xref: /linux-6.15/include/linux/time.h (revision 5e8d780d)
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_MSEC	1000L
33 #define NSEC_PER_USEC	1000L
34 #define NSEC_PER_MSEC	1000000L
35 #define USEC_PER_SEC	1000000L
36 #define NSEC_PER_SEC	1000000000L
37 #define FSEC_PER_SEC	1000000000000000L
38 
39 static inline int timespec_equal(struct timespec *a, struct timespec *b)
40 {
41 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
42 }
43 
44 /*
45  * lhs < rhs:  return <0
46  * lhs == rhs: return 0
47  * lhs > rhs:  return >0
48  */
49 static inline int timespec_compare(struct timespec *lhs, struct timespec *rhs)
50 {
51 	if (lhs->tv_sec < rhs->tv_sec)
52 		return -1;
53 	if (lhs->tv_sec > rhs->tv_sec)
54 		return 1;
55 	return lhs->tv_nsec - rhs->tv_nsec;
56 }
57 
58 static inline int timeval_compare(struct timeval *lhs, struct timeval *rhs)
59 {
60 	if (lhs->tv_sec < rhs->tv_sec)
61 		return -1;
62 	if (lhs->tv_sec > rhs->tv_sec)
63 		return 1;
64 	return lhs->tv_usec - rhs->tv_usec;
65 }
66 
67 extern unsigned long mktime(const unsigned int year, const unsigned int mon,
68 			    const unsigned int day, const unsigned int hour,
69 			    const unsigned int min, const unsigned int sec);
70 
71 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
72 
73 /*
74  * Returns true if the timespec is norm, false if denorm:
75  */
76 #define timespec_valid(ts) \
77 	(((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
78 
79 extern struct timespec xtime;
80 extern struct timespec wall_to_monotonic;
81 extern seqlock_t xtime_lock;
82 
83 void timekeeping_init(void);
84 
85 static inline unsigned long get_seconds(void)
86 {
87 	return xtime.tv_sec;
88 }
89 
90 struct timespec current_kernel_time(void);
91 
92 #define CURRENT_TIME		(current_kernel_time())
93 #define CURRENT_TIME_SEC	((struct timespec) { xtime.tv_sec, 0 })
94 
95 extern void do_gettimeofday(struct timeval *tv);
96 extern int do_settimeofday(struct timespec *tv);
97 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
98 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
99 extern long do_utimes(int dfd, char __user *filename, struct timeval *times);
100 struct itimerval;
101 extern int do_setitimer(int which, struct itimerval *value,
102 			struct itimerval *ovalue);
103 extern unsigned int alarm_setitimer(unsigned int seconds);
104 extern int do_getitimer(int which, struct itimerval *value);
105 extern void getnstimeofday(struct timespec *tv);
106 
107 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
108 extern int timekeeping_is_continuous(void);
109 
110 /**
111  * timespec_to_ns - Convert timespec to nanoseconds
112  * @ts:		pointer to the timespec variable to be converted
113  *
114  * Returns the scalar nanosecond representation of the timespec
115  * parameter.
116  */
117 static inline s64 timespec_to_ns(const struct timespec *ts)
118 {
119 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
120 }
121 
122 /**
123  * timeval_to_ns - Convert timeval to nanoseconds
124  * @ts:		pointer to the timeval variable to be converted
125  *
126  * Returns the scalar nanosecond representation of the timeval
127  * parameter.
128  */
129 static inline s64 timeval_to_ns(const struct timeval *tv)
130 {
131 	return ((s64) tv->tv_sec * NSEC_PER_SEC) +
132 		tv->tv_usec * NSEC_PER_USEC;
133 }
134 
135 /**
136  * ns_to_timespec - Convert nanoseconds to timespec
137  * @nsec:	the nanoseconds value to be converted
138  *
139  * Returns the timespec representation of the nsec parameter.
140  */
141 extern struct timespec ns_to_timespec(const s64 nsec);
142 
143 /**
144  * ns_to_timeval - Convert nanoseconds to timeval
145  * @nsec:	the nanoseconds value to be converted
146  *
147  * Returns the timeval representation of the nsec parameter.
148  */
149 extern struct timeval ns_to_timeval(const s64 nsec);
150 
151 /**
152  * timespec_add_ns - Adds nanoseconds to a timespec
153  * @a:		pointer to timespec to be incremented
154  * @ns:		unsigned nanoseconds value to be added
155  */
156 static inline void timespec_add_ns(struct timespec *a, u64 ns)
157 {
158 	ns += a->tv_nsec;
159 	while(unlikely(ns >= NSEC_PER_SEC)) {
160 		ns -= NSEC_PER_SEC;
161 		a->tv_sec++;
162 	}
163 	a->tv_nsec = ns;
164 }
165 #endif /* __KERNEL__ */
166 
167 #define NFDBITS			__NFDBITS
168 
169 #define FD_SETSIZE		__FD_SETSIZE
170 #define FD_SET(fd,fdsetp)	__FD_SET(fd,fdsetp)
171 #define FD_CLR(fd,fdsetp)	__FD_CLR(fd,fdsetp)
172 #define FD_ISSET(fd,fdsetp)	__FD_ISSET(fd,fdsetp)
173 #define FD_ZERO(fdsetp)		__FD_ZERO(fdsetp)
174 
175 /*
176  * Names of the interval timers, and structure
177  * defining a timer setting:
178  */
179 #define	ITIMER_REAL		0
180 #define	ITIMER_VIRTUAL		1
181 #define	ITIMER_PROF		2
182 
183 struct itimerspec {
184 	struct timespec it_interval;	/* timer period */
185 	struct timespec it_value;	/* timer expiration */
186 };
187 
188 struct itimerval {
189 	struct timeval it_interval;	/* timer interval */
190 	struct timeval it_value;	/* current value */
191 };
192 
193 /*
194  * The IDs of the various system clocks (for POSIX.1b interval timers):
195  */
196 #define CLOCK_REALTIME			0
197 #define CLOCK_MONOTONIC			1
198 #define CLOCK_PROCESS_CPUTIME_ID	2
199 #define CLOCK_THREAD_CPUTIME_ID		3
200 
201 /*
202  * The IDs of various hardware clocks:
203  */
204 #define CLOCK_SGI_CYCLE			10
205 #define MAX_CLOCKS			16
206 #define CLOCKS_MASK			(CLOCK_REALTIME | CLOCK_MONOTONIC)
207 #define CLOCKS_MONO			CLOCK_MONOTONIC
208 
209 /*
210  * The various flags for setting POSIX.1b interval timers:
211  */
212 #define TIMER_ABSTIME			0x01
213 
214 #endif
215