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/proc_fs.h>
  11 #include <linux/init.h>
  12 #include <linux/poll.h>
  13 #include <acpi/acpi_drivers.h>
  14 #include <net/netlink.h>
  15 #include <net/genetlink.h>
  16
  17 #define _COMPONENT              ACPI_SYSTEM_COMPONENT
  18 ACPI_MODULE_NAME("event");
  19
  20 #ifdef CONFIG_ACPI_PROC_EVENT
  21 /* Global vars for handling event proc entry */
  22 static DEFINE_SPINLOCK(acpi_system_event_lock);
  23 int event_is_open = 0;
  24 extern struct list_head acpi_bus_event_list;
  25 extern wait_queue_head_t acpi_bus_event_queue;
  26
  27 static int acpi_system_open_event(struct inode *inode, struct file *file)
  28 {
  29         spin_lock_irq(&acpi_system_event_lock);
  30
  31         if (event_is_open)
  32                 goto out_busy;
  33
  34         event_is_open = 1;
  35
  36         spin_unlock_irq(&acpi_system_event_lock);
  37         return 0;
  38
  39       out_busy:
  40         spin_unlock_irq(&acpi_system_event_lock);
  41         return -EBUSY;
  42 }
  43
  44 static ssize_t
  45 acpi_system_read_event(struct file *file, char __user * buffer, size_t count,
  46                        loff_t * ppos)
  47 {
  48         int result = 0;
  49         struct acpi_bus_event event;
  50         static char str[ACPI_MAX_STRING];
  51         static int chars_remaining = 0;
  52         static char *ptr;
  53
  54         if (!chars_remaining) {
  55                 memset(&event, 0, sizeof(struct acpi_bus_event));
  56
  57                 if ((file->f_flags & O_NONBLOCK)
  58                     && (list_empty(&acpi_bus_event_list)))
  59                         return -EAGAIN;
  60
  61                 result = acpi_bus_receive_event(&event);
  62                 if (result)
  63                         return result;
  64
  65                 chars_remaining = sprintf(str, "%s %s %08x %08x\n",
  66                                           event.device_class ? event.
  67                                           device_class : "<unknown>",
  68                                           event.bus_id ? event.
  69                                           bus_id : "<unknown>", event.type,
  70                                           event.data);
  71                 ptr = str;
  72         }
  73
  74         if (chars_remaining < count) {
  75                 count = chars_remaining;
  76         }
  77
  78         if (copy_to_user(buffer, ptr, count))
  79                 return -EFAULT;
  80
  81         *ppos += count;
  82         chars_remaining -= count;
  83         ptr += count;
  84
  85         return count;
  86 }
  87
  88 static int acpi_system_close_event(struct inode *inode, struct file *file)
  89 {
  90         spin_lock_irq(&acpi_system_event_lock);
  91         event_is_open = 0;
  92         spin_unlock_irq(&acpi_system_event_lock);
  93         return 0;
  94 }
  95
  96 static unsigned int acpi_system_poll_event(struct file *file, poll_table * wait)
  97 {
  98         poll_wait(file, &acpi_bus_event_queue, wait);
  99         if (!list_empty(&acpi_bus_event_list))
 100                 return POLLIN | POLLRDNORM;
 101         return 0;
 102 }
 103
 104 static const struct file_operations acpi_system_event_ops = {
 105         .open = acpi_system_open_event,
 106         .read = acpi_system_read_event,
 107         .release = acpi_system_close_event,
 108         .poll = acpi_system_poll_event,
 109 };
 110 #endif  /* CONFIG_ACPI_PROC_EVENT */
 111
 112 #ifdef CONFIG_NET
 113 static unsigned int acpi_event_seqnum;
 114 struct acpi_genl_event {
 115         acpi_device_class device_class;
 116         char bus_id[15];
 117         u32 type;
 118         u32 data;
 119 };
 120
 121 /* attributes of acpi_genl_family */
 122 enum {
 123         ACPI_GENL_ATTR_UNSPEC,
 124         ACPI_GENL_ATTR_EVENT,   /* ACPI event info needed by user space */
 125         __ACPI_GENL_ATTR_MAX,
 126 };
 127 #define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
 128
 129 /* commands supported by the acpi_genl_family */
 130 enum {
 131         ACPI_GENL_CMD_UNSPEC,
 132         ACPI_GENL_CMD_EVENT,    /* kernel->user notifications for ACPI events */
 133         __ACPI_GENL_CMD_MAX,
 134 };
 135 #define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
 136
 137 #define ACPI_GENL_FAMILY_NAME           "acpi_event"
 138 #define ACPI_GENL_VERSION               0x01
 139 #define ACPI_GENL_MCAST_GROUP_NAME      "acpi_mc_group"
 140
 141 static struct genl_family acpi_event_genl_family = {
 142         .id = GENL_ID_GENERATE,
 143         .name = ACPI_GENL_FAMILY_NAME,
 144         .version = ACPI_GENL_VERSION,
 145         .maxattr = ACPI_GENL_ATTR_MAX,
 146 };
 147
 148 static struct genl_multicast_group acpi_event_mcgrp = {
 149         .name = ACPI_GENL_MCAST_GROUP_NAME,
 150 };
 151
 152 int acpi_bus_generate_netlink_event(const char *device_class,
 153                                       const char *bus_id,
 154                                       u8 type, int data)
 155 {
 156         struct sk_buff *skb;
 157         struct nlattr *attr;
 158         struct acpi_genl_event *event;
 159         void *msg_header;
 160         int size;
 161         int result;
 162
 163         /* allocate memory */
 164         size = nla_total_size(sizeof(struct acpi_genl_event)) +
 165             nla_total_size(0);
 166
 167         skb = genlmsg_new(size, GFP_ATOMIC);
 168         if (!skb)
 169                 return -ENOMEM;
 170
 171         /* add the genetlink message header */
 172         msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
 173                                  &acpi_event_genl_family, 0,
 174                                  ACPI_GENL_CMD_EVENT);
 175         if (!msg_header) {
 176                 nlmsg_free(skb);
 177                 return -ENOMEM;
 178         }
 179
 180         /* fill the data */
 181         attr =
 182             nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
 183                         sizeof(struct acpi_genl_event));
 184         if (!attr) {
 185                 nlmsg_free(skb);
 186                 return -EINVAL;
 187         }
 188
 189         event = nla_data(attr);
 190         if (!event) {
 191                 nlmsg_free(skb);
 192                 return -EINVAL;
 193         }
 194
 195         memset(event, 0, sizeof(struct acpi_genl_event));
 196
 197         strcpy(event->device_class, device_class);
 198         strcpy(event->bus_id, bus_id);
 199         event->type = type;
 200         event->data = data;
 201
 202         /* send multicast genetlink message */
 203         result = genlmsg_end(skb, msg_header);
 204         if (result < 0) {
 205                 nlmsg_free(skb);
 206                 return result;
 207         }
 208
 209         result =
 210             genlmsg_multicast(skb, 0, acpi_event_mcgrp.id, GFP_ATOMIC);
 211         if (result)
 212                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 213                                   "Failed to send a Genetlink message!\n"));
 214         return 0;
 215 }
 216
 217 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 218
 219 static int acpi_event_genetlink_init(void)
 220 {
 221         int result;
 222
 223         result = genl_register_family(&acpi_event_genl_family);
 224         if (result)
 225                 return result;
 226
 227         result = genl_register_mc_group(&acpi_event_genl_family,
 228                                         &acpi_event_mcgrp);
 229         if (result)
 230                 genl_unregister_family(&acpi_event_genl_family);
 231
 232         return result;
 233 }
 234
 235 #else
 236 int acpi_bus_generate_netlink_event(const char *device_class,
 237                                       const char *bus_id,
 238                                       u8 type, int data)
 239 {
 240         return 0;
 241 }
 242
 243 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 244
 245 static int acpi_event_genetlink_init(void)
 246 {
 247         return -ENODEV;
 248 }
 249 #endif
 250
 251 static int __init acpi_event_init(void)
 252 {
 253 #ifdef CONFIG_ACPI_PROC_EVENT
 254         struct proc_dir_entry *entry;
 255 #endif
 256         int error = 0;
 257
 258         if (acpi_disabled)
 259                 return 0;
 260
 261         /* create genetlink for acpi event */
 262         error = acpi_event_genetlink_init();
 263         if (error)
 264                 printk(KERN_WARNING PREFIX
 265                        "Failed to create genetlink family for ACPI event\n");
 266
 267 #ifdef CONFIG_ACPI_PROC_EVENT
 268         /* 'event' [R] */
 269         entry = create_proc_entry("event", S_IRUSR, acpi_root_dir);
 270         if (entry)
 271                 entry->proc_fops = &acpi_system_event_ops;
 272         else
 273                 return -ENODEV;
 274 #endif
 275
 276         return 0;
 277 }
 278
 279 fs_initcall(acpi_event_init);