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 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 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 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 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 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 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 128 round_jiffies_up(unsigned long j) 129 { 130 return roundup(j, hz); 131 } 132 133 static inline unsigned long 134 round_jiffies_up_relative(unsigned long j) 135 { 136 return roundup(j, hz); 137 } 138 139 #endif /* _LINUX_TIMER_H_ */ 140