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 <linux/gfp.h>
14 #include <acpi/acpi_drivers.h>
15 #include <net/netlink.h>
16 #include <net/genetlink.h>
17
18 #include "internal.h"
19
20 #define _COMPONENT ACPI_SYSTEM_COMPONENT
21 ACPI_MODULE_NAME("event");
22
23 #ifdef CONFIG_ACPI_PROC_EVENT
24 /* Global vars for handling event proc entry */
25 static DEFINE_SPINLOCK(acpi_system_event_lock);
26 int event_is_open = 0;
27 extern struct list_head acpi_bus_event_list;
28 extern wait_queue_head_t acpi_bus_event_queue;
29
acpi_system_open_event(struct inode * inode,struct file * file)30 static int acpi_system_open_event(struct inode *inode, struct file *file)
31 {
32 spin_lock_irq(&acpi_system_event_lock);
33
34 if (event_is_open)
35 goto out_busy;
36
37 event_is_open = 1;
38
39 spin_unlock_irq(&acpi_system_event_lock);
40 return 0;
41
42 out_busy:
43 spin_unlock_irq(&acpi_system_event_lock);
44 return -EBUSY;
45 }
46
47 static ssize_t
acpi_system_read_event(struct file * file,char __user * buffer,size_t count,loff_t * ppos)48 acpi_system_read_event(struct file *file, char __user * buffer, size_t count,
49 loff_t * ppos)
50 {
51 int result = 0;
52 struct acpi_bus_event event;
53 static char str[ACPI_MAX_STRING];
54 static int chars_remaining = 0;
55 static char *ptr;
56
57 if (!chars_remaining) {
58 memset(&event, 0, sizeof(struct acpi_bus_event));
59
60 if ((file->f_flags & O_NONBLOCK)
61 && (list_empty(&acpi_bus_event_list)))
62 return -EAGAIN;
63
64 result = acpi_bus_receive_event(&event);
65 if (result)
66 return result;
67
68 chars_remaining = sprintf(str, "%s %s %08x %08x\n",
69 event.device_class ? event.
70 device_class : "<unknown>",
71 event.bus_id ? event.
72 bus_id : "<unknown>", event.type,
73 event.data);
74 ptr = str;
75 }
76
77 if (chars_remaining < count) {
78 count = chars_remaining;
79 }
80
81 if (copy_to_user(buffer, ptr, count))
82 return -EFAULT;
83
84 *ppos += count;
85 chars_remaining -= count;
86 ptr += count;
87
88 return count;
89 }
90
acpi_system_close_event(struct inode * inode,struct file * file)91 static int acpi_system_close_event(struct inode *inode, struct file *file)
92 {
93 spin_lock_irq(&acpi_system_event_lock);
94 event_is_open = 0;
95 spin_unlock_irq(&acpi_system_event_lock);
96 return 0;
97 }
98
acpi_system_poll_event(struct file * file,poll_table * wait)99 static unsigned int acpi_system_poll_event(struct file *file, poll_table * wait)
100 {
101 poll_wait(file, &acpi_bus_event_queue, wait);
102 if (!list_empty(&acpi_bus_event_list))
103 return POLLIN | POLLRDNORM;
104 return 0;
105 }
106
107 static const struct file_operations acpi_system_event_ops = {
108 .owner = THIS_MODULE,
109 .open = acpi_system_open_event,
110 .read = acpi_system_read_event,
111 .release = acpi_system_close_event,
112 .poll = acpi_system_poll_event,
113 .llseek = default_llseek,
114 };
115 #endif /* CONFIG_ACPI_PROC_EVENT */
116
117 /* ACPI notifier chain */
118 static BLOCKING_NOTIFIER_HEAD(acpi_chain_head);
119
acpi_notifier_call_chain(struct acpi_device * dev,u32 type,u32 data)120 int acpi_notifier_call_chain(struct acpi_device *dev, u32 type, u32 data)
121 {
122 struct acpi_bus_event event;
123
124 strcpy(event.device_class, dev->pnp.device_class);
125 strcpy(event.bus_id, dev->pnp.bus_id);
126 event.type = type;
127 event.data = data;
128 return (blocking_notifier_call_chain(&acpi_chain_head, 0, (void *)&event)
129 == NOTIFY_BAD) ? -EINVAL : 0;
130 }
131 EXPORT_SYMBOL(acpi_notifier_call_chain);
132
register_acpi_notifier(struct notifier_block * nb)133 int register_acpi_notifier(struct notifier_block *nb)
134 {
135 return blocking_notifier_chain_register(&acpi_chain_head, nb);
136 }
137 EXPORT_SYMBOL(register_acpi_notifier);
138
unregister_acpi_notifier(struct notifier_block * nb)139 int unregister_acpi_notifier(struct notifier_block *nb)
140 {
141 return blocking_notifier_chain_unregister(&acpi_chain_head, nb);
142 }
143 EXPORT_SYMBOL(unregister_acpi_notifier);
144
145 #ifdef CONFIG_NET
146 static unsigned int acpi_event_seqnum;
147 struct acpi_genl_event {
148 acpi_device_class device_class;
149 char bus_id[15];
150 u32 type;
151 u32 data;
152 };
153
154 /* attributes of acpi_genl_family */
155 enum {
156 ACPI_GENL_ATTR_UNSPEC,
157 ACPI_GENL_ATTR_EVENT, /* ACPI event info needed by user space */
158 __ACPI_GENL_ATTR_MAX,
159 };
160 #define ACPI_GENL_ATTR_MAX (__ACPI_GENL_ATTR_MAX - 1)
161
162 /* commands supported by the acpi_genl_family */
163 enum {
164 ACPI_GENL_CMD_UNSPEC,
165 ACPI_GENL_CMD_EVENT, /* kernel->user notifications for ACPI events */
166 __ACPI_GENL_CMD_MAX,
167 };
168 #define ACPI_GENL_CMD_MAX (__ACPI_GENL_CMD_MAX - 1)
169
170 #define ACPI_GENL_FAMILY_NAME "acpi_event"
171 #define ACPI_GENL_VERSION 0x01
172 #define ACPI_GENL_MCAST_GROUP_NAME "acpi_mc_group"
173
174 static struct genl_family acpi_event_genl_family = {
175 .id = GENL_ID_GENERATE,
176 .name = ACPI_GENL_FAMILY_NAME,
177 .version = ACPI_GENL_VERSION,
178 .maxattr = ACPI_GENL_ATTR_MAX,
179 };
180
181 static struct genl_multicast_group acpi_event_mcgrp = {
182 .name = ACPI_GENL_MCAST_GROUP_NAME,
183 };
184
acpi_bus_generate_netlink_event(const char * device_class,const char * bus_id,u8 type,int data)185 int acpi_bus_generate_netlink_event(const char *device_class,
186 const char *bus_id,
187 u8 type, int data)
188 {
189 struct sk_buff *skb;
190 struct nlattr *attr;
191 struct acpi_genl_event *event;
192 void *msg_header;
193 int size;
194 int result;
195
196 /* allocate memory */
197 size = nla_total_size(sizeof(struct acpi_genl_event)) +
198 nla_total_size(0);
199
200 skb = genlmsg_new(size, GFP_ATOMIC);
201 if (!skb)
202 return -ENOMEM;
203
204 /* add the genetlink message header */
205 msg_header = genlmsg_put(skb, 0, acpi_event_seqnum++,
206 &acpi_event_genl_family, 0,
207 ACPI_GENL_CMD_EVENT);
208 if (!msg_header) {
209 nlmsg_free(skb);
210 return -ENOMEM;
211 }
212
213 /* fill the data */
214 attr =
215 nla_reserve(skb, ACPI_GENL_ATTR_EVENT,
216 sizeof(struct acpi_genl_event));
217 if (!attr) {
218 nlmsg_free(skb);
219 return -EINVAL;
220 }
221
222 event = nla_data(attr);
223 if (!event) {
224 nlmsg_free(skb);
225 return -EINVAL;
226 }
227
228 memset(event, 0, sizeof(struct acpi_genl_event));
229
230 strcpy(event->device_class, device_class);
231 strcpy(event->bus_id, bus_id);
232 event->type = type;
233 event->data = data;
234
235 /* send multicast genetlink message */
236 result = genlmsg_end(skb, msg_header);
237 if (result < 0) {
238 nlmsg_free(skb);
239 return result;
240 }
241
242 genlmsg_multicast(skb, 0, acpi_event_mcgrp.id, GFP_ATOMIC);
243 return 0;
244 }
245
246 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
247
acpi_event_genetlink_init(void)248 static int acpi_event_genetlink_init(void)
249 {
250 int result;
251
252 result = genl_register_family(&acpi_event_genl_family);
253 if (result)
254 return result;
255
256 result = genl_register_mc_group(&acpi_event_genl_family,
257 &acpi_event_mcgrp);
258 if (result)
259 genl_unregister_family(&acpi_event_genl_family);
260
261 return result;
262 }
263
264 #else
acpi_bus_generate_netlink_event(const char * device_class,const char * bus_id,u8 type,int data)265 int acpi_bus_generate_netlink_event(const char *device_class,
266 const char *bus_id,
267 u8 type, int data)
268 {
269 return 0;
270 }
271
272 EXPORT_SYMBOL(acpi_bus_generate_netlink_event);
273
acpi_event_genetlink_init(void)274 static int acpi_event_genetlink_init(void)
275 {
276 return -ENODEV;
277 }
278 #endif
279
acpi_event_init(void)280 static int __init acpi_event_init(void)
281 {
282 #ifdef CONFIG_ACPI_PROC_EVENT
283 struct proc_dir_entry *entry;
284 #endif
285 int error = 0;
286
287 if (acpi_disabled)
288 return 0;
289
290 /* create genetlink for acpi event */
291 error = acpi_event_genetlink_init();
292 if (error)
293 printk(KERN_WARNING PREFIX
294 "Failed to create genetlink family for ACPI event\n");
295
296 #ifdef CONFIG_ACPI_PROC_EVENT
297 /* 'event' [R] */
298 entry = proc_create("event", S_IRUSR, acpi_root_dir,
299 &acpi_system_event_ops);
300 if (!entry)
301 return -ENODEV;
302 #endif
303
304 return 0;
305 }
306
307 fs_initcall(acpi_event_init);
308