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