drivers/char/tpm/tpm_tis_core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2005, 2006 IBM Corporation
   4  * Copyright (C) 2014, 2015 Intel Corporation
   5  *
   6  * Authors:
   7  * Leendert van Doorn <leendert@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 device driver implements the TPM interface as defined in
  16  * the TCG TPM Interface Spec version 1.2, revision 1.0.
  17  */
  18 #include <linux/init.h>
  19 #include <linux/module.h>
  20 #include <linux/moduleparam.h>
  21 #include <linux/pnp.h>
  22 #include <linux/slab.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/wait.h>
  25 #include <linux/acpi.h>
  26 #include <linux/freezer.h>
  27 #include "tpm.h"
  28 #include "tpm_tis_core.h"
  29
  30 static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value);
  31
  32 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
  33                                         bool check_cancel, bool *canceled)
  34 {
  35         u8 status = chip->ops->status(chip);
  36
  37         *canceled = false;
  38         if ((status & mask) == mask)
  39                 return true;
  40         if (check_cancel && chip->ops->req_canceled(chip, status)) {
  41                 *canceled = true;
  42                 return true;
  43         }
  44         return false;
  45 }
  46
  47 static int wait_for_tpm_stat(struct tpm_chip *chip, u8 mask,
  48                 unsigned long timeout, wait_queue_head_t *queue,
  49                 bool check_cancel)
  50 {
  51         unsigned long stop;
  52         long rc;
  53         u8 status;
  54         bool canceled = false;
  55
  56         /* check current status */
  57         status = chip->ops->status(chip);
  58         if ((status & mask) == mask)
  59                 return 0;
  60
  61         stop = jiffies + timeout;
  62
  63         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
  64 again:
  65                 timeout = stop - jiffies;
  66                 if ((long)timeout <= 0)
  67                         return -ETIME;
  68                 rc = wait_event_interruptible_timeout(*queue,
  69                         wait_for_tpm_stat_cond(chip, mask, check_cancel,
  70                                                &canceled),
  71                         timeout);
  72                 if (rc > 0) {
  73                         if (canceled)
  74                                 return -ECANCELED;
  75                         return 0;
  76                 }
  77                 if (rc == -ERESTARTSYS && freezing(current)) {
  78                         clear_thread_flag(TIF_SIGPENDING);
  79                         goto again;
  80                 }
  81         } else {
  82                 do {
  83                         usleep_range(TPM_TIMEOUT_USECS_MIN,
  84                                      TPM_TIMEOUT_USECS_MAX);
  85                         status = chip->ops->status(chip);
  86                         if ((status & mask) == mask)
  87                                 return 0;
  88                 } while (time_before(jiffies, stop));
  89         }
  90         return -ETIME;
  91 }
  92
  93 /* Before we attempt to access the TPM we must see that the valid bit is set.
  94  * The specification says that this bit is 0 at reset and remains 0 until the
  95  * 'TPM has gone through its self test and initialization and has established
  96  * correct values in the other bits.'
  97  */
  98 static int wait_startup(struct tpm_chip *chip, int l)
  99 {
 100         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 101         unsigned long stop = jiffies + chip->timeout_a;
 102
 103         do {
 104                 int rc;
 105                 u8 access;
 106
 107                 rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
 108                 if (rc < 0)
 109                         return rc;
 110
 111                 if (access & TPM_ACCESS_VALID)
 112                         return 0;
 113                 tpm_msleep(TPM_TIMEOUT);
 114         } while (time_before(jiffies, stop));
 115         return -1;
 116 }
 117
 118 static bool check_locality(struct tpm_chip *chip, int l)
 119 {
 120         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 121         int rc;
 122         u8 access;
 123
 124         rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
 125         if (rc < 0)
 126                 return false;
 127
 128         if ((access & (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) ==
 129             (TPM_ACCESS_ACTIVE_LOCALITY | TPM_ACCESS_VALID)) {
 130                 priv->locality = l;
 131                 return true;
 132         }
 133
 134         return false;
 135 }
 136
 137 static bool locality_inactive(struct tpm_chip *chip, int l)
 138 {
 139         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 140         int rc;
 141         u8 access;
 142
 143         rc = tpm_tis_read8(priv, TPM_ACCESS(l), &access);
 144         if (rc < 0)
 145                 return false;
 146
 147         if ((access & (TPM_ACCESS_VALID | TPM_ACCESS_ACTIVE_LOCALITY))
 148             == TPM_ACCESS_VALID)
 149                 return true;
 150
 151         return false;
 152 }
 153
 154 static int release_locality(struct tpm_chip *chip, int l)
 155 {
 156         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 157         unsigned long stop, timeout;
 158         long rc;
 159
 160         tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_ACTIVE_LOCALITY);
 161
 162         stop = jiffies + chip->timeout_a;
 163
 164         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
 165 again:
 166                 timeout = stop - jiffies;
 167                 if ((long)timeout <= 0)
 168                         return -1;
 169
 170                 rc = wait_event_interruptible_timeout(priv->int_queue,
 171                                                       (locality_inactive(chip, l)),
 172                                                       timeout);
 173
 174                 if (rc > 0)
 175                         return 0;
 176
 177                 if (rc == -ERESTARTSYS && freezing(current)) {
 178                         clear_thread_flag(TIF_SIGPENDING);
 179                         goto again;
 180                 }
 181         } else {
 182                 do {
 183                         if (locality_inactive(chip, l))
 184                                 return 0;
 185                         tpm_msleep(TPM_TIMEOUT);
 186                 } while (time_before(jiffies, stop));
 187         }
 188         return -1;
 189 }
 190
 191 static int request_locality(struct tpm_chip *chip, int l)
 192 {
 193         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 194         unsigned long stop, timeout;
 195         long rc;
 196
 197         if (check_locality(chip, l))
 198                 return l;
 199
 200         rc = tpm_tis_write8(priv, TPM_ACCESS(l), TPM_ACCESS_REQUEST_USE);
 201         if (rc < 0)
 202                 return rc;
 203
 204         stop = jiffies + chip->timeout_a;
 205
 206         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
 207 again:
 208                 timeout = stop - jiffies;
 209                 if ((long)timeout <= 0)
 210                         return -1;
 211                 rc = wait_event_interruptible_timeout(priv->int_queue,
 212                                                       (check_locality
 213                                                        (chip, l)),
 214                                                       timeout);
 215                 if (rc > 0)
 216                         return l;
 217                 if (rc == -ERESTARTSYS && freezing(current)) {
 218                         clear_thread_flag(TIF_SIGPENDING);
 219                         goto again;
 220                 }
 221         } else {
 222                 /* wait for burstcount */
 223                 do {
 224                         if (check_locality(chip, l))
 225                                 return l;
 226                         tpm_msleep(TPM_TIMEOUT);
 227                 } while (time_before(jiffies, stop));
 228         }
 229         return -1;
 230 }
 231
 232 static u8 tpm_tis_status(struct tpm_chip *chip)
 233 {
 234         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 235         int rc;
 236         u8 status;
 237
 238         rc = tpm_tis_read8(priv, TPM_STS(priv->locality), &status);
 239         if (rc < 0)
 240                 return 0;
 241
 242         return status;
 243 }
 244
 245 static void tpm_tis_ready(struct tpm_chip *chip)
 246 {
 247         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 248
 249         /* this causes the current command to be aborted */
 250         tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_COMMAND_READY);
 251 }
 252
 253 static int get_burstcount(struct tpm_chip *chip)
 254 {
 255         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 256         unsigned long stop;
 257         int burstcnt, rc;
 258         u32 value;
 259
 260         /* wait for burstcount */
 261         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 262                 stop = jiffies + chip->timeout_a;
 263         else
 264                 stop = jiffies + chip->timeout_d;
 265         do {
 266                 rc = tpm_tis_read32(priv, TPM_STS(priv->locality), &value);
 267                 if (rc < 0)
 268                         return rc;
 269
 270                 burstcnt = (value >> 8) & 0xFFFF;
 271                 if (burstcnt)
 272                         return burstcnt;
 273                 usleep_range(TPM_TIMEOUT_USECS_MIN, TPM_TIMEOUT_USECS_MAX);
 274         } while (time_before(jiffies, stop));
 275         return -EBUSY;
 276 }
 277
 278 static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count)
 279 {
 280         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 281         int size = 0, burstcnt, rc;
 282
 283         while (size < count) {
 284                 rc = wait_for_tpm_stat(chip,
 285                                  TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 286                                  chip->timeout_c,
 287                                  &priv->read_queue, true);
 288                 if (rc < 0)
 289                         return rc;
 290                 burstcnt = get_burstcount(chip);
 291                 if (burstcnt < 0) {
 292                         dev_err(&chip->dev, "Unable to read burstcount\n");
 293                         return burstcnt;
 294                 }
 295                 burstcnt = min_t(int, burstcnt, count - size);
 296
 297                 rc = tpm_tis_read_bytes(priv, TPM_DATA_FIFO(priv->locality),
 298                                         burstcnt, buf + size);
 299                 if (rc < 0)
 300                         return rc;
 301
 302                 size += burstcnt;
 303         }
 304         return size;
 305 }
 306
 307 static int tpm_tis_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 308 {
 309         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 310         int size = 0;
 311         int status;
 312         u32 expected;
 313
 314         if (count < TPM_HEADER_SIZE) {
 315                 size = -EIO;
 316                 goto out;
 317         }
 318
 319         size = recv_data(chip, buf, TPM_HEADER_SIZE);
 320         /* read first 10 bytes, including tag, paramsize, and result */
 321         if (size < TPM_HEADER_SIZE) {
 322                 dev_err(&chip->dev, "Unable to read header\n");
 323                 goto out;
 324         }
 325
 326         expected = be32_to_cpu(*(__be32 *) (buf + 2));
 327         if (expected > count || expected < TPM_HEADER_SIZE) {
 328                 size = -EIO;
 329                 goto out;
 330         }
 331
 332         size += recv_data(chip, &buf[TPM_HEADER_SIZE],
 333                           expected - TPM_HEADER_SIZE);
 334         if (size < expected) {
 335                 dev_err(&chip->dev, "Unable to read remainder of result\n");
 336                 size = -ETIME;
 337                 goto out;
 338         }
 339
 340         if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
 341                                 &priv->int_queue, false) < 0) {
 342                 size = -ETIME;
 343                 goto out;
 344         }
 345         status = tpm_tis_status(chip);
 346         if (status & TPM_STS_DATA_AVAIL) {      /* retry? */
 347                 dev_err(&chip->dev, "Error left over data\n");
 348                 size = -EIO;
 349                 goto out;
 350         }
 351
 352 out:
 353         tpm_tis_ready(chip);
 354         return size;
 355 }
 356
 357 /*
 358  * If interrupts are used (signaled by an irq set in the vendor structure)
 359  * tpm.c can skip polling for the data to be available as the interrupt is
 360  * waited for here
 361  */
 362 static int tpm_tis_send_data(struct tpm_chip *chip, const u8 *buf, size_t len)
 363 {
 364         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 365         int rc, status, burstcnt;
 366         size_t count = 0;
 367         bool itpm = priv->flags & TPM_TIS_ITPM_WORKAROUND;
 368
 369         status = tpm_tis_status(chip);
 370         if ((status & TPM_STS_COMMAND_READY) == 0) {
 371                 tpm_tis_ready(chip);
 372                 if (wait_for_tpm_stat
 373                     (chip, TPM_STS_COMMAND_READY, chip->timeout_b,
 374                      &priv->int_queue, false) < 0) {
 375                         rc = -ETIME;
 376                         goto out_err;
 377                 }
 378         }
 379
 380         while (count < len - 1) {
 381                 burstcnt = get_burstcount(chip);
 382                 if (burstcnt < 0) {
 383                         dev_err(&chip->dev, "Unable to read burstcount\n");
 384                         rc = burstcnt;
 385                         goto out_err;
 386                 }
 387                 burstcnt = min_t(int, burstcnt, len - count - 1);
 388                 rc = tpm_tis_write_bytes(priv, TPM_DATA_FIFO(priv->locality),
 389                                          burstcnt, buf + count);
 390                 if (rc < 0)
 391                         goto out_err;
 392
 393                 count += burstcnt;
 394
 395                 if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
 396                                         &priv->int_queue, false) < 0) {
 397                         rc = -ETIME;
 398                         goto out_err;
 399                 }
 400                 status = tpm_tis_status(chip);
 401                 if (!itpm && (status & TPM_STS_DATA_EXPECT) == 0) {
 402                         rc = -EIO;
 403                         goto out_err;
 404                 }
 405         }
 406
 407         /* write last byte */
 408         rc = tpm_tis_write8(priv, TPM_DATA_FIFO(priv->locality), buf[count]);
 409         if (rc < 0)
 410                 goto out_err;
 411
 412         if (wait_for_tpm_stat(chip, TPM_STS_VALID, chip->timeout_c,
 413                                 &priv->int_queue, false) < 0) {
 414                 rc = -ETIME;
 415                 goto out_err;
 416         }
 417         status = tpm_tis_status(chip);
 418         if (!itpm && (status & TPM_STS_DATA_EXPECT) != 0) {
 419                 rc = -EIO;
 420                 goto out_err;
 421         }
 422
 423         return 0;
 424
 425 out_err:
 426         tpm_tis_ready(chip);
 427         return rc;
 428 }
 429
 430 static void disable_interrupts(struct tpm_chip *chip)
 431 {
 432         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 433         u32 intmask;
 434         int rc;
 435
 436         rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
 437         if (rc < 0)
 438                 intmask = 0;
 439
 440         intmask &= ~TPM_GLOBAL_INT_ENABLE;
 441         rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
 442
 443         devm_free_irq(chip->dev.parent, priv->irq, chip);
 444         priv->irq = 0;
 445         chip->flags &= ~TPM_CHIP_FLAG_IRQ;
 446 }
 447
 448 /*
 449  * If interrupts are used (signaled by an irq set in the vendor structure)
 450  * tpm.c can skip polling for the data to be available as the interrupt is
 451  * waited for here
 452  */
 453 static int tpm_tis_send_main(struct tpm_chip *chip, const u8 *buf, size_t len)
 454 {
 455         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 456         int rc;
 457         u32 ordinal;
 458         unsigned long dur;
 459
 460         rc = tpm_tis_send_data(chip, buf, len);
 461         if (rc < 0)
 462                 return rc;
 463
 464         /* go and do it */
 465         rc = tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO);
 466         if (rc < 0)
 467                 goto out_err;
 468
 469         if (chip->flags & TPM_CHIP_FLAG_IRQ) {
 470                 ordinal = be32_to_cpu(*((__be32 *) (buf + 6)));
 471
 472                 dur = tpm_calc_ordinal_duration(chip, ordinal);
 473                 if (wait_for_tpm_stat
 474                     (chip, TPM_STS_DATA_AVAIL | TPM_STS_VALID, dur,
 475                      &priv->read_queue, false) < 0) {
 476                         rc = -ETIME;
 477                         goto out_err;
 478                 }
 479         }
 480         return 0;
 481 out_err:
 482         tpm_tis_ready(chip);
 483         return rc;
 484 }
 485
 486 static int tpm_tis_send(struct tpm_chip *chip, u8 *buf, size_t len)
 487 {
 488         int rc, irq;
 489         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 490
 491         if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || priv->irq_tested)
 492                 return tpm_tis_send_main(chip, buf, len);
 493
 494         /* Verify receipt of the expected IRQ */
 495         irq = priv->irq;
 496         priv->irq = 0;
 497         chip->flags &= ~TPM_CHIP_FLAG_IRQ;
 498         rc = tpm_tis_send_main(chip, buf, len);
 499         priv->irq = irq;
 500         chip->flags |= TPM_CHIP_FLAG_IRQ;
 501         if (!priv->irq_tested)
 502                 tpm_msleep(1);
 503         if (!priv->irq_tested)
 504                 disable_interrupts(chip);
 505         priv->irq_tested = true;
 506         return rc;
 507 }
 508
 509 struct tis_vendor_timeout_override {
 510         u32 did_vid;
 511         unsigned long timeout_us[4];
 512 };
 513
 514 static const struct tis_vendor_timeout_override vendor_timeout_overrides[] = {
 515         /* Atmel 3204 */
 516         { 0x32041114, { (TIS_SHORT_TIMEOUT*1000), (TIS_LONG_TIMEOUT*1000),
 517                         (TIS_SHORT_TIMEOUT*1000), (TIS_SHORT_TIMEOUT*1000) } },
 518 };
 519
 520 static void tpm_tis_update_timeouts(struct tpm_chip *chip,
 521                                     unsigned long *timeout_cap)
 522 {
 523         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 524         int i, rc;
 525         u32 did_vid;
 526
 527         chip->timeout_adjusted = false;
 528
 529         if (chip->ops->clk_enable != NULL)
 530                 chip->ops->clk_enable(chip, true);
 531
 532         rc = tpm_tis_read32(priv, TPM_DID_VID(0), &did_vid);
 533         if (rc < 0) {
 534                 dev_warn(&chip->dev, "%s: failed to read did_vid: %d\n",
 535                          __func__, rc);
 536                 goto out;
 537         }
 538
 539         for (i = 0; i != ARRAY_SIZE(vendor_timeout_overrides); i++) {
 540                 if (vendor_timeout_overrides[i].did_vid != did_vid)
 541                         continue;
 542                 memcpy(timeout_cap, vendor_timeout_overrides[i].timeout_us,
 543                        sizeof(vendor_timeout_overrides[i].timeout_us));
 544                 chip->timeout_adjusted = true;
 545         }
 546
 547 out:
 548         if (chip->ops->clk_enable != NULL)
 549                 chip->ops->clk_enable(chip, false);
 550
 551         return;
 552 }
 553
 554 /*
 555  * Early probing for iTPM with STS_DATA_EXPECT flaw.
 556  * Try sending command without itpm flag set and if that
 557  * fails, repeat with itpm flag set.
 558  */
 559 static int probe_itpm(struct tpm_chip *chip)
 560 {
 561         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 562         int rc = 0;
 563         static const u8 cmd_getticks[] = {
 564                 0x00, 0xc1, 0x00, 0x00, 0x00, 0x0a,
 565                 0x00, 0x00, 0x00, 0xf1
 566         };
 567         size_t len = sizeof(cmd_getticks);
 568         u16 vendor;
 569
 570         if (priv->flags & TPM_TIS_ITPM_WORKAROUND)
 571                 return 0;
 572
 573         rc = tpm_tis_read16(priv, TPM_DID_VID(0), &vendor);
 574         if (rc < 0)
 575                 return rc;
 576
 577         /* probe only iTPMS */
 578         if (vendor != TPM_VID_INTEL)
 579                 return 0;
 580
 581         if (request_locality(chip, 0) != 0)
 582                 return -EBUSY;
 583
 584         rc = tpm_tis_send_data(chip, cmd_getticks, len);
 585         if (rc == 0)
 586                 goto out;
 587
 588         tpm_tis_ready(chip);
 589
 590         priv->flags |= TPM_TIS_ITPM_WORKAROUND;
 591
 592         rc = tpm_tis_send_data(chip, cmd_getticks, len);
 593         if (rc == 0)
 594                 dev_info(&chip->dev, "Detected an iTPM.\n");
 595         else {
 596                 priv->flags &= ~TPM_TIS_ITPM_WORKAROUND;
 597                 rc = -EFAULT;
 598         }
 599
 600 out:
 601         tpm_tis_ready(chip);
 602         release_locality(chip, priv->locality);
 603
 604         return rc;
 605 }
 606
 607 static bool tpm_tis_req_canceled(struct tpm_chip *chip, u8 status)
 608 {
 609         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 610
 611         switch (priv->manufacturer_id) {
 612         case TPM_VID_WINBOND:
 613                 return ((status == TPM_STS_VALID) ||
 614                         (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY)));
 615         case TPM_VID_STM:
 616                 return (status == (TPM_STS_VALID | TPM_STS_COMMAND_READY));
 617         default:
 618                 return (status == TPM_STS_COMMAND_READY);
 619         }
 620 }
 621
 622 static irqreturn_t tis_int_handler(int dummy, void *dev_id)
 623 {
 624         struct tpm_chip *chip = dev_id;
 625         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 626         u32 interrupt;
 627         int i, rc;
 628
 629         rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
 630         if (rc < 0)
 631                 return IRQ_NONE;
 632
 633         if (interrupt == 0)
 634                 return IRQ_NONE;
 635
 636         priv->irq_tested = true;
 637         if (interrupt & TPM_INTF_DATA_AVAIL_INT)
 638                 wake_up_interruptible(&priv->read_queue);
 639         if (interrupt & TPM_INTF_LOCALITY_CHANGE_INT)
 640                 for (i = 0; i < 5; i++)
 641                         if (check_locality(chip, i))
 642                                 break;
 643         if (interrupt &
 644             (TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_STS_VALID_INT |
 645              TPM_INTF_CMD_READY_INT))
 646                 wake_up_interruptible(&priv->int_queue);
 647
 648         /* Clear interrupts handled with TPM_EOI */
 649         rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), interrupt);
 650         if (rc < 0)
 651                 return IRQ_NONE;
 652
 653         tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
 654         return IRQ_HANDLED;
 655 }
 656
 657 static int tpm_tis_gen_interrupt(struct tpm_chip *chip)
 658 {
 659         const char *desc = "attempting to generate an interrupt";
 660         u32 cap2;
 661         cap_t cap;
 662
 663         if (chip->flags & TPM_CHIP_FLAG_TPM2)
 664                 return tpm2_get_tpm_pt(chip, 0x100, &cap2, desc);
 665         else
 666                 return tpm1_getcap(chip, TPM_CAP_PROP_TIS_TIMEOUT, &cap, desc,
 667                                   0);
 668 }
 669
 670 /* Register the IRQ and issue a command that will cause an interrupt. If an
 671  * irq is seen then leave the chip setup for IRQ operation, otherwise reverse
 672  * everything and leave in polling mode. Returns 0 on success.
 673  */
 674 static int tpm_tis_probe_irq_single(struct tpm_chip *chip, u32 intmask,
 675                                     int flags, int irq)
 676 {
 677         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 678         u8 original_int_vec;
 679         int rc;
 680         u32 int_status;
 681
 682         if (devm_request_irq(chip->dev.parent, irq, tis_int_handler, flags,
 683                              dev_name(&chip->dev), chip) != 0) {
 684                 dev_info(&chip->dev, "Unable to request irq: %d for probe\n",
 685                          irq);
 686                 return -1;
 687         }
 688         priv->irq = irq;
 689
 690         rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
 691                            &original_int_vec);
 692         if (rc < 0)
 693                 return rc;
 694
 695         rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), irq);
 696         if (rc < 0)
 697                 return rc;
 698
 699         rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &int_status);
 700         if (rc < 0)
 701                 return rc;
 702
 703         /* Clear all existing */
 704         rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), int_status);
 705         if (rc < 0)
 706                 return rc;
 707
 708         /* Turn on */
 709         rc = tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality),
 710                              intmask | TPM_GLOBAL_INT_ENABLE);
 711         if (rc < 0)
 712                 return rc;
 713
 714         priv->irq_tested = false;
 715
 716         /* Generate an interrupt by having the core call through to
 717          * tpm_tis_send
 718          */
 719         rc = tpm_tis_gen_interrupt(chip);
 720         if (rc < 0)
 721                 return rc;
 722
 723         /* tpm_tis_send will either confirm the interrupt is working or it
 724          * will call disable_irq which undoes all of the above.
 725          */
 726         if (!(chip->flags & TPM_CHIP_FLAG_IRQ)) {
 727                 rc = tpm_tis_write8(priv, original_int_vec,
 728                                 TPM_INT_VECTOR(priv->locality));
 729                 if (rc < 0)
 730                         return rc;
 731
 732                 return 1;
 733         }
 734
 735         return 0;
 736 }
 737
 738 /* Try to find the IRQ the TPM is using. This is for legacy x86 systems that
 739  * do not have ACPI/etc. We typically expect the interrupt to be declared if
 740  * present.
 741  */
 742 static void tpm_tis_probe_irq(struct tpm_chip *chip, u32 intmask)
 743 {
 744         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 745         u8 original_int_vec;
 746         int i, rc;
 747
 748         rc = tpm_tis_read8(priv, TPM_INT_VECTOR(priv->locality),
 749                            &original_int_vec);
 750         if (rc < 0)
 751                 return;
 752
 753         if (!original_int_vec) {
 754                 if (IS_ENABLED(CONFIG_X86))
 755                         for (i = 3; i <= 15; i++)
 756                                 if (!tpm_tis_probe_irq_single(chip, intmask, 0,
 757                                                               i))
 758                                         return;
 759         } else if (!tpm_tis_probe_irq_single(chip, intmask, 0,
 760                                              original_int_vec))
 761                 return;
 762 }
 763
 764 void tpm_tis_remove(struct tpm_chip *chip)
 765 {
 766         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
 767         u32 reg = TPM_INT_ENABLE(priv->locality);
 768         u32 interrupt;
 769         int rc;
 770
 771         tpm_tis_clkrun_enable(chip, true);
 772
 773         rc = tpm_tis_read32(priv, reg, &interrupt);
 774         if (rc < 0)
 775                 interrupt = 0;
 776
 777         tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
 778
 779         tpm_tis_clkrun_enable(chip, false);
 780
 781         if (priv->ilb_base_addr)
 782                 iounmap(priv->ilb_base_addr);
 783 }
 784 EXPORT_SYMBOL_GPL(tpm_tis_remove);
 785
 786 /**
 787  * tpm_tis_clkrun_enable() - Keep clkrun protocol disabled for entire duration
 788  *                           of a single TPM command
 789  * @chip:       TPM chip to use
 790  * @value:      1 - Disable CLKRUN protocol, so that clocks are free running
 791  *              0 - Enable CLKRUN protocol
 792  * Call this function directly in tpm_tis_remove() in error or driver removal
 793  * path, since the chip->ops is set to NULL in tpm_chip_unregister().
 794  */
 795 static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value)
 796 {
 797         struct tpm_tis_data *data = dev_get_drvdata(&chip->dev);
 798         u32 clkrun_val;
 799
 800         if (!IS_ENABLED(CONFIG_X86) || !is_bsw() ||
 801             !data->ilb_base_addr)
 802                 return;
 803
 804         if (value) {
 805                 data->clkrun_enabled++;
 806                 if (data->clkrun_enabled > 1)
 807                         return;
 808                 clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
 809
 810                 /* Disable LPC CLKRUN# */
 811                 clkrun_val &= ~LPC_CLKRUN_EN;
 812                 iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
 813
 814                 /*
 815                  * Write any random value on port 0x80 which is on LPC, to make
 816                  * sure LPC clock is running before sending any TPM command.
 817                  */
 818                 outb(0xCC, 0x80);
 819         } else {
 820                 data->clkrun_enabled--;
 821                 if (data->clkrun_enabled)
 822                         return;
 823
 824                 clkrun_val = ioread32(data->ilb_base_addr + LPC_CNTRL_OFFSET);
 825
 826                 /* Enable LPC CLKRUN# */
 827                 clkrun_val |= LPC_CLKRUN_EN;
 828                 iowrite32(clkrun_val, data->ilb_base_addr + LPC_CNTRL_OFFSET);
 829
 830                 /*
 831                  * Write any random value on port 0x80 which is on LPC, to make
 832                  * sure LPC clock is running before sending any TPM command.
 833                  */
 834                 outb(0xCC, 0x80);
 835         }
 836 }
 837
 838 static const struct tpm_class_ops tpm_tis = {
 839         .flags = TPM_OPS_AUTO_STARTUP,
 840         .status = tpm_tis_status,
 841         .recv = tpm_tis_recv,
 842         .send = tpm_tis_send,
 843         .cancel = tpm_tis_ready,
 844         .update_timeouts = tpm_tis_update_timeouts,
 845         .req_complete_mask = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 846         .req_complete_val = TPM_STS_DATA_AVAIL | TPM_STS_VALID,
 847         .req_canceled = tpm_tis_req_canceled,
 848         .request_locality = request_locality,
 849         .relinquish_locality = release_locality,
 850         .clk_enable = tpm_tis_clkrun_enable,
 851 };
 852
 853 int tpm_tis_core_init(struct device *dev, struct tpm_tis_data *priv, int irq,
 854                       const struct tpm_tis_phy_ops *phy_ops,
 855                       acpi_handle acpi_dev_handle)
 856 {
 857         u32 vendor;
 858         u32 intfcaps;
 859         u32 intmask;
 860         u32 clkrun_val;
 861         u8 rid;
 862         int rc, probe;
 863         struct tpm_chip *chip;
 864
 865         chip = tpmm_chip_alloc(dev, &tpm_tis);
 866         if (IS_ERR(chip))
 867                 return PTR_ERR(chip);
 868
 869 #ifdef CONFIG_ACPI
 870         chip->acpi_dev_handle = acpi_dev_handle;
 871 #endif
 872
 873         chip->hwrng.quality = priv->rng_quality;
 874
 875         /* Maximum timeouts */
 876         chip->timeout_a = msecs_to_jiffies(TIS_TIMEOUT_A_MAX);
 877         chip->timeout_b = msecs_to_jiffies(TIS_TIMEOUT_B_MAX);
 878         chip->timeout_c = msecs_to_jiffies(TIS_TIMEOUT_C_MAX);
 879         chip->timeout_d = msecs_to_jiffies(TIS_TIMEOUT_D_MAX);
 880         priv->phy_ops = phy_ops;
 881         dev_set_drvdata(&chip->dev, priv);
 882
 883         if (is_bsw()) {
 884                 priv->ilb_base_addr = ioremap(INTEL_LEGACY_BLK_BASE_ADDR,
 885                                         ILB_REMAP_SIZE);
 886                 if (!priv->ilb_base_addr)
 887                         return -ENOMEM;
 888
 889                 clkrun_val = ioread32(priv->ilb_base_addr + LPC_CNTRL_OFFSET);
 890                 /* Check if CLKRUN# is already not enabled in the LPC bus */
 891                 if (!(clkrun_val & LPC_CLKRUN_EN)) {
 892                         iounmap(priv->ilb_base_addr);
 893                         priv->ilb_base_addr = NULL;
 894                 }
 895         }
 896
 897         if (chip->ops->clk_enable != NULL)
 898                 chip->ops->clk_enable(chip, true);
 899
 900         if (wait_startup(chip, 0) != 0) {
 901                 rc = -ENODEV;
 902                 goto out_err;
 903         }
 904
 905         /* Take control of the TPM's interrupt hardware and shut it off */
 906         rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
 907         if (rc < 0)
 908                 goto out_err;
 909
 910         intmask |= TPM_INTF_CMD_READY_INT | TPM_INTF_LOCALITY_CHANGE_INT |
 911                    TPM_INTF_DATA_AVAIL_INT | TPM_INTF_STS_VALID_INT;
 912         intmask &= ~TPM_GLOBAL_INT_ENABLE;
 913         tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
 914
 915         rc = tpm_chip_start(chip);
 916         if (rc)
 917                 goto out_err;
 918         rc = tpm2_probe(chip);
 919         tpm_chip_stop(chip);
 920         if (rc)
 921                 goto out_err;
 922
 923         rc = tpm_tis_read32(priv, TPM_DID_VID(0), &vendor);
 924         if (rc < 0)
 925                 goto out_err;
 926
 927         priv->manufacturer_id = vendor;
 928
 929         rc = tpm_tis_read8(priv, TPM_RID(0), &rid);
 930         if (rc < 0)
 931                 goto out_err;
 932
 933         dev_info(dev, "%s TPM (device-id 0x%X, rev-id %d)\n",
 934                  (chip->flags & TPM_CHIP_FLAG_TPM2) ? "2.0" : "1.2",
 935                  vendor >> 16, rid);
 936
 937         probe = probe_itpm(chip);
 938         if (probe < 0) {
 939                 rc = -ENODEV;
 940                 goto out_err;
 941         }
 942
 943         /* Figure out the capabilities */
 944         rc = tpm_tis_read32(priv, TPM_INTF_CAPS(priv->locality), &intfcaps);
 945         if (rc < 0)
 946                 goto out_err;
 947
 948         dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
 949                 intfcaps);
 950         if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
 951                 dev_dbg(dev, "\tBurst Count Static\n");
 952         if (intfcaps & TPM_INTF_CMD_READY_INT)
 953                 dev_dbg(dev, "\tCommand Ready Int Support\n");
 954         if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
 955                 dev_dbg(dev, "\tInterrupt Edge Falling\n");
 956         if (intfcaps & TPM_INTF_INT_EDGE_RISING)
 957                 dev_dbg(dev, "\tInterrupt Edge Rising\n");
 958         if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
 959                 dev_dbg(dev, "\tInterrupt Level Low\n");
 960         if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
 961                 dev_dbg(dev, "\tInterrupt Level High\n");
 962         if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
 963                 dev_dbg(dev, "\tLocality Change Int Support\n");
 964         if (intfcaps & TPM_INTF_STS_VALID_INT)
 965                 dev_dbg(dev, "\tSts Valid Int Support\n");
 966         if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
 967                 dev_dbg(dev, "\tData Avail Int Support\n");
 968
 969         /* INTERRUPT Setup */
 970         init_waitqueue_head(&priv->read_queue);
 971         init_waitqueue_head(&priv->int_queue);
 972         if (irq != -1) {
 973                 /* Before doing irq testing issue a command to the TPM in polling mode
 974                  * to make sure it works. May as well use that command to set the
 975                  * proper timeouts for the driver.
 976                  */
 977                 if (tpm_get_timeouts(chip)) {
 978                         dev_err(dev, "Could not get TPM timeouts and durations\n");
 979                         rc = -ENODEV;
 980                         goto out_err;
 981                 }
 982
 983                 tpm_chip_start(chip);
 984                 chip->flags |= TPM_CHIP_FLAG_IRQ;
 985                 if (irq) {
 986                         tpm_tis_probe_irq_single(chip, intmask, IRQF_SHARED,
 987                                                  irq);
 988                         if (!(chip->flags & TPM_CHIP_FLAG_IRQ))
 989                                 dev_err(&chip->dev, FW_BUG
 990                                         "TPM interrupt not working, polling instead\n");
 991                 } else {
 992                         tpm_tis_probe_irq(chip, intmask);
 993                 }
 994                 tpm_chip_stop(chip);
 995         }
 996
 997         rc = tpm_chip_register(chip);
 998         if (rc)
 999                 goto out_err;
1000
1001         if (chip->ops->clk_enable != NULL)
1002                 chip->ops->clk_enable(chip, false);
1003
1004         return 0;
1005 out_err:
1006         if ((chip->ops != NULL) && (chip->ops->clk_enable != NULL))
1007                 chip->ops->clk_enable(chip, false);
1008
1009         tpm_tis_remove(chip);
1010
1011         return rc;
1012 }
1013 EXPORT_SYMBOL_GPL(tpm_tis_core_init);
1014
1015 #ifdef CONFIG_PM_SLEEP
1016 static void tpm_tis_reenable_interrupts(struct tpm_chip *chip)
1017 {
1018         struct tpm_tis_data *priv = dev_get_drvdata(&chip->dev);
1019         u32 intmask;
1020         int rc;
1021
1022         if (chip->ops->clk_enable != NULL)
1023                 chip->ops->clk_enable(chip, true);
1024
1025         /* reenable interrupts that device may have lost or
1026          * BIOS/firmware may have disabled
1027          */
1028         rc = tpm_tis_write8(priv, TPM_INT_VECTOR(priv->locality), priv->irq);
1029         if (rc < 0)
1030                 goto out;
1031
1032         rc = tpm_tis_read32(priv, TPM_INT_ENABLE(priv->locality), &intmask);
1033         if (rc < 0)
1034                 goto out;
1035
1036         intmask |= TPM_INTF_CMD_READY_INT
1037             | TPM_INTF_LOCALITY_CHANGE_INT | TPM_INTF_DATA_AVAIL_INT
1038             | TPM_INTF_STS_VALID_INT | TPM_GLOBAL_INT_ENABLE;
1039
1040         tpm_tis_write32(priv, TPM_INT_ENABLE(priv->locality), intmask);
1041
1042 out:
1043         if (chip->ops->clk_enable != NULL)
1044                 chip->ops->clk_enable(chip, false);
1045
1046         return;
1047 }
1048
1049 int tpm_tis_resume(struct device *dev)
1050 {
1051         struct tpm_chip *chip = dev_get_drvdata(dev);
1052         int ret;
1053
1054         if (chip->flags & TPM_CHIP_FLAG_IRQ)
1055                 tpm_tis_reenable_interrupts(chip);
1056
1057         ret = tpm_pm_resume(dev);
1058         if (ret)
1059                 return ret;
1060
1061         /* TPM 1.2 requires self-test on resume. This function actually returns
1062          * an error code but for unknown reason it isn't handled.
1063          */
1064         if (!(chip->flags & TPM_CHIP_FLAG_TPM2))
1065                 tpm1_do_selftest(chip);
1066
1067         return 0;
1068 }
1069 EXPORT_SYMBOL_GPL(tpm_tis_resume);
1070 #endif
1071
1072 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
1073 MODULE_DESCRIPTION("TPM Driver");
1074 MODULE_VERSION("2.0");
1075 MODULE_LICENSE("GPL");