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
et_register(struct eventtimer * et)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
et_deregister(struct eventtimer * et)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
et_change_frequency(struct eventtimer * et,uint64_t newfreq)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 *
et_find(const char * name,int check,int want)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
et_init(struct eventtimer * et,et_event_cb_t * event,et_deregister_cb_t * deregister,void * arg)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
et_start(struct eventtimer * et,sbintime_t first,sbintime_t period)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
et_stop(struct eventtimer * et)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
et_ban(struct eventtimer * et)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
et_free(struct eventtimer * et)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
sysctl_kern_eventtimer_choice(SYSCTL_HANDLER_ARGS)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