xref: /linux-6.15/include/linux/time64.h (revision 85bf19e7)
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 /*
11  * This wants to go into uapi/linux/time.h once we agreed about the
12  * userspace interfaces.
13  */
14 #if __BITS_PER_LONG == 64
15 # define timespec64 timespec
16 #define itimerspec64 itimerspec
17 #else
18 struct timespec64 {
19 	time64_t	tv_sec;			/* seconds */
20 	long		tv_nsec;		/* nanoseconds */
21 };
22 
23 struct itimerspec64 {
24 	struct timespec64 it_interval;
25 	struct timespec64 it_value;
26 };
27 
28 #endif
29 
30 /* Parameters used to convert the timespec values: */
31 #define MSEC_PER_SEC	1000L
32 #define USEC_PER_MSEC	1000L
33 #define NSEC_PER_USEC	1000L
34 #define NSEC_PER_MSEC	1000000L
35 #define USEC_PER_SEC	1000000L
36 #define NSEC_PER_SEC	1000000000L
37 #define FSEC_PER_SEC	1000000000000000LL
38 
39 /* Located here for timespec[64]_valid_strict */
40 #define TIME64_MAX			((s64)~((u64)1 << 63))
41 #define KTIME_MAX			((s64)~((u64)1 << 63))
42 #define KTIME_SEC_MAX			(KTIME_MAX / NSEC_PER_SEC)
43 
44 #if __BITS_PER_LONG == 64
45 
46 static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
47 {
48 	return ts64;
49 }
50 
51 static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
52 {
53 	return ts;
54 }
55 
56 # define timespec64_equal		timespec_equal
57 # define timespec64_compare		timespec_compare
58 # define set_normalized_timespec64	set_normalized_timespec
59 # define timespec64_add			timespec_add
60 # define timespec64_sub			timespec_sub
61 # define timespec64_valid		timespec_valid
62 # define timespec64_valid_strict	timespec_valid_strict
63 # define timespec64_to_ns		timespec_to_ns
64 # define ns_to_timespec64		ns_to_timespec
65 # define timespec64_add_ns		timespec_add_ns
66 
67 #else
68 
69 static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
70 {
71 	struct timespec ret;
72 
73 	ret.tv_sec = (time_t)ts64.tv_sec;
74 	ret.tv_nsec = ts64.tv_nsec;
75 	return ret;
76 }
77 
78 static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
79 {
80 	struct timespec64 ret;
81 
82 	ret.tv_sec = ts.tv_sec;
83 	ret.tv_nsec = ts.tv_nsec;
84 	return ret;
85 }
86 
87 static inline int timespec64_equal(const struct timespec64 *a,
88 				   const struct timespec64 *b)
89 {
90 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
91 }
92 
93 /*
94  * lhs < rhs:  return <0
95  * lhs == rhs: return 0
96  * lhs > rhs:  return >0
97  */
98 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
99 {
100 	if (lhs->tv_sec < rhs->tv_sec)
101 		return -1;
102 	if (lhs->tv_sec > rhs->tv_sec)
103 		return 1;
104 	return lhs->tv_nsec - rhs->tv_nsec;
105 }
106 
107 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
108 
109 static inline struct timespec64 timespec64_add(struct timespec64 lhs,
110 						struct timespec64 rhs)
111 {
112 	struct timespec64 ts_delta;
113 	set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
114 				lhs.tv_nsec + rhs.tv_nsec);
115 	return ts_delta;
116 }
117 
118 /*
119  * sub = lhs - rhs, in normalized form
120  */
121 static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
122 						struct timespec64 rhs)
123 {
124 	struct timespec64 ts_delta;
125 	set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
126 				lhs.tv_nsec - rhs.tv_nsec);
127 	return ts_delta;
128 }
129 
130 /*
131  * Returns true if the timespec64 is norm, false if denorm:
132  */
133 static inline bool timespec64_valid(const struct timespec64 *ts)
134 {
135 	/* Dates before 1970 are bogus */
136 	if (ts->tv_sec < 0)
137 		return false;
138 	/* Can't have more nanoseconds then a second */
139 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
140 		return false;
141 	return true;
142 }
143 
144 static inline bool timespec64_valid_strict(const struct timespec64 *ts)
145 {
146 	if (!timespec64_valid(ts))
147 		return false;
148 	/* Disallow values that could overflow ktime_t */
149 	if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
150 		return false;
151 	return true;
152 }
153 
154 /**
155  * timespec64_to_ns - Convert timespec64 to nanoseconds
156  * @ts:		pointer to the timespec64 variable to be converted
157  *
158  * Returns the scalar nanosecond representation of the timespec64
159  * parameter.
160  */
161 static inline s64 timespec64_to_ns(const struct timespec64 *ts)
162 {
163 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
164 }
165 
166 /**
167  * ns_to_timespec64 - Convert nanoseconds to timespec64
168  * @nsec:	the nanoseconds value to be converted
169  *
170  * Returns the timespec64 representation of the nsec parameter.
171  */
172 extern struct timespec64 ns_to_timespec64(const s64 nsec);
173 
174 /**
175  * timespec64_add_ns - Adds nanoseconds to a timespec64
176  * @a:		pointer to timespec64 to be incremented
177  * @ns:		unsigned nanoseconds value to be added
178  *
179  * This must always be inlined because its used from the x86-64 vdso,
180  * which cannot call other kernel functions.
181  */
182 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
183 {
184 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
185 	a->tv_nsec = ns;
186 }
187 
188 #endif
189 
190 /*
191  * timespec64_add_safe assumes both values are positive and checks for
192  * overflow. It will return TIME64_MAX in case of overflow.
193  */
194 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
195 					 const struct timespec64 rhs);
196 
197 #endif /* _LINUX_TIME64_H */
198