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