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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> | |
5a0e3ad6 | 22 | #include <linux/slab.h> |
1b2b03f8 KK |
23 | #include <linux/timer.h> |
24 | #include <linux/miscdevice.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/mISDNif.h> | |
76a64921 | 27 | #include <linux/mutex.h> |
5b834354 | 28 | #include "core.h" |
1b2b03f8 | 29 | |
76a64921 | 30 | static DEFINE_MUTEX(mISDN_mutex); |
dfa96ec1 | 31 | static u_int *debug; |
1b2b03f8 KK |
32 | |
33 | ||
34 | struct mISDNtimerdev { | |
35 | int next_id; | |
36 | struct list_head pending; | |
37 | struct list_head expired; | |
38 | wait_queue_head_t wait; | |
39 | u_int work; | |
40 | spinlock_t lock; /* protect lists */ | |
41 | }; | |
42 | ||
43 | struct mISDNtimer { | |
44 | struct list_head list; | |
45 | struct mISDNtimerdev *dev; | |
46 | struct timer_list tl; | |
47 | int id; | |
48 | }; | |
49 | ||
50 | static int | |
51 | mISDN_open(struct inode *ino, struct file *filep) | |
52 | { | |
53 | struct mISDNtimerdev *dev; | |
54 | ||
55 | if (*debug & DEBUG_TIMER) | |
56 | printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); | |
57 | dev = kmalloc(sizeof(struct mISDNtimerdev) , GFP_KERNEL); | |
58 | if (!dev) | |
59 | return -ENOMEM; | |
60 | dev->next_id = 1; | |
61 | INIT_LIST_HEAD(&dev->pending); | |
62 | INIT_LIST_HEAD(&dev->expired); | |
63 | spin_lock_init(&dev->lock); | |
64 | dev->work = 0; | |
65 | init_waitqueue_head(&dev->wait); | |
66 | filep->private_data = dev; | |
67 | __module_get(THIS_MODULE); | |
6bff338b | 68 | return nonseekable_open(ino, filep); |
1b2b03f8 KK |
69 | } |
70 | ||
71 | static int | |
72 | mISDN_close(struct inode *ino, struct file *filep) | |
73 | { | |
74 | struct mISDNtimerdev *dev = filep->private_data; | |
75 | struct mISDNtimer *timer, *next; | |
76 | ||
77 | if (*debug & DEBUG_TIMER) | |
78 | printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); | |
79 | list_for_each_entry_safe(timer, next, &dev->pending, list) { | |
80 | del_timer(&timer->tl); | |
81 | kfree(timer); | |
82 | } | |
83 | list_for_each_entry_safe(timer, next, &dev->expired, list) { | |
84 | kfree(timer); | |
85 | } | |
86 | kfree(dev); | |
87 | module_put(THIS_MODULE); | |
88 | return 0; | |
89 | } | |
90 | ||
91 | static ssize_t | |
c46f0a2d | 92 | mISDN_read(struct file *filep, char __user *buf, size_t count, loff_t *off) |
1b2b03f8 KK |
93 | { |
94 | struct mISDNtimerdev *dev = filep->private_data; | |
95 | struct mISDNtimer *timer; | |
96 | u_long flags; | |
97 | int ret = 0; | |
98 | ||
99 | if (*debug & DEBUG_TIMER) | |
100 | printk(KERN_DEBUG "%s(%p, %p, %d, %p)\n", __func__, | |
475be4d8 | 101 | filep, buf, (int)count, off); |
1b2b03f8 KK |
102 | |
103 | if (list_empty(&dev->expired) && (dev->work == 0)) { | |
104 | if (filep->f_flags & O_NONBLOCK) | |
105 | return -EAGAIN; | |
106 | wait_event_interruptible(dev->wait, (dev->work || | |
475be4d8 | 107 | !list_empty(&dev->expired))); |
1b2b03f8 KK |
108 | if (signal_pending(current)) |
109 | return -ERESTARTSYS; | |
110 | } | |
111 | if (count < sizeof(int)) | |
112 | return -ENOSPC; | |
113 | if (dev->work) | |
114 | dev->work = 0; | |
115 | if (!list_empty(&dev->expired)) { | |
116 | spin_lock_irqsave(&dev->lock, flags); | |
117 | timer = (struct mISDNtimer *)dev->expired.next; | |
118 | list_del(&timer->list); | |
119 | spin_unlock_irqrestore(&dev->lock, flags); | |
c46f0a2d | 120 | if (put_user(timer->id, (int __user *)buf)) |
1b2b03f8 KK |
121 | ret = -EFAULT; |
122 | else | |
123 | ret = sizeof(int); | |
124 | kfree(timer); | |
125 | } | |
126 | return ret; | |
127 | } | |
128 | ||
1b2b03f8 KK |
129 | static unsigned int |
130 | mISDN_poll(struct file *filep, poll_table *wait) | |
131 | { | |
132 | struct mISDNtimerdev *dev = filep->private_data; | |
133 | unsigned int mask = POLLERR; | |
134 | ||
135 | if (*debug & DEBUG_TIMER) | |
136 | printk(KERN_DEBUG "%s(%p, %p)\n", __func__, filep, wait); | |
137 | if (dev) { | |
138 | poll_wait(filep, &dev->wait, wait); | |
139 | mask = 0; | |
140 | if (dev->work || !list_empty(&dev->expired)) | |
141 | mask |= (POLLIN | POLLRDNORM); | |
142 | if (*debug & DEBUG_TIMER) | |
143 | printk(KERN_DEBUG "%s work(%d) empty(%d)\n", __func__, | |
475be4d8 | 144 | dev->work, list_empty(&dev->expired)); |
1b2b03f8 KK |
145 | } |
146 | return mask; | |
147 | } | |
148 | ||
149 | static void | |
ce425a9f | 150 | dev_expire_timer(unsigned long data) |
1b2b03f8 | 151 | { |
ce425a9f | 152 | struct mISDNtimer *timer = (void *)data; |
1b2b03f8 KK |
153 | u_long flags; |
154 | ||
155 | spin_lock_irqsave(&timer->dev->lock, flags); | |
211174ea | 156 | list_move_tail(&timer->list, &timer->dev->expired); |
1b2b03f8 KK |
157 | spin_unlock_irqrestore(&timer->dev->lock, flags); |
158 | wake_up_interruptible(&timer->dev->wait); | |
159 | } | |
160 | ||
161 | static int | |
162 | misdn_add_timer(struct mISDNtimerdev *dev, int timeout) | |
163 | { | |
475be4d8 | 164 | int id; |
1b2b03f8 KK |
165 | u_long flags; |
166 | struct mISDNtimer *timer; | |
167 | ||
168 | if (!timeout) { | |
169 | dev->work = 1; | |
170 | wake_up_interruptible(&dev->wait); | |
171 | id = 0; | |
172 | } else { | |
173 | timer = kzalloc(sizeof(struct mISDNtimer), GFP_KERNEL); | |
174 | if (!timer) | |
175 | return -ENOMEM; | |
176 | spin_lock_irqsave(&dev->lock, flags); | |
177 | timer->id = dev->next_id++; | |
178 | if (dev->next_id < 0) | |
179 | dev->next_id = 1; | |
180 | list_add_tail(&timer->list, &dev->pending); | |
181 | spin_unlock_irqrestore(&dev->lock, flags); | |
182 | timer->dev = dev; | |
183 | timer->tl.data = (long)timer; | |
ce425a9f | 184 | timer->tl.function = dev_expire_timer; |
1b2b03f8 KK |
185 | init_timer(&timer->tl); |
186 | timer->tl.expires = jiffies + ((HZ * (u_long)timeout) / 1000); | |
187 | add_timer(&timer->tl); | |
188 | id = timer->id; | |
189 | } | |
190 | return id; | |
191 | } | |
192 | ||
193 | static int | |
194 | misdn_del_timer(struct mISDNtimerdev *dev, int id) | |
195 | { | |
196 | u_long flags; | |
197 | struct mISDNtimer *timer; | |
198 | int ret = 0; | |
199 | ||
200 | spin_lock_irqsave(&dev->lock, flags); | |
201 | list_for_each_entry(timer, &dev->pending, list) { | |
202 | if (timer->id == id) { | |
203 | list_del_init(&timer->list); | |
ce425a9f AK |
204 | /* RED-PEN AK: race -- timer can be still running on |
205 | * other CPU. Needs reference count I think | |
206 | */ | |
1b2b03f8 KK |
207 | del_timer(&timer->tl); |
208 | ret = timer->id; | |
209 | kfree(timer); | |
210 | goto unlock; | |
211 | } | |
212 | } | |
213 | unlock: | |
214 | spin_unlock_irqrestore(&dev->lock, flags); | |
215 | return ret; | |
216 | } | |
217 | ||
703c631e AB |
218 | static long |
219 | mISDN_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) | |
1b2b03f8 KK |
220 | { |
221 | struct mISDNtimerdev *dev = filep->private_data; | |
222 | int id, tout, ret = 0; | |
223 | ||
224 | ||
225 | if (*debug & DEBUG_TIMER) | |
226 | printk(KERN_DEBUG "%s(%p, %x, %lx)\n", __func__, | |
475be4d8 | 227 | filep, cmd, arg); |
76a64921 | 228 | mutex_lock(&mISDN_mutex); |
1b2b03f8 KK |
229 | switch (cmd) { |
230 | case IMADDTIMER: | |
231 | if (get_user(tout, (int __user *)arg)) { | |
232 | ret = -EFAULT; | |
233 | break; | |
234 | } | |
235 | id = misdn_add_timer(dev, tout); | |
236 | if (*debug & DEBUG_TIMER) | |
237 | printk(KERN_DEBUG "%s add %d id %d\n", __func__, | |
475be4d8 | 238 | tout, id); |
1b2b03f8 KK |
239 | if (id < 0) { |
240 | ret = id; | |
241 | break; | |
242 | } | |
243 | if (put_user(id, (int __user *)arg)) | |
244 | ret = -EFAULT; | |
245 | break; | |
246 | case IMDELTIMER: | |
247 | if (get_user(id, (int __user *)arg)) { | |
248 | ret = -EFAULT; | |
249 | break; | |
250 | } | |
251 | if (*debug & DEBUG_TIMER) | |
252 | printk(KERN_DEBUG "%s del id %d\n", __func__, id); | |
253 | id = misdn_del_timer(dev, id); | |
254 | if (put_user(id, (int __user *)arg)) | |
255 | ret = -EFAULT; | |
256 | break; | |
257 | default: | |
258 | ret = -EINVAL; | |
259 | } | |
76a64921 | 260 | mutex_unlock(&mISDN_mutex); |
1b2b03f8 KK |
261 | return ret; |
262 | } | |
263 | ||
eac74af9 | 264 | static const struct file_operations mISDN_fops = { |
1b2b03f8 | 265 | .read = mISDN_read, |
1b2b03f8 | 266 | .poll = mISDN_poll, |
703c631e | 267 | .unlocked_ioctl = mISDN_ioctl, |
1b2b03f8 KK |
268 | .open = mISDN_open, |
269 | .release = mISDN_close, | |
6038f373 | 270 | .llseek = no_llseek, |
1b2b03f8 KK |
271 | }; |
272 | ||
273 | static struct miscdevice mISDNtimer = { | |
274 | .minor = MISC_DYNAMIC_MINOR, | |
275 | .name = "mISDNtimer", | |
276 | .fops = &mISDN_fops, | |
277 | }; | |
278 | ||
279 | int | |
dfa96ec1 | 280 | mISDN_inittimer(u_int *deb) |
1b2b03f8 KK |
281 | { |
282 | int err; | |
283 | ||
284 | debug = deb; | |
285 | err = misc_register(&mISDNtimer); | |
286 | if (err) | |
287 | printk(KERN_WARNING "mISDN: Could not register timer device\n"); | |
288 | return err; | |
289 | } | |
290 | ||
291 | void mISDN_timer_cleanup(void) | |
292 | { | |
293 | misc_deregister(&mISDNtimer); | |
294 | } |