2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2010-2013 Alexander Motin <mav@FreeBSD.org>
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
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.
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
32 #include <sys/param.h>
33 #include <sys/kernel.h>
35 #include <sys/sysctl.h>
36 #include <sys/systm.h>
37 #include <sys/queue.h>
38 #include <sys/timeet.h>
40 #include "opt_timer.h"
42 SLIST_HEAD(et_eventtimers_list, eventtimer);
43 static struct et_eventtimers_list eventtimers = SLIST_HEAD_INITIALIZER(et_eventtimers);
45 struct mtx et_eventtimers_mtx;
46 MTX_SYSINIT(et_eventtimers_init, &et_eventtimers_mtx, "et_mtx", MTX_DEF);
48 SYSCTL_NODE(_kern, OID_AUTO, eventtimer, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
50 static SYSCTL_NODE(_kern_eventtimer, OID_AUTO, et,
51 CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
55 * Register a new event timer hardware.
58 et_register(struct eventtimer *et)
60 struct eventtimer *tmp, *next;
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);
67 printf("Event timer \"%s\" "
68 "frequency %ju Hz quality %d\n",
69 et->et_name, (uintmax_t)et->et_frequency,
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");
88 if (SLIST_EMPTY(&eventtimers) ||
89 SLIST_FIRST(&eventtimers)->et_quality < et->et_quality) {
90 SLIST_INSERT_HEAD(&eventtimers, et, et_all);
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);
105 * Deregister event timer hardware.
108 et_deregister(struct eventtimer *et)
112 if (et->et_deregister_cb != NULL) {
113 if ((err = et->et_deregister_cb(et, et->et_arg)) != 0)
118 SLIST_REMOVE(&eventtimers, et, eventtimer, et_all);
120 sysctl_remove_oid(et->et_sysctl, 1, 1);
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
130 et_change_frequency(struct eventtimer *et, uint64_t newfreq)
133 #ifndef NO_EVENTTIMERS
134 cpu_et_frequency(et, newfreq);
139 * Find free event timer hardware with specified parameters.
142 et_find(const char *name, int check, int want)
144 struct eventtimer *et = NULL;
146 SLIST_FOREACH(et, &eventtimers, et_all) {
149 if (name != NULL && strcasecmp(et->et_name, name) != 0)
151 if (name == NULL && et->et_quality < 0)
153 if ((et->et_flags & check) != want)
161 * Initialize event timer hardware. Set callbacks.
164 et_init(struct eventtimer *et, et_event_cb_t *event,
165 et_deregister_cb_t *deregister, void *arg)
174 et->et_event_cb = event;
175 et->et_deregister_cb = deregister;
181 * Start event timer hardware.
182 * first - delay before first tick.
183 * period - period of subsequent periodic ticks.
186 et_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
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"));
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;
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;
208 return (et->et_start(et, first, period));
211 /* Stop event timer hardware. */
213 et_stop(struct eventtimer *et)
219 return (et->et_stop(et));
223 /* Mark event timer hardware as broken. */
225 et_ban(struct eventtimer *et)
228 et->et_flags &= ~(ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT);
232 /* Free event timer hardware. */
234 et_free(struct eventtimer *et)
244 /* Report list of supported event timer hardware via sysctl. */
246 sysctl_kern_eventtimer_choice(SYSCTL_HANDLER_ARGS)
249 struct eventtimer *et;
252 sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL);
255 SLIST_FOREACH(et, &eventtimers, et_all) {
256 if (et != SLIST_FIRST(&eventtimers))
258 sbuf_printf(&sb, "%s(%d)", et->et_name, et->et_quality);
262 error = sbuf_finish(&sb);
264 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
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");