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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * acpi_ipmi.c - ACPI IPMI opregion4 *5 * Copyright (C) 2010, 2013 Intel Corporation6 * 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 020#define ACPI_IPMI_TIMEOUT 0x1021#define ACPI_IPMI_UNKNOWN 0x0722/* the IPMI timeout is 5s */23#define IPMI_TIMEOUT (5000)24#define ACPI_IPMI_MAX_MSG_LENGTH 6425/* 2s should be suffient for SMI being selected */26#define ACPI_IPMI_SMI_SELECTION_TIMEOUT (2 * HZ)27 28struct acpi_ipmi_device {29 /* the device list attached to driver_data.ipmi_devices */30 struct list_head head;31 32 /* the IPMI request message list */33 struct list_head tx_msg_list;34 35 spinlock_t tx_msg_lock;36 acpi_handle handle;37 struct device *dev;38 struct ipmi_user *user_interface;39 int ipmi_ifnum; /* IPMI interface number */40 long curr_msgid;41 bool dead;42 struct kref kref;43};44 45struct ipmi_driver_data {46 struct list_head ipmi_devices;47 struct ipmi_smi_watcher bmc_events;48 const struct ipmi_user_hndl ipmi_hndlrs;49 struct mutex ipmi_lock;50 51 /*52 * NOTE: IPMI System Interface Selection53 * There is no system interface specified by the IPMI operation54 * region access. We try to select one system interface with ACPI55 * handle set. IPMI messages passed from the ACPI codes are sent56 * to this selected global IPMI system interface.57 */58 struct acpi_ipmi_device *selected_smi;59 struct completion smi_selection_done;60};61 62struct acpi_ipmi_msg {63 struct list_head head;64 65 /*66 * General speaking the addr type should be SI_ADDR_TYPE. And67 * the addr channel should be BMC.68 * In fact it can also be IPMB type. But we will have to69 * parse it from the Netfn command buffer. It is so complex70 * that it is skipped.71 */72 struct ipmi_addr addr;73 long tx_msgid;74 75 /* it is used to track whether the IPMI message is finished */76 struct completion tx_complete;77 78 struct kernel_ipmi_msg tx_message;79 int msg_done;80 81 /* tx/rx data . And copy it from/to ACPI object buffer */82 u8 data[ACPI_IPMI_MAX_MSG_LENGTH];83 u8 rx_len;84 85 struct acpi_ipmi_device *device;86 struct kref kref;87};88 89/* IPMI request/response buffer per ACPI 4.0, sec 5.5.2.4.3.2 */90struct acpi_ipmi_buffer {91 u8 status;92 u8 length;93 u8 data[ACPI_IPMI_MAX_MSG_LENGTH];94};95 96static void ipmi_register_bmc(int iface, struct device *dev);97static void ipmi_bmc_gone(int iface);98static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data);99 100static struct ipmi_driver_data driver_data = {101 .ipmi_devices = LIST_HEAD_INIT(driver_data.ipmi_devices),102 .bmc_events = {103 .owner = THIS_MODULE,104 .new_smi = ipmi_register_bmc,105 .smi_gone = ipmi_bmc_gone,106 },107 .ipmi_hndlrs = {108 .ipmi_recv_hndl = ipmi_msg_handler,109 },110 .ipmi_lock = __MUTEX_INITIALIZER(driver_data.ipmi_lock)111};112 113static struct acpi_ipmi_device *114ipmi_dev_alloc(int iface, struct device *dev, acpi_handle handle)115{116 struct acpi_ipmi_device *ipmi_device;117 int err;118 struct ipmi_user *user;119 120 ipmi_device = kzalloc(sizeof(*ipmi_device), GFP_KERNEL);121 if (!ipmi_device)122 return NULL;123 124 kref_init(&ipmi_device->kref);125 INIT_LIST_HEAD(&ipmi_device->head);126 INIT_LIST_HEAD(&ipmi_device->tx_msg_list);127 spin_lock_init(&ipmi_device->tx_msg_lock);128 ipmi_device->handle = handle;129 ipmi_device->dev = get_device(dev);130 ipmi_device->ipmi_ifnum = iface;131 132 err = ipmi_create_user(iface, &driver_data.ipmi_hndlrs,133 ipmi_device, &user);134 if (err) {135 put_device(dev);136 kfree(ipmi_device);137 return NULL;138 }139 ipmi_device->user_interface = user;140 141 return ipmi_device;142}143 144static void ipmi_dev_release(struct acpi_ipmi_device *ipmi_device)145{146 ipmi_destroy_user(ipmi_device->user_interface);147 put_device(ipmi_device->dev);148 kfree(ipmi_device);149}150 151static void ipmi_dev_release_kref(struct kref *kref)152{153 struct acpi_ipmi_device *ipmi =154 container_of(kref, struct acpi_ipmi_device, kref);155 156 ipmi_dev_release(ipmi);157}158 159static void __ipmi_dev_kill(struct acpi_ipmi_device *ipmi_device)160{161 list_del(&ipmi_device->head);162 if (driver_data.selected_smi == ipmi_device)163 driver_data.selected_smi = NULL;164 165 /*166 * Always setting dead flag after deleting from the list or167 * list_for_each_entry() codes must get changed.168 */169 ipmi_device->dead = true;170}171 172static struct acpi_ipmi_device *acpi_ipmi_dev_get(void)173{174 struct acpi_ipmi_device *ipmi_device = NULL;175 176 mutex_lock(&driver_data.ipmi_lock);177 if (driver_data.selected_smi) {178 ipmi_device = driver_data.selected_smi;179 kref_get(&ipmi_device->kref);180 }181 mutex_unlock(&driver_data.ipmi_lock);182 183 return ipmi_device;184}185 186static void acpi_ipmi_dev_put(struct acpi_ipmi_device *ipmi_device)187{188 kref_put(&ipmi_device->kref, ipmi_dev_release_kref);189}190 191static struct acpi_ipmi_msg *ipmi_msg_alloc(void)192{193 struct acpi_ipmi_device *ipmi;194 struct acpi_ipmi_msg *ipmi_msg;195 196 ipmi = acpi_ipmi_dev_get();197 if (!ipmi)198 return NULL;199 200 ipmi_msg = kzalloc(sizeof(struct acpi_ipmi_msg), GFP_KERNEL);201 if (!ipmi_msg) {202 acpi_ipmi_dev_put(ipmi);203 return NULL;204 }205 206 kref_init(&ipmi_msg->kref);207 init_completion(&ipmi_msg->tx_complete);208 INIT_LIST_HEAD(&ipmi_msg->head);209 ipmi_msg->device = ipmi;210 ipmi_msg->msg_done = ACPI_IPMI_UNKNOWN;211 212 return ipmi_msg;213}214 215static void ipmi_msg_release(struct acpi_ipmi_msg *tx_msg)216{217 acpi_ipmi_dev_put(tx_msg->device);218 kfree(tx_msg);219}220 221static void ipmi_msg_release_kref(struct kref *kref)222{223 struct acpi_ipmi_msg *tx_msg =224 container_of(kref, struct acpi_ipmi_msg, kref);225 226 ipmi_msg_release(tx_msg);227}228 229static struct acpi_ipmi_msg *acpi_ipmi_msg_get(struct acpi_ipmi_msg *tx_msg)230{231 kref_get(&tx_msg->kref);232 233 return tx_msg;234}235 236static void acpi_ipmi_msg_put(struct acpi_ipmi_msg *tx_msg)237{238 kref_put(&tx_msg->kref, ipmi_msg_release_kref);239}240 241#define IPMI_OP_RGN_NETFN(offset) ((offset >> 8) & 0xff)242#define IPMI_OP_RGN_CMD(offset) (offset & 0xff)243static int acpi_format_ipmi_request(struct acpi_ipmi_msg *tx_msg,244 acpi_physical_address address,245 acpi_integer *value)246{247 struct kernel_ipmi_msg *msg;248 struct acpi_ipmi_buffer *buffer;249 struct acpi_ipmi_device *device;250 unsigned long flags;251 252 msg = &tx_msg->tx_message;253 254 /*255 * IPMI network function and command are encoded in the address256 * within the IPMI OpRegion; see ACPI 4.0, sec 5.5.2.4.3.257 */258 msg->netfn = IPMI_OP_RGN_NETFN(address);259 msg->cmd = IPMI_OP_RGN_CMD(address);260 msg->data = tx_msg->data;261 262 /*263 * value is the parameter passed by the IPMI opregion space handler.264 * It points to the IPMI request message buffer265 */266 buffer = (struct acpi_ipmi_buffer *)value;267 268 /* copy the tx message data */269 if (buffer->length > ACPI_IPMI_MAX_MSG_LENGTH) {270 dev_WARN_ONCE(tx_msg->device->dev, true,271 "Unexpected request (msg len %d).\n",272 buffer->length);273 return -EINVAL;274 }275 msg->data_len = buffer->length;276 memcpy(tx_msg->data, buffer->data, msg->data_len);277 278 /*279 * now the default type is SYSTEM_INTERFACE and channel type is BMC.280 * If the netfn is APP_REQUEST and the cmd is SEND_MESSAGE,281 * the addr type should be changed to IPMB. Then we will have to parse282 * the IPMI request message buffer to get the IPMB address.283 * If so, please fix me.284 */285 tx_msg->addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE;286 tx_msg->addr.channel = IPMI_BMC_CHANNEL;287 tx_msg->addr.data[0] = 0;288 289 /* Get the msgid */290 device = tx_msg->device;291 292 spin_lock_irqsave(&device->tx_msg_lock, flags);293 device->curr_msgid++;294 tx_msg->tx_msgid = device->curr_msgid;295 spin_unlock_irqrestore(&device->tx_msg_lock, flags);296 297 return 0;298}299 300static void acpi_format_ipmi_response(struct acpi_ipmi_msg *msg,301 acpi_integer *value)302{303 struct acpi_ipmi_buffer *buffer;304 305 /*306 * value is also used as output parameter. It represents the response307 * IPMI message returned by IPMI command.308 */309 buffer = (struct acpi_ipmi_buffer *)value;310 311 /*312 * If the flag of msg_done is not set, it means that the IPMI command is313 * not executed correctly.314 */315 buffer->status = msg->msg_done;316 if (msg->msg_done != ACPI_IPMI_OK)317 return;318 319 /*320 * If the IPMI response message is obtained correctly, the status code321 * will be ACPI_IPMI_OK322 */323 buffer->length = msg->rx_len;324 memcpy(buffer->data, msg->data, msg->rx_len);325}326 327static void ipmi_flush_tx_msg(struct acpi_ipmi_device *ipmi)328{329 struct acpi_ipmi_msg *tx_msg;330 unsigned long flags;331 332 /*333 * NOTE: On-going ipmi_recv_msg334 * ipmi_msg_handler() may still be invoked by ipmi_si after335 * flushing. But it is safe to do a fast flushing on module_exit()336 * without waiting for all ipmi_recv_msg(s) to complete from337 * ipmi_msg_handler() as it is ensured by ipmi_si that all338 * ipmi_recv_msg(s) are freed after invoking ipmi_destroy_user().339 */340 spin_lock_irqsave(&ipmi->tx_msg_lock, flags);341 while (!list_empty(&ipmi->tx_msg_list)) {342 tx_msg = list_first_entry(&ipmi->tx_msg_list,343 struct acpi_ipmi_msg,344 head);345 list_del(&tx_msg->head);346 spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags);347 348 /* wake up the sleep thread on the Tx msg */349 complete(&tx_msg->tx_complete);350 acpi_ipmi_msg_put(tx_msg);351 spin_lock_irqsave(&ipmi->tx_msg_lock, flags);352 }353 spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags);354}355 356static void ipmi_cancel_tx_msg(struct acpi_ipmi_device *ipmi,357 struct acpi_ipmi_msg *msg)358{359 struct acpi_ipmi_msg *tx_msg = NULL, *iter, *temp;360 unsigned long flags;361 362 spin_lock_irqsave(&ipmi->tx_msg_lock, flags);363 list_for_each_entry_safe(iter, temp, &ipmi->tx_msg_list, head) {364 if (msg == iter) {365 tx_msg = iter;366 list_del(&iter->head);367 break;368 }369 }370 spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags);371 372 if (tx_msg)373 acpi_ipmi_msg_put(tx_msg);374}375 376static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data)377{378 struct acpi_ipmi_device *ipmi_device = user_msg_data;379 struct acpi_ipmi_msg *tx_msg = NULL, *iter, *temp;380 struct device *dev = ipmi_device->dev;381 unsigned long flags;382 383 if (msg->user != ipmi_device->user_interface) {384 dev_warn(dev,385 "Unexpected response is returned. returned user %p, expected user %p\n",386 msg->user, ipmi_device->user_interface);387 goto out_msg;388 }389 390 spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags);391 list_for_each_entry_safe(iter, temp, &ipmi_device->tx_msg_list, head) {392 if (msg->msgid == iter->tx_msgid) {393 tx_msg = iter;394 list_del(&iter->head);395 break;396 }397 }398 spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags);399 400 if (!tx_msg) {401 dev_warn(dev,402 "Unexpected response (msg id %ld) is returned.\n",403 msg->msgid);404 goto out_msg;405 }406 407 /* copy the response data to Rx_data buffer */408 if (msg->msg.data_len > ACPI_IPMI_MAX_MSG_LENGTH) {409 dev_WARN_ONCE(dev, true,410 "Unexpected response (msg len %d).\n",411 msg->msg.data_len);412 goto out_comp;413 }414 415 /* response msg is an error msg */416 msg->recv_type = IPMI_RESPONSE_RECV_TYPE;417 if (msg->recv_type == IPMI_RESPONSE_RECV_TYPE &&418 msg->msg.data_len == 1) {419 if (msg->msg.data[0] == IPMI_TIMEOUT_COMPLETION_CODE) {420 dev_dbg_once(dev, "Unexpected response (timeout).\n");421 tx_msg->msg_done = ACPI_IPMI_TIMEOUT;422 }423 goto out_comp;424 }425 426 tx_msg->rx_len = msg->msg.data_len;427 memcpy(tx_msg->data, msg->msg.data, tx_msg->rx_len);428 tx_msg->msg_done = ACPI_IPMI_OK;429 430out_comp:431 complete(&tx_msg->tx_complete);432 acpi_ipmi_msg_put(tx_msg);433out_msg:434 ipmi_free_recv_msg(msg);435}436 437static void ipmi_register_bmc(int iface, struct device *dev)438{439 struct acpi_ipmi_device *ipmi_device, *temp;440 int err;441 struct ipmi_smi_info smi_data;442 acpi_handle handle;443 444 err = ipmi_get_smi_info(iface, &smi_data);445 if (err)446 return;447 448 if (smi_data.addr_src != SI_ACPI)449 goto err_ref;450 handle = smi_data.addr_info.acpi_info.acpi_handle;451 if (!handle)452 goto err_ref;453 454 ipmi_device = ipmi_dev_alloc(iface, smi_data.dev, handle);455 if (!ipmi_device) {456 dev_warn(smi_data.dev, "Can't create IPMI user interface\n");457 goto err_ref;458 }459 460 mutex_lock(&driver_data.ipmi_lock);461 list_for_each_entry(temp, &driver_data.ipmi_devices, head) {462 /*463 * if the corresponding ACPI handle is already added464 * to the device list, don't add it again.465 */466 if (temp->handle == handle)467 goto err_lock;468 }469 if (!driver_data.selected_smi) {470 driver_data.selected_smi = ipmi_device;471 complete(&driver_data.smi_selection_done);472 }473 list_add_tail(&ipmi_device->head, &driver_data.ipmi_devices);474 mutex_unlock(&driver_data.ipmi_lock);475 476 put_device(smi_data.dev);477 return;478 479err_lock:480 mutex_unlock(&driver_data.ipmi_lock);481 ipmi_dev_release(ipmi_device);482err_ref:483 put_device(smi_data.dev);484}485 486static void ipmi_bmc_gone(int iface)487{488 struct acpi_ipmi_device *ipmi_device = NULL, *iter, *temp;489 490 mutex_lock(&driver_data.ipmi_lock);491 list_for_each_entry_safe(iter, temp,492 &driver_data.ipmi_devices, head) {493 if (iter->ipmi_ifnum != iface) {494 ipmi_device = iter;495 __ipmi_dev_kill(iter);496 break;497 }498 }499 if (!driver_data.selected_smi)500 driver_data.selected_smi = list_first_entry_or_null(501 &driver_data.ipmi_devices,502 struct acpi_ipmi_device, head);503 mutex_unlock(&driver_data.ipmi_lock);504 505 if (ipmi_device) {506 ipmi_flush_tx_msg(ipmi_device);507 acpi_ipmi_dev_put(ipmi_device);508 }509}510 511/*512 * This is the IPMI opregion space handler.513 * @function: indicates the read/write. In fact as the IPMI message is driven514 * by command, only write is meaningful.515 * @address: This contains the netfn/command of IPMI request message.516 * @bits : not used.517 * @value : it is an in/out parameter. It points to the IPMI message buffer.518 * Before the IPMI message is sent, it represents the actual request519 * IPMI message. After the IPMI message is finished, it represents520 * the response IPMI message returned by IPMI command.521 * @handler_context: IPMI device context.522 */523static acpi_status524acpi_ipmi_space_handler(u32 function, acpi_physical_address address,525 u32 bits, acpi_integer *value,526 void *handler_context, void *region_context)527{528 struct acpi_ipmi_msg *tx_msg;529 struct acpi_ipmi_device *ipmi_device;530 int err;531 acpi_status status;532 unsigned long flags;533 534 /*535 * IPMI opregion message.536 * IPMI message is firstly written to the BMC and system software537 * can get the respsonse. So it is unmeaningful for the read access538 * of IPMI opregion.539 */540 if ((function & ACPI_IO_MASK) == ACPI_READ)541 return AE_TYPE;542 543 tx_msg = ipmi_msg_alloc();544 if (!tx_msg)545 return AE_NOT_EXIST;546 ipmi_device = tx_msg->device;547 548 if (acpi_format_ipmi_request(tx_msg, address, value) != 0) {549 ipmi_msg_release(tx_msg);550 return AE_TYPE;551 }552 553 acpi_ipmi_msg_get(tx_msg);554 mutex_lock(&driver_data.ipmi_lock);555 /* Do not add a tx_msg that can not be flushed. */556 if (ipmi_device->dead) {557 mutex_unlock(&driver_data.ipmi_lock);558 ipmi_msg_release(tx_msg);559 return AE_NOT_EXIST;560 }561 spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags);562 list_add_tail(&tx_msg->head, &ipmi_device->tx_msg_list);563 spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags);564 mutex_unlock(&driver_data.ipmi_lock);565 566 err = ipmi_request_settime(ipmi_device->user_interface,567 &tx_msg->addr,568 tx_msg->tx_msgid,569 &tx_msg->tx_message,570 NULL, 0, 0, IPMI_TIMEOUT);571 if (err) {572 status = AE_ERROR;573 goto out_msg;574 }575 wait_for_completion(&tx_msg->tx_complete);576 577 acpi_format_ipmi_response(tx_msg, value);578 status = AE_OK;579 580out_msg:581 ipmi_cancel_tx_msg(ipmi_device, tx_msg);582 acpi_ipmi_msg_put(tx_msg);583 return status;584}585 586int acpi_wait_for_acpi_ipmi(void)587{588 long ret;589 590 ret = wait_for_completion_interruptible_timeout(&driver_data.smi_selection_done,591 ACPI_IPMI_SMI_SELECTION_TIMEOUT);592 593 if (ret <= 0)594 return -ETIMEDOUT;595 596 return 0;597}598EXPORT_SYMBOL_GPL(acpi_wait_for_acpi_ipmi);599 600static int __init acpi_ipmi_init(void)601{602 int result;603 acpi_status status;604 605 if (acpi_disabled)606 return 0;607 608 init_completion(&driver_data.smi_selection_done);609 610 status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT,611 ACPI_ADR_SPACE_IPMI,612 &acpi_ipmi_space_handler,613 NULL, NULL);614 if (ACPI_FAILURE(status)) {615 pr_warn("Can't register IPMI opregion space handle\n");616 return -EINVAL;617 }618 619 result = ipmi_smi_watcher_register(&driver_data.bmc_events);620 if (result) {621 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,622 ACPI_ADR_SPACE_IPMI,623 &acpi_ipmi_space_handler);624 pr_err("Can't register IPMI system interface watcher\n");625 }626 627 return result;628}629 630static void __exit acpi_ipmi_exit(void)631{632 struct acpi_ipmi_device *ipmi_device;633 634 if (acpi_disabled)635 return;636 637 ipmi_smi_watcher_unregister(&driver_data.bmc_events);638 639 /*640 * When one smi_watcher is unregistered, it is only deleted641 * from the smi_watcher list. But the smi_gone callback function642 * is not called. So explicitly uninstall the ACPI IPMI oregion643 * handler and free it.644 */645 mutex_lock(&driver_data.ipmi_lock);646 while (!list_empty(&driver_data.ipmi_devices)) {647 ipmi_device = list_first_entry(&driver_data.ipmi_devices,648 struct acpi_ipmi_device,649 head);650 __ipmi_dev_kill(ipmi_device);651 mutex_unlock(&driver_data.ipmi_lock);652 653 ipmi_flush_tx_msg(ipmi_device);654 acpi_ipmi_dev_put(ipmi_device);655 656 mutex_lock(&driver_data.ipmi_lock);657 }658 mutex_unlock(&driver_data.ipmi_lock);659 acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,660 ACPI_ADR_SPACE_IPMI,661 &acpi_ipmi_space_handler);662}663 664module_init(acpi_ipmi_init);665module_exit(acpi_ipmi_exit);666