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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef _LINUX_JIFFIES_H |
3 | #define _LINUX_JIFFIES_H | |
4 | ||
7c30f352 | 5 | #include <linux/cache.h> |
b296a6d5 | 6 | #include <linux/limits.h> |
f8bd2258 | 7 | #include <linux/math64.h> |
b296a6d5 | 8 | #include <linux/minmax.h> |
1da177e4 LT |
9 | #include <linux/types.h> |
10 | #include <linux/time.h> | |
11 | #include <linux/timex.h> | |
97b01d2e | 12 | #include <vdso/jiffies.h> |
1da177e4 | 13 | #include <asm/param.h> /* for HZ */ |
ca42aaf0 | 14 | #include <generated/timeconst.h> |
1da177e4 LT |
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 | |
e118adef PM |
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 | |
1da177e4 | 43 | #else |
37679011 | 44 | # error Invalid value of HZ. |
1da177e4 LT |
45 | #endif |
46 | ||
25985edc | 47 | /* Suppose we want to divide two numbers NOM and DEN: NOM/DEN, then we can |
1da177e4 LT |
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 | */ | |
0d94df56 UZ |
56 | #define SH_DIV(NOM,DEN,LSH) ( (((NOM) / (DEN)) << (LSH)) \ |
57 | + ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN)) | |
1da177e4 | 58 | |
a7ea3bbf | 59 | /* LATCH is used in the interval timer and ftape setup. */ |
015a830d | 60 | #define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */ |
a7ea3bbf | 61 | |
b3c869d3 | 62 | extern int register_refined_jiffies(long clock_tick_rate); |
1da177e4 | 63 | |
efefc977 RW |
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) | |
1da177e4 | 69 | |
60b0a8c3 MK |
70 | #ifndef __jiffy_arch_data |
71 | #define __jiffy_arch_data | |
72 | #endif | |
73 | ||
1da177e4 | 74 | /* |
6d07a31f | 75 | * The 64-bit value is not atomic on 32-bit systems - you MUST NOT read it |
d6ad4187 | 76 | * without sampling the sequence number in jiffies_lock. |
1da177e4 | 77 | * get_jiffies_64() will do this for you as appropriate. |
6d07a31f RD |
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 | |
1da177e4 | 84 | */ |
7c30f352 | 85 | extern u64 __cacheline_aligned_in_smp jiffies_64; |
60b0a8c3 | 86 | extern unsigned long volatile __cacheline_aligned_in_smp __jiffy_arch_data jiffies; |
1da177e4 LT |
87 | |
88 | #if (BITS_PER_LONG < 64) | |
89 | u64 get_jiffies_64(void); | |
90 | #else | |
6d07a31f RD |
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 | */ | |
1da177e4 LT |
99 | static inline u64 get_jiffies_64(void) |
100 | { | |
101 | return (u64)jiffies; | |
102 | } | |
103 | #endif | |
104 | ||
c92a7eb6 AMB |
105 | /** |
106 | * DOC: General information about time_* inlines | |
107 | * | |
108 | * These inlines deal with timer wrapping correctly. You are strongly encouraged | |
109 | * to use them: | |
110 | * | |
111 | * #. Because people otherwise forget | |
112 | * #. Because if the timer wrap changes in future you won't have to alter your | |
113 | * driver code. | |
6d07a31f RD |
114 | */ |
115 | ||
116 | /** | |
117 | * time_after - returns true if the time a is after time b. | |
118 | * @a: first comparable as unsigned long | |
119 | * @b: second comparable as unsigned long | |
1da177e4 LT |
120 | * |
121 | * Do this with "<0" and ">=0" to only test the sign of the result. A | |
122 | * good compiler would generate better code (and a really good compiler | |
123 | * wouldn't care). Gcc is currently neither. | |
6d07a31f RD |
124 | * |
125 | * Return: %true is time a is after time b, otherwise %false. | |
1da177e4 LT |
126 | */ |
127 | #define time_after(a,b) \ | |
128 | (typecheck(unsigned long, a) && \ | |
129 | typecheck(unsigned long, b) && \ | |
5a581b36 | 130 | ((long)((b) - (a)) < 0)) |
6d07a31f RD |
131 | /** |
132 | * time_before - returns true if the time a is before time b. | |
133 | * @a: first comparable as unsigned long | |
134 | * @b: second comparable as unsigned long | |
135 | * | |
136 | * Return: %true is time a is before time b, otherwise %false. | |
137 | */ | |
1da177e4 LT |
138 | #define time_before(a,b) time_after(b,a) |
139 | ||
6d07a31f RD |
140 | /** |
141 | * time_after_eq - returns true if the time a is after or the same as time b. | |
142 | * @a: first comparable as unsigned long | |
143 | * @b: second comparable as unsigned long | |
144 | * | |
145 | * Return: %true is time a is after or the same as time b, otherwise %false. | |
146 | */ | |
1da177e4 LT |
147 | #define time_after_eq(a,b) \ |
148 | (typecheck(unsigned long, a) && \ | |
149 | typecheck(unsigned long, b) && \ | |
5a581b36 | 150 | ((long)((a) - (b)) >= 0)) |
6d07a31f RD |
151 | /** |
152 | * time_before_eq - returns true if the time a is before or the same as time b. | |
153 | * @a: first comparable as unsigned long | |
154 | * @b: second comparable as unsigned long | |
155 | * | |
156 | * Return: %true is time a is before or the same as time b, otherwise %false. | |
157 | */ | |
1da177e4 LT |
158 | #define time_before_eq(a,b) time_after_eq(b,a) |
159 | ||
6d07a31f RD |
160 | /** |
161 | * time_in_range - Calculate whether a is in the range of [b, c]. | |
162 | * @a: time to test | |
163 | * @b: beginning of the range | |
164 | * @c: end of the range | |
165 | * | |
166 | * Return: %true is time a is in the range [b, c], otherwise %false. | |
64672d55 | 167 | */ |
c7e15961 FOL |
168 | #define time_in_range(a,b,c) \ |
169 | (time_after_eq(a,b) && \ | |
170 | time_before_eq(a,c)) | |
171 | ||
6d07a31f RD |
172 | /** |
173 | * time_in_range_open - Calculate whether a is in the range of [b, c). | |
174 | * @a: time to test | |
175 | * @b: beginning of the range | |
176 | * @c: end of the range | |
177 | * | |
178 | * Return: %true is time a is in the range [b, c), otherwise %false. | |
64672d55 PS |
179 | */ |
180 | #define time_in_range_open(a,b,c) \ | |
181 | (time_after_eq(a,b) && \ | |
182 | time_before(a,c)) | |
183 | ||
3b171672 DZ |
184 | /* Same as above, but does so with platform independent 64bit types. |
185 | * These must be used when utilizing jiffies_64 (i.e. return value of | |
6d07a31f RD |
186 | * get_jiffies_64()). */ |
187 | ||
188 | /** | |
189 | * time_after64 - returns true if the time a is after time b. | |
190 | * @a: first comparable as __u64 | |
191 | * @b: second comparable as __u64 | |
192 | * | |
193 | * This must be used when utilizing jiffies_64 (i.e. return value of | |
194 | * get_jiffies_64()). | |
195 | * | |
196 | * Return: %true is time a is after time b, otherwise %false. | |
197 | */ | |
3b171672 DZ |
198 | #define time_after64(a,b) \ |
199 | (typecheck(__u64, a) && \ | |
200 | typecheck(__u64, b) && \ | |
5a581b36 | 201 | ((__s64)((b) - (a)) < 0)) |
6d07a31f RD |
202 | /** |
203 | * time_before64 - returns true if the time a is before time b. | |
204 | * @a: first comparable as __u64 | |
205 | * @b: second comparable as __u64 | |
206 | * | |
207 | * This must be used when utilizing jiffies_64 (i.e. return value of | |
208 | * get_jiffies_64()). | |
209 | * | |
210 | * Return: %true is time a is before time b, otherwise %false. | |
211 | */ | |
3b171672 DZ |
212 | #define time_before64(a,b) time_after64(b,a) |
213 | ||
6d07a31f RD |
214 | /** |
215 | * time_after_eq64 - returns true if the time a is after or the same as time b. | |
216 | * @a: first comparable as __u64 | |
217 | * @b: second comparable as __u64 | |
218 | * | |
219 | * This must be used when utilizing jiffies_64 (i.e. return value of | |
220 | * get_jiffies_64()). | |
221 | * | |
222 | * Return: %true is time a is after or the same as time b, otherwise %false. | |
223 | */ | |
3b171672 DZ |
224 | #define time_after_eq64(a,b) \ |
225 | (typecheck(__u64, a) && \ | |
226 | typecheck(__u64, b) && \ | |
5a581b36 | 227 | ((__s64)((a) - (b)) >= 0)) |
6d07a31f RD |
228 | /** |
229 | * time_before_eq64 - returns true if the time a is before or the same as time b. | |
230 | * @a: first comparable as __u64 | |
231 | * @b: second comparable as __u64 | |
232 | * | |
233 | * This must be used when utilizing jiffies_64 (i.e. return value of | |
234 | * get_jiffies_64()). | |
235 | * | |
236 | * Return: %true is time a is before or the same as time b, otherwise %false. | |
237 | */ | |
3b171672 DZ |
238 | #define time_before_eq64(a,b) time_after_eq64(b,a) |
239 | ||
6d07a31f RD |
240 | /** |
241 | * time_in_range64 - Calculate whether a is in the range of [b, c]. | |
242 | * @a: time to test | |
243 | * @b: beginning of the range | |
244 | * @c: end of the range | |
245 | * | |
246 | * Return: %true is time a is in the range [b, c], otherwise %false. | |
247 | */ | |
1bc2774d ET |
248 | #define time_in_range64(a, b, c) \ |
249 | (time_after_eq64(a, b) && \ | |
250 | time_before_eq64(a, c)) | |
251 | ||
3f34d024 | 252 | /* |
6d07a31f | 253 | * These eight macros compare jiffies[_64] and 'a' for convenience. |
3f34d024 DY |
254 | */ |
255 | ||
6d07a31f RD |
256 | /** |
257 | * time_is_before_jiffies - return true if a is before jiffies | |
258 | * @a: time (unsigned long) to compare to jiffies | |
259 | * | |
260 | * Return: %true is time a is before jiffies, otherwise %false. | |
261 | */ | |
3f34d024 | 262 | #define time_is_before_jiffies(a) time_after(jiffies, a) |
6d07a31f RD |
263 | /** |
264 | * time_is_before_jiffies64 - return true if a is before jiffies_64 | |
265 | * @a: time (__u64) to compare to jiffies_64 | |
266 | * | |
267 | * Return: %true is time a is before jiffies_64, otherwise %false. | |
268 | */ | |
3740dcdf | 269 | #define time_is_before_jiffies64(a) time_after64(get_jiffies_64(), a) |
3f34d024 | 270 | |
6d07a31f RD |
271 | /** |
272 | * time_is_after_jiffies - return true if a is after jiffies | |
273 | * @a: time (unsigned long) to compare to jiffies | |
274 | * | |
275 | * Return: %true is time a is after jiffies, otherwise %false. | |
276 | */ | |
3f34d024 | 277 | #define time_is_after_jiffies(a) time_before(jiffies, a) |
6d07a31f RD |
278 | /** |
279 | * time_is_after_jiffies64 - return true if a is after jiffies_64 | |
280 | * @a: time (__u64) to compare to jiffies_64 | |
281 | * | |
282 | * Return: %true is time a is after jiffies_64, otherwise %false. | |
283 | */ | |
3740dcdf | 284 | #define time_is_after_jiffies64(a) time_before64(get_jiffies_64(), a) |
3f34d024 | 285 | |
6d07a31f RD |
286 | /** |
287 | * time_is_before_eq_jiffies - return true if a is before or equal to jiffies | |
288 | * @a: time (unsigned long) to compare to jiffies | |
289 | * | |
290 | * Return: %true is time a is before or the same as jiffies, otherwise %false. | |
291 | */ | |
3f34d024 | 292 | #define time_is_before_eq_jiffies(a) time_after_eq(jiffies, a) |
6d07a31f RD |
293 | /** |
294 | * time_is_before_eq_jiffies64 - return true if a is before or equal to jiffies_64 | |
295 | * @a: time (__u64) to compare to jiffies_64 | |
296 | * | |
297 | * Return: %true is time a is before or the same jiffies_64, otherwise %false. | |
298 | */ | |
3740dcdf | 299 | #define time_is_before_eq_jiffies64(a) time_after_eq64(get_jiffies_64(), a) |
3f34d024 | 300 | |
6d07a31f RD |
301 | /** |
302 | * time_is_after_eq_jiffies - return true if a is after or equal to jiffies | |
303 | * @a: time (unsigned long) to compare to jiffies | |
304 | * | |
305 | * Return: %true is time a is after or the same as jiffies, otherwise %false. | |
306 | */ | |
3f34d024 | 307 | #define time_is_after_eq_jiffies(a) time_before_eq(jiffies, a) |
6d07a31f RD |
308 | /** |
309 | * time_is_after_eq_jiffies64 - return true if a is after or equal to jiffies_64 | |
310 | * @a: time (__u64) to compare to jiffies_64 | |
311 | * | |
312 | * Return: %true is time a is after or the same as jiffies_64, otherwise %false. | |
313 | */ | |
3740dcdf | 314 | #define time_is_after_eq_jiffies64(a) time_before_eq64(get_jiffies_64(), a) |
3f34d024 | 315 | |
1da177e4 | 316 | /* |
6d07a31f | 317 | * Have the 32-bit jiffies value wrap 5 minutes after boot |
1da177e4 LT |
318 | * so jiffies wrap bugs show up earlier. |
319 | */ | |
320 | #define INITIAL_JIFFIES ((unsigned long)(unsigned int) (-300*HZ)) | |
321 | ||
322 | /* | |
323 | * Change timeval to jiffies, trying to avoid the | |
324 | * most obvious overflows.. | |
325 | * | |
326 | * And some not so obvious. | |
327 | * | |
9f907c01 | 328 | * Note that we don't want to return LONG_MAX, because |
1da177e4 LT |
329 | * for various timeout reasons we often end up having |
330 | * to wait "jiffies+1" in order to guarantee that we wait | |
331 | * at _least_ "jiffies" - so "jiffies+1" had better still | |
332 | * be positive. | |
333 | */ | |
9f907c01 | 334 | #define MAX_JIFFY_OFFSET ((LONG_MAX >> 1)-1) |
1da177e4 | 335 | |
bfe8df3d RD |
336 | extern unsigned long preset_lpj; |
337 | ||
1da177e4 LT |
338 | /* |
339 | * We want to do realistic conversions of time so we need to use the same | |
340 | * values the update wall clock code uses as the jiffies size. This value | |
341 | * is: TICK_NSEC (which is defined in timex.h). This | |
3eb05676 | 342 | * is a constant and is in nanoseconds. We will use scaled math |
1da177e4 LT |
343 | * with a set of scales defined here as SEC_JIFFIE_SC, USEC_JIFFIE_SC and |
344 | * NSEC_JIFFIE_SC. Note that these defines contain nothing but | |
345 | * constants and so are computed at compile time. SHIFT_HZ (computed in | |
346 | * timex.h) adjusts the scaling for different HZ values. | |
347 | ||
348 | * Scaled math??? What is that? | |
349 | * | |
350 | * Scaled math is a way to do integer math on values that would, | |
351 | * otherwise, either overflow, underflow, or cause undesired div | |
352 | * instructions to appear in the execution path. In short, we "scale" | |
353 | * up the operands so they take more bits (more precision, less | |
354 | * underflow), do the desired operation and then "scale" the result back | |
355 | * by the same amount. If we do the scaling by shifting we avoid the | |
356 | * costly mpy and the dastardly div instructions. | |
357 | ||
358 | * Suppose, for example, we want to convert from seconds to jiffies | |
359 | * where jiffies is defined in nanoseconds as NSEC_PER_JIFFIE. The | |
360 | * simple math is: jiff = (sec * NSEC_PER_SEC) / NSEC_PER_JIFFIE; We | |
361 | * observe that (NSEC_PER_SEC / NSEC_PER_JIFFIE) is a constant which we | |
362 | * might calculate at compile time, however, the result will only have | |
363 | * about 3-4 bits of precision (less for smaller values of HZ). | |
364 | * | |
365 | * So, we scale as follows: | |
366 | * jiff = (sec) * (NSEC_PER_SEC / NSEC_PER_JIFFIE); | |
367 | * jiff = ((sec) * ((NSEC_PER_SEC * SCALE)/ NSEC_PER_JIFFIE)) / SCALE; | |
368 | * Then we make SCALE a power of two so: | |
369 | * jiff = ((sec) * ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) >> SCALE; | |
370 | * Now we define: | |
371 | * #define SEC_CONV = ((NSEC_PER_SEC << SCALE)/ NSEC_PER_JIFFIE)) | |
372 | * jiff = (sec * SEC_CONV) >> SCALE; | |
373 | * | |
374 | * Often the math we use will expand beyond 32-bits so we tell C how to | |
375 | * do this and pass the 64-bit result of the mpy through the ">> SCALE" | |
376 | * which should take the result back to 32-bits. We want this expansion | |
377 | * to capture as much precision as possible. At the same time we don't | |
378 | * want to overflow so we pick the SCALE to avoid this. In this file, | |
379 | * that means using a different scale for each range of HZ values (as | |
380 | * defined in timex.h). | |
381 | * | |
382 | * For those who want to know, gcc will give a 64-bit result from a "*" | |
383 | * operator if the result is a long long AND at least one of the | |
384 | * operands is cast to long long (usually just prior to the "*" so as | |
385 | * not to confuse it into thinking it really has a 64-bit operand, | |
3eb05676 | 386 | * which, buy the way, it can do, but it takes more code and at least 2 |
1da177e4 LT |
387 | * mpys). |
388 | ||
389 | * We also need to be aware that one second in nanoseconds is only a | |
390 | * couple of bits away from overflowing a 32-bit word, so we MUST use | |
391 | * 64-bits to get the full range time in nanoseconds. | |
392 | ||
393 | */ | |
394 | ||
395 | /* | |
396 | * Here are the scales we will use. One for seconds, nanoseconds and | |
397 | * microseconds. | |
398 | * | |
399 | * Within the limits of cpp we do a rough cut at the SEC_JIFFIE_SC and | |
400 | * check if the sign bit is set. If not, we bump the shift count by 1. | |
401 | * (Gets an extra bit of precision where we can use it.) | |
402 | * We know it is set for HZ = 1024 and HZ = 100 not for 1000. | |
403 | * Haven't tested others. | |
404 | ||
405 | * Limits of cpp (for #if expressions) only long (no long long), but | |
406 | * then we only need the most signicant bit. | |
407 | */ | |
408 | ||
409 | #define SEC_JIFFIE_SC (31 - SHIFT_HZ) | |
410 | #if !((((NSEC_PER_SEC << 2) / TICK_NSEC) << (SEC_JIFFIE_SC - 2)) & 0x80000000) | |
411 | #undef SEC_JIFFIE_SC | |
412 | #define SEC_JIFFIE_SC (32 - SHIFT_HZ) | |
413 | #endif | |
414 | #define NSEC_JIFFIE_SC (SEC_JIFFIE_SC + 29) | |
1da177e4 LT |
415 | #define SEC_CONVERSION ((unsigned long)((((u64)NSEC_PER_SEC << SEC_JIFFIE_SC) +\ |
416 | TICK_NSEC -1) / (u64)TICK_NSEC)) | |
417 | ||
418 | #define NSEC_CONVERSION ((unsigned long)((((u64)1 << NSEC_JIFFIE_SC) +\ | |
419 | TICK_NSEC -1) / (u64)TICK_NSEC)) | |
1da177e4 LT |
420 | /* |
421 | * The maximum jiffie value is (MAX_INT >> 1). Here we translate that | |
422 | * into seconds. The 64-bit case will overflow if we are not careful, | |
423 | * so use the messy SH_DIV macro to do it. Still all constants. | |
424 | */ | |
425 | #if BITS_PER_LONG < 64 | |
426 | # define MAX_SEC_IN_JIFFIES \ | |
427 | (long)((u64)((u64)MAX_JIFFY_OFFSET * TICK_NSEC) / NSEC_PER_SEC) | |
6d07a31f | 428 | #else /* take care of overflow on 64-bit machines */ |
1da177e4 LT |
429 | # define MAX_SEC_IN_JIFFIES \ |
430 | (SH_DIV((MAX_JIFFY_OFFSET >> SEC_JIFFIE_SC) * TICK_NSEC, NSEC_PER_SEC, 1) - 1) | |
431 | ||
432 | #endif | |
433 | ||
434 | /* | |
8b9365d7 | 435 | * Convert various time units to each other: |
1da177e4 | 436 | */ |
8b9365d7 IM |
437 | extern unsigned int jiffies_to_msecs(const unsigned long j); |
438 | extern unsigned int jiffies_to_usecs(const unsigned long j); | |
8fe8ff09 | 439 | |
6d07a31f RD |
440 | /** |
441 | * jiffies_to_nsecs - Convert jiffies to nanoseconds | |
442 | * @j: jiffies value | |
443 | * | |
444 | * Return: nanoseconds value | |
445 | */ | |
8fe8ff09 KH |
446 | static inline u64 jiffies_to_nsecs(const unsigned long j) |
447 | { | |
448 | return (u64)jiffies_to_usecs(j) * NSEC_PER_USEC; | |
449 | } | |
450 | ||
07e5f5e3 | 451 | extern u64 jiffies64_to_nsecs(u64 j); |
3b15d09f | 452 | extern u64 jiffies64_to_msecs(u64 j); |
07e5f5e3 | 453 | |
ca42aaf0 NMG |
454 | extern unsigned long __msecs_to_jiffies(const unsigned int m); |
455 | #if HZ <= MSEC_PER_SEC && !(MSEC_PER_SEC % HZ) | |
456 | /* | |
457 | * HZ is equal to or smaller than 1000, and 1000 is a nice round | |
458 | * multiple of HZ, divide with the factor between them, but round | |
459 | * upwards: | |
460 | */ | |
461 | static inline unsigned long _msecs_to_jiffies(const unsigned int m) | |
462 | { | |
4e3d9cb0 | 463 | return (m + (MSEC_PER_SEC / HZ) - 1) / (MSEC_PER_SEC / HZ); |
ca42aaf0 NMG |
464 | } |
465 | #elif HZ > MSEC_PER_SEC && !(HZ % MSEC_PER_SEC) | |
466 | /* | |
467 | * HZ is larger than 1000, and HZ is a nice round multiple of 1000 - | |
468 | * simply multiply with the factor between them. | |
469 | * | |
470 | * But first make sure the multiplication result cannot overflow: | |
471 | */ | |
472 | static inline unsigned long _msecs_to_jiffies(const unsigned int m) | |
473 | { | |
4e3d9cb0 TG |
474 | if (m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) |
475 | return MAX_JIFFY_OFFSET; | |
476 | return m * (HZ / MSEC_PER_SEC); | |
ca42aaf0 NMG |
477 | } |
478 | #else | |
479 | /* | |
480 | * Generic case - multiply, round and divide. But first check that if | |
481 | * we are doing a net multiplication, that we wouldn't overflow: | |
482 | */ | |
483 | static inline unsigned long _msecs_to_jiffies(const unsigned int m) | |
484 | { | |
4e3d9cb0 TG |
485 | if (HZ > MSEC_PER_SEC && m > jiffies_to_msecs(MAX_JIFFY_OFFSET)) |
486 | return MAX_JIFFY_OFFSET; | |
ca42aaf0 | 487 | |
4e3d9cb0 | 488 | return (MSEC_TO_HZ_MUL32 * m + MSEC_TO_HZ_ADJ32) >> MSEC_TO_HZ_SHR32; |
ca42aaf0 NMG |
489 | } |
490 | #endif | |
491 | /** | |
492 | * msecs_to_jiffies: - convert milliseconds to jiffies | |
493 | * @m: time in milliseconds | |
494 | * | |
495 | * conversion is done as follows: | |
496 | * | |
497 | * - negative values mean 'infinite timeout' (MAX_JIFFY_OFFSET) | |
498 | * | |
499 | * - 'too large' values [that would result in larger than | |
500 | * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. | |
501 | * | |
502 | * - all other values are converted to jiffies by either multiplying | |
503 | * the input value by a factor or dividing it with a factor and | |
504 | * handling any 32-bit overflows. | |
505 | * for the details see __msecs_to_jiffies() | |
506 | * | |
daa67b4b NMG |
507 | * msecs_to_jiffies() checks for the passed in value being a constant |
508 | * via __builtin_constant_p() allowing gcc to eliminate most of the | |
6d07a31f | 509 | * code. __msecs_to_jiffies() is called if the value passed does not |
daa67b4b NMG |
510 | * allow constant folding and the actual conversion must be done at |
511 | * runtime. | |
6d07a31f | 512 | * The HZ range specific helpers _msecs_to_jiffies() are called both |
daa67b4b NMG |
513 | * directly here and from __msecs_to_jiffies() in the case where |
514 | * constant folding is not possible. | |
6d07a31f RD |
515 | * |
516 | * Return: jiffies value | |
ca42aaf0 | 517 | */ |
accd0b9e | 518 | static __always_inline unsigned long msecs_to_jiffies(const unsigned int m) |
ca42aaf0 | 519 | { |
daa67b4b NMG |
520 | if (__builtin_constant_p(m)) { |
521 | if ((int)m < 0) | |
522 | return MAX_JIFFY_OFFSET; | |
523 | return _msecs_to_jiffies(m); | |
524 | } else { | |
525 | return __msecs_to_jiffies(m); | |
526 | } | |
ca42aaf0 NMG |
527 | } |
528 | ||
ae60d6a0 | 529 | extern unsigned long __usecs_to_jiffies(const unsigned int u); |
e0758676 | 530 | #if !(USEC_PER_SEC % HZ) |
ae60d6a0 NMG |
531 | static inline unsigned long _usecs_to_jiffies(const unsigned int u) |
532 | { | |
533 | return (u + (USEC_PER_SEC / HZ) - 1) / (USEC_PER_SEC / HZ); | |
534 | } | |
ae60d6a0 NMG |
535 | #else |
536 | static inline unsigned long _usecs_to_jiffies(const unsigned int u) | |
537 | { | |
538 | return (USEC_TO_HZ_MUL32 * u + USEC_TO_HZ_ADJ32) | |
539 | >> USEC_TO_HZ_SHR32; | |
540 | } | |
541 | #endif | |
542 | ||
c569a23d NMG |
543 | /** |
544 | * usecs_to_jiffies: - convert microseconds to jiffies | |
545 | * @u: time in microseconds | |
546 | * | |
547 | * conversion is done as follows: | |
548 | * | |
549 | * - 'too large' values [that would result in larger than | |
550 | * MAX_JIFFY_OFFSET values] mean 'infinite timeout' too. | |
551 | * | |
552 | * - all other values are converted to jiffies by either multiplying | |
553 | * the input value by a factor or dividing it with a factor and | |
554 | * handling any 32-bit overflows as for msecs_to_jiffies. | |
555 | * | |
556 | * usecs_to_jiffies() checks for the passed in value being a constant | |
557 | * via __builtin_constant_p() allowing gcc to eliminate most of the | |
6d07a31f | 558 | * code. __usecs_to_jiffies() is called if the value passed does not |
c569a23d NMG |
559 | * allow constant folding and the actual conversion must be done at |
560 | * runtime. | |
6d07a31f | 561 | * The HZ range specific helpers _usecs_to_jiffies() are called both |
c569a23d NMG |
562 | * directly here and from __msecs_to_jiffies() in the case where |
563 | * constant folding is not possible. | |
6d07a31f RD |
564 | * |
565 | * Return: jiffies value | |
c569a23d | 566 | */ |
accd0b9e | 567 | static __always_inline unsigned long usecs_to_jiffies(const unsigned int u) |
ae60d6a0 | 568 | { |
c569a23d NMG |
569 | if (__builtin_constant_p(u)) { |
570 | if (u > jiffies_to_usecs(MAX_JIFFY_OFFSET)) | |
571 | return MAX_JIFFY_OFFSET; | |
572 | return _usecs_to_jiffies(u); | |
573 | } else { | |
574 | return __usecs_to_jiffies(u); | |
575 | } | |
ae60d6a0 NMG |
576 | } |
577 | ||
9ca30850 BW |
578 | extern unsigned long timespec64_to_jiffies(const struct timespec64 *value); |
579 | extern void jiffies_to_timespec64(const unsigned long jiffies, | |
580 | struct timespec64 *value); | |
cbbc719f | 581 | extern clock_t jiffies_to_clock_t(unsigned long x); |
6d07a31f | 582 | |
a399a805 ED |
583 | static inline clock_t jiffies_delta_to_clock_t(long delta) |
584 | { | |
585 | return jiffies_to_clock_t(max(0L, delta)); | |
586 | } | |
587 | ||
14d32b25 MC |
588 | static inline unsigned int jiffies_delta_to_msecs(long delta) |
589 | { | |
590 | return jiffies_to_msecs(max(0L, delta)); | |
591 | } | |
592 | ||
8b9365d7 IM |
593 | extern unsigned long clock_t_to_jiffies(unsigned long x); |
594 | extern u64 jiffies_64_to_clock_t(u64 x); | |
595 | extern u64 nsec_to_clock_t(u64 x); | |
a1dabb6b | 596 | extern u64 nsecs_to_jiffies64(u64 n); |
b7b20df9 | 597 | extern unsigned long nsecs_to_jiffies(u64 n); |
8b9365d7 IM |
598 | |
599 | #define TIMESTAMP_SIZE 30 | |
1da177e4 LT |
600 | |
601 | #endif |