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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 | /* | |
28 | * ktime_t: | |
29 | * | |
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 | |
34 | * operations. | |
35 | * | |
36 | */ | |
37 | union ktime { | |
38 | s64 tv64; | |
39 | }; | |
40 | ||
41 | typedef union ktime ktime_t; /* Kill this */ | |
42 | ||
43 | /** | |
44 | * ktime_set - Set a ktime_t variable from a seconds/nanoseconds value | |
45 | * @secs: seconds to set | |
46 | * @nsecs: nanoseconds to set | |
47 | * | |
48 | * Return: The ktime_t representation of the value. | |
49 | */ | |
50 | static inline ktime_t ktime_set(const s64 secs, const unsigned long nsecs) | |
51 | { | |
52 | if (unlikely(secs >= KTIME_SEC_MAX)) | |
53 | return (ktime_t){ .tv64 = KTIME_MAX }; | |
54 | ||
55 | return (ktime_t) { .tv64 = secs * NSEC_PER_SEC + (s64)nsecs }; | |
56 | } | |
57 | ||
58 | /* Subtract two ktime_t variables. rem = lhs -rhs: */ | |
59 | #define ktime_sub(lhs, rhs) \ | |
60 | ({ (ktime_t){ .tv64 = (lhs).tv64 - (rhs).tv64 }; }) | |
61 | ||
62 | /* Add two ktime_t variables. res = lhs + rhs: */ | |
63 | #define ktime_add(lhs, rhs) \ | |
64 | ({ (ktime_t){ .tv64 = (lhs).tv64 + (rhs).tv64 }; }) | |
65 | ||
66 | /* | |
67 | * Same as ktime_add(), but avoids undefined behaviour on overflow; however, | |
68 | * this means that you must check the result for overflow yourself. | |
69 | */ | |
70 | #define ktime_add_unsafe(lhs, rhs) \ | |
71 | ({ (ktime_t){ .tv64 = (u64) (lhs).tv64 + (rhs).tv64 }; }) | |
72 | ||
73 | /* | |
74 | * Add a ktime_t variable and a scalar nanosecond value. | |
75 | * res = kt + nsval: | |
76 | */ | |
77 | #define ktime_add_ns(kt, nsval) \ | |
78 | ({ (ktime_t){ .tv64 = (kt).tv64 + (nsval) }; }) | |
79 | ||
80 | /* | |
81 | * Subtract a scalar nanosecod from a ktime_t variable | |
82 | * res = kt - nsval: | |
83 | */ | |
84 | #define ktime_sub_ns(kt, nsval) \ | |
85 | ({ (ktime_t){ .tv64 = (kt).tv64 - (nsval) }; }) | |
86 | ||
87 | /* convert a timespec to ktime_t format: */ | |
88 | static inline ktime_t timespec_to_ktime(struct timespec ts) | |
89 | { | |
90 | return ktime_set(ts.tv_sec, ts.tv_nsec); | |
91 | } | |
92 | ||
93 | /* convert a timespec64 to ktime_t format: */ | |
94 | static inline ktime_t timespec64_to_ktime(struct timespec64 ts) | |
95 | { | |
96 | return ktime_set(ts.tv_sec, ts.tv_nsec); | |
97 | } | |
98 | ||
99 | /* convert a timeval to ktime_t format: */ | |
100 | static inline ktime_t timeval_to_ktime(struct timeval tv) | |
101 | { | |
102 | return ktime_set(tv.tv_sec, tv.tv_usec * NSEC_PER_USEC); | |
103 | } | |
104 | ||
105 | /* Map the ktime_t to timespec conversion to ns_to_timespec function */ | |
106 | #define ktime_to_timespec(kt) ns_to_timespec((kt).tv64) | |
107 | ||
108 | /* Map the ktime_t to timespec conversion to ns_to_timespec function */ | |
109 | #define ktime_to_timespec64(kt) ns_to_timespec64((kt).tv64) | |
110 | ||
111 | /* Map the ktime_t to timeval conversion to ns_to_timeval function */ | |
112 | #define ktime_to_timeval(kt) ns_to_timeval((kt).tv64) | |
113 | ||
114 | /* Convert ktime_t to nanoseconds - NOP in the scalar storage format: */ | |
115 | #define ktime_to_ns(kt) ((kt).tv64) | |
116 | ||
117 | ||
118 | /** | |
119 | * ktime_equal - Compares two ktime_t variables to see if they are equal | |
120 | * @cmp1: comparable1 | |
121 | * @cmp2: comparable2 | |
122 | * | |
123 | * Compare two ktime_t variables. | |
124 | * | |
125 | * Return: 1 if equal. | |
126 | */ | |
127 | static inline int ktime_equal(const ktime_t cmp1, const ktime_t cmp2) | |
128 | { | |
129 | return cmp1.tv64 == cmp2.tv64; | |
130 | } | |
131 | ||
132 | /** | |
133 | * ktime_compare - Compares two ktime_t variables for less, greater or equal | |
134 | * @cmp1: comparable1 | |
135 | * @cmp2: comparable2 | |
136 | * | |
137 | * Return: ... | |
138 | * cmp1 < cmp2: return <0 | |
139 | * cmp1 == cmp2: return 0 | |
140 | * cmp1 > cmp2: return >0 | |
141 | */ | |
142 | static inline int ktime_compare(const ktime_t cmp1, const ktime_t cmp2) | |
143 | { | |
144 | if (cmp1.tv64 < cmp2.tv64) | |
145 | return -1; | |
146 | if (cmp1.tv64 > cmp2.tv64) | |
147 | return 1; | |
148 | return 0; | |
149 | } | |
150 | ||
151 | /** | |
152 | * ktime_after - Compare if a ktime_t value is bigger than another one. | |
153 | * @cmp1: comparable1 | |
154 | * @cmp2: comparable2 | |
155 | * | |
156 | * Return: true if cmp1 happened after cmp2. | |
157 | */ | |
158 | static inline bool ktime_after(const ktime_t cmp1, const ktime_t cmp2) | |
159 | { | |
160 | return ktime_compare(cmp1, cmp2) > 0; | |
161 | } | |
162 | ||
163 | /** | |
164 | * ktime_before - Compare if a ktime_t value is smaller than another one. | |
165 | * @cmp1: comparable1 | |
166 | * @cmp2: comparable2 | |
167 | * | |
168 | * Return: true if cmp1 happened before cmp2. | |
169 | */ | |
170 | static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2) | |
171 | { | |
172 | return ktime_compare(cmp1, cmp2) < 0; | |
173 | } | |
174 | ||
175 | #if BITS_PER_LONG < 64 | |
176 | extern s64 __ktime_divns(const ktime_t kt, s64 div); | |
177 | static inline s64 ktime_divns(const ktime_t kt, s64 div) | |
178 | { | |
179 | /* | |
180 | * Negative divisors could cause an inf loop, | |
181 | * so bug out here. | |
182 | */ | |
183 | BUG_ON(div < 0); | |
184 | if (__builtin_constant_p(div) && !(div >> 32)) { | |
185 | s64 ns = kt.tv64; | |
186 | u64 tmp = ns < 0 ? -ns : ns; | |
187 | ||
188 | do_div(tmp, div); | |
189 | return ns < 0 ? -tmp : tmp; | |
190 | } else { | |
191 | return __ktime_divns(kt, div); | |
192 | } | |
193 | } | |
194 | #else /* BITS_PER_LONG < 64 */ | |
195 | static inline s64 ktime_divns(const ktime_t kt, s64 div) | |
196 | { | |
197 | /* | |
198 | * 32-bit implementation cannot handle negative divisors, | |
199 | * so catch them on 64bit as well. | |
200 | */ | |
201 | WARN_ON(div < 0); | |
202 | return kt.tv64 / div; | |
203 | } | |
204 | #endif | |
205 | ||
206 | static inline s64 ktime_to_us(const ktime_t kt) | |
207 | { | |
208 | return ktime_divns(kt, NSEC_PER_USEC); | |
209 | } | |
210 | ||
211 | static inline s64 ktime_to_ms(const ktime_t kt) | |
212 | { | |
213 | return ktime_divns(kt, NSEC_PER_MSEC); | |
214 | } | |
215 | ||
216 | static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier) | |
217 | { | |
218 | return ktime_to_us(ktime_sub(later, earlier)); | |
219 | } | |
220 | ||
221 | static inline s64 ktime_ms_delta(const ktime_t later, const ktime_t earlier) | |
222 | { | |
223 | return ktime_to_ms(ktime_sub(later, earlier)); | |
224 | } | |
225 | ||
226 | static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec) | |
227 | { | |
228 | return ktime_add_ns(kt, usec * NSEC_PER_USEC); | |
229 | } | |
230 | ||
231 | static inline ktime_t ktime_add_ms(const ktime_t kt, const u64 msec) | |
232 | { | |
233 | return ktime_add_ns(kt, msec * NSEC_PER_MSEC); | |
234 | } | |
235 | ||
236 | static inline ktime_t ktime_sub_us(const ktime_t kt, const u64 usec) | |
237 | { | |
238 | return ktime_sub_ns(kt, usec * NSEC_PER_USEC); | |
239 | } | |
240 | ||
241 | static inline ktime_t ktime_sub_ms(const ktime_t kt, const u64 msec) | |
242 | { | |
243 | return ktime_sub_ns(kt, msec * NSEC_PER_MSEC); | |
244 | } | |
245 | ||
246 | extern ktime_t ktime_add_safe(const ktime_t lhs, const ktime_t rhs); | |
247 | ||
248 | /** | |
249 | * ktime_to_timespec_cond - convert a ktime_t variable to timespec | |
250 | * format only if the variable contains data | |
251 | * @kt: the ktime_t variable to convert | |
252 | * @ts: the timespec variable to store the result in | |
253 | * | |
254 | * Return: %true if there was a successful conversion, %false if kt was 0. | |
255 | */ | |
256 | static inline __must_check bool ktime_to_timespec_cond(const ktime_t kt, | |
257 | struct timespec *ts) | |
258 | { | |
259 | if (kt.tv64) { | |
260 | *ts = ktime_to_timespec(kt); | |
261 | return true; | |
262 | } else { | |
263 | return false; | |
264 | } | |
265 | } | |
266 | ||
267 | /** | |
268 | * ktime_to_timespec64_cond - convert a ktime_t variable to timespec64 | |
269 | * format only if the variable contains data | |
270 | * @kt: the ktime_t variable to convert | |
271 | * @ts: the timespec variable to store the result in | |
272 | * | |
273 | * Return: %true if there was a successful conversion, %false if kt was 0. | |
274 | */ | |
275 | static inline __must_check bool ktime_to_timespec64_cond(const ktime_t kt, | |
276 | struct timespec64 *ts) | |
277 | { | |
278 | if (kt.tv64) { | |
279 | *ts = ktime_to_timespec64(kt); | |
280 | return true; | |
281 | } else { | |
282 | return false; | |
283 | } | |
284 | } | |
285 | ||
286 | /* | |
287 | * The resolution of the clocks. The resolution value is returned in | |
288 | * the clock_getres() system call to give application programmers an | |
289 | * idea of the (in)accuracy of timers. Timer values are rounded up to | |
290 | * this resolution values. | |
291 | */ | |
292 | #define LOW_RES_NSEC TICK_NSEC | |
293 | #define KTIME_LOW_RES (ktime_t){ .tv64 = LOW_RES_NSEC } | |
294 | ||
295 | static inline ktime_t ns_to_ktime(u64 ns) | |
296 | { | |
297 | static const ktime_t ktime_zero = { .tv64 = 0 }; | |
298 | ||
299 | return ktime_add_ns(ktime_zero, ns); | |
300 | } | |
301 | ||
302 | static inline ktime_t ms_to_ktime(u64 ms) | |
303 | { | |
304 | static const ktime_t ktime_zero = { .tv64 = 0 }; | |
305 | ||
306 | return ktime_add_ms(ktime_zero, ms); | |
307 | } | |
308 | ||
309 | # include <linux/timekeeping.h> | |
310 | ||
311 | #endif |