[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/timer.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mISDNif.h>
#include "core.h"

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 (*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 __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 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 const 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(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>
	22	#include <linux/timer.h>
	23	#include <linux/miscdevice.h>
	24	#include <linux/module.h>
	25	#include <linux/mISDNif.h>
5b834354	26	#include "core.h"
1b2b03f8	27
dfa96ec1	28	static u_int *debug;
1b2b03f8 KK	29
	30
	31	struct mISDNtimerdev {
	32	int next_id;
	33	struct list_head pending;
	34	struct list_head expired;
	35	wait_queue_head_t wait;
	36	u_int work;
	37	spinlock_t lock; /* protect lists */
	38	};
	39
	40	struct mISDNtimer {
	41	struct list_head list;
	42	struct mISDNtimerdev *dev;
	43	struct timer_list tl;
	44	int id;
	45	};
	46
	47	static int
	48	mISDN_open(struct inode ino, struct file filep)
	49	{
	50	struct mISDNtimerdev *dev;
	51
	52	if (*debug & DEBUG_TIMER)
	53	printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep);
	54	dev = kmalloc(sizeof(struct mISDNtimerdev) , GFP_KERNEL);
	55	if (!dev)
	56	return -ENOMEM;
	57	dev->next_id = 1;
	58	INIT_LIST_HEAD(&dev->pending);
	59	INIT_LIST_HEAD(&dev->expired);
	60	spin_lock_init(&dev->lock);
	61	dev->work = 0;
	62	init_waitqueue_head(&dev->wait);
	63	filep->private_data = dev;
	64	__module_get(THIS_MODULE);
6bff338b	65	return nonseekable_open(ino, filep);
1b2b03f8 KK	66	}
	67
	68	static int
	69	mISDN_close(struct inode ino, struct file filep)
	70	{
	71	struct mISDNtimerdev *dev = filep->private_data;
	72	struct mISDNtimer timer, next;
	73
	74	if (*debug & DEBUG_TIMER)
	75	printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep);
	76	list_for_each_entry_safe(timer, next, &dev->pending, list) {
	77	del_timer(&timer->tl);
	78	kfree(timer);
	79	}
	80	list_for_each_entry_safe(timer, next, &dev->expired, list) {
	81	kfree(timer);
	82	}
	83	kfree(dev);
	84	module_put(THIS_MODULE);
	85	return 0;
	86	}
	87
	88	static ssize_t
c46f0a2d	89	mISDN_read(struct file filep, char __user buf, size_t count, loff_t *off)
1b2b03f8 KK	90	{
	91	struct mISDNtimerdev *dev = filep->private_data;
	92	struct mISDNtimer *timer;
	93	u_long flags;
	94	int ret = 0;
	95
	96	if (*debug & DEBUG_TIMER)
	97	printk(KERN_DEBUG "%s(%p, %p, %d, %p)\n", __func__,
	98	filep, buf, (int)count, off);
	99	if (*off != filep->f_pos)
	100	return -ESPIPE;
	101
	102	if (list_empty(&dev->expired) && (dev->work == 0)) {
	103	if (filep->f_flags & O_NONBLOCK)
	104	return -EAGAIN;
	105	wait_event_interruptible(dev->wait, (dev->work \|\|
	106	!list_empty(&dev->expired)));
	107	if (signal_pending(current))
	108	return -ERESTARTSYS;
	109	}
	110	if (count < sizeof(int))
	111	return -ENOSPC;
	112	if (dev->work)
	113	dev->work = 0;
	114	if (!list_empty(&dev->expired)) {
	115	spin_lock_irqsave(&dev->lock, flags);
	116	timer = (struct mISDNtimer *)dev->expired.next;
	117	list_del(&timer->list);
	118	spin_unlock_irqrestore(&dev->lock, flags);
c46f0a2d	119	if (put_user(timer->id, (int __user *)buf))
1b2b03f8 KK	120	ret = -EFAULT;
	121	else
	122	ret = sizeof(int);
	123	kfree(timer);
	124	}
	125	return ret;
	126	}
	127
1b2b03f8 KK	128	static unsigned int
	129	mISDN_poll(struct file filep, poll_table wait)
	130	{
	131	struct mISDNtimerdev *dev = filep->private_data;
	132	unsigned int mask = POLLERR;
	133
	134	if (*debug & DEBUG_TIMER)
	135	printk(KERN_DEBUG "%s(%p, %p)\n", __func__, filep, wait);
	136	if (dev) {
	137	poll_wait(filep, &dev->wait, wait);
	138	mask = 0;
	139	if (dev->work \|\| !list_empty(&dev->expired))
	140	mask \|= (POLLIN \| POLLRDNORM);
	141	if (*debug & DEBUG_TIMER)
	142	printk(KERN_DEBUG "%s work(%d) empty(%d)\n", __func__,
	143	dev->work, list_empty(&dev->expired));
	144	}
	145	return mask;
	146	}
	147
	148	static void
ce425a9f	149	dev_expire_timer(unsigned long data)
1b2b03f8	150	{
ce425a9f	151	struct mISDNtimer timer = (void )data;
1b2b03f8 KK	152	u_long flags;
	153
	154	spin_lock_irqsave(&timer->dev->lock, flags);
211174ea	155	list_move_tail(&timer->list, &timer->dev->expired);
1b2b03f8 KK	156	spin_unlock_irqrestore(&timer->dev->lock, flags);
	157	wake_up_interruptible(&timer->dev->wait);
	158	}
	159
	160	static int
	161	misdn_add_timer(struct mISDNtimerdev *dev, int timeout)
	162	{
	163	int id;
	164	u_long flags;
	165	struct mISDNtimer *timer;
	166
	167	if (!timeout) {
	168	dev->work = 1;
	169	wake_up_interruptible(&dev->wait);
	170	id = 0;
	171	} else {
	172	timer = kzalloc(sizeof(struct mISDNtimer), GFP_KERNEL);
	173	if (!timer)
	174	return -ENOMEM;
	175	spin_lock_irqsave(&dev->lock, flags);
	176	timer->id = dev->next_id++;
	177	if (dev->next_id < 0)
	178	dev->next_id = 1;
	179	list_add_tail(&timer->list, &dev->pending);
	180	spin_unlock_irqrestore(&dev->lock, flags);
	181	timer->dev = dev;
	182	timer->tl.data = (long)timer;
ce425a9f	183	timer->tl.function = dev_expire_timer;
1b2b03f8 KK	184	init_timer(&timer->tl);
	185	timer->tl.expires = jiffies + ((HZ * (u_long)timeout) / 1000);
	186	add_timer(&timer->tl);
	187	id = timer->id;
	188	}
	189	return id;
	190	}
	191
	192	static int
	193	misdn_del_timer(struct mISDNtimerdev *dev, int id)
	194	{
	195	u_long flags;
	196	struct mISDNtimer *timer;
	197	int ret = 0;
	198
	199	spin_lock_irqsave(&dev->lock, flags);
	200	list_for_each_entry(timer, &dev->pending, list) {
	201	if (timer->id == id) {
	202	list_del_init(&timer->list);
ce425a9f AK	203	/* RED-PEN AK: race -- timer can be still running on
	204	* other CPU. Needs reference count I think
	205	*/
1b2b03f8 KK	206	del_timer(&timer->tl);
	207	ret = timer->id;
	208	kfree(timer);
	209	goto unlock;
	210	}
	211	}
	212	unlock:
	213	spin_unlock_irqrestore(&dev->lock, flags);
	214	return ret;
	215	}
	216
	217	static int
	218	mISDN_ioctl(struct inode inode, struct file filep, unsigned int cmd,
	219	unsigned long arg)
	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__,
	227	filep, cmd, arg);
	228	switch (cmd) {
	229	case IMADDTIMER:
	230	if (get_user(tout, (int __user *)arg)) {
	231	ret = -EFAULT;
	232	break;
	233	}
	234	id = misdn_add_timer(dev, tout);
	235	if (*debug & DEBUG_TIMER)
	236	printk(KERN_DEBUG "%s add %d id %d\n", __func__,
	237	tout, id);
	238	if (id < 0) {
	239	ret = id;
	240	break;
	241	}
	242	if (put_user(id, (int __user *)arg))
	243	ret = -EFAULT;
	244	break;
	245	case IMDELTIMER:
	246	if (get_user(id, (int __user *)arg)) {
	247	ret = -EFAULT;
	248	break;
	249	}
	250	if (*debug & DEBUG_TIMER)
	251	printk(KERN_DEBUG "%s del id %d\n", __func__, id);
	252	id = misdn_del_timer(dev, id);
	253	if (put_user(id, (int __user *)arg))
	254	ret = -EFAULT;
	255	break;
	256	default:
	257	ret = -EINVAL;
	258	}
	259	return ret;
	260	}
	261
eac74af9	262	static const struct file_operations mISDN_fops = {
1b2b03f8	263	.read = mISDN_read,
1b2b03f8 KK	264	.poll = mISDN_poll,
	265	.ioctl = mISDN_ioctl,
	266	.open = mISDN_open,
	267	.release = mISDN_close,
	268	};
	269
	270	static struct miscdevice mISDNtimer = {
	271	.minor = MISC_DYNAMIC_MINOR,
	272	.name = "mISDNtimer",
	273	.fops = &mISDN_fops,
	274	};
	275
	276	int
dfa96ec1	277	mISDN_inittimer(u_int *deb)
1b2b03f8 KK	278	{
	279	int err;
	280
	281	debug = deb;
	282	err = misc_register(&mISDNtimer);
	283	if (err)
	284	printk(KERN_WARNING "mISDN: Could not register timer device\n");
	285	return err;
	286	}
	287
	288	void mISDN_timer_cleanup(void)
	289	{
	290	misc_deregister(&mISDNtimer);
	291	}