xref: /freebsd/sys/compat/linuxkpi/common/src/linux_hrtimer.c (revision d93a896ef95946b0bf1219866fcb324b78543444)
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("$FreeBSD$");
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 
40 /* hrtimer flags */
41 #define	HRTIMER_ACTIVE		0x01
42 
43 static void
44 hrtimer_call_handler(void *arg)
45 {
46 	struct hrtimer *hrtimer;
47 	enum hrtimer_restart ret;
48 
49 	hrtimer = arg;
50 	ret = hrtimer->function(hrtimer);
51 	MPASS(ret == HRTIMER_NORESTART);
52 	hrtimer->flags &= ~HRTIMER_ACTIVE;
53 }
54 
55 bool
56 linux_hrtimer_active(struct hrtimer *hrtimer)
57 {
58 	bool ret;
59 
60 	mtx_lock(&hrtimer->mtx);
61 	ret = (hrtimer->flags & HRTIMER_ACTIVE) != 0;
62 	mtx_unlock(&hrtimer->mtx);
63 	return (ret);
64 }
65 
66 int
67 linux_hrtimer_cancel(struct hrtimer *hrtimer)
68 {
69 
70 	if (!hrtimer_active(hrtimer))
71 		return (0);
72 	(void)callout_drain(&hrtimer->callout);
73 	return (1);
74 }
75 
76 void
77 linux_hrtimer_init(struct hrtimer *hrtimer)
78 {
79 
80 	hrtimer->function = NULL;
81 	hrtimer->flags = 0;
82 	mtx_init(&hrtimer->mtx, "hrtimer", NULL, MTX_DEF | MTX_RECURSE);
83 	callout_init_mtx(&hrtimer->callout, &hrtimer->mtx, 0);
84 }
85 
86 void
87 linux_hrtimer_set_expires(struct hrtimer *hrtimer __unused,
88     ktime_t time __unused)
89 {
90 }
91 
92 void
93 linux_hrtimer_start(struct hrtimer *hrtimer, ktime_t time)
94 {
95 
96 	linux_hrtimer_start_range_ns(hrtimer, time, 0);
97 }
98 
99 void
100 linux_hrtimer_start_range_ns(struct hrtimer *hrtimer, ktime_t time, int64_t nsec)
101 {
102 
103 	mtx_lock(&hrtimer->mtx);
104 	callout_reset_sbt(&hrtimer->callout, nstosbt(time.tv64), nstosbt(nsec),
105 	    hrtimer_call_handler, hrtimer, 0);
106 	hrtimer->flags |= HRTIMER_ACTIVE;
107 	mtx_unlock(&hrtimer->mtx);
108 }
109