xref: /linux-6.15/include/linux/time.h (revision 4f3865fb)
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 /*
42  * lhs < rhs:  return <0
43  * lhs == rhs: return 0
44  * lhs > rhs:  return >0
45  */
46 static inline int timespec_compare(struct timespec *lhs, struct timespec *rhs)
47 {
48 	if (lhs->tv_sec < rhs->tv_sec)
49 		return -1;
50 	if (lhs->tv_sec > rhs->tv_sec)
51 		return 1;
52 	return lhs->tv_nsec - rhs->tv_nsec;
53 }
54 
55 static inline int timeval_compare(struct timeval *lhs, struct timeval *rhs)
56 {
57 	if (lhs->tv_sec < rhs->tv_sec)
58 		return -1;
59 	if (lhs->tv_sec > rhs->tv_sec)
60 		return 1;
61 	return lhs->tv_usec - rhs->tv_usec;
62 }
63 
64 extern unsigned long mktime(const unsigned int year, const unsigned int mon,
65 			    const unsigned int day, const unsigned int hour,
66 			    const unsigned int min, const unsigned int sec);
67 
68 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
69 
70 /*
71  * Returns true if the timespec is norm, false if denorm:
72  */
73 #define timespec_valid(ts) \
74 	(((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
75 
76 extern struct timespec xtime;
77 extern struct timespec wall_to_monotonic;
78 extern seqlock_t xtime_lock;
79 
80 static inline unsigned long get_seconds(void)
81 {
82 	return xtime.tv_sec;
83 }
84 
85 struct timespec current_kernel_time(void);
86 
87 #define CURRENT_TIME		(current_kernel_time())
88 #define CURRENT_TIME_SEC	((struct timespec) { xtime.tv_sec, 0 })
89 
90 extern void do_gettimeofday(struct timeval *tv);
91 extern int do_settimeofday(struct timespec *tv);
92 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
93 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
94 extern long do_utimes(int dfd, char __user *filename, struct timeval *times);
95 struct itimerval;
96 extern int do_setitimer(int which, struct itimerval *value,
97 			struct itimerval *ovalue);
98 extern unsigned int alarm_setitimer(unsigned int seconds);
99 extern int do_getitimer(int which, struct itimerval *value);
100 extern void getnstimeofday(struct timespec *tv);
101 
102 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
103 
104 /**
105  * timespec_to_ns - Convert timespec to nanoseconds
106  * @ts:		pointer to the timespec variable to be converted
107  *
108  * Returns the scalar nanosecond representation of the timespec
109  * parameter.
110  */
111 static inline s64 timespec_to_ns(const struct timespec *ts)
112 {
113 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
114 }
115 
116 /**
117  * timeval_to_ns - Convert timeval to nanoseconds
118  * @ts:		pointer to the timeval variable to be converted
119  *
120  * Returns the scalar nanosecond representation of the timeval
121  * parameter.
122  */
123 static inline s64 timeval_to_ns(const struct timeval *tv)
124 {
125 	return ((s64) tv->tv_sec * NSEC_PER_SEC) +
126 		tv->tv_usec * NSEC_PER_USEC;
127 }
128 
129 /**
130  * ns_to_timespec - Convert nanoseconds to timespec
131  * @nsec:	the nanoseconds value to be converted
132  *
133  * Returns the timespec representation of the nsec parameter.
134  */
135 extern struct timespec ns_to_timespec(const s64 nsec);
136 
137 /**
138  * ns_to_timeval - Convert nanoseconds to timeval
139  * @nsec:	the nanoseconds value to be converted
140  *
141  * Returns the timeval representation of the nsec parameter.
142  */
143 extern struct timeval ns_to_timeval(const s64 nsec);
144 
145 #endif /* __KERNEL__ */
146 
147 #define NFDBITS			__NFDBITS
148 
149 #define FD_SETSIZE		__FD_SETSIZE
150 #define FD_SET(fd,fdsetp)	__FD_SET(fd,fdsetp)
151 #define FD_CLR(fd,fdsetp)	__FD_CLR(fd,fdsetp)
152 #define FD_ISSET(fd,fdsetp)	__FD_ISSET(fd,fdsetp)
153 #define FD_ZERO(fdsetp)		__FD_ZERO(fdsetp)
154 
155 /*
156  * Names of the interval timers, and structure
157  * defining a timer setting:
158  */
159 #define	ITIMER_REAL		0
160 #define	ITIMER_VIRTUAL		1
161 #define	ITIMER_PROF		2
162 
163 struct itimerspec {
164 	struct timespec it_interval;	/* timer period */
165 	struct timespec it_value;	/* timer expiration */
166 };
167 
168 struct itimerval {
169 	struct timeval it_interval;	/* timer interval */
170 	struct timeval it_value;	/* current value */
171 };
172 
173 /*
174  * The IDs of the various system clocks (for POSIX.1b interval timers):
175  */
176 #define CLOCK_REALTIME			0
177 #define CLOCK_MONOTONIC			1
178 #define CLOCK_PROCESS_CPUTIME_ID	2
179 #define CLOCK_THREAD_CPUTIME_ID		3
180 
181 /*
182  * The IDs of various hardware clocks:
183  */
184 #define CLOCK_SGI_CYCLE			10
185 #define MAX_CLOCKS			16
186 #define CLOCKS_MASK			(CLOCK_REALTIME | CLOCK_MONOTONIC)
187 #define CLOCKS_MONO			CLOCK_MONOTONIC
188 
189 /*
190  * The various flags for setting POSIX.1b interval timers:
191  */
192 #define TIMER_ABSTIME			0x01
193 
194 #endif
195