xref: /openbmc/linux/include/linux/time64.h (revision 791d3ef2e11100449837dc0b6fe884e60ca3a484)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_TIME64_H
3 #define _LINUX_TIME64_H
4 
5 #include <linux/math64.h>
6 
7 typedef __s64 time64_t;
8 typedef __u64 timeu64_t;
9 
10 /* CONFIG_64BIT_TIME enables new 64 bit time_t syscalls in the compat path
11  * and 32-bit emulation.
12  */
13 #ifndef CONFIG_64BIT_TIME
14 #define __kernel_timespec timespec
15 #endif
16 
17 #include <uapi/linux/time.h>
18 
19 struct timespec64 {
20 	time64_t	tv_sec;			/* seconds */
21 	long		tv_nsec;		/* nanoseconds */
22 };
23 
24 struct itimerspec64 {
25 	struct timespec64 it_interval;
26 	struct timespec64 it_value;
27 };
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 static inline int timespec64_equal(const struct timespec64 *a,
44 				   const struct timespec64 *b)
45 {
46 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
47 }
48 
49 /*
50  * lhs < rhs:  return <0
51  * lhs == rhs: return 0
52  * lhs > rhs:  return >0
53  */
54 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
55 {
56 	if (lhs->tv_sec < rhs->tv_sec)
57 		return -1;
58 	if (lhs->tv_sec > rhs->tv_sec)
59 		return 1;
60 	return lhs->tv_nsec - rhs->tv_nsec;
61 }
62 
63 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
64 
65 static inline struct timespec64 timespec64_add(struct timespec64 lhs,
66 						struct timespec64 rhs)
67 {
68 	struct timespec64 ts_delta;
69 	set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
70 				lhs.tv_nsec + rhs.tv_nsec);
71 	return ts_delta;
72 }
73 
74 /*
75  * sub = lhs - rhs, in normalized form
76  */
77 static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
78 						struct timespec64 rhs)
79 {
80 	struct timespec64 ts_delta;
81 	set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
82 				lhs.tv_nsec - rhs.tv_nsec);
83 	return ts_delta;
84 }
85 
86 /*
87  * Returns true if the timespec64 is norm, false if denorm:
88  */
89 static inline bool timespec64_valid(const struct timespec64 *ts)
90 {
91 	/* Dates before 1970 are bogus */
92 	if (ts->tv_sec < 0)
93 		return false;
94 	/* Can't have more nanoseconds then a second */
95 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
96 		return false;
97 	return true;
98 }
99 
100 static inline bool timespec64_valid_strict(const struct timespec64 *ts)
101 {
102 	if (!timespec64_valid(ts))
103 		return false;
104 	/* Disallow values that could overflow ktime_t */
105 	if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
106 		return false;
107 	return true;
108 }
109 
110 /**
111  * timespec64_to_ns - Convert timespec64 to nanoseconds
112  * @ts:		pointer to the timespec64 variable to be converted
113  *
114  * Returns the scalar nanosecond representation of the timespec64
115  * parameter.
116  */
117 static inline s64 timespec64_to_ns(const struct timespec64 *ts)
118 {
119 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
120 }
121 
122 /**
123  * ns_to_timespec64 - Convert nanoseconds to timespec64
124  * @nsec:	the nanoseconds value to be converted
125  *
126  * Returns the timespec64 representation of the nsec parameter.
127  */
128 extern struct timespec64 ns_to_timespec64(const s64 nsec);
129 
130 /**
131  * timespec64_add_ns - Adds nanoseconds to a timespec64
132  * @a:		pointer to timespec64 to be incremented
133  * @ns:		unsigned nanoseconds value to be added
134  *
135  * This must always be inlined because its used from the x86-64 vdso,
136  * which cannot call other kernel functions.
137  */
138 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
139 {
140 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
141 	a->tv_nsec = ns;
142 }
143 
144 /*
145  * timespec64_add_safe assumes both values are positive and checks for
146  * overflow. It will return TIME64_MAX in case of overflow.
147  */
148 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
149 					 const struct timespec64 rhs);
150 
151 #endif /* _LINUX_TIME64_H */
152