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