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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright 2001 MontaVista Software Inc.
3 * Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
4 * Copyright (c) 2003, 2004 Maciej W. Rozycki
5 *
6 * Common time service routines for MIPS machines. See
7 * Documentation/mips/time.README.
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
13 */
Pete Popovbdf21b12005-07-14 17:47:57 +000014#include <linux/config.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/types.h>
16#include <linux/kernel.h>
17#include <linux/init.h>
18#include <linux/sched.h>
19#include <linux/param.h>
20#include <linux/time.h>
21#include <linux/timex.h>
22#include <linux/smp.h>
23#include <linux/kernel_stat.h>
24#include <linux/spinlock.h>
25#include <linux/interrupt.h>
26#include <linux/module.h>
27
28#include <asm/bootinfo.h>
Ralf Baechleec74e362005-07-13 11:48:45 +000029#include <asm/cache.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <asm/compiler.h>
31#include <asm/cpu.h>
32#include <asm/cpu-features.h>
33#include <asm/div64.h>
34#include <asm/sections.h>
35#include <asm/time.h>
36
37/*
38 * The integer part of the number of usecs per jiffy is taken from tick,
39 * but the fractional part is not recorded, so we calculate it using the
40 * initial value of HZ. This aids systems where tick isn't really an
41 * integer (e.g. for HZ = 128).
42 */
43#define USECS_PER_JIFFY TICK_SIZE
44#define USECS_PER_JIFFY_FRAC ((unsigned long)(u32)((1000000ULL << 32) / HZ))
45
46#define TICK_SIZE (tick_nsec / 1000)
47
48u64 jiffies_64 = INITIAL_JIFFIES;
49
50EXPORT_SYMBOL(jiffies_64);
51
52/*
53 * forward reference
54 */
55extern volatile unsigned long wall_jiffies;
56
57DEFINE_SPINLOCK(rtc_lock);
58
59/*
60 * By default we provide the null RTC ops
61 */
62static unsigned long null_rtc_get_time(void)
63{
64 return mktime(2000, 1, 1, 0, 0, 0);
65}
66
67static int null_rtc_set_time(unsigned long sec)
68{
69 return 0;
70}
71
72unsigned long (*rtc_get_time)(void) = null_rtc_get_time;
73int (*rtc_set_time)(unsigned long) = null_rtc_set_time;
74int (*rtc_set_mmss)(unsigned long);
75
76
77/* usecs per counter cycle, shifted to left by 32 bits */
78static unsigned int sll32_usecs_per_cycle;
79
80/* how many counter cycles in a jiffy */
Ralf Baechleec74e362005-07-13 11:48:45 +000081static unsigned long cycles_per_jiffy __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
83/* Cycle counter value at the previous timer interrupt.. */
84static unsigned int timerhi, timerlo;
85
86/* expirelo is the count value for next CPU timer interrupt */
87static unsigned int expirelo;
88
89
90/*
91 * Null timer ack for systems not needing one (e.g. i8254).
92 */
93static void null_timer_ack(void) { /* nothing */ }
94
95/*
96 * Null high precision timer functions for systems lacking one.
97 */
98static unsigned int null_hpt_read(void)
99{
100 return 0;
101}
102
Ralf Baechleec74e362005-07-13 11:48:45 +0000103static void null_hpt_init(unsigned int count)
104{
105 /* nothing */
106}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107
108
109/*
110 * Timer ack for an R4k-compatible timer of a known frequency.
111 */
112static void c0_timer_ack(void)
113{
114 unsigned int count;
115
Pete Popovbdf21b12005-07-14 17:47:57 +0000116#ifndef CONFIG_SOC_PNX8550 /* pnx8550 resets to zero */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 /* Ack this timer interrupt and set the next one. */
118 expirelo += cycles_per_jiffy;
Pete Popovbdf21b12005-07-14 17:47:57 +0000119#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 write_c0_compare(expirelo);
121
122 /* Check to see if we have missed any timer interrupts. */
123 count = read_c0_count();
124 if ((count - expirelo) < 0x7fffffff) {
125 /* missed_timer_count++; */
126 expirelo = count + cycles_per_jiffy;
127 write_c0_compare(expirelo);
128 }
129}
130
131/*
132 * High precision timer functions for a R4k-compatible timer.
133 */
134static unsigned int c0_hpt_read(void)
135{
136 return read_c0_count();
137}
138
139/* For use solely as a high precision timer. */
140static void c0_hpt_init(unsigned int count)
141{
142 write_c0_count(read_c0_count() - count);
143}
144
145/* For use both as a high precision timer and an interrupt source. */
146static void c0_hpt_timer_init(unsigned int count)
147{
148 count = read_c0_count() - count;
149 expirelo = (count / cycles_per_jiffy + 1) * cycles_per_jiffy;
150 write_c0_count(expirelo - cycles_per_jiffy);
151 write_c0_compare(expirelo);
152 write_c0_count(count);
153}
154
155int (*mips_timer_state)(void);
156void (*mips_timer_ack)(void);
157unsigned int (*mips_hpt_read)(void);
158void (*mips_hpt_init)(unsigned int);
159
160
161/*
162 * This version of gettimeofday has microsecond resolution and better than
163 * microsecond precision on fast machines with cycle counter.
164 */
165void do_gettimeofday(struct timeval *tv)
166{
167 unsigned long seq;
168 unsigned long lost;
169 unsigned long usec, sec;
170 unsigned long max_ntp_tick = tick_usec - tickadj;
171
172 do {
173 seq = read_seqbegin(&xtime_lock);
174
175 usec = do_gettimeoffset();
176
177 lost = jiffies - wall_jiffies;
178
179 /*
180 * If time_adjust is negative then NTP is slowing the clock
181 * so make sure not to go into next possible interval.
182 * Better to lose some accuracy than have time go backwards..
183 */
184 if (unlikely(time_adjust < 0)) {
185 usec = min(usec, max_ntp_tick);
186
187 if (lost)
188 usec += lost * max_ntp_tick;
189 } else if (unlikely(lost))
190 usec += lost * tick_usec;
191
192 sec = xtime.tv_sec;
193 usec += (xtime.tv_nsec / 1000);
194
195 } while (read_seqretry(&xtime_lock, seq));
196
197 while (usec >= 1000000) {
198 usec -= 1000000;
199 sec++;
200 }
201
202 tv->tv_sec = sec;
203 tv->tv_usec = usec;
204}
205
206EXPORT_SYMBOL(do_gettimeofday);
207
208int do_settimeofday(struct timespec *tv)
209{
210 time_t wtm_sec, sec = tv->tv_sec;
211 long wtm_nsec, nsec = tv->tv_nsec;
212
213 if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
214 return -EINVAL;
215
216 write_seqlock_irq(&xtime_lock);
217
218 /*
219 * This is revolting. We need to set "xtime" correctly. However,
220 * the value in this location is the value at the most recent update
221 * of wall time. Discover what correction gettimeofday() would have
222 * made, and then undo it!
223 */
224 nsec -= do_gettimeoffset() * NSEC_PER_USEC;
225 nsec -= (jiffies - wall_jiffies) * tick_nsec;
226
227 wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
228 wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);
229
230 set_normalized_timespec(&xtime, sec, nsec);
231 set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec);
232
john stultzb149ee22005-09-06 15:17:46 -0700233 ntp_clear();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 write_sequnlock_irq(&xtime_lock);
235 clock_was_set();
236 return 0;
237}
238
239EXPORT_SYMBOL(do_settimeofday);
240
241/*
242 * Gettimeoffset routines. These routines returns the time duration
243 * since last timer interrupt in usecs.
244 *
245 * If the exact CPU counter frequency is known, use fixed_rate_gettimeoffset.
246 * Otherwise use calibrate_gettimeoffset()
247 *
248 * If the CPU does not have the counter register, you can either supply
249 * your own gettimeoffset() routine, or use null_gettimeoffset(), which
250 * gives the same resolution as HZ.
251 */
252
253static unsigned long null_gettimeoffset(void)
254{
255 return 0;
256}
257
258
259/* The function pointer to one of the gettimeoffset funcs. */
260unsigned long (*do_gettimeoffset)(void) = null_gettimeoffset;
261
262
263static unsigned long fixed_rate_gettimeoffset(void)
264{
265 u32 count;
266 unsigned long res;
267
268 /* Get last timer tick in absolute kernel time */
269 count = mips_hpt_read();
270
271 /* .. relative to previous jiffy (32 bits is enough) */
272 count -= timerlo;
273
274 __asm__("multu %1,%2"
275 : "=h" (res)
276 : "r" (count), "r" (sll32_usecs_per_cycle)
277 : "lo", GCC_REG_ACCUM);
278
279 /*
280 * Due to possible jiffies inconsistencies, we need to check
281 * the result so that we'll get a timer that is monotonic.
282 */
283 if (res >= USECS_PER_JIFFY)
284 res = USECS_PER_JIFFY - 1;
285
286 return res;
287}
288
289
290/*
291 * Cached "1/(clocks per usec) * 2^32" value.
292 * It has to be recalculated once each jiffy.
293 */
294static unsigned long cached_quotient;
295
296/* Last jiffy when calibrate_divXX_gettimeoffset() was called. */
297static unsigned long last_jiffies;
298
299/*
300 * This is moved from dec/time.c:do_ioasic_gettimeoffset() by Maciej.
301 */
302static unsigned long calibrate_div32_gettimeoffset(void)
303{
304 u32 count;
305 unsigned long res, tmp;
306 unsigned long quotient;
307
308 tmp = jiffies;
309
310 quotient = cached_quotient;
311
312 if (last_jiffies != tmp) {
313 last_jiffies = tmp;
314 if (last_jiffies != 0) {
315 unsigned long r0;
316 do_div64_32(r0, timerhi, timerlo, tmp);
317 do_div64_32(quotient, USECS_PER_JIFFY,
318 USECS_PER_JIFFY_FRAC, r0);
319 cached_quotient = quotient;
320 }
321 }
322
323 /* Get last timer tick in absolute kernel time */
324 count = mips_hpt_read();
325
326 /* .. relative to previous jiffy (32 bits is enough) */
327 count -= timerlo;
328
329 __asm__("multu %1,%2"
330 : "=h" (res)
331 : "r" (count), "r" (quotient)
332 : "lo", GCC_REG_ACCUM);
333
334 /*
335 * Due to possible jiffies inconsistencies, we need to check
336 * the result so that we'll get a timer that is monotonic.
337 */
338 if (res >= USECS_PER_JIFFY)
339 res = USECS_PER_JIFFY - 1;
340
341 return res;
342}
343
344static unsigned long calibrate_div64_gettimeoffset(void)
345{
346 u32 count;
347 unsigned long res, tmp;
348 unsigned long quotient;
349
350 tmp = jiffies;
351
352 quotient = cached_quotient;
353
354 if (last_jiffies != tmp) {
355 last_jiffies = tmp;
356 if (last_jiffies) {
357 unsigned long r0;
358 __asm__(".set push\n\t"
359 ".set mips3\n\t"
360 "lwu %0,%3\n\t"
361 "dsll32 %1,%2,0\n\t"
362 "or %1,%1,%0\n\t"
363 "ddivu $0,%1,%4\n\t"
364 "mflo %1\n\t"
365 "dsll32 %0,%5,0\n\t"
366 "or %0,%0,%6\n\t"
367 "ddivu $0,%0,%1\n\t"
368 "mflo %0\n\t"
369 ".set pop"
370 : "=&r" (quotient), "=&r" (r0)
371 : "r" (timerhi), "m" (timerlo),
372 "r" (tmp), "r" (USECS_PER_JIFFY),
373 "r" (USECS_PER_JIFFY_FRAC)
374 : "hi", "lo", GCC_REG_ACCUM);
375 cached_quotient = quotient;
376 }
377 }
378
379 /* Get last timer tick in absolute kernel time */
380 count = mips_hpt_read();
381
382 /* .. relative to previous jiffy (32 bits is enough) */
383 count -= timerlo;
384
385 __asm__("multu %1,%2"
386 : "=h" (res)
387 : "r" (count), "r" (quotient)
388 : "lo", GCC_REG_ACCUM);
389
390 /*
391 * Due to possible jiffies inconsistencies, we need to check
392 * the result so that we'll get a timer that is monotonic.
393 */
394 if (res >= USECS_PER_JIFFY)
395 res = USECS_PER_JIFFY - 1;
396
397 return res;
398}
399
400
401/* last time when xtime and rtc are sync'ed up */
402static long last_rtc_update;
403
404/*
405 * local_timer_interrupt() does profiling and process accounting
406 * on a per-CPU basis.
407 *
408 * In UP mode, it is invoked from the (global) timer_interrupt.
409 *
410 * In SMP mode, it might invoked by per-CPU timer interrupt, or
411 * a broadcasted inter-processor interrupt which itself is triggered
412 * by the global timer interrupt.
413 */
414void local_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
415{
416 if (current->pid)
417 profile_tick(CPU_PROFILING, regs);
418 update_process_times(user_mode(regs));
419}
420
421/*
422 * High-level timer interrupt service routines. This function
423 * is set as irqaction->handler and is invoked through do_IRQ.
424 */
425irqreturn_t timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
426{
427 unsigned long j;
428 unsigned int count;
429
430 count = mips_hpt_read();
431 mips_timer_ack();
432
433 /* Update timerhi/timerlo for intra-jiffy calibration. */
434 timerhi += count < timerlo; /* Wrap around */
435 timerlo = count;
436
437 /*
438 * call the generic timer interrupt handling
439 */
440 do_timer(regs);
441
442 /*
443 * If we have an externally synchronized Linux clock, then update
444 * CMOS clock accordingly every ~11 minutes. rtc_set_time() has to be
445 * called as close as possible to 500 ms before the new second starts.
446 */
447 write_seqlock(&xtime_lock);
john stultzb149ee22005-09-06 15:17:46 -0700448 if (ntp_synced() &&
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 xtime.tv_sec > last_rtc_update + 660 &&
450 (xtime.tv_nsec / 1000) >= 500000 - ((unsigned) TICK_SIZE) / 2 &&
451 (xtime.tv_nsec / 1000) <= 500000 + ((unsigned) TICK_SIZE) / 2) {
452 if (rtc_set_mmss(xtime.tv_sec) == 0) {
453 last_rtc_update = xtime.tv_sec;
454 } else {
455 /* do it again in 60 s */
456 last_rtc_update = xtime.tv_sec - 600;
457 }
458 }
459 write_sequnlock(&xtime_lock);
460
461 /*
462 * If jiffies has overflown in this timer_interrupt, we must
463 * update the timer[hi]/[lo] to make fast gettimeoffset funcs
464 * quotient calc still valid. -arca
465 *
466 * The first timer interrupt comes late as interrupts are
467 * enabled long after timers are initialized. Therefore the
468 * high precision timer is fast, leading to wrong gettimeoffset()
469 * calculations. We deal with it by setting it based on the
470 * number of its ticks between the second and the third interrupt.
471 * That is still somewhat imprecise, but it's a good estimate.
472 * --macro
473 */
474 j = jiffies;
475 if (j < 4) {
476 static unsigned int prev_count;
477 static int hpt_initialized;
478
479 switch (j) {
480 case 0:
481 timerhi = timerlo = 0;
482 mips_hpt_init(count);
483 break;
484 case 2:
485 prev_count = count;
486 break;
487 case 3:
488 if (!hpt_initialized) {
489 unsigned int c3 = 3 * (count - prev_count);
490
491 timerhi = 0;
492 timerlo = c3;
493 mips_hpt_init(count - c3);
494 hpt_initialized = 1;
495 }
496 break;
497 default:
498 break;
499 }
500 }
501
502 /*
503 * In UP mode, we call local_timer_interrupt() to do profiling
504 * and process accouting.
505 *
506 * In SMP mode, local_timer_interrupt() is invoked by appropriate
507 * low-level local timer interrupt handler.
508 */
509 local_timer_interrupt(irq, dev_id, regs);
510
511 return IRQ_HANDLED;
512}
513
514asmlinkage void ll_timer_interrupt(int irq, struct pt_regs *regs)
515{
516 irq_enter();
517 kstat_this_cpu.irqs[irq]++;
518
519 /* we keep interrupt disabled all the time */
520 timer_interrupt(irq, NULL, regs);
521
522 irq_exit();
523}
524
525asmlinkage void ll_local_timer_interrupt(int irq, struct pt_regs *regs)
526{
527 irq_enter();
528 if (smp_processor_id() != 0)
529 kstat_this_cpu.irqs[irq]++;
530
531 /* we keep interrupt disabled all the time */
532 local_timer_interrupt(irq, NULL, regs);
533
534 irq_exit();
535}
536
537/*
538 * time_init() - it does the following things.
539 *
540 * 1) board_time_init() -
541 * a) (optional) set up RTC routines,
542 * b) (optional) calibrate and set the mips_hpt_frequency
543 * (only needed if you intended to use fixed_rate_gettimeoffset
544 * or use cpu counter as timer interrupt source)
545 * 2) setup xtime based on rtc_get_time().
546 * 3) choose a appropriate gettimeoffset routine.
547 * 4) calculate a couple of cached variables for later usage
548 * 5) board_timer_setup() -
549 * a) (optional) over-write any choices made above by time_init().
550 * b) machine specific code should setup the timer irqaction.
551 * c) enable the timer interrupt
552 */
553
554void (*board_time_init)(void);
555void (*board_timer_setup)(struct irqaction *irq);
556
557unsigned int mips_hpt_frequency;
558
559static struct irqaction timer_irqaction = {
560 .handler = timer_interrupt,
561 .flags = SA_INTERRUPT,
562 .name = "timer",
563};
564
565static unsigned int __init calibrate_hpt(void)
566{
567 u64 frequency;
568 u32 hpt_start, hpt_end, hpt_count, hz;
569
570 const int loops = HZ / 10;
571 int log_2_loops = 0;
572 int i;
573
574 /*
575 * We want to calibrate for 0.1s, but to avoid a 64-bit
576 * division we round the number of loops up to the nearest
577 * power of 2.
578 */
579 while (loops > 1 << log_2_loops)
580 log_2_loops++;
581 i = 1 << log_2_loops;
582
583 /*
584 * Wait for a rising edge of the timer interrupt.
585 */
586 while (mips_timer_state());
587 while (!mips_timer_state());
588
589 /*
590 * Now see how many high precision timer ticks happen
591 * during the calculated number of periods between timer
592 * interrupts.
593 */
594 hpt_start = mips_hpt_read();
595 do {
596 while (mips_timer_state());
597 while (!mips_timer_state());
598 } while (--i);
599 hpt_end = mips_hpt_read();
600
601 hpt_count = hpt_end - hpt_start;
602 hz = HZ;
603 frequency = (u64)hpt_count * (u64)hz;
604
605 return frequency >> log_2_loops;
606}
607
608void __init time_init(void)
609{
610 if (board_time_init)
611 board_time_init();
612
613 if (!rtc_set_mmss)
614 rtc_set_mmss = rtc_set_time;
615
616 xtime.tv_sec = rtc_get_time();
617 xtime.tv_nsec = 0;
618
619 set_normalized_timespec(&wall_to_monotonic,
620 -xtime.tv_sec, -xtime.tv_nsec);
621
622 /* Choose appropriate high precision timer routines. */
623 if (!cpu_has_counter && !mips_hpt_read) {
624 /* No high precision timer -- sorry. */
625 mips_hpt_read = null_hpt_read;
626 mips_hpt_init = null_hpt_init;
627 } else if (!mips_hpt_frequency && !mips_timer_state) {
628 /* A high precision timer of unknown frequency. */
629 if (!mips_hpt_read) {
630 /* No external high precision timer -- use R4k. */
631 mips_hpt_read = c0_hpt_read;
632 mips_hpt_init = c0_hpt_init;
633 }
634
635 if ((current_cpu_data.isa_level == MIPS_CPU_ISA_M32) ||
636 (current_cpu_data.isa_level == MIPS_CPU_ISA_I) ||
637 (current_cpu_data.isa_level == MIPS_CPU_ISA_II))
638 /*
639 * We need to calibrate the counter but we don't have
640 * 64-bit division.
641 */
642 do_gettimeoffset = calibrate_div32_gettimeoffset;
643 else
644 /*
645 * We need to calibrate the counter but we *do* have
646 * 64-bit division.
647 */
648 do_gettimeoffset = calibrate_div64_gettimeoffset;
649 } else {
650 /* We know counter frequency. Or we can get it. */
651 if (!mips_hpt_read) {
652 /* No external high precision timer -- use R4k. */
653 mips_hpt_read = c0_hpt_read;
654
655 if (mips_timer_state)
656 mips_hpt_init = c0_hpt_init;
657 else {
658 /* No external timer interrupt -- use R4k. */
659 mips_hpt_init = c0_hpt_timer_init;
660 mips_timer_ack = c0_timer_ack;
661 }
662 }
663 if (!mips_hpt_frequency)
664 mips_hpt_frequency = calibrate_hpt();
665
666 do_gettimeoffset = fixed_rate_gettimeoffset;
667
668 /* Calculate cache parameters. */
669 cycles_per_jiffy = (mips_hpt_frequency + HZ / 2) / HZ;
670
671 /* sll32_usecs_per_cycle = 10^6 * 2^32 / mips_counter_freq */
672 do_div64_32(sll32_usecs_per_cycle,
673 1000000, mips_hpt_frequency / 2,
674 mips_hpt_frequency);
675
676 /* Report the high precision timer rate for a reference. */
677 printk("Using %u.%03u MHz high precision timer.\n",
678 ((mips_hpt_frequency + 500) / 1000) / 1000,
679 ((mips_hpt_frequency + 500) / 1000) % 1000);
680 }
681
682 if (!mips_timer_ack)
683 /* No timer interrupt ack (e.g. i8254). */
684 mips_timer_ack = null_timer_ack;
685
686 /* This sets up the high precision timer for the first interrupt. */
687 mips_hpt_init(mips_hpt_read());
688
689 /*
690 * Call board specific timer interrupt setup.
691 *
692 * this pointer must be setup in machine setup routine.
693 *
694 * Even if a machine chooses to use a low-level timer interrupt,
695 * it still needs to setup the timer_irqaction.
696 * In that case, it might be better to set timer_irqaction.handler
697 * to be NULL function so that we are sure the high-level code
698 * is not invoked accidentally.
699 */
700 board_timer_setup(&timer_irqaction);
701}
702
703#define FEBRUARY 2
704#define STARTOFTIME 1970
705#define SECDAY 86400L
706#define SECYR (SECDAY * 365)
707#define leapyear(y) ((!((y) % 4) && ((y) % 100)) || !((y) % 400))
708#define days_in_year(y) (leapyear(y) ? 366 : 365)
709#define days_in_month(m) (month_days[(m) - 1])
710
711static int month_days[12] = {
712 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
713};
714
715void to_tm(unsigned long tim, struct rtc_time *tm)
716{
717 long hms, day, gday;
718 int i;
719
720 gday = day = tim / SECDAY;
721 hms = tim % SECDAY;
722
723 /* Hours, minutes, seconds are easy */
724 tm->tm_hour = hms / 3600;
725 tm->tm_min = (hms % 3600) / 60;
726 tm->tm_sec = (hms % 3600) % 60;
727
728 /* Number of years in days */
729 for (i = STARTOFTIME; day >= days_in_year(i); i++)
730 day -= days_in_year(i);
731 tm->tm_year = i;
732
733 /* Number of months in days left */
734 if (leapyear(tm->tm_year))
735 days_in_month(FEBRUARY) = 29;
736 for (i = 1; day >= days_in_month(i); i++)
737 day -= days_in_month(i);
738 days_in_month(FEBRUARY) = 28;
739 tm->tm_mon = i - 1; /* tm_mon starts from 0 to 11 */
740
741 /* Days are what is left over (+1) from all that. */
742 tm->tm_mday = day + 1;
743
744 /*
745 * Determine the day of week
746 */
747 tm->tm_wday = (gday + 4) % 7; /* 1970/1/1 was Thursday */
748}
749
750EXPORT_SYMBOL(rtc_lock);
751EXPORT_SYMBOL(to_tm);
752EXPORT_SYMBOL(rtc_set_time);
753EXPORT_SYMBOL(rtc_get_time);
754
755unsigned long long sched_clock(void)
756{
757 return (unsigned long long)jiffies*(1000000000/HZ);
758}