projects/linux·blob v4.12 · refs

273 lines · 7.6 KiB

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
9extern struct timezone sys_tz;
10
11#define TIME_T_MAX (time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
12
13static inline int timespec_equal(const struct timespec *a,
14 const struct timespec *b)
15{
16 return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
17}
18
19/*
20 * lhs < rhs: return <0
21 * lhs == rhs: return 0
22 * lhs > rhs: return >0
23 */
24static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
25{
26 if (lhs->tv_sec < rhs->tv_sec)
27 return -1;
28 if (lhs->tv_sec > rhs->tv_sec)
29 return 1;
30 return lhs->tv_nsec - rhs->tv_nsec;
31}
32
33static inline int timeval_compare(const struct timeval *lhs, const struct timeval *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_usec - rhs->tv_usec;
40}
41
42extern time64_t mktime64(const unsigned int year, const unsigned int mon,
43 const unsigned int day, const unsigned int hour,
44 const unsigned int min, const unsigned int sec);
45
46/**
47 * Deprecated. Use mktime64().
48 */
49static inline unsigned long mktime(const unsigned int year,
50 const unsigned int mon, const unsigned int day,
51 const unsigned int hour, const unsigned int min,
52 const unsigned int sec)
53{
54 return mktime64(year, mon, day, hour, min, sec);
55}
56
57extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
58
59/*
60 * timespec_add_safe assumes both values are positive and checks
61 * for overflow. It will return TIME_T_MAX if the reutrn would be
62 * smaller then either of the arguments.
63 */
64extern struct timespec timespec_add_safe(const struct timespec lhs,
65 const struct timespec rhs);
66
67
68static inline struct timespec timespec_add(struct timespec lhs,
69 struct timespec rhs)
70{
71 struct timespec ts_delta;
72 set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
73 lhs.tv_nsec + rhs.tv_nsec);
74 return ts_delta;
75}
76
77/*
78 * sub = lhs - rhs, in normalized form
79 */
80static inline struct timespec timespec_sub(struct timespec lhs,
81 struct timespec rhs)
82{
83 struct timespec ts_delta;
84 set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
85 lhs.tv_nsec - rhs.tv_nsec);
86 return ts_delta;
87}
88
89/*
90 * Returns true if the timespec is norm, false if denorm:
91 */
92static inline bool timespec_valid(const struct timespec *ts)
93{
94 /* Dates before 1970 are bogus */
95 if (ts->tv_sec < 0)
96 return false;
97 /* Can't have more nanoseconds then a second */
98 if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
99 return false;
100 return true;
101}
102
103static inline bool timespec_valid_strict(const struct timespec *ts)
104{
105 if (!timespec_valid(ts))
106 return false;
107 /* Disallow values that could overflow ktime_t */
108 if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
109 return false;
110 return true;
111}
112
113static inline bool timeval_valid(const struct timeval *tv)
114{
115 /* Dates before 1970 are bogus */
116 if (tv->tv_sec < 0)
117 return false;
118
119 /* Can't have more microseconds then a second */
120 if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
121 return false;
122
123 return true;
124}
125
126extern struct timespec timespec_trunc(struct timespec t, unsigned gran);
127
128/*
129 * Validates if a timespec/timeval used to inject a time offset is valid.
130 * Offsets can be postive or negative. The value of the timeval/timespec
131 * is the sum of its fields, but *NOTE*: the field tv_usec/tv_nsec must
132 * always be non-negative.
133 */
134static inline bool timeval_inject_offset_valid(const struct timeval *tv)
135{
136 /* We don't check the tv_sec as it can be positive or negative */
137
138 /* Can't have more microseconds then a second */
139 if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
140 return false;
141 return true;
142}
143
144static inline bool timespec_inject_offset_valid(const struct timespec *ts)
145{
146 /* We don't check the tv_sec as it can be positive or negative */
147
148 /* Can't have more nanoseconds then a second */
149 if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)
150 return false;
151 return true;
152}
153
154/* Some architectures do not supply their own clocksource.
155 * This is mainly the case in architectures that get their
156 * inter-tick times by reading the counter on their interval
157 * timer. Since these timers wrap every tick, they're not really
158 * useful as clocksources. Wrapping them to act like one is possible
159 * but not very efficient. So we provide a callout these arches
160 * can implement for use with the jiffies clocksource to provide
161 * finer then tick granular time.
162 */
163#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
164extern u32 (*arch_gettimeoffset)(void);
165#endif
166
167struct itimerval;
168extern int do_setitimer(int which, struct itimerval *value,
169 struct itimerval *ovalue);
170extern int do_getitimer(int which, struct itimerval *value);
171
172extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);
173
174struct tms;
175extern void do_sys_times(struct tms *);
176
177/*
178 * Similar to the struct tm in userspace <time.h>, but it needs to be here so
179 * that the kernel source is self contained.
180 */
181struct tm {
182 /*
183 * the number of seconds after the minute, normally in the range
184 * 0 to 59, but can be up to 60 to allow for leap seconds
185 */
186 int tm_sec;
187 /* the number of minutes after the hour, in the range 0 to 59*/
188 int tm_min;
189 /* the number of hours past midnight, in the range 0 to 23 */
190 int tm_hour;
191 /* the day of the month, in the range 1 to 31 */
192 int tm_mday;
193 /* the number of months since January, in the range 0 to 11 */
194 int tm_mon;
195 /* the number of years since 1900 */
196 long tm_year;
197 /* the number of days since Sunday, in the range 0 to 6 */
198 int tm_wday;
199 /* the number of days since January 1, in the range 0 to 365 */
200 int tm_yday;
201};
202
203void time64_to_tm(time64_t totalsecs, int offset, struct tm *result);
204
205/**
206 * time_to_tm - converts the calendar time to local broken-down time
207 *
208 * @totalsecs the number of seconds elapsed since 00:00:00 on January 1, 1970,
209 * Coordinated Universal Time (UTC).
210 * @offset offset seconds adding to totalsecs.
211 * @result pointer to struct tm variable to receive broken-down time
212 */
213static inline void time_to_tm(time_t totalsecs, int offset, struct tm *result)
214{
215 time64_to_tm(totalsecs, offset, result);
216}
217
218/**
219 * timespec_to_ns - Convert timespec to nanoseconds
220 * @ts: pointer to the timespec variable to be converted
221 *
222 * Returns the scalar nanosecond representation of the timespec
223 * parameter.
224 */
225static inline s64 timespec_to_ns(const struct timespec *ts)
226{
227 return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
228}
229
230/**
231 * timeval_to_ns - Convert timeval to nanoseconds
232 * @ts: pointer to the timeval variable to be converted
233 *
234 * Returns the scalar nanosecond representation of the timeval
235 * parameter.
236 */
237static inline s64 timeval_to_ns(const struct timeval *tv)
238{
239 return ((s64) tv->tv_sec * NSEC_PER_SEC) +
240 tv->tv_usec * NSEC_PER_USEC;
241}
242
243/**
244 * ns_to_timespec - Convert nanoseconds to timespec
245 * @nsec: the nanoseconds value to be converted
246 *
247 * Returns the timespec representation of the nsec parameter.
248 */
249extern struct timespec ns_to_timespec(const s64 nsec);
250
251/**
252 * ns_to_timeval - Convert nanoseconds to timeval
253 * @nsec: the nanoseconds value to be converted
254 *
255 * Returns the timeval representation of the nsec parameter.
256 */
257extern struct timeval ns_to_timeval(const s64 nsec);
258
259/**
260 * timespec_add_ns - Adds nanoseconds to a timespec
261 * @a: pointer to timespec to be incremented
262 * @ns: unsigned nanoseconds value to be added
263 *
264 * This must always be inlined because its used from the x86-64 vdso,
265 * which cannot call other kernel functions.
266 */
267static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
268{
269 a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
270 a->tv_nsec = ns;
271}
272
273#endif