git.oblomov.eu Git - linux-2.6/blob - drivers/char/tpm/tpm.c

   1 /*
   2  * Copyright (C) 2004 IBM Corporation
   3  *
   4  * Authors:
   5  * Leendert van Doorn <leendert@watson.ibm.com>
   6  * Dave Safford <safford@watson.ibm.com>
   7  * Reiner Sailer <sailer@watson.ibm.com>
   8  * Kylene Hall <kjhall@us.ibm.com>
   9  *
  10  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
  11  *
  12  * Device driver for TCG/TCPA TPM (trusted platform module).
  13  * Specifications at www.trustedcomputinggroup.org
  14  *
  15  * This program is free software; you can redistribute it and/or
  16  * modify it under the terms of the GNU General Public License as
  17  * published by the Free Software Foundation, version 2 of the
  18  * License.
  19  *
  20  * Note, the TPM chip is not interrupt driven (only polling)
  21  * and can have very long timeouts (minutes!). Hence the unusual
  22  * calls to msleep.
  23  *
  24  */
  25
  26 #include <linux/poll.h>
  27 #include <linux/mutex.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/smp_lock.h>
  30
  31 #include "tpm.h"
  32
  33 enum tpm_const {
  34         TPM_MINOR = 224,        /* officially assigned */
  35         TPM_BUFSIZE = 2048,
  36         TPM_NUM_DEVICES = 256,
  37 };
  38
  39 enum tpm_duration {
  40         TPM_SHORT = 0,
  41         TPM_MEDIUM = 1,
  42         TPM_LONG = 2,
  43         TPM_UNDEFINED,
  44 };
  45
  46 #define TPM_MAX_ORDINAL 243
  47 #define TPM_MAX_PROTECTED_ORDINAL 12
  48 #define TPM_PROTECTED_ORDINAL_MASK 0xFF
  49
  50 static LIST_HEAD(tpm_chip_list);
  51 static DEFINE_SPINLOCK(driver_lock);
  52 static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
  53
  54 /*
  55  * Array with one entry per ordinal defining the maximum amount
  56  * of time the chip could take to return the result.  The ordinal
  57  * designation of short, medium or long is defined in a table in
  58  * TCG Specification TPM Main Part 2 TPM Structures Section 17. The
  59  * values of the SHORT, MEDIUM, and LONG durations are retrieved
  60  * from the chip during initialization with a call to tpm_get_timeouts.
  61  */
  62 static const u8 tpm_protected_ordinal_duration[TPM_MAX_PROTECTED_ORDINAL] = {
  63         TPM_UNDEFINED,          /* 0 */
  64         TPM_UNDEFINED,
  65         TPM_UNDEFINED,
  66         TPM_UNDEFINED,
  67         TPM_UNDEFINED,
  68         TPM_UNDEFINED,          /* 5 */
  69         TPM_UNDEFINED,
  70         TPM_UNDEFINED,
  71         TPM_UNDEFINED,
  72         TPM_UNDEFINED,
  73         TPM_SHORT,              /* 10 */
  74         TPM_SHORT,
  75 };
  76
  77 static const u8 tpm_ordinal_duration[TPM_MAX_ORDINAL] = {
  78         TPM_UNDEFINED,          /* 0 */
  79         TPM_UNDEFINED,
  80         TPM_UNDEFINED,
  81         TPM_UNDEFINED,
  82         TPM_UNDEFINED,
  83         TPM_UNDEFINED,          /* 5 */
  84         TPM_UNDEFINED,
  85         TPM_UNDEFINED,
  86         TPM_UNDEFINED,
  87         TPM_UNDEFINED,
  88         TPM_SHORT,              /* 10 */
  89         TPM_SHORT,
  90         TPM_MEDIUM,
  91         TPM_LONG,
  92         TPM_LONG,
  93         TPM_MEDIUM,             /* 15 */
  94         TPM_SHORT,
  95         TPM_SHORT,
  96         TPM_MEDIUM,
  97         TPM_LONG,
  98         TPM_SHORT,              /* 20 */
  99         TPM_SHORT,
 100         TPM_MEDIUM,
 101         TPM_MEDIUM,
 102         TPM_MEDIUM,
 103         TPM_SHORT,              /* 25 */
 104         TPM_SHORT,
 105         TPM_MEDIUM,
 106         TPM_SHORT,
 107         TPM_SHORT,
 108         TPM_MEDIUM,             /* 30 */
 109         TPM_LONG,
 110         TPM_MEDIUM,
 111         TPM_SHORT,
 112         TPM_SHORT,
 113         TPM_SHORT,              /* 35 */
 114         TPM_MEDIUM,
 115         TPM_MEDIUM,
 116         TPM_UNDEFINED,
 117         TPM_UNDEFINED,
 118         TPM_MEDIUM,             /* 40 */
 119         TPM_LONG,
 120         TPM_MEDIUM,
 121         TPM_SHORT,
 122         TPM_SHORT,
 123         TPM_SHORT,              /* 45 */
 124         TPM_SHORT,
 125         TPM_SHORT,
 126         TPM_SHORT,
 127         TPM_LONG,
 128         TPM_MEDIUM,             /* 50 */
 129         TPM_MEDIUM,
 130         TPM_UNDEFINED,
 131         TPM_UNDEFINED,
 132         TPM_UNDEFINED,
 133         TPM_UNDEFINED,          /* 55 */
 134         TPM_UNDEFINED,
 135         TPM_UNDEFINED,
 136         TPM_UNDEFINED,
 137         TPM_UNDEFINED,
 138         TPM_MEDIUM,             /* 60 */
 139         TPM_MEDIUM,
 140         TPM_MEDIUM,
 141         TPM_SHORT,
 142         TPM_SHORT,
 143         TPM_MEDIUM,             /* 65 */
 144         TPM_UNDEFINED,
 145         TPM_UNDEFINED,
 146         TPM_UNDEFINED,
 147         TPM_UNDEFINED,
 148         TPM_SHORT,              /* 70 */
 149         TPM_SHORT,
 150         TPM_UNDEFINED,
 151         TPM_UNDEFINED,
 152         TPM_UNDEFINED,
 153         TPM_UNDEFINED,          /* 75 */
 154         TPM_UNDEFINED,
 155         TPM_UNDEFINED,
 156         TPM_UNDEFINED,
 157         TPM_UNDEFINED,
 158         TPM_LONG,               /* 80 */
 159         TPM_UNDEFINED,
 160         TPM_MEDIUM,
 161         TPM_LONG,
 162         TPM_SHORT,
 163         TPM_UNDEFINED,          /* 85 */
 164         TPM_UNDEFINED,
 165         TPM_UNDEFINED,
 166         TPM_UNDEFINED,
 167         TPM_UNDEFINED,
 168         TPM_SHORT,              /* 90 */
 169         TPM_SHORT,
 170         TPM_SHORT,
 171         TPM_SHORT,
 172         TPM_SHORT,
 173         TPM_UNDEFINED,          /* 95 */
 174         TPM_UNDEFINED,
 175         TPM_UNDEFINED,
 176         TPM_UNDEFINED,
 177         TPM_UNDEFINED,
 178         TPM_MEDIUM,             /* 100 */
 179         TPM_SHORT,
 180         TPM_SHORT,
 181         TPM_UNDEFINED,
 182         TPM_UNDEFINED,
 183         TPM_UNDEFINED,          /* 105 */
 184         TPM_UNDEFINED,
 185         TPM_UNDEFINED,
 186         TPM_UNDEFINED,
 187         TPM_UNDEFINED,
 188         TPM_SHORT,              /* 110 */
 189         TPM_SHORT,
 190         TPM_SHORT,
 191         TPM_SHORT,
 192         TPM_SHORT,
 193         TPM_SHORT,              /* 115 */
 194         TPM_SHORT,
 195         TPM_SHORT,
 196         TPM_UNDEFINED,
 197         TPM_UNDEFINED,
 198         TPM_LONG,               /* 120 */
 199         TPM_LONG,
 200         TPM_MEDIUM,
 201         TPM_UNDEFINED,
 202         TPM_SHORT,
 203         TPM_SHORT,              /* 125 */
 204         TPM_SHORT,
 205         TPM_LONG,
 206         TPM_SHORT,
 207         TPM_SHORT,
 208         TPM_SHORT,              /* 130 */
 209         TPM_MEDIUM,
 210         TPM_UNDEFINED,
 211         TPM_SHORT,
 212         TPM_MEDIUM,
 213         TPM_UNDEFINED,          /* 135 */
 214         TPM_UNDEFINED,
 215         TPM_UNDEFINED,
 216         TPM_UNDEFINED,
 217         TPM_UNDEFINED,
 218         TPM_SHORT,              /* 140 */
 219         TPM_SHORT,
 220         TPM_UNDEFINED,
 221         TPM_UNDEFINED,
 222         TPM_UNDEFINED,
 223         TPM_UNDEFINED,          /* 145 */
 224         TPM_UNDEFINED,
 225         TPM_UNDEFINED,
 226         TPM_UNDEFINED,
 227         TPM_UNDEFINED,
 228         TPM_SHORT,              /* 150 */
 229         TPM_MEDIUM,
 230         TPM_MEDIUM,
 231         TPM_SHORT,
 232         TPM_SHORT,
 233         TPM_UNDEFINED,          /* 155 */
 234         TPM_UNDEFINED,
 235         TPM_UNDEFINED,
 236         TPM_UNDEFINED,
 237         TPM_UNDEFINED,
 238         TPM_SHORT,              /* 160 */
 239         TPM_SHORT,
 240         TPM_SHORT,
 241         TPM_SHORT,
 242         TPM_UNDEFINED,
 243         TPM_UNDEFINED,          /* 165 */
 244         TPM_UNDEFINED,
 245         TPM_UNDEFINED,
 246         TPM_UNDEFINED,
 247         TPM_UNDEFINED,
 248         TPM_LONG,               /* 170 */
 249         TPM_UNDEFINED,
 250         TPM_UNDEFINED,
 251         TPM_UNDEFINED,
 252         TPM_UNDEFINED,
 253         TPM_UNDEFINED,          /* 175 */
 254         TPM_UNDEFINED,
 255         TPM_UNDEFINED,
 256         TPM_UNDEFINED,
 257         TPM_UNDEFINED,
 258         TPM_MEDIUM,             /* 180 */
 259         TPM_SHORT,
 260         TPM_MEDIUM,
 261         TPM_MEDIUM,
 262         TPM_MEDIUM,
 263         TPM_MEDIUM,             /* 185 */
 264         TPM_SHORT,
 265         TPM_UNDEFINED,
 266         TPM_UNDEFINED,
 267         TPM_UNDEFINED,
 268         TPM_UNDEFINED,          /* 190 */
 269         TPM_UNDEFINED,
 270         TPM_UNDEFINED,
 271         TPM_UNDEFINED,
 272         TPM_UNDEFINED,
 273         TPM_UNDEFINED,          /* 195 */
 274         TPM_UNDEFINED,
 275         TPM_UNDEFINED,
 276         TPM_UNDEFINED,
 277         TPM_UNDEFINED,
 278         TPM_SHORT,              /* 200 */
 279         TPM_UNDEFINED,
 280         TPM_UNDEFINED,
 281         TPM_UNDEFINED,
 282         TPM_SHORT,
 283         TPM_SHORT,              /* 205 */
 284         TPM_SHORT,
 285         TPM_SHORT,
 286         TPM_SHORT,
 287         TPM_SHORT,
 288         TPM_MEDIUM,             /* 210 */
 289         TPM_UNDEFINED,
 290         TPM_MEDIUM,
 291         TPM_MEDIUM,
 292         TPM_MEDIUM,
 293         TPM_UNDEFINED,          /* 215 */
 294         TPM_MEDIUM,
 295         TPM_UNDEFINED,
 296         TPM_UNDEFINED,
 297         TPM_SHORT,
 298         TPM_SHORT,              /* 220 */
 299         TPM_SHORT,
 300         TPM_SHORT,
 301         TPM_SHORT,
 302         TPM_SHORT,
 303         TPM_UNDEFINED,          /* 225 */
 304         TPM_UNDEFINED,
 305         TPM_UNDEFINED,
 306         TPM_UNDEFINED,
 307         TPM_UNDEFINED,
 308         TPM_SHORT,              /* 230 */
 309         TPM_LONG,
 310         TPM_MEDIUM,
 311         TPM_UNDEFINED,
 312         TPM_UNDEFINED,
 313         TPM_UNDEFINED,          /* 235 */
 314         TPM_UNDEFINED,
 315         TPM_UNDEFINED,
 316         TPM_UNDEFINED,
 317         TPM_UNDEFINED,
 318         TPM_SHORT,              /* 240 */
 319         TPM_UNDEFINED,
 320         TPM_MEDIUM,
 321 };
 322
 323 static void user_reader_timeout(unsigned long ptr)
 324 {
 325         struct tpm_chip *chip = (struct tpm_chip *) ptr;
 326
 327         schedule_work(&chip->work);
 328 }
 329
 330 static void timeout_work(struct work_struct *work)
 331 {
 332         struct tpm_chip *chip = container_of(work, struct tpm_chip, work);
 333
 334         mutex_lock(&chip->buffer_mutex);
 335         atomic_set(&chip->data_pending, 0);
 336         memset(chip->data_buffer, 0, TPM_BUFSIZE);
 337         mutex_unlock(&chip->buffer_mutex);
 338 }
 339
 340 /*
 341  * Returns max number of jiffies to wait
 342  */
 343 unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip,
 344                                            u32 ordinal)
 345 {
 346         int duration_idx = TPM_UNDEFINED;
 347         int duration = 0;
 348
 349         if (ordinal < TPM_MAX_ORDINAL)
 350                 duration_idx = tpm_ordinal_duration[ordinal];
 351         else if ((ordinal & TPM_PROTECTED_ORDINAL_MASK) <
 352                  TPM_MAX_PROTECTED_ORDINAL)
 353                 duration_idx =
 354                     tpm_protected_ordinal_duration[ordinal &
 355                                                    TPM_PROTECTED_ORDINAL_MASK];
 356
 357         if (duration_idx != TPM_UNDEFINED)
 358                 duration = chip->vendor.duration[duration_idx];
 359         if (duration <= 0)
 360                 return 2 * 60 * HZ;
 361         else
 362                 return duration;
 363 }
 364 EXPORT_SYMBOL_GPL(tpm_calc_ordinal_duration);
 365
 366 /*
 367  * Internal kernel interface to transmit TPM commands
 368  */
 369 static ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
 370                             size_t bufsiz)
 371 {
 372         ssize_t rc;
 373         u32 count, ordinal;
 374         unsigned long stop;
 375
 376         count = be32_to_cpu(*((__be32 *) (buf + 2)));
 377         ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 378         if (count == 0)
 379                 return -ENODATA;
 380         if (count > bufsiz) {
 381                 dev_err(chip->dev,
 382                         "invalid count value %x %zx \n", count, bufsiz);
 383                 return -E2BIG;
 384         }
 385
 386         mutex_lock(&chip->tpm_mutex);
 387
 388         if ((rc = chip->vendor.send(chip, (u8 *) buf, count)) < 0) {
 389                 dev_err(chip->dev,
 390                         "tpm_transmit: tpm_send: error %zd\n", rc);
 391                 goto out;
 392         }
 393
 394         if (chip->vendor.irq)
 395                 goto out_recv;
 396
 397         stop = jiffies + tpm_calc_ordinal_duration(chip, ordinal);
 398         do {
 399                 u8 status = chip->vendor.status(chip);
 400                 if ((status & chip->vendor.req_complete_mask) ==
 401                     chip->vendor.req_complete_val)
 402                         goto out_recv;
 403
 404                 if ((status == chip->vendor.req_canceled)) {
 405                         dev_err(chip->dev, "Operation Canceled\n");
 406                         rc = -ECANCELED;
 407                         goto out;
 408                 }
 409
 410                 msleep(TPM_TIMEOUT);    /* CHECK */
 411                 rmb();
 412         } while (time_before(jiffies, stop));
 413
 414         chip->vendor.cancel(chip);
 415         dev_err(chip->dev, "Operation Timed out\n");
 416         rc = -ETIME;
 417         goto out;
 418
 419 out_recv:
 420         rc = chip->vendor.recv(chip, (u8 *) buf, bufsiz);
 421         if (rc < 0)
 422                 dev_err(chip->dev,
 423                         "tpm_transmit: tpm_recv: error %zd\n", rc);
 424 out:
 425         mutex_unlock(&chip->tpm_mutex);
 426         return rc;
 427 }
 428
 429 #define TPM_DIGEST_SIZE 20
 430 #define TPM_ERROR_SIZE 10
 431 #define TPM_RET_CODE_IDX 6
 432
 433 enum tpm_capabilities {
 434         TPM_CAP_FLAG = cpu_to_be32(4),
 435         TPM_CAP_PROP = cpu_to_be32(5),
 436         CAP_VERSION_1_1 = cpu_to_be32(0x06),
 437         CAP_VERSION_1_2 = cpu_to_be32(0x1A)
 438 };
 439
 440 enum tpm_sub_capabilities {
 441         TPM_CAP_PROP_PCR = cpu_to_be32(0x101),
 442         TPM_CAP_PROP_MANUFACTURER = cpu_to_be32(0x103),
 443         TPM_CAP_FLAG_PERM = cpu_to_be32(0x108),
 444         TPM_CAP_FLAG_VOL = cpu_to_be32(0x109),
 445         TPM_CAP_PROP_OWNER = cpu_to_be32(0x111),
 446         TPM_CAP_PROP_TIS_TIMEOUT = cpu_to_be32(0x115),
 447         TPM_CAP_PROP_TIS_DURATION = cpu_to_be32(0x120),
 448
 449 };
 450
 451 static ssize_t transmit_cmd(struct tpm_chip *chip, struct tpm_cmd_t *cmd,
 452                             int len, const char *desc)
 453 {
 454         int err;
 455
 456         len = tpm_transmit(chip,(u8 *) cmd, len);
 457         if (len <  0)
 458                 return len;
 459         if (len == TPM_ERROR_SIZE) {
 460                 err = be32_to_cpu(cmd->header.out.return_code);
 461                 dev_dbg(chip->dev, "A TPM error (%d) occurred %s\n", err, desc);
 462                 return err;
 463         }
 464         return 0;
 465 }
 466
 467 #define TPM_INTERNAL_RESULT_SIZE 200
 468 #define TPM_TAG_RQU_COMMAND cpu_to_be16(193)
 469 #define TPM_ORD_GET_CAP cpu_to_be32(101)
 470
 471 static const struct tpm_input_header tpm_getcap_header = {
 472         .tag = TPM_TAG_RQU_COMMAND,
 473         .length = cpu_to_be32(22),
 474         .ordinal = TPM_ORD_GET_CAP
 475 };
 476
 477 ssize_t tpm_getcap(struct device *dev, __be32 subcap_id, cap_t *cap,
 478                    const char *desc)
 479 {
 480         struct tpm_cmd_t tpm_cmd;
 481         int rc;
 482         struct tpm_chip *chip = dev_get_drvdata(dev);
 483
 484         tpm_cmd.header.in = tpm_getcap_header;
 485         if (subcap_id == CAP_VERSION_1_1 || subcap_id == CAP_VERSION_1_2) {
 486                 tpm_cmd.params.getcap_in.cap = subcap_id;
 487                 /*subcap field not necessary */
 488                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(0);
 489                 tpm_cmd.header.in.length -= cpu_to_be32(sizeof(__be32));
 490         } else {
 491                 if (subcap_id == TPM_CAP_FLAG_PERM ||
 492                     subcap_id == TPM_CAP_FLAG_VOL)
 493                         tpm_cmd.params.getcap_in.cap = TPM_CAP_FLAG;
 494                 else
 495                         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 496                 tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 497                 tpm_cmd.params.getcap_in.subcap = subcap_id;
 498         }
 499         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE, desc);
 500         if (!rc)
 501                 *cap = tpm_cmd.params.getcap_out.cap;
 502         return rc;
 503 }
 504
 505 void tpm_gen_interrupt(struct tpm_chip *chip)
 506 {
 507         struct  tpm_cmd_t tpm_cmd;
 508         ssize_t rc;
 509
 510         tpm_cmd.header.in = tpm_getcap_header;
 511         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 512         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 513         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 514
 515         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 516                         "attempting to determine the timeouts");
 517 }
 518 EXPORT_SYMBOL_GPL(tpm_gen_interrupt);
 519
 520 void tpm_get_timeouts(struct tpm_chip *chip)
 521 {
 522         struct tpm_cmd_t tpm_cmd;
 523         struct timeout_t *timeout_cap;
 524         struct duration_t *duration_cap;
 525         ssize_t rc;
 526         u32 timeout;
 527
 528         tpm_cmd.header.in = tpm_getcap_header;
 529         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 530         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 531         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_TIMEOUT;
 532
 533         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 534                         "attempting to determine the timeouts");
 535         if (rc)
 536                 goto duration;
 537
 538         if (be32_to_cpu(tpm_cmd.header.out.length)
 539             != 4 * sizeof(u32))
 540                 goto duration;
 541
 542         timeout_cap = &tpm_cmd.params.getcap_out.cap.timeout;
 543         /* Don't overwrite default if value is 0 */
 544         timeout = be32_to_cpu(timeout_cap->a);
 545         if (timeout)
 546                 chip->vendor.timeout_a = usecs_to_jiffies(timeout);
 547         timeout = be32_to_cpu(timeout_cap->b);
 548         if (timeout)
 549                 chip->vendor.timeout_b = usecs_to_jiffies(timeout);
 550         timeout = be32_to_cpu(timeout_cap->c);
 551         if (timeout)
 552                 chip->vendor.timeout_c = usecs_to_jiffies(timeout);
 553         timeout = be32_to_cpu(timeout_cap->d);
 554         if (timeout)
 555                 chip->vendor.timeout_d = usecs_to_jiffies(timeout);
 556
 557 duration:
 558         tpm_cmd.header.in = tpm_getcap_header;
 559         tpm_cmd.params.getcap_in.cap = TPM_CAP_PROP;
 560         tpm_cmd.params.getcap_in.subcap_size = cpu_to_be32(4);
 561         tpm_cmd.params.getcap_in.subcap = TPM_CAP_PROP_TIS_DURATION;
 562
 563         rc = transmit_cmd(chip, &tpm_cmd, TPM_INTERNAL_RESULT_SIZE,
 564                         "attempting to determine the durations");
 565         if (rc)
 566                 return;
 567
 568         if (be32_to_cpu(tpm_cmd.header.out.return_code)
 569             != 3 * sizeof(u32))
 570                 return;
 571         duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 572         chip->vendor.duration[TPM_SHORT] =
 573             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));
 574         /* The Broadcom BCM0102 chipset in a Dell Latitude D820 gets the above
 575          * value wrong and apparently reports msecs rather than usecs. So we
 576          * fix up the resulting too-small TPM_SHORT value to make things work.
 577          */
 578         if (chip->vendor.duration[TPM_SHORT] < (HZ/100))
 579                 chip->vendor.duration[TPM_SHORT] = HZ;
 580
 581         chip->vendor.duration[TPM_MEDIUM] =
 582             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_medium));
 583         chip->vendor.duration[TPM_LONG] =
 584             usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_long));
 585 }
 586 EXPORT_SYMBOL_GPL(tpm_get_timeouts);
 587
 588 void tpm_continue_selftest(struct tpm_chip *chip)
 589 {
 590         u8 data[] = {
 591                 0, 193,                 /* TPM_TAG_RQU_COMMAND */
 592                 0, 0, 0, 10,            /* length */
 593                 0, 0, 0, 83,            /* TPM_ORD_GetCapability */
 594         };
 595
 596         tpm_transmit(chip, data, sizeof(data));
 597 }
 598 EXPORT_SYMBOL_GPL(tpm_continue_selftest);
 599
 600 ssize_t tpm_show_enabled(struct device * dev, struct device_attribute * attr,
 601                         char *buf)
 602 {
 603         cap_t cap;
 604         ssize_t rc;
 605
 606         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 607                          "attempting to determine the permanent enabled state");
 608         if (rc)
 609                 return 0;
 610
 611         rc = sprintf(buf, "%d\n", !cap.perm_flags.disable);
 612         return rc;
 613 }
 614 EXPORT_SYMBOL_GPL(tpm_show_enabled);
 615
 616 ssize_t tpm_show_active(struct device * dev, struct device_attribute * attr,
 617                         char *buf)
 618 {
 619         cap_t cap;
 620         ssize_t rc;
 621
 622         rc = tpm_getcap(dev, TPM_CAP_FLAG_PERM, &cap,
 623                          "attempting to determine the permanent active state");
 624         if (rc)
 625                 return 0;
 626
 627         rc = sprintf(buf, "%d\n", !cap.perm_flags.deactivated);
 628         return rc;
 629 }
 630 EXPORT_SYMBOL_GPL(tpm_show_active);
 631
 632 ssize_t tpm_show_owned(struct device * dev, struct device_attribute * attr,
 633                         char *buf)
 634 {
 635         cap_t cap;
 636         ssize_t rc;
 637
 638         rc = tpm_getcap(dev, TPM_CAP_PROP_OWNER, &cap,
 639                          "attempting to determine the owner state");
 640         if (rc)
 641                 return 0;
 642
 643         rc = sprintf(buf, "%d\n", cap.owned);
 644         return rc;
 645 }
 646 EXPORT_SYMBOL_GPL(tpm_show_owned);
 647
 648 ssize_t tpm_show_temp_deactivated(struct device * dev,
 649                                 struct device_attribute * attr, char *buf)
 650 {
 651         cap_t cap;
 652         ssize_t rc;
 653
 654         rc = tpm_getcap(dev, TPM_CAP_FLAG_VOL, &cap,
 655                          "attempting to determine the temporary state");
 656         if (rc)
 657                 return 0;
 658
 659         rc = sprintf(buf, "%d\n", cap.stclear_flags.deactivated);
 660         return rc;
 661 }
 662 EXPORT_SYMBOL_GPL(tpm_show_temp_deactivated);
 663
 664 /*
 665  * tpm_chip_find_get - return tpm_chip for given chip number
 666  */
 667 static struct tpm_chip *tpm_chip_find_get(int chip_num)
 668 {
 669         struct tpm_chip *pos, *chip = NULL;
 670
 671         rcu_read_lock();
 672         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
 673                 if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
 674                         continue;
 675
 676                 if (try_module_get(pos->dev->driver->owner)) {
 677                         chip = pos;
 678                         break;
 679                 }
 680         }
 681         rcu_read_unlock();
 682         return chip;
 683 }
 684
 685 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 686 #define READ_PCR_RESULT_SIZE 30
 687 static struct tpm_input_header pcrread_header = {
 688         .tag = TPM_TAG_RQU_COMMAND,
 689         .length = cpu_to_be32(14),
 690         .ordinal = TPM_ORDINAL_PCRREAD
 691 };
 692
 693 int __tpm_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
 694 {
 695         int rc;
 696         struct tpm_cmd_t cmd;
 697
 698         cmd.header.in = pcrread_header;
 699         cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);
 700         BUILD_BUG_ON(cmd.header.in.length > READ_PCR_RESULT_SIZE);
 701         rc = transmit_cmd(chip, &cmd, cmd.header.in.length,
 702                           "attempting to read a pcr value");
 703
 704         if (rc == 0)
 705                 memcpy(res_buf, cmd.params.pcrread_out.pcr_result,
 706                        TPM_DIGEST_SIZE);
 707         return rc;
 708 }
 709
 710 /**
 711  * tpm_pcr_read - read a pcr value
 712  * @chip_num:   tpm idx # or ANY
 713  * @pcr_idx:    pcr idx to retrieve
 714  * @res_buf:    TPM_PCR value
 715  *              size of res_buf is 20 bytes (or NULL if you don't care)
 716  *
 717  * The TPM driver should be built-in, but for whatever reason it
 718  * isn't, protect against the chip disappearing, by incrementing
 719  * the module usage count.
 720  */
 721 int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
 722 {
 723         struct tpm_chip *chip;
 724         int rc;
 725
 726         chip = tpm_chip_find_get(chip_num);
 727         if (chip == NULL)
 728                 return -ENODEV;
 729         rc = __tpm_pcr_read(chip, pcr_idx, res_buf);
 730         module_put(chip->dev->driver->owner);
 731         return rc;
 732 }
 733 EXPORT_SYMBOL_GPL(tpm_pcr_read);
 734
 735 /**
 736  * tpm_pcr_extend - extend pcr value with hash
 737  * @chip_num:   tpm idx # or AN&
 738  * @pcr_idx:    pcr idx to extend
 739  * @hash:       hash value used to extend pcr value
 740  *
 741  * The TPM driver should be built-in, but for whatever reason it
 742  * isn't, protect against the chip disappearing, by incrementing
 743  * the module usage count.
 744  */
 745 #define TPM_ORD_PCR_EXTEND cpu_to_be32(20)
 746 #define EXTEND_PCR_SIZE 34
 747 static struct tpm_input_header pcrextend_header = {
 748         .tag = TPM_TAG_RQU_COMMAND,
 749         .length = cpu_to_be32(34),
 750         .ordinal = TPM_ORD_PCR_EXTEND
 751 };
 752
 753 int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
 754 {
 755         struct tpm_cmd_t cmd;
 756         int rc;
 757         struct tpm_chip *chip;
 758
 759         chip = tpm_chip_find_get(chip_num);
 760         if (chip == NULL)
 761                 return -ENODEV;
 762
 763         cmd.header.in = pcrextend_header;
 764         BUILD_BUG_ON(be32_to_cpu(cmd.header.in.length) > EXTEND_PCR_SIZE);
 765         cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
 766         memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
 767         rc = transmit_cmd(chip, &cmd, cmd.header.in.length,
 768                           "attempting extend a PCR value");
 769
 770         module_put(chip->dev->driver->owner);
 771         return rc;
 772 }
 773 EXPORT_SYMBOL_GPL(tpm_pcr_extend);
 774
 775 ssize_t tpm_show_pcrs(struct device *dev, struct device_attribute *attr,
 776                       char *buf)
 777 {
 778         cap_t cap;
 779         u8 digest[TPM_DIGEST_SIZE];
 780         ssize_t rc;
 781         int i, j, num_pcrs;
 782         char *str = buf;
 783         struct tpm_chip *chip = dev_get_drvdata(dev);
 784
 785         rc = tpm_getcap(dev, TPM_CAP_PROP_PCR, &cap,
 786                         "attempting to determine the number of PCRS");
 787         if (rc)
 788                 return 0;
 789
 790         num_pcrs = be32_to_cpu(cap.num_pcrs);
 791         for (i = 0; i < num_pcrs; i++) {
 792                 rc = __tpm_pcr_read(chip, i, digest);
 793                 if (rc)
 794                         break;
 795                 str += sprintf(str, "PCR-%02d: ", i);
 796                 for (j = 0; j < TPM_DIGEST_SIZE; j++)
 797                         str += sprintf(str, "%02X ", digest[j]);
 798                 str += sprintf(str, "\n");
 799         }
 800         return str - buf;
 801 }
 802 EXPORT_SYMBOL_GPL(tpm_show_pcrs);
 803
 804 #define  READ_PUBEK_RESULT_SIZE 314
 805 #define TPM_ORD_READPUBEK cpu_to_be32(124)
 806 struct tpm_input_header tpm_readpubek_header = {
 807         .tag = TPM_TAG_RQU_COMMAND,
 808         .length = cpu_to_be32(30),
 809         .ordinal = TPM_ORD_READPUBEK
 810 };
 811
 812 ssize_t tpm_show_pubek(struct device *dev, struct device_attribute *attr,
 813                        char *buf)
 814 {
 815         u8 *data;
 816         struct tpm_cmd_t tpm_cmd;
 817         ssize_t err;
 818         int i, rc;
 819         char *str = buf;
 820
 821         struct tpm_chip *chip = dev_get_drvdata(dev);
 822
 823         tpm_cmd.header.in = tpm_readpubek_header;
 824         err = transmit_cmd(chip, &tpm_cmd, READ_PUBEK_RESULT_SIZE,
 825                         "attempting to read the PUBEK");
 826         if (err)
 827                 goto out;
 828
 829         /*
 830            ignore header 10 bytes
 831            algorithm 32 bits (1 == RSA )
 832            encscheme 16 bits
 833            sigscheme 16 bits
 834            parameters (RSA 12->bytes: keybit, #primes, expbit)
 835            keylenbytes 32 bits
 836            256 byte modulus
 837            ignore checksum 20 bytes
 838          */
 839         data = tpm_cmd.params.readpubek_out_buffer;
 840         str +=
 841             sprintf(str,
 842                     "Algorithm: %02X %02X %02X %02X\nEncscheme: %02X %02X\n"
 843                     "Sigscheme: %02X %02X\nParameters: %02X %02X %02X %02X"
 844                     " %02X %02X %02X %02X %02X %02X %02X %02X\n"
 845                     "Modulus length: %d\nModulus: \n",
 846                     data[10], data[11], data[12], data[13], data[14],
 847                     data[15], data[16], data[17], data[22], data[23],
 848                     data[24], data[25], data[26], data[27], data[28],
 849                     data[29], data[30], data[31], data[32], data[33],
 850                     be32_to_cpu(*((__be32 *) (data + 34))));
 851
 852         for (i = 0; i < 256; i++) {
 853                 str += sprintf(str, "%02X ", data[i + 38]);
 854                 if ((i + 1) % 16 == 0)
 855                         str += sprintf(str, "\n");
 856         }
 857 out:
 858         rc = str - buf;
 859         return rc;
 860 }
 861 EXPORT_SYMBOL_GPL(tpm_show_pubek);
 862
 863
 864 ssize_t tpm_show_caps(struct device *dev, struct device_attribute *attr,
 865                       char *buf)
 866 {
 867         cap_t cap;
 868         ssize_t rc;
 869         char *str = buf;
 870
 871         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
 872                         "attempting to determine the manufacturer");
 873         if (rc)
 874                 return 0;
 875         str += sprintf(str, "Manufacturer: 0x%x\n",
 876                        be32_to_cpu(cap.manufacturer_id));
 877
 878         rc = tpm_getcap(dev, CAP_VERSION_1_1, &cap,
 879                         "attempting to determine the 1.1 version");
 880         if (rc)
 881                 return 0;
 882         str += sprintf(str,
 883                        "TCG version: %d.%d\nFirmware version: %d.%d\n",
 884                        cap.tpm_version.Major, cap.tpm_version.Minor,
 885                        cap.tpm_version.revMajor, cap.tpm_version.revMinor);
 886         return str - buf;
 887 }
 888 EXPORT_SYMBOL_GPL(tpm_show_caps);
 889
 890 ssize_t tpm_show_caps_1_2(struct device * dev,
 891                           struct device_attribute * attr, char *buf)
 892 {
 893         cap_t cap;
 894         ssize_t rc;
 895         char *str = buf;
 896
 897         rc = tpm_getcap(dev, TPM_CAP_PROP_MANUFACTURER, &cap,
 898                         "attempting to determine the manufacturer");
 899         if (rc)
 900                 return 0;
 901         str += sprintf(str, "Manufacturer: 0x%x\n",
 902                        be32_to_cpu(cap.manufacturer_id));
 903         rc = tpm_getcap(dev, CAP_VERSION_1_2, &cap,
 904                          "attempting to determine the 1.2 version");
 905         if (rc)
 906                 return 0;
 907         str += sprintf(str,
 908                        "TCG version: %d.%d\nFirmware version: %d.%d\n",
 909                        cap.tpm_version_1_2.Major, cap.tpm_version_1_2.Minor,
 910                        cap.tpm_version_1_2.revMajor,
 911                        cap.tpm_version_1_2.revMinor);
 912         return str - buf;
 913 }
 914 EXPORT_SYMBOL_GPL(tpm_show_caps_1_2);
 915
 916 ssize_t tpm_store_cancel(struct device *dev, struct device_attribute *attr,
 917                         const char *buf, size_t count)
 918 {
 919         struct tpm_chip *chip = dev_get_drvdata(dev);
 920         if (chip == NULL)
 921                 return 0;
 922
 923         chip->vendor.cancel(chip);
 924         return count;
 925 }
 926 EXPORT_SYMBOL_GPL(tpm_store_cancel);
 927
 928 /*
 929  * Device file system interface to the TPM
 930  *
 931  * It's assured that the chip will be opened just once,
 932  * by the check of is_open variable, which is protected
 933  * by driver_lock.
 934  */
 935 int tpm_open(struct inode *inode, struct file *file)
 936 {
 937         int minor = iminor(inode);
 938         struct tpm_chip *chip = NULL, *pos;
 939
 940         rcu_read_lock();
 941         list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
 942                 if (pos->vendor.miscdev.minor == minor) {
 943                         chip = pos;
 944                         get_device(chip->dev);
 945                         break;
 946                 }
 947         }
 948         rcu_read_unlock();
 949
 950         if (!chip)
 951                 return -ENODEV;
 952
 953         if (test_and_set_bit(0, &chip->is_open)) {
 954                 dev_dbg(chip->dev, "Another process owns this TPM\n");
 955                 put_device(chip->dev);
 956                 return -EBUSY;
 957         }
 958
 959         chip->data_buffer = kmalloc(TPM_BUFSIZE * sizeof(u8), GFP_KERNEL);
 960         if (chip->data_buffer == NULL) {
 961                 clear_bit(0, &chip->is_open);
 962                 put_device(chip->dev);
 963                 return -ENOMEM;
 964         }
 965
 966         atomic_set(&chip->data_pending, 0);
 967
 968         file->private_data = chip;
 969         return 0;
 970 }
 971 EXPORT_SYMBOL_GPL(tpm_open);
 972
 973 /*
 974  * Called on file close
 975  */
 976 int tpm_release(struct inode *inode, struct file *file)
 977 {
 978         struct tpm_chip *chip = file->private_data;
 979
 980         del_singleshot_timer_sync(&chip->user_read_timer);
 981         flush_scheduled_work();
 982         file->private_data = NULL;
 983         atomic_set(&chip->data_pending, 0);
 984         kfree(chip->data_buffer);
 985         clear_bit(0, &chip->is_open);
 986         put_device(chip->dev);
 987         return 0;
 988 }
 989 EXPORT_SYMBOL_GPL(tpm_release);
 990
 991 ssize_t tpm_write(struct file *file, const char __user *buf,
 992                   size_t size, loff_t *off)
 993 {
 994         struct tpm_chip *chip = file->private_data;
 995         size_t in_size = size, out_size;
 996
 997         /* cannot perform a write until the read has cleared
 998            either via tpm_read or a user_read_timer timeout */
 999         while (atomic_read(&chip->data_pending) != 0)
1000                 msleep(TPM_TIMEOUT);
1001
1002         mutex_lock(&chip->buffer_mutex);
1003
1004         if (in_size > TPM_BUFSIZE)
1005                 in_size = TPM_BUFSIZE;
1006
1007         if (copy_from_user
1008             (chip->data_buffer, (void __user *) buf, in_size)) {
1009                 mutex_unlock(&chip->buffer_mutex);
1010                 return -EFAULT;
1011         }
1012
1013         /* atomic tpm command send and result receive */
1014         out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
1015
1016         atomic_set(&chip->data_pending, out_size);
1017         mutex_unlock(&chip->buffer_mutex);
1018
1019         /* Set a timeout by which the reader must come claim the result */
1020         mod_timer(&chip->user_read_timer, jiffies + (60 * HZ));
1021
1022         return in_size;
1023 }
1024 EXPORT_SYMBOL_GPL(tpm_write);
1025
1026 ssize_t tpm_read(struct file *file, char __user *buf,
1027                  size_t size, loff_t *off)
1028 {
1029         struct tpm_chip *chip = file->private_data;
1030         ssize_t ret_size;
1031
1032         del_singleshot_timer_sync(&chip->user_read_timer);
1033         flush_scheduled_work();
1034         ret_size = atomic_read(&chip->data_pending);
1035         atomic_set(&chip->data_pending, 0);
1036         if (ret_size > 0) {     /* relay data */
1037                 if (size < ret_size)
1038                         ret_size = size;
1039
1040                 mutex_lock(&chip->buffer_mutex);
1041                 if (copy_to_user(buf, chip->data_buffer, ret_size))
1042                         ret_size = -EFAULT;
1043                 mutex_unlock(&chip->buffer_mutex);
1044         }
1045
1046         return ret_size;
1047 }
1048 EXPORT_SYMBOL_GPL(tpm_read);
1049
1050 void tpm_remove_hardware(struct device *dev)
1051 {
1052         struct tpm_chip *chip = dev_get_drvdata(dev);
1053
1054         if (chip == NULL) {
1055                 dev_err(dev, "No device data found\n");
1056                 return;
1057         }
1058
1059         spin_lock(&driver_lock);
1060         list_del_rcu(&chip->list);
1061         spin_unlock(&driver_lock);
1062         synchronize_rcu();
1063
1064         misc_deregister(&chip->vendor.miscdev);
1065         sysfs_remove_group(&dev->kobj, chip->vendor.attr_group);
1066         tpm_bios_log_teardown(chip->bios_dir);
1067
1068         /* write it this way to be explicit (chip->dev == dev) */
1069         put_device(chip->dev);
1070 }
1071 EXPORT_SYMBOL_GPL(tpm_remove_hardware);
1072
1073 /*
1074  * We are about to suspend. Save the TPM state
1075  * so that it can be restored.
1076  */
1077 int tpm_pm_suspend(struct device *dev, pm_message_t pm_state)
1078 {
1079         struct tpm_chip *chip = dev_get_drvdata(dev);
1080         u8 savestate[] = {
1081                 0, 193,         /* TPM_TAG_RQU_COMMAND */
1082                 0, 0, 0, 10,    /* blob length (in bytes) */
1083                 0, 0, 0, 152    /* TPM_ORD_SaveState */
1084         };
1085
1086         if (chip == NULL)
1087                 return -ENODEV;
1088
1089         tpm_transmit(chip, savestate, sizeof(savestate));
1090         return 0;
1091 }
1092 EXPORT_SYMBOL_GPL(tpm_pm_suspend);
1093
1094 /*
1095  * Resume from a power safe. The BIOS already restored
1096  * the TPM state.
1097  */
1098 int tpm_pm_resume(struct device *dev)
1099 {
1100         struct tpm_chip *chip = dev_get_drvdata(dev);
1101
1102         if (chip == NULL)
1103                 return -ENODEV;
1104
1105         return 0;
1106 }
1107 EXPORT_SYMBOL_GPL(tpm_pm_resume);
1108
1109 /* In case vendor provided release function, call it too.*/
1110
1111 void tpm_dev_vendor_release(struct tpm_chip *chip)
1112 {
1113         if (chip->vendor.release)
1114                 chip->vendor.release(chip->dev);
1115
1116         clear_bit(chip->dev_num, dev_mask);
1117         kfree(chip->vendor.miscdev.name);
1118 }
1119 EXPORT_SYMBOL_GPL(tpm_dev_vendor_release);
1120
1121
1122 /*
1123  * Once all references to platform device are down to 0,
1124  * release all allocated structures.
1125  */
1126 void tpm_dev_release(struct device *dev)
1127 {
1128         struct tpm_chip *chip = dev_get_drvdata(dev);
1129
1130         tpm_dev_vendor_release(chip);
1131
1132         chip->release(dev);
1133         kfree(chip);
1134 }
1135 EXPORT_SYMBOL_GPL(tpm_dev_release);
1136
1137 /*
1138  * Called from tpm_<specific>.c probe function only for devices
1139  * the driver has determined it should claim.  Prior to calling
1140  * this function the specific probe function has called pci_enable_device
1141  * upon errant exit from this function specific probe function should call
1142  * pci_disable_device
1143  */
1144 struct tpm_chip *tpm_register_hardware(struct device *dev,
1145                                         const struct tpm_vendor_specific *entry)
1146 {
1147 #define DEVNAME_SIZE 7
1148
1149         char *devname;
1150         struct tpm_chip *chip;
1151
1152         /* Driver specific per-device data */
1153         chip = kzalloc(sizeof(*chip), GFP_KERNEL);
1154         devname = kmalloc(DEVNAME_SIZE, GFP_KERNEL);
1155
1156         if (chip == NULL || devname == NULL)
1157                 goto out_free;
1158
1159         mutex_init(&chip->buffer_mutex);
1160         mutex_init(&chip->tpm_mutex);
1161         INIT_LIST_HEAD(&chip->list);
1162
1163         INIT_WORK(&chip->work, timeout_work);
1164
1165         setup_timer(&chip->user_read_timer, user_reader_timeout,
1166                         (unsigned long)chip);
1167
1168         memcpy(&chip->vendor, entry, sizeof(struct tpm_vendor_specific));
1169
1170         chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);
1171
1172         if (chip->dev_num >= TPM_NUM_DEVICES) {
1173                 dev_err(dev, "No available tpm device numbers\n");
1174                 goto out_free;
1175         } else if (chip->dev_num == 0)
1176                 chip->vendor.miscdev.minor = TPM_MINOR;
1177         else
1178                 chip->vendor.miscdev.minor = MISC_DYNAMIC_MINOR;
1179
1180         set_bit(chip->dev_num, dev_mask);
1181
1182         scnprintf(devname, DEVNAME_SIZE, "%s%d", "tpm", chip->dev_num);
1183         chip->vendor.miscdev.name = devname;
1184
1185         chip->vendor.miscdev.parent = dev;
1186         chip->dev = get_device(dev);
1187         chip->release = dev->release;
1188         dev->release = tpm_dev_release;
1189         dev_set_drvdata(dev, chip);
1190
1191         if (misc_register(&chip->vendor.miscdev)) {
1192                 dev_err(chip->dev,
1193                         "unable to misc_register %s, minor %d\n",
1194                         chip->vendor.miscdev.name,
1195                         chip->vendor.miscdev.minor);
1196                 put_device(chip->dev);
1197                 return NULL;
1198         }
1199
1200         if (sysfs_create_group(&dev->kobj, chip->vendor.attr_group)) {
1201                 misc_deregister(&chip->vendor.miscdev);
1202                 put_device(chip->dev);
1203
1204                 return NULL;
1205         }
1206
1207         chip->bios_dir = tpm_bios_log_setup(devname);
1208
1209         /* Make chip available */
1210         spin_lock(&driver_lock);
1211         list_add_rcu(&chip->list, &tpm_chip_list);
1212         spin_unlock(&driver_lock);
1213
1214         return chip;
1215
1216 out_free:
1217         kfree(chip);
1218         kfree(devname);
1219         return NULL;
1220 }
1221 EXPORT_SYMBOL_GPL(tpm_register_hardware);
1222
1223 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1224 MODULE_DESCRIPTION("TPM Driver");
1225 MODULE_VERSION("2.0");
1226 MODULE_LICENSE("GPL");