diff options
Diffstat (limited to 'drivers/isdn/mISDN/timerdev.c')
| -rw-r--r-- | drivers/isdn/mISDN/timerdev.c | 291 |
1 files changed, 291 insertions, 0 deletions
diff --git a/drivers/isdn/mISDN/timerdev.c b/drivers/isdn/mISDN/timerdev.c new file mode 100644 index 0000000..875fabe --- /dev/null +++ b/drivers/isdn/mISDN/timerdev.c @@ -0,0 +1,291 @@ +/* + * + * general timer device for using in ISDN stacks + * + * Author Karsten Keil <kkeil@novell.com> + * + * Copyright 2008 by Karsten Keil <kkeil@novell.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/poll.h> +#include <linux/vmalloc.h> +#include <linux/timer.h> +#include <linux/miscdevice.h> +#include <linux/module.h> +#include <linux/mISDNif.h> + +static int *debug; + + +struct mISDNtimerdev { + int next_id; + struct list_head pending; + struct list_head expired; + wait_queue_head_t wait; + u_int work; + spinlock_t lock; /* protect lists */ +}; + +struct mISDNtimer { + struct list_head list; + struct mISDNtimerdev *dev; + struct timer_list tl; + int id; +}; + +static int +mISDN_open(struct inode *ino, struct file *filep) +{ + struct mISDNtimerdev *dev; + + if (*debug & DEBUG_TIMER) + printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); + dev = kmalloc(sizeof(struct mISDNtimerdev) , GFP_KERNEL); + if (!dev) + return -ENOMEM; + dev->next_id = 1; + INIT_LIST_HEAD(&dev->pending); + INIT_LIST_HEAD(&dev->expired); + spin_lock_init(&dev->lock); + dev->work = 0; + init_waitqueue_head(&dev->wait); + filep->private_data = dev; + __module_get(THIS_MODULE); + return nonseekable_open(ino, filep); +} + +static int +mISDN_close(struct inode *ino, struct file *filep) +{ + struct mISDNtimerdev *dev = filep->private_data; + struct mISDNtimer *timer, *next; + + if (*debug & DEBUG_TIMER) + printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep); + list_for_each_entry_safe(timer, next, &dev->pending, list) { + del_timer(&timer->tl); + kfree(timer); + } + list_for_each_entry_safe(timer, next, &dev->expired, list) { + kfree(timer); + } + kfree(dev); + module_put(THIS_MODULE); + return 0; +} + +static ssize_t +mISDN_read(struct file *filep, char *buf, size_t count, loff_t *off) +{ + struct mISDNtimerdev *dev = filep->private_data; + struct mISDNtimer *timer; + u_long flags; + int ret = 0; + + if (*debug & DEBUG_TIMER) + printk(KERN_DEBUG "%s(%p, %p, %d, %p)\n", __func__, + filep, buf, (int)count, off); + if (*off != filep->f_pos) + return -ESPIPE; + + if (list_empty(&dev->expired) && (dev->work == 0)) { + if (filep->f_flags & O_NONBLOCK) + return -EAGAIN; + wait_event_interruptible(dev->wait, (dev->work || + !list_empty(&dev->expired))); + if (signal_pending(current)) + return -ERESTARTSYS; + } + if (count < sizeof(int)) + return -ENOSPC; + if (dev->work) + dev->work = 0; + if (!list_empty(&dev->expired)) { + spin_lock_irqsave(&dev->lock, flags); + timer = (struct mISDNtimer *)dev->expired.next; + list_del(&timer->list); + spin_unlock_irqrestore(&dev->lock, flags); + if (put_user(timer->id, (int *)buf)) + ret = -EFAULT; + else + ret = sizeof(int); + kfree(timer); + } + return ret; +} + +static unsigned int +mISDN_poll(struct file *filep, poll_table *wait) +{ + struct mISDNtimerdev *dev = filep->private_data; + unsigned int mask = POLLERR; + + if (*debug & DEBUG_TIMER) + printk(KERN_DEBUG "%s(%p, %p)\n", __func__, filep, wait); + if (dev) { + poll_wait(filep, &dev->wait, wait); + mask = 0; + if (dev->work || !list_empty(&dev->expired)) + mask |= (POLLIN | POLLRDNORM); + if (*debug & DEBUG_TIMER) + printk(KERN_DEBUG "%s work(%d) empty(%d)\n", __func__, + dev->work, list_empty(&dev->expired)); + } + return mask; +} + +static void +dev_expire_timer(unsigned long data) +{ + struct mISDNtimer *timer = (void *)data; + u_long flags; + + spin_lock_irqsave(&timer->dev->lock, flags); + list_del(&timer->list); + list_add_tail(&timer->list, &timer->dev->expired); + spin_unlock_irqrestore(&timer->dev->lock, flags); + wake_up_interruptible(&timer->dev->wait); +} + +static int +misdn_add_timer(struct mISDNtimerdev *dev, int timeout) +{ + int id; + u_long flags; + struct mISDNtimer *timer; + + if (!timeout) { + dev->work = 1; + wake_up_interruptible(&dev->wait); + id = 0; + } else { + timer = kzalloc(sizeof(struct mISDNtimer), GFP_KERNEL); + if (!timer) + return -ENOMEM; + spin_lock_irqsave(&dev->lock, flags); + timer->id = dev->next_id++; + if (dev->next_id < 0) + dev->next_id = 1; + list_add_tail(&timer->list, &dev->pending); + spin_unlock_irqrestore(&dev->lock, flags); + timer->dev = dev; + timer->tl.data = (long)timer; + timer->tl.function = dev_expire_timer; + init_timer(&timer->tl); + timer->tl.expires = jiffies + ((HZ * (u_long)timeout) / 1000); + add_timer(&timer->tl); + id = timer->id; + } + return id; +} + +static int +misdn_del_timer(struct mISDNtimerdev *dev, int id) +{ + u_long flags; + struct mISDNtimer *timer; + int ret = 0; + + spin_lock_irqsave(&dev->lock, flags); + list_for_each_entry(timer, &dev->pending, list) { + if (timer->id == id) { + list_del_init(&timer->list); + /* RED-PEN AK: race -- timer can be still running on + * other CPU. Needs reference count I think + */ + del_timer(&timer->tl); + ret = timer->id; + kfree(timer); + goto unlock; + } + } +unlock: + spin_unlock_irqrestore(&dev->lock, flags); + return ret; +} + +static int +mISDN_ioctl(struct inode *inode, struct file *filep, unsigned int cmd, + unsigned long arg) +{ + struct mISDNtimerdev *dev = filep->private_data; + int id, tout, ret = 0; + + + if (*debug & DEBUG_TIMER) + printk(KERN_DEBUG "%s(%p, %x, %lx)\n", __func__, + filep, cmd, arg); + switch (cmd) { + case IMADDTIMER: + if (get_user(tout, (int __user *)arg)) { + ret = -EFAULT; + break; + } + id = misdn_add_timer(dev, tout); + if (*debug & DEBUG_TIMER) + printk(KERN_DEBUG "%s add %d id %d\n", __func__, + tout, id); + if (id < 0) { + ret = id; + break; + } + if (put_user(id, (int __user *)arg)) + ret = -EFAULT; + break; + case IMDELTIMER: + if (get_user(id, (int __user *)arg)) { + ret = -EFAULT; + break; + } + if (*debug & DEBUG_TIMER) + printk(KERN_DEBUG "%s del id %d\n", __func__, id); + id = misdn_del_timer(dev, id); + if (put_user(id, (int __user *)arg)) + ret = -EFAULT; + break; + default: + ret = -EINVAL; + } + return ret; +} + +static struct file_operations mISDN_fops = { + .read = mISDN_read, + .poll = mISDN_poll, + .ioctl = mISDN_ioctl, + .open = mISDN_open, + .release = mISDN_close, +}; + +static struct miscdevice mISDNtimer = { + .minor = MISC_DYNAMIC_MINOR, + .name = "mISDNtimer", + .fops = &mISDN_fops, +}; + +int +mISDN_inittimer(int *deb) +{ + int err; + + debug = deb; + err = misc_register(&mISDNtimer); + if (err) + printk(KERN_WARNING "mISDN: Could not register timer device\n"); + return err; +} + +void mISDN_timer_cleanup(void) +{ + misc_deregister(&mISDNtimer); +} |
