xref: /freebsd-11-stable/sys/compat/linuxkpi/common/src/linux_hrtimer.c (revision 3475bcf346566804a2ded55d1d58a55f346266b1)
1 /*-
2  * Copyright (c) 2017 Mark Johnston <markj@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 unmodified, this list of conditions, and the following
10  *    disclaimer.
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/systm.h>
32 #include <sys/lock.h>
33 #include <sys/mutex.h>
34 #include <sys/time.h>
35 
36 #include <machine/cpu.h>
37 
38 #include <linux/hrtimer.h>
39 
40 static void
hrtimer_call_handler(void * arg)41 hrtimer_call_handler(void *arg)
42 {
43 	struct hrtimer *hrtimer;
44 	enum hrtimer_restart ret;
45 
46 	hrtimer = arg;
47 	ret = hrtimer->function(hrtimer);
48 
49 	if (ret == HRTIMER_RESTART) {
50 		callout_schedule_sbt(&hrtimer->callout,
51 		    nstosbt(hrtimer->expires), nstosbt(hrtimer->precision), 0);
52 	} else {
53 		callout_deactivate(&hrtimer->callout);
54 	}
55 }
56 
57 bool
linux_hrtimer_active(struct hrtimer * hrtimer)58 linux_hrtimer_active(struct hrtimer *hrtimer)
59 {
60 	bool ret;
61 
62 	mtx_lock(&hrtimer->mtx);
63 	ret = callout_active(&hrtimer->callout);
64 	mtx_unlock(&hrtimer->mtx);
65 
66 	return (ret);
67 }
68 
69 /*
70  * Cancel active hrtimer.
71  * Return 1 if timer was active and cancellation succeeded, or 0 otherwise.
72  */
73 int
linux_hrtimer_cancel(struct hrtimer * hrtimer)74 linux_hrtimer_cancel(struct hrtimer *hrtimer)
75 {
76 
77 	return (callout_drain(&hrtimer->callout) > 0);
78 }
79 
80 void
linux_hrtimer_init(struct hrtimer * hrtimer)81 linux_hrtimer_init(struct hrtimer *hrtimer)
82 {
83 
84 	memset(hrtimer, 0, sizeof(*hrtimer));
85 	mtx_init(&hrtimer->mtx, "hrtimer", NULL,
86 	    MTX_DEF | MTX_RECURSE | MTX_NOWITNESS);
87 	callout_init_mtx(&hrtimer->callout, &hrtimer->mtx, 0);
88 }
89 
90 void
linux_hrtimer_set_expires(struct hrtimer * hrtimer,ktime_t time)91 linux_hrtimer_set_expires(struct hrtimer *hrtimer, ktime_t time)
92 {
93 	hrtimer->expires = ktime_to_ns(time);
94 }
95 
96 void
linux_hrtimer_start(struct hrtimer * hrtimer,ktime_t time)97 linux_hrtimer_start(struct hrtimer *hrtimer, ktime_t time)
98 {
99 
100 	linux_hrtimer_start_range_ns(hrtimer, time, 0);
101 }
102 
103 void
linux_hrtimer_start_range_ns(struct hrtimer * hrtimer,ktime_t time,int64_t nsec)104 linux_hrtimer_start_range_ns(struct hrtimer *hrtimer, ktime_t time,
105     int64_t nsec)
106 {
107 
108 	mtx_lock(&hrtimer->mtx);
109 	hrtimer->precision = nsec;
110 	callout_reset_sbt(&hrtimer->callout, nstosbt(ktime_to_ns(time)),
111 	    nstosbt(nsec), hrtimer_call_handler, hrtimer, 0);
112 	mtx_unlock(&hrtimer->mtx);
113 }
114 
115 void
linux_hrtimer_forward_now(struct hrtimer * hrtimer,ktime_t interval)116 linux_hrtimer_forward_now(struct hrtimer *hrtimer, ktime_t interval)
117 {
118 
119 	mtx_lock(&hrtimer->mtx);
120 	callout_reset_sbt(&hrtimer->callout, nstosbt(ktime_to_ns(interval)),
121 	    nstosbt(hrtimer->precision), hrtimer_call_handler, hrtimer, 0);
122 	mtx_unlock(&hrtimer->mtx);
123 }
124 
125