summaryrefslogtreecommitdiff
path: root/drivers/acpi/event.c
blob: 96a9aaaaf9f705895f2ce40d80f3952ac231fee0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
// SPDX-License-Identifier: GPL-2.0
/*
 * event.c - exporting ACPI events via procfs
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *
 */

#define pr_fmt(fmt) "ACPI: " fmt

#include <linux/spinlock.h>
#include <linux/export.h>
#include <linux/proc_fs.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/gfp.h>
#include <linux/acpi.h>
#include <net/netlink.h>
#include <net/genetlink.h>

#include "internal.h"

/* ACPI notifier chain */
static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);

int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
{
	struct acpi_bus_event event;

	strscpy(event.device_class, dev->pnp.device_class);
	strscpy(event.bus_id, dev->pnp.bus_id);
	event.type = type;
	event.data = data;
	return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
			== NOTIFY_BAD) ? -EINVAL : 0;
}
EXPORT_SYMBOL(acpi_notifier_call_chain);

int register_acpi_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_register(&acpi_chain_head, nb);
}
EXPORT_SYMBOL(register_acpi_notifier);

int unregister_acpi_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
}
EXPORT_SYMBOL(unregister_acpi_notifier);

#ifdef CONFIG_NET
static unsigned int acpi_event_seqnum;
struct acpi_genl_event {
	acpi_device_class device_class;
	char bus_id[15];
	u32 type;
	u32 data;
};

/* attributes of acpi_genl_family */
enum {
	ACPI_GENL_ATTR_UNSPEC,
	ACPI_GENL_ATTR_EVENT,	/* ACPI event info needed by user space */
	__ACPI_GENL_ATTR_MAX,
};
#define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)

/* commands supported by the acpi_genl_family */
enum {
	ACPI_GENL_CMD_UNSPEC,
	ACPI_GENL_CMD_EVENT,	/* kernel->user notifications for ACPI events */
	__ACPI_GENL_CMD_MAX,
};
#define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)

#define ACPI_GENL_FAMILY_NAME		"acpi_event"
#define ACPI_GENL_VERSION		0x01
#define ACPI_GENL_MCAST_GROUP_NAME 	"acpi_mc_group"

static const struct genl_multicast_group acpi_event_mcgrps[] = {
	{ .name = ACPI_GENL_MCAST_GROUP_NAME, },
};

static struct genl_family acpi_event_genl_family __ro_after_init = {
	.module = THIS_MODULE,
	.name = ACPI_GENL_FAMILY_NAME,
	.version = ACPI_GENL_VERSION,
	.maxattr = ACPI_GENL_ATTR_MAX,
	.mcgrps = acpi_event_mcgrps,
	.n_mcgrps = ARRAY_SIZE(acpi_event_mcgrps),
};

int acpi_bus_generate_netlink_event(const char *device_class,
				      const char *bus_id,
				      u8 type, int data)
{
	struct sk_buff *skb;
	struct nlattr *attr;
	struct acpi_genl_event *event;
	void *msg_header;
	int size;

	/* allocate memory */
	size = nla_total_size(sizeof(struct acpi_genl_event)) +
	    nla_total_size(0);

	skb = genlmsg_new(size, GFP_ATOMIC);
	if (!skb)
		return -ENOMEM;

	/* add the genetlink message header */
	msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
				 &acpi_event_genl_family, 0,
				 ACPI_GENL_CMD_EVENT);
	if (!msg_header) {
		nlmsg_free(skb);
		return -ENOMEM;
	}

	/* fill the data */
	attr =
	    nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
			sizeof(struct acpi_genl_event));
	if (!attr) {
		nlmsg_free(skb);
		return -EINVAL;
	}

	event = nla_data(attr);
	memset(event, 0, sizeof(struct acpi_genl_event));

	strscpy(event->device_class, device_class, sizeof(event->device_class));
	strscpy(event->bus_id, bus_id, sizeof(event->bus_id));
	event->type = type;
	event->data = data;

	/* send multicast genetlink message */
	genlmsg_end(skb, msg_header);

	genlmsg_multicast(&acpi_event_genl_family, skb, 0, 0, GFP_ATOMIC);
	return 0;
}

EXPORT_SYMBOL(acpi_bus_generate_netlink_event);

static int __init acpi_event_genetlink_init(void)
{
	return genl_register_family(&acpi_event_genl_family);
}

#else
int acpi_bus_generate_netlink_event(const char *device_class,
				      const char *bus_id,
				      u8 type, int data)
{
	return 0;
}

EXPORT_SYMBOL(acpi_bus_generate_netlink_event);

static int acpi_event_genetlink_init(void)
{
	return -ENODEV;
}
#endif

static int __init acpi_event_init(void)
{
	int error;

	if (acpi_disabled)
		return 0;

	/* create genetlink for acpi event */
	error = acpi_event_genetlink_init();
	if (error)
		pr_warn("Failed to create genetlink family for ACPI event\n");

	return 0;
}

fs_initcall(acpi_event_init);