xref: /linux-6.15/include/linux/time64.h (revision 8ea8814f)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_TIME64_H
3 #define _LINUX_TIME64_H
4 
5 #include <linux/math64.h>
6 
7 typedef __s64 time64_t;
8 typedef __u64 timeu64_t;
9 
10 #include <uapi/linux/time.h>
11 
12 struct timespec64 {
13 	time64_t	tv_sec;			/* seconds */
14 	long		tv_nsec;		/* nanoseconds */
15 };
16 
17 struct itimerspec64 {
18 	struct timespec64 it_interval;
19 	struct timespec64 it_value;
20 };
21 
22 /* Parameters used to convert the timespec values: */
23 #define MSEC_PER_SEC	1000L
24 #define USEC_PER_MSEC	1000L
25 #define NSEC_PER_USEC	1000L
26 #define NSEC_PER_MSEC	1000000L
27 #define USEC_PER_SEC	1000000L
28 #define NSEC_PER_SEC	1000000000L
29 #define FSEC_PER_SEC	1000000000000000LL
30 
31 /* Located here for timespec[64]_valid_strict */
32 #define TIME64_MAX			((s64)~((u64)1 << 63))
33 #define KTIME_MAX			((s64)~((u64)1 << 63))
34 #define KTIME_SEC_MAX			(KTIME_MAX / NSEC_PER_SEC)
35 
36 static inline int timespec64_equal(const struct timespec64 *a,
37 				   const struct timespec64 *b)
38 {
39 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
40 }
41 
42 /*
43  * lhs < rhs:  return <0
44  * lhs == rhs: return 0
45  * lhs > rhs:  return >0
46  */
47 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
48 {
49 	if (lhs->tv_sec < rhs->tv_sec)
50 		return -1;
51 	if (lhs->tv_sec > rhs->tv_sec)
52 		return 1;
53 	return lhs->tv_nsec - rhs->tv_nsec;
54 }
55 
56 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
57 
58 static inline struct timespec64 timespec64_add(struct timespec64 lhs,
59 						struct timespec64 rhs)
60 {
61 	struct timespec64 ts_delta;
62 	set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
63 				lhs.tv_nsec + rhs.tv_nsec);
64 	return ts_delta;
65 }
66 
67 /*
68  * sub = lhs - rhs, in normalized form
69  */
70 static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
71 						struct timespec64 rhs)
72 {
73 	struct timespec64 ts_delta;
74 	set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
75 				lhs.tv_nsec - rhs.tv_nsec);
76 	return ts_delta;
77 }
78 
79 /*
80  * Returns true if the timespec64 is norm, false if denorm:
81  */
82 static inline bool timespec64_valid(const struct timespec64 *ts)
83 {
84 	/* Dates before 1970 are bogus */
85 	if (ts->tv_sec < 0)
86 		return false;
87 	/* Can't have more nanoseconds then a second */
88 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
89 		return false;
90 	return true;
91 }
92 
93 static inline bool timespec64_valid_strict(const struct timespec64 *ts)
94 {
95 	if (!timespec64_valid(ts))
96 		return false;
97 	/* Disallow values that could overflow ktime_t */
98 	if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
99 		return false;
100 	return true;
101 }
102 
103 /**
104  * timespec64_to_ns - Convert timespec64 to nanoseconds
105  * @ts:		pointer to the timespec64 variable to be converted
106  *
107  * Returns the scalar nanosecond representation of the timespec64
108  * parameter.
109  */
110 static inline s64 timespec64_to_ns(const struct timespec64 *ts)
111 {
112 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
113 }
114 
115 /**
116  * ns_to_timespec64 - Convert nanoseconds to timespec64
117  * @nsec:	the nanoseconds value to be converted
118  *
119  * Returns the timespec64 representation of the nsec parameter.
120  */
121 extern struct timespec64 ns_to_timespec64(const s64 nsec);
122 
123 /**
124  * timespec64_add_ns - Adds nanoseconds to a timespec64
125  * @a:		pointer to timespec64 to be incremented
126  * @ns:		unsigned nanoseconds value to be added
127  *
128  * This must always be inlined because its used from the x86-64 vdso,
129  * which cannot call other kernel functions.
130  */
131 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
132 {
133 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
134 	a->tv_nsec = ns;
135 }
136 
137 /*
138  * timespec64_add_safe assumes both values are positive and checks for
139  * overflow. It will return TIME64_MAX in case of overflow.
140  */
141 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
142 					 const struct timespec64 rhs);
143 
144 #endif /* _LINUX_TIME64_H */
145