xref: /linux-6.15/include/linux/time.h (revision 4e57b681)
1 #ifndef _LINUX_TIME_H
2 #define _LINUX_TIME_H
3 
4 #include <linux/types.h>
5 
6 #ifdef __KERNEL__
7 #include <linux/seqlock.h>
8 #endif
9 
10 #ifndef _STRUCT_TIMESPEC
11 #define _STRUCT_TIMESPEC
12 struct timespec {
13 	time_t	tv_sec;		/* seconds */
14 	long	tv_nsec;	/* nanoseconds */
15 };
16 #endif /* _STRUCT_TIMESPEC */
17 
18 struct timeval {
19 	time_t		tv_sec;		/* seconds */
20 	suseconds_t	tv_usec;	/* microseconds */
21 };
22 
23 struct timezone {
24 	int	tz_minuteswest;	/* minutes west of Greenwich */
25 	int	tz_dsttime;	/* type of dst correction */
26 };
27 
28 #ifdef __KERNEL__
29 
30 /* Parameters used to convert the timespec values */
31 #define MSEC_PER_SEC (1000L)
32 #define USEC_PER_SEC (1000000L)
33 #define NSEC_PER_SEC (1000000000L)
34 #define NSEC_PER_USEC (1000L)
35 
36 static __inline__ int timespec_equal(struct timespec *a, struct timespec *b)
37 {
38 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
39 }
40 
41 /* Converts Gregorian date to seconds since 1970-01-01 00:00:00.
42  * Assumes input in normal date format, i.e. 1980-12-31 23:59:59
43  * => year=1980, mon=12, day=31, hour=23, min=59, sec=59.
44  *
45  * [For the Julian calendar (which was used in Russia before 1917,
46  * Britain & colonies before 1752, anywhere else before 1582,
47  * and is still in use by some communities) leave out the
48  * -year/100+year/400 terms, and add 10.]
49  *
50  * This algorithm was first published by Gauss (I think).
51  *
52  * WARNING: this function will overflow on 2106-02-07 06:28:16 on
53  * machines were long is 32-bit! (However, as time_t is signed, we
54  * will already get problems at other places on 2038-01-19 03:14:08)
55  */
56 static inline unsigned long
57 mktime (unsigned int year, unsigned int mon,
58 	unsigned int day, unsigned int hour,
59 	unsigned int min, unsigned int sec)
60 {
61 	if (0 >= (int) (mon -= 2)) {	/* 1..12 -> 11,12,1..10 */
62 		mon += 12;		/* Puts Feb last since it has leap day */
63 		year -= 1;
64 	}
65 
66 	return (((
67 		(unsigned long) (year/4 - year/100 + year/400 + 367*mon/12 + day) +
68 			year*365 - 719499
69 	    )*24 + hour /* now have hours */
70 	  )*60 + min /* now have minutes */
71 	)*60 + sec; /* finally seconds */
72 }
73 
74 extern struct timespec xtime;
75 extern struct timespec wall_to_monotonic;
76 extern seqlock_t xtime_lock;
77 
78 static inline unsigned long get_seconds(void)
79 {
80 	return xtime.tv_sec;
81 }
82 
83 struct timespec current_kernel_time(void);
84 
85 #define CURRENT_TIME (current_kernel_time())
86 #define CURRENT_TIME_SEC ((struct timespec) { xtime.tv_sec, 0 })
87 
88 extern void do_gettimeofday(struct timeval *tv);
89 extern int do_settimeofday(struct timespec *tv);
90 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
91 extern void clock_was_set(void); // call when ever the clock is set
92 extern int do_posix_clock_monotonic_gettime(struct timespec *tp);
93 extern long do_utimes(char __user * filename, struct timeval * times);
94 struct itimerval;
95 extern int do_setitimer(int which, struct itimerval *value, struct itimerval *ovalue);
96 extern int do_getitimer(int which, struct itimerval *value);
97 extern void getnstimeofday (struct timespec *tv);
98 
99 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
100 
101 static inline void
102 set_normalized_timespec (struct timespec *ts, time_t sec, long nsec)
103 {
104 	while (nsec > NSEC_PER_SEC) {
105 		nsec -= NSEC_PER_SEC;
106 		++sec;
107 	}
108 	while (nsec < 0) {
109 		nsec += NSEC_PER_SEC;
110 		--sec;
111 	}
112 	ts->tv_sec = sec;
113 	ts->tv_nsec = nsec;
114 }
115 
116 #endif /* __KERNEL__ */
117 
118 #define NFDBITS			__NFDBITS
119 
120 #define FD_SETSIZE		__FD_SETSIZE
121 #define FD_SET(fd,fdsetp)	__FD_SET(fd,fdsetp)
122 #define FD_CLR(fd,fdsetp)	__FD_CLR(fd,fdsetp)
123 #define FD_ISSET(fd,fdsetp)	__FD_ISSET(fd,fdsetp)
124 #define FD_ZERO(fdsetp)		__FD_ZERO(fdsetp)
125 
126 /*
127  * Names of the interval timers, and structure
128  * defining a timer setting.
129  */
130 #define	ITIMER_REAL	0
131 #define	ITIMER_VIRTUAL	1
132 #define	ITIMER_PROF	2
133 
134 struct  itimerspec {
135         struct  timespec it_interval;    /* timer period */
136         struct  timespec it_value;       /* timer expiration */
137 };
138 
139 struct	itimerval {
140 	struct	timeval it_interval;	/* timer interval */
141 	struct	timeval it_value;	/* current value */
142 };
143 
144 
145 /*
146  * The IDs of the various system clocks (for POSIX.1b interval timers).
147  */
148 #define CLOCK_REALTIME		  0
149 #define CLOCK_MONOTONIC	  1
150 #define CLOCK_PROCESS_CPUTIME_ID 2
151 #define CLOCK_THREAD_CPUTIME_ID	 3
152 #define CLOCK_REALTIME_HR	 4
153 #define CLOCK_MONOTONIC_HR	  5
154 
155 /*
156  * The IDs of various hardware clocks
157  */
158 
159 
160 #define CLOCK_SGI_CYCLE 10
161 #define MAX_CLOCKS 16
162 #define CLOCKS_MASK  (CLOCK_REALTIME | CLOCK_MONOTONIC | \
163                      CLOCK_REALTIME_HR | CLOCK_MONOTONIC_HR)
164 #define CLOCKS_MONO (CLOCK_MONOTONIC & CLOCK_MONOTONIC_HR)
165 
166 /*
167  * The various flags for setting POSIX.1b interval timers.
168  */
169 
170 #define TIMER_ABSTIME 0x01
171 
172 
173 #endif
174