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184 lines · 4.2 KiB

1// SPDX-License-Identifier: GPL-2.0
2/*
3 * event.c - exporting ACPI events via procfs
4 *
5 * Copyright (C) 2001, 2002 Andy Grover <[email protected]>
6 * Copyright (C) 2001, 2002 Paul Diefenbaugh <[email protected]>
7 *
8 */
9
10#define pr_fmt(fmt) "ACPI: " fmt
11
12#include <linux/spinlock.h>
13#include <linux/export.h>
14#include <linux/proc_fs.h>
15#include <linux/init.h>
16#include <linux/poll.h>
17#include <linux/gfp.h>
18#include <linux/acpi.h>
19#include <net/netlink.h>
20#include <net/genetlink.h>
21
22#include "internal.h"
23
24/* ACPI notifier chain */
25static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
26
27int acpi_notifier_call_chain(const char *device_class,
28 const char *bus_id, u32 type, u32 data)
29{
30 struct acpi_bus_event event;
31
32 strscpy(event.device_class, device_class);
33 strscpy(event.bus_id, 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;
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 pr_warn("Failed to create genetlink family for ACPI event\n");
180
181 return 0;
182}
183
184fs_initcall(acpi_event_init);