1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2010-2013 Alexander Motin <mav@FreeBSD.org> 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer, 12 * without modification, immediately at the beginning of the file. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/kernel.h> 34 #include <sys/sbuf.h> 35 #include <sys/sysctl.h> 36 #include <sys/systm.h> 37 #include <sys/queue.h> 38 #include <sys/timeet.h> 39 40 #include "opt_timer.h" 41 42 SLIST_HEAD(et_eventtimers_list, eventtimer); 43 static struct et_eventtimers_list eventtimers = SLIST_HEAD_INITIALIZER(et_eventtimers); 44 45 struct mtx et_eventtimers_mtx; 46 MTX_SYSINIT(et_eventtimers_init, &et_eventtimers_mtx, "et_mtx", MTX_DEF); 47 48 SYSCTL_NODE(_kern, OID_AUTO, eventtimer, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 49 "Event timers"); 50 static SYSCTL_NODE(_kern_eventtimer, OID_AUTO, et, 51 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 52 ""); 53 54 /* 55 * Register a new event timer hardware. 56 */ 57 int 58 et_register(struct eventtimer *et) 59 { 60 struct eventtimer *tmp, *next; 61 62 if (et->et_quality >= 0 || bootverbose) { 63 if (et->et_frequency == 0) { 64 printf("Event timer \"%s\" quality %d\n", 65 et->et_name, et->et_quality); 66 } else { 67 printf("Event timer \"%s\" " 68 "frequency %ju Hz quality %d\n", 69 et->et_name, (uintmax_t)et->et_frequency, 70 et->et_quality); 71 } 72 } 73 KASSERT(et->et_start, ("et_register: timer has no start function")); 74 et->et_sysctl = SYSCTL_ADD_NODE_WITH_LABEL(NULL, 75 SYSCTL_STATIC_CHILDREN(_kern_eventtimer_et), OID_AUTO, et->et_name, 76 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 77 "event timer description", "eventtimer"); 78 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO, 79 "flags", CTLFLAG_RD, &(et->et_flags), 0, 80 "Event timer capabilities"); 81 SYSCTL_ADD_UQUAD(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO, 82 "frequency", CTLFLAG_RD, &(et->et_frequency), 83 "Event timer base frequency"); 84 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO, 85 "quality", CTLFLAG_RD, &(et->et_quality), 0, 86 "Goodness of event timer"); 87 ET_LOCK(); 88 if (SLIST_EMPTY(&eventtimers) || 89 SLIST_FIRST(&eventtimers)->et_quality < et->et_quality) { 90 SLIST_INSERT_HEAD(&eventtimers, et, et_all); 91 } else { 92 SLIST_FOREACH(tmp, &eventtimers, et_all) { 93 next = SLIST_NEXT(tmp, et_all); 94 if (next == NULL || next->et_quality < et->et_quality) { 95 SLIST_INSERT_AFTER(tmp, et, et_all); 96 break; 97 } 98 } 99 } 100 ET_UNLOCK(); 101 return (0); 102 } 103 104 /* 105 * Deregister event timer hardware. 106 */ 107 int 108 et_deregister(struct eventtimer *et) 109 { 110 int err = 0; 111 112 if (et->et_deregister_cb != NULL) { 113 if ((err = et->et_deregister_cb(et, et->et_arg)) != 0) 114 return (err); 115 } 116 117 ET_LOCK(); 118 SLIST_REMOVE(&eventtimers, et, eventtimer, et_all); 119 ET_UNLOCK(); 120 sysctl_remove_oid(et->et_sysctl, 1, 1); 121 return (0); 122 } 123 124 /* 125 * Change the frequency of the given timer. If it is the active timer, 126 * reconfigure it on all CPUs (reschedules all current events based on the new 127 * timer frequency). 128 */ 129 void 130 et_change_frequency(struct eventtimer *et, uint64_t newfreq) 131 { 132 133 #ifndef NO_EVENTTIMERS 134 cpu_et_frequency(et, newfreq); 135 #endif 136 } 137 138 /* 139 * Find free event timer hardware with specified parameters. 140 */ 141 struct eventtimer * 142 et_find(const char *name, int check, int want) 143 { 144 struct eventtimer *et = NULL; 145 146 SLIST_FOREACH(et, &eventtimers, et_all) { 147 if (et->et_active) 148 continue; 149 if (name != NULL && strcasecmp(et->et_name, name) != 0) 150 continue; 151 if (name == NULL && et->et_quality < 0) 152 continue; 153 if ((et->et_flags & check) != want) 154 continue; 155 break; 156 } 157 return (et); 158 } 159 160 /* 161 * Initialize event timer hardware. Set callbacks. 162 */ 163 int 164 et_init(struct eventtimer *et, et_event_cb_t *event, 165 et_deregister_cb_t *deregister, void *arg) 166 { 167 168 if (event == NULL) 169 return (EINVAL); 170 if (et->et_active) 171 return (EBUSY); 172 173 et->et_active = 1; 174 et->et_event_cb = event; 175 et->et_deregister_cb = deregister; 176 et->et_arg = arg; 177 return (0); 178 } 179 180 /* 181 * Start event timer hardware. 182 * first - delay before first tick. 183 * period - period of subsequent periodic ticks. 184 */ 185 int 186 et_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 187 { 188 189 if (!et->et_active) 190 return (ENXIO); 191 KASSERT(period >= 0, ("et_start: negative period")); 192 KASSERT((et->et_flags & ET_FLAGS_PERIODIC) || period == 0, 193 ("et_start: period specified for oneshot-only timer")); 194 KASSERT((et->et_flags & ET_FLAGS_ONESHOT) || period != 0, 195 ("et_start: period not specified for periodic-only timer")); 196 if (period != 0) { 197 if (period < et->et_min_period) 198 period = et->et_min_period; 199 else if (period > et->et_max_period) 200 period = et->et_max_period; 201 } 202 if (period == 0 || first != 0) { 203 if (first < et->et_min_period) 204 first = et->et_min_period; 205 else if (first > et->et_max_period) 206 first = et->et_max_period; 207 } 208 return (et->et_start(et, first, period)); 209 } 210 211 /* Stop event timer hardware. */ 212 int 213 et_stop(struct eventtimer *et) 214 { 215 216 if (!et->et_active) 217 return (ENXIO); 218 if (et->et_stop) 219 return (et->et_stop(et)); 220 return (0); 221 } 222 223 /* Mark event timer hardware as broken. */ 224 int 225 et_ban(struct eventtimer *et) 226 { 227 228 et->et_flags &= ~(ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT); 229 return (0); 230 } 231 232 /* Free event timer hardware. */ 233 int 234 et_free(struct eventtimer *et) 235 { 236 237 if (!et->et_active) 238 return (ENXIO); 239 240 et->et_active = 0; 241 return (0); 242 } 243 244 /* Report list of supported event timer hardware via sysctl. */ 245 static int 246 sysctl_kern_eventtimer_choice(SYSCTL_HANDLER_ARGS) 247 { 248 struct sbuf sb; 249 struct eventtimer *et; 250 int error; 251 252 sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL); 253 254 ET_LOCK(); 255 SLIST_FOREACH(et, &eventtimers, et_all) { 256 if (et != SLIST_FIRST(&eventtimers)) 257 sbuf_putc(&sb, ' '); 258 sbuf_printf(&sb, "%s(%d)", et->et_name, et->et_quality); 259 } 260 ET_UNLOCK(); 261 262 error = sbuf_finish(&sb); 263 if (error == 0) 264 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb)); 265 sbuf_delete(&sb); 266 return (error); 267 } 268 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, choice, 269 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 270 0, 0, sysctl_kern_eventtimer_choice, "A", "Present event timers"); 271 272