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 */
28 typedef 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 */
ktime_set(const s64 secs,const unsigned long nsecs)37 static 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: */
timespec_to_ktime(struct timespec ts)70 static 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: */
timespec64_to_ktime(struct timespec64 ts)76 static 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: */
timeval_to_ktime(struct timeval tv)82 static 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 */
ktime_to_ns(const ktime_t kt)97 static 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 */
ktime_compare(const ktime_t cmp1,const ktime_t cmp2)112 static 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 */
ktime_after(const ktime_t cmp1,const ktime_t cmp2)128 static 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 */
ktime_before(const ktime_t cmp1,const ktime_t cmp2)140 static 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
146 extern s64 __ktime_divns(const ktime_t kt, s64 div);
ktime_divns(const ktime_t kt,s64 div)147 static 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 */
ktime_divns(const ktime_t kt,s64 div)165 static 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
ktime_to_us(const ktime_t kt)176 static inline s64 ktime_to_us(const ktime_t kt)
177 {
178 return ktime_divns(kt, NSEC_PER_USEC);
179 }
180
ktime_to_ms(const ktime_t kt)181 static inline s64 ktime_to_ms(const ktime_t kt)
182 {
183 return ktime_divns(kt, NSEC_PER_MSEC);
184 }
185
ktime_us_delta(const ktime_t later,const ktime_t earlier)186 static 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
ktime_ms_delta(const ktime_t later,const ktime_t earlier)191 static 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
ktime_add_us(const ktime_t kt,const u64 usec)196 static 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
ktime_add_ms(const ktime_t kt,const u64 msec)201 static 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
ktime_sub_us(const ktime_t kt,const u64 usec)206 static 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
ktime_sub_ms(const ktime_t kt,const u64 msec)211 static 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
216 extern 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 */
ktime_to_timespec_cond(const ktime_t kt,struct timespec * ts)226 static 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 */
ktime_to_timespec64_cond(const ktime_t kt,struct timespec64 * ts)245 static 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 #include <vdso/ktime.h>
257
ns_to_ktime(u64 ns)258 static inline ktime_t ns_to_ktime(u64 ns)
259 {
260 return ns;
261 }
262
ms_to_ktime(u64 ms)263 static inline ktime_t ms_to_ktime(u64 ms)
264 {
265 return ms * NSEC_PER_MSEC;
266 }
267
268 # include <linux/timekeeping.h>
269 # include <linux/timekeeping32.h>
270
271 #endif
272