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