1 files changed, 294 insertions, 0 deletions
diff --git a/drivers/isdn/mISDN/timerdev.c b/drivers/isdn/mISDN/timerdev.c
new file mode 100644
index 00000000..1094667d
--- /dev/null
+++ b/drivers/isdn/mISDN/timerdev.c
@@ -0,0 +1,294 @@
+/*
+ *
+ * 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;
+	__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 __user *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 (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 __user *)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_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;
+	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 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 = {
+	.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);
+}