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 | #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 */ |
25 | static BLOCKING_NOTIFIER_HEAD(acpi_chain_head); |
26 | |
27 | int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data) |
28 | { |
29 | struct acpi_bus_event event; |
30 | |
31 | strcpy(p: event.device_class, q: dev->pnp.device_class); |
32 | strcpy(p: event.bus_id, q: dev->pnp.bus_id); |
33 | event.type = type; |
34 | event.data = data; |
35 | return (blocking_notifier_call_chain(nh: &acpi_chain_head, val: 0, v: (void *)&event) |
36 | == NOTIFY_BAD) ? -EINVAL : 0; |
37 | } |
38 | EXPORT_SYMBOL(acpi_notifier_call_chain); |
39 | |
40 | int register_acpi_notifier(struct notifier_block *nb) |
41 | { |
42 | return blocking_notifier_chain_register(nh: &acpi_chain_head, nb); |
43 | } |
44 | EXPORT_SYMBOL(register_acpi_notifier); |
45 | |
46 | int unregister_acpi_notifier(struct notifier_block *nb) |
47 | { |
48 | return blocking_notifier_chain_unregister(nh: &acpi_chain_head, nb); |
49 | } |
50 | EXPORT_SYMBOL(unregister_acpi_notifier); |
51 | |
52 | #ifdef CONFIG_NET |
53 | static unsigned int acpi_event_seqnum; |
54 | struct acpi_genl_event { |
55 | acpi_device_class device_class; |
56 | char bus_id[15]; |
57 | u32 type; |
58 | u32 data; |
59 | }; |
60 | |
61 | /* attributes of acpi_genl_family */ |
62 | enum { |
63 | ACPI_GENL_ATTR_UNSPEC, |
64 | ACPI_GENL_ATTR_EVENT, /* ACPI event info needed by user space */ |
65 | __ACPI_GENL_ATTR_MAX, |
66 | }; |
67 | #define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1) |
68 | |
69 | /* commands supported by the acpi_genl_family */ |
70 | enum { |
71 | ACPI_GENL_CMD_UNSPEC, |
72 | ACPI_GENL_CMD_EVENT, /* kernel->user notifications for ACPI events */ |
73 | __ACPI_GENL_CMD_MAX, |
74 | }; |
75 | #define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1) |
76 | |
77 | #define ACPI_GENL_FAMILY_NAME "acpi_event" |
78 | #define ACPI_GENL_VERSION 0x01 |
79 | #define ACPI_GENL_MCAST_GROUP_NAME "acpi_mc_group" |
80 | |
81 | static const struct genl_multicast_group acpi_event_mcgrps[] = { |
82 | { .name = ACPI_GENL_MCAST_GROUP_NAME, }, |
83 | }; |
84 | |
85 | static struct genl_family acpi_event_genl_family __ro_after_init = { |
86 | .module = THIS_MODULE, |
87 | .name = ACPI_GENL_FAMILY_NAME, |
88 | .version = ACPI_GENL_VERSION, |
89 | .maxattr = ACPI_GENL_ATTR_MAX, |
90 | .mcgrps = acpi_event_mcgrps, |
91 | .n_mcgrps = ARRAY_SIZE(acpi_event_mcgrps), |
92 | }; |
93 | |
94 | int acpi_bus_generate_netlink_event(const char *device_class, |
95 | const char *bus_id, |
96 | u8 type, int data) |
97 | { |
98 | struct sk_buff *skb; |
99 | struct nlattr *attr; |
100 | struct acpi_genl_event *event; |
101 | void *; |
102 | int size; |
103 | |
104 | /* allocate memory */ |
105 | size = nla_total_size(payload: sizeof(struct acpi_genl_event)) + |
106 | nla_total_size(payload: 0); |
107 | |
108 | skb = genlmsg_new(payload: size, GFP_ATOMIC); |
109 | if (!skb) |
110 | return -ENOMEM; |
111 | |
112 | /* add the genetlink message header */ |
113 | msg_header = genlmsg_put(skb, portid: 0, seq: acpi_event_seqnum++, |
114 | family: &acpi_event_genl_family, flags: 0, |
115 | cmd: ACPI_GENL_CMD_EVENT); |
116 | if (!msg_header) { |
117 | nlmsg_free(skb); |
118 | return -ENOMEM; |
119 | } |
120 | |
121 | /* fill the data */ |
122 | attr = |
123 | nla_reserve(skb, attrtype: ACPI_GENL_ATTR_EVENT, |
124 | attrlen: sizeof(struct acpi_genl_event)); |
125 | if (!attr) { |
126 | nlmsg_free(skb); |
127 | return -EINVAL; |
128 | } |
129 | |
130 | event = nla_data(nla: attr); |
131 | memset(event, 0, sizeof(struct acpi_genl_event)); |
132 | |
133 | strscpy(p: event->device_class, q: device_class, size: sizeof(event->device_class)); |
134 | strscpy(p: event->bus_id, q: bus_id, size: sizeof(event->bus_id)); |
135 | event->type = type; |
136 | event->data = data; |
137 | |
138 | /* send multicast genetlink message */ |
139 | genlmsg_end(skb, hdr: msg_header); |
140 | |
141 | genlmsg_multicast(family: &acpi_event_genl_family, skb, portid: 0, group: 0, GFP_ATOMIC); |
142 | return 0; |
143 | } |
144 | |
145 | EXPORT_SYMBOL(acpi_bus_generate_netlink_event); |
146 | |
147 | static int __init acpi_event_genetlink_init(void) |
148 | { |
149 | return genl_register_family(family: &acpi_event_genl_family); |
150 | } |
151 | |
152 | #else |
153 | int acpi_bus_generate_netlink_event(const char *device_class, |
154 | const char *bus_id, |
155 | u8 type, int data) |
156 | { |
157 | return 0; |
158 | } |
159 | |
160 | EXPORT_SYMBOL(acpi_bus_generate_netlink_event); |
161 | |
162 | static int acpi_event_genetlink_init(void) |
163 | { |
164 | return -ENODEV; |
165 | } |
166 | #endif |
167 | |
168 | static int __init acpi_event_init(void) |
169 | { |
170 | int error; |
171 | |
172 | if (acpi_disabled) |
173 | return 0; |
174 | |
175 | /* create genetlink for acpi event */ |
176 | error = acpi_event_genetlink_init(); |
177 | if (error) |
178 | pr_warn("Failed to create genetlink family for ACPI event\n" ); |
179 | |
180 | return 0; |
181 | } |
182 | |
183 | fs_initcall(acpi_event_init); |
184 | |