2 * Common time routines among all ppc machines.
4 * Written by Cort Dougan (cort@cs.nmt.edu) to merge
5 * Paul Mackerras' version and mine for PReP and Pmac.
6 * MPC8xx/MBX changes by Dan Malek (dmalek@jlc.net).
7 * Converted for 64-bit by Mike Corrigan (mikejc@us.ibm.com)
9 * First round of bugfixes by Gabriel Paubert (paubert@iram.es)
10 * to make clock more stable (2.4.0-test5). The only thing
11 * that this code assumes is that the timebases have been synchronized
12 * by firmware on SMP and are never stopped (never do sleep
13 * on SMP then, nap and doze are OK).
15 * Speeded up do_gettimeofday by getting rid of references to
16 * xtime (which required locks for consistency). (mikejc@us.ibm.com)
18 * TODO (not necessarily in this file):
19 * - improve precision and reproducibility of timebase frequency
20 * measurement at boot time. (for iSeries, we calibrate the timebase
21 * against the Titan chip's clock.)
22 * - for astronomical applications: add a new function to get
23 * non ambiguous timestamps even around leap seconds. This needs
24 * a new timestamp format and a good name.
26 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
27 * "A Kernel Model for Precision Timekeeping" by Dave Mills
29 * This program is free software; you can redistribute it and/or
30 * modify it under the terms of the GNU General Public License
31 * as published by the Free Software Foundation; either version
32 * 2 of the License, or (at your option) any later version.
35 #include <linux/errno.h>
36 #include <linux/module.h>
37 #include <linux/sched.h>
38 #include <linux/kernel.h>
39 #include <linux/param.h>
40 #include <linux/string.h>
42 #include <linux/interrupt.h>
43 #include <linux/timex.h>
44 #include <linux/kernel_stat.h>
45 #include <linux/time.h>
46 #include <linux/init.h>
47 #include <linux/profile.h>
48 #include <linux/cpu.h>
49 #include <linux/security.h>
50 #include <linux/percpu.h>
51 #include <linux/rtc.h>
52 #include <linux/jiffies.h>
53 #include <linux/posix-timers.h>
54 #include <linux/irq.h>
55 #include <linux/delay.h>
56 #include <linux/irq_work.h>
57 #include <asm/trace.h>
60 #include <asm/processor.h>
61 #include <asm/nvram.h>
62 #include <asm/cache.h>
63 #include <asm/machdep.h>
64 #include <asm/uaccess.h>
68 #include <asm/div64.h>
70 #include <asm/vdso_datapage.h>
71 #include <asm/firmware.h>
72 #include <asm/cputime.h>
73 #ifdef CONFIG_PPC_ISERIES
74 #include <asm/iseries/it_lp_queue.h>
75 #include <asm/iseries/hv_call_xm.h>
78 /* powerpc clocksource/clockevent code */
80 #include <linux/clockchips.h>
81 #include <linux/clocksource.h>
83 static cycle_t rtc_read(struct clocksource *);
84 static struct clocksource clocksource_rtc = {
87 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
88 .mask = CLOCKSOURCE_MASK(64),
90 .mult = 0, /* To be filled in */
94 static cycle_t timebase_read(struct clocksource *);
95 static struct clocksource clocksource_timebase = {
98 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
99 .mask = CLOCKSOURCE_MASK(64),
101 .mult = 0, /* To be filled in */
102 .read = timebase_read,
105 #define DECREMENTER_MAX 0x7fffffff
107 static int decrementer_set_next_event(unsigned long evt,
108 struct clock_event_device *dev);
109 static void decrementer_set_mode(enum clock_event_mode mode,
110 struct clock_event_device *dev);
112 static struct clock_event_device decrementer_clockevent = {
113 .name = "decrementer",
115 .shift = 0, /* To be filled in */
116 .mult = 0, /* To be filled in */
118 .set_next_event = decrementer_set_next_event,
119 .set_mode = decrementer_set_mode,
120 .features = CLOCK_EVT_FEAT_ONESHOT,
123 struct decrementer_clock {
124 struct clock_event_device event;
128 static DEFINE_PER_CPU(struct decrementer_clock, decrementers);
130 #ifdef CONFIG_PPC_ISERIES
131 static unsigned long __initdata iSeries_recal_titan;
132 static signed long __initdata iSeries_recal_tb;
134 /* Forward declaration is only needed for iSereis compiles */
135 static void __init clocksource_init(void);
138 #define XSEC_PER_SEC (1024*1024)
141 #define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
143 /* compute ((xsec << 12) * max) >> 32 */
144 #define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
147 unsigned long tb_ticks_per_jiffy;
148 unsigned long tb_ticks_per_usec = 100; /* sane default */
149 EXPORT_SYMBOL(tb_ticks_per_usec);
150 unsigned long tb_ticks_per_sec;
151 EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */
153 DEFINE_SPINLOCK(rtc_lock);
154 EXPORT_SYMBOL_GPL(rtc_lock);
156 static u64 tb_to_ns_scale __read_mostly;
157 static unsigned tb_to_ns_shift __read_mostly;
158 static unsigned long boot_tb __read_mostly;
160 extern struct timezone sys_tz;
161 static long timezone_offset;
163 unsigned long ppc_proc_freq;
164 EXPORT_SYMBOL_GPL(ppc_proc_freq);
165 unsigned long ppc_tb_freq;
166 EXPORT_SYMBOL_GPL(ppc_tb_freq);
168 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
170 * Factors for converting from cputime_t (timebase ticks) to
171 * jiffies, milliseconds, seconds, and clock_t (1/USER_HZ seconds).
172 * These are all stored as 0.64 fixed-point binary fractions.
174 u64 __cputime_jiffies_factor;
175 EXPORT_SYMBOL(__cputime_jiffies_factor);
176 u64 __cputime_msec_factor;
177 EXPORT_SYMBOL(__cputime_msec_factor);
178 u64 __cputime_sec_factor;
179 EXPORT_SYMBOL(__cputime_sec_factor);
180 u64 __cputime_clockt_factor;
181 EXPORT_SYMBOL(__cputime_clockt_factor);
182 DEFINE_PER_CPU(unsigned long, cputime_last_delta);
183 DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta);
185 cputime_t cputime_one_jiffy;
187 void (*dtl_consumer)(struct dtl_entry *, u64);
189 static void calc_cputime_factors(void)
191 struct div_result res;
193 div128_by_32(HZ, 0, tb_ticks_per_sec, &res);
194 __cputime_jiffies_factor = res.result_low;
195 div128_by_32(1000, 0, tb_ticks_per_sec, &res);
196 __cputime_msec_factor = res.result_low;
197 div128_by_32(1, 0, tb_ticks_per_sec, &res);
198 __cputime_sec_factor = res.result_low;
199 div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res);
200 __cputime_clockt_factor = res.result_low;
204 * Read the SPURR on systems that have it, otherwise the PURR,
205 * or if that doesn't exist return the timebase value passed in.
207 static u64 read_spurr(u64 tb)
209 if (cpu_has_feature(CPU_FTR_SPURR))
210 return mfspr(SPRN_SPURR);
211 if (cpu_has_feature(CPU_FTR_PURR))
212 return mfspr(SPRN_PURR);
216 #ifdef CONFIG_PPC_SPLPAR
219 * Scan the dispatch trace log and count up the stolen time.
220 * Should be called with interrupts disabled.
222 static u64 scan_dispatch_log(u64 stop_tb)
224 u64 i = local_paca->dtl_ridx;
225 struct dtl_entry *dtl = local_paca->dtl_curr;
226 struct dtl_entry *dtl_end = local_paca->dispatch_log_end;
227 struct lppaca *vpa = local_paca->lppaca_ptr;
232 if (i == vpa->dtl_idx)
234 while (i < vpa->dtl_idx) {
236 dtl_consumer(dtl, i);
238 tb_delta = dtl->enqueue_to_dispatch_time +
239 dtl->ready_to_enqueue_time;
241 if (i + N_DISPATCH_LOG < vpa->dtl_idx) {
242 /* buffer has overflowed */
243 i = vpa->dtl_idx - N_DISPATCH_LOG;
244 dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
253 dtl = local_paca->dispatch_log;
255 local_paca->dtl_ridx = i;
256 local_paca->dtl_curr = dtl;
261 * Accumulate stolen time by scanning the dispatch trace log.
262 * Called on entry from user mode.
264 void accumulate_stolen_time(void)
268 sst = scan_dispatch_log(get_paca()->starttime_user);
269 ust = scan_dispatch_log(get_paca()->starttime);
270 get_paca()->system_time -= sst;
271 get_paca()->user_time -= ust;
272 get_paca()->stolen_time += ust + sst;
275 static inline u64 calculate_stolen_time(u64 stop_tb)
279 if (get_paca()->dtl_ridx != get_paca()->lppaca_ptr->dtl_idx) {
280 stolen = scan_dispatch_log(stop_tb);
281 get_paca()->system_time -= stolen;
284 stolen += get_paca()->stolen_time;
285 get_paca()->stolen_time = 0;
289 #else /* CONFIG_PPC_SPLPAR */
290 static inline u64 calculate_stolen_time(u64 stop_tb)
295 #endif /* CONFIG_PPC_SPLPAR */
298 * Account time for a transition between system, hard irq
301 void account_system_vtime(struct task_struct *tsk)
303 u64 now, nowscaled, delta, deltascaled;
305 u64 stolen, udelta, sys_scaled, user_scaled;
307 local_irq_save(flags);
309 nowscaled = read_spurr(now);
310 get_paca()->system_time += now - get_paca()->starttime;
311 get_paca()->starttime = now;
312 deltascaled = nowscaled - get_paca()->startspurr;
313 get_paca()->startspurr = nowscaled;
315 stolen = calculate_stolen_time(now);
317 delta = get_paca()->system_time;
318 get_paca()->system_time = 0;
319 udelta = get_paca()->user_time - get_paca()->utime_sspurr;
320 get_paca()->utime_sspurr = get_paca()->user_time;
323 * Because we don't read the SPURR on every kernel entry/exit,
324 * deltascaled includes both user and system SPURR ticks.
325 * Apportion these ticks to system SPURR ticks and user
326 * SPURR ticks in the same ratio as the system time (delta)
327 * and user time (udelta) values obtained from the timebase
328 * over the same interval. The system ticks get accounted here;
329 * the user ticks get saved up in paca->user_time_scaled to be
330 * used by account_process_tick.
333 user_scaled = udelta;
334 if (deltascaled != delta + udelta) {
336 sys_scaled = deltascaled * delta / (delta + udelta);
337 user_scaled = deltascaled - sys_scaled;
339 sys_scaled = deltascaled;
342 get_paca()->user_time_scaled += user_scaled;
344 if (in_irq() || idle_task(smp_processor_id()) != tsk) {
345 account_system_time(tsk, 0, delta, sys_scaled);
347 account_steal_time(stolen);
349 account_idle_time(delta + stolen);
351 local_irq_restore(flags);
353 EXPORT_SYMBOL_GPL(account_system_vtime);
356 * Transfer the user and system times accumulated in the paca
357 * by the exception entry and exit code to the generic process
358 * user and system time records.
359 * Must be called with interrupts disabled.
360 * Assumes that account_system_vtime() has been called recently
361 * (i.e. since the last entry from usermode) so that
362 * get_paca()->user_time_scaled is up to date.
364 void account_process_tick(struct task_struct *tsk, int user_tick)
366 cputime_t utime, utimescaled;
368 utime = get_paca()->user_time;
369 utimescaled = get_paca()->user_time_scaled;
370 get_paca()->user_time = 0;
371 get_paca()->user_time_scaled = 0;
372 get_paca()->utime_sspurr = 0;
373 account_user_time(tsk, utime, utimescaled);
376 #else /* ! CONFIG_VIRT_CPU_ACCOUNTING */
377 #define calc_cputime_factors()
380 void __delay(unsigned long loops)
388 /* the RTCL register wraps at 1000000000 */
389 diff = get_rtcl() - start;
392 } while (diff < loops);
395 while (get_tbl() - start < loops)
400 EXPORT_SYMBOL(__delay);
402 void udelay(unsigned long usecs)
404 __delay(tb_ticks_per_usec * usecs);
406 EXPORT_SYMBOL(udelay);
409 unsigned long profile_pc(struct pt_regs *regs)
411 unsigned long pc = instruction_pointer(regs);
413 if (in_lock_functions(pc))
418 EXPORT_SYMBOL(profile_pc);
421 #ifdef CONFIG_PPC_ISERIES
424 * This function recalibrates the timebase based on the 49-bit time-of-day
425 * value in the Titan chip. The Titan is much more accurate than the value
426 * returned by the service processor for the timebase frequency.
429 static int __init iSeries_tb_recal(void)
431 unsigned long titan, tb;
433 /* Make sure we only run on iSeries */
434 if (!firmware_has_feature(FW_FEATURE_ISERIES))
438 titan = HvCallXm_loadTod();
439 if ( iSeries_recal_titan ) {
440 unsigned long tb_ticks = tb - iSeries_recal_tb;
441 unsigned long titan_usec = (titan - iSeries_recal_titan) >> 12;
442 unsigned long new_tb_ticks_per_sec = (tb_ticks * USEC_PER_SEC)/titan_usec;
443 unsigned long new_tb_ticks_per_jiffy =
444 DIV_ROUND_CLOSEST(new_tb_ticks_per_sec, HZ);
445 long tick_diff = new_tb_ticks_per_jiffy - tb_ticks_per_jiffy;
447 /* make sure tb_ticks_per_sec and tb_ticks_per_jiffy are consistent */
448 new_tb_ticks_per_sec = new_tb_ticks_per_jiffy * HZ;
450 if ( tick_diff < 0 ) {
451 tick_diff = -tick_diff;
455 if ( tick_diff < tb_ticks_per_jiffy/25 ) {
456 printk( "Titan recalibrate: new tb_ticks_per_jiffy = %lu (%c%ld)\n",
457 new_tb_ticks_per_jiffy, sign, tick_diff );
458 tb_ticks_per_jiffy = new_tb_ticks_per_jiffy;
459 tb_ticks_per_sec = new_tb_ticks_per_sec;
460 calc_cputime_factors();
461 vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
462 setup_cputime_one_jiffy();
465 printk( "Titan recalibrate: FAILED (difference > 4 percent)\n"
466 " new tb_ticks_per_jiffy = %lu\n"
467 " old tb_ticks_per_jiffy = %lu\n",
468 new_tb_ticks_per_jiffy, tb_ticks_per_jiffy );
472 iSeries_recal_titan = titan;
473 iSeries_recal_tb = tb;
475 /* Called here as now we know accurate values for the timebase */
479 late_initcall(iSeries_tb_recal);
481 /* Called from platform early init */
482 void __init iSeries_time_init_early(void)
484 iSeries_recal_tb = get_tb();
485 iSeries_recal_titan = HvCallXm_loadTod();
487 #endif /* CONFIG_PPC_ISERIES */
489 #ifdef CONFIG_IRQ_WORK
492 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
495 static inline unsigned long test_irq_work_pending(void)
499 asm volatile("lbz %0,%1(13)"
501 : "i" (offsetof(struct paca_struct, irq_work_pending)));
505 static inline void set_irq_work_pending_flag(void)
507 asm volatile("stb %0,%1(13)" : :
509 "i" (offsetof(struct paca_struct, irq_work_pending)));
512 static inline void clear_irq_work_pending(void)
514 asm volatile("stb %0,%1(13)" : :
516 "i" (offsetof(struct paca_struct, irq_work_pending)));
521 DEFINE_PER_CPU(u8, irq_work_pending);
523 #define set_irq_work_pending_flag() __get_cpu_var(irq_work_pending) = 1
524 #define test_irq_work_pending() __get_cpu_var(irq_work_pending)
525 #define clear_irq_work_pending() __get_cpu_var(irq_work_pending) = 0
527 #endif /* 32 vs 64 bit */
529 void set_irq_work_pending(void)
532 set_irq_work_pending_flag();
537 #else /* CONFIG_IRQ_WORK */
539 #define test_irq_work_pending() 0
540 #define clear_irq_work_pending()
542 #endif /* CONFIG_IRQ_WORK */
545 * For iSeries shared processors, we have to let the hypervisor
546 * set the hardware decrementer. We set a virtual decrementer
547 * in the lppaca and call the hypervisor if the virtual
548 * decrementer is less than the current value in the hardware
549 * decrementer. (almost always the new decrementer value will
550 * be greater than the current hardware decementer so the hypervisor
551 * call will not be needed)
555 * timer_interrupt - gets called when the decrementer overflows,
556 * with interrupts disabled.
558 void timer_interrupt(struct pt_regs * regs)
560 struct pt_regs *old_regs;
561 struct decrementer_clock *decrementer = &__get_cpu_var(decrementers);
562 struct clock_event_device *evt = &decrementer->event;
565 trace_timer_interrupt_entry(regs);
567 __get_cpu_var(irq_stat).timer_irqs++;
569 /* Ensure a positive value is written to the decrementer, or else
570 * some CPUs will continuue to take decrementer exceptions */
571 set_dec(DECREMENTER_MAX);
573 #if defined(CONFIG_PPC32) && defined(CONFIG_PMAC)
574 if (atomic_read(&ppc_n_lost_interrupts) != 0)
578 old_regs = set_irq_regs(regs);
581 if (test_irq_work_pending()) {
582 clear_irq_work_pending();
586 #ifdef CONFIG_PPC_ISERIES
587 if (firmware_has_feature(FW_FEATURE_ISERIES))
588 get_lppaca()->int_dword.fields.decr_int = 0;
591 now = get_tb_or_rtc();
592 if (now >= decrementer->next_tb) {
593 decrementer->next_tb = ~(u64)0;
594 if (evt->event_handler)
595 evt->event_handler(evt);
597 now = decrementer->next_tb - now;
598 if (now <= DECREMENTER_MAX)
602 #ifdef CONFIG_PPC_ISERIES
603 if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending())
604 process_hvlpevents();
608 /* collect purr register values often, for accurate calculations */
609 if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
610 struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
611 cu->current_tb = mfspr(SPRN_PURR);
616 set_irq_regs(old_regs);
618 trace_timer_interrupt_exit(regs);
621 #ifdef CONFIG_SUSPEND
622 static void generic_suspend_disable_irqs(void)
624 /* Disable the decrementer, so that it doesn't interfere
633 static void generic_suspend_enable_irqs(void)
638 /* Overrides the weak version in kernel/power/main.c */
639 void arch_suspend_disable_irqs(void)
641 if (ppc_md.suspend_disable_irqs)
642 ppc_md.suspend_disable_irqs();
643 generic_suspend_disable_irqs();
646 /* Overrides the weak version in kernel/power/main.c */
647 void arch_suspend_enable_irqs(void)
649 generic_suspend_enable_irqs();
650 if (ppc_md.suspend_enable_irqs)
651 ppc_md.suspend_enable_irqs();
656 * Scheduler clock - returns current time in nanosec units.
658 * Note: mulhdu(a, b) (multiply high double unsigned) returns
659 * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
660 * are 64-bit unsigned numbers.
662 unsigned long long sched_clock(void)
666 return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
669 static int __init get_freq(char *name, int cells, unsigned long *val)
671 struct device_node *cpu;
672 const unsigned int *fp;
675 /* The cpu node should have timebase and clock frequency properties */
676 cpu = of_find_node_by_type(NULL, "cpu");
679 fp = of_get_property(cpu, name, NULL);
682 *val = of_read_ulong(fp, cells);
691 /* should become __cpuinit when secondary_cpu_time_init also is */
692 void start_cpu_decrementer(void)
694 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
695 /* Clear any pending timer interrupts */
696 mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS);
698 /* Enable decrementer interrupt */
699 mtspr(SPRN_TCR, TCR_DIE);
700 #endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */
703 void __init generic_calibrate_decr(void)
705 ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
707 if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&
708 !get_freq("timebase-frequency", 1, &ppc_tb_freq)) {
710 printk(KERN_ERR "WARNING: Estimating decrementer frequency "
714 ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */
716 if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&
717 !get_freq("clock-frequency", 1, &ppc_proc_freq)) {
719 printk(KERN_ERR "WARNING: Estimating processor frequency "
724 int update_persistent_clock(struct timespec now)
728 if (!ppc_md.set_rtc_time)
731 to_tm(now.tv_sec + 1 + timezone_offset, &tm);
735 return ppc_md.set_rtc_time(&tm);
738 static void __read_persistent_clock(struct timespec *ts)
741 static int first = 1;
744 /* XXX this is a litle fragile but will work okay in the short term */
747 if (ppc_md.time_init)
748 timezone_offset = ppc_md.time_init();
750 /* get_boot_time() isn't guaranteed to be safe to call late */
751 if (ppc_md.get_boot_time) {
752 ts->tv_sec = ppc_md.get_boot_time() - timezone_offset;
756 if (!ppc_md.get_rtc_time) {
760 ppc_md.get_rtc_time(&tm);
762 ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
763 tm.tm_hour, tm.tm_min, tm.tm_sec);
766 void read_persistent_clock(struct timespec *ts)
768 __read_persistent_clock(ts);
770 /* Sanitize it in case real time clock is set below EPOCH */
771 if (ts->tv_sec < 0) {
778 /* clocksource code */
779 static cycle_t rtc_read(struct clocksource *cs)
781 return (cycle_t)get_rtc();
784 static cycle_t timebase_read(struct clocksource *cs)
786 return (cycle_t)get_tb();
789 void update_vsyscall(struct timespec *wall_time, struct timespec *wtm,
790 struct clocksource *clock, u32 mult)
792 u64 new_tb_to_xs, new_stamp_xsec;
795 if (clock != &clocksource_timebase)
798 /* Make userspace gettimeofday spin until we're done. */
799 ++vdso_data->tb_update_count;
802 /* XXX this assumes clock->shift == 22 */
803 /* 4611686018 ~= 2^(20+64-22) / 1e9 */
804 new_tb_to_xs = (u64) mult * 4611686018ULL;
805 new_stamp_xsec = (u64) wall_time->tv_nsec * XSEC_PER_SEC;
806 do_div(new_stamp_xsec, 1000000000);
807 new_stamp_xsec += (u64) wall_time->tv_sec * XSEC_PER_SEC;
809 BUG_ON(wall_time->tv_nsec >= NSEC_PER_SEC);
810 /* this is tv_nsec / 1e9 as a 0.32 fraction */
811 frac_sec = ((u64) wall_time->tv_nsec * 18446744073ULL) >> 32;
814 * tb_update_count is used to allow the userspace gettimeofday code
815 * to assure itself that it sees a consistent view of the tb_to_xs and
816 * stamp_xsec variables. It reads the tb_update_count, then reads
817 * tb_to_xs and stamp_xsec and then reads tb_update_count again. If
818 * the two values of tb_update_count match and are even then the
819 * tb_to_xs and stamp_xsec values are consistent. If not, then it
820 * loops back and reads them again until this criteria is met.
821 * We expect the caller to have done the first increment of
822 * vdso_data->tb_update_count already.
824 vdso_data->tb_orig_stamp = clock->cycle_last;
825 vdso_data->stamp_xsec = new_stamp_xsec;
826 vdso_data->tb_to_xs = new_tb_to_xs;
827 vdso_data->wtom_clock_sec = wtm->tv_sec;
828 vdso_data->wtom_clock_nsec = wtm->tv_nsec;
829 vdso_data->stamp_xtime = *wall_time;
830 vdso_data->stamp_sec_fraction = frac_sec;
832 ++(vdso_data->tb_update_count);
835 void update_vsyscall_tz(void)
837 /* Make userspace gettimeofday spin until we're done. */
838 ++vdso_data->tb_update_count;
840 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
841 vdso_data->tz_dsttime = sys_tz.tz_dsttime;
843 ++vdso_data->tb_update_count;
846 static void __init clocksource_init(void)
848 struct clocksource *clock;
851 clock = &clocksource_rtc;
853 clock = &clocksource_timebase;
855 clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift);
857 if (clocksource_register(clock)) {
858 printk(KERN_ERR "clocksource: %s is already registered\n",
863 printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
864 clock->name, clock->mult, clock->shift);
867 static int decrementer_set_next_event(unsigned long evt,
868 struct clock_event_device *dev)
870 __get_cpu_var(decrementers).next_tb = get_tb_or_rtc() + evt;
875 static void decrementer_set_mode(enum clock_event_mode mode,
876 struct clock_event_device *dev)
878 if (mode != CLOCK_EVT_MODE_ONESHOT)
879 decrementer_set_next_event(DECREMENTER_MAX, dev);
882 static inline uint64_t div_sc64(unsigned long ticks, unsigned long nsec,
885 uint64_t tmp = ((uint64_t)ticks) << shift;
891 static void __init setup_clockevent_multiplier(unsigned long hz)
893 u64 mult, shift = 32;
896 mult = div_sc64(hz, NSEC_PER_SEC, shift);
897 if (mult && (mult >> 32UL) == 0UL)
903 decrementer_clockevent.shift = shift;
904 decrementer_clockevent.mult = mult;
907 static void register_decrementer_clockevent(int cpu)
909 struct clock_event_device *dec = &per_cpu(decrementers, cpu).event;
911 *dec = decrementer_clockevent;
912 dec->cpumask = cpumask_of(cpu);
914 printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
915 dec->name, dec->mult, dec->shift, cpu);
917 clockevents_register_device(dec);
920 static void __init init_decrementer_clockevent(void)
922 int cpu = smp_processor_id();
924 setup_clockevent_multiplier(ppc_tb_freq);
925 decrementer_clockevent.max_delta_ns =
926 clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent);
927 decrementer_clockevent.min_delta_ns =
928 clockevent_delta2ns(2, &decrementer_clockevent);
930 register_decrementer_clockevent(cpu);
933 void secondary_cpu_time_init(void)
935 /* Start the decrementer on CPUs that have manual control
938 start_cpu_decrementer();
940 /* FIME: Should make unrelatred change to move snapshot_timebase
942 register_decrementer_clockevent(smp_processor_id());
945 /* This function is only called on the boot processor */
946 void __init time_init(void)
948 struct div_result res;
953 /* 601 processor: dec counts down by 128 every 128ns */
954 ppc_tb_freq = 1000000000;
956 /* Normal PowerPC with timebase register */
957 ppc_md.calibrate_decr();
958 printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n",
959 ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
960 printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n",
961 ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
964 tb_ticks_per_jiffy = ppc_tb_freq / HZ;
965 tb_ticks_per_sec = ppc_tb_freq;
966 tb_ticks_per_usec = ppc_tb_freq / 1000000;
967 calc_cputime_factors();
968 setup_cputime_one_jiffy();
971 * Compute scale factor for sched_clock.
972 * The calibrate_decr() function has set tb_ticks_per_sec,
973 * which is the timebase frequency.
974 * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
975 * the 128-bit result as a 64.64 fixed-point number.
976 * We then shift that number right until it is less than 1.0,
977 * giving us the scale factor and shift count to use in
980 div128_by_32(1000000000, 0, tb_ticks_per_sec, &res);
981 scale = res.result_low;
982 for (shift = 0; res.result_high != 0; ++shift) {
983 scale = (scale >> 1) | (res.result_high << 63);
984 res.result_high >>= 1;
986 tb_to_ns_scale = scale;
987 tb_to_ns_shift = shift;
988 /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
989 boot_tb = get_tb_or_rtc();
991 /* If platform provided a timezone (pmac), we correct the time */
992 if (timezone_offset) {
993 sys_tz.tz_minuteswest = -timezone_offset / 60;
994 sys_tz.tz_dsttime = 0;
997 vdso_data->tb_update_count = 0;
998 vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
1000 /* Start the decrementer on CPUs that have manual control
1003 start_cpu_decrementer();
1005 /* Register the clocksource, if we're not running on iSeries */
1006 if (!firmware_has_feature(FW_FEATURE_ISERIES))
1009 init_decrementer_clockevent();
1014 #define STARTOFTIME 1970
1015 #define SECDAY 86400L
1016 #define SECYR (SECDAY * 365)
1017 #define leapyear(year) ((year) % 4 == 0 && \
1018 ((year) % 100 != 0 || (year) % 400 == 0))
1019 #define days_in_year(a) (leapyear(a) ? 366 : 365)
1020 #define days_in_month(a) (month_days[(a) - 1])
1022 static int month_days[12] = {
1023 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
1027 * This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
1029 void GregorianDay(struct rtc_time * tm)
1034 int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
1036 lastYear = tm->tm_year - 1;
1039 * Number of leap corrections to apply up to end of last year
1041 leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400;
1044 * This year is a leap year if it is divisible by 4 except when it is
1045 * divisible by 100 unless it is divisible by 400
1047 * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
1049 day = tm->tm_mon > 2 && leapyear(tm->tm_year);
1051 day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] +
1054 tm->tm_wday = day % 7;
1057 void to_tm(int tim, struct rtc_time * tm)
1060 register long hms, day;
1065 /* Hours, minutes, seconds are easy */
1066 tm->tm_hour = hms / 3600;
1067 tm->tm_min = (hms % 3600) / 60;
1068 tm->tm_sec = (hms % 3600) % 60;
1070 /* Number of years in days */
1071 for (i = STARTOFTIME; day >= days_in_year(i); i++)
1072 day -= days_in_year(i);
1075 /* Number of months in days left */
1076 if (leapyear(tm->tm_year))
1077 days_in_month(FEBRUARY) = 29;
1078 for (i = 1; day >= days_in_month(i); i++)
1079 day -= days_in_month(i);
1080 days_in_month(FEBRUARY) = 28;
1083 /* Days are what is left over (+1) from all that. */
1084 tm->tm_mday = day + 1;
1087 * Determine the day of week
1093 * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
1096 void div128_by_32(u64 dividend_high, u64 dividend_low,
1097 unsigned divisor, struct div_result *dr)
1099 unsigned long a, b, c, d;
1100 unsigned long w, x, y, z;
1103 a = dividend_high >> 32;
1104 b = dividend_high & 0xffffffff;
1105 c = dividend_low >> 32;
1106 d = dividend_low & 0xffffffff;
1109 ra = ((u64)(a - (w * divisor)) << 32) + b;
1111 rb = ((u64) do_div(ra, divisor) << 32) + c;
1114 rc = ((u64) do_div(rb, divisor) << 32) + d;
1117 do_div(rc, divisor);
1120 dr->result_high = ((u64)w << 32) + x;
1121 dr->result_low = ((u64)y << 32) + z;
1125 /* We don't need to calibrate delay, we use the CPU timebase for that */
1126 void calibrate_delay(void)
1128 /* Some generic code (such as spinlock debug) use loops_per_jiffy
1129 * as the number of __delay(1) in a jiffy, so make it so
1131 loops_per_jiffy = tb_ticks_per_jiffy;
1134 static int __init rtc_init(void)
1136 struct platform_device *pdev;
1138 if (!ppc_md.get_rtc_time)
1141 pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
1143 return PTR_ERR(pdev);
1148 module_init(rtc_init);