drivers/acpi/event.c

   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
  22 ACPI_MODULE_NAME("event");
  23
  24 /* ACPI notifier chain */
  25 static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
  26
  27 int 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 }
  38 EXPORT_SYMBOL(acpi_notifier_call_chain);
  39
  40 int register_acpi_notifier(struct notifier_block *nb)
  41 {
  42         return blocking_notifier_chain_register(&acpi_chain_head, nb);
  43 }
  44 EXPORT_SYMBOL(register_acpi_notifier);
  45
  46 int unregister_acpi_notifier(struct notifier_block *nb)
  47 {
  48         return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
  49 }
  50 EXPORT_SYMBOL(unregister_acpi_notifier);
  51
  52 #ifdef CONFIG_NET
  53 static unsigned int acpi_event_seqnum;
  54 struct 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 */
  62 enum {
  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 */
  70 enum {
  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
  81 static const struct genl_multicast_group acpi_event_mcgrps[] = {
  82         { .name = ACPI_GENL_MCAST_GROUP_NAME, },
  83 };
  84
  85 static struct genl_family acpi_event_genl_family = {
  86         .id = GENL_ID_GENERATE,
  87         .name = ACPI_GENL_FAMILY_NAME,
  88         .version = ACPI_GENL_VERSION,
  89         .maxattr = ACPI_GENL_ATTR_MAX,
  90         .mcgrps = acpi_event_mcgrps,
  91         .n_mcgrps = ARRAY_SIZE(acpi_event_mcgrps),
  92 };
  93
  94 int acpi_bus_generate_netlink_event(const char *device_class,
  95                                       const char *bus_id,
  96                                       u8 type, int data)
  97 {
  98         struct sk_buff *skb;
  99         struct nlattr *attr;
 100         struct acpi_genl_event *event;
 101         void *msg_header;
 102         int size;
 103         int result;
 104
 105         /* allocate memory */
 106         size = nla_total_size(sizeof(struct acpi_genl_event)) +
 107             nla_total_size(0);
 108
 109         skb = genlmsg_new(size, GFP_ATOMIC);
 110         if (!skb)
 111                 return -ENOMEM;
 112
 113         /* add the genetlink message header */
 114         msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
 115                                  &acpi_event_genl_family, 0,
 116                                  ACPI_GENL_CMD_EVENT);
 117         if (!msg_header) {
 118                 nlmsg_free(skb);
 119                 return -ENOMEM;
 120         }
 121
 122         /* fill the data */
 123         attr =
 124             nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
 125                         sizeof(struct acpi_genl_event));
 126         if (!attr) {
 127                 nlmsg_free(skb);
 128                 return -EINVAL;
 129         }
 130
 131         event = nla_data(attr);
 132         memset(event, 0, sizeof(struct acpi_genl_event));
 133
 134         strcpy(event->device_class, device_class);
 135         strcpy(event->bus_id, bus_id);
 136         event->type = type;
 137         event->data = data;
 138
 139         /* send multicast genetlink message */
 140         result = genlmsg_end(skb, msg_header);
 141         if (result < 0) {
 142                 nlmsg_free(skb);
 143                 return result;
 144         }
 145
 146         genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC);
 147         return 0;
 148 }
 149
 150 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 151
 152 static int acpi_event_genetlink_init(void)
 153 {
 154         return genl_register_family(&acpi_event_genl_family);
 155 }
 156
 157 #else
 158 int acpi_bus_generate_netlink_event(const char *device_class,
 159                                       const char *bus_id,
 160                                       u8 type, int data)
 161 {
 162         return 0;
 163 }
 164
 165 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 166
 167 static int acpi_event_genetlink_init(void)
 168 {
 169         return -ENODEV;
 170 }
 171 #endif
 172
 173 static int __init acpi_event_init(void)
 174 {
 175         int error = 0;
 176
 177         if (acpi_disabled)
 178                 return 0;
 179
 180         /* create genetlink for acpi event */
 181         error = acpi_event_genetlink_init();
 182         if (error)
 183                 printk(KERN_WARNING PREFIX
 184                        "Failed to create genetlink family for ACPI event\n");
 185         return 0;
 186 }
 187
 188 fs_initcall(acpi_event_init);