Revision 1ab5ecb90cb6a3df1476e052f76a6e8f6511cb3d authored by Stanislav Kinsbursky on 12 March 2012, 02:59:41 UTC, committed by David S. Miller on 13 March 2012, 00:14:00 UTC
v3: added previously removed sock_put() to the tun_release() callback, because sk_release_kernel() doesn't drop the socket reference. v2: sk_release_kernel() used for socket release. Dummy tun_release() is required for sk_release_kernel() ---> sock_release() ---> sock->ops->release() call. TUN was designed to destroy it's socket on network namesapce shutdown. But this will never happen for persistent device, because it's socket holds network namespace. This patch removes of holding network namespace by TUN socket and replaces it by creating socket in init_net and then changing it's net it to desired one. On shutdown socket is moved back to init_net prior to final put. Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent de5c374
mpcore_wdt.c
/*
* Watchdog driver for the mpcore watchdog timer
*
* (c) Copyright 2004 ARM Limited
*
* Based on the SoftDog driver:
* (c) Copyright 1996 Alan Cox <alan@lxorguk.ukuu.org.uk>,
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
* warranty for any of this software. This material is provided
* "AS-IS" and at no charge.
*
* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
*
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <asm/smp_twd.h>
struct mpcore_wdt {
unsigned long timer_alive;
struct device *dev;
void __iomem *base;
int irq;
unsigned int perturb;
char expect_close;
};
static struct platform_device *mpcore_wdt_dev;
static DEFINE_SPINLOCK(wdt_lock);
#define TIMER_MARGIN 60
static int mpcore_margin = TIMER_MARGIN;
module_param(mpcore_margin, int, 0);
MODULE_PARM_DESC(mpcore_margin,
"MPcore timer margin in seconds. (0 < mpcore_margin < 65536, default="
__MODULE_STRING(TIMER_MARGIN) ")");
static int nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, int, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
#define ONLY_TESTING 0
static int mpcore_noboot = ONLY_TESTING;
module_param(mpcore_noboot, int, 0);
MODULE_PARM_DESC(mpcore_noboot, "MPcore watchdog action, "
"set to 1 to ignore reboots, 0 to reboot (default="
__MODULE_STRING(ONLY_TESTING) ")");
/*
* This is the interrupt handler. Note that we only use this
* in testing mode, so don't actually do a reboot here.
*/
static irqreturn_t mpcore_wdt_fire(int irq, void *arg)
{
struct mpcore_wdt *wdt = arg;
/* Check it really was our interrupt */
if (readl(wdt->base + TWD_WDOG_INTSTAT)) {
dev_printk(KERN_CRIT, wdt->dev,
"Triggered - Reboot ignored.\n");
/* Clear the interrupt on the watchdog */
writel(1, wdt->base + TWD_WDOG_INTSTAT);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
/*
* mpcore_wdt_keepalive - reload the timer
*
* Note that the spec says a DIFFERENT value must be written to the reload
* register each time. The "perturb" variable deals with this by adding 1
* to the count every other time the function is called.
*/
static void mpcore_wdt_keepalive(struct mpcore_wdt *wdt)
{
unsigned long count;
spin_lock(&wdt_lock);
/* Assume prescale is set to 256 */
count = __raw_readl(wdt->base + TWD_WDOG_COUNTER);
count = (0xFFFFFFFFU - count) * (HZ / 5);
count = (count / 256) * mpcore_margin;
/* Reload the counter */
writel(count + wdt->perturb, wdt->base + TWD_WDOG_LOAD);
wdt->perturb = wdt->perturb ? 0 : 1;
spin_unlock(&wdt_lock);
}
static void mpcore_wdt_stop(struct mpcore_wdt *wdt)
{
spin_lock(&wdt_lock);
writel(0x12345678, wdt->base + TWD_WDOG_DISABLE);
writel(0x87654321, wdt->base + TWD_WDOG_DISABLE);
writel(0x0, wdt->base + TWD_WDOG_CONTROL);
spin_unlock(&wdt_lock);
}
static void mpcore_wdt_start(struct mpcore_wdt *wdt)
{
dev_printk(KERN_INFO, wdt->dev, "enabling watchdog.\n");
/* This loads the count register but does NOT start the count yet */
mpcore_wdt_keepalive(wdt);
if (mpcore_noboot) {
/* Enable watchdog - prescale=256, watchdog mode=0, enable=1 */
writel(0x0000FF01, wdt->base + TWD_WDOG_CONTROL);
} else {
/* Enable watchdog - prescale=256, watchdog mode=1, enable=1 */
writel(0x0000FF09, wdt->base + TWD_WDOG_CONTROL);
}
}
static int mpcore_wdt_set_heartbeat(int t)
{
if (t < 0x0001 || t > 0xFFFF)
return -EINVAL;
mpcore_margin = t;
return 0;
}
/*
* /dev/watchdog handling
*/
static int mpcore_wdt_open(struct inode *inode, struct file *file)
{
struct mpcore_wdt *wdt = platform_get_drvdata(mpcore_wdt_dev);
if (test_and_set_bit(0, &wdt->timer_alive))
return -EBUSY;
if (nowayout)
__module_get(THIS_MODULE);
file->private_data = wdt;
/*
* Activate timer
*/
mpcore_wdt_start(wdt);
return nonseekable_open(inode, file);
}
static int mpcore_wdt_release(struct inode *inode, struct file *file)
{
struct mpcore_wdt *wdt = file->private_data;
/*
* Shut off the timer.
* Lock it in if it's a module and we set nowayout
*/
if (wdt->expect_close == 42)
mpcore_wdt_stop(wdt);
else {
dev_printk(KERN_CRIT, wdt->dev,
"unexpected close, not stopping watchdog!\n");
mpcore_wdt_keepalive(wdt);
}
clear_bit(0, &wdt->timer_alive);
wdt->expect_close = 0;
return 0;
}
static ssize_t mpcore_wdt_write(struct file *file, const char *data,
size_t len, loff_t *ppos)
{
struct mpcore_wdt *wdt = file->private_data;
/*
* Refresh the timer.
*/
if (len) {
if (!nowayout) {
size_t i;
/* In case it was set long ago */
wdt->expect_close = 0;
for (i = 0; i != len; i++) {
char c;
if (get_user(c, data + i))
return -EFAULT;
if (c == 'V')
wdt->expect_close = 42;
}
}
mpcore_wdt_keepalive(wdt);
}
return len;
}
static const struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT |
WDIOF_KEEPALIVEPING |
WDIOF_MAGICCLOSE,
.identity = "MPcore Watchdog",
};
static long mpcore_wdt_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
struct mpcore_wdt *wdt = file->private_data;
int ret;
union {
struct watchdog_info ident;
int i;
} uarg;
if (_IOC_DIR(cmd) && _IOC_SIZE(cmd) > sizeof(uarg))
return -ENOTTY;
if (_IOC_DIR(cmd) & _IOC_WRITE) {
ret = copy_from_user(&uarg, (void __user *)arg, _IOC_SIZE(cmd));
if (ret)
return -EFAULT;
}
switch (cmd) {
case WDIOC_GETSUPPORT:
uarg.ident = ident;
ret = 0;
break;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
uarg.i = 0;
ret = 0;
break;
case WDIOC_SETOPTIONS:
ret = -EINVAL;
if (uarg.i & WDIOS_DISABLECARD) {
mpcore_wdt_stop(wdt);
ret = 0;
}
if (uarg.i & WDIOS_ENABLECARD) {
mpcore_wdt_start(wdt);
ret = 0;
}
break;
case WDIOC_KEEPALIVE:
mpcore_wdt_keepalive(wdt);
ret = 0;
break;
case WDIOC_SETTIMEOUT:
ret = mpcore_wdt_set_heartbeat(uarg.i);
if (ret)
break;
mpcore_wdt_keepalive(wdt);
/* Fall */
case WDIOC_GETTIMEOUT:
uarg.i = mpcore_margin;
ret = 0;
break;
default:
return -ENOTTY;
}
if (ret == 0 && _IOC_DIR(cmd) & _IOC_READ) {
ret = copy_to_user((void __user *)arg, &uarg, _IOC_SIZE(cmd));
if (ret)
ret = -EFAULT;
}
return ret;
}
/*
* System shutdown handler. Turn off the watchdog if we're
* restarting or halting the system.
*/
static void mpcore_wdt_shutdown(struct platform_device *dev)
{
struct mpcore_wdt *wdt = platform_get_drvdata(dev);
if (system_state == SYSTEM_RESTART || system_state == SYSTEM_HALT)
mpcore_wdt_stop(wdt);
}
/*
* Kernel Interfaces
*/
static const struct file_operations mpcore_wdt_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = mpcore_wdt_write,
.unlocked_ioctl = mpcore_wdt_ioctl,
.open = mpcore_wdt_open,
.release = mpcore_wdt_release,
};
static struct miscdevice mpcore_wdt_miscdev = {
.minor = WATCHDOG_MINOR,
.name = "watchdog",
.fops = &mpcore_wdt_fops,
};
static int __devinit mpcore_wdt_probe(struct platform_device *dev)
{
struct mpcore_wdt *wdt;
struct resource *res;
int ret;
/* We only accept one device, and it must have an id of -1 */
if (dev->id != -1)
return -ENODEV;
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
if (!res) {
ret = -ENODEV;
goto err_out;
}
wdt = kzalloc(sizeof(struct mpcore_wdt), GFP_KERNEL);
if (!wdt) {
ret = -ENOMEM;
goto err_out;
}
wdt->dev = &dev->dev;
wdt->irq = platform_get_irq(dev, 0);
if (wdt->irq < 0) {
ret = -ENXIO;
goto err_free;
}
wdt->base = ioremap(res->start, resource_size(res));
if (!wdt->base) {
ret = -ENOMEM;
goto err_free;
}
mpcore_wdt_miscdev.parent = &dev->dev;
ret = misc_register(&mpcore_wdt_miscdev);
if (ret) {
dev_printk(KERN_ERR, wdt->dev,
"cannot register miscdev on minor=%d (err=%d)\n",
WATCHDOG_MINOR, ret);
goto err_misc;
}
ret = request_irq(wdt->irq, mpcore_wdt_fire, 0, "mpcore_wdt", wdt);
if (ret) {
dev_printk(KERN_ERR, wdt->dev,
"cannot register IRQ%d for watchdog\n", wdt->irq);
goto err_irq;
}
mpcore_wdt_stop(wdt);
platform_set_drvdata(dev, wdt);
mpcore_wdt_dev = dev;
return 0;
err_irq:
misc_deregister(&mpcore_wdt_miscdev);
err_misc:
iounmap(wdt->base);
err_free:
kfree(wdt);
err_out:
return ret;
}
static int __devexit mpcore_wdt_remove(struct platform_device *dev)
{
struct mpcore_wdt *wdt = platform_get_drvdata(dev);
platform_set_drvdata(dev, NULL);
misc_deregister(&mpcore_wdt_miscdev);
mpcore_wdt_dev = NULL;
free_irq(wdt->irq, wdt);
iounmap(wdt->base);
kfree(wdt);
return 0;
}
#ifdef CONFIG_PM
static int mpcore_wdt_suspend(struct platform_device *dev, pm_message_t msg)
{
struct mpcore_wdt *wdt = platform_get_drvdata(dev);
mpcore_wdt_stop(wdt); /* Turn the WDT off */
return 0;
}
static int mpcore_wdt_resume(struct platform_device *dev)
{
struct mpcore_wdt *wdt = platform_get_drvdata(dev);
/* re-activate timer */
if (test_bit(0, &wdt->timer_alive))
mpcore_wdt_start(wdt);
return 0;
}
#else
#define mpcore_wdt_suspend NULL
#define mpcore_wdt_resume NULL
#endif
/* work with hotplug and coldplug */
MODULE_ALIAS("platform:mpcore_wdt");
static struct platform_driver mpcore_wdt_driver = {
.probe = mpcore_wdt_probe,
.remove = __devexit_p(mpcore_wdt_remove),
.suspend = mpcore_wdt_suspend,
.resume = mpcore_wdt_resume,
.shutdown = mpcore_wdt_shutdown,
.driver = {
.owner = THIS_MODULE,
.name = "mpcore_wdt",
},
};
static char banner[] __initdata = KERN_INFO "MPcore Watchdog Timer: 0.1. "
"mpcore_noboot=%d mpcore_margin=%d sec (nowayout= %d)\n";
static int __init mpcore_wdt_init(void)
{
/*
* Check that the margin value is within it's range;
* if not reset to the default
*/
if (mpcore_wdt_set_heartbeat(mpcore_margin)) {
mpcore_wdt_set_heartbeat(TIMER_MARGIN);
printk(KERN_INFO "mpcore_margin value must be 0 < mpcore_margin < 65536, using %d\n",
TIMER_MARGIN);
}
printk(banner, mpcore_noboot, mpcore_margin, nowayout);
return platform_driver_register(&mpcore_wdt_driver);
}
static void __exit mpcore_wdt_exit(void)
{
platform_driver_unregister(&mpcore_wdt_driver);
}
module_init(mpcore_wdt_init);
module_exit(mpcore_wdt_exit);
MODULE_AUTHOR("ARM Limited");
MODULE_DESCRIPTION("MPcore Watchdog Device Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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