drivers/char/tpm/tpm.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
  34 enum tpm_const {
  35         TPM_MINOR = 224,        /* officially assigned */
  36         TPM_BUFSIZE = 4096,
  37         TPM_NUM_DEVICES = 256,
  38 };
  39
  40 enum tpm_duration {
  41         TPM_SHORT = 0,
  42         TPM_MEDIUM = 1,
  43         TPM_LONG = 2,
  44         TPM_UNDEFINED,
  45 };
  46
  47 #define TPM_MAX_ORDINAL 243
  48 #define TPM_MAX_PROTECTED_ORDINAL 12
  49 #define TPM_PROTECTED_ORDINAL_MASK 0xFF
  50
  51 /*
  52  * Bug workaround - some TPM's don't flush the most
  53  * recently changed pcr on suspend, so force the flush
  54  * with an extend to the selected _unused_ non-volatile pcr.
  55  */
  56 static int tpm_suspend_pcr;
  57 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  58 MODULE_PARM_DESC(suspend_pcr,
  59                  "PCR to use for dummy writes to faciltate flush on suspend.");
  60
  61 static LIST_HEAD(tpm_chip_list);
  62 static DEFINE_SPINLOCK(driver_lock);
  63 static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
  64
  65 /*
  66  * Array with one entry per ordinal defining the maximum amount
  67  * of time the chip could take to return the result.  The ordinal
  68  * designation of short, medium or long is defined in a table in
  69  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  70  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  71  * from the chip during initialization with a call to tpm_get_timeouts.
  72  */
  73 static const u8 tpm_protected_ordinal_duration[TPM_MAX_PROTECTED_ORDINAL] = {
  74         TPM_UNDEFINED,          /* 0 */
  75         TPM_UNDEFINED,
  76         TPM_UNDEFINED,
  77         TPM_UNDEFINED,
  78         TPM_UNDEFINED,
  79         TPM_UNDEFINED,          /* 5 */
  80         TPM_UNDEFINED,
  81         TPM_UNDEFINED,
  82         TPM_UNDEFINED,
  83         TPM_UNDEFINED,
  84         TPM_SHORT,              /* 10 */
  85         TPM_SHORT,
  86 };
  87
  88 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  89         TPM_UNDEFINED,          /* 0 */
  90         TPM_UNDEFINED,
  91         TPM_UNDEFINED,
  92         TPM_UNDEFINED,
  93         TPM_UNDEFINED,
  94         TPM_UNDEFINED,          /* 5 */
  95         TPM_UNDEFINED,
  96         TPM_UNDEFINED,
  97         TPM_UNDEFINED,
  98         TPM_UNDEFINED,
  99         TPM_SHORT,              /* 10 */
 100         TPM_SHORT,
 101         TPM_MEDIUM,
 102         TPM_LONG,
 103         TPM_LONG,
 104         TPM_MEDIUM,             /* 15 */
 105         TPM_SHORT,
 106         TPM_SHORT,
 107         TPM_MEDIUM,
 108         TPM_LONG,
 109         TPM_SHORT,              /* 20 */
 110         TPM_SHORT,
 111         TPM_MEDIUM,
 112         TPM_MEDIUM,
 113         TPM_MEDIUM,
 114         TPM_SHORT,              /* 25 */
 115         TPM_SHORT,
 116         TPM_MEDIUM,
 117         TPM_SHORT,
 118         TPM_SHORT,
 119         TPM_MEDIUM,             /* 30 */
 120         TPM_LONG,
 121         TPM_MEDIUM,
 122         TPM_SHORT,
 123         TPM_SHORT,
 124         TPM_SHORT,              /* 35 */
 125         TPM_MEDIUM,
 126         TPM_MEDIUM,
 127         TPM_UNDEFINED,
 128         TPM_UNDEFINED,
 129         TPM_MEDIUM,             /* 40 */
 130         TPM_LONG,
 131         TPM_MEDIUM,
 132         TPM_SHORT,
 133         TPM_SHORT,
 134         TPM_SHORT,              /* 45 */
 135         TPM_SHORT,
 136         TPM_SHORT,
 137         TPM_SHORT,
 138         TPM_LONG,
 139         TPM_MEDIUM,             /* 50 */
 140         TPM_MEDIUM,
 141         TPM_UNDEFINED,
 142         TPM_UNDEFINED,
 143         TPM_UNDEFINED,
 144         TPM_UNDEFINED,          /* 55 */
 145         TPM_UNDEFINED,
 146         TPM_UNDEFINED,
 147         TPM_UNDEFINED,
 148         TPM_UNDEFINED,
 149         TPM_MEDIUM,             /* 60 */
 150         TPM_MEDIUM,
 151         TPM_MEDIUM,
 152         TPM_SHORT,
 153         TPM_SHORT,
 154         TPM_MEDIUM,             /* 65 */
 155         TPM_UNDEFINED,
 156         TPM_UNDEFINED,
 157         TPM_UNDEFINED,
 158         TPM_UNDEFINED,
 159         TPM_SHORT,              /* 70 */
 160         TPM_SHORT,
 161         TPM_UNDEFINED,
 162         TPM_UNDEFINED,
 163         TPM_UNDEFINED,
 164         TPM_UNDEFINED,          /* 75 */
 165         TPM_UNDEFINED,
 166         TPM_UNDEFINED,
 167         TPM_UNDEFINED,
 168         TPM_UNDEFINED,
 169         TPM_LONG,               /* 80 */
 170         TPM_UNDEFINED,
 171         TPM_MEDIUM,
 172         TPM_LONG,
 173         TPM_SHORT,
 174         TPM_UNDEFINED,          /* 85 */
 175         TPM_UNDEFINED,
 176         TPM_UNDEFINED,
 177         TPM_UNDEFINED,
 178         TPM_UNDEFINED,
 179         TPM_SHORT,              /* 90 */
 180         TPM_SHORT,
 181         TPM_SHORT,
 182         TPM_SHORT,
 183         TPM_SHORT,
 184         TPM_UNDEFINED,          /* 95 */
 185         TPM_UNDEFINED,
 186         TPM_UNDEFINED,
 187         TPM_UNDEFINED,
 188         TPM_UNDEFINED,
 189         TPM_MEDIUM,             /* 100 */
 190         TPM_SHORT,
 191         TPM_SHORT,
 192         TPM_UNDEFINED,
 193         TPM_UNDEFINED,
 194         TPM_UNDEFINED,          /* 105 */
 195         TPM_UNDEFINED,
 196         TPM_UNDEFINED,
 197         TPM_UNDEFINED,
 198         TPM_UNDEFINED,
 199         TPM_SHORT,              /* 110 */
 200         TPM_SHORT,
 201         TPM_SHORT,
 202         TPM_SHORT,
 203         TPM_SHORT,
 204         TPM_SHORT,              /* 115 */
 205         TPM_SHORT,
 206         TPM_SHORT,
 207         TPM_UNDEFINED,
 208         TPM_UNDEFINED,
 209         TPM_LONG,               /* 120 */
 210         TPM_LONG,
 211         TPM_MEDIUM,
 212         TPM_UNDEFINED,
 213         TPM_SHORT,
 214         TPM_SHORT,              /* 125 */
 215         TPM_SHORT,
 216         TPM_LONG,
 217         TPM_SHORT,
 218         TPM_SHORT,
 219         TPM_SHORT,              /* 130 */
 220         TPM_MEDIUM,
 221         TPM_UNDEFINED,
 222         TPM_SHORT,
 223         TPM_MEDIUM,
 224         TPM_UNDEFINED,          /* 135 */
 225         TPM_UNDEFINED,
 226         TPM_UNDEFINED,
 227         TPM_UNDEFINED,
 228         TPM_UNDEFINED,
 229         TPM_SHORT,              /* 140 */
 230         TPM_SHORT,
 231         TPM_UNDEFINED,
 232         TPM_UNDEFINED,
 233         TPM_UNDEFINED,
 234         TPM_UNDEFINED,          /* 145 */
 235         TPM_UNDEFINED,
 236         TPM_UNDEFINED,
 237         TPM_UNDEFINED,
 238         TPM_UNDEFINED,
 239         TPM_SHORT,              /* 150 */
 240         TPM_MEDIUM,
 241         TPM_MEDIUM,
 242         TPM_SHORT,
 243         TPM_SHORT,
 244         TPM_UNDEFINED,          /* 155 */
 245         TPM_UNDEFINED,
 246         TPM_UNDEFINED,
 247         TPM_UNDEFINED,
 248         TPM_UNDEFINED,
 249         TPM_SHORT,              /* 160 */
 250         TPM_SHORT,
 251         TPM_SHORT,
 252         TPM_SHORT,
 253         TPM_UNDEFINED,
 254         TPM_UNDEFINED,          /* 165 */
 255         TPM_UNDEFINED,
 256         TPM_UNDEFINED,
 257         TPM_UNDEFINED,
 258         TPM_UNDEFINED,
 259         TPM_LONG,               /* 170 */
 260         TPM_UNDEFINED,
 261         TPM_UNDEFINED,
 262         TPM_UNDEFINED,
 263         TPM_UNDEFINED,
 264         TPM_UNDEFINED,          /* 175 */
 265         TPM_UNDEFINED,
 266         TPM_UNDEFINED,
 267         TPM_UNDEFINED,
 268         TPM_UNDEFINED,
 269         TPM_MEDIUM,             /* 180 */
 270         TPM_SHORT,
 271         TPM_MEDIUM,
 272         TPM_MEDIUM,
 273         TPM_MEDIUM,
 274         TPM_MEDIUM,             /* 185 */
 275         TPM_SHORT,
 276         TPM_UNDEFINED,
 277         TPM_UNDEFINED,
 278         TPM_UNDEFINED,
 279         TPM_UNDEFINED,          /* 190 */
 280         TPM_UNDEFINED,
 281         TPM_UNDEFINED,
 282         TPM_UNDEFINED,
 283         TPM_UNDEFINED,
 284         TPM_UNDEFINED,          /* 195 */
 285         TPM_UNDEFINED,
 286         TPM_UNDEFINED,
 287         TPM_UNDEFINED,
 288         TPM_UNDEFINED,
 289         TPM_SHORT,              /* 200 */
 290         TPM_UNDEFINED,
 291         TPM_UNDEFINED,
 292         TPM_UNDEFINED,
 293         TPM_SHORT,
 294         TPM_SHORT,              /* 205 */
 295         TPM_SHORT,
 296         TPM_SHORT,
 297         TPM_SHORT,
 298         TPM_SHORT,
 299         TPM_MEDIUM,             /* 210 */
 300         TPM_UNDEFINED,
 301         TPM_MEDIUM,
 302         TPM_MEDIUM,
 303         TPM_MEDIUM,
 304         TPM_UNDEFINED,          /* 215 */
 305         TPM_MEDIUM,
 306         TPM_UNDEFINED,
 307         TPM_UNDEFINED,
 308         TPM_SHORT,
 309         TPM_SHORT,              /* 220 */
 310         TPM_SHORT,
 311         TPM_SHORT,
 312         TPM_SHORT,
 313         TPM_SHORT,
 314         TPM_UNDEFINED,          /* 225 */
 315         TPM_UNDEFINED,
 316         TPM_UNDEFINED,
 317         TPM_UNDEFINED,
 318         TPM_UNDEFINED,
 319         TPM_SHORT,              /* 230 */
 320         TPM_LONG,
 321         TPM_MEDIUM,
 322         TPM_UNDEFINED,
 323         TPM_UNDEFINED,
 324         TPM_UNDEFINED,          /* 235 */
 325         TPM_UNDEFINED,
 326         TPM_UNDEFINED,
 327         TPM_UNDEFINED,
 328         TPM_UNDEFINED,
 329         TPM_SHORT,              /* 240 */
 330         TPM_UNDEFINED,
 331         TPM_MEDIUM,
 332 };
 333
 334 static void user_reader_timeout(unsigned long ptr)
 335 {
 336         struct tpm_chip *chip = (struct tpm_chip *) ptr;
 337
 338         schedule_work(&chip->work);
 339 }
 340
 341 static void timeout_work(struct work_struct *work)
 342 {
 343         struct tpm_chip *chip = container_of(work, struct tpm_chip, work);
 344
 345         mutex_lock(&chip->buffer_mutex);
 346         atomic_set(&chip->data_pending, 0);
 347         memset(chip->data_buffer, 0, TPM_BUFSIZE);
 348         mutex_unlock(&chip->buffer_mutex);
 349 }
 350
 351 /*
 352  * Returns max number of jiffies to wait
 353  */
 354 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 355                                            u32 ordinal)
 356 {
 357         int duration_idx = TPM_UNDEFINED;
 358         int duration = 0;
 359
 360         if (ordinal < TPM_MAX_ORDINAL)
 361                 duration_idx = tpm_ordinal_duration[ordinal];
 362         else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
 363                  TPM_MAX_PROTECTED_ORDINAL)
 364                 duration_idx =
 365                     tpm_protected_ordinal_duration[ordinal &
 366                                                    TPM_PROTECTED_ORDINAL_MASK];
 367
 368         if (duration_idx != TPM_UNDEFINED)
 369                 duration = chip->vendor.duration[duration_idx];
 370         if (duration <= 0)
 371                 return 2 * 60 * HZ;
 372         else
 373                 return duration;
 374 }
 375 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 376
 377 /*
 378  * Internal kernel interface to transmit TPM commands
 379  */
 380 static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 381                             size_t bufsiz)
 382 {
 383         ssize_t rc;
 384         u32 count, ordinal;
 385         unsigned long stop;
 386
 387         if (bufsiz > TPM_BUFSIZE)
 388                 bufsiz = TPM_BUFSIZE;
 389
 390         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 391         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 392         if (count == 0)
 393                 return -ENODATA;
 394         if (count > bufsiz) {
 395                 dev_err(chip->dev,
 396                         "invalid count value %x %zx \n", count, bufsiz);
 397                 return -E2BIG;
 398         }
 399
 400         mutex_lock(&chip->tpm_mutex);
 401
 402         if ((rc = chip->vendor.send(chip, (u8 *) buf, count)) < 0) {
 403                 dev_err(chip->dev,
 404                         "tpm_transmit: tpm_send: error %zd\n", rc);
 405                 goto out;
 406         }
 407
 408         if (chip->vendor.irq)
 409                 goto out_recv;
 410
 411         stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 412         do {
 413                 u8 status = chip->vendor.status(chip);
 414                 if ((status & chip->vendor.req_complete_mask) ==
 415                     chip->vendor.req_complete_val)
 416                         goto out_recv;
 417
 418                 if ((status == chip->vendor.req_canceled)) {
 419                         dev_err(chip->dev, "Operation Canceled\n");
 420                         rc = -ECANCELED;
 421                         goto out;
 422                 }
 423
 424                 msleep(TPM_TIMEOUT);    /* CHECK */
 425                 rmb();
 426         } while (time_before(jiffies, stop));
 427
 428         chip->vendor.cancel(chip);
 429         dev_err(chip->dev, "Operation Timed out\n");
 430         rc = -ETIME;
 431         goto out;
 432
 433 out_recv:
 434         rc = chip->vendor.recv(chip, (u8 *) buf, bufsiz);
 435         if (rc < 0)
 436                 dev_err(chip->dev,
 437                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 438 out:
 439         mutex_unlock(&chip->tpm_mutex);
 440         return rc;
 441 }
 442
 443 #define TPM_DIGEST_SIZE 20
 444 #define TPM_RET_CODE_IDX 6
 445
 446 enum tpm_capabilities {
 447         TPM_CAP_FLAG = cpu_to_be32(4),
 448         TPM_CAP_PROP = cpu_to_be32(5),
 449         CAP_VERSION_1_1 = cpu_to_be32(0x06),
 450         CAP_VERSION_1_2 = cpu_to_be32(0x1A)
 451 };
 452
 453 enum tpm_sub_capabilities {
 454         TPM_CAP_PROP_PCR = cpu_to_be32(0x101),
 455         TPM_CAP_PROP_MANUFACTURER = cpu_to_be32(0x103),
 456         TPM_CAP_FLAG_PERM = cpu_to_be32(0x108),
 457         TPM_CAP_FLAG_VOL = cpu_to_be32(0x109),
 458         TPM_CAP_PROP_OWNER = cpu_to_be32(0x111),
 459         TPM_CAP_PROP_TIS_TIMEOUT = cpu_to_be32(0x115),
 460         TPM_CAP_PROP_TIS_DURATION = cpu_to_be32(0x120),
 461
 462 };
 463
 464 static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
 465                             int len, const char *desc)
 466 {
 467         int err;
 468
 469         len = tpm_transmit(chip,(u8 *) cmd, len);
 470         if (len <  0)
 471                 return len;
 472         else if (len < TPM_HEADER_SIZE)
 473                 return -EFAULT;
 474
 475         err = be32_to_cpu(cmd->header.out.return_code);
 476         if (err != 0)
 477                 dev_err(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
 478
 479         return err;
 480 }
 481
 482 #define TPM_INTERNAL_RESULT_SIZE 200
 483 #define TPM_TAG_RQU_COMMAND cpu_to_be16(193)
 484 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 485
 486 static const struct tpm_input_header tpm_getcap_header = {
 487         .tag = TPM_TAG_RQU_COMMAND,
 488         .length = cpu_to_be32(22),
 489         .ordinal = TPM_ORD_GET_CAP
 490 };
 491
 492 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
 493                    const char *desc)
 494 {
 495         struct tpm_cmd_t tpm_cmd;
 496         int rc;
 497         struct tpm_chip *chip = dev_get_drvdata(dev);
 498
 499         tpm_cmd.header.in = tpm_getcap_header;
 500         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 501                 tpm_cmd.params.getcap_in.cap = subcap_id;
 502                 /*subcap field not necessary */
 503                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 504                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 505         } else {
 506                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 507                     subcap_id == TPM_CAP_FLAG_VOL)
 508                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 509                 else
 510                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 511                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 512                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 513         }
 514         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
 515         if (!rc)
 516                 *cap = tpm_cmd.params.getcap_out.cap;
 517         return rc;
 518 }
 519
 520 void tpm_gen_interrupt(struct tpm_chip *chip)
 521 {
 522         struct  tpm_cmd_t tpm_cmd;
 523         ssize_t rc;
 524
 525         tpm_cmd.header.in = tpm_getcap_header;
 526         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 527         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 528         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 529
 530         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 531                         "attempting to determine the timeouts");
 532 }
 533 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 534
 535 int tpm_get_timeouts(struct tpm_chip *chip)
 536 {
 537         struct tpm_cmd_t tpm_cmd;
 538         struct timeout_t *timeout_cap;
 539         struct duration_t *duration_cap;
 540         ssize_t rc;
 541         u32 timeout;
 542         unsigned int scale = 1;
 543
 544         tpm_cmd.header.in = tpm_getcap_header;
 545         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 546         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 547         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 548
 549         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 550                         "attempting to determine the timeouts");
 551         if (rc)
 552                 goto duration;
 553
 554         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 555             be32_to_cpu(tpm_cmd.header.out.length)
 556             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 557                 return -EINVAL;
 558
 559         timeout_cap = &tpm_cmd.params.getcap_out.cap.timeout;
 560         /* Don't overwrite default if value is 0 */
 561         timeout = be32_to_cpu(timeout_cap->a);
 562         if (timeout && timeout < 1000) {
 563                 /* timeouts in msec rather usec */
 564                 scale = 1000;
 565                 chip->vendor.timeout_adjusted = true;
 566         }
 567         if (timeout)
 568                 chip->vendor.timeout_a = usecs_to_jiffies(timeout * scale);
 569         timeout = be32_to_cpu(timeout_cap->b);
 570         if (timeout)
 571                 chip->vendor.timeout_b = usecs_to_jiffies(timeout * scale);
 572         timeout = be32_to_cpu(timeout_cap->c);
 573         if (timeout)
 574                 chip->vendor.timeout_c = usecs_to_jiffies(timeout * scale);
 575         timeout = be32_to_cpu(timeout_cap->d);
 576         if (timeout)
 577                 chip->vendor.timeout_d = usecs_to_jiffies(timeout * scale);
 578
 579 duration:
 580         tpm_cmd.header.in = tpm_getcap_header;
 581         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 582         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 583         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 584
 585         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 586                         "attempting to determine the durations");
 587         if (rc)
 588                 return rc;
 589
 590         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 591             be32_to_cpu(tpm_cmd.header.out.length)
 592             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 593                 return -EINVAL;
 594
 595         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 596         chip->vendor.duration[TPM_SHORT] =
 597             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 598         chip->vendor.duration[TPM_MEDIUM] =
 599             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 600         chip->vendor.duration[TPM_LONG] =
 601             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 602
 603         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 604          * value wrong and apparently reports msecs rather than usecs. So we
 605          * fix up the resulting too-small TPM_SHORT value to make things work.
 606          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 607          */
 608         if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
 609                 chip->vendor.duration[TPM_SHORT] = HZ;
 610                 chip->vendor.duration[TPM_MEDIUM] *= 1000;
 611                 chip->vendor.duration[TPM_LONG] *= 1000;
 612                 chip->vendor.duration_adjusted = true;
 613                 dev_info(chip->dev, "Adjusting TPM timeout parameters.");
 614         }
 615         return 0;
 616 }
 617 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 618
 619 #define TPM_ORD_CONTINUE_SELFTEST 83
 620 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 621
 622 static struct tpm_input_header continue_selftest_header = {
 623         .tag = TPM_TAG_RQU_COMMAND,
 624         .length = cpu_to_be32(10),
 625         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 626 };
 627
 628 /**
 629  * tpm_continue_selftest -- run TPM's selftest
 630  * @chip: TPM chip to use
 631  *
 632  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 633  * a TPM error code.
 634  */
 635 static int tpm_continue_selftest(struct tpm_chip *chip)
 636 {
 637         int rc;
 638         struct tpm_cmd_t cmd;
 639
 640         cmd.header.in = continue_selftest_header;
 641         rc = transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 642                           "continue selftest");
 643         return rc;
 644 }
 645
 646 ssize_t tpm_show_enabled(struct device * dev, struct device_attribute * attr,
 647                         char *buf)
 648 {
 649         cap_t cap;
 650         ssize_t rc;
 651
 652         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 653                          "attempting to determine the permanent enabled state");
 654         if (rc)
 655                 return 0;
 656
 657         rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
 658         return rc;
 659 }
 660 EXPORT_SYMBOL_GPL(tpm_show_enabled);
 661
 662 ssize_t tpm_show_active(struct device * dev, struct device_attribute * attr,
 663                         char *buf)
 664 {
 665         cap_t cap;
 666         ssize_t rc;
 667
 668         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 669                          "attempting to determine the permanent active state");
 670         if (rc)
 671                 return 0;
 672
 673         rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
 674         return rc;
 675 }
 676 EXPORT_SYMBOL_GPL(tpm_show_active);
 677
 678 ssize_t tpm_show_owned(struct device * dev, struct device_attribute * attr,
 679                         char *buf)
 680 {
 681         cap_t cap;
 682         ssize_t rc;
 683
 684         rc = tpm_getcap(dev, TPM_CAP_PROP_OWNER, &cap,
 685                          "attempting to determine the owner state");
 686         if (rc)
 687                 return 0;
 688
 689         rc = sprintf(buf, "%d\n", cap.owned);
 690         return rc;
 691 }
 692 EXPORT_SYMBOL_GPL(tpm_show_owned);
 693
 694 ssize_t tpm_show_temp_deactivated(struct device * dev,
 695                                 struct device_attribute * attr, char *buf)
 696 {
 697         cap_t cap;
 698         ssize_t rc;
 699
 700         rc = tpm_getcap(dev, TPM_CAP_FLAG_VOL, &cap,
 701                          "attempting to determine the temporary state");
 702         if (rc)
 703                 return 0;
 704
 705         rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
 706         return rc;
 707 }
 708 EXPORT_SYMBOL_GPL(tpm_show_temp_deactivated);
 709
 710 /*
 711  * tpm_chip_find_get - return tpm_chip for given chip number
 712  */
 713 static struct tpm_chip *tpm_chip_find_get(int chip_num)
 714 {
 715         struct tpm_chip *pos, *chip = NULL;
 716
 717         rcu_read_lock();
 718         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
 719                 if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
 720                         continue;
 721
 722                 if (try_module_get(pos->dev->driver->owner)) {
 723                         chip = pos;
 724                         break;
 725                 }
 726         }
 727         rcu_read_unlock();
 728         return chip;
 729 }
 730
 731 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 732 #define READ_PCR_RESULT_SIZE 30
 733 static struct tpm_input_header pcrread_header = {
 734         .tag = TPM_TAG_RQU_COMMAND,
 735         .length = cpu_to_be32(14),
 736         .ordinal = TPM_ORDINAL_PCRREAD
 737 };
 738
 739 static int __tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 740 {
 741         int rc;
 742         struct tpm_cmd_t cmd;
 743
 744         cmd.header.in = pcrread_header;
 745         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 746         rc = transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 747                           "attempting to read a pcr value");
 748
 749         if (rc == 0)
 750                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 751                        TPM_DIGEST_SIZE);
 752         return rc;
 753 }
 754
 755 /**
 756  * tpm_pcr_read - read a pcr value
 757  * @chip_num:   tpm idx # or ANY
 758  * @pcr_idx:    pcr idx to retrieve
 759  * @res_buf:    TPM_PCR value
 760  *              size of res_buf is 20 bytes (or NULL if you don't care)
 761  *
 762  * The TPM driver should be built-in, but for whatever reason it
 763  * isn't, protect against the chip disappearing, by incrementing
 764  * the module usage count.
 765  */
 766 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 767 {
 768         struct tpm_chip *chip;
 769         int rc;
 770
 771         chip = tpm_chip_find_get(chip_num);
 772         if (chip == NULL)
 773                 return -ENODEV;
 774         rc = __tpm_pcr_read(chip, pcr_idx, res_buf);
 775         tpm_chip_put(chip);
 776         return rc;
 777 }
 778 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 779
 780 /**
 781  * tpm_pcr_extend - extend pcr value with hash
 782  * @chip_num:   tpm idx # or AN&
 783  * @pcr_idx:    pcr idx to extend
 784  * @hash:       hash value used to extend pcr value
 785  *
 786  * The TPM driver should be built-in, but for whatever reason it
 787  * isn't, protect against the chip disappearing, by incrementing
 788  * the module usage count.
 789  */
 790 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 791 #define EXTEND_PCR_RESULT_SIZE 34
 792 static struct tpm_input_header pcrextend_header = {
 793         .tag = TPM_TAG_RQU_COMMAND,
 794         .length = cpu_to_be32(34),
 795         .ordinal = TPM_ORD_PCR_EXTEND
 796 };
 797
 798 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 799 {
 800         struct tpm_cmd_t cmd;
 801         int rc;
 802         struct tpm_chip *chip;
 803
 804         chip = tpm_chip_find_get(chip_num);
 805         if (chip == NULL)
 806                 return -ENODEV;
 807
 808         cmd.header.in = pcrextend_header;
 809         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 810         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 811         rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 812                           "attempting extend a PCR value");
 813
 814         tpm_chip_put(chip);
 815         return rc;
 816 }
 817 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 818
 819 /**
 820  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 821  *                   can receive further commands
 822  * @chip: TPM chip to use
 823  *
 824  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 825  * a TPM error code.
 826  */
 827 int tpm_do_selftest(struct tpm_chip *chip)
 828 {
 829         int rc;
 830         u8 digest[TPM_DIGEST_SIZE];
 831         unsigned int loops;
 832         unsigned int delay_msec = 1000;
 833         unsigned long duration;
 834
 835         duration = tpm_calc_ordinal_duration(chip,
 836                                              TPM_ORD_CONTINUE_SELFTEST);
 837
 838         loops = jiffies_to_msecs(duration) / delay_msec;
 839
 840         rc = tpm_continue_selftest(chip);
 841         /* This may fail if there was no TPM driver during a suspend/resume
 842          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 843          */
 844         if (rc)
 845                 return rc;
 846
 847         do {
 848                 rc = __tpm_pcr_read(chip, 0, digest);
 849                 if (rc != TPM_WARN_DOING_SELFTEST)
 850                         return rc;
 851                 msleep(delay_msec);
 852         } while (--loops > 0);
 853
 854         return rc;
 855 }
 856 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 857
 858 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 859 {
 860         struct tpm_chip *chip;
 861         int rc;
 862
 863         chip = tpm_chip_find_get(chip_num);
 864         if (chip == NULL)
 865                 return -ENODEV;
 866
 867         rc = transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
 868
 869         tpm_chip_put(chip);
 870         return rc;
 871 }
 872 EXPORT_SYMBOL_GPL(tpm_send);
 873
 874 ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
 875                       char *buf)
 876 {
 877         cap_t cap;
 878         u8 digest[TPM_DIGEST_SIZE];
 879         ssize_t rc;
 880         int i, j, num_pcrs;
 881         char *str = buf;
 882         struct tpm_chip *chip = dev_get_drvdata(dev);
 883
 884         rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap,
 885                         "attempting to determine the number of PCRS");
 886         if (rc)
 887                 return 0;
 888
 889         num_pcrs = be32_to_cpu(cap.num_pcrs);
 890         for (i = 0; i < num_pcrs; i++) {
 891                 rc = __tpm_pcr_read(chip, i, digest);
 892                 if (rc)
 893                         break;
 894                 str += sprintf(str, "PCR-%02d: ", i);
 895                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
 896                         str += sprintf(str, "%02X ", digest[j]);
 897                 str += sprintf(str, "\n");
 898         }
 899         return str - buf;
 900 }
 901 EXPORT_SYMBOL_GPL(tpm_show_pcrs);
 902
 903 #define  READ_PUBEK_RESULT_SIZE 314
 904 #define TPM_ORD_READPUBEK cpu_to_be32(124)
 905 struct tpm_input_header tpm_readpubek_header = {
 906         .tag = TPM_TAG_RQU_COMMAND,
 907         .length = cpu_to_be32(30),
 908         .ordinal = TPM_ORD_READPUBEK
 909 };
 910
 911 ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
 912                        char *buf)
 913 {
 914         u8 *data;
 915         struct tpm_cmd_t tpm_cmd;
 916         ssize_t err;
 917         int i, rc;
 918         char *str = buf;
 919
 920         struct tpm_chip *chip = dev_get_drvdata(dev);
 921
 922         tpm_cmd.header.in = tpm_readpubek_header;
 923         err = transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
 924                         "attempting to read the PUBEK");
 925         if (err)
 926                 goto out;
 927
 928         /*
 929            ignore header 10 bytes
 930            algorithm 32 bits (1 == RSA )
 931            encscheme 16 bits
 932            sigscheme 16 bits
 933            parameters (RSA 12->bytes: keybit, #primes, expbit)
 934            keylenbytes 32 bits
 935            256 byte modulus
 936            ignore checksum 20 bytes
 937          */
 938         data = tpm_cmd.params.readpubek_out_buffer;
 939         str +=
 940             sprintf(str,
 941                     "Algorithm: %02X %02X %02X %02X\n"
 942                     "Encscheme: %02X %02X\n"
 943                     "Sigscheme: %02X %02X\n"
 944                     "Parameters: %02X %02X %02X %02X "
 945                     "%02X %02X %02X %02X "
 946                     "%02X %02X %02X %02X\n"
 947                     "Modulus length: %d\n"
 948                     "Modulus:\n",
 949                     data[0], data[1], data[2], data[3],
 950                     data[4], data[5],
 951                     data[6], data[7],
 952                     data[12], data[13], data[14], data[15],
 953                     data[16], data[17], data[18], data[19],
 954                     data[20], data[21], data[22], data[23],
 955                     be32_to_cpu(*((__be32 *) (data + 24))));
 956
 957         for (i = 0; i < 256; i++) {
 958                 str += sprintf(str, "%02X ", data[i + 28]);
 959                 if ((i + 1) % 16 == 0)
 960                         str += sprintf(str, "\n");
 961         }
 962 out:
 963         rc = str - buf;
 964         return rc;
 965 }
 966 EXPORT_SYMBOL_GPL(tpm_show_pubek);
 967
 968
 969 ssize_t tpm_show_caps(struct device *dev, struct device_attribute *attr,
 970                       char *buf)
 971 {
 972         cap_t cap;
 973         ssize_t rc;
 974         char *str = buf;
 975
 976         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
 977                         "attempting to determine the manufacturer");
 978         if (rc)
 979                 return 0;
 980         str += sprintf(str, "Manufacturer: 0x%x\n",
 981                        be32_to_cpu(cap.manufacturer_id));
 982
 983         rc = tpm_getcap(dev, CAP_VERSION_1_1, &cap,
 984                         "attempting to determine the 1.1 version");
 985         if (rc)
 986                 return 0;
 987         str += sprintf(str,
 988                        "TCG version: %d.%d\nFirmware version: %d.%d\n",
 989                        cap.tpm_version.Major, cap.tpm_version.Minor,
 990                        cap.tpm_version.revMajor, cap.tpm_version.revMinor);
 991         return str - buf;
 992 }
 993 EXPORT_SYMBOL_GPL(tpm_show_caps);
 994
 995 ssize_t tpm_show_caps_1_2(struct device * dev,
 996                           struct device_attribute * attr, char *buf)
 997 {
 998         cap_t cap;
 999         ssize_t rc;
1000         char *str = buf;
1001
1002         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
1003                         "attempting to determine the manufacturer");
1004         if (rc)
1005                 return 0;
1006         str += sprintf(str, "Manufacturer: 0x%x\n",
1007                        be32_to_cpu(cap.manufacturer_id));
1008         rc = tpm_getcap(dev, CAP_VERSION_1_2, &cap,
1009                          "attempting to determine the 1.2 version");
1010         if (rc)
1011                 return 0;
1012         str += sprintf(str,
1013                        "TCG version: %d.%d\nFirmware version: %d.%d\n",
1014                        cap.tpm_version_1_2.Major, cap.tpm_version_1_2.Minor,
1015                        cap.tpm_version_1_2.revMajor,
1016                        cap.tpm_version_1_2.revMinor);
1017         return str - buf;
1018 }
1019 EXPORT_SYMBOL_GPL(tpm_show_caps_1_2);
1020
1021 ssize_t tpm_show_durations(struct device *dev, struct device_attribute *attr,
1022                           char *buf)
1023 {
1024         struct tpm_chip *chip = dev_get_drvdata(dev);
1025
1026         if (chip->vendor.duration[TPM_LONG] == 0)
1027                 return 0;
1028
1029         return sprintf(buf, "%d %d %d [%s]\n",
1030                        jiffies_to_usecs(chip->vendor.duration[TPM_SHORT]),
1031                        jiffies_to_usecs(chip->vendor.duration[TPM_MEDIUM]),
1032                        jiffies_to_usecs(chip->vendor.duration[TPM_LONG]),
1033                        chip->vendor.duration_adjusted
1034                        ? "adjusted" : "original");
1035 }
1036 EXPORT_SYMBOL_GPL(tpm_show_durations);
1037
1038 ssize_t tpm_show_timeouts(struct device *dev, struct device_attribute *attr,
1039                           char *buf)
1040 {
1041         struct tpm_chip *chip = dev_get_drvdata(dev);
1042
1043         return sprintf(buf, "%d %d %d %d [%s]\n",
1044                        jiffies_to_usecs(chip->vendor.timeout_a),
1045                        jiffies_to_usecs(chip->vendor.timeout_b),
1046                        jiffies_to_usecs(chip->vendor.timeout_c),
1047                        jiffies_to_usecs(chip->vendor.timeout_d),
1048                        chip->vendor.timeout_adjusted
1049                        ? "adjusted" : "original");
1050 }
1051 EXPORT_SYMBOL_GPL(tpm_show_timeouts);
1052
1053 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
1054                         const char *buf, size_t count)
1055 {
1056         struct tpm_chip *chip = dev_get_drvdata(dev);
1057         if (chip == NULL)
1058                 return 0;
1059
1060         chip->vendor.cancel(chip);
1061         return count;
1062 }
1063 EXPORT_SYMBOL_GPL(tpm_store_cancel);
1064
1065 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
1066                          wait_queue_head_t *queue)
1067 {
1068         unsigned long stop;
1069         long rc;
1070         u8 status;
1071
1072         /* check current status */
1073         status = chip->vendor.status(chip);
1074         if ((status & mask) == mask)
1075                 return 0;
1076
1077         stop = jiffies + timeout;
1078
1079         if (chip->vendor.irq) {
1080 again:
1081                 timeout = stop - jiffies;
1082                 if ((long)timeout <= 0)
1083                         return -ETIME;
1084                 rc = wait_event_interruptible_timeout(*queue,
1085                                                       ((chip->vendor.status(chip)
1086                                                       & mask) == mask),
1087                                                       timeout);
1088                 if (rc > 0)
1089                         return 0;
1090                 if (rc == -ERESTARTSYS && freezing(current)) {
1091                         clear_thread_flag(TIF_SIGPENDING);
1092                         goto again;
1093                 }
1094         } else {
1095                 do {
1096                         msleep(TPM_TIMEOUT);
1097                         status = chip->vendor.status(chip);
1098                         if ((status & mask) == mask)
1099                                 return 0;
1100                 } while (time_before(jiffies, stop));
1101         }
1102         return -ETIME;
1103 }
1104 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
1105 /*
1106  * Device file system interface to the TPM
1107  *
1108  * It's assured that the chip will be opened just once,
1109  * by the check of is_open variable, which is protected
1110  * by driver_lock.
1111  */
1112 int tpm_open(struct inode *inode, struct file *file)
1113 {
1114         int minor = iminor(inode);
1115         struct tpm_chip *chip = NULL, *pos;
1116
1117         rcu_read_lock();
1118         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
1119                 if (pos->vendor.miscdev.minor == minor) {
1120                         chip = pos;
1121                         get_device(chip->dev);
1122                         break;
1123                 }
1124         }
1125         rcu_read_unlock();
1126
1127         if (!chip)
1128                 return -ENODEV;
1129
1130         if (test_and_set_bit(0, &chip->is_open)) {
1131                 dev_dbg(chip->dev, "Another process owns this TPM\n");
1132                 put_device(chip->dev);
1133                 return -EBUSY;
1134         }
1135
1136         chip->data_buffer = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
1137         if (chip->data_buffer == NULL) {
1138                 clear_bit(0, &chip->is_open);
1139                 put_device(chip->dev);
1140                 return -ENOMEM;
1141         }
1142
1143         atomic_set(&chip->data_pending, 0);
1144
1145         file->private_data = chip;
1146         return 0;
1147 }
1148 EXPORT_SYMBOL_GPL(tpm_open);
1149
1150 /*
1151  * Called on file close
1152  */
1153 int tpm_release(struct inode *inode, struct file *file)
1154 {
1155         struct tpm_chip *chip = file->private_data;
1156
1157         del_singleshot_timer_sync(&chip->user_read_timer);
1158         flush_work_sync(&chip->work);
1159         file->private_data = NULL;
1160         atomic_set(&chip->data_pending, 0);
1161         kfree(chip->data_buffer);
1162         clear_bit(0, &chip->is_open);
1163         put_device(chip->dev);
1164         return 0;
1165 }
1166 EXPORT_SYMBOL_GPL(tpm_release);
1167
1168 ssize_t tpm_write(struct file *file, const char __user *buf,
1169                   size_t size, loff_t *off)
1170 {
1171         struct tpm_chip *chip = file->private_data;
1172         size_t in_size = size, out_size;
1173
1174         /* cannot perform a write until the read has cleared
1175            either via tpm_read or a user_read_timer timeout */
1176         while (atomic_read(&chip->data_pending) != 0)
1177                 msleep(TPM_TIMEOUT);
1178
1179         mutex_lock(&chip->buffer_mutex);
1180
1181         if (in_size > TPM_BUFSIZE)
1182                 in_size = TPM_BUFSIZE;
1183
1184         if (copy_from_user
1185             (chip->data_buffer, (void __user *) buf, in_size)) {
1186                 mutex_unlock(&chip->buffer_mutex);
1187                 return -EFAULT;
1188         }
1189
1190         /* atomic tpm command send and result receive */
1191         out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
1192
1193         atomic_set(&chip->data_pending, out_size);
1194         mutex_unlock(&chip->buffer_mutex);
1195
1196         /* Set a timeout by which the reader must come claim the result */
1197         mod_timer(&chip->user_read_timer, jiffies + (60 * HZ));
1198
1199         return in_size;
1200 }
1201 EXPORT_SYMBOL_GPL(tpm_write);
1202
1203 ssize_t tpm_read(struct file *file, char __user *buf,
1204                  size_t size, loff_t *off)
1205 {
1206         struct tpm_chip *chip = file->private_data;
1207         ssize_t ret_size;
1208         int rc;
1209
1210         del_singleshot_timer_sync(&chip->user_read_timer);
1211         flush_work_sync(&chip->work);
1212         ret_size = atomic_read(&chip->data_pending);
1213         atomic_set(&chip->data_pending, 0);
1214         if (ret_size > 0) {     /* relay data */
1215                 if (size < ret_size)
1216                         ret_size = size;
1217
1218                 mutex_lock(&chip->buffer_mutex);
1219                 rc = copy_to_user(buf, chip->data_buffer, ret_size);
1220                 memset(chip->data_buffer, 0, ret_size);
1221                 if (rc)
1222                         ret_size = -EFAULT;
1223
1224                 mutex_unlock(&chip->buffer_mutex);
1225         }
1226
1227         return ret_size;
1228 }
1229 EXPORT_SYMBOL_GPL(tpm_read);
1230
1231 void tpm_remove_hardware(struct device *dev)
1232 {
1233         struct tpm_chip *chip = dev_get_drvdata(dev);
1234
1235         if (chip == NULL) {
1236                 dev_err(dev, "No device data found\n");
1237                 return;
1238         }
1239
1240         spin_lock(&driver_lock);
1241         list_del_rcu(&chip->list);
1242         spin_unlock(&driver_lock);
1243         synchronize_rcu();
1244
1245         misc_deregister(&chip->vendor.miscdev);
1246         sysfs_remove_group(&dev->kobj, chip->vendor.attr_group);
1247         tpm_bios_log_teardown(chip->bios_dir);
1248
1249         /* write it this way to be explicit (chip->dev == dev) */
1250         put_device(chip->dev);
1251 }
1252 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
1253
1254 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
1255 #define SAVESTATE_RESULT_SIZE 10
1256
1257 static struct tpm_input_header savestate_header = {
1258         .tag = TPM_TAG_RQU_COMMAND,
1259         .length = cpu_to_be32(10),
1260         .ordinal = TPM_ORD_SAVESTATE
1261 };
1262
1263 /*
1264  * We are about to suspend. Save the TPM state
1265  * so that it can be restored.
1266  */
1267 int tpm_pm_suspend(struct device *dev, pm_message_t pm_state)
1268 {
1269         struct tpm_chip *chip = dev_get_drvdata(dev);
1270         struct tpm_cmd_t cmd;
1271         int rc;
1272
1273         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1274
1275         if (chip == NULL)
1276                 return -ENODEV;
1277
1278         /* for buggy tpm, flush pcrs with extend to selected dummy */
1279         if (tpm_suspend_pcr) {
1280                 cmd.header.in = pcrextend_header;
1281                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
1282                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
1283                        TPM_DIGEST_SIZE);
1284                 rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
1285                                   "extending dummy pcr before suspend");
1286         }
1287
1288         /* now do the actual savestate */
1289         cmd.header.in = savestate_header;
1290         rc = transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE,
1291                           "sending savestate before suspend");
1292         return rc;
1293 }
1294 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1295
1296 /*
1297  * Resume from a power safe. The BIOS already restored
1298  * the TPM state.
1299  */
1300 int tpm_pm_resume(struct device *dev)
1301 {
1302         struct tpm_chip *chip = dev_get_drvdata(dev);
1303
1304         if (chip == NULL)
1305                 return -ENODEV;
1306
1307         return 0;
1308 }
1309 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1310
1311 /* In case vendor provided release function, call it too.*/
1312
1313 void tpm_dev_vendor_release(struct tpm_chip *chip)
1314 {
1315         if (chip->vendor.release)
1316                 chip->vendor.release(chip->dev);
1317
1318         clear_bit(chip->dev_num, dev_mask);
1319         kfree(chip->vendor.miscdev.name);
1320 }
1321 EXPORT_SYMBOL_GPL(tpm_dev_vendor_release);
1322
1323
1324 /*
1325  * Once all references to platform device are down to 0,
1326  * release all allocated structures.
1327  */
1328 void tpm_dev_release(struct device *dev)
1329 {
1330         struct tpm_chip *chip = dev_get_drvdata(dev);
1331
1332         tpm_dev_vendor_release(chip);
1333
1334         chip->release(dev);
1335         kfree(chip);
1336 }
1337 EXPORT_SYMBOL_GPL(tpm_dev_release);
1338
1339 /*
1340  * Called from tpm_<specific>.c probe function only for devices
1341  * the driver has determined it should claim.  Prior to calling
1342  * this function the specific probe function has called pci_enable_device
1343  * upon errant exit from this function specific probe function should call
1344  * pci_disable_device
1345  */
1346 struct tpm_chip *tpm_register_hardware(struct device *dev,
1347                                         const struct tpm_vendor_specific *entry)
1348 {
1349 #define DEVNAME_SIZE 7
1350
1351         char *devname;
1352         struct tpm_chip *chip;
1353
1354         /* Driver specific per-device data */
1355         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
1356         devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL);
1357
1358         if (chip == NULL || devname == NULL)
1359                 goto out_free;
1360
1361         mutex_init(&chip->buffer_mutex);
1362         mutex_init(&chip->tpm_mutex);
1363         INIT_LIST_HEAD(&chip->list);
1364
1365         INIT_WORK(&chip->work, timeout_work);
1366
1367         setup_timer(&chip->user_read_timer, user_reader_timeout,
1368                         (unsigned long)chip);
1369
1370         memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
1371
1372         chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);
1373
1374         if (chip->dev_num >= TPM_NUM_DEVICES) {
1375                 dev_err(dev, "No available tpm device numbers\n");
1376                 goto out_free;
1377         } else if (chip->dev_num == 0)
1378                 chip->vendor.miscdev.minor = TPM_MINOR;
1379         else
1380                 chip->vendor.miscdev.minor = MISC_DYNAMIC_MINOR;
1381
1382         set_bit(chip->dev_num, dev_mask);
1383
1384         scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num);
1385         chip->vendor.miscdev.name = devname;
1386
1387         chip->vendor.miscdev.parent = dev;
1388         chip->dev = get_device(dev);
1389         chip->release = dev->release;
1390         dev->release = tpm_dev_release;
1391         dev_set_drvdata(dev, chip);
1392
1393         if (misc_register(&chip->vendor.miscdev)) {
1394                 dev_err(chip->dev,
1395                         "unable to misc_register %s, minor %d\n",
1396                         chip->vendor.miscdev.name,
1397                         chip->vendor.miscdev.minor);
1398                 put_device(chip->dev);
1399                 return NULL;
1400         }
1401
1402         if (sysfs_create_group(&dev->kobj, chip->vendor.attr_group)) {
1403                 misc_deregister(&chip->vendor.miscdev);
1404                 put_device(chip->dev);
1405
1406                 return NULL;
1407         }
1408
1409         chip->bios_dir = tpm_bios_log_setup(devname);
1410
1411         /* Make chip available */
1412         spin_lock(&driver_lock);
1413         list_add_rcu(&chip->list, &tpm_chip_list);
1414         spin_unlock(&driver_lock);
1415
1416         return chip;
1417
1418 out_free:
1419         kfree(chip);
1420         kfree(devname);
1421         return NULL;
1422 }
1423 EXPORT_SYMBOL_GPL(tpm_register_hardware);
1424
1425 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1426 MODULE_DESCRIPTION("TPM Driver");
1427 MODULE_VERSION("2.0");
1428 MODULE_LICENSE("GPL");