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/tpm_eventlog.h>
  33
  34 #include "tpm.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  */
  46 static int tpm_suspend_pcr;
  47 module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
  48 MODULE_PARM_DESC(suspend_pcr,
  49                  "PCR to use for dummy writes to facilitate 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  */
  59 static 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  */
 308 unsigned 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 }
 328 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 329
 330 static int tpm_validate_command(struct tpm_chip *chip,
 331                                  struct tpm_space *space,
 332                                  const u8 *cmd,
 333                                  size_t len)
 334 {
 335         const struct tpm_input_header *header = (const void *)cmd;
 336         int i;
 337         u32 cc;
 338         u32 attrs;
 339         unsigned int nr_handles;
 340
 341         if (len < TPM_HEADER_SIZE)
 342                 return -EINVAL;
 343
 344         if (!space)
 345                 return 0;
 346
 347         if (chip->flags & TPM_CHIP_FLAG_TPM2 && chip->nr_commands) {
 348                 cc = be32_to_cpu(header->ordinal);
 349
 350                 i = tpm2_find_cc(chip, cc);
 351                 if (i < 0) {
 352                         dev_dbg(&chip->dev, "0x%04X is an invalid command\n",
 353                                 cc);
 354                         return -EOPNOTSUPP;
 355                 }
 356
 357                 attrs = chip->cc_attrs_tbl[i];
 358                 nr_handles =
 359                         4 * ((attrs >> TPM2_CC_ATTR_CHANDLES) & GENMASK(2, 0));
 360                 if (len < TPM_HEADER_SIZE + 4 * nr_handles)
 361                         goto err_len;
 362         }
 363
 364         return 0;
 365 err_len:
 366         dev_dbg(&chip->dev,
 367                 "%s: insufficient command length %zu", __func__, len);
 368         return -EINVAL;
 369 }
 370
 371 static int tpm_request_locality(struct tpm_chip *chip, unsigned int flags)
 372 {
 373         int rc;
 374
 375         if (flags & TPM_TRANSMIT_NESTED)
 376                 return 0;
 377
 378         if (!chip->ops->request_locality)
 379                 return 0;
 380
 381         rc = chip->ops->request_locality(chip, 0);
 382         if (rc < 0)
 383                 return rc;
 384
 385         chip->locality = rc;
 386
 387         return 0;
 388 }
 389
 390 static void tpm_relinquish_locality(struct tpm_chip *chip, unsigned int flags)
 391 {
 392         int rc;
 393
 394         if (flags & TPM_TRANSMIT_NESTED)
 395                 return;
 396
 397         if (!chip->ops->relinquish_locality)
 398                 return;
 399
 400         rc = chip->ops->relinquish_locality(chip, chip->locality);
 401         if (rc)
 402                 dev_err(&chip->dev, "%s: : error %d\n", __func__, rc);
 403
 404         chip->locality = -1;
 405 }
 406
 407 static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
 408 {
 409         if (flags & TPM_TRANSMIT_NESTED)
 410                 return 0;
 411
 412         if (!chip->ops->cmd_ready)
 413                 return 0;
 414
 415         return chip->ops->cmd_ready(chip);
 416 }
 417
 418 static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
 419 {
 420         if (flags & TPM_TRANSMIT_NESTED)
 421                 return 0;
 422
 423         if (!chip->ops->go_idle)
 424                 return 0;
 425
 426         return chip->ops->go_idle(chip);
 427 }
 428
 429 static ssize_t tpm_try_transmit(struct tpm_chip *chip,
 430                                 struct tpm_space *space,
 431                                 u8 *buf, size_t bufsiz,
 432                                 unsigned int flags)
 433 {
 434         struct tpm_output_header *header = (void *)buf;
 435         int rc;
 436         ssize_t len = 0;
 437         u32 count, ordinal;
 438         unsigned long stop;
 439         bool need_locality;
 440
 441         rc = tpm_validate_command(chip, space, buf, bufsiz);
 442         if (rc == -EINVAL)
 443                 return rc;
 444         /*
 445          * If the command is not implemented by the TPM, synthesize a
 446          * response with a TPM2_RC_COMMAND_CODE return for user-space.
 447          */
 448         if (rc == -EOPNOTSUPP) {
 449                 header->length = cpu_to_be32(sizeof(*header));
 450                 header->tag = cpu_to_be16(TPM2_ST_NO_SESSIONS);
 451                 header->return_code = cpu_to_be32(TPM2_RC_COMMAND_CODE |
 452                                                   TSS2_RESMGR_TPM_RC_LAYER);
 453                 return sizeof(*header);
 454         }
 455
 456         if (bufsiz > TPM_BUFSIZE)
 457                 bufsiz = TPM_BUFSIZE;
 458
 459         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 460         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 461         if (count == 0)
 462                 return -ENODATA;
 463         if (count > bufsiz) {
 464                 dev_err(&chip->dev,
 465                         "invalid count value %x %zx\n", count, bufsiz);
 466                 return -E2BIG;
 467         }
 468
 469         if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
 470                 mutex_lock(&chip->tpm_mutex);
 471
 472         if (chip->ops->clk_enable != NULL)
 473                 chip->ops->clk_enable(chip, true);
 474
 475         /* Store the decision as chip->locality will be changed. */
 476         need_locality = chip->locality == -1;
 477
 478         if (need_locality) {
 479                 rc = tpm_request_locality(chip, flags);
 480                 if (rc < 0) {
 481                         need_locality = false;
 482                         goto out_locality;
 483                 }
 484         }
 485
 486         rc = tpm_cmd_ready(chip, flags);
 487         if (rc)
 488                 goto out_locality;
 489
 490         rc = tpm2_prepare_space(chip, space, ordinal, buf);
 491         if (rc)
 492                 goto out;
 493
 494         rc = chip->ops->send(chip, buf, count);
 495         if (rc < 0) {
 496                 if (rc != -EPIPE)
 497                         dev_err(&chip->dev,
 498                                 "%s: send(): error %d\n", __func__, rc);
 499                 goto out;
 500         }
 501
 502         /* A sanity check. send() should just return zero on success e.g.
 503          * not the command length.
 504          */
 505         if (rc > 0) {
 506                 dev_warn(&chip->dev,
 507                          "%s: send(): invalid value %d\n", __func__, rc);
 508                 rc = 0;
 509         }
 510
 511         if (chip->flags & TPM_CHIP_FLAG_IRQ)
 512                 goto out_recv;
 513
 514         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 515                 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
 516         else
 517                 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 518         do {
 519                 u8 status = chip->ops->status(chip);
 520                 if ((status & chip->ops->req_complete_mask) ==
 521                     chip->ops->req_complete_val)
 522                         goto out_recv;
 523
 524                 if (chip->ops->req_canceled(chip, status)) {
 525                         dev_err(&chip->dev, "Operation Canceled\n");
 526                         rc = -ECANCELED;
 527                         goto out;
 528                 }
 529
 530                 tpm_msleep(TPM_TIMEOUT_POLL);
 531                 rmb();
 532         } while (time_before(jiffies, stop));
 533
 534         chip->ops->cancel(chip);
 535         dev_err(&chip->dev, "Operation Timed out\n");
 536         rc = -ETIME;
 537         goto out;
 538
 539 out_recv:
 540         len = chip->ops->recv(chip, buf, bufsiz);
 541         if (len < 0) {
 542                 rc = len;
 543                 dev_err(&chip->dev,
 544                         "tpm_transmit: tpm_recv: error %d\n", rc);
 545                 goto out;
 546         } else if (len < TPM_HEADER_SIZE) {
 547                 rc = -EFAULT;
 548                 goto out;
 549         }
 550
 551         if (len != be32_to_cpu(header->length)) {
 552                 rc = -EFAULT;
 553                 goto out;
 554         }
 555
 556         rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
 557         if (rc)
 558                 dev_err(&chip->dev, "tpm2_commit_space: error %d\n", rc);
 559
 560 out:
 561         /* may fail but do not override previous error value in rc */
 562         tpm_go_idle(chip, flags);
 563
 564 out_locality:
 565         if (need_locality)
 566                 tpm_relinquish_locality(chip, flags);
 567
 568         if (chip->ops->clk_enable != NULL)
 569                 chip->ops->clk_enable(chip, false);
 570
 571         if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
 572                 mutex_unlock(&chip->tpm_mutex);
 573         return rc ? rc : len;
 574 }
 575
 576 /**
 577  * tpm_transmit - Internal kernel interface to transmit TPM commands.
 578  *
 579  * @chip: TPM chip to use
 580  * @space: tpm space
 581  * @buf: TPM command buffer
 582  * @bufsiz: length of the TPM command buffer
 583  * @flags: tpm transmit flags - bitmap
 584  *
 585  * A wrapper around tpm_try_transmit that handles TPM2_RC_RETRY
 586  * returns from the TPM and retransmits the command after a delay up
 587  * to a maximum wait of TPM2_DURATION_LONG.
 588  *
 589  * Note: TPM1 never returns TPM2_RC_RETRY so the retry logic is TPM2
 590  * only
 591  *
 592  * Return:
 593  *     the length of the return when the operation is successful.
 594  *     A negative number for system errors (errno).
 595  */
 596 ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
 597                      u8 *buf, size_t bufsiz, unsigned int flags)
 598 {
 599         struct tpm_output_header *header = (struct tpm_output_header *)buf;
 600         /* space for header and handles */
 601         u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
 602         unsigned int delay_msec = TPM2_DURATION_SHORT;
 603         u32 rc = 0;
 604         ssize_t ret;
 605         const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
 606                                      bufsiz);
 607         /* the command code is where the return code will be */
 608         u32 cc = be32_to_cpu(header->return_code);
 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 && rc != TPM2_RC_TESTING)
 623                         break;
 624                 /*
 625                  * return immediately if self test returns test
 626                  * still running to shorten boot time.
 627                  */
 628                 if (rc == TPM2_RC_TESTING && cc == TPM2_CC_SELF_TEST)
 629                         break;
 630
 631                 if (delay_msec > TPM2_DURATION_LONG) {
 632                         if (rc == TPM2_RC_RETRY)
 633                                 dev_err(&chip->dev, "in retry loop\n");
 634                         else
 635                                 dev_err(&chip->dev,
 636                                         "self test is still running\n");
 637                         break;
 638                 }
 639                 tpm_msleep(delay_msec);
 640                 delay_msec *= 2;
 641                 memcpy(buf, save, save_size);
 642         }
 643         return ret;
 644 }
 645 /**
 646  * tpm_transmit_cmd - send a tpm command to the device
 647  *    The function extracts tpm out header return code
 648  *
 649  * @chip: TPM chip to use
 650  * @space: tpm space
 651  * @buf: TPM command buffer
 652  * @bufsiz: length of the buffer
 653  * @min_rsp_body_length: minimum expected length of response body
 654  * @flags: tpm transmit flags - bitmap
 655  * @desc: command description used in the error message
 656  *
 657  * Return:
 658  *     0 when the operation is successful.
 659  *     A negative number for system errors (errno).
 660  *     A positive number for a TPM error.
 661  */
 662 ssize_t tpm_transmit_cmd(struct tpm_chip *chip, struct tpm_space *space,
 663                          void *buf, size_t bufsiz,
 664                          size_t min_rsp_body_length, unsigned int flags,
 665                          const char *desc)
 666 {
 667         const struct tpm_output_header *header = buf;
 668         int err;
 669         ssize_t len;
 670
 671         len = tpm_transmit(chip, space, buf, bufsiz, flags);
 672         if (len <  0)
 673                 return len;
 674
 675         err = be32_to_cpu(header->return_code);
 676         if (err != 0 && err != TPM_ERR_DISABLED && err != TPM_ERR_DEACTIVATED
 677             && desc)
 678                 dev_err(&chip->dev, "A TPM error (%d) occurred %s\n", err,
 679                         desc);
 680         if (err)
 681                 return err;
 682
 683         if (len < min_rsp_body_length + TPM_HEADER_SIZE)
 684                 return -EFAULT;
 685
 686         return 0;
 687 }
 688 EXPORT_SYMBOL_GPL(tpm_transmit_cmd);
 689
 690 #define TPM_ORD_STARTUP 153
 691 #define TPM_ST_CLEAR 1
 692
 693 /**
 694  * tpm_startup - turn on the TPM
 695  * @chip: TPM chip to use
 696  *
 697  * Normally the firmware should start the TPM. This function is provided as a
 698  * workaround if this does not happen. A legal case for this could be for
 699  * example when a TPM emulator is used.
 700  *
 701  * Return: same as tpm_transmit_cmd()
 702  */
 703 int tpm_startup(struct tpm_chip *chip)
 704 {
 705         struct tpm_buf buf;
 706         int rc;
 707
 708         dev_info(&chip->dev, "starting up the TPM manually\n");
 709
 710         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 711                 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
 712                 if (rc < 0)
 713                         return rc;
 714
 715                 tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
 716         } else {
 717                 rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_STARTUP);
 718                 if (rc < 0)
 719                         return rc;
 720
 721                 tpm_buf_append_u16(&buf, TPM_ST_CLEAR);
 722         }
 723
 724         rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
 725                               "attempting to start the TPM");
 726
 727         tpm_buf_destroy(&buf);
 728         return rc;
 729 }
 730
 731 #define TPM_DIGEST_SIZE 20
 732 #define TPM_RET_CODE_IDX 6
 733 #define TPM_INTERNAL_RESULT_SIZE 200
 734 #define TPM_ORD_GET_CAP 101
 735 #define TPM_ORD_GET_RANDOM 70
 736
 737 static const struct tpm_input_header tpm_getcap_header = {
 738         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
 739         .length = cpu_to_be32(22),
 740         .ordinal = cpu_to_be32(TPM_ORD_GET_CAP)
 741 };
 742
 743 ssize_t tpm_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,
 744                    const char *desc, size_t min_cap_length)
 745 {
 746         struct tpm_buf buf;
 747         int rc;
 748
 749         rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_GET_CAP);
 750         if (rc)
 751                 return rc;
 752
 753         if (subcap_id == TPM_CAP_VERSION_1_1 ||
 754             subcap_id == TPM_CAP_VERSION_1_2) {
 755                 tpm_buf_append_u32(&buf, subcap_id);
 756                 tpm_buf_append_u32(&buf, 0);
 757         } else {
 758                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 759                     subcap_id == TPM_CAP_FLAG_VOL)
 760                         tpm_buf_append_u32(&buf, TPM_CAP_FLAG);
 761                 else
 762                         tpm_buf_append_u32(&buf, TPM_CAP_PROP);
 763
 764                 tpm_buf_append_u32(&buf, 4);
 765                 tpm_buf_append_u32(&buf, subcap_id);
 766         }
 767         rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
 768                               min_cap_length, 0, desc);
 769         if (!rc)
 770                 *cap = *(cap_t *)&buf.data[TPM_HEADER_SIZE + 4];
 771
 772         tpm_buf_destroy(&buf);
 773         return rc;
 774 }
 775 EXPORT_SYMBOL_GPL(tpm_getcap);
 776
 777 int tpm_get_timeouts(struct tpm_chip *chip)
 778 {
 779         cap_t cap;
 780         unsigned long timeout_old[4], timeout_chip[4], timeout_eff[4];
 781         ssize_t rc;
 782
 783         if (chip->flags & TPM_CHIP_FLAG_HAVE_TIMEOUTS)
 784                 return 0;
 785
 786         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
 787                 /* Fixed timeouts for TPM2 */
 788                 chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
 789                 chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
 790                 chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
 791                 chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
 792                 chip->duration[TPM_SHORT] =
 793                     msecs_to_jiffies(TPM2_DURATION_SHORT);
 794                 chip->duration[TPM_MEDIUM] =
 795                     msecs_to_jiffies(TPM2_DURATION_MEDIUM);
 796                 chip->duration[TPM_LONG] =
 797                     msecs_to_jiffies(TPM2_DURATION_LONG);
 798                 chip->duration[TPM_LONG_LONG] =
 799                     msecs_to_jiffies(TPM2_DURATION_LONG_LONG);
 800
 801                 chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
 802                 return 0;
 803         }
 804
 805         rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
 806                         sizeof(cap.timeout));
 807         if (rc == TPM_ERR_INVALID_POSTINIT) {
 808                 if (tpm_startup(chip))
 809                         return rc;
 810
 811                 rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
 812                                 "attempting to determine the timeouts",
 813                                 sizeof(cap.timeout));
 814         }
 815
 816         if (rc) {
 817                 dev_err(&chip->dev,
 818                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 819                         rc);
 820                 return rc;
 821         }
 822
 823         timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
 824         timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
 825         timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
 826         timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
 827         timeout_chip[0] = be32_to_cpu(cap.timeout.a);
 828         timeout_chip[1] = be32_to_cpu(cap.timeout.b);
 829         timeout_chip[2] = be32_to_cpu(cap.timeout.c);
 830         timeout_chip[3] = be32_to_cpu(cap.timeout.d);
 831         memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
 832
 833         /*
 834          * Provide ability for vendor overrides of timeout values in case
 835          * of misreporting.
 836          */
 837         if (chip->ops->update_timeouts != NULL)
 838                 chip->timeout_adjusted =
 839                         chip->ops->update_timeouts(chip, timeout_eff);
 840
 841         if (!chip->timeout_adjusted) {
 842                 /* Restore default if chip reported 0 */
 843                 int i;
 844
 845                 for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
 846                         if (timeout_eff[i])
 847                                 continue;
 848
 849                         timeout_eff[i] = timeout_old[i];
 850                         chip->timeout_adjusted = true;
 851                 }
 852
 853                 if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
 854                         /* timeouts in msec rather usec */
 855                         for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
 856                                 timeout_eff[i] *= 1000;
 857                         chip->timeout_adjusted = true;
 858                 }
 859         }
 860
 861         /* Report adjusted timeouts */
 862         if (chip->timeout_adjusted) {
 863                 dev_info(&chip->dev,
 864                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 865                          timeout_chip[0], timeout_eff[0],
 866                          timeout_chip[1], timeout_eff[1],
 867                          timeout_chip[2], timeout_eff[2],
 868                          timeout_chip[3], timeout_eff[3]);
 869         }
 870
 871         chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
 872         chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
 873         chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
 874         chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
 875
 876         rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
 877                         "attempting to determine the durations",
 878                         sizeof(cap.duration));
 879         if (rc)
 880                 return rc;
 881
 882         chip->duration[TPM_SHORT] =
 883                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
 884         chip->duration[TPM_MEDIUM] =
 885                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
 886         chip->duration[TPM_LONG] =
 887                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
 888         chip->duration[TPM_LONG_LONG] = 0; /* not used under 1.2 */
 889
 890         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 891          * value wrong and apparently reports msecs rather than usecs. So we
 892          * fix up the resulting too-small TPM_SHORT value to make things work.
 893          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 894          */
 895         if (chip->duration[TPM_SHORT] < (HZ / 100)) {
 896                 chip->duration[TPM_SHORT] = HZ;
 897                 chip->duration[TPM_MEDIUM] *= 1000;
 898                 chip->duration[TPM_LONG] *= 1000;
 899                 chip->duration_adjusted = true;
 900                 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 901         }
 902
 903         chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
 904         return 0;
 905 }
 906 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 907
 908 #define TPM_ORD_CONTINUE_SELFTEST 83
 909 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 910
 911 static const struct tpm_input_header continue_selftest_header = {
 912         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
 913         .length = cpu_to_be32(10),
 914         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 915 };
 916
 917 /**
 918  * tpm_continue_selftest -- run TPM's selftest
 919  * @chip: TPM chip to use
 920  *
 921  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 922  * a TPM error code.
 923  */
 924 static int tpm_continue_selftest(struct tpm_chip *chip)
 925 {
 926         int rc;
 927         struct tpm_cmd_t cmd;
 928
 929         cmd.header.in = continue_selftest_header;
 930         rc = tpm_transmit_cmd(chip, NULL, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 931                               0, 0, "continue selftest");
 932         return rc;
 933 }
 934
 935 #define TPM_ORDINAL_PCRREAD 21
 936 #define READ_PCR_RESULT_SIZE 30
 937 #define READ_PCR_RESULT_BODY_SIZE 20
 938 static const struct tpm_input_header pcrread_header = {
 939         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
 940         .length = cpu_to_be32(14),
 941         .ordinal = cpu_to_be32(TPM_ORDINAL_PCRREAD)
 942 };
 943
 944 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 945 {
 946         int rc;
 947         struct tpm_cmd_t cmd;
 948
 949         cmd.header.in = pcrread_header;
 950         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 951         rc = tpm_transmit_cmd(chip, NULL, &cmd, READ_PCR_RESULT_SIZE,
 952                               READ_PCR_RESULT_BODY_SIZE, 0,
 953                               "attempting to read a pcr value");
 954
 955         if (rc == 0)
 956                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 957                        TPM_DIGEST_SIZE);
 958         return rc;
 959 }
 960
 961 /**
 962  * tpm_is_tpm2 - do we a have a TPM2 chip?
 963  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
 964  *
 965  * Return:
 966  * 1 if we have a TPM2 chip.
 967  * 0 if we don't have a TPM2 chip.
 968  * A negative number for system errors (errno).
 969  */
 970 int tpm_is_tpm2(struct tpm_chip *chip)
 971 {
 972         int rc;
 973
 974         chip = tpm_find_get_ops(chip);
 975         if (!chip)
 976                 return -ENODEV;
 977
 978         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 979
 980         tpm_put_ops(chip);
 981
 982         return rc;
 983 }
 984 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 985
 986 /**
 987  * tpm_pcr_read - read a PCR value from SHA1 bank
 988  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
 989  * @pcr_idx:    the PCR to be retrieved
 990  * @res_buf:    the value of the PCR
 991  *
 992  * Return: same as with tpm_transmit_cmd()
 993  */
 994 int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 995 {
 996         int rc;
 997
 998         chip = tpm_find_get_ops(chip);
 999         if (!chip)
1000                 return -ENODEV;
1001         if (chip->flags & TPM_CHIP_FLAG_TPM2)
1002                 rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
1003         else
1004                 rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
1005         tpm_put_ops(chip);
1006         return rc;
1007 }
1008 EXPORT_SYMBOL_GPL(tpm_pcr_read);
1009
1010 #define TPM_ORD_PCR_EXTEND 20
1011 #define EXTEND_PCR_RESULT_SIZE 34
1012 #define EXTEND_PCR_RESULT_BODY_SIZE 20
1013 static const struct tpm_input_header pcrextend_header = {
1014         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1015         .length = cpu_to_be32(34),
1016         .ordinal = cpu_to_be32(TPM_ORD_PCR_EXTEND)
1017 };
1018
1019 static int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash,
1020                            char *log_msg)
1021 {
1022         struct tpm_buf buf;
1023         int rc;
1024
1025         rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCR_EXTEND);
1026         if (rc)
1027                 return rc;
1028
1029         tpm_buf_append_u32(&buf, pcr_idx);
1030         tpm_buf_append(&buf, hash, TPM_DIGEST_SIZE);
1031
1032         rc = tpm_transmit_cmd(chip, NULL, buf.data, EXTEND_PCR_RESULT_SIZE,
1033                               EXTEND_PCR_RESULT_BODY_SIZE, 0, log_msg);
1034         tpm_buf_destroy(&buf);
1035         return rc;
1036 }
1037
1038 /**
1039  * tpm_pcr_extend - extend a PCR value in SHA1 bank.
1040  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
1041  * @pcr_idx:    the PCR to be retrieved
1042  * @hash:       the hash value used to extend the PCR value
1043  *
1044  * Note: with TPM 2.0 extends also those banks with a known digest size to the
1045  * cryto subsystem in order to prevent malicious use of those PCR banks. In the
1046  * future we should dynamically determine digest sizes.
1047  *
1048  * Return: same as with tpm_transmit_cmd()
1049  */
1050 int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
1051 {
1052         int rc;
1053         struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
1054         u32 count = 0;
1055         int i;
1056
1057         chip = tpm_find_get_ops(chip);
1058         if (!chip)
1059                 return -ENODEV;
1060
1061         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1062                 memset(digest_list, 0, sizeof(digest_list));
1063
1064                 for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
1065                             chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
1066                         digest_list[i].alg_id = chip->active_banks[i];
1067                         memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
1068                         count++;
1069                 }
1070
1071                 rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);
1072                 tpm_put_ops(chip);
1073                 return rc;
1074         }
1075
1076         rc = tpm1_pcr_extend(chip, pcr_idx, hash,
1077                              "attempting extend a PCR value");
1078         tpm_put_ops(chip);
1079         return rc;
1080 }
1081 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
1082
1083 /**
1084  * tpm_do_selftest - have the TPM continue its selftest and wait until it
1085  *                   can receive further commands
1086  * @chip: TPM chip to use
1087  *
1088  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
1089  * a TPM error code.
1090  */
1091 int tpm_do_selftest(struct tpm_chip *chip)
1092 {
1093         int rc;
1094         unsigned int loops;
1095         unsigned int delay_msec = 100;
1096         unsigned long duration;
1097         u8 dummy[TPM_DIGEST_SIZE];
1098
1099         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
1100
1101         loops = jiffies_to_msecs(duration) / delay_msec;
1102
1103         rc = tpm_continue_selftest(chip);
1104         if (rc == TPM_ERR_INVALID_POSTINIT) {
1105                 chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
1106                 dev_info(&chip->dev, "TPM not ready (%d)\n", rc);
1107         }
1108         /* This may fail if there was no TPM driver during a suspend/resume
1109          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
1110          */
1111         if (rc)
1112                 return rc;
1113
1114         do {
1115                 /* Attempt to read a PCR value */
1116                 rc = tpm_pcr_read_dev(chip, 0, dummy);
1117
1118                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
1119                  * around 300ms while the self test is ongoing, keep trying
1120                  * until the self test duration expires. */
1121                 if (rc == -ETIME) {
1122                         dev_info(
1123                             &chip->dev, HW_ERR
1124                             "TPM command timed out during continue self test");
1125                         tpm_msleep(delay_msec);
1126                         continue;
1127                 }
1128
1129                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
1130                         dev_info(&chip->dev,
1131                                  "TPM is disabled/deactivated (0x%X)\n", rc);
1132                         /* TPM is disabled and/or deactivated; driver can
1133                          * proceed and TPM does handle commands for
1134                          * suspend/resume correctly
1135                          */
1136                         return 0;
1137                 }
1138                 if (rc != TPM_WARN_DOING_SELFTEST)
1139                         return rc;
1140                 tpm_msleep(delay_msec);
1141         } while (--loops > 0);
1142
1143         return rc;
1144 }
1145 EXPORT_SYMBOL_GPL(tpm_do_selftest);
1146
1147 /**
1148  * tpm1_auto_startup - Perform the standard automatic TPM initialization
1149  *                     sequence
1150  * @chip: TPM chip to use
1151  *
1152  * Returns 0 on success, < 0 in case of fatal error.
1153  */
1154 int tpm1_auto_startup(struct tpm_chip *chip)
1155 {
1156         int rc;
1157
1158         rc = tpm_get_timeouts(chip);
1159         if (rc)
1160                 goto out;
1161         rc = tpm_do_selftest(chip);
1162         if (rc) {
1163                 dev_err(&chip->dev, "TPM self test failed\n");
1164                 goto out;
1165         }
1166
1167         return rc;
1168 out:
1169         if (rc > 0)
1170                 rc = -ENODEV;
1171         return rc;
1172 }
1173
1174 /**
1175  * tpm_send - send a TPM command
1176  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
1177  * @cmd:        a TPM command buffer
1178  * @buflen:     the length of the TPM command buffer
1179  *
1180  * Return: same as with tpm_transmit_cmd()
1181  */
1182 int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
1183 {
1184         int rc;
1185
1186         chip = tpm_find_get_ops(chip);
1187         if (!chip)
1188                 return -ENODEV;
1189
1190         rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0,
1191                               "attempting to a send a command");
1192         tpm_put_ops(chip);
1193         return rc;
1194 }
1195 EXPORT_SYMBOL_GPL(tpm_send);
1196
1197 #define TPM_ORD_SAVESTATE 152
1198 #define SAVESTATE_RESULT_SIZE 10
1199
1200 static const struct tpm_input_header savestate_header = {
1201         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1202         .length = cpu_to_be32(10),
1203         .ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)
1204 };
1205
1206 /*
1207  * We are about to suspend. Save the TPM state
1208  * so that it can be restored.
1209  */
1210 int tpm_pm_suspend(struct device *dev)
1211 {
1212         struct tpm_chip *chip = dev_get_drvdata(dev);
1213         struct tpm_cmd_t cmd;
1214         int rc, try;
1215
1216         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1217
1218         if (chip == NULL)
1219                 return -ENODEV;
1220
1221         if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
1222                 return 0;
1223
1224         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1225                 tpm2_shutdown(chip, TPM2_SU_STATE);
1226                 return 0;
1227         }
1228
1229         /* for buggy tpm, flush pcrs with extend to selected dummy */
1230         if (tpm_suspend_pcr)
1231                 rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
1232                                      "extending dummy pcr before suspend");
1233
1234         /* now do the actual savestate */
1235         for (try = 0; try < TPM_RETRY; try++) {
1236                 cmd.header.in = savestate_header;
1237                 rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,
1238                                       0, 0, NULL);
1239
1240                 /*
1241                  * If the TPM indicates that it is too busy to respond to
1242                  * this command then retry before giving up.  It can take
1243                  * several seconds for this TPM to be ready.
1244                  *
1245                  * This can happen if the TPM has already been sent the
1246                  * SaveState command before the driver has loaded.  TCG 1.2
1247                  * specification states that any communication after SaveState
1248                  * may cause the TPM to invalidate previously saved state.
1249                  */
1250                 if (rc != TPM_WARN_RETRY)
1251                         break;
1252                 tpm_msleep(TPM_TIMEOUT_RETRY);
1253         }
1254
1255         if (rc)
1256                 dev_err(&chip->dev,
1257                         "Error (%d) sending savestate before suspend\n", rc);
1258         else if (try > 0)
1259                 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1260                          try * TPM_TIMEOUT_RETRY);
1261
1262         return rc;
1263 }
1264 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1265
1266 /*
1267  * Resume from a power safe. The BIOS already restored
1268  * the TPM state.
1269  */
1270 int tpm_pm_resume(struct device *dev)
1271 {
1272         struct tpm_chip *chip = dev_get_drvdata(dev);
1273
1274         if (chip == NULL)
1275                 return -ENODEV;
1276
1277         return 0;
1278 }
1279 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1280
1281 #define TPM_GETRANDOM_RESULT_SIZE       18
1282 static const struct tpm_input_header tpm_getrandom_header = {
1283         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1284         .length = cpu_to_be32(14),
1285         .ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
1286 };
1287
1288 /**
1289  * tpm_get_random() - get random bytes from the TPM's RNG
1290  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
1291  * @out:        destination buffer for the random bytes
1292  * @max:        the max number of bytes to write to @out
1293  *
1294  * Return: same as with tpm_transmit_cmd()
1295  */
1296 int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
1297 {
1298         struct tpm_cmd_t tpm_cmd;
1299         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
1300         int err, total = 0, retries = 5;
1301         u8 *dest = out;
1302
1303         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1304                 return -EINVAL;
1305
1306         chip = tpm_find_get_ops(chip);
1307         if (!chip)
1308                 return -ENODEV;
1309
1310         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1311                 err = tpm2_get_random(chip, out, max);
1312                 tpm_put_ops(chip);
1313                 return err;
1314         }
1315
1316         do {
1317                 tpm_cmd.header.in = tpm_getrandom_header;
1318                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1319
1320                 err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
1321                                        TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1322                                        offsetof(struct tpm_getrandom_out,
1323                                                 rng_data),
1324                                        0, "attempting get random");
1325                 if (err)
1326                         break;
1327
1328                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1329                 if (recd > num_bytes) {
1330                         total = -EFAULT;
1331                         break;
1332                 }
1333
1334                 rlength = be32_to_cpu(tpm_cmd.header.out.length);
1335                 if (rlength < TPM_HEADER_SIZE +
1336                               offsetof(struct tpm_getrandom_out, rng_data) +
1337                               recd) {
1338                         total = -EFAULT;
1339                         break;
1340                 }
1341                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1342
1343                 dest += recd;
1344                 total += recd;
1345                 num_bytes -= recd;
1346         } while (retries-- && total < max);
1347
1348         tpm_put_ops(chip);
1349         return total ? total : -EIO;
1350 }
1351 EXPORT_SYMBOL_GPL(tpm_get_random);
1352
1353 /**
1354  * tpm_seal_trusted() - seal a trusted key payload
1355  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
1356  * @options:    authentication values and other options
1357  * @payload:    the key data in clear and encrypted form
1358  *
1359  * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
1360  * the keyring subsystem.
1361  *
1362  * Return: same as with tpm_transmit_cmd()
1363  */
1364 int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload,
1365                      struct trusted_key_options *options)
1366 {
1367         int rc;
1368
1369         chip = tpm_find_get_ops(chip);
1370         if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1371                 return -ENODEV;
1372
1373         rc = tpm2_seal_trusted(chip, payload, options);
1374
1375         tpm_put_ops(chip);
1376         return rc;
1377 }
1378 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1379
1380 /**
1381  * tpm_unseal_trusted() - unseal a trusted key
1382  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
1383  * @options:    authentication values and other options
1384  * @payload:    the key data in clear and encrypted form
1385  *
1386  * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
1387  * the keyring subsystem.
1388  *
1389  * Return: same as with tpm_transmit_cmd()
1390  */
1391 int tpm_unseal_trusted(struct tpm_chip *chip,
1392                        struct trusted_key_payload *payload,
1393                        struct trusted_key_options *options)
1394 {
1395         int rc;
1396
1397         chip = tpm_find_get_ops(chip);
1398         if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1399                 return -ENODEV;
1400
1401         rc = tpm2_unseal_trusted(chip, payload, options);
1402
1403         tpm_put_ops(chip);
1404
1405         return rc;
1406 }
1407 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1408
1409 static int __init tpm_init(void)
1410 {
1411         int rc;
1412
1413         tpm_class = class_create(THIS_MODULE, "tpm");
1414         if (IS_ERR(tpm_class)) {
1415                 pr_err("couldn't create tpm class\n");
1416                 return PTR_ERR(tpm_class);
1417         }
1418
1419         tpmrm_class = class_create(THIS_MODULE, "tpmrm");
1420         if (IS_ERR(tpmrm_class)) {
1421                 pr_err("couldn't create tpmrm class\n");
1422                 class_destroy(tpm_class);
1423                 return PTR_ERR(tpmrm_class);
1424         }
1425
1426         rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm");
1427         if (rc < 0) {
1428                 pr_err("tpm: failed to allocate char dev region\n");
1429                 class_destroy(tpmrm_class);
1430                 class_destroy(tpm_class);
1431                 return rc;
1432         }
1433
1434         return 0;
1435 }
1436
1437 static void __exit tpm_exit(void)
1438 {
1439         idr_destroy(&dev_nums_idr);
1440         class_destroy(tpm_class);
1441         class_destroy(tpmrm_class);
1442         unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
1443 }
1444
1445 subsys_initcall(tpm_init);
1446 module_exit(tpm_exit);
1447
1448 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1449 MODULE_DESCRIPTION("TPM Driver");
1450 MODULE_VERSION("2.0");
1451 MODULE_LICENSE("GPL");