linux/drivers/watchdog/xen_wdt.c
Thomas Gleixner 2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
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 as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00

211 lines
4.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Xen Watchdog Driver
*
* (c) Copyright 2010 Novell, Inc.
*/
#define DRV_NAME "xen_wdt"
#include <linux/bug.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/hrtimer.h>
#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <xen/xen.h>
#include <asm/xen/hypercall.h>
#include <xen/interface/sched.h>
static struct platform_device *platform_device;
static struct sched_watchdog wdt;
static time64_t wdt_expires;
#define WATCHDOG_TIMEOUT 60 /* in seconds */
static unsigned int timeout;
module_param(timeout, uint, S_IRUGO);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds "
"(default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, S_IRUGO);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static inline time64_t set_timeout(struct watchdog_device *wdd)
{
wdt.timeout = wdd->timeout;
return ktime_get_seconds() + wdd->timeout;
}
static int xen_wdt_start(struct watchdog_device *wdd)
{
time64_t expires;
int err;
expires = set_timeout(wdd);
if (!wdt.id)
err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt);
else
err = -EBUSY;
if (err > 0) {
wdt.id = err;
wdt_expires = expires;
err = 0;
} else
BUG_ON(!err);
return err;
}
static int xen_wdt_stop(struct watchdog_device *wdd)
{
int err = 0;
wdt.timeout = 0;
if (wdt.id)
err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt);
if (!err)
wdt.id = 0;
return err;
}
static int xen_wdt_kick(struct watchdog_device *wdd)
{
time64_t expires;
int err;
expires = set_timeout(wdd);
if (wdt.id)
err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt);
else
err = -ENXIO;
if (!err)
wdt_expires = expires;
return err;
}
static unsigned int xen_wdt_get_timeleft(struct watchdog_device *wdd)
{
return wdt_expires - ktime_get_seconds();
}
static struct watchdog_info xen_wdt_info = {
.identity = DRV_NAME,
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
};
static const struct watchdog_ops xen_wdt_ops = {
.owner = THIS_MODULE,
.start = xen_wdt_start,
.stop = xen_wdt_stop,
.ping = xen_wdt_kick,
.get_timeleft = xen_wdt_get_timeleft,
};
static struct watchdog_device xen_wdt_dev = {
.info = &xen_wdt_info,
.ops = &xen_wdt_ops,
.timeout = WATCHDOG_TIMEOUT,
};
static int xen_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct sched_watchdog wd = { .id = ~0 };
int ret = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wd);
if (ret == -ENOSYS) {
dev_err(dev, "watchdog not supported by hypervisor\n");
return -ENODEV;
}
if (ret != -EINVAL) {
dev_err(dev, "unexpected hypervisor error (%d)\n", ret);
return -ENODEV;
}
watchdog_init_timeout(&xen_wdt_dev, timeout, NULL);
watchdog_set_nowayout(&xen_wdt_dev, nowayout);
watchdog_stop_on_reboot(&xen_wdt_dev);
watchdog_stop_on_unregister(&xen_wdt_dev);
ret = devm_watchdog_register_device(dev, &xen_wdt_dev);
if (ret) {
dev_err(dev, "cannot register watchdog device (%d)\n", ret);
return ret;
}
dev_info(dev, "initialized (timeout=%ds, nowayout=%d)\n",
xen_wdt_dev.timeout, nowayout);
return 0;
}
static int xen_wdt_suspend(struct platform_device *dev, pm_message_t state)
{
typeof(wdt.id) id = wdt.id;
int rc = xen_wdt_stop(&xen_wdt_dev);
wdt.id = id;
return rc;
}
static int xen_wdt_resume(struct platform_device *dev)
{
if (!wdt.id)
return 0;
wdt.id = 0;
return xen_wdt_start(&xen_wdt_dev);
}
static struct platform_driver xen_wdt_driver = {
.probe = xen_wdt_probe,
.suspend = xen_wdt_suspend,
.resume = xen_wdt_resume,
.driver = {
.name = DRV_NAME,
},
};
static int __init xen_wdt_init_module(void)
{
int err;
if (!xen_domain())
return -ENODEV;
err = platform_driver_register(&xen_wdt_driver);
if (err)
return err;
platform_device = platform_device_register_simple(DRV_NAME,
-1, NULL, 0);
if (IS_ERR(platform_device)) {
err = PTR_ERR(platform_device);
platform_driver_unregister(&xen_wdt_driver);
}
return err;
}
static void __exit xen_wdt_cleanup_module(void)
{
platform_device_unregister(platform_device);
platform_driver_unregister(&xen_wdt_driver);
}
module_init(xen_wdt_init_module);
module_exit(xen_wdt_cleanup_module);
MODULE_AUTHOR("Jan Beulich <jbeulich@novell.com>");
MODULE_DESCRIPTION("Xen WatchDog Timer Driver");
MODULE_LICENSE("GPL");