xref: /linux-6.15/include/linux/time.h (revision 7ec7fb39)
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 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, long 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 unsigned long read_persistent_clock(void);
105 extern int update_persistent_clock(struct timespec now);
106 extern int no_sync_cmos_clock __read_mostly;
107 void timekeeping_init(void);
108 
109 unsigned long get_seconds(void);
110 struct timespec current_kernel_time(void);
111 
112 #define CURRENT_TIME		(current_kernel_time())
113 #define CURRENT_TIME_SEC	((struct timespec) { get_seconds(), 0 })
114 
115 extern void do_gettimeofday(struct timeval *tv);
116 extern int do_settimeofday(struct timespec *tv);
117 extern int do_sys_settimeofday(struct timespec *tv, struct timezone *tz);
118 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
119 extern long do_utimes(int dfd, char __user *filename, struct timespec *times, int flags);
120 struct itimerval;
121 extern int do_setitimer(int which, struct itimerval *value,
122 			struct itimerval *ovalue);
123 extern unsigned int alarm_setitimer(unsigned int seconds);
124 extern int do_getitimer(int which, struct itimerval *value);
125 extern void getnstimeofday(struct timespec *tv);
126 extern void getrawmonotonic(struct timespec *ts);
127 extern void getboottime(struct timespec *ts);
128 extern void monotonic_to_bootbased(struct timespec *ts);
129 
130 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
131 extern int timekeeping_valid_for_hres(void);
132 extern void update_wall_time(void);
133 extern void update_xtime_cache(u64 nsec);
134 
135 struct tms;
136 extern void do_sys_times(struct tms *);
137 
138 /**
139  * timespec_to_ns - Convert timespec to nanoseconds
140  * @ts:		pointer to the timespec variable to be converted
141  *
142  * Returns the scalar nanosecond representation of the timespec
143  * parameter.
144  */
145 static inline s64 timespec_to_ns(const struct timespec *ts)
146 {
147 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
148 }
149 
150 /**
151  * timeval_to_ns - Convert timeval to nanoseconds
152  * @ts:		pointer to the timeval variable to be converted
153  *
154  * Returns the scalar nanosecond representation of the timeval
155  * parameter.
156  */
157 static inline s64 timeval_to_ns(const struct timeval *tv)
158 {
159 	return ((s64) tv->tv_sec * NSEC_PER_SEC) +
160 		tv->tv_usec * NSEC_PER_USEC;
161 }
162 
163 /**
164  * ns_to_timespec - Convert nanoseconds to timespec
165  * @nsec:	the nanoseconds value to be converted
166  *
167  * Returns the timespec representation of the nsec parameter.
168  */
169 extern struct timespec ns_to_timespec(const s64 nsec);
170 
171 /**
172  * ns_to_timeval - Convert nanoseconds to timeval
173  * @nsec:	the nanoseconds value to be converted
174  *
175  * Returns the timeval representation of the nsec parameter.
176  */
177 extern struct timeval ns_to_timeval(const s64 nsec);
178 
179 /**
180  * timespec_add_ns - Adds nanoseconds to a timespec
181  * @a:		pointer to timespec to be incremented
182  * @ns:		unsigned nanoseconds value to be added
183  *
184  * This must always be inlined because its used from the x86-64 vdso,
185  * which cannot call other kernel functions.
186  */
187 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
188 {
189 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
190 	a->tv_nsec = ns;
191 }
192 #endif /* __KERNEL__ */
193 
194 #define NFDBITS			__NFDBITS
195 
196 #define FD_SETSIZE		__FD_SETSIZE
197 #define FD_SET(fd,fdsetp)	__FD_SET(fd,fdsetp)
198 #define FD_CLR(fd,fdsetp)	__FD_CLR(fd,fdsetp)
199 #define FD_ISSET(fd,fdsetp)	__FD_ISSET(fd,fdsetp)
200 #define FD_ZERO(fdsetp)		__FD_ZERO(fdsetp)
201 
202 /*
203  * Names of the interval timers, and structure
204  * defining a timer setting:
205  */
206 #define	ITIMER_REAL		0
207 #define	ITIMER_VIRTUAL		1
208 #define	ITIMER_PROF		2
209 
210 struct itimerspec {
211 	struct timespec it_interval;	/* timer period */
212 	struct timespec it_value;	/* timer expiration */
213 };
214 
215 struct itimerval {
216 	struct timeval it_interval;	/* timer interval */
217 	struct timeval it_value;	/* current value */
218 };
219 
220 /*
221  * The IDs of the various system clocks (for POSIX.1b interval timers):
222  */
223 #define CLOCK_REALTIME			0
224 #define CLOCK_MONOTONIC			1
225 #define CLOCK_PROCESS_CPUTIME_ID	2
226 #define CLOCK_THREAD_CPUTIME_ID		3
227 #define CLOCK_MONOTONIC_RAW		4
228 
229 /*
230  * The IDs of various hardware clocks:
231  */
232 #define CLOCK_SGI_CYCLE			10
233 #define MAX_CLOCKS			16
234 #define CLOCKS_MASK			(CLOCK_REALTIME | CLOCK_MONOTONIC)
235 #define CLOCKS_MONO			CLOCK_MONOTONIC
236 
237 /*
238  * The various flags for setting POSIX.1b interval timers:
239  */
240 #define TIMER_ABSTIME			0x01
241 
242 #endif
243