Commit | Line | Data |
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1b2b03f8 KK |
1 | /* |
2 | * | |
3 | * general timer device for using in ISDN stacks | |
4 | * | |
5 | * Author Karsten Keil <kkeil@novell.com> | |
6 | * | |
7 | * Copyright 2008 by Karsten Keil <kkeil@novell.com> | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License version 2 as | |
11 | * published by the Free Software Foundation. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | */ | |
19 | ||
20 | #include <linux/poll.h> | |
21 | #include <linux/vmalloc.h> | |
22 | #include <linux/timer.h> | |
23 | #include <linux/miscdevice.h> | |
24 | #include <linux/module.h> | |
25 | #include <linux/mISDNif.h> | |
26 | ||
27 | static int *debug; | |
28 | ||
29 | ||
30 | struct mISDNtimerdev { | |
31 | int next_id; | |
32 | struct list_head pending; | |
33 | struct list_head expired; | |
34 | wait_queue_head_t wait; | |
35 | u_int work; | |
36 | spinlock_t lock; /* protect lists */ | |
37 | }; | |
38 | ||
39 | struct mISDNtimer { | |
40 | struct list_head list; | |
41 | struct mISDNtimerdev *dev; | |
42 | struct timer_list tl; | |
43 | int id; | |
44 | }; | |
45 | ||
46 | static int | |
47 | mISDN_open(struct inode *ino, struct file *filep) | |
48 | { | |
49 | struct mISDNtimerdev *dev; | |
50 | ||
51 | if (*debug & DEBUG_TIMER) | |
52 | printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); | |
53 | dev = kmalloc(sizeof(struct mISDNtimerdev) , GFP_KERNEL); | |
54 | if (!dev) | |
55 | return -ENOMEM; | |
56 | dev->next_id = 1; | |
57 | INIT_LIST_HEAD(&dev->pending); | |
58 | INIT_LIST_HEAD(&dev->expired); | |
59 | spin_lock_init(&dev->lock); | |
60 | dev->work = 0; | |
61 | init_waitqueue_head(&dev->wait); | |
62 | filep->private_data = dev; | |
63 | __module_get(THIS_MODULE); | |
64 | return 0; | |
65 | } | |
66 | ||
67 | static int | |
68 | mISDN_close(struct inode *ino, struct file *filep) | |
69 | { | |
70 | struct mISDNtimerdev *dev = filep->private_data; | |
71 | struct mISDNtimer *timer, *next; | |
72 | ||
73 | if (*debug & DEBUG_TIMER) | |
74 | printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); | |
75 | list_for_each_entry_safe(timer, next, &dev->pending, list) { | |
76 | del_timer(&timer->tl); | |
77 | kfree(timer); | |
78 | } | |
79 | list_for_each_entry_safe(timer, next, &dev->expired, list) { | |
80 | kfree(timer); | |
81 | } | |
82 | kfree(dev); | |
83 | module_put(THIS_MODULE); | |
84 | return 0; | |
85 | } | |
86 | ||
87 | static ssize_t | |
88 | mISDN_read(struct file *filep, char *buf, size_t count, loff_t *off) | |
89 | { | |
90 | struct mISDNtimerdev *dev = filep->private_data; | |
91 | struct mISDNtimer *timer; | |
92 | u_long flags; | |
93 | int ret = 0; | |
94 | ||
95 | if (*debug & DEBUG_TIMER) | |
96 | printk(KERN_DEBUG "%s(%p, %p, %d, %p)\n", __func__, | |
97 | filep, buf, (int)count, off); | |
98 | if (*off != filep->f_pos) | |
99 | return -ESPIPE; | |
100 | ||
101 | if (list_empty(&dev->expired) && (dev->work == 0)) { | |
102 | if (filep->f_flags & O_NONBLOCK) | |
103 | return -EAGAIN; | |
104 | wait_event_interruptible(dev->wait, (dev->work || | |
105 | !list_empty(&dev->expired))); | |
106 | if (signal_pending(current)) | |
107 | return -ERESTARTSYS; | |
108 | } | |
109 | if (count < sizeof(int)) | |
110 | return -ENOSPC; | |
111 | if (dev->work) | |
112 | dev->work = 0; | |
113 | if (!list_empty(&dev->expired)) { | |
114 | spin_lock_irqsave(&dev->lock, flags); | |
115 | timer = (struct mISDNtimer *)dev->expired.next; | |
116 | list_del(&timer->list); | |
117 | spin_unlock_irqrestore(&dev->lock, flags); | |
118 | if (put_user(timer->id, (int *)buf)) | |
119 | ret = -EFAULT; | |
120 | else | |
121 | ret = sizeof(int); | |
122 | kfree(timer); | |
123 | } | |
124 | return ret; | |
125 | } | |
126 | ||
127 | static loff_t | |
128 | mISDN_llseek(struct file *filep, loff_t offset, int orig) | |
129 | { | |
130 | return -ESPIPE; | |
131 | } | |
132 | ||
133 | static ssize_t | |
134 | mISDN_write(struct file *filep, const char *buf, size_t count, loff_t *off) | |
135 | { | |
136 | return -EOPNOTSUPP; | |
137 | } | |
138 | ||
139 | static unsigned int | |
140 | mISDN_poll(struct file *filep, poll_table *wait) | |
141 | { | |
142 | struct mISDNtimerdev *dev = filep->private_data; | |
143 | unsigned int mask = POLLERR; | |
144 | ||
145 | if (*debug & DEBUG_TIMER) | |
146 | printk(KERN_DEBUG "%s(%p, %p)\n", __func__, filep, wait); | |
147 | if (dev) { | |
148 | poll_wait(filep, &dev->wait, wait); | |
149 | mask = 0; | |
150 | if (dev->work || !list_empty(&dev->expired)) | |
151 | mask |= (POLLIN | POLLRDNORM); | |
152 | if (*debug & DEBUG_TIMER) | |
153 | printk(KERN_DEBUG "%s work(%d) empty(%d)\n", __func__, | |
154 | dev->work, list_empty(&dev->expired)); | |
155 | } | |
156 | return mask; | |
157 | } | |
158 | ||
159 | static void | |
160 | dev_expire_timer(struct mISDNtimer *timer) | |
161 | { | |
162 | u_long flags; | |
163 | ||
164 | spin_lock_irqsave(&timer->dev->lock, flags); | |
165 | list_del(&timer->list); | |
166 | list_add_tail(&timer->list, &timer->dev->expired); | |
167 | spin_unlock_irqrestore(&timer->dev->lock, flags); | |
168 | wake_up_interruptible(&timer->dev->wait); | |
169 | } | |
170 | ||
171 | static int | |
172 | misdn_add_timer(struct mISDNtimerdev *dev, int timeout) | |
173 | { | |
174 | int id; | |
175 | u_long flags; | |
176 | struct mISDNtimer *timer; | |
177 | ||
178 | if (!timeout) { | |
179 | dev->work = 1; | |
180 | wake_up_interruptible(&dev->wait); | |
181 | id = 0; | |
182 | } else { | |
183 | timer = kzalloc(sizeof(struct mISDNtimer), GFP_KERNEL); | |
184 | if (!timer) | |
185 | return -ENOMEM; | |
186 | spin_lock_irqsave(&dev->lock, flags); | |
187 | timer->id = dev->next_id++; | |
188 | if (dev->next_id < 0) | |
189 | dev->next_id = 1; | |
190 | list_add_tail(&timer->list, &dev->pending); | |
191 | spin_unlock_irqrestore(&dev->lock, flags); | |
192 | timer->dev = dev; | |
193 | timer->tl.data = (long)timer; | |
194 | timer->tl.function = (void *) dev_expire_timer; | |
195 | init_timer(&timer->tl); | |
196 | timer->tl.expires = jiffies + ((HZ * (u_long)timeout) / 1000); | |
197 | add_timer(&timer->tl); | |
198 | id = timer->id; | |
199 | } | |
200 | return id; | |
201 | } | |
202 | ||
203 | static int | |
204 | misdn_del_timer(struct mISDNtimerdev *dev, int id) | |
205 | { | |
206 | u_long flags; | |
207 | struct mISDNtimer *timer; | |
208 | int ret = 0; | |
209 | ||
210 | spin_lock_irqsave(&dev->lock, flags); | |
211 | list_for_each_entry(timer, &dev->pending, list) { | |
212 | if (timer->id == id) { | |
213 | list_del_init(&timer->list); | |
214 | del_timer(&timer->tl); | |
215 | ret = timer->id; | |
216 | kfree(timer); | |
217 | goto unlock; | |
218 | } | |
219 | } | |
220 | unlock: | |
221 | spin_unlock_irqrestore(&dev->lock, flags); | |
222 | return ret; | |
223 | } | |
224 | ||
225 | static int | |
226 | mISDN_ioctl(struct inode *inode, struct file *filep, unsigned int cmd, | |
227 | unsigned long arg) | |
228 | { | |
229 | struct mISDNtimerdev *dev = filep->private_data; | |
230 | int id, tout, ret = 0; | |
231 | ||
232 | ||
233 | if (*debug & DEBUG_TIMER) | |
234 | printk(KERN_DEBUG "%s(%p, %x, %lx)\n", __func__, | |
235 | filep, cmd, arg); | |
236 | switch (cmd) { | |
237 | case IMADDTIMER: | |
238 | if (get_user(tout, (int __user *)arg)) { | |
239 | ret = -EFAULT; | |
240 | break; | |
241 | } | |
242 | id = misdn_add_timer(dev, tout); | |
243 | if (*debug & DEBUG_TIMER) | |
244 | printk(KERN_DEBUG "%s add %d id %d\n", __func__, | |
245 | tout, id); | |
246 | if (id < 0) { | |
247 | ret = id; | |
248 | break; | |
249 | } | |
250 | if (put_user(id, (int __user *)arg)) | |
251 | ret = -EFAULT; | |
252 | break; | |
253 | case IMDELTIMER: | |
254 | if (get_user(id, (int __user *)arg)) { | |
255 | ret = -EFAULT; | |
256 | break; | |
257 | } | |
258 | if (*debug & DEBUG_TIMER) | |
259 | printk(KERN_DEBUG "%s del id %d\n", __func__, id); | |
260 | id = misdn_del_timer(dev, id); | |
261 | if (put_user(id, (int __user *)arg)) | |
262 | ret = -EFAULT; | |
263 | break; | |
264 | default: | |
265 | ret = -EINVAL; | |
266 | } | |
267 | return ret; | |
268 | } | |
269 | ||
270 | static struct file_operations mISDN_fops = { | |
271 | .llseek = mISDN_llseek, | |
272 | .read = mISDN_read, | |
273 | .write = mISDN_write, | |
274 | .poll = mISDN_poll, | |
275 | .ioctl = mISDN_ioctl, | |
276 | .open = mISDN_open, | |
277 | .release = mISDN_close, | |
278 | }; | |
279 | ||
280 | static struct miscdevice mISDNtimer = { | |
281 | .minor = MISC_DYNAMIC_MINOR, | |
282 | .name = "mISDNtimer", | |
283 | .fops = &mISDN_fops, | |
284 | }; | |
285 | ||
286 | int | |
287 | mISDN_inittimer(int *deb) | |
288 | { | |
289 | int err; | |
290 | ||
291 | debug = deb; | |
292 | err = misc_register(&mISDNtimer); | |
293 | if (err) | |
294 | printk(KERN_WARNING "mISDN: Could not register timer device\n"); | |
295 | return err; | |
296 | } | |
297 | ||
298 | void mISDN_timer_cleanup(void) | |
299 | { | |
300 | misc_deregister(&mISDNtimer); | |
301 | } |