1 /*- 2 * Copyright (c) 2004 Poul-Henning Kamp 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer 10 * in this position and unchanged. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR 16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 25 * 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/conf.h> 34 #include <sys/uio.h> 35 #include <sys/kernel.h> 36 #include <sys/malloc.h> 37 #include <sys/module.h> 38 #include <sys/watchdog.h> 39 #include <sys/bus.h> 40 #include <machine/bus.h> 41 42 static struct cdev *wd_dev; 43 static volatile u_int wd_last_u; 44 45 static int 46 kern_do_pat(u_int utim) 47 { 48 int error; 49 50 if ((utim & WD_LASTVAL) != 0 && (utim & WD_INTERVAL) > 0) 51 return (EINVAL); 52 53 if ((utim & WD_LASTVAL) != 0) { 54 MPASS((wd_last_u & ~WD_INTERVAL) == 0); 55 utim &= ~WD_LASTVAL; 56 utim |= wd_last_u; 57 } else 58 wd_last_u = (utim & WD_INTERVAL); 59 if ((utim & WD_INTERVAL) == WD_TO_NEVER) { 60 utim = 0; 61 62 /* Assume all is well; watchdog signals failure. */ 63 error = 0; 64 } else { 65 /* Assume no watchdog available; watchdog flags success */ 66 error = EOPNOTSUPP; 67 } 68 EVENTHANDLER_INVOKE(watchdog_list, utim, &error); 69 return (error); 70 } 71 72 static int 73 wd_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t data, 74 int flags __unused, struct thread *td) 75 { 76 u_int u; 77 78 if (cmd != WDIOCPATPAT) 79 return (ENOIOCTL); 80 u = *(u_int *)data; 81 if (u & ~(WD_ACTIVE | WD_PASSIVE | WD_LASTVAL | WD_INTERVAL)) 82 return (EINVAL); 83 if ((u & (WD_ACTIVE | WD_PASSIVE)) == (WD_ACTIVE | WD_PASSIVE)) 84 return (EINVAL); 85 if ((u & (WD_ACTIVE | WD_PASSIVE)) == 0 && ((u & WD_INTERVAL) > 0 || 86 (u & WD_LASTVAL) != 0)) 87 return (EINVAL); 88 if (u & WD_PASSIVE) 89 return (ENOSYS); /* XXX Not implemented yet */ 90 u &= ~(WD_ACTIVE | WD_PASSIVE); 91 92 return (kern_do_pat(u)); 93 } 94 95 u_int 96 wdog_kern_last_timeout(void) 97 { 98 99 return (wd_last_u); 100 } 101 102 int 103 wdog_kern_pat(u_int utim) 104 { 105 106 if (utim & ~(WD_LASTVAL | WD_INTERVAL)) 107 return (EINVAL); 108 109 return (kern_do_pat(utim)); 110 } 111 112 static struct cdevsw wd_cdevsw = { 113 .d_version = D_VERSION, 114 .d_ioctl = wd_ioctl, 115 .d_name = "watchdog", 116 }; 117 118 static int 119 watchdog_modevent(module_t mod __unused, int type, void *data __unused) 120 { 121 switch(type) { 122 case MOD_LOAD: 123 wd_dev = make_dev(&wd_cdevsw, 0, 124 UID_ROOT, GID_WHEEL, 0600, _PATH_WATCHDOG); 125 return 0; 126 case MOD_UNLOAD: 127 destroy_dev(wd_dev); 128 return 0; 129 case MOD_SHUTDOWN: 130 return 0; 131 default: 132 return EOPNOTSUPP; 133 } 134 } 135 136 DEV_MODULE(watchdog, watchdog_modevent, NULL); 137