[linux-2.6-block.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;
	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);
}
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;
6bff338b	67	return nonseekable_open(ino, filep);
1b2b03f8 KK	68	}
	69
	70	static int
	71	mISDN_close(struct inode ino, struct file filep)
	72	{
	73	struct mISDNtimerdev *dev = filep->private_data;
c08c464d	74	struct list_head *list = &dev->pending;
1b2b03f8 KK	75	struct mISDNtimer timer, next;
	76
	77	if (*debug & DEBUG_TIMER)
	78	printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep);
c08c464d AV	79
	80	spin_lock_irq(&dev->lock);
	81	while (!list_empty(list)) {
	82	timer = list_first_entry(list, struct mISDNtimer, list);
	83	spin_unlock_irq(&dev->lock);
	84	del_timer_sync(&timer->tl);
	85	spin_lock_irq(&dev->lock);
	86	/* it might have been moved to ->expired */
	87	list_del(&timer->list);
1b2b03f8 KK	88	kfree(timer);
1b2b03f8 KK	89	}
c08c464d AV	90	spin_unlock_irq(&dev->lock);
c08c464d AV	91
1b2b03f8 KK	92	list_for_each_entry_safe(timer, next, &dev->expired, list) {
	93	kfree(timer);
	94	}
	95	kfree(dev);
1b2b03f8 KK	96	return 0;
	97	}
	98
	99	static ssize_t
c46f0a2d	100	mISDN_read(struct file filep, char __user buf, size_t count, loff_t *off)
1b2b03f8 KK	101	{
1b2b03f8 KK	102	struct mISDNtimerdev *dev = filep->private_data;
ebb06be1	103	struct list_head *list = &dev->expired;
1b2b03f8	104	struct mISDNtimer *timer;
1b2b03f8 KK	105	int ret = 0;
	106
	107	if (*debug & DEBUG_TIMER)
	108	printk(KERN_DEBUG "%s(%p, %p, %d, %p)\n", __func__,
475be4d8	109	filep, buf, (int)count, off);
1b2b03f8	110
ebb06be1 AV	111	if (count < sizeof(int))
	112	return -ENOSPC;
	113
	114	spin_lock_irq(&dev->lock);
	115	while (list_empty(list) && (dev->work == 0)) {
	116	spin_unlock_irq(&dev->lock);
1b2b03f8 KK	117	if (filep->f_flags & O_NONBLOCK)
	118	return -EAGAIN;
	119	wait_event_interruptible(dev->wait, (dev->work \|\|
ebb06be1	120	!list_empty(list)));
1b2b03f8 KK	121	if (signal_pending(current))
1b2b03f8 KK	122	return -ERESTARTSYS;
ebb06be1	123	spin_lock_irq(&dev->lock);
1b2b03f8	124	}
1b2b03f8 KK	125	if (dev->work)
1b2b03f8 KK	126	dev->work = 0;
ebb06be1 AV	127	if (!list_empty(list)) {
ebb06be1 AV	128	timer = list_first_entry(list, struct mISDNtimer, list);
1b2b03f8	129	list_del(&timer->list);
ebb06be1	130	spin_unlock_irq(&dev->lock);
c46f0a2d	131	if (put_user(timer->id, (int __user *)buf))
1b2b03f8 KK	132	ret = -EFAULT;
	133	else
	134	ret = sizeof(int);
	135	kfree(timer);
ebb06be1 AV	136	} else {
ebb06be1 AV	137	spin_unlock_irq(&dev->lock);
1b2b03f8 KK	138	}
	139	return ret;
	140	}
	141
1b2b03f8 KK	142	static unsigned int
	143	mISDN_poll(struct file filep, poll_table wait)
	144	{
	145	struct mISDNtimerdev *dev = filep->private_data;
	146	unsigned int mask = POLLERR;
	147
	148	if (*debug & DEBUG_TIMER)
	149	printk(KERN_DEBUG "%s(%p, %p)\n", __func__, filep, wait);
	150	if (dev) {
	151	poll_wait(filep, &dev->wait, wait);
	152	mask = 0;
	153	if (dev->work \|\| !list_empty(&dev->expired))
	154	mask \|= (POLLIN \| POLLRDNORM);
	155	if (*debug & DEBUG_TIMER)
	156	printk(KERN_DEBUG "%s work(%d) empty(%d)\n", __func__,
475be4d8	157	dev->work, list_empty(&dev->expired));
1b2b03f8 KK	158	}
	159	return mask;
	160	}
	161
	162	static void
ce425a9f	163	dev_expire_timer(unsigned long data)
1b2b03f8	164	{
ce425a9f	165	struct mISDNtimer timer = (void )data;
1b2b03f8 KK	166	u_long flags;
	167
	168	spin_lock_irqsave(&timer->dev->lock, flags);
1b108956 AV	169	if (timer->id >= 0)
1b108956 AV	170	list_move_tail(&timer->list, &timer->dev->expired);
1b2b03f8 KK	171	spin_unlock_irqrestore(&timer->dev->lock, flags);
	172	wake_up_interruptible(&timer->dev->wait);
	173	}
	174
	175	static int
	176	misdn_add_timer(struct mISDNtimerdev *dev, int timeout)
	177	{
475be4d8	178	int id;
1b2b03f8 KK	179	struct mISDNtimer *timer;
	180
	181	if (!timeout) {
	182	dev->work = 1;
	183	wake_up_interruptible(&dev->wait);
	184	id = 0;
	185	} else {
	186	timer = kzalloc(sizeof(struct mISDNtimer), GFP_KERNEL);
	187	if (!timer)
	188	return -ENOMEM;
1678ec00 AV	189	timer->dev = dev;
	190	setup_timer(&timer->tl, dev_expire_timer, (long)timer);
	191	spin_lock_irq(&dev->lock);
	192	id = timer->id = dev->next_id++;
1b2b03f8 KK	193	if (dev->next_id < 0)
	194	dev->next_id = 1;
	195	list_add_tail(&timer->list, &dev->pending);
1b2b03f8 KK	196	timer->tl.expires = jiffies + ((HZ * (u_long)timeout) / 1000);
1b2b03f8 KK	197	add_timer(&timer->tl);
1678ec00	198	spin_unlock_irq(&dev->lock);
1b2b03f8 KK	199	}
	200	return id;
	201	}
	202
	203	static int
	204	misdn_del_timer(struct mISDNtimerdev *dev, int id)
	205	{
1b2b03f8	206	struct mISDNtimer *timer;
1b2b03f8	207
1b108956	208	spin_lock_irq(&dev->lock);
1b2b03f8 KK	209	list_for_each_entry(timer, &dev->pending, list) {
	210	if (timer->id == id) {
	211	list_del_init(&timer->list);
1b108956 AV	212	timer->id = -1;
	213	spin_unlock_irq(&dev->lock);
	214	del_timer_sync(&timer->tl);
1b2b03f8	215	kfree(timer);
1b108956	216	return id;
1b2b03f8 KK	217	}
1b2b03f8 KK	218	}
1b108956 AV	219	spin_unlock_irq(&dev->lock);
1b108956 AV	220	return 0;
1b2b03f8 KK	221	}
1b2b03f8 KK	222
703c631e AB	223	static long
703c631e AB	224	mISDN_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
1b2b03f8 KK	225	{
	226	struct mISDNtimerdev *dev = filep->private_data;
	227	int id, tout, ret = 0;
	228
	229
	230	if (*debug & DEBUG_TIMER)
	231	printk(KERN_DEBUG "%s(%p, %x, %lx)\n", __func__,
475be4d8	232	filep, cmd, arg);
76a64921	233	mutex_lock(&mISDN_mutex);
1b2b03f8 KK	234	switch (cmd) {
	235	case IMADDTIMER:
	236	if (get_user(tout, (int __user *)arg)) {
	237	ret = -EFAULT;
	238	break;
	239	}
	240	id = misdn_add_timer(dev, tout);
	241	if (*debug & DEBUG_TIMER)
	242	printk(KERN_DEBUG "%s add %d id %d\n", __func__,
475be4d8	243	tout, id);
1b2b03f8 KK	244	if (id < 0) {
	245	ret = id;
	246	break;
	247	}
	248	if (put_user(id, (int __user *)arg))
	249	ret = -EFAULT;
	250	break;
	251	case IMDELTIMER:
	252	if (get_user(id, (int __user *)arg)) {
	253	ret = -EFAULT;
	254	break;
	255	}
	256	if (*debug & DEBUG_TIMER)
	257	printk(KERN_DEBUG "%s del id %d\n", __func__, id);
	258	id = misdn_del_timer(dev, id);
	259	if (put_user(id, (int __user *)arg))
	260	ret = -EFAULT;
	261	break;
	262	default:
	263	ret = -EINVAL;
	264	}
76a64921	265	mutex_unlock(&mISDN_mutex);
1b2b03f8 KK	266	return ret;
	267	}
	268
eac74af9	269	static const struct file_operations mISDN_fops = {
89b107ad	270	.owner = THIS_MODULE,
1b2b03f8	271	.read = mISDN_read,
1b2b03f8	272	.poll = mISDN_poll,
703c631e	273	.unlocked_ioctl = mISDN_ioctl,
1b2b03f8 KK	274	.open = mISDN_open,
1b2b03f8 KK	275	.release = mISDN_close,
6038f373	276	.llseek = no_llseek,
1b2b03f8 KK	277	};
	278
	279	static struct miscdevice mISDNtimer = {
	280	.minor = MISC_DYNAMIC_MINOR,
	281	.name = "mISDNtimer",
	282	.fops = &mISDN_fops,
	283	};
	284
	285	int
dfa96ec1	286	mISDN_inittimer(u_int *deb)
1b2b03f8 KK	287	{
	288	int err;
	289
	290	debug = deb;
	291	err = misc_register(&mISDNtimer);
	292	if (err)
	293	printk(KERN_WARNING "mISDN: Could not register timer device\n");
	294	return err;
	295	}
	296
	297	void mISDN_timer_cleanup(void)
	298	{
	299	misc_deregister(&mISDNtimer);
	300	}