Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 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> |
Hannes Eder | 5b83435 | 2008-12-12 21:15:17 -0800 | [diff] [blame] | 26 | #include "core.h" |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 27 | |
Hannes Eder | dfa96ec | 2008-12-12 21:13:45 -0800 | [diff] [blame] | 28 | static u_int *debug; |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 29 | |
| 30 | |
| 31 | struct mISDNtimerdev { |
| 32 | int next_id; |
| 33 | struct list_head pending; |
| 34 | struct list_head expired; |
| 35 | wait_queue_head_t wait; |
| 36 | u_int work; |
| 37 | spinlock_t lock; /* protect lists */ |
| 38 | }; |
| 39 | |
| 40 | struct mISDNtimer { |
| 41 | struct list_head list; |
| 42 | struct mISDNtimerdev *dev; |
| 43 | struct timer_list tl; |
| 44 | int id; |
| 45 | }; |
| 46 | |
| 47 | static int |
| 48 | mISDN_open(struct inode *ino, struct file *filep) |
| 49 | { |
| 50 | struct mISDNtimerdev *dev; |
| 51 | |
| 52 | if (*debug & DEBUG_TIMER) |
| 53 | printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); |
| 54 | dev = kmalloc(sizeof(struct mISDNtimerdev) , GFP_KERNEL); |
| 55 | if (!dev) |
| 56 | return -ENOMEM; |
| 57 | dev->next_id = 1; |
| 58 | INIT_LIST_HEAD(&dev->pending); |
| 59 | INIT_LIST_HEAD(&dev->expired); |
| 60 | spin_lock_init(&dev->lock); |
| 61 | dev->work = 0; |
| 62 | init_waitqueue_head(&dev->wait); |
| 63 | filep->private_data = dev; |
| 64 | __module_get(THIS_MODULE); |
Andrew Morton | 6bff338 | 2008-10-13 18:42:07 -0700 | [diff] [blame] | 65 | return nonseekable_open(ino, filep); |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 66 | } |
| 67 | |
| 68 | static int |
| 69 | mISDN_close(struct inode *ino, struct file *filep) |
| 70 | { |
| 71 | struct mISDNtimerdev *dev = filep->private_data; |
| 72 | struct mISDNtimer *timer, *next; |
| 73 | |
| 74 | if (*debug & DEBUG_TIMER) |
| 75 | printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); |
| 76 | list_for_each_entry_safe(timer, next, &dev->pending, list) { |
| 77 | del_timer(&timer->tl); |
| 78 | kfree(timer); |
| 79 | } |
| 80 | list_for_each_entry_safe(timer, next, &dev->expired, list) { |
| 81 | kfree(timer); |
| 82 | } |
| 83 | kfree(dev); |
| 84 | module_put(THIS_MODULE); |
| 85 | return 0; |
| 86 | } |
| 87 | |
| 88 | static ssize_t |
Hannes Eder | c46f0a2 | 2008-12-12 21:19:18 -0800 | [diff] [blame^] | 89 | mISDN_read(struct file *filep, char __user *buf, size_t count, loff_t *off) |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 90 | { |
| 91 | struct mISDNtimerdev *dev = filep->private_data; |
| 92 | struct mISDNtimer *timer; |
| 93 | u_long flags; |
| 94 | int ret = 0; |
| 95 | |
| 96 | if (*debug & DEBUG_TIMER) |
| 97 | printk(KERN_DEBUG "%s(%p, %p, %d, %p)\n", __func__, |
| 98 | filep, buf, (int)count, off); |
| 99 | if (*off != filep->f_pos) |
| 100 | return -ESPIPE; |
| 101 | |
| 102 | if (list_empty(&dev->expired) && (dev->work == 0)) { |
| 103 | if (filep->f_flags & O_NONBLOCK) |
| 104 | return -EAGAIN; |
| 105 | wait_event_interruptible(dev->wait, (dev->work || |
| 106 | !list_empty(&dev->expired))); |
| 107 | if (signal_pending(current)) |
| 108 | return -ERESTARTSYS; |
| 109 | } |
| 110 | if (count < sizeof(int)) |
| 111 | return -ENOSPC; |
| 112 | if (dev->work) |
| 113 | dev->work = 0; |
| 114 | if (!list_empty(&dev->expired)) { |
| 115 | spin_lock_irqsave(&dev->lock, flags); |
| 116 | timer = (struct mISDNtimer *)dev->expired.next; |
| 117 | list_del(&timer->list); |
| 118 | spin_unlock_irqrestore(&dev->lock, flags); |
Hannes Eder | c46f0a2 | 2008-12-12 21:19:18 -0800 | [diff] [blame^] | 119 | if (put_user(timer->id, (int __user *)buf)) |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 120 | ret = -EFAULT; |
| 121 | else |
| 122 | ret = sizeof(int); |
| 123 | kfree(timer); |
| 124 | } |
| 125 | return ret; |
| 126 | } |
| 127 | |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 128 | static unsigned int |
| 129 | mISDN_poll(struct file *filep, poll_table *wait) |
| 130 | { |
| 131 | struct mISDNtimerdev *dev = filep->private_data; |
| 132 | unsigned int mask = POLLERR; |
| 133 | |
| 134 | if (*debug & DEBUG_TIMER) |
| 135 | printk(KERN_DEBUG "%s(%p, %p)\n", __func__, filep, wait); |
| 136 | if (dev) { |
| 137 | poll_wait(filep, &dev->wait, wait); |
| 138 | mask = 0; |
| 139 | if (dev->work || !list_empty(&dev->expired)) |
| 140 | mask |= (POLLIN | POLLRDNORM); |
| 141 | if (*debug & DEBUG_TIMER) |
| 142 | printk(KERN_DEBUG "%s work(%d) empty(%d)\n", __func__, |
| 143 | dev->work, list_empty(&dev->expired)); |
| 144 | } |
| 145 | return mask; |
| 146 | } |
| 147 | |
| 148 | static void |
Andi Kleen | ce425a9 | 2008-09-22 19:18:15 -0700 | [diff] [blame] | 149 | dev_expire_timer(unsigned long data) |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 150 | { |
Andi Kleen | ce425a9 | 2008-09-22 19:18:15 -0700 | [diff] [blame] | 151 | struct mISDNtimer *timer = (void *)data; |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 152 | u_long flags; |
| 153 | |
| 154 | spin_lock_irqsave(&timer->dev->lock, flags); |
| 155 | list_del(&timer->list); |
| 156 | list_add_tail(&timer->list, &timer->dev->expired); |
| 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 | { |
| 164 | int id; |
| 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; |
Andi Kleen | ce425a9 | 2008-09-22 19:18:15 -0700 | [diff] [blame] | 184 | timer->tl.function = dev_expire_timer; |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 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); |
Andi Kleen | ce425a9 | 2008-09-22 19:18:15 -0700 | [diff] [blame] | 204 | /* RED-PEN AK: race -- timer can be still running on |
| 205 | * other CPU. Needs reference count I think |
| 206 | */ |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 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 | |
| 218 | static int |
| 219 | mISDN_ioctl(struct inode *inode, struct file *filep, unsigned int cmd, |
| 220 | unsigned long arg) |
| 221 | { |
| 222 | struct mISDNtimerdev *dev = filep->private_data; |
| 223 | int id, tout, ret = 0; |
| 224 | |
| 225 | |
| 226 | if (*debug & DEBUG_TIMER) |
| 227 | printk(KERN_DEBUG "%s(%p, %x, %lx)\n", __func__, |
| 228 | filep, cmd, arg); |
| 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__, |
| 238 | tout, id); |
| 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 | } |
| 260 | return ret; |
| 261 | } |
| 262 | |
| 263 | static struct file_operations mISDN_fops = { |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 264 | .read = mISDN_read, |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 265 | .poll = mISDN_poll, |
| 266 | .ioctl = mISDN_ioctl, |
| 267 | .open = mISDN_open, |
| 268 | .release = mISDN_close, |
| 269 | }; |
| 270 | |
| 271 | static struct miscdevice mISDNtimer = { |
| 272 | .minor = MISC_DYNAMIC_MINOR, |
| 273 | .name = "mISDNtimer", |
| 274 | .fops = &mISDN_fops, |
| 275 | }; |
| 276 | |
| 277 | int |
Hannes Eder | dfa96ec | 2008-12-12 21:13:45 -0800 | [diff] [blame] | 278 | mISDN_inittimer(u_int *deb) |
Karsten Keil | 1b2b03f | 2008-07-27 01:54:58 +0200 | [diff] [blame] | 279 | { |
| 280 | int err; |
| 281 | |
| 282 | debug = deb; |
| 283 | err = misc_register(&mISDNtimer); |
| 284 | if (err) |
| 285 | printk(KERN_WARNING "mISDN: Could not register timer device\n"); |
| 286 | return err; |
| 287 | } |
| 288 | |
| 289 | void mISDN_timer_cleanup(void) |
| 290 | { |
| 291 | misc_deregister(&mISDNtimer); |
| 292 | } |