xref: /linux-6.15/include/linux/time.h (revision 2d6ffcca)
1 #ifndef _LINUX_TIME_H
2 #define _LINUX_TIME_H
3 
4 #include <linux/types.h>
5 
6 #ifdef __KERNEL__
7 # include <linux/cache.h>
8 # include <linux/seqlock.h>
9 # include <linux/math64.h>
10 #endif
11 
12 #ifndef _STRUCT_TIMESPEC
13 #define _STRUCT_TIMESPEC
14 struct timespec {
15 	time_t	tv_sec;		/* seconds */
16 	long	tv_nsec;	/* nanoseconds */
17 };
18 #endif
19 
20 struct timeval {
21 	time_t		tv_sec;		/* seconds */
22 	suseconds_t	tv_usec;	/* microseconds */
23 };
24 
25 struct timezone {
26 	int	tz_minuteswest;	/* minutes west of Greenwich */
27 	int	tz_dsttime;	/* type of dst correction */
28 };
29 
30 #ifdef __KERNEL__
31 
32 /* Parameters used to convert the timespec values: */
33 #define MSEC_PER_SEC	1000L
34 #define USEC_PER_MSEC	1000L
35 #define NSEC_PER_USEC	1000L
36 #define NSEC_PER_MSEC	1000000L
37 #define USEC_PER_SEC	1000000L
38 #define NSEC_PER_SEC	1000000000L
39 #define FSEC_PER_SEC	1000000000000000L
40 
41 static inline int timespec_equal(const struct timespec *a,
42                                  const struct timespec *b)
43 {
44 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
45 }
46 
47 /*
48  * lhs < rhs:  return <0
49  * lhs == rhs: return 0
50  * lhs > rhs:  return >0
51  */
52 static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
53 {
54 	if (lhs->tv_sec < rhs->tv_sec)
55 		return -1;
56 	if (lhs->tv_sec > rhs->tv_sec)
57 		return 1;
58 	return lhs->tv_nsec - rhs->tv_nsec;
59 }
60 
61 static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
62 {
63 	if (lhs->tv_sec < rhs->tv_sec)
64 		return -1;
65 	if (lhs->tv_sec > rhs->tv_sec)
66 		return 1;
67 	return lhs->tv_usec - rhs->tv_usec;
68 }
69 
70 extern unsigned long mktime(const unsigned int year, const unsigned int mon,
71 			    const unsigned int day, const unsigned int hour,
72 			    const unsigned int min, const unsigned int sec);
73 
74 extern void set_normalized_timespec(struct timespec *ts, time_t sec, long nsec);
75 
76 /*
77  * sub = lhs - rhs, in normalized form
78  */
79 static inline struct timespec timespec_sub(struct timespec lhs,
80 						struct timespec rhs)
81 {
82 	struct timespec ts_delta;
83 	set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
84 				lhs.tv_nsec - rhs.tv_nsec);
85 	return ts_delta;
86 }
87 
88 /*
89  * Returns true if the timespec is norm, false if denorm:
90  */
91 #define timespec_valid(ts) \
92 	(((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
93 
94 extern struct timespec xtime;
95 extern struct timespec wall_to_monotonic;
96 extern seqlock_t xtime_lock;
97 
98 extern unsigned long read_persistent_clock(void);
99 extern int update_persistent_clock(struct timespec now);
100 extern int no_sync_cmos_clock __read_mostly;
101 void timekeeping_init(void);
102 
103 unsigned long get_seconds(void);
104 struct timespec current_kernel_time(void);
105 
106 #define CURRENT_TIME		(current_kernel_time())
107 #define CURRENT_TIME_SEC	((struct timespec) { get_seconds(), 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_valid_for_hres(void);
125 extern void update_wall_time(void);
126 extern void update_xtime_cache(u64 nsec);
127 
128 /**
129  * timespec_to_ns - Convert timespec to nanoseconds
130  * @ts:		pointer to the timespec variable to be converted
131  *
132  * Returns the scalar nanosecond representation of the timespec
133  * parameter.
134  */
135 static inline s64 timespec_to_ns(const struct timespec *ts)
136 {
137 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
138 }
139 
140 /**
141  * timeval_to_ns - Convert timeval to nanoseconds
142  * @ts:		pointer to the timeval variable to be converted
143  *
144  * Returns the scalar nanosecond representation of the timeval
145  * parameter.
146  */
147 static inline s64 timeval_to_ns(const struct timeval *tv)
148 {
149 	return ((s64) tv->tv_sec * NSEC_PER_SEC) +
150 		tv->tv_usec * NSEC_PER_USEC;
151 }
152 
153 /**
154  * ns_to_timespec - Convert nanoseconds to timespec
155  * @nsec:	the nanoseconds value to be converted
156  *
157  * Returns the timespec representation of the nsec parameter.
158  */
159 extern struct timespec ns_to_timespec(const s64 nsec);
160 
161 /**
162  * ns_to_timeval - Convert nanoseconds to timeval
163  * @nsec:	the nanoseconds value to be converted
164  *
165  * Returns the timeval representation of the nsec parameter.
166  */
167 extern struct timeval ns_to_timeval(const s64 nsec);
168 
169 /**
170  * timespec_add_ns - Adds nanoseconds to a timespec
171  * @a:		pointer to timespec to be incremented
172  * @ns:		unsigned nanoseconds value to be added
173  *
174  * This must always be inlined because its used from the x86-64 vdso,
175  * which cannot call other kernel functions.
176  */
177 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
178 {
179 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
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