drivers/char/tpm/tpm_crb.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2014 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 device driver implements the TPM interface as defined in
  11  * the TCG CRB 2.0 TPM specification.
  12  */
  13
  14 #include <linux/acpi.h>
  15 #include <linux/highmem.h>
  16 #include <linux/rculist.h>
  17 #include <linux/module.h>
  18 #include <linux/pm_runtime.h>
  19 #ifdef CONFIG_ARM64
  20 #include <linux/arm-smccc.h>
  21 #endif
  22 #include "tpm.h"
  23
  24 #define ACPI_SIG_TPM2 "TPM2"
  25 #define TPM_CRB_MAX_RESOURCES 3
  26
  27 static const guid_t crb_acpi_start_guid =
  28         GUID_INIT(0x6BBF6CAB, 0x5463, 0x4714,
  29                   0xB7, 0xCD, 0xF0, 0x20, 0x3C, 0x03, 0x68, 0xD4);
  30
  31 enum crb_defaults {
  32         CRB_ACPI_START_REVISION_ID = 1,
  33         CRB_ACPI_START_INDEX = 1,
  34 };
  35
  36 enum crb_loc_ctrl {
  37         CRB_LOC_CTRL_REQUEST_ACCESS     = BIT(0),
  38         CRB_LOC_CTRL_RELINQUISH         = BIT(1),
  39 };
  40
  41 enum crb_loc_state {
  42         CRB_LOC_STATE_LOC_ASSIGNED      = BIT(1),
  43         CRB_LOC_STATE_TPM_REG_VALID_STS = BIT(7),
  44 };
  45
  46 enum crb_ctrl_req {
  47         CRB_CTRL_REQ_CMD_READY  = BIT(0),
  48         CRB_CTRL_REQ_GO_IDLE    = BIT(1),
  49 };
  50
  51 enum crb_ctrl_sts {
  52         CRB_CTRL_STS_ERROR      = BIT(0),
  53         CRB_CTRL_STS_TPM_IDLE   = BIT(1),
  54 };
  55
  56 enum crb_start {
  57         CRB_START_INVOKE        = BIT(0),
  58 };
  59
  60 enum crb_cancel {
  61         CRB_CANCEL_INVOKE       = BIT(0),
  62 };
  63
  64 struct crb_regs_head {
  65         u32 loc_state;
  66         u32 reserved1;
  67         u32 loc_ctrl;
  68         u32 loc_sts;
  69         u8 reserved2[32];
  70         u64 intf_id;
  71         u64 ctrl_ext;
  72 } __packed;
  73
  74 struct crb_regs_tail {
  75         u32 ctrl_req;
  76         u32 ctrl_sts;
  77         u32 ctrl_cancel;
  78         u32 ctrl_start;
  79         u32 ctrl_int_enable;
  80         u32 ctrl_int_sts;
  81         u32 ctrl_cmd_size;
  82         u32 ctrl_cmd_pa_low;
  83         u32 ctrl_cmd_pa_high;
  84         u32 ctrl_rsp_size;
  85         u64 ctrl_rsp_pa;
  86 } __packed;
  87
  88 enum crb_status {
  89         CRB_DRV_STS_COMPLETE    = BIT(0),
  90 };
  91
  92 struct crb_priv {
  93         u32 sm;
  94         const char *hid;
  95         struct crb_regs_head __iomem *regs_h;
  96         struct crb_regs_tail __iomem *regs_t;
  97         u8 __iomem *cmd;
  98         u8 __iomem *rsp;
  99         u32 cmd_size;
 100         u32 smc_func_id;
 101 };
 102
 103 struct tpm2_crb_smc {
 104         u32 interrupt;
 105         u8 interrupt_flags;
 106         u8 op_flags;
 107         u16 reserved2;
 108         u32 smc_func_id;
 109 };
 110
 111 static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
 112                                 unsigned long timeout)
 113 {
 114         ktime_t start;
 115         ktime_t stop;
 116
 117         start = ktime_get();
 118         stop = ktime_add(start, ms_to_ktime(timeout));
 119
 120         do {
 121                 if ((ioread32(reg) & mask) == value)
 122                         return true;
 123
 124                 usleep_range(50, 100);
 125         } while (ktime_before(ktime_get(), stop));
 126
 127         return ((ioread32(reg) & mask) == value);
 128 }
 129
 130 /**
 131  * __crb_go_idle - request tpm crb device to go the idle state
 132  *
 133  * @dev:  crb device
 134  * @priv: crb private data
 135  *
 136  * Write CRB_CTRL_REQ_GO_IDLE to TPM_CRB_CTRL_REQ
 137  * The device should respond within TIMEOUT_C by clearing the bit.
 138  * Anyhow, we do not wait here as a consequent CMD_READY request
 139  * will be handled correctly even if idle was not completed.
 140  *
 141  * The function does nothing for devices with ACPI-start method
 142  * or SMC-start method.
 143  *
 144  * Return: 0 always
 145  */
 146 static int __crb_go_idle(struct device *dev, struct crb_priv *priv)
 147 {
 148         if ((priv->sm == ACPI_TPM2_START_METHOD) ||
 149             (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) ||
 150             (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC))
 151                 return 0;
 152
 153         iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req);
 154
 155         if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req,
 156                                  CRB_CTRL_REQ_GO_IDLE/* mask */,
 157                                  0, /* value */
 158                                  TPM2_TIMEOUT_C)) {
 159                 dev_warn(dev, "goIdle timed out\n");
 160                 return -ETIME;
 161         }
 162
 163         return 0;
 164 }
 165
 166 static int crb_go_idle(struct tpm_chip *chip)
 167 {
 168         struct device *dev = &chip->dev;
 169         struct crb_priv *priv = dev_get_drvdata(dev);
 170
 171         return __crb_go_idle(dev, priv);
 172 }
 173
 174 /**
 175  * __crb_cmd_ready - request tpm crb device to enter ready state
 176  *
 177  * @dev:  crb device
 178  * @priv: crb private data
 179  *
 180  * Write CRB_CTRL_REQ_CMD_READY to TPM_CRB_CTRL_REQ
 181  * and poll till the device acknowledge it by clearing the bit.
 182  * The device should respond within TIMEOUT_C.
 183  *
 184  * The function does nothing for devices with ACPI-start method
 185  * or SMC-start method.
 186  *
 187  * Return: 0 on success -ETIME on timeout;
 188  */
 189 static int __crb_cmd_ready(struct device *dev, struct crb_priv *priv)
 190 {
 191         if ((priv->sm == ACPI_TPM2_START_METHOD) ||
 192             (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) ||
 193             (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC))
 194                 return 0;
 195
 196         iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
 197         if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req,
 198                                  CRB_CTRL_REQ_CMD_READY /* mask */,
 199                                  0, /* value */
 200                                  TPM2_TIMEOUT_C)) {
 201                 dev_warn(dev, "cmdReady timed out\n");
 202                 return -ETIME;
 203         }
 204
 205         return 0;
 206 }
 207
 208 static int crb_cmd_ready(struct tpm_chip *chip)
 209 {
 210         struct device *dev = &chip->dev;
 211         struct crb_priv *priv = dev_get_drvdata(dev);
 212
 213         return __crb_cmd_ready(dev, priv);
 214 }
 215
 216 static int __crb_request_locality(struct device *dev,
 217                                   struct crb_priv *priv, int loc)
 218 {
 219         u32 value = CRB_LOC_STATE_LOC_ASSIGNED |
 220                     CRB_LOC_STATE_TPM_REG_VALID_STS;
 221
 222         if (!priv->regs_h)
 223                 return 0;
 224
 225         iowrite32(CRB_LOC_CTRL_REQUEST_ACCESS, &priv->regs_h->loc_ctrl);
 226         if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, value, value,
 227                                  TPM2_TIMEOUT_C)) {
 228                 dev_warn(dev, "TPM_LOC_STATE_x.requestAccess timed out\n");
 229                 return -ETIME;
 230         }
 231
 232         return 0;
 233 }
 234
 235 static int crb_request_locality(struct tpm_chip *chip, int loc)
 236 {
 237         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 238
 239         return __crb_request_locality(&chip->dev, priv, loc);
 240 }
 241
 242 static int __crb_relinquish_locality(struct device *dev,
 243                                      struct crb_priv *priv, int loc)
 244 {
 245         u32 mask = CRB_LOC_STATE_LOC_ASSIGNED |
 246                    CRB_LOC_STATE_TPM_REG_VALID_STS;
 247         u32 value = CRB_LOC_STATE_TPM_REG_VALID_STS;
 248
 249         if (!priv->regs_h)
 250                 return 0;
 251
 252         iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl);
 253         if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, mask, value,
 254                                  TPM2_TIMEOUT_C)) {
 255                 dev_warn(dev, "TPM_LOC_STATE_x.requestAccess timed out\n");
 256                 return -ETIME;
 257         }
 258
 259         return 0;
 260 }
 261
 262 static int crb_relinquish_locality(struct tpm_chip *chip, int loc)
 263 {
 264         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 265
 266         return __crb_relinquish_locality(&chip->dev, priv, loc);
 267 }
 268
 269 static u8 crb_status(struct tpm_chip *chip)
 270 {
 271         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 272         u8 sts = 0;
 273
 274         if ((ioread32(&priv->regs_t->ctrl_start) & CRB_START_INVOKE) !=
 275             CRB_START_INVOKE)
 276                 sts |= CRB_DRV_STS_COMPLETE;
 277
 278         return sts;
 279 }
 280
 281 static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count)
 282 {
 283         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 284         unsigned int expected;
 285
 286         /* A sanity check that the upper layer wants to get at least the header
 287          * as that is the minimum size for any TPM response.
 288          */
 289         if (count < TPM_HEADER_SIZE)
 290                 return -EIO;
 291
 292         /* If this bit is set, according to the spec, the TPM is in
 293          * unrecoverable condition.
 294          */
 295         if (ioread32(&priv->regs_t->ctrl_sts) & CRB_CTRL_STS_ERROR)
 296                 return -EIO;
 297
 298         /* Read the first 8 bytes in order to get the length of the response.
 299          * We read exactly a quad word in order to make sure that the remaining
 300          * reads will be aligned.
 301          */
 302         memcpy_fromio(buf, priv->rsp, 8);
 303
 304         expected = be32_to_cpup((__be32 *)&buf[2]);
 305         if (expected > count || expected < TPM_HEADER_SIZE)
 306                 return -EIO;
 307
 308         memcpy_fromio(&buf[8], &priv->rsp[8], expected - 8);
 309
 310         return expected;
 311 }
 312
 313 static int crb_do_acpi_start(struct tpm_chip *chip)
 314 {
 315         union acpi_object *obj;
 316         int rc;
 317
 318         obj = acpi_evaluate_dsm(chip->acpi_dev_handle,
 319                                 &crb_acpi_start_guid,
 320                                 CRB_ACPI_START_REVISION_ID,
 321                                 CRB_ACPI_START_INDEX,
 322                                 NULL);
 323         if (!obj)
 324                 return -ENXIO;
 325         rc = obj->integer.value == 0 ? 0 : -ENXIO;
 326         ACPI_FREE(obj);
 327         return rc;
 328 }
 329
 330 #ifdef CONFIG_ARM64
 331 /*
 332  * This is a TPM Command Response Buffer start method that invokes a
 333  * Secure Monitor Call to requrest the firmware to execute or cancel
 334  * a TPM 2.0 command.
 335  */
 336 static int tpm_crb_smc_start(struct device *dev, unsigned long func_id)
 337 {
 338         struct arm_smccc_res res;
 339
 340         arm_smccc_smc(func_id, 0, 0, 0, 0, 0, 0, 0, &res);
 341         if (res.a0 != 0) {
 342                 dev_err(dev,
 343                         FW_BUG "tpm_crb_smc_start() returns res.a0 = 0x%lx\n",
 344                         res.a0);
 345                 return -EIO;
 346         }
 347
 348         return 0;
 349 }
 350 #else
 351 static int tpm_crb_smc_start(struct device *dev, unsigned long func_id)
 352 {
 353         dev_err(dev, FW_BUG "tpm_crb: incorrect start method\n");
 354         return -EINVAL;
 355 }
 356 #endif
 357
 358 static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
 359 {
 360         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 361         int rc = 0;
 362
 363         /* Zero the cancel register so that the next command will not get
 364          * canceled.
 365          */
 366         iowrite32(0, &priv->regs_t->ctrl_cancel);
 367
 368         if (len > priv->cmd_size) {
 369                 dev_err(&chip->dev, "invalid command count value %zd %d\n",
 370                         len, priv->cmd_size);
 371                 return -E2BIG;
 372         }
 373
 374         memcpy_toio(priv->cmd, buf, len);
 375
 376         /* Make sure that cmd is populated before issuing start. */
 377         wmb();
 378
 379         /* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
 380          * report only ACPI start but in practice seems to require both
 381          * CRB start, hence invoking CRB start method if hid == MSFT0101.
 382          */
 383         if ((priv->sm == ACPI_TPM2_COMMAND_BUFFER) ||
 384             (priv->sm == ACPI_TPM2_MEMORY_MAPPED) ||
 385             (!strcmp(priv->hid, "MSFT0101")))
 386                 iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
 387
 388         if ((priv->sm == ACPI_TPM2_START_METHOD) ||
 389             (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD))
 390                 rc = crb_do_acpi_start(chip);
 391
 392         if (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
 393                 iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
 394                 rc = tpm_crb_smc_start(&chip->dev, priv->smc_func_id);
 395         }
 396
 397         return rc;
 398 }
 399
 400 static void crb_cancel(struct tpm_chip *chip)
 401 {
 402         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 403
 404         iowrite32(CRB_CANCEL_INVOKE, &priv->regs_t->ctrl_cancel);
 405
 406         if (((priv->sm == ACPI_TPM2_START_METHOD) ||
 407             (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)) &&
 408              crb_do_acpi_start(chip))
 409                 dev_err(&chip->dev, "ACPI Start failed\n");
 410 }
 411
 412 static bool crb_req_canceled(struct tpm_chip *chip, u8 status)
 413 {
 414         struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 415         u32 cancel = ioread32(&priv->regs_t->ctrl_cancel);
 416
 417         return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE;
 418 }
 419
 420 static const struct tpm_class_ops tpm_crb = {
 421         .flags = TPM_OPS_AUTO_STARTUP,
 422         .status = crb_status,
 423         .recv = crb_recv,
 424         .send = crb_send,
 425         .cancel = crb_cancel,
 426         .req_canceled = crb_req_canceled,
 427         .go_idle  = crb_go_idle,
 428         .cmd_ready = crb_cmd_ready,
 429         .request_locality = crb_request_locality,
 430         .relinquish_locality = crb_relinquish_locality,
 431         .req_complete_mask = CRB_DRV_STS_COMPLETE,
 432         .req_complete_val = CRB_DRV_STS_COMPLETE,
 433 };
 434
 435 static int crb_check_resource(struct acpi_resource *ares, void *data)
 436 {
 437         struct resource *iores_array = data;
 438         struct resource_win win;
 439         struct resource *res = &(win.res);
 440         int i;
 441
 442         if (acpi_dev_resource_memory(ares, res) ||
 443             acpi_dev_resource_address_space(ares, &win)) {
 444                 for (i = 0; i < TPM_CRB_MAX_RESOURCES + 1; ++i) {
 445                         if (resource_type(iores_array + i) != IORESOURCE_MEM) {
 446                                 iores_array[i] = *res;
 447                                 iores_array[i].name = NULL;
 448                                 break;
 449                         }
 450                 }
 451         }
 452
 453         return 1;
 454 }
 455
 456 static void __iomem *crb_map_res(struct device *dev, struct resource *iores,
 457                                  void __iomem **iobase_ptr, u64 start, u32 size)
 458 {
 459         struct resource new_res = {
 460                 .start  = start,
 461                 .end    = start + size - 1,
 462                 .flags  = IORESOURCE_MEM,
 463         };
 464
 465         /* Detect a 64 bit address on a 32 bit system */
 466         if (start != new_res.start)
 467                 return (void __iomem *) ERR_PTR(-EINVAL);
 468
 469         if (!iores)
 470                 return devm_ioremap_resource(dev, &new_res);
 471
 472         if (!*iobase_ptr) {
 473                 *iobase_ptr = devm_ioremap_resource(dev, iores);
 474                 if (IS_ERR(*iobase_ptr))
 475                         return *iobase_ptr;
 476         }
 477
 478         return *iobase_ptr + (new_res.start - iores->start);
 479 }
 480
 481 /*
 482  * Work around broken BIOSs that return inconsistent values from the ACPI
 483  * region vs the registers. Trust the ACPI region. Such broken systems
 484  * probably cannot send large TPM commands since the buffer will be truncated.
 485  */
 486 static u64 crb_fixup_cmd_size(struct device *dev, struct resource *io_res,
 487                               u64 start, u64 size)
 488 {
 489         if (io_res->start > start || io_res->end < start)
 490                 return size;
 491
 492         if (start + size - 1 <= io_res->end)
 493                 return size;
 494
 495         dev_err(dev,
 496                 FW_BUG "ACPI region does not cover the entire command/response buffer. %pr vs %llx %llx\n",
 497                 io_res, start, size);
 498
 499         return io_res->end - start + 1;
 500 }
 501
 502 static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
 503                       struct acpi_table_tpm2 *buf)
 504 {
 505         struct list_head acpi_resource_list;
 506         struct resource iores_array[TPM_CRB_MAX_RESOURCES + 1] = { {0} };
 507         void __iomem *iobase_array[TPM_CRB_MAX_RESOURCES] = {NULL};
 508         struct device *dev = &device->dev;
 509         struct resource *iores;
 510         void __iomem **iobase_ptr;
 511         int i;
 512         u32 pa_high, pa_low;
 513         u64 cmd_pa;
 514         u32 cmd_size;
 515         __le64 __rsp_pa;
 516         u64 rsp_pa;
 517         u32 rsp_size;
 518         int ret;
 519
 520         INIT_LIST_HEAD(&acpi_resource_list);
 521         ret = acpi_dev_get_resources(device, &acpi_resource_list,
 522                                      crb_check_resource, iores_array);
 523         if (ret < 0)
 524                 return ret;
 525         acpi_dev_free_resource_list(&acpi_resource_list);
 526
 527         if (resource_type(iores_array) != IORESOURCE_MEM) {
 528                 dev_err(dev, FW_BUG "TPM2 ACPI table does not define a memory resource\n");
 529                 return -EINVAL;
 530         } else if (resource_type(iores_array + TPM_CRB_MAX_RESOURCES) ==
 531                 IORESOURCE_MEM) {
 532                 dev_warn(dev, "TPM2 ACPI table defines too many memory resources\n");
 533                 memset(iores_array + TPM_CRB_MAX_RESOURCES,
 534                        0, sizeof(*iores_array));
 535                 iores_array[TPM_CRB_MAX_RESOURCES].flags = 0;
 536         }
 537
 538         iores = NULL;
 539         iobase_ptr = NULL;
 540         for (i = 0; resource_type(iores_array + i) == IORESOURCE_MEM; ++i) {
 541                 if (buf->control_address >= iores_array[i].start &&
 542                     buf->control_address + sizeof(struct crb_regs_tail) - 1 <=
 543                     iores_array[i].end) {
 544                         iores = iores_array + i;
 545                         iobase_ptr = iobase_array + i;
 546                         break;
 547                 }
 548         }
 549
 550         priv->regs_t = crb_map_res(dev, iores, iobase_ptr, buf->control_address,
 551                                    sizeof(struct crb_regs_tail));
 552
 553         if (IS_ERR(priv->regs_t))
 554                 return PTR_ERR(priv->regs_t);
 555
 556         /* The ACPI IO region starts at the head area and continues to include
 557          * the control area, as one nice sane region except for some older
 558          * stuff that puts the control area outside the ACPI IO region.
 559          */
 560         if ((priv->sm == ACPI_TPM2_COMMAND_BUFFER) ||
 561             (priv->sm == ACPI_TPM2_MEMORY_MAPPED)) {
 562                 if (iores &&
 563                     buf->control_address == iores->start +
 564                     sizeof(*priv->regs_h))
 565                         priv->regs_h = *iobase_ptr;
 566                 else
 567                         dev_warn(dev, FW_BUG "Bad ACPI memory layout");
 568         }
 569
 570         ret = __crb_request_locality(dev, priv, 0);
 571         if (ret)
 572                 return ret;
 573
 574         /*
 575          * PTT HW bug w/a: wake up the device to access
 576          * possibly not retained registers.
 577          */
 578         ret = __crb_cmd_ready(dev, priv);
 579         if (ret)
 580                 goto out_relinquish_locality;
 581
 582         pa_high = ioread32(&priv->regs_t->ctrl_cmd_pa_high);
 583         pa_low  = ioread32(&priv->regs_t->ctrl_cmd_pa_low);
 584         cmd_pa = ((u64)pa_high << 32) | pa_low;
 585         cmd_size = ioread32(&priv->regs_t->ctrl_cmd_size);
 586
 587         iores = NULL;
 588         iobase_ptr = NULL;
 589         for (i = 0; iores_array[i].end; ++i) {
 590                 if (cmd_pa >= iores_array[i].start &&
 591                     cmd_pa <= iores_array[i].end) {
 592                         iores = iores_array + i;
 593                         iobase_ptr = iobase_array + i;
 594                         break;
 595                 }
 596         }
 597
 598         if (iores)
 599                 cmd_size = crb_fixup_cmd_size(dev, iores, cmd_pa, cmd_size);
 600
 601         dev_dbg(dev, "cmd_hi = %X cmd_low = %X cmd_size %X\n",
 602                 pa_high, pa_low, cmd_size);
 603
 604         priv->cmd = crb_map_res(dev, iores, iobase_ptr, cmd_pa, cmd_size);
 605         if (IS_ERR(priv->cmd)) {
 606                 ret = PTR_ERR(priv->cmd);
 607                 goto out;
 608         }
 609
 610         memcpy_fromio(&__rsp_pa, &priv->regs_t->ctrl_rsp_pa, 8);
 611         rsp_pa = le64_to_cpu(__rsp_pa);
 612         rsp_size = ioread32(&priv->regs_t->ctrl_rsp_size);
 613
 614         iores = NULL;
 615         iobase_ptr = NULL;
 616         for (i = 0; resource_type(iores_array + i) == IORESOURCE_MEM; ++i) {
 617                 if (rsp_pa >= iores_array[i].start &&
 618                     rsp_pa <= iores_array[i].end) {
 619                         iores = iores_array + i;
 620                         iobase_ptr = iobase_array + i;
 621                         break;
 622                 }
 623         }
 624
 625         if (iores)
 626                 rsp_size = crb_fixup_cmd_size(dev, iores, rsp_pa, rsp_size);
 627
 628         if (cmd_pa != rsp_pa) {
 629                 priv->rsp = crb_map_res(dev, iores, iobase_ptr,
 630                                         rsp_pa, rsp_size);
 631                 ret = PTR_ERR_OR_ZERO(priv->rsp);
 632                 goto out;
 633         }
 634
 635         /* According to the PTP specification, overlapping command and response
 636          * buffer sizes must be identical.
 637          */
 638         if (cmd_size != rsp_size) {
 639                 dev_err(dev, FW_BUG "overlapping command and response buffer sizes are not identical");
 640                 ret = -EINVAL;
 641                 goto out;
 642         }
 643
 644         priv->rsp = priv->cmd;
 645
 646 out:
 647         if (!ret)
 648                 priv->cmd_size = cmd_size;
 649
 650         __crb_go_idle(dev, priv);
 651
 652 out_relinquish_locality:
 653
 654         __crb_relinquish_locality(dev, priv, 0);
 655
 656         return ret;
 657 }
 658
 659 static int crb_acpi_add(struct acpi_device *device)
 660 {
 661         struct acpi_table_tpm2 *buf;
 662         struct crb_priv *priv;
 663         struct tpm_chip *chip;
 664         struct device *dev = &device->dev;
 665         struct tpm2_crb_smc *crb_smc;
 666         acpi_status status;
 667         u32 sm;
 668         int rc;
 669
 670         status = acpi_get_table(ACPI_SIG_TPM2, 1,
 671                                 (struct acpi_table_header **) &buf);
 672         if (ACPI_FAILURE(status) || buf->header.length < sizeof(*buf)) {
 673                 dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n");
 674                 return -EINVAL;
 675         }
 676
 677         /* Should the FIFO driver handle this? */
 678         sm = buf->start_method;
 679         if (sm == ACPI_TPM2_MEMORY_MAPPED)
 680                 return -ENODEV;
 681
 682         priv = devm_kzalloc(dev, sizeof(struct crb_priv), GFP_KERNEL);
 683         if (!priv)
 684                 return -ENOMEM;
 685
 686         if (sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
 687                 if (buf->header.length < (sizeof(*buf) + sizeof(*crb_smc))) {
 688                         dev_err(dev,
 689                                 FW_BUG "TPM2 ACPI table has wrong size %u for start method type %d\n",
 690                                 buf->header.length,
 691                                 ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC);
 692                         return -EINVAL;
 693                 }
 694                 crb_smc = ACPI_ADD_PTR(struct tpm2_crb_smc, buf, sizeof(*buf));
 695                 priv->smc_func_id = crb_smc->smc_func_id;
 696         }
 697
 698         priv->sm = sm;
 699         priv->hid = acpi_device_hid(device);
 700
 701         rc = crb_map_io(device, priv, buf);
 702         if (rc)
 703                 return rc;
 704
 705         chip = tpmm_chip_alloc(dev, &tpm_crb);
 706         if (IS_ERR(chip))
 707                 return PTR_ERR(chip);
 708
 709         dev_set_drvdata(&chip->dev, priv);
 710         chip->acpi_dev_handle = device->handle;
 711         chip->flags = TPM_CHIP_FLAG_TPM2;
 712
 713         return tpm_chip_register(chip);
 714 }
 715
 716 static int crb_acpi_remove(struct acpi_device *device)
 717 {
 718         struct device *dev = &device->dev;
 719         struct tpm_chip *chip = dev_get_drvdata(dev);
 720
 721         tpm_chip_unregister(chip);
 722
 723         return 0;
 724 }
 725
 726 static const struct dev_pm_ops crb_pm = {
 727         SET_SYSTEM_SLEEP_PM_OPS(tpm_pm_suspend, tpm_pm_resume)
 728 };
 729
 730 static const struct acpi_device_id crb_device_ids[] = {
 731         {"MSFT0101", 0},
 732         {"", 0},
 733 };
 734 MODULE_DEVICE_TABLE(acpi, crb_device_ids);
 735
 736 static struct acpi_driver crb_acpi_driver = {
 737         .name = "tpm_crb",
 738         .ids = crb_device_ids,
 739         .ops = {
 740                 .add = crb_acpi_add,
 741                 .remove = crb_acpi_remove,
 742         },
 743         .drv = {
 744                 .pm = &crb_pm,
 745         },
 746 };
 747
 748 module_acpi_driver(crb_acpi_driver);
 749 MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>");
 750 MODULE_DESCRIPTION("TPM2 Driver");
 751 MODULE_VERSION("0.1");
 752 MODULE_LICENSE("GPL");