LXR linux/drivers/char/tpm/tpm-interface.c

   1/*
   2 * Copyright (C) 2004 IBM Corporation
   3 * Copyright (C) 2014 Intel Corporation
   4 *
   5 * Authors:
   6 * Leendert van Doorn <leendert@watson.ibm.com>
   7 * Dave Safford <safford@watson.ibm.com>
   8 * Reiner Sailer <sailer@watson.ibm.com>
   9 * Kylene Hall <kjhall@us.ibm.com>
  10 *
  11 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  12 *
  13 * Device driver for TCG/TCPA TPM (trusted platform module).
  14 * Specifications at www.trustedcomputinggroup.org
  15 *
  16 * This program is free software; you can redistribute it and/or
  17 * modify it under the terms of the GNU General Public License as
  18 * published by the Free Software Foundation, version 2 of the
  19 * License.
  20 *
  21 * Note, the TPM chip is not interrupt driven (only polling)
  22 * and can have very long timeouts (minutes!). Hence the unusual
  23 * calls to msleep.
  24 *
  25 */
  26
  27#include <linux/poll.h>
  28#include <linux/slab.h>
  29#include <linux/mutex.h>
  30#include <linux/spinlock.h>
  31#include <linux/freezer.h>
  32
  33#include "tpm.h"
  34#include "tpm_eventlog.h"
  35
  36#define TPM_MAX_ORDINAL 243
  37#define TSC_MAX_ORDINAL 12
  38#define TPM_PROTECTED_COMMAND 0x00
  39#define TPM_CONNECTION_COMMAND 0x40
  40
  41/*
  42 * Bug workaround - some TPM's don't flush the most
  43 * recently changed pcr on suspend, so force the flush
  44 * with an extend to the selected _unused_ non-volatile pcr.
  45 */
  46static int tpm_suspend_pcr;
  47module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  48MODULE_PARM_DESC(suspend_pcr,
  49                 "PCR to use for dummy writes to faciltate flush on suspend.");
  50
  51/*
  52 * Array with one entry per ordinal defining the maximum amount
  53 * of time the chip could take to return the result.  The ordinal
  54 * designation of short, medium or long is defined in a table in
  55 * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  56 * values of the SHORT, MEDIUM, and LONG durations are retrieved
  57 * from the chip during initialization with a call to tpm_get_timeouts.
  58 */
  59static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  60        TPM_UNDEFINED,          /* 0 */
  61        TPM_UNDEFINED,
  62        TPM_UNDEFINED,
  63        TPM_UNDEFINED,
  64        TPM_UNDEFINED,
  65        TPM_UNDEFINED,          /* 5 */
  66        TPM_UNDEFINED,
  67        TPM_UNDEFINED,
  68        TPM_UNDEFINED,
  69        TPM_UNDEFINED,
  70        TPM_SHORT,              /* 10 */
  71        TPM_SHORT,
  72        TPM_MEDIUM,
  73        TPM_LONG,
  74        TPM_LONG,
  75        TPM_MEDIUM,             /* 15 */
  76        TPM_SHORT,
  77        TPM_SHORT,
  78        TPM_MEDIUM,
  79        TPM_LONG,
  80        TPM_SHORT,              /* 20 */
  81        TPM_SHORT,
  82        TPM_MEDIUM,
  83        TPM_MEDIUM,
  84        TPM_MEDIUM,
  85        TPM_SHORT,              /* 25 */
  86        TPM_SHORT,
  87        TPM_MEDIUM,
  88        TPM_SHORT,
  89        TPM_SHORT,
  90        TPM_MEDIUM,             /* 30 */
  91        TPM_LONG,
  92        TPM_MEDIUM,
  93        TPM_SHORT,
  94        TPM_SHORT,
  95        TPM_SHORT,              /* 35 */
  96        TPM_MEDIUM,
  97        TPM_MEDIUM,
  98        TPM_UNDEFINED,
  99        TPM_UNDEFINED,
 100        TPM_MEDIUM,             /* 40 */
 101        TPM_LONG,
 102        TPM_MEDIUM,
 103        TPM_SHORT,
 104        TPM_SHORT,
 105        TPM_SHORT,              /* 45 */
 106        TPM_SHORT,
 107        TPM_SHORT,
 108        TPM_SHORT,
 109        TPM_LONG,
 110        TPM_MEDIUM,             /* 50 */
 111        TPM_MEDIUM,
 112        TPM_UNDEFINED,
 113        TPM_UNDEFINED,
 114        TPM_UNDEFINED,
 115        TPM_UNDEFINED,          /* 55 */
 116        TPM_UNDEFINED,
 117        TPM_UNDEFINED,
 118        TPM_UNDEFINED,
 119        TPM_UNDEFINED,
 120        TPM_MEDIUM,             /* 60 */
 121        TPM_MEDIUM,
 122        TPM_MEDIUM,
 123        TPM_SHORT,
 124        TPM_SHORT,
 125        TPM_MEDIUM,             /* 65 */
 126        TPM_UNDEFINED,
 127        TPM_UNDEFINED,
 128        TPM_UNDEFINED,
 129        TPM_UNDEFINED,
 130        TPM_SHORT,              /* 70 */
 131        TPM_SHORT,
 132        TPM_UNDEFINED,
 133        TPM_UNDEFINED,
 134        TPM_UNDEFINED,
 135        TPM_UNDEFINED,          /* 75 */
 136        TPM_UNDEFINED,
 137        TPM_UNDEFINED,
 138        TPM_UNDEFINED,
 139        TPM_UNDEFINED,
 140        TPM_LONG,               /* 80 */
 141        TPM_UNDEFINED,
 142        TPM_MEDIUM,
 143        TPM_LONG,
 144        TPM_SHORT,
 145        TPM_UNDEFINED,          /* 85 */
 146        TPM_UNDEFINED,
 147        TPM_UNDEFINED,
 148        TPM_UNDEFINED,
 149        TPM_UNDEFINED,
 150        TPM_SHORT,              /* 90 */
 151        TPM_SHORT,
 152        TPM_SHORT,
 153        TPM_SHORT,
 154        TPM_SHORT,
 155        TPM_UNDEFINED,          /* 95 */
 156        TPM_UNDEFINED,
 157        TPM_UNDEFINED,
 158        TPM_UNDEFINED,
 159        TPM_UNDEFINED,
 160        TPM_MEDIUM,             /* 100 */
 161        TPM_SHORT,
 162        TPM_SHORT,
 163        TPM_UNDEFINED,
 164        TPM_UNDEFINED,
 165        TPM_UNDEFINED,          /* 105 */
 166        TPM_UNDEFINED,
 167        TPM_UNDEFINED,
 168        TPM_UNDEFINED,
 169        TPM_UNDEFINED,
 170        TPM_SHORT,              /* 110 */
 171        TPM_SHORT,
 172        TPM_SHORT,
 173        TPM_SHORT,
 174        TPM_SHORT,
 175        TPM_SHORT,              /* 115 */
 176        TPM_SHORT,
 177        TPM_SHORT,
 178        TPM_UNDEFINED,
 179        TPM_UNDEFINED,
 180        TPM_LONG,               /* 120 */
 181        TPM_LONG,
 182        TPM_MEDIUM,
 183        TPM_UNDEFINED,
 184        TPM_SHORT,
 185        TPM_SHORT,              /* 125 */
 186        TPM_SHORT,
 187        TPM_LONG,
 188        TPM_SHORT,
 189        TPM_SHORT,
 190        TPM_SHORT,              /* 130 */
 191        TPM_MEDIUM,
 192        TPM_UNDEFINED,
 193        TPM_SHORT,
 194        TPM_MEDIUM,
 195        TPM_UNDEFINED,          /* 135 */
 196        TPM_UNDEFINED,
 197        TPM_UNDEFINED,
 198        TPM_UNDEFINED,
 199        TPM_UNDEFINED,
 200        TPM_SHORT,              /* 140 */
 201        TPM_SHORT,
 202        TPM_UNDEFINED,
 203        TPM_UNDEFINED,
 204        TPM_UNDEFINED,
 205        TPM_UNDEFINED,          /* 145 */
 206        TPM_UNDEFINED,
 207        TPM_UNDEFINED,
 208        TPM_UNDEFINED,
 209        TPM_UNDEFINED,
 210        TPM_SHORT,              /* 150 */
 211        TPM_MEDIUM,
 212        TPM_MEDIUM,
 213        TPM_SHORT,
 214        TPM_SHORT,
 215        TPM_UNDEFINED,          /* 155 */
 216        TPM_UNDEFINED,
 217        TPM_UNDEFINED,
 218        TPM_UNDEFINED,
 219        TPM_UNDEFINED,
 220        TPM_SHORT,              /* 160 */
 221        TPM_SHORT,
 222        TPM_SHORT,
 223        TPM_SHORT,
 224        TPM_UNDEFINED,
 225        TPM_UNDEFINED,          /* 165 */
 226        TPM_UNDEFINED,
 227        TPM_UNDEFINED,
 228        TPM_UNDEFINED,
 229        TPM_UNDEFINED,
 230        TPM_LONG,               /* 170 */
 231        TPM_UNDEFINED,
 232        TPM_UNDEFINED,
 233        TPM_UNDEFINED,
 234        TPM_UNDEFINED,
 235        TPM_UNDEFINED,          /* 175 */
 236        TPM_UNDEFINED,
 237        TPM_UNDEFINED,
 238        TPM_UNDEFINED,
 239        TPM_UNDEFINED,
 240        TPM_MEDIUM,             /* 180 */
 241        TPM_SHORT,
 242        TPM_MEDIUM,
 243        TPM_MEDIUM,
 244        TPM_MEDIUM,
 245        TPM_MEDIUM,             /* 185 */
 246        TPM_SHORT,
 247        TPM_UNDEFINED,
 248        TPM_UNDEFINED,
 249        TPM_UNDEFINED,
 250        TPM_UNDEFINED,          /* 190 */
 251        TPM_UNDEFINED,
 252        TPM_UNDEFINED,
 253        TPM_UNDEFINED,
 254        TPM_UNDEFINED,
 255        TPM_UNDEFINED,          /* 195 */
 256        TPM_UNDEFINED,
 257        TPM_UNDEFINED,
 258        TPM_UNDEFINED,
 259        TPM_UNDEFINED,
 260        TPM_SHORT,              /* 200 */
 261        TPM_UNDEFINED,
 262        TPM_UNDEFINED,
 263        TPM_UNDEFINED,
 264        TPM_SHORT,
 265        TPM_SHORT,              /* 205 */
 266        TPM_SHORT,
 267        TPM_SHORT,
 268        TPM_SHORT,
 269        TPM_SHORT,
 270        TPM_MEDIUM,             /* 210 */
 271        TPM_UNDEFINED,
 272        TPM_MEDIUM,
 273        TPM_MEDIUM,
 274        TPM_MEDIUM,
 275        TPM_UNDEFINED,          /* 215 */
 276        TPM_MEDIUM,
 277        TPM_UNDEFINED,
 278        TPM_UNDEFINED,
 279        TPM_SHORT,
 280        TPM_SHORT,              /* 220 */
 281        TPM_SHORT,
 282        TPM_SHORT,
 283        TPM_SHORT,
 284        TPM_SHORT,
 285        TPM_UNDEFINED,          /* 225 */
 286        TPM_UNDEFINED,
 287        TPM_UNDEFINED,
 288        TPM_UNDEFINED,
 289        TPM_UNDEFINED,
 290        TPM_SHORT,              /* 230 */
 291        TPM_LONG,
 292        TPM_MEDIUM,
 293        TPM_UNDEFINED,
 294        TPM_UNDEFINED,
 295        TPM_UNDEFINED,          /* 235 */
 296        TPM_UNDEFINED,
 297        TPM_UNDEFINED,
 298        TPM_UNDEFINED,
 299        TPM_UNDEFINED,
 300        TPM_SHORT,              /* 240 */
 301        TPM_UNDEFINED,
 302        TPM_MEDIUM,
 303};
 304
 305/*
 306 * Returns max number of jiffies to wait
 307 */
 308unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 309                                           u32 ordinal)
 310{
 311        int duration_idx = TPM_UNDEFINED;
 312        int duration = 0;
 313
 314        /*
 315         * We only have a duration table for protected commands, where the upper
 316         * 16 bits are 0. For the few other ordinals the fallback will be used.
 317         */
 318        if (ordinal < TPM_MAX_ORDINAL)
 319                duration_idx = tpm_ordinal_duration[ordinal];
 320
 321        if (duration_idx != TPM_UNDEFINED)
 322                duration = chip->duration[duration_idx];
 323        if (duration <= 0)
 324                return 2 * 60 * HZ;
 325        else
 326                return duration;
 327}
 328EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 329
 330/*
 331 * Internal kernel interface to transmit TPM commands
 332 */
 333ssize_t tpm_transmit(struct tpm_chip *chip, const u8 *buf, size_t bufsiz,
 334                     unsigned int flags)
 335{
 336        ssize_t rc;
 337        u32 count, ordinal;
 338        unsigned long stop;
 339
 340        if (bufsiz < TPM_HEADER_SIZE)
 341                return -EINVAL;
 342
 343        if (bufsiz > TPM_BUFSIZE)
 344                bufsiz = TPM_BUFSIZE;
 345
 346        count = be32_to_cpu(*((__be32 *) (buf + 2)));
 347        ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 348        if (count == 0)
 349                return -ENODATA;
 350        if (count > bufsiz) {
 351                dev_err(&chip->dev,
 352                        "invalid count value %x %zx\n", count, bufsiz);
 353                return -E2BIG;
 354        }
 355
 356        if (!(flags & TPM_TRANSMIT_UNLOCKED))
 357                mutex_lock(&chip->tpm_mutex);
 358
 359        rc = chip->ops->send(chip, (u8 *) buf, count);
 360        if (rc < 0) {
 361                dev_err(&chip->dev,
 362                        "tpm_transmit: tpm_send: error %zd\n", rc);
 363                goto out;
 364        }
 365
 366        if (chip->flags & TPM_CHIP_FLAG_IRQ)
 367                goto out_recv;
 368
 369        if (chip->flags & TPM_CHIP_FLAG_TPM2)
 370                stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
 371        else
 372                stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 373        do {
 374                u8 status = chip->ops->status(chip);
 375                if ((status & chip->ops->req_complete_mask) ==
 376                    chip->ops->req_complete_val)
 377                        goto out_recv;
 378
 379                if (chip->ops->req_canceled(chip, status)) {
 380                        dev_err(&chip->dev, "Operation Canceled\n");
 381                        rc = -ECANCELED;
 382                        goto out;
 383                }
 384
 385                msleep(TPM_TIMEOUT);    /* CHECK */
 386                rmb();
 387        } while (time_before(jiffies, stop));
 388
 389        chip->ops->cancel(chip);
 390        dev_err(&chip->dev, "Operation Timed out\n");
 391        rc = -ETIME;
 392        goto out;
 393
 394out_recv:
 395        rc = chip->ops->recv(chip, (u8 *) buf, bufsiz);
 396        if (rc < 0)
 397                dev_err(&chip->dev,
 398                        "tpm_transmit: tpm_recv: error %zd\n", rc);
 399out:
 400        if (!(flags & TPM_TRANSMIT_UNLOCKED))
 401                mutex_unlock(&chip->tpm_mutex);
 402        return rc;
 403}
 404
 405#define TPM_DIGEST_SIZE 20
 406#define TPM_RET_CODE_IDX 6
 407
 408ssize_t tpm_transmit_cmd(struct tpm_chip *chip, const void *cmd,
 409                         int len, unsigned int flags, const char *desc)
 410{
 411        const struct tpm_output_header *header;
 412        int err;
 413
 414        len = tpm_transmit(chip, (const u8 *)cmd, len, flags);
 415        if (len <  0)
 416                return len;
 417        else if (len < TPM_HEADER_SIZE)
 418                return -EFAULT;
 419
 420        header = cmd;
 421
 422        err = be32_to_cpu(header->return_code);
 423        if (err != 0 && desc)
 424                dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
 425                        desc);
 426
 427        return err;
 428}
 429
 430#define TPM_INTERNAL_RESULT_SIZE 200
 431#define TPM_ORD_GET_CAP cpu_to_be32(101)
 432#define TPM_ORD_GET_RANDOM cpu_to_be32(70)
 433
 434static const struct tpm_input_header tpm_getcap_header = {
 435        .tag = TPM_TAG_RQU_COMMAND,
 436        .length = cpu_to_be32(22),
 437        .ordinal = TPM_ORD_GET_CAP
 438};
 439
 440ssize_t tpm_getcap(struct tpm_chip *chip, __be32 subcap_id, cap_t *cap,
 441                   const char *desc)
 442{
 443        struct tpm_cmd_t tpm_cmd;
 444        int rc;
 445
 446        tpm_cmd.header.in = tpm_getcap_header;
 447        if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 448                tpm_cmd.params.getcap_in.cap = subcap_id;
 449                /*subcap field not necessary */
 450                tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 451                tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 452        } else {
 453                if (subcap_id == TPM_CAP_FLAG_PERM ||
 454                    subcap_id == TPM_CAP_FLAG_VOL)
 455                        tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 456                else
 457                        tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 458                tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 459                tpm_cmd.params.getcap_in.subcap = subcap_id;
 460        }
 461        rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 462                              desc);
 463        if (!rc)
 464                *cap = tpm_cmd.params.getcap_out.cap;
 465        return rc;
 466}
 467EXPORT_SYMBOL_GPL(tpm_getcap);
 468
 469#define TPM_ORD_STARTUP cpu_to_be32(153)
 470#define TPM_ST_CLEAR cpu_to_be16(1)
 471#define TPM_ST_STATE cpu_to_be16(2)
 472#define TPM_ST_DEACTIVATED cpu_to_be16(3)
 473static const struct tpm_input_header tpm_startup_header = {
 474        .tag = TPM_TAG_RQU_COMMAND,
 475        .length = cpu_to_be32(12),
 476        .ordinal = TPM_ORD_STARTUP
 477};
 478
 479static int tpm_startup(struct tpm_chip *chip, __be16 startup_type)
 480{
 481        struct tpm_cmd_t start_cmd;
 482        start_cmd.header.in = tpm_startup_header;
 483
 484        start_cmd.params.startup_in.startup_type = startup_type;
 485        return tpm_transmit_cmd(chip, &start_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 486                                "attempting to start the TPM");
 487}
 488
 489int tpm_get_timeouts(struct tpm_chip *chip)
 490{
 491        struct tpm_cmd_t tpm_cmd;
 492        unsigned long new_timeout[4];
 493        unsigned long old_timeout[4];
 494        struct duration_t *duration_cap;
 495        ssize_t rc;
 496
 497        if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 498                /* Fixed timeouts for TPM2 */
 499                chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
 500                chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
 501                chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
 502                chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
 503                chip->duration[TPM_SHORT] =
 504                    msecs_to_jiffies(TPM2_DURATION_SHORT);
 505                chip->duration[TPM_MEDIUM] =
 506                    msecs_to_jiffies(TPM2_DURATION_MEDIUM);
 507                chip->duration[TPM_LONG] =
 508                    msecs_to_jiffies(TPM2_DURATION_LONG);
 509                return 0;
 510        }
 511
 512        tpm_cmd.header.in = tpm_getcap_header;
 513        tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 514        tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 515        tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 516        rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 517                              NULL);
 518
 519        if (rc == TPM_ERR_INVALID_POSTINIT) {
 520                /* The TPM is not started, we are the first to talk to it.
 521                   Execute a startup command. */
 522                dev_info(&chip->dev, "Issuing TPM_STARTUP");
 523                if (tpm_startup(chip, TPM_ST_CLEAR))
 524                        return rc;
 525
 526                tpm_cmd.header.in = tpm_getcap_header;
 527                tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 528                tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 529                tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 530                rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 531                                      0, NULL);
 532        }
 533        if (rc) {
 534                dev_err(&chip->dev,
 535                        "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 536                        rc);
 537                goto duration;
 538        }
 539
 540        if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 541            be32_to_cpu(tpm_cmd.header.out.length)
 542            != sizeof(tpm_cmd.header.out) + sizeof(u32) + 4 * sizeof(u32))
 543                return -EINVAL;
 544
 545        old_timeout[0] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.a);
 546        old_timeout[1] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.b);
 547        old_timeout[2] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.c);
 548        old_timeout[3] = be32_to_cpu(tpm_cmd.params.getcap_out.cap.timeout.d);
 549        memcpy(new_timeout, old_timeout, sizeof(new_timeout));
 550
 551        /*
 552         * Provide ability for vendor overrides of timeout values in case
 553         * of misreporting.
 554         */
 555        if (chip->ops->update_timeouts != NULL)
 556                chip->timeout_adjusted =
 557                        chip->ops->update_timeouts(chip, new_timeout);
 558
 559        if (!chip->timeout_adjusted) {
 560                /* Don't overwrite default if value is 0 */
 561                if (new_timeout[0] != 0 && new_timeout[0] < 1000) {
 562                        int i;
 563
 564                        /* timeouts in msec rather usec */
 565                        for (i = 0; i != ARRAY_SIZE(new_timeout); i++)
 566                                new_timeout[i] *= 1000;
 567                        chip->timeout_adjusted = true;
 568                }
 569        }
 570
 571        /* Report adjusted timeouts */
 572        if (chip->timeout_adjusted) {
 573                dev_info(&chip->dev,
 574                         HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 575                         old_timeout[0], new_timeout[0],
 576                         old_timeout[1], new_timeout[1],
 577                         old_timeout[2], new_timeout[2],
 578                         old_timeout[3], new_timeout[3]);
 579        }
 580
 581        chip->timeout_a = usecs_to_jiffies(new_timeout[0]);
 582        chip->timeout_b = usecs_to_jiffies(new_timeout[1]);
 583        chip->timeout_c = usecs_to_jiffies(new_timeout[2]);
 584        chip->timeout_d = usecs_to_jiffies(new_timeout[3]);
 585
 586duration:
 587        tpm_cmd.header.in = tpm_getcap_header;
 588        tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 589        tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 590        tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 591
 592        rc = tpm_transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, 0,
 593                              "attempting to determine the durations");
 594        if (rc)
 595                return rc;
 596
 597        if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
 598            be32_to_cpu(tpm_cmd.header.out.length)
 599            != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 600                return -EINVAL;
 601
 602        duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 603        chip->duration[TPM_SHORT] =
 604            usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 605        chip->duration[TPM_MEDIUM] =
 606            usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 607        chip->duration[TPM_LONG] =
 608            usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 609
 610        /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 611         * value wrong and apparently reports msecs rather than usecs. So we
 612         * fix up the resulting too-small TPM_SHORT value to make things work.
 613         * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 614         */
 615        if (chip->duration[TPM_SHORT] < (HZ / 100)) {
 616                chip->duration[TPM_SHORT] = HZ;
 617                chip->duration[TPM_MEDIUM] *= 1000;
 618                chip->duration[TPM_LONG] *= 1000;
 619                chip->duration_adjusted = true;
 620                dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 621        }
 622        return 0;
 623}
 624EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 625
 626#define TPM_ORD_CONTINUE_SELFTEST 83
 627#define CONTINUE_SELFTEST_RESULT_SIZE 10
 628
 629static const struct tpm_input_header continue_selftest_header = {
 630        .tag = TPM_TAG_RQU_COMMAND,
 631        .length = cpu_to_be32(10),
 632        .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 633};
 634
 635/**
 636 * tpm_continue_selftest -- run TPM's selftest
 637 * @chip: TPM chip to use
 638 *
 639 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 640 * a TPM error code.
 641 */
 642static int tpm_continue_selftest(struct tpm_chip *chip)
 643{
 644        int rc;
 645        struct tpm_cmd_t cmd;
 646
 647        cmd.header.in = continue_selftest_header;
 648        rc = tpm_transmit_cmd(chip, &cmd, CONTINUE_SELFTEST_RESULT_SIZE, 0,
 649                              "continue selftest");
 650        return rc;
 651}
 652
 653#define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 654#define READ_PCR_RESULT_SIZE 30
 655static const struct tpm_input_header pcrread_header = {
 656        .tag = TPM_TAG_RQU_COMMAND,
 657        .length = cpu_to_be32(14),
 658        .ordinal = TPM_ORDINAL_PCRREAD
 659};
 660
 661int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 662{
 663        int rc;
 664        struct tpm_cmd_t cmd;
 665
 666        cmd.header.in = pcrread_header;
 667        cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 668        rc = tpm_transmit_cmd(chip, &cmd, READ_PCR_RESULT_SIZE, 0,
 669                              "attempting to read a pcr value");
 670
 671        if (rc == 0)
 672                memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 673                       TPM_DIGEST_SIZE);
 674        return rc;
 675}
 676
 677/**
 678 * tpm_is_tpm2 - is the chip a TPM2 chip?
 679 * @chip_num:   tpm idx # or ANY
 680 *
 681 * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 682 * is a TPM2 chip.
 683 */
 684int tpm_is_tpm2(u32 chip_num)
 685{
 686        struct tpm_chip *chip;
 687        int rc;
 688
 689        chip = tpm_chip_find_get(chip_num);
 690        if (chip == NULL)
 691                return -ENODEV;
 692
 693        rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 694
 695        tpm_put_ops(chip);
 696
 697        return rc;
 698}
 699EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 700
 701/**
 702 * tpm_pcr_read - read a pcr value
 703 * @chip_num:   tpm idx # or ANY
 704 * @pcr_idx:    pcr idx to retrieve
 705 * @res_buf:    TPM_PCR value
 706 *              size of res_buf is 20 bytes (or NULL if you don't care)
 707 *
 708 * The TPM driver should be built-in, but for whatever reason it
 709 * isn't, protect against the chip disappearing, by incrementing
 710 * the module usage count.
 711 */
 712int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 713{
 714        struct tpm_chip *chip;
 715        int rc;
 716
 717        chip = tpm_chip_find_get(chip_num);
 718        if (chip == NULL)
 719                return -ENODEV;
 720        if (chip->flags & TPM_CHIP_FLAG_TPM2)
 721                rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 722        else
 723                rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 724        tpm_put_ops(chip);
 725        return rc;
 726}
 727EXPORT_SYMBOL_GPL(tpm_pcr_read);
 728
 729/**
 730 * tpm_pcr_extend - extend pcr value with hash
 731 * @chip_num:   tpm idx # or AN&
 732 * @pcr_idx:    pcr idx to extend
 733 * @hash:       hash value used to extend pcr value
 734 *
 735 * The TPM driver should be built-in, but for whatever reason it
 736 * isn't, protect against the chip disappearing, by incrementing
 737 * the module usage count.
 738 */
 739#define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 740#define EXTEND_PCR_RESULT_SIZE 34
 741static const struct tpm_input_header pcrextend_header = {
 742        .tag = TPM_TAG_RQU_COMMAND,
 743        .length = cpu_to_be32(34),
 744        .ordinal = TPM_ORD_PCR_EXTEND
 745};
 746
 747int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 748{
 749        struct tpm_cmd_t cmd;
 750        int rc;
 751        struct tpm_chip *chip;
 752
 753        chip = tpm_chip_find_get(chip_num);
 754        if (chip == NULL)
 755                return -ENODEV;
 756
 757        if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 758                rc = tpm2_pcr_extend(chip, pcr_idx, hash);
 759                tpm_put_ops(chip);
 760                return rc;
 761        }
 762
 763        cmd.header.in = pcrextend_header;
 764        cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 765        memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 766        rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 767                              "attempting extend a PCR value");
 768
 769        tpm_put_ops(chip);
 770        return rc;
 771}
 772EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 773
 774/**
 775 * tpm_do_selftest - have the TPM continue its selftest and wait until it
 776 *                   can receive further commands
 777 * @chip: TPM chip to use
 778 *
 779 * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 780 * a TPM error code.
 781 */
 782int tpm_do_selftest(struct tpm_chip *chip)
 783{
 784        int rc;
 785        unsigned int loops;
 786        unsigned int delay_msec = 100;
 787        unsigned long duration;
 788        u8 dummy[TPM_DIGEST_SIZE];
 789
 790        duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
 791
 792        loops = jiffies_to_msecs(duration) / delay_msec;
 793
 794        rc = tpm_continue_selftest(chip);
 795        /* This may fail if there was no TPM driver during a suspend/resume
 796         * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
 797         */
 798        if (rc)
 799                return rc;
 800
 801        do {
 802                /* Attempt to read a PCR value */
 803                rc = tpm_pcr_read_dev(chip, 0, dummy);
 804
 805                /* Some buggy TPMs will not respond to tpm_tis_ready() for
 806                 * around 300ms while the self test is ongoing, keep trying
 807                 * until the self test duration expires. */
 808                if (rc == -ETIME) {
 809                        dev_info(
 810                            &chip->dev, HW_ERR
 811                            "TPM command timed out during continue self test");
 812                        msleep(delay_msec);
 813                        continue;
 814                }
 815
 816                if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
 817                        dev_info(&chip->dev,
 818                                 "TPM is disabled/deactivated (0x%X)\n", rc);
 819                        /* TPM is disabled and/or deactivated; driver can
 820                         * proceed and TPM does handle commands for
 821                         * suspend/resume correctly
 822                         */
 823                        return 0;
 824                }
 825                if (rc != TPM_WARN_DOING_SELFTEST)
 826                        return rc;
 827                msleep(delay_msec);
 828        } while (--loops > 0);
 829
 830        return rc;
 831}
 832EXPORT_SYMBOL_GPL(tpm_do_selftest);
 833
 834/**
 835 * tpm1_auto_startup - Perform the standard automatic TPM initialization
 836 *                     sequence
 837 * @chip: TPM chip to use
 838 *
 839 * Returns 0 on success, < 0 in case of fatal error.
 840 */
 841int tpm1_auto_startup(struct tpm_chip *chip)
 842{
 843        int rc;
 844
 845        rc = tpm_get_timeouts(chip);
 846        if (rc)
 847                goto out;
 848        rc = tpm_do_selftest(chip);
 849        if (rc) {
 850                dev_err(&chip->dev, "TPM self test failed\n");
 851                goto out;
 852        }
 853
 854        return rc;
 855out:
 856        if (rc > 0)
 857                rc = -ENODEV;
 858        return rc;
 859}
 860
 861int tpm_send(u32 chip_num, void *cmd, size_t buflen)
 862{
 863        struct tpm_chip *chip;
 864        int rc;
 865
 866        chip = tpm_chip_find_get(chip_num);
 867        if (chip == NULL)
 868                return -ENODEV;
 869
 870        rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
 871
 872        tpm_put_ops(chip);
 873        return rc;
 874}
 875EXPORT_SYMBOL_GPL(tpm_send);
 876
 877static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
 878                                        bool check_cancel, bool *canceled)
 879{
 880        u8 status = chip->ops->status(chip);
 881
 882        *canceled = false;
 883        if ((status & mask) == mask)
 884                return true;
 885        if (check_cancel && chip->ops->req_canceled(chip, status)) {
 886                *canceled = true;
 887                return true;
 888        }
 889        return false;
 890}
 891
 892int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
 893                      wait_queue_head_t *queue, bool check_cancel)
 894{
 895        unsigned long stop;
 896        long rc;
 897        u8 status;
 898        bool canceled = false;
 899
 900        /* check current status */
 901        status = chip->ops->status(chip);
 902        if ((status & mask) == mask)
 903                return 0;
 904
 905        stop = jiffies + timeout;
 906
 907        if (chip->flags & TPM_CHIP_FLAG_IRQ) {
 908again:
 909                timeout = stop - jiffies;
 910                if ((long)timeout <= 0)
 911                        return -ETIME;
 912                rc = wait_event_interruptible_timeout(*queue,
 913                        wait_for_tpm_stat_cond(chip, mask, check_cancel,
 914                                               &canceled),
 915                        timeout);
 916                if (rc > 0) {
 917                        if (canceled)
 918                                return -ECANCELED;
 919                        return 0;
 920                }
 921                if (rc == -ERESTARTSYS && freezing(current)) {
 922                        clear_thread_flag(TIF_SIGPENDING);
 923                        goto again;
 924                }
 925        } else {
 926                do {
 927                        msleep(TPM_TIMEOUT);
 928                        status = chip->ops->status(chip);
 929                        if ((status & mask) == mask)
 930                                return 0;
 931                } while (time_before(jiffies, stop));
 932        }
 933        return -ETIME;
 934}
 935EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 936
 937#define TPM_ORD_SAVESTATE cpu_to_be32(152)
 938#define SAVESTATE_RESULT_SIZE 10
 939
 940static const struct tpm_input_header savestate_header = {
 941        .tag = TPM_TAG_RQU_COMMAND,
 942        .length = cpu_to_be32(10),
 943        .ordinal = TPM_ORD_SAVESTATE
 944};
 945
 946/*
 947 * We are about to suspend. Save the TPM state
 948 * so that it can be restored.
 949 */
 950int tpm_pm_suspend(struct device *dev)
 951{
 952        struct tpm_chip *chip = dev_get_drvdata(dev);
 953        struct tpm_cmd_t cmd;
 954        int rc, try;
 955
 956        u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
 957
 958        if (chip == NULL)
 959                return -ENODEV;
 960
 961        if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 962                tpm2_shutdown(chip, TPM2_SU_STATE);
 963                return 0;
 964        }
 965
 966        /* for buggy tpm, flush pcrs with extend to selected dummy */
 967        if (tpm_suspend_pcr) {
 968                cmd.header.in = pcrextend_header;
 969                cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
 970                memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
 971                       TPM_DIGEST_SIZE);
 972                rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
 973                                      "extending dummy pcr before suspend");
 974        }
 975
 976        /* now do the actual savestate */
 977        for (try = 0; try < TPM_RETRY; try++) {
 978                cmd.header.in = savestate_header;
 979                rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
 980                                      NULL);
 981
 982                /*
 983                 * If the TPM indicates that it is too busy to respond to
 984                 * this command then retry before giving up.  It can take
 985                 * several seconds for this TPM to be ready.
 986                 *
 987                 * This can happen if the TPM has already been sent the
 988                 * SaveState command before the driver has loaded.  TCG 1.2
 989                 * specification states that any communication after SaveState
 990                 * may cause the TPM to invalidate previously saved state.
 991                 */
 992                if (rc != TPM_WARN_RETRY)
 993                        break;
 994                msleep(TPM_TIMEOUT_RETRY);
 995        }
 996
 997        if (rc)
 998                dev_err(&chip->dev,
 999                        "Error (%d) sending savestate before suspend\n", rc);
1000        else if (try > 0)

1001                dev_warn(&chip->dev, "TPM savestate took %dms\n",
1002                         try * TPM_TIMEOUT_RETRY);
1003
1004        return rc;
1005}
1006EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1007
1008/*
1009 * Resume from a power safe. The BIOS already restored
1010 * the TPM state.
1011 */
1012int tpm_pm_resume(struct device *dev)
1013{
1014        struct tpm_chip *chip = dev_get_drvdata(dev);
1015
1016        if (chip == NULL)
1017                return -ENODEV;
1018
1019        return 0;
1020}
1021EXPORT_SYMBOL_GPL(tpm_pm_resume);
1022
1023#define TPM_GETRANDOM_RESULT_SIZE       18
1024static const struct tpm_input_header tpm_getrandom_header = {
1025        .tag = TPM_TAG_RQU_COMMAND,
1026        .length = cpu_to_be32(14),
1027        .ordinal = TPM_ORD_GET_RANDOM
1028};
1029
1030/**
1031 * tpm_get_random() - Get random bytes from the tpm's RNG
1032 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1033 * @out: destination buffer for the random bytes
1034 * @max: the max number of bytes to write to @out
1035 *
1036 * Returns < 0 on error and the number of bytes read on success
1037 */
1038int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1039{
1040        struct tpm_chip *chip;
1041        struct tpm_cmd_t tpm_cmd;
1042        u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
1043        int err, total = 0, retries = 5;
1044        u8 *dest = out;
1045
1046        if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1047                return -EINVAL;
1048
1049        chip = tpm_chip_find_get(chip_num);
1050        if (chip == NULL)
1051                return -ENODEV;
1052
1053        if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1054                err = tpm2_get_random(chip, out, max);
1055                tpm_put_ops(chip);
1056                return err;
1057        }
1058
1059        do {
1060                tpm_cmd.header.in = tpm_getrandom_header;
1061                tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1062
1063                err = tpm_transmit_cmd(chip, &tpm_cmd,
1064                                       TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1065                                       0, "attempting get random");
1066                if (err)
1067                        break;
1068
1069                recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1070                memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1071
1072                dest += recd;
1073                total += recd;
1074                num_bytes -= recd;
1075        } while (retries-- && total < max);
1076
1077        tpm_put_ops(chip);
1078        return total ? total : -EIO;
1079}
1080EXPORT_SYMBOL_GPL(tpm_get_random);
1081
1082/**
1083 * tpm_seal_trusted() - seal a trusted key
1084 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1085 * @options: authentication values and other options
1086 * @payload: the key data in clear and encrypted form
1087 *
1088 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1089 * are supported.
1090 */
1091int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1092                     struct trusted_key_options *options)
1093{
1094        struct tpm_chip *chip;
1095        int rc;
1096
1097        chip = tpm_chip_find_get(chip_num);
1098        if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1099                return -ENODEV;
1100
1101        rc = tpm2_seal_trusted(chip, payload, options);
1102
1103        tpm_put_ops(chip);
1104        return rc;
1105}
1106EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1107
1108/**
1109 * tpm_unseal_trusted() - unseal a trusted key
1110 * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1111 * @options: authentication values and other options
1112 * @payload: the key data in clear and encrypted form
1113 *
1114 * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1115 * are supported.
1116 */
1117int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1118                       struct trusted_key_options *options)
1119{
1120        struct tpm_chip *chip;
1121        int rc;
1122
1123        chip = tpm_chip_find_get(chip_num);
1124        if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1125                return -ENODEV;
1126
1127        rc = tpm2_unseal_trusted(chip, payload, options);
1128
1129        tpm_put_ops(chip);
1130
1131        return rc;
1132}
1133EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1134
1135static int __init tpm_init(void)
1136{
1137        int rc;
1138
1139        tpm_class = class_create(THIS_MODULE, "tpm");
1140        if (IS_ERR(tpm_class)) {
1141                pr_err("couldn't create tpm class\n");
1142                return PTR_ERR(tpm_class);
1143        }
1144
1145        rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
1146        if (rc < 0) {
1147                pr_err("tpm: failed to allocate char dev region\n");
1148                class_destroy(tpm_class);
1149                return rc;
1150        }
1151
1152        return 0;
1153}
1154
1155static void __exit tpm_exit(void)
1156{
1157        idr_destroy(&dev_nums_idr);
1158        class_destroy(tpm_class);
1159        unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
1160}
1161
1162subsys_initcall(tpm_init);
1163module_exit(tpm_exit);
1164
1165MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1166MODULE_DESCRIPTION("TPM Driver");
1167MODULE_VERSION("2.0");
1168MODULE_LICENSE("GPL");
1169