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 15MODULE_AUTHOR("Zhao Yakui"); 16MODULE_DESCRIPTION("ACPI IPMI Opregion driver"); 17MODULE_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 26struct 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 43struct 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 59struct 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 */ 87struct acpi_ipmi_buffer { 88 u8 status; 89 u8 length; 90 u8 data[ACPI_IPMI_MAX_MSG_LENGTH]; 91}; 92 93static void ipmi_register_bmc(int iface, struct device *dev); 94static void ipmi_bmc_gone(int iface); 95static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data); 96 97static 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 110static struct acpi_ipmi_device * 111ipmi_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 141static 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 148static 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 156static 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 169static 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 183static void acpi_ipmi_dev_put(struct acpi_ipmi_device *ipmi_device) 184{ 185 kref_put(&ipmi_device->kref, ipmi_dev_release_kref); 186} 187 188static 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 212static 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 218static 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 226static 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 233static 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) 240static 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 297static 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 324static 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 353static void ipmi_cancel_tx_msg(struct acpi_ipmi_device *ipmi, 354 struct acpi_ipmi_msg *msg) 355{ 356 struct acpi_ipmi_msg *tx_msg = NULL, *iter, *temp; 357 unsigned long flags; 358 359 spin_lock_irqsave(&ipmi->tx_msg_lock, flags); 360 list_for_each_entry_safe(iter, temp, &ipmi->tx_msg_list, head) { 361 if (msg == iter) { 362 tx_msg = iter; 363 list_del(&iter->head); 364 break; 365 } 366 } 367 spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags); 368 369 if (tx_msg) 370 acpi_ipmi_msg_put(tx_msg); 371} 372 373static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data) 374{ 375 struct acpi_ipmi_device *ipmi_device = user_msg_data; 376 struct acpi_ipmi_msg *tx_msg = NULL, *iter, *temp; 377 struct device *dev = ipmi_device->dev; 378 unsigned long flags; 379 380 if (msg->user != ipmi_device->user_interface) { 381 dev_warn(dev, 382 "Unexpected response is returned. returned user %p, expected user %p\n", 383 msg->user, ipmi_device->user_interface); 384 goto out_msg; 385 } 386 387 spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags); 388 list_for_each_entry_safe(iter, temp, &ipmi_device->tx_msg_list, head) { 389 if (msg->msgid == iter->tx_msgid) { 390 tx_msg = iter; 391 list_del(&iter->head); 392 break; 393 } 394 } 395 spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags); 396 397 if (!tx_msg) { 398 dev_warn(dev, 399 "Unexpected response (msg id %ld) is returned.\n", 400 msg->msgid); 401 goto out_msg; 402 } 403 404 /* copy the response data to Rx_data buffer */ 405 if (msg->msg.data_len > ACPI_IPMI_MAX_MSG_LENGTH) { 406 dev_WARN_ONCE(dev, true, 407 "Unexpected response (msg len %d).\n", 408 msg->msg.data_len); 409 goto out_comp; 410 } 411 412 /* response msg is an error msg */ 413 msg->recv_type = IPMI_RESPONSE_RECV_TYPE; 414 if (msg->recv_type == IPMI_RESPONSE_RECV_TYPE && 415 msg->msg.data_len == 1) { 416 if (msg->msg.data[0] == IPMI_TIMEOUT_COMPLETION_CODE) { 417 dev_dbg_once(dev, "Unexpected response (timeout).\n"); 418 tx_msg->msg_done = ACPI_IPMI_TIMEOUT; 419 } 420 goto out_comp; 421 } 422 423 tx_msg->rx_len = msg->msg.data_len; 424 memcpy(tx_msg->data, msg->msg.data, tx_msg->rx_len); 425 tx_msg->msg_done = ACPI_IPMI_OK; 426 427out_comp: 428 complete(&tx_msg->tx_complete); 429 acpi_ipmi_msg_put(tx_msg); 430out_msg: 431 ipmi_free_recv_msg(msg); 432} 433 434static void ipmi_register_bmc(int iface, struct device *dev) 435{ 436 struct acpi_ipmi_device *ipmi_device, *temp; 437 int err; 438 struct ipmi_smi_info smi_data; 439 acpi_handle handle; 440 441 err = ipmi_get_smi_info(iface, &smi_data); 442 if (err) 443 return; 444 445 if (smi_data.addr_src != SI_ACPI) 446 goto err_ref; 447 handle = smi_data.addr_info.acpi_info.acpi_handle; 448 if (!handle) 449 goto err_ref; 450 451 ipmi_device = ipmi_dev_alloc(iface, smi_data.dev, handle); 452 if (!ipmi_device) { 453 dev_warn(smi_data.dev, "Can't create IPMI user interface\n"); 454 goto err_ref; 455 } 456 457 mutex_lock(&driver_data.ipmi_lock); 458 list_for_each_entry(temp, &driver_data.ipmi_devices, head) { 459 /* 460 * if the corresponding ACPI handle is already added 461 * to the device list, don't add it again. 462 */ 463 if (temp->handle == handle) 464 goto err_lock; 465 } 466 if (!driver_data.selected_smi) 467 driver_data.selected_smi = ipmi_device; 468 list_add_tail(&ipmi_device->head, &driver_data.ipmi_devices); 469 mutex_unlock(&driver_data.ipmi_lock); 470 471 put_device(smi_data.dev); 472 return; 473 474err_lock: 475 mutex_unlock(&driver_data.ipmi_lock); 476 ipmi_dev_release(ipmi_device); 477err_ref: 478 put_device(smi_data.dev); 479} 480 481static void ipmi_bmc_gone(int iface) 482{ 483 struct acpi_ipmi_device *ipmi_device = NULL, *iter, *temp; 484 485 mutex_lock(&driver_data.ipmi_lock); 486 list_for_each_entry_safe(iter, temp, 487 &driver_data.ipmi_devices, head) { 488 if (iter->ipmi_ifnum != iface) { 489 ipmi_device = iter; 490 __ipmi_dev_kill(iter); 491 break; 492 } 493 } 494 if (!driver_data.selected_smi) 495 driver_data.selected_smi = list_first_entry_or_null( 496 &driver_data.ipmi_devices, 497 struct acpi_ipmi_device, head); 498 mutex_unlock(&driver_data.ipmi_lock); 499 500 if (ipmi_device) { 501 ipmi_flush_tx_msg(ipmi_device); 502 acpi_ipmi_dev_put(ipmi_device); 503 } 504} 505 506/* 507 * This is the IPMI opregion space handler. 508 * @function: indicates the read/write. In fact as the IPMI message is driven 509 * by command, only write is meaningful. 510 * @address: This contains the netfn/command of IPMI request message. 511 * @bits : not used. 512 * @value : it is an in/out parameter. It points to the IPMI message buffer. 513 * Before the IPMI message is sent, it represents the actual request 514 * IPMI message. After the IPMI message is finished, it represents 515 * the response IPMI message returned by IPMI command. 516 * @handler_context: IPMI device context. 517 */ 518static acpi_status 519acpi_ipmi_space_handler(u32 function, acpi_physical_address address, 520 u32 bits, acpi_integer *value, 521 void *handler_context, void *region_context) 522{ 523 struct acpi_ipmi_msg *tx_msg; 524 struct acpi_ipmi_device *ipmi_device; 525 int err; 526 acpi_status status; 527 unsigned long flags; 528 529 /* 530 * IPMI opregion message. 531 * IPMI message is firstly written to the BMC and system software 532 * can get the respsonse. So it is unmeaningful for the read access 533 * of IPMI opregion. 534 */ 535 if ((function & ACPI_IO_MASK) == ACPI_READ) 536 return AE_TYPE; 537 538 tx_msg = ipmi_msg_alloc(); 539 if (!tx_msg) 540 return AE_NOT_EXIST; 541 ipmi_device = tx_msg->device; 542 543 if (acpi_format_ipmi_request(tx_msg, address, value) != 0) { 544 ipmi_msg_release(tx_msg); 545 return AE_TYPE; 546 } 547 548 acpi_ipmi_msg_get(tx_msg); 549 mutex_lock(&driver_data.ipmi_lock); 550 /* Do not add a tx_msg that can not be flushed. */ 551 if (ipmi_device->dead) { 552 mutex_unlock(&driver_data.ipmi_lock); 553 ipmi_msg_release(tx_msg); 554 return AE_NOT_EXIST; 555 } 556 spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags); 557 list_add_tail(&tx_msg->head, &ipmi_device->tx_msg_list); 558 spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags); 559 mutex_unlock(&driver_data.ipmi_lock); 560 561 err = ipmi_request_settime(ipmi_device->user_interface, 562 &tx_msg->addr, 563 tx_msg->tx_msgid, 564 &tx_msg->tx_message, 565 NULL, 0, 0, IPMI_TIMEOUT); 566 if (err) { 567 status = AE_ERROR; 568 goto out_msg; 569 } 570 wait_for_completion(&tx_msg->tx_complete); 571 572 acpi_format_ipmi_response(tx_msg, value); 573 status = AE_OK; 574 575out_msg: 576 ipmi_cancel_tx_msg(ipmi_device, tx_msg); 577 acpi_ipmi_msg_put(tx_msg); 578 return status; 579} 580 581static int __init acpi_ipmi_init(void) 582{ 583 int result; 584 acpi_status status; 585 586 if (acpi_disabled) 587 return 0; 588 589 status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT, 590 ACPI_ADR_SPACE_IPMI, 591 &acpi_ipmi_space_handler, 592 NULL, NULL); 593 if (ACPI_FAILURE(status)) { 594 pr_warn("Can't register IPMI opregion space handle\n"); 595 return -EINVAL; 596 } 597 598 result = ipmi_smi_watcher_register(&driver_data.bmc_events); 599 if (result) { 600 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT, 601 ACPI_ADR_SPACE_IPMI, 602 &acpi_ipmi_space_handler); 603 pr_err("Can't register IPMI system interface watcher\n"); 604 } 605 606 return result; 607} 608 609static void __exit acpi_ipmi_exit(void) 610{ 611 struct acpi_ipmi_device *ipmi_device; 612 613 if (acpi_disabled) 614 return; 615 616 ipmi_smi_watcher_unregister(&driver_data.bmc_events); 617 618 /* 619 * When one smi_watcher is unregistered, it is only deleted 620 * from the smi_watcher list. But the smi_gone callback function 621 * is not called. So explicitly uninstall the ACPI IPMI oregion 622 * handler and free it. 623 */ 624 mutex_lock(&driver_data.ipmi_lock); 625 while (!list_empty(&driver_data.ipmi_devices)) { 626 ipmi_device = list_first_entry(&driver_data.ipmi_devices, 627 struct acpi_ipmi_device, 628 head); 629 __ipmi_dev_kill(ipmi_device); 630 mutex_unlock(&driver_data.ipmi_lock); 631 632 ipmi_flush_tx_msg(ipmi_device); 633 acpi_ipmi_dev_put(ipmi_device); 634 635 mutex_lock(&driver_data.ipmi_lock); 636 } 637 mutex_unlock(&driver_data.ipmi_lock); 638 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT, 639 ACPI_ADR_SPACE_IPMI, 640 &acpi_ipmi_space_handler); 641} 642 643module_init(acpi_ipmi_init); 644module_exit(acpi_ipmi_exit); 645