xref: /freebsd/sys/sys/timeet.h (revision 81ad6265)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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  * $FreeBSD$
29  */
30 
31 #ifndef _SYS_TIMEEC_H_
32 #define	_SYS_TIMEEC_H_
33 
34 #ifndef _KERNEL
35 #error "no user-serviceable parts inside"
36 #endif
37 
38 #include <sys/lock.h>
39 #include <sys/mutex.h>
40 #include <sys/queue.h>
41 #include <sys/time.h>
42 
43 /*
44  * `struct eventtimer' is the interface between the hardware which implements
45  * a event timer and the MI code which uses this to receive time events.
46  */
47 
48 struct eventtimer;
49 typedef int et_start_t(struct eventtimer *et,
50     sbintime_t first, sbintime_t period);
51 typedef int et_stop_t(struct eventtimer *et);
52 typedef void et_event_cb_t(struct eventtimer *et, void *arg);
53 typedef int et_deregister_cb_t(struct eventtimer *et, void *arg);
54 
55 struct eventtimer {
56 	SLIST_ENTRY(eventtimer)	et_all;
57 		/* Pointer to the next event timer. */
58 	const char		*et_name;
59 		/* Name of the event timer. */
60 	int			et_flags;
61 		/* Set of capabilities flags: */
62 #define ET_FLAGS_PERIODIC	1
63 #define ET_FLAGS_ONESHOT	2
64 #define ET_FLAGS_PERCPU		4
65 #define ET_FLAGS_C3STOP		8
66 #define ET_FLAGS_POW2DIV	16
67 	int			et_quality;
68 		/*
69 		 * Used to determine if this timecounter is better than
70 		 * another timecounter. Higher means better.
71 		 */
72 	int			et_active;
73 	u_int64_t		et_frequency;
74 		/* Base frequency in Hz. */
75 	sbintime_t		et_min_period;
76 	sbintime_t		et_max_period;
77 	et_start_t		*et_start;
78 	et_stop_t		*et_stop;
79 	et_event_cb_t		*et_event_cb;
80 	et_deregister_cb_t	*et_deregister_cb;
81 	void 			*et_arg;
82 	void			*et_priv;
83 	struct sysctl_oid	*et_sysctl;
84 		/* Pointer to the event timer's private parts. */
85 };
86 
87 extern struct mtx	et_eventtimers_mtx;
88 #define	ET_LOCK()	mtx_lock(&et_eventtimers_mtx)
89 #define	ET_UNLOCK()	mtx_unlock(&et_eventtimers_mtx)
90 
91 /* Driver API */
92 int	et_register(struct eventtimer *et);
93 int	et_deregister(struct eventtimer *et);
94 void	et_change_frequency(struct eventtimer *et, uint64_t newfreq);
95 /* Consumer API  */
96 struct eventtimer *et_find(const char *name, int check, int want);
97 int	et_init(struct eventtimer *et, et_event_cb_t *event,
98     et_deregister_cb_t *deregister, void *arg);
99 int	et_start(struct eventtimer *et, sbintime_t first, sbintime_t period);
100 int	et_stop(struct eventtimer *et);
101 int	et_ban(struct eventtimer *et);
102 int	et_free(struct eventtimer *et);
103 
104 #ifdef SYSCTL_DECL
105 SYSCTL_DECL(_kern_eventtimer);
106 #endif
107 #endif /* !_SYS_TIMETC_H_ */
108