linux_hrtimer.c revision 335411 
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: stable/11/sys/compat/linuxkpi/common/src/linux_hrtimer.c 335411 2018-06-20 06:35:37Z hselasky $");
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
40static void
41hrtimer_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
57bool
58linux_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 */
73int
74linux_hrtimer_cancel(struct hrtimer *hrtimer)
75{
76
77	return (callout_drain(&hrtimer->callout) > 0);
78}
79
80void
81linux_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
90void
91linux_hrtimer_set_expires(struct hrtimer *hrtimer, ktime_t time)
92{
93	hrtimer->expires = ktime_to_ns(time);
94}
95
96void
97linux_hrtimer_start(struct hrtimer *hrtimer, ktime_t time)
98{
99
100	linux_hrtimer_start_range_ns(hrtimer, time, 0);
101}
102
103void
104linux_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
115void
116linux_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