         TPM_UNDEFINED,
 158         TPM_UNDEFINED,
 159         TPM_UNDEFINED,
 160         TPM_MEDIUM,             /* 100 */
 161         TPM_SHORT,
 162         TPM_SHORT,
 163         TPM_UNDEFINED,
 164         TPM_UNDEFINED,
 165         TPM_UNDEFINED,          /* 105 */
 166         TPM_UNDEFINED,
 167         TPM_UNDEFINED,
 168         TPM_UNDEFINED,
 169         TPM_UNDEFINED,
 170         TPM_SHORT,              /* 110 */
 171         TPM_SHORT,
 172         TPM_SHORT,
 173         TPM_SHORT,
 174         TPM_SHORT,
 175         TPM_SHORT,              /* 115 */
 176         TPM_SHORT,
 177         TPM_SHORT,
 178         TPM_UNDEFINED,
 179         TPM_UNDEFINED,
 180         TPM_LONG,               /* 120 */
 181         TPM_LONG,
 182         TPM_MEDIUM,
 183         TPM_UNDEFINED,
 184         TPM_SHORT,
 185         TPM_SHORT,              /* 125 */
 186         TPM_SHORT,
 187         TPM_LONG,
 188         TPM_SHORT,
 189         TPM_SHORT,
 190         TPM_SHORT,              /* 130 */
 191         TPM_MEDIUM,
 192         TPM_UNDEFINED,
 193         TPM_SHORT,
 194         TPM_MEDIUM,
 195         TPM_UNDEFINED,          /* 135 */
 196         TPM_UNDEFINED,
 197         TPM_UNDEFINED,
 198         TPM_UNDEFINED,
 199         TPM_UNDEFINED,
 200         TPM_SHORT,              /* 140 */
 201         TPM_SHORT,
 202         TPM_UNDEFINED,
 203         TPM_UNDEFINED,
 204         TPM_UNDEFINED,
 205         TPM_UNDEFINED,          /* 145 */
 206         TPM_UNDEFINED,
 207         TPM_UNDEFINED,
 208         TPM_UNDEFINED,
 209         TPM_UNDEFINED,
 210         TPM_SHORT,              /* 150 */
 211         TPM_MEDIUM,
 212         TPM_MEDIUM,
 213         TPM_SHORT,
 214         TPM_SHORT,
 215         TPM_UNDEFINED,          /* 155 */
 216         TPM_UNDEFINED,
 217         TPM_UNDEFINED,
 218         TPM_UNDEFINED,
 219         TPM_UNDEFINED,
 220         TPM_SHORT,              /* 160 */
 221         TPM_SHORT,
 222         TPM_SHORT,
 223         TPM_SHORT,
 224         TPM_UNDEFINED,
 225         TPM_UNDEFINED,          /* 165 */
 226         TPM_UNDEFINED,
 227         TPM_UNDEFINED,
 228         TPM_UNDEFINED,
 229         TPM_UNDEFINED,
 230         TPM_LONG,               /* 170 */
 231         TPM_UNDEFINED,
 232         TPM_UNDEFINED,
 233         TPM_UNDEFINED,
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,          /* 175 */
 236         TPM_UNDEFINED,
 237         TPM_UNDEFINED,
 238         TPM_UNDEFINED,
 239         TPM_UNDEFINED,
 240         TPM_MEDIUM,             /* 180 */
 241         TPM_SHORT,
 242         TPM_MEDIUM,
 243         TPM_MEDIUM,
 244         TPM_MEDIUM,
 245         TPM_MEDIUM,             /* 185 */
 246         TPM_SHORT,
 247         TPM_UNDEFINED,
 248         TPM_UNDEFINED,
 249         TPM_UNDEFINED,
 250         TPM_UNDEFINED,          /* 190 */
 251         TPM_UNDEFINED,
 252         TPM_UNDEFINED,
 253         TPM_UNDEFINED,
 254         TPM_UNDEFINED,
 255         TPM_UNDEFINED,          /* 195 */
 256         TPM_UNDEFINED,
 257         TPM_UNDEFINED,
 258         TPM_UNDEFINED,
 259         TPM_UNDEFINED,
 260         TPM_SHORT,              /* 200 */
 261         TPM_UNDEFINED,
 262         TPM_UNDEFINED,
 263         TPM_UNDEFINED,
 264         TPM_SHORT,
 265         TPM_SHORT,              /* 205 */
 266         TPM_SHORT,
 267         TPM_SHORT,
 268         TPM_SHORT,
 269         TPM_SHORT,
 270         TPM_MEDIUM,             /* 210 */
 271         TPM_UNDEFINED,
 272         TPM_MEDIUM,
 273         TPM_MEDIUM,
 274         TPM_MEDIUM,
 275         TPM_UNDEFINED,          /* 215 */
 276         TPM_MEDIUM,
 277         TPM_UNDEFINED,
 278         TPM_UNDEFINED,
 279         TPM_SHORT,
 280         TPM_SHORT,              /* 220 */
 281         TPM_SHORT,
 282         TPM_SHORT,
 283         TPM_SHORT,
 284         TPM_SHORT,
 285         TPM_UNDEFINED,          /* 225 */
 286         TPM_UNDEFINED,
 287         TPM_UNDEFINED,
 288         TPM_UNDEFINED,
 289         TPM_UNDEFINED,
 290         TPM_SHORT,              /* 230 */
 291         TPM_LONG,
 292         TPM_MEDIUM,
 293         TPM_UNDEFINED,
 294         TPM_UNDEFINED,
 295         TPM_UNDEFINED,          /* 235 */
 296         TPM_UNDEFINED,
 297         TPM_UNDEFINED,
 298         TPM_UNDEFINED,
 299         TPM_UNDEFINED,
 300         TPM_SHORT,              /* 240 */
 301         TPM_UNDEFINED,
 302         TPM_MEDIUM,
 303 };
 304
 305 /*
 306  * Returns max number of jiffies to wait
 307  */
 308 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 309                                            u32 ordinal)
 310 {
 311         int duration_idx = TPM_UNDEFINED;
 312         int duration = 0;
 313         u8 category = (ordinal >> 24) & 0xFF;
 314
 315         if ((category == TPM_PROTECTED_COMMAND && ordinal < TPM_MAX_ORDINAL) ||
 316             (category == TPM_CONNECTION_COMMAND && ordinal < TSC_MAX_ORDINAL))
 317                 duration_idx = tpm_ordinal_duration[ordinal];
 318
 319         if (duration_idx != TPM_UNDEFINED)
 320                 duration = chip->vendor.duration[duration_idx];
 321         if (duration <= 0)
 322                 return 2 * 60 * HZ;
 323         else
 324                 return duration;
 325 }
 326 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 327
 328 /*
 329  * Internal kernel interface to transmit TPM commands
 330  */
 331 ssize_t tpm_transmit(struct tpm_chip *chip, const 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         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 364                 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
 365         else
 366                 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 367         do {
 368                 u8 status = chip->ops->status(chip);
 369                 if ((status & chip->ops->req_complete_mask) ==
 370                     chip->ops->req_complete_val)
 371                         goto out_recv;
 372
 373                 if (chip->ops->req_canceled(chip, status)) {
 374                         dev_err(chip->pdev, "Operation Canceled\n");
 375                         rc = -ECANCELED;
 376                         goto out;
 377                 }
 378
 379                 msleep(TPM_TIMEOUT);    /* CHECK */
 380                 rmb();
 381         } while (time_before(jiffies, stop));
 382
 383         chip->ops->cancel(chip);
 384         dev_err(chip->pdev, "Operation Timed out\n");
 385         rc = -ETIME;
 386         goto out;
 387
 388 out_recv:
 389         rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
 390         if (rc < 0)
 391                 dev_err(chip->pdev,
 392                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 393 out:
 394         mutex_unlock(&chip->tpm_mutex);
 395         return rc;
 396 }
 397
 398 #define TPM_DIGEST_SIZE 20
 399 #define TPM_RET_CODE_IDX 6
 400
 401 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, void *cmd,
 402                          int len, const char *desc)
 403 {
 404         struct tpm_output_header *header;
 405         int err;
 406
 407         len = tpm_transmit(chip, (u8 *) cmd, len);
 408         if (len <  0)
 409                 return len;
 410         else if (len < TPM_HEADER_SIZE)
 411                 return -EFAULT;
 412
 413         header = cmd;
 414
 415         err = be32_to_cpu(header->return_code);
 416         if (err != 0 && desc)
 417                 dev_err(chip->pdev, "A TPM error (%d) occurred %s\n", err,
 418                         desc);
 419
 420         return err;
 421 }
 422
 423 #define TPM_INTERNAL_RESULT_SIZE 200
 424 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 425 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 426
 427 static const struct tpm_input_header tpm_getcap_header = {
 428         .tag = TPM_TAG_RQU_COMMAND,
 429         .length = cpu_to_be32(22),
 430         .ordinal = TPM_ORD_GET_CAP
 431 };
 432
 433 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
 434                    const char *desc)
 435 {
 436         struct tpm_cmd_t tpm_cmd;
 437         int rc;
 438         struct tpm_chip *chip = dev_get_drvdata(dev);
 439
 440         tpm_cmd.header.in = tpm_getcap_header;
 441         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 442                 tpm_cmd.params.getcap_in.cap = subcap_id;
 443                 /*subcap field not necessary */
 444                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 445                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 446         } else {
 447                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 448                     subcap_id == TPM_CAP_FLAG_VOL)
 449                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 450                 else
 451                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 452                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 453                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 454         }
 455         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
 456         if (!rc)
 457                 *cap = tpm_cmd.params.getcap_out.cap;
 458         return rc;
 459 }
 460
 461 void tpm_gen_interrupt(struct tpm_chip *chip)
 462 {
 463         struct  tpm_cmd_t tpm_cmd;
 464         ssize_t rc;
 465
 466         tpm_cmd.header.in = tpm_getcap_header;
 467         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 468         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 469         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 470
 471         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 472                               "attempting to determine the timeouts");
 473 }
 474 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 475
 476 #define TPM_ORD_STARTUP cpu_to_be32(153)
 477 #define TPM_ST_CLEAR cpu_to_be16(1)
 478 #define TPM_ST_STATE cpu_to_be16(2)
 479 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 480 static const struct tpm_input_header tpm_startup_header = {
 481         .tag = TPM_TAG_RQU_COMMAND,
 482         .length = cpu_to_be32(12),
 483         .ordinal = TPM_ORD_STARTUP
 484 };
 485
 486 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 487 {
 488         struct tpm_cmd_t start_cmd;
 489         start_cmd.header.in = tpm_startup_header;
 490
 491         start_cmd.params.startup_in.startup_type = startup_type;
 492         return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
 493                                 "attempting to start the TPM");
 494 }
 495
 496 int tpm_get_timeouts(struct tpm_chip *chip)
 497 {
 498         struct tpm_cmd_t tpm_cmd;
 499         unsigned long new_timeout[4];
 500         unsigned long old_timeout[4];
 501         struct duration_t *duration_cap;
 502         ssize_t rc;
 503
 504         tpm_cmd.header.in = tpm_getcap_header;
 505         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 506         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 507         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 508         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
 509
 510         if (rc == TPM_ERR_INVALID_POSTINIT) {
 511                 /* The TPM is not started, we are the first to talk to it.
 512                    Execute a startup command. */
 513                 dev_info(chip->pdev, "Issuing TPM_STARTUP");
 514                 if (tpm_startup(chip, TPM_ST_CLEAR))
 515                         return rc;
 516
 517                 tpm_cmd.header.in = tpm_getcap_header;
 518                 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 519                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 520                 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 521                 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 522                                   NULL);
 523         }
 524         if (rc) {
 525                 dev_err(chip->pdev,
 526                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 527                         rc);
 528                 goto duration;
 529         }
 530
 531         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 532             be32_to_cpu(tpm_cmd.header.out.length)
 533             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 534                 return -EINVAL;
 535
 536         old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
 537         old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
 538         old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
 539         old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
 540         memcpy(new_timeout, old_timeout, sizeof(new_timeout));
 541
 542         /*
 543          * Provide ability for vendor overrides of timeout values in case
 544          * of misreporting.
 545          */
 546         if (chip->ops->update_timeouts != NULL)
 547                 chip->vendor.timeout_adjusted =
 548                         chip->ops->update_timeouts(chip, new_timeout);
 549
 550         if (!chip->vendor.timeout_adjusted) {
 551                 /* Don't overwrite default if value is 0 */
 552                 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
 553                         int i;
 554
 555                         /* timeouts in msec rather usec */
 556                         for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
 557                                 new_timeout[i] *= 1000;
 558                         chip->vendor.timeout_adjusted = true;
 559                 }
 560         }
 561
 562         /* Report adjusted timeouts */
 563         if (chip->vendor.timeout_adjusted) {
 564                 dev_info(chip->pdev,
 565                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 566                          old_timeout[0], new_timeout[0],
 567                          old_timeout[1], new_timeout[1],
 568                          old_timeout[2], new_timeout[2],
 569                          old_timeout[3], new_timeout[3]);
 570         }
 571
 572         chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
 573         chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
 574         chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
 575         chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
 576
 577 duration:
 578         tpm_cmd.header.in = tpm_getcap_header;
 579         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 580         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 581         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 582
 583         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 584                               "attempting to determine the durations");
 585         if (rc)
 586                 return rc;
 587
 588         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 589             be32_to_cpu(tpm_cmd.header.out.length)
 590             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 591                 return -EINVAL;
 592
 593         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 594         chip->vendor.duration[TPM_SHORT] =
 595             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 596         chip->vendor.duration[TPM_MEDIUM] =
 597             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 598         chip->vendor.duration[TPM_LONG] =
 599             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 600
 601         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 602          * value wrong and apparently reports msecs rather than usecs. So we
 603          * fix up the resulting too-small TPM_SHORT value to make things work.
 604          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 605          */
 606         if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
 607                 chip->vendor.duration[TPM_SHORT] = HZ;
 608                 chip->vendor.duration[TPM_MEDIUM] *= 1000;
 609                 chip->vendor.duration[TPM_LONG] *= 1000;
 610                 chip->vendor.duration_adjusted = true;
 611                 dev_info(chip->pdev, "Adjusting TPM timeout parameters.");
 612         }
 613         return 0;
 614 }
 615 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 616
 617 #define TPM_ORD_CONTINUE_SELFTEST 83
 618 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 619
 620 static struct tpm_input_header continue_selftest_header = {
 621         .tag = TPM_TAG_RQU_COMMAND,
 622         .length = cpu_to_be32(10),
 623         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 624 };
 625
 626 /**
 627  * tpm_continue_selftest -- run TPM's selftest
 628  * @chip: TPM chip to use
 629  *
 630  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 631  * a TPM error code.
 632  */
 633 static int tpm_continue_selftest(struct tpm_chip *chip)
 634 {
 635         int rc;
 636         struct tpm_cmd_t cmd;
 637
 638         cmd.header.in = continue_selftest_header;
 639         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 640                               "continue selftest");
 641         return rc;
 642 }
 643
 644 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 645 #define READ_PCR_RESULT_SIZE 30
 646 static struct tpm_input_header pcrread_header = {
 647         .tag = TPM_TAG_RQU_COMMAND,
 648         .length = cpu_to_be32(14),
 649         .ordinal = TPM_ORDINAL_PCRREAD
 650 };
 651
 652 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 653 {
 654         int rc;
 655         struct tpm_cmd_t cmd;
 656
 657         cmd.header.in = pcrread_header;
 658         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 659         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 660                               "attempting to read a pcr value");
 661
 662         if (rc == 0)
 663                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 664                        TPM_DIGEST_SIZE);
 665         return rc;
 666 }
 667
 668 /**
 669  * tpm_pcr_read - read a pcr value
 670  * @chip_num:   tpm idx # or ANY
 671  * @pcr_idx:    pcr idx to retrieve
 672  * @res_buf:    TPM_PCR value
 673  *              size of res_buf is 20 bytes (or NULL if you don't care)
 674  *
 675  * The TPM driver should be built-in, but for whatever reason it
 676  * isn't, protect against the chip disappearing, by incrementing
 677  * the module usage count.
 678  */
 679 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 680 {
 681         struct tpm_chip *chip;
 682         int rc;
 683
 684         chip = tpm_chip_find_get(chip_num);
 685         if (chip == NULL)
 686                 return -ENODEV;
 687         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 688                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 689         else
 690                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 691         tpm_chip_put(chip);
 692         return rc;
 693 }
 694 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 695
 696 /**
 697  * tpm_pcr_extend - extend pcr value with hash
 698  * @chip_num:   tpm idx # or AN&
 699  * @pcr_idx:    pcr idx to extend
 700  * @hash:       hash value used to extend pcr value
 701  *
 702  * The TPM driver should be built-in, but for whatever reason it
 703  * isn't, protect against the chip disappearing, by incrementing
 704  * the module usage count.
 705  */
 706 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 707 #define EXTEND_PCR_RESULT_SIZE 34
 708 static struct tpm_input_header pcrextend_header = {
 709         .tag = TPM_TAG_RQU_COMMAND,
 710         .length = cpu_to_be32(34),
 711         .ordinal = TPM_ORD_PCR_EXTEND
 712 };
 713
 714 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 715 {
 716         struct tpm_cmd_t cmd;
 717         int rc;
 718         struct tpm_chip *chip;
 719
 720         chip = tpm_chip_find_get(chip_num);
 721         if (chip == NULL)
 722                 return -ENODEV;
 723
 724         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 725                 rc = tpm2_pcr_extend(chip, pcr_idx, hash);
 726                 tpm_chip_put(chip);
 727                 return rc;
 728         }
 729
 730         cmd.header.in = pcrextend_header;
 731         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 732         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 733         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 734                               "attempting extend a PCR value");
 735
 736         tpm_chip_put(chip);
 737         return rc;
 738 }
 739 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 740
 741 /**
 742  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 743  *                   can receive further commands
 744  * @chip: TPM chip to use
 745  *
 746  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 747  * a TPM error code.
 748  */
 749 int tpm_do_selftest(struct tpm_chip *chip)
 750 {
 751         int rc;
 752         unsigned int loops;
 753         unsigned int delay_msec = 100;
 754         unsigned long duration;
 755         struct tpm_cmd_t cmd;
 756
 757         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 758
 759         loops = jiffies_to_msecs(duration) / delay_msec;
 760
 761         rc = tpm_continue_selftest(chip);
 762         /* This may fail if there was no TPM driver during a suspend/resume
 763          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 764          */
 765         if (rc)
 766                 return rc;
 767
 768         do {
 769                 /* Attempt to read a PCR value */
 770                 cmd.header.in = pcrread_header;
 771                 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
 772                 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
 773                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 774                  * around 300ms while the self test is ongoing, keep trying
 775                  * until the self test duration expires. */
 776                 if (rc == -ETIME) {
 777                         dev_info(chip->pdev, HW_ERR "TPM command timed out during continue self test");
 778                         msleep(delay_msec);
 779                         continue;
 780                 }
 781
 782                 if (rc < TPM_HEADER_SIZE)
 783                         return -EFAULT;
 784
 785                 rc = be32_to_cpu(cmd.header.out.return_code);
 786                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 787                         dev_info(chip->pdev,
 788                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 789                         /* TPM is disabled and/or deactivated; driver can
 790                          * proceed and TPM does handle commands for
 791                          * suspend/resume correctly
 792                          */
 793                         return 0;
 794                 }
 795                 if (rc != TPM_WARN_DOING_SELFTEST)
 796                         return rc;
 797                 msleep(delay_msec);
 798         } while (--loops > 0);
 799
 800         return rc;
 801 }
 802 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 803
 804 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 805 {
 806         struct tpm_chip *chip;
 807         int rc;
 808
 809         chip = tpm_chip_find_get(chip_num);
 810         if (chip == NULL)
 811                 return -ENODEV;
 812
 813         rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
 814
 815         tpm_chip_put(chip);
 816         return rc;
 817 }
 818 EXPORT_SYMBOL_GPL(tpm_send);
 819
 820 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 821                                         bool check_cancel, bool *canceled)
 822 {
 823         u8 status = chip->ops->status(chip);
 824
 825         *canceled = false;
 826         if ((status & mask) == mask)
 827                 return true;
 828         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 829                 *canceled = true;
 830                 return true;
 831         }
 832         return false;
 833 }
 834
 835 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 836                       wait_queue_head_t *queue, bool check_cancel)
 837 {
 838         unsigned long stop;
 839         long rc;
 840         u8 status;
 841         bool canceled = false;
 842
 843         /* check current status */
 844         status = chip->ops->status(chip);
 845         if ((status & mask) == mask)
 846                 return 0;
 847
 848         stop = jiffies + timeout;
 849
 850         if (chip->vendor.irq) {
 851 again:
 852                 timeout = stop - jiffies;
 853                 if ((long)timeout <= 0)
 854                         return -ETIME;
 855                 rc = wait_event_interruptible_timeout(*queue,
 856                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 857                                                &canceled),
 858                         timeout);
 859                 if (rc > 0) {
 860                         if (canceled)
 861                                 return -ECANCELED;
 862                         return 0;
 863                 }
 864                 if (rc == -ERESTARTSYS && freezing(current)) {
 865                         clear_thread_flag(TIF_SIGPENDING);
 866                         goto again;
 867                 }
 868         } else {
 869                 do {
 870                         msleep(TPM_TIMEOUT);
 871                         status = chip->ops->status(chip);
 872                         if ((status & mask) == mask)
 873                                 return 0;
 874                 } while (time_before(jiffies, stop));
 875         }
 876         return -ETIME;
 877 }
 878 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 879
 880 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 881 #define SAVESTATE_RESULT_SIZE 10
 882
 883 static struct tpm_input_header savestate_header = {
 884         .tag = TPM_TAG_RQU_COMMAND,
 885         .length = cpu_to_be32(10),
 886         .ordinal = TPM_ORD_SAVESTATE
 887 };
 888
 889 /*
 890  * We are about to suspend. Save the TPM state
 891  * so that it can be restored.
 892  */
 893 int tpm_pm_suspend(struct device *dev)
 894 {
 895         struct tpm_chip *chip = dev_get_drvdata(dev);
 896         struct tpm_cmd_t cmd;
 897         int rc, try;
 898
 899         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 900
 901         if (chip == NULL)
 902                 return -ENODEV;
 903
 904         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 905                 tpm2_shutdown(chip, TPM2_SU_STATE);
 906                 return 0;
 907         }
 908
 909         /* for buggy tpm, flush pcrs with extend to selected dummy */
 910         if (tpm_suspend_pcr) {
 911                 cmd.header.in = pcrextend_header;
 912                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 913                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 914                        TPM_DIGEST_SIZE);
 915                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 916                                       "extending dummy pcr before suspend");
 917         }
 918
 919         /* now do the actual savestate */
 920         for (try = 0; try < TPM_RETRY; try++) {
 921                 cmd.header.in = savestate_header;
 922                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
 923
 924                 /*
 925                  * If the TPM indicates that it is too busy to respond to
 926                  * this command then retry before giving up.  It can take
 927                  * several seconds for this TPM to be ready.
 928                  *
 929                  * This can happen if the TPM has already been sent the
 930                  * SaveState command before the driver has loaded.  TCG 1.2
 931                  * specification states that any communication after SaveState
 932                  * may cause the TPM to invalidate previously saved state.
 933                  */
 934                 if (rc != TPM_WARN_RETRY)
 935                         break;
 936                 msleep(TPM_TIMEOUT_RETRY);
 937         }
 938
 939         if (rc)
 940                 dev_err(chip->pdev,
 941                         "Error (%d) sending savestate before suspend\n", rc);
 942         else if (try > 0)
 943                 dev_warn(chip->pdev, "TPM savestate took %dms\n",
 944                          try * TPM_TIMEOUT_RETRY);
 945
 946         return rc;
 947 }
 948 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
 949
 950 /*
 951  * Resume from a power safe. The BIOS already restored
 952  * the TPM state.
 953  */
 954 int tpm_pm_resume(struct device *dev)
 955 {
 956         struct tpm_chip *chip = dev_get_drvdata(dev);
 957
 958         if (chip == NULL)
 959                 return -ENODEV;
 960
 961         return 0;
 962 }
 963 EXPORT_SYMBOL_GPL(tpm_pm_resume);
 964
 965 #define TPM_GETRANDOM_RESULT_SIZE       18
 966 static struct tpm_input_header tpm_getrandom_header = {
 967         .tag = TPM_TAG_RQU_COMMAND,
 968         .length = cpu_to_be32(14),
 969         .ordinal = TPM_ORD_GET_RANDOM
 970 };
 971
 972 /**
 973  * tpm_get_random() - Get random bytes from the tpm's RNG
 974  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
 975  * @out: destination buffer for the random bytes
 976  * @max: the max number of bytes to write to @out
 977  *
 978  * Returns < 0 on error and the number of bytes read on success
 979  */
 980 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
 981 {
 982         struct tpm_chip *chip;
 983         struct tpm_cmd_t tpm_cmd;
 984         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
 985         int err, total = 0, retries = 5;
 986         u8 *dest = out;
 987
 988         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
 989                 return -EINVAL;
 990
 991         chip = tpm_chip_find_get(chip_num);
 992         if (chip == NULL)
 993                 return -ENODEV;
 994
 995         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 996                 err = tpm2_get_random(chip, out, max);
 997                 tpm_chip_put(chip);
 998                 return err;
 999         }
1000
1001         do {
1002                 tpm_cmd.header.in = tpm_getrandom_header;
1003                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1004
1005                 err = tpm_transmit_cmd(chip, &tpm_cmd,
1006                                    TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1007                                    "attempting get random");
1008                 if (err)
1009                         break;
1010
1011                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1012                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1013
1014                 dest += recd;
1015                 total += recd;
1016                 num_bytes -= recd;
1017         } while (retries-- && total < max);
1018
1019         tpm_chip_put(chip);
1020         return total ? total : -EIO;
1021 }
1022 EXPORT_SYMBOL_GPL(tpm_get_random);
1023
1024 static int __init tpm_init(void)
1025 {
1026         int rc;
1027
1028         tpm_class = class_create(THIS_MODULE, "tpm");
1029         if (IS_ERR(tpm_class)) {
1030                 pr_err("couldn't create tpm class\n");
1031                 return PTR_ERR(tpm_class);
1032         }
1033
1034         rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1035         if (rc < 0) {
1036                 pr_err("tpm: failed to allocate char dev region\n");
1037                 class_destroy(tpm_class);
1038                 return rc;
1039         }
1040
1041         return 0;
1042 }
1043
1044 static void __exit tpm_exit(void)
1045 {
1046         class_destroy(tpm_class);
1047         unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1048 }
1049
1050 subsys_initcall(tpm_init);
1051 module_exit(tpm_exit);
1052
1053 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1054 MODULE_DESCRIPTION("TPM Driver");
1055 MODULE_VERSION("2.0");
1056 MODULE_LICENSE("GPL");