add kern.watchdog sysctl and generic watchdog interface;

based on feedback and discussions with mickey, henric, fgsch and jakob.
ok art@, mickey@, jakob@, henric@

1 files changed, 116 insertions, 0 deletions

diff --git a/sys/kern/kern_watchdog.c b/sys/kern/kern_watchdog.c
new file mode 100644
index 00000000000..8ace7b27c57
--- /dev/null
+++ b/sys/kern/kern_watchdog.c
@@ -0,0 +1,116 @@
+/*      $OpenBSD: kern_watchdog.c,v 1.1 2003/01/21 16:59:23 markus Exp $        */
+
+/*
+ * Copyright (c) 2003 Markus Friedl.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/systm.h>
+#include <sys/sysctl.h>
+#include <sys/time.h>
+
+void	wdog_init(void);
+void	wdog_tickle(void *arg);
+void	wdog_shutdown(void *arg);
+int	(*wdog_ctl_cb)(void *, int) = NULL;
+void	*wdog_ctl_cb_arg = NULL;
+int	wdog_period = 0;
+int	wdog_auto = 1;
+struct timeout	wdog_timeout;
+
+void
+wdog_init(void)
+{
+	timeout_set(&wdog_timeout, wdog_tickle, NULL);
+	shutdownhook_establish(wdog_shutdown, NULL);
+}
+
+void
+wdog_register(void *cb_arg, int (*cb)(void *, int))
+{
+	if (wdog_ctl_cb != NULL)
+		return;
+	wdog_init();
+	wdog_ctl_cb = cb;
+	wdog_ctl_cb_arg = cb_arg;
+}
+
+void
+wdog_tickle(void *arg)
+{
+	if (wdog_ctl_cb == NULL)
+		return;
+	(void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, wdog_period);
+	timeout_add(&wdog_timeout, wdog_period * hz / 2);
+}
+
+void
+wdog_shutdown(void *arg)
+{
+	if (wdog_ctl_cb == NULL)
+		return;
+	timeout_del(&wdog_timeout);
+	(void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, 0);
+}
+
+int
+sysctl_wdog(name, namelen, oldp, oldlenp, newp, newlen)
+	int *name;
+	u_int namelen;
+	void *oldp;
+	size_t *oldlenp;
+	void *newp;
+	size_t newlen;
+{
+	int error, period;
+
+	if (wdog_ctl_cb == NULL)
+		return (EOPNOTSUPP);
+
+	switch (name[0]) {
+	case KERN_WATCHDOG_PERIOD:
+		period = wdog_period;
+		error = sysctl_int(oldp, oldlenp, newp, newlen, &period);
+		if (error)
+			return (error);
+		if (newp) {
+			timeout_del(&wdog_timeout);
+			wdog_period = (*wdog_ctl_cb)(wdog_ctl_cb_arg, period);
+		}
+		break;
+	case KERN_WATCHDOG_AUTO:
+		error = sysctl_int(oldp, oldlenp, newp, newlen, &wdog_auto);
+		if (error)
+			return (error);
+		break;
+	default:
+		return (EINVAL);
+	} 
+
+	timeout_del(&wdog_timeout);
+	if (wdog_auto && wdog_period > 0) {
+		(void) (*wdog_ctl_cb)(wdog_ctl_cb_arg, wdog_period);
+		timeout_add(&wdog_timeout, wdog_period * hz / 2);
+	}
+	return (error);
+}