drivers/char/tpm/tpm-interface.c

   1 /*
   2  * Copyright (C) 2004 IBM Corporation
   3  *
   4  * Authors:
   5  * Leendert van Doorn <leendert@watson.ibm.com>
   6  * Dave Safford <safford@watson.ibm.com>
   7  * Reiner Sailer <sailer@watson.ibm.com>
   8  * Kylene Hall <kjhall@us.ibm.com>
   9  *
  10  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  11  *
  12  * Device driver for TCG/TCPA TPM (trusted platform module).
  13  * Specifications at www.trustedcomputinggroup.org
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License as
  17  * published by the Free Software Foundation, version 2 of the
  18  * License.
  19  *
  20  * Note, the TPM chip is not interrupt driven (only polling)
  21  * and can have very long timeouts (minutes!). Hence the unusual
  22  * calls to msleep.
  23  *
  24  */
  25
  26 #include <linux/poll.h>
  27 #include <linux/slab.h>
  28 #include <linux/mutex.h>
  29 #include <linux/spinlock.h>
  30 #include <linux/freezer.h>
  31
  32 #include "tpm.h"
  33 #include "tpm_eventlog.h"
  34
  35 #define TPM_MAX_ORDINAL 243
  36 #define TSC_MAX_ORDINAL 12
  37 #define TPM_PROTECTED_COMMAND 0x00
  38 #define TPM_CONNECTION_COMMAND 0x40
  39
  40 /*
  41  * Bug workaround - some TPM's don't flush the most
  42  * recently changed pcr on suspend, so force the flush
  43  * with an extend to the selected _unused_ non-volatile pcr.
  44  */
  45 static int tpm_suspend_pcr;
  46 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  47 MODULE_PARM_DESC(suspend_pcr,
  48                  "PCR to use for dummy writes to faciltate flush on suspend.");
  49
  50 static LIST_HEAD(tpm_chip_list);
  51 static DEFINE_SPINLOCK(driver_lock);
  52 static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
  53
  54 /*
  55  * Array with one entry per ordinal defining the maximum amount
  56  * of time the chip could take to return the result.  The ordinal
  57  * designation of short, medium or long is defined in a table in
  58  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  59  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  60  * from the chip during initialization with a call to tpm_get_timeouts.
  61  */
  62 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  63         TPM_UNDEFINED,          /* 0 */
  64         TPM_UNDEFINED,
  65         TPM_UNDEFINED,
  66         TPM_UNDEFINED,
  67         TPM_UNDEFINED,
  68         TPM_UNDEFINED,          /* 5 */
  69         TPM_UNDEFINED,
  70         TPM_UNDEFINED,
  71         TPM_UNDEFINED,
  72         TPM_UNDEFINED,
  73         TPM_SHORT,              /* 10 */
  74         TPM_SHORT,
  75         TPM_MEDIUM,
  76         TPM_LONG,
  77         TPM_LONG,
  78         TPM_MEDIUM,             /* 15 */
  79         TPM_SHORT,
  80         TPM_SHORT,
  81         TPM_MEDIUM,
  82         TPM_LONG,
  83         TPM_SHORT,              /* 20 */
  84         TPM_SHORT,
  85         TPM_MEDIUM,
  86         TPM_MEDIUM,
  87         TPM_MEDIUM,
  88         TPM_SHORT,              /* 25 */
  89         TPM_SHORT,
  90         TPM_MEDIUM,
  91         TPM_SHORT,
  92         TPM_SHORT,
  93         TPM_MEDIUM,             /* 30 */
  94         TPM_LONG,
  95         TPM_MEDIUM,
  96         TPM_SHORT,
  97         TPM_SHORT,
  98         TPM_SHORT,              /* 35 */
  99         TPM_MEDIUM,
 100         TPM_MEDIUM,
 101         TPM_UNDEFINED,
 102         TPM_UNDEFINED,
 103         TPM_MEDIUM,             /* 40 */
 104         TPM_LONG,
 105         TPM_MEDIUM,
 106         TPM_SHORT,
 107         TPM_SHORT,
 108         TPM_SHORT,              /* 45 */
 109         TPM_SHORT,
 110         TPM_SHORT,
 111         TPM_SHORT,
 112         TPM_LONG,
 113         TPM_MEDIUM,             /* 50 */
 114         TPM_MEDIUM,
 115         TPM_UNDEFINED,
 116         TPM_UNDEFINED,
 117         TPM_UNDEFINED,
 118         TPM_UNDEFINED,          /* 55 */
 119         TPM_UNDEFINED,
 120         TPM_UNDEFINED,
 121         TPM_UNDEFINED,
 122         TPM_UNDEFINED,
 123         TPM_MEDIUM,             /* 60 */
 124         TPM_MEDIUM,
 125         TPM_MEDIUM,
 126         TPM_SHORT,
 127         TPM_SHORT,
 128         TPM_MEDIUM,             /* 65 */
 129         TPM_UNDEFINED,
 130         TPM_UNDEFINED,
 131         TPM_UNDEFINED,
 132         TPM_UNDEFINED,
 133         TPM_SHORT,              /* 70 */
 134         TPM_SHORT,
 135         TPM_UNDEFINED,
 136         TPM_UNDEFINED,
 137         TPM_UNDEFINED,
 138         TPM_UNDEFINED,          /* 75 */
 139         TPM_UNDEFINED,
 140         TPM_UNDEFINED,
 141         TPM_UNDEFINED,
 142         TPM_UNDEFINED,
 143         TPM_LONG,               /* 80 */
 144         TPM_UNDEFINED,
 145         TPM_MEDIUM,
 146         TPM_LONG,
 147         TPM_SHORT,
 148         TPM_UNDEFINED,          /* 85 */
 149         TPM_UNDEFINED,
 150         TPM_UNDEFINED,
 151         TPM_UNDEFINED,
 152         TPM_UNDEFINED,
 153         TPM_SHORT,              /* 90 */
 154         TPM_SHORT,
 155         TPM_SHORT,
 156         TPM_SHORT,
 157         TPM_SHORT,
 158         TPM_UNDEFINED,          /* 95 */
 159         TPM_UNDEFINED,
 160         TPM_UNDEFINED,
 161         TPM_UNDEFINED,
 162         TPM_UNDEFINED,
 163         TPM_MEDIUM,             /* 100 */
 164         TPM_SHORT,
 165         TPM_SHORT,
 166         TPM_UNDEFINED,
 167         TPM_UNDEFINED,
 168         TPM_UNDEFINED,          /* 105 */
 169         TPM_UNDEFINED,
 170         TPM_UNDEFINED,
 171         TPM_UNDEFINED,
 172         TPM_UNDEFINED,
 173         TPM_SHORT,              /* 110 */
 174         TPM_SHORT,
 175         TPM_SHORT,
 176         TPM_SHORT,
 177         TPM_SHORT,
 178         TPM_SHORT,              /* 115 */
 179         TPM_SHORT,
 180         TPM_SHORT,
 181         TPM_UNDEFINED,
 182         TPM_UNDEFINED,
 183         TPM_LONG,               /* 120 */
 184         TPM_LONG,
 185         TPM_MEDIUM,
 186         TPM_UNDEFINED,
 187         TPM_SHORT,
 188         TPM_SHORT,              /* 125 */
 189         TPM_SHORT,
 190         TPM_LONG,
 191         TPM_SHORT,
 192         TPM_SHORT,
 193         TPM_SHORT,              /* 130 */
 194         TPM_MEDIUM,
 195         TPM_UNDEFINED,
 196         TPM_SHORT,
 197         TPM_MEDIUM,
 198         TPM_UNDEFINED,          /* 135 */
 199         TPM_UNDEFINED,
 200         TPM_UNDEFINED,
 201         TPM_UNDEFINED,
 202         TPM_UNDEFINED,
 203         TPM_SHORT,              /* 140 */
 204         TPM_SHORT,
 205         TPM_UNDEFINED,
 206         TPM_UNDEFINED,
 207         TPM_UNDEFINED,
 208         TPM_UNDEFINED,          /* 145 */
 209         TPM_UNDEFINED,
 210         TPM_UNDEFINED,
 211         TPM_UNDEFINED,
 212         TPM_UNDEFINED,
 213         TPM_SHORT,              /* 150 */
 214         TPM_MEDIUM,
 215         TPM_MEDIUM,
 216         TPM_SHORT,
 217         TPM_SHORT,
 218         TPM_UNDEFINED,          /* 155 */
 219         TPM_UNDEFINED,
 220         TPM_UNDEFINED,
 221         TPM_UNDEFINED,
 222         TPM_UNDEFINED,
 223         TPM_SHORT,              /* 160 */
 224         TPM_SHORT,
 225         TPM_SHORT,
 226         TPM_SHORT,
 227         TPM_UNDEFINED,
 228         TPM_UNDEFINED,          /* 165 */
 229         TPM_UNDEFINED,
 230         TPM_UNDEFINED,
 231         TPM_UNDEFINED,
 232         TPM_UNDEFINED,
 233         TPM_LONG,               /* 170 */
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,
 236         TPM_UNDEFINED,
 237         TPM_UNDEFINED,
 238         TPM_UNDEFINED,          /* 175 */
 239         TPM_UNDEFINED,
 240         TPM_UNDEFINED,
 241         TPM_UNDEFINED,
 242         TPM_UNDEFINED,
 243         TPM_MEDIUM,             /* 180 */
 244         TPM_SHORT,
 245         TPM_MEDIUM,
 246         TPM_MEDIUM,
 247         TPM_MEDIUM,
 248         TPM_MEDIUM,             /* 185 */
 249         TPM_SHORT,
 250         TPM_UNDEFINED,
 251         TPM_UNDEFINED,
 252         TPM_UNDEFINED,
 253         TPM_UNDEFINED,          /* 190 */
 254         TPM_UNDEFINED,
 255         TPM_UNDEFINED,
 256         TPM_UNDEFINED,
 257         TPM_UNDEFINED,
 258         TPM_UNDEFINED,          /* 195 */
 259         TPM_UNDEFINED,
 260         TPM_UNDEFINED,
 261         TPM_UNDEFINED,
 262         TPM_UNDEFINED,
 263         TPM_SHORT,              /* 200 */
 264         TPM_UNDEFINED,
 265         TPM_UNDEFINED,
 266         TPM_UNDEFINED,
 267         TPM_SHORT,
 268         TPM_SHORT,              /* 205 */
 269         TPM_SHORT,
 270         TPM_SHORT,
 271         TPM_SHORT,
 272         TPM_SHORT,
 273         TPM_MEDIUM,             /* 210 */
 274         TPM_UNDEFINED,
 275         TPM_MEDIUM,
 276         TPM_MEDIUM,
 277         TPM_MEDIUM,
 278         TPM_UNDEFINED,          /* 215 */
 279         TPM_MEDIUM,
 280         TPM_UNDEFINED,
 281         TPM_UNDEFINED,
 282         TPM_SHORT,
 283         TPM_SHORT,              /* 220 */
 284         TPM_SHORT,
 285         TPM_SHORT,
 286         TPM_SHORT,
 287         TPM_SHORT,
 288         TPM_UNDEFINED,          /* 225 */
 289         TPM_UNDEFINED,
 290         TPM_UNDEFINED,
 291         TPM_UNDEFINED,
 292         TPM_UNDEFINED,
 293         TPM_SHORT,              /* 230 */
 294         TPM_LONG,
 295         TPM_MEDIUM,
 296         TPM_UNDEFINED,
 297         TPM_UNDEFINED,
 298         TPM_UNDEFINED,          /* 235 */
 299         TPM_UNDEFINED,
 300         TPM_UNDEFINED,
 301         TPM_UNDEFINED,
 302         TPM_UNDEFINED,
 303         TPM_SHORT,              /* 240 */
 304         TPM_UNDEFINED,
 305         TPM_MEDIUM,
 306 };
 307
 308 /*
 309  * Returns max number of jiffies to wait
 310  */
 311 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 312                                            u32 ordinal)
 313 {
 314         int duration_idx = TPM_UNDEFINED;
 315         int duration = 0;
 316         u8 category = (ordinal >> 24) & 0xFF;
 317
 318         if ((category == TPM_PROTECTED_COMMAND && ordinal < TPM_MAX_ORDINAL) ||
 319             (category == TPM_CONNECTION_COMMAND && ordinal < TSC_MAX_ORDINAL))
 320                 duration_idx = tpm_ordinal_duration[ordinal];
 321
 322         if (duration_idx != TPM_UNDEFINED)
 323                 duration = chip->vendor.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  * Internal kernel interface to transmit TPM commands
 333  */
 334 ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 335                      size_t bufsiz)
 336 {
 337         ssize_t rc;
 338         u32 count, ordinal;
 339         unsigned long stop;
 340
 341         if (bufsiz > TPM_BUFSIZE)
 342                 bufsiz = TPM_BUFSIZE;
 343
 344         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 345         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 346         if (count == 0)
 347                 return -ENODATA;
 348         if (count > bufsiz) {
 349                 dev_err(chip->dev,
 350                         "invalid count value %x %zx\n", count, bufsiz);
 351                 return -E2BIG;
 352         }
 353
 354         mutex_lock(&chip->tpm_mutex);
 355
 356         rc = chip->ops->send(chip, (u8 *) buf, count);
 357         if (rc < 0) {
 358                 dev_err(chip->dev,
 359                         "tpm_transmit: tpm_send: error %zd\n", rc);
 360                 goto out;
 361         }
 362
 363         if (chip->vendor.irq)
 364                 goto out_recv;
 365
 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->dev, "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->dev, "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->dev,
 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->dev, "A TPM error (%d) occurred %s\n", err, desc);
 418
 419         return err;
 420 }
 421
 422 #define TPM_INTERNAL_RESULT_SIZE 200
 423 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 424 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 425
 426 static const struct tpm_input_header tpm_getcap_header = {
 427         .tag = TPM_TAG_RQU_COMMAND,
 428         .length = cpu_to_be32(22),
 429         .ordinal = TPM_ORD_GET_CAP
 430 };
 431
 432 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
 433                    const char *desc)
 434 {
 435         struct tpm_cmd_t tpm_cmd;
 436         int rc;
 437         struct tpm_chip *chip = dev_get_drvdata(dev);
 438
 439         tpm_cmd.header.in = tpm_getcap_header;
 440         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 441                 tpm_cmd.params.getcap_in.cap = subcap_id;
 442                 /*subcap field not necessary */
 443                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 444                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 445         } else {
 446                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 447                     subcap_id == TPM_CAP_FLAG_VOL)
 448                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 449                 else
 450                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 451                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 452                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 453         }
 454         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
 455         if (!rc)
 456                 *cap = tpm_cmd.params.getcap_out.cap;
 457         return rc;
 458 }
 459
 460 void tpm_gen_interrupt(struct tpm_chip *chip)
 461 {
 462         struct  tpm_cmd_t tpm_cmd;
 463         ssize_t rc;
 464
 465         tpm_cmd.header.in = tpm_getcap_header;
 466         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 467         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 468         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 469
 470         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 471                               "attempting to determine the timeouts");
 472 }
 473 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 474
 475 #define TPM_ORD_STARTUP cpu_to_be32(153)
 476 #define TPM_ST_CLEAR cpu_to_be16(1)
 477 #define TPM_ST_STATE cpu_to_be16(2)
 478 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 479 static const struct tpm_input_header tpm_startup_header = {
 480         .tag = TPM_TAG_RQU_COMMAND,
 481         .length = cpu_to_be32(12),
 482         .ordinal = TPM_ORD_STARTUP
 483 };
 484
 485 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 486 {
 487         struct tpm_cmd_t start_cmd;
 488         start_cmd.header.in = tpm_startup_header;
 489         start_cmd.params.startup_in.startup_type = startup_type;
 490         return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
 491                                 "attempting to start the TPM");
 492 }
 493
 494 int tpm_get_timeouts(struct tpm_chip *chip)
 495 {
 496         struct tpm_cmd_t tpm_cmd;
 497         unsigned long new_timeout[4];
 498         unsigned long old_timeout[4];
 499         struct duration_t *duration_cap;
 500         ssize_t rc;
 501
 502         tpm_cmd.header.in = tpm_getcap_header;
 503         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 504         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 505         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 506         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
 507
 508         if (rc == TPM_ERR_INVALID_POSTINIT) {
 509                 /* The TPM is not started, we are the first to talk to it.
 510                    Execute a startup command. */
 511                 dev_info(chip->dev, "Issuing TPM_STARTUP");
 512                 if (tpm_startup(chip, TPM_ST_CLEAR))
 513                         return rc;
 514
 515                 tpm_cmd.header.in = tpm_getcap_header;
 516                 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 517                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 518                 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 519                 rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 520                                   NULL);
 521         }
 522         if (rc) {
 523                 dev_err(chip->dev,
 524                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 525                         rc);
 526                 goto duration;
 527         }
 528
 529         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 530             be32_to_cpu(tpm_cmd.header.out.length)
 531             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 532                 return -EINVAL;
 533
 534         old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
 535         old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
 536         old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
 537         old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
 538         memcpy(new_timeout, old_timeout, sizeof(new_timeout));
 539
 540         /*
 541          * Provide ability for vendor overrides of timeout values in case
 542          * of misreporting.
 543          */
 544         if (chip->ops->update_timeouts != NULL)
 545                 chip->vendor.timeout_adjusted =
 546                         chip->ops->update_timeouts(chip, new_timeout);
 547
 548         if (!chip->vendor.timeout_adjusted) {
 549                 /* Don't overwrite default if value is 0 */
 550                 if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
 551                         int i;
 552
 553                         /* timeouts in msec rather usec */
 554                         for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
 555                                 new_timeout[i] *= 1000;
 556                         chip->vendor.timeout_adjusted = true;
 557                 }
 558         }
 559
 560         /* Report adjusted timeouts */
 561         if (chip->vendor.timeout_adjusted) {
 562                 dev_info(chip->dev,
 563                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 564                          old_timeout[0], new_timeout[0],
 565                          old_timeout[1], new_timeout[1],
 566                          old_timeout[2], new_timeout[2],
 567                          old_timeout[3], new_timeout[3]);
 568         }
 569
 570         chip->vendor.timeout_a = usecs_to_jiffies(new_timeout[0]);
 571         chip->vendor.timeout_b = usecs_to_jiffies(new_timeout[1]);
 572         chip->vendor.timeout_c = usecs_to_jiffies(new_timeout[2]);
 573         chip->vendor.timeout_d = usecs_to_jiffies(new_timeout[3]);
 574
 575 duration:
 576         tpm_cmd.header.in = tpm_getcap_header;
 577         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 578         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 579         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 580
 581         rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 582                               "attempting to determine the durations");
 583         if (rc)
 584                 return rc;
 585
 586         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 587             be32_to_cpu(tpm_cmd.header.out.length)
 588             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 589                 return -EINVAL;
 590
 591         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 592         chip->vendor.duration[TPM_SHORT] =
 593             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 594         chip->vendor.duration[TPM_MEDIUM] =
 595             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 596         chip->vendor.duration[TPM_LONG] =
 597             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 598
 599         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 600          * value wrong and apparently reports msecs rather than usecs. So we
 601          * fix up the resulting too-small TPM_SHORT value to make things work.
 602          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 603          */
 604         if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
 605                 chip->vendor.duration[TPM_SHORT] = HZ;
 606                 chip->vendor.duration[TPM_MEDIUM] *= 1000;
 607                 chip->vendor.duration[TPM_LONG] *= 1000;
 608                 chip->vendor.duration_adjusted = true;
 609                 dev_info(chip->dev, "Adjusting TPM timeout parameters.");
 610         }
 611         return 0;
 612 }
 613 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 614
 615 #define TPM_ORD_CONTINUE_SELFTEST 83
 616 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 617
 618 static struct tpm_input_header continue_selftest_header = {
 619         .tag = TPM_TAG_RQU_COMMAND,
 620         .length = cpu_to_be32(10),
 621         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 622 };
 623
 624 /**
 625  * tpm_continue_selftest -- run TPM's selftest
 626  * @chip: TPM chip to use
 627  *
 628  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 629  * a TPM error code.
 630  */
 631 static int tpm_continue_selftest(struct tpm_chip *chip)
 632 {
 633         int rc;
 634         struct tpm_cmd_t cmd;
 635
 636         cmd.header.in = continue_selftest_header;
 637         rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 638                               "continue selftest");
 639         return rc;
 640 }
 641
 642 /*
 643  * tpm_chip_find_get - return tpm_chip for given chip number
 644  */
 645 static struct tpm_chip *tpm_chip_find_get(int chip_num)
 646 {
 647         struct tpm_chip *pos, *chip = NULL;
 648
 649         rcu_read_lock();
 650         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
 651                 if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
 652                         continue;
 653
 654                 if (try_module_get(pos->dev->driver->owner)) {
 655                         chip = pos;
 656                         break;
 657                 }
 658         }
 659         rcu_read_unlock();
 660         return chip;
 661 }
 662
 663 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 664 #define READ_PCR_RESULT_SIZE 30
 665 static struct tpm_input_header pcrread_header = {
 666         .tag = TPM_TAG_RQU_COMMAND,
 667         .length = cpu_to_be32(14),
 668         .ordinal = TPM_ORDINAL_PCRREAD
 669 };
 670
 671 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 672 {
 673         int rc;
 674         struct tpm_cmd_t cmd;
 675
 676         cmd.header.in = pcrread_header;
 677         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 678         rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 679                               "attempting to read a pcr value");
 680
 681         if (rc == 0)
 682                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 683                        TPM_DIGEST_SIZE);
 684         return rc;
 685 }
 686
 687 /**
 688  * tpm_pcr_read - read a pcr value
 689  * @chip_num:   tpm idx # or ANY
 690  * @pcr_idx:    pcr idx to retrieve
 691  * @res_buf:    TPM_PCR value
 692  *              size of res_buf is 20 bytes (or NULL if you don't care)
 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 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 699 {
 700         struct tpm_chip *chip;
 701         int rc;
 702
 703         chip = tpm_chip_find_get(chip_num);
 704         if (chip == NULL)
 705                 return -ENODEV;
 706         rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 707         tpm_chip_put(chip);
 708         return rc;
 709 }
 710 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 711
 712 /**
 713  * tpm_pcr_extend - extend pcr value with hash
 714  * @chip_num:   tpm idx # or AN&
 715  * @pcr_idx:    pcr idx to extend
 716  * @hash:       hash value used to extend pcr value
 717  *
 718  * The TPM driver should be built-in, but for whatever reason it
 719  * isn't, protect against the chip disappearing, by incrementing
 720  * the module usage count.
 721  */
 722 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 723 #define EXTEND_PCR_RESULT_SIZE 34
 724 static struct tpm_input_header pcrextend_header = {
 725         .tag = TPM_TAG_RQU_COMMAND,
 726         .length = cpu_to_be32(34),
 727         .ordinal = TPM_ORD_PCR_EXTEND
 728 };
 729
 730 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 731 {
 732         struct tpm_cmd_t cmd;
 733         int rc;
 734         struct tpm_chip *chip;
 735
 736         chip = tpm_chip_find_get(chip_num);
 737         if (chip == NULL)
 738                 return -ENODEV;
 739
 740         cmd.header.in = pcrextend_header;
 741         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 742         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 743         rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 744                               "attempting extend a PCR value");
 745
 746         tpm_chip_put(chip);
 747         return rc;
 748 }
 749 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 750
 751 /**
 752  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 753  *                   can receive further commands
 754  * @chip: TPM chip to use
 755  *
 756  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 757  * a TPM error code.
 758  */
 759 int tpm_do_selftest(struct tpm_chip *chip)
 760 {
 761         int rc;
 762         unsigned int loops;
 763         unsigned int delay_msec = 100;
 764         unsigned long duration;
 765         struct tpm_cmd_t cmd;
 766
 767         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 768
 769         loops = jiffies_to_msecs(duration) / delay_msec;
 770
 771         rc = tpm_continue_selftest(chip);
 772         /* This may fail if there was no TPM driver during a suspend/resume
 773          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 774          */
 775         if (rc)
 776                 return rc;
 777
 778         do {
 779                 /* Attempt to read a PCR value */
 780                 cmd.header.in = pcrread_header;
 781                 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
 782                 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
 783                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 784                  * around 300ms while the self test is ongoing, keep trying
 785                  * until the self test duration expires. */
 786                 if (rc == -ETIME) {
 787                         dev_info(chip->dev, HW_ERR "TPM command timed out during continue self test");
 788                         msleep(delay_msec);
 789                         continue;
 790                 }
 791
 792                 if (rc < TPM_HEADER_SIZE)
 793                         return -EFAULT;
 794
 795                 rc = be32_to_cpu(cmd.header.out.return_code);
 796                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 797                         dev_info(chip->dev,
 798                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 799                         /* TPM is disabled and/or deactivated; driver can
 800                          * proceed and TPM does handle commands for
 801                          * suspend/resume correctly
 802                          */
 803                         return 0;
 804                 }
 805                 if (rc != TPM_WARN_DOING_SELFTEST)
 806                         return rc;
 807                 msleep(delay_msec);
 808         } while (--loops > 0);
 809
 810         return rc;
 811 }
 812 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 813
 814 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 815 {
 816         struct tpm_chip *chip;
 817         int rc;
 818
 819         chip = tpm_chip_find_get(chip_num);
 820         if (chip == NULL)
 821                 return -ENODEV;
 822
 823         rc = tpm_transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
 824
 825         tpm_chip_put(chip);
 826         return rc;
 827 }
 828 EXPORT_SYMBOL_GPL(tpm_send);
 829
 830 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 831                                         bool check_cancel, bool *canceled)
 832 {
 833         u8 status = chip->ops->status(chip);
 834
 835         *canceled = false;
 836         if ((status & mask) == mask)
 837                 return true;
 838         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 839                 *canceled = true;
 840                 return true;
 841         }
 842         return false;
 843 }
 844
 845 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 846                       wait_queue_head_t *queue, bool check_cancel)
 847 {
 848         unsigned long stop;
 849         long rc;
 850         u8 status;
 851         bool canceled = false;
 852
 853         /* check current status */
 854         status = chip->ops->status(chip);
 855         if ((status & mask) == mask)
 856                 return 0;
 857
 858         stop = jiffies + timeout;
 859
 860         if (chip->vendor.irq) {
 861 again:
 862                 timeout = stop - jiffies;
 863                 if ((long)timeout <= 0)
 864                         return -ETIME;
 865                 rc = wait_event_interruptible_timeout(*queue,
 866                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 867                                                &canceled),
 868                         timeout);
 869                 if (rc > 0) {
 870                         if (canceled)
 871                                 return -ECANCELED;
 872                         return 0;
 873                 }
 874                 if (rc == -ERESTARTSYS && freezing(current)) {
 875                         clear_thread_flag(TIF_SIGPENDING);
 876                         goto again;
 877                 }
 878         } else {
 879                 do {
 880                         msleep(TPM_TIMEOUT);
 881                         status = chip->ops->status(chip);
 882                         if ((status & mask) == mask)
 883                                 return 0;
 884                 } while (time_before(jiffies, stop));
 885         }
 886         return -ETIME;
 887 }
 888 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 889
 890 void tpm_remove_hardware(struct device *dev)
 891 {
 892         struct tpm_chip *chip = dev_get_drvdata(dev);
 893
 894         if (chip == NULL) {
 895                 dev_err(dev, "No device data found\n");
 896                 return;
 897         }
 898
 899         spin_lock(&driver_lock);
 900         list_del_rcu(&chip->list);
 901         spin_unlock(&driver_lock);
 902         synchronize_rcu();
 903
 904         tpm_dev_del_device(chip);
 905         tpm_sysfs_del_device(chip);
 906         tpm_remove_ppi(&dev->kobj);
 907         tpm_bios_log_teardown(chip->bios_dir);
 908
 909         /* write it this way to be explicit (chip->dev == dev) */
 910         put_device(chip->dev);
 911 }
 912 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
 913
 914 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 915 #define SAVESTATE_RESULT_SIZE 10
 916
 917 static struct tpm_input_header savestate_header = {
 918         .tag = TPM_TAG_RQU_COMMAND,
 919         .length = cpu_to_be32(10),
 920         .ordinal = TPM_ORD_SAVESTATE
 921 };
 922
 923 /*
 924  * We are about to suspend. Save the TPM state
 925  * so that it can be restored.
 926  */
 927 int tpm_pm_suspend(struct device *dev)
 928 {
 929         struct tpm_chip *chip = dev_get_drvdata(dev);
 930         struct tpm_cmd_t cmd;
 931         int rc, try;
 932
 933         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 934
 935         if (chip == NULL)
 936                 return -ENODEV;
 937
 938         /* for buggy tpm, flush pcrs with extend to selected dummy */
 939         if (tpm_suspend_pcr) {
 940                 cmd.header.in = pcrextend_header;
 941                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 942                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 943                        TPM_DIGEST_SIZE);
 944                 rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 945                                       "extending dummy pcr before suspend");
 946         }
 947
 948         /* now do the actual savestate */
 949         for (try = 0; try < TPM_RETRY; try++) {
 950                 cmd.header.in = savestate_header;
 951                 rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
 952
 953                 /*
 954                  * If the TPM indicates that it is too busy to respond to
 955                  * this command then retry before giving up.  It can take
 956                  * several seconds for this TPM to be ready.
 957                  *
 958                  * This can happen if the TPM has already been sent the
 959                  * SaveState command before the driver has loaded.  TCG 1.2
 960                  * specification states that any communication after SaveState
 961                  * may cause the TPM to invalidate previously saved state.
 962                  */
 963                 if (rc != TPM_WARN_RETRY)
 964                         break;
 965                 msleep(TPM_TIMEOUT_RETRY);
 966         }
 967
 968         if (rc)
 969                 dev_err(chip->dev,
 970                         "Error (%d) sending savestate before suspend\n", rc);
 971         else if (try > 0)
 972                 dev_warn(chip->dev, "TPM savestate took %dms\n",
 973                          try * TPM_TIMEOUT_RETRY);
 974
 975         return rc;
 976 }
 977 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
 978
 979 /*
 980  * Resume from a power safe. The BIOS already restored
 981  * the TPM state.
 982  */
 983 int tpm_pm_resume(struct device *dev)
 984 {
 985         struct tpm_chip *chip = dev_get_drvdata(dev);
 986
 987         if (chip == NULL)
 988                 return -ENODEV;
 989
 990         return 0;
 991 }
 992 EXPORT_SYMBOL_GPL(tpm_pm_resume);
 993
 994 #define TPM_GETRANDOM_RESULT_SIZE       18
 995 static struct tpm_input_header tpm_getrandom_header = {
 996         .tag = TPM_TAG_RQU_COMMAND,
 997         .length = cpu_to_be32(14),
 998         .ordinal = TPM_ORD_GET_RANDOM
 999 };
1000
1001 /**
1002  * tpm_get_random() - Get random bytes from the tpm's RNG
1003  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1004  * @out: destination buffer for the random bytes
1005  * @max: the max number of bytes to write to @out
1006  *
1007  * Returns < 0 on error and the number of bytes read on success
1008  */
1009 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1010 {
1011         struct tpm_chip *chip;
1012         struct tpm_cmd_t tpm_cmd;
1013         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1014         int err, total = 0, retries = 5;
1015         u8 *dest = out;
1016
1017         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1018                 return -EINVAL;
1019
1020         chip = tpm_chip_find_get(chip_num);
1021         if (chip == NULL)
1022                 return -ENODEV;
1023
1024         do {
1025                 tpm_cmd.header.in = tpm_getrandom_header;
1026                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1027
1028                 err = tpm_transmit_cmd(chip, &tpm_cmd,
1029                                    TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1030                                    "attempting get random");
1031                 if (err)
1032                         break;
1033
1034                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1035                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1036
1037                 dest += recd;
1038                 total += recd;
1039                 num_bytes -= recd;
1040         } while (retries-- && total < max);
1041
1042         tpm_chip_put(chip);
1043         return total ? total : -EIO;
1044 }
1045 EXPORT_SYMBOL_GPL(tpm_get_random);
1046
1047 /* In case vendor provided release function, call it too.*/
1048
1049 void tpm_dev_vendor_release(struct tpm_chip *chip)
1050 {
1051         if (!chip)
1052                 return;
1053
1054         clear_bit(chip->dev_num, dev_mask);
1055 }
1056 EXPORT_SYMBOL_GPL(tpm_dev_vendor_release);
1057
1058
1059 /*
1060  * Once all references to platform device are down to 0,
1061  * release all allocated structures.
1062  */
1063 static void tpm_dev_release(struct device *dev)
1064 {
1065         struct tpm_chip *chip = dev_get_drvdata(dev);
1066
1067         if (!chip)
1068                 return;
1069
1070         tpm_dev_vendor_release(chip);
1071
1072         chip->release(dev);
1073         kfree(chip);
1074 }
1075
1076 /*
1077  * Called from tpm_<specific>.c probe function only for devices
1078  * the driver has determined it should claim.  Prior to calling
1079  * this function the specific probe function has called pci_enable_device
1080  * upon errant exit from this function specific probe function should call
1081  * pci_disable_device
1082  */
1083 struct tpm_chip *tpm_register_hardware(struct device *dev,
1084                                        const struct tpm_class_ops *ops)
1085 {
1086         struct tpm_chip *chip;
1087
1088         /* Driver specific per-device data */
1089         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
1090
1091         if (chip == NULL)
1092                 return NULL;
1093
1094         mutex_init(&chip->tpm_mutex);
1095         INIT_LIST_HEAD(&chip->list);
1096
1097         chip->ops = ops;
1098         chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);
1099
1100         if (chip->dev_num >= TPM_NUM_DEVICES) {
1101                 dev_err(dev, "No available tpm device numbers\n");
1102                 goto out_free;
1103         }
1104
1105         set_bit(chip->dev_num, dev_mask);
1106
1107         scnprintf(chip->devname, sizeof(chip->devname), "%s%d", "tpm",
1108                   chip->dev_num);
1109
1110         chip->dev = get_device(dev);
1111         chip->release = dev->release;
1112         dev->release = tpm_dev_release;
1113         dev_set_drvdata(dev, chip);
1114
1115         if (tpm_dev_add_device(chip))
1116                 goto put_device;
1117
1118         if (tpm_sysfs_add_device(chip))
1119                 goto del_misc;
1120
1121         if (tpm_add_ppi(&dev->kobj))
1122                 goto del_sysfs;
1123
1124         chip->bios_dir = tpm_bios_log_setup(chip->devname);
1125
1126         /* Make chip available */
1127         spin_lock(&driver_lock);
1128         list_add_tail_rcu(&chip->list, &tpm_chip_list);
1129         spin_unlock(&driver_lock);
1130
1131         return chip;
1132
1133 del_sysfs:
1134         tpm_sysfs_del_device(chip);
1135 del_misc:
1136         tpm_dev_del_device(chip);
1137 put_device:
1138         put_device(chip->dev);
1139 out_free:
1140         kfree(chip);
1141         return NULL;
1142 }
1143 EXPORT_SYMBOL_GPL(tpm_register_hardware);
1144
1145 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1146 MODULE_DESCRIPTION("TPM Driver");
1147 MODULE_VERSION("2.0");
1148 MODULE_LICENSE("GPL");