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