xref: /linux-6.15/include/linux/time64.h (revision 02cc2ccf)
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 
9 /*
10  * This wants to go into uapi/linux/time.h once we agreed about the
11  * userspace interfaces.
12  */
13 #if __BITS_PER_LONG == 64
14 # define timespec64 timespec
15 #else
16 struct timespec64 {
17 	time64_t	tv_sec;			/* seconds */
18 	long		tv_nsec;		/* nanoseconds */
19 };
20 #endif
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 #if __BITS_PER_LONG == 64
37 
38 static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
39 {
40 	return ts64;
41 }
42 
43 static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
44 {
45 	return ts;
46 }
47 
48 # define timespec64_equal		timespec_equal
49 # define timespec64_compare		timespec_compare
50 # define set_normalized_timespec64	set_normalized_timespec
51 # define timespec64_add_safe		timespec_add_safe
52 # define timespec64_add			timespec_add
53 # define timespec64_sub			timespec_sub
54 # define timespec64_valid		timespec_valid
55 # define timespec64_valid_strict	timespec_valid_strict
56 # define timespec64_to_ns		timespec_to_ns
57 # define ns_to_timespec64		ns_to_timespec
58 # define timespec64_add_ns		timespec_add_ns
59 
60 #else
61 
62 static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
63 {
64 	struct timespec ret;
65 
66 	ret.tv_sec = (time_t)ts64.tv_sec;
67 	ret.tv_nsec = ts64.tv_nsec;
68 	return ret;
69 }
70 
71 static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
72 {
73 	struct timespec64 ret;
74 
75 	ret.tv_sec = ts.tv_sec;
76 	ret.tv_nsec = ts.tv_nsec;
77 	return ret;
78 }
79 
80 static inline int timespec64_equal(const struct timespec64 *a,
81 				   const struct timespec64 *b)
82 {
83 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
84 }
85 
86 /*
87  * lhs < rhs:  return <0
88  * lhs == rhs: return 0
89  * lhs > rhs:  return >0
90  */
91 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
92 {
93 	if (lhs->tv_sec < rhs->tv_sec)
94 		return -1;
95 	if (lhs->tv_sec > rhs->tv_sec)
96 		return 1;
97 	return lhs->tv_nsec - rhs->tv_nsec;
98 }
99 
100 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
101 
102 /*
103  * timespec64_add_safe assumes both values are positive and checks for
104  * overflow. It will return TIME_T_MAX if the returned value would be
105  * smaller then either of the arguments.
106  */
107 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
108 					 const struct timespec64 rhs);
109 
110 
111 static inline struct timespec64 timespec64_add(struct timespec64 lhs,
112 						struct timespec64 rhs)
113 {
114 	struct timespec64 ts_delta;
115 	set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
116 				lhs.tv_nsec + rhs.tv_nsec);
117 	return ts_delta;
118 }
119 
120 /*
121  * sub = lhs - rhs, in normalized form
122  */
123 static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
124 						struct timespec64 rhs)
125 {
126 	struct timespec64 ts_delta;
127 	set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
128 				lhs.tv_nsec - rhs.tv_nsec);
129 	return ts_delta;
130 }
131 
132 /*
133  * Returns true if the timespec64 is norm, false if denorm:
134  */
135 static inline bool timespec64_valid(const struct timespec64 *ts)
136 {
137 	/* Dates before 1970 are bogus */
138 	if (ts->tv_sec < 0)
139 		return false;
140 	/* Can't have more nanoseconds then a second */
141 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
142 		return false;
143 	return true;
144 }
145 
146 static inline bool timespec64_valid_strict(const struct timespec64 *ts)
147 {
148 	if (!timespec64_valid(ts))
149 		return false;
150 	/* Disallow values that could overflow ktime_t */
151 	if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
152 		return false;
153 	return true;
154 }
155 
156 /**
157  * timespec64_to_ns - Convert timespec64 to nanoseconds
158  * @ts:		pointer to the timespec64 variable to be converted
159  *
160  * Returns the scalar nanosecond representation of the timespec64
161  * parameter.
162  */
163 static inline s64 timespec64_to_ns(const struct timespec64 *ts)
164 {
165 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
166 }
167 
168 /**
169  * ns_to_timespec64 - Convert nanoseconds to timespec64
170  * @nsec:	the nanoseconds value to be converted
171  *
172  * Returns the timespec64 representation of the nsec parameter.
173  */
174 extern struct timespec64 ns_to_timespec64(const s64 nsec);
175 
176 /**
177  * timespec64_add_ns - Adds nanoseconds to a timespec64
178  * @a:		pointer to timespec64 to be incremented
179  * @ns:		unsigned nanoseconds value to be added
180  *
181  * This must always be inlined because its used from the x86-64 vdso,
182  * which cannot call other kernel functions.
183  */
184 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
185 {
186 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
187 	a->tv_nsec = ns;
188 }
189 
190 #endif
191 
192 #endif /* _LINUX_TIME64_H */
193