1/*-
2 * Copyright (c) 2010 Alexander Motin <mav@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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.
14 *
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.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/param.h>
31#include <sys/kernel.h>
32#include <sys/sysctl.h>
33#include <sys/systm.h>
34#include <sys/queue.h>
35#include <sys/timeet.h>
36
37SLIST_HEAD(et_eventtimers_list, eventtimer);
38static struct et_eventtimers_list eventtimers = SLIST_HEAD_INITIALIZER(et_eventtimers);
39
40struct mtx	et_eventtimers_mtx;
41MTX_SYSINIT(et_eventtimers_init, &et_eventtimers_mtx, "et_mtx", MTX_DEF);
42
43SYSCTL_NODE(_kern, OID_AUTO, eventtimer, CTLFLAG_RW, 0, "Event timers");
44static SYSCTL_NODE(_kern_eventtimer, OID_AUTO, et, CTLFLAG_RW, 0, "");
45
46/*
47 * Register a new event timer hardware.
48 */
49int
50et_register(struct eventtimer *et)
51{
52	struct eventtimer *tmp, *next;
53
54	if (et->et_quality >= 0 || bootverbose) {
55		if (et->et_frequency == 0) {
56			printf("Event timer \"%s\" quality %d\n",
57			    et->et_name, et->et_quality);
58		} else {
59			printf("Event timer \"%s\" "
60			    "frequency %ju Hz quality %d\n",
61			    et->et_name, (uintmax_t)et->et_frequency,
62			    et->et_quality);
63		}
64	}
65	et->et_sysctl = SYSCTL_ADD_NODE(NULL,
66	    SYSCTL_STATIC_CHILDREN(_kern_eventtimer_et), OID_AUTO, et->et_name,
67	    CTLFLAG_RW, 0, "event timer description");
68	SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO,
69	    "flags", CTLFLAG_RD, &(et->et_flags), 0,
70	    "Event timer capabilities");
71	SYSCTL_ADD_UQUAD(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO,
72	    "frequency", CTLFLAG_RD, &(et->et_frequency),
73	    "Event timer base frequency");
74	SYSCTL_ADD_INT(NULL, SYSCTL_CHILDREN(et->et_sysctl), OID_AUTO,
75	    "quality", CTLFLAG_RD, &(et->et_quality), 0,
76	    "Goodness of event timer");
77	ET_LOCK();
78	if (SLIST_EMPTY(&eventtimers) ||
79	    SLIST_FIRST(&eventtimers)->et_quality < et->et_quality) {
80		SLIST_INSERT_HEAD(&eventtimers, et, et_all);
81	} else {
82		SLIST_FOREACH(tmp, &eventtimers, et_all) {
83			next = SLIST_NEXT(tmp, et_all);
84			if (next == NULL || next->et_quality < et->et_quality) {
85				SLIST_INSERT_AFTER(tmp, et, et_all);
86				break;
87			}
88		}
89	}
90	ET_UNLOCK();
91	return (0);
92}
93
94/*
95 * Deregister event timer hardware.
96 */
97int
98et_deregister(struct eventtimer *et)
99{
100	int err = 0;
101
102	if (et->et_deregister_cb != NULL) {
103		if ((err = et->et_deregister_cb(et, et->et_arg)) != 0)
104			return (err);
105	}
106
107	ET_LOCK();
108	SLIST_REMOVE(&eventtimers, et, eventtimer, et_all);
109	ET_UNLOCK();
110	sysctl_remove_oid(et->et_sysctl, 1, 1);
111	return (0);
112}
113
114/*
115 * Find free event timer hardware with specified parameters.
116 */
117struct eventtimer *
118et_find(const char *name, int check, int want)
119{
120	struct eventtimer *et = NULL;
121
122	SLIST_FOREACH(et, &eventtimers, et_all) {
123		if (et->et_active)
124			continue;
125		if (name != NULL && strcasecmp(et->et_name, name) != 0)
126			continue;
127		if (name == NULL && et->et_quality < 0)
128			continue;
129		if ((et->et_flags & check) != want)
130			continue;
131		break;
132	}
133	return (et);
134}
135
136/*
137 * Initialize event timer hardware. Set callbacks.
138 */
139int
140et_init(struct eventtimer *et, et_event_cb_t *event,
141    et_deregister_cb_t *deregister, void *arg)
142{
143
144	if (event == NULL)
145		return (EINVAL);
146	if (et->et_active)
147		return (EBUSY);
148
149	et->et_active = 1;
150	et->et_event_cb = event;
151	et->et_deregister_cb = deregister;
152	et->et_arg = arg;
153	return (0);
154}
155
156/*
157 * Start event timer hardware.
158 * first - delay before first tick.
159 * period - period of subsequent periodic ticks.
160 */
161int
162et_start(struct eventtimer *et,
163    struct bintime *first, struct bintime *period)
164{
165
166	if (!et->et_active)
167		return (ENXIO);
168	if (first == NULL && period == NULL)
169		return (EINVAL);
170	if ((et->et_flags & ET_FLAGS_PERIODIC) == 0 &&
171	    period != NULL)
172		return (ENODEV);
173	if ((et->et_flags & ET_FLAGS_ONESHOT) == 0 &&
174	    period == NULL)
175		return (ENODEV);
176	if (first != NULL) {
177		if (first->sec < et->et_min_period.sec ||
178		    (first->sec == et->et_min_period.sec &&
179		     first->frac < et->et_min_period.frac))
180		        first = &et->et_min_period;
181		if (first->sec > et->et_max_period.sec ||
182		    (first->sec == et->et_max_period.sec &&
183		     first->frac > et->et_max_period.frac))
184		        first = &et->et_max_period;
185	}
186	if (period != NULL) {
187		if (period->sec < et->et_min_period.sec ||
188		    (period->sec == et->et_min_period.sec &&
189		     period->frac < et->et_min_period.frac))
190		        period = &et->et_min_period;
191		if (period->sec > et->et_max_period.sec ||
192		    (period->sec == et->et_max_period.sec &&
193		     period->frac > et->et_max_period.frac))
194		        period = &et->et_max_period;
195	}
196	if (et->et_start)
197		return (et->et_start(et, first, period));
198	return (0);
199}
200
201/* Stop event timer hardware. */
202int
203et_stop(struct eventtimer *et)
204{
205
206	if (!et->et_active)
207		return (ENXIO);
208	if (et->et_stop)
209		return (et->et_stop(et));
210	return (0);
211}
212
213/* Mark event timer hardware as broken. */
214int
215et_ban(struct eventtimer *et)
216{
217
218	et->et_flags &= ~(ET_FLAGS_PERIODIC | ET_FLAGS_ONESHOT);
219	return (0);
220}
221
222/* Free event timer hardware. */
223int
224et_free(struct eventtimer *et)
225{
226
227	if (!et->et_active)
228		return (ENXIO);
229
230	et->et_active = 0;
231	return (0);
232}
233
234/* Report list of supported event timers hardware via sysctl. */
235static int
236sysctl_kern_eventtimer_choice(SYSCTL_HANDLER_ARGS)
237{
238	char buf[512], *spc;
239	struct eventtimer *et;
240	int error, off;
241
242	spc = "";
243	error = 0;
244	buf[0] = 0;
245	off = 0;
246	ET_LOCK();
247	SLIST_FOREACH(et, &eventtimers, et_all) {
248		off += snprintf(buf + off, sizeof(buf) - off, "%s%s(%d)",
249		    spc, et->et_name, et->et_quality);
250		spc = " ";
251	}
252	ET_UNLOCK();
253	error = SYSCTL_OUT(req, buf, strlen(buf));
254	return (error);
255}
256SYSCTL_PROC(_kern_eventtimer, OID_AUTO, choice,
257    CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_MPSAFE,
258    0, 0, sysctl_kern_eventtimer_choice, "A", "Present event timers");
259
260