xref: /linux-6.15/include/linux/time.h (revision d5b7ffbf)
1 #ifndef _LINUX_TIME_H
2 #define _LINUX_TIME_H
3 
4 # include <linux/cache.h>
5 # include <linux/seqlock.h>
6 # include <linux/math64.h>
7 # include <linux/time64.h>
8 
9 extern struct timezone sys_tz;
10 
11 int get_timespec64(struct timespec64 *ts,
12 		const struct timespec __user *uts);
13 int put_timespec64(const struct timespec64 *ts,
14 		struct timespec __user *uts);
15 int get_itimerspec64(struct itimerspec64 *it,
16 			const struct itimerspec __user *uit);
17 int put_itimerspec64(const struct itimerspec64 *it,
18 			struct itimerspec __user *uit);
19 
20 #define TIME_T_MAX	(time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
21 
22 static inline int timespec_equal(const struct timespec *a,
23                                  const struct timespec *b)
24 {
25 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
26 }
27 
28 /*
29  * lhs < rhs:  return <0
30  * lhs == rhs: return 0
31  * lhs > rhs:  return >0
32  */
33 static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
34 {
35 	if (lhs->tv_sec < rhs->tv_sec)
36 		return -1;
37 	if (lhs->tv_sec > rhs->tv_sec)
38 		return 1;
39 	return lhs->tv_nsec - rhs->tv_nsec;
40 }
41 
42 static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
43 {
44 	if (lhs->tv_sec < rhs->tv_sec)
45 		return -1;
46 	if (lhs->tv_sec > rhs->tv_sec)
47 		return 1;
48 	return lhs->tv_usec - rhs->tv_usec;
49 }
50 
51 extern time64_t mktime64(const unsigned int year, const unsigned int mon,
52 			const unsigned int day, const unsigned int hour,
53 			const unsigned int min, const unsigned int sec);
54 
55 /**
56  * Deprecated. Use mktime64().
57  */
58 static inline unsigned long mktime(const unsigned int year,
59 			const unsigned int mon, const unsigned int day,
60 			const unsigned int hour, const unsigned int min,
61 			const unsigned int sec)
62 {
63 	return mktime64(year, mon, day, hour, min, sec);
64 }
65 
66 extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
67 
68 /*
69  * timespec_add_safe assumes both values are positive and checks
70  * for overflow. It will return TIME_T_MAX if the reutrn would be
71  * smaller then either of the arguments.
72  */
73 extern struct timespec timespec_add_safe(const struct timespec lhs,
74 					 const struct timespec rhs);
75 
76 
77 static inline struct timespec timespec_add(struct timespec lhs,
78 						struct timespec rhs)
79 {
80 	struct timespec ts_delta;
81 	set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
82 				lhs.tv_nsec + rhs.tv_nsec);
83 	return ts_delta;
84 }
85 
86 /*
87  * sub = lhs - rhs, in normalized form
88  */
89 static inline struct timespec timespec_sub(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  * Returns true if the timespec is norm, false if denorm:
100  */
101 static inline bool timespec_valid(const struct timespec *ts)
102 {
103 	/* Dates before 1970 are bogus */
104 	if (ts->tv_sec < 0)
105 		return false;
106 	/* Can't have more nanoseconds then a second */
107 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
108 		return false;
109 	return true;
110 }
111 
112 static inline bool timespec_valid_strict(const struct timespec *ts)
113 {
114 	if (!timespec_valid(ts))
115 		return false;
116 	/* Disallow values that could overflow ktime_t */
117 	if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
118 		return false;
119 	return true;
120 }
121 
122 static inline bool timeval_valid(const struct timeval *tv)
123 {
124 	/* Dates before 1970 are bogus */
125 	if (tv->tv_sec < 0)
126 		return false;
127 
128 	/* Can't have more microseconds then a second */
129 	if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
130 		return false;
131 
132 	return true;
133 }
134 
135 extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
136 
137 /*
138  * Validates if a timespec/timeval used to inject a time offset is valid.
139  * Offsets can be postive or negative. The value of the timeval/timespec
140  * is the sum of its fields, but *NOTE*: the field tv_usec/tv_nsec must
141  * always be non-negative.
142  */
143 static inline bool timeval_inject_offset_valid(const struct timeval *tv)
144 {
145 	/* We don't check the tv_sec as it can be positive or negative */
146 
147 	/* Can't have more microseconds then a second */
148 	if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
149 		return false;
150 	return true;
151 }
152 
153 static inline bool timespec_inject_offset_valid(const struct timespec *ts)
154 {
155 	/* We don't check the tv_sec as it can be positive or negative */
156 
157 	/* Can't have more nanoseconds then a second */
158 	if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)
159 		return false;
160 	return true;
161 }
162 
163 /* Some architectures do not supply their own clocksource.
164  * This is mainly the case in architectures that get their
165  * inter-tick times by reading the counter on their interval
166  * timer. Since these timers wrap every tick, they're not really
167  * useful as clocksources. Wrapping them to act like one is possible
168  * but not very efficient. So we provide a callout these arches
169  * can implement for use with the jiffies clocksource to provide
170  * finer then tick granular time.
171  */
172 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
173 extern u32 (*arch_gettimeoffset)(void);
174 #endif
175 
176 struct itimerval;
177 extern int do_setitimer(int which, struct itimerval *value,
178 			struct itimerval *ovalue);
179 extern int do_getitimer(int which, struct itimerval *value);
180 
181 extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
182 
183 struct tms;
184 extern void do_sys_times(struct tms *);
185 
186 /*
187  * Similar to the struct tm in userspace <time.h>, but it needs to be here so
188  * that the kernel source is self contained.
189  */
190 struct tm {
191 	/*
192 	 * the number of seconds after the minute, normally in the range
193 	 * 0 to 59, but can be up to 60 to allow for leap seconds
194 	 */
195 	int tm_sec;
196 	/* the number of minutes after the hour, in the range 0 to 59*/
197 	int tm_min;
198 	/* the number of hours past midnight, in the range 0 to 23 */
199 	int tm_hour;
200 	/* the day of the month, in the range 1 to 31 */
201 	int tm_mday;
202 	/* the number of months since January, in the range 0 to 11 */
203 	int tm_mon;
204 	/* the number of years since 1900 */
205 	long tm_year;
206 	/* the number of days since Sunday, in the range 0 to 6 */
207 	int tm_wday;
208 	/* the number of days since January 1, in the range 0 to 365 */
209 	int tm_yday;
210 };
211 
212 void time64_to_tm(time64_t totalsecs, int offset, struct tm *result);
213 
214 /**
215  * time_to_tm - converts the calendar time to local broken-down time
216  *
217  * @totalsecs	the number of seconds elapsed since 00:00:00 on January 1, 1970,
218  *		Coordinated Universal Time (UTC).
219  * @offset	offset seconds adding to totalsecs.
220  * @result	pointer to struct tm variable to receive broken-down time
221  */
222 static inline void time_to_tm(time_t totalsecs, int offset, struct tm *result)
223 {
224 	time64_to_tm(totalsecs, offset, result);
225 }
226 
227 /**
228  * timespec_to_ns - Convert timespec to nanoseconds
229  * @ts:		pointer to the timespec variable to be converted
230  *
231  * Returns the scalar nanosecond representation of the timespec
232  * parameter.
233  */
234 static inline s64 timespec_to_ns(const struct timespec *ts)
235 {
236 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
237 }
238 
239 /**
240  * timeval_to_ns - Convert timeval to nanoseconds
241  * @ts:		pointer to the timeval variable to be converted
242  *
243  * Returns the scalar nanosecond representation of the timeval
244  * parameter.
245  */
246 static inline s64 timeval_to_ns(const struct timeval *tv)
247 {
248 	return ((s64) tv->tv_sec * NSEC_PER_SEC) +
249 		tv->tv_usec * NSEC_PER_USEC;
250 }
251 
252 /**
253  * ns_to_timespec - Convert nanoseconds to timespec
254  * @nsec:	the nanoseconds value to be converted
255  *
256  * Returns the timespec representation of the nsec parameter.
257  */
258 extern struct timespec ns_to_timespec(const s64 nsec);
259 
260 /**
261  * ns_to_timeval - Convert nanoseconds to timeval
262  * @nsec:	the nanoseconds value to be converted
263  *
264  * Returns the timeval representation of the nsec parameter.
265  */
266 extern struct timeval ns_to_timeval(const s64 nsec);
267 
268 /**
269  * timespec_add_ns - Adds nanoseconds to a timespec
270  * @a:		pointer to timespec to be incremented
271  * @ns:		unsigned nanoseconds value to be added
272  *
273  * This must always be inlined because its used from the x86-64 vdso,
274  * which cannot call other kernel functions.
275  */
276 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
277 {
278 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
279 	a->tv_nsec = ns;
280 }
281 
282 static inline bool itimerspec64_valid(const struct itimerspec64 *its)
283 {
284 	if (!timespec64_valid(&(its->it_interval)) ||
285 		!timespec64_valid(&(its->it_value)))
286 		return false;
287 
288 	return true;
289 }
290 
291 #endif
292