1 /* 2 * Copyright (C) 2014 Intel Corporation 3 * 4 * Authors: 5 * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> 6 * 7 * Maintained by: <tpmdd-devel@lists.sourceforge.net> 8 * 9 * This device driver implements the TPM interface as defined in 10 * the TCG CRB 2.0 TPM specification. 11 * 12 * This program is free software; you can redistribute it and/or 13 * modify it under the terms of the GNU General Public License 14 * as published by the Free Software Foundation; version 2 15 * of the License. 16 */ 17 18 #include <linux/acpi.h> 19 #include <linux/highmem.h> 20 #include <linux/rculist.h> 21 #include <linux/module.h> 22 #include <linux/pm_runtime.h> 23 #include "tpm.h" 24 25 #define ACPI_SIG_TPM2 "TPM2" 26 27 static const u8 CRB_ACPI_START_UUID[] = { 28 /* 0000 */ 0xAB, 0x6C, 0xBF, 0x6B, 0x63, 0x54, 0x14, 0x47, 29 /* 0008 */ 0xB7, 0xCD, 0xF0, 0x20, 0x3C, 0x03, 0x68, 0xD4 30 }; 31 32 enum crb_defaults { 33 CRB_ACPI_START_REVISION_ID = 1, 34 CRB_ACPI_START_INDEX = 1, 35 }; 36 37 enum crb_ctrl_req { 38 CRB_CTRL_REQ_CMD_READY = BIT(0), 39 CRB_CTRL_REQ_GO_IDLE = BIT(1), 40 }; 41 42 enum crb_ctrl_sts { 43 CRB_CTRL_STS_ERROR = BIT(0), 44 CRB_CTRL_STS_TPM_IDLE = BIT(1), 45 }; 46 47 enum crb_start { 48 CRB_START_INVOKE = BIT(0), 49 }; 50 51 enum crb_cancel { 52 CRB_CANCEL_INVOKE = BIT(0), 53 }; 54 55 struct crb_control_area { 56 u32 req; 57 u32 sts; 58 u32 cancel; 59 u32 start; 60 u32 int_enable; 61 u32 int_sts; 62 u32 cmd_size; 63 u32 cmd_pa_low; 64 u32 cmd_pa_high; 65 u32 rsp_size; 66 u64 rsp_pa; 67 } __packed; 68 69 enum crb_status { 70 CRB_DRV_STS_COMPLETE = BIT(0), 71 }; 72 73 enum crb_flags { 74 CRB_FL_ACPI_START = BIT(0), 75 CRB_FL_CRB_START = BIT(1), 76 }; 77 78 struct crb_priv { 79 unsigned int flags; 80 void __iomem *iobase; 81 struct crb_control_area __iomem *cca; 82 u8 __iomem *cmd; 83 u8 __iomem *rsp; 84 u32 cmd_size; 85 }; 86 87 /** 88 * crb_go_idle - request tpm crb device to go the idle state 89 * 90 * @dev: crb device 91 * @priv: crb private data 92 * 93 * Write CRB_CTRL_REQ_GO_IDLE to TPM_CRB_CTRL_REQ 94 * The device should respond within TIMEOUT_C by clearing the bit. 95 * Anyhow, we do not wait here as a consequent CMD_READY request 96 * will be handled correctly even if idle was not completed. 97 * 98 * The function does nothing for devices with ACPI-start method. 99 * 100 * Return: 0 always 101 */ 102 static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv) 103 { 104 if (priv->flags & CRB_FL_ACPI_START) 105 return 0; 106 107 iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->cca->req); 108 /* we don't really care when this settles */ 109 110 return 0; 111 } 112 113 /** 114 * crb_cmd_ready - request tpm crb device to enter ready state 115 * 116 * @dev: crb device 117 * @priv: crb private data 118 * 119 * Write CRB_CTRL_REQ_CMD_READY to TPM_CRB_CTRL_REQ 120 * and poll till the device acknowledge it by clearing the bit. 121 * The device should respond within TIMEOUT_C. 122 * 123 * The function does nothing for devices with ACPI-start method 124 * 125 * Return: 0 on success -ETIME on timeout; 126 */ 127 static int __maybe_unused crb_cmd_ready(struct device *dev, 128 struct crb_priv *priv) 129 { 130 ktime_t stop, start; 131 132 if (priv->flags & CRB_FL_ACPI_START) 133 return 0; 134 135 iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->cca->req); 136 137 start = ktime_get(); 138 stop = ktime_add(start, ms_to_ktime(TPM2_TIMEOUT_C)); 139 do { 140 if (!(ioread32(&priv->cca->req) & CRB_CTRL_REQ_CMD_READY)) 141 return 0; 142 usleep_range(50, 100); 143 } while (ktime_before(ktime_get(), stop)); 144 145 if (ioread32(&priv->cca->req) & CRB_CTRL_REQ_CMD_READY) { 146 dev_warn(dev, "cmdReady timed out\n"); 147 return -ETIME; 148 } 149 150 return 0; 151 } 152 153 static u8 crb_status(struct tpm_chip *chip) 154 { 155 struct crb_priv *priv = dev_get_drvdata(&chip->dev); 156 u8 sts = 0; 157 158 if ((ioread32(&priv->cca->start) & CRB_START_INVOKE) != 159 CRB_START_INVOKE) 160 sts |= CRB_DRV_STS_COMPLETE; 161 162 return sts; 163 } 164 165 static int crb_recv(struct tpm_chip *chip, u8 *buf, size_t count) 166 { 167 struct crb_priv *priv = dev_get_drvdata(&chip->dev); 168 unsigned int expected; 169 170 /* sanity check */ 171 if (count < 6) 172 return -EIO; 173 174 if (ioread32(&priv->cca->sts) & CRB_CTRL_STS_ERROR) 175 return -EIO; 176 177 memcpy_fromio(buf, priv->rsp, 6); 178 expected = be32_to_cpup((__be32 *) &buf[2]); 179 180 if (expected > count) 181 return -EIO; 182 183 memcpy_fromio(&buf[6], &priv->rsp[6], expected - 6); 184 185 return expected; 186 } 187 188 static int crb_do_acpi_start(struct tpm_chip *chip) 189 { 190 union acpi_object *obj; 191 int rc; 192 193 obj = acpi_evaluate_dsm(chip->acpi_dev_handle, 194 CRB_ACPI_START_UUID, 195 CRB_ACPI_START_REVISION_ID, 196 CRB_ACPI_START_INDEX, 197 NULL); 198 if (!obj) 199 return -ENXIO; 200 rc = obj->integer.value == 0 ? 0 : -ENXIO; 201 ACPI_FREE(obj); 202 return rc; 203 } 204 205 static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len) 206 { 207 struct crb_priv *priv = dev_get_drvdata(&chip->dev); 208 int rc = 0; 209 210 /* Zero the cancel register so that the next command will not get 211 * canceled. 212 */ 213 iowrite32(0, &priv->cca->cancel); 214 215 if (len > priv->cmd_size) { 216 dev_err(&chip->dev, "invalid command count value %zd %d\n", 217 len, priv->cmd_size); 218 return -E2BIG; 219 } 220 221 memcpy_toio(priv->cmd, buf, len); 222 223 /* Make sure that cmd is populated before issuing start. */ 224 wmb(); 225 226 if (priv->flags & CRB_FL_CRB_START) 227 iowrite32(CRB_START_INVOKE, &priv->cca->start); 228 229 if (priv->flags & CRB_FL_ACPI_START) 230 rc = crb_do_acpi_start(chip); 231 232 return rc; 233 } 234 235 static void crb_cancel(struct tpm_chip *chip) 236 { 237 struct crb_priv *priv = dev_get_drvdata(&chip->dev); 238 239 iowrite32(CRB_CANCEL_INVOKE, &priv->cca->cancel); 240 241 if ((priv->flags & CRB_FL_ACPI_START) && crb_do_acpi_start(chip)) 242 dev_err(&chip->dev, "ACPI Start failed\n"); 243 } 244 245 static bool crb_req_canceled(struct tpm_chip *chip, u8 status) 246 { 247 struct crb_priv *priv = dev_get_drvdata(&chip->dev); 248 u32 cancel = ioread32(&priv->cca->cancel); 249 250 return (cancel & CRB_CANCEL_INVOKE) == CRB_CANCEL_INVOKE; 251 } 252 253 static const struct tpm_class_ops tpm_crb = { 254 .flags = TPM_OPS_AUTO_STARTUP, 255 .status = crb_status, 256 .recv = crb_recv, 257 .send = crb_send, 258 .cancel = crb_cancel, 259 .req_canceled = crb_req_canceled, 260 .req_complete_mask = CRB_DRV_STS_COMPLETE, 261 .req_complete_val = CRB_DRV_STS_COMPLETE, 262 }; 263 264 static int crb_check_resource(struct acpi_resource *ares, void *data) 265 { 266 struct resource *io_res = data; 267 struct resource_win win; 268 struct resource *res = &(win.res); 269 270 if (acpi_dev_resource_memory(ares, res) || 271 acpi_dev_resource_address_space(ares, &win)) { 272 *io_res = *res; 273 io_res->name = NULL; 274 } 275 276 return 1; 277 } 278 279 static void __iomem *crb_map_res(struct device *dev, struct crb_priv *priv, 280 struct resource *io_res, u64 start, u32 size) 281 { 282 struct resource new_res = { 283 .start = start, 284 .end = start + size - 1, 285 .flags = IORESOURCE_MEM, 286 }; 287 288 /* Detect a 64 bit address on a 32 bit system */ 289 if (start != new_res.start) 290 return (void __iomem *) ERR_PTR(-EINVAL); 291 292 if (!resource_contains(io_res, &new_res)) 293 return devm_ioremap_resource(dev, &new_res); 294 295 return priv->iobase + (new_res.start - io_res->start); 296 } 297 298 static int crb_map_io(struct acpi_device *device, struct crb_priv *priv, 299 struct acpi_table_tpm2 *buf) 300 { 301 struct list_head resources; 302 struct resource io_res; 303 struct device *dev = &device->dev; 304 u32 pa_high, pa_low; 305 u64 cmd_pa; 306 u32 cmd_size; 307 u64 rsp_pa; 308 u32 rsp_size; 309 int ret; 310 311 INIT_LIST_HEAD(&resources); 312 ret = acpi_dev_get_resources(device, &resources, crb_check_resource, 313 &io_res); 314 if (ret < 0) 315 return ret; 316 acpi_dev_free_resource_list(&resources); 317 318 if (resource_type(&io_res) != IORESOURCE_MEM) { 319 dev_err(dev, FW_BUG "TPM2 ACPI table does not define a memory resource\n"); 320 return -EINVAL; 321 } 322 323 priv->iobase = devm_ioremap_resource(dev, &io_res); 324 if (IS_ERR(priv->iobase)) 325 return PTR_ERR(priv->iobase); 326 327 priv->cca = crb_map_res(dev, priv, &io_res, buf->control_address, 328 sizeof(struct crb_control_area)); 329 if (IS_ERR(priv->cca)) 330 return PTR_ERR(priv->cca); 331 332 /* 333 * PTT HW bug w/a: wake up the device to access 334 * possibly not retained registers. 335 */ 336 ret = crb_cmd_ready(dev, priv); 337 if (ret) 338 return ret; 339 340 pa_high = ioread32(&priv->cca->cmd_pa_high); 341 pa_low = ioread32(&priv->cca->cmd_pa_low); 342 cmd_pa = ((u64)pa_high << 32) | pa_low; 343 cmd_size = ioread32(&priv->cca->cmd_size); 344 345 dev_dbg(dev, "cmd_hi = %X cmd_low = %X cmd_size %X\n", 346 pa_high, pa_low, cmd_size); 347 348 priv->cmd = crb_map_res(dev, priv, &io_res, cmd_pa, cmd_size); 349 if (IS_ERR(priv->cmd)) { 350 ret = PTR_ERR(priv->cmd); 351 goto out; 352 } 353 354 memcpy_fromio(&rsp_pa, &priv->cca->rsp_pa, 8); 355 rsp_pa = le64_to_cpu(rsp_pa); 356 rsp_size = ioread32(&priv->cca->rsp_size); 357 358 if (cmd_pa != rsp_pa) { 359 priv->rsp = crb_map_res(dev, priv, &io_res, rsp_pa, rsp_size); 360 ret = PTR_ERR_OR_ZERO(priv->rsp); 361 goto out; 362 } 363 364 /* According to the PTP specification, overlapping command and response 365 * buffer sizes must be identical. 366 */ 367 if (cmd_size != rsp_size) { 368 dev_err(dev, FW_BUG "overlapping command and response buffer sizes are not identical"); 369 ret = -EINVAL; 370 goto out; 371 } 372 373 priv->cmd_size = cmd_size; 374 375 priv->rsp = priv->cmd; 376 377 out: 378 crb_go_idle(dev, priv); 379 380 return ret; 381 } 382 383 static int crb_acpi_add(struct acpi_device *device) 384 { 385 struct acpi_table_tpm2 *buf; 386 struct crb_priv *priv; 387 struct tpm_chip *chip; 388 struct device *dev = &device->dev; 389 acpi_status status; 390 u32 sm; 391 int rc; 392 393 status = acpi_get_table(ACPI_SIG_TPM2, 1, 394 (struct acpi_table_header **) &buf); 395 if (ACPI_FAILURE(status) || buf->header.length < sizeof(*buf)) { 396 dev_err(dev, FW_BUG "failed to get TPM2 ACPI table\n"); 397 return -EINVAL; 398 } 399 400 /* Should the FIFO driver handle this? */ 401 sm = buf->start_method; 402 if (sm == ACPI_TPM2_MEMORY_MAPPED) 403 return -ENODEV; 404 405 priv = devm_kzalloc(dev, sizeof(struct crb_priv), GFP_KERNEL); 406 if (!priv) 407 return -ENOMEM; 408 409 /* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs 410 * report only ACPI start but in practice seems to require both 411 * ACPI start and CRB start. 412 */ 413 if (sm == ACPI_TPM2_COMMAND_BUFFER || sm == ACPI_TPM2_MEMORY_MAPPED || 414 !strcmp(acpi_device_hid(device), "MSFT0101")) 415 priv->flags |= CRB_FL_CRB_START; 416 417 if (sm == ACPI_TPM2_START_METHOD || 418 sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) 419 priv->flags |= CRB_FL_ACPI_START; 420 421 rc = crb_map_io(device, priv, buf); 422 if (rc) 423 return rc; 424 425 chip = tpmm_chip_alloc(dev, &tpm_crb); 426 if (IS_ERR(chip)) 427 return PTR_ERR(chip); 428 429 dev_set_drvdata(&chip->dev, priv); 430 chip->acpi_dev_handle = device->handle; 431 chip->flags = TPM_CHIP_FLAG_TPM2; 432 433 rc = crb_cmd_ready(dev, priv); 434 if (rc) 435 return rc; 436 437 pm_runtime_get_noresume(dev); 438 pm_runtime_set_active(dev); 439 pm_runtime_enable(dev); 440 441 rc = tpm_chip_register(chip); 442 if (rc) { 443 crb_go_idle(dev, priv); 444 pm_runtime_put_noidle(dev); 445 pm_runtime_disable(dev); 446 return rc; 447 } 448 449 pm_runtime_put(dev); 450 451 return 0; 452 } 453 454 static int crb_acpi_remove(struct acpi_device *device) 455 { 456 struct device *dev = &device->dev; 457 struct tpm_chip *chip = dev_get_drvdata(dev); 458 459 tpm_chip_unregister(chip); 460 461 pm_runtime_disable(dev); 462 463 return 0; 464 } 465 466 #ifdef CONFIG_PM 467 static int crb_pm_runtime_suspend(struct device *dev) 468 { 469 struct tpm_chip *chip = dev_get_drvdata(dev); 470 struct crb_priv *priv = dev_get_drvdata(&chip->dev); 471 472 return crb_go_idle(dev, priv); 473 } 474 475 static int crb_pm_runtime_resume(struct device *dev) 476 { 477 struct tpm_chip *chip = dev_get_drvdata(dev); 478 struct crb_priv *priv = dev_get_drvdata(&chip->dev); 479 480 return crb_cmd_ready(dev, priv); 481 } 482 #endif /* CONFIG_PM */ 483 484 static const struct dev_pm_ops crb_pm = { 485 SET_SYSTEM_SLEEP_PM_OPS(tpm_pm_suspend, tpm_pm_resume) 486 SET_RUNTIME_PM_OPS(crb_pm_runtime_suspend, crb_pm_runtime_resume, NULL) 487 }; 488 489 static struct acpi_device_id crb_device_ids[] = { 490 {"MSFT0101", 0}, 491 {"", 0}, 492 }; 493 MODULE_DEVICE_TABLE(acpi, crb_device_ids); 494 495 static struct acpi_driver crb_acpi_driver = { 496 .name = "tpm_crb", 497 .ids = crb_device_ids, 498 .ops = { 499 .add = crb_acpi_add, 500 .remove = crb_acpi_remove, 501 }, 502 .drv = { 503 .pm = &crb_pm, 504 }, 505 }; 506 507 module_acpi_driver(crb_acpi_driver); 508 MODULE_AUTHOR("Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>"); 509 MODULE_DESCRIPTION("TPM2 Driver"); 510 MODULE_VERSION("0.1"); 511 MODULE_LICENSE("GPL"); 512