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 #include <sys/param.h>
28 #include <sys/systm.h>
29 #include <sys/lock.h>
30 #include <sys/mutex.h>
31 #include <sys/time.h>
32 
33 #include <machine/cpu.h>
34 
35 #include <linux/hrtimer.h>
36 
37 static void
38 hrtimer_call_handler(void *arg)
39 {
40 	struct hrtimer *hrtimer;
41 	enum hrtimer_restart ret;
42 
43 	hrtimer = arg;
44 	ret = hrtimer->function(hrtimer);
45 
46 	if (ret == HRTIMER_RESTART) {
47 		callout_schedule_sbt(&hrtimer->callout,
48 		    nstosbt(hrtimer->expires), nstosbt(hrtimer->precision), 0);
49 	} else {
50 		callout_deactivate(&hrtimer->callout);
51 	}
52 }
53 
54 bool
55 linux_hrtimer_active(struct hrtimer *hrtimer)
56 {
57 	bool ret;
58 
59 	mtx_lock(&hrtimer->mtx);
60 	ret = callout_active(&hrtimer->callout);
61 	mtx_unlock(&hrtimer->mtx);
62 
63 	return (ret);
64 }
65 
66 /*
67  * Try to cancel active hrtimer.
68  * Return 1 if timer was active and cancellation succeeded, 0 if timer was
69  * inactive, or -1 if the timer is being serviced and can't be cancelled.
70  */
71 int
72 linux_hrtimer_try_to_cancel(struct hrtimer *hrtimer)
73 {
74 	int ret;
75 
76 	mtx_lock(&hrtimer->mtx);
77 	ret = callout_stop(&hrtimer->callout);
78 	mtx_unlock(&hrtimer->mtx);
79 	if (ret > 0) {
80 		return (1);
81 	} else if (ret < 0) {
82 		return (0);
83 	} else {
84 		return (-1);
85 	}
86 }
87 
88 /*
89  * Cancel active hrtimer.
90  * Return 1 if timer was active and cancellation succeeded, or 0 otherwise.
91  */
92 int
93 linux_hrtimer_cancel(struct hrtimer *hrtimer)
94 {
95 
96 	return (callout_drain(&hrtimer->callout) > 0);
97 }
98 
99 void
100 linux_hrtimer_init(struct hrtimer *hrtimer)
101 {
102 
103 	memset(hrtimer, 0, sizeof(*hrtimer));
104 	mtx_init(&hrtimer->mtx, "hrtimer", NULL,
105 	    MTX_DEF | MTX_RECURSE | MTX_NOWITNESS);
106 	callout_init_mtx(&hrtimer->callout, &hrtimer->mtx, 0);
107 }
108 
109 void
110 linux_hrtimer_set_expires(struct hrtimer *hrtimer, ktime_t time)
111 {
112 	hrtimer->expires = ktime_to_ns(time);
113 }
114 
115 void
116 linux_hrtimer_start(struct hrtimer *hrtimer, ktime_t time)
117 {
118 
119 	linux_hrtimer_start_range_ns(hrtimer, time, 0);
120 }
121 
122 void
123 linux_hrtimer_start_range_ns(struct hrtimer *hrtimer, ktime_t time,
124     int64_t nsec)
125 {
126 
127 	mtx_lock(&hrtimer->mtx);
128 	hrtimer->precision = nsec;
129 	callout_reset_sbt(&hrtimer->callout, nstosbt(ktime_to_ns(time)),
130 	    nstosbt(nsec), hrtimer_call_handler, hrtimer, 0);
131 	mtx_unlock(&hrtimer->mtx);
132 }
133 
134 void
135 linux_hrtimer_forward_now(struct hrtimer *hrtimer, ktime_t interval)
136 {
137 
138 	mtx_lock(&hrtimer->mtx);
139 	callout_reset_sbt(&hrtimer->callout, nstosbt(ktime_to_ns(interval)),
140 	    nstosbt(hrtimer->precision), hrtimer_call_handler, hrtimer, 0);
141 	mtx_unlock(&hrtimer->mtx);
142 }
143