linux/drivers/acpi/acpi_ipmi.c
Kai-Heng Feng 670e98a34a ACPI: IPMI: Add helper to wait for when SMI is selected
On Dell servers, many APCI methods of acpi_power_meter module evaluate
variables inside IPMI region, so the region handler needs to be
installed. In addition to that, the handler needs to be fully
functional, and that depends on SMI being selected.

So add a helper to let acpi_power_meter know when the handler is
installed and ready to be used.

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20240320084317.366853-1-kai.heng.feng@canonical.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2024-04-28 10:07:34 -07:00

666 lines
17 KiB
C

// 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
/* 2s should be suffient for SMI being selected */
#define ACPI_IPMI_SMI_SELECTION_TIMEOUT (2 * HZ)
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 completion smi_selection_done;
};
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;
complete(&driver_data.smi_selection_done);
}
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;
}
int acpi_wait_for_acpi_ipmi(void)
{
long ret;
ret = wait_for_completion_interruptible_timeout(&driver_data.smi_selection_done,
ACPI_IPMI_SMI_SELECTION_TIMEOUT);
if (ret <= 0)
return -ETIMEDOUT;
return 0;
}
EXPORT_SYMBOL_GPL(acpi_wait_for_acpi_ipmi);
static int __init acpi_ipmi_init(void)
{
int result;
acpi_status status;
if (acpi_disabled)
return 0;
init_completion(&driver_data.smi_selection_done);
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);