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/sched.h>
  27 #include <linux/poll.h>
  28 #include <linux/spinlock.h>
  29 #include "tpm.h"
  30
  31 enum tpm_const {
  32         TPM_MINOR = 224,        /* officially assigned */
  33         TPM_BUFSIZE = 2048,
  34         TPM_NUM_DEVICES = 256,
  35         TPM_NUM_MASK_ENTRIES = TPM_NUM_DEVICES / (8 * sizeof(int))
  36 };
  37
  38 enum tpm_duration {
  39         TPM_SHORT = 0,
  40         TPM_MEDIUM = 1,
  41         TPM_LONG = 2,
  42         TPM_UNDEFINED,
  43 };
  44
  45 #define TPM_MAX_ORDINAL 243
  46 #define TPM_MAX_PROTECTED_ORDINAL 12
  47 #define TPM_PROTECTED_ORDINAL_MASK 0xFF
  48
  49 static LIST_HEAD(tpm_chip_list);
  50 static DEFINE_SPINLOCK(driver_lock);
  51 static int dev_mask[TPM_NUM_MASK_ENTRIES];
  52
  53 /*
  54  * Array with one entry per ordinal defining the maximum amount
  55  * of time the chip could take to return the result.  The ordinal
  56  * designation of short, medium or long is defined in a table in
  57  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  58  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  59  * from the chip during initialization with a call to tpm_get_timeouts.
  60  */
  61 static const u8 tpm_protected_ordinal_duration[TPM_MAX_PROTECTED_ORDINAL] = {
  62         TPM_UNDEFINED,          /* 0 */
  63         TPM_UNDEFINED,
  64         TPM_UNDEFINED,
  65         TPM_UNDEFINED,
  66         TPM_UNDEFINED,
  67         TPM_UNDEFINED,          /* 5 */
  68         TPM_UNDEFINED,
  69         TPM_UNDEFINED,
  70         TPM_UNDEFINED,
  71         TPM_UNDEFINED,
  72         TPM_SHORT,              /* 10 */
  73         TPM_SHORT,
  74 };
  75
  76 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  77         TPM_UNDEFINED,          /* 0 */
  78         TPM_UNDEFINED,
  79         TPM_UNDEFINED,
  80         TPM_UNDEFINED,
  81         TPM_UNDEFINED,
  82         TPM_UNDEFINED,          /* 5 */
  83         TPM_UNDEFINED,
  84         TPM_UNDEFINED,
  85         TPM_UNDEFINED,
  86         TPM_UNDEFINED,
  87         TPM_SHORT,              /* 10 */
  88         TPM_SHORT,
  89         TPM_MEDIUM,
  90         TPM_LONG,
  91         TPM_LONG,
  92         TPM_MEDIUM,             /* 15 */
  93         TPM_SHORT,
  94         TPM_SHORT,
  95         TPM_MEDIUM,
  96         TPM_LONG,
  97         TPM_SHORT,              /* 20 */
  98         TPM_SHORT,
  99         TPM_MEDIUM,
 100         TPM_MEDIUM,
 101         TPM_MEDIUM,
 102         TPM_SHORT,              /* 25 */
 103         TPM_SHORT,
 104         TPM_MEDIUM,
 105         TPM_SHORT,
 106         TPM_SHORT,
 107         TPM_MEDIUM,             /* 30 */
 108         TPM_LONG,
 109         TPM_MEDIUM,
 110         TPM_SHORT,
 111         TPM_SHORT,
 112         TPM_SHORT,              /* 35 */
 113         TPM_MEDIUM,
 114         TPM_MEDIUM,
 115         TPM_UNDEFINED,
 116         TPM_UNDEFINED,
 117         TPM_MEDIUM,             /* 40 */
 118         TPM_LONG,
 119         TPM_MEDIUM,
 120         TPM_SHORT,
 121         TPM_SHORT,
 122         TPM_SHORT,              /* 45 */
 123         TPM_SHORT,
 124         TPM_SHORT,
 125         TPM_SHORT,
 126         TPM_LONG,
 127         TPM_MEDIUM,             /* 50 */
 128         TPM_MEDIUM,
 129         TPM_UNDEFINED,
 130         TPM_UNDEFINED,
 131         TPM_UNDEFINED,
 132         TPM_UNDEFINED,          /* 55 */
 133         TPM_UNDEFINED,
 134         TPM_UNDEFINED,
 135         TPM_UNDEFINED,
 136         TPM_UNDEFINED,
 137         TPM_MEDIUM,             /* 60 */
 138         TPM_MEDIUM,
 139         TPM_MEDIUM,
 140         TPM_SHORT,
 141         TPM_SHORT,
 142         TPM_MEDIUM,             /* 65 */
 143         TPM_UNDEFINED,
 144         TPM_UNDEFINED,
 145         TPM_UNDEFINED,
 146         TPM_UNDEFINED,
 147         TPM_SHORT,              /* 70 */
 148         TPM_SHORT,
 149         TPM_UNDEFINED,
 150         TPM_UNDEFINED,
 151         TPM_UNDEFINED,
 152         TPM_UNDEFINED,          /* 75 */
 153         TPM_UNDEFINED,
 154         TPM_UNDEFINED,
 155         TPM_UNDEFINED,
 156         TPM_UNDEFINED,
 157         TPM_LONG,               /* 80 */
 158         TPM_UNDEFINED,
 159         TPM_MEDIUM,
 160         TPM_LONG,
 161         TPM_SHORT,
 162         TPM_UNDEFINED,          /* 85 */
 163         TPM_UNDEFINED,
 164         TPM_UNDEFINED,
 165         TPM_UNDEFINED,
 166         TPM_UNDEFINED,
 167         TPM_SHORT,              /* 90 */
 168         TPM_SHORT,
 169         TPM_SHORT,
 170         TPM_SHORT,
 171         TPM_SHORT,
 172         TPM_UNDEFINED,          /* 95 */
 173         TPM_UNDEFINED,
 174         TPM_UNDEFINED,
 175         TPM_UNDEFINED,
 176         TPM_UNDEFINED,
 177         TPM_MEDIUM,             /* 100 */
 178         TPM_SHORT,
 179         TPM_SHORT,
 180         TPM_UNDEFINED,
 181         TPM_UNDEFINED,
 182         TPM_UNDEFINED,          /* 105 */
 183         TPM_UNDEFINED,
 184         TPM_UNDEFINED,
 185         TPM_UNDEFINED,
 186         TPM_UNDEFINED,
 187         TPM_SHORT,              /* 110 */
 188         TPM_SHORT,
 189         TPM_SHORT,
 190         TPM_SHORT,
 191         TPM_SHORT,
 192         TPM_SHORT,              /* 115 */
 193         TPM_SHORT,
 194         TPM_SHORT,
 195         TPM_UNDEFINED,
 196         TPM_UNDEFINED,
 197         TPM_LONG,               /* 120 */
 198         TPM_LONG,
 199         TPM_MEDIUM,
 200         TPM_UNDEFINED,
 201         TPM_SHORT,
 202         TPM_SHORT,              /* 125 */
 203         TPM_SHORT,
 204         TPM_LONG,
 205         TPM_SHORT,
 206         TPM_SHORT,
 207         TPM_SHORT,              /* 130 */
 208         TPM_MEDIUM,
 209         TPM_UNDEFINED,
 210         TPM_SHORT,
 211         TPM_MEDIUM,
 212         TPM_UNDEFINED,          /* 135 */
 213         TPM_UNDEFINED,
 214         TPM_UNDEFINED,
 215         TPM_UNDEFINED,
 216         TPM_UNDEFINED,
 217         TPM_SHORT,              /* 140 */
 218         TPM_SHORT,
 219         TPM_UNDEFINED,
 220         TPM_UNDEFINED,
 221         TPM_UNDEFINED,
 222         TPM_UNDEFINED,          /* 145 */
 223         TPM_UNDEFINED,
 224         TPM_UNDEFINED,
 225         TPM_UNDEFINED,
 226         TPM_UNDEFINED,
 227         TPM_SHORT,              /* 150 */
 228         TPM_MEDIUM,
 229         TPM_MEDIUM,
 230         TPM_SHORT,
 231         TPM_SHORT,
 232         TPM_UNDEFINED,          /* 155 */
 233         TPM_UNDEFINED,
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,
 236         TPM_UNDEFINED,
 237         TPM_SHORT,              /* 160 */
 238         TPM_SHORT,
 239         TPM_SHORT,
 240         TPM_SHORT,
 241         TPM_UNDEFINED,
 242         TPM_UNDEFINED,          /* 165 */
 243         TPM_UNDEFINED,
 244         TPM_UNDEFINED,
 245         TPM_UNDEFINED,
 246         TPM_UNDEFINED,
 247         TPM_LONG,               /* 170 */
 248         TPM_UNDEFINED,
 249         TPM_UNDEFINED,
 250         TPM_UNDEFINED,
 251         TPM_UNDEFINED,
 252         TPM_UNDEFINED,          /* 175 */
 253         TPM_UNDEFINED,
 254         TPM_UNDEFINED,
 255         TPM_UNDEFINED,
 256         TPM_UNDEFINED,
 257         TPM_MEDIUM,             /* 180 */
 258         TPM_SHORT,
 259         TPM_MEDIUM,
 260         TPM_MEDIUM,
 261         TPM_MEDIUM,
 262         TPM_MEDIUM,             /* 185 */
 263         TPM_SHORT,
 264         TPM_UNDEFINED,
 265         TPM_UNDEFINED,
 266         TPM_UNDEFINED,
 267         TPM_UNDEFINED,          /* 190 */
 268         TPM_UNDEFINED,
 269         TPM_UNDEFINED,
 270         TPM_UNDEFINED,
 271         TPM_UNDEFINED,
 272         TPM_UNDEFINED,          /* 195 */
 273         TPM_UNDEFINED,
 274         TPM_UNDEFINED,
 275         TPM_UNDEFINED,
 276         TPM_UNDEFINED,
 277         TPM_SHORT,              /* 200 */
 278         TPM_UNDEFINED,
 279         TPM_UNDEFINED,
 280         TPM_UNDEFINED,
 281         TPM_SHORT,
 282         TPM_SHORT,              /* 205 */
 283         TPM_SHORT,
 284         TPM_SHORT,
 285         TPM_SHORT,
 286         TPM_SHORT,
 287         TPM_MEDIUM,             /* 210 */
 288         TPM_UNDEFINED,
 289         TPM_MEDIUM,
 290         TPM_MEDIUM,
 291         TPM_MEDIUM,
 292         TPM_UNDEFINED,          /* 215 */
 293         TPM_MEDIUM,
 294         TPM_UNDEFINED,
 295         TPM_UNDEFINED,
 296         TPM_SHORT,
 297         TPM_SHORT,              /* 220 */
 298         TPM_SHORT,
 299         TPM_SHORT,
 300         TPM_SHORT,
 301         TPM_SHORT,
 302         TPM_UNDEFINED,          /* 225 */
 303         TPM_UNDEFINED,
 304         TPM_UNDEFINED,
 305         TPM_UNDEFINED,
 306         TPM_UNDEFINED,
 307         TPM_SHORT,              /* 230 */
 308         TPM_LONG,
 309         TPM_MEDIUM,
 310         TPM_UNDEFINED,
 311         TPM_UNDEFINED,
 312         TPM_UNDEFINED,          /* 235 */
 313         TPM_UNDEFINED,
 314         TPM_UNDEFINED,
 315         TPM_UNDEFINED,
 316         TPM_UNDEFINED,
 317         TPM_SHORT,              /* 240 */
 318         TPM_UNDEFINED,
 319         TPM_MEDIUM,
 320 };
 321
 322 static void user_reader_timeout(unsigned long ptr)
 323 {
 324         struct tpm_chip *chip = (struct tpm_chip *) ptr;
 325
 326         schedule_work(&chip->work);
 327 }
 328
 329 static void timeout_work(void *ptr)
 330 {
 331         struct tpm_chip *chip = ptr;
 332
 333         down(&chip->buffer_mutex);
 334         atomic_set(&chip->data_pending, 0);
 335         memset(chip->data_buffer, 0, TPM_BUFSIZE);
 336         up(&chip->buffer_mutex);
 337 }
 338
 339 /*
 340  * Returns max number of jiffies to wait
 341  */
 342 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 343                                            u32 ordinal)
 344 {
 345         int duration_idx = TPM_UNDEFINED;
 346         int duration = 0;
 347
 348         if (ordinal < TPM_MAX_ORDINAL)
 349                 duration_idx = tpm_ordinal_duration[ordinal];
 350         else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
 351                  TPM_MAX_PROTECTED_ORDINAL)
 352                 duration_idx =
 353                     tpm_protected_ordinal_duration[ordinal &
 354                                                    TPM_PROTECTED_ORDINAL_MASK];
 355
 356         if (duration_idx != TPM_UNDEFINED)
 357                 duration = chip->vendor.duration[duration_idx] * HZ / 1000;
 358         if (duration <= 0)
 359                 return 2 * 60 * HZ;
 360         else
 361                 return duration;
 362 }
 363 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 364
 365 /*
 366  * Internal kernel interface to transmit TPM commands
 367  */
 368 static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 369                             size_t bufsiz)
 370 {
 371         ssize_t rc;
 372         u32 count, ordinal;
 373         unsigned long stop;
 374
 375         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 376         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 377         if (count == 0)
 378                 return -ENODATA;
 379         if (count > bufsiz) {
 380                 dev_err(chip->dev,
 381                         "invalid count value %x %zx \n", count, bufsiz);
 382                 return -E2BIG;
 383         }
 384
 385         down(&chip->tpm_mutex);
 386
 387         if ((rc = chip->vendor.send(chip, (u8 *) buf, count)) < 0) {
 388                 dev_err(chip->dev,
 389                         "tpm_transmit: tpm_send: error %zd\n", rc);
 390                 goto out;
 391         }
 392
 393         stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 394         do {
 395                 u8 status = chip->vendor.status(chip);
 396                 if ((status & chip->vendor.req_complete_mask) ==
 397                     chip->vendor.req_complete_val)
 398                         goto out_recv;
 399
 400                 if ((status == chip->vendor.req_canceled)) {
 401                         dev_err(chip->dev, "Operation Canceled\n");
 402                         rc = -ECANCELED;
 403                         goto out;
 404                 }
 405
 406                 msleep(TPM_TIMEOUT);    /* CHECK */
 407                 rmb();
 408         } while (time_before(jiffies, stop));
 409
 410         chip->vendor.cancel(chip);
 411         dev_err(chip->dev, "Operation Timed out\n");
 412         rc = -ETIME;
 413         goto out;
 414
 415 out_recv:
 416         rc = chip->vendor.recv(chip, (u8 *) buf, bufsiz);
 417         if (rc < 0)
 418                 dev_err(chip->dev,
 419                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 420 out:
 421         up(&chip->tpm_mutex);
 422         return rc;
 423 }
 424
 425 #define TPM_DIGEST_SIZE 20
 426 #define TPM_ERROR_SIZE 10
 427 #define TPM_RET_CODE_IDX 6
 428 #define TPM_GET_CAP_RET_SIZE_IDX 10
 429 #define TPM_GET_CAP_RET_UINT32_1_IDX 14
 430 #define TPM_GET_CAP_RET_UINT32_2_IDX 18
 431 #define TPM_GET_CAP_RET_UINT32_3_IDX 22
 432 #define TPM_GET_CAP_RET_UINT32_4_IDX 26
 433
 434 #define TPM_CAP_IDX 13
 435 #define TPM_CAP_SUBCAP_IDX 21
 436
 437 enum tpm_capabilities {
 438         TPM_CAP_PROP = 5,
 439 };
 440
 441 enum tpm_sub_capabilities {
 442         TPM_CAP_PROP_PCR = 0x1,
 443         TPM_CAP_PROP_MANUFACTURER = 0x3,
 444 };
 445
 446 /*
 447  * This is a semi generic GetCapability command for use
 448  * with the capability type TPM_CAP_PROP or TPM_CAP_FLAG
 449  * and their associated sub_capabilities.
 450  */
 451
 452 static const u8 tpm_cap[] = {
 453         0, 193,                 /* TPM_TAG_RQU_COMMAND */
 454         0, 0, 0, 22,            /* length */
 455         0, 0, 0, 101,           /* TPM_ORD_GetCapability */
 456         0, 0, 0, 0,             /* TPM_CAP_<TYPE> */
 457         0, 0, 0, 4,             /* TPM_CAP_SUB_<TYPE> size */
 458         0, 0, 1, 0              /* TPM_CAP_SUB_<TYPE> */
 459 };
 460
 461 static ssize_t transmit_cmd(struct tpm_chip *chip, u8 *data, int len,
 462                             char *desc)
 463 {
 464         int err;
 465
 466         len = tpm_transmit(chip, data, len);
 467         if (len <  0)
 468                 return len;
 469         if (len == TPM_ERROR_SIZE) {
 470                 err = be32_to_cpu(*((__be32 *) (data + TPM_RET_CODE_IDX)));
 471                 dev_dbg(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
 472                 return err;
 473         }
 474         return 0;
 475 }
 476
 477 static const u8 pcrread[] = {
 478         0, 193,                 /* TPM_TAG_RQU_COMMAND */
 479         0, 0, 0, 14,            /* length */
 480         0, 0, 0, 21,            /* TPM_ORD_PcrRead */
 481         0, 0, 0, 0              /* PCR index */
 482 };
 483
 484 ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
 485                       char *buf)
 486 {
 487         u8 data[30];
 488         ssize_t rc;
 489         int i, j, num_pcrs;
 490         __be32 index;
 491         char *str = buf;
 492
 493         struct tpm_chip *chip = dev_get_drvdata(dev);
 494         if (chip == NULL)
 495                 return -ENODEV;
 496
 497         memcpy(data, tpm_cap, sizeof(tpm_cap));
 498         data[TPM_CAP_IDX] = TPM_CAP_PROP;
 499         data[TPM_CAP_SUBCAP_IDX] = TPM_CAP_PROP_PCR;
 500
 501         rc = transmit_cmd(chip, data, sizeof(data),
 502                         "attempting to determine the number of PCRS");
 503         if (rc)
 504                 return 0;
 505
 506         num_pcrs = be32_to_cpu(*((__be32 *) (data + 14)));
 507         for (i = 0; i < num_pcrs; i++) {
 508                 memcpy(data, pcrread, sizeof(pcrread));
 509                 index = cpu_to_be32(i);
 510                 memcpy(data + 10, &index, 4);
 511                 rc = transmit_cmd(chip, data, sizeof(data),
 512                                 "attempting to read a PCR");
 513                 if (rc)
 514                         goto out;
 515                 str += sprintf(str, "PCR-%02d: ", i);
 516                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
 517                         str += sprintf(str, "%02X ", *(data + 10 + j));
 518                 str += sprintf(str, "\n");
 519         }
 520 out:
 521         return str - buf;
 522 }
 523 EXPORT_SYMBOL_GPL(tpm_show_pcrs);
 524
 525 #define  READ_PUBEK_RESULT_SIZE 314
 526 static const u8 readpubek[] = {
 527         0, 193,                 /* TPM_TAG_RQU_COMMAND */
 528         0, 0, 0, 30,            /* length */
 529         0, 0, 0, 124,           /* TPM_ORD_ReadPubek */
 530 };
 531
 532 ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
 533                        char *buf)
 534 {
 535         u8 *data;
 536         ssize_t err;
 537         int i, rc;
 538         char *str = buf;
 539
 540         struct tpm_chip *chip = dev_get_drvdata(dev);
 541         if (chip == NULL)
 542                 return -ENODEV;
 543
 544         data = kzalloc(READ_PUBEK_RESULT_SIZE, GFP_KERNEL);
 545         if (!data)
 546                 return -ENOMEM;
 547
 548         memcpy(data, readpubek, sizeof(readpubek));
 549
 550         err = transmit_cmd(chip, data, READ_PUBEK_RESULT_SIZE,
 551                         "attempting to read the PUBEK");
 552         if (err)
 553                 goto out;
 554
 555         /*
 556            ignore header 10 bytes
 557            algorithm 32 bits (1 == RSA )
 558            encscheme 16 bits
 559            sigscheme 16 bits
 560            parameters (RSA 12->bytes: keybit, #primes, expbit)
 561            keylenbytes 32 bits
 562            256 byte modulus
 563            ignore checksum 20 bytes
 564          */
 565
 566         str +=
 567             sprintf(str,
 568                     "Algorithm: %02X %02X %02X %02X\nEncscheme: %02X %02X\n"
 569                     "Sigscheme: %02X %02X\nParameters: %02X %02X %02X %02X"
 570                     " %02X %02X %02X %02X %02X %02X %02X %02X\n"
 571                     "Modulus length: %d\nModulus: \n",
 572                     data[10], data[11], data[12], data[13], data[14],
 573                     data[15], data[16], data[17], data[22], data[23],
 574                     data[24], data[25], data[26], data[27], data[28],
 575                     data[29], data[30], data[31], data[32], data[33],
 576                     be32_to_cpu(*((__be32 *) (data + 34))));
 577
 578         for (i = 0; i < 256; i++) {
 579                 str += sprintf(str, "%02X ", data[i + 38]);
 580                 if ((i + 1) % 16 == 0)
 581                         str += sprintf(str, "\n");
 582         }
 583 out:
 584         rc = str - buf;
 585         kfree(data);
 586         return rc;
 587 }
 588 EXPORT_SYMBOL_GPL(tpm_show_pubek);
 589
 590 #define CAP_VERSION_1_1 6
 591 #define CAP_VERSION_IDX 13
 592 static const u8 cap_version[] = {
 593         0, 193,                 /* TPM_TAG_RQU_COMMAND */
 594         0, 0, 0, 18,            /* length */
 595         0, 0, 0, 101,           /* TPM_ORD_GetCapability */
 596         0, 0, 0, 0,
 597         0, 0, 0, 0
 598 };
 599
 600 ssize_t tpm_show_caps(struct device *dev, struct device_attribute *attr,
 601                       char *buf)
 602 {
 603         u8 data[30];
 604         ssize_t rc;
 605         char *str = buf;
 606
 607         struct tpm_chip *chip = dev_get_drvdata(dev);
 608         if (chip == NULL)
 609                 return -ENODEV;
 610
 611         memcpy(data, tpm_cap, sizeof(tpm_cap));
 612         data[TPM_CAP_IDX] = TPM_CAP_PROP;
 613         data[TPM_CAP_SUBCAP_IDX] = TPM_CAP_PROP_MANUFACTURER;
 614
 615         rc = transmit_cmd(chip, data, sizeof(data),
 616                         "attempting to determine the manufacturer");
 617         if (rc)
 618                 return 0;
 619
 620         str += sprintf(str, "Manufacturer: 0x%x\n",
 621                        be32_to_cpu(*((__be32 *) (data + TPM_GET_CAP_RET_UINT32_1_IDX))));
 622
 623         memcpy(data, cap_version, sizeof(cap_version));
 624         data[CAP_VERSION_IDX] = CAP_VERSION_1_1;
 625         rc = transmit_cmd(chip, data, sizeof(data),
 626                         "attempting to determine the 1.1 version");
 627         if (rc)
 628                 goto out;
 629
 630         str += sprintf(str,
 631                        "TCG version: %d.%d\nFirmware version: %d.%d\n",
 632                        (int) data[14], (int) data[15], (int) data[16],
 633                        (int) data[17]);
 634
 635 out:
 636         return str - buf;
 637 }
 638 EXPORT_SYMBOL_GPL(tpm_show_caps);
 639
 640 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
 641                         const char *buf, size_t count)
 642 {
 643         struct tpm_chip *chip = dev_get_drvdata(dev);
 644         if (chip == NULL)
 645                 return 0;
 646
 647         chip->vendor.cancel(chip);
 648         return count;
 649 }
 650 EXPORT_SYMBOL_GPL(tpm_store_cancel);
 651
 652 /*
 653  * Device file system interface to the TPM
 654  */
 655 int tpm_open(struct inode *inode, struct file *file)
 656 {
 657         int rc = 0, minor = iminor(inode);
 658         struct tpm_chip *chip = NULL, *pos;
 659
 660         spin_lock(&driver_lock);
 661
 662         list_for_each_entry(pos, &tpm_chip_list, list) {
 663                 if (pos->vendor.miscdev.minor == minor) {
 664                         chip = pos;
 665                         break;
 666                 }
 667         }
 668
 669         if (chip == NULL) {
 670                 rc = -ENODEV;
 671                 goto err_out;
 672         }
 673
 674         if (chip->num_opens) {
 675                 dev_dbg(chip->dev, "Another process owns this TPM\n");
 676                 rc = -EBUSY;
 677                 goto err_out;
 678         }
 679
 680         chip->num_opens++;
 681         get_device(chip->dev);
 682
 683         spin_unlock(&driver_lock);
 684
 685         chip->data_buffer = kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
 686         if (chip->data_buffer == NULL) {
 687                 chip->num_opens--;
 688                 put_device(chip->dev);
 689                 return -ENOMEM;
 690         }
 691
 692         atomic_set(&chip->data_pending, 0);
 693
 694         file->private_data = chip;
 695         return 0;
 696
 697 err_out:
 698         spin_unlock(&driver_lock);
 699         return rc;
 700 }
 701 EXPORT_SYMBOL_GPL(tpm_open);
 702
 703 int tpm_release(struct inode *inode, struct file *file)
 704 {
 705         struct tpm_chip *chip = file->private_data;
 706
 707         spin_lock(&driver_lock);
 708         file->private_data = NULL;
 709         chip->num_opens--;
 710         del_singleshot_timer_sync(&chip->user_read_timer);
 711         flush_scheduled_work();
 712         atomic_set(&chip->data_pending, 0);
 713         put_device(chip->dev);
 714         kfree(chip->data_buffer);
 715         spin_unlock(&driver_lock);
 716         return 0;
 717 }
 718 EXPORT_SYMBOL_GPL(tpm_release);
 719
 720 ssize_t tpm_write(struct file *file, const char __user *buf,
 721                   size_t size, loff_t *off)
 722 {
 723         struct tpm_chip *chip = file->private_data;
 724         int in_size = size, out_size;
 725
 726         /* cannot perform a write until the read has cleared
 727            either via tpm_read or a user_read_timer timeout */
 728         while (atomic_read(&chip->data_pending) != 0)
 729                 msleep(TPM_TIMEOUT);
 730
 731         down(&chip->buffer_mutex);
 732
 733         if (in_size > TPM_BUFSIZE)
 734                 in_size = TPM_BUFSIZE;
 735
 736         if (copy_from_user
 737             (chip->data_buffer, (void __user *) buf, in_size)) {
 738                 up(&chip->buffer_mutex);
 739                 return -EFAULT;
 740         }
 741
 742         /* atomic tpm command send and result receive */
 743         out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
 744
 745         atomic_set(&chip->data_pending, out_size);
 746         up(&chip->buffer_mutex);
 747
 748         /* Set a timeout by which the reader must come claim the result */
 749         mod_timer(&chip->user_read_timer, jiffies + (60 * HZ));
 750
 751         return in_size;
 752 }
 753 EXPORT_SYMBOL_GPL(tpm_write);
 754
 755 ssize_t tpm_read(struct file *file, char __user *buf,
 756                  size_t size, loff_t *off)
 757 {
 758         struct tpm_chip *chip = file->private_data;
 759         int ret_size;
 760
 761         del_singleshot_timer_sync(&chip->user_read_timer);
 762         flush_scheduled_work();
 763         ret_size = atomic_read(&chip->data_pending);
 764         atomic_set(&chip->data_pending, 0);
 765         if (ret_size > 0) {     /* relay data */
 766                 if (size < ret_size)
 767                         ret_size = size;
 768
 769                 down(&chip->buffer_mutex);
 770                 if (copy_to_user(buf, chip->data_buffer, ret_size))
 771                         ret_size = -EFAULT;
 772                 up(&chip->buffer_mutex);
 773         }
 774
 775         return ret_size;
 776 }
 777 EXPORT_SYMBOL_GPL(tpm_read);
 778
 779 void tpm_remove_hardware(struct device *dev)
 780 {
 781         struct tpm_chip *chip = dev_get_drvdata(dev);
 782
 783         if (chip == NULL) {
 784                 dev_err(dev, "No device data found\n");
 785                 return;
 786         }
 787
 788         spin_lock(&driver_lock);
 789
 790         list_del(&chip->list);
 791
 792         spin_unlock(&driver_lock);
 793
 794         dev_set_drvdata(dev, NULL);
 795         misc_deregister(&chip->vendor.miscdev);
 796         kfree(chip->vendor.miscdev.name);
 797
 798         sysfs_remove_group(&dev->kobj, chip->vendor.attr_group);
 799         tpm_bios_log_teardown(chip->bios_dir);
 800
 801         dev_mask[chip->dev_num / TPM_NUM_MASK_ENTRIES] &=
 802             ~(1 << (chip->dev_num % TPM_NUM_MASK_ENTRIES));
 803
 804         kfree(chip);
 805
 806         put_device(dev);
 807 }
 808 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
 809
 810 static u8 savestate[] = {
 811         0, 193,                 /* TPM_TAG_RQU_COMMAND */
 812         0, 0, 0, 10,            /* blob length (in bytes) */
 813         0, 0, 0, 152            /* TPM_ORD_SaveState */
 814 };
 815
 816 /*
 817  * We are about to suspend. Save the TPM state
 818  * so that it can be restored.
 819  */
 820 int tpm_pm_suspend(struct device *dev, pm_message_t pm_state)
 821 {
 822         struct tpm_chip *chip = dev_get_drvdata(dev);
 823         if (chip == NULL)
 824                 return -ENODEV;
 825
 826         tpm_transmit(chip, savestate, sizeof(savestate));
 827         return 0;
 828 }
 829 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
 830
 831 /*
 832  * Resume from a power safe. The BIOS already restored
 833  * the TPM state.
 834  */
 835 int tpm_pm_resume(struct device *dev)
 836 {
 837         struct tpm_chip *chip = dev_get_drvdata(dev);
 838
 839         if (chip == NULL)
 840                 return -ENODEV;
 841
 842         return 0;
 843 }
 844 EXPORT_SYMBOL_GPL(tpm_pm_resume);
 845
 846 /*
 847  * Called from tpm_<specific>.c probe function only for devices
 848  * the driver has determined it should claim.  Prior to calling
 849  * this function the specific probe function has called pci_enable_device
 850  * upon errant exit from this function specific probe function should call
 851  * pci_disable_device
 852  */
 853 struct tpm_chip *tpm_register_hardware(struct device *dev, const struct tpm_vendor_specific
 854                                        *entry)
 855 {
 856 #define DEVNAME_SIZE 7
 857
 858         char *devname;
 859         struct tpm_chip *chip;
 860         int i, j;
 861
 862         /* Driver specific per-device data */
 863         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
 864         if (chip == NULL)
 865                 return NULL;
 866
 867         init_MUTEX(&chip->buffer_mutex);
 868         init_MUTEX(&chip->tpm_mutex);
 869         INIT_LIST_HEAD(&chip->list);
 870
 871         INIT_WORK(&chip->work, timeout_work, chip);
 872
 873         init_timer(&chip->user_read_timer);
 874         chip->user_read_timer.function = user_reader_timeout;
 875         chip->user_read_timer.data = (unsigned long) chip;
 876
 877         memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
 878
 879         chip->dev_num = -1;
 880
 881         for (i = 0; i < TPM_NUM_MASK_ENTRIES; i++)
 882                 for (j = 0; j < 8 * sizeof(int); j++)
 883                         if ((dev_mask[i] & (1 << j)) == 0) {
 884                                 chip->dev_num =
 885                                     i * TPM_NUM_MASK_ENTRIES + j;
 886                                 dev_mask[i] |= 1 << j;
 887                                 goto dev_num_search_complete;
 888                         }
 889
 890 dev_num_search_complete:
 891         if (chip->dev_num < 0) {
 892                 dev_err(dev, "No available tpm device numbers\n");
 893                 kfree(chip);
 894                 return NULL;
 895         } else if (chip->dev_num == 0)
 896                 chip->vendor.miscdev.minor = TPM_MINOR;
 897         else
 898                 chip->vendor.miscdev.minor = MISC_DYNAMIC_MINOR;
 899
 900         devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL);
 901         scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num);
 902         chip->vendor.miscdev.name = devname;
 903
 904         chip->vendor.miscdev.dev = dev;
 905         chip->dev = get_device(dev);
 906
 907         if (misc_register(&chip->vendor.miscdev)) {
 908                 dev_err(chip->dev,
 909                         "unable to misc_register %s, minor %d\n",
 910                         chip->vendor.miscdev.name,
 911                         chip->vendor.miscdev.minor);
 912                 put_device(dev);
 913                 kfree(chip);
 914                 dev_mask[i] &= !(1 << j);
 915                 return NULL;
 916         }
 917
 918         spin_lock(&driver_lock);
 919
 920         dev_set_drvdata(dev, chip);
 921
 922         list_add(&chip->list, &tpm_chip_list);
 923
 924         spin_unlock(&driver_lock);
 925
 926         sysfs_create_group(&dev->kobj, chip->vendor.attr_group);
 927
 928         chip->bios_dir = tpm_bios_log_setup(devname);
 929
 930         return chip;
 931 }
 932 EXPORT_SYMBOL_GPL(tpm_register_hardware);
 933
 934 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 935 MODULE_DESCRIPTION("TPM Driver");
 936 MODULE_VERSION("2.0");
 937 MODULE_LICENSE("GPL");