1 files changed, 54 insertions, 201 deletions

diff --git a/drivers/watchdog/xen_wdt.c b/drivers/watchdog/xen_wdt.c
index cf0e650c2015..f1c016d015b3 100644
--- a/drivers/watchdog/xen_wdt.c
+++ b/drivers/watchdog/xen_wdt.c
@@ -9,10 +9,7 @@
  *	2 of the License, or (at your option) any later version.
  */
 
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#define DRV_NAME	"wdt"
-#define DRV_VERSION	"0.01"
+#define DRV_NAME	"xen_wdt"
 
 #include <linux/bug.h>
 #include <linux/errno.h>
@@ -21,25 +18,20 @@
 #include <linux/kernel.h>
 #include <linux/ktime.h>
 #include <linux/init.h>
-#include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/platform_device.h>
-#include <linux/spinlock.h>
-#include <linux/uaccess.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 DEFINE_SPINLOCK(wdt_lock);
 static struct sched_watchdog wdt;
-static __kernel_time_t wdt_expires;
-static bool is_active, expect_release;
+static time64_t wdt_expires;
 
 #define WATCHDOG_TIMEOUT 60 /* in seconds */
-static unsigned int timeout = WATCHDOG_TIMEOUT;
+static unsigned int timeout;
 module_param(timeout, uint, S_IRUGO);
 MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds "
 	"(default=" __MODULE_STRING(WATCHDOG_TIMEOUT) ")");
@@ -49,20 +41,18 @@ module_param(nowayout, bool, S_IRUGO);
 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
 	"(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
-static inline __kernel_time_t set_timeout(void)
+static inline time64_t set_timeout(struct watchdog_device *wdd)
 {
-	wdt.timeout = timeout;
-	return ktime_to_timespec(ktime_get()).tv_sec + timeout;
+	wdt.timeout = wdd->timeout;
+	return ktime_get_seconds() + wdd->timeout;
 }
 
-static int xen_wdt_start(void)
+static int xen_wdt_start(struct watchdog_device *wdd)
 {
-	__kernel_time_t expires;
+	time64_t expires;
 	int err;
 
-	spin_lock(&wdt_lock);
-
-	expires = set_timeout();
+	expires = set_timeout(wdd);
 	if (!wdt.id)
 		err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt);
 	else
@@ -74,36 +64,28 @@ static int xen_wdt_start(void)
 	} else
 		BUG_ON(!err);
 
-	spin_unlock(&wdt_lock);
-
 	return err;
 }
 
-static int xen_wdt_stop(void)
+static int xen_wdt_stop(struct watchdog_device *wdd)
 {
 	int err = 0;
 
-	spin_lock(&wdt_lock);
-
 	wdt.timeout = 0;
 	if (wdt.id)
 		err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt);
 	if (!err)
 		wdt.id = 0;
 
-	spin_unlock(&wdt_lock);
-
 	return err;
 }
 
-static int xen_wdt_kick(void)
+static int xen_wdt_kick(struct watchdog_device *wdd)
 {
-	__kernel_time_t expires;
+	time64_t expires;
 	int err;
 
-	spin_lock(&wdt_lock);
-
-	expires = set_timeout();
+	expires = set_timeout(wdd);
 	if (wdt.id)
 		err = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wdt);
 	else
@@ -111,195 +93,72 @@ static int xen_wdt_kick(void)
 	if (!err)
 		wdt_expires = expires;
 
-	spin_unlock(&wdt_lock);
-
-	return err;
-}
-
-static int xen_wdt_open(struct inode *inode, struct file *file)
-{
-	int err;
-
-	/* /dev/watchdog can only be opened once */
-	if (xchg(&is_active, true))
-		return -EBUSY;
-
-	err = xen_wdt_start();
-	if (err == -EBUSY)
-		err = xen_wdt_kick();
-	return err ?: nonseekable_open(inode, file);
-}
-
-static int xen_wdt_release(struct inode *inode, struct file *file)
-{
-	int err = 0;
-
-	if (expect_release)
-		err = xen_wdt_stop();
-	else {
-		pr_crit("unexpected close, not stopping watchdog!\n");
-		xen_wdt_kick();
-	}
-	is_active = err;
-	expect_release = false;
 	return err;
 }
 
-static ssize_t xen_wdt_write(struct file *file, const char __user *data,
-			     size_t len, loff_t *ppos)
+static unsigned int xen_wdt_get_timeleft(struct watchdog_device *wdd)
 {
-	/* See if we got the magic character 'V' and reload the timer */
-	if (len) {
-		if (!nowayout) {
-			size_t i;
-
-			/* in case it was set long ago */
-			expect_release = false;
-
-			/* scan to see whether or not we got the magic
-			   character */
-			for (i = 0; i != len; i++) {
-				char c;
-				if (get_user(c, data + i))
-					return -EFAULT;
-				if (c == 'V')
-					expect_release = true;
-			}
-		}
-
-		/* someone wrote to us, we should reload the timer */
-		xen_wdt_kick();
-	}
-	return len;
+	return wdt_expires - ktime_get_seconds();
 }
 
-static long xen_wdt_ioctl(struct file *file, unsigned int cmd,
-			  unsigned long arg)
-{
-	int new_options, retval = -EINVAL;
-	int new_timeout;
-	int __user *argp = (void __user *)arg;
-	static const struct watchdog_info ident = {
-		.options =		WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
-		.firmware_version =	0,
-		.identity =		DRV_NAME,
-	};
-
-	switch (cmd) {
-	case WDIOC_GETSUPPORT:
-		return copy_to_user(argp, &ident, sizeof(ident)) ? -EFAULT : 0;
-
-	case WDIOC_GETSTATUS:
-	case WDIOC_GETBOOTSTATUS:
-		return put_user(0, argp);
-
-	case WDIOC_SETOPTIONS:
-		if (get_user(new_options, argp))
-			return -EFAULT;
-
-		if (new_options & WDIOS_DISABLECARD)
-			retval = xen_wdt_stop();
-		if (new_options & WDIOS_ENABLECARD) {
-			retval = xen_wdt_start();
-			if (retval == -EBUSY)
-				retval = xen_wdt_kick();
-		}
-		return retval;
-
-	case WDIOC_KEEPALIVE:
-		xen_wdt_kick();
-		return 0;
-
-	case WDIOC_SETTIMEOUT:
-		if (get_user(new_timeout, argp))
-			return -EFAULT;
-		if (!new_timeout)
-			return -EINVAL;
-		timeout = new_timeout;
-		xen_wdt_kick();
-		/* fall through */
-	case WDIOC_GETTIMEOUT:
-		return put_user(timeout, argp);
-
-	case WDIOC_GETTIMELEFT:
-		retval = wdt_expires - ktime_to_timespec(ktime_get()).tv_sec;
-		return put_user(retval, argp);
-	}
-
-	return -ENOTTY;
-}
+static struct watchdog_info xen_wdt_info = {
+	.identity = DRV_NAME,
+	.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
+};
 
-static const struct file_operations xen_wdt_fops = {
-	.owner =		THIS_MODULE,
-	.llseek =		no_llseek,
-	.write =		xen_wdt_write,
-	.unlocked_ioctl =	xen_wdt_ioctl,
-	.open =			xen_wdt_open,
-	.release =		xen_wdt_release,
+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 miscdevice xen_wdt_miscdev = {
-	.minor =	WATCHDOG_MINOR,
-	.name =		"watchdog",
-	.fops =		&xen_wdt_fops,
+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 *dev)
+static int xen_wdt_probe(struct platform_device *pdev)
 {
 	struct sched_watchdog wd = { .id = ~0 };
 	int ret = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wd);
 
-	switch (ret) {
-	case -EINVAL:
-		if (!timeout) {
-			timeout = WATCHDOG_TIMEOUT;
-			pr_info("timeout value invalid, using %d\n", timeout);
-		}
-
-		ret = misc_register(&xen_wdt_miscdev);
-		if (ret) {
-			pr_err("cannot register miscdev on minor=%d (%d)\n",
-			       WATCHDOG_MINOR, ret);
-			break;
-		}
-
-		pr_info("initialized (timeout=%ds, nowayout=%d)\n",
-			timeout, nowayout);
-		break;
-
-	case -ENOSYS:
-		pr_info("not supported\n");
-		ret = -ENODEV;
-		break;
-
-	default:
-		pr_info("bogus return value %d\n", ret);
-		break;
+	if (ret == -ENOSYS) {
+		dev_err(&pdev->dev, "watchdog not supported by hypervisor\n");
+		return -ENODEV;
 	}
 
-	return ret;
-}
+	if (ret != -EINVAL) {
+		dev_err(&pdev->dev, "unexpected hypervisor error (%d)\n", ret);
+		return -ENODEV;
+	}
 
-static int xen_wdt_remove(struct platform_device *dev)
-{
-	/* Stop the timer before we leave */
-	if (!nowayout)
-		xen_wdt_stop();
+	if (watchdog_init_timeout(&xen_wdt_dev, timeout, NULL))
+		dev_info(&pdev->dev, "timeout value invalid, using %d\n",
+			xen_wdt_dev.timeout);
+	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(&pdev->dev, &xen_wdt_dev);
+	if (ret) {
+		dev_err(&pdev->dev, "cannot register watchdog device (%d)\n",
+			ret);
+		return ret;
+	}
 
-	misc_deregister(&xen_wdt_miscdev);
+	dev_info(&pdev->dev, "initialized (timeout=%ds, nowayout=%d)\n",
+		xen_wdt_dev.timeout, nowayout);
 
 	return 0;
 }
 
-static void xen_wdt_shutdown(struct platform_device *dev)
-{
-	xen_wdt_stop();
-}
-
 static int xen_wdt_suspend(struct platform_device *dev, pm_message_t state)
 {
 	typeof(wdt.id) id = wdt.id;
-	int rc = xen_wdt_stop();
+	int rc = xen_wdt_stop(&xen_wdt_dev);
 
 	wdt.id = id;
 	return rc;
@@ -310,13 +169,11 @@ static int xen_wdt_resume(struct platform_device *dev)
 	if (!wdt.id)
 		return 0;
 	wdt.id = 0;
-	return xen_wdt_start();
+	return xen_wdt_start(&xen_wdt_dev);
 }
 
 static struct platform_driver xen_wdt_driver = {
 	.probe          = xen_wdt_probe,
-	.remove         = xen_wdt_remove,
-	.shutdown       = xen_wdt_shutdown,
 	.suspend        = xen_wdt_suspend,
 	.resume         = xen_wdt_resume,
 	.driver         = {
@@ -331,8 +188,6 @@ static int __init xen_wdt_init_module(void)
 	if (!xen_domain())
 		return -ENODEV;
 
-	pr_info("Xen WatchDog Timer Driver v%s\n", DRV_VERSION);
-
 	err = platform_driver_register(&xen_wdt_driver);
 	if (err)
 		return err;
@@ -351,7 +206,6 @@ static void __exit xen_wdt_cleanup_module(void)
 {
 	platform_device_unregister(platform_device);
 	platform_driver_unregister(&xen_wdt_driver);
-	pr_info("module unloaded\n");
 }
 
 module_init(xen_wdt_init_module);
@@ -359,5 +213,4 @@ module_exit(xen_wdt_cleanup_module);
 
 MODULE_AUTHOR("Jan Beulich <jbeulich@novell.com>");
 MODULE_DESCRIPTION("Xen WatchDog Timer Driver");
-MODULE_VERSION(DRV_VERSION);
 MODULE_LICENSE("GPL");