summaryrefslogtreecommitdiff
path: root/include/linux/time.h
blob: 3877136bbdf8381fed3b2998644e9f62aba8b643 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
#ifndef _LINUX_TIME_H
#define _LINUX_TIME_H

# include <linux/cache.h>
# include <linux/seqlock.h>
# include <linux/math64.h>
# include <linux/time64.h>

extern struct timezone sys_tz;

int get_timespec64(struct timespec64 *ts,
		const struct timespec __user *uts);
int put_timespec64(const struct timespec64 *ts,
		struct timespec __user *uts);
int get_itimerspec64(struct itimerspec64 *it,
			const struct itimerspec __user *uit);
int put_itimerspec64(const struct itimerspec64 *it,
			struct itimerspec __user *uit);

#define TIME_T_MAX	(time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)

static inline int timespec_equal(const struct timespec *a,
                                 const struct timespec *b)
{
	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
}

/*
 * lhs < rhs:  return <0
 * lhs == rhs: return 0
 * lhs > rhs:  return >0
 */
static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
{
	if (lhs->tv_sec < rhs->tv_sec)
		return -1;
	if (lhs->tv_sec > rhs->tv_sec)
		return 1;
	return lhs->tv_nsec - rhs->tv_nsec;
}

static inline int timeval_compare(const struct timeval *lhs, const struct timeval *rhs)
{
	if (lhs->tv_sec < rhs->tv_sec)
		return -1;
	if (lhs->tv_sec > rhs->tv_sec)
		return 1;
	return lhs->tv_usec - rhs->tv_usec;
}

extern time64_t mktime64(const unsigned int year, const unsigned int mon,
			const unsigned int day, const unsigned int hour,
			const unsigned int min, const unsigned int sec);

/**
 * Deprecated. Use mktime64().
 */
static inline unsigned long mktime(const unsigned int year,
			const unsigned int mon, const unsigned int day,
			const unsigned int hour, const unsigned int min,
			const unsigned int sec)
{
	return mktime64(year, mon, day, hour, min, sec);
}

extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);

/*
 * timespec_add_safe assumes both values are positive and checks
 * for overflow. It will return TIME_T_MAX if the reutrn would be
 * smaller then either of the arguments.
 */
extern struct timespec timespec_add_safe(const struct timespec lhs,
					 const struct timespec rhs);


static inline struct timespec timespec_add(struct timespec lhs,
						struct timespec rhs)
{
	struct timespec ts_delta;
	set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
				lhs.tv_nsec + rhs.tv_nsec);
	return ts_delta;
}

/*
 * sub = lhs - rhs, in normalized form
 */
static inline struct timespec timespec_sub(struct timespec lhs,
						struct timespec rhs)
{
	struct timespec ts_delta;
	set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
				lhs.tv_nsec - rhs.tv_nsec);
	return ts_delta;
}

/*
 * Returns true if the timespec is norm, false if denorm:
 */
static inline bool timespec_valid(const struct timespec *ts)
{
	/* Dates before 1970 are bogus */
	if (ts->tv_sec < 0)
		return false;
	/* Can't have more nanoseconds then a second */
	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
		return false;
	return true;
}

static inline bool timespec_valid_strict(const struct timespec *ts)
{
	if (!timespec_valid(ts))
		return false;
	/* Disallow values that could overflow ktime_t */
	if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
		return false;
	return true;
}

static inline bool timeval_valid(const struct timeval *tv)
{
	/* Dates before 1970 are bogus */
	if (tv->tv_sec < 0)
		return false;

	/* Can't have more microseconds then a second */
	if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
		return false;

	return true;
}

extern struct timespec timespec_trunc(struct timespec t, unsigned gran);

/*
 * Validates if a timespec/timeval used to inject a time offset is valid.
 * Offsets can be postive or negative. The value of the timeval/timespec
 * is the sum of its fields, but *NOTE*: the field tv_usec/tv_nsec must
 * always be non-negative.
 */
static inline bool timeval_inject_offset_valid(const struct timeval *tv)
{
	/* We don't check the tv_sec as it can be positive or negative */

	/* Can't have more microseconds then a second */
	if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
		return false;
	return true;
}

static inline bool timespec_inject_offset_valid(const struct timespec *ts)
{
	/* We don't check the tv_sec as it can be positive or negative */

	/* Can't have more nanoseconds then a second */
	if (ts->tv_nsec < 0 || ts->tv_nsec >= NSEC_PER_SEC)
		return false;
	return true;
}

/* Some architectures do not supply their own clocksource.
 * This is mainly the case in architectures that get their
 * inter-tick times by reading the counter on their interval
 * timer. Since these timers wrap every tick, they're not really
 * useful as clocksources. Wrapping them to act like one is possible
 * but not very efficient. So we provide a callout these arches
 * can implement for use with the jiffies clocksource to provide
 * finer then tick granular time.
 */
#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
extern u32 (*arch_gettimeoffset)(void);
#endif

struct itimerval;
extern int do_setitimer(int which, struct itimerval *value,
			struct itimerval *ovalue);
extern int do_getitimer(int which, struct itimerval *value);

extern long do_utimes(int dfd, const char __user *filename, struct timespec *times, int flags);

/*
 * Similar to the struct tm in userspace <time.h>, but it needs to be here so
 * that the kernel source is self contained.
 */
struct tm {
	/*
	 * the number of seconds after the minute, normally in the range
	 * 0 to 59, but can be up to 60 to allow for leap seconds
	 */
	int tm_sec;
	/* the number of minutes after the hour, in the range 0 to 59*/
	int tm_min;
	/* the number of hours past midnight, in the range 0 to 23 */
	int tm_hour;
	/* the day of the month, in the range 1 to 31 */
	int tm_mday;
	/* the number of months since January, in the range 0 to 11 */
	int tm_mon;
	/* the number of years since 1900 */
	long tm_year;
	/* the number of days since Sunday, in the range 0 to 6 */
	int tm_wday;
	/* the number of days since January 1, in the range 0 to 365 */
	int tm_yday;
};

void time64_to_tm(time64_t totalsecs, int offset, struct tm *result);

/**
 * time_to_tm - converts the calendar time to local broken-down time
 *
 * @totalsecs	the number of seconds elapsed since 00:00:00 on January 1, 1970,
 *		Coordinated Universal Time (UTC).
 * @offset	offset seconds adding to totalsecs.
 * @result	pointer to struct tm variable to receive broken-down time
 */
static inline void time_to_tm(time_t totalsecs, int offset, struct tm *result)
{
	time64_to_tm(totalsecs, offset, result);
}

/**
 * timespec_to_ns - Convert timespec to nanoseconds
 * @ts:		pointer to the timespec variable to be converted
 *
 * Returns the scalar nanosecond representation of the timespec
 * parameter.
 */
static inline s64 timespec_to_ns(const struct timespec *ts)
{
	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
}

/**
 * timeval_to_ns - Convert timeval to nanoseconds
 * @ts:		pointer to the timeval variable to be converted
 *
 * Returns the scalar nanosecond representation of the timeval
 * parameter.
 */
static inline s64 timeval_to_ns(const struct timeval *tv)
{
	return ((s64) tv->tv_sec * NSEC_PER_SEC) +
		tv->tv_usec * NSEC_PER_USEC;
}

/**
 * ns_to_timespec - Convert nanoseconds to timespec
 * @nsec:	the nanoseconds value to be converted
 *
 * Returns the timespec representation of the nsec parameter.
 */
extern struct timespec ns_to_timespec(const s64 nsec);

/**
 * ns_to_timeval - Convert nanoseconds to timeval
 * @nsec:	the nanoseconds value to be converted
 *
 * Returns the timeval representation of the nsec parameter.
 */
extern struct timeval ns_to_timeval(const s64 nsec);

/**
 * timespec_add_ns - Adds nanoseconds to a timespec
 * @a:		pointer to timespec to be incremented
 * @ns:		unsigned nanoseconds value to be added
 *
 * This must always be inlined because its used from the x86-64 vdso,
 * which cannot call other kernel functions.
 */
static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
{
	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
	a->tv_nsec = ns;
}

static inline bool itimerspec64_valid(const struct itimerspec64 *its)
{
	if (!timespec64_valid(&(its->it_interval)) ||
		!timespec64_valid(&(its->it_value)))
		return false;

	return true;
}

/**
 * time_after32 - compare two 32-bit relative times
 * @a:	the time which may be after @b
 * @b:	the time which may be before @a
 *
 * time_after32(a, b) returns true if the time @a is after time @b.
 * time_before32(b, a) returns true if the time @b is before time @a.
 *
 * Similar to time_after(), compare two 32-bit timestamps for relative
 * times.  This is useful for comparing 32-bit seconds values that can't
 * be converted to 64-bit values (e.g. due to disk format or wire protocol
 * issues) when it is known that the times are less than 68 years apart.
 */
#define time_after32(a, b)	((s32)((u32)(b) - (u32)(a)) < 0)
#define time_before32(b, a)	time_after32(a, b)
#endif