Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_TIME64_H
3#define _LINUX_TIME64_H
4
5#include <linux/math64.h>
6#include <vdso/time64.h>
7
8typedef __s64 time64_t;
9typedef __u64 timeu64_t;
10
11#include <uapi/linux/time.h>
12
13struct timespec64 {
14 time64_t tv_sec; /* seconds */
15 long tv_nsec; /* nanoseconds */
16};
17
18struct itimerspec64 {
19 struct timespec64 it_interval;
20 struct timespec64 it_value;
21};
22
23/* Parameters used to convert the timespec values: */
24#define PSEC_PER_NSEC 1000L
25
26/* Located here for timespec[64]_valid_strict */
27#define TIME64_MAX ((s64)~((u64)1 << 63))
28#define TIME64_MIN (-TIME64_MAX - 1)
29
30#define KTIME_MAX ((s64)~((u64)1 << 63))
31#define KTIME_MIN (-KTIME_MAX - 1)
32#define KTIME_SEC_MAX (KTIME_MAX / NSEC_PER_SEC)
33#define KTIME_SEC_MIN (KTIME_MIN / NSEC_PER_SEC)
34
35/*
36 * Limits for settimeofday():
37 *
38 * To prevent setting the time close to the wraparound point time setting
39 * is limited so a reasonable uptime can be accomodated. Uptime of 30 years
40 * should be really sufficient, which means the cutoff is 2232. At that
41 * point the cutoff is just a small part of the larger problem.
42 */
43#define TIME_UPTIME_SEC_MAX (30LL * 365 * 24 *3600)
44#define TIME_SETTOD_SEC_MAX (KTIME_SEC_MAX - TIME_UPTIME_SEC_MAX)
45
46static inline int timespec64_equal(const struct timespec64 *a,
47 const struct timespec64 *b)
48{
49 return (a->tv_sec == b->tv_sec) && (a->tv_nsec == b->tv_nsec);
50}
51
52static inline bool timespec64_is_epoch(const struct timespec64 *ts)
53{
54 return ts->tv_sec == 0 && ts->tv_nsec == 0;
55}
56
57/*
58 * lhs < rhs: return <0
59 * lhs == rhs: return 0
60 * lhs > rhs: return >0
61 */
62static inline int timespec64_compare(const struct timespec64 *lhs, const struct timespec64 *rhs)
63{
64 if (lhs->tv_sec < rhs->tv_sec)
65 return -1;
66 if (lhs->tv_sec > rhs->tv_sec)
67 return 1;
68 return lhs->tv_nsec - rhs->tv_nsec;
69}
70
71extern void set_normalized_timespec64(struct timespec64 *ts, time64_t sec, s64 nsec);
72
73static inline struct timespec64 timespec64_add(struct timespec64 lhs,
74 struct timespec64 rhs)
75{
76 struct timespec64 ts_delta;
77 set_normalized_timespec64(&ts_delta, lhs.tv_sec + rhs.tv_sec,
78 lhs.tv_nsec + rhs.tv_nsec);
79 return ts_delta;
80}
81
82/*
83 * sub = lhs - rhs, in normalized form
84 */
85static inline struct timespec64 timespec64_sub(struct timespec64 lhs,
86 struct timespec64 rhs)
87{
88 struct timespec64 ts_delta;
89 set_normalized_timespec64(&ts_delta, lhs.tv_sec - rhs.tv_sec,
90 lhs.tv_nsec - rhs.tv_nsec);
91 return ts_delta;
92}
93
94/*
95 * Returns true if the timespec64 is norm, false if denorm:
96 */
97static inline bool timespec64_valid(const struct timespec64 *ts)
98{
99 /* Dates before 1970 are bogus */
100 if (ts->tv_sec < 0)
101 return false;
102 /* Can't have more nanoseconds then a second */
103 if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
104 return false;
105 return true;
106}
107
108static inline bool timespec64_valid_strict(const struct timespec64 *ts)
109{
110 if (!timespec64_valid(ts))
111 return false;
112 /* Disallow values that could overflow ktime_t */
113 if ((unsigned long long)ts->tv_sec >= KTIME_SEC_MAX)
114 return false;
115 return true;
116}
117
118static inline bool timespec64_valid_settod(const struct timespec64 *ts)
119{
120 if (!timespec64_valid(ts))
121 return false;
122 /* Disallow values which cause overflow issues vs. CLOCK_REALTIME */
123 if ((unsigned long long)ts->tv_sec >= TIME_SETTOD_SEC_MAX)
124 return false;
125 return true;
126}
127
128/**
129 * timespec64_to_ns - Convert timespec64 to nanoseconds
130 * @ts: pointer to the timespec64 variable to be converted
131 *
132 * Returns the scalar nanosecond representation of the timespec64
133 * parameter.
134 */
135static inline s64 timespec64_to_ns(const struct timespec64 *ts)
136{
137 /* Prevent multiplication overflow / underflow */
138 if (ts->tv_sec >= KTIME_SEC_MAX)
139 return KTIME_MAX;
140
141 if (ts->tv_sec <= KTIME_SEC_MIN)
142 return KTIME_MIN;
143
144 return ((s64) ts->tv_sec * NSEC_PER_SEC) + ts->tv_nsec;
145}
146
147/**
148 * ns_to_timespec64 - Convert nanoseconds to timespec64
149 * @nsec: the nanoseconds value to be converted
150 *
151 * Returns the timespec64 representation of the nsec parameter.
152 */
153extern struct timespec64 ns_to_timespec64(s64 nsec);
154
155/**
156 * timespec64_add_ns - Adds nanoseconds to a timespec64
157 * @a: pointer to timespec64 to be incremented
158 * @ns: unsigned nanoseconds value to be added
159 *
160 * This must always be inlined because its used from the x86-64 vdso,
161 * which cannot call other kernel functions.
162 */
163static __always_inline void timespec64_add_ns(struct timespec64 *a, u64 ns)
164{
165 a->tv_sec += __iter_div_u64_rem(a->tv_nsec + ns, NSEC_PER_SEC, &ns);
166 a->tv_nsec = ns;
167}
168
169/*
170 * timespec64_add_safe assumes both values are positive and checks for
171 * overflow. It will return TIME64_MAX in case of overflow.
172 */
173extern struct timespec64 timespec64_add_safe(const struct timespec64 lhs,
174 const struct timespec64 rhs);
175
176#endif /* _LINUX_TIME64_H */