xref: /linux-6.15/include/linux/time.h (revision e8fa600e)
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	1000000000000000LL
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 
80 /*
81  * timespec_add_safe assumes both values are positive and checks
82  * for overflow. It will return TIME_T_MAX if the reutrn would be
83  * smaller then either of the arguments.
84  */
85 extern struct timespec timespec_add_safe(const struct timespec lhs,
86 					 const struct timespec rhs);
87 
88 
89 static inline struct timespec timespec_add(struct timespec lhs,
90 						struct timespec rhs)
91 {
92 	struct timespec ts_delta;
93 	set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
94 				lhs.tv_nsec + rhs.tv_nsec);
95 	return ts_delta;
96 }
97 
98 /*
99  * sub = lhs - rhs, in normalized form
100  */
101 static inline struct timespec timespec_sub(struct timespec lhs,
102 						struct timespec rhs)
103 {
104 	struct timespec ts_delta;
105 	set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
106 				lhs.tv_nsec - rhs.tv_nsec);
107 	return ts_delta;
108 }
109 
110 /*
111  * Returns true if the timespec is norm, false if denorm:
112  */
113 #define timespec_valid(ts) \
114 	(((ts)->tv_sec >= 0) && (((unsigned long) (ts)->tv_nsec) < NSEC_PER_SEC))
115 
116 extern void read_persistent_clock(struct timespec *ts);
117 extern void read_boot_clock(struct timespec *ts);
118 extern int update_persistent_clock(struct timespec now);
119 void timekeeping_init(void);
120 extern int timekeeping_suspended;
121 
122 unsigned long get_seconds(void);
123 struct timespec current_kernel_time(void);
124 struct timespec __current_kernel_time(void); /* does not take xtime_lock */
125 struct timespec get_monotonic_coarse(void);
126 void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
127 				struct timespec *wtom, struct timespec *sleep);
128 void timekeeping_inject_sleeptime(struct timespec *delta);
129 
130 #define CURRENT_TIME		(current_kernel_time())
131 #define CURRENT_TIME_SEC	((struct timespec) { get_seconds(), 0 })
132 
133 /* Some architectures do not supply their own clocksource.
134  * This is mainly the case in architectures that get their
135  * inter-tick times by reading the counter on their interval
136  * timer. Since these timers wrap every tick, they're not really
137  * useful as clocksources. Wrapping them to act like one is possible
138  * but not very efficient. So we provide a callout these arches
139  * can implement for use with the jiffies clocksource to provide
140  * finer then tick granular time.
141  */
142 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
143 extern u32 arch_gettimeoffset(void);
144 #else
145 static inline u32 arch_gettimeoffset(void) { return 0; }
146 #endif
147 
148 extern void do_gettimeofday(struct timeval *tv);
149 extern int do_settimeofday(const struct timespec *tv);
150 extern int do_sys_settimeofday(const struct timespec *tv,
151 			       const struct timezone *tz);
152 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
153 extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
154 struct itimerval;
155 extern int do_setitimer(int which, struct itimerval *value,
156 			struct itimerval *ovalue);
157 extern unsigned int alarm_setitimer(unsigned int seconds);
158 extern int do_getitimer(int which, struct itimerval *value);
159 extern void getnstimeofday(struct timespec *tv);
160 extern void getrawmonotonic(struct timespec *ts);
161 extern void getnstime_raw_and_real(struct timespec *ts_raw,
162 		struct timespec *ts_real);
163 extern void getboottime(struct timespec *ts);
164 extern void monotonic_to_bootbased(struct timespec *ts);
165 extern void get_monotonic_boottime(struct timespec *ts);
166 
167 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
168 extern int timekeeping_valid_for_hres(void);
169 extern u64 timekeeping_max_deferment(void);
170 extern int timekeeping_inject_offset(struct timespec *ts);
171 
172 struct tms;
173 extern void do_sys_times(struct tms *);
174 
175 /*
176  * Similar to the struct tm in userspace <time.h>, but it needs to be here so
177  * that the kernel source is self contained.
178  */
179 struct tm {
180 	/*
181 	 * the number of seconds after the minute, normally in the range
182 	 * 0 to 59, but can be up to 60 to allow for leap seconds
183 	 */
184 	int tm_sec;
185 	/* the number of minutes after the hour, in the range 0 to 59*/
186 	int tm_min;
187 	/* the number of hours past midnight, in the range 0 to 23 */
188 	int tm_hour;
189 	/* the day of the month, in the range 1 to 31 */
190 	int tm_mday;
191 	/* the number of months since January, in the range 0 to 11 */
192 	int tm_mon;
193 	/* the number of years since 1900 */
194 	long tm_year;
195 	/* the number of days since Sunday, in the range 0 to 6 */
196 	int tm_wday;
197 	/* the number of days since January 1, in the range 0 to 365 */
198 	int tm_yday;
199 };
200 
201 void time_to_tm(time_t totalsecs, int offset, struct tm *result);
202 
203 /**
204  * timespec_to_ns - Convert timespec to nanoseconds
205  * @ts:		pointer to the timespec variable to be converted
206  *
207  * Returns the scalar nanosecond representation of the timespec
208  * parameter.
209  */
210 static inline s64 timespec_to_ns(const struct timespec *ts)
211 {
212 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
213 }
214 
215 /**
216  * timeval_to_ns - Convert timeval to nanoseconds
217  * @ts:		pointer to the timeval variable to be converted
218  *
219  * Returns the scalar nanosecond representation of the timeval
220  * parameter.
221  */
222 static inline s64 timeval_to_ns(const struct timeval *tv)
223 {
224 	return ((s64) tv->tv_sec * NSEC_PER_SEC) +
225 		tv->tv_usec * NSEC_PER_USEC;
226 }
227 
228 /**
229  * ns_to_timespec - Convert nanoseconds to timespec
230  * @nsec:	the nanoseconds value to be converted
231  *
232  * Returns the timespec representation of the nsec parameter.
233  */
234 extern struct timespec ns_to_timespec(const s64 nsec);
235 
236 /**
237  * ns_to_timeval - Convert nanoseconds to timeval
238  * @nsec:	the nanoseconds value to be converted
239  *
240  * Returns the timeval representation of the nsec parameter.
241  */
242 extern struct timeval ns_to_timeval(const s64 nsec);
243 
244 /**
245  * timespec_add_ns - Adds nanoseconds to a timespec
246  * @a:		pointer to timespec to be incremented
247  * @ns:		unsigned nanoseconds value to be added
248  *
249  * This must always be inlined because its used from the x86-64 vdso,
250  * which cannot call other kernel functions.
251  */
252 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
253 {
254 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
255 	a->tv_nsec = ns;
256 }
257 
258 #endif /* __KERNEL__ */
259 
260 /*
261  * Names of the interval timers, and structure
262  * defining a timer setting:
263  */
264 #define	ITIMER_REAL		0
265 #define	ITIMER_VIRTUAL		1
266 #define	ITIMER_PROF		2
267 
268 struct itimerspec {
269 	struct timespec it_interval;	/* timer period */
270 	struct timespec it_value;	/* timer expiration */
271 };
272 
273 struct itimerval {
274 	struct timeval it_interval;	/* timer interval */
275 	struct timeval it_value;	/* current value */
276 };
277 
278 /*
279  * The IDs of the various system clocks (for POSIX.1b interval timers):
280  */
281 #define CLOCK_REALTIME			0
282 #define CLOCK_MONOTONIC			1
283 #define CLOCK_PROCESS_CPUTIME_ID	2
284 #define CLOCK_THREAD_CPUTIME_ID		3
285 #define CLOCK_MONOTONIC_RAW		4
286 #define CLOCK_REALTIME_COARSE		5
287 #define CLOCK_MONOTONIC_COARSE		6
288 #define CLOCK_BOOTTIME			7
289 #define CLOCK_REALTIME_ALARM		8
290 #define CLOCK_BOOTTIME_ALARM		9
291 
292 /*
293  * The IDs of various hardware clocks:
294  */
295 #define CLOCK_SGI_CYCLE			10
296 #define MAX_CLOCKS			16
297 #define CLOCKS_MASK			(CLOCK_REALTIME | CLOCK_MONOTONIC)
298 #define CLOCKS_MONO			CLOCK_MONOTONIC
299 
300 /*
301  * The various flags for setting POSIX.1b interval timers:
302  */
303 #define TIMER_ABSTIME			0x01
304 
305 #endif
306