linux/drivers/char/tpm/tpm_crb.c
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   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
  27static const guid_t crb_acpi_start_guid =
  28        GUID_INIT(0x6BBF6CAB, 0x5463, 0x4714,
  29                  0xB7, 0xCD, 0xF0, 0x20, 0x3C, 0x03, 0x68, 0xD4);
  30
  31enum crb_defaults {
  32        CRB_ACPI_START_REVISION_ID = 1,
  33        CRB_ACPI_START_INDEX = 1,
  34};
  35
  36enum crb_loc_ctrl {
  37        CRB_LOC_CTRL_REQUEST_ACCESS     = BIT(0),
  38        CRB_LOC_CTRL_RELINQUISH         = BIT(1),
  39};
  40
  41enum crb_loc_state {
  42        CRB_LOC_STATE_LOC_ASSIGNED      = BIT(1),
  43        CRB_LOC_STATE_TPM_REG_VALID_STS = BIT(7),
  44};
  45
  46enum crb_ctrl_req {
  47        CRB_CTRL_REQ_CMD_READY  = BIT(0),
  48        CRB_CTRL_REQ_GO_IDLE    = BIT(1),
  49};
  50
  51enum crb_ctrl_sts {
  52        CRB_CTRL_STS_ERROR      = BIT(0),
  53        CRB_CTRL_STS_TPM_IDLE   = BIT(1),
  54};
  55
  56enum crb_start {
  57        CRB_START_INVOKE        = BIT(0),
  58};
  59
  60enum crb_cancel {
  61        CRB_CANCEL_INVOKE       = BIT(0),
  62};
  63
  64struct 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
  74struct 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
  88enum crb_status {
  89        CRB_DRV_STS_COMPLETE    = BIT(0),
  90};
  91
  92struct 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
 103struct tpm2_crb_smc {
 104        u32 interrupt;
 105        u8 interrupt_flags;
 106        u8 op_flags;
 107        u16 reserved2;
 108        u32 smc_func_id;
 109};
 110
 111static 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 */
 146static 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
 166static 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 */
 189static 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
 208static 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
 216static 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
 235static 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
 242static 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
 262static 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
 269static 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
 281static 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
 313static 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 */
 336static 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
 351static 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
 358static 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
 400static 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
 412static 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
 420static 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
 435static 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
 456static 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 */
 486static 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
 502static 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
 646out:
 647        if (!ret)
 648                priv->cmd_size = cmd_size;
 649
 650        __crb_go_idle(dev, priv);
 651
 652out_relinquish_locality:
 653
 654        __crb_relinquish_locality(dev, priv, 0);
 655
 656        return ret;
 657}
 658
 659static 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
 716static 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
 726static const struct dev_pm_ops crb_pm = {
 727        SET_SYSTEM_SLEEP_PM_OPS(tpm_pm_suspend, tpm_pm_resume)
 728};
 729
 730static const struct acpi_device_id crb_device_ids[] = {
 731        {"MSFT0101", 0},
 732        {"", 0},
 733};
 734MODULE_DEVICE_TABLE(acpi, crb_device_ids);
 735
 736static 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
 748module_acpi_driver(crb_acpi_driver);
 749MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>");
 750MODULE_DESCRIPTION("TPM2 Driver");
 751MODULE_VERSION("0.1");
 752MODULE_LICENSE("GPL");
 753