linux-stable/drivers/isdn/mISDN/timerdev.c
Thomas Gleixner 1802d0beec treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 655 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070034.575739538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:41 -07:00

293 lines
6.4 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
*
* general timer device for using in ISDN stacks
*
* Author Karsten Keil <kkeil@novell.com>
*
* Copyright 2008 by Karsten Keil <kkeil@novell.com>
*/
#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 <linux/sched/signal.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 __poll_t
mISDN_poll(struct file *filep, poll_table *wait)
{
struct mISDNtimerdev *dev = filep->private_data;
__poll_t mask = EPOLLERR;
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 |= (EPOLLIN | EPOLLRDNORM);
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(struct timer_list *t)
{
struct mISDNtimer *timer = from_timer(timer, t, tl);
u_long flags;
spin_lock_irqsave(&timer->dev->lock, flags);
if (timer->id >= 0)
list_move_tail(&timer->list, &timer->dev->expired);
wake_up_interruptible(&timer->dev->wait);
spin_unlock_irqrestore(&timer->dev->lock, flags);
}
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;
timer_setup(&timer->tl, dev_expire_timer, 0);
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);
}