https://github.com/torvalds/linux
Tip revision: 724e6d3fe8003c3f60bf404bf22e4e331327c596 authored by Linus Torvalds on 12 February 2010, 19:07:45 UTC
Linux 2.6.33-rc8
Linux 2.6.33-rc8
Tip revision: 724e6d3
event.c
/*
* event.c - exporting ACPI events via procfs
*
* Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
* Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
*
*/
#include <linux/spinlock.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <acpi/acpi_drivers.h>
#include <net/netlink.h>
#include <net/genetlink.h>
#include "internal.h"
#define _COMPONENT ACPI_SYSTEM_COMPONENT
ACPI_MODULE_NAME("event");
#ifdef CONFIG_ACPI_PROC_EVENT
/* Global vars for handling event proc entry */
static DEFINE_SPINLOCK(acpi_system_event_lock);
int event_is_open = 0;
extern struct list_head acpi_bus_event_list;
extern wait_queue_head_t acpi_bus_event_queue;
static int acpi_system_open_event(struct inode *inode, struct file *file)
{
spin_lock_irq(&acpi_system_event_lock);
if (event_is_open)
goto out_busy;
event_is_open = 1;
spin_unlock_irq(&acpi_system_event_lock);
return 0;
out_busy:
spin_unlock_irq(&acpi_system_event_lock);
return -EBUSY;
}
static ssize_t
acpi_system_read_event(struct file *file, char __user * buffer, size_t count,
loff_t * ppos)
{
int result = 0;
struct acpi_bus_event event;
static char str[ACPI_MAX_STRING];
static int chars_remaining = 0;
static char *ptr;
if (!chars_remaining) {
memset(&event, 0, sizeof(struct acpi_bus_event));
if ((file->f_flags & O_NONBLOCK)
&& (list_empty(&acpi_bus_event_list)))
return -EAGAIN;
result = acpi_bus_receive_event(&event);
if (result)
return result;
chars_remaining = sprintf(str, "%s %s %08x %08x\n",
event.device_class ? event.
device_class : "<unknown>",
event.bus_id ? event.
bus_id : "<unknown>", event.type,
event.data);
ptr = str;
}
if (chars_remaining < count) {
count = chars_remaining;
}
if (copy_to_user(buffer, ptr, count))
return -EFAULT;
*ppos += count;
chars_remaining -= count;
ptr += count;
return count;
}
static int acpi_system_close_event(struct inode *inode, struct file *file)
{
spin_lock_irq(&acpi_system_event_lock);
event_is_open = 0;
spin_unlock_irq(&acpi_system_event_lock);
return 0;
}
static unsigned int acpi_system_poll_event(struct file *file, poll_table * wait)
{
poll_wait(file, &acpi_bus_event_queue, wait);
if (!list_empty(&acpi_bus_event_list))
return POLLIN | POLLRDNORM;
return 0;
}
static const struct file_operations acpi_system_event_ops = {
.owner = THIS_MODULE,
.open = acpi_system_open_event,
.read = acpi_system_read_event,
.release = acpi_system_close_event,
.poll = acpi_system_poll_event,
};
#endif /* CONFIG_ACPI_PROC_EVENT */
/* ACPI notifier chain */
static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
{
struct acpi_bus_event event;
strcpy(event.device_class, dev->pnp.device_class);
strcpy(event.bus_id, dev->pnp.bus_id);
event.type = type;
event.data = data;
return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
== NOTIFY_BAD) ? -EINVAL : 0;
}
EXPORT_SYMBOL(acpi_notifier_call_chain);
int register_acpi_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_register(&acpi_chain_head, nb);
}
EXPORT_SYMBOL(register_acpi_notifier);
int unregister_acpi_notifier(struct notifier_block *nb)
{
return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
}
EXPORT_SYMBOL(unregister_acpi_notifier);
#ifdef CONFIG_NET
static unsigned int acpi_event_seqnum;
struct acpi_genl_event {
acpi_device_class device_class;
char bus_id[15];
u32 type;
u32 data;
};
/* attributes of acpi_genl_family */
enum {
ACPI_GENL_ATTR_UNSPEC,
ACPI_GENL_ATTR_EVENT, /* ACPI event info needed by user space */
__ACPI_GENL_ATTR_MAX,
};
#define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
/* commands supported by the acpi_genl_family */
enum {
ACPI_GENL_CMD_UNSPEC,
ACPI_GENL_CMD_EVENT, /* kernel->user notifications for ACPI events */
__ACPI_GENL_CMD_MAX,
};
#define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
#define ACPI_GENL_FAMILY_NAME "acpi_event"
#define ACPI_GENL_VERSION 0x01
#define ACPI_GENL_MCAST_GROUP_NAME "acpi_mc_group"
static struct genl_family acpi_event_genl_family = {
.id = GENL_ID_GENERATE,
.name = ACPI_GENL_FAMILY_NAME,
.version = ACPI_GENL_VERSION,
.maxattr = ACPI_GENL_ATTR_MAX,
};
static struct genl_multicast_group acpi_event_mcgrp = {
.name = ACPI_GENL_MCAST_GROUP_NAME,
};
int acpi_bus_generate_netlink_event(const char *device_class,
const char *bus_id,
u8 type, int data)
{
struct sk_buff *skb;
struct nlattr *attr;
struct acpi_genl_event *event;
void *msg_header;
int size;
int result;
/* allocate memory */
size = nla_total_size(sizeof(struct acpi_genl_event)) +
nla_total_size(0);
skb = genlmsg_new(size, GFP_ATOMIC);
if (!skb)
return -ENOMEM;
/* add the genetlink message header */
msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
&acpi_event_genl_family, 0,
ACPI_GENL_CMD_EVENT);
if (!msg_header) {
nlmsg_free(skb);
return -ENOMEM;
}
/* fill the data */
attr =
nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
sizeof(struct acpi_genl_event));
if (!attr) {
nlmsg_free(skb);
return -EINVAL;
}
event = nla_data(attr);
if (!event) {
nlmsg_free(skb);
return -EINVAL;
}
memset(event, 0, sizeof(struct acpi_genl_event));
strcpy(event->device_class, device_class);
strcpy(event->bus_id, bus_id);
event->type = type;
event->data = data;
/* send multicast genetlink message */
result = genlmsg_end(skb, msg_header);
if (result < 0) {
nlmsg_free(skb);
return result;
}
genlmsg_multicast(skb, 0, acpi_event_mcgrp.id, GFP_ATOMIC);
return 0;
}
EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
static int acpi_event_genetlink_init(void)
{
int result;
result = genl_register_family(&acpi_event_genl_family);
if (result)
return result;
result = genl_register_mc_group(&acpi_event_genl_family,
&acpi_event_mcgrp);
if (result)
genl_unregister_family(&acpi_event_genl_family);
return result;
}
#else
int acpi_bus_generate_netlink_event(const char *device_class,
const char *bus_id,
u8 type, int data)
{
return 0;
}
EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
static int acpi_event_genetlink_init(void)
{
return -ENODEV;
}
#endif
static int __init acpi_event_init(void)
{
#ifdef CONFIG_ACPI_PROC_EVENT
struct proc_dir_entry *entry;
#endif
int error = 0;
if (acpi_disabled)
return 0;
/* create genetlink for acpi event */
error = acpi_event_genetlink_init();
if (error)
printk(KERN_WARNING PREFIX
"Failed to create genetlink family for ACPI event\n");
#ifdef CONFIG_ACPI_PROC_EVENT
/* 'event' [R] */
entry = proc_create("event", S_IRUSR, acpi_root_dir,
&acpi_system_event_ops);
if (!entry)
return -ENODEV;
#endif
return 0;
}
fs_initcall(acpi_event_init);