11b2b03f8SKarsten Keil /* 21b2b03f8SKarsten Keil * 31b2b03f8SKarsten Keil * general timer device for using in ISDN stacks 41b2b03f8SKarsten Keil * 51b2b03f8SKarsten Keil * Author Karsten Keil <kkeil@novell.com> 61b2b03f8SKarsten Keil * 71b2b03f8SKarsten Keil * Copyright 2008 by Karsten Keil <kkeil@novell.com> 81b2b03f8SKarsten Keil * 91b2b03f8SKarsten Keil * This program is free software; you can redistribute it and/or modify 101b2b03f8SKarsten Keil * it under the terms of the GNU General Public License version 2 as 111b2b03f8SKarsten Keil * published by the Free Software Foundation. 121b2b03f8SKarsten Keil * 131b2b03f8SKarsten Keil * This program is distributed in the hope that it will be useful, 141b2b03f8SKarsten Keil * but WITHOUT ANY WARRANTY; without even the implied warranty of 151b2b03f8SKarsten Keil * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 161b2b03f8SKarsten Keil * GNU General Public License for more details. 171b2b03f8SKarsten Keil * 181b2b03f8SKarsten Keil */ 191b2b03f8SKarsten Keil 201b2b03f8SKarsten Keil #include <linux/poll.h> 211b2b03f8SKarsten Keil #include <linux/vmalloc.h> 225a0e3ad6STejun Heo #include <linux/slab.h> 231b2b03f8SKarsten Keil #include <linux/timer.h> 241b2b03f8SKarsten Keil #include <linux/miscdevice.h> 251b2b03f8SKarsten Keil #include <linux/module.h> 261b2b03f8SKarsten Keil #include <linux/mISDNif.h> 27703c631eSArnd Bergmann #include <linux/smp_lock.h> 285b834354SHannes Eder #include "core.h" 291b2b03f8SKarsten Keil 30dfa96ec1SHannes Eder static u_int *debug; 311b2b03f8SKarsten Keil 321b2b03f8SKarsten Keil 331b2b03f8SKarsten Keil struct mISDNtimerdev { 341b2b03f8SKarsten Keil int next_id; 351b2b03f8SKarsten Keil struct list_head pending; 361b2b03f8SKarsten Keil struct list_head expired; 371b2b03f8SKarsten Keil wait_queue_head_t wait; 381b2b03f8SKarsten Keil u_int work; 391b2b03f8SKarsten Keil spinlock_t lock; /* protect lists */ 401b2b03f8SKarsten Keil }; 411b2b03f8SKarsten Keil 421b2b03f8SKarsten Keil struct mISDNtimer { 431b2b03f8SKarsten Keil struct list_head list; 441b2b03f8SKarsten Keil struct mISDNtimerdev *dev; 451b2b03f8SKarsten Keil struct timer_list tl; 461b2b03f8SKarsten Keil int id; 471b2b03f8SKarsten Keil }; 481b2b03f8SKarsten Keil 491b2b03f8SKarsten Keil static int 501b2b03f8SKarsten Keil mISDN_open(struct inode *ino, struct file *filep) 511b2b03f8SKarsten Keil { 521b2b03f8SKarsten Keil struct mISDNtimerdev *dev; 531b2b03f8SKarsten Keil 541b2b03f8SKarsten Keil if (*debug & DEBUG_TIMER) 551b2b03f8SKarsten Keil printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); 561b2b03f8SKarsten Keil dev = kmalloc(sizeof(struct mISDNtimerdev) , GFP_KERNEL); 571b2b03f8SKarsten Keil if (!dev) 581b2b03f8SKarsten Keil return -ENOMEM; 591b2b03f8SKarsten Keil dev->next_id = 1; 601b2b03f8SKarsten Keil INIT_LIST_HEAD(&dev->pending); 611b2b03f8SKarsten Keil INIT_LIST_HEAD(&dev->expired); 621b2b03f8SKarsten Keil spin_lock_init(&dev->lock); 631b2b03f8SKarsten Keil dev->work = 0; 641b2b03f8SKarsten Keil init_waitqueue_head(&dev->wait); 651b2b03f8SKarsten Keil filep->private_data = dev; 661b2b03f8SKarsten Keil __module_get(THIS_MODULE); 676bff338bSAndrew Morton return nonseekable_open(ino, filep); 681b2b03f8SKarsten Keil } 691b2b03f8SKarsten Keil 701b2b03f8SKarsten Keil static int 711b2b03f8SKarsten Keil mISDN_close(struct inode *ino, struct file *filep) 721b2b03f8SKarsten Keil { 731b2b03f8SKarsten Keil struct mISDNtimerdev *dev = filep->private_data; 741b2b03f8SKarsten Keil struct mISDNtimer *timer, *next; 751b2b03f8SKarsten Keil 761b2b03f8SKarsten Keil if (*debug & DEBUG_TIMER) 771b2b03f8SKarsten Keil printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); 781b2b03f8SKarsten Keil list_for_each_entry_safe(timer, next, &dev->pending, list) { 791b2b03f8SKarsten Keil del_timer(&timer->tl); 801b2b03f8SKarsten Keil kfree(timer); 811b2b03f8SKarsten Keil } 821b2b03f8SKarsten Keil list_for_each_entry_safe(timer, next, &dev->expired, list) { 831b2b03f8SKarsten Keil kfree(timer); 841b2b03f8SKarsten Keil } 851b2b03f8SKarsten Keil kfree(dev); 861b2b03f8SKarsten Keil module_put(THIS_MODULE); 871b2b03f8SKarsten Keil return 0; 881b2b03f8SKarsten Keil } 891b2b03f8SKarsten Keil 901b2b03f8SKarsten Keil static ssize_t 91c46f0a2dSHannes Eder mISDN_read(struct file *filep, char __user *buf, size_t count, loff_t *off) 921b2b03f8SKarsten Keil { 931b2b03f8SKarsten Keil struct mISDNtimerdev *dev = filep->private_data; 941b2b03f8SKarsten Keil struct mISDNtimer *timer; 951b2b03f8SKarsten Keil u_long flags; 961b2b03f8SKarsten Keil int ret = 0; 971b2b03f8SKarsten Keil 981b2b03f8SKarsten Keil if (*debug & DEBUG_TIMER) 991b2b03f8SKarsten Keil printk(KERN_DEBUG "%s(%p, %p, %d, %p)\n", __func__, 1001b2b03f8SKarsten Keil filep, buf, (int)count, off); 1011b2b03f8SKarsten Keil if (*off != filep->f_pos) 1021b2b03f8SKarsten Keil return -ESPIPE; 1031b2b03f8SKarsten Keil 1041b2b03f8SKarsten Keil if (list_empty(&dev->expired) && (dev->work == 0)) { 1051b2b03f8SKarsten Keil if (filep->f_flags & O_NONBLOCK) 1061b2b03f8SKarsten Keil return -EAGAIN; 1071b2b03f8SKarsten Keil wait_event_interruptible(dev->wait, (dev->work || 1081b2b03f8SKarsten Keil !list_empty(&dev->expired))); 1091b2b03f8SKarsten Keil if (signal_pending(current)) 1101b2b03f8SKarsten Keil return -ERESTARTSYS; 1111b2b03f8SKarsten Keil } 1121b2b03f8SKarsten Keil if (count < sizeof(int)) 1131b2b03f8SKarsten Keil return -ENOSPC; 1141b2b03f8SKarsten Keil if (dev->work) 1151b2b03f8SKarsten Keil dev->work = 0; 1161b2b03f8SKarsten Keil if (!list_empty(&dev->expired)) { 1171b2b03f8SKarsten Keil spin_lock_irqsave(&dev->lock, flags); 1181b2b03f8SKarsten Keil timer = (struct mISDNtimer *)dev->expired.next; 1191b2b03f8SKarsten Keil list_del(&timer->list); 1201b2b03f8SKarsten Keil spin_unlock_irqrestore(&dev->lock, flags); 121c46f0a2dSHannes Eder if (put_user(timer->id, (int __user *)buf)) 1221b2b03f8SKarsten Keil ret = -EFAULT; 1231b2b03f8SKarsten Keil else 1241b2b03f8SKarsten Keil ret = sizeof(int); 1251b2b03f8SKarsten Keil kfree(timer); 1261b2b03f8SKarsten Keil } 1271b2b03f8SKarsten Keil return ret; 1281b2b03f8SKarsten Keil } 1291b2b03f8SKarsten Keil 1301b2b03f8SKarsten Keil static unsigned int 1311b2b03f8SKarsten Keil mISDN_poll(struct file *filep, poll_table *wait) 1321b2b03f8SKarsten Keil { 1331b2b03f8SKarsten Keil struct mISDNtimerdev *dev = filep->private_data; 1341b2b03f8SKarsten Keil unsigned int mask = POLLERR; 1351b2b03f8SKarsten Keil 1361b2b03f8SKarsten Keil if (*debug & DEBUG_TIMER) 1371b2b03f8SKarsten Keil printk(KERN_DEBUG "%s(%p, %p)\n", __func__, filep, wait); 1381b2b03f8SKarsten Keil if (dev) { 1391b2b03f8SKarsten Keil poll_wait(filep, &dev->wait, wait); 1401b2b03f8SKarsten Keil mask = 0; 1411b2b03f8SKarsten Keil if (dev->work || !list_empty(&dev->expired)) 1421b2b03f8SKarsten Keil mask |= (POLLIN | POLLRDNORM); 1431b2b03f8SKarsten Keil if (*debug & DEBUG_TIMER) 1441b2b03f8SKarsten Keil printk(KERN_DEBUG "%s work(%d) empty(%d)\n", __func__, 1451b2b03f8SKarsten Keil dev->work, list_empty(&dev->expired)); 1461b2b03f8SKarsten Keil } 1471b2b03f8SKarsten Keil return mask; 1481b2b03f8SKarsten Keil } 1491b2b03f8SKarsten Keil 1501b2b03f8SKarsten Keil static void 151ce425a9fSAndi Kleen dev_expire_timer(unsigned long data) 1521b2b03f8SKarsten Keil { 153ce425a9fSAndi Kleen struct mISDNtimer *timer = (void *)data; 1541b2b03f8SKarsten Keil u_long flags; 1551b2b03f8SKarsten Keil 1561b2b03f8SKarsten Keil spin_lock_irqsave(&timer->dev->lock, flags); 157211174eaSEric Sesterhenn list_move_tail(&timer->list, &timer->dev->expired); 1581b2b03f8SKarsten Keil spin_unlock_irqrestore(&timer->dev->lock, flags); 1591b2b03f8SKarsten Keil wake_up_interruptible(&timer->dev->wait); 1601b2b03f8SKarsten Keil } 1611b2b03f8SKarsten Keil 1621b2b03f8SKarsten Keil static int 1631b2b03f8SKarsten Keil misdn_add_timer(struct mISDNtimerdev *dev, int timeout) 1641b2b03f8SKarsten Keil { 1651b2b03f8SKarsten Keil int id; 1661b2b03f8SKarsten Keil u_long flags; 1671b2b03f8SKarsten Keil struct mISDNtimer *timer; 1681b2b03f8SKarsten Keil 1691b2b03f8SKarsten Keil if (!timeout) { 1701b2b03f8SKarsten Keil dev->work = 1; 1711b2b03f8SKarsten Keil wake_up_interruptible(&dev->wait); 1721b2b03f8SKarsten Keil id = 0; 1731b2b03f8SKarsten Keil } else { 1741b2b03f8SKarsten Keil timer = kzalloc(sizeof(struct mISDNtimer), GFP_KERNEL); 1751b2b03f8SKarsten Keil if (!timer) 1761b2b03f8SKarsten Keil return -ENOMEM; 1771b2b03f8SKarsten Keil spin_lock_irqsave(&dev->lock, flags); 1781b2b03f8SKarsten Keil timer->id = dev->next_id++; 1791b2b03f8SKarsten Keil if (dev->next_id < 0) 1801b2b03f8SKarsten Keil dev->next_id = 1; 1811b2b03f8SKarsten Keil list_add_tail(&timer->list, &dev->pending); 1821b2b03f8SKarsten Keil spin_unlock_irqrestore(&dev->lock, flags); 1831b2b03f8SKarsten Keil timer->dev = dev; 1841b2b03f8SKarsten Keil timer->tl.data = (long)timer; 185ce425a9fSAndi Kleen timer->tl.function = dev_expire_timer; 1861b2b03f8SKarsten Keil init_timer(&timer->tl); 1871b2b03f8SKarsten Keil timer->tl.expires = jiffies + ((HZ * (u_long)timeout) / 1000); 1881b2b03f8SKarsten Keil add_timer(&timer->tl); 1891b2b03f8SKarsten Keil id = timer->id; 1901b2b03f8SKarsten Keil } 1911b2b03f8SKarsten Keil return id; 1921b2b03f8SKarsten Keil } 1931b2b03f8SKarsten Keil 1941b2b03f8SKarsten Keil static int 1951b2b03f8SKarsten Keil misdn_del_timer(struct mISDNtimerdev *dev, int id) 1961b2b03f8SKarsten Keil { 1971b2b03f8SKarsten Keil u_long flags; 1981b2b03f8SKarsten Keil struct mISDNtimer *timer; 1991b2b03f8SKarsten Keil int ret = 0; 2001b2b03f8SKarsten Keil 2011b2b03f8SKarsten Keil spin_lock_irqsave(&dev->lock, flags); 2021b2b03f8SKarsten Keil list_for_each_entry(timer, &dev->pending, list) { 2031b2b03f8SKarsten Keil if (timer->id == id) { 2041b2b03f8SKarsten Keil list_del_init(&timer->list); 205ce425a9fSAndi Kleen /* RED-PEN AK: race -- timer can be still running on 206ce425a9fSAndi Kleen * other CPU. Needs reference count I think 207ce425a9fSAndi Kleen */ 2081b2b03f8SKarsten Keil del_timer(&timer->tl); 2091b2b03f8SKarsten Keil ret = timer->id; 2101b2b03f8SKarsten Keil kfree(timer); 2111b2b03f8SKarsten Keil goto unlock; 2121b2b03f8SKarsten Keil } 2131b2b03f8SKarsten Keil } 2141b2b03f8SKarsten Keil unlock: 2151b2b03f8SKarsten Keil spin_unlock_irqrestore(&dev->lock, flags); 2161b2b03f8SKarsten Keil return ret; 2171b2b03f8SKarsten Keil } 2181b2b03f8SKarsten Keil 219703c631eSArnd Bergmann static long 220703c631eSArnd Bergmann mISDN_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) 2211b2b03f8SKarsten Keil { 2221b2b03f8SKarsten Keil struct mISDNtimerdev *dev = filep->private_data; 2231b2b03f8SKarsten Keil int id, tout, ret = 0; 2241b2b03f8SKarsten Keil 2251b2b03f8SKarsten Keil 2261b2b03f8SKarsten Keil if (*debug & DEBUG_TIMER) 2271b2b03f8SKarsten Keil printk(KERN_DEBUG "%s(%p, %x, %lx)\n", __func__, 2281b2b03f8SKarsten Keil filep, cmd, arg); 229703c631eSArnd Bergmann lock_kernel(); 2301b2b03f8SKarsten Keil switch (cmd) { 2311b2b03f8SKarsten Keil case IMADDTIMER: 2321b2b03f8SKarsten Keil if (get_user(tout, (int __user *)arg)) { 2331b2b03f8SKarsten Keil ret = -EFAULT; 2341b2b03f8SKarsten Keil break; 2351b2b03f8SKarsten Keil } 2361b2b03f8SKarsten Keil id = misdn_add_timer(dev, tout); 2371b2b03f8SKarsten Keil if (*debug & DEBUG_TIMER) 2381b2b03f8SKarsten Keil printk(KERN_DEBUG "%s add %d id %d\n", __func__, 2391b2b03f8SKarsten Keil tout, id); 2401b2b03f8SKarsten Keil if (id < 0) { 2411b2b03f8SKarsten Keil ret = id; 2421b2b03f8SKarsten Keil break; 2431b2b03f8SKarsten Keil } 2441b2b03f8SKarsten Keil if (put_user(id, (int __user *)arg)) 2451b2b03f8SKarsten Keil ret = -EFAULT; 2461b2b03f8SKarsten Keil break; 2471b2b03f8SKarsten Keil case IMDELTIMER: 2481b2b03f8SKarsten Keil if (get_user(id, (int __user *)arg)) { 2491b2b03f8SKarsten Keil ret = -EFAULT; 2501b2b03f8SKarsten Keil break; 2511b2b03f8SKarsten Keil } 2521b2b03f8SKarsten Keil if (*debug & DEBUG_TIMER) 2531b2b03f8SKarsten Keil printk(KERN_DEBUG "%s del id %d\n", __func__, id); 2541b2b03f8SKarsten Keil id = misdn_del_timer(dev, id); 2551b2b03f8SKarsten Keil if (put_user(id, (int __user *)arg)) 2561b2b03f8SKarsten Keil ret = -EFAULT; 2571b2b03f8SKarsten Keil break; 2581b2b03f8SKarsten Keil default: 2591b2b03f8SKarsten Keil ret = -EINVAL; 2601b2b03f8SKarsten Keil } 261703c631eSArnd Bergmann unlock_kernel(); 2621b2b03f8SKarsten Keil return ret; 2631b2b03f8SKarsten Keil } 2641b2b03f8SKarsten Keil 265eac74af9SKarsten Keil static const struct file_operations mISDN_fops = { 2661b2b03f8SKarsten Keil .read = mISDN_read, 2671b2b03f8SKarsten Keil .poll = mISDN_poll, 268703c631eSArnd Bergmann .unlocked_ioctl = mISDN_ioctl, 2691b2b03f8SKarsten Keil .open = mISDN_open, 2701b2b03f8SKarsten Keil .release = mISDN_close, 2711b2b03f8SKarsten Keil }; 2721b2b03f8SKarsten Keil 2731b2b03f8SKarsten Keil static struct miscdevice mISDNtimer = { 2741b2b03f8SKarsten Keil .minor = MISC_DYNAMIC_MINOR, 2751b2b03f8SKarsten Keil .name = "mISDNtimer", 2761b2b03f8SKarsten Keil .fops = &mISDN_fops, 2771b2b03f8SKarsten Keil }; 2781b2b03f8SKarsten Keil 2791b2b03f8SKarsten Keil int 280dfa96ec1SHannes Eder mISDN_inittimer(u_int *deb) 2811b2b03f8SKarsten Keil { 2821b2b03f8SKarsten Keil int err; 2831b2b03f8SKarsten Keil 2841b2b03f8SKarsten Keil debug = deb; 2851b2b03f8SKarsten Keil err = misc_register(&mISDNtimer); 2861b2b03f8SKarsten Keil if (err) 2871b2b03f8SKarsten Keil printk(KERN_WARNING "mISDN: Could not register timer device\n"); 2881b2b03f8SKarsten Keil return err; 2891b2b03f8SKarsten Keil } 2901b2b03f8SKarsten Keil 2911b2b03f8SKarsten Keil void mISDN_timer_cleanup(void) 2921b2b03f8SKarsten Keil { 2931b2b03f8SKarsten Keil misc_deregister(&mISDNtimer); 2941b2b03f8SKarsten Keil } 295