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                         goto out_no_locality;
 482         }
 483
 484         rc = tpm_cmd_ready(chip, flags);
 485         if (rc)
 486                 goto out;
 487
 488         rc = tpm2_prepare_space(chip, space, ordinal, buf);
 489         if (rc)
 490                 goto out;
 491
 492         rc = chip->ops->send(chip, buf, count);
 493         if (rc < 0) {
 494                 if (rc != -EPIPE)
 495                         dev_err(&chip->dev,
 496                                 "%s: tpm_send: error %d\n", __func__, rc);
 497                 goto out;
 498         }
 499
 500         if (chip->flags & TPM_CHIP_FLAG_IRQ)
 501                 goto out_recv;
 502
 503         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 504                 stop = jiffies + tpm2_calc_ordinal_duration(chip, ordinal);
 505         else
 506                 stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 507         do {
 508                 u8 status = chip->ops->status(chip);
 509                 if ((status & chip->ops->req_complete_mask) ==
 510                     chip->ops->req_complete_val)
 511                         goto out_recv;
 512
 513                 if (chip->ops->req_canceled(chip, status)) {
 514                         dev_err(&chip->dev, "Operation Canceled\n");
 515                         rc = -ECANCELED;
 516                         goto out;
 517                 }
 518
 519                 tpm_msleep(TPM_TIMEOUT_POLL);
 520                 rmb();
 521         } while (time_before(jiffies, stop));
 522
 523         chip->ops->cancel(chip);
 524         dev_err(&chip->dev, "Operation Timed out\n");
 525         rc = -ETIME;
 526         goto out;
 527
 528 out_recv:
 529         len = chip->ops->recv(chip, buf, bufsiz);
 530         if (len < 0) {
 531                 rc = len;
 532                 dev_err(&chip->dev,
 533                         "tpm_transmit: tpm_recv: error %d\n", rc);
 534                 goto out;
 535         } else if (len < TPM_HEADER_SIZE) {
 536                 rc = -EFAULT;
 537                 goto out;
 538         }
 539
 540         if (len != be32_to_cpu(header->length)) {
 541                 rc = -EFAULT;
 542                 goto out;
 543         }
 544
 545         rc = tpm2_commit_space(chip, space, ordinal, buf, &len);
 546         if (rc)
 547                 dev_err(&chip->dev, "tpm2_commit_space: error %d\n", rc);
 548
 549 out:
 550         rc = tpm_go_idle(chip, flags);
 551         if (rc)
 552                 goto out;
 553
 554         if (need_locality)
 555                 tpm_relinquish_locality(chip, flags);
 556
 557 out_no_locality:
 558         if (chip->ops->clk_enable != NULL)
 559                 chip->ops->clk_enable(chip, false);
 560
 561         if (!(flags & TPM_TRANSMIT_UNLOCKED) && !(flags & TPM_TRANSMIT_NESTED))
 562                 mutex_unlock(&chip->tpm_mutex);
 563         return rc ? rc : len;
 564 }
 565
 566 /**
 567  * tpm_transmit - Internal kernel interface to transmit TPM commands.
 568  *
 569  * @chip: TPM chip to use
 570  * @space: tpm space
 571  * @buf: TPM command buffer
 572  * @bufsiz: length of the TPM command buffer
 573  * @flags: tpm transmit flags - bitmap
 574  *
 575  * A wrapper around tpm_try_transmit that handles TPM2_RC_RETRY
 576  * returns from the TPM and retransmits the command after a delay up
 577  * to a maximum wait of TPM2_DURATION_LONG.
 578  *
 579  * Note: TPM1 never returns TPM2_RC_RETRY so the retry logic is TPM2
 580  * only
 581  *
 582  * Return:
 583  *     the length of the return when the operation is successful.
 584  *     A negative number for system errors (errno).
 585  */
 586 ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space,
 587                      u8 *buf, size_t bufsiz, unsigned int flags)
 588 {
 589         struct tpm_output_header *header = (struct tpm_output_header *)buf;
 590         /* space for header and handles */
 591         u8 save[TPM_HEADER_SIZE + 3*sizeof(u32)];
 592         unsigned int delay_msec = TPM2_DURATION_SHORT;
 593         u32 rc = 0;
 594         ssize_t ret;
 595         const size_t save_size = min(space ? sizeof(save) : TPM_HEADER_SIZE,
 596                                      bufsiz);
 597         /* the command code is where the return code will be */
 598         u32 cc = be32_to_cpu(header->return_code);
 599
 600         /*
 601          * Subtlety here: if we have a space, the handles will be
 602          * transformed, so when we restore the header we also have to
 603          * restore the handles.
 604          */
 605         memcpy(save, buf, save_size);
 606
 607         for (;;) {
 608                 ret = tpm_try_transmit(chip, space, buf, bufsiz, flags);
 609                 if (ret < 0)
 610                         break;
 611                 rc = be32_to_cpu(header->return_code);
 612                 if (rc != TPM2_RC_RETRY && rc != TPM2_RC_TESTING)
 613                         break;
 614                 /*
 615                  * return immediately if self test returns test
 616                  * still running to shorten boot time.
 617                  */
 618                 if (rc == TPM2_RC_TESTING && cc == TPM2_CC_SELF_TEST)
 619                         break;
 620
 621                 if (delay_msec > TPM2_DURATION_LONG) {
 622                         if (rc == TPM2_RC_RETRY)
 623                                 dev_err(&chip->dev, "in retry loop\n");
 624                         else
 625                                 dev_err(&chip->dev,
 626                                         "self test is still running\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                          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, 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                 chip->duration[TPM_LONG_LONG] =
 789                     msecs_to_jiffies(TPM2_DURATION_LONG_LONG);
 790
 791                 chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
 792                 return 0;
 793         }
 794
 795         rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, NULL,
 796                         sizeof(cap.timeout));
 797         if (rc == TPM_ERR_INVALID_POSTINIT) {
 798                 if (tpm_startup(chip))
 799                         return rc;
 800
 801                 rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap,
 802                                 "attempting to determine the timeouts",
 803                                 sizeof(cap.timeout));
 804         }
 805
 806         if (rc) {
 807                 dev_err(&chip->dev,
 808                         "A TPM error (%zd) occurred attempting to determine the timeouts\n",
 809                         rc);
 810                 return rc;
 811         }
 812
 813         timeout_old[0] = jiffies_to_usecs(chip->timeout_a);
 814         timeout_old[1] = jiffies_to_usecs(chip->timeout_b);
 815         timeout_old[2] = jiffies_to_usecs(chip->timeout_c);
 816         timeout_old[3] = jiffies_to_usecs(chip->timeout_d);
 817         timeout_chip[0] = be32_to_cpu(cap.timeout.a);
 818         timeout_chip[1] = be32_to_cpu(cap.timeout.b);
 819         timeout_chip[2] = be32_to_cpu(cap.timeout.c);
 820         timeout_chip[3] = be32_to_cpu(cap.timeout.d);
 821         memcpy(timeout_eff, timeout_chip, sizeof(timeout_eff));
 822
 823         /*
 824          * Provide ability for vendor overrides of timeout values in case
 825          * of misreporting.
 826          */
 827         if (chip->ops->update_timeouts != NULL)
 828                 chip->timeout_adjusted =
 829                         chip->ops->update_timeouts(chip, timeout_eff);
 830
 831         if (!chip->timeout_adjusted) {
 832                 /* Restore default if chip reported 0 */
 833                 int i;
 834
 835                 for (i = 0; i < ARRAY_SIZE(timeout_eff); i++) {
 836                         if (timeout_eff[i])
 837                                 continue;
 838
 839                         timeout_eff[i] = timeout_old[i];
 840                         chip->timeout_adjusted = true;
 841                 }
 842
 843                 if (timeout_eff[0] != 0 && timeout_eff[0] < 1000) {
 844                         /* timeouts in msec rather usec */
 845                         for (i = 0; i != ARRAY_SIZE(timeout_eff); i++)
 846                                 timeout_eff[i] *= 1000;
 847                         chip->timeout_adjusted = true;
 848                 }
 849         }
 850
 851         /* Report adjusted timeouts */
 852         if (chip->timeout_adjusted) {
 853                 dev_info(&chip->dev,
 854                          HW_ERR "Adjusting reported timeouts: A %lu->%luus B %lu->%luus C %lu->%luus D %lu->%luus\n",
 855                          timeout_chip[0], timeout_eff[0],
 856                          timeout_chip[1], timeout_eff[1],
 857                          timeout_chip[2], timeout_eff[2],
 858                          timeout_chip[3], timeout_eff[3]);
 859         }
 860
 861         chip->timeout_a = usecs_to_jiffies(timeout_eff[0]);
 862         chip->timeout_b = usecs_to_jiffies(timeout_eff[1]);
 863         chip->timeout_c = usecs_to_jiffies(timeout_eff[2]);
 864         chip->timeout_d = usecs_to_jiffies(timeout_eff[3]);
 865
 866         rc = tpm_getcap(chip, TPM_CAP_PROP_TIS_DURATION, &cap,
 867                         "attempting to determine the durations",
 868                         sizeof(cap.duration));
 869         if (rc)
 870                 return rc;
 871
 872         chip->duration[TPM_SHORT] =
 873                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_short));
 874         chip->duration[TPM_MEDIUM] =
 875                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_medium));
 876         chip->duration[TPM_LONG] =
 877                 usecs_to_jiffies(be32_to_cpu(cap.duration.tpm_long));
 878         chip->duration[TPM_LONG_LONG] = 0; /* not used under 1.2 */
 879
 880         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 881          * value wrong and apparently reports msecs rather than usecs. So we
 882          * fix up the resulting too-small TPM_SHORT value to make things work.
 883          * We also scale the TPM_MEDIUM and -_LONG values by 1000.
 884          */
 885         if (chip->duration[TPM_SHORT] < (HZ / 100)) {
 886                 chip->duration[TPM_SHORT] = HZ;
 887                 chip->duration[TPM_MEDIUM] *= 1000;
 888                 chip->duration[TPM_LONG] *= 1000;
 889                 chip->duration_adjusted = true;
 890                 dev_info(&chip->dev, "Adjusting TPM timeout parameters.");
 891         }
 892
 893         chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
 894         return 0;
 895 }
 896 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 897
 898 #define TPM_ORD_CONTINUE_SELFTEST 83
 899 #define CONTINUE_SELFTEST_RESULT_SIZE 10
 900
 901 static const struct tpm_input_header continue_selftest_header = {
 902         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
 903         .length = cpu_to_be32(10),
 904         .ordinal = cpu_to_be32(TPM_ORD_CONTINUE_SELFTEST),
 905 };
 906
 907 /**
 908  * tpm_continue_selftest -- run TPM's selftest
 909  * @chip: TPM chip to use
 910  *
 911  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
 912  * a TPM error code.
 913  */
 914 static int tpm_continue_selftest(struct tpm_chip *chip)
 915 {
 916         int rc;
 917         struct tpm_cmd_t cmd;
 918
 919         cmd.header.in = continue_selftest_header;
 920         rc = tpm_transmit_cmd(chip, NULL, &cmd, CONTINUE_SELFTEST_RESULT_SIZE,
 921                               0, 0, "continue selftest");
 922         return rc;
 923 }
 924
 925 #define TPM_ORDINAL_PCRREAD 21
 926 #define READ_PCR_RESULT_SIZE 30
 927 #define READ_PCR_RESULT_BODY_SIZE 20
 928 static const struct tpm_input_header pcrread_header = {
 929         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
 930         .length = cpu_to_be32(14),
 931         .ordinal = cpu_to_be32(TPM_ORDINAL_PCRREAD)
 932 };
 933
 934 int tpm_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 935 {
 936         int rc;
 937         struct tpm_cmd_t cmd;
 938
 939         cmd.header.in = pcrread_header;
 940         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 941         rc = tpm_transmit_cmd(chip, NULL, &cmd, READ_PCR_RESULT_SIZE,
 942                               READ_PCR_RESULT_BODY_SIZE, 0,
 943                               "attempting to read a pcr value");
 944
 945         if (rc == 0)
 946                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 947                        TPM_DIGEST_SIZE);
 948         return rc;
 949 }
 950
 951 /**
 952  * tpm_is_tpm2 - do we a have a TPM2 chip?
 953  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
 954  *
 955  * Return:
 956  * 1 if we have a TPM2 chip.
 957  * 0 if we don't have a TPM2 chip.
 958  * A negative number for system errors (errno).
 959  */
 960 int tpm_is_tpm2(struct tpm_chip *chip)
 961 {
 962         int rc;
 963
 964         chip = tpm_find_get_ops(chip);
 965         if (!chip)
 966                 return -ENODEV;
 967
 968         rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
 969
 970         tpm_put_ops(chip);
 971
 972         return rc;
 973 }
 974 EXPORT_SYMBOL_GPL(tpm_is_tpm2);
 975
 976 /**
 977  * tpm_pcr_read - read a PCR value from SHA1 bank
 978  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
 979  * @pcr_idx:    the PCR to be retrieved
 980  * @res_buf:    the value of the PCR
 981  *
 982  * Return: same as with tpm_transmit_cmd()
 983  */
 984 int tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 985 {
 986         int rc;
 987
 988         chip = tpm_find_get_ops(chip);
 989         if (!chip)
 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 a PCR value in SHA1 bank.
1030  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
1031  * @pcr_idx:    the PCR to be retrieved
1032  * @hash:       the hash value used to extend the PCR value
1033  *
1034  * Note: with TPM 2.0 extends also those banks with a known digest size to the
1035  * cryto subsystem in order to prevent malicious use of those PCR banks. In the
1036  * future we should dynamically determine digest sizes.
1037  *
1038  * Return: same as with tpm_transmit_cmd()
1039  */
1040 int tpm_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
1041 {
1042         int rc;
1043         struct tpm2_digest digest_list[ARRAY_SIZE(chip->active_banks)];
1044         u32 count = 0;
1045         int i;
1046
1047         chip = tpm_find_get_ops(chip);
1048         if (!chip)
1049                 return -ENODEV;
1050
1051         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1052                 memset(digest_list, 0, sizeof(digest_list));
1053
1054                 for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
1055                             chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
1056                         digest_list[i].alg_id = chip->active_banks[i];
1057                         memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
1058                         count++;
1059                 }
1060
1061                 rc = tpm2_pcr_extend(chip, pcr_idx, count, digest_list);
1062                 tpm_put_ops(chip);
1063                 return rc;
1064         }
1065
1066         rc = tpm1_pcr_extend(chip, pcr_idx, hash,
1067                              "attempting extend a PCR value");
1068         tpm_put_ops(chip);
1069         return rc;
1070 }
1071 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
1072
1073 /**
1074  * tpm_do_selftest - have the TPM continue its selftest and wait until it
1075  *                   can receive further commands
1076  * @chip: TPM chip to use
1077  *
1078  * Returns 0 on success, < 0 in case of fatal error or a value > 0 representing
1079  * a TPM error code.
1080  */
1081 int tpm_do_selftest(struct tpm_chip *chip)
1082 {
1083         int rc;
1084         unsigned int loops;
1085         unsigned int delay_msec = 100;
1086         unsigned long duration;
1087         u8 dummy[TPM_DIGEST_SIZE];
1088
1089         duration = tpm_calc_ordinal_duration(chip, TPM_ORD_CONTINUE_SELFTEST);
1090
1091         loops = jiffies_to_msecs(duration) / delay_msec;
1092
1093         rc = tpm_continue_selftest(chip);
1094         if (rc == TPM_ERR_INVALID_POSTINIT) {
1095                 chip->flags |= TPM_CHIP_FLAG_ALWAYS_POWERED;
1096                 dev_info(&chip->dev, "TPM not ready (%d)\n", rc);
1097         }
1098         /* This may fail if there was no TPM driver during a suspend/resume
1099          * cycle; some may return 10 (BAD_ORDINAL), others 28 (FAILEDSELFTEST)
1100          */
1101         if (rc)
1102                 return rc;
1103
1104         do {
1105                 /* Attempt to read a PCR value */
1106                 rc = tpm_pcr_read_dev(chip, 0, dummy);
1107
1108                 /* Some buggy TPMs will not respond to tpm_tis_ready() for
1109                  * around 300ms while the self test is ongoing, keep trying
1110                  * until the self test duration expires. */
1111                 if (rc == -ETIME) {
1112                         dev_info(
1113                             &chip->dev, HW_ERR
1114                             "TPM command timed out during continue self test");
1115                         tpm_msleep(delay_msec);
1116                         continue;
1117                 }
1118
1119                 if (rc == TPM_ERR_DISABLED || rc == TPM_ERR_DEACTIVATED) {
1120                         dev_info(&chip->dev,
1121                                  "TPM is disabled/deactivated (0x%X)\n", rc);
1122                         /* TPM is disabled and/or deactivated; driver can
1123                          * proceed and TPM does handle commands for
1124                          * suspend/resume correctly
1125                          */
1126                         return 0;
1127                 }
1128                 if (rc != TPM_WARN_DOING_SELFTEST)
1129                         return rc;
1130                 tpm_msleep(delay_msec);
1131         } while (--loops > 0);
1132
1133         return rc;
1134 }
1135 EXPORT_SYMBOL_GPL(tpm_do_selftest);
1136
1137 /**
1138  * tpm1_auto_startup - Perform the standard automatic TPM initialization
1139  *                     sequence
1140  * @chip: TPM chip to use
1141  *
1142  * Returns 0 on success, < 0 in case of fatal error.
1143  */
1144 int tpm1_auto_startup(struct tpm_chip *chip)
1145 {
1146         int rc;
1147
1148         rc = tpm_get_timeouts(chip);
1149         if (rc)
1150                 goto out;
1151         rc = tpm_do_selftest(chip);
1152         if (rc) {
1153                 dev_err(&chip->dev, "TPM self test failed\n");
1154                 goto out;
1155         }
1156
1157         return rc;
1158 out:
1159         if (rc > 0)
1160                 rc = -ENODEV;
1161         return rc;
1162 }
1163
1164 /**
1165  * tpm_send - send a TPM command
1166  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
1167  * @cmd:        a TPM command buffer
1168  * @buflen:     the length of the TPM command buffer
1169  *
1170  * Return: same as with tpm_transmit_cmd()
1171  */
1172 int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
1173 {
1174         int rc;
1175
1176         chip = tpm_find_get_ops(chip);
1177         if (!chip)
1178                 return -ENODEV;
1179
1180         rc = tpm_transmit_cmd(chip, NULL, cmd, buflen, 0, 0,
1181                               "attempting to a send a command");
1182         tpm_put_ops(chip);
1183         return rc;
1184 }
1185 EXPORT_SYMBOL_GPL(tpm_send);
1186
1187 #define TPM_ORD_SAVESTATE 152
1188 #define SAVESTATE_RESULT_SIZE 10
1189
1190 static const struct tpm_input_header savestate_header = {
1191         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1192         .length = cpu_to_be32(10),
1193         .ordinal = cpu_to_be32(TPM_ORD_SAVESTATE)
1194 };
1195
1196 /*
1197  * We are about to suspend. Save the TPM state
1198  * so that it can be restored.
1199  */
1200 int tpm_pm_suspend(struct device *dev)
1201 {
1202         struct tpm_chip *chip = dev_get_drvdata(dev);
1203         struct tpm_cmd_t cmd;
1204         int rc, try;
1205
1206         u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
1207
1208         if (chip == NULL)
1209                 return -ENODEV;
1210
1211         if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
1212                 return 0;
1213
1214         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1215                 tpm2_shutdown(chip, TPM2_SU_STATE);
1216                 return 0;
1217         }
1218
1219         /* for buggy tpm, flush pcrs with extend to selected dummy */
1220         if (tpm_suspend_pcr)
1221                 rc = tpm1_pcr_extend(chip, tpm_suspend_pcr, dummy_hash,
1222                                      "extending dummy pcr before suspend");
1223
1224         /* now do the actual savestate */
1225         for (try = 0; try < TPM_RETRY; try++) {
1226                 cmd.header.in = savestate_header;
1227                 rc = tpm_transmit_cmd(chip, NULL, &cmd, SAVESTATE_RESULT_SIZE,
1228                                       0, 0, NULL);
1229
1230                 /*
1231                  * If the TPM indicates that it is too busy to respond to
1232                  * this command then retry before giving up.  It can take
1233                  * several seconds for this TPM to be ready.
1234                  *
1235                  * This can happen if the TPM has already been sent the
1236                  * SaveState command before the driver has loaded.  TCG 1.2
1237                  * specification states that any communication after SaveState
1238                  * may cause the TPM to invalidate previously saved state.
1239                  */
1240                 if (rc != TPM_WARN_RETRY)
1241                         break;
1242                 tpm_msleep(TPM_TIMEOUT_RETRY);
1243         }
1244
1245         if (rc)
1246                 dev_err(&chip->dev,
1247                         "Error (%d) sending savestate before suspend\n", rc);
1248         else if (try > 0)
1249                 dev_warn(&chip->dev, "TPM savestate took %dms\n",
1250                          try * TPM_TIMEOUT_RETRY);
1251
1252         return rc;
1253 }
1254 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1255
1256 /*
1257  * Resume from a power safe. The BIOS already restored
1258  * the TPM state.
1259  */
1260 int tpm_pm_resume(struct device *dev)
1261 {
1262         struct tpm_chip *chip = dev_get_drvdata(dev);
1263
1264         if (chip == NULL)
1265                 return -ENODEV;
1266
1267         return 0;
1268 }
1269 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1270
1271 #define TPM_GETRANDOM_RESULT_SIZE       18
1272 static const struct tpm_input_header tpm_getrandom_header = {
1273         .tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),
1274         .length = cpu_to_be32(14),
1275         .ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)
1276 };
1277
1278 /**
1279  * tpm_get_random() - get random bytes from the TPM's RNG
1280  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
1281  * @out:        destination buffer for the random bytes
1282  * @max:        the max number of bytes to write to @out
1283  *
1284  * Return: same as with tpm_transmit_cmd()
1285  */
1286 int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
1287 {
1288         struct tpm_cmd_t tpm_cmd;
1289         u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;
1290         int err, total = 0, retries = 5;
1291         u8 *dest = out;
1292
1293         if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
1294                 return -EINVAL;
1295
1296         chip = tpm_find_get_ops(chip);
1297         if (!chip)
1298                 return -ENODEV;
1299
1300         if (chip->flags & TPM_CHIP_FLAG_TPM2) {
1301                 err = tpm2_get_random(chip, out, max);
1302                 tpm_put_ops(chip);
1303                 return err;
1304         }
1305
1306         do {
1307                 tpm_cmd.header.in = tpm_getrandom_header;
1308                 tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
1309
1310                 err = tpm_transmit_cmd(chip, NULL, &tpm_cmd,
1311                                        TPM_GETRANDOM_RESULT_SIZE + num_bytes,
1312                                        offsetof(struct tpm_getrandom_out,
1313                                                 rng_data),
1314                                        0, "attempting get random");
1315                 if (err)
1316                         break;
1317
1318                 recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
1319                 if (recd > num_bytes) {
1320                         total = -EFAULT;
1321                         break;
1322                 }
1323
1324                 rlength = be32_to_cpu(tpm_cmd.header.out.length);
1325                 if (rlength < TPM_HEADER_SIZE +
1326                               offsetof(struct tpm_getrandom_out, rng_data) +
1327                               recd) {
1328                         total = -EFAULT;
1329                         break;
1330                 }
1331                 memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
1332
1333                 dest += recd;
1334                 total += recd;
1335                 num_bytes -= recd;
1336         } while (retries-- && total < max);
1337
1338         tpm_put_ops(chip);
1339         return total ? total : -EIO;
1340 }
1341 EXPORT_SYMBOL_GPL(tpm_get_random);
1342
1343 /**
1344  * tpm_seal_trusted() - seal a trusted key payload
1345  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
1346  * @options:    authentication values and other options
1347  * @payload:    the key data in clear and encrypted form
1348  *
1349  * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
1350  * the keyring subsystem.
1351  *
1352  * Return: same as with tpm_transmit_cmd()
1353  */
1354 int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload,
1355                      struct trusted_key_options *options)
1356 {
1357         int rc;
1358
1359         chip = tpm_find_get_ops(chip);
1360         if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1361                 return -ENODEV;
1362
1363         rc = tpm2_seal_trusted(chip, payload, options);
1364
1365         tpm_put_ops(chip);
1366         return rc;
1367 }
1368 EXPORT_SYMBOL_GPL(tpm_seal_trusted);
1369
1370 /**
1371  * tpm_unseal_trusted() - unseal a trusted key
1372  * @chip:       a &struct tpm_chip instance, %NULL for the default chip
1373  * @options:    authentication values and other options
1374  * @payload:    the key data in clear and encrypted form
1375  *
1376  * Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
1377  * the keyring subsystem.
1378  *
1379  * Return: same as with tpm_transmit_cmd()
1380  */
1381 int tpm_unseal_trusted(struct tpm_chip *chip,
1382                        struct trusted_key_payload *payload,
1383                        struct trusted_key_options *options)
1384 {
1385         int rc;
1386
1387         chip = tpm_find_get_ops(chip);
1388         if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
1389                 return -ENODEV;
1390
1391         rc = tpm2_unseal_trusted(chip, payload, options);
1392
1393         tpm_put_ops(chip);
1394
1395         return rc;
1396 }
1397 EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
1398
1399 static int __init tpm_init(void)
1400 {
1401         int rc;
1402
1403         tpm_class = class_create(THIS_MODULE, "tpm");
1404         if (IS_ERR(tpm_class)) {
1405                 pr_err("couldn't create tpm class\n");
1406                 return PTR_ERR(tpm_class);
1407         }
1408
1409         tpmrm_class = class_create(THIS_MODULE, "tpmrm");
1410         if (IS_ERR(tpmrm_class)) {
1411                 pr_err("couldn't create tpmrm class\n");
1412                 rc = PTR_ERR(tpmrm_class);
1413                 goto out_destroy_tpm_class;
1414         }
1415
1416         rc = alloc_chrdev_region(&tpm_devt, 0, 2*TPM_NUM_DEVICES, "tpm");
1417         if (rc < 0) {
1418                 pr_err("tpm: failed to allocate char dev region\n");
1419                 goto out_destroy_tpmrm_class;
1420         }
1421
1422         rc = tpm_dev_common_init();
1423         if (rc) {
1424                 pr_err("tpm: failed to allocate char dev region\n");
1425                 goto out_unreg_chrdev;
1426         }
1427
1428         return 0;
1429
1430 out_unreg_chrdev:
1431         unregister_chrdev_region(tpm_devt, 2 * TPM_NUM_DEVICES);
1432 out_destroy_tpmrm_class:
1433         class_destroy(tpmrm_class);
1434 out_destroy_tpm_class:
1435         class_destroy(tpm_class);
1436
1437         return rc;
1438 }
1439
1440 static void __exit tpm_exit(void)
1441 {
1442         idr_destroy(&dev_nums_idr);
1443         class_destroy(tpm_class);
1444         class_destroy(tpmrm_class);
1445         unregister_chrdev_region(tpm_devt, 2*TPM_NUM_DEVICES);
1446         tpm_dev_common_exit();
1447 }
1448
1449 subsys_initcall(tpm_init);
1450 module_exit(tpm_exit);
1451
1452 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1453 MODULE_DESCRIPTION("TPM Driver");
1454 MODULE_VERSION("2.0");
1455 MODULE_LICENSE("GPL");