xref: /linux-6.15/include/linux/time.h (revision 8b4a4080)
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(const struct timespec *a,
40                                  const struct timespec *b)
41 {
42 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
43 }
44 
45 /*
46  * lhs < rhs:  return <0
47  * lhs == rhs: return 0
48  * lhs > rhs:  return >0
49  */
50 static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
51 {
52 	if (lhs->tv_sec < rhs->tv_sec)
53 		return -1;
54 	if (lhs->tv_sec > rhs->tv_sec)
55 		return 1;
56 	return lhs->tv_nsec - rhs->tv_nsec;
57 }
58 
59 static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
60 {
61 	if (lhs->tv_sec < rhs->tv_sec)
62 		return -1;
63 	if (lhs->tv_sec > rhs->tv_sec)
64 		return 1;
65 	return lhs->tv_usec - rhs->tv_usec;
66 }
67 
68 extern unsigned long mktime(const unsigned int year, const unsigned int mon,
69 			    const unsigned int day, const unsigned int hour,
70 			    const unsigned int min, const unsigned int sec);
71 
72 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
73 
74 /*
75  * sub = lhs - rhs, in normalized form
76  */
77 static inline struct timespec timespec_sub(struct timespec lhs,
78 						struct timespec rhs)
79 {
80 	struct timespec ts_delta;
81 	set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
82 				lhs.tv_nsec - rhs.tv_nsec);
83 	return ts_delta;
84 }
85 
86 /*
87  * Returns true if the timespec is norm, false if denorm:
88  */
89 #define timespec_valid(ts) \
90 	(((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
91 
92 extern struct timespec xtime;
93 extern struct timespec wall_to_monotonic;
94 extern seqlock_t xtime_lock __attribute__((weak));
95 
96 extern unsigned long read_persistent_clock(void);
97 void timekeeping_init(void);
98 
99 static inline unsigned long get_seconds(void)
100 {
101 	return xtime.tv_sec;
102 }
103 
104 struct timespec current_kernel_time(void);
105 
106 #define CURRENT_TIME		(current_kernel_time())
107 #define CURRENT_TIME_SEC	((struct timespec) { xtime.tv_sec, 0 })
108 
109 extern void do_gettimeofday(struct timeval *tv);
110 extern int do_settimeofday(struct timespec *tv);
111 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
112 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
113 extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
114 struct itimerval;
115 extern int do_setitimer(int which, struct itimerval *value,
116 			struct itimerval *ovalue);
117 extern unsigned int alarm_setitimer(unsigned int seconds);
118 extern int do_getitimer(int which, struct itimerval *value);
119 extern void getnstimeofday(struct timespec *tv);
120 extern void getboottime(struct timespec *ts);
121 extern void monotonic_to_bootbased(struct timespec *ts);
122 
123 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
124 extern int timekeeping_is_continuous(void);
125 extern void update_wall_time(void);
126 
127 /**
128  * timespec_to_ns - Convert timespec to nanoseconds
129  * @ts:		pointer to the timespec variable to be converted
130  *
131  * Returns the scalar nanosecond representation of the timespec
132  * parameter.
133  */
134 static inline s64 timespec_to_ns(const struct timespec *ts)
135 {
136 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
137 }
138 
139 /**
140  * timeval_to_ns - Convert timeval to nanoseconds
141  * @ts:		pointer to the timeval variable to be converted
142  *
143  * Returns the scalar nanosecond representation of the timeval
144  * parameter.
145  */
146 static inline s64 timeval_to_ns(const struct timeval *tv)
147 {
148 	return ((s64) tv->tv_sec * NSEC_PER_SEC) +
149 		tv->tv_usec * NSEC_PER_USEC;
150 }
151 
152 /**
153  * ns_to_timespec - Convert nanoseconds to timespec
154  * @nsec:	the nanoseconds value to be converted
155  *
156  * Returns the timespec representation of the nsec parameter.
157  */
158 extern struct timespec ns_to_timespec(const s64 nsec);
159 
160 /**
161  * ns_to_timeval - Convert nanoseconds to timeval
162  * @nsec:	the nanoseconds value to be converted
163  *
164  * Returns the timeval representation of the nsec parameter.
165  */
166 extern struct timeval ns_to_timeval(const s64 nsec);
167 
168 /**
169  * timespec_add_ns - Adds nanoseconds to a timespec
170  * @a:		pointer to timespec to be incremented
171  * @ns:		unsigned nanoseconds value to be added
172  */
173 static inline void timespec_add_ns(struct timespec *a, u64 ns)
174 {
175 	ns += a->tv_nsec;
176 	while(unlikely(ns >= NSEC_PER_SEC)) {
177 		ns -= NSEC_PER_SEC;
178 		a->tv_sec++;
179 	}
180 	a->tv_nsec = ns;
181 }
182 #endif /* __KERNEL__ */
183 
184 #define NFDBITS			__NFDBITS
185 
186 #define FD_SETSIZE		__FD_SETSIZE
187 #define FD_SET(fd,fdsetp)	__FD_SET(fd,fdsetp)
188 #define FD_CLR(fd,fdsetp)	__FD_CLR(fd,fdsetp)
189 #define FD_ISSET(fd,fdsetp)	__FD_ISSET(fd,fdsetp)
190 #define FD_ZERO(fdsetp)		__FD_ZERO(fdsetp)
191 
192 /*
193  * Names of the interval timers, and structure
194  * defining a timer setting:
195  */
196 #define	ITIMER_REAL		0
197 #define	ITIMER_VIRTUAL		1
198 #define	ITIMER_PROF		2
199 
200 struct itimerspec {
201 	struct timespec it_interval;	/* timer period */
202 	struct timespec it_value;	/* timer expiration */
203 };
204 
205 struct itimerval {
206 	struct timeval it_interval;	/* timer interval */
207 	struct timeval it_value;	/* current value */
208 };
209 
210 /*
211  * The IDs of the various system clocks (for POSIX.1b interval timers):
212  */
213 #define CLOCK_REALTIME			0
214 #define CLOCK_MONOTONIC			1
215 #define CLOCK_PROCESS_CPUTIME_ID	2
216 #define CLOCK_THREAD_CPUTIME_ID		3
217 
218 /*
219  * The IDs of various hardware clocks:
220  */
221 #define CLOCK_SGI_CYCLE			10
222 #define MAX_CLOCKS			16
223 #define CLOCKS_MASK			(CLOCK_REALTIME | CLOCK_MONOTONIC)
224 #define CLOCKS_MONO			CLOCK_MONOTONIC
225 
226 /*
227  * The various flags for setting POSIX.1b interval timers:
228  */
229 #define TIMER_ABSTIME			0x01
230 
231 #endif
232