xref: /linux-6.15/include/linux/time.h (revision ad0cd62a)
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 	__kernel_time_t	tv_sec;			/* seconds */
16 	long		tv_nsec;		/* nanoseconds */
17 };
18 #endif
19 
20 struct timeval {
21 	__kernel_time_t		tv_sec;		/* seconds */
22 	__kernel_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 extern struct timezone sys_tz;
33 
34 /* Parameters used to convert the timespec values: */
35 #define MSEC_PER_SEC	1000L
36 #define USEC_PER_MSEC	1000L
37 #define NSEC_PER_USEC	1000L
38 #define NSEC_PER_MSEC	1000000L
39 #define USEC_PER_SEC	1000000L
40 #define NSEC_PER_SEC	1000000000L
41 #define FSEC_PER_SEC	1000000000000000L
42 
43 #define TIME_T_MAX	(time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
44 
45 static inline int timespec_equal(const struct timespec *a,
46                                  const struct timespec *b)
47 {
48 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
49 }
50 
51 /*
52  * lhs < rhs:  return <0
53  * lhs == rhs: return 0
54  * lhs > rhs:  return >0
55  */
56 static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
57 {
58 	if (lhs->tv_sec < rhs->tv_sec)
59 		return -1;
60 	if (lhs->tv_sec > rhs->tv_sec)
61 		return 1;
62 	return lhs->tv_nsec - rhs->tv_nsec;
63 }
64 
65 static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
66 {
67 	if (lhs->tv_sec < rhs->tv_sec)
68 		return -1;
69 	if (lhs->tv_sec > rhs->tv_sec)
70 		return 1;
71 	return lhs->tv_usec - rhs->tv_usec;
72 }
73 
74 extern unsigned long mktime(const unsigned int year, const unsigned int mon,
75 			    const unsigned int day, const unsigned int hour,
76 			    const unsigned int min, const unsigned int sec);
77 
78 extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
79 extern struct timespec timespec_add_safe(const struct timespec lhs,
80 					 const struct timespec rhs);
81 
82 /*
83  * sub = lhs - rhs, in normalized form
84  */
85 static inline struct timespec timespec_sub(struct timespec lhs,
86 						struct timespec rhs)
87 {
88 	struct timespec ts_delta;
89 	set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
90 				lhs.tv_nsec - rhs.tv_nsec);
91 	return ts_delta;
92 }
93 
94 /*
95  * Returns true if the timespec is norm, false if denorm:
96  */
97 #define timespec_valid(ts) \
98 	(((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
99 
100 extern struct timespec xtime;
101 extern struct timespec wall_to_monotonic;
102 extern seqlock_t xtime_lock;
103 
104 extern void read_persistent_clock(struct timespec *ts);
105 extern void read_boot_clock(struct timespec *ts);
106 extern int update_persistent_clock(struct timespec now);
107 extern int no_sync_cmos_clock __read_mostly;
108 void timekeeping_init(void);
109 extern int timekeeping_suspended;
110 
111 unsigned long get_seconds(void);
112 struct timespec current_kernel_time(void);
113 struct timespec __current_kernel_time(void); /* does not hold xtime_lock */
114 struct timespec get_monotonic_coarse(void);
115 
116 #define CURRENT_TIME		(current_kernel_time())
117 #define CURRENT_TIME_SEC	((struct timespec) { get_seconds(), 0 })
118 
119 /* Some architectures do not supply their own clocksource.
120  * This is mainly the case in architectures that get their
121  * inter-tick times by reading the counter on their interval
122  * timer. Since these timers wrap every tick, they're not really
123  * useful as clocksources. Wrapping them to act like one is possible
124  * but not very efficient. So we provide a callout these arches
125  * can implement for use with the jiffies clocksource to provide
126  * finer then tick granular time.
127  */
128 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
129 extern u32 arch_gettimeoffset(void);
130 #else
131 static inline u32 arch_gettimeoffset(void) { return 0; }
132 #endif
133 
134 extern void do_gettimeofday(struct timeval *tv);
135 extern int do_settimeofday(struct timespec *tv);
136 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
137 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
138 extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
139 struct itimerval;
140 extern int do_setitimer(int which, struct itimerval *value,
141 			struct itimerval *ovalue);
142 extern unsigned int alarm_setitimer(unsigned int seconds);
143 extern int do_getitimer(int which, struct itimerval *value);
144 extern void getnstimeofday(struct timespec *tv);
145 extern void getrawmonotonic(struct timespec *ts);
146 extern void getboottime(struct timespec *ts);
147 extern void monotonic_to_bootbased(struct timespec *ts);
148 
149 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
150 extern int timekeeping_valid_for_hres(void);
151 extern void update_wall_time(void);
152 extern void update_xtime_cache(u64 nsec);
153 extern void timekeeping_leap_insert(int leapsecond);
154 
155 struct tms;
156 extern void do_sys_times(struct tms *);
157 
158 /*
159  * Similar to the struct tm in userspace <time.h>, but it needs to be here so
160  * that the kernel source is self contained.
161  */
162 struct tm {
163 	/*
164 	 * the number of seconds after the minute, normally in the range
165 	 * 0 to 59, but can be up to 60 to allow for leap seconds
166 	 */
167 	int tm_sec;
168 	/* the number of minutes after the hour, in the range 0 to 59*/
169 	int tm_min;
170 	/* the number of hours past midnight, in the range 0 to 23 */
171 	int tm_hour;
172 	/* the day of the month, in the range 1 to 31 */
173 	int tm_mday;
174 	/* the number of months since January, in the range 0 to 11 */
175 	int tm_mon;
176 	/* the number of years since 1900 */
177 	long tm_year;
178 	/* the number of days since Sunday, in the range 0 to 6 */
179 	int tm_wday;
180 	/* the number of days since January 1, in the range 0 to 365 */
181 	int tm_yday;
182 };
183 
184 void time_to_tm(time_t totalsecs, int offset, struct tm *result);
185 
186 /**
187  * timespec_to_ns - Convert timespec to nanoseconds
188  * @ts:		pointer to the timespec variable to be converted
189  *
190  * Returns the scalar nanosecond representation of the timespec
191  * parameter.
192  */
193 static inline s64 timespec_to_ns(const struct timespec *ts)
194 {
195 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
196 }
197 
198 /**
199  * timeval_to_ns - Convert timeval to nanoseconds
200  * @ts:		pointer to the timeval variable to be converted
201  *
202  * Returns the scalar nanosecond representation of the timeval
203  * parameter.
204  */
205 static inline s64 timeval_to_ns(const struct timeval *tv)
206 {
207 	return ((s64) tv->tv_sec * NSEC_PER_SEC) +
208 		tv->tv_usec * NSEC_PER_USEC;
209 }
210 
211 /**
212  * ns_to_timespec - Convert nanoseconds to timespec
213  * @nsec:	the nanoseconds value to be converted
214  *
215  * Returns the timespec representation of the nsec parameter.
216  */
217 extern struct timespec ns_to_timespec(const s64 nsec);
218 
219 /**
220  * ns_to_timeval - Convert nanoseconds to timeval
221  * @nsec:	the nanoseconds value to be converted
222  *
223  * Returns the timeval representation of the nsec parameter.
224  */
225 extern struct timeval ns_to_timeval(const s64 nsec);
226 
227 /**
228  * timespec_add_ns - Adds nanoseconds to a timespec
229  * @a:		pointer to timespec to be incremented
230  * @ns:		unsigned nanoseconds value to be added
231  *
232  * This must always be inlined because its used from the x86-64 vdso,
233  * which cannot call other kernel functions.
234  */
235 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
236 {
237 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
238 	a->tv_nsec = ns;
239 }
240 #endif /* __KERNEL__ */
241 
242 #define NFDBITS			__NFDBITS
243 
244 #define FD_SETSIZE		__FD_SETSIZE
245 #define FD_SET(fd,fdsetp)	__FD_SET(fd,fdsetp)
246 #define FD_CLR(fd,fdsetp)	__FD_CLR(fd,fdsetp)
247 #define FD_ISSET(fd,fdsetp)	__FD_ISSET(fd,fdsetp)
248 #define FD_ZERO(fdsetp)		__FD_ZERO(fdsetp)
249 
250 /*
251  * Names of the interval timers, and structure
252  * defining a timer setting:
253  */
254 #define	ITIMER_REAL		0
255 #define	ITIMER_VIRTUAL		1
256 #define	ITIMER_PROF		2
257 
258 struct itimerspec {
259 	struct timespec it_interval;	/* timer period */
260 	struct timespec it_value;	/* timer expiration */
261 };
262 
263 struct itimerval {
264 	struct timeval it_interval;	/* timer interval */
265 	struct timeval it_value;	/* current value */
266 };
267 
268 /*
269  * The IDs of the various system clocks (for POSIX.1b interval timers):
270  */
271 #define CLOCK_REALTIME			0
272 #define CLOCK_MONOTONIC			1
273 #define CLOCK_PROCESS_CPUTIME_ID	2
274 #define CLOCK_THREAD_CPUTIME_ID		3
275 #define CLOCK_MONOTONIC_RAW		4
276 #define CLOCK_REALTIME_COARSE		5
277 #define CLOCK_MONOTONIC_COARSE		6
278 
279 /*
280  * The IDs of various hardware clocks:
281  */
282 #define CLOCK_SGI_CYCLE			10
283 #define MAX_CLOCKS			16
284 #define CLOCKS_MASK			(CLOCK_REALTIME | CLOCK_MONOTONIC)
285 #define CLOCKS_MONO			CLOCK_MONOTONIC
286 
287 /*
288  * The various flags for setting POSIX.1b interval timers:
289  */
290 #define TIMER_ABSTIME			0x01
291 
292 #endif
293