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
23 ACPI_MODULE_NAME("event");
24
25 /* ACPI notifier chain */
26 static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
27
acpi_notifier_call_chain(struct acpi_device * dev,u32 type,u32 data)28 int 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 }
39 EXPORT_SYMBOL(acpi_notifier_call_chain);
40
register_acpi_notifier(struct notifier_block * nb)41 int register_acpi_notifier(struct notifier_block *nb)
42 {
43 return blocking_notifier_chain_register(&acpi_chain_head, nb);
44 }
45 EXPORT_SYMBOL(register_acpi_notifier);
46
unregister_acpi_notifier(struct notifier_block * nb)47 int unregister_acpi_notifier(struct notifier_block *nb)
48 {
49 return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
50 }
51 EXPORT_SYMBOL(unregister_acpi_notifier);
52
53 #ifdef CONFIG_NET
54 static unsigned int acpi_event_seqnum;
55 struct 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 */
63 enum {
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 */
71 enum {
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
82 static const struct genl_multicast_group acpi_event_mcgrps[] = {
83 { .name = ACPI_GENL_MCAST_GROUP_NAME, },
84 };
85
86 static 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
acpi_bus_generate_netlink_event(const char * device_class,const char * bus_id,u8 type,int data)95 int 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
146 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
147
acpi_event_genetlink_init(void)148 static int __init acpi_event_genetlink_init(void)
149 {
150 return genl_register_family(&acpi_event_genl_family);
151 }
152
153 #else
acpi_bus_generate_netlink_event(const char * device_class,const char * bus_id,u8 type,int data)154 int 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
161 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
162
acpi_event_genetlink_init(void)163 static int acpi_event_genetlink_init(void)
164 {
165 return -ENODEV;
166 }
167 #endif
168
acpi_event_init(void)169 static 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
184 fs_initcall(acpi_event_init);
185