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 u64 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
;
235 if (i
== vpa
->dtl_idx
)
237 while (i
< vpa
->dtl_idx
) {
239 dtl_consumer(dtl
, i
);
241 tb_delta
= dtl
->enqueue_to_dispatch_time
+
242 dtl
->ready_to_enqueue_time
;
244 if (i
+ N_DISPATCH_LOG
< vpa
->dtl_idx
) {
245 /* buffer has overflowed */
246 i
= vpa
->dtl_idx
- N_DISPATCH_LOG
;
247 dtl
= local_paca
->dispatch_log
+ (i
% N_DISPATCH_LOG
);
256 dtl
= local_paca
->dispatch_log
;
258 local_paca
->dtl_ridx
= i
;
259 local_paca
->dtl_curr
= dtl
;
264 * Accumulate stolen time by scanning the dispatch trace log.
265 * Called on entry from user mode.
267 void accumulate_stolen_time(void)
271 u8 save_soft_enabled
= local_paca
->soft_enabled
;
272 u8 save_hard_enabled
= local_paca
->hard_enabled
;
274 /* We are called early in the exception entry, before
275 * soft/hard_enabled are sync'ed to the expected state
276 * for the exception. We are hard disabled but the PACA
277 * needs to reflect that so various debug stuff doesn't
280 local_paca
->soft_enabled
= 0;
281 local_paca
->hard_enabled
= 0;
283 sst
= scan_dispatch_log(local_paca
->starttime_user
);
284 ust
= scan_dispatch_log(local_paca
->starttime
);
285 local_paca
->system_time
-= sst
;
286 local_paca
->user_time
-= ust
;
287 local_paca
->stolen_time
+= ust
+ sst
;
289 local_paca
->soft_enabled
= save_soft_enabled
;
290 local_paca
->hard_enabled
= save_hard_enabled
;
293 static inline u64
calculate_stolen_time(u64 stop_tb
)
297 if (get_paca()->dtl_ridx
!= get_paca()->lppaca_ptr
->dtl_idx
) {
298 stolen
= scan_dispatch_log(stop_tb
);
299 get_paca()->system_time
-= stolen
;
302 stolen
+= get_paca()->stolen_time
;
303 get_paca()->stolen_time
= 0;
307 #else /* CONFIG_PPC_SPLPAR */
308 static inline u64
calculate_stolen_time(u64 stop_tb
)
313 #endif /* CONFIG_PPC_SPLPAR */
316 * Account time for a transition between system, hard irq
319 void account_system_vtime(struct task_struct
*tsk
)
321 u64 now
, nowscaled
, delta
, deltascaled
;
323 u64 stolen
, udelta
, sys_scaled
, user_scaled
;
325 local_irq_save(flags
);
327 nowscaled
= read_spurr(now
);
328 get_paca()->system_time
+= now
- get_paca()->starttime
;
329 get_paca()->starttime
= now
;
330 deltascaled
= nowscaled
- get_paca()->startspurr
;
331 get_paca()->startspurr
= nowscaled
;
333 stolen
= calculate_stolen_time(now
);
335 delta
= get_paca()->system_time
;
336 get_paca()->system_time
= 0;
337 udelta
= get_paca()->user_time
- get_paca()->utime_sspurr
;
338 get_paca()->utime_sspurr
= get_paca()->user_time
;
341 * Because we don't read the SPURR on every kernel entry/exit,
342 * deltascaled includes both user and system SPURR ticks.
343 * Apportion these ticks to system SPURR ticks and user
344 * SPURR ticks in the same ratio as the system time (delta)
345 * and user time (udelta) values obtained from the timebase
346 * over the same interval. The system ticks get accounted here;
347 * the user ticks get saved up in paca->user_time_scaled to be
348 * used by account_process_tick.
351 user_scaled
= udelta
;
352 if (deltascaled
!= delta
+ udelta
) {
354 sys_scaled
= deltascaled
* delta
/ (delta
+ udelta
);
355 user_scaled
= deltascaled
- sys_scaled
;
357 sys_scaled
= deltascaled
;
360 get_paca()->user_time_scaled
+= user_scaled
;
362 if (in_interrupt() || idle_task(smp_processor_id()) != tsk
) {
363 account_system_time(tsk
, 0, delta
, sys_scaled
);
365 account_steal_time(stolen
);
367 account_idle_time(delta
+ stolen
);
369 local_irq_restore(flags
);
371 EXPORT_SYMBOL_GPL(account_system_vtime
);
374 * Transfer the user and system times accumulated in the paca
375 * by the exception entry and exit code to the generic process
376 * user and system time records.
377 * Must be called with interrupts disabled.
378 * Assumes that account_system_vtime() has been called recently
379 * (i.e. since the last entry from usermode) so that
380 * get_paca()->user_time_scaled is up to date.
382 void account_process_tick(struct task_struct
*tsk
, int user_tick
)
384 cputime_t utime
, utimescaled
;
386 utime
= get_paca()->user_time
;
387 utimescaled
= get_paca()->user_time_scaled
;
388 get_paca()->user_time
= 0;
389 get_paca()->user_time_scaled
= 0;
390 get_paca()->utime_sspurr
= 0;
391 account_user_time(tsk
, utime
, utimescaled
);
394 #else /* ! CONFIG_VIRT_CPU_ACCOUNTING */
395 #define calc_cputime_factors()
398 void __delay(unsigned long loops
)
406 /* the RTCL register wraps at 1000000000 */
407 diff
= get_rtcl() - start
;
410 } while (diff
< loops
);
413 while (get_tbl() - start
< loops
)
418 EXPORT_SYMBOL(__delay
);
420 void udelay(unsigned long usecs
)
422 __delay(tb_ticks_per_usec
* usecs
);
424 EXPORT_SYMBOL(udelay
);
427 unsigned long profile_pc(struct pt_regs
*regs
)
429 unsigned long pc
= instruction_pointer(regs
);
431 if (in_lock_functions(pc
))
436 EXPORT_SYMBOL(profile_pc
);
439 #ifdef CONFIG_PPC_ISERIES
442 * This function recalibrates the timebase based on the 49-bit time-of-day
443 * value in the Titan chip. The Titan is much more accurate than the value
444 * returned by the service processor for the timebase frequency.
447 static int __init
iSeries_tb_recal(void)
449 unsigned long titan
, tb
;
451 /* Make sure we only run on iSeries */
452 if (!firmware_has_feature(FW_FEATURE_ISERIES
))
456 titan
= HvCallXm_loadTod();
457 if ( iSeries_recal_titan
) {
458 unsigned long tb_ticks
= tb
- iSeries_recal_tb
;
459 unsigned long titan_usec
= (titan
- iSeries_recal_titan
) >> 12;
460 unsigned long new_tb_ticks_per_sec
= (tb_ticks
* USEC_PER_SEC
)/titan_usec
;
461 unsigned long new_tb_ticks_per_jiffy
=
462 DIV_ROUND_CLOSEST(new_tb_ticks_per_sec
, HZ
);
463 long tick_diff
= new_tb_ticks_per_jiffy
- tb_ticks_per_jiffy
;
465 /* make sure tb_ticks_per_sec and tb_ticks_per_jiffy are consistent */
466 new_tb_ticks_per_sec
= new_tb_ticks_per_jiffy
* HZ
;
468 if ( tick_diff
< 0 ) {
469 tick_diff
= -tick_diff
;
473 if ( tick_diff
< tb_ticks_per_jiffy
/25 ) {
474 printk( "Titan recalibrate: new tb_ticks_per_jiffy = %lu (%c%ld)\n",
475 new_tb_ticks_per_jiffy
, sign
, tick_diff
);
476 tb_ticks_per_jiffy
= new_tb_ticks_per_jiffy
;
477 tb_ticks_per_sec
= new_tb_ticks_per_sec
;
478 calc_cputime_factors();
479 vdso_data
->tb_ticks_per_sec
= tb_ticks_per_sec
;
480 setup_cputime_one_jiffy();
483 printk( "Titan recalibrate: FAILED (difference > 4 percent)\n"
484 " new tb_ticks_per_jiffy = %lu\n"
485 " old tb_ticks_per_jiffy = %lu\n",
486 new_tb_ticks_per_jiffy
, tb_ticks_per_jiffy
);
490 iSeries_recal_titan
= titan
;
491 iSeries_recal_tb
= tb
;
493 /* Called here as now we know accurate values for the timebase */
497 late_initcall(iSeries_tb_recal
);
499 /* Called from platform early init */
500 void __init
iSeries_time_init_early(void)
502 iSeries_recal_tb
= get_tb();
503 iSeries_recal_titan
= HvCallXm_loadTod();
505 #endif /* CONFIG_PPC_ISERIES */
507 #ifdef CONFIG_IRQ_WORK
510 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
513 static inline unsigned long test_irq_work_pending(void)
517 asm volatile("lbz %0,%1(13)"
519 : "i" (offsetof(struct paca_struct
, irq_work_pending
)));
523 static inline void set_irq_work_pending_flag(void)
525 asm volatile("stb %0,%1(13)" : :
527 "i" (offsetof(struct paca_struct
, irq_work_pending
)));
530 static inline void clear_irq_work_pending(void)
532 asm volatile("stb %0,%1(13)" : :
534 "i" (offsetof(struct paca_struct
, irq_work_pending
)));
539 DEFINE_PER_CPU(u8
, irq_work_pending
);
541 #define set_irq_work_pending_flag() __get_cpu_var(irq_work_pending) = 1
542 #define test_irq_work_pending() __get_cpu_var(irq_work_pending)
543 #define clear_irq_work_pending() __get_cpu_var(irq_work_pending) = 0
545 #endif /* 32 vs 64 bit */
547 void set_irq_work_pending(void)
550 set_irq_work_pending_flag();
555 #else /* CONFIG_IRQ_WORK */
557 #define test_irq_work_pending() 0
558 #define clear_irq_work_pending()
560 #endif /* CONFIG_IRQ_WORK */
563 * For iSeries shared processors, we have to let the hypervisor
564 * set the hardware decrementer. We set a virtual decrementer
565 * in the lppaca and call the hypervisor if the virtual
566 * decrementer is less than the current value in the hardware
567 * decrementer. (almost always the new decrementer value will
568 * be greater than the current hardware decementer so the hypervisor
569 * call will not be needed)
573 * timer_interrupt - gets called when the decrementer overflows,
574 * with interrupts disabled.
576 void timer_interrupt(struct pt_regs
* regs
)
578 struct pt_regs
*old_regs
;
579 struct decrementer_clock
*decrementer
= &__get_cpu_var(decrementers
);
580 struct clock_event_device
*evt
= &decrementer
->event
;
583 /* Ensure a positive value is written to the decrementer, or else
584 * some CPUs will continue to take decrementer exceptions.
586 set_dec(DECREMENTER_MAX
);
588 /* Some implementations of hotplug will get timer interrupts while
589 * offline, just ignore these
591 if (!cpu_online(smp_processor_id()))
594 trace_timer_interrupt_entry(regs
);
596 __get_cpu_var(irq_stat
).timer_irqs
++;
598 #if defined(CONFIG_PPC32) && defined(CONFIG_PMAC)
599 if (atomic_read(&ppc_n_lost_interrupts
) != 0)
603 old_regs
= set_irq_regs(regs
);
606 if (test_irq_work_pending()) {
607 clear_irq_work_pending();
611 #ifdef CONFIG_PPC_ISERIES
612 if (firmware_has_feature(FW_FEATURE_ISERIES
))
613 get_lppaca()->int_dword
.fields
.decr_int
= 0;
616 now
= get_tb_or_rtc();
617 if (now
>= decrementer
->next_tb
) {
618 decrementer
->next_tb
= ~(u64
)0;
619 if (evt
->event_handler
)
620 evt
->event_handler(evt
);
622 now
= decrementer
->next_tb
- now
;
623 if (now
<= DECREMENTER_MAX
)
627 #ifdef CONFIG_PPC_ISERIES
628 if (firmware_has_feature(FW_FEATURE_ISERIES
) && hvlpevent_is_pending())
629 process_hvlpevents();
633 /* collect purr register values often, for accurate calculations */
634 if (firmware_has_feature(FW_FEATURE_SPLPAR
)) {
635 struct cpu_usage
*cu
= &__get_cpu_var(cpu_usage_array
);
636 cu
->current_tb
= mfspr(SPRN_PURR
);
641 set_irq_regs(old_regs
);
643 trace_timer_interrupt_exit(regs
);
646 #ifdef CONFIG_SUSPEND
647 static void generic_suspend_disable_irqs(void)
649 /* Disable the decrementer, so that it doesn't interfere
658 static void generic_suspend_enable_irqs(void)
663 /* Overrides the weak version in kernel/power/main.c */
664 void arch_suspend_disable_irqs(void)
666 if (ppc_md
.suspend_disable_irqs
)
667 ppc_md
.suspend_disable_irqs();
668 generic_suspend_disable_irqs();
671 /* Overrides the weak version in kernel/power/main.c */
672 void arch_suspend_enable_irqs(void)
674 generic_suspend_enable_irqs();
675 if (ppc_md
.suspend_enable_irqs
)
676 ppc_md
.suspend_enable_irqs();
681 * Scheduler clock - returns current time in nanosec units.
683 * Note: mulhdu(a, b) (multiply high double unsigned) returns
684 * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
685 * are 64-bit unsigned numbers.
687 unsigned long long sched_clock(void)
691 return mulhdu(get_tb() - boot_tb
, tb_to_ns_scale
) << tb_to_ns_shift
;
694 static int __init
get_freq(char *name
, int cells
, unsigned long *val
)
696 struct device_node
*cpu
;
697 const unsigned int *fp
;
700 /* The cpu node should have timebase and clock frequency properties */
701 cpu
= of_find_node_by_type(NULL
, "cpu");
704 fp
= of_get_property(cpu
, name
, NULL
);
707 *val
= of_read_ulong(fp
, cells
);
716 /* should become __cpuinit when secondary_cpu_time_init also is */
717 void start_cpu_decrementer(void)
719 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
720 /* Clear any pending timer interrupts */
721 mtspr(SPRN_TSR
, TSR_ENW
| TSR_WIS
| TSR_DIS
| TSR_FIS
);
723 /* Enable decrementer interrupt */
724 mtspr(SPRN_TCR
, TCR_DIE
);
725 #endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */
728 void __init
generic_calibrate_decr(void)
730 ppc_tb_freq
= DEFAULT_TB_FREQ
; /* hardcoded default */
732 if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq
) &&
733 !get_freq("timebase-frequency", 1, &ppc_tb_freq
)) {
735 printk(KERN_ERR
"WARNING: Estimating decrementer frequency "
739 ppc_proc_freq
= DEFAULT_PROC_FREQ
; /* hardcoded default */
741 if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq
) &&
742 !get_freq("clock-frequency", 1, &ppc_proc_freq
)) {
744 printk(KERN_ERR
"WARNING: Estimating processor frequency "
749 int update_persistent_clock(struct timespec now
)
753 if (!ppc_md
.set_rtc_time
)
756 to_tm(now
.tv_sec
+ 1 + timezone_offset
, &tm
);
760 return ppc_md
.set_rtc_time(&tm
);
763 static void __read_persistent_clock(struct timespec
*ts
)
766 static int first
= 1;
769 /* XXX this is a litle fragile but will work okay in the short term */
772 if (ppc_md
.time_init
)
773 timezone_offset
= ppc_md
.time_init();
775 /* get_boot_time() isn't guaranteed to be safe to call late */
776 if (ppc_md
.get_boot_time
) {
777 ts
->tv_sec
= ppc_md
.get_boot_time() - timezone_offset
;
781 if (!ppc_md
.get_rtc_time
) {
785 ppc_md
.get_rtc_time(&tm
);
787 ts
->tv_sec
= mktime(tm
.tm_year
+1900, tm
.tm_mon
+1, tm
.tm_mday
,
788 tm
.tm_hour
, tm
.tm_min
, tm
.tm_sec
);
791 void read_persistent_clock(struct timespec
*ts
)
793 __read_persistent_clock(ts
);
795 /* Sanitize it in case real time clock is set below EPOCH */
796 if (ts
->tv_sec
< 0) {
803 /* clocksource code */
804 static cycle_t
rtc_read(struct clocksource
*cs
)
806 return (cycle_t
)get_rtc();
809 static cycle_t
timebase_read(struct clocksource
*cs
)
811 return (cycle_t
)get_tb();
814 void update_vsyscall(struct timespec
*wall_time
, struct timespec
*wtm
,
815 struct clocksource
*clock
, u32 mult
)
817 u64 new_tb_to_xs
, new_stamp_xsec
;
820 if (clock
!= &clocksource_timebase
)
823 /* Make userspace gettimeofday spin until we're done. */
824 ++vdso_data
->tb_update_count
;
827 /* XXX this assumes clock->shift == 22 */
828 /* 4611686018 ~= 2^(20+64-22) / 1e9 */
829 new_tb_to_xs
= (u64
) mult
* 4611686018ULL;
830 new_stamp_xsec
= (u64
) wall_time
->tv_nsec
* XSEC_PER_SEC
;
831 do_div(new_stamp_xsec
, 1000000000);
832 new_stamp_xsec
+= (u64
) wall_time
->tv_sec
* XSEC_PER_SEC
;
834 BUG_ON(wall_time
->tv_nsec
>= NSEC_PER_SEC
);
835 /* this is tv_nsec / 1e9 as a 0.32 fraction */
836 frac_sec
= ((u64
) wall_time
->tv_nsec
* 18446744073ULL) >> 32;
839 * tb_update_count is used to allow the userspace gettimeofday code
840 * to assure itself that it sees a consistent view of the tb_to_xs and
841 * stamp_xsec variables. It reads the tb_update_count, then reads
842 * tb_to_xs and stamp_xsec and then reads tb_update_count again. If
843 * the two values of tb_update_count match and are even then the
844 * tb_to_xs and stamp_xsec values are consistent. If not, then it
845 * loops back and reads them again until this criteria is met.
846 * We expect the caller to have done the first increment of
847 * vdso_data->tb_update_count already.
849 vdso_data
->tb_orig_stamp
= clock
->cycle_last
;
850 vdso_data
->stamp_xsec
= new_stamp_xsec
;
851 vdso_data
->tb_to_xs
= new_tb_to_xs
;
852 vdso_data
->wtom_clock_sec
= wtm
->tv_sec
;
853 vdso_data
->wtom_clock_nsec
= wtm
->tv_nsec
;
854 vdso_data
->stamp_xtime
= *wall_time
;
855 vdso_data
->stamp_sec_fraction
= frac_sec
;
857 ++(vdso_data
->tb_update_count
);
860 void update_vsyscall_tz(void)
862 /* Make userspace gettimeofday spin until we're done. */
863 ++vdso_data
->tb_update_count
;
865 vdso_data
->tz_minuteswest
= sys_tz
.tz_minuteswest
;
866 vdso_data
->tz_dsttime
= sys_tz
.tz_dsttime
;
868 ++vdso_data
->tb_update_count
;
871 static void __init
clocksource_init(void)
873 struct clocksource
*clock
;
876 clock
= &clocksource_rtc
;
878 clock
= &clocksource_timebase
;
880 clock
->mult
= clocksource_hz2mult(tb_ticks_per_sec
, clock
->shift
);
882 if (clocksource_register(clock
)) {
883 printk(KERN_ERR
"clocksource: %s is already registered\n",
888 printk(KERN_INFO
"clocksource: %s mult[%x] shift[%d] registered\n",
889 clock
->name
, clock
->mult
, clock
->shift
);
892 static int decrementer_set_next_event(unsigned long evt
,
893 struct clock_event_device
*dev
)
895 __get_cpu_var(decrementers
).next_tb
= get_tb_or_rtc() + evt
;
900 static void decrementer_set_mode(enum clock_event_mode mode
,
901 struct clock_event_device
*dev
)
903 if (mode
!= CLOCK_EVT_MODE_ONESHOT
)
904 decrementer_set_next_event(DECREMENTER_MAX
, dev
);
907 static inline uint64_t div_sc64(unsigned long ticks
, unsigned long nsec
,
910 uint64_t tmp
= ((uint64_t)ticks
) << shift
;
916 static void __init
setup_clockevent_multiplier(unsigned long hz
)
918 u64 mult
, shift
= 32;
921 mult
= div_sc64(hz
, NSEC_PER_SEC
, shift
);
922 if (mult
&& (mult
>> 32UL) == 0UL)
928 decrementer_clockevent
.shift
= shift
;
929 decrementer_clockevent
.mult
= mult
;
932 static void register_decrementer_clockevent(int cpu
)
934 struct clock_event_device
*dec
= &per_cpu(decrementers
, cpu
).event
;
936 *dec
= decrementer_clockevent
;
937 dec
->cpumask
= cpumask_of(cpu
);
939 printk_once(KERN_DEBUG
"clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
940 dec
->name
, dec
->mult
, dec
->shift
, cpu
);
942 clockevents_register_device(dec
);
945 static void __init
init_decrementer_clockevent(void)
947 int cpu
= smp_processor_id();
949 setup_clockevent_multiplier(ppc_tb_freq
);
950 decrementer_clockevent
.max_delta_ns
=
951 clockevent_delta2ns(DECREMENTER_MAX
, &decrementer_clockevent
);
952 decrementer_clockevent
.min_delta_ns
=
953 clockevent_delta2ns(2, &decrementer_clockevent
);
955 register_decrementer_clockevent(cpu
);
958 void secondary_cpu_time_init(void)
960 /* Start the decrementer on CPUs that have manual control
963 start_cpu_decrementer();
965 /* FIME: Should make unrelatred change to move snapshot_timebase
967 register_decrementer_clockevent(smp_processor_id());
970 /* This function is only called on the boot processor */
971 void __init
time_init(void)
973 struct div_result res
;
978 /* 601 processor: dec counts down by 128 every 128ns */
979 ppc_tb_freq
= 1000000000;
981 /* Normal PowerPC with timebase register */
982 ppc_md
.calibrate_decr();
983 printk(KERN_DEBUG
"time_init: decrementer frequency = %lu.%.6lu MHz\n",
984 ppc_tb_freq
/ 1000000, ppc_tb_freq
% 1000000);
985 printk(KERN_DEBUG
"time_init: processor frequency = %lu.%.6lu MHz\n",
986 ppc_proc_freq
/ 1000000, ppc_proc_freq
% 1000000);
989 tb_ticks_per_jiffy
= ppc_tb_freq
/ HZ
;
990 tb_ticks_per_sec
= ppc_tb_freq
;
991 tb_ticks_per_usec
= ppc_tb_freq
/ 1000000;
992 calc_cputime_factors();
993 setup_cputime_one_jiffy();
996 * Compute scale factor for sched_clock.
997 * The calibrate_decr() function has set tb_ticks_per_sec,
998 * which is the timebase frequency.
999 * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
1000 * the 128-bit result as a 64.64 fixed-point number.
1001 * We then shift that number right until it is less than 1.0,
1002 * giving us the scale factor and shift count to use in
1005 div128_by_32(1000000000, 0, tb_ticks_per_sec
, &res
);
1006 scale
= res
.result_low
;
1007 for (shift
= 0; res
.result_high
!= 0; ++shift
) {
1008 scale
= (scale
>> 1) | (res
.result_high
<< 63);
1009 res
.result_high
>>= 1;
1011 tb_to_ns_scale
= scale
;
1012 tb_to_ns_shift
= shift
;
1013 /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
1014 boot_tb
= get_tb_or_rtc();
1016 /* If platform provided a timezone (pmac), we correct the time */
1017 if (timezone_offset
) {
1018 sys_tz
.tz_minuteswest
= -timezone_offset
/ 60;
1019 sys_tz
.tz_dsttime
= 0;
1022 vdso_data
->tb_update_count
= 0;
1023 vdso_data
->tb_ticks_per_sec
= tb_ticks_per_sec
;
1025 /* Start the decrementer on CPUs that have manual control
1028 start_cpu_decrementer();
1030 /* Register the clocksource, if we're not running on iSeries */
1031 if (!firmware_has_feature(FW_FEATURE_ISERIES
))
1034 init_decrementer_clockevent();
1039 #define STARTOFTIME 1970
1040 #define SECDAY 86400L
1041 #define SECYR (SECDAY * 365)
1042 #define leapyear(year) ((year) % 4 == 0 && \
1043 ((year) % 100 != 0 || (year) % 400 == 0))
1044 #define days_in_year(a) (leapyear(a) ? 366 : 365)
1045 #define days_in_month(a) (month_days[(a) - 1])
1047 static int month_days
[12] = {
1048 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
1052 * This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
1054 void GregorianDay(struct rtc_time
* tm
)
1059 int MonthOffset
[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
1061 lastYear
= tm
->tm_year
- 1;
1064 * Number of leap corrections to apply up to end of last year
1066 leapsToDate
= lastYear
/ 4 - lastYear
/ 100 + lastYear
/ 400;
1069 * This year is a leap year if it is divisible by 4 except when it is
1070 * divisible by 100 unless it is divisible by 400
1072 * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
1074 day
= tm
->tm_mon
> 2 && leapyear(tm
->tm_year
);
1076 day
+= lastYear
*365 + leapsToDate
+ MonthOffset
[tm
->tm_mon
-1] +
1079 tm
->tm_wday
= day
% 7;
1082 void to_tm(int tim
, struct rtc_time
* tm
)
1085 register long hms
, day
;
1090 /* Hours, minutes, seconds are easy */
1091 tm
->tm_hour
= hms
/ 3600;
1092 tm
->tm_min
= (hms
% 3600) / 60;
1093 tm
->tm_sec
= (hms
% 3600) % 60;
1095 /* Number of years in days */
1096 for (i
= STARTOFTIME
; day
>= days_in_year(i
); i
++)
1097 day
-= days_in_year(i
);
1100 /* Number of months in days left */
1101 if (leapyear(tm
->tm_year
))
1102 days_in_month(FEBRUARY
) = 29;
1103 for (i
= 1; day
>= days_in_month(i
); i
++)
1104 day
-= days_in_month(i
);
1105 days_in_month(FEBRUARY
) = 28;
1108 /* Days are what is left over (+1) from all that. */
1109 tm
->tm_mday
= day
+ 1;
1112 * Determine the day of week
1118 * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
1121 void div128_by_32(u64 dividend_high
, u64 dividend_low
,
1122 unsigned divisor
, struct div_result
*dr
)
1124 unsigned long a
, b
, c
, d
;
1125 unsigned long w
, x
, y
, z
;
1128 a
= dividend_high
>> 32;
1129 b
= dividend_high
& 0xffffffff;
1130 c
= dividend_low
>> 32;
1131 d
= dividend_low
& 0xffffffff;
1134 ra
= ((u64
)(a
- (w
* divisor
)) << 32) + b
;
1136 rb
= ((u64
) do_div(ra
, divisor
) << 32) + c
;
1139 rc
= ((u64
) do_div(rb
, divisor
) << 32) + d
;
1142 do_div(rc
, divisor
);
1145 dr
->result_high
= ((u64
)w
<< 32) + x
;
1146 dr
->result_low
= ((u64
)y
<< 32) + z
;
1150 /* We don't need to calibrate delay, we use the CPU timebase for that */
1151 void calibrate_delay(void)
1153 /* Some generic code (such as spinlock debug) use loops_per_jiffy
1154 * as the number of __delay(1) in a jiffy, so make it so
1156 loops_per_jiffy
= tb_ticks_per_jiffy
;
1159 static int __init
rtc_init(void)
1161 struct platform_device
*pdev
;
1163 if (!ppc_md
.get_rtc_time
)
1166 pdev
= platform_device_register_simple("rtc-generic", -1, NULL
, 0);
1168 return PTR_ERR(pdev
);
1173 module_init(rtc_init
);