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 /* ACPI notifier chain */
23 static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
24
acpi_notifier_call_chain(struct acpi_device * dev,u32 type,u32 data)25 int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
26 {
27 struct acpi_bus_event event;
28
29 strcpy(event.device_class, dev->pnp.device_class);
30 strcpy(event.bus_id, dev->pnp.bus_id);
31 event.type = type;
32 event.data = data;
33 return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
34 == NOTIFY_BAD) ? -EINVAL : 0;
35 }
36 EXPORT_SYMBOL(acpi_notifier_call_chain);
37
register_acpi_notifier(struct notifier_block * nb)38 int register_acpi_notifier(struct notifier_block *nb)
39 {
40 return blocking_notifier_chain_register(&acpi_chain_head, nb);
41 }
42 EXPORT_SYMBOL(register_acpi_notifier);
43
unregister_acpi_notifier(struct notifier_block * nb)44 int unregister_acpi_notifier(struct notifier_block *nb)
45 {
46 return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
47 }
48 EXPORT_SYMBOL(unregister_acpi_notifier);
49
50 #ifdef CONFIG_NET
51 static unsigned int acpi_event_seqnum;
52 struct acpi_genl_event {
53 acpi_device_class device_class;
54 char bus_id[15];
55 u32 type;
56 u32 data;
57 };
58
59 /* attributes of acpi_genl_family */
60 enum {
61 ACPI_GENL_ATTR_UNSPEC,
62 ACPI_GENL_ATTR_EVENT, /* ACPI event info needed by user space */
63 __ACPI_GENL_ATTR_MAX,
64 };
65 #define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
66
67 /* commands supported by the acpi_genl_family */
68 enum {
69 ACPI_GENL_CMD_UNSPEC,
70 ACPI_GENL_CMD_EVENT, /* kernel->user notifications for ACPI events */
71 __ACPI_GENL_CMD_MAX,
72 };
73 #define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
74
75 #define ACPI_GENL_FAMILY_NAME "acpi_event"
76 #define ACPI_GENL_VERSION 0x01
77 #define ACPI_GENL_MCAST_GROUP_NAME "acpi_mc_group"
78
79 static const struct genl_multicast_group acpi_event_mcgrps[] = {
80 { .name = ACPI_GENL_MCAST_GROUP_NAME, },
81 };
82
83 static struct genl_family acpi_event_genl_family __ro_after_init = {
84 .module = THIS_MODULE,
85 .name = ACPI_GENL_FAMILY_NAME,
86 .version = ACPI_GENL_VERSION,
87 .maxattr = ACPI_GENL_ATTR_MAX,
88 .mcgrps = acpi_event_mcgrps,
89 .n_mcgrps = ARRAY_SIZE(acpi_event_mcgrps),
90 };
91
acpi_bus_generate_netlink_event(const char * device_class,const char * bus_id,u8 type,int data)92 int 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
102 /* allocate memory */
103 size = nla_total_size(sizeof(struct acpi_genl_event)) +
104 nla_total_size(0);
105
106 skb = genlmsg_new(size, GFP_ATOMIC);
107 if (!skb)
108 return -ENOMEM;
109
110 /* add the genetlink message header */
111 msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
112 &acpi_event_genl_family, 0,
113 ACPI_GENL_CMD_EVENT);
114 if (!msg_header) {
115 nlmsg_free(skb);
116 return -ENOMEM;
117 }
118
119 /* fill the data */
120 attr =
121 nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
122 sizeof(struct acpi_genl_event));
123 if (!attr) {
124 nlmsg_free(skb);
125 return -EINVAL;
126 }
127
128 event = nla_data(attr);
129 memset(event, 0, sizeof(struct acpi_genl_event));
130
131 strscpy(event->device_class, device_class, sizeof(event->device_class));
132 strscpy(event->bus_id, bus_id, sizeof(event->bus_id));
133 event->type = type;
134 event->data = data;
135
136 /* send multicast genetlink message */
137 genlmsg_end(skb, msg_header);
138
139 genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC);
140 return 0;
141 }
142
143 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
144
acpi_event_genetlink_init(void)145 static int __init acpi_event_genetlink_init(void)
146 {
147 return genl_register_family(&acpi_event_genl_family);
148 }
149
150 #else
acpi_bus_generate_netlink_event(const char * device_class,const char * bus_id,u8 type,int data)151 int acpi_bus_generate_netlink_event(const char *device_class,
152 const char *bus_id,
153 u8 type, int data)
154 {
155 return 0;
156 }
157
158 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
159
acpi_event_genetlink_init(void)160 static int acpi_event_genetlink_init(void)
161 {
162 return -ENODEV;
163 }
164 #endif
165
acpi_event_init(void)166 static int __init acpi_event_init(void)
167 {
168 int error = 0;
169
170 if (acpi_disabled)
171 return 0;
172
173 /* create genetlink for acpi event */
174 error = acpi_event_genetlink_init();
175 if (error)
176 printk(KERN_WARNING PREFIX
177 "Failed to create genetlink family for ACPI event\n");
178 return 0;
179 }
180
181 fs_initcall(acpi_event_init);
182