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/perf_event.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(ppc_proc_freq
);
165 unsigned long ppc_tb_freq
;
167 static DEFINE_PER_CPU(u64
, last_jiffy
);
169 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
171 * Factors for converting from cputime_t (timebase ticks) to
172 * jiffies, milliseconds, seconds, and clock_t (1/USER_HZ seconds).
173 * These are all stored as 0.64 fixed-point binary fractions.
175 u64 __cputime_jiffies_factor
;
176 EXPORT_SYMBOL(__cputime_jiffies_factor
);
177 u64 __cputime_msec_factor
;
178 EXPORT_SYMBOL(__cputime_msec_factor
);
179 u64 __cputime_sec_factor
;
180 EXPORT_SYMBOL(__cputime_sec_factor
);
181 u64 __cputime_clockt_factor
;
182 EXPORT_SYMBOL(__cputime_clockt_factor
);
183 DEFINE_PER_CPU(unsigned long, cputime_last_delta
);
184 DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta
);
186 cputime_t cputime_one_jiffy
;
188 static void calc_cputime_factors(void)
190 struct div_result res
;
192 div128_by_32(HZ
, 0, tb_ticks_per_sec
, &res
);
193 __cputime_jiffies_factor
= res
.result_low
;
194 div128_by_32(1000, 0, tb_ticks_per_sec
, &res
);
195 __cputime_msec_factor
= res
.result_low
;
196 div128_by_32(1, 0, tb_ticks_per_sec
, &res
);
197 __cputime_sec_factor
= res
.result_low
;
198 div128_by_32(USER_HZ
, 0, tb_ticks_per_sec
, &res
);
199 __cputime_clockt_factor
= res
.result_low
;
203 * Read the PURR on systems that have it, otherwise the timebase.
205 static u64
read_purr(void)
207 if (cpu_has_feature(CPU_FTR_PURR
))
208 return mfspr(SPRN_PURR
);
213 * Read the SPURR on systems that have it, otherwise the purr
215 static u64
read_spurr(u64 purr
)
218 * cpus without PURR won't have a SPURR
219 * We already know the former when we use this, so tell gcc
221 if (cpu_has_feature(CPU_FTR_PURR
) && cpu_has_feature(CPU_FTR_SPURR
))
222 return mfspr(SPRN_SPURR
);
227 * Account time for a transition between system, hard irq
230 void account_system_vtime(struct task_struct
*tsk
)
232 u64 now
, nowscaled
, delta
, deltascaled
, sys_time
;
235 local_irq_save(flags
);
237 nowscaled
= read_spurr(now
);
238 delta
= now
- get_paca()->startpurr
;
239 deltascaled
= nowscaled
- get_paca()->startspurr
;
240 get_paca()->startpurr
= now
;
241 get_paca()->startspurr
= nowscaled
;
242 if (!in_interrupt()) {
243 /* deltascaled includes both user and system time.
244 * Hence scale it based on the purr ratio to estimate
246 sys_time
= get_paca()->system_time
;
247 if (get_paca()->user_time
)
248 deltascaled
= deltascaled
* sys_time
/
249 (sys_time
+ get_paca()->user_time
);
251 get_paca()->system_time
= 0;
253 if (in_irq() || idle_task(smp_processor_id()) != tsk
)
254 account_system_time(tsk
, 0, delta
, deltascaled
);
256 account_idle_time(delta
);
257 __get_cpu_var(cputime_last_delta
) = delta
;
258 __get_cpu_var(cputime_scaled_last_delta
) = deltascaled
;
259 local_irq_restore(flags
);
261 EXPORT_SYMBOL_GPL(account_system_vtime
);
264 * Transfer the user and system times accumulated in the paca
265 * by the exception entry and exit code to the generic process
266 * user and system time records.
267 * Must be called with interrupts disabled.
269 void account_process_tick(struct task_struct
*tsk
, int user_tick
)
271 cputime_t utime
, utimescaled
;
273 utime
= get_paca()->user_time
;
274 get_paca()->user_time
= 0;
275 utimescaled
= cputime_to_scaled(utime
);
276 account_user_time(tsk
, utime
, utimescaled
);
280 * Stuff for accounting stolen time.
282 struct cpu_purr_data
{
283 int initialized
; /* thread is running */
284 u64 tb
; /* last TB value read */
285 u64 purr
; /* last PURR value read */
286 u64 spurr
; /* last SPURR value read */
290 * Each entry in the cpu_purr_data array is manipulated only by its
291 * "owner" cpu -- usually in the timer interrupt but also occasionally
292 * in process context for cpu online. As long as cpus do not touch
293 * each others' cpu_purr_data, disabling local interrupts is
294 * sufficient to serialize accesses.
296 static DEFINE_PER_CPU(struct cpu_purr_data
, cpu_purr_data
);
298 static void snapshot_tb_and_purr(void *data
)
301 struct cpu_purr_data
*p
= &__get_cpu_var(cpu_purr_data
);
303 local_irq_save(flags
);
304 p
->tb
= get_tb_or_rtc();
305 p
->purr
= mfspr(SPRN_PURR
);
308 local_irq_restore(flags
);
312 * Called during boot when all cpus have come up.
314 void snapshot_timebases(void)
316 if (!cpu_has_feature(CPU_FTR_PURR
))
318 on_each_cpu(snapshot_tb_and_purr
, NULL
, 1);
322 * Must be called with interrupts disabled.
324 void calculate_steal_time(void)
328 struct cpu_purr_data
*pme
;
330 pme
= &__get_cpu_var(cpu_purr_data
);
331 if (!pme
->initialized
)
332 return; /* !CPU_FTR_PURR or early in early boot */
334 purr
= mfspr(SPRN_PURR
);
335 stolen
= (tb
- pme
->tb
) - (purr
- pme
->purr
);
337 if (idle_task(smp_processor_id()) != current
)
338 account_steal_time(stolen
);
340 account_idle_time(stolen
);
346 #ifdef CONFIG_PPC_SPLPAR
348 * Must be called before the cpu is added to the online map when
349 * a cpu is being brought up at runtime.
351 static void snapshot_purr(void)
353 struct cpu_purr_data
*pme
;
356 if (!cpu_has_feature(CPU_FTR_PURR
))
358 local_irq_save(flags
);
359 pme
= &__get_cpu_var(cpu_purr_data
);
361 pme
->purr
= mfspr(SPRN_PURR
);
362 pme
->initialized
= 1;
363 local_irq_restore(flags
);
366 #endif /* CONFIG_PPC_SPLPAR */
368 #else /* ! CONFIG_VIRT_CPU_ACCOUNTING */
369 #define calc_cputime_factors()
370 #define calculate_steal_time() do { } while (0)
373 #if !(defined(CONFIG_VIRT_CPU_ACCOUNTING) && defined(CONFIG_PPC_SPLPAR))
374 #define snapshot_purr() do { } while (0)
378 * Called when a cpu comes up after the system has finished booting,
379 * i.e. as a result of a hotplug cpu action.
381 void snapshot_timebase(void)
383 __get_cpu_var(last_jiffy
) = get_tb_or_rtc();
387 void __delay(unsigned long loops
)
395 /* the RTCL register wraps at 1000000000 */
396 diff
= get_rtcl() - start
;
399 } while (diff
< loops
);
402 while (get_tbl() - start
< loops
)
407 EXPORT_SYMBOL(__delay
);
409 void udelay(unsigned long usecs
)
411 __delay(tb_ticks_per_usec
* usecs
);
413 EXPORT_SYMBOL(udelay
);
416 unsigned long profile_pc(struct pt_regs
*regs
)
418 unsigned long pc
= instruction_pointer(regs
);
420 if (in_lock_functions(pc
))
425 EXPORT_SYMBOL(profile_pc
);
428 #ifdef CONFIG_PPC_ISERIES
431 * This function recalibrates the timebase based on the 49-bit time-of-day
432 * value in the Titan chip. The Titan is much more accurate than the value
433 * returned by the service processor for the timebase frequency.
436 static int __init
iSeries_tb_recal(void)
438 unsigned long titan
, tb
;
440 /* Make sure we only run on iSeries */
441 if (!firmware_has_feature(FW_FEATURE_ISERIES
))
445 titan
= HvCallXm_loadTod();
446 if ( iSeries_recal_titan
) {
447 unsigned long tb_ticks
= tb
- iSeries_recal_tb
;
448 unsigned long titan_usec
= (titan
- iSeries_recal_titan
) >> 12;
449 unsigned long new_tb_ticks_per_sec
= (tb_ticks
* USEC_PER_SEC
)/titan_usec
;
450 unsigned long new_tb_ticks_per_jiffy
=
451 DIV_ROUND_CLOSEST(new_tb_ticks_per_sec
, HZ
);
452 long tick_diff
= new_tb_ticks_per_jiffy
- tb_ticks_per_jiffy
;
454 /* make sure tb_ticks_per_sec and tb_ticks_per_jiffy are consistent */
455 new_tb_ticks_per_sec
= new_tb_ticks_per_jiffy
* HZ
;
457 if ( tick_diff
< 0 ) {
458 tick_diff
= -tick_diff
;
462 if ( tick_diff
< tb_ticks_per_jiffy
/25 ) {
463 printk( "Titan recalibrate: new tb_ticks_per_jiffy = %lu (%c%ld)\n",
464 new_tb_ticks_per_jiffy
, sign
, tick_diff
);
465 tb_ticks_per_jiffy
= new_tb_ticks_per_jiffy
;
466 tb_ticks_per_sec
= new_tb_ticks_per_sec
;
467 calc_cputime_factors();
468 vdso_data
->tb_ticks_per_sec
= tb_ticks_per_sec
;
469 setup_cputime_one_jiffy();
472 printk( "Titan recalibrate: FAILED (difference > 4 percent)\n"
473 " new tb_ticks_per_jiffy = %lu\n"
474 " old tb_ticks_per_jiffy = %lu\n",
475 new_tb_ticks_per_jiffy
, tb_ticks_per_jiffy
);
479 iSeries_recal_titan
= titan
;
480 iSeries_recal_tb
= tb
;
482 /* Called here as now we know accurate values for the timebase */
486 late_initcall(iSeries_tb_recal
);
488 /* Called from platform early init */
489 void __init
iSeries_time_init_early(void)
491 iSeries_recal_tb
= get_tb();
492 iSeries_recal_titan
= HvCallXm_loadTod();
494 #endif /* CONFIG_PPC_ISERIES */
496 #ifdef CONFIG_PERF_EVENTS
499 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
502 static inline unsigned long test_perf_event_pending(void)
506 asm volatile("lbz %0,%1(13)"
508 : "i" (offsetof(struct paca_struct
, perf_event_pending
)));
512 static inline void set_perf_event_pending_flag(void)
514 asm volatile("stb %0,%1(13)" : :
516 "i" (offsetof(struct paca_struct
, perf_event_pending
)));
519 static inline void clear_perf_event_pending(void)
521 asm volatile("stb %0,%1(13)" : :
523 "i" (offsetof(struct paca_struct
, perf_event_pending
)));
528 DEFINE_PER_CPU(u8
, perf_event_pending
);
530 #define set_perf_event_pending_flag() __get_cpu_var(perf_event_pending) = 1
531 #define test_perf_event_pending() __get_cpu_var(perf_event_pending)
532 #define clear_perf_event_pending() __get_cpu_var(perf_event_pending) = 0
534 #endif /* 32 vs 64 bit */
536 void set_perf_event_pending(void)
539 set_perf_event_pending_flag();
544 #else /* CONFIG_PERF_EVENTS */
546 #define test_perf_event_pending() 0
547 #define clear_perf_event_pending()
549 #endif /* CONFIG_PERF_EVENTS */
552 * For iSeries shared processors, we have to let the hypervisor
553 * set the hardware decrementer. We set a virtual decrementer
554 * in the lppaca and call the hypervisor if the virtual
555 * decrementer is less than the current value in the hardware
556 * decrementer. (almost always the new decrementer value will
557 * be greater than the current hardware decementer so the hypervisor
558 * call will not be needed)
562 * timer_interrupt - gets called when the decrementer overflows,
563 * with interrupts disabled.
565 void timer_interrupt(struct pt_regs
* regs
)
567 struct pt_regs
*old_regs
;
568 struct decrementer_clock
*decrementer
= &__get_cpu_var(decrementers
);
569 struct clock_event_device
*evt
= &decrementer
->event
;
572 trace_timer_interrupt_entry(regs
);
574 __get_cpu_var(irq_stat
).timer_irqs
++;
576 /* Ensure a positive value is written to the decrementer, or else
577 * some CPUs will continuue to take decrementer exceptions */
578 set_dec(DECREMENTER_MAX
);
581 if (atomic_read(&ppc_n_lost_interrupts
) != 0)
585 now
= get_tb_or_rtc();
586 if (now
< decrementer
->next_tb
) {
587 /* not time for this event yet */
588 now
= decrementer
->next_tb
- now
;
589 if (now
<= DECREMENTER_MAX
)
591 trace_timer_interrupt_exit(regs
);
594 old_regs
= set_irq_regs(regs
);
597 calculate_steal_time();
599 if (test_perf_event_pending()) {
600 clear_perf_event_pending();
601 perf_event_do_pending();
604 #ifdef CONFIG_PPC_ISERIES
605 if (firmware_has_feature(FW_FEATURE_ISERIES
))
606 get_lppaca()->int_dword
.fields
.decr_int
= 0;
609 if (evt
->event_handler
)
610 evt
->event_handler(evt
);
612 #ifdef CONFIG_PPC_ISERIES
613 if (firmware_has_feature(FW_FEATURE_ISERIES
) && hvlpevent_is_pending())
614 process_hvlpevents();
618 /* collect purr register values often, for accurate calculations */
619 if (firmware_has_feature(FW_FEATURE_SPLPAR
)) {
620 struct cpu_usage
*cu
= &__get_cpu_var(cpu_usage_array
);
621 cu
->current_tb
= mfspr(SPRN_PURR
);
626 set_irq_regs(old_regs
);
628 trace_timer_interrupt_exit(regs
);
631 #ifdef CONFIG_SUSPEND
632 static void generic_suspend_disable_irqs(void)
634 /* Disable the decrementer, so that it doesn't interfere
643 static void generic_suspend_enable_irqs(void)
648 /* Overrides the weak version in kernel/power/main.c */
649 void arch_suspend_disable_irqs(void)
651 if (ppc_md
.suspend_disable_irqs
)
652 ppc_md
.suspend_disable_irqs();
653 generic_suspend_disable_irqs();
656 /* Overrides the weak version in kernel/power/main.c */
657 void arch_suspend_enable_irqs(void)
659 generic_suspend_enable_irqs();
660 if (ppc_md
.suspend_enable_irqs
)
661 ppc_md
.suspend_enable_irqs();
666 * Scheduler clock - returns current time in nanosec units.
668 * Note: mulhdu(a, b) (multiply high double unsigned) returns
669 * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
670 * are 64-bit unsigned numbers.
672 unsigned long long sched_clock(void)
676 return mulhdu(get_tb() - boot_tb
, tb_to_ns_scale
) << tb_to_ns_shift
;
679 static int __init
get_freq(char *name
, int cells
, unsigned long *val
)
681 struct device_node
*cpu
;
682 const unsigned int *fp
;
685 /* The cpu node should have timebase and clock frequency properties */
686 cpu
= of_find_node_by_type(NULL
, "cpu");
689 fp
= of_get_property(cpu
, name
, NULL
);
692 *val
= of_read_ulong(fp
, cells
);
701 /* should become __cpuinit when secondary_cpu_time_init also is */
702 void start_cpu_decrementer(void)
704 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
705 /* Clear any pending timer interrupts */
706 mtspr(SPRN_TSR
, TSR_ENW
| TSR_WIS
| TSR_DIS
| TSR_FIS
);
708 /* Enable decrementer interrupt */
709 mtspr(SPRN_TCR
, TCR_DIE
);
710 #endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */
713 void __init
generic_calibrate_decr(void)
715 ppc_tb_freq
= DEFAULT_TB_FREQ
; /* hardcoded default */
717 if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq
) &&
718 !get_freq("timebase-frequency", 1, &ppc_tb_freq
)) {
720 printk(KERN_ERR
"WARNING: Estimating decrementer frequency "
724 ppc_proc_freq
= DEFAULT_PROC_FREQ
; /* hardcoded default */
726 if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq
) &&
727 !get_freq("clock-frequency", 1, &ppc_proc_freq
)) {
729 printk(KERN_ERR
"WARNING: Estimating processor frequency "
734 int update_persistent_clock(struct timespec now
)
738 if (!ppc_md
.set_rtc_time
)
741 to_tm(now
.tv_sec
+ 1 + timezone_offset
, &tm
);
745 return ppc_md
.set_rtc_time(&tm
);
748 static void __read_persistent_clock(struct timespec
*ts
)
751 static int first
= 1;
754 /* XXX this is a litle fragile but will work okay in the short term */
757 if (ppc_md
.time_init
)
758 timezone_offset
= ppc_md
.time_init();
760 /* get_boot_time() isn't guaranteed to be safe to call late */
761 if (ppc_md
.get_boot_time
) {
762 ts
->tv_sec
= ppc_md
.get_boot_time() - timezone_offset
;
766 if (!ppc_md
.get_rtc_time
) {
770 ppc_md
.get_rtc_time(&tm
);
772 ts
->tv_sec
= mktime(tm
.tm_year
+1900, tm
.tm_mon
+1, tm
.tm_mday
,
773 tm
.tm_hour
, tm
.tm_min
, tm
.tm_sec
);
776 void read_persistent_clock(struct timespec
*ts
)
778 __read_persistent_clock(ts
);
780 /* Sanitize it in case real time clock is set below EPOCH */
781 if (ts
->tv_sec
< 0) {
788 /* clocksource code */
789 static cycle_t
rtc_read(struct clocksource
*cs
)
791 return (cycle_t
)get_rtc();
794 static cycle_t
timebase_read(struct clocksource
*cs
)
796 return (cycle_t
)get_tb();
799 void update_vsyscall(struct timespec
*wall_time
, struct timespec
*wtm
,
800 struct clocksource
*clock
, u32 mult
)
802 u64 new_tb_to_xs
, new_stamp_xsec
;
805 if (clock
!= &clocksource_timebase
)
808 /* Make userspace gettimeofday spin until we're done. */
809 ++vdso_data
->tb_update_count
;
812 /* XXX this assumes clock->shift == 22 */
813 /* 4611686018 ~= 2^(20+64-22) / 1e9 */
814 new_tb_to_xs
= (u64
) mult
* 4611686018ULL;
815 new_stamp_xsec
= (u64
) wall_time
->tv_nsec
* XSEC_PER_SEC
;
816 do_div(new_stamp_xsec
, 1000000000);
817 new_stamp_xsec
+= (u64
) wall_time
->tv_sec
* XSEC_PER_SEC
;
819 BUG_ON(wall_time
->tv_nsec
>= NSEC_PER_SEC
);
820 /* this is tv_nsec / 1e9 as a 0.32 fraction */
821 frac_sec
= ((u64
) wall_time
->tv_nsec
* 18446744073ULL) >> 32;
824 * tb_update_count is used to allow the userspace gettimeofday code
825 * to assure itself that it sees a consistent view of the tb_to_xs and
826 * stamp_xsec variables. It reads the tb_update_count, then reads
827 * tb_to_xs and stamp_xsec and then reads tb_update_count again. If
828 * the two values of tb_update_count match and are even then the
829 * tb_to_xs and stamp_xsec values are consistent. If not, then it
830 * loops back and reads them again until this criteria is met.
831 * We expect the caller to have done the first increment of
832 * vdso_data->tb_update_count already.
834 vdso_data
->tb_orig_stamp
= clock
->cycle_last
;
835 vdso_data
->stamp_xsec
= new_stamp_xsec
;
836 vdso_data
->tb_to_xs
= new_tb_to_xs
;
837 vdso_data
->wtom_clock_sec
= wtm
->tv_sec
;
838 vdso_data
->wtom_clock_nsec
= wtm
->tv_nsec
;
839 vdso_data
->stamp_xtime
= *wall_time
;
840 vdso_data
->stamp_sec_fraction
= frac_sec
;
842 ++(vdso_data
->tb_update_count
);
845 void update_vsyscall_tz(void)
847 /* Make userspace gettimeofday spin until we're done. */
848 ++vdso_data
->tb_update_count
;
850 vdso_data
->tz_minuteswest
= sys_tz
.tz_minuteswest
;
851 vdso_data
->tz_dsttime
= sys_tz
.tz_dsttime
;
853 ++vdso_data
->tb_update_count
;
856 static void __init
clocksource_init(void)
858 struct clocksource
*clock
;
861 clock
= &clocksource_rtc
;
863 clock
= &clocksource_timebase
;
865 clock
->mult
= clocksource_hz2mult(tb_ticks_per_sec
, clock
->shift
);
867 if (clocksource_register(clock
)) {
868 printk(KERN_ERR
"clocksource: %s is already registered\n",
873 printk(KERN_INFO
"clocksource: %s mult[%x] shift[%d] registered\n",
874 clock
->name
, clock
->mult
, clock
->shift
);
877 static int decrementer_set_next_event(unsigned long evt
,
878 struct clock_event_device
*dev
)
880 __get_cpu_var(decrementers
).next_tb
= get_tb_or_rtc() + evt
;
885 static void decrementer_set_mode(enum clock_event_mode mode
,
886 struct clock_event_device
*dev
)
888 if (mode
!= CLOCK_EVT_MODE_ONESHOT
)
889 decrementer_set_next_event(DECREMENTER_MAX
, dev
);
892 static inline uint64_t div_sc64(unsigned long ticks
, unsigned long nsec
,
895 uint64_t tmp
= ((uint64_t)ticks
) << shift
;
901 static void __init
setup_clockevent_multiplier(unsigned long hz
)
903 u64 mult
, shift
= 32;
906 mult
= div_sc64(hz
, NSEC_PER_SEC
, shift
);
907 if (mult
&& (mult
>> 32UL) == 0UL)
913 decrementer_clockevent
.shift
= shift
;
914 decrementer_clockevent
.mult
= mult
;
917 static void register_decrementer_clockevent(int cpu
)
919 struct clock_event_device
*dec
= &per_cpu(decrementers
, cpu
).event
;
921 *dec
= decrementer_clockevent
;
922 dec
->cpumask
= cpumask_of(cpu
);
924 printk_once(KERN_DEBUG
"clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
925 dec
->name
, dec
->mult
, dec
->shift
, cpu
);
927 clockevents_register_device(dec
);
930 static void __init
init_decrementer_clockevent(void)
932 int cpu
= smp_processor_id();
934 setup_clockevent_multiplier(ppc_tb_freq
);
935 decrementer_clockevent
.max_delta_ns
=
936 clockevent_delta2ns(DECREMENTER_MAX
, &decrementer_clockevent
);
937 decrementer_clockevent
.min_delta_ns
=
938 clockevent_delta2ns(2, &decrementer_clockevent
);
940 register_decrementer_clockevent(cpu
);
943 void secondary_cpu_time_init(void)
945 /* Start the decrementer on CPUs that have manual control
948 start_cpu_decrementer();
950 /* FIME: Should make unrelatred change to move snapshot_timebase
952 register_decrementer_clockevent(smp_processor_id());
955 /* This function is only called on the boot processor */
956 void __init
time_init(void)
958 struct div_result res
;
963 /* 601 processor: dec counts down by 128 every 128ns */
964 ppc_tb_freq
= 1000000000;
966 /* Normal PowerPC with timebase register */
967 ppc_md
.calibrate_decr();
968 printk(KERN_DEBUG
"time_init: decrementer frequency = %lu.%.6lu MHz\n",
969 ppc_tb_freq
/ 1000000, ppc_tb_freq
% 1000000);
970 printk(KERN_DEBUG
"time_init: processor frequency = %lu.%.6lu MHz\n",
971 ppc_proc_freq
/ 1000000, ppc_proc_freq
% 1000000);
974 tb_ticks_per_jiffy
= ppc_tb_freq
/ HZ
;
975 tb_ticks_per_sec
= ppc_tb_freq
;
976 tb_ticks_per_usec
= ppc_tb_freq
/ 1000000;
977 calc_cputime_factors();
978 setup_cputime_one_jiffy();
981 * Compute scale factor for sched_clock.
982 * The calibrate_decr() function has set tb_ticks_per_sec,
983 * which is the timebase frequency.
984 * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
985 * the 128-bit result as a 64.64 fixed-point number.
986 * We then shift that number right until it is less than 1.0,
987 * giving us the scale factor and shift count to use in
990 div128_by_32(1000000000, 0, tb_ticks_per_sec
, &res
);
991 scale
= res
.result_low
;
992 for (shift
= 0; res
.result_high
!= 0; ++shift
) {
993 scale
= (scale
>> 1) | (res
.result_high
<< 63);
994 res
.result_high
>>= 1;
996 tb_to_ns_scale
= scale
;
997 tb_to_ns_shift
= shift
;
998 /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
999 boot_tb
= get_tb_or_rtc();
1001 /* If platform provided a timezone (pmac), we correct the time */
1002 if (timezone_offset
) {
1003 sys_tz
.tz_minuteswest
= -timezone_offset
/ 60;
1004 sys_tz
.tz_dsttime
= 0;
1007 vdso_data
->tb_update_count
= 0;
1008 vdso_data
->tb_ticks_per_sec
= tb_ticks_per_sec
;
1010 /* Start the decrementer on CPUs that have manual control
1013 start_cpu_decrementer();
1015 /* Register the clocksource, if we're not running on iSeries */
1016 if (!firmware_has_feature(FW_FEATURE_ISERIES
))
1019 init_decrementer_clockevent();
1024 #define STARTOFTIME 1970
1025 #define SECDAY 86400L
1026 #define SECYR (SECDAY * 365)
1027 #define leapyear(year) ((year) % 4 == 0 && \
1028 ((year) % 100 != 0 || (year) % 400 == 0))
1029 #define days_in_year(a) (leapyear(a) ? 366 : 365)
1030 #define days_in_month(a) (month_days[(a) - 1])
1032 static int month_days
[12] = {
1033 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
1037 * This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
1039 void GregorianDay(struct rtc_time
* tm
)
1044 int MonthOffset
[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
1046 lastYear
= tm
->tm_year
- 1;
1049 * Number of leap corrections to apply up to end of last year
1051 leapsToDate
= lastYear
/ 4 - lastYear
/ 100 + lastYear
/ 400;
1054 * This year is a leap year if it is divisible by 4 except when it is
1055 * divisible by 100 unless it is divisible by 400
1057 * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
1059 day
= tm
->tm_mon
> 2 && leapyear(tm
->tm_year
);
1061 day
+= lastYear
*365 + leapsToDate
+ MonthOffset
[tm
->tm_mon
-1] +
1064 tm
->tm_wday
= day
% 7;
1067 void to_tm(int tim
, struct rtc_time
* tm
)
1070 register long hms
, day
;
1075 /* Hours, minutes, seconds are easy */
1076 tm
->tm_hour
= hms
/ 3600;
1077 tm
->tm_min
= (hms
% 3600) / 60;
1078 tm
->tm_sec
= (hms
% 3600) % 60;
1080 /* Number of years in days */
1081 for (i
= STARTOFTIME
; day
>= days_in_year(i
); i
++)
1082 day
-= days_in_year(i
);
1085 /* Number of months in days left */
1086 if (leapyear(tm
->tm_year
))
1087 days_in_month(FEBRUARY
) = 29;
1088 for (i
= 1; day
>= days_in_month(i
); i
++)
1089 day
-= days_in_month(i
);
1090 days_in_month(FEBRUARY
) = 28;
1093 /* Days are what is left over (+1) from all that. */
1094 tm
->tm_mday
= day
+ 1;
1097 * Determine the day of week
1103 * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
1106 void div128_by_32(u64 dividend_high
, u64 dividend_low
,
1107 unsigned divisor
, struct div_result
*dr
)
1109 unsigned long a
, b
, c
, d
;
1110 unsigned long w
, x
, y
, z
;
1113 a
= dividend_high
>> 32;
1114 b
= dividend_high
& 0xffffffff;
1115 c
= dividend_low
>> 32;
1116 d
= dividend_low
& 0xffffffff;
1119 ra
= ((u64
)(a
- (w
* divisor
)) << 32) + b
;
1121 rb
= ((u64
) do_div(ra
, divisor
) << 32) + c
;
1124 rc
= ((u64
) do_div(rb
, divisor
) << 32) + d
;
1127 do_div(rc
, divisor
);
1130 dr
->result_high
= ((u64
)w
<< 32) + x
;
1131 dr
->result_low
= ((u64
)y
<< 32) + z
;
1135 /* We don't need to calibrate delay, we use the CPU timebase for that */
1136 void calibrate_delay(void)
1138 /* Some generic code (such as spinlock debug) use loops_per_jiffy
1139 * as the number of __delay(1) in a jiffy, so make it so
1141 loops_per_jiffy
= tb_ticks_per_jiffy
;
1144 static int __init
rtc_init(void)
1146 struct platform_device
*pdev
;
1148 if (!ppc_md
.get_rtc_time
)
1151 pdev
= platform_device_register_simple("rtc-generic", -1, NULL
, 0);
1153 return PTR_ERR(pdev
);
1158 module_init(rtc_init
);