1/*
2 * include/linux/ktime.h
3 *
4 * ktime_t - nanosecond-resolution time format.
5 *
6 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
7 * Copyright(C) 2005, Red Hat, Inc., Ingo Molnar
8 *
9 * data type definitions, declarations, prototypes and macros.
10 *
11 * Started by: Thomas Gleixner and Ingo Molnar
12 *
13 * Credits:
14 *
15 * Roman Zippel provided the ideas and primary code snippets of
16 * the ktime_t union and further simplifications of the original
17 * code.
18 *
19 * For licencing details see kernel-base/COPYING
20 */
21#ifndef _LINUX_KTIME_H
22#define _LINUX_KTIME_H
23
24#include <linux/time.h>
25#include <linux/jiffies.h>
26
27/* Nanosecond scalar representation for kernel time values */
28typedef s64 ktime_t;
29
30/**
31 * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value
32 * @secs: seconds to set
33 * @nsecs: nanoseconds to set
34 *
35 * Return: The ktime_t representation of the value.
36 */
37static inline ktime_t ktime_set(const s64 secs, const unsigned long nsecs)
38{
39 if (unlikely(secs >= KTIME_SEC_MAX))
40 return KTIME_MAX;
41
42 return secs * NSEC_PER_SEC + (s64)nsecs;
43}
44
45/* Subtract two ktime_t variables. rem = lhs -rhs: */
46#define ktime_sub(lhs, rhs) ((lhs) - (rhs))
47
48/* Add two ktime_t variables. res = lhs + rhs: */
49#define ktime_add(lhs, rhs) ((lhs) + (rhs))
50
51/*
52 * Same as ktime_add(), but avoids undefined behaviour on overflow; however,
53 * this means that you must check the result for overflow yourself.
54 */
55#define ktime_add_unsafe(lhs, rhs) ((u64) (lhs) + (rhs))
56
57/*
58 * Add a ktime_t variable and a scalar nanosecond value.
59 * res = kt + nsval:
60 */
61#define ktime_add_ns(kt, nsval) ((kt) + (nsval))
62
63/*
64 * Subtract a scalar nanosecod from a ktime_t variable
65 * res = kt - nsval:
66 */
67#define ktime_sub_ns(kt, nsval) ((kt) - (nsval))
68
69/* convert a timespec to ktime_t format: */
70static inline ktime_t timespec_to_ktime(struct timespec ts)
71{
72 return ktime_set(ts.tv_sec, ts.tv_nsec);
73}
74
75/* convert a timespec64 to ktime_t format: */
76static inline ktime_t timespec64_to_ktime(struct timespec64 ts)
77{
78 return ktime_set(ts.tv_sec, ts.tv_nsec);
79}
80
81/* convert a timeval to ktime_t format: */
82static inline ktime_t timeval_to_ktime(struct timeval tv)
83{
84 return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC);
85}
86
87/* Map the ktime_t to timespec conversion to ns_to_timespec function */
88#define ktime_to_timespec(kt) ns_to_timespec((kt))
89
90/* Map the ktime_t to timespec conversion to ns_to_timespec function */
91#define ktime_to_timespec64(kt) ns_to_timespec64((kt))
92
93/* Map the ktime_t to timeval conversion to ns_to_timeval function */
94#define ktime_to_timeval(kt) ns_to_timeval((kt))
95
96/* Convert ktime_t to nanoseconds */
97static inline s64 ktime_to_ns(const ktime_t kt)
98{
99 return kt;
100}
101
102/**
103 * ktime_compare - Compares two ktime_t variables for less, greater or equal
104 * @cmp1: comparable1
105 * @cmp2: comparable2
106 *
107 * Return: ...
108 * cmp1 < cmp2: return <0
109 * cmp1 == cmp2: return 0
110 * cmp1 > cmp2: return >0
111 */
112static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2)
113{
114 if (cmp1 < cmp2)
115 return -1;
116 if (cmp1 > cmp2)
117 return 1;
118 return 0;
119}
120
121/**
122 * ktime_after - Compare if a ktime_t value is bigger than another one.
123 * @cmp1: comparable1
124 * @cmp2: comparable2
125 *
126 * Return: true if cmp1 happened after cmp2.
127 */
128static inline bool ktime_after(const ktime_t cmp1, const ktime_t cmp2)
129{
130 return ktime_compare(cmp1, cmp2) > 0;
131}
132
133/**
134 * ktime_before - Compare if a ktime_t value is smaller than another one.
135 * @cmp1: comparable1
136 * @cmp2: comparable2
137 *
138 * Return: true if cmp1 happened before cmp2.
139 */
140static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2)
141{
142 return ktime_compare(cmp1, cmp2) < 0;
143}
144
145#if BITS_PER_LONG < 64
146extern s64 __ktime_divns(const ktime_t kt, s64 div);
147static inline s64 ktime_divns(const ktime_t kt, s64 div)
148{
149 /*
150 * Negative divisors could cause an inf loop,
151 * so bug out here.
152 */
153 BUG_ON(div < 0);
154 if (__builtin_constant_p(div) && !(div >> 32)) {
155 s64 ns = kt;
156 u64 tmp = ns < 0 ? -ns : ns;
157
158 do_div(tmp, div);
159 return ns < 0 ? -tmp : tmp;
160 } else {
161 return __ktime_divns(kt, div);
162 }
163}
164#else /* BITS_PER_LONG < 64 */
165static inline s64 ktime_divns(const ktime_t kt, s64 div)
166{
167 /*
168 * 32-bit implementation cannot handle negative divisors,
169 * so catch them on 64bit as well.
170 */
171 WARN_ON(div < 0);
172 return kt / div;
173}
174#endif
175
176static inline s64 ktime_to_us(const ktime_t kt)
177{
178 return ktime_divns(kt, NSEC_PER_USEC);
179}
180
181static inline s64 ktime_to_ms(const ktime_t kt)
182{
183 return ktime_divns(kt, NSEC_PER_MSEC);
184}
185
186static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)
187{
188 return ktime_to_us(ktime_sub(later, earlier));
189}
190
191static inline s64 ktime_ms_delta(const ktime_t later, const ktime_t earlier)
192{
193 return ktime_to_ms(ktime_sub(later, earlier));
194}
195
196static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec)
197{
198 return ktime_add_ns(kt, usec * NSEC_PER_USEC);
199}
200
201static inline ktime_t ktime_add_ms(const ktime_t kt, const u64 msec)
202{
203 return ktime_add_ns(kt, msec * NSEC_PER_MSEC);
204}
205
206static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec)
207{
208 return ktime_sub_ns(kt, usec * NSEC_PER_USEC);
209}
210
211static inline ktime_t ktime_sub_ms(const ktime_t kt, const u64 msec)
212{
213 return ktime_sub_ns(kt, msec * NSEC_PER_MSEC);
214}
215
216extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs);
217
218/**
219 * ktime_to_timespec_cond - convert a ktime_t variable to timespec
220 * format only if the variable contains data
221 * @kt: the ktime_t variable to convert
222 * @ts: the timespec variable to store the result in
223 *
224 * Return: %true if there was a successful conversion, %false if kt was 0.
225 */
226static inline __must_check bool ktime_to_timespec_cond(const ktime_t kt,
227 struct timespec *ts)
228{
229 if (kt) {
230 *ts = ktime_to_timespec(kt);
231 return true;
232 } else {
233 return false;
234 }
235}
236
237/**
238 * ktime_to_timespec64_cond - convert a ktime_t variable to timespec64
239 * format only if the variable contains data
240 * @kt: the ktime_t variable to convert
241 * @ts: the timespec variable to store the result in
242 *
243 * Return: %true if there was a successful conversion, %false if kt was 0.
244 */
245static inline __must_check bool ktime_to_timespec64_cond(const ktime_t kt,
246 struct timespec64 *ts)
247{
248 if (kt) {
249 *ts = ktime_to_timespec64(kt);
250 return true;
251 } else {
252 return false;
253 }
254}
255
256/*
257 * The resolution of the clocks. The resolution value is returned in
258 * the clock_getres() system call to give application programmers an
259 * idea of the (in)accuracy of timers. Timer values are rounded up to
260 * this resolution values.
261 */
262#define LOW_RES_NSEC TICK_NSEC
263#define KTIME_LOW_RES (LOW_RES_NSEC)
264
265static inline ktime_t ns_to_ktime(u64 ns)
266{
267 return ns;
268}
269
270static inline ktime_t ms_to_ktime(u64 ms)
271{
272 return ms * NSEC_PER_MSEC;
273}
274
275# include <linux/timekeeping.h>
276# include <linux/timekeeping32.h>
277
278#endif
279