Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 216 insertions, 0 deletions

diff --git a/drivers/watchdog/xen_wdt.c b/drivers/watchdog/xen_wdt.c
new file mode 100644
index 000000000..f1c016d01
--- /dev/null
+++ b/drivers/watchdog/xen_wdt.c
@@ -0,0 +1,216 @@
+/*
+ *	Xen Watchdog Driver
+ *
+ *	(c) Copyright 2010 Novell, Inc.
+ *
+ *	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.
+ */
+
+#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 sched_watchdog wd = { .id = ~0 };
+	int ret = HYPERVISOR_sched_op(SCHEDOP_watchdog, &wd);
+
+	if (ret == -ENOSYS) {
+		dev_err(&pdev->dev, "watchdog not supported by hypervisor\n");
+		return -ENODEV;
+	}
+
+	if (ret != -EINVAL) {
+		dev_err(&pdev->dev, "unexpected hypervisor error (%d)\n", ret);
+		return -ENODEV;
+	}
+
+	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;
+	}
+
+	dev_info(&pdev->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");