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, 0, "Event timers"); 49 static SYSCTL_NODE(_kern_eventtimer, OID_AUTO, et, CTLFLAG_RW, 0, ""); 50 51 /* 52 * Register a new event timer hardware. 53 */ 54 int 55 et_register(struct eventtimer *et) 56 { 57 struct eventtimer *tmp, *next; 58 59 if (et->et_quality >= 0 || bootverbose) { 60 if (et->et_frequency == 0) { 61 printf("Event timer \"%s\" quality %d\n", 62 et->et_name, et->et_quality); 63 } else { 64 printf("Event timer \"%s\" " 65 "frequency %ju Hz quality %d\n", 66 et->et_name, (uintmax_t)et->et_frequency, 67 et->et_quality); 68 } 69 } 70 KASSERT(et->et_start, ("et_register: timer has no start function")); 71 et->et_sysctl = SYSCTL_ADD_NODE_WITH_LABEL(NULL, 72 SYSCTL_STATIC_CHILDREN(_kern_eventtimer_et), OID_AUTO, et->et_name, 73 CTLFLAG_RW, 0, "event timer description", "eventtimer"); 74 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO, 75 "flags", CTLFLAG_RD, &(et->et_flags), 0, 76 "Event timer capabilities"); 77 SYSCTL_ADD_UQUAD(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO, 78 "frequency", CTLFLAG_RD, &(et->et_frequency), 79 "Event timer base frequency"); 80 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO, 81 "quality", CTLFLAG_RD, &(et->et_quality), 0, 82 "Goodness of event timer"); 83 ET_LOCK(); 84 if (SLIST_EMPTY(&eventtimers) || 85 SLIST_FIRST(&eventtimers)->et_quality < et->et_quality) { 86 SLIST_INSERT_HEAD(&eventtimers, et, et_all); 87 } else { 88 SLIST_FOREACH(tmp, &eventtimers, et_all) { 89 next = SLIST_NEXT(tmp, et_all); 90 if (next == NULL || next->et_quality < et->et_quality) { 91 SLIST_INSERT_AFTER(tmp, et, et_all); 92 break; 93 } 94 } 95 } 96 ET_UNLOCK(); 97 return (0); 98 } 99 100 /* 101 * Deregister event timer hardware. 102 */ 103 int 104 et_deregister(struct eventtimer *et) 105 { 106 int err = 0; 107 108 if (et->et_deregister_cb != NULL) { 109 if ((err = et->et_deregister_cb(et, et->et_arg)) != 0) 110 return (err); 111 } 112 113 ET_LOCK(); 114 SLIST_REMOVE(&eventtimers, et, eventtimer, et_all); 115 ET_UNLOCK(); 116 sysctl_remove_oid(et->et_sysctl, 1, 1); 117 return (0); 118 } 119 120 /* 121 * Change the frequency of the given timer. If it is the active timer, 122 * reconfigure it on all CPUs (reschedules all current events based on the new 123 * timer frequency). 124 */ 125 void 126 et_change_frequency(struct eventtimer *et, uint64_t newfreq) 127 { 128 129 #ifndef NO_EVENTTIMERS 130 cpu_et_frequency(et, newfreq); 131 #endif 132 } 133 134 /* 135 * Find free event timer hardware with specified parameters. 136 */ 137 struct eventtimer * 138 et_find(const char *name, int check, int want) 139 { 140 struct eventtimer *et = NULL; 141 142 SLIST_FOREACH(et, &eventtimers, et_all) { 143 if (et->et_active) 144 continue; 145 if (name != NULL && strcasecmp(et->et_name, name) != 0) 146 continue; 147 if (name == NULL && et->et_quality < 0) 148 continue; 149 if ((et->et_flags & check) != want) 150 continue; 151 break; 152 } 153 return (et); 154 } 155 156 /* 157 * Initialize event timer hardware. Set callbacks. 158 */ 159 int 160 et_init(struct eventtimer *et, et_event_cb_t *event, 161 et_deregister_cb_t *deregister, void *arg) 162 { 163 164 if (event == NULL) 165 return (EINVAL); 166 if (et->et_active) 167 return (EBUSY); 168 169 et->et_active = 1; 170 et->et_event_cb = event; 171 et->et_deregister_cb = deregister; 172 et->et_arg = arg; 173 return (0); 174 } 175 176 /* 177 * Start event timer hardware. 178 * first - delay before first tick. 179 * period - period of subsequent periodic ticks. 180 */ 181 int 182 et_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 183 { 184 185 if (!et->et_active) 186 return (ENXIO); 187 KASSERT(period >= 0, ("et_start: negative period")); 188 KASSERT((et->et_flags & ET_FLAGS_PERIODIC) || period == 0, 189 ("et_start: period specified for oneshot-only timer")); 190 KASSERT((et->et_flags & ET_FLAGS_ONESHOT) || period != 0, 191 ("et_start: period not specified for periodic-only timer")); 192 if (period != 0) { 193 if (period < et->et_min_period) 194 period = et->et_min_period; 195 else if (period > et->et_max_period) 196 period = et->et_max_period; 197 } 198 if (period == 0 || first != 0) { 199 if (first < et->et_min_period) 200 first = et->et_min_period; 201 else if (first > et->et_max_period) 202 first = et->et_max_period; 203 } 204 return (et->et_start(et, first, period)); 205 } 206 207 /* Stop event timer hardware. */ 208 int 209 et_stop(struct eventtimer *et) 210 { 211 212 if (!et->et_active) 213 return (ENXIO); 214 if (et->et_stop) 215 return (et->et_stop(et)); 216 return (0); 217 } 218 219 /* Mark event timer hardware as broken. */ 220 int 221 et_ban(struct eventtimer *et) 222 { 223 224 et->et_flags &= ~(ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT); 225 return (0); 226 } 227 228 /* Free event timer hardware. */ 229 int 230 et_free(struct eventtimer *et) 231 { 232 233 if (!et->et_active) 234 return (ENXIO); 235 236 et->et_active = 0; 237 return (0); 238 } 239 240 /* Report list of supported event timer hardware via sysctl. */ 241 static int 242 sysctl_kern_eventtimer_choice(SYSCTL_HANDLER_ARGS) 243 { 244 struct sbuf sb; 245 struct eventtimer *et; 246 int error; 247 248 sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL); 249 250 ET_LOCK(); 251 SLIST_FOREACH(et, &eventtimers, et_all) { 252 if (et != SLIST_FIRST(&eventtimers)) 253 sbuf_putc(&sb, ' '); 254 sbuf_printf(&sb, "%s(%d)", et->et_name, et->et_quality); 255 } 256 ET_UNLOCK(); 257 258 error = sbuf_finish(&sb); 259 if (error == 0) 260 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb)); 261 sbuf_delete(&sb); 262 return (error); 263 } 264 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, choice, 265 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 266 0, 0, sysctl_kern_eventtimer_choice, "A", "Present event timers"); 267 268