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
36static void
37hrtimer_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
53bool
54linux_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 */
70int
71linux_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 */
91int
92linux_hrtimer_cancel(struct hrtimer *hrtimer)
93{
94
95	return (callout_drain(&hrtimer->callout) > 0);
96}
97
98void
99linux_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
108void
109linux_hrtimer_set_expires(struct hrtimer *hrtimer, ktime_t time)
110{
111	hrtimer->expires = ktime_to_ns(time);
112}
113
114void
115linux_hrtimer_start(struct hrtimer *hrtimer, ktime_t time)
116{
117
118	linux_hrtimer_start_range_ns(hrtimer, time, 0);
119}
120
121void
122linux_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
133void
134linux_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