1 /*
2 * event.c - exporting ACPI events via procfs
3 *
4 * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5 * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6 *
7 */
8
9 #include <linux/spinlock.h>
10 #include <linux/proc_fs.h>
11 #include <linux/init.h>
12 #include <linux/poll.h>
13 #include <acpi/acpi_drivers.h>
14 #include <net/netlink.h>
15 #include <net/genetlink.h>
16
17 #define _COMPONENT ACPI_SYSTEM_COMPONENT
18 ACPI_MODULE_NAME("event");
19
20 #ifdef CONFIG_ACPI_PROC_EVENT
21 /* Global vars for handling event proc entry */
22 static DEFINE_SPINLOCK(acpi_system_event_lock);
23 int event_is_open = 0;
24 extern struct list_head acpi_bus_event_list;
25 extern wait_queue_head_t acpi_bus_event_queue;
26
27 static int acpi_system_open_event(struct inode *inode, struct file *file)
28 {
29 spin_lock_irq(&acpi_system_event_lock);
30
31 if (event_is_open)
32 goto out_busy;
33
34 event_is_open = 1;
35
36 spin_unlock_irq(&acpi_system_event_lock);
37 return 0;
38
39 out_busy:
40 spin_unlock_irq(&acpi_system_event_lock);
41 return -EBUSY;
42 }
43
44 static ssize_t
45 acpi_system_read_event(struct file *file, char __user * buffer, size_t count,
46 loff_t * ppos)
47 {
48 int result = 0;
49 struct acpi_bus_event event;
50 static char str[ACPI_MAX_STRING];
51 static int chars_remaining = 0;
52 static char *ptr;
53
54 if (!chars_remaining) {
55 memset(&event, 0, sizeof(struct acpi_bus_event));
56
57 if ((file->f_flags & O_NONBLOCK)
58 && (list_empty(&acpi_bus_event_list)))
59 return -EAGAIN;
60
61 result = acpi_bus_receive_event(&event);
62 if (result)
63 return result;
64
65 chars_remaining = sprintf(str, "%s %s %08x %08x\n",
66 event.device_class ? event.
67 device_class : "<unknown>",
68 event.bus_id ? event.
69 bus_id : "<unknown>", event.type,
70 event.data);
71 ptr = str;
72 }
73
74 if (chars_remaining < count) {
75 count = chars_remaining;
76 }
77
78 if (copy_to_user(buffer, ptr, count))
79 return -EFAULT;
80
81 *ppos += count;
82 chars_remaining -= count;
83 ptr += count;
84
85 return count;
86 }
87
88 static int acpi_system_close_event(struct inode *inode, struct file *file)
89 {
90 spin_lock_irq(&acpi_system_event_lock);
91 event_is_open = 0;
92 spin_unlock_irq(&acpi_system_event_lock);
93 return 0;
94 }
95
96 static unsigned int acpi_system_poll_event(struct file *file, poll_table * wait)
97 {
98 poll_wait(file, &acpi_bus_event_queue, wait);
99 if (!list_empty(&acpi_bus_event_list))
100 return POLLIN | POLLRDNORM;
101 return 0;
102 }
103
104 static const struct file_operations acpi_system_event_ops = {
105 .owner = THIS_MODULE,
106 .open = acpi_system_open_event,
107 .read = acpi_system_read_event,
108 .release = acpi_system_close_event,
109 .poll = acpi_system_poll_event,
110 };
111 #endif /* CONFIG_ACPI_PROC_EVENT */
112
113 /* ACPI notifier chain */
114 static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
115
116 int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
117 {
118 struct acpi_bus_event event;
119
120 strcpy(event.device_class, dev->pnp.device_class);
121 strcpy(event.bus_id, dev->pnp.bus_id);
122 event.type = type;
123 event.data = data;
124 return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
125 == NOTIFY_BAD) ? -EINVAL : 0;
126 }
127 EXPORT_SYMBOL(acpi_notifier_call_chain);
128
129 int register_acpi_notifier(struct notifier_block *nb)
130 {
131 return blocking_notifier_chain_register(&acpi_chain_head, nb);
132 }
133 EXPORT_SYMBOL(register_acpi_notifier);
134
135 int unregister_acpi_notifier(struct notifier_block *nb)
136 {
137 return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
138 }
139 EXPORT_SYMBOL(unregister_acpi_notifier);
140
141 #ifdef CONFIG_NET
142 static unsigned int acpi_event_seqnum;
143 struct acpi_genl_event {
144 acpi_device_class device_class;
145 char bus_id[15];
146 u32 type;
147 u32 data;
148 };
149
150 /* attributes of acpi_genl_family */
151 enum {
152 ACPI_GENL_ATTR_UNSPEC,
153 ACPI_GENL_ATTR_EVENT, /* ACPI event info needed by user space */
154 __ACPI_GENL_ATTR_MAX,
155 };
156 #define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
157
158 /* commands supported by the acpi_genl_family */
159 enum {
160 ACPI_GENL_CMD_UNSPEC,
161 ACPI_GENL_CMD_EVENT, /* kernel->user notifications for ACPI events */
162 __ACPI_GENL_CMD_MAX,
163 };
164 #define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
165
166 #define ACPI_GENL_FAMILY_NAME "acpi_event"
167 #define ACPI_GENL_VERSION 0x01
168 #define ACPI_GENL_MCAST_GROUP_NAME "acpi_mc_group"
169
170 static struct genl_family acpi_event_genl_family = {
171 .id = GENL_ID_GENERATE,
172 .name = ACPI_GENL_FAMILY_NAME,
173 .version = ACPI_GENL_VERSION,
174 .maxattr = ACPI_GENL_ATTR_MAX,
175 };
176
177 static struct genl_multicast_group acpi_event_mcgrp = {
178 .name = ACPI_GENL_MCAST_GROUP_NAME,
179 };
180
181 int acpi_bus_generate_netlink_event(const char *device_class,
182 const char *bus_id,
183 u8 type, int data)
184 {
185 struct sk_buff *skb;
186 struct nlattr *attr;
187 struct acpi_genl_event *event;
188 void *msg_header;
189 int size;
190 int result;
191
192 /* allocate memory */
193 size = nla_total_size(sizeof(struct acpi_genl_event)) +
194 nla_total_size(0);
195
196 skb = genlmsg_new(size, GFP_ATOMIC);
197 if (!skb)
198 return -ENOMEM;
199
200 /* add the genetlink message header */
201 msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
202 &acpi_event_genl_family, 0,
203 ACPI_GENL_CMD_EVENT);
204 if (!msg_header) {
205 nlmsg_free(skb);
206 return -ENOMEM;
207 }
208
209 /* fill the data */
210 attr =
211 nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
212 sizeof(struct acpi_genl_event));
213 if (!attr) {
214 nlmsg_free(skb);
215 return -EINVAL;
216 }
217
218 event = nla_data(attr);
219 if (!event) {
220 nlmsg_free(skb);
221 return -EINVAL;
222 }
223
224 memset(event, 0, sizeof(struct acpi_genl_event));
225
226 strcpy(event->device_class, device_class);
227 strcpy(event->bus_id, bus_id);
228 event->type = type;
229 event->data = data;
230
231 /* send multicast genetlink message */
232 result = genlmsg_end(skb, msg_header);
233 if (result < 0) {
234 nlmsg_free(skb);
235 return result;
236 }
237
238 genlmsg_multicast(skb, 0, acpi_event_mcgrp.id, GFP_ATOMIC);
239 return 0;
240 }
241
242 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
243
244 static int acpi_event_genetlink_init(void)
245 {
246 int result;
247
248 result = genl_register_family(&acpi_event_genl_family);
249 if (result)
250 return result;
251
252 result = genl_register_mc_group(&acpi_event_genl_family,
253 &acpi_event_mcgrp);
254 if (result)
255 genl_unregister_family(&acpi_event_genl_family);
256
257 return result;
258 }
259
260 #else
261 int acpi_bus_generate_netlink_event(const char *device_class,
262 const char *bus_id,
263 u8 type, int data)
264 {
265 return 0;
266 }
267
268 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
269
270 static int acpi_event_genetlink_init(void)
271 {
272 return -ENODEV;
273 }
274 #endif
275
276 static int __init acpi_event_init(void)
277 {
278 #ifdef CONFIG_ACPI_PROC_EVENT
279 struct proc_dir_entry *entry;
280 #endif
281 int error = 0;
282
283 if (acpi_disabled)
284 return 0;
285
286 /* create genetlink for acpi event */
287 error = acpi_event_genetlink_init();
288 if (error)
289 printk(KERN_WARNING PREFIX
290 "Failed to create genetlink family for ACPI event\n");
291
292 #ifdef CONFIG_ACPI_PROC_EVENT
293 /* 'event' [R] */
294 entry = proc_create("event", S_IRUSR, acpi_root_dir,
295 &acpi_system_event_ops);
296 if (!entry)
297 return -ENODEV;
298 #endif
299
300 return 0;
301 }
302
303 fs_initcall(acpi_event_init);
304
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