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      1 /*	$NetBSD: time.h,v 1.11 2021/12/19 12:30:23 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_TIME_H_
     33 #define _LINUX_TIME_H_
     34 
     35 #include <sys/time.h>
     36 
     37 #include <linux/math64.h>
     38 #include <linux/seqlock.h>
     39 
     40 #define	timespec64	timespec	/* take that, 2038 */
     41 
     42 #define NSEC_PER_USEC	1000L
     43 #define NSEC_PER_MSEC	1000000L
     44 #define	NSEC_PER_SEC	1000000000L
     45 #define USEC_PER_MSEC	1000L
     46 
     47 /*
     48  * XXX get_seconds as implemented by Linux is a Y2038 bug waiting to
     49  * happen on 32-bit systems because it returns unsigned long.  Some
     50  * callers in Linux (implicitly) convert the result to time_t, though.
     51  * We'll pretend get_seconds returns time_t and make sure all our
     52  * callers treat it as if it did.
     53  */
     54 
     55 static inline time_t
     56 get_seconds(void)
     57 {
     58 	return time_second;
     59 }
     60 
     61 static inline void
     62 getrawmonotonic(struct timespec *ts)
     63 {
     64 	getnanouptime(ts);
     65 }
     66 
     67 static inline void
     68 do_gettimeofday(struct timeval *tv)
     69 {
     70 	microtime(tv);
     71 }
     72 
     73 static inline bool
     74 timespec_valid(const struct timespec *ts)
     75 {
     76 	if (ts->tv_sec < 0)
     77 		return false;
     78 	if (1000000000L <= ts->tv_nsec)
     79 		return false;
     80 	return true;
     81 }
     82 
     83 static inline struct timespec
     84 ns_to_timespec(const int64_t nsec)
     85 {
     86 	struct timespec ts;
     87 
     88 	ts.tv_sec = (nsec / 1000000000L);
     89 	ts.tv_nsec = (nsec % 1000000000L);
     90 	if (ts.tv_nsec < 0) {
     91 		ts.tv_sec -= 1;
     92 		ts.tv_nsec += 1000000000L;
     93 	}
     94 
     95 	return ts;
     96 }
     97 
     98 static inline int64_t
     99 timespec_to_ns(const struct timespec *ts)
    100 {
    101 	return (((int64_t)ts->tv_sec * 1000000000LL) + ts->tv_nsec);
    102 }
    103 
    104 static inline struct timeval
    105 ns_to_timeval(int64_t nsec)
    106 {
    107 	struct timespec ts;
    108 	struct timeval tv;
    109 
    110 	ts = ns_to_timespec(nsec);
    111 	TIMESPEC_TO_TIMEVAL(&tv, &ts);
    112 
    113 	return tv;
    114 }
    115 
    116 static inline int64_t
    117 timeval_to_ns(const struct timeval *tv)
    118 {
    119 	return (((int64_t)tv->tv_sec * 1000000000UL) + (tv->tv_usec * 1000ul));
    120 }
    121 
    122 static inline struct timespec
    123 timespec_sub(struct timespec a, struct timespec b)
    124 {
    125 	struct timespec d;
    126 
    127 	timespecsub(&a, &b, &d);
    128 
    129 	return d;
    130 }
    131 
    132 static inline void
    133 set_normalized_timespec(struct timespec *ts, time_t sec, int64_t nsec)
    134 {
    135 	while (nsec >= 1000000000L) {
    136 		nsec -= 1000000000L;
    137 		sec += 1;
    138 	}
    139 	while (nsec < 0) {
    140 		nsec += 1000000000L;
    141 		sec -= 1;
    142 	}
    143 	ts->tv_sec = sec;
    144 	ts->tv_nsec = nsec;
    145 }
    146 
    147 static inline bool
    148 time_after32(uint32_t a, uint32_t b)
    149 {
    150 	return (int32_t)(b - a) < 0;
    151 }
    152 
    153 #endif  /* _LINUX_TIME_H_ */
    154