xref: /linux-6.15/include/linux/time.h (revision ba6e8564)
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(const struct timespec *lhs, const 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(const struct timeval *lhs, const 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  * sub = lhs - rhs, in normalized form
75  */
76 static inline struct timespec timespec_sub(struct timespec lhs,
77 						struct timespec rhs)
78 {
79 	struct timespec ts_delta;
80 	set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
81 				lhs.tv_nsec - rhs.tv_nsec);
82 	return ts_delta;
83 }
84 
85 /*
86  * Returns true if the timespec is norm, false if denorm:
87  */
88 #define timespec_valid(ts) \
89 	(((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
90 
91 extern struct timespec xtime;
92 extern struct timespec wall_to_monotonic;
93 extern seqlock_t xtime_lock __attribute__((weak));
94 
95 extern unsigned long read_persistent_clock(void);
96 void timekeeping_init(void);
97 
98 static inline unsigned long get_seconds(void)
99 {
100 	return xtime.tv_sec;
101 }
102 
103 struct timespec current_kernel_time(void);
104 
105 #define CURRENT_TIME		(current_kernel_time())
106 #define CURRENT_TIME_SEC	((struct timespec) { xtime.tv_sec, 0 })
107 
108 extern void do_gettimeofday(struct timeval *tv);
109 extern int do_settimeofday(struct timespec *tv);
110 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
111 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
112 extern long do_utimes(int dfd, char __user *filename, struct timeval *times);
113 struct itimerval;
114 extern int do_setitimer(int which, struct itimerval *value,
115 			struct itimerval *ovalue);
116 extern unsigned int alarm_setitimer(unsigned int seconds);
117 extern int do_getitimer(int which, struct itimerval *value);
118 extern void getnstimeofday(struct timespec *tv);
119 
120 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
121 extern int timekeeping_is_continuous(void);
122 
123 /**
124  * timespec_to_ns - Convert timespec to nanoseconds
125  * @ts:		pointer to the timespec variable to be converted
126  *
127  * Returns the scalar nanosecond representation of the timespec
128  * parameter.
129  */
130 static inline s64 timespec_to_ns(const struct timespec *ts)
131 {
132 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
133 }
134 
135 /**
136  * timeval_to_ns - Convert timeval to nanoseconds
137  * @ts:		pointer to the timeval variable to be converted
138  *
139  * Returns the scalar nanosecond representation of the timeval
140  * parameter.
141  */
142 static inline s64 timeval_to_ns(const struct timeval *tv)
143 {
144 	return ((s64) tv->tv_sec * NSEC_PER_SEC) +
145 		tv->tv_usec * NSEC_PER_USEC;
146 }
147 
148 /**
149  * ns_to_timespec - Convert nanoseconds to timespec
150  * @nsec:	the nanoseconds value to be converted
151  *
152  * Returns the timespec representation of the nsec parameter.
153  */
154 extern struct timespec ns_to_timespec(const s64 nsec);
155 
156 /**
157  * ns_to_timeval - Convert nanoseconds to timeval
158  * @nsec:	the nanoseconds value to be converted
159  *
160  * Returns the timeval representation of the nsec parameter.
161  */
162 extern struct timeval ns_to_timeval(const s64 nsec);
163 
164 /**
165  * timespec_add_ns - Adds nanoseconds to a timespec
166  * @a:		pointer to timespec to be incremented
167  * @ns:		unsigned nanoseconds value to be added
168  */
169 static inline void timespec_add_ns(struct timespec *a, u64 ns)
170 {
171 	ns += a->tv_nsec;
172 	while(unlikely(ns >= NSEC_PER_SEC)) {
173 		ns -= NSEC_PER_SEC;
174 		a->tv_sec++;
175 	}
176 	a->tv_nsec = ns;
177 }
178 #endif /* __KERNEL__ */
179 
180 #define NFDBITS			__NFDBITS
181 
182 #define FD_SETSIZE		__FD_SETSIZE
183 #define FD_SET(fd,fdsetp)	__FD_SET(fd,fdsetp)
184 #define FD_CLR(fd,fdsetp)	__FD_CLR(fd,fdsetp)
185 #define FD_ISSET(fd,fdsetp)	__FD_ISSET(fd,fdsetp)
186 #define FD_ZERO(fdsetp)		__FD_ZERO(fdsetp)
187 
188 /*
189  * Names of the interval timers, and structure
190  * defining a timer setting:
191  */
192 #define	ITIMER_REAL		0
193 #define	ITIMER_VIRTUAL		1
194 #define	ITIMER_PROF		2
195 
196 struct itimerspec {
197 	struct timespec it_interval;	/* timer period */
198 	struct timespec it_value;	/* timer expiration */
199 };
200 
201 struct itimerval {
202 	struct timeval it_interval;	/* timer interval */
203 	struct timeval it_value;	/* current value */
204 };
205 
206 /*
207  * The IDs of the various system clocks (for POSIX.1b interval timers):
208  */
209 #define CLOCK_REALTIME			0
210 #define CLOCK_MONOTONIC			1
211 #define CLOCK_PROCESS_CPUTIME_ID	2
212 #define CLOCK_THREAD_CPUTIME_ID		3
213 
214 /*
215  * The IDs of various hardware clocks:
216  */
217 #define CLOCK_SGI_CYCLE			10
218 #define MAX_CLOCKS			16
219 #define CLOCKS_MASK			(CLOCK_REALTIME | CLOCK_MONOTONIC)
220 #define CLOCKS_MONO			CLOCK_MONOTONIC
221 
222 /*
223  * The various flags for setting POSIX.1b interval timers:
224  */
225 #define TIMER_ABSTIME			0x01
226 
227 #endif
228