xref: /linux-6.15/include/linux/time32.h (revision 5dbf2012)
1 #ifndef _LINUX_TIME32_H
2 #define _LINUX_TIME32_H
3 /*
4  * These are all interfaces based on the old time_t definition
5  * that overflows in 2038 on 32-bit architectures. New code
6  * should use the replacements based on time64_t and timespec64.
7  *
8  * Any interfaces in here that become unused as we migrate
9  * code to time64_t should get removed.
10  */
11 
12 #include <linux/time64.h>
13 
14 #define TIME_T_MAX	(time_t)((1UL << ((sizeof(time_t) << 3) - 1)) - 1)
15 
16 static inline int timespec_equal(const struct timespec *a,
17 				 const struct timespec *b)
18 {
19 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
20 }
21 
22 /*
23  * lhs < rhs:  return <0
24  * lhs == rhs: return 0
25  * lhs > rhs:  return >0
26  */
27 static inline int timespec_compare(const struct timespec *lhs, const struct timespec *rhs)
28 {
29 	if (lhs->tv_sec < rhs->tv_sec)
30 		return -1;
31 	if (lhs->tv_sec > rhs->tv_sec)
32 		return 1;
33 	return lhs->tv_nsec - rhs->tv_nsec;
34 }
35 
36 extern void set_normalized_timespec(struct timespec *ts, time_t sec, s64 nsec);
37 
38 static inline struct timespec timespec_add(struct timespec lhs,
39 						struct timespec rhs)
40 {
41 	struct timespec ts_delta;
42 
43 	set_normalized_timespec(&ts_delta, lhs.tv_sec + rhs.tv_sec,
44 				lhs.tv_nsec + rhs.tv_nsec);
45 	return ts_delta;
46 }
47 
48 /*
49  * sub = lhs - rhs, in normalized form
50  */
51 static inline struct timespec timespec_sub(struct timespec lhs,
52 						struct timespec rhs)
53 {
54 	struct timespec ts_delta;
55 
56 	set_normalized_timespec(&ts_delta, lhs.tv_sec - rhs.tv_sec,
57 				lhs.tv_nsec - rhs.tv_nsec);
58 	return ts_delta;
59 }
60 
61 /*
62  * Returns true if the timespec is norm, false if denorm:
63  */
64 static inline bool timespec_valid(const struct timespec *ts)
65 {
66 	/* Dates before 1970 are bogus */
67 	if (ts->tv_sec < 0)
68 		return false;
69 	/* Can't have more nanoseconds then a second */
70 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
71 		return false;
72 	return true;
73 }
74 
75 static inline bool timespec_valid_strict(const struct timespec *ts)
76 {
77 	if (!timespec_valid(ts))
78 		return false;
79 	/* Disallow values that could overflow ktime_t */
80 	if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
81 		return false;
82 	return true;
83 }
84 
85 /**
86  * timespec_to_ns - Convert timespec to nanoseconds
87  * @ts:		pointer to the timespec variable to be converted
88  *
89  * Returns the scalar nanosecond representation of the timespec
90  * parameter.
91  */
92 static inline s64 timespec_to_ns(const struct timespec *ts)
93 {
94 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
95 }
96 
97 /**
98  * ns_to_timespec - Convert nanoseconds to timespec
99  * @nsec:	the nanoseconds value to be converted
100  *
101  * Returns the timespec representation of the nsec parameter.
102  */
103 extern struct timespec ns_to_timespec(const s64 nsec);
104 
105 /**
106  * timespec_add_ns - Adds nanoseconds to a timespec
107  * @a:		pointer to timespec to be incremented
108  * @ns:		unsigned nanoseconds value to be added
109  *
110  * This must always be inlined because its used from the x86-64 vdso,
111  * which cannot call other kernel functions.
112  */
113 static __always_inline void timespec_add_ns(struct timespec *a, u64 ns)
114 {
115 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
116 	a->tv_nsec = ns;
117 }
118 
119 /**
120  * time_to_tm - converts the calendar time to local broken-down time
121  *
122  * @totalsecs	the number of seconds elapsed since 00:00:00 on January 1, 1970,
123  *		Coordinated Universal Time (UTC).
124  * @offset	offset seconds adding to totalsecs.
125  * @result	pointer to struct tm variable to receive broken-down time
126  */
127 static inline void time_to_tm(time_t totalsecs, int offset, struct tm *result)
128 {
129 	time64_to_tm(totalsecs, offset, result);
130 }
131 
132 static inline unsigned long mktime(const unsigned int year,
133 			const unsigned int mon, const unsigned int day,
134 			const unsigned int hour, const unsigned int min,
135 			const unsigned int sec)
136 {
137 	return mktime64(year, mon, day, hour, min, sec);
138 }
139 
140 static inline bool timeval_valid(const struct timeval *tv)
141 {
142 	/* Dates before 1970 are bogus */
143 	if (tv->tv_sec < 0)
144 		return false;
145 
146 	/* Can't have more microseconds then a second */
147 	if (tv->tv_usec < 0 || tv->tv_usec >= USEC_PER_SEC)
148 		return false;
149 
150 	return true;
151 }
152 
153 extern struct timespec timespec_trunc(struct timespec t, unsigned int gran);
154 
155 /**
156  * timeval_to_ns - Convert timeval to nanoseconds
157  * @ts:		pointer to the timeval variable to be converted
158  *
159  * Returns the scalar nanosecond representation of the timeval
160  * parameter.
161  */
162 static inline s64 timeval_to_ns(const struct timeval *tv)
163 {
164 	return ((s64) tv->tv_sec * NSEC_PER_SEC) +
165 		tv->tv_usec * NSEC_PER_USEC;
166 }
167 
168 /**
169  * ns_to_timeval - Convert nanoseconds to timeval
170  * @nsec:	the nanoseconds value to be converted
171  *
172  * Returns the timeval representation of the nsec parameter.
173  */
174 extern struct timeval ns_to_timeval(const s64 nsec);
175 
176 #endif
177