linux/drivers/char/tpm/tpm2-cmd.c
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   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
  17static 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
  25int 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 */
  67static 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_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 */
 128unsigned 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
 141struct 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 */
 161int 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);
 214out:
 215        tpm_buf_destroy(&buf);
 216        return rc;
 217}
 218
 219struct 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 */
 235int 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
 272struct 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 */
 288int 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;
 338out:
 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 */
 348void 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}
 365EXPORT_SYMBOL_GPL(tpm2_flush_context);
 366
 367struct 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 */
 386ssize_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}
 408EXPORT_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 */
 420void 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 */
 446static 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 */
 483int 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}
 505EXPORT_SYMBOL_GPL(tpm2_probe);
 506
 507static 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
 533struct tpm2_pcr_selection {
 534        __be16  hash_alg;
 535        u8  size_of_select;
 536        u8  pcr_select[3];
 537} __packed;
 538
 539ssize_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;
 612out:
 613        tpm_buf_destroy(&buf);
 614
 615        return rc;
 616}
 617
 618int 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                rc = -EFAULT;
 660                tpm_buf_destroy(&buf);
 661                goto out;
 662        }
 663
 664        chip->nr_commands = nr_commands;
 665
 666        attrs = (__be32 *)&buf.data[TPM_HEADER_SIZE + 9];
 667        for (i = 0; i < nr_commands; i++, attrs++) {
 668                chip->cc_attrs_tbl[i] = be32_to_cpup(attrs);
 669                cc = chip->cc_attrs_tbl[i] & 0xFFFF;
 670
 671                if (cc == TPM2_CC_CONTEXT_SAVE || cc == TPM2_CC_FLUSH_CONTEXT) {
 672                        chip->cc_attrs_tbl[i] &=
 673                                ~(GENMASK(2, 0) << TPM2_CC_ATTR_CHANDLES);
 674                        chip->cc_attrs_tbl[i] |= 1 << TPM2_CC_ATTR_CHANDLES;
 675                }
 676        }
 677
 678        tpm_buf_destroy(&buf);
 679
 680out:
 681        if (rc > 0)
 682                rc = -ENODEV;
 683        return rc;
 684}
 685EXPORT_SYMBOL_GPL(tpm2_get_cc_attrs_tbl);
 686
 687/**
 688 * tpm2_startup - turn on the TPM
 689 * @chip: TPM chip to use
 690 *
 691 * Normally the firmware should start the TPM. This function is provided as a
 692 * workaround if this does not happen. A legal case for this could be for
 693 * example when a TPM emulator is used.
 694 *
 695 * Return: same as tpm_transmit_cmd()
 696 */
 697
 698static int tpm2_startup(struct tpm_chip *chip)
 699{
 700        struct tpm_buf buf;
 701        int rc;
 702
 703        dev_info(&chip->dev, "starting up the TPM manually\n");
 704
 705        rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
 706        if (rc < 0)
 707                return rc;
 708
 709        tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
 710        rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM");
 711        tpm_buf_destroy(&buf);
 712
 713        return rc;
 714}
 715
 716/**
 717 * tpm2_auto_startup - Perform the standard automatic TPM initialization
 718 *                     sequence
 719 * @chip: TPM chip to use
 720 *
 721 * Returns 0 on success, < 0 in case of fatal error.
 722 */
 723int tpm2_auto_startup(struct tpm_chip *chip)
 724{
 725        int rc;
 726
 727        rc = tpm2_get_timeouts(chip);
 728        if (rc)
 729                goto out;
 730
 731        rc = tpm2_do_selftest(chip);
 732        if (rc && rc != TPM2_RC_INITIALIZE)
 733                goto out;
 734
 735        if (rc == TPM2_RC_INITIALIZE) {
 736                rc = tpm2_startup(chip);
 737                if (rc)
 738                        goto out;
 739
 740                rc = tpm2_do_selftest(chip);
 741                if (rc)
 742                        goto out;
 743        }
 744
 745        rc = tpm2_get_cc_attrs_tbl(chip);
 746
 747out:
 748        if (rc > 0)
 749                rc = -ENODEV;
 750        return rc;
 751}
 752
 753int tpm2_find_cc(struct tpm_chip *chip, u32 cc)
 754{
 755        int i;
 756
 757        for (i = 0; i < chip->nr_commands; i++)
 758                if (cc == (chip->cc_attrs_tbl[i] & GENMASK(15, 0)))
 759                        return i;
 760
 761        return -1;
 762}
 763