xref: /linux-6.15/include/linux/time64.h (revision abc8f96e)
1 #ifndef _LINUX_TIME64_H
2 #define _LINUX_TIME64_H
3 
4 #include <uapi/linux/time.h>
5 #include <linux/math64.h>
6 
7 typedef __s64 time64_t;
8 typedef __u64 timeu64_t;
9 
10 #if __BITS_PER_LONG == 64
11 /* this trick allows us to optimize out timespec64_to_timespec */
12 # define timespec64 timespec
13 #define itimerspec64 itimerspec
14 #else
15 struct timespec64 {
16 	time64_t	tv_sec;			/* seconds */
17 	long		tv_nsec;		/* nanoseconds */
18 };
19 
20 struct itimerspec64 {
21 	struct timespec64 it_interval;
22 	struct timespec64 it_value;
23 };
24 
25 #endif
26 
27 /* Parameters used to convert the timespec values: */
28 #define MSEC_PER_SEC	1000L
29 #define USEC_PER_MSEC	1000L
30 #define NSEC_PER_USEC	1000L
31 #define NSEC_PER_MSEC	1000000L
32 #define USEC_PER_SEC	1000000L
33 #define NSEC_PER_SEC	1000000000L
34 #define FSEC_PER_SEC	1000000000000000LL
35 
36 /* Located here for timespec[64]_valid_strict */
37 #define TIME64_MAX			((s64)~((u64)1 << 63))
38 #define KTIME_MAX			((s64)~((u64)1 << 63))
39 #define KTIME_SEC_MAX			(KTIME_MAX / NSEC_PER_SEC)
40 
41 static inline int timespec64_equal(const struct timespec64 *a,
42 				   const struct timespec64 *b)
43 {
44 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
45 }
46 
47 /*
48  * lhs < rhs:  return <0
49  * lhs == rhs: return 0
50  * lhs > rhs:  return >0
51  */
52 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
53 {
54 	if (lhs->tv_sec < rhs->tv_sec)
55 		return -1;
56 	if (lhs->tv_sec > rhs->tv_sec)
57 		return 1;
58 	return lhs->tv_nsec - rhs->tv_nsec;
59 }
60 
61 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
62 
63 static inline struct timespec64 timespec64_add(struct timespec64 lhs,
64 						struct timespec64 rhs)
65 {
66 	struct timespec64 ts_delta;
67 	set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
68 				lhs.tv_nsec + rhs.tv_nsec);
69 	return ts_delta;
70 }
71 
72 /*
73  * sub = lhs - rhs, in normalized form
74  */
75 static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
76 						struct timespec64 rhs)
77 {
78 	struct timespec64 ts_delta;
79 	set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
80 				lhs.tv_nsec - rhs.tv_nsec);
81 	return ts_delta;
82 }
83 
84 /*
85  * Returns true if the timespec64 is norm, false if denorm:
86  */
87 static inline bool timespec64_valid(const struct timespec64 *ts)
88 {
89 	/* Dates before 1970 are bogus */
90 	if (ts->tv_sec < 0)
91 		return false;
92 	/* Can't have more nanoseconds then a second */
93 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
94 		return false;
95 	return true;
96 }
97 
98 static inline bool timespec64_valid_strict(const struct timespec64 *ts)
99 {
100 	if (!timespec64_valid(ts))
101 		return false;
102 	/* Disallow values that could overflow ktime_t */
103 	if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
104 		return false;
105 	return true;
106 }
107 
108 /**
109  * timespec64_to_ns - Convert timespec64 to nanoseconds
110  * @ts:		pointer to the timespec64 variable to be converted
111  *
112  * Returns the scalar nanosecond representation of the timespec64
113  * parameter.
114  */
115 static inline s64 timespec64_to_ns(const struct timespec64 *ts)
116 {
117 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
118 }
119 
120 /**
121  * ns_to_timespec64 - Convert nanoseconds to timespec64
122  * @nsec:	the nanoseconds value to be converted
123  *
124  * Returns the timespec64 representation of the nsec parameter.
125  */
126 extern struct timespec64 ns_to_timespec64(const s64 nsec);
127 
128 /**
129  * timespec64_add_ns - Adds nanoseconds to a timespec64
130  * @a:		pointer to timespec64 to be incremented
131  * @ns:		unsigned nanoseconds value to be added
132  *
133  * This must always be inlined because its used from the x86-64 vdso,
134  * which cannot call other kernel functions.
135  */
136 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
137 {
138 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
139 	a->tv_nsec = ns;
140 }
141 
142 /*
143  * timespec64_add_safe assumes both values are positive and checks for
144  * overflow. It will return TIME64_MAX in case of overflow.
145  */
146 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
147 					 const struct timespec64 rhs);
148 
149 #endif /* _LINUX_TIME64_H */
150