xref: /linux-6.15/include/linux/time64.h (revision bb970707)
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 #define itimerspec64 itimerspec
16 #else
17 struct timespec64 {
18 	time64_t	tv_sec;			/* seconds */
19 	long		tv_nsec;		/* nanoseconds */
20 };
21 
22 struct itimerspec64 {
23 	struct timespec64 it_interval;
24 	struct timespec64 it_value;
25 };
26 
27 #endif
28 
29 /* Parameters used to convert the timespec values: */
30 #define MSEC_PER_SEC	1000L
31 #define USEC_PER_MSEC	1000L
32 #define NSEC_PER_USEC	1000L
33 #define NSEC_PER_MSEC	1000000L
34 #define USEC_PER_SEC	1000000L
35 #define NSEC_PER_SEC	1000000000L
36 #define FSEC_PER_SEC	1000000000000000LL
37 
38 /* Located here for timespec[64]_valid_strict */
39 #define TIME64_MAX			((s64)~((u64)1 << 63))
40 #define KTIME_MAX			((s64)~((u64)1 << 63))
41 #define KTIME_SEC_MAX			(KTIME_MAX / NSEC_PER_SEC)
42 
43 #if __BITS_PER_LONG == 64
44 
45 static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
46 {
47 	return ts64;
48 }
49 
50 static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
51 {
52 	return ts;
53 }
54 
55 static inline struct itimerspec itimerspec64_to_itimerspec(struct itimerspec64 *its64)
56 {
57 	return *its64;
58 }
59 
60 static inline struct itimerspec64 itimerspec_to_itimerspec64(struct itimerspec *its)
61 {
62 	return *its;
63 }
64 
65 # define timespec64_equal		timespec_equal
66 # define timespec64_compare		timespec_compare
67 # define set_normalized_timespec64	set_normalized_timespec
68 # define timespec64_add			timespec_add
69 # define timespec64_sub			timespec_sub
70 # define timespec64_valid		timespec_valid
71 # define timespec64_valid_strict	timespec_valid_strict
72 # define timespec64_to_ns		timespec_to_ns
73 # define ns_to_timespec64		ns_to_timespec
74 # define timespec64_add_ns		timespec_add_ns
75 
76 #else
77 
78 static inline struct timespec timespec64_to_timespec(const struct timespec64 ts64)
79 {
80 	struct timespec ret;
81 
82 	ret.tv_sec = (time_t)ts64.tv_sec;
83 	ret.tv_nsec = ts64.tv_nsec;
84 	return ret;
85 }
86 
87 static inline struct timespec64 timespec_to_timespec64(const struct timespec ts)
88 {
89 	struct timespec64 ret;
90 
91 	ret.tv_sec = ts.tv_sec;
92 	ret.tv_nsec = ts.tv_nsec;
93 	return ret;
94 }
95 
96 static inline struct itimerspec itimerspec64_to_itimerspec(struct itimerspec64 *its64)
97 {
98 	struct itimerspec ret;
99 
100 	ret.it_interval = timespec64_to_timespec(its64->it_interval);
101 	ret.it_value = timespec64_to_timespec(its64->it_value);
102 	return ret;
103 }
104 
105 static inline struct itimerspec64 itimerspec_to_itimerspec64(struct itimerspec *its)
106 {
107 	struct itimerspec64 ret;
108 
109 	ret.it_interval = timespec_to_timespec64(its->it_interval);
110 	ret.it_value = timespec_to_timespec64(its->it_value);
111 	return ret;
112 }
113 
114 static inline int timespec64_equal(const struct timespec64 *a,
115 				   const struct timespec64 *b)
116 {
117 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
118 }
119 
120 /*
121  * lhs < rhs:  return <0
122  * lhs == rhs: return 0
123  * lhs > rhs:  return >0
124  */
125 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
126 {
127 	if (lhs->tv_sec < rhs->tv_sec)
128 		return -1;
129 	if (lhs->tv_sec > rhs->tv_sec)
130 		return 1;
131 	return lhs->tv_nsec - rhs->tv_nsec;
132 }
133 
134 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
135 
136 static inline struct timespec64 timespec64_add(struct timespec64 lhs,
137 						struct timespec64 rhs)
138 {
139 	struct timespec64 ts_delta;
140 	set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
141 				lhs.tv_nsec + rhs.tv_nsec);
142 	return ts_delta;
143 }
144 
145 /*
146  * sub = lhs - rhs, in normalized form
147  */
148 static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
149 						struct timespec64 rhs)
150 {
151 	struct timespec64 ts_delta;
152 	set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
153 				lhs.tv_nsec - rhs.tv_nsec);
154 	return ts_delta;
155 }
156 
157 /*
158  * Returns true if the timespec64 is norm, false if denorm:
159  */
160 static inline bool timespec64_valid(const struct timespec64 *ts)
161 {
162 	/* Dates before 1970 are bogus */
163 	if (ts->tv_sec < 0)
164 		return false;
165 	/* Can't have more nanoseconds then a second */
166 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
167 		return false;
168 	return true;
169 }
170 
171 static inline bool timespec64_valid_strict(const struct timespec64 *ts)
172 {
173 	if (!timespec64_valid(ts))
174 		return false;
175 	/* Disallow values that could overflow ktime_t */
176 	if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
177 		return false;
178 	return true;
179 }
180 
181 /**
182  * timespec64_to_ns - Convert timespec64 to nanoseconds
183  * @ts:		pointer to the timespec64 variable to be converted
184  *
185  * Returns the scalar nanosecond representation of the timespec64
186  * parameter.
187  */
188 static inline s64 timespec64_to_ns(const struct timespec64 *ts)
189 {
190 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
191 }
192 
193 /**
194  * ns_to_timespec64 - Convert nanoseconds to timespec64
195  * @nsec:	the nanoseconds value to be converted
196  *
197  * Returns the timespec64 representation of the nsec parameter.
198  */
199 extern struct timespec64 ns_to_timespec64(const s64 nsec);
200 
201 /**
202  * timespec64_add_ns - Adds nanoseconds to a timespec64
203  * @a:		pointer to timespec64 to be incremented
204  * @ns:		unsigned nanoseconds value to be added
205  *
206  * This must always be inlined because its used from the x86-64 vdso,
207  * which cannot call other kernel functions.
208  */
209 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
210 {
211 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
212 	a->tv_nsec = ns;
213 }
214 
215 #endif
216 
217 /*
218  * timespec64_add_safe assumes both values are positive and checks for
219  * overflow. It will return TIME64_MAX in case of overflow.
220  */
221 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
222 					 const struct timespec64 rhs);
223 
224 #endif /* _LINUX_TIME64_H */
225