LXR linux/drivers/acpi/event.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * event.c - exporting ACPI events via procfs
   4 *
   5 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7 *
   8 */
   9
  10#include <linux/spinlock.h>
  11#include <linux/export.h>
  12#include <linux/proc_fs.h>
  13#include <linux/init.h>
  14#include <linux/poll.h>
  15#include <linux/gfp.h>
  16#include <linux/acpi.h>
  17#include <net/netlink.h>
  18#include <net/genetlink.h>
  19
  20#include "internal.h"
  21
  22#define _COMPONENT              ACPI_SYSTEM_COMPONENT
  23ACPI_MODULE_NAME("event");
  24
  25/* ACPI notifier chain */
  26static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
  27
  28int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
  29{
  30        struct acpi_bus_event event;
  31
  32        strcpy(event.device_class, dev->pnp.device_class);
  33        strcpy(event.bus_id, dev->pnp.bus_id);
  34        event.type = type;
  35        event.data = data;
  36        return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
  37                        == NOTIFY_BAD) ? -EINVAL : 0;
  38}
  39EXPORT_SYMBOL(acpi_notifier_call_chain);
  40
  41int register_acpi_notifier(struct notifier_block *nb)
  42{
  43        return blocking_notifier_chain_register(&acpi_chain_head, nb);
  44}
  45EXPORT_SYMBOL(register_acpi_notifier);
  46
  47int unregister_acpi_notifier(struct notifier_block *nb)
  48{
  49        return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
  50}
  51EXPORT_SYMBOL(unregister_acpi_notifier);
  52
  53#ifdef CONFIG_NET
  54static unsigned int acpi_event_seqnum;
  55struct acpi_genl_event {
  56        acpi_device_class device_class;
  57        char bus_id[15];
  58        u32 type;
  59        u32 data;
  60};
  61
  62/* attributes of acpi_genl_family */
  63enum {
  64        ACPI_GENL_ATTR_UNSPEC,
  65        ACPI_GENL_ATTR_EVENT,   /* ACPI event info needed by user space */
  66        __ACPI_GENL_ATTR_MAX,
  67};
  68#define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
  69
  70/* commands supported by the acpi_genl_family */
  71enum {
  72        ACPI_GENL_CMD_UNSPEC,
  73        ACPI_GENL_CMD_EVENT,    /* kernel->user notifications for ACPI events */
  74        __ACPI_GENL_CMD_MAX,
  75};
  76#define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
  77
  78#define ACPI_GENL_FAMILY_NAME           "acpi_event"
  79#define ACPI_GENL_VERSION               0x01
  80#define ACPI_GENL_MCAST_GROUP_NAME      "acpi_mc_group"
  81
  82static const struct genl_multicast_group acpi_event_mcgrps[] = {
  83        { .name = ACPI_GENL_MCAST_GROUP_NAME, },
  84};
  85
  86static struct genl_family acpi_event_genl_family __ro_after_init = {
  87        .module = THIS_MODULE,
  88        .name = ACPI_GENL_FAMILY_NAME,
  89        .version = ACPI_GENL_VERSION,
  90        .maxattr = ACPI_GENL_ATTR_MAX,
  91        .mcgrps = acpi_event_mcgrps,
  92        .n_mcgrps = ARRAY_SIZE(acpi_event_mcgrps),
  93};
  94
  95int acpi_bus_generate_netlink_event(const char *device_class,
  96                                      const char *bus_id,
  97                                      u8 type, int data)
  98{
  99        struct sk_buff *skb;
 100        struct nlattr *attr;
 101        struct acpi_genl_event *event;
 102        void *msg_header;
 103        int size;
 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        strscpy(event->device_class, device_class, sizeof(event->device_class));
 135        strscpy(event->bus_id, bus_id, sizeof(event->bus_id));
 136        event->type = type;
 137        event->data = data;
 138
 139        /* send multicast genetlink message */
 140        genlmsg_end(skb, msg_header);
 141
 142        genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC);
 143        return 0;
 144}
 145
 146EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 147
 148static int __init acpi_event_genetlink_init(void)
 149{
 150        return genl_register_family(&acpi_event_genl_family);
 151}
 152
 153#else
 154int acpi_bus_generate_netlink_event(const char *device_class,
 155                                      const char *bus_id,
 156                                      u8 type, int data)
 157{
 158        return 0;
 159}
 160
 161EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
 162
 163static int acpi_event_genetlink_init(void)
 164{
 165        return -ENODEV;
 166}
 167#endif
 168
 169static int __init acpi_event_init(void)
 170{
 171        int error = 0;
 172
 173        if (acpi_disabled)
 174                return 0;
 175
 176        /* create genetlink for acpi event */
 177        error = acpi_event_genetlink_init();
 178        if (error)
 179                printk(KERN_WARNING PREFIX
 180                       "Failed to create genetlink family for ACPI event\n");
 181        return 0;
 182}
 183
 184fs_initcall(acpi_event_init);
 185