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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_JIFFIES_H
3#define _LINUX_JIFFIES_H
4
5#include <linux/cache.h>
6#include <linux/limits.h>
7#include <linux/math64.h>
8#include <linux/minmax.h>
9#include <linux/types.h>
10#include <linux/time.h>
11#include <linux/timex.h>
12#include <vdso/jiffies.h>
13#include <asm/param.h> /* for HZ */
14#include <generated/timeconst.h>
15
16/*
17 * The following defines establish the engineering parameters of the PLL
18 * model. The HZ variable establishes the timer interrupt frequency, 100 Hz
19 * for the SunOS kernel, 256 Hz for the Ultrix kernel and 1024 Hz for the
20 * OSF/1 kernel. The SHIFT_HZ define expresses the same value as the
21 * nearest power of two in order to avoid hardware multiply operations.
22 */
23#if HZ >= 12 && HZ < 24
24# define SHIFT_HZ 4
25#elif HZ >= 24 && HZ < 48
26# define SHIFT_HZ 5
27#elif HZ >= 48 && HZ < 96
28# define SHIFT_HZ 6
29#elif HZ >= 96 && HZ < 192
30# define SHIFT_HZ 7
31#elif HZ >= 192 && HZ < 384
32# define SHIFT_HZ 8
33#elif HZ >= 384 && HZ < 768
34# define SHIFT_HZ 9
35#elif HZ >= 768 && HZ < 1536
36# define SHIFT_HZ 10
37#elif HZ >= 1536 && HZ < 3072
38# define SHIFT_HZ 11
39#elif HZ >= 3072 && HZ < 6144
40# define SHIFT_HZ 12
41#elif HZ >= 6144 && HZ < 12288
42# define SHIFT_HZ 13
43#else
44# error Invalid value of HZ.
45#endif
46
47/* Suppose we want to divide two numbers NOM and DEN: NOM/DEN, then we can
48 * improve accuracy by shifting LSH bits, hence calculating:
49 * (NOM << LSH) / DEN
50 * This however means trouble for large NOM, because (NOM << LSH) may no
51 * longer fit in 32 bits. The following way of calculating this gives us
52 * some slack, under the following conditions:
53 * - (NOM / DEN) fits in (32 - LSH) bits.
54 * - (NOM % DEN) fits in (32 - LSH) bits.
55 */
56#define SH_DIV(NOM,DEN,LSH) ( (((NOM) / (DEN)) << (LSH)) \
57 + ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN))
58
59/* LATCH is used in the interval timer and ftape setup. */
60#define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */
61
62extern void register_refined_jiffies(long clock_tick_rate);
63
64/* TICK_USEC is the time between ticks in usec */
65#define TICK_USEC ((USEC_PER_SEC + HZ/2) / HZ)
66
67/* USER_TICK_USEC is the time between ticks in usec assuming fake USER_HZ */
68#define USER_TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ)
69
70/*
71 * The 64-bit value is not atomic on 32-bit systems - you MUST NOT read it
72 * without sampling the sequence number in jiffies_lock.
73 * get_jiffies_64() will do this for you as appropriate.
74 *
75 * jiffies and jiffies_64 are at the same address for little-endian systems
76 * and for 64-bit big-endian systems.
77 * On 32-bit big-endian systems, jiffies is the lower 32 bits of jiffies_64
78 * (i.e., at address @jiffies_64 + 4).
79 * See arch/ARCH/kernel/vmlinux.lds.S
80 */
81extern u64 __cacheline_aligned_in_smp jiffies_64;
82extern unsigned long volatile __cacheline_aligned_in_smp jiffies;
83
84#if (BITS_PER_LONG < 64)
85u64 get_jiffies_64(void);
86#else
87/**
88 * get_jiffies_64 - read the 64-bit non-atomic jiffies_64 value
89 *
90 * When BITS_PER_LONG < 64, this uses sequence number sampling using
91 * jiffies_lock to protect the 64-bit read.
92 *
93 * Return: current 64-bit jiffies value
94 */
95static inline u64 get_jiffies_64(void)
96{
97 return (u64)jiffies;
98}
99#endif
100
101/**
102 * DOC: General information about time_* inlines
103 *
104 * These inlines deal with timer wrapping correctly. You are strongly encouraged
105 * to use them:
106 *
107 * #. Because people otherwise forget
108 * #. Because if the timer wrap changes in future you won't have to alter your
109 * driver code.
110 */
111
112/**
113 * time_after - returns true if the time a is after time b.
114 * @a: first comparable as unsigned long
115 * @b: second comparable as unsigned long
116 *
117 * Do this with "<0" and ">=0" to only test the sign of the result. A
118 * good compiler would generate better code (and a really good compiler
119 * wouldn't care). Gcc is currently neither.
120 *
121 * Return: %true is time a is after time b, otherwise %false.
122 */
123#define time_after(a,b) \
124 (typecheck(unsigned long, a) && \
125 typecheck(unsigned long, b) && \
126 ((long)((b) - (a)) < 0))
127/**
128 * time_before - returns true if the time a is before time b.
129 * @a: first comparable as unsigned long
130 * @b: second comparable as unsigned long
131 *
132 * Return: %true is time a is before time b, otherwise %false.
133 */
134#define time_before(a,b) time_after(b,a)
135
136/**
137 * time_after_eq - returns true if the time a is after or the same as time b.
138 * @a: first comparable as unsigned long
139 * @b: second comparable as unsigned long
140 *
141 * Return: %true is time a is after or the same as time b, otherwise %false.
142 */
143#define time_after_eq(a,b) \
144 (typecheck(unsigned long, a) && \
145 typecheck(unsigned long, b) && \
146 ((long)((a) - (b)) >= 0))
147/**
148 * time_before_eq - returns true if the time a is before or the same as time b.
149 * @a: first comparable as unsigned long
150 * @b: second comparable as unsigned long
151 *
152 * Return: %true is time a is before or the same as time b, otherwise %false.
153 */
154#define time_before_eq(a,b) time_after_eq(b,a)
155
156/**
157 * time_in_range - Calculate whether a is in the range of [b, c].
158 * @a: time to test
159 * @b: beginning of the range
160 * @c: end of the range
161 *
162 * Return: %true is time a is in the range [b, c], otherwise %false.
163 */
164#define time_in_range(a,b,c) \
165 (time_after_eq(a,b) && \
166 time_before_eq(a,c))
167
168/**
169 * time_in_range_open - Calculate whether a is in the range of [b, c).
170 * @a: time to test
171 * @b: beginning of the range
172 * @c: end of the range
173 *
174 * Return: %true is time a is in the range [b, c), otherwise %false.
175 */
176#define time_in_range_open(a,b,c) \
177 (time_after_eq(a,b) && \
178 time_before(a,c))
179
180/* Same as above, but does so with platform independent 64bit types.
181 * These must be used when utilizing jiffies_64 (i.e. return value of
182 * get_jiffies_64()). */
183
184/**
185 * time_after64 - returns true if the time a is after time b.
186 * @a: first comparable as __u64
187 * @b: second comparable as __u64
188 *
189 * This must be used when utilizing jiffies_64 (i.e. return value of
190 * get_jiffies_64()).
191 *
192 * Return: %true is time a is after time b, otherwise %false.
193 */
194#define time_after64(a,b) \
195 (typecheck(__u64, a) && \
196 typecheck(__u64, b) && \
197 ((__s64)((b) - (a)) < 0))
198/**
199 * time_before64 - returns true if the time a is before time b.
200 * @a: first comparable as __u64
201 * @b: second comparable as __u64
202 *
203 * This must be used when utilizing jiffies_64 (i.e. return value of
204 * get_jiffies_64()).
205 *
206 * Return: %true is time a is before time b, otherwise %false.
207 */
208#define time_before64(a,b) time_after64(b,a)
209
210/**
211 * time_after_eq64 - returns true if the time a is after or the same as time b.
212 * @a: first comparable as __u64
213 * @b: second comparable as __u64
214 *
215 * This must be used when utilizing jiffies_64 (i.e. return value of
216 * get_jiffies_64()).
217 *
218 * Return: %true is time a is after or the same as time b, otherwise %false.
219 */
220#define time_after_eq64(a,b) \
221 (typecheck(__u64, a) && \
222 typecheck(__u64, b) && \
223 ((__s64)((a) - (b)) >= 0))
224/**
225 * time_before_eq64 - returns true if the time a is before or the same as time b.
226 * @a: first comparable as __u64
227 * @b: second comparable as __u64
228 *
229 * This must be used when utilizing jiffies_64 (i.e. return value of
230 * get_jiffies_64()).
231 *
232 * Return: %true is time a is before or the same as time b, otherwise %false.
233 */
234#define time_before_eq64(a,b) time_after_eq64(b,a)
235
236/**
237 * time_in_range64 - Calculate whether a is in the range of [b, c].
238 * @a: time to test
239 * @b: beginning of the range
240 * @c: end of the range
241 *
242 * Return: %true is time a is in the range [b, c], otherwise %false.
243 */
244#define time_in_range64(a, b, c) \
245 (time_after_eq64(a, b) && \
246 time_before_eq64(a, c))
247
248/*
249 * These eight macros compare jiffies[_64] and 'a' for convenience.
250 */
251
252/**
253 * time_is_before_jiffies - return true if a is before jiffies
254 * @a: time (unsigned long) to compare to jiffies
255 *
256 * Return: %true is time a is before jiffies, otherwise %false.
257 */
258#define time_is_before_jiffies(a) time_after(jiffies, a)
259/**
260 * time_is_before_jiffies64 - return true if a is before jiffies_64
261 * @a: time (__u64) to compare to jiffies_64
262 *
263 * Return: %true is time a is before jiffies_64, otherwise %false.
264 */
265#define time_is_before_jiffies64(a) time_after64(get_jiffies_64(), a)
266
267/**
268 * time_is_after_jiffies - return true if a is after jiffies
269 * @a: time (unsigned long) to compare to jiffies
270 *
271 * Return: %true is time a is after jiffies, otherwise %false.
272 */
273#define time_is_after_jiffies(a) time_before(jiffies, a)
274/**
275 * time_is_after_jiffies64 - return true if a is after jiffies_64
276 * @a: time (__u64) to compare to jiffies_64
277 *
278 * Return: %true is time a is after jiffies_64, otherwise %false.
279 */
280#define time_is_after_jiffies64(a) time_before64(get_jiffies_64(), a)
281
282/**
283 * time_is_before_eq_jiffies - return true if a is before or equal to jiffies
284 * @a: time (unsigned long) to compare to jiffies
285 *
286 * Return: %true is time a is before or the same as jiffies, otherwise %false.
287 */
288#define time_is_before_eq_jiffies(a) time_after_eq(jiffies, a)
289/**
290 * time_is_before_eq_jiffies64 - return true if a is before or equal to jiffies_64
291 * @a: time (__u64) to compare to jiffies_64
292 *
293 * Return: %true is time a is before or the same jiffies_64, otherwise %false.
294 */
295#define time_is_before_eq_jiffies64(a) time_after_eq64(get_jiffies_64(), a)
296
297/**
298 * time_is_after_eq_jiffies - return true if a is after or equal to jiffies
299 * @a: time (unsigned long) to compare to jiffies
300 *
301 * Return: %true is time a is after or the same as jiffies, otherwise %false.
302 */
303#define time_is_after_eq_jiffies(a) time_before_eq(jiffies, a)
304/**
305 * time_is_after_eq_jiffies64 - return true if a is after or equal to jiffies_64
306 * @a: time (__u64) to compare to jiffies_64
307 *
308 * Return: %true is time a is after or the same as jiffies_64, otherwise %false.
309 */
310#define time_is_after_eq_jiffies64(a) time_before_eq64(get_jiffies_64(), a)
311
312/*
313 * Have the 32-bit jiffies value wrap 5 minutes after boot
314 * so jiffies wrap bugs show up earlier.
315 */
316#define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ))
317
318/*
319 * Change timeval to jiffies, trying to avoid the
320 * most obvious overflows..
321 *
322 * And some not so obvious.
323 *
324 * Note that we don't want to return LONG_MAX, because
325 * for various timeout reasons we often end up having
326 * to wait "jiffies+1" in order to guarantee that we wait
327 * at _least_ "jiffies" - so "jiffies+1" had better still
328 * be positive.
329 */
330#define MAX_JIFFY_OFFSET ((LONG_MAX >> 1)-1)
331
332extern unsigned long preset_lpj;
333
334/*
335 * We want to do realistic conversions of time so we need to use the same
336 * values the update wall clock code uses as the jiffies size. This value
337 * is: TICK_NSEC (which is defined in timex.h). This
338 * is a constant and is in nanoseconds. We will use scaled math
339 * with a set of scales defined here as SEC_JIFFIE_SC, USEC_JIFFIE_SC and
340 * NSEC_JIFFIE_SC. Note that these defines contain nothing but
341 * constants and so are computed at compile time. SHIFT_HZ (computed in
342 * timex.h) adjusts the scaling for different HZ values.
343
344 * Scaled math??? What is that?
345 *
346 * Scaled math is a way to do integer math on values that would,
347 * otherwise, either overflow, underflow, or cause undesired div
348 * instructions to appear in the execution path. In short, we "scale"
349 * up the operands so they take more bits (more precision, less
350 * underflow), do the desired operation and then "scale" the result back
351 * by the same amount. If we do the scaling by shifting we avoid the
352 * costly mpy and the dastardly div instructions.
353
354 * Suppose, for example, we want to convert from seconds to jiffies
355 * where jiffies is defined in nanoseconds as NSEC_PER_JIFFIE. The
356 * simple math is: jiff = (sec * NSEC_PER_SEC) / NSEC_PER_JIFFIE; We
357 * observe that (NSEC_PER_SEC / NSEC_PER_JIFFIE) is a constant which we
358 * might calculate at compile time, however, the result will only have
359 * about 3-4 bits of precision (less for smaller values of HZ).
360 *
361 * So, we scale as follows:
362 * jiff = (sec) * (NSEC_PER_SEC / NSEC_PER_JIFFIE);
363 * jiff = ((sec) * ((NSEC_PER_SEC * SCALE)/ NSEC_PER_JIFFIE)) / SCALE;
364 * Then we make SCALE a power of two so:
365 * jiff = ((sec) * ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) >> SCALE;
366 * Now we define:
367 * #define SEC_CONV = ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE))
368 * jiff = (sec * SEC_CONV) >> SCALE;
369 *
370 * Often the math we use will expand beyond 32-bits so we tell C how to
371 * do this and pass the 64-bit result of the mpy through the ">> SCALE"
372 * which should take the result back to 32-bits. We want this expansion
373 * to capture as much precision as possible. At the same time we don't
374 * want to overflow so we pick the SCALE to avoid this. In this file,
375 * that means using a different scale for each range of HZ values (as
376 * defined in timex.h).
377 *
378 * For those who want to know, gcc will give a 64-bit result from a "*"
379 * operator if the result is a long long AND at least one of the
380 * operands is cast to long long (usually just prior to the "*" so as
381 * not to confuse it into thinking it really has a 64-bit operand,
382 * which, buy the way, it can do, but it takes more code and at least 2
383 * mpys).
384
385 * We also need to be aware that one second in nanoseconds is only a
386 * couple of bits away from overflowing a 32-bit word, so we MUST use
387 * 64-bits to get the full range time in nanoseconds.
388
389 */
390
391/*
392 * Here are the scales we will use. One for seconds, nanoseconds and
393 * microseconds.
394 *
395 * Within the limits of cpp we do a rough cut at the SEC_JIFFIE_SC and
396 * check if the sign bit is set. If not, we bump the shift count by 1.
397 * (Gets an extra bit of precision where we can use it.)
398 * We know it is set for HZ = 1024 and HZ = 100 not for 1000.
399 * Haven't tested others.
400
401 * Limits of cpp (for #if expressions) only long (no long long), but
402 * then we only need the most signicant bit.
403 */
404
405#define SEC_JIFFIE_SC (31 - SHIFT_HZ)
406#if !((((NSEC_PER_SEC << 2) / TICK_NSEC) << (SEC_JIFFIE_SC - 2)) & 0x80000000)
407#undef SEC_JIFFIE_SC
408#define SEC_JIFFIE_SC (32 - SHIFT_HZ)
409#endif
410#define NSEC_JIFFIE_SC (SEC_JIFFIE_SC + 29)
411#define SEC_CONVERSION ((unsigned long)((((u64)NSEC_PER_SEC << SEC_JIFFIE_SC) +\
412 TICK_NSEC -1) / (u64)TICK_NSEC))
413
414#define NSEC_CONVERSION ((unsigned long)((((u64)1 << NSEC_JIFFIE_SC) +\
415 TICK_NSEC -1) / (u64)TICK_NSEC))
416/*
417 * The maximum jiffy value is (MAX_INT >> 1). Here we translate that
418 * into seconds. The 64-bit case will overflow if we are not careful,
419 * so use the messy SH_DIV macro to do it. Still all constants.
420 */
421#if BITS_PER_LONG < 64
422# define MAX_SEC_IN_JIFFIES \
423 (long)((u64)((u64)MAX_JIFFY_OFFSET * TICK_NSEC) / NSEC_PER_SEC)
424#else /* take care of overflow on 64-bit machines */
425# define MAX_SEC_IN_JIFFIES \
426 (SH_DIV((MAX_JIFFY_OFFSET >> SEC_JIFFIE_SC) * TICK_NSEC, NSEC_PER_SEC, 1) - 1)
427
428#endif
429
430/*
431 * Convert various time units to each other:
432 */
433
434#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
435/**
436 * jiffies_to_msecs - Convert jiffies to milliseconds
437 * @j: jiffies value
438 *
439 * This inline version takes care of HZ in {100,250,1000}.
440 *
441 * Return: milliseconds value
442 */
443static inline unsigned int jiffies_to_msecs(const unsigned long j)
444{
445 return (MSEC_PER_SEC / HZ) * j;
446}
447#else
448unsigned int jiffies_to_msecs(const unsigned long j);
449#endif
450
451#if !(USEC_PER_SEC % HZ)
452/**
453 * jiffies_to_usecs - Convert jiffies to microseconds
454 * @j: jiffies value
455 *
456 * Return: microseconds value
457 */
458static inline unsigned int jiffies_to_usecs(const unsigned long j)
459{
460 /*
461 * Hz usually doesn't go much further MSEC_PER_SEC.
462 * jiffies_to_usecs() and usecs_to_jiffies() depend on that.
463 */
464 BUILD_BUG_ON(HZ > USEC_PER_SEC);
465
466 return (USEC_PER_SEC / HZ) * j;
467}
468#else
469unsigned int jiffies_to_usecs(const unsigned long j);
470#endif
471
472/**
473 * jiffies_to_nsecs - Convert jiffies to nanoseconds
474 * @j: jiffies value
475 *
476 * Return: nanoseconds value
477 */
478static inline u64 jiffies_to_nsecs(const unsigned long j)
479{
480 return (u64)jiffies_to_usecs(j) * NSEC_PER_USEC;
481}
482
483extern u64 jiffies64_to_nsecs(u64 j);
484extern u64 jiffies64_to_msecs(u64 j);
485
486extern unsigned long __msecs_to_jiffies(const unsigned int m);
487#if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ)
488/*
489 * HZ is equal to or smaller than 1000, and 1000 is a nice round
490 * multiple of HZ, divide with the factor between them, but round
491 * upwards:
492 */
493static inline unsigned long _msecs_to_jiffies(const unsigned int m)
494{
495 return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ);
496}
497#elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC)
498/*
499 * HZ is larger than 1000, and HZ is a nice round multiple of 1000 -
500 * simply multiply with the factor between them.
501 *
502 * But first make sure the multiplication result cannot overflow:
503 */
504static inline unsigned long _msecs_to_jiffies(const unsigned int m)
505{
506 if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET))
507 return MAX_JIFFY_OFFSET;
508 return m * (HZ / MSEC_PER_SEC);
509}
510#else
511/*
512 * Generic case - multiply, round and divide. But first check that if
513 * we are doing a net multiplication, that we wouldn't overflow:
514 */
515static inline unsigned long _msecs_to_jiffies(const unsigned int m)
516{
517 if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET))
518 return MAX_JIFFY_OFFSET;
519
520 return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) >> MSEC_TO_HZ_SHR32;
521}
522#endif
523/**
524 * msecs_to_jiffies: - convert milliseconds to jiffies
525 * @m: time in milliseconds
526 *
527 * conversion is done as follows:
528 *
529 * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET)
530 *
531 * - 'too large' values [that would result in larger than
532 * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too.
533 *
534 * - all other values are converted to jiffies by either multiplying
535 * the input value by a factor or dividing it with a factor and
536 * handling any 32-bit overflows.
537 * for the details see _msecs_to_jiffies()
538 *
539 * msecs_to_jiffies() checks for the passed in value being a constant
540 * via __builtin_constant_p() allowing gcc to eliminate most of the
541 * code. __msecs_to_jiffies() is called if the value passed does not
542 * allow constant folding and the actual conversion must be done at
543 * runtime.
544 * The HZ range specific helpers _msecs_to_jiffies() are called both
545 * directly here and from __msecs_to_jiffies() in the case where
546 * constant folding is not possible.
547 *
548 * Return: jiffies value
549 */
550static __always_inline unsigned long msecs_to_jiffies(const unsigned int m)
551{
552 if (__builtin_constant_p(m)) {
553 if ((int)m < 0)
554 return MAX_JIFFY_OFFSET;
555 return _msecs_to_jiffies(m);
556 } else {
557 return __msecs_to_jiffies(m);
558 }
559}
560
561/**
562 * secs_to_jiffies: - convert seconds to jiffies
563 * @_secs: time in seconds
564 *
565 * Conversion is done by simple multiplication with HZ
566 *
567 * secs_to_jiffies() is defined as a macro rather than a static inline
568 * function so it can be used in static initializers.
569 *
570 * Return: jiffies value
571 */
572#define secs_to_jiffies(_secs) (unsigned long)((_secs) * HZ)
573
574extern unsigned long __usecs_to_jiffies(const unsigned int u);
575#if !(USEC_PER_SEC % HZ)
576static inline unsigned long _usecs_to_jiffies(const unsigned int u)
577{
578 return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ);
579}
580#else
581static inline unsigned long _usecs_to_jiffies(const unsigned int u)
582{
583 return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32)
584 >> USEC_TO_HZ_SHR32;
585}
586#endif
587
588/**
589 * usecs_to_jiffies: - convert microseconds to jiffies
590 * @u: time in microseconds
591 *
592 * conversion is done as follows:
593 *
594 * - 'too large' values [that would result in larger than
595 * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too.
596 *
597 * - all other values are converted to jiffies by either multiplying
598 * the input value by a factor or dividing it with a factor and
599 * handling any 32-bit overflows as for msecs_to_jiffies.
600 *
601 * usecs_to_jiffies() checks for the passed in value being a constant
602 * via __builtin_constant_p() allowing gcc to eliminate most of the
603 * code. __usecs_to_jiffies() is called if the value passed does not
604 * allow constant folding and the actual conversion must be done at
605 * runtime.
606 * The HZ range specific helpers _usecs_to_jiffies() are called both
607 * directly here and from __msecs_to_jiffies() in the case where
608 * constant folding is not possible.
609 *
610 * Return: jiffies value
611 */
612static __always_inline unsigned long usecs_to_jiffies(const unsigned int u)
613{
614 if (__builtin_constant_p(u)) {
615 if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET))
616 return MAX_JIFFY_OFFSET;
617 return _usecs_to_jiffies(u);
618 } else {
619 return __usecs_to_jiffies(u);
620 }
621}
622
623extern unsigned long timespec64_to_jiffies(const struct timespec64 *value);
624extern void jiffies_to_timespec64(const unsigned long jiffies,
625 struct timespec64 *value);
626extern clock_t jiffies_to_clock_t(unsigned long x);
627
628static inline clock_t jiffies_delta_to_clock_t(long delta)
629{
630 return jiffies_to_clock_t(max(0L, delta));
631}
632
633static inline unsigned int jiffies_delta_to_msecs(long delta)
634{
635 return jiffies_to_msecs(max(0L, delta));
636}
637
638extern unsigned long clock_t_to_jiffies(unsigned long x);
639extern u64 jiffies_64_to_clock_t(u64 x);
640extern u64 nsec_to_clock_t(u64 x);
641extern u64 nsecs_to_jiffies64(u64 n);
642extern unsigned long nsecs_to_jiffies(u64 n);
643
644#define TIMESTAMP_SIZE 30
645
646struct ctl_table;
647int proc_dointvec_jiffies(const struct ctl_table *table, int dir, void *buffer,
648 size_t *lenp, loff_t *ppos);
649int proc_dointvec_ms_jiffies_minmax(const struct ctl_table *table, int dir,
650 void *buffer, size_t *lenp, loff_t *ppos);
651int proc_dointvec_userhz_jiffies(const struct ctl_table *table, int dir,
652 void *buffer, size_t *lenp, loff_t *ppos);
653int proc_dointvec_ms_jiffies(const struct ctl_table *table, int dir, void *buffer,
654 size_t *lenp, loff_t *ppos);
655int proc_doulongvec_ms_jiffies_minmax(const struct ctl_table *table, int dir,
656 void *buffer, size_t *lenp, loff_t *ppos);
657
658#endif