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 static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
 402                             int len, const char *desc)
 403 {
 404         int err;
 405
 406         len = tpm_transmit(chip, (u8 *) cmd, len);
 407         if (len <  0)
 408                 return len;
 409         else if (len < TPM_HEADER_SIZE)
 410                 return -EFAULT;
 411
 412         err = be32_to_cpu(cmd->header.out.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 = 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 = 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 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 = 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 = 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 = 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 = transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 635                           "continue selftest");
 636         return rc;
 637 }
 638
 639 /*
 640  * tpm_chip_find_get - return tpm_chip for given chip number
 641  */
 642 static struct tpm_chip *tpm_chip_find_get(int chip_num)
 643 {
 644         struct tpm_chip *pos, *chip = NULL;
 645
 646         rcu_read_lock();
 647         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
 648                 if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
 649                         continue;
 650
 651                 if (try_module_get(pos->dev->driver->owner)) {
 652                         chip = pos;
 653                         break;
 654                 }
 655         }
 656         rcu_read_unlock();
 657         return chip;
 658 }
 659
 660 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 661 #define READ_PCR_RESULT_SIZE 30
 662 static struct tpm_input_header pcrread_header = {
 663         .tag = TPM_TAG_RQU_COMMAND,
 664         .length = cpu_to_be32(14),
 665         .ordinal = TPM_ORDINAL_PCRREAD
 666 };
 667
 668 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 669 {
 670         int rc;
 671         struct tpm_cmd_t cmd;
 672
 673         cmd.header.in = pcrread_header;
 674         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 675         rc = transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 676                           "attempting to read a pcr value");
 677
 678         if (rc == 0)
 679                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 680                        TPM_DIGEST_SIZE);
 681         return rc;
 682 }
 683
 684 /**
 685  * tpm_pcr_read - read a pcr value
 686  * @chip_num:   tpm idx # or ANY
 687  * @pcr_idx:    pcr idx to retrieve
 688  * @res_buf:    TPM_PCR value
 689  *              size of res_buf is 20 bytes (or NULL if you don't care)
 690  *
 691  * The TPM driver should be built-in, but for whatever reason it
 692  * isn't, protect against the chip disappearing, by incrementing
 693  * the module usage count.
 694  */
 695 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 696 {
 697         struct tpm_chip *chip;
 698         int rc;
 699
 700         chip = tpm_chip_find_get(chip_num);
 701         if (chip == NULL)
 702                 return -ENODEV;
 703         rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 704         tpm_chip_put(chip);
 705         return rc;
 706 }
 707 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 708
 709 /**
 710  * tpm_pcr_extend - extend pcr value with hash
 711  * @chip_num:   tpm idx # or AN&
 712  * @pcr_idx:    pcr idx to extend
 713  * @hash:       hash value used to extend pcr value
 714  *
 715  * The TPM driver should be built-in, but for whatever reason it
 716  * isn't, protect against the chip disappearing, by incrementing
 717  * the module usage count.
 718  */
 719 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 720 #define EXTEND_PCR_RESULT_SIZE 34
 721 static struct tpm_input_header pcrextend_header = {
 722         .tag = TPM_TAG_RQU_COMMAND,
 723         .length = cpu_to_be32(34),
 724         .ordinal = TPM_ORD_PCR_EXTEND
 725 };
 726
 727 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 728 {
 729         struct tpm_cmd_t cmd;
 730         int rc;
 731         struct tpm_chip *chip;
 732
 733         chip = tpm_chip_find_get(chip_num);
 734         if (chip == NULL)
 735                 return -ENODEV;
 736
 737         cmd.header.in = pcrextend_header;
 738         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 739         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 740         rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 741                           "attempting extend a PCR value");
 742
 743         tpm_chip_put(chip);
 744         return rc;
 745 }
 746 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 747
 748 /**
 749  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 750  *                   can receive further commands
 751  * @chip: TPM chip to use
 752  *
 753  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 754  * a TPM error code.
 755  */
 756 int tpm_do_selftest(struct tpm_chip *chip)
 757 {
 758         int rc;
 759         unsigned int loops;
 760         unsigned int delay_msec = 100;
 761         unsigned long duration;
 762         struct tpm_cmd_t cmd;
 763
 764         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 765
 766         loops = jiffies_to_msecs(duration) / delay_msec;
 767
 768         rc = tpm_continue_selftest(chip);
 769         /* This may fail if there was no TPM driver during a suspend/resume
 770          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 771          */
 772         if (rc)
 773                 return rc;
 774
 775         do {
 776                 /* Attempt to read a PCR value */
 777                 cmd.header.in = pcrread_header;
 778                 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
 779                 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
 780                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 781                  * around 300ms while the self test is ongoing, keep trying
 782                  * until the self test duration expires. */
 783                 if (rc == -ETIME) {
 784                         dev_info(chip->dev, HW_ERR "TPM command timed out during continue self test");
 785                         msleep(delay_msec);
 786                         continue;
 787                 }
 788
 789                 if (rc < TPM_HEADER_SIZE)
 790                         return -EFAULT;
 791
 792                 rc = be32_to_cpu(cmd.header.out.return_code);
 793                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 794                         dev_info(chip->dev,
 795                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 796                         /* TPM is disabled and/or deactivated; driver can
 797                          * proceed and TPM does handle commands for
 798                          * suspend/resume correctly
 799                          */
 800                         return 0;
 801                 }
 802                 if (rc != TPM_WARN_DOING_SELFTEST)
 803                         return rc;
 804                 msleep(delay_msec);
 805         } while (--loops > 0);
 806
 807         return rc;
 808 }
 809 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 810
 811 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 812 {
 813         struct tpm_chip *chip;
 814         int rc;
 815
 816         chip = tpm_chip_find_get(chip_num);
 817         if (chip == NULL)
 818                 return -ENODEV;
 819
 820         rc = transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
 821
 822         tpm_chip_put(chip);
 823         return rc;
 824 }
 825 EXPORT_SYMBOL_GPL(tpm_send);
 826
 827 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 828                                         bool check_cancel, bool *canceled)
 829 {
 830         u8 status = chip->ops->status(chip);
 831
 832         *canceled = false;
 833         if ((status & mask) == mask)
 834                 return true;
 835         if (check_cancel && chip->ops->req_canceled(chip, status)) {
 836                 *canceled = true;
 837                 return true;
 838         }
 839         return false;
 840 }
 841
 842 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 843                       wait_queue_head_t *queue, bool check_cancel)
 844 {
 845         unsigned long stop;
 846         long rc;
 847         u8 status;
 848         bool canceled = false;
 849
 850         /* check current status */
 851         status = chip->ops->status(chip);
 852         if ((status & mask) == mask)
 853                 return 0;
 854
 855         stop = jiffies + timeout;
 856
 857         if (chip->vendor.irq) {
 858 again:
 859                 timeout = stop - jiffies;
 860                 if ((long)timeout <= 0)
 861                         return -ETIME;
 862                 rc = wait_event_interruptible_timeout(*queue,
 863                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 864                                                &canceled),
 865                         timeout);
 866                 if (rc > 0) {
 867                         if (canceled)
 868                                 return -ECANCELED;
 869                         return 0;
 870                 }
 871                 if (rc == -ERESTARTSYS && freezing(current)) {
 872                         clear_thread_flag(TIF_SIGPENDING);
 873                         goto again;
 874                 }
 875         } else {
 876                 do {
 877                         msleep(TPM_TIMEOUT);
 878                         status = chip->ops->status(chip);
 879                         if ((status & mask) == mask)
 880                                 return 0;
 881                 } while (time_before(jiffies, stop));
 882         }
 883         return -ETIME;
 884 }
 885 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 886
 887 void tpm_remove_hardware(struct device *dev)
 888 {
 889         struct tpm_chip *chip = dev_get_drvdata(dev);
 890
 891         if (chip == NULL) {
 892                 dev_err(dev, "No device data found\n");
 893                 return;
 894         }
 895
 896         spin_lock(&driver_lock);
 897         list_del_rcu(&chip->list);
 898         spin_unlock(&driver_lock);
 899         synchronize_rcu();
 900
 901         tpm_dev_del_device(chip);
 902         tpm_sysfs_del_device(chip);
 903         tpm_remove_ppi(&dev->kobj);
 904         tpm_bios_log_teardown(chip->bios_dir);
 905
 906         /* write it this way to be explicit (chip->dev == dev) */
 907         put_device(chip->dev);
 908 }
 909 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
 910
 911 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 912 #define SAVESTATE_RESULT_SIZE 10
 913
 914 static struct tpm_input_header savestate_header = {
 915         .tag = TPM_TAG_RQU_COMMAND,
 916         .length = cpu_to_be32(10),
 917         .ordinal = TPM_ORD_SAVESTATE
 918 };
 919
 920 /*
 921  * We are about to suspend. Save the TPM state
 922  * so that it can be restored.
 923  */
 924 int tpm_pm_suspend(struct device *dev)
 925 {
 926         struct tpm_chip *chip = dev_get_drvdata(dev);
 927         struct tpm_cmd_t cmd;
 928         int rc, try;
 929
 930         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 931
 932         if (chip == NULL)
 933                 return -ENODEV;
 934
 935         /* for buggy tpm, flush pcrs with extend to selected dummy */
 936         if (tpm_suspend_pcr) {
 937                 cmd.header.in = pcrextend_header;
 938                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 939                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 940                        TPM_DIGEST_SIZE);
 941                 rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 942                                   "extending dummy pcr before suspend");
 943         }
 944
 945         /* now do the actual savestate */
 946         for (try = 0; try < TPM_RETRY; try++) {
 947                 cmd.header.in = savestate_header;
 948                 rc = transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
 949
 950                 /*
 951                  * If the TPM indicates that it is too busy to respond to
 952                  * this command then retry before giving up.  It can take
 953                  * several seconds for this TPM to be ready.
 954                  *
 955                  * This can happen if the TPM has already been sent the
 956                  * SaveState command before the driver has loaded.  TCG 1.2
 957                  * specification states that any communication after SaveState
 958                  * may cause the TPM to invalidate previously saved state.
 959                  */
 960                 if (rc != TPM_WARN_RETRY)
 961                         break;
 962                 msleep(TPM_TIMEOUT_RETRY);
 963         }
 964
 965         if (rc)
 966                 dev_err(chip->dev,
 967                         "Error (%d) sending savestate before suspend\n", rc);
 968         else if (try > 0)
 969                 dev_warn(chip->dev, "TPM savestate took %dms\n",
 970                          try * TPM_TIMEOUT_RETRY);
 971
 972         return rc;
 973 }
 974 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
 975
 976 /*
 977  * Resume from a power safe. The BIOS already restored
 978  * the TPM state.
 979  */
 980 int tpm_pm_resume(struct device *dev)
 981 {
 982         struct tpm_chip *chip = dev_get_drvdata(dev);
 983
 984         if (chip == NULL)
 985                 return -ENODEV;
 986
 987         return 0;
 988 }
 989 EXPORT_SYMBOL_GPL(tpm_pm_resume);
 990
 991 #define TPM_GETRANDOM_RESULT_SIZE       18
 992 static struct tpm_input_header tpm_getrandom_header = {
 993         .tag = TPM_TAG_RQU_COMMAND,
 994         .length = cpu_to_be32(14),
 995         .ordinal = TPM_ORD_GET_RANDOM
 996 };
 997
 998 /**
 999  * tpm_get_random() - Get random bytes from the tpm's RNG
1000  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1001  * @out: destination buffer for the random bytes
1002  * @max: the max number of bytes to write to @out
1003  *
1004  * Returns < 0 on error and the number of bytes read on success
1005  */
1006 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1007 {
1008         struct tpm_chip *chip;
1009         struct tpm_cmd_t tpm_cmd;
1010         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1011         int err, total = 0, retries = 5;
1012         u8 *dest = out;
1013
1014         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1015                 return -EINVAL;
1016
1017         chip = tpm_chip_find_get(chip_num);
1018         if (chip == NULL)
1019                 return -ENODEV;
1020
1021         do {
1022                 tpm_cmd.header.in = tpm_getrandom_header;
1023                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1024
1025                 err = transmit_cmd(chip, &tpm_cmd,
1026                                    TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1027                                    "attempting get random");
1028                 if (err)
1029                         break;
1030
1031                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1032                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1033
1034                 dest += recd;
1035                 total += recd;
1036                 num_bytes -= recd;
1037         } while (retries-- && total < max);
1038
1039         tpm_chip_put(chip);
1040         return total ? total : -EIO;
1041 }
1042 EXPORT_SYMBOL_GPL(tpm_get_random);
1043
1044 /* In case vendor provided release function, call it too.*/
1045
1046 void tpm_dev_vendor_release(struct tpm_chip *chip)
1047 {
1048         if (!chip)
1049                 return;
1050
1051         clear_bit(chip->dev_num, dev_mask);
1052 }
1053 EXPORT_SYMBOL_GPL(tpm_dev_vendor_release);
1054
1055
1056 /*
1057  * Once all references to platform device are down to 0,
1058  * release all allocated structures.
1059  */
1060 static void tpm_dev_release(struct device *dev)
1061 {
1062         struct tpm_chip *chip = dev_get_drvdata(dev);
1063
1064         if (!chip)
1065                 return;
1066
1067         tpm_dev_vendor_release(chip);
1068
1069         chip->release(dev);
1070         kfree(chip);
1071 }
1072
1073 /*
1074  * Called from tpm_<specific>.c probe function only for devices
1075  * the driver has determined it should claim.  Prior to calling
1076  * this function the specific probe function has called pci_enable_device
1077  * upon errant exit from this function specific probe function should call
1078  * pci_disable_device
1079  */
1080 struct tpm_chip *tpm_register_hardware(struct device *dev,
1081                                        const struct tpm_class_ops *ops)
1082 {
1083         struct tpm_chip *chip;
1084
1085         /* Driver specific per-device data */
1086         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
1087
1088         if (chip == NULL)
1089                 return NULL;
1090
1091         mutex_init(&chip->tpm_mutex);
1092         INIT_LIST_HEAD(&chip->list);
1093
1094         chip->ops = ops;
1095         chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);
1096
1097         if (chip->dev_num >= TPM_NUM_DEVICES) {
1098                 dev_err(dev, "No available tpm device numbers\n");
1099                 goto out_free;
1100         }
1101
1102         set_bit(chip->dev_num, dev_mask);
1103
1104         scnprintf(chip->devname, sizeof(chip->devname), "%s%d", "tpm",
1105                   chip->dev_num);
1106
1107         chip->dev = get_device(dev);
1108         chip->release = dev->release;
1109         dev->release = tpm_dev_release;
1110         dev_set_drvdata(dev, chip);
1111
1112         if (tpm_dev_add_device(chip))
1113                 goto put_device;
1114
1115         if (tpm_sysfs_add_device(chip))
1116                 goto del_misc;
1117
1118         if (tpm_add_ppi(&dev->kobj))
1119                 goto del_sysfs;
1120
1121         chip->bios_dir = tpm_bios_log_setup(chip->devname);
1122
1123         /* Make chip available */
1124         spin_lock(&driver_lock);
1125         list_add_rcu(&chip->list, &tpm_chip_list);
1126         spin_unlock(&driver_lock);
1127
1128         return chip;
1129
1130 del_sysfs:
1131         tpm_sysfs_del_device(chip);
1132 del_misc:
1133         tpm_dev_del_device(chip);
1134 put_device:
1135         put_device(chip->dev);
1136 out_free:
1137         kfree(chip);
1138         return NULL;
1139 }
1140 EXPORT_SYMBOL_GPL(tpm_register_hardware);
1141
1142 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1143 MODULE_DESCRIPTION("TPM Driver");
1144 MODULE_VERSION("2.0");
1145 MODULE_LICENSE("GPL");