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 #include <linux/pm_runtime.h>
  33
  34 #include "tpm.h"
  35 #include "tpm_eventlog.h"
  36
  37 #define TPM_MAX_ORDINAL 243
  38 #define TSC_MAX_ORDINAL 12
  39 #define TPM_PROTECTED_COMMAND 0x00
  40 #define TPM_CONNECTION_COMMAND 0x40
  41
  42 /*
  43  * Bug workaround - some TPM's don't flush the most
  44  * recently changed pcr on suspend, so force the flush
  45  * with an extend to the selected _unused_ non-volatile pcr.
  46  */
  47 static int tpm_suspend_pcr;
  48 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  49 MODULE_PARM_DESC(suspend_pcr,
  50                  "PCR to use for dummy writes to facilitate flush on suspend.");
  51
  52 /*
  53  * Array with one entry per ordinal defining the maximum amount
  54  * of time the chip could take to return the result.  The ordinal
  55  * designation of short, medium or long is defined in a table in
  56  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  57  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  58  * from the chip during initialization with a call to tpm_get_timeouts.
  59  */
  60 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  61         TPM_UNDEFINED,          /* 0 */
  62         TPM_UNDEFINED,
  63         TPM_UNDEFINED,
  64         TPM_UNDEFINED,
  65         TPM_UNDEFINED,
  66         TPM_UNDEFINED,          /* 5 */
  67         TPM_UNDEFINED,
  68         TPM_UNDEFINED,
  69         TPM_UNDEFINED,
  70         TPM_UNDEFINED,
  71         TPM_SHORT,              /* 10 */
  72         TPM_SHORT,
  73         TPM_MEDIUM,
  74         TPM_LONG,
  75         TPM_LONG,
  76         TPM_MEDIUM,             /* 15 */
  77         TPM_SHORT,
  78         TPM_SHORT,
  79         TPM_MEDIUM,
  80         TPM_LONG,
  81         TPM_SHORT,              /* 20 */
  82         TPM_SHORT,
  83         TPM_MEDIUM,
  84         TPM_MEDIUM,
  85         TPM_MEDIUM,
  86         TPM_SHORT,              /* 25 */
  87         TPM_SHORT,
  88         TPM_MEDIUM,
  89         TPM_SHORT,
  90         TPM_SHORT,
  91         TPM_MEDIUM,             /* 30 */
  92         TPM_LONG,
  93         TPM_MEDIUM,
  94         TPM_SHORT,
  95         TPM_SHORT,
  96         TPM_SHORT,              /* 35 */
  97         TPM_MEDIUM,
  98         TPM_MEDIUM,
  99         TPM_UNDEFINED,
 100         TPM_UNDEFINED,
 101         TPM_MEDIUM,             /* 40 */
 102         TPM_LONG,
 103         TPM_MEDIUM,
 104         TPM_SHORT,
 105         TPM_SHORT,
 106         TPM_SHORT,              /* 45 */
 107         TPM_SHORT,
 108         TPM_SHORT,
 109         TPM_SHORT,
 110         TPM_LONG,
 111         TPM_MEDIUM,             /* 50 */
 112         TPM_MEDIUM,
 113         TPM_UNDEFINED,
 114         TPM_UNDEFINED,
 115         TPM_UNDEFINED,
 116         TPM_UNDEFINED,          /* 55 */
 117         TPM_UNDEFINED,
 118         TPM_UNDEFINED,
 119         TPM_UNDEFINED,
 120         TPM_UNDEFINED,
 121         TPM_MEDIUM,             /* 60 */
 122         TPM_MEDIUM,
 123         TPM_MEDIUM,
 124         TPM_SHORT,
 125         TPM_SHORT,
 126         TPM_MEDIUM,             /* 65 */
 127         TPM_UNDEFINED,
 128         TPM_UNDEFINED,
 129         TPM_UNDEFINED,
 130         TPM_UNDEFINED,
 131         TPM_SHORT,              /* 70 */
 132         TPM_SHORT,
 133         TPM_UNDEFINED,
 134         TPM_UNDEFINED,
 135         TPM_UNDEFINED,
 136         TPM_UNDEFINED,          /* 75 */
 137         TPM_UNDEFINED,
 138         TPM_UNDEFINED,
 139         TPM_UNDEFINED,
 140         TPM_UNDEFINED,
 141         TPM_LONG,               /* 80 */
 142         TPM_UNDEFINED,
 143         TPM_MEDIUM,
 144         TPM_LONG,
 145         TPM_SHORT,
 146         TPM_UNDEFINED,          /* 85 */
 147         TPM_UNDEFINED,
 148         TPM_UNDEFINED,
 149         TPM_UNDEFINED,
 150         TPM_UNDEFINED,
 151         TPM_SHORT,              /* 90 */
 152         TPM_SHORT,
 153         TPM_SHORT,
 154         TPM_SHORT,
 155         TPM_SHORT,
 156         TPM_UNDEFINED,          /* 95 */
 157         TPM_UNDEFINED,
 158         TPM_UNDEFINED,
 159         TPM_UNDEFINED,
 160         TPM_UNDEFINED,
 161         TPM_MEDIUM,             /* 100 */
 162         TPM_SHORT,
 163         TPM_SHORT,
 164         TPM_UNDEFINED,
 165         TPM_UNDEFINED,
 166         TPM_UNDEFINED,          /* 105 */
 167         TPM_UNDEFINED,
 168         TPM_UNDEFINED,
 169         TPM_UNDEFINED,
 170         TPM_UNDEFINED,
 171         TPM_SHORT,              /* 110 */
 172         TPM_SHORT,
 173         TPM_SHORT,
 174         TPM_SHORT,
 175         TPM_SHORT,
 176         TPM_SHORT,              /* 115 */
 177         TPM_SHORT,
 178         TPM_SHORT,
 179         TPM_UNDEFINED,
 180         TPM_UNDEFINED,
 181         TPM_LONG,               /* 120 */
 182         TPM_LONG,
 183         TPM_MEDIUM,
 184         TPM_UNDEFINED,
 185         TPM_SHORT,
 186         TPM_SHORT,              /* 125 */
 187         TPM_SHORT,
 188         TPM_LONG,
 189         TPM_SHORT,
 190         TPM_SHORT,
 191         TPM_SHORT,              /* 130 */
 192         TPM_MEDIUM,
 193         TPM_UNDEFINED,
 194         TPM_SHORT,
 195         TPM_MEDIUM,
 196         TPM_UNDEFINED,          /* 135 */
 197         TPM_UNDEFINED,
 198         TPM_UNDEFINED,
 199         TPM_UNDEFINED,
 200         TPM_UNDEFINED,
 201         TPM_SHORT,              /* 140 */
 202         TPM_SHORT,
 203         TPM_UNDEFINED,
 204         TPM_UNDEFINED,
 205         TPM_UNDEFINED,
 206         TPM_UNDEFINED,          /* 145 */
 207         TPM_UNDEFINED,
 208         TPM_UNDEFINED,
 209         TPM_UNDEFINED,
 210         TPM_UNDEFINED,
 211         TPM_SHORT,              /* 150 */
 212         TPM_MEDIUM,
 213         TPM_MEDIUM,
 214         TPM_SHORT,
 215         TPM_SHORT,
 216         TPM_UNDEFINED,          /* 155 */
 217         TPM_UNDEFINED,
 218         TPM_UNDEFINED,
 219         TPM_UNDEFINED,
 220         TPM_UNDEFINED,
 221         TPM_SHORT,              /* 160 */
 222         TPM_SHORT,
 223         TPM_SHORT,
 224         TPM_SHORT,
 225         TPM_UNDEFINED,
 226         TPM_UNDEFINED,          /* 165 */
 227         TPM_UNDEFINED,
 228         TPM_UNDEFINED,
 229         TPM_UNDEFINED,
 230         TPM_UNDEFINED,
 231         TPM_LONG,               /* 170 */
 232         TPM_UNDEFINED,
 233         TPM_UNDEFINED,
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,
 236         TPM_UNDEFINED,          /* 175 */
 237         TPM_UNDEFINED,
 238         TPM_UNDEFINED,
 239         TPM_UNDEFINED,
 240         TPM_UNDEFINED,
 241         TPM_MEDIUM,             /* 180 */
 242         TPM_SHORT,
 243         TPM_MEDIUM,
 244         TPM_MEDIUM,
 245         TPM_MEDIUM,
 246         TPM_MEDIUM,             /* 185 */
 247         TPM_SHORT,
 248         TPM_UNDEFINED,
 249         TPM_UNDEFINED,
 250         TPM_UNDEFINED,
 251         TPM_UNDEFINED,          /* 190 */
 252         TPM_UNDEFINED,
 253         TPM_UNDEFINED,
 254         TPM_UNDEFINED,
 255         TPM_UNDEFINED,
 256         TPM_UNDEFINED,          /* 195 */
 257         TPM_UNDEFINED,
 258         TPM_UNDEFINED,
 259         TPM_UNDEFINED,
 260         TPM_UNDEFINED,
 261         TPM_SHORT,              /* 200 */
 262         TPM_UNDEFINED,
 263         TPM_UNDEFINED,
 264         TPM_UNDEFINED,
 265         TPM_SHORT,
 266         TPM_SHORT,              /* 205 */
 267         TPM_SHORT,
 268         TPM_SHORT,
 269         TPM_SHORT,
 270         TPM_SHORT,
 271         TPM_MEDIUM,             /* 210 */
 272         TPM_UNDEFINED,
 273         TPM_MEDIUM,
 274         TPM_MEDIUM,
 275         TPM_MEDIUM,
 276         TPM_UNDEFINED,          /* 215 */
 277         TPM_MEDIUM,
 278         TPM_UNDEFINED,
 279         TPM_UNDEFINED,
 280         TPM_SHORT,
 281         TPM_SHORT,              /* 220 */
 282         TPM_SHORT,
 283         TPM_SHORT,
 284         TPM_SHORT,
 285         TPM_SHORT,
 286         TPM_UNDEFINED,          /* 225 */
 287         TPM_UNDEFINED,
 288         TPM_UNDEFINED,
 289         TPM_UNDEFINED,
 290         TPM_UNDEFINED,
 291         TPM_SHORT,              /* 230 */
 292         TPM_LONG,
 293         TPM_MEDIUM,
 294         TPM_UNDEFINED,
 295         TPM_UNDEFINED,
 296         TPM_UNDEFINED,          /* 235 */
 297         TPM_UNDEFINED,
 298         TPM_UNDEFINED,
 299         TPM_UNDEFINED,
 300         TPM_UNDEFINED,
 301         TPM_SHORT,              /* 240 */
 302         TPM_UNDEFINED,
 303         TPM_MEDIUM,
 304 };
 305
 306 /*
 307  * Returns max number of jiffies to wait
 308  */
 309 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 310                                            u32 ordinal)
 311 {
 312         int duration_idx = TPM_UNDEFINED;
 313         int duration = 0;
 314
 315         /*
 316          * We only have a duration table for protected commands, where the upper
 317          * 16 bits are 0. For the few other ordinals the fallback will be used.
 318          */
 319         if (ordinal < TPM_MAX_ORDINAL)
 320                 duration_idx = tpm_ordinal_duration[ordinal];
 321
 322         if (duration_idx != TPM_UNDEFINED)
 323                 duration = chip->duration[duration_idx];
 324         if (duration <= 0)
 325                 return 2 * 60 * HZ;
 326         else
 327                 return duration;
 328 }
 329 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 330
 331 static int tpm_validate_command(struct tpm_chip *chip,
 332                                  struct tpm_space *space,
 333                                  const u8 *cmd,
 334                                  size_t len)
 335 {
 336         const struct tpm_input_header *header = (const void *)cmd;
 337         int i;
 338         u32 cc;
 339         u32 attrs;
 340         unsigned int nr_handles;
 341
 342         if (len < TPM_HEADER_SIZE)
 343                 return -EINVAL;
 344
 345         if (!space)
 346                 return 0;
 347
 348         if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
 349                 cc = be32_to_cpu(header->ordinal);
 350
 351                 i = tpm2_find_cc(chip, cc);
 352                 if (i < 0) {
 353                         dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
 354                                 cc);
 355                         return -EOPNOTSUPP;
 356                 }
 357
 358                 attrs = chip->cc_attrs_tbl[i];
 359                 nr_handles =
 360                         4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
 361                 if (len < TPM_HEADER_SIZE + 4 * nr_handles)
 362                         goto err_len;
 363         }
 364
 365         return 0;
 366 err_len:
 367         dev_dbg(&chip->dev,
 368                 "%s: insufficient command length %zu", __func__, len);
 369         return -EINVAL;
 370 }
 371
 372 static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
 373 {
 374         int rc;
 375
 376         if (flags & TPM_TRANSMIT_RAW)
 377                 return 0;
 378
 379         if (!chip->ops->request_locality)
 380                 return 0;
 381
 382         rc = chip->ops->request_locality(chip, 0);
 383         if (rc < 0)
 384                 return rc;
 385
 386         chip->locality = rc;
 387
 388         return 0;
 389 }
 390
 391 static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
 392 {
 393         int rc;
 394
 395         if (flags & TPM_TRANSMIT_RAW)
 396                 return;
 397
 398         if (!chip->ops->relinquish_locality)
 399                 return;
 400
 401         rc = chip->ops->relinquish_locality(chip, chip->locality);
 402         if (rc)
 403                 dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
 404
 405         chip->locality = -1;
 406 }
 407
 408 static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
 409 {
 410         if (flags & TPM_TRANSMIT_RAW)
 411                 return 0;
 412
 413         if (!chip->ops->cmd_ready)
 414                 return 0;
 415
 416         return chip->ops->cmd_ready(chip);
 417 }
 418
 419 static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
 420 {
 421         if (flags & TPM_TRANSMIT_RAW)
 422                 return 0;
 423
 424         if (!chip->ops->go_idle)
 425                 return 0;
 426
 427         return chip->ops->go_idle(chip);
 428 }
 429
 430 static ssize_t tpm_try_transmit(struct tpm_chip *chip,
 431                                 struct tpm_space *space,
 432                                 u8 *buf, size_t bufsiz,
 433                                 unsigned int flags)
 434 {
 435         struct tpm_output_header *header = (void *)buf;
 436         int rc;
 437         ssize_t len = 0;
 438         u32 count, ordinal;
 439         unsigned long stop;
 440         bool need_locality;
 441
 442         rc = tpm_validate_command(chip, space, buf, bufsiz);
 443         if (rc == -EINVAL)
 444                 return rc;
 445         /*
 446          * If the command is not implemented by the TPM, synthesize a
 447          * response with a TPM2_RC_COMMAND_CODE return for user-space.
 448          */
 449         if (rc == -EOPNOTSUPP) {
 450                 header->length = cpu_to_be32(sizeof(*header));
 451                 header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
 452                 header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
 453                                                   TSS2_RESMGR_TPM_RC_LAYER);
 454                 return sizeof(*header);
 455         }
 456
 457         if (bufsiz > TPM_BUFSIZE)
 458                 bufsiz = TPM_BUFSIZE;
 459
 460         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 461         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 462         if (count == 0)
 463                 return -ENODATA;
 464         if (count > bufsiz) {
 465                 dev_err(&chip->dev,
 466                         "invalid count value %x %zx\n", count, bufsiz);
 467                 return -E2BIG;
 468         }
 469
 470         if (!(flags & TPM_TRANSMIT_UNLOCKED))
 471                 mutex_lock(&chip->tpm_mutex);
 472
 473
 474         if (chip->ops->clk_enable != NULL)
 475                 chip->ops->clk_enable(chip, true);
 476
 477         /* Store the decision as chip->locality will be changed. */
 478         need_locality = chip->locality == -1;
 479
 480         if (need_locality) {
 481                 rc = tpm_request_locality(chip, flags);
 482                 if (rc < 0) {
 483                         need_locality = false;
 484                         goto out_locality;
 485                 }
 486         }
 487
 488         rc = tpm_cmd_ready(chip, flags);
 489         if (rc)
 490                 goto out_locality;
 491
 492         rc = tpm2_prepare_space(chip, space, ordinal, buf);
 493         if (rc)
 494                 goto out;
 495
 496         rc = chip->ops->send(chip, (u8 *) buf, count);
 497         if (rc < 0) {
 498                 if (rc != -EPIPE)
 499                         dev_err(&chip->dev,
 500                                 "%s: send(): error %d\n", __func__, rc);
 501                 goto out;
 502         }
 503
 504         /* A sanity check. send() should just return zero on success e.g.
 505          * not the command length.
 506          */
 507         if (rc > 0) {
 508                 dev_warn(&chip->dev,
 509                          "%s: send(): invalid value %d\n", __func__, rc);
 510                 rc = 0;
 511         }
 512
 513         if (chip->flags & TPM_CHIP_FLAG_IRQ)
 514                 goto out_recv;
 515
 516         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 517                 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
 518         else
 519                 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 520         do {
 521                 u8 status = chip->ops->status(chip);
 522                 if ((status & chip->ops->req_complete_mask) ==
 523                     chip->ops->req_complete_val)
 524                         goto out_recv;
 525
 526                 if (chip->ops->req_canceled(chip, status)) {
 527                         dev_err(&chip->dev, "Operation Canceled\n");
 528                         rc = -ECANCELED;
 529                         goto out;
 530                 }
 531
 532                 tpm_msleep(TPM_TIMEOUT);
 533                 rmb();
 534         } while (time_before(jiffies, stop));
 535
 536         chip->ops->cancel(chip);
 537         dev_err(&chip->dev, "Operation Timed out\n");
 538         rc = -ETIME;
 539         goto out;
 540
 541 out_recv:
 542         len = chip->ops->recv(chip, (u8 *) buf, bufsiz);
 543         if (len < 0) {
 544                 rc = len;
 545                 dev_err(&chip->dev,
 546                         "tpm_transmit: tpm_recv: error %d\n", rc);
 547                 goto out;
 548         } else if (len < TPM_HEADER_SIZE) {
 549                 rc = -EFAULT;
 550                 goto out;
 551         }
 552
 553         if (len != be32_to_cpu(header->length)) {
 554                 rc = -EFAULT;
 555                 goto out;
 556         }
 557
 558         rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
 559         if (rc)
 560                 dev_err(&chip->dev, "tpm2_commit_space: error %d\n", rc);
 561
 562 out:
 563         /* may fail but do not override previous error value in rc */
 564         tpm_go_idle(chip, flags);
 565
 566 out_locality:
 567         if (need_locality)
 568                 tpm_relinquish_locality(chip, flags);
 569
 570         if (chip->ops->clk_enable != NULL)
 571                 chip->ops->clk_enable(chip, false);
 572
 573         if (!(flags & TPM_TRANSMIT_UNLOCKED))
 574                 mutex_unlock(&chip->tpm_mutex);
 575         return rc ? rc : len;
 576 }
 577
 578 /**
 579  * tpm_transmit - Internal kernel interface to transmit TPM commands.
 580  *
 581  * @chip: TPM chip to use
 582  * @space: tpm space
 583  * @buf: TPM command buffer
 584  * @bufsiz: length of the TPM command buffer
 585  * @flags: tpm transmit flags - bitmap
 586  *
 587  * A wrapper around tpm_try_transmit that handles TPM2_RC_RETRY
 588  * returns from the TPM and retransmits the command after a delay up
 589  * to a maximum wait of TPM2_DURATION_LONG.
 590  *
 591  * Note: TPM1 never returns TPM2_RC_RETRY so the retry logic is TPM2
 592  * only
 593  *
 594  * Return:
 595  *     the length of the return when the operation is successful.
 596  *     A negative number for system errors (errno).
 597  */
 598 ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
 599                      u8 *buf, size_t bufsiz, unsigned int flags)
 600 {
 601         struct tpm_output_header *header = (struct tpm_output_header *)buf;
 602         /* space for header and handles */
 603         u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
 604         unsigned int delay_msec = TPM2_DURATION_SHORT;
 605         u32 rc = 0;
 606         ssize_t ret;
 607         const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
 608                                      bufsiz);
 609
 610         /*
 611          * Subtlety here: if we have a space, the handles will be
 612          * transformed, so when we restore the header we also have to
 613          * restore the handles.
 614          */
 615         memcpy(save, buf, save_size);
 616
 617         for (;;) {
 618                 ret = tpm_try_transmit(chip, space, buf, bufsiz, flags);
 619                 if (ret < 0)
 620                         break;
 621                 rc = be32_to_cpu(header->return_code);
 622                 if (rc != TPM2_RC_RETRY)
 623                         break;
 624
 625                 if (delay_msec > TPM2_DURATION_LONG) {
 626                         dev_err(&chip->dev, "TPM is in retry loop\n");
 627                         break;
 628                 }
 629                 tpm_msleep(delay_msec);
 630                 delay_msec *= 2;
 631                 memcpy(buf, save, save_size);
 632         }
 633         return ret;
 634 }
 635 /**
 636  * tpm_transmit_cmd - send a tpm command to the device
 637  *    The function extracts tpm out header return code
 638  *
 639  * @chip: TPM chip to use
 640  * @space: tpm space
 641  * @buf: TPM command buffer
 642  * @bufsiz: length of the buffer
 643  * @min_rsp_body_length: minimum expected length of response body
 644  * @flags: tpm transmit flags - bitmap
 645  * @desc: command description used in the error message
 646  *
 647  * Return:
 648  *     0 when the operation is successful.
 649  *     A negative number for system errors (errno).
 650  *     A positive number for a TPM error.
 651  */
 652 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
 653                          const void *buf, size_t bufsiz,
 654                          size_t min_rsp_body_length, unsigned int flags,
 655                          const char *desc)
 656 {
 657         const struct tpm_output_header *header = buf;
 658         int err;
 659         ssize_t len;
 660
 661         len = tpm_transmit(chip, space, (u8 *)buf, bufsiz, flags);
 662         if (len <  0)
 663                 return len;
 664
 665         err = be32_to_cpu(header->return_code);
 666         if (err != 0 && err != TPM_ERR_DISABLED && err != TPM_ERR_DEACTIVATED
 667             && desc)
 668                 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
 669                         desc);
 670         if (err)
 671                 return err;
 672
 673         if (len < min_rsp_body_length + TPM_HEADER_SIZE)
 674                 return -EFAULT;
 675
 676         return 0;
 677 }
 678 EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
 679
 680 #define TPM_ORD_STARTUP 153
 681 #define TPM_ST_CLEAR 1
 682
 683 /**
 684  * tpm_startup - turn on the TPM
 685  * @chip: TPM chip to use
 686  *
 687  * Normally the firmware should start the TPM. This function is provided as a
 688  * workaround if this does not happen. A legal case for this could be for
 689  * example when a TPM emulator is used.
 690  *
 691  * Return: same as tpm_transmit_cmd()
 692  */
 693 int tpm_startup(struct tpm_chip *chip)
 694 {
 695         struct tpm_buf buf;
 696         int rc;
 697
 698         dev_info(&chip->dev, "starting up the TPM manually\n");
 699
 700         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 701                 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
 702                 if (rc < 0)
 703                         return rc;
 704
 705                 tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
 706         } else {
 707                 rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
 708                 if (rc < 0)
 709                         return rc;
 710
 711                 tpm_buf_append_u16(&buf, TPM_ST_CLEAR);
 712         }
 713
 714         rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
 715                               "attempting to start the TPM");
 716
 717         tpm_buf_destroy(&buf);
 718         return rc;
 719 }
 720
 721 #define TPM_DIGEST_SIZE 20
 722 #define TPM_RET_CODE_IDX 6
 723 #define TPM_INTERNAL_RESULT_SIZE 200
 724 #define TPM_ORD_GET_CAP 101
 725 #define TPM_ORD_GET_RANDOM 70
 726
 727 static const struct tpm_input_header tpm_getcap_header = {
 728         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
 729         .length = cpu_to_be32(22),
 730         .ordinal = cpu_to_be32(TPM_ORD_GET_CAP)
 731 };
 732
 733 ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
 734                    const char *desc, size_t min_cap_length)
 735 {
 736         struct tpm_buf buf;
 737         int rc;
 738
 739         rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
 740         if (rc)
 741                 return rc;
 742
 743         if (subcap_id == TPM_CAP_VERSION_1_1 ||
 744             subcap_id == TPM_CAP_VERSION_1_2) {
 745                 tpm_buf_append_u32(&buf, subcap_id);
 746                 tpm_buf_append_u32(&buf, 0);
 747         } else {
 748                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 749                     subcap_id == TPM_CAP_FLAG_VOL)
 750                         tpm_buf_append_u32(&buf, TPM_CAP_FLAG);
 751                 else
 752                         tpm_buf_append_u32(&buf, TPM_CAP_PROP);
 753
 754                 tpm_buf_append_u32(&buf, 4);
 755                 tpm_buf_append_u32(&buf, subcap_id);
 756         }
 757         rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
 758                               min_cap_length, 0, desc);
 759         if (!rc)
 760                 *cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
 761
 762         tpm_buf_destroy(&buf);
 763         return rc;
 764 }
 765 EXPORT_SYMBOL_GPL(tpm_getcap);
 766
 767 int tpm_get_timeouts(struct tpm_chip *chip)
 768 {
 769         cap_t cap;
 770         unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
 771         ssize_t rc;
 772
 773         if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
 774                 return 0;
 775
 776         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 777                 /* Fixed timeouts for TPM2 */
 778                 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
 779                 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
 780                 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
 781                 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
 782                 chip->duration[TPM_SHORT] =
 783                     msecs_to_jiffies(TPM2_DURATION_SHORT);
 784                 chip->duration[TPM_MEDIUM] =
 785                     msecs_to_jiffies(TPM2_DURATION_MEDIUM);
 786                 chip->duration[TPM_LONG] =
 787                     msecs_to_jiffies(TPM2_DURATION_LONG);
 788
 789                 chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
 790                 return 0;
 791         }
 792
 793         rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
 794                         sizeof(cap.timeout));
 795         if (rc == TPM_ERR_INVALID_POSTINIT) {
 796                 if (tpm_startup(chip))
 797                         return rc;
 798
 799                 rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
 800                                 "attempting to determine the timeouts",
 801                                 sizeof(cap.timeout));
 802         }
 803
 804         if (rc) {
 805                 dev_err(&chip->dev,
 806                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 807                         rc);
 808                 return rc;
 809         }
 810
 811         timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
 812         timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
 813         timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
 814         timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
 815         timeout_chip[0] = be32_to_cpu(cap.timeout.a);
 816         timeout_chip[1] = be32_to_cpu(cap.timeout.b);
 817         timeout_chip[2] = be32_to_cpu(cap.timeout.c);
 818         timeout_chip[3] = be32_to_cpu(cap.timeout.d);
 819         memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
 820
 821         /*
 822          * Provide ability for vendor overrides of timeout values in case
 823          * of misreporting.
 824          */
 825         if (chip->ops->update_timeouts != NULL)
 826                 chip->timeout_adjusted =
 827                         chip->ops->update_timeouts(chip, timeout_eff);
 828
 829         if (!chip->timeout_adjusted) {
 830                 /* Restore default if chip reported 0 */
 831                 int i;
 832
 833                 for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
 834                         if (timeout_eff[i])
 835                                 continue;
 836
 837                         timeout_eff[i] = timeout_old[i];
 838                         chip->timeout_adjusted = true;
 839                 }
 840
 841                 if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
 842                         /* timeouts in msec rather usec */
 843                         for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
 844                                 timeout_eff[i] *= 1000;
 845                         chip->timeout_adjusted = true;
 846                 }
 847         }
 848
 849         /* Report adjusted timeouts */
 850         if (chip->timeout_adjusted) {
 851                 dev_info(&chip->dev,
 852                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 853                          timeout_chip[0], timeout_eff[0],
 854                          timeout_chip[1], timeout_eff[1],
 855                          timeout_chip[2], timeout_eff[2],
 856                          timeout_chip[3], timeout_eff[3]);
 857         }
 858
 859         chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
 860         chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
 861         chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
 862         chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
 863
 864         rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
 865                         "attempting to determine the durations",
 866                         sizeof(cap.duration));
 867         if (rc)
 868                 return rc;
 869
 870         chip->duration[TPM_SHORT] =
 871                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
 872         chip->duration[TPM_MEDIUM] =
 873                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
 874         chip->duration[TPM_LONG] =
 875                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
 876
 877         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 878          * value wrong and apparently reports msecs rather than usecs. So we
 879          * fix up the resulting too-small TPM_SHORT value to make things work.
 880          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 881          */
 882         if (chip->duration[TPM_SHORT] < (HZ / 100)) {
 883                 chip->duration[TPM_SHORT] = HZ;
 884                 chip->duration[TPM_MEDIUM] *= 1000;
 885                 chip->duration[TPM_LONG] *= 1000;
 886                 chip->duration_adjusted = true;
 887                 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 888         }
 889
 890         chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
 891         return 0;
 892 }
 893 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 894
 895 #define TPM_ORD_CONTINUE_SELFTEST 83
 896 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 897
 898 static const struct tpm_input_header continue_selftest_header = {
 899         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
 900         .length = cpu_to_be32(10),
 901         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 902 };
 903
 904 /**
 905  * tpm_continue_selftest -- run TPM's selftest
 906  * @chip: TPM chip to use
 907  *
 908  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 909  * a TPM error code.
 910  */
 911 static int tpm_continue_selftest(struct tpm_chip *chip)
 912 {
 913         int rc;
 914         struct tpm_cmd_t cmd;
 915
 916         cmd.header.in = continue_selftest_header;
 917         rc = tpm_transmit_cmd(chip, NULL, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 918                               0, 0, "continue selftest");
 919         return rc;
 920 }
 921
 922 #define TPM_ORDINAL_PCRREAD 21
 923 #define READ_PCR_RESULT_SIZE 30
 924 #define READ_PCR_RESULT_BODY_SIZE 20
 925 static const struct tpm_input_header pcrread_header = {
 926         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
 927         .length = cpu_to_be32(14),
 928         .ordinal = cpu_to_be32(TPM_ORDINAL_PCRREAD)
 929 };
 930
 931 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 932 {
 933         int rc;
 934         struct tpm_cmd_t cmd;
 935
 936         cmd.header.in = pcrread_header;
 937         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 938         rc = tpm_transmit_cmd(chip, NULL, &cmd, READ_PCR_RESULT_SIZE,
 939                               READ_PCR_RESULT_BODY_SIZE, 0,
 940                               "attempting to read a pcr value");
 941
 942         if (rc == 0)
 943                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 944                        TPM_DIGEST_SIZE);
 945         return rc;
 946 }
 947
 948 /**
 949  * tpm_is_tpm2 - is the chip a TPM2 chip?
 950  * @chip_num:   tpm idx # or ANY
 951  *
 952  * Returns < 0 on error, and 1 or 0 on success depending whether the chip
 953  * is a TPM2 chip.
 954  */
 955 int tpm_is_tpm2(u32 chip_num)
 956 {
 957         struct tpm_chip *chip;
 958         int rc;
 959
 960         chip = tpm_chip_find_get(chip_num);
 961         if (chip == NULL)
 962                 return -ENODEV;
 963
 964         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 965
 966         tpm_put_ops(chip);
 967
 968         return rc;
 969 }
 970 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 971
 972 /**
 973  * tpm_pcr_read - read a pcr value
 974  * @chip_num:   tpm idx # or ANY
 975  * @pcr_idx:    pcr idx to retrieve
 976  * @res_buf:    TPM_PCR value
 977  *              size of res_buf is 20 bytes (or NULL if you don't care)
 978  *
 979  * The TPM driver should be built-in, but for whatever reason it
 980  * isn't, protect against the chip disappearing, by incrementing
 981  * the module usage count.
 982  */
 983 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 984 {
 985         struct tpm_chip *chip;
 986         int rc;
 987
 988         chip = tpm_chip_find_get(chip_num);
 989         if (chip == NULL)
 990                 return -ENODEV;
 991         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 992                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
 993         else
 994                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
 995         tpm_put_ops(chip);
 996         return rc;
 997 }
 998 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 999
1000 #define TPM_ORD_PCR_EXTEND 20
1001 #define EXTEND_PCR_RESULT_SIZE 34
1002 #define EXTEND_PCR_RESULT_BODY_SIZE 20
1003 static const struct tpm_input_header pcrextend_header = {
1004         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1005         .length = cpu_to_be32(34),
1006         .ordinal = cpu_to_be32(TPM_ORD_PCR_EXTEND)
1007 };
1008
1009 static int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash,
1010                            char *log_msg)
1011 {
1012         struct tpm_buf buf;
1013         int rc;
1014
1015         rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND);
1016         if (rc)
1017                 return rc;
1018
1019         tpm_buf_append_u32(&buf, pcr_idx);
1020         tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);
1021
1022         rc = tpm_transmit_cmd(chip, NULL, buf.data, EXTEND_PCR_RESULT_SIZE,
1023                               EXTEND_PCR_RESULT_BODY_SIZE, 0, log_msg);
1024         tpm_buf_destroy(&buf);
1025         return rc;
1026 }
1027
1028 /**
1029  * tpm_pcr_extend - extend pcr value with hash
1030  * @chip_num:   tpm idx # or AN&
1031  * @pcr_idx:    pcr idx to extend
1032  * @hash:       hash value used to extend pcr value
1033  *
1034  * The TPM driver should be built-in, but for whatever reason it
1035  * isn't, protect against the chip disappearing, by incrementing
1036  * the module usage count.
1037  */
1038 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
1039 {
1040         int rc;
1041         struct tpm_chip *chip;
1042         struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
1043         u32 count = 0;
1044         int i;
1045
1046         chip = tpm_chip_find_get(chip_num);
1047         if (chip == NULL)
1048                 return -ENODEV;
1049
1050         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1051                 memset(digest_list, 0, sizeof(digest_list));
1052
1053                 for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
1054                             chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
1055                         digest_list[i].alg_id = chip->active_banks[i];
1056                         memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
1057                         count++;
1058                 }
1059
1060                 rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);
1061                 tpm_put_ops(chip);
1062                 return rc;
1063         }
1064
1065         rc = tpm1_pcr_extend(chip, pcr_idx, hash,
1066                              "attempting extend a PCR value");
1067         tpm_put_ops(chip);
1068         return rc;
1069 }
1070 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
1071
1072 /**
1073  * tpm_do_selftest - have the TPM continue its selftest and wait until it
1074  *                   can receive further commands
1075  * @chip: TPM chip to use
1076  *
1077  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
1078  * a TPM error code.
1079  */
1080 int tpm_do_selftest(struct tpm_chip *chip)
1081 {
1082         int rc;
1083         unsigned int loops;
1084         unsigned int delay_msec = 100;
1085         unsigned long duration;
1086         u8 dummy[TPM_DIGEST_SIZE];
1087
1088         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
1089
1090         loops = jiffies_to_msecs(duration) / delay_msec;
1091
1092         rc = tpm_continue_selftest(chip);
1093         if (rc == TPM_ERR_INVALID_POSTINIT) {
1094                 chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
1095                 dev_info(&chip->dev, "TPM not ready (%d)\n", rc);
1096         }
1097         /* This may fail if there was no TPM driver during a suspend/resume
1098          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
1099          */
1100         if (rc)
1101                 return rc;
1102
1103         do {
1104                 /* Attempt to read a PCR value */
1105                 rc = tpm_pcr_read_dev(chip, 0, dummy);
1106
1107                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
1108                  * around 300ms while the self test is ongoing, keep trying
1109                  * until the self test duration expires. */
1110                 if (rc == -ETIME) {
1111                         dev_info(
1112                             &chip->dev, HW_ERR
1113                             "TPM command timed out during continue self test");
1114                         tpm_msleep(delay_msec);
1115                         continue;
1116                 }
1117
1118                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
1119                         dev_info(&chip->dev,
1120                                  "TPM is disabled/deactivated (0x%X)\n", rc);
1121                         /* TPM is disabled and/or deactivated; driver can
1122                          * proceed and TPM does handle commands for
1123                          * suspend/resume correctly
1124                          */
1125                         return 0;
1126                 }
1127                 if (rc != TPM_WARN_DOING_SELFTEST)
1128                         return rc;
1129                 tpm_msleep(delay_msec);
1130         } while (--loops > 0);
1131
1132         return rc;
1133 }
1134 EXPORT_SYMBOL_GPL(tpm_do_selftest);
1135
1136 /**
1137  * tpm1_auto_startup - Perform the standard automatic TPM initialization
1138  *                     sequence
1139  * @chip: TPM chip to use
1140  *
1141  * Returns 0 on success, < 0 in case of fatal error.
1142  */
1143 int tpm1_auto_startup(struct tpm_chip *chip)
1144 {
1145         int rc;
1146
1147         rc = tpm_get_timeouts(chip);
1148         if (rc)
1149                 goto out;
1150         rc = tpm_do_selftest(chip);
1151         if (rc) {
1152                 dev_err(&chip->dev, "TPM self test failed\n");
1153                 goto out;
1154         }
1155
1156         return rc;
1157 out:
1158         if (rc > 0)
1159                 rc = -ENODEV;
1160         return rc;
1161 }
1162
1163 int tpm_send(u32 chip_num, void *cmd, size_t buflen)
1164 {
1165         struct tpm_chip *chip;
1166         int rc;
1167
1168         chip = tpm_chip_find_get(chip_num);
1169         if (chip == NULL)
1170                 return -ENODEV;
1171
1172         rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0,
1173                               "attempting tpm_cmd");
1174         tpm_put_ops(chip);
1175         return rc;
1176 }
1177 EXPORT_SYMBOL_GPL(tpm_send);
1178
1179 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
1180                                         bool check_cancel, bool *canceled)
1181 {
1182         u8 status = chip->ops->status(chip);
1183
1184         *canceled = false;
1185         if ((status & mask) == mask)
1186                 return true;
1187         if (check_cancel && chip->ops->req_canceled(chip, status)) {
1188                 *canceled = true;
1189                 return true;
1190         }
1191         return false;
1192 }
1193
1194 int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask, unsigned long timeout,
1195                       wait_queue_head_t *queue, bool check_cancel)
1196 {
1197         unsigned long stop;
1198         long rc;
1199         u8 status;
1200         bool canceled = false;
1201
1202         /* check current status */
1203         status = chip->ops->status(chip);
1204         if ((status & mask) == mask)
1205                 return 0;
1206
1207         stop = jiffies + timeout;
1208
1209         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
1210 again:
1211                 timeout = stop - jiffies;
1212                 if ((long)timeout <= 0)
1213                         return -ETIME;
1214                 rc = wait_event_interruptible_timeout(*queue,
1215                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
1216                                                &canceled),
1217                         timeout);
1218                 if (rc > 0) {
1219                         if (canceled)
1220                                 return -ECANCELED;
1221                         return 0;
1222                 }
1223                 if (rc == -ERESTARTSYS && freezing(current)) {
1224                         clear_thread_flag(TIF_SIGPENDING);
1225                         goto again;
1226                 }
1227         } else {
1228                 do {
1229                         tpm_msleep(TPM_TIMEOUT);
1230                         status = chip->ops->status(chip);
1231                         if ((status & mask) == mask)
1232                                 return 0;
1233                 } while (time_before(jiffies, stop));
1234         }
1235         return -ETIME;
1236 }
1237 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
1238
1239 #define TPM_ORD_SAVESTATE 152
1240 #define SAVESTATE_RESULT_SIZE 10
1241
1242 static const struct tpm_input_header savestate_header = {
1243         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1244         .length = cpu_to_be32(10),
1245         .ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)
1246 };
1247
1248 /*
1249  * We are about to suspend. Save the TPM state
1250  * so that it can be restored.
1251  */
1252 int tpm_pm_suspend(struct device *dev)
1253 {
1254         struct tpm_chip *chip = dev_get_drvdata(dev);
1255         struct tpm_cmd_t cmd;
1256         int rc, try;
1257
1258         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1259
1260         if (chip == NULL)
1261                 return -ENODEV;
1262
1263         if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
1264                 return 0;
1265
1266         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1267                 tpm2_shutdown(chip, TPM2_SU_STATE);
1268                 return 0;
1269         }
1270
1271         /* for buggy tpm, flush pcrs with extend to selected dummy */
1272         if (tpm_suspend_pcr)
1273                 rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
1274                                      "extending dummy pcr before suspend");
1275
1276         /* now do the actual savestate */
1277         for (try = 0; try < TPM_RETRY; try++) {
1278                 cmd.header.in = savestate_header;
1279                 rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,
1280                                       0, 0, NULL);
1281
1282                 /*
1283                  * If the TPM indicates that it is too busy to respond to
1284                  * this command then retry before giving up.  It can take
1285                  * several seconds for this TPM to be ready.
1286                  *
1287                  * This can happen if the TPM has already been sent the
1288                  * SaveState command before the driver has loaded.  TCG 1.2
1289                  * specification states that any communication after SaveState
1290                  * may cause the TPM to invalidate previously saved state.
1291                  */
1292                 if (rc != TPM_WARN_RETRY)
1293                         break;
1294                 tpm_msleep(TPM_TIMEOUT_RETRY);
1295         }
1296
1297         if (rc)
1298                 dev_err(&chip->dev,
1299                         "Error (%d) sending savestate before suspend\n", rc);
1300         else if (try > 0)
1301                 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1302                          try * TPM_TIMEOUT_RETRY);
1303
1304         return rc;
1305 }
1306 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1307
1308 /*
1309  * Resume from a power safe. The BIOS already restored
1310  * the TPM state.
1311  */
1312 int tpm_pm_resume(struct device *dev)
1313 {
1314         struct tpm_chip *chip = dev_get_drvdata(dev);
1315
1316         if (chip == NULL)
1317                 return -ENODEV;
1318
1319         return 0;
1320 }
1321 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1322
1323 #define TPM_GETRANDOM_RESULT_SIZE       18
1324 static const struct tpm_input_header tpm_getrandom_header = {
1325         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1326         .length = cpu_to_be32(14),
1327         .ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
1328 };
1329
1330 /**
1331  * tpm_get_random() - Get random bytes from the tpm's RNG
1332  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1333  * @out: destination buffer for the random bytes
1334  * @max: the max number of bytes to write to @out
1335  *
1336  * Returns < 0 on error and the number of bytes read on success
1337  */
1338 int tpm_get_random(u32 chip_num, u8 *out, size_t max)
1339 {
1340         struct tpm_chip *chip;
1341         struct tpm_cmd_t tpm_cmd;
1342         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
1343         int err, total = 0, retries = 5;
1344         u8 *dest = out;
1345
1346         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1347                 return -EINVAL;
1348
1349         chip = tpm_chip_find_get(chip_num);
1350         if (chip == NULL)
1351                 return -ENODEV;
1352
1353         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1354                 err = tpm2_get_random(chip, out, max);
1355                 tpm_put_ops(chip);
1356                 return err;
1357         }
1358
1359         do {
1360                 tpm_cmd.header.in = tpm_getrandom_header;
1361                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1362
1363                 err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
1364                                        TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1365                                        offsetof(struct tpm_getrandom_out,
1366                                                 rng_data),
1367                                        0, "attempting get random");
1368                 if (err)
1369                         break;
1370
1371                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1372                 if (recd > num_bytes) {
1373                         total = -EFAULT;
1374                         break;
1375                 }
1376
1377                 rlength = be32_to_cpu(tpm_cmd.header.out.length);
1378                 if (rlength < offsetof(struct tpm_getrandom_out, rng_data) +
1379                               recd) {
1380                         total = -EFAULT;
1381                         break;
1382                 }
1383                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1384
1385                 dest += recd;
1386                 total += recd;
1387                 num_bytes -= recd;
1388         } while (retries-- && total < max);
1389
1390         tpm_put_ops(chip);
1391         return total ? total : -EIO;
1392 }
1393 EXPORT_SYMBOL_GPL(tpm_get_random);
1394
1395 /**
1396  * tpm_seal_trusted() - seal a trusted key
1397  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1398  * @options: authentication values and other options
1399  * @payload: the key data in clear and encrypted form
1400  *
1401  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1402  * are supported.
1403  */
1404 int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1405                      struct trusted_key_options *options)
1406 {
1407         struct tpm_chip *chip;
1408         int rc;
1409
1410         chip = tpm_chip_find_get(chip_num);
1411         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1412                 return -ENODEV;
1413
1414         rc = tpm2_seal_trusted(chip, payload, options);
1415
1416         tpm_put_ops(chip);
1417         return rc;
1418 }
1419 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1420
1421 /**
1422  * tpm_unseal_trusted() - unseal a trusted key
1423  * @chip_num: A specific chip number for the request or TPM_ANY_NUM
1424  * @options: authentication values and other options
1425  * @payload: the key data in clear and encrypted form
1426  *
1427  * Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
1428  * are supported.
1429  */
1430 int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
1431                        struct trusted_key_options *options)
1432 {
1433         struct tpm_chip *chip;
1434         int rc;
1435
1436         chip = tpm_chip_find_get(chip_num);
1437         if (chip == NULL || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1438                 return -ENODEV;
1439
1440         rc = tpm2_unseal_trusted(chip, payload, options);
1441
1442         tpm_put_ops(chip);
1443
1444         return rc;
1445 }
1446 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1447
1448 static int __init tpm_init(void)
1449 {
1450         int rc;
1451
1452         tpm_class = class_create(THIS_MODULE, "tpm");
1453         if (IS_ERR(tpm_class)) {
1454                 pr_err("couldn't create tpm class\n");
1455                 return PTR_ERR(tpm_class);
1456         }
1457
1458         tpmrm_class = class_create(THIS_MODULE, "tpmrm");
1459         if (IS_ERR(tpmrm_class)) {
1460                 pr_err("couldn't create tpmrm class\n");
1461                 class_destroy(tpm_class);
1462                 return PTR_ERR(tpmrm_class);
1463         }
1464
1465         rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm");
1466         if (rc < 0) {
1467                 pr_err("tpm: failed to allocate char dev region\n");
1468                 class_destroy(tpmrm_class);
1469                 class_destroy(tpm_class);
1470                 return rc;
1471         }
1472
1473         return 0;
1474 }
1475
1476 static void __exit tpm_exit(void)
1477 {
1478         idr_destroy(&dev_nums_idr);
1479         class_destroy(tpm_class);
1480         class_destroy(tpmrm_class);
1481         unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
1482 }
1483
1484 subsys_initcall(tpm_init);
1485 module_exit(tpm_exit);
1486
1487 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1488 MODULE_DESCRIPTION("TPM Driver");
1489 MODULE_VERSION("2.0");
1490 MODULE_LICENSE("GPL");