--- /dev/null
+/*
+ *
+ * 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/slab.h>
+#include <linux/timer.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/mISDNif.h>
+#include <linux/mutex.h>
+#include "core.h"
+
+static DEFINE_MUTEX(mISDN_mutex);
+static u_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;
+ return nonseekable_open(ino, filep);
+}
+
+static int
+mISDN_close(struct inode *ino, struct file *filep)
+{
+ struct mISDNtimerdev *dev = filep->private_data;
+ struct list_head *list = &dev->pending;
+ struct mISDNtimer *timer, *next;
+
+ if (*debug & DEBUG_TIMER)
+ printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep);
+
+ spin_lock_irq(&dev->lock);
+ while (!list_empty(list)) {
+ timer = list_first_entry(list, struct mISDNtimer, list);
+ spin_unlock_irq(&dev->lock);
+ del_timer_sync(&timer->tl);
+ spin_lock_irq(&dev->lock);
+ /* it might have been moved to ->expired */
+ list_del(&timer->list);
+ kfree(timer);
+ }
+ spin_unlock_irq(&dev->lock);
+
+ list_for_each_entry_safe(timer, next, &dev->expired, list) {
+ kfree(timer);
+ }
+ kfree(dev);
+ return 0;
+}
+
+static ssize_t
+mISDN_read(struct file *filep, char __user *buf, size_t count, loff_t *off)
+{
+ struct mISDNtimerdev *dev = filep->private_data;
+ struct list_head *list = &dev->expired;
+ struct mISDNtimer *timer;
+ int ret = 0;
+
+ if (*debug & DEBUG_TIMER)
+ printk(KERN_DEBUG "%s(%p, %p, %d, %p)\n", __func__,
+ filep, buf, (int)count, off);
+
+ if (count < sizeof(int))
+ return -ENOSPC;
+
+ spin_lock_irq(&dev->lock);
+ while (list_empty(list) && (dev->work == 0)) {
+ spin_unlock_irq(&dev->lock);
+ if (filep->f_flags & O_NONBLOCK)
+ return -EAGAIN;
+ wait_event_interruptible(dev->wait, (dev->work ||
+ !list_empty(list)));
+ if (signal_pending(current))
+ return -ERESTARTSYS;
+ spin_lock_irq(&dev->lock);
+ }
+ if (dev->work)
+ dev->work = 0;
+ if (!list_empty(list)) {
+ timer = list_first_entry(list, struct mISDNtimer, list);
+ list_del(&timer->list);
+ spin_unlock_irq(&dev->lock);
+ if (put_user(timer->id, (int __user *)buf))
+ ret = -EFAULT;
+ else
+ ret = sizeof(int);
+ kfree(timer);
+ } else {
+ spin_unlock_irq(&dev->lock);
+ }
+ 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);
+ if (timer->id >= 0)
+ list_move_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;
+ 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;
+ timer->dev = dev;
+ setup_timer(&timer->tl, dev_expire_timer, (long)timer);
+ spin_lock_irq(&dev->lock);
+ id = timer->id = dev->next_id++;
+ if (dev->next_id < 0)
+ dev->next_id = 1;
+ list_add_tail(&timer->list, &dev->pending);
+ timer->tl.expires = jiffies + ((HZ * (u_long)timeout) / 1000);
+ add_timer(&timer->tl);
+ spin_unlock_irq(&dev->lock);
+ }
+ return id;
+}
+
+static int
+misdn_del_timer(struct mISDNtimerdev *dev, int id)
+{
+ struct mISDNtimer *timer;
+
+ spin_lock_irq(&dev->lock);
+ list_for_each_entry(timer, &dev->pending, list) {
+ if (timer->id == id) {
+ list_del_init(&timer->list);
+ timer->id = -1;
+ spin_unlock_irq(&dev->lock);
+ del_timer_sync(&timer->tl);
+ kfree(timer);
+ return id;
+ }
+ }
+ spin_unlock_irq(&dev->lock);
+ return 0;
+}
+
+static long
+mISDN_ioctl(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);
+ mutex_lock(&mISDN_mutex);
+ 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;
+ }
+ mutex_unlock(&mISDN_mutex);
+ return ret;
+}
+
+static const struct file_operations mISDN_fops = {
+ .owner = THIS_MODULE,
+ .read = mISDN_read,
+ .poll = mISDN_poll,
+ .unlocked_ioctl = mISDN_ioctl,
+ .open = mISDN_open,
+ .release = mISDN_close,
+ .llseek = no_llseek,
+};
+
+static struct miscdevice mISDNtimer = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "mISDNtimer",
+ .fops = &mISDN_fops,
+};
+
+int
+mISDN_inittimer(u_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);
+}
Code Review / kvmfornfv.git / blobdiff