1 /*-
2  * Copyright (c) 2017 Mark Johnston <markj@FreeBSD.org>
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice unmodified, this list of conditions, and the following
9  *    disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/lock.h>
32 #include <sys/mutex.h>
33 #include <sys/time.h>
34 
35 #include <machine/cpu.h>
36 
37 #include <linux/hrtimer.h>
38 
39 static void
40 hrtimer_call_handler(void *arg)
41 {
42 	struct hrtimer *hrtimer;
43 	enum hrtimer_restart ret;
44 
45 	hrtimer = arg;
46 	ret = hrtimer->function(hrtimer);
47 
48 	if (ret == HRTIMER_RESTART) {
49 		callout_schedule_sbt(&hrtimer->callout,
50 		    nstosbt(hrtimer->expires), nstosbt(hrtimer->precision), 0);
51 	} else {
52 		callout_deactivate(&hrtimer->callout);
53 	}
54 }
55 
56 bool
57 linux_hrtimer_active(struct hrtimer *hrtimer)
58 {
59 	bool ret;
60 
61 	mtx_lock(&hrtimer->mtx);
62 	ret = callout_active(&hrtimer->callout);
63 	mtx_unlock(&hrtimer->mtx);
64 
65 	return (ret);
66 }
67 
68 /*
69  * Try to cancel active hrtimer.
70  * Return 1 if timer was active and cancellation succeeded, 0 if timer was
71  * inactive, or -1 if the timer is being serviced and can't be cancelled.
72  */
73 int
74 linux_hrtimer_try_to_cancel(struct hrtimer *hrtimer)
75 {
76 	int ret;
77 
78 	mtx_lock(&hrtimer->mtx);
79 	ret = callout_stop(&hrtimer->callout);
80 	mtx_unlock(&hrtimer->mtx);
81 	if (ret > 0) {
82 		return (1);
83 	} else if (ret < 0) {
84 		return (0);
85 	} else {
86 		return (-1);
87 	}
88 }
89 
90 /*
91  * Cancel active hrtimer.
92  * Return 1 if timer was active and cancellation succeeded, or 0 otherwise.
93  */
94 int
95 linux_hrtimer_cancel(struct hrtimer *hrtimer)
96 {
97 
98 	return (callout_drain(&hrtimer->callout) > 0);
99 }
100 
101 void
102 linux_hrtimer_init(struct hrtimer *hrtimer)
103 {
104 
105 	memset(hrtimer, 0, sizeof(*hrtimer));
106 	mtx_init(&hrtimer->mtx, "hrtimer", NULL,
107 	    MTX_DEF | MTX_RECURSE | MTX_NOWITNESS);
108 	callout_init_mtx(&hrtimer->callout, &hrtimer->mtx, 0);
109 }
110 
111 void
112 linux_hrtimer_set_expires(struct hrtimer *hrtimer, ktime_t time)
113 {
114 	hrtimer->expires = ktime_to_ns(time);
115 }
116 
117 void
118 linux_hrtimer_start(struct hrtimer *hrtimer, ktime_t time)
119 {
120 
121 	linux_hrtimer_start_range_ns(hrtimer, time, 0);
122 }
123 
124 void
125 linux_hrtimer_start_range_ns(struct hrtimer *hrtimer, ktime_t time,
126     int64_t nsec)
127 {
128 
129 	mtx_lock(&hrtimer->mtx);
130 	hrtimer->precision = nsec;
131 	callout_reset_sbt(&hrtimer->callout, nstosbt(ktime_to_ns(time)),
132 	    nstosbt(nsec), hrtimer_call_handler, hrtimer, 0);
133 	mtx_unlock(&hrtimer->mtx);
134 }
135 
136 void
137 linux_hrtimer_forward_now(struct hrtimer *hrtimer, ktime_t interval)
138 {
139 
140 	mtx_lock(&hrtimer->mtx);
141 	callout_reset_sbt(&hrtimer->callout, nstosbt(ktime_to_ns(interval)),
142 	    nstosbt(hrtimer->precision), hrtimer_call_handler, hrtimer, 0);
143 	mtx_unlock(&hrtimer->mtx);
144 }
145