Line data Source code
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 : #include <asm/bug.h>
27 :
28 : /* Nanosecond scalar representation for kernel time values */
29 : typedef s64 ktime_t;
30 :
31 : /**
32 : * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value
33 : * @secs: seconds to set
34 : * @nsecs: nanoseconds to set
35 : *
36 : * Return: The ktime_t representation of the value.
37 : */
38 : static inline ktime_t ktime_set(const s64 secs, const unsigned long nsecs)
39 : {
40 2 : if (unlikely(secs >= KTIME_SEC_MAX))
41 : return KTIME_MAX;
42 :
43 3 : return secs * NSEC_PER_SEC + (s64)nsecs;
44 : }
45 :
46 : /* Subtract two ktime_t variables. rem = lhs -rhs: */
47 : #define ktime_sub(lhs, rhs) ((lhs) - (rhs))
48 :
49 : /* Add two ktime_t variables. res = lhs + rhs: */
50 : #define ktime_add(lhs, rhs) ((lhs) + (rhs))
51 :
52 : /*
53 : * Same as ktime_add(), but avoids undefined behaviour on overflow; however,
54 : * this means that you must check the result for overflow yourself.
55 : */
56 : #define ktime_add_unsafe(lhs, rhs) ((u64) (lhs) + (rhs))
57 :
58 : /*
59 : * Add a ktime_t variable and a scalar nanosecond value.
60 : * res = kt + nsval:
61 : */
62 : #define ktime_add_ns(kt, nsval) ((kt) + (nsval))
63 :
64 : /*
65 : * Subtract a scalar nanosecod from a ktime_t variable
66 : * res = kt - nsval:
67 : */
68 : #define ktime_sub_ns(kt, nsval) ((kt) - (nsval))
69 :
70 : /* convert a timespec64 to ktime_t format: */
71 : static inline ktime_t timespec64_to_ktime(struct timespec64 ts)
72 : {
73 4 : return ktime_set(ts.tv_sec, ts.tv_nsec);
74 : }
75 :
76 : /* Map the ktime_t to timespec conversion to ns_to_timespec function */
77 : #define ktime_to_timespec64(kt) ns_to_timespec64((kt))
78 :
79 : /* Convert ktime_t to nanoseconds */
80 : static inline s64 ktime_to_ns(const ktime_t kt)
81 : {
82 : return kt;
83 : }
84 :
85 : /**
86 : * ktime_compare - Compares two ktime_t variables for less, greater or equal
87 : * @cmp1: comparable1
88 : * @cmp2: comparable2
89 : *
90 : * Return: ...
91 : * cmp1 < cmp2: return <0
92 : * cmp1 == cmp2: return 0
93 : * cmp1 > cmp2: return >0
94 : */
95 : static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2)
96 : {
97 5 : if (cmp1 < cmp2)
98 : return -1;
99 0 : if (cmp1 > cmp2)
100 : return 1;
101 : return 0;
102 : }
103 :
104 : /**
105 : * ktime_after - Compare if a ktime_t value is bigger than another one.
106 : * @cmp1: comparable1
107 : * @cmp2: comparable2
108 : *
109 : * Return: true if cmp1 happened after cmp2.
110 : */
111 : static inline bool ktime_after(const ktime_t cmp1, const ktime_t cmp2)
112 : {
113 0 : return ktime_compare(cmp1, cmp2) > 0;
114 : }
115 :
116 : /**
117 : * ktime_before - Compare if a ktime_t value is smaller than another one.
118 : * @cmp1: comparable1
119 : * @cmp2: comparable2
120 : *
121 : * Return: true if cmp1 happened before cmp2.
122 : */
123 : static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2)
124 : {
125 5 : return ktime_compare(cmp1, cmp2) < 0;
126 : }
127 :
128 : #if BITS_PER_LONG < 64
129 : extern s64 __ktime_divns(const ktime_t kt, s64 div);
130 : static inline s64 ktime_divns(const ktime_t kt, s64 div)
131 : {
132 : /*
133 : * Negative divisors could cause an inf loop,
134 : * so bug out here.
135 : */
136 : BUG_ON(div < 0);
137 : if (__builtin_constant_p(div) && !(div >> 32)) {
138 : s64 ns = kt;
139 : u64 tmp = ns < 0 ? -ns : ns;
140 :
141 : do_div(tmp, div);
142 : return ns < 0 ? -tmp : tmp;
143 : } else {
144 : return __ktime_divns(kt, div);
145 : }
146 : }
147 : #else /* BITS_PER_LONG < 64 */
148 : static inline s64 ktime_divns(const ktime_t kt, s64 div)
149 : {
150 : /*
151 : * 32-bit implementation cannot handle negative divisors,
152 : * so catch them on 64bit as well.
153 : */
154 0 : WARN_ON(div < 0);
155 0 : return kt / div;
156 : }
157 : #endif
158 :
159 : static inline s64 ktime_to_us(const ktime_t kt)
160 : {
161 0 : return ktime_divns(kt, NSEC_PER_USEC);
162 : }
163 :
164 : static inline s64 ktime_to_ms(const ktime_t kt)
165 : {
166 0 : return ktime_divns(kt, NSEC_PER_MSEC);
167 : }
168 :
169 : static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)
170 : {
171 0 : return ktime_to_us(ktime_sub(later, earlier));
172 : }
173 :
174 : static inline s64 ktime_ms_delta(const ktime_t later, const ktime_t earlier)
175 : {
176 0 : return ktime_to_ms(ktime_sub(later, earlier));
177 : }
178 :
179 : static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec)
180 : {
181 0 : return ktime_add_ns(kt, usec * NSEC_PER_USEC);
182 : }
183 :
184 : static inline ktime_t ktime_add_ms(const ktime_t kt, const u64 msec)
185 : {
186 : return ktime_add_ns(kt, msec * NSEC_PER_MSEC);
187 : }
188 :
189 : static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec)
190 : {
191 : return ktime_sub_ns(kt, usec * NSEC_PER_USEC);
192 : }
193 :
194 : static inline ktime_t ktime_sub_ms(const ktime_t kt, const u64 msec)
195 : {
196 : return ktime_sub_ns(kt, msec * NSEC_PER_MSEC);
197 : }
198 :
199 : extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs);
200 :
201 : /**
202 : * ktime_to_timespec64_cond - convert a ktime_t variable to timespec64
203 : * format only if the variable contains data
204 : * @kt: the ktime_t variable to convert
205 : * @ts: the timespec variable to store the result in
206 : *
207 : * Return: %true if there was a successful conversion, %false if kt was 0.
208 : */
209 : static inline __must_check bool ktime_to_timespec64_cond(const ktime_t kt,
210 : struct timespec64 *ts)
211 : {
212 : if (kt) {
213 : *ts = ktime_to_timespec64(kt);
214 : return true;
215 : } else {
216 : return false;
217 : }
218 : }
219 :
220 : #include <vdso/ktime.h>
221 :
222 : static inline ktime_t ns_to_ktime(u64 ns)
223 : {
224 13 : return ns;
225 : }
226 :
227 : static inline ktime_t ms_to_ktime(u64 ms)
228 : {
229 : return ms * NSEC_PER_MSEC;
230 : }
231 :
232 : # include <linux/timekeeping.h>
233 :
234 : #endif
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