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 */
25static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
26
27int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
28{
29	struct acpi_bus_event event;
30
31	strcpy(event.device_class, dev->pnp.device_class);
32	strcpy(event.bus_id, dev->pnp.bus_id);
33	event.type = type;
34	event.data = data;
35	return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
36			== NOTIFY_BAD) ? -EINVAL : 0;
37}
38EXPORT_SYMBOL(acpi_notifier_call_chain);
39
40int register_acpi_notifier(struct notifier_block *nb)
41{
42	return blocking_notifier_chain_register(&acpi_chain_head, nb);
43}
44EXPORT_SYMBOL(register_acpi_notifier);
45
46int unregister_acpi_notifier(struct notifier_block *nb)
47{
48	return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
49}
50EXPORT_SYMBOL(unregister_acpi_notifier);
51
52#ifdef CONFIG_NET
53static unsigned int acpi_event_seqnum;
54struct 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 */
62enum {
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 */
70enum {
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
81static const struct genl_multicast_group acpi_event_mcgrps[] = {
82	{ .name = ACPI_GENL_MCAST_GROUP_NAME, },
83};
84
85static 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
94int 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 *msg_header;
102	int size;
103
104	/* allocate memory */
105	size = nla_total_size(sizeof(struct acpi_genl_event)) +
106	    nla_total_size(0);
107
108	skb = genlmsg_new(size, GFP_ATOMIC);
109	if (!skb)
110		return -ENOMEM;
111
112	/* add the genetlink message header */
113	msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
114				 &acpi_event_genl_family, 0,
115				 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, ACPI_GENL_ATTR_EVENT,
124			sizeof(struct acpi_genl_event));
125	if (!attr) {
126		nlmsg_free(skb);
127		return -EINVAL;
128	}
129
130	event = nla_data(attr);
131	memset(event, 0, sizeof(struct acpi_genl_event));
132
133	strscpy(event->device_class, device_class, sizeof(event->device_class));
134	strscpy(event->bus_id, bus_id, sizeof(event->bus_id));
135	event->type = type;
136	event->data = data;
137
138	/* send multicast genetlink message */
139	genlmsg_end(skb, msg_header);
140
141	genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC);
142	return 0;
143}
144
145EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
146
147static int __init acpi_event_genetlink_init(void)
148{
149	return genl_register_family(&acpi_event_genl_family);
150}
151
152#else
153int 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
160EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
161
162static int acpi_event_genetlink_init(void)
163{
164	return -ENODEV;
165}
166#endif
167
168static 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
183fs_initcall(acpi_event_init);
184