xref: /linux-6.15/include/linux/time.h (revision 5dbf2012)
1 #ifndef _LINUX_TIME_H
2 #define _LINUX_TIME_H
3 
4 # include <linux/cache.h>
5 # include <linux/seqlock.h>
6 # include <linux/math64.h>
7 # include <linux/time64.h>
8 
9 extern struct timezone sys_tz;
10 
11 int get_timespec64(struct timespec64 *ts,
12 		const struct timespec __user *uts);
13 int put_timespec64(const struct timespec64 *ts,
14 		struct timespec __user *uts);
15 int get_itimerspec64(struct itimerspec64 *it,
16 			const struct itimerspec __user *uit);
17 int put_itimerspec64(const struct itimerspec64 *it,
18 			struct itimerspec __user *uit);
19 
20 extern time64_t mktime64(const unsigned int year, const unsigned int mon,
21 			const unsigned int day, const unsigned int hour,
22 			const unsigned int min, const unsigned int sec);
23 
24 /* Some architectures do not supply their own clocksource.
25  * This is mainly the case in architectures that get their
26  * inter-tick times by reading the counter on their interval
27  * timer. Since these timers wrap every tick, they're not really
28  * useful as clocksources. Wrapping them to act like one is possible
29  * but not very efficient. So we provide a callout these arches
30  * can implement for use with the jiffies clocksource to provide
31  * finer then tick granular time.
32  */
33 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
34 extern u32 (*arch_gettimeoffset)(void);
35 #endif
36 
37 struct itimerval;
38 extern int do_setitimer(int which, struct itimerval *value,
39 			struct itimerval *ovalue);
40 extern int do_getitimer(int which, struct itimerval *value);
41 
42 extern long do_utimes(int dfd, const char __user *filename, struct timespec64 *times, int flags);
43 
44 /*
45  * Similar to the struct tm in userspace <time.h>, but it needs to be here so
46  * that the kernel source is self contained.
47  */
48 struct tm {
49 	/*
50 	 * the number of seconds after the minute, normally in the range
51 	 * 0 to 59, but can be up to 60 to allow for leap seconds
52 	 */
53 	int tm_sec;
54 	/* the number of minutes after the hour, in the range 0 to 59*/
55 	int tm_min;
56 	/* the number of hours past midnight, in the range 0 to 23 */
57 	int tm_hour;
58 	/* the day of the month, in the range 1 to 31 */
59 	int tm_mday;
60 	/* the number of months since January, in the range 0 to 11 */
61 	int tm_mon;
62 	/* the number of years since 1900 */
63 	long tm_year;
64 	/* the number of days since Sunday, in the range 0 to 6 */
65 	int tm_wday;
66 	/* the number of days since January 1, in the range 0 to 365 */
67 	int tm_yday;
68 };
69 
70 void time64_to_tm(time64_t totalsecs, int offset, struct tm *result);
71 
72 # include <linux/time32.h>
73 
74 static inline bool itimerspec64_valid(const struct itimerspec64 *its)
75 {
76 	if (!timespec64_valid(&(its->it_interval)) ||
77 		!timespec64_valid(&(its->it_value)))
78 		return false;
79 
80 	return true;
81 }
82 
83 /**
84  * time_after32 - compare two 32-bit relative times
85  * @a:	the time which may be after @b
86  * @b:	the time which may be before @a
87  *
88  * time_after32(a, b) returns true if the time @a is after time @b.
89  * time_before32(b, a) returns true if the time @b is before time @a.
90  *
91  * Similar to time_after(), compare two 32-bit timestamps for relative
92  * times.  This is useful for comparing 32-bit seconds values that can't
93  * be converted to 64-bit values (e.g. due to disk format or wire protocol
94  * issues) when it is known that the times are less than 68 years apart.
95  */
96 #define time_after32(a, b)	((s32)((u32)(b) - (u32)(a)) < 0)
97 #define time_before32(b, a)	time_after32(a, b)
98 #endif
99