1 /* $NetBSD: timer.h,v 1.17 2021/12/19 12:33:48 riastradh Exp $ */
2
3 /*-
4 * Copyright (c) 2013 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Taylor R. Campbell.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #ifndef _LINUX_TIMER_H_
33 #define _LINUX_TIMER_H_
34
35 #include <sys/callout.h>
36
37 #include <linux/jiffies.h>
38 #include <linux/ktime.h>
39
40 struct timer_list {
41 struct callout tl_callout;
42 };
43
44 #define from_timer(V, T, F) container_of(T, __typeof__(*(V)), F)
45
46 #define TIMER_IRQSAFE __BIT(0)
47
48 static inline void
timer_setup(struct timer_list * timer,void (* fn)(struct timer_list *),int flags)49 timer_setup(struct timer_list *timer, void (*fn)(struct timer_list *),
50 int flags)
51 {
52
53 callout_init(&timer->tl_callout, 0);
54
55 /* XXX Super-sketchy casts! */
56 callout_setfunc(&timer->tl_callout, (void (*)(void *))(void *)fn,
57 (void *)timer);
58 }
59
60 static inline int
mod_timer(struct timer_list * timer,unsigned long then)61 mod_timer(struct timer_list *timer, unsigned long then)
62 {
63 const unsigned long now = jiffies;
64 int pending;
65
66 pending = callout_pending(&timer->tl_callout);
67 callout_schedule(&timer->tl_callout, (now < then? (then - now) : 0));
68 return pending;
69 }
70
71 static inline void
mod_timer_pinned(struct timer_list * timer,unsigned long then)72 mod_timer_pinned(struct timer_list *timer, unsigned long then)
73 {
74
75 /* XXX Stay on the same CPU it was originally on... */
76 mod_timer(timer, then);
77 }
78
79 static inline int
del_timer(struct timer_list * timer)80 del_timer(struct timer_list *timer)
81 {
82
83 /*
84 * Linux: `del_timer of an inactive timer returns 0, del_timer
85 * of an active timer returns 1.'
86 *
87 * NetBSD: `callout_stop will return a non-zero value if the
88 * callout was EXPIRED.', meaning it is no longer pending.
89 */
90 if (!callout_pending(&timer->tl_callout))
91 return 0; /* not active */
92 if (callout_stop(&timer->tl_callout))
93 return 0; /* too late, already expired */
94 return 1; /* we stopped it while active */
95 }
96
97 static inline int
del_timer_sync(struct timer_list * timer)98 del_timer_sync(struct timer_list *timer)
99 {
100
101 /*
102 * Linux: `The function returns whether it has deactivated a
103 * pending timer or not.'
104 *
105 * NetBSD: `[callout_halt] will return a non-zero value if the
106 * callout was EXPIRED.', meaning it is no longer pending.
107 */
108 if (!callout_pending(&timer->tl_callout))
109 return 0; /* not active */
110 if (callout_halt(&timer->tl_callout, NULL))
111 return 0; /* too late, already expired */
112 return 1; /* we stopped it while active */
113 }
114
115 static inline bool
timer_pending(struct timer_list * timer)116 timer_pending(struct timer_list *timer)
117 {
118
119 return callout_pending(&timer->tl_callout);
120 }
121
122 /*
123 * XXX This is bogus -- the Linux version does various machinations to
124 * give some jitter so that stuff doesn't wake up all at once.
125 */
126
127 static inline unsigned long
round_jiffies_up(unsigned long j)128 round_jiffies_up(unsigned long j)
129 {
130 return roundup(j, hz);
131 }
132
133 static inline unsigned long
round_jiffies_up_relative(unsigned long j)134 round_jiffies_up_relative(unsigned long j)
135 {
136 return roundup(j, hz);
137 }
138
139 #endif /* _LINUX_TIMER_H_ */
140