/*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#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;
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_WARN_ONCE(dev, true,
"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);
