2 * Copyright (c) 2010-2013 Alexander Motin <mav@FreeBSD.org>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
30 #include <sys/param.h>
31 #include <sys/kernel.h>
33 #include <sys/sysctl.h>
34 #include <sys/systm.h>
35 #include <sys/queue.h>
36 #include <sys/timeet.h>
38 #include "opt_timer.h"
40 SLIST_HEAD(et_eventtimers_list, eventtimer);
41 static struct et_eventtimers_list eventtimers = SLIST_HEAD_INITIALIZER(et_eventtimers);
43 struct mtx et_eventtimers_mtx;
44 MTX_SYSINIT(et_eventtimers_init, &et_eventtimers_mtx, "et_mtx", MTX_DEF);
46 SYSCTL_NODE(_kern, OID_AUTO, eventtimer, CTLFLAG_RW, 0, "Event timers");
47 static SYSCTL_NODE(_kern_eventtimer, OID_AUTO, et, CTLFLAG_RW, 0, "");
50 * Register a new event timer hardware.
53 et_register(struct eventtimer *et)
55 struct eventtimer *tmp, *next;
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);
62 printf("Event timer \"%s\" "
63 "frequency %ju Hz quality %d\n",
64 et->et_name, (uintmax_t)et->et_frequency,
68 KASSERT(et->et_start, ("et_register: timer has no start function"));
69 et->et_sysctl = SYSCTL_ADD_NODE(NULL,
70 SYSCTL_STATIC_CHILDREN(_kern_eventtimer_et), OID_AUTO, et->et_name,
71 CTLFLAG_RW, 0, "event timer description");
72 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO,
73 "flags", CTLFLAG_RD, &(et->et_flags), 0,
74 "Event timer capabilities");
75 SYSCTL_ADD_UQUAD(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO,
76 "frequency", CTLFLAG_RD, &(et->et_frequency),
77 "Event timer base frequency");
78 SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO,
79 "quality", CTLFLAG_RD, &(et->et_quality), 0,
80 "Goodness of event timer");
82 if (SLIST_EMPTY(&eventtimers) ||
83 SLIST_FIRST(&eventtimers)->et_quality < et->et_quality) {
84 SLIST_INSERT_HEAD(&eventtimers, et, et_all);
86 SLIST_FOREACH(tmp, &eventtimers, et_all) {
87 next = SLIST_NEXT(tmp, et_all);
88 if (next == NULL || next->et_quality < et->et_quality) {
89 SLIST_INSERT_AFTER(tmp, et, et_all);
99 * Deregister event timer hardware.
102 et_deregister(struct eventtimer *et)
106 if (et->et_deregister_cb != NULL) {
107 if ((err = et->et_deregister_cb(et, et->et_arg)) != 0)
112 SLIST_REMOVE(&eventtimers, et, eventtimer, et_all);
114 sysctl_remove_oid(et->et_sysctl, 1, 1);
119 * Change the frequency of the given timer. If it is the active timer,
120 * reconfigure it on all CPUs (reschedules all current events based on the new
124 et_change_frequency(struct eventtimer *et, uint64_t newfreq)
127 #ifndef NO_EVENTTIMERS
128 cpu_et_frequency(et, newfreq);
133 * Find free event timer hardware with specified parameters.
136 et_find(const char *name, int check, int want)
138 struct eventtimer *et = NULL;
140 SLIST_FOREACH(et, &eventtimers, et_all) {
143 if (name != NULL && strcasecmp(et->et_name, name) != 0)
145 if (name == NULL && et->et_quality < 0)
147 if ((et->et_flags & check) != want)
155 * Initialize event timer hardware. Set callbacks.
158 et_init(struct eventtimer *et, et_event_cb_t *event,
159 et_deregister_cb_t *deregister, void *arg)
168 et->et_event_cb = event;
169 et->et_deregister_cb = deregister;
175 * Start event timer hardware.
176 * first - delay before first tick.
177 * period - period of subsequent periodic ticks.
180 et_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
185 KASSERT(period >= 0, ("et_start: negative period"));
186 KASSERT((et->et_flags & ET_FLAGS_PERIODIC) || period == 0,
187 ("et_start: period specified for oneshot-only timer"));
188 KASSERT((et->et_flags & ET_FLAGS_ONESHOT) || period != 0,
189 ("et_start: period not specified for periodic-only timer"));
191 if (period < et->et_min_period)
192 period = et->et_min_period;
193 else if (period > et->et_max_period)
194 period = et->et_max_period;
196 if (period == 0 || first != 0) {
197 if (first < et->et_min_period)
198 first = et->et_min_period;
199 else if (first > et->et_max_period)
200 first = et->et_max_period;
202 return (et->et_start(et, first, period));
205 /* Stop event timer hardware. */
207 et_stop(struct eventtimer *et)
213 return (et->et_stop(et));
217 /* Mark event timer hardware as broken. */
219 et_ban(struct eventtimer *et)
222 et->et_flags &= ~(ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT);
226 /* Free event timer hardware. */
228 et_free(struct eventtimer *et)
238 /* Report list of supported event timer hardware via sysctl. */
240 sysctl_kern_eventtimer_choice(SYSCTL_HANDLER_ARGS)
243 struct eventtimer *et;
246 sbuf_new(&sb, NULL, 256, SBUF_AUTOEXTEND | SBUF_INCLUDENUL);
249 SLIST_FOREACH(et, &eventtimers, et_all) {
250 if (et != SLIST_FIRST(&eventtimers))
252 sbuf_printf(&sb, "%s(%d)", et->et_name, et->et_quality);
256 error = sbuf_finish(&sb);
258 error = SYSCTL_OUT(req, sbuf_data(&sb), sbuf_len(&sb));
262 SYSCTL_PROC(_kern_eventtimer, OID_AUTO, choice,
263 CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
264 0, 0, sysctl_kern_eventtimer_choice, "A", "Present event timers");