xref: /linux-6.15/include/linux/time.h (revision 87c2ce3b)
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
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 extern unsigned long mktime(const unsigned int year, const unsigned int mon,
42 			    const unsigned int day, const unsigned int hour,
43 			    const unsigned int min, const unsigned int sec);
44 
45 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
46 
47 /*
48  * Returns true if the timespec is norm, false if denorm:
49  */
50 #define timespec_valid(ts) \
51 	(((ts)->tv_sec >= 0) && (((unsigned) (ts)->tv_nsec) < NSEC_PER_SEC))
52 
53 /*
54  * 64-bit nanosec type. Large enough to span 292+ years in nanosecond
55  * resolution. Ought to be enough for a while.
56  */
57 typedef s64 nsec_t;
58 
59 extern struct timespec xtime;
60 extern struct timespec wall_to_monotonic;
61 extern seqlock_t xtime_lock;
62 
63 static inline unsigned long get_seconds(void)
64 {
65 	return xtime.tv_sec;
66 }
67 
68 struct timespec current_kernel_time(void);
69 
70 #define CURRENT_TIME		(current_kernel_time())
71 #define CURRENT_TIME_SEC	((struct timespec) { xtime.tv_sec, 0 })
72 
73 extern void do_gettimeofday(struct timeval *tv);
74 extern int do_settimeofday(struct timespec *tv);
75 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
76 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
77 extern long do_utimes(char __user *filename, struct timeval *times);
78 struct itimerval;
79 extern int do_setitimer(int which, struct itimerval *value,
80 			struct itimerval *ovalue);
81 extern int do_getitimer(int which, struct itimerval *value);
82 extern void getnstimeofday(struct timespec *tv);
83 
84 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
85 
86 /**
87  * timespec_to_ns - Convert timespec to nanoseconds
88  * @ts:		pointer to the timespec variable to be converted
89  *
90  * Returns the scalar nanosecond representation of the timespec
91  * parameter.
92  */
93 static inline nsec_t timespec_to_ns(const struct timespec *ts)
94 {
95 	return ((nsec_t) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
96 }
97 
98 /**
99  * timeval_to_ns - Convert timeval to nanoseconds
100  * @ts:		pointer to the timeval variable to be converted
101  *
102  * Returns the scalar nanosecond representation of the timeval
103  * parameter.
104  */
105 static inline nsec_t timeval_to_ns(const struct timeval *tv)
106 {
107 	return ((nsec_t) tv->tv_sec * NSEC_PER_SEC) +
108 		tv->tv_usec * NSEC_PER_USEC;
109 }
110 
111 /**
112  * ns_to_timespec - Convert nanoseconds to timespec
113  * @nsec:	the nanoseconds value to be converted
114  *
115  * Returns the timespec representation of the nsec parameter.
116  */
117 extern struct timespec ns_to_timespec(const nsec_t nsec);
118 
119 /**
120  * ns_to_timeval - Convert nanoseconds to timeval
121  * @nsec:	the nanoseconds value to be converted
122  *
123  * Returns the timeval representation of the nsec parameter.
124  */
125 extern struct timeval ns_to_timeval(const nsec_t nsec);
126 
127 #endif /* __KERNEL__ */
128 
129 #define NFDBITS			__NFDBITS
130 
131 #define FD_SETSIZE		__FD_SETSIZE
132 #define FD_SET(fd,fdsetp)	__FD_SET(fd,fdsetp)
133 #define FD_CLR(fd,fdsetp)	__FD_CLR(fd,fdsetp)
134 #define FD_ISSET(fd,fdsetp)	__FD_ISSET(fd,fdsetp)
135 #define FD_ZERO(fdsetp)		__FD_ZERO(fdsetp)
136 
137 /*
138  * Names of the interval timers, and structure
139  * defining a timer setting:
140  */
141 #define	ITIMER_REAL		0
142 #define	ITIMER_VIRTUAL		1
143 #define	ITIMER_PROF		2
144 
145 struct itimerspec {
146 	struct timespec it_interval;	/* timer period */
147 	struct timespec it_value;	/* timer expiration */
148 };
149 
150 struct itimerval {
151 	struct timeval it_interval;	/* timer interval */
152 	struct timeval it_value;	/* current value */
153 };
154 
155 /*
156  * The IDs of the various system clocks (for POSIX.1b interval timers):
157  */
158 #define CLOCK_REALTIME			0
159 #define CLOCK_MONOTONIC			1
160 #define CLOCK_PROCESS_CPUTIME_ID	2
161 #define CLOCK_THREAD_CPUTIME_ID		3
162 
163 /*
164  * The IDs of various hardware clocks:
165  */
166 #define CLOCK_SGI_CYCLE			10
167 #define MAX_CLOCKS			16
168 #define CLOCKS_MASK			(CLOCK_REALTIME | CLOCK_MONOTONIC)
169 #define CLOCKS_MONO			CLOCK_MONOTONIC
170 
171 /*
172  * The various flags for setting POSIX.1b interval timers:
173  */
174 #define TIMER_ABSTIME			0x01
175 
176 #endif
177