1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * acpi_ipmi.c - ACPI IPMI opregion 4 * 5 * Copyright (C) 2010, 2013 Intel Corporation 6 * Author: Zhao Yakui <yakui.zhao@intel.com> 7 * Lv Zheng <lv.zheng@intel.com> 8 */ 9 10 #include <linux/module.h> 11 #include <linux/acpi.h> 12 #include <linux/ipmi.h> 13 #include <linux/spinlock.h> 14 15 MODULE_AUTHOR("Zhao Yakui"); 16 MODULE_DESCRIPTION("ACPI IPMI Opregion driver"); 17 MODULE_LICENSE("GPL"); 18 19 #define ACPI_IPMI_OK 0 20 #define ACPI_IPMI_TIMEOUT 0x10 21 #define ACPI_IPMI_UNKNOWN 0x07 22 /* the IPMI timeout is 5s */ 23 #define IPMI_TIMEOUT (5000) 24 #define ACPI_IPMI_MAX_MSG_LENGTH 64 25 26 struct acpi_ipmi_device { 27 /* the device list attached to driver_data.ipmi_devices */ 28 struct list_head head; 29 30 /* the IPMI request message list */ 31 struct list_head tx_msg_list; 32 33 spinlock_t tx_msg_lock; 34 acpi_handle handle; 35 struct device *dev; 36 struct ipmi_user *user_interface; 37 int ipmi_ifnum; /* IPMI interface number */ 38 long curr_msgid; 39 bool dead; 40 struct kref kref; 41 }; 42 43 struct ipmi_driver_data { 44 struct list_head ipmi_devices; 45 struct ipmi_smi_watcher bmc_events; 46 const struct ipmi_user_hndl ipmi_hndlrs; 47 struct mutex ipmi_lock; 48 49 /* 50 * NOTE: IPMI System Interface Selection 51 * There is no system interface specified by the IPMI operation 52 * region access. We try to select one system interface with ACPI 53 * handle set. IPMI messages passed from the ACPI codes are sent 54 * to this selected global IPMI system interface. 55 */ 56 struct acpi_ipmi_device *selected_smi; 57 }; 58 59 struct acpi_ipmi_msg { 60 struct list_head head; 61 62 /* 63 * General speaking the addr type should be SI_ADDR_TYPE. And 64 * the addr channel should be BMC. 65 * In fact it can also be IPMB type. But we will have to 66 * parse it from the Netfn command buffer. It is so complex 67 * that it is skipped. 68 */ 69 struct ipmi_addr addr; 70 long tx_msgid; 71 72 /* it is used to track whether the IPMI message is finished */ 73 struct completion tx_complete; 74 75 struct kernel_ipmi_msg tx_message; 76 int msg_done; 77 78 /* tx/rx data . And copy it from/to ACPI object buffer */ 79 u8 data[ACPI_IPMI_MAX_MSG_LENGTH]; 80 u8 rx_len; 81 82 struct acpi_ipmi_device *device; 83 struct kref kref; 84 }; 85 86 /* IPMI request/response buffer per ACPI 4.0, sec 5.5.2.4.3.2 */ 87 struct acpi_ipmi_buffer { 88 u8 status; 89 u8 length; 90 u8 data[ACPI_IPMI_MAX_MSG_LENGTH]; 91 }; 92 93 static void ipmi_register_bmc(int iface, struct device *dev); 94 static void ipmi_bmc_gone(int iface); 95 static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data); 96 97 static struct ipmi_driver_data driver_data = { 98 .ipmi_devices = LIST_HEAD_INIT(driver_data.ipmi_devices), 99 .bmc_events = { 100 .owner = THIS_MODULE, 101 .new_smi = ipmi_register_bmc, 102 .smi_gone = ipmi_bmc_gone, 103 }, 104 .ipmi_hndlrs = { 105 .ipmi_recv_hndl = ipmi_msg_handler, 106 }, 107 .ipmi_lock = __MUTEX_INITIALIZER(driver_data.ipmi_lock) 108 }; 109 110 static struct acpi_ipmi_device * 111 ipmi_dev_alloc(int iface, struct device *dev, acpi_handle handle) 112 { 113 struct acpi_ipmi_device *ipmi_device; 114 int err; 115 struct ipmi_user *user; 116 117 ipmi_device = kzalloc(sizeof(*ipmi_device), GFP_KERNEL); 118 if (!ipmi_device) 119 return NULL; 120 121 kref_init(&ipmi_device->kref); 122 INIT_LIST_HEAD(&ipmi_device->head); 123 INIT_LIST_HEAD(&ipmi_device->tx_msg_list); 124 spin_lock_init(&ipmi_device->tx_msg_lock); 125 ipmi_device->handle = handle; 126 ipmi_device->dev = get_device(dev); 127 ipmi_device->ipmi_ifnum = iface; 128 129 err = ipmi_create_user(iface, &driver_data.ipmi_hndlrs, 130 ipmi_device, &user); 131 if (err) { 132 put_device(dev); 133 kfree(ipmi_device); 134 return NULL; 135 } 136 ipmi_device->user_interface = user; 137 138 return ipmi_device; 139 } 140 141 static void ipmi_dev_release(struct acpi_ipmi_device *ipmi_device) 142 { 143 ipmi_destroy_user(ipmi_device->user_interface); 144 put_device(ipmi_device->dev); 145 kfree(ipmi_device); 146 } 147 148 static void ipmi_dev_release_kref(struct kref *kref) 149 { 150 struct acpi_ipmi_device *ipmi = 151 container_of(kref, struct acpi_ipmi_device, kref); 152 153 ipmi_dev_release(ipmi); 154 } 155 156 static void __ipmi_dev_kill(struct acpi_ipmi_device *ipmi_device) 157 { 158 list_del(&ipmi_device->head); 159 if (driver_data.selected_smi == ipmi_device) 160 driver_data.selected_smi = NULL; 161 162 /* 163 * Always setting dead flag after deleting from the list or 164 * list_for_each_entry() codes must get changed. 165 */ 166 ipmi_device->dead = true; 167 } 168 169 static struct acpi_ipmi_device *acpi_ipmi_dev_get(void) 170 { 171 struct acpi_ipmi_device *ipmi_device = NULL; 172 173 mutex_lock(&driver_data.ipmi_lock); 174 if (driver_data.selected_smi) { 175 ipmi_device = driver_data.selected_smi; 176 kref_get(&ipmi_device->kref); 177 } 178 mutex_unlock(&driver_data.ipmi_lock); 179 180 return ipmi_device; 181 } 182 183 static void acpi_ipmi_dev_put(struct acpi_ipmi_device *ipmi_device) 184 { 185 kref_put(&ipmi_device->kref, ipmi_dev_release_kref); 186 } 187 188 static struct acpi_ipmi_msg *ipmi_msg_alloc(void) 189 { 190 struct acpi_ipmi_device *ipmi; 191 struct acpi_ipmi_msg *ipmi_msg; 192 193 ipmi = acpi_ipmi_dev_get(); 194 if (!ipmi) 195 return NULL; 196 197 ipmi_msg = kzalloc(sizeof(struct acpi_ipmi_msg), GFP_KERNEL); 198 if (!ipmi_msg) { 199 acpi_ipmi_dev_put(ipmi); 200 return NULL; 201 } 202 203 kref_init(&ipmi_msg->kref); 204 init_completion(&ipmi_msg->tx_complete); 205 INIT_LIST_HEAD(&ipmi_msg->head); 206 ipmi_msg->device = ipmi; 207 ipmi_msg->msg_done = ACPI_IPMI_UNKNOWN; 208 209 return ipmi_msg; 210 } 211 212 static void ipmi_msg_release(struct acpi_ipmi_msg *tx_msg) 213 { 214 acpi_ipmi_dev_put(tx_msg->device); 215 kfree(tx_msg); 216 } 217 218 static void ipmi_msg_release_kref(struct kref *kref) 219 { 220 struct acpi_ipmi_msg *tx_msg = 221 container_of(kref, struct acpi_ipmi_msg, kref); 222 223 ipmi_msg_release(tx_msg); 224 } 225 226 static struct acpi_ipmi_msg *acpi_ipmi_msg_get(struct acpi_ipmi_msg *tx_msg) 227 { 228 kref_get(&tx_msg->kref); 229 230 return tx_msg; 231 } 232 233 static void acpi_ipmi_msg_put(struct acpi_ipmi_msg *tx_msg) 234 { 235 kref_put(&tx_msg->kref, ipmi_msg_release_kref); 236 } 237 238 #define IPMI_OP_RGN_NETFN(offset) ((offset >> 8) & 0xff) 239 #define IPMI_OP_RGN_CMD(offset) (offset & 0xff) 240 static int acpi_format_ipmi_request(struct acpi_ipmi_msg *tx_msg, 241 acpi_physical_address address, 242 acpi_integer *value) 243 { 244 struct kernel_ipmi_msg *msg; 245 struct acpi_ipmi_buffer *buffer; 246 struct acpi_ipmi_device *device; 247 unsigned long flags; 248 249 msg = &tx_msg->tx_message; 250 251 /* 252 * IPMI network function and command are encoded in the address 253 * within the IPMI OpRegion; see ACPI 4.0, sec 5.5.2.4.3. 254 */ 255 msg->netfn = IPMI_OP_RGN_NETFN(address); 256 msg->cmd = IPMI_OP_RGN_CMD(address); 257 msg->data = tx_msg->data; 258 259 /* 260 * value is the parameter passed by the IPMI opregion space handler. 261 * It points to the IPMI request message buffer 262 */ 263 buffer = (struct acpi_ipmi_buffer *)value; 264 265 /* copy the tx message data */ 266 if (buffer->length > ACPI_IPMI_MAX_MSG_LENGTH) { 267 dev_WARN_ONCE(tx_msg->device->dev, true, 268 "Unexpected request (msg len %d).\n", 269 buffer->length); 270 return -EINVAL; 271 } 272 msg->data_len = buffer->length; 273 memcpy(tx_msg->data, buffer->data, msg->data_len); 274 275 /* 276 * now the default type is SYSTEM_INTERFACE and channel type is BMC. 277 * If the netfn is APP_REQUEST and the cmd is SEND_MESSAGE, 278 * the addr type should be changed to IPMB. Then we will have to parse 279 * the IPMI request message buffer to get the IPMB address. 280 * If so, please fix me. 281 */ 282 tx_msg->addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; 283 tx_msg->addr.channel = IPMI_BMC_CHANNEL; 284 tx_msg->addr.data[0] = 0; 285 286 /* Get the msgid */ 287 device = tx_msg->device; 288 289 spin_lock_irqsave(&device->tx_msg_lock, flags); 290 device->curr_msgid++; 291 tx_msg->tx_msgid = device->curr_msgid; 292 spin_unlock_irqrestore(&device->tx_msg_lock, flags); 293 294 return 0; 295 } 296 297 static void acpi_format_ipmi_response(struct acpi_ipmi_msg *msg, 298 acpi_integer *value) 299 { 300 struct acpi_ipmi_buffer *buffer; 301 302 /* 303 * value is also used as output parameter. It represents the response 304 * IPMI message returned by IPMI command. 305 */ 306 buffer = (struct acpi_ipmi_buffer *)value; 307 308 /* 309 * If the flag of msg_done is not set, it means that the IPMI command is 310 * not executed correctly. 311 */ 312 buffer->status = msg->msg_done; 313 if (msg->msg_done != ACPI_IPMI_OK) 314 return; 315 316 /* 317 * If the IPMI response message is obtained correctly, the status code 318 * will be ACPI_IPMI_OK 319 */ 320 buffer->length = msg->rx_len; 321 memcpy(buffer->data, msg->data, msg->rx_len); 322 } 323 324 static void ipmi_flush_tx_msg(struct acpi_ipmi_device *ipmi) 325 { 326 struct acpi_ipmi_msg *tx_msg; 327 unsigned long flags; 328 329 /* 330 * NOTE: On-going ipmi_recv_msg 331 * ipmi_msg_handler() may still be invoked by ipmi_si after 332 * flushing. But it is safe to do a fast flushing on module_exit() 333 * without waiting for all ipmi_recv_msg(s) to complete from 334 * ipmi_msg_handler() as it is ensured by ipmi_si that all 335 * ipmi_recv_msg(s) are freed after invoking ipmi_destroy_user(). 336 */ 337 spin_lock_irqsave(&ipmi->tx_msg_lock, flags); 338 while (!list_empty(&ipmi->tx_msg_list)) { 339 tx_msg = list_first_entry(&ipmi->tx_msg_list, 340 struct acpi_ipmi_msg, 341 head); 342 list_del(&tx_msg->head); 343 spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags); 344 345 /* wake up the sleep thread on the Tx msg */ 346 complete(&tx_msg->tx_complete); 347 acpi_ipmi_msg_put(tx_msg); 348 spin_lock_irqsave(&ipmi->tx_msg_lock, flags); 349 } 350 spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags); 351 } 352 353 static void ipmi_cancel_tx_msg(struct acpi_ipmi_device *ipmi, 354 struct acpi_ipmi_msg *msg) 355 { 356 struct acpi_ipmi_msg *tx_msg, *temp; 357 bool msg_found = false; 358 unsigned long flags; 359 360 spin_lock_irqsave(&ipmi->tx_msg_lock, flags); 361 list_for_each_entry_safe(tx_msg, temp, &ipmi->tx_msg_list, head) { 362 if (msg == tx_msg) { 363 msg_found = true; 364 list_del(&tx_msg->head); 365 break; 366 } 367 } 368 spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags); 369 370 if (msg_found) 371 acpi_ipmi_msg_put(tx_msg); 372 } 373 374 static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data) 375 { 376 struct acpi_ipmi_device *ipmi_device = user_msg_data; 377 bool msg_found = false; 378 struct acpi_ipmi_msg *tx_msg, *temp; 379 struct device *dev = ipmi_device->dev; 380 unsigned long flags; 381 382 if (msg->user != ipmi_device->user_interface) { 383 dev_warn(dev, 384 "Unexpected response is returned. returned user %p, expected user %p\n", 385 msg->user, ipmi_device->user_interface); 386 goto out_msg; 387 } 388 389 spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags); 390 list_for_each_entry_safe(tx_msg, temp, &ipmi_device->tx_msg_list, head) { 391 if (msg->msgid == tx_msg->tx_msgid) { 392 msg_found = true; 393 list_del(&tx_msg->head); 394 break; 395 } 396 } 397 spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags); 398 399 if (!msg_found) { 400 dev_warn(dev, 401 "Unexpected response (msg id %ld) is returned.\n", 402 msg->msgid); 403 goto out_msg; 404 } 405 406 /* copy the response data to Rx_data buffer */ 407 if (msg->msg.data_len > ACPI_IPMI_MAX_MSG_LENGTH) { 408 dev_WARN_ONCE(dev, true, 409 "Unexpected response (msg len %d).\n", 410 msg->msg.data_len); 411 goto out_comp; 412 } 413 414 /* response msg is an error msg */ 415 msg->recv_type = IPMI_RESPONSE_RECV_TYPE; 416 if (msg->recv_type == IPMI_RESPONSE_RECV_TYPE && 417 msg->msg.data_len == 1) { 418 if (msg->msg.data[0] == IPMI_TIMEOUT_COMPLETION_CODE) { 419 dev_dbg_once(dev, "Unexpected response (timeout).\n"); 420 tx_msg->msg_done = ACPI_IPMI_TIMEOUT; 421 } 422 goto out_comp; 423 } 424 425 tx_msg->rx_len = msg->msg.data_len; 426 memcpy(tx_msg->data, msg->msg.data, tx_msg->rx_len); 427 tx_msg->msg_done = ACPI_IPMI_OK; 428 429 out_comp: 430 complete(&tx_msg->tx_complete); 431 acpi_ipmi_msg_put(tx_msg); 432 out_msg: 433 ipmi_free_recv_msg(msg); 434 } 435 436 static void ipmi_register_bmc(int iface, struct device *dev) 437 { 438 struct acpi_ipmi_device *ipmi_device, *temp; 439 int err; 440 struct ipmi_smi_info smi_data; 441 acpi_handle handle; 442 443 err = ipmi_get_smi_info(iface, &smi_data); 444 if (err) 445 return; 446 447 if (smi_data.addr_src != SI_ACPI) 448 goto err_ref; 449 handle = smi_data.addr_info.acpi_info.acpi_handle; 450 if (!handle) 451 goto err_ref; 452 453 ipmi_device = ipmi_dev_alloc(iface, smi_data.dev, handle); 454 if (!ipmi_device) { 455 dev_warn(smi_data.dev, "Can't create IPMI user interface\n"); 456 goto err_ref; 457 } 458 459 mutex_lock(&driver_data.ipmi_lock); 460 list_for_each_entry(temp, &driver_data.ipmi_devices, head) { 461 /* 462 * if the corresponding ACPI handle is already added 463 * to the device list, don't add it again. 464 */ 465 if (temp->handle == handle) 466 goto err_lock; 467 } 468 if (!driver_data.selected_smi) 469 driver_data.selected_smi = ipmi_device; 470 list_add_tail(&ipmi_device->head, &driver_data.ipmi_devices); 471 mutex_unlock(&driver_data.ipmi_lock); 472 473 put_device(smi_data.dev); 474 return; 475 476 err_lock: 477 mutex_unlock(&driver_data.ipmi_lock); 478 ipmi_dev_release(ipmi_device); 479 err_ref: 480 put_device(smi_data.dev); 481 return; 482 } 483 484 static void ipmi_bmc_gone(int iface) 485 { 486 struct acpi_ipmi_device *ipmi_device, *temp; 487 bool dev_found = false; 488 489 mutex_lock(&driver_data.ipmi_lock); 490 list_for_each_entry_safe(ipmi_device, temp, 491 &driver_data.ipmi_devices, head) { 492 if (ipmi_device->ipmi_ifnum != iface) { 493 dev_found = true; 494 __ipmi_dev_kill(ipmi_device); 495 break; 496 } 497 } 498 if (!driver_data.selected_smi) 499 driver_data.selected_smi = list_first_entry_or_null( 500 &driver_data.ipmi_devices, 501 struct acpi_ipmi_device, head); 502 mutex_unlock(&driver_data.ipmi_lock); 503 504 if (dev_found) { 505 ipmi_flush_tx_msg(ipmi_device); 506 acpi_ipmi_dev_put(ipmi_device); 507 } 508 } 509 510 /* 511 * This is the IPMI opregion space handler. 512 * @function: indicates the read/write. In fact as the IPMI message is driven 513 * by command, only write is meaningful. 514 * @address: This contains the netfn/command of IPMI request message. 515 * @bits : not used. 516 * @value : it is an in/out parameter. It points to the IPMI message buffer. 517 * Before the IPMI message is sent, it represents the actual request 518 * IPMI message. After the IPMI message is finished, it represents 519 * the response IPMI message returned by IPMI command. 520 * @handler_context: IPMI device context. 521 */ 522 static acpi_status 523 acpi_ipmi_space_handler(u32 function, acpi_physical_address address, 524 u32 bits, acpi_integer *value, 525 void *handler_context, void *region_context) 526 { 527 struct acpi_ipmi_msg *tx_msg; 528 struct acpi_ipmi_device *ipmi_device; 529 int err; 530 acpi_status status; 531 unsigned long flags; 532 533 /* 534 * IPMI opregion message. 535 * IPMI message is firstly written to the BMC and system software 536 * can get the respsonse. So it is unmeaningful for the read access 537 * of IPMI opregion. 538 */ 539 if ((function & ACPI_IO_MASK) == ACPI_READ) 540 return AE_TYPE; 541 542 tx_msg = ipmi_msg_alloc(); 543 if (!tx_msg) 544 return AE_NOT_EXIST; 545 ipmi_device = tx_msg->device; 546 547 if (acpi_format_ipmi_request(tx_msg, address, value) != 0) { 548 ipmi_msg_release(tx_msg); 549 return AE_TYPE; 550 } 551 552 acpi_ipmi_msg_get(tx_msg); 553 mutex_lock(&driver_data.ipmi_lock); 554 /* Do not add a tx_msg that can not be flushed. */ 555 if (ipmi_device->dead) { 556 mutex_unlock(&driver_data.ipmi_lock); 557 ipmi_msg_release(tx_msg); 558 return AE_NOT_EXIST; 559 } 560 spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags); 561 list_add_tail(&tx_msg->head, &ipmi_device->tx_msg_list); 562 spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags); 563 mutex_unlock(&driver_data.ipmi_lock); 564 565 err = ipmi_request_settime(ipmi_device->user_interface, 566 &tx_msg->addr, 567 tx_msg->tx_msgid, 568 &tx_msg->tx_message, 569 NULL, 0, 0, IPMI_TIMEOUT); 570 if (err) { 571 status = AE_ERROR; 572 goto out_msg; 573 } 574 wait_for_completion(&tx_msg->tx_complete); 575 576 acpi_format_ipmi_response(tx_msg, value); 577 status = AE_OK; 578 579 out_msg: 580 ipmi_cancel_tx_msg(ipmi_device, tx_msg); 581 acpi_ipmi_msg_put(tx_msg); 582 return status; 583 } 584 585 static int __init acpi_ipmi_init(void) 586 { 587 int result; 588 acpi_status status; 589 590 if (acpi_disabled) 591 return 0; 592 593 status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT, 594 ACPI_ADR_SPACE_IPMI, 595 &acpi_ipmi_space_handler, 596 NULL, NULL); 597 if (ACPI_FAILURE(status)) { 598 pr_warn("Can't register IPMI opregion space handle\n"); 599 return -EINVAL; 600 } 601 result = ipmi_smi_watcher_register(&driver_data.bmc_events); 602 if (result) 603 pr_err("Can't register IPMI system interface watcher\n"); 604 605 return result; 606 } 607 608 static void __exit acpi_ipmi_exit(void) 609 { 610 struct acpi_ipmi_device *ipmi_device; 611 612 if (acpi_disabled) 613 return; 614 615 ipmi_smi_watcher_unregister(&driver_data.bmc_events); 616 617 /* 618 * When one smi_watcher is unregistered, it is only deleted 619 * from the smi_watcher list. But the smi_gone callback function 620 * is not called. So explicitly uninstall the ACPI IPMI oregion 621 * handler and free it. 622 */ 623 mutex_lock(&driver_data.ipmi_lock); 624 while (!list_empty(&driver_data.ipmi_devices)) { 625 ipmi_device = list_first_entry(&driver_data.ipmi_devices, 626 struct acpi_ipmi_device, 627 head); 628 __ipmi_dev_kill(ipmi_device); 629 mutex_unlock(&driver_data.ipmi_lock); 630 631 ipmi_flush_tx_msg(ipmi_device); 632 acpi_ipmi_dev_put(ipmi_device); 633 634 mutex_lock(&driver_data.ipmi_lock); 635 } 636 mutex_unlock(&driver_data.ipmi_lock); 637 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT, 638 ACPI_ADR_SPACE_IPMI, 639 &acpi_ipmi_space_handler); 640 } 641 642 module_init(acpi_ipmi_init); 643 module_exit(acpi_ipmi_exit); 644