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293 lines
6.4 KiB
293 lines
6.4 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* |
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* general timer device for using in ISDN stacks |
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* |
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* Author Karsten Keil <[email protected]> |
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* |
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* Copyright 2008 by Karsten Keil <[email protected]> |
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*/ |
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#include <linux/poll.h> |
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#include <linux/vmalloc.h> |
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#include <linux/slab.h> |
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#include <linux/timer.h> |
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#include <linux/miscdevice.h> |
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#include <linux/module.h> |
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#include <linux/mISDNif.h> |
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#include <linux/mutex.h> |
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#include <linux/sched/signal.h> |
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#include "core.h" |
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static DEFINE_MUTEX(mISDN_mutex); |
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static u_int *debug; |
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struct mISDNtimerdev { |
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int next_id; |
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struct list_head pending; |
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struct list_head expired; |
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wait_queue_head_t wait; |
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u_int work; |
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spinlock_t lock; /* protect lists */ |
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}; |
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struct mISDNtimer { |
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struct list_head list; |
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struct mISDNtimerdev *dev; |
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struct timer_list tl; |
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int id; |
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}; |
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static int |
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mISDN_open(struct inode *ino, struct file *filep) |
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{ |
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struct mISDNtimerdev *dev; |
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if (*debug & DEBUG_TIMER) |
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printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); |
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dev = kmalloc(sizeof(struct mISDNtimerdev) , GFP_KERNEL); |
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if (!dev) |
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return -ENOMEM; |
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dev->next_id = 1; |
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INIT_LIST_HEAD(&dev->pending); |
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INIT_LIST_HEAD(&dev->expired); |
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spin_lock_init(&dev->lock); |
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dev->work = 0; |
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init_waitqueue_head(&dev->wait); |
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filep->private_data = dev; |
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return nonseekable_open(ino, filep); |
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} |
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static int |
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mISDN_close(struct inode *ino, struct file *filep) |
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{ |
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struct mISDNtimerdev *dev = filep->private_data; |
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struct list_head *list = &dev->pending; |
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struct mISDNtimer *timer, *next; |
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if (*debug & DEBUG_TIMER) |
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printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); |
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spin_lock_irq(&dev->lock); |
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while (!list_empty(list)) { |
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timer = list_first_entry(list, struct mISDNtimer, list); |
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spin_unlock_irq(&dev->lock); |
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del_timer_sync(&timer->tl); |
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spin_lock_irq(&dev->lock); |
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/* it might have been moved to ->expired */ |
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list_del(&timer->list); |
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kfree(timer); |
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} |
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spin_unlock_irq(&dev->lock); |
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list_for_each_entry_safe(timer, next, &dev->expired, list) { |
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kfree(timer); |
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} |
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kfree(dev); |
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return 0; |
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} |
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static ssize_t |
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mISDN_read(struct file *filep, char __user *buf, size_t count, loff_t *off) |
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{ |
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struct mISDNtimerdev *dev = filep->private_data; |
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struct list_head *list = &dev->expired; |
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struct mISDNtimer *timer; |
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int ret = 0; |
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if (*debug & DEBUG_TIMER) |
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printk(KERN_DEBUG "%s(%p, %p, %d, %p)\n", __func__, |
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filep, buf, (int)count, off); |
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if (count < sizeof(int)) |
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return -ENOSPC; |
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spin_lock_irq(&dev->lock); |
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while (list_empty(list) && (dev->work == 0)) { |
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spin_unlock_irq(&dev->lock); |
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if (filep->f_flags & O_NONBLOCK) |
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return -EAGAIN; |
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wait_event_interruptible(dev->wait, (dev->work || |
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!list_empty(list))); |
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if (signal_pending(current)) |
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return -ERESTARTSYS; |
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spin_lock_irq(&dev->lock); |
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} |
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if (dev->work) |
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dev->work = 0; |
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if (!list_empty(list)) { |
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timer = list_first_entry(list, struct mISDNtimer, list); |
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list_del(&timer->list); |
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spin_unlock_irq(&dev->lock); |
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if (put_user(timer->id, (int __user *)buf)) |
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ret = -EFAULT; |
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else |
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ret = sizeof(int); |
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kfree(timer); |
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} else { |
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spin_unlock_irq(&dev->lock); |
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} |
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return ret; |
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} |
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static __poll_t |
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mISDN_poll(struct file *filep, poll_table *wait) |
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{ |
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struct mISDNtimerdev *dev = filep->private_data; |
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__poll_t mask = EPOLLERR; |
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if (*debug & DEBUG_TIMER) |
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printk(KERN_DEBUG "%s(%p, %p)\n", __func__, filep, wait); |
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if (dev) { |
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poll_wait(filep, &dev->wait, wait); |
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mask = 0; |
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if (dev->work || !list_empty(&dev->expired)) |
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mask |= (EPOLLIN | EPOLLRDNORM); |
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if (*debug & DEBUG_TIMER) |
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printk(KERN_DEBUG "%s work(%d) empty(%d)\n", __func__, |
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dev->work, list_empty(&dev->expired)); |
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} |
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return mask; |
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} |
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static void |
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dev_expire_timer(struct timer_list *t) |
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{ |
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struct mISDNtimer *timer = from_timer(timer, t, tl); |
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u_long flags; |
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spin_lock_irqsave(&timer->dev->lock, flags); |
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if (timer->id >= 0) |
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list_move_tail(&timer->list, &timer->dev->expired); |
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wake_up_interruptible(&timer->dev->wait); |
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spin_unlock_irqrestore(&timer->dev->lock, flags); |
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} |
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static int |
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misdn_add_timer(struct mISDNtimerdev *dev, int timeout) |
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{ |
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int id; |
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struct mISDNtimer *timer; |
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if (!timeout) { |
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dev->work = 1; |
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wake_up_interruptible(&dev->wait); |
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id = 0; |
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} else { |
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timer = kzalloc(sizeof(struct mISDNtimer), GFP_KERNEL); |
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if (!timer) |
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return -ENOMEM; |
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timer->dev = dev; |
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timer_setup(&timer->tl, dev_expire_timer, 0); |
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spin_lock_irq(&dev->lock); |
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id = timer->id = dev->next_id++; |
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if (dev->next_id < 0) |
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dev->next_id = 1; |
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list_add_tail(&timer->list, &dev->pending); |
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timer->tl.expires = jiffies + ((HZ * (u_long)timeout) / 1000); |
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add_timer(&timer->tl); |
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spin_unlock_irq(&dev->lock); |
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} |
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return id; |
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} |
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static int |
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misdn_del_timer(struct mISDNtimerdev *dev, int id) |
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{ |
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struct mISDNtimer *timer; |
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spin_lock_irq(&dev->lock); |
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list_for_each_entry(timer, &dev->pending, list) { |
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if (timer->id == id) { |
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list_del_init(&timer->list); |
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timer->id = -1; |
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spin_unlock_irq(&dev->lock); |
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del_timer_sync(&timer->tl); |
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kfree(timer); |
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return id; |
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} |
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} |
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spin_unlock_irq(&dev->lock); |
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return 0; |
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} |
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static long |
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mISDN_ioctl(struct file *filep, unsigned int cmd, unsigned long arg) |
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{ |
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struct mISDNtimerdev *dev = filep->private_data; |
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int id, tout, ret = 0; |
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if (*debug & DEBUG_TIMER) |
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printk(KERN_DEBUG "%s(%p, %x, %lx)\n", __func__, |
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filep, cmd, arg); |
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mutex_lock(&mISDN_mutex); |
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switch (cmd) { |
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case IMADDTIMER: |
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if (get_user(tout, (int __user *)arg)) { |
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ret = -EFAULT; |
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break; |
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} |
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id = misdn_add_timer(dev, tout); |
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if (*debug & DEBUG_TIMER) |
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printk(KERN_DEBUG "%s add %d id %d\n", __func__, |
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tout, id); |
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if (id < 0) { |
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ret = id; |
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break; |
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} |
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if (put_user(id, (int __user *)arg)) |
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ret = -EFAULT; |
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break; |
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case IMDELTIMER: |
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if (get_user(id, (int __user *)arg)) { |
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ret = -EFAULT; |
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break; |
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} |
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if (*debug & DEBUG_TIMER) |
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printk(KERN_DEBUG "%s del id %d\n", __func__, id); |
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id = misdn_del_timer(dev, id); |
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if (put_user(id, (int __user *)arg)) |
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ret = -EFAULT; |
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break; |
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default: |
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ret = -EINVAL; |
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} |
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mutex_unlock(&mISDN_mutex); |
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return ret; |
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} |
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static const struct file_operations mISDN_fops = { |
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.owner = THIS_MODULE, |
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.read = mISDN_read, |
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.poll = mISDN_poll, |
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.unlocked_ioctl = mISDN_ioctl, |
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.open = mISDN_open, |
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.release = mISDN_close, |
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.llseek = no_llseek, |
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}; |
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static struct miscdevice mISDNtimer = { |
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.minor = MISC_DYNAMIC_MINOR, |
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.name = "mISDNtimer", |
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.fops = &mISDN_fops, |
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}; |
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int |
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mISDN_inittimer(u_int *deb) |
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{ |
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int err; |
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debug = deb; |
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err = misc_register(&mISDNtimer); |
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if (err) |
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printk(KERN_WARNING "mISDN: Could not register timer device\n"); |
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return err; |
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} |
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void mISDN_timer_cleanup(void) |
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{ |
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misc_deregister(&mISDNtimer); |
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}
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