xref: /openbmc/linux/include/linux/time64.h (revision 53809828)
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 #define __kernel_itimerspec itimerspec
16 #endif
17 
18 #include <uapi/linux/time.h>
19 
20 struct timespec64 {
21 	time64_t	tv_sec;			/* seconds */
22 	long		tv_nsec;		/* nanoseconds */
23 };
24 
25 struct itimerspec64 {
26 	struct timespec64 it_interval;
27 	struct timespec64 it_value;
28 };
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 static inline int timespec64_equal(const struct timespec64 *a,
45 				   const struct timespec64 *b)
46 {
47 	return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
48 }
49 
50 /*
51  * lhs < rhs:  return <0
52  * lhs == rhs: return 0
53  * lhs > rhs:  return >0
54  */
55 static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
56 {
57 	if (lhs->tv_sec < rhs->tv_sec)
58 		return -1;
59 	if (lhs->tv_sec > rhs->tv_sec)
60 		return 1;
61 	return lhs->tv_nsec - rhs->tv_nsec;
62 }
63 
64 extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
65 
66 static inline struct timespec64 timespec64_add(struct timespec64 lhs,
67 						struct timespec64 rhs)
68 {
69 	struct timespec64 ts_delta;
70 	set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
71 				lhs.tv_nsec + rhs.tv_nsec);
72 	return ts_delta;
73 }
74 
75 /*
76  * sub = lhs - rhs, in normalized form
77  */
78 static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
79 						struct timespec64 rhs)
80 {
81 	struct timespec64 ts_delta;
82 	set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
83 				lhs.tv_nsec - rhs.tv_nsec);
84 	return ts_delta;
85 }
86 
87 /*
88  * Returns true if the timespec64 is norm, false if denorm:
89  */
90 static inline bool timespec64_valid(const struct timespec64 *ts)
91 {
92 	/* Dates before 1970 are bogus */
93 	if (ts->tv_sec < 0)
94 		return false;
95 	/* Can't have more nanoseconds then a second */
96 	if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
97 		return false;
98 	return true;
99 }
100 
101 static inline bool timespec64_valid_strict(const struct timespec64 *ts)
102 {
103 	if (!timespec64_valid(ts))
104 		return false;
105 	/* Disallow values that could overflow ktime_t */
106 	if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
107 		return false;
108 	return true;
109 }
110 
111 /**
112  * timespec64_to_ns - Convert timespec64 to nanoseconds
113  * @ts:		pointer to the timespec64 variable to be converted
114  *
115  * Returns the scalar nanosecond representation of the timespec64
116  * parameter.
117  */
118 static inline s64 timespec64_to_ns(const struct timespec64 *ts)
119 {
120 	return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
121 }
122 
123 /**
124  * ns_to_timespec64 - Convert nanoseconds to timespec64
125  * @nsec:	the nanoseconds value to be converted
126  *
127  * Returns the timespec64 representation of the nsec parameter.
128  */
129 extern struct timespec64 ns_to_timespec64(const s64 nsec);
130 
131 /**
132  * timespec64_add_ns - Adds nanoseconds to a timespec64
133  * @a:		pointer to timespec64 to be incremented
134  * @ns:		unsigned nanoseconds value to be added
135  *
136  * This must always be inlined because its used from the x86-64 vdso,
137  * which cannot call other kernel functions.
138  */
139 static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
140 {
141 	a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
142 	a->tv_nsec = ns;
143 }
144 
145 /*
146  * timespec64_add_safe assumes both values are positive and checks for
147  * overflow. It will return TIME64_MAX in case of overflow.
148  */
149 extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
150 					 const struct timespec64 rhs);
151 
152 #endif /* _LINUX_TIME64_H */
153