drivers/char/tpm/tpm2-cmd.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2014, 2015 Intel Corporation
   4  *
   5  * Authors:
   6  * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
   7  *
   8  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
   9  *
  10  * This file contains TPM2 protocol implementations of the commands
  11  * used by the kernel internally.
  12  */
  13
  14 #include "tpm.h"
  15 #include <crypto/hash_info.h>
  16
  17 static struct tpm2_hash tpm2_hash_map[] = {
  18         {HASH_ALGO_SHA1, TPM_ALG_SHA1},
  19         {HASH_ALGO_SHA256, TPM_ALG_SHA256},
  20         {HASH_ALGO_SHA384, TPM_ALG_SHA384},
  21         {HASH_ALGO_SHA512, TPM_ALG_SHA512},
  22         {HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
  23 };
  24
  25 int tpm2_get_timeouts(struct tpm_chip *chip)
  26 {
  27         /* Fixed timeouts for TPM2 */
  28         chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
  29         chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
  30         chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
  31         chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
  32
  33         /* PTP spec timeouts */
  34         chip->duration[TPM_SHORT] = msecs_to_jiffies(TPM2_DURATION_SHORT);
  35         chip->duration[TPM_MEDIUM] = msecs_to_jiffies(TPM2_DURATION_MEDIUM);
  36         chip->duration[TPM_LONG] = msecs_to_jiffies(TPM2_DURATION_LONG);
  37
  38         /* Key creation commands long timeouts */
  39         chip->duration[TPM_LONG_LONG] =
  40                 msecs_to_jiffies(TPM2_DURATION_LONG_LONG);
  41
  42         chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
  43
  44         return 0;
  45 }
  46
  47 /**
  48  * tpm2_ordinal_duration_index() - returns an index to the chip duration table
  49  * @ordinal: TPM command ordinal.
  50  *
  51  * The function returns an index to the chip duration table
  52  * (enum tpm_duration), that describes the maximum amount of
  53  * time the chip could take to return the result for a  particular ordinal.
  54  *
  55  * The values of the MEDIUM, and LONG durations are taken
  56  * from the PC Client Profile (PTP) specification (750, 2000 msec)
  57  *
  58  * LONG_LONG is for commands that generates keys which empirically takes
  59  * a longer time on some systems.
  60  *
  61  * Return:
  62  * * TPM_MEDIUM
  63  * * TPM_LONG
  64  * * TPM_LONG_LONG
  65  * * TPM_UNDEFINED
  66  */
  67 static u8 tpm2_ordinal_duration_index(u32 ordinal)
  68 {
  69         switch (ordinal) {
  70         /* Startup */
  71         case TPM2_CC_STARTUP:                 /* 144 */
  72                 return TPM_MEDIUM;
  73
  74         case TPM2_CC_SELF_TEST:               /* 143 */
  75                 return TPM_LONG;
  76
  77         case TPM2_CC_GET_RANDOM:              /* 17B */
  78                 return TPM_LONG;
  79
  80         case TPM2_CC_SEQUENCE_UPDATE:         /* 15C */
  81                 return TPM_MEDIUM;
  82         case TPM2_CC_SEQUENCE_COMPLETE:       /* 13E */
  83                 return TPM_MEDIUM;
  84         case TPM2_CC_EVENT_SEQUENCE_COMPLETE: /* 185 */
  85                 return TPM_MEDIUM;
  86         case TPM2_CC_HASH_SEQUENCE_START:     /* 186 */
  87                 return TPM_MEDIUM;
  88
  89         case TPM2_CC_VERIFY_SIGNATURE:        /* 177 */
  90                 return TPM_LONG;
  91
  92         case TPM2_CC_PCR_EXTEND:              /* 182 */
  93                 return TPM_MEDIUM;
  94
  95         case TPM2_CC_HIERARCHY_CONTROL:       /* 121 */
  96                 return TPM_LONG;
  97         case TPM2_CC_HIERARCHY_CHANGE_AUTH:   /* 129 */
  98                 return TPM_LONG;
  99
 100         case TPM2_CC_GET_CAPABILITY:          /* 17A */
 101                 return TPM_MEDIUM;
 102
 103         case TPM2_CC_NV_READ:                 /* 14E */
 104                 return TPM_LONG;
 105
 106         case TPM2_CC_CREATE_PRIMARY:          /* 131 */
 107                 return TPM_LONG_LONG;
 108         case TPM2_CC_CREATE:                  /* 153 */
 109                 return TPM_LONG_LONG;
 110         case TPM2_CC_CREATE_LOADED:           /* 191 */
 111                 return TPM_LONG_LONG;
 112
 113         default:
 114                 return TPM_UNDEFINED;
 115         }
 116 }
 117
 118 /**
 119  * tpm2_calc_ordinal_duration() - calculate the maximum command duration
 120  * @chip:    TPM chip to use.
 121  * @ordinal: TPM command ordinal.
 122  *
 123  * The function returns the maximum amount of time the chip could take
 124  * to return the result for a particular ordinal in jiffies.
 125  *
 126  * Return: A maximal duration time for an ordinal in jiffies.
 127  */
 128 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
 129 {
 130         unsigned int index;
 131
 132         index = tpm2_ordinal_duration_index(ordinal);
 133
 134         if (index != TPM_UNDEFINED)
 135                 return chip->duration[index];
 136         else
 137                 return msecs_to_jiffies(TPM2_DURATION_DEFAULT);
 138 }
 139
 140
 141 struct tpm2_pcr_read_out {
 142         __be32  update_cnt;
 143         __be32  pcr_selects_cnt;
 144         __be16  hash_alg;
 145         u8      pcr_select_size;
 146         u8      pcr_select[TPM2_PCR_SELECT_MIN];
 147         __be32  digests_cnt;
 148         __be16  digest_size;
 149         u8      digest[];
 150 } __packed;
 151
 152 /**
 153  * tpm2_pcr_read() - read a PCR value
 154  * @chip:       TPM chip to use.
 155  * @pcr_idx:    index of the PCR to read.
 156  * @digest:     PCR bank and buffer current PCR value is written to.
 157  * @digest_size_ptr:    pointer to variable that stores the digest size.
 158  *
 159  * Return: Same as with tpm_transmit_cmd.
 160  */
 161 int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
 162                   struct tpm_digest *digest, u16 *digest_size_ptr)
 163 {
 164         int i;
 165         int rc;
 166         struct tpm_buf buf;
 167         struct tpm2_pcr_read_out *out;
 168         u8 pcr_select[TPM2_PCR_SELECT_MIN] = {0};
 169         u16 digest_size;
 170         u16 expected_digest_size = 0;
 171
 172         if (pcr_idx >= TPM2_PLATFORM_PCR)
 173                 return -EINVAL;
 174
 175         if (!digest_size_ptr) {
 176                 for (i = 0; i < chip->nr_allocated_banks &&
 177                      chip->allocated_banks[i].alg_id != digest->alg_id; i++)
 178                         ;
 179
 180                 if (i == chip->nr_allocated_banks)
 181                         return -EINVAL;
 182
 183                 expected_digest_size = chip->allocated_banks[i].digest_size;
 184         }
 185
 186         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_PCR_READ);
 187         if (rc)
 188                 return rc;
 189
 190         pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
 191
 192         tpm_buf_append_u32(&buf, 1);
 193         tpm_buf_append_u16(&buf, digest->alg_id);
 194         tpm_buf_append_u8(&buf, TPM2_PCR_SELECT_MIN);
 195         tpm_buf_append(&buf, (const unsigned char *)pcr_select,
 196                        sizeof(pcr_select));
 197
 198         rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to read a pcr value");
 199         if (rc)
 200                 goto out;
 201
 202         out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
 203         digest_size = be16_to_cpu(out->digest_size);
 204         if (digest_size > sizeof(digest->digest) ||
 205             (!digest_size_ptr && digest_size != expected_digest_size)) {
 206                 rc = -EINVAL;
 207                 goto out;
 208         }
 209
 210         if (digest_size_ptr)
 211                 *digest_size_ptr = digest_size;
 212
 213         memcpy(digest->digest, out->digest, digest_size);
 214 out:
 215         tpm_buf_destroy(&buf);
 216         return rc;
 217 }
 218
 219 struct tpm2_null_auth_area {
 220         __be32  handle;
 221         __be16  nonce_size;
 222         u8  attributes;
 223         __be16  auth_size;
 224 } __packed;
 225
 226 /**
 227  * tpm2_pcr_extend() - extend a PCR value
 228  *
 229  * @chip:       TPM chip to use.
 230  * @pcr_idx:    index of the PCR.
 231  * @digests:    list of pcr banks and corresponding digest values to extend.
 232  *
 233  * Return: Same as with tpm_transmit_cmd.
 234  */
 235 int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
 236                     struct tpm_digest *digests)
 237 {
 238         struct tpm_buf buf;
 239         struct tpm2_null_auth_area auth_area;
 240         int rc;
 241         int i;
 242
 243         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
 244         if (rc)
 245                 return rc;
 246
 247         tpm_buf_append_u32(&buf, pcr_idx);
 248
 249         auth_area.handle = cpu_to_be32(TPM2_RS_PW);
 250         auth_area.nonce_size = 0;
 251         auth_area.attributes = 0;
 252         auth_area.auth_size = 0;
 253
 254         tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area));
 255         tpm_buf_append(&buf, (const unsigned char *)&auth_area,
 256                        sizeof(auth_area));
 257         tpm_buf_append_u32(&buf, chip->nr_allocated_banks);
 258
 259         for (i = 0; i < chip->nr_allocated_banks; i++) {
 260                 tpm_buf_append_u16(&buf, digests[i].alg_id);
 261                 tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest,
 262                                chip->allocated_banks[i].digest_size);
 263         }
 264
 265         rc = tpm_transmit_cmd(chip, &buf, 0, "attempting extend a PCR value");
 266
 267         tpm_buf_destroy(&buf);
 268
 269         return rc;
 270 }
 271
 272 struct tpm2_get_random_out {
 273         __be16 size;
 274         u8 buffer[TPM_MAX_RNG_DATA];
 275 } __packed;
 276
 277 /**
 278  * tpm2_get_random() - get random bytes from the TPM RNG
 279  *
 280  * @chip:       a &tpm_chip instance
 281  * @dest:       destination buffer
 282  * @max:        the max number of random bytes to pull
 283  *
 284  * Return:
 285  *   size of the buffer on success,
 286  *   -errno otherwise (positive TPM return codes are masked to -EIO)
 287  */
 288 int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
 289 {
 290         struct tpm2_get_random_out *out;
 291         struct tpm_buf buf;
 292         u32 recd;
 293         u32 num_bytes = max;
 294         int err;
 295         int total = 0;
 296         int retries = 5;
 297         u8 *dest_ptr = dest;
 298
 299         if (!num_bytes || max > TPM_MAX_RNG_DATA)
 300                 return -EINVAL;
 301
 302         err = tpm_buf_init(&buf, 0, 0);
 303         if (err)
 304                 return err;
 305
 306         do {
 307                 tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM);
 308                 tpm_buf_append_u16(&buf, num_bytes);
 309                 err = tpm_transmit_cmd(chip, &buf,
 310                                        offsetof(struct tpm2_get_random_out,
 311                                                 buffer),
 312                                        "attempting get random");
 313                 if (err) {
 314                         if (err > 0)
 315                                 err = -EIO;
 316                         goto out;
 317                 }
 318
 319                 out = (struct tpm2_get_random_out *)
 320                         &buf.data[TPM_HEADER_SIZE];
 321                 recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
 322                 if (tpm_buf_length(&buf) <
 323                     TPM_HEADER_SIZE +
 324                     offsetof(struct tpm2_get_random_out, buffer) +
 325                     recd) {
 326                         err = -EFAULT;
 327                         goto out;
 328                 }
 329                 memcpy(dest_ptr, out->buffer, recd);
 330
 331                 dest_ptr += recd;
 332                 total += recd;
 333                 num_bytes -= recd;
 334         } while (retries-- && total < max);
 335
 336         tpm_buf_destroy(&buf);
 337         return total ? total : -EIO;
 338 out:
 339         tpm_buf_destroy(&buf);
 340         return err;
 341 }
 342
 343 /**
 344  * tpm2_flush_context() - execute a TPM2_FlushContext command
 345  * @chip:       TPM chip to use
 346  * @handle:     context handle
 347  */
 348 void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
 349 {
 350         struct tpm_buf buf;
 351         int rc;
 352
 353         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
 354         if (rc) {
 355                 dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
 356                          handle);
 357                 return;
 358         }
 359
 360         tpm_buf_append_u32(&buf, handle);
 361
 362         tpm_transmit_cmd(chip, &buf, 0, "flushing context");
 363         tpm_buf_destroy(&buf);
 364 }
 365 EXPORT_SYMBOL_GPL(tpm2_flush_context);
 366
 367 struct tpm2_get_cap_out {
 368         u8 more_data;
 369         __be32 subcap_id;
 370         __be32 property_cnt;
 371         __be32 property_id;
 372         __be32 value;
 373 } __packed;
 374
 375 /**
 376  * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
 377  * @chip:               a &tpm_chip instance
 378  * @property_id:        property ID.
 379  * @value:              output variable.
 380  * @desc:               passed to tpm_transmit_cmd()
 381  *
 382  * Return:
 383  *   0 on success,
 384  *   -errno or a TPM return code otherwise
 385  */
 386 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
 387                         const char *desc)
 388 {
 389         struct tpm2_get_cap_out *out;
 390         struct tpm_buf buf;
 391         int rc;
 392
 393         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
 394         if (rc)
 395                 return rc;
 396         tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
 397         tpm_buf_append_u32(&buf, property_id);
 398         tpm_buf_append_u32(&buf, 1);
 399         rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
 400         if (!rc) {
 401                 out = (struct tpm2_get_cap_out *)
 402                         &buf.data[TPM_HEADER_SIZE];
 403                 *value = be32_to_cpu(out->value);
 404         }
 405         tpm_buf_destroy(&buf);
 406         return rc;
 407 }
 408 EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
 409
 410 /**
 411  * tpm2_shutdown() - send a TPM shutdown command
 412  *
 413  * Sends a TPM shutdown command. The shutdown command is used in call
 414  * sites where the system is going down. If it fails, there is not much
 415  * that can be done except print an error message.
 416  *
 417  * @chip:               a &tpm_chip instance
 418  * @shutdown_type:      TPM_SU_CLEAR or TPM_SU_STATE.
 419  */
 420 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
 421 {
 422         struct tpm_buf buf;
 423         int rc;
 424
 425         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
 426         if (rc)
 427                 return;
 428         tpm_buf_append_u16(&buf, shutdown_type);
 429         tpm_transmit_cmd(chip, &buf, 0, "stopping the TPM");
 430         tpm_buf_destroy(&buf);
 431 }
 432
 433 /**
 434  * tpm2_do_selftest() - ensure that all self tests have passed
 435  *
 436  * @chip: TPM chip to use
 437  *
 438  * Return: Same as with tpm_transmit_cmd.
 439  *
 440  * The TPM can either run all self tests synchronously and then return
 441  * RC_SUCCESS once all tests were successful. Or it can choose to run the tests
 442  * asynchronously and return RC_TESTING immediately while the self tests still
 443  * execute in the background. This function handles both cases and waits until
 444  * all tests have completed.
 445  */
 446 static int tpm2_do_selftest(struct tpm_chip *chip)
 447 {
 448         struct tpm_buf buf;
 449         int full;
 450         int rc;
 451
 452         for (full = 0; full < 2; full++) {
 453                 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST);
 454                 if (rc)
 455                         return rc;
 456
 457                 tpm_buf_append_u8(&buf, full);
 458                 rc = tpm_transmit_cmd(chip, &buf, 0,
 459                                       "attempting the self test");
 460                 tpm_buf_destroy(&buf);
 461
 462                 if (rc == TPM2_RC_TESTING)
 463                         rc = TPM2_RC_SUCCESS;
 464                 if (rc == TPM2_RC_INITIALIZE || rc == TPM2_RC_SUCCESS)
 465                         return rc;
 466         }
 467
 468         return rc;
 469 }
 470
 471 /**
 472  * tpm2_probe() - probe for the TPM 2.0 protocol
 473  * @chip:       a &tpm_chip instance
 474  *
 475  * Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the
 476  * other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by
 477  * this function if this is the case.
 478  *
 479  * Return:
 480  *   0 on success,
 481  *   -errno otherwise
 482  */
 483 int tpm2_probe(struct tpm_chip *chip)
 484 {
 485         struct tpm_header *out;
 486         struct tpm_buf buf;
 487         int rc;
 488
 489         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
 490         if (rc)
 491                 return rc;
 492         tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
 493         tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
 494         tpm_buf_append_u32(&buf, 1);
 495         rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
 496         /* We ignore TPM return codes on purpose. */
 497         if (rc >=  0) {
 498                 out = (struct tpm_header *)buf.data;
 499                 if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
 500                         chip->flags |= TPM_CHIP_FLAG_TPM2;
 501         }
 502         tpm_buf_destroy(&buf);
 503         return 0;
 504 }
 505 EXPORT_SYMBOL_GPL(tpm2_probe);
 506
 507 static int tpm2_init_bank_info(struct tpm_chip *chip, u32 bank_index)
 508 {
 509         struct tpm_bank_info *bank = chip->allocated_banks + bank_index;
 510         struct tpm_digest digest = { .alg_id = bank->alg_id };
 511         int i;
 512
 513         /*
 514          * Avoid unnecessary PCR read operations to reduce overhead
 515          * and obtain identifiers of the crypto subsystem.
 516          */
 517         for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
 518                 enum hash_algo crypto_algo = tpm2_hash_map[i].crypto_id;
 519
 520                 if (bank->alg_id != tpm2_hash_map[i].tpm_id)
 521                         continue;
 522
 523                 bank->digest_size = hash_digest_size[crypto_algo];
 524                 bank->crypto_id = crypto_algo;
 525                 return 0;
 526         }
 527
 528         bank->crypto_id = HASH_ALGO__LAST;
 529
 530         return tpm2_pcr_read(chip, 0, &digest, &bank->digest_size);
 531 }
 532
 533 struct tpm2_pcr_selection {
 534         __be16  hash_alg;
 535         u8  size_of_select;
 536         u8  pcr_select[3];
 537 } __packed;
 538
 539 ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
 540 {
 541         struct tpm2_pcr_selection pcr_selection;
 542         struct tpm_buf buf;
 543         void *marker;
 544         void *end;
 545         void *pcr_select_offset;
 546         u32 sizeof_pcr_selection;
 547         u32 nr_possible_banks;
 548         u32 nr_alloc_banks = 0;
 549         u16 hash_alg;
 550         u32 rsp_len;
 551         int rc;
 552         int i = 0;
 553
 554         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
 555         if (rc)
 556                 return rc;
 557
 558         tpm_buf_append_u32(&buf, TPM2_CAP_PCRS);
 559         tpm_buf_append_u32(&buf, 0);
 560         tpm_buf_append_u32(&buf, 1);
 561
 562         rc = tpm_transmit_cmd(chip, &buf, 9, "get tpm pcr allocation");
 563         if (rc)
 564                 goto out;
 565
 566         nr_possible_banks = be32_to_cpup(
 567                 (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]);
 568
 569         chip->allocated_banks = kcalloc(nr_possible_banks,
 570                                         sizeof(*chip->allocated_banks),
 571                                         GFP_KERNEL);
 572         if (!chip->allocated_banks) {
 573                 rc = -ENOMEM;
 574                 goto out;
 575         }
 576
 577         marker = &buf.data[TPM_HEADER_SIZE + 9];
 578
 579         rsp_len = be32_to_cpup((__be32 *)&buf.data[2]);
 580         end = &buf.data[rsp_len];
 581
 582         for (i = 0; i < nr_possible_banks; i++) {
 583                 pcr_select_offset = marker +
 584                         offsetof(struct tpm2_pcr_selection, size_of_select);
 585                 if (pcr_select_offset >= end) {
 586                         rc = -EFAULT;
 587                         break;
 588                 }
 589
 590                 memcpy(&pcr_selection, marker, sizeof(pcr_selection));
 591                 hash_alg = be16_to_cpu(pcr_selection.hash_alg);
 592
 593                 pcr_select_offset = memchr_inv(pcr_selection.pcr_select, 0,
 594                                                pcr_selection.size_of_select);
 595                 if (pcr_select_offset) {
 596                         chip->allocated_banks[nr_alloc_banks].alg_id = hash_alg;
 597
 598                         rc = tpm2_init_bank_info(chip, nr_alloc_banks);
 599                         if (rc < 0)
 600                                 break;
 601
 602                         nr_alloc_banks++;
 603                 }
 604
 605                 sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) +
 606                         sizeof(pcr_selection.size_of_select) +
 607                         pcr_selection.size_of_select;
 608                 marker = marker + sizeof_pcr_selection;
 609         }
 610
 611         chip->nr_allocated_banks = nr_alloc_banks;
 612 out:
 613         tpm_buf_destroy(&buf);
 614
 615         return rc;
 616 }
 617
 618 static int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
 619 {
 620         struct tpm_buf buf;
 621         u32 nr_commands;
 622         __be32 *attrs;
 623         u32 cc;
 624         int i;
 625         int rc;
 626
 627         rc = tpm2_get_tpm_pt(chip, TPM_PT_TOTAL_COMMANDS, &nr_commands, NULL);
 628         if (rc)
 629                 goto out;
 630
 631         if (nr_commands > 0xFFFFF) {
 632                 rc = -EFAULT;
 633                 goto out;
 634         }
 635
 636         chip->cc_attrs_tbl = devm_kcalloc(&chip->dev, 4, nr_commands,
 637                                           GFP_KERNEL);
 638         if (!chip->cc_attrs_tbl) {
 639                 rc = -ENOMEM;
 640                 goto out;
 641         }
 642
 643         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
 644         if (rc)
 645                 goto out;
 646
 647         tpm_buf_append_u32(&buf, TPM2_CAP_COMMANDS);
 648         tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
 649         tpm_buf_append_u32(&buf, nr_commands);
 650
 651         rc = tpm_transmit_cmd(chip, &buf, 9 + 4 * nr_commands, NULL);
 652         if (rc) {
 653                 tpm_buf_destroy(&buf);
 654                 goto out;
 655         }
 656
 657         if (nr_commands !=
 658             be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) {
 659                 tpm_buf_destroy(&buf);
 660                 goto out;
 661         }
 662
 663         chip->nr_commands = nr_commands;
 664
 665         attrs = (__be32 *)&buf.data[TPM_HEADER_SIZE + 9];
 666         for (i = 0; i < nr_commands; i++, attrs++) {
 667                 chip->cc_attrs_tbl[i] = be32_to_cpup(attrs);
 668                 cc = chip->cc_attrs_tbl[i] & 0xFFFF;
 669
 670                 if (cc == TPM2_CC_CONTEXT_SAVE || cc == TPM2_CC_FLUSH_CONTEXT) {
 671                         chip->cc_attrs_tbl[i] &=
 672                                 ~(GENMASK(2, 0) << TPM2_CC_ATTR_CHANDLES);
 673                         chip->cc_attrs_tbl[i] |= 1 << TPM2_CC_ATTR_CHANDLES;
 674                 }
 675         }
 676
 677         tpm_buf_destroy(&buf);
 678
 679 out:
 680         if (rc > 0)
 681                 rc = -ENODEV;
 682         return rc;
 683 }
 684
 685 /**
 686  * tpm2_startup - turn on the TPM
 687  * @chip: TPM chip to use
 688  *
 689  * Normally the firmware should start the TPM. This function is provided as a
 690  * workaround if this does not happen. A legal case for this could be for
 691  * example when a TPM emulator is used.
 692  *
 693  * Return: same as tpm_transmit_cmd()
 694  */
 695
 696 static int tpm2_startup(struct tpm_chip *chip)
 697 {
 698         struct tpm_buf buf;
 699         int rc;
 700
 701         dev_info(&chip->dev, "starting up the TPM manually\n");
 702
 703         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
 704         if (rc < 0)
 705                 return rc;
 706
 707         tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
 708         rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM");
 709         tpm_buf_destroy(&buf);
 710
 711         return rc;
 712 }
 713
 714 /**
 715  * tpm2_auto_startup - Perform the standard automatic TPM initialization
 716  *                     sequence
 717  * @chip: TPM chip to use
 718  *
 719  * Returns 0 on success, < 0 in case of fatal error.
 720  */
 721 int tpm2_auto_startup(struct tpm_chip *chip)
 722 {
 723         int rc;
 724
 725         rc = tpm2_get_timeouts(chip);
 726         if (rc)
 727                 goto out;
 728
 729         rc = tpm2_do_selftest(chip);
 730         if (rc && rc != TPM2_RC_INITIALIZE)
 731                 goto out;
 732
 733         if (rc == TPM2_RC_INITIALIZE) {
 734                 rc = tpm2_startup(chip);
 735                 if (rc)
 736                         goto out;
 737
 738                 rc = tpm2_do_selftest(chip);
 739                 if (rc)
 740                         goto out;
 741         }
 742
 743         rc = tpm2_get_cc_attrs_tbl(chip);
 744
 745 out:
 746         if (rc > 0)
 747                 rc = -ENODEV;
 748         return rc;
 749 }
 750
 751 int tpm2_find_cc(struct tpm_chip *chip, u32 cc)
 752 {
 753         int i;
 754
 755         for (i = 0; i < chip->nr_commands; i++)
 756                 if (cc == (chip->cc_attrs_tbl[i] & GENMASK(15, 0)))
 757                         return i;
 758
 759         return -1;
 760 }