xref: /linux-6.15/include/linux/time64.h (revision 361a3bf0)
1 #ifndef _LINUX_TIME64_H
2 #define _LINUX_TIME64_H
3 
4 #include <uapi/linux/time.h>
5 
6 typedef __s64 time64_t;
7 
8 /*
9  * This wants to go into uapi/linux/time.h once we agreed about the
10  * userspace interfaces.
11  */
12 #if __BITS_PER_LONG == 64
13 # define timespec64 timespec
14 #else
15 struct timespec64 {
16 	time64_t	tv_sec;			/* seconds */
17 	long		tv_nsec;		/* nanoseconds */
18 };
19 #endif
20 
21 /* Parameters used to convert the timespec values: */
22 #define MSEC_PER_SEC	1000L
23 #define USEC_PER_MSEC	1000L
24 #define NSEC_PER_USEC	1000L
25 #define NSEC_PER_MSEC	1000000L
26 #define USEC_PER_SEC	1000000L
27 #define NSEC_PER_SEC	1000000000L
28 #define FSEC_PER_SEC	1000000000000000LL
29 
30 /* Located here for timespec[64]_valid_strict */
31 #define KTIME_MAX			((s64)~((u64)1 << 63))
32 #define KTIME_SEC_MAX			(KTIME_MAX / NSEC_PER_SEC)
33 
34 #if __BITS_PER_LONG == 64
35 
36 # define timespec64_equal		timespec_equal
37 # define timespec64_compare		timespec_compare
38 # define set_normalized_timespec64	set_normalized_timespec
39 # define timespec64_add_safe		timespec_add_safe
40 # define timespec64_add			timespec_add
41 # define timespec64_sub			timespec_sub
42 # define timespec64_valid		timespec_valid
43 # define timespec64_valid_strict	timespec_valid_strict
44 # define timespec64_to_ns		timespec_to_ns
45 # define ns_to_timespec64		ns_to_timespec
46 # define timespec64_add_ns		timespec_add_ns
47 
48 #else
49 
50 static inline int timespec64_equal(const struct timespec64 *a,
51 				   const struct timespec64 *b)
52 {
53 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
54 }
55 
56 /*
57  * lhs < rhs:  return <0
58  * lhs == rhs: return 0
59  * lhs > rhs:  return >0
60  */
61 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
62 {
63 	if (lhs->tv_sec < rhs->tv_sec)
64 		return -1;
65 	if (lhs->tv_sec > rhs->tv_sec)
66 		return 1;
67 	return lhs->tv_nsec - rhs->tv_nsec;
68 }
69 
70 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
71 
72 /*
73  * timespec64_add_safe assumes both values are positive and checks for
74  * overflow. It will return TIME_T_MAX if the returned value would be
75  * smaller then either of the arguments.
76  */
77 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
78 					 const struct timespec64 rhs);
79 
80 
81 static inline struct timespec64 timespec64_add(struct timespec64 lhs,
82 						struct timespec64 rhs)
83 {
84 	struct timespec64 ts_delta;
85 	set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
86 				lhs.tv_nsec + rhs.tv_nsec);
87 	return ts_delta;
88 }
89 
90 /*
91  * sub = lhs - rhs, in normalized form
92  */
93 static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
94 						struct timespec64 rhs)
95 {
96 	struct timespec64 ts_delta;
97 	set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
98 				lhs.tv_nsec - rhs.tv_nsec);
99 	return ts_delta;
100 }
101 
102 /*
103  * Returns true if the timespec64 is norm, false if denorm:
104  */
105 static inline bool timespec64_valid(const struct timespec64 *ts)
106 {
107 	/* Dates before 1970 are bogus */
108 	if (ts->tv_sec < 0)
109 		return false;
110 	/* Can't have more nanoseconds then a second */
111 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
112 		return false;
113 	return true;
114 }
115 
116 static inline bool timespec64_valid_strict(const struct timespec64 *ts)
117 {
118 	if (!timespec64_valid(ts))
119 		return false;
120 	/* Disallow values that could overflow ktime_t */
121 	if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
122 		return false;
123 	return true;
124 }
125 
126 /**
127  * timespec64_to_ns - Convert timespec64 to nanoseconds
128  * @ts:		pointer to the timespec64 variable to be converted
129  *
130  * Returns the scalar nanosecond representation of the timespec64
131  * parameter.
132  */
133 static inline s64 timespec64_to_ns(const struct timespec64 *ts)
134 {
135 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
136 }
137 
138 /**
139  * ns_to_timespec64 - Convert nanoseconds to timespec64
140  * @nsec:	the nanoseconds value to be converted
141  *
142  * Returns the timespec64 representation of the nsec parameter.
143  */
144 extern struct timespec64 ns_to_timespec64(const s64 nsec);
145 
146 /**
147  * timespec64_add_ns - Adds nanoseconds to a timespec64
148  * @a:		pointer to timespec64 to be incremented
149  * @ns:		unsigned nanoseconds value to be added
150  *
151  * This must always be inlined because its used from the x86-64 vdso,
152  * which cannot call other kernel functions.
153  */
154 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
155 {
156 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
157 	a->tv_nsec = ns;
158 }
159 
160 #endif
161 
162 #endif /* _LINUX_TIME64_H */
163