[deliverable/linux.git] / drivers / isdn / mISDN / timerdev.c

/*
 *
 * 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);
}
Commit	Line	Data
1b2b03f8 KK	1	/*
	2	*
	3	* general timer device for using in ISDN stacks
	4	*
	5	* Author Karsten Keil <kkeil@novell.com>
	6	*
	7	* Copyright 2008 by Karsten Keil <kkeil@novell.com>
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	*/
	19
	20	#include <linux/poll.h>
	21	#include <linux/vmalloc.h>
5a0e3ad6	22	#include <linux/slab.h>
1b2b03f8 KK	23	#include <linux/timer.h>
	24	#include <linux/miscdevice.h>
	25	#include <linux/module.h>
	26	#include <linux/mISDNif.h>
76a64921	27	#include <linux/mutex.h>
5b834354	28	#include "core.h"
1b2b03f8	29
76a64921	30	static DEFINE_MUTEX(mISDN_mutex);
dfa96ec1	31	static u_int *debug;
1b2b03f8 KK	32
	33
	34	struct mISDNtimerdev {
	35	int next_id;
	36	struct list_head pending;
	37	struct list_head expired;
	38	wait_queue_head_t wait;
	39	u_int work;
	40	spinlock_t lock; /* protect lists */
	41	};
	42
	43	struct mISDNtimer {
	44	struct list_head list;
	45	struct mISDNtimerdev *dev;
	46	struct timer_list tl;
	47	int id;
	48	};
	49
	50	static int
	51	mISDN_open(struct inode ino, struct file filep)
	52	{
	53	struct mISDNtimerdev *dev;
	54
	55	if (*debug & DEBUG_TIMER)
	56	printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep);
	57	dev = kmalloc(sizeof(struct mISDNtimerdev) , GFP_KERNEL);
	58	if (!dev)
	59	return -ENOMEM;
	60	dev->next_id = 1;
	61	INIT_LIST_HEAD(&dev->pending);
	62	INIT_LIST_HEAD(&dev->expired);
	63	spin_lock_init(&dev->lock);
	64	dev->work = 0;
	65	init_waitqueue_head(&dev->wait);
	66	filep->private_data = dev;
	67	__module_get(THIS_MODULE);
6bff338b	68	return nonseekable_open(ino, filep);
1b2b03f8 KK	69	}
	70
	71	static int
	72	mISDN_close(struct inode ino, struct file filep)
	73	{
	74	struct mISDNtimerdev *dev = filep->private_data;
	75	struct mISDNtimer timer, next;
	76
	77	if (*debug & DEBUG_TIMER)
	78	printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep);
	79	list_for_each_entry_safe(timer, next, &dev->pending, list) {
	80	del_timer(&timer->tl);
	81	kfree(timer);
	82	}
	83	list_for_each_entry_safe(timer, next, &dev->expired, list) {
	84	kfree(timer);
	85	}
	86	kfree(dev);
	87	module_put(THIS_MODULE);
	88	return 0;
	89	}
	90
	91	static ssize_t
c46f0a2d	92	mISDN_read(struct file filep, char __user buf, size_t count, loff_t *off)
1b2b03f8 KK	93	{
	94	struct mISDNtimerdev *dev = filep->private_data;
	95	struct mISDNtimer *timer;
	96	u_long flags;
	97	int ret = 0;
	98
	99	if (*debug & DEBUG_TIMER)
	100	printk(KERN_DEBUG "%s(%p, %p, %d, %p)\n", __func__,
475be4d8	101	filep, buf, (int)count, off);
1b2b03f8 KK	102
	103	if (list_empty(&dev->expired) && (dev->work == 0)) {
	104	if (filep->f_flags & O_NONBLOCK)
	105	return -EAGAIN;
	106	wait_event_interruptible(dev->wait, (dev->work \|\|
475be4d8	107	!list_empty(&dev->expired)));
1b2b03f8 KK	108	if (signal_pending(current))
	109	return -ERESTARTSYS;
	110	}
	111	if (count < sizeof(int))
	112	return -ENOSPC;
	113	if (dev->work)
	114	dev->work = 0;
	115	if (!list_empty(&dev->expired)) {
	116	spin_lock_irqsave(&dev->lock, flags);
	117	timer = (struct mISDNtimer *)dev->expired.next;
	118	list_del(&timer->list);
	119	spin_unlock_irqrestore(&dev->lock, flags);
c46f0a2d	120	if (put_user(timer->id, (int __user *)buf))
1b2b03f8 KK	121	ret = -EFAULT;
	122	else
	123	ret = sizeof(int);
	124	kfree(timer);
	125	}
	126	return ret;
	127	}
	128
1b2b03f8 KK	129	static unsigned int
	130	mISDN_poll(struct file filep, poll_table wait)
	131	{
	132	struct mISDNtimerdev *dev = filep->private_data;
	133	unsigned int mask = POLLERR;
	134
	135	if (*debug & DEBUG_TIMER)
	136	printk(KERN_DEBUG "%s(%p, %p)\n", __func__, filep, wait);
	137	if (dev) {
	138	poll_wait(filep, &dev->wait, wait);
	139	mask = 0;
	140	if (dev->work \|\| !list_empty(&dev->expired))
	141	mask \|= (POLLIN \| POLLRDNORM);
	142	if (*debug & DEBUG_TIMER)
	143	printk(KERN_DEBUG "%s work(%d) empty(%d)\n", __func__,
475be4d8	144	dev->work, list_empty(&dev->expired));
1b2b03f8 KK	145	}
	146	return mask;
	147	}
	148
	149	static void
ce425a9f	150	dev_expire_timer(unsigned long data)
1b2b03f8	151	{
ce425a9f	152	struct mISDNtimer timer = (void )data;
1b2b03f8 KK	153	u_long flags;
	154
	155	spin_lock_irqsave(&timer->dev->lock, flags);
211174ea	156	list_move_tail(&timer->list, &timer->dev->expired);
1b2b03f8 KK	157	spin_unlock_irqrestore(&timer->dev->lock, flags);
	158	wake_up_interruptible(&timer->dev->wait);
	159	}
	160
	161	static int
	162	misdn_add_timer(struct mISDNtimerdev *dev, int timeout)
	163	{
475be4d8	164	int id;
1b2b03f8 KK	165	u_long flags;
	166	struct mISDNtimer *timer;
	167
	168	if (!timeout) {
	169	dev->work = 1;
	170	wake_up_interruptible(&dev->wait);
	171	id = 0;
	172	} else {
	173	timer = kzalloc(sizeof(struct mISDNtimer), GFP_KERNEL);
	174	if (!timer)
	175	return -ENOMEM;
	176	spin_lock_irqsave(&dev->lock, flags);
	177	timer->id = dev->next_id++;
	178	if (dev->next_id < 0)
	179	dev->next_id = 1;
	180	list_add_tail(&timer->list, &dev->pending);
	181	spin_unlock_irqrestore(&dev->lock, flags);
	182	timer->dev = dev;
	183	timer->tl.data = (long)timer;
ce425a9f	184	timer->tl.function = dev_expire_timer;
1b2b03f8 KK	185	init_timer(&timer->tl);
	186	timer->tl.expires = jiffies + ((HZ * (u_long)timeout) / 1000);
	187	add_timer(&timer->tl);
	188	id = timer->id;
	189	}
	190	return id;
	191	}
	192
	193	static int
	194	misdn_del_timer(struct mISDNtimerdev *dev, int id)
	195	{
	196	u_long flags;
	197	struct mISDNtimer *timer;
	198	int ret = 0;
	199
	200	spin_lock_irqsave(&dev->lock, flags);
	201	list_for_each_entry(timer, &dev->pending, list) {
	202	if (timer->id == id) {
	203	list_del_init(&timer->list);
ce425a9f AK	204	/* RED-PEN AK: race -- timer can be still running on
	205	* other CPU. Needs reference count I think
	206	*/
1b2b03f8 KK	207	del_timer(&timer->tl);
	208	ret = timer->id;
	209	kfree(timer);
	210	goto unlock;
	211	}
	212	}
	213	unlock:
	214	spin_unlock_irqrestore(&dev->lock, flags);
	215	return ret;
	216	}
	217
703c631e AB	218	static long
703c631e AB	219	mISDN_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
1b2b03f8 KK	220	{
	221	struct mISDNtimerdev *dev = filep->private_data;
	222	int id, tout, ret = 0;
	223
	224
	225	if (*debug & DEBUG_TIMER)
	226	printk(KERN_DEBUG "%s(%p, %x, %lx)\n", __func__,
475be4d8	227	filep, cmd, arg);
76a64921	228	mutex_lock(&mISDN_mutex);
1b2b03f8 KK	229	switch (cmd) {
	230	case IMADDTIMER:
	231	if (get_user(tout, (int __user *)arg)) {
	232	ret = -EFAULT;
	233	break;
	234	}
	235	id = misdn_add_timer(dev, tout);
	236	if (*debug & DEBUG_TIMER)
	237	printk(KERN_DEBUG "%s add %d id %d\n", __func__,
475be4d8	238	tout, id);
1b2b03f8 KK	239	if (id < 0) {
	240	ret = id;
	241	break;
	242	}
	243	if (put_user(id, (int __user *)arg))
	244	ret = -EFAULT;
	245	break;
	246	case IMDELTIMER:
	247	if (get_user(id, (int __user *)arg)) {
	248	ret = -EFAULT;
	249	break;
	250	}
	251	if (*debug & DEBUG_TIMER)
	252	printk(KERN_DEBUG "%s del id %d\n", __func__, id);
	253	id = misdn_del_timer(dev, id);
	254	if (put_user(id, (int __user *)arg))
	255	ret = -EFAULT;
	256	break;
	257	default:
	258	ret = -EINVAL;
	259	}
76a64921	260	mutex_unlock(&mISDN_mutex);
1b2b03f8 KK	261	return ret;
	262	}
	263
eac74af9	264	static const struct file_operations mISDN_fops = {
1b2b03f8	265	.read = mISDN_read,
1b2b03f8	266	.poll = mISDN_poll,
703c631e	267	.unlocked_ioctl = mISDN_ioctl,
1b2b03f8 KK	268	.open = mISDN_open,
1b2b03f8 KK	269	.release = mISDN_close,
6038f373	270	.llseek = no_llseek,
1b2b03f8 KK	271	};
	272
	273	static struct miscdevice mISDNtimer = {
	274	.minor = MISC_DYNAMIC_MINOR,
	275	.name = "mISDNtimer",
	276	.fops = &mISDN_fops,
	277	};
	278
	279	int
dfa96ec1	280	mISDN_inittimer(u_int *deb)
1b2b03f8 KK	281	{
	282	int err;
	283
	284	debug = deb;
	285	err = misc_register(&mISDNtimer);
	286	if (err)
	287	printk(KERN_WARNING "mISDN: Could not register timer device\n");
	288	return err;
	289	}
	290
	291	void mISDN_timer_cleanup(void)
	292	{
	293	misc_deregister(&mISDNtimer);
	294	}