2 * include/linux/ktime.h
4 * ktime_t - nanosecond-resolution time format.
6 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
7 * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
9 * data type definitions, declarations, prototypes and macros.
11 * Started by: Thomas Gleixner and Ingo Molnar
15 * Roman Zippel provided the ideas and primary code snippets of
16 * the ktime_t union and further simplifications of the original
19 * For licencing details see kernel-base/COPYING
21 #ifndef _LINUX_KTIME_H
22 #define _LINUX_KTIME_H
24 #include <linux/time.h>
25 #include <linux/jiffies.h>
30 * A single 64-bit variable is used to store the hrtimers
31 * internal representation of time values in scalar nanoseconds. The
32 * design plays out best on 64-bit CPUs, where most conversions are
33 * NOPs and most arithmetic ktime_t operations are plain arithmetic
41 typedef union ktime ktime_t
; /* Kill this */
44 * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value
45 * @secs: seconds to set
46 * @nsecs: nanoseconds to set
48 * Return: The ktime_t representation of the value.
50 static inline ktime_t
ktime_set(const s64 secs
, const unsigned long nsecs
)
52 if (unlikely(secs
>= KTIME_SEC_MAX
))
53 return (ktime_t
){ .tv64
= KTIME_MAX
};
55 return (ktime_t
) { .tv64
= secs
* NSEC_PER_SEC
+ (s64
)nsecs
};
58 /* Subtract two ktime_t variables. rem = lhs -rhs: */
59 #define ktime_sub(lhs, rhs) \
60 ({ (ktime_t){ .tv64 = (lhs).tv64 - (rhs).tv64 }; })
62 /* Add two ktime_t variables. res = lhs + rhs: */
63 #define ktime_add(lhs, rhs) \
64 ({ (ktime_t){ .tv64 = (lhs).tv64 + (rhs).tv64 }; })
67 * Add a ktime_t variable and a scalar nanosecond value.
70 #define ktime_add_ns(kt, nsval) \
71 ({ (ktime_t){ .tv64 = (kt).tv64 + (nsval) }; })
74 * Subtract a scalar nanosecod from a ktime_t variable
77 #define ktime_sub_ns(kt, nsval) \
78 ({ (ktime_t){ .tv64 = (kt).tv64 - (nsval) }; })
80 /* convert a timespec to ktime_t format: */
81 static inline ktime_t
timespec_to_ktime(struct timespec ts
)
83 return ktime_set(ts
.tv_sec
, ts
.tv_nsec
);
86 /* convert a timespec64 to ktime_t format: */
87 static inline ktime_t
timespec64_to_ktime(struct timespec64 ts
)
89 return ktime_set(ts
.tv_sec
, ts
.tv_nsec
);
92 /* convert a timeval to ktime_t format: */
93 static inline ktime_t
timeval_to_ktime(struct timeval tv
)
95 return ktime_set(tv
.tv_sec
, tv
.tv_usec
* NSEC_PER_USEC
);
98 /* Map the ktime_t to timespec conversion to ns_to_timespec function */
99 #define ktime_to_timespec(kt) ns_to_timespec((kt).tv64)
101 /* Map the ktime_t to timespec conversion to ns_to_timespec function */
102 #define ktime_to_timespec64(kt) ns_to_timespec64((kt).tv64)
104 /* Map the ktime_t to timeval conversion to ns_to_timeval function */
105 #define ktime_to_timeval(kt) ns_to_timeval((kt).tv64)
107 /* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */
108 #define ktime_to_ns(kt) ((kt).tv64)
112 * ktime_equal - Compares two ktime_t variables to see if they are equal
116 * Compare two ktime_t variables.
118 * Return: 1 if equal.
120 static inline int ktime_equal(const ktime_t cmp1
, const ktime_t cmp2
)
122 return cmp1
.tv64
== cmp2
.tv64
;
126 * ktime_compare - Compares two ktime_t variables for less, greater or equal
131 * cmp1 < cmp2: return <0
132 * cmp1 == cmp2: return 0
133 * cmp1 > cmp2: return >0
135 static inline int ktime_compare(const ktime_t cmp1
, const ktime_t cmp2
)
137 if (cmp1
.tv64
< cmp2
.tv64
)
139 if (cmp1
.tv64
> cmp2
.tv64
)
145 * ktime_after - Compare if a ktime_t value is bigger than another one.
149 * Return: true if cmp1 happened after cmp2.
151 static inline bool ktime_after(const ktime_t cmp1
, const ktime_t cmp2
)
153 return ktime_compare(cmp1
, cmp2
) > 0;
157 * ktime_before - Compare if a ktime_t value is smaller than another one.
161 * Return: true if cmp1 happened before cmp2.
163 static inline bool ktime_before(const ktime_t cmp1
, const ktime_t cmp2
)
165 return ktime_compare(cmp1
, cmp2
) < 0;
168 #if BITS_PER_LONG < 64
169 extern u64
__ktime_divns(const ktime_t kt
, s64 div
);
170 static inline u64
ktime_divns(const ktime_t kt
, s64 div
)
172 if (__builtin_constant_p(div
) && !(div
>> 32)) {
177 return __ktime_divns(kt
, div
);
180 #else /* BITS_PER_LONG < 64 */
181 # define ktime_divns(kt, div) (u64)((kt).tv64 / (div))
184 static inline s64
ktime_to_us(const ktime_t kt
)
186 return ktime_divns(kt
, NSEC_PER_USEC
);
189 static inline s64
ktime_to_ms(const ktime_t kt
)
191 return ktime_divns(kt
, NSEC_PER_MSEC
);
194 static inline s64
ktime_us_delta(const ktime_t later
, const ktime_t earlier
)
196 return ktime_to_us(ktime_sub(later
, earlier
));
199 static inline s64
ktime_ms_delta(const ktime_t later
, const ktime_t earlier
)
201 return ktime_to_ms(ktime_sub(later
, earlier
));
204 static inline ktime_t
ktime_add_us(const ktime_t kt
, const u64 usec
)
206 return ktime_add_ns(kt
, usec
* NSEC_PER_USEC
);
209 static inline ktime_t
ktime_add_ms(const ktime_t kt
, const u64 msec
)
211 return ktime_add_ns(kt
, msec
* NSEC_PER_MSEC
);
214 static inline ktime_t
ktime_sub_us(const ktime_t kt
, const u64 usec
)
216 return ktime_sub_ns(kt
, usec
* NSEC_PER_USEC
);
219 extern ktime_t
ktime_add_safe(const ktime_t lhs
, const ktime_t rhs
);
222 * ktime_to_timespec_cond - convert a ktime_t variable to timespec
223 * format only if the variable contains data
224 * @kt: the ktime_t variable to convert
225 * @ts: the timespec variable to store the result in
227 * Return: %true if there was a successful conversion, %false if kt was 0.
229 static inline __must_check
bool ktime_to_timespec_cond(const ktime_t kt
,
233 *ts
= ktime_to_timespec(kt
);
241 * ktime_to_timespec64_cond - convert a ktime_t variable to timespec64
242 * format only if the variable contains data
243 * @kt: the ktime_t variable to convert
244 * @ts: the timespec variable to store the result in
246 * Return: %true if there was a successful conversion, %false if kt was 0.
248 static inline __must_check
bool ktime_to_timespec64_cond(const ktime_t kt
,
249 struct timespec64
*ts
)
252 *ts
= ktime_to_timespec64(kt
);
260 * The resolution of the clocks. The resolution value is returned in
261 * the clock_getres() system call to give application programmers an
262 * idea of the (in)accuracy of timers. Timer values are rounded up to
263 * this resolution values.
265 #define LOW_RES_NSEC TICK_NSEC
266 #define KTIME_LOW_RES (ktime_t){ .tv64 = LOW_RES_NSEC }
268 static inline ktime_t
ns_to_ktime(u64 ns
)
270 static const ktime_t ktime_zero
= { .tv64
= 0 };
272 return ktime_add_ns(ktime_zero
, ns
);
275 static inline ktime_t
ms_to_ktime(u64 ms
)
277 static const ktime_t ktime_zero
= { .tv64
= 0 };
279 return ktime_add_ms(ktime_zero
, ms
);
282 # include <linux/timekeeping.h>