1 /*- 2 * Copyright (c) 2010-2013 Alexander Motin <mav@FreeBSD.org> 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 * without modification, immediately at the beginning of the file. 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 AUTHOR ``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 #include <sys/cdefs.h> 28 __FBSDID("$FreeBSD$"); 29 30 #include <sys/param.h> 31 #include <sys/kernel.h> 32 #include <sys/sysctl.h> 33 #include <sys/systm.h> 34 #include <sys/queue.h> 35 #include <sys/timeet.h> 36 37 SLIST_HEAD(et_eventtimers_list, eventtimer); 38 static struct et_eventtimers_list eventtimers = SLIST_HEAD_INITIALIZER(et_eventtimers); 39 40 struct mtx et_eventtimers_mtx; 41 MTX_SYSINIT(et_eventtimers_init, &et_eventtimers_mtx, "et_mtx", MTX_DEF); 42 43 SYSCTL_NODE(_kern, OID_AUTO, eventtimer, CTLFLAG_RW, 0, "Event timers"); 44 static SYSCTL_NODE(_kern_eventtimer, OID_AUTO, et, CTLFLAG_RW, 0, ""); 45 46 /* 47 * Register a new event timer hardware. 48 */ 49 int 50 et_register(struct eventtimer *et) 51 { 52 struct eventtimer *tmp, *next; 53 54 if (et->et_quality >= 0 || bootverbose) { 55 if (et->et_frequency == 0) { 56 printf("Event timer \"%s\" quality %d\n", 57 et->et_name, et->et_quality); 58 } else { 59 printf("Event timer \"%s\" " 60 "frequency %ju Hz quality %d\n", 61 et->et_name, (uintmax_t)et->et_frequency, 62 et->et_quality); 63 } 64 } 65 KASSERT(et->et_start, ("et_register: timer has no start function")); 66 et->et_sysctl = SYSCTL_ADD_NODE(NULL, 67 SYSCTL_STATIC_CHILDREN(_kern_eventtimer_et), OID_AUTO, et->et_name, 68 CTLFLAG_RW, 0, "event timer description"); 69 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO, 70 "flags", CTLFLAG_RD, &(et->et_flags), 0, 71 "Event timer capabilities"); 72 SYSCTL_ADD_UQUAD(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO, 73 "frequency", CTLFLAG_RD, &(et->et_frequency), 74 "Event timer base frequency"); 75 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO, 76 "quality", CTLFLAG_RD, &(et->et_quality), 0, 77 "Goodness of event timer"); 78 ET_LOCK(); 79 if (SLIST_EMPTY(&eventtimers) || 80 SLIST_FIRST(&eventtimers)->et_quality < et->et_quality) { 81 SLIST_INSERT_HEAD(&eventtimers, et, et_all); 82 } else { 83 SLIST_FOREACH(tmp, &eventtimers, et_all) { 84 next = SLIST_NEXT(tmp, et_all); 85 if (next == NULL || next->et_quality < et->et_quality) { 86 SLIST_INSERT_AFTER(tmp, et, et_all); 87 break; 88 } 89 } 90 } 91 ET_UNLOCK(); 92 return (0); 93 } 94 95 /* 96 * Deregister event timer hardware. 97 */ 98 int 99 et_deregister(struct eventtimer *et) 100 { 101 int err = 0; 102 103 if (et->et_deregister_cb != NULL) { 104 if ((err = et->et_deregister_cb(et, et->et_arg)) != 0) 105 return (err); 106 } 107 108 ET_LOCK(); 109 SLIST_REMOVE(&eventtimers, et, eventtimer, et_all); 110 ET_UNLOCK(); 111 sysctl_remove_oid(et->et_sysctl, 1, 1); 112 return (0); 113 } 114 115 /* 116 * Find free event timer hardware with specified parameters. 117 */ 118 struct eventtimer * 119 et_find(const char *name, int check, int want) 120 { 121 struct eventtimer *et = NULL; 122 123 SLIST_FOREACH(et, &eventtimers, et_all) { 124 if (et->et_active) 125 continue; 126 if (name != NULL && strcasecmp(et->et_name, name) != 0) 127 continue; 128 if (name == NULL && et->et_quality < 0) 129 continue; 130 if ((et->et_flags & check) != want) 131 continue; 132 break; 133 } 134 return (et); 135 } 136 137 /* 138 * Initialize event timer hardware. Set callbacks. 139 */ 140 int 141 et_init(struct eventtimer *et, et_event_cb_t *event, 142 et_deregister_cb_t *deregister, void *arg) 143 { 144 145 if (event == NULL) 146 return (EINVAL); 147 if (et->et_active) 148 return (EBUSY); 149 150 et->et_active = 1; 151 et->et_event_cb = event; 152 et->et_deregister_cb = deregister; 153 et->et_arg = arg; 154 return (0); 155 } 156 157 /* 158 * Start event timer hardware. 159 * first - delay before first tick. 160 * period - period of subsequent periodic ticks. 161 */ 162 int 163 et_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 164 { 165 166 if (!et->et_active) 167 return (ENXIO); 168 KASSERT(period >= 0, ("et_start: negative period")); 169 KASSERT((et->et_flags & ET_FLAGS_PERIODIC) || period == 0, 170 ("et_start: period specified for oneshot-only timer")); 171 KASSERT((et->et_flags & ET_FLAGS_ONESHOT) || period != 0, 172 ("et_start: period not specified for periodic-only timer")); 173 if (period != 0) { 174 if (period < et->et_min_period) 175 period = et->et_min_period; 176 else if (period > et->et_max_period) 177 period = et->et_max_period; 178 } 179 if (period == 0 || first != 0) { 180 if (first < et->et_min_period) 181 first = et->et_min_period; 182 else if (first > et->et_max_period) 183 first = et->et_max_period; 184 } 185 return (et->et_start(et, first, period)); 186 } 187 188 /* Stop event timer hardware. */ 189 int 190 et_stop(struct eventtimer *et) 191 { 192 193 if (!et->et_active) 194 return (ENXIO); 195 if (et->et_stop) 196 return (et->et_stop(et)); 197 return (0); 198 } 199 200 /* Mark event timer hardware as broken. */ 201 int 202 et_ban(struct eventtimer *et) 203 { 204 205 et->et_flags &= ~(ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT); 206 return (0); 207 } 208 209 /* Free event timer hardware. */ 210 int 211 et_free(struct eventtimer *et) 212 { 213 214 if (!et->et_active) 215 return (ENXIO); 216 217 et->et_active = 0; 218 return (0); 219 } 220 221 /* Report list of supported event timers hardware via sysctl. */ 222 static int 223 sysctl_kern_eventtimer_choice(SYSCTL_HANDLER_ARGS) 224 { 225 char buf[512], *spc; 226 struct eventtimer *et; 227 int error, off; 228 229 spc = ""; 230 error = 0; 231 buf[0] = 0; 232 off = 0; 233 ET_LOCK(); 234 SLIST_FOREACH(et, &eventtimers, et_all) { 235 off += snprintf(buf + off, sizeof(buf) - off, "%s%s(%d)", 236 spc, et->et_name, et->et_quality); 237 spc = " "; 238 } 239 ET_UNLOCK(); 240 error = SYSCTL_OUT(req, buf, strlen(buf)); 241 return (error); 242 } 243 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, choice, 244 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 245 0, 0, sysctl_kern_eventtimer_choice, "A", "Present event timers"); 246 247