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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /drivers/acpi/acpi_ipmi.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/acpi/acpi_ipmi.c')
-rw-r--r--drivers/acpi/acpi_ipmi.c644
1 files changed, 644 insertions, 0 deletions
diff --git a/drivers/acpi/acpi_ipmi.c b/drivers/acpi/acpi_ipmi.c
new file mode 100644
index 0000000000..0555f68c2d
--- /dev/null
+++ b/drivers/acpi/acpi_ipmi.c
@@ -0,0 +1,644 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * 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>
+ */
+
+#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;
+ struct ipmi_user *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;
+ struct ipmi_user *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 = NULL, *iter, *temp;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ipmi->tx_msg_lock, flags);
+ list_for_each_entry_safe(iter, temp, &ipmi->tx_msg_list, head) {
+ if (msg == iter) {
+ tx_msg = iter;
+ list_del(&iter->head);
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&ipmi->tx_msg_lock, flags);
+
+ if (tx_msg)
+ 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;
+ struct acpi_ipmi_msg *tx_msg = NULL, *iter, *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(iter, temp, &ipmi_device->tx_msg_list, head) {
+ if (msg->msgid == iter->tx_msgid) {
+ tx_msg = iter;
+ list_del(&iter->head);
+ break;
+ }
+ }
+ spin_unlock_irqrestore(&ipmi_device->tx_msg_lock, flags);
+
+ if (!tx_msg) {
+ 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);
+}
+
+static void ipmi_bmc_gone(int iface)
+{
+ struct acpi_ipmi_device *ipmi_device = NULL, *iter, *temp;
+
+ mutex_lock(&driver_data.ipmi_lock);
+ list_for_each_entry_safe(iter, temp,
+ &driver_data.ipmi_devices, head) {
+ if (iter->ipmi_ifnum != iface) {
+ ipmi_device = iter;
+ __ipmi_dev_kill(iter);
+ 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 (ipmi_device) {
+ 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) {
+ acpi_remove_address_space_handler(ACPI_ROOT_OBJECT,
+ ACPI_ADR_SPACE_IPMI,
+ &acpi_ipmi_space_handler);
+ 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);