linux/drivers/acpi/event.c
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   1/*
   2 * event.c - exporting ACPI events via procfs
   3 *
   4 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6 *
   7 */
   8
   9#include <linux/spinlock.h>
  10#include <linux/export.h>
  11#include <linux/proc_fs.h>
  12#include <linux/init.h>
  13#include <linux/poll.h>
  14#include <linux/gfp.h>
  15#include <acpi/acpi_drivers.h>
  16#include <net/netlink.h>
  17#include <net/genetlink.h>
  18
  19#include "internal.h"
  20
  21#define _COMPONENT              ACPI_SYSTEM_COMPONENT
  22ACPI_MODULE_NAME("event");
  23
  24/* ACPI notifier chain */
  25static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
  26
  27int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
  28{
  29        struct acpi_bus_event event;
  30
  31        strcpy(event.device_class, dev->pnp.device_class);
  32        strcpy(event.bus_id, dev->pnp.bus_id);
  33        event.type = type;
  34        event.data = data;
  35        return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
  36                        == NOTIFY_BAD) ? -EINVAL : 0;
  37}
  38EXPORT_SYMBOL(acpi_notifier_call_chain);
  39
  40int register_acpi_notifier(struct notifier_block *nb)
  41{
  42        return blocking_notifier_chain_register(&acpi_chain_head, nb);
  43}
  44EXPORT_SYMBOL(register_acpi_notifier);
  45
  46int unregister_acpi_notifier(struct notifier_block *nb)
  47{
  48        return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
  49}
  50EXPORT_SYMBOL(unregister_acpi_notifier);
  51
  52#ifdef CONFIG_NET
  53static unsigned int acpi_event_seqnum;
  54struct acpi_genl_event {
  55        acpi_device_class device_class;
  56        char bus_id[15];
  57        u32 type;
  58        u32 data;
  59};
  60
  61/* attributes of acpi_genl_family */
  62enum {
  63        ACPI_GENL_ATTR_UNSPEC,
  64        ACPI_GENL_ATTR_EVENT,   /* ACPI event info needed by user space */
  65        __ACPI_GENL_ATTR_MAX,
  66};
  67#define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
  68
  69/* commands supported by the acpi_genl_family */
  70enum {
  71        ACPI_GENL_CMD_UNSPEC,
  72        ACPI_GENL_CMD_EVENT,    /* kernel->user notifications for ACPI events */
  73        __ACPI_GENL_CMD_MAX,
  74};
  75#define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
  76
  77#define ACPI_GENL_FAMILY_NAME           "acpi_event"
  78#define ACPI_GENL_VERSION               0x01
  79#define ACPI_GENL_MCAST_GROUP_NAME      "acpi_mc_group"
  80
  81static struct genl_family acpi_event_genl_family = {
  82        .id = GENL_ID_GENERATE,
  83        .name = ACPI_GENL_FAMILY_NAME,
  84        .version = ACPI_GENL_VERSION,
  85        .maxattr = ACPI_GENL_ATTR_MAX,
  86};
  87
  88static struct genl_multicast_group acpi_event_mcgrp = {
  89        .name = ACPI_GENL_MCAST_GROUP_NAME,
  90};
  91
  92int acpi_bus_generate_netlink_event(const char *device_class,
  93                                      const char *bus_id,
  94                                      u8 type, int data)
  95{
  96        struct sk_buff *skb;
  97        struct nlattr *attr;
  98        struct acpi_genl_event *event;
  99        void *msg_header;
 100        int size;
 101        int result;
 102
 103        /* allocate memory */
 104        size = nla_total_size(sizeof(struct acpi_genl_event)) +
 105            nla_total_size(0);
 106
 107        skb = genlmsg_new(size, GFP_ATOMIC);
 108        if (!skb)
 109                return -ENOMEM;
 110
 111        /* add the genetlink message header */
 112        msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
 113                                 &acpi_event_genl_family, 0,
 114                                 ACPI_GENL_CMD_EVENT);
 115        if (!msg_header) {
 116                nlmsg_free(skb);
 117                return -ENOMEM;
 118        }
 119
 120        /* fill the data */
 121        attr =
 122            nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
 123                        sizeof(struct acpi_genl_event));
 124        if (!attr) {
 125                nlmsg_free(skb);
 126                return -EINVAL;
 127        }
 128
 129        event = nla_data(attr);
 130        if (!event) {
 131                nlmsg_free(skb);
 132                return -EINVAL;
 133        }
 134
 135        memset(event, 0, sizeof(struct acpi_genl_event));
 136
 137        strcpy(event->device_class, device_class);
 138        strcpy(event->bus_id, bus_id);
 139        event->type = type;
 140        event->data = data;
 141
 142        /* send multicast genetlink message */
 143        result = genlmsg_end(skb, msg_header);
 144        if (result < 0) {
 145                nlmsg_free(skb);
 146                return result;
 147        }
 148
 149        genlmsg_multicast(skb, 0, acpi_event_mcgrp.id, GFP_ATOMIC);
 150        return 0;
 151}
 152
 153EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 154
 155static int acpi_event_genetlink_init(void)
 156{
 157        int result;
 158
 159        result = genl_register_family(&acpi_event_genl_family);
 160        if (result)
 161                return result;
 162
 163        result = genl_register_mc_group(&acpi_event_genl_family,
 164                                        &acpi_event_mcgrp);
 165        if (result)
 166                genl_unregister_family(&acpi_event_genl_family);
 167
 168        return result;
 169}
 170
 171#else
 172int acpi_bus_generate_netlink_event(const char *device_class,
 173                                      const char *bus_id,
 174                                      u8 type, int data)
 175{
 176        return 0;
 177}
 178
 179EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 180
 181static int acpi_event_genetlink_init(void)
 182{
 183        return -ENODEV;
 184}
 185#endif
 186
 187static int __init acpi_event_init(void)
 188{
 189        int error = 0;
 190
 191        if (acpi_disabled)
 192                return 0;
 193
 194        /* create genetlink for acpi event */
 195        error = acpi_event_genetlink_init();
 196        if (error)
 197                printk(KERN_WARNING PREFIX
 198                       "Failed to create genetlink family for ACPI event\n");
 199        return 0;
 200}
 201
 202fs_initcall(acpi_event_init);
 203
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