diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/acpi/acpi_ipmi.c | 656 |
1 files changed, 656 insertions, 0 deletions
diff --git a/drivers/acpi/acpi_ipmi.c b/drivers/acpi/acpi_ipmi.c new file mode 100644 index 000000000..1b64419e2 --- /dev/null +++ b/drivers/acpi/acpi_ipmi.c @@ -0,0 +1,656 @@ +/* + * acpi_ipmi.c - ACPI IPMI opregion + * + * Copyright (C) 2010, 2013 Intel Corporation + * Author: Zhao Yakui <yakui.zhao@intel.com> + * Lv Zheng <lv.zheng@intel.com> + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or (at + * your option) any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + */ + +#include <linux/module.h> +#include <linux/acpi.h> +#include <linux/ipmi.h> +#include <linux/spinlock.h> + +MODULE_AUTHOR("Zhao Yakui"); +MODULE_DESCRIPTION("ACPI IPMI Opregion driver"); +MODULE_LICENSE("GPL"); + +#define ACPI_IPMI_OK 0 +#define ACPI_IPMI_TIMEOUT 0x10 +#define ACPI_IPMI_UNKNOWN 0x07 +/* the IPMI timeout is 5s */ +#define IPMI_TIMEOUT (5000) +#define ACPI_IPMI_MAX_MSG_LENGTH 64 + +struct acpi_ipmi_device { + /* the device list attached to driver_data.ipmi_devices */ + struct list_head head; + + /* the IPMI request message list */ + struct list_head tx_msg_list; + + spinlock_t tx_msg_lock; + acpi_handle handle; + struct device *dev; + ipmi_user_t user_interface; + int ipmi_ifnum; /* IPMI interface number */ + long curr_msgid; + bool dead; + struct kref kref; +}; + +struct ipmi_driver_data { + struct list_head ipmi_devices; + struct ipmi_smi_watcher bmc_events; + const struct ipmi_user_hndl ipmi_hndlrs; + struct mutex ipmi_lock; + + /* + * NOTE: IPMI System Interface Selection + * There is no system interface specified by the IPMI operation + * region access. We try to select one system interface with ACPI + * handle set. IPMI messages passed from the ACPI codes are sent + * to this selected global IPMI system interface. + */ + struct acpi_ipmi_device *selected_smi; +}; + +struct acpi_ipmi_msg { + struct list_head head; + + /* + * General speaking the addr type should be SI_ADDR_TYPE. And + * the addr channel should be BMC. + * In fact it can also be IPMB type. But we will have to + * parse it from the Netfn command buffer. It is so complex + * that it is skipped. + */ + struct ipmi_addr addr; + long tx_msgid; + + /* it is used to track whether the IPMI message is finished */ + struct completion tx_complete; + + struct kernel_ipmi_msg tx_message; + int msg_done; + + /* tx/rx data . And copy it from/to ACPI object buffer */ + u8 data[ACPI_IPMI_MAX_MSG_LENGTH]; + u8 rx_len; + + struct acpi_ipmi_device *device; + struct kref kref; +}; + +/* IPMI request/response buffer per ACPI 4.0, sec 5.5.2.4.3.2 */ +struct acpi_ipmi_buffer { + u8 status; + u8 length; + u8 data[ACPI_IPMI_MAX_MSG_LENGTH]; +}; + +static void ipmi_register_bmc(int iface, struct device *dev); +static void ipmi_bmc_gone(int iface); +static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data); + +static struct ipmi_driver_data driver_data = { + .ipmi_devices = LIST_HEAD_INIT(driver_data.ipmi_devices), + .bmc_events = { + .owner = THIS_MODULE, + .new_smi = ipmi_register_bmc, + .smi_gone = ipmi_bmc_gone, + }, + .ipmi_hndlrs = { + .ipmi_recv_hndl = ipmi_msg_handler, + }, + .ipmi_lock = __MUTEX_INITIALIZER(driver_data.ipmi_lock) +}; + +static struct acpi_ipmi_device * +ipmi_dev_alloc(int iface, struct device *dev, acpi_handle handle) +{ + struct acpi_ipmi_device *ipmi_device; + int err; + ipmi_user_t user; + + ipmi_device = kzalloc(sizeof(*ipmi_device), GFP_KERNEL); + if (!ipmi_device) + return NULL; + + kref_init(&ipmi_device->kref); + INIT_LIST_HEAD(&ipmi_device->head); + INIT_LIST_HEAD(&ipmi_device->tx_msg_list); + spin_lock_init(&ipmi_device->tx_msg_lock); + ipmi_device->handle = handle; + ipmi_device->dev = get_device(dev); + ipmi_device->ipmi_ifnum = iface; + + err = ipmi_create_user(iface, &driver_data.ipmi_hndlrs, + ipmi_device, &user); + if (err) { + put_device(dev); + kfree(ipmi_device); + return NULL; + } + ipmi_device->user_interface = user; + + return ipmi_device; +} + +static void ipmi_dev_release(struct acpi_ipmi_device *ipmi_device) +{ + ipmi_destroy_user(ipmi_device->user_interface); + put_device(ipmi_device->dev); + kfree(ipmi_device); +} + +static void ipmi_dev_release_kref(struct kref *kref) +{ + struct acpi_ipmi_device *ipmi = + container_of(kref, struct acpi_ipmi_device, kref); + + ipmi_dev_release(ipmi); +} + +static void __ipmi_dev_kill(struct acpi_ipmi_device *ipmi_device) +{ + list_del(&ipmi_device->head); + if (driver_data.selected_smi == ipmi_device) + driver_data.selected_smi = NULL; + + /* + * Always setting dead flag after deleting from the list or + * list_for_each_entry() codes must get changed. + */ + ipmi_device->dead = true; +} + +static struct acpi_ipmi_device *acpi_ipmi_dev_get(void) +{ + struct acpi_ipmi_device *ipmi_device = NULL; + + mutex_lock(&driver_data.ipmi_lock); + if (driver_data.selected_smi) { + ipmi_device = driver_data.selected_smi; + kref_get(&ipmi_device->kref); + } + mutex_unlock(&driver_data.ipmi_lock); + + return ipmi_device; +} + +static void acpi_ipmi_dev_put(struct acpi_ipmi_device *ipmi_device) +{ + kref_put(&ipmi_device->kref, ipmi_dev_release_kref); +} + +static struct acpi_ipmi_msg *ipmi_msg_alloc(void) +{ + struct acpi_ipmi_device *ipmi; + struct acpi_ipmi_msg *ipmi_msg; + + ipmi = acpi_ipmi_dev_get(); + if (!ipmi) + return NULL; + + ipmi_msg = kzalloc(sizeof(struct acpi_ipmi_msg), GFP_KERNEL); + if (!ipmi_msg) { + acpi_ipmi_dev_put(ipmi); + return NULL; + } + + kref_init(&ipmi_msg->kref); + init_completion(&ipmi_msg->tx_complete); + INIT_LIST_HEAD(&ipmi_msg->head); + ipmi_msg->device = ipmi; + ipmi_msg->msg_done = ACPI_IPMI_UNKNOWN; + + return ipmi_msg; +} + +static void ipmi_msg_release(struct acpi_ipmi_msg *tx_msg) +{ + acpi_ipmi_dev_put(tx_msg->device); + kfree(tx_msg); +} + +static void ipmi_msg_release_kref(struct kref *kref) +{ + struct acpi_ipmi_msg *tx_msg = + container_of(kref, struct acpi_ipmi_msg, kref); + + ipmi_msg_release(tx_msg); +} + +static struct acpi_ipmi_msg *acpi_ipmi_msg_get(struct acpi_ipmi_msg *tx_msg) +{ + kref_get(&tx_msg->kref); + + return tx_msg; +} + +static void acpi_ipmi_msg_put(struct acpi_ipmi_msg *tx_msg) +{ + kref_put(&tx_msg->kref, ipmi_msg_release_kref); +} + +#define IPMI_OP_RGN_NETFN(offset) ((offset >> 8) & 0xff) +#define IPMI_OP_RGN_CMD(offset) (offset & 0xff) +static int acpi_format_ipmi_request(struct acpi_ipmi_msg *tx_msg, + acpi_physical_address address, + acpi_integer *value) +{ + struct kernel_ipmi_msg *msg; + struct acpi_ipmi_buffer *buffer; + struct acpi_ipmi_device *device; + unsigned long flags; + + msg = &tx_msg->tx_message; + + /* + * IPMI network function and command are encoded in the address + * within the IPMI OpRegion; see ACPI 4.0, sec 5.5.2.4.3. + */ + msg->netfn = IPMI_OP_RGN_NETFN(address); + msg->cmd = IPMI_OP_RGN_CMD(address); + msg->data = tx_msg->data; + + /* + * value is the parameter passed by the IPMI opregion space handler. + * It points to the IPMI request message buffer + */ + buffer = (struct acpi_ipmi_buffer *)value; + + /* copy the tx message data */ + if (buffer->length > ACPI_IPMI_MAX_MSG_LENGTH) { + dev_WARN_ONCE(tx_msg->device->dev, true, + "Unexpected request (msg len %d).\n", + buffer->length); + return -EINVAL; + } + msg->data_len = buffer->length; + memcpy(tx_msg->data, buffer->data, msg->data_len); + + /* + * now the default type is SYSTEM_INTERFACE and channel type is BMC. + * If the netfn is APP_REQUEST and the cmd is SEND_MESSAGE, + * the addr type should be changed to IPMB. Then we will have to parse + * the IPMI request message buffer to get the IPMB address. + * If so, please fix me. + */ + tx_msg->addr.addr_type = IPMI_SYSTEM_INTERFACE_ADDR_TYPE; + tx_msg->addr.channel = IPMI_BMC_CHANNEL; + tx_msg->addr.data[0] = 0; + + /* Get the msgid */ + device = tx_msg->device; + + spin_lock_irqsave(&device->tx_msg_lock, flags); + device->curr_msgid++; + tx_msg->tx_msgid = device->curr_msgid; + spin_unlock_irqrestore(&device->tx_msg_lock, flags); + + return 0; +} + +static void acpi_format_ipmi_response(struct acpi_ipmi_msg *msg, + acpi_integer *value) +{ + struct acpi_ipmi_buffer *buffer; + + /* + * value is also used as output parameter. It represents the response + * IPMI message returned by IPMI command. + */ + buffer = (struct acpi_ipmi_buffer *)value; + + /* + * If the flag of msg_done is not set, it means that the IPMI command is + * not executed correctly. + */ + buffer->status = msg->msg_done; + if (msg->msg_done != ACPI_IPMI_OK) + return; + + /* + * If the IPMI response message is obtained correctly, the status code + * will be ACPI_IPMI_OK + */ + buffer->length = msg->rx_len; + memcpy(buffer->data, msg->data, msg->rx_len); +} + +static void ipmi_flush_tx_msg(struct acpi_ipmi_device *ipmi) +{ + struct acpi_ipmi_msg *tx_msg; + unsigned long flags; + + /* + * NOTE: On-going ipmi_recv_msg + * ipmi_msg_handler() may still be invoked by ipmi_si after + * flushing. But it is safe to do a fast flushing on module_exit() + * without waiting for all ipmi_recv_msg(s) to complete from + * ipmi_msg_handler() as it is ensured by ipmi_si that all + * ipmi_recv_msg(s) are freed after invoking ipmi_destroy_user(). + */ + spin_lock_irqsave(&ipmi->tx_msg_lock, flags); + while (!list_empty(&ipmi->tx_msg_list)) { + tx_msg = list_first_entry(&ipmi->tx_msg_list, + struct acpi_ipmi_msg, + head); + list_del(&tx_msg->head); + spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags); + + /* wake up the sleep thread on the Tx msg */ + complete(&tx_msg->tx_complete); + acpi_ipmi_msg_put(tx_msg); + spin_lock_irqsave(&ipmi->tx_msg_lock, flags); + } + spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags); +} + +static void ipmi_cancel_tx_msg(struct acpi_ipmi_device *ipmi, + struct acpi_ipmi_msg *msg) +{ + struct acpi_ipmi_msg *tx_msg, *temp; + bool msg_found = false; + unsigned long flags; + + spin_lock_irqsave(&ipmi->tx_msg_lock, flags); + list_for_each_entry_safe(tx_msg, temp, &ipmi->tx_msg_list, head) { + if (msg == tx_msg) { + msg_found = true; + list_del(&tx_msg->head); + break; + } + } + spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags); + + if (msg_found) + acpi_ipmi_msg_put(tx_msg); +} + +static void ipmi_msg_handler(struct ipmi_recv_msg *msg, void *user_msg_data) +{ + struct acpi_ipmi_device *ipmi_device = user_msg_data; + bool msg_found = false; + struct acpi_ipmi_msg *tx_msg, *temp; + struct device *dev = ipmi_device->dev; + unsigned long flags; + + if (msg->user != ipmi_device->user_interface) { + dev_warn(dev, + "Unexpected response is returned. returned user %p, expected user %p\n", + msg->user, ipmi_device->user_interface); + goto out_msg; + } + + spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags); + list_for_each_entry_safe(tx_msg, temp, &ipmi_device->tx_msg_list, head) { + if (msg->msgid == tx_msg->tx_msgid) { + msg_found = true; + list_del(&tx_msg->head); + break; + } + } + spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags); + + if (!msg_found) { + dev_warn(dev, + "Unexpected response (msg id %ld) is returned.\n", + msg->msgid); + goto out_msg; + } + + /* copy the response data to Rx_data buffer */ + if (msg->msg.data_len > ACPI_IPMI_MAX_MSG_LENGTH) { + dev_WARN_ONCE(dev, true, + "Unexpected response (msg len %d).\n", + msg->msg.data_len); + goto out_comp; + } + + /* response msg is an error msg */ + msg->recv_type = IPMI_RESPONSE_RECV_TYPE; + if (msg->recv_type == IPMI_RESPONSE_RECV_TYPE && + msg->msg.data_len == 1) { + if (msg->msg.data[0] == IPMI_TIMEOUT_COMPLETION_CODE) { + dev_dbg_once(dev, "Unexpected response (timeout).\n"); + tx_msg->msg_done = ACPI_IPMI_TIMEOUT; + } + goto out_comp; + } + + tx_msg->rx_len = msg->msg.data_len; + memcpy(tx_msg->data, msg->msg.data, tx_msg->rx_len); + tx_msg->msg_done = ACPI_IPMI_OK; + +out_comp: + complete(&tx_msg->tx_complete); + acpi_ipmi_msg_put(tx_msg); +out_msg: + ipmi_free_recv_msg(msg); +} + +static void ipmi_register_bmc(int iface, struct device *dev) +{ + struct acpi_ipmi_device *ipmi_device, *temp; + int err; + struct ipmi_smi_info smi_data; + acpi_handle handle; + + err = ipmi_get_smi_info(iface, &smi_data); + if (err) + return; + + if (smi_data.addr_src != SI_ACPI) + goto err_ref; + handle = smi_data.addr_info.acpi_info.acpi_handle; + if (!handle) + goto err_ref; + + ipmi_device = ipmi_dev_alloc(iface, smi_data.dev, handle); + if (!ipmi_device) { + dev_warn(smi_data.dev, "Can't create IPMI user interface\n"); + goto err_ref; + } + + mutex_lock(&driver_data.ipmi_lock); + list_for_each_entry(temp, &driver_data.ipmi_devices, head) { + /* + * if the corresponding ACPI handle is already added + * to the device list, don't add it again. + */ + if (temp->handle == handle) + goto err_lock; + } + if (!driver_data.selected_smi) + driver_data.selected_smi = ipmi_device; + list_add_tail(&ipmi_device->head, &driver_data.ipmi_devices); + mutex_unlock(&driver_data.ipmi_lock); + + put_device(smi_data.dev); + return; + +err_lock: + mutex_unlock(&driver_data.ipmi_lock); + ipmi_dev_release(ipmi_device); +err_ref: + put_device(smi_data.dev); + return; +} + +static void ipmi_bmc_gone(int iface) +{ + struct acpi_ipmi_device *ipmi_device, *temp; + bool dev_found = false; + + mutex_lock(&driver_data.ipmi_lock); + list_for_each_entry_safe(ipmi_device, temp, + &driver_data.ipmi_devices, head) { + if (ipmi_device->ipmi_ifnum != iface) { + dev_found = true; + __ipmi_dev_kill(ipmi_device); + break; + } + } + if (!driver_data.selected_smi) + driver_data.selected_smi = list_first_entry_or_null( + &driver_data.ipmi_devices, + struct acpi_ipmi_device, head); + mutex_unlock(&driver_data.ipmi_lock); + + if (dev_found) { + ipmi_flush_tx_msg(ipmi_device); + acpi_ipmi_dev_put(ipmi_device); + } +} + +/* + * This is the IPMI opregion space handler. + * @function: indicates the read/write. In fact as the IPMI message is driven + * by command, only write is meaningful. + * @address: This contains the netfn/command of IPMI request message. + * @bits : not used. + * @value : it is an in/out parameter. It points to the IPMI message buffer. + * Before the IPMI message is sent, it represents the actual request + * IPMI message. After the IPMI message is finished, it represents + * the response IPMI message returned by IPMI command. + * @handler_context: IPMI device context. + */ +static acpi_status +acpi_ipmi_space_handler(u32 function, acpi_physical_address address, + u32 bits, acpi_integer *value, + void *handler_context, void *region_context) +{ + struct acpi_ipmi_msg *tx_msg; + struct acpi_ipmi_device *ipmi_device; + int err; + acpi_status status; + unsigned long flags; + + /* + * IPMI opregion message. + * IPMI message is firstly written to the BMC and system software + * can get the respsonse. So it is unmeaningful for the read access + * of IPMI opregion. + */ + if ((function & ACPI_IO_MASK) == ACPI_READ) + return AE_TYPE; + + tx_msg = ipmi_msg_alloc(); + if (!tx_msg) + return AE_NOT_EXIST; + ipmi_device = tx_msg->device; + + if (acpi_format_ipmi_request(tx_msg, address, value) != 0) { + ipmi_msg_release(tx_msg); + return AE_TYPE; + } + + acpi_ipmi_msg_get(tx_msg); + mutex_lock(&driver_data.ipmi_lock); + /* Do not add a tx_msg that can not be flushed. */ + if (ipmi_device->dead) { + mutex_unlock(&driver_data.ipmi_lock); + ipmi_msg_release(tx_msg); + return AE_NOT_EXIST; + } + spin_lock_irqsave(&ipmi_device->tx_msg_lock, flags); + list_add_tail(&tx_msg->head, &ipmi_device->tx_msg_list); + spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags); + mutex_unlock(&driver_data.ipmi_lock); + + err = ipmi_request_settime(ipmi_device->user_interface, + &tx_msg->addr, + tx_msg->tx_msgid, + &tx_msg->tx_message, + NULL, 0, 0, IPMI_TIMEOUT); + if (err) { + status = AE_ERROR; + goto out_msg; + } + wait_for_completion(&tx_msg->tx_complete); + + acpi_format_ipmi_response(tx_msg, value); + status = AE_OK; + +out_msg: + ipmi_cancel_tx_msg(ipmi_device, tx_msg); + acpi_ipmi_msg_put(tx_msg); + return status; +} + +static int __init acpi_ipmi_init(void) +{ + int result; + acpi_status status; + + if (acpi_disabled) + return 0; + + status = acpi_install_address_space_handler(ACPI_ROOT_OBJECT, + ACPI_ADR_SPACE_IPMI, + &acpi_ipmi_space_handler, + NULL, NULL); + if (ACPI_FAILURE(status)) { + pr_warn("Can't register IPMI opregion space handle\n"); + return -EINVAL; + } + result = ipmi_smi_watcher_register(&driver_data.bmc_events); + if (result) + pr_err("Can't register IPMI system interface watcher\n"); + + return result; +} + +static void __exit acpi_ipmi_exit(void) +{ + struct acpi_ipmi_device *ipmi_device; + + if (acpi_disabled) + return; + + ipmi_smi_watcher_unregister(&driver_data.bmc_events); + + /* + * When one smi_watcher is unregistered, it is only deleted + * from the smi_watcher list. But the smi_gone callback function + * is not called. So explicitly uninstall the ACPI IPMI oregion + * handler and free it. + */ + mutex_lock(&driver_data.ipmi_lock); + while (!list_empty(&driver_data.ipmi_devices)) { + ipmi_device = list_first_entry(&driver_data.ipmi_devices, + struct acpi_ipmi_device, + head); + __ipmi_dev_kill(ipmi_device); + mutex_unlock(&driver_data.ipmi_lock); + + ipmi_flush_tx_msg(ipmi_device); + acpi_ipmi_dev_put(ipmi_device); + + mutex_lock(&driver_data.ipmi_lock); + } + mutex_unlock(&driver_data.ipmi_lock); + acpi_remove_address_space_handler(ACPI_ROOT_OBJECT, + ACPI_ADR_SPACE_IPMI, + &acpi_ipmi_space_handler); +} + +module_init(acpi_ipmi_init); +module_exit(acpi_ipmi_exit); |