1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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/param.h> 30 #include <sys/kernel.h> 31 #include <sys/sbuf.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 | CTLFLAG_MPSAFE, 0, 44 "Event timers"); 45 static SYSCTL_NODE(_kern_eventtimer, OID_AUTO, et, 46 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 47 ""); 48 49 /* 50 * Register a new event timer hardware. 51 */ 52 int 53 et_register(struct eventtimer *et) 54 { 55 struct eventtimer *tmp, *next; 56 57 if (et->et_quality >= 0 || bootverbose) { 58 if (et->et_frequency == 0) { 59 printf("Event timer \"%s\" quality %d\n", 60 et->et_name, et->et_quality); 61 } else { 62 printf("Event timer \"%s\" " 63 "frequency %ju Hz quality %d\n", 64 et->et_name, (uintmax_t)et->et_frequency, 65 et->et_quality); 66 } 67 } 68 KASSERT(et->et_start, ("et_register: timer has no start function")); 69 et->et_sysctl = SYSCTL_ADD_NODE_WITH_LABEL(NULL, 70 SYSCTL_STATIC_CHILDREN(_kern_eventtimer_et), OID_AUTO, et->et_name, 71 CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 72 "event timer description", "eventtimer"); 73 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO, 74 "flags", CTLFLAG_RD, &(et->et_flags), 0, 75 "Event timer capabilities"); 76 SYSCTL_ADD_UQUAD(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO, 77 "frequency", CTLFLAG_RD, &(et->et_frequency), 78 "Event timer base frequency"); 79 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO, 80 "quality", CTLFLAG_RD, &(et->et_quality), 0, 81 "Goodness of event timer"); 82 ET_LOCK(); 83 if (SLIST_EMPTY(&eventtimers) || 84 SLIST_FIRST(&eventtimers)->et_quality < et->et_quality) { 85 SLIST_INSERT_HEAD(&eventtimers, et, et_all); 86 } else { 87 SLIST_FOREACH(tmp, &eventtimers, et_all) { 88 next = SLIST_NEXT(tmp, et_all); 89 if (next == NULL || next->et_quality < et->et_quality) { 90 SLIST_INSERT_AFTER(tmp, et, et_all); 91 break; 92 } 93 } 94 } 95 ET_UNLOCK(); 96 return (0); 97 } 98 99 /* 100 * Deregister event timer hardware. 101 */ 102 int 103 et_deregister(struct eventtimer *et) 104 { 105 int err = 0; 106 107 if (et->et_deregister_cb != NULL) { 108 if ((err = et->et_deregister_cb(et, et->et_arg)) != 0) 109 return (err); 110 } 111 112 ET_LOCK(); 113 SLIST_REMOVE(&eventtimers, et, eventtimer, et_all); 114 ET_UNLOCK(); 115 sysctl_remove_oid(et->et_sysctl, 1, 1); 116 return (0); 117 } 118 119 /* 120 * Change the frequency of the given timer. If it is the active timer, 121 * reconfigure it on all CPUs (reschedules all current events based on the new 122 * timer frequency). 123 */ 124 void 125 et_change_frequency(struct eventtimer *et, uint64_t newfreq) 126 { 127 128 cpu_et_frequency(et, newfreq); 129 } 130 131 /* 132 * Find free event timer hardware with specified parameters. 133 */ 134 struct eventtimer * 135 et_find(const char *name, int check, int want) 136 { 137 struct eventtimer *et = NULL; 138 139 SLIST_FOREACH(et, &eventtimers, et_all) { 140 if (et->et_active) 141 continue; 142 if (name != NULL && strcasecmp(et->et_name, name) != 0) 143 continue; 144 if (name == NULL && et->et_quality < 0) 145 continue; 146 if ((et->et_flags & check) != want) 147 continue; 148 break; 149 } 150 return (et); 151 } 152 153 /* 154 * Initialize event timer hardware. Set callbacks. 155 */ 156 int 157 et_init(struct eventtimer *et, et_event_cb_t *event, 158 et_deregister_cb_t *deregister, void *arg) 159 { 160 161 if (event == NULL) 162 return (EINVAL); 163 if (et->et_active) 164 return (EBUSY); 165 166 et->et_active = 1; 167 et->et_event_cb = event; 168 et->et_deregister_cb = deregister; 169 et->et_arg = arg; 170 return (0); 171 } 172 173 /* 174 * Start event timer hardware. 175 * first - delay before first tick. 176 * period - period of subsequent periodic ticks. 177 */ 178 int 179 et_start(struct eventtimer *et, sbintime_t first, sbintime_t period) 180 { 181 182 if (!et->et_active) 183 return (ENXIO); 184 KASSERT(period >= 0, ("et_start: negative period")); 185 KASSERT((et->et_flags & ET_FLAGS_PERIODIC) || period == 0, 186 ("et_start: period specified for oneshot-only timer")); 187 KASSERT((et->et_flags & ET_FLAGS_ONESHOT) || period != 0, 188 ("et_start: period not specified for periodic-only timer")); 189 if (period != 0) { 190 if (period < et->et_min_period) 191 period = et->et_min_period; 192 else if (period > et->et_max_period) 193 period = et->et_max_period; 194 } 195 if (period == 0 || first != 0) { 196 if (first < et->et_min_period) 197 first = et->et_min_period; 198 else if (first > et->et_max_period) 199 first = et->et_max_period; 200 } 201 return (et->et_start(et, first, period)); 202 } 203 204 /* Stop event timer hardware. */ 205 int 206 et_stop(struct eventtimer *et) 207 { 208 209 if (!et->et_active) 210 return (ENXIO); 211 if (et->et_stop) 212 return (et->et_stop(et)); 213 return (0); 214 } 215 216 /* Mark event timer hardware as broken. */ 217 int 218 et_ban(struct eventtimer *et) 219 { 220 221 et->et_flags &= ~(ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT); 222 return (0); 223 } 224 225 /* Free event timer hardware. */ 226 int 227 et_free(struct eventtimer *et) 228 { 229 230 if (!et->et_active) 231 return (ENXIO); 232 233 et->et_active = 0; 234 return (0); 235 } 236 237 /* Report list of supported event timer hardware via sysctl. */ 238 static int 239 sysctl_kern_eventtimer_choice(SYSCTL_HANDLER_ARGS) 240 { 241 struct sbuf sb; 242 struct eventtimer *et; 243 int error; 244 245 sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL); 246 247 ET_LOCK(); 248 SLIST_FOREACH(et, &eventtimers, et_all) { 249 if (et != SLIST_FIRST(&eventtimers)) 250 sbuf_putc(&sb, ' '); 251 sbuf_printf(&sb, "%s(%d)", et->et_name, et->et_quality); 252 } 253 ET_UNLOCK(); 254 255 error = sbuf_finish(&sb); 256 if (error == 0) 257 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb)); 258 sbuf_delete(&sb); 259 return (error); 260 } 261 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, choice, 262 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE, 263 0, 0, sysctl_kern_eventtimer_choice, "A", "Present event timers"); 264