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->vendor.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->vendor.status(chip);
 369                 if ((status & chip->vendor.req_complete_mask) ==
 370                     chip->vendor.req_complete_val)
 371                         goto out_recv;
 372
 373                 if (chip->vendor.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->vendor.cancel(chip);
 384         dev_err(chip->dev, "Operation Timed out\n");
 385         rc = -ETIME;
 386         goto out;
 387
 388 out_recv:
 389         rc = chip->vendor.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         struct timeout_t *timeout_cap;
 495         struct duration_t *duration_cap;
 496         ssize_t rc;
 497         u32 timeout;
 498         unsigned int scale = 1;
 499
 500         tpm_cmd.header.in = tpm_getcap_header;
 501         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 502         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 503         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 504         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
 505
 506         if (rc == TPM_ERR_INVALID_POSTINIT) {
 507                 /* The TPM is not started, we are the first to talk to it.
 508                    Execute a startup command. */
 509                 dev_info(chip->dev, "Issuing TPM_STARTUP");
 510                 if (tpm_startup(chip, TPM_ST_CLEAR))
 511                         return rc;
 512
 513                 tpm_cmd.header.in = tpm_getcap_header;
 514                 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 515                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 516                 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 517                 rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 518                                   NULL);
 519         }
 520         if (rc) {
 521                 dev_err(chip->dev,
 522                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 523                         rc);
 524                 goto duration;
 525         }
 526
 527         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 528             be32_to_cpu(tpm_cmd.header.out.length)
 529             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 530                 return -EINVAL;
 531
 532         timeout_cap = &tpm_cmd.params.getcap_out.cap.timeout;
 533         /* Don't overwrite default if value is 0 */
 534         timeout = be32_to_cpu(timeout_cap->a);
 535         if (timeout && timeout < 1000) {
 536                 /* timeouts in msec rather usec */
 537                 scale = 1000;
 538                 chip->vendor.timeout_adjusted = true;
 539         }
 540         if (timeout)
 541                 chip->vendor.timeout_a = usecs_to_jiffies(timeout * scale);
 542         timeout = be32_to_cpu(timeout_cap->b);
 543         if (timeout)
 544                 chip->vendor.timeout_b = usecs_to_jiffies(timeout * scale);
 545         timeout = be32_to_cpu(timeout_cap->c);
 546         if (timeout)
 547                 chip->vendor.timeout_c = usecs_to_jiffies(timeout * scale);
 548         timeout = be32_to_cpu(timeout_cap->d);
 549         if (timeout)
 550                 chip->vendor.timeout_d = usecs_to_jiffies(timeout * scale);
 551
 552 duration:
 553         tpm_cmd.header.in = tpm_getcap_header;
 554         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 555         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 556         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 557
 558         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 559                         "attempting to determine the durations");
 560         if (rc)
 561                 return rc;
 562
 563         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 564             be32_to_cpu(tpm_cmd.header.out.length)
 565             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 566                 return -EINVAL;
 567
 568         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 569         chip->vendor.duration[TPM_SHORT] =
 570             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 571         chip->vendor.duration[TPM_MEDIUM] =
 572             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 573         chip->vendor.duration[TPM_LONG] =
 574             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 575
 576         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 577          * value wrong and apparently reports msecs rather than usecs. So we
 578          * fix up the resulting too-small TPM_SHORT value to make things work.
 579          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 580          */
 581         if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
 582                 chip->vendor.duration[TPM_SHORT] = HZ;
 583                 chip->vendor.duration[TPM_MEDIUM] *= 1000;
 584                 chip->vendor.duration[TPM_LONG] *= 1000;
 585                 chip->vendor.duration_adjusted = true;
 586                 dev_info(chip->dev, "Adjusting TPM timeout parameters.");
 587         }
 588         return 0;
 589 }
 590 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 591
 592 #define TPM_ORD_CONTINUE_SELFTEST 83
 593 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 594
 595 static struct tpm_input_header continue_selftest_header = {
 596         .tag = TPM_TAG_RQU_COMMAND,
 597         .length = cpu_to_be32(10),
 598         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 599 };
 600
 601 /**
 602  * tpm_continue_selftest -- run TPM's selftest
 603  * @chip: TPM chip to use
 604  *
 605  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 606  * a TPM error code.
 607  */
 608 static int tpm_continue_selftest(struct tpm_chip *chip)
 609 {
 610         int rc;
 611         struct tpm_cmd_t cmd;
 612
 613         cmd.header.in = continue_selftest_header;
 614         rc = transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 615                           "continue selftest");
 616         return rc;
 617 }
 618
 619 /*
 620  * tpm_chip_find_get - return tpm_chip for given chip number
 621  */
 622 static struct tpm_chip *tpm_chip_find_get(int chip_num)
 623 {
 624         struct tpm_chip *pos, *chip = NULL;
 625
 626         rcu_read_lock();
 627         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
 628                 if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
 629                         continue;
 630
 631                 if (try_module_get(pos->dev->driver->owner)) {
 632                         chip = pos;
 633                         break;
 634                 }
 635         }
 636         rcu_read_unlock();
 637         return chip;
 638 }
 639
 640 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 641 #define READ_PCR_RESULT_SIZE 30
 642 static struct tpm_input_header pcrread_header = {
 643         .tag = TPM_TAG_RQU_COMMAND,
 644         .length = cpu_to_be32(14),
 645         .ordinal = TPM_ORDINAL_PCRREAD
 646 };
 647
 648 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 649 {
 650         int rc;
 651         struct tpm_cmd_t cmd;
 652
 653         cmd.header.in = pcrread_header;
 654         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 655         rc = transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 656                           "attempting to read a pcr value");
 657
 658         if (rc == 0)
 659                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 660                        TPM_DIGEST_SIZE);
 661         return rc;
 662 }
 663
 664 /**
 665  * tpm_pcr_read - read a pcr value
 666  * @chip_num:   tpm idx # or ANY
 667  * @pcr_idx:    pcr idx to retrieve
 668  * @res_buf:    TPM_PCR value
 669  *              size of res_buf is 20 bytes (or NULL if you don't care)
 670  *
 671  * The TPM driver should be built-in, but for whatever reason it
 672  * isn't, protect against the chip disappearing, by incrementing
 673  * the module usage count.
 674  */
 675 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 676 {
 677         struct tpm_chip *chip;
 678         int rc;
 679
 680         chip = tpm_chip_find_get(chip_num);
 681         if (chip == NULL)
 682                 return -ENODEV;
 683         rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 684         tpm_chip_put(chip);
 685         return rc;
 686 }
 687 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 688
 689 /**
 690  * tpm_pcr_extend - extend pcr value with hash
 691  * @chip_num:   tpm idx # or AN&
 692  * @pcr_idx:    pcr idx to extend
 693  * @hash:       hash value used to extend pcr value
 694  *
 695  * The TPM driver should be built-in, but for whatever reason it
 696  * isn't, protect against the chip disappearing, by incrementing
 697  * the module usage count.
 698  */
 699 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 700 #define EXTEND_PCR_RESULT_SIZE 34
 701 static struct tpm_input_header pcrextend_header = {
 702         .tag = TPM_TAG_RQU_COMMAND,
 703         .length = cpu_to_be32(34),
 704         .ordinal = TPM_ORD_PCR_EXTEND
 705 };
 706
 707 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 708 {
 709         struct tpm_cmd_t cmd;
 710         int rc;
 711         struct tpm_chip *chip;
 712
 713         chip = tpm_chip_find_get(chip_num);
 714         if (chip == NULL)
 715                 return -ENODEV;
 716
 717         cmd.header.in = pcrextend_header;
 718         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 719         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 720         rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 721                           "attempting extend a PCR value");
 722
 723         tpm_chip_put(chip);
 724         return rc;
 725 }
 726 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 727
 728 /**
 729  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 730  *                   can receive further commands
 731  * @chip: TPM chip to use
 732  *
 733  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 734  * a TPM error code.
 735  */
 736 int tpm_do_selftest(struct tpm_chip *chip)
 737 {
 738         int rc;
 739         unsigned int loops;
 740         unsigned int delay_msec = 100;
 741         unsigned long duration;
 742         struct tpm_cmd_t cmd;
 743
 744         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 745
 746         loops = jiffies_to_msecs(duration) / delay_msec;
 747
 748         rc = tpm_continue_selftest(chip);
 749         /* This may fail if there was no TPM driver during a suspend/resume
 750          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 751          */
 752         if (rc)
 753                 return rc;
 754
 755         do {
 756                 /* Attempt to read a PCR value */
 757                 cmd.header.in = pcrread_header;
 758                 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
 759                 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
 760                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
 761                  * around 300ms while the self test is ongoing, keep trying
 762                  * until the self test duration expires. */
 763                 if (rc == -ETIME) {
 764                         dev_info(chip->dev, HW_ERR "TPM command timed out during continue self test");
 765                         msleep(delay_msec);
 766                         continue;
 767                 }
 768
 769                 if (rc < TPM_HEADER_SIZE)
 770                         return -EFAULT;
 771
 772                 rc = be32_to_cpu(cmd.header.out.return_code);
 773                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 774                         dev_info(chip->dev,
 775                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 776                         /* TPM is disabled and/or deactivated; driver can
 777                          * proceed and TPM does handle commands for
 778                          * suspend/resume correctly
 779                          */
 780                         return 0;
 781                 }
 782                 if (rc != TPM_WARN_DOING_SELFTEST)
 783                         return rc;
 784                 msleep(delay_msec);
 785         } while (--loops > 0);
 786
 787         return rc;
 788 }
 789 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 790
 791 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 792 {
 793         struct tpm_chip *chip;
 794         int rc;
 795
 796         chip = tpm_chip_find_get(chip_num);
 797         if (chip == NULL)
 798                 return -ENODEV;
 799
 800         rc = transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
 801
 802         tpm_chip_put(chip);
 803         return rc;
 804 }
 805 EXPORT_SYMBOL_GPL(tpm_send);
 806
 807 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 808                                         bool check_cancel, bool *canceled)
 809 {
 810         u8 status = chip->vendor.status(chip);
 811
 812         *canceled = false;
 813         if ((status & mask) == mask)
 814                 return true;
 815         if (check_cancel && chip->vendor.req_canceled(chip, status)) {
 816                 *canceled = true;
 817                 return true;
 818         }
 819         return false;
 820 }
 821
 822 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 823                       wait_queue_head_t *queue, bool check_cancel)
 824 {
 825         unsigned long stop;
 826         long rc;
 827         u8 status;
 828         bool canceled = false;
 829
 830         /* check current status */
 831         status = chip->vendor.status(chip);
 832         if ((status & mask) == mask)
 833                 return 0;
 834
 835         stop = jiffies + timeout;
 836
 837         if (chip->vendor.irq) {
 838 again:
 839                 timeout = stop - jiffies;
 840                 if ((long)timeout <= 0)
 841                         return -ETIME;
 842                 rc = wait_event_interruptible_timeout(*queue,
 843                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
 844                                                &canceled),
 845                         timeout);
 846                 if (rc > 0) {
 847                         if (canceled)
 848                                 return -ECANCELED;
 849                         return 0;
 850                 }
 851                 if (rc == -ERESTARTSYS && freezing(current)) {
 852                         clear_thread_flag(TIF_SIGPENDING);
 853                         goto again;
 854                 }
 855         } else {
 856                 do {
 857                         msleep(TPM_TIMEOUT);
 858                         status = chip->vendor.status(chip);
 859                         if ((status & mask) == mask)
 860                                 return 0;
 861                 } while (time_before(jiffies, stop));
 862         }
 863         return -ETIME;
 864 }
 865 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 866
 867 void tpm_remove_hardware(struct device *dev)
 868 {
 869         struct tpm_chip *chip = dev_get_drvdata(dev);
 870
 871         if (chip == NULL) {
 872                 dev_err(dev, "No device data found\n");
 873                 return;
 874         }
 875
 876         spin_lock(&driver_lock);
 877         list_del_rcu(&chip->list);
 878         spin_unlock(&driver_lock);
 879         synchronize_rcu();
 880
 881         tpm_dev_del_device(chip);
 882         tpm_sysfs_del_device(chip);
 883         tpm_remove_ppi(&dev->kobj);
 884         tpm_bios_log_teardown(chip->bios_dir);
 885
 886         /* write it this way to be explicit (chip->dev == dev) */
 887         put_device(chip->dev);
 888 }
 889 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
 890
 891 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 892 #define SAVESTATE_RESULT_SIZE 10
 893
 894 static struct tpm_input_header savestate_header = {
 895         .tag = TPM_TAG_RQU_COMMAND,
 896         .length = cpu_to_be32(10),
 897         .ordinal = TPM_ORD_SAVESTATE
 898 };
 899
 900 /*
 901  * We are about to suspend. Save the TPM state
 902  * so that it can be restored.
 903  */
 904 int tpm_pm_suspend(struct device *dev)
 905 {
 906         struct tpm_chip *chip = dev_get_drvdata(dev);
 907         struct tpm_cmd_t cmd;
 908         int rc, try;
 909
 910         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 911
 912         if (chip == NULL)
 913                 return -ENODEV;
 914
 915         /* for buggy tpm, flush pcrs with extend to selected dummy */
 916         if (tpm_suspend_pcr) {
 917                 cmd.header.in = pcrextend_header;
 918                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 919                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 920                        TPM_DIGEST_SIZE);
 921                 rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 922                                   "extending dummy pcr before suspend");
 923         }
 924
 925         /* now do the actual savestate */
 926         for (try = 0; try < TPM_RETRY; try++) {
 927                 cmd.header.in = savestate_header;
 928                 rc = transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, NULL);
 929
 930                 /*
 931                  * If the TPM indicates that it is too busy to respond to
 932                  * this command then retry before giving up.  It can take
 933                  * several seconds for this TPM to be ready.
 934                  *
 935                  * This can happen if the TPM has already been sent the
 936                  * SaveState command before the driver has loaded.  TCG 1.2
 937                  * specification states that any communication after SaveState
 938                  * may cause the TPM to invalidate previously saved state.
 939                  */
 940                 if (rc != TPM_WARN_RETRY)
 941                         break;
 942                 msleep(TPM_TIMEOUT_RETRY);
 943         }
 944
 945         if (rc)
 946                 dev_err(chip->dev,
 947                         "Error (%d) sending savestate before suspend\n", rc);
 948         else if (try > 0)
 949                 dev_warn(chip->dev, "TPM savestate took %dms\n",
 950                          try * TPM_TIMEOUT_RETRY);
 951
 952         return rc;
 953 }
 954 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
 955
 956 /*
 957  * Resume from a power safe. The BIOS already restored
 958  * the TPM state.
 959  */
 960 int tpm_pm_resume(struct device *dev)
 961 {
 962         struct tpm_chip *chip = dev_get_drvdata(dev);
 963
 964         if (chip == NULL)
 965                 return -ENODEV;
 966
 967         return 0;
 968 }
 969 EXPORT_SYMBOL_GPL(tpm_pm_resume);
 970
 971 #define TPM_GETRANDOM_RESULT_SIZE       18
 972 static struct tpm_input_header tpm_getrandom_header = {
 973         .tag = TPM_TAG_RQU_COMMAND,
 974         .length = cpu_to_be32(14),
 975         .ordinal = TPM_ORD_GET_RANDOM
 976 };
 977
 978 /**
 979  * tpm_get_random() - Get random bytes from the tpm's RNG
 980  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
 981  * @out: destination buffer for the random bytes
 982  * @max: the max number of bytes to write to @out
 983  *
 984  * Returns < 0 on error and the number of bytes read on success
 985  */
 986 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
 987 {
 988         struct tpm_chip *chip;
 989         struct tpm_cmd_t tpm_cmd;
 990         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
 991         int err, total = 0, retries = 5;
 992         u8 *dest = out;
 993
 994         chip = tpm_chip_find_get(chip_num);
 995         if (chip == NULL)
 996                 return -ENODEV;
 997
 998         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
 999                 return -EINVAL;
1000
1001         do {
1002                 tpm_cmd.header.in = tpm_getrandom_header;
1003                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1004
1005                 err = transmit_cmd(chip, &tpm_cmd,
1006                                    TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1007                                    "attempting get random");
1008                 if (err)
1009                         break;
1010
1011                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1012                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1013
1014                 dest += recd;
1015                 total += recd;
1016                 num_bytes -= recd;
1017         } while (retries-- && total < max);
1018
1019         return total ? total : -EIO;
1020 }
1021 EXPORT_SYMBOL_GPL(tpm_get_random);
1022
1023 /* In case vendor provided release function, call it too.*/
1024
1025 void tpm_dev_vendor_release(struct tpm_chip *chip)
1026 {
1027         if (!chip)
1028                 return;
1029
1030         if (chip->vendor.release)
1031                 chip->vendor.release(chip->dev);
1032
1033         clear_bit(chip->dev_num, dev_mask);
1034 }
1035 EXPORT_SYMBOL_GPL(tpm_dev_vendor_release);
1036
1037
1038 /*
1039  * Once all references to platform device are down to 0,
1040  * release all allocated structures.
1041  */
1042 static void tpm_dev_release(struct device *dev)
1043 {
1044         struct tpm_chip *chip = dev_get_drvdata(dev);
1045
1046         if (!chip)
1047                 return;
1048
1049         tpm_dev_vendor_release(chip);
1050
1051         chip->release(dev);
1052         kfree(chip);
1053 }
1054
1055 /*
1056  * Called from tpm_<specific>.c probe function only for devices
1057  * the driver has determined it should claim.  Prior to calling
1058  * this function the specific probe function has called pci_enable_device
1059  * upon errant exit from this function specific probe function should call
1060  * pci_disable_device
1061  */
1062 struct tpm_chip *tpm_register_hardware(struct device *dev,
1063                                         const struct tpm_vendor_specific *entry)
1064 {
1065         struct tpm_chip *chip;
1066
1067         /* Driver specific per-device data */
1068         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
1069
1070         if (chip == NULL)
1071                 return NULL;
1072
1073         mutex_init(&chip->tpm_mutex);
1074         INIT_LIST_HEAD(&chip->list);
1075
1076         memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
1077
1078         chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);
1079
1080         if (chip->dev_num >= TPM_NUM_DEVICES) {
1081                 dev_err(dev, "No available tpm device numbers\n");
1082                 goto out_free;
1083         }
1084
1085         set_bit(chip->dev_num, dev_mask);
1086
1087         scnprintf(chip->devname, sizeof(chip->devname), "%s%d", "tpm",
1088                   chip->dev_num);
1089
1090         chip->dev = get_device(dev);
1091         chip->release = dev->release;
1092         dev->release = tpm_dev_release;
1093         dev_set_drvdata(dev, chip);
1094
1095         if (tpm_dev_add_device(chip))
1096                 goto put_device;
1097
1098         if (tpm_sysfs_add_device(chip))
1099                 goto del_misc;
1100
1101         if (tpm_add_ppi(&dev->kobj))
1102                 goto del_misc;
1103
1104         chip->bios_dir = tpm_bios_log_setup(chip->devname);
1105
1106         /* Make chip available */
1107         spin_lock(&driver_lock);
1108         list_add_rcu(&chip->list, &tpm_chip_list);
1109         spin_unlock(&driver_lock);
1110
1111         return chip;
1112
1113 del_misc:
1114         tpm_dev_del_device(chip);
1115 put_device:
1116         put_device(chip->dev);
1117 out_free:
1118         kfree(chip);
1119         return NULL;
1120 }
1121 EXPORT_SYMBOL_GPL(tpm_register_hardware);
1122
1123 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1124 MODULE_DESCRIPTION("TPM Driver");
1125 MODULE_VERSION("2.0");
1126 MODULE_LICENSE("GPL");