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 #include "tpm_eventlog.h"
  34
  35 enum tpm_duration {
  36         TPM_SHORT = 0,
  37         TPM_MEDIUM = 1,
  38         TPM_LONG = 2,
  39         TPM_UNDEFINED,
  40 };
  41
  42 #define TPM_MAX_ORDINAL 243
  43 #define TSC_MAX_ORDINAL 12
  44 #define TPM_PROTECTED_COMMAND 0x00
  45 #define TPM_CONNECTION_COMMAND 0x40
  46
  47 /*
  48  * Bug workaround - some TPM's don't flush the most
  49  * recently changed pcr on suspend, so force the flush
  50  * with an extend to the selected _unused_ non-volatile pcr.
  51  */
  52 static int tpm_suspend_pcr;
  53 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  54 MODULE_PARM_DESC(suspend_pcr,
  55                  "PCR to use for dummy writes to faciltate flush on suspend.");
  56
  57 static LIST_HEAD(tpm_chip_list);
  58 static DEFINE_SPINLOCK(driver_lock);
  59 static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
  60
  61 /*
  62  * Array with one entry per ordinal defining the maximum amount
  63  * of time the chip could take to return the result.  The ordinal
  64  * designation of short, medium or long is defined in a table in
  65  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  66  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  67  * from the chip during initialization with a call to tpm_get_timeouts.
  68  */
  69 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  70         TPM_UNDEFINED,          /* 0 */
  71         TPM_UNDEFINED,
  72         TPM_UNDEFINED,
  73         TPM_UNDEFINED,
  74         TPM_UNDEFINED,
  75         TPM_UNDEFINED,          /* 5 */
  76         TPM_UNDEFINED,
  77         TPM_UNDEFINED,
  78         TPM_UNDEFINED,
  79         TPM_UNDEFINED,
  80         TPM_SHORT,              /* 10 */
  81         TPM_SHORT,
  82         TPM_MEDIUM,
  83         TPM_LONG,
  84         TPM_LONG,
  85         TPM_MEDIUM,             /* 15 */
  86         TPM_SHORT,
  87         TPM_SHORT,
  88         TPM_MEDIUM,
  89         TPM_LONG,
  90         TPM_SHORT,              /* 20 */
  91         TPM_SHORT,
  92         TPM_MEDIUM,
  93         TPM_MEDIUM,
  94         TPM_MEDIUM,
  95         TPM_SHORT,              /* 25 */
  96         TPM_SHORT,
  97         TPM_MEDIUM,
  98         TPM_SHORT,
  99         TPM_SHORT,
 100         TPM_MEDIUM,             /* 30 */
 101         TPM_LONG,
 102         TPM_MEDIUM,
 103         TPM_SHORT,
 104         TPM_SHORT,
 105         TPM_SHORT,              /* 35 */
 106         TPM_MEDIUM,
 107         TPM_MEDIUM,
 108         TPM_UNDEFINED,
 109         TPM_UNDEFINED,
 110         TPM_MEDIUM,             /* 40 */
 111         TPM_LONG,
 112         TPM_MEDIUM,
 113         TPM_SHORT,
 114         TPM_SHORT,
 115         TPM_SHORT,              /* 45 */
 116         TPM_SHORT,
 117         TPM_SHORT,
 118         TPM_SHORT,
 119         TPM_LONG,
 120         TPM_MEDIUM,             /* 50 */
 121         TPM_MEDIUM,
 122         TPM_UNDEFINED,
 123         TPM_UNDEFINED,
 124         TPM_UNDEFINED,
 125         TPM_UNDEFINED,          /* 55 */
 126         TPM_UNDEFINED,
 127         TPM_UNDEFINED,
 128         TPM_UNDEFINED,
 129         TPM_UNDEFINED,
 130         TPM_MEDIUM,             /* 60 */
 131         TPM_MEDIUM,
 132         TPM_MEDIUM,
 133         TPM_SHORT,
 134         TPM_SHORT,
 135         TPM_MEDIUM,             /* 65 */
 136         TPM_UNDEFINED,
 137         TPM_UNDEFINED,
 138         TPM_UNDEFINED,
 139         TPM_UNDEFINED,
 140         TPM_SHORT,              /* 70 */
 141         TPM_SHORT,
 142         TPM_UNDEFINED,
 143         TPM_UNDEFINED,
 144         TPM_UNDEFINED,
 145         TPM_UNDEFINED,          /* 75 */
 146         TPM_UNDEFINED,
 147         TPM_UNDEFINED,
 148         TPM_UNDEFINED,
 149         TPM_UNDEFINED,
 150         TPM_LONG,               /* 80 */
 151         TPM_UNDEFINED,
 152         TPM_MEDIUM,
 153         TPM_LONG,
 154         TPM_SHORT,
 155         TPM_UNDEFINED,          /* 85 */
 156         TPM_UNDEFINED,
 157         TPM_UNDEFINED,
 158         TPM_UNDEFINED,
 159         TPM_UNDEFINED,
 160         TPM_SHORT,              /* 90 */
 161         TPM_SHORT,
 162         TPM_SHORT,
 163         TPM_SHORT,
 164         TPM_SHORT,
 165         TPM_UNDEFINED,          /* 95 */
 166         TPM_UNDEFINED,
 167         TPM_UNDEFINED,
 168         TPM_UNDEFINED,
 169         TPM_UNDEFINED,
 170         TPM_MEDIUM,             /* 100 */
 171         TPM_SHORT,
 172         TPM_SHORT,
 173         TPM_UNDEFINED,
 174         TPM_UNDEFINED,
 175         TPM_UNDEFINED,          /* 105 */
 176         TPM_UNDEFINED,
 177         TPM_UNDEFINED,
 178         TPM_UNDEFINED,
 179         TPM_UNDEFINED,
 180         TPM_SHORT,              /* 110 */
 181         TPM_SHORT,
 182         TPM_SHORT,
 183         TPM_SHORT,
 184         TPM_SHORT,
 185         TPM_SHORT,              /* 115 */
 186         TPM_SHORT,
 187         TPM_SHORT,
 188         TPM_UNDEFINED,
 189         TPM_UNDEFINED,
 190         TPM_LONG,               /* 120 */
 191         TPM_LONG,
 192         TPM_MEDIUM,
 193         TPM_UNDEFINED,
 194         TPM_SHORT,
 195         TPM_SHORT,              /* 125 */
 196         TPM_SHORT,
 197         TPM_LONG,
 198         TPM_SHORT,
 199         TPM_SHORT,
 200         TPM_SHORT,              /* 130 */
 201         TPM_MEDIUM,
 202         TPM_UNDEFINED,
 203         TPM_SHORT,
 204         TPM_MEDIUM,
 205         TPM_UNDEFINED,          /* 135 */
 206         TPM_UNDEFINED,
 207         TPM_UNDEFINED,
 208         TPM_UNDEFINED,
 209         TPM_UNDEFINED,
 210         TPM_SHORT,              /* 140 */
 211         TPM_SHORT,
 212         TPM_UNDEFINED,
 213         TPM_UNDEFINED,
 214         TPM_UNDEFINED,
 215         TPM_UNDEFINED,          /* 145 */
 216         TPM_UNDEFINED,
 217         TPM_UNDEFINED,
 218         TPM_UNDEFINED,
 219         TPM_UNDEFINED,
 220         TPM_SHORT,              /* 150 */
 221         TPM_MEDIUM,
 222         TPM_MEDIUM,
 223         TPM_SHORT,
 224         TPM_SHORT,
 225         TPM_UNDEFINED,          /* 155 */
 226         TPM_UNDEFINED,
 227         TPM_UNDEFINED,
 228         TPM_UNDEFINED,
 229         TPM_UNDEFINED,
 230         TPM_SHORT,              /* 160 */
 231         TPM_SHORT,
 232         TPM_SHORT,
 233         TPM_SHORT,
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,          /* 165 */
 236         TPM_UNDEFINED,
 237         TPM_UNDEFINED,
 238         TPM_UNDEFINED,
 239         TPM_UNDEFINED,
 240         TPM_LONG,               /* 170 */
 241         TPM_UNDEFINED,
 242         TPM_UNDEFINED,
 243         TPM_UNDEFINED,
 244         TPM_UNDEFINED,
 245         TPM_UNDEFINED,          /* 175 */
 246         TPM_UNDEFINED,
 247         TPM_UNDEFINED,
 248         TPM_UNDEFINED,
 249         TPM_UNDEFINED,
 250         TPM_MEDIUM,             /* 180 */
 251         TPM_SHORT,
 252         TPM_MEDIUM,
 253         TPM_MEDIUM,
 254         TPM_MEDIUM,
 255         TPM_MEDIUM,             /* 185 */
 256         TPM_SHORT,
 257         TPM_UNDEFINED,
 258         TPM_UNDEFINED,
 259         TPM_UNDEFINED,
 260         TPM_UNDEFINED,          /* 190 */
 261         TPM_UNDEFINED,
 262         TPM_UNDEFINED,
 263         TPM_UNDEFINED,
 264         TPM_UNDEFINED,
 265         TPM_UNDEFINED,          /* 195 */
 266         TPM_UNDEFINED,
 267         TPM_UNDEFINED,
 268         TPM_UNDEFINED,
 269         TPM_UNDEFINED,
 270         TPM_SHORT,              /* 200 */
 271         TPM_UNDEFINED,
 272         TPM_UNDEFINED,
 273         TPM_UNDEFINED,
 274         TPM_SHORT,
 275         TPM_SHORT,              /* 205 */
 276         TPM_SHORT,
 277         TPM_SHORT,
 278         TPM_SHORT,
 279         TPM_SHORT,
 280         TPM_MEDIUM,             /* 210 */
 281         TPM_UNDEFINED,
 282         TPM_MEDIUM,
 283         TPM_MEDIUM,
 284         TPM_MEDIUM,
 285         TPM_UNDEFINED,          /* 215 */
 286         TPM_MEDIUM,
 287         TPM_UNDEFINED,
 288         TPM_UNDEFINED,
 289         TPM_SHORT,
 290         TPM_SHORT,              /* 220 */
 291         TPM_SHORT,
 292         TPM_SHORT,
 293         TPM_SHORT,
 294         TPM_SHORT,
 295         TPM_UNDEFINED,          /* 225 */
 296         TPM_UNDEFINED,
 297         TPM_UNDEFINED,
 298         TPM_UNDEFINED,
 299         TPM_UNDEFINED,
 300         TPM_SHORT,              /* 230 */
 301         TPM_LONG,
 302         TPM_MEDIUM,
 303         TPM_UNDEFINED,
 304         TPM_UNDEFINED,
 305         TPM_UNDEFINED,          /* 235 */
 306         TPM_UNDEFINED,
 307         TPM_UNDEFINED,
 308         TPM_UNDEFINED,
 309         TPM_UNDEFINED,
 310         TPM_SHORT,              /* 240 */
 311         TPM_UNDEFINED,
 312         TPM_MEDIUM,
 313 };
 314
 315 static void user_reader_timeout(unsigned long ptr)
 316 {
 317         struct tpm_chip *chip = (struct tpm_chip *) ptr;
 318
 319         schedule_work(&chip->work);
 320 }
 321
 322 static void timeout_work(struct work_struct *work)
 323 {
 324         struct tpm_chip *chip = container_of(work, struct tpm_chip, work);
 325
 326         mutex_lock(&chip->buffer_mutex);
 327         atomic_set(&chip->data_pending, 0);
 328         memset(chip->data_buffer, 0, TPM_BUFSIZE);
 329         mutex_unlock(&chip->buffer_mutex);
 330 }
 331
 332 /*
 333  * Returns max number of jiffies to wait
 334  */
 335 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 336                                            u32 ordinal)
 337 {
 338         int duration_idx = TPM_UNDEFINED;
 339         int duration = 0;
 340         u8 category = (ordinal >> 24) & 0xFF;
 341
 342         if ((category == TPM_PROTECTED_COMMAND && ordinal < TPM_MAX_ORDINAL) ||
 343             (category == TPM_CONNECTION_COMMAND && ordinal < TSC_MAX_ORDINAL))
 344                 duration_idx = tpm_ordinal_duration[ordinal];
 345
 346         if (duration_idx != TPM_UNDEFINED)
 347                 duration = chip->vendor.duration[duration_idx];
 348         if (duration <= 0)
 349                 return 2 * 60 * HZ;
 350         else
 351                 return duration;
 352 }
 353 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 354
 355 /*
 356  * Internal kernel interface to transmit TPM commands
 357  */
 358 static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 359                             size_t bufsiz)
 360 {
 361         ssize_t rc;
 362         u32 count, ordinal;
 363         unsigned long stop;
 364
 365         if (bufsiz > TPM_BUFSIZE)
 366                 bufsiz = TPM_BUFSIZE;
 367
 368         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 369         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 370         if (count == 0)
 371                 return -ENODATA;
 372         if (count > bufsiz) {
 373                 dev_err(chip->dev,
 374                         "invalid count value %x %zx \n", count, bufsiz);
 375                 return -E2BIG;
 376         }
 377
 378         mutex_lock(&chip->tpm_mutex);
 379
 380         if ((rc = chip->vendor.send(chip, (u8 *) buf, count)) < 0) {
 381                 dev_err(chip->dev,
 382                         "tpm_transmit: tpm_send: error %zd\n", rc);
 383                 goto out;
 384         }
 385
 386         if (chip->vendor.irq)
 387                 goto out_recv;
 388
 389         stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 390         do {
 391                 u8 status = chip->vendor.status(chip);
 392                 if ((status & chip->vendor.req_complete_mask) ==
 393                     chip->vendor.req_complete_val)
 394                         goto out_recv;
 395
 396                 if ((status == chip->vendor.req_canceled)) {
 397                         dev_err(chip->dev, "Operation Canceled\n");
 398                         rc = -ECANCELED;
 399                         goto out;
 400                 }
 401
 402                 msleep(TPM_TIMEOUT);    /* CHECK */
 403                 rmb();
 404         } while (time_before(jiffies, stop));
 405
 406         chip->vendor.cancel(chip);
 407         dev_err(chip->dev, "Operation Timed out\n");
 408         rc = -ETIME;
 409         goto out;
 410
 411 out_recv:
 412         rc = chip->vendor.recv(chip, (u8 *) buf, bufsiz);
 413         if (rc < 0)
 414                 dev_err(chip->dev,
 415                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 416 out:
 417         mutex_unlock(&chip->tpm_mutex);
 418         return rc;
 419 }
 420
 421 #define TPM_DIGEST_SIZE 20
 422 #define TPM_RET_CODE_IDX 6
 423
 424 enum tpm_capabilities {
 425         TPM_CAP_FLAG = cpu_to_be32(4),
 426         TPM_CAP_PROP = cpu_to_be32(5),
 427         CAP_VERSION_1_1 = cpu_to_be32(0x06),
 428         CAP_VERSION_1_2 = cpu_to_be32(0x1A)
 429 };
 430
 431 enum tpm_sub_capabilities {
 432         TPM_CAP_PROP_PCR = cpu_to_be32(0x101),
 433         TPM_CAP_PROP_MANUFACTURER = cpu_to_be32(0x103),
 434         TPM_CAP_FLAG_PERM = cpu_to_be32(0x108),
 435         TPM_CAP_FLAG_VOL = cpu_to_be32(0x109),
 436         TPM_CAP_PROP_OWNER = cpu_to_be32(0x111),
 437         TPM_CAP_PROP_TIS_TIMEOUT = cpu_to_be32(0x115),
 438         TPM_CAP_PROP_TIS_DURATION = cpu_to_be32(0x120),
 439
 440 };
 441
 442 static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
 443                             int len, const char *desc)
 444 {
 445         int err;
 446
 447         len = tpm_transmit(chip,(u8 *) cmd, len);
 448         if (len <  0)
 449                 return len;
 450         else if (len < TPM_HEADER_SIZE)
 451                 return -EFAULT;
 452
 453         err = be32_to_cpu(cmd->header.out.return_code);
 454         if (err != 0 && desc)
 455                 dev_err(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
 456
 457         return err;
 458 }
 459
 460 #define TPM_INTERNAL_RESULT_SIZE 200
 461 #define TPM_TAG_RQU_COMMAND cpu_to_be16(193)
 462 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 463 #define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 464
 465 static const struct tpm_input_header tpm_getcap_header = {
 466         .tag = TPM_TAG_RQU_COMMAND,
 467         .length = cpu_to_be32(22),
 468         .ordinal = TPM_ORD_GET_CAP
 469 };
 470
 471 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
 472                    const char *desc)
 473 {
 474         struct tpm_cmd_t tpm_cmd;
 475         int rc;
 476         struct tpm_chip *chip = dev_get_drvdata(dev);
 477
 478         tpm_cmd.header.in = tpm_getcap_header;
 479         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 480                 tpm_cmd.params.getcap_in.cap = subcap_id;
 481                 /*subcap field not necessary */
 482                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 483                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 484         } else {
 485                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 486                     subcap_id == TPM_CAP_FLAG_VOL)
 487                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 488                 else
 489                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 490                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 491                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 492         }
 493         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
 494         if (!rc)
 495                 *cap = tpm_cmd.params.getcap_out.cap;
 496         return rc;
 497 }
 498
 499 void tpm_gen_interrupt(struct tpm_chip *chip)
 500 {
 501         struct  tpm_cmd_t tpm_cmd;
 502         ssize_t rc;
 503
 504         tpm_cmd.header.in = tpm_getcap_header;
 505         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 506         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 507         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 508
 509         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 510                         "attempting to determine the timeouts");
 511 }
 512 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 513
 514 #define TPM_ORD_STARTUP cpu_to_be32(153)
 515 #define TPM_ST_CLEAR cpu_to_be16(1)
 516 #define TPM_ST_STATE cpu_to_be16(2)
 517 #define TPM_ST_DEACTIVATED cpu_to_be16(3)
 518 static const struct tpm_input_header tpm_startup_header = {
 519         .tag = TPM_TAG_RQU_COMMAND,
 520         .length = cpu_to_be32(12),
 521         .ordinal = TPM_ORD_STARTUP
 522 };
 523
 524 static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 525 {
 526         struct tpm_cmd_t start_cmd;
 527         start_cmd.header.in = tpm_startup_header;
 528         start_cmd.params.startup_in.startup_type = startup_type;
 529         return transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE,
 530                             "attempting to start the TPM");
 531 }
 532
 533 int tpm_get_timeouts(struct tpm_chip *chip)
 534 {
 535         struct tpm_cmd_t tpm_cmd;
 536         struct timeout_t *timeout_cap;
 537         struct duration_t *duration_cap;
 538         ssize_t rc;
 539         u32 timeout;
 540         unsigned int scale = 1;
 541
 542         tpm_cmd.header.in = tpm_getcap_header;
 543         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 544         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 545         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 546         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, NULL);
 547
 548         if (rc == TPM_ERR_INVALID_POSTINIT) {
 549                 /* The TPM is not started, we are the first to talk to it.
 550                    Execute a startup command. */
 551                 dev_info(chip->dev, "Issuing TPM_STARTUP");
 552                 if (tpm_startup(chip, TPM_ST_CLEAR))
 553                         return rc;
 554
 555                 tpm_cmd.header.in = tpm_getcap_header;
 556                 tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 557                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 558                 tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 559                 rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 560                                   NULL);
 561         }
 562         if (rc) {
 563                 dev_err(chip->dev,
 564                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 565                         rc);
 566                 goto duration;
 567         }
 568
 569         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 570             be32_to_cpu(tpm_cmd.header.out.length)
 571             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 572                 return -EINVAL;
 573
 574         timeout_cap = &tpm_cmd.params.getcap_out.cap.timeout;
 575         /* Don't overwrite default if value is 0 */
 576         timeout = be32_to_cpu(timeout_cap->a);
 577         if (timeout && timeout < 1000) {
 578                 /* timeouts in msec rather usec */
 579                 scale = 1000;
 580                 chip->vendor.timeout_adjusted = true;
 581         }
 582         if (timeout)
 583                 chip->vendor.timeout_a = usecs_to_jiffies(timeout * scale);
 584         timeout = be32_to_cpu(timeout_cap->b);
 585         if (timeout)
 586                 chip->vendor.timeout_b = usecs_to_jiffies(timeout * scale);
 587         timeout = be32_to_cpu(timeout_cap->c);
 588         if (timeout)
 589                 chip->vendor.timeout_c = usecs_to_jiffies(timeout * scale);
 590         timeout = be32_to_cpu(timeout_cap->d);
 591         if (timeout)
 592                 chip->vendor.timeout_d = usecs_to_jiffies(timeout * scale);
 593
 594 duration:
 595         tpm_cmd.header.in = tpm_getcap_header;
 596         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 597         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 598         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 599
 600         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 601                         "attempting to determine the durations");
 602         if (rc)
 603                 return rc;
 604
 605         if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 606             be32_to_cpu(tpm_cmd.header.out.length)
 607             != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 608                 return -EINVAL;
 609
 610         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 611         chip->vendor.duration[TPM_SHORT] =
 612             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 613         chip->vendor.duration[TPM_MEDIUM] =
 614             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 615         chip->vendor.duration[TPM_LONG] =
 616             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 617
 618         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 619          * value wrong and apparently reports msecs rather than usecs. So we
 620          * fix up the resulting too-small TPM_SHORT value to make things work.
 621          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 622          */
 623         if (chip->vendor.duration[TPM_SHORT] < (HZ / 100)) {
 624                 chip->vendor.duration[TPM_SHORT] = HZ;
 625                 chip->vendor.duration[TPM_MEDIUM] *= 1000;
 626                 chip->vendor.duration[TPM_LONG] *= 1000;
 627                 chip->vendor.duration_adjusted = true;
 628                 dev_info(chip->dev, "Adjusting TPM timeout parameters.");
 629         }
 630         return 0;
 631 }
 632 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 633
 634 #define TPM_ORD_CONTINUE_SELFTEST 83
 635 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 636
 637 static struct tpm_input_header continue_selftest_header = {
 638         .tag = TPM_TAG_RQU_COMMAND,
 639         .length = cpu_to_be32(10),
 640         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 641 };
 642
 643 /**
 644  * tpm_continue_selftest -- run TPM's selftest
 645  * @chip: TPM chip to use
 646  *
 647  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 648  * a TPM error code.
 649  */
 650 static int tpm_continue_selftest(struct tpm_chip *chip)
 651 {
 652         int rc;
 653         struct tpm_cmd_t cmd;
 654
 655         cmd.header.in = continue_selftest_header;
 656         rc = transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 657                           "continue selftest");
 658         return rc;
 659 }
 660
 661 ssize_t tpm_show_enabled(struct device * dev, struct device_attribute * attr,
 662                         char *buf)
 663 {
 664         cap_t cap;
 665         ssize_t rc;
 666
 667         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 668                          "attempting to determine the permanent enabled state");
 669         if (rc)
 670                 return 0;
 671
 672         rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
 673         return rc;
 674 }
 675 EXPORT_SYMBOL_GPL(tpm_show_enabled);
 676
 677 ssize_t tpm_show_active(struct device * dev, struct device_attribute * attr,
 678                         char *buf)
 679 {
 680         cap_t cap;
 681         ssize_t rc;
 682
 683         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 684                          "attempting to determine the permanent active state");
 685         if (rc)
 686                 return 0;
 687
 688         rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
 689         return rc;
 690 }
 691 EXPORT_SYMBOL_GPL(tpm_show_active);
 692
 693 ssize_t tpm_show_owned(struct device * dev, struct device_attribute * attr,
 694                         char *buf)
 695 {
 696         cap_t cap;
 697         ssize_t rc;
 698
 699         rc = tpm_getcap(dev, TPM_CAP_PROP_OWNER, &cap,
 700                          "attempting to determine the owner state");
 701         if (rc)
 702                 return 0;
 703
 704         rc = sprintf(buf, "%d\n", cap.owned);
 705         return rc;
 706 }
 707 EXPORT_SYMBOL_GPL(tpm_show_owned);
 708
 709 ssize_t tpm_show_temp_deactivated(struct device * dev,
 710                                 struct device_attribute * attr, char *buf)
 711 {
 712         cap_t cap;
 713         ssize_t rc;
 714
 715         rc = tpm_getcap(dev, TPM_CAP_FLAG_VOL, &cap,
 716                          "attempting to determine the temporary state");
 717         if (rc)
 718                 return 0;
 719
 720         rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
 721         return rc;
 722 }
 723 EXPORT_SYMBOL_GPL(tpm_show_temp_deactivated);
 724
 725 /*
 726  * tpm_chip_find_get - return tpm_chip for given chip number
 727  */
 728 static struct tpm_chip *tpm_chip_find_get(int chip_num)
 729 {
 730         struct tpm_chip *pos, *chip = NULL;
 731
 732         rcu_read_lock();
 733         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
 734                 if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
 735                         continue;
 736
 737                 if (try_module_get(pos->dev->driver->owner)) {
 738                         chip = pos;
 739                         break;
 740                 }
 741         }
 742         rcu_read_unlock();
 743         return chip;
 744 }
 745
 746 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 747 #define READ_PCR_RESULT_SIZE 30
 748 static struct tpm_input_header pcrread_header = {
 749         .tag = TPM_TAG_RQU_COMMAND,
 750         .length = cpu_to_be32(14),
 751         .ordinal = TPM_ORDINAL_PCRREAD
 752 };
 753
 754 static int __tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 755 {
 756         int rc;
 757         struct tpm_cmd_t cmd;
 758
 759         cmd.header.in = pcrread_header;
 760         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 761         rc = transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE,
 762                           "attempting to read a pcr value");
 763
 764         if (rc == 0)
 765                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 766                        TPM_DIGEST_SIZE);
 767         return rc;
 768 }
 769
 770 /**
 771  * tpm_pcr_read - read a pcr value
 772  * @chip_num:   tpm idx # or ANY
 773  * @pcr_idx:    pcr idx to retrieve
 774  * @res_buf:    TPM_PCR value
 775  *              size of res_buf is 20 bytes (or NULL if you don't care)
 776  *
 777  * The TPM driver should be built-in, but for whatever reason it
 778  * isn't, protect against the chip disappearing, by incrementing
 779  * the module usage count.
 780  */
 781 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 782 {
 783         struct tpm_chip *chip;
 784         int rc;
 785
 786         chip = tpm_chip_find_get(chip_num);
 787         if (chip == NULL)
 788                 return -ENODEV;
 789         rc = __tpm_pcr_read(chip, pcr_idx, res_buf);
 790         tpm_chip_put(chip);
 791         return rc;
 792 }
 793 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 794
 795 /**
 796  * tpm_pcr_extend - extend pcr value with hash
 797  * @chip_num:   tpm idx # or AN&
 798  * @pcr_idx:    pcr idx to extend
 799  * @hash:       hash value used to extend pcr value
 800  *
 801  * The TPM driver should be built-in, but for whatever reason it
 802  * isn't, protect against the chip disappearing, by incrementing
 803  * the module usage count.
 804  */
 805 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 806 #define EXTEND_PCR_RESULT_SIZE 34
 807 static struct tpm_input_header pcrextend_header = {
 808         .tag = TPM_TAG_RQU_COMMAND,
 809         .length = cpu_to_be32(34),
 810         .ordinal = TPM_ORD_PCR_EXTEND
 811 };
 812
 813 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 814 {
 815         struct tpm_cmd_t cmd;
 816         int rc;
 817         struct tpm_chip *chip;
 818
 819         chip = tpm_chip_find_get(chip_num);
 820         if (chip == NULL)
 821                 return -ENODEV;
 822
 823         cmd.header.in = pcrextend_header;
 824         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 825         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 826         rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
 827                           "attempting extend a PCR value");
 828
 829         tpm_chip_put(chip);
 830         return rc;
 831 }
 832 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 833
 834 /**
 835  * tpm_do_selftest - have the TPM continue its selftest and wait until it
 836  *                   can receive further commands
 837  * @chip: TPM chip to use
 838  *
 839  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 840  * a TPM error code.
 841  */
 842 int tpm_do_selftest(struct tpm_chip *chip)
 843 {
 844         int rc;
 845         unsigned int loops;
 846         unsigned int delay_msec = 1000;
 847         unsigned long duration;
 848         struct tpm_cmd_t cmd;
 849
 850         duration = tpm_calc_ordinal_duration(chip,
 851                                              TPM_ORD_CONTINUE_SELFTEST);
 852
 853         loops = jiffies_to_msecs(duration) / delay_msec;
 854
 855         rc = tpm_continue_selftest(chip);
 856         /* This may fail if there was no TPM driver during a suspend/resume
 857          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 858          */
 859         if (rc)
 860                 return rc;
 861
 862         do {
 863                 /* Attempt to read a PCR value */
 864                 cmd.header.in = pcrread_header;
 865                 cmd.params.pcrread_in.pcr_idx = cpu_to_be32(0);
 866                 rc = tpm_transmit(chip, (u8 *) &cmd, READ_PCR_RESULT_SIZE);
 867
 868                 if (rc < TPM_HEADER_SIZE)
 869                         return -EFAULT;
 870
 871                 rc = be32_to_cpu(cmd.header.out.return_code);
 872                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 873                         dev_info(chip->dev,
 874                                  "TPM is disabled/deactivated (0x%X)\n", rc);
 875                         /* TPM is disabled and/or deactivated; driver can
 876                          * proceed and TPM does handle commands for
 877                          * suspend/resume correctly
 878                          */
 879                         return 0;
 880                 }
 881                 if (rc != TPM_WARN_DOING_SELFTEST)
 882                         return rc;
 883                 msleep(delay_msec);
 884         } while (--loops > 0);
 885
 886         return rc;
 887 }
 888 EXPORT_SYMBOL_GPL(tpm_do_selftest);
 889
 890 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 891 {
 892         struct tpm_chip *chip;
 893         int rc;
 894
 895         chip = tpm_chip_find_get(chip_num);
 896         if (chip == NULL)
 897                 return -ENODEV;
 898
 899         rc = transmit_cmd(chip, cmd, buflen, "attempting tpm_cmd");
 900
 901         tpm_chip_put(chip);
 902         return rc;
 903 }
 904 EXPORT_SYMBOL_GPL(tpm_send);
 905
 906 ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
 907                       char *buf)
 908 {
 909         cap_t cap;
 910         u8 digest[TPM_DIGEST_SIZE];
 911         ssize_t rc;
 912         int i, j, num_pcrs;
 913         char *str = buf;
 914         struct tpm_chip *chip = dev_get_drvdata(dev);
 915
 916         rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap,
 917                         "attempting to determine the number of PCRS");
 918         if (rc)
 919                 return 0;
 920
 921         num_pcrs = be32_to_cpu(cap.num_pcrs);
 922         for (i = 0; i < num_pcrs; i++) {
 923                 rc = __tpm_pcr_read(chip, i, digest);
 924                 if (rc)
 925                         break;
 926                 str += sprintf(str, "PCR-%02d: ", i);
 927                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
 928                         str += sprintf(str, "%02X ", digest[j]);
 929                 str += sprintf(str, "\n");
 930         }
 931         return str - buf;
 932 }
 933 EXPORT_SYMBOL_GPL(tpm_show_pcrs);
 934
 935 #define  READ_PUBEK_RESULT_SIZE 314
 936 #define TPM_ORD_READPUBEK cpu_to_be32(124)
 937 static struct tpm_input_header tpm_readpubek_header = {
 938         .tag = TPM_TAG_RQU_COMMAND,
 939         .length = cpu_to_be32(30),
 940         .ordinal = TPM_ORD_READPUBEK
 941 };
 942
 943 ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
 944                        char *buf)
 945 {
 946         u8 *data;
 947         struct tpm_cmd_t tpm_cmd;
 948         ssize_t err;
 949         int i, rc;
 950         char *str = buf;
 951
 952         struct tpm_chip *chip = dev_get_drvdata(dev);
 953
 954         tpm_cmd.header.in = tpm_readpubek_header;
 955         err = transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
 956                         "attempting to read the PUBEK");
 957         if (err)
 958                 goto out;
 959
 960         /*
 961            ignore header 10 bytes
 962            algorithm 32 bits (1 == RSA )
 963            encscheme 16 bits
 964            sigscheme 16 bits
 965            parameters (RSA 12->bytes: keybit, #primes, expbit)
 966            keylenbytes 32 bits
 967            256 byte modulus
 968            ignore checksum 20 bytes
 969          */
 970         data = tpm_cmd.params.readpubek_out_buffer;
 971         str +=
 972             sprintf(str,
 973                     "Algorithm: %02X %02X %02X %02X\n"
 974                     "Encscheme: %02X %02X\n"
 975                     "Sigscheme: %02X %02X\n"
 976                     "Parameters: %02X %02X %02X %02X "
 977                     "%02X %02X %02X %02X "
 978                     "%02X %02X %02X %02X\n"
 979                     "Modulus length: %d\n"
 980                     "Modulus:\n",
 981                     data[0], data[1], data[2], data[3],
 982                     data[4], data[5],
 983                     data[6], data[7],
 984                     data[12], data[13], data[14], data[15],
 985                     data[16], data[17], data[18], data[19],
 986                     data[20], data[21], data[22], data[23],
 987                     be32_to_cpu(*((__be32 *) (data + 24))));
 988
 989         for (i = 0; i < 256; i++) {
 990                 str += sprintf(str, "%02X ", data[i + 28]);
 991                 if ((i + 1) % 16 == 0)
 992                         str += sprintf(str, "\n");
 993         }
 994 out:
 995         rc = str - buf;
 996         return rc;
 997 }
 998 EXPORT_SYMBOL_GPL(tpm_show_pubek);
 999
1000
1001 ssize_t tpm_show_caps(struct device *dev, struct device_attribute *attr,
1002                       char *buf)
1003 {
1004         cap_t cap;
1005         ssize_t rc;
1006         char *str = buf;
1007
1008         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
1009                         "attempting to determine the manufacturer");
1010         if (rc)
1011                 return 0;
1012         str += sprintf(str, "Manufacturer: 0x%x\n",
1013                        be32_to_cpu(cap.manufacturer_id));
1014
1015         rc = tpm_getcap(dev, CAP_VERSION_1_1, &cap,
1016                         "attempting to determine the 1.1 version");
1017         if (rc)
1018                 return 0;
1019         str += sprintf(str,
1020                        "TCG version: %d.%d\nFirmware version: %d.%d\n",
1021                        cap.tpm_version.Major, cap.tpm_version.Minor,
1022                        cap.tpm_version.revMajor, cap.tpm_version.revMinor);
1023         return str - buf;
1024 }
1025 EXPORT_SYMBOL_GPL(tpm_show_caps);
1026
1027 ssize_t tpm_show_caps_1_2(struct device * dev,
1028                           struct device_attribute * attr, char *buf)
1029 {
1030         cap_t cap;
1031         ssize_t rc;
1032         char *str = buf;
1033
1034         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
1035                         "attempting to determine the manufacturer");
1036         if (rc)
1037                 return 0;
1038         str += sprintf(str, "Manufacturer: 0x%x\n",
1039                        be32_to_cpu(cap.manufacturer_id));
1040         rc = tpm_getcap(dev, CAP_VERSION_1_2, &cap,
1041                          "attempting to determine the 1.2 version");
1042         if (rc)
1043                 return 0;
1044         str += sprintf(str,
1045                        "TCG version: %d.%d\nFirmware version: %d.%d\n",
1046                        cap.tpm_version_1_2.Major, cap.tpm_version_1_2.Minor,
1047                        cap.tpm_version_1_2.revMajor,
1048                        cap.tpm_version_1_2.revMinor);
1049         return str - buf;
1050 }
1051 EXPORT_SYMBOL_GPL(tpm_show_caps_1_2);
1052
1053 ssize_t tpm_show_durations(struct device *dev, struct device_attribute *attr,
1054                           char *buf)
1055 {
1056         struct tpm_chip *chip = dev_get_drvdata(dev);
1057
1058         if (chip->vendor.duration[TPM_LONG] == 0)
1059                 return 0;
1060
1061         return sprintf(buf, "%d %d %d [%s]\n",
1062                        jiffies_to_usecs(chip->vendor.duration[TPM_SHORT]),
1063                        jiffies_to_usecs(chip->vendor.duration[TPM_MEDIUM]),
1064                        jiffies_to_usecs(chip->vendor.duration[TPM_LONG]),
1065                        chip->vendor.duration_adjusted
1066                        ? "adjusted" : "original");
1067 }
1068 EXPORT_SYMBOL_GPL(tpm_show_durations);
1069
1070 ssize_t tpm_show_timeouts(struct device *dev, struct device_attribute *attr,
1071                           char *buf)
1072 {
1073         struct tpm_chip *chip = dev_get_drvdata(dev);
1074
1075         return sprintf(buf, "%d %d %d %d [%s]\n",
1076                        jiffies_to_usecs(chip->vendor.timeout_a),
1077                        jiffies_to_usecs(chip->vendor.timeout_b),
1078                        jiffies_to_usecs(chip->vendor.timeout_c),
1079                        jiffies_to_usecs(chip->vendor.timeout_d),
1080                        chip->vendor.timeout_adjusted
1081                        ? "adjusted" : "original");
1082 }
1083 EXPORT_SYMBOL_GPL(tpm_show_timeouts);
1084
1085 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
1086                         const char *buf, size_t count)
1087 {
1088         struct tpm_chip *chip = dev_get_drvdata(dev);
1089         if (chip == NULL)
1090                 return 0;
1091
1092         chip->vendor.cancel(chip);
1093         return count;
1094 }
1095 EXPORT_SYMBOL_GPL(tpm_store_cancel);
1096
1097 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
1098                          wait_queue_head_t *queue)
1099 {
1100         unsigned long stop;
1101         long rc;
1102         u8 status;
1103
1104         /* check current status */
1105         status = chip->vendor.status(chip);
1106         if ((status & mask) == mask)
1107                 return 0;
1108
1109         stop = jiffies + timeout;
1110
1111         if (chip->vendor.irq) {
1112 again:
1113                 timeout = stop - jiffies;
1114                 if ((long)timeout <= 0)
1115                         return -ETIME;
1116                 rc = wait_event_interruptible_timeout(*queue,
1117                                                       ((chip->vendor.status(chip)
1118                                                       & mask) == mask),
1119                                                       timeout);
1120                 if (rc > 0)
1121                         return 0;
1122                 if (rc == -ERESTARTSYS && freezing(current)) {
1123                         clear_thread_flag(TIF_SIGPENDING);
1124                         goto again;
1125                 }
1126         } else {
1127                 do {
1128                         msleep(TPM_TIMEOUT);
1129                         status = chip->vendor.status(chip);
1130                         if ((status & mask) == mask)
1131                                 return 0;
1132                 } while (time_before(jiffies, stop));
1133         }
1134         return -ETIME;
1135 }
1136 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
1137 /*
1138  * Device file system interface to the TPM
1139  *
1140  * It's assured that the chip will be opened just once,
1141  * by the check of is_open variable, which is protected
1142  * by driver_lock.
1143  */
1144 int tpm_open(struct inode *inode, struct file *file)
1145 {
1146         int minor = iminor(inode);
1147         struct tpm_chip *chip = NULL, *pos;
1148
1149         rcu_read_lock();
1150         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
1151                 if (pos->vendor.miscdev.minor == minor) {
1152                         chip = pos;
1153                         get_device(chip->dev);
1154                         break;
1155                 }
1156         }
1157         rcu_read_unlock();
1158
1159         if (!chip)
1160                 return -ENODEV;
1161
1162         if (test_and_set_bit(0, &chip->is_open)) {
1163                 dev_dbg(chip->dev, "Another process owns this TPM\n");
1164                 put_device(chip->dev);
1165                 return -EBUSY;
1166         }
1167
1168         chip->data_buffer = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
1169         if (chip->data_buffer == NULL) {
1170                 clear_bit(0, &chip->is_open);
1171                 put_device(chip->dev);
1172                 return -ENOMEM;
1173         }
1174
1175         atomic_set(&chip->data_pending, 0);
1176
1177         file->private_data = chip;
1178         return 0;
1179 }
1180 EXPORT_SYMBOL_GPL(tpm_open);
1181
1182 /*
1183  * Called on file close
1184  */
1185 int tpm_release(struct inode *inode, struct file *file)
1186 {
1187         struct tpm_chip *chip = file->private_data;
1188
1189         del_singleshot_timer_sync(&chip->user_read_timer);
1190         flush_work(&chip->work);
1191         file->private_data = NULL;
1192         atomic_set(&chip->data_pending, 0);
1193         kzfree(chip->data_buffer);
1194         clear_bit(0, &chip->is_open);
1195         put_device(chip->dev);
1196         return 0;
1197 }
1198 EXPORT_SYMBOL_GPL(tpm_release);
1199
1200 ssize_t tpm_write(struct file *file, const char __user *buf,
1201                   size_t size, loff_t *off)
1202 {
1203         struct tpm_chip *chip = file->private_data;
1204         size_t in_size = size;
1205         ssize_t out_size;
1206
1207         /* cannot perform a write until the read has cleared
1208            either via tpm_read or a user_read_timer timeout.
1209            This also prevents splitted buffered writes from blocking here.
1210         */
1211         if (atomic_read(&chip->data_pending) != 0)
1212                 return -EBUSY;
1213
1214         if (in_size > TPM_BUFSIZE)
1215                 return -E2BIG;
1216
1217         mutex_lock(&chip->buffer_mutex);
1218
1219         if (copy_from_user
1220             (chip->data_buffer, (void __user *) buf, in_size)) {
1221                 mutex_unlock(&chip->buffer_mutex);
1222                 return -EFAULT;
1223         }
1224
1225         /* atomic tpm command send and result receive */
1226         out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
1227         if (out_size < 0) {
1228                 mutex_unlock(&chip->buffer_mutex);
1229                 return out_size;
1230         }
1231
1232         atomic_set(&chip->data_pending, out_size);
1233         mutex_unlock(&chip->buffer_mutex);
1234
1235         /* Set a timeout by which the reader must come claim the result */
1236         mod_timer(&chip->user_read_timer, jiffies + (60 * HZ));
1237
1238         return in_size;
1239 }
1240 EXPORT_SYMBOL_GPL(tpm_write);
1241
1242 ssize_t tpm_read(struct file *file, char __user *buf,
1243                  size_t size, loff_t *off)
1244 {
1245         struct tpm_chip *chip = file->private_data;
1246         ssize_t ret_size;
1247         int rc;
1248
1249         del_singleshot_timer_sync(&chip->user_read_timer);
1250         flush_work(&chip->work);
1251         ret_size = atomic_read(&chip->data_pending);
1252         if (ret_size > 0) {     /* relay data */
1253                 ssize_t orig_ret_size = ret_size;
1254                 if (size < ret_size)
1255                         ret_size = size;
1256
1257                 mutex_lock(&chip->buffer_mutex);
1258                 rc = copy_to_user(buf, chip->data_buffer, ret_size);
1259                 memset(chip->data_buffer, 0, orig_ret_size);
1260                 if (rc)
1261                         ret_size = -EFAULT;
1262
1263                 mutex_unlock(&chip->buffer_mutex);
1264         }
1265
1266         atomic_set(&chip->data_pending, 0);
1267
1268         return ret_size;
1269 }
1270 EXPORT_SYMBOL_GPL(tpm_read);
1271
1272 void tpm_remove_hardware(struct device *dev)
1273 {
1274         struct tpm_chip *chip = dev_get_drvdata(dev);
1275
1276         if (chip == NULL) {
1277                 dev_err(dev, "No device data found\n");
1278                 return;
1279         }
1280
1281         spin_lock(&driver_lock);
1282         list_del_rcu(&chip->list);
1283         spin_unlock(&driver_lock);
1284         synchronize_rcu();
1285
1286         misc_deregister(&chip->vendor.miscdev);
1287         sysfs_remove_group(&dev->kobj, chip->vendor.attr_group);
1288         tpm_remove_ppi(&dev->kobj);
1289         tpm_bios_log_teardown(chip->bios_dir);
1290
1291         /* write it this way to be explicit (chip->dev == dev) */
1292         put_device(chip->dev);
1293 }
1294 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
1295
1296 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
1297 #define SAVESTATE_RESULT_SIZE 10
1298
1299 static struct tpm_input_header savestate_header = {
1300         .tag = TPM_TAG_RQU_COMMAND,
1301         .length = cpu_to_be32(10),
1302         .ordinal = TPM_ORD_SAVESTATE
1303 };
1304
1305 /*
1306  * We are about to suspend. Save the TPM state
1307  * so that it can be restored.
1308  */
1309 int tpm_pm_suspend(struct device *dev)
1310 {
1311         struct tpm_chip *chip = dev_get_drvdata(dev);
1312         struct tpm_cmd_t cmd;
1313         int rc;
1314
1315         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1316
1317         if (chip == NULL)
1318                 return -ENODEV;
1319
1320         /* for buggy tpm, flush pcrs with extend to selected dummy */
1321         if (tpm_suspend_pcr) {
1322                 cmd.header.in = pcrextend_header;
1323                 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
1324                 memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
1325                        TPM_DIGEST_SIZE);
1326                 rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE,
1327                                   "extending dummy pcr before suspend");
1328         }
1329
1330         /* now do the actual savestate */
1331         cmd.header.in = savestate_header;
1332         rc = transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE,
1333                           "sending savestate before suspend");
1334         return rc;
1335 }
1336 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1337
1338 /*
1339  * Resume from a power safe. The BIOS already restored
1340  * the TPM state.
1341  */
1342 int tpm_pm_resume(struct device *dev)
1343 {
1344         struct tpm_chip *chip = dev_get_drvdata(dev);
1345
1346         if (chip == NULL)
1347                 return -ENODEV;
1348
1349         return 0;
1350 }
1351 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1352
1353 #define TPM_GETRANDOM_RESULT_SIZE       18
1354 static struct tpm_input_header tpm_getrandom_header = {
1355         .tag = TPM_TAG_RQU_COMMAND,
1356         .length = cpu_to_be32(14),
1357         .ordinal = TPM_ORD_GET_RANDOM
1358 };
1359
1360 /**
1361  * tpm_get_random() - Get random bytes from the tpm's RNG
1362  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1363  * @out: destination buffer for the random bytes
1364  * @max: the max number of bytes to write to @out
1365  *
1366  * Returns < 0 on error and the number of bytes read on success
1367  */
1368 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1369 {
1370         struct tpm_chip *chip;
1371         struct tpm_cmd_t tpm_cmd;
1372         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1373         int err, total = 0, retries = 5;
1374         u8 *dest = out;
1375
1376         chip = tpm_chip_find_get(chip_num);
1377         if (chip == NULL)
1378                 return -ENODEV;
1379
1380         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1381                 return -EINVAL;
1382
1383         do {
1384                 tpm_cmd.header.in = tpm_getrandom_header;
1385                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1386
1387                 err = transmit_cmd(chip, &tpm_cmd,
1388                                    TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1389                                    "attempting get random");
1390                 if (err)
1391                         break;
1392
1393                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1394                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1395
1396                 dest += recd;
1397                 total += recd;
1398                 num_bytes -= recd;
1399         } while (retries-- && total < max);
1400
1401         return total ? total : -EIO;
1402 }
1403 EXPORT_SYMBOL_GPL(tpm_get_random);
1404
1405 /* In case vendor provided release function, call it too.*/
1406
1407 void tpm_dev_vendor_release(struct tpm_chip *chip)
1408 {
1409         if (!chip)
1410                 return;
1411
1412         if (chip->vendor.release)
1413                 chip->vendor.release(chip->dev);
1414
1415         clear_bit(chip->dev_num, dev_mask);
1416         kfree(chip->vendor.miscdev.name);
1417 }
1418 EXPORT_SYMBOL_GPL(tpm_dev_vendor_release);
1419
1420
1421 /*
1422  * Once all references to platform device are down to 0,
1423  * release all allocated structures.
1424  */
1425 static void tpm_dev_release(struct device *dev)
1426 {
1427         struct tpm_chip *chip = dev_get_drvdata(dev);
1428
1429         if (!chip)
1430                 return;
1431
1432         tpm_dev_vendor_release(chip);
1433
1434         chip->release(dev);
1435         kfree(chip);
1436 }
1437 EXPORT_SYMBOL_GPL(tpm_dev_release);
1438
1439 /*
1440  * Called from tpm_<specific>.c probe function only for devices
1441  * the driver has determined it should claim.  Prior to calling
1442  * this function the specific probe function has called pci_enable_device
1443  * upon errant exit from this function specific probe function should call
1444  * pci_disable_device
1445  */
1446 struct tpm_chip *tpm_register_hardware(struct device *dev,
1447                                         const struct tpm_vendor_specific *entry)
1448 {
1449 #define DEVNAME_SIZE 7
1450
1451         char *devname;
1452         struct tpm_chip *chip;
1453
1454         /* Driver specific per-device data */
1455         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
1456         devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL);
1457
1458         if (chip == NULL || devname == NULL)
1459                 goto out_free;
1460
1461         mutex_init(&chip->buffer_mutex);
1462         mutex_init(&chip->tpm_mutex);
1463         INIT_LIST_HEAD(&chip->list);
1464
1465         INIT_WORK(&chip->work, timeout_work);
1466
1467         setup_timer(&chip->user_read_timer, user_reader_timeout,
1468                         (unsigned long)chip);
1469
1470         memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
1471
1472         chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);
1473
1474         if (chip->dev_num >= TPM_NUM_DEVICES) {
1475                 dev_err(dev, "No available tpm device numbers\n");
1476                 goto out_free;
1477         } else if (chip->dev_num == 0)
1478                 chip->vendor.miscdev.minor = TPM_MINOR;
1479         else
1480                 chip->vendor.miscdev.minor = MISC_DYNAMIC_MINOR;
1481
1482         set_bit(chip->dev_num, dev_mask);
1483
1484         scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num);
1485         chip->vendor.miscdev.name = devname;
1486
1487         chip->vendor.miscdev.parent = dev;
1488         chip->dev = get_device(dev);
1489         chip->release = dev->release;
1490         dev->release = tpm_dev_release;
1491         dev_set_drvdata(dev, chip);
1492
1493         if (misc_register(&chip->vendor.miscdev)) {
1494                 dev_err(chip->dev,
1495                         "unable to misc_register %s, minor %d\n",
1496                         chip->vendor.miscdev.name,
1497                         chip->vendor.miscdev.minor);
1498                 goto put_device;
1499         }
1500
1501         if (sysfs_create_group(&dev->kobj, chip->vendor.attr_group)) {
1502                 misc_deregister(&chip->vendor.miscdev);
1503                 goto put_device;
1504         }
1505
1506         if (tpm_add_ppi(&dev->kobj)) {
1507                 misc_deregister(&chip->vendor.miscdev);
1508                 goto put_device;
1509         }
1510
1511         chip->bios_dir = tpm_bios_log_setup(devname);
1512
1513         /* Make chip available */
1514         spin_lock(&driver_lock);
1515         list_add_rcu(&chip->list, &tpm_chip_list);
1516         spin_unlock(&driver_lock);
1517
1518         return chip;
1519
1520 put_device:
1521         put_device(chip->dev);
1522 out_free:
1523         kfree(chip);
1524         kfree(devname);
1525         return NULL;
1526 }
1527 EXPORT_SYMBOL_GPL(tpm_register_hardware);
1528
1529 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1530 MODULE_DESCRIPTION("TPM Driver");
1531 MODULE_VERSION("2.0");
1532 MODULE_LICENSE("GPL");