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.
21 * - for astronomical applications: add a new function to get
22 * non ambiguous timestamps even around leap seconds. This needs
23 * a new timestamp format and a good name.
25 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
26 * "A Kernel Model for Precision Timekeeping" by Dave Mills
28 * This program is free software; you can redistribute it and/or
29 * modify it under the terms of the GNU General Public License
30 * as published by the Free Software Foundation; either version
31 * 2 of the License, or (at your option) any later version.
34 #include <linux/errno.h>
35 #include <linux/export.h>
36 #include <linux/sched.h>
37 #include <linux/kernel.h>
38 #include <linux/param.h>
39 #include <linux/string.h>
41 #include <linux/interrupt.h>
42 #include <linux/timex.h>
43 #include <linux/kernel_stat.h>
44 #include <linux/time.h>
45 #include <linux/clockchips.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>
74 /* powerpc clocksource/clockevent code */
76 #include <linux/clockchips.h>
77 #include <linux/timekeeper_internal.h>
79 static cycle_t
rtc_read(struct clocksource
*);
80 static struct clocksource clocksource_rtc
= {
83 .flags
= CLOCK_SOURCE_IS_CONTINUOUS
,
84 .mask
= CLOCKSOURCE_MASK(64),
88 static cycle_t
timebase_read(struct clocksource
*);
89 static struct clocksource clocksource_timebase
= {
92 .flags
= CLOCK_SOURCE_IS_CONTINUOUS
,
93 .mask
= CLOCKSOURCE_MASK(64),
94 .read
= timebase_read
,
97 #define DECREMENTER_MAX 0x7fffffff
99 static int decrementer_set_next_event(unsigned long evt
,
100 struct clock_event_device
*dev
);
101 static void decrementer_set_mode(enum clock_event_mode mode
,
102 struct clock_event_device
*dev
);
104 struct clock_event_device decrementer_clockevent
= {
105 .name
= "decrementer",
108 .set_next_event
= decrementer_set_next_event
,
109 .set_mode
= decrementer_set_mode
,
110 .features
= CLOCK_EVT_FEAT_ONESHOT
| CLOCK_EVT_FEAT_C3STOP
,
112 EXPORT_SYMBOL(decrementer_clockevent
);
114 DEFINE_PER_CPU(u64
, decrementers_next_tb
);
115 static DEFINE_PER_CPU(struct clock_event_device
, decrementers
);
117 #define XSEC_PER_SEC (1024*1024)
120 #define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
122 /* compute ((xsec << 12) * max) >> 32 */
123 #define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
126 unsigned long tb_ticks_per_jiffy
;
127 unsigned long tb_ticks_per_usec
= 100; /* sane default */
128 EXPORT_SYMBOL(tb_ticks_per_usec
);
129 unsigned long tb_ticks_per_sec
;
130 EXPORT_SYMBOL(tb_ticks_per_sec
); /* for cputime_t conversions */
132 DEFINE_SPINLOCK(rtc_lock
);
133 EXPORT_SYMBOL_GPL(rtc_lock
);
135 static u64 tb_to_ns_scale __read_mostly
;
136 static unsigned tb_to_ns_shift __read_mostly
;
137 static u64 boot_tb __read_mostly
;
139 extern struct timezone sys_tz
;
140 static long timezone_offset
;
142 unsigned long ppc_proc_freq
;
143 EXPORT_SYMBOL_GPL(ppc_proc_freq
);
144 unsigned long ppc_tb_freq
;
145 EXPORT_SYMBOL_GPL(ppc_tb_freq
);
147 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
149 * Factors for converting from cputime_t (timebase ticks) to
150 * jiffies, microseconds, seconds, and clock_t (1/USER_HZ seconds).
151 * These are all stored as 0.64 fixed-point binary fractions.
153 u64 __cputime_jiffies_factor
;
154 EXPORT_SYMBOL(__cputime_jiffies_factor
);
155 u64 __cputime_usec_factor
;
156 EXPORT_SYMBOL(__cputime_usec_factor
);
157 u64 __cputime_sec_factor
;
158 EXPORT_SYMBOL(__cputime_sec_factor
);
159 u64 __cputime_clockt_factor
;
160 EXPORT_SYMBOL(__cputime_clockt_factor
);
161 DEFINE_PER_CPU(unsigned long, cputime_last_delta
);
162 DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta
);
164 cputime_t cputime_one_jiffy
;
166 void (*dtl_consumer
)(struct dtl_entry
*, u64
);
168 static void calc_cputime_factors(void)
170 struct div_result res
;
172 div128_by_32(HZ
, 0, tb_ticks_per_sec
, &res
);
173 __cputime_jiffies_factor
= res
.result_low
;
174 div128_by_32(1000000, 0, tb_ticks_per_sec
, &res
);
175 __cputime_usec_factor
= res
.result_low
;
176 div128_by_32(1, 0, tb_ticks_per_sec
, &res
);
177 __cputime_sec_factor
= res
.result_low
;
178 div128_by_32(USER_HZ
, 0, tb_ticks_per_sec
, &res
);
179 __cputime_clockt_factor
= res
.result_low
;
183 * Read the SPURR on systems that have it, otherwise the PURR,
184 * or if that doesn't exist return the timebase value passed in.
186 static u64
read_spurr(u64 tb
)
188 if (cpu_has_feature(CPU_FTR_SPURR
))
189 return mfspr(SPRN_SPURR
);
190 if (cpu_has_feature(CPU_FTR_PURR
))
191 return mfspr(SPRN_PURR
);
195 #ifdef CONFIG_PPC_SPLPAR
198 * Scan the dispatch trace log and count up the stolen time.
199 * Should be called with interrupts disabled.
201 static u64
scan_dispatch_log(u64 stop_tb
)
203 u64 i
= local_paca
->dtl_ridx
;
204 struct dtl_entry
*dtl
= local_paca
->dtl_curr
;
205 struct dtl_entry
*dtl_end
= local_paca
->dispatch_log_end
;
206 struct lppaca
*vpa
= local_paca
->lppaca_ptr
;
214 if (i
== be64_to_cpu(vpa
->dtl_idx
))
216 while (i
< be64_to_cpu(vpa
->dtl_idx
)) {
217 dtb
= be64_to_cpu(dtl
->timebase
);
218 tb_delta
= be32_to_cpu(dtl
->enqueue_to_dispatch_time
) +
219 be32_to_cpu(dtl
->ready_to_enqueue_time
);
221 if (i
+ N_DISPATCH_LOG
< be64_to_cpu(vpa
->dtl_idx
)) {
222 /* buffer has overflowed */
223 i
= be64_to_cpu(vpa
->dtl_idx
) - N_DISPATCH_LOG
;
224 dtl
= local_paca
->dispatch_log
+ (i
% N_DISPATCH_LOG
);
230 dtl_consumer(dtl
, i
);
235 dtl
= local_paca
->dispatch_log
;
237 local_paca
->dtl_ridx
= i
;
238 local_paca
->dtl_curr
= dtl
;
243 * Accumulate stolen time by scanning the dispatch trace log.
244 * Called on entry from user mode.
246 void accumulate_stolen_time(void)
250 u8 save_soft_enabled
= local_paca
->soft_enabled
;
252 /* We are called early in the exception entry, before
253 * soft/hard_enabled are sync'ed to the expected state
254 * for the exception. We are hard disabled but the PACA
255 * needs to reflect that so various debug stuff doesn't
258 local_paca
->soft_enabled
= 0;
260 sst
= scan_dispatch_log(local_paca
->starttime_user
);
261 ust
= scan_dispatch_log(local_paca
->starttime
);
262 local_paca
->system_time
-= sst
;
263 local_paca
->user_time
-= ust
;
264 local_paca
->stolen_time
+= ust
+ sst
;
266 local_paca
->soft_enabled
= save_soft_enabled
;
269 static inline u64
calculate_stolen_time(u64 stop_tb
)
273 if (get_paca()->dtl_ridx
!= be64_to_cpu(get_lppaca()->dtl_idx
)) {
274 stolen
= scan_dispatch_log(stop_tb
);
275 get_paca()->system_time
-= stolen
;
278 stolen
+= get_paca()->stolen_time
;
279 get_paca()->stolen_time
= 0;
283 #else /* CONFIG_PPC_SPLPAR */
284 static inline u64
calculate_stolen_time(u64 stop_tb
)
289 #endif /* CONFIG_PPC_SPLPAR */
292 * Account time for a transition between system, hard irq
295 static u64
vtime_delta(struct task_struct
*tsk
,
296 u64
*sys_scaled
, u64
*stolen
)
298 u64 now
, nowscaled
, deltascaled
;
299 u64 udelta
, delta
, user_scaled
;
301 WARN_ON_ONCE(!irqs_disabled());
304 nowscaled
= read_spurr(now
);
305 get_paca()->system_time
+= now
- get_paca()->starttime
;
306 get_paca()->starttime
= now
;
307 deltascaled
= nowscaled
- get_paca()->startspurr
;
308 get_paca()->startspurr
= nowscaled
;
310 *stolen
= calculate_stolen_time(now
);
312 delta
= get_paca()->system_time
;
313 get_paca()->system_time
= 0;
314 udelta
= get_paca()->user_time
- get_paca()->utime_sspurr
;
315 get_paca()->utime_sspurr
= get_paca()->user_time
;
318 * Because we don't read the SPURR on every kernel entry/exit,
319 * deltascaled includes both user and system SPURR ticks.
320 * Apportion these ticks to system SPURR ticks and user
321 * SPURR ticks in the same ratio as the system time (delta)
322 * and user time (udelta) values obtained from the timebase
323 * over the same interval. The system ticks get accounted here;
324 * the user ticks get saved up in paca->user_time_scaled to be
325 * used by account_process_tick.
328 user_scaled
= udelta
;
329 if (deltascaled
!= delta
+ udelta
) {
331 *sys_scaled
= deltascaled
* delta
/ (delta
+ udelta
);
332 user_scaled
= deltascaled
- *sys_scaled
;
334 *sys_scaled
= deltascaled
;
337 get_paca()->user_time_scaled
+= user_scaled
;
342 void vtime_account_system(struct task_struct
*tsk
)
344 u64 delta
, sys_scaled
, stolen
;
346 delta
= vtime_delta(tsk
, &sys_scaled
, &stolen
);
347 account_system_time(tsk
, 0, delta
, sys_scaled
);
349 account_steal_time(stolen
);
351 EXPORT_SYMBOL_GPL(vtime_account_system
);
353 void vtime_account_idle(struct task_struct
*tsk
)
355 u64 delta
, sys_scaled
, stolen
;
357 delta
= vtime_delta(tsk
, &sys_scaled
, &stolen
);
358 account_idle_time(delta
+ stolen
);
362 * Transfer the user time accumulated in the paca
363 * by the exception entry and exit code to the generic
364 * process user time records.
365 * Must be called with interrupts disabled.
366 * Assumes that vtime_account_system/idle() has been called
367 * recently (i.e. since the last entry from usermode) so that
368 * get_paca()->user_time_scaled is up to date.
370 void vtime_account_user(struct task_struct
*tsk
)
372 cputime_t utime
, utimescaled
;
374 utime
= get_paca()->user_time
;
375 utimescaled
= get_paca()->user_time_scaled
;
376 get_paca()->user_time
= 0;
377 get_paca()->user_time_scaled
= 0;
378 get_paca()->utime_sspurr
= 0;
379 account_user_time(tsk
, utime
, utimescaled
);
382 #else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
383 #define calc_cputime_factors()
386 void __delay(unsigned long loops
)
394 /* the RTCL register wraps at 1000000000 */
395 diff
= get_rtcl() - start
;
398 } while (diff
< loops
);
401 while (get_tbl() - start
< loops
)
406 EXPORT_SYMBOL(__delay
);
408 void udelay(unsigned long usecs
)
410 __delay(tb_ticks_per_usec
* usecs
);
412 EXPORT_SYMBOL(udelay
);
415 unsigned long profile_pc(struct pt_regs
*regs
)
417 unsigned long pc
= instruction_pointer(regs
);
419 if (in_lock_functions(pc
))
424 EXPORT_SYMBOL(profile_pc
);
427 #ifdef CONFIG_IRQ_WORK
430 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
433 static inline unsigned long test_irq_work_pending(void)
437 asm volatile("lbz %0,%1(13)"
439 : "i" (offsetof(struct paca_struct
, irq_work_pending
)));
443 static inline void set_irq_work_pending_flag(void)
445 asm volatile("stb %0,%1(13)" : :
447 "i" (offsetof(struct paca_struct
, irq_work_pending
)));
450 static inline void clear_irq_work_pending(void)
452 asm volatile("stb %0,%1(13)" : :
454 "i" (offsetof(struct paca_struct
, irq_work_pending
)));
459 DEFINE_PER_CPU(u8
, irq_work_pending
);
461 #define set_irq_work_pending_flag() __get_cpu_var(irq_work_pending) = 1
462 #define test_irq_work_pending() __get_cpu_var(irq_work_pending)
463 #define clear_irq_work_pending() __get_cpu_var(irq_work_pending) = 0
465 #endif /* 32 vs 64 bit */
467 void arch_irq_work_raise(void)
470 set_irq_work_pending_flag();
475 #else /* CONFIG_IRQ_WORK */
477 #define test_irq_work_pending() 0
478 #define clear_irq_work_pending()
480 #endif /* CONFIG_IRQ_WORK */
482 void __timer_interrupt(void)
484 struct pt_regs
*regs
= get_irq_regs();
485 u64
*next_tb
= &__get_cpu_var(decrementers_next_tb
);
486 struct clock_event_device
*evt
= &__get_cpu_var(decrementers
);
489 trace_timer_interrupt_entry(regs
);
491 if (test_irq_work_pending()) {
492 clear_irq_work_pending();
496 now
= get_tb_or_rtc();
497 if (now
>= *next_tb
) {
499 if (evt
->event_handler
)
500 evt
->event_handler(evt
);
501 __get_cpu_var(irq_stat
).timer_irqs_event
++;
503 now
= *next_tb
- now
;
504 if (now
<= DECREMENTER_MAX
)
506 /* We may have raced with new irq work */
507 if (test_irq_work_pending())
509 __get_cpu_var(irq_stat
).timer_irqs_others
++;
513 /* collect purr register values often, for accurate calculations */
514 if (firmware_has_feature(FW_FEATURE_SPLPAR
)) {
515 struct cpu_usage
*cu
= &__get_cpu_var(cpu_usage_array
);
516 cu
->current_tb
= mfspr(SPRN_PURR
);
520 trace_timer_interrupt_exit(regs
);
524 * timer_interrupt - gets called when the decrementer overflows,
525 * with interrupts disabled.
527 void timer_interrupt(struct pt_regs
* regs
)
529 struct pt_regs
*old_regs
;
530 u64
*next_tb
= &__get_cpu_var(decrementers_next_tb
);
532 /* Ensure a positive value is written to the decrementer, or else
533 * some CPUs will continue to take decrementer exceptions.
535 set_dec(DECREMENTER_MAX
);
537 /* Some implementations of hotplug will get timer interrupts while
538 * offline, just ignore these and we also need to set
539 * decrementers_next_tb as MAX to make sure __check_irq_replay
540 * don't replay timer interrupt when return, otherwise we'll trap
543 if (!cpu_online(smp_processor_id())) {
548 /* Conditionally hard-enable interrupts now that the DEC has been
549 * bumped to its maximum value
551 may_hard_irq_enable();
554 #if defined(CONFIG_PPC32) && defined(CONFIG_PPC_PMAC)
555 if (atomic_read(&ppc_n_lost_interrupts
) != 0)
559 old_regs
= set_irq_regs(regs
);
564 set_irq_regs(old_regs
);
568 * Hypervisor decrementer interrupts shouldn't occur but are sometimes
569 * left pending on exit from a KVM guest. We don't need to do anything
570 * to clear them, as they are edge-triggered.
572 void hdec_interrupt(struct pt_regs
*regs
)
576 #ifdef CONFIG_SUSPEND
577 static void generic_suspend_disable_irqs(void)
579 /* Disable the decrementer, so that it doesn't interfere
583 set_dec(DECREMENTER_MAX
);
585 set_dec(DECREMENTER_MAX
);
588 static void generic_suspend_enable_irqs(void)
593 /* Overrides the weak version in kernel/power/main.c */
594 void arch_suspend_disable_irqs(void)
596 if (ppc_md
.suspend_disable_irqs
)
597 ppc_md
.suspend_disable_irqs();
598 generic_suspend_disable_irqs();
601 /* Overrides the weak version in kernel/power/main.c */
602 void arch_suspend_enable_irqs(void)
604 generic_suspend_enable_irqs();
605 if (ppc_md
.suspend_enable_irqs
)
606 ppc_md
.suspend_enable_irqs();
611 * Scheduler clock - returns current time in nanosec units.
613 * Note: mulhdu(a, b) (multiply high double unsigned) returns
614 * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
615 * are 64-bit unsigned numbers.
617 unsigned long long sched_clock(void)
621 return mulhdu(get_tb() - boot_tb
, tb_to_ns_scale
) << tb_to_ns_shift
;
624 static int __init
get_freq(char *name
, int cells
, unsigned long *val
)
626 struct device_node
*cpu
;
630 /* The cpu node should have timebase and clock frequency properties */
631 cpu
= of_find_node_by_type(NULL
, "cpu");
634 fp
= of_get_property(cpu
, name
, NULL
);
637 *val
= of_read_ulong(fp
, cells
);
646 void start_cpu_decrementer(void)
648 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
649 /* Clear any pending timer interrupts */
650 mtspr(SPRN_TSR
, TSR_ENW
| TSR_WIS
| TSR_DIS
| TSR_FIS
);
652 /* Enable decrementer interrupt */
653 mtspr(SPRN_TCR
, TCR_DIE
);
654 #endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */
657 void __init
generic_calibrate_decr(void)
659 ppc_tb_freq
= DEFAULT_TB_FREQ
; /* hardcoded default */
661 if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq
) &&
662 !get_freq("timebase-frequency", 1, &ppc_tb_freq
)) {
664 printk(KERN_ERR
"WARNING: Estimating decrementer frequency "
668 ppc_proc_freq
= DEFAULT_PROC_FREQ
; /* hardcoded default */
670 if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq
) &&
671 !get_freq("clock-frequency", 1, &ppc_proc_freq
)) {
673 printk(KERN_ERR
"WARNING: Estimating processor frequency "
678 int update_persistent_clock(struct timespec now
)
682 if (!ppc_md
.set_rtc_time
)
685 to_tm(now
.tv_sec
+ 1 + timezone_offset
, &tm
);
689 return ppc_md
.set_rtc_time(&tm
);
692 static void __read_persistent_clock(struct timespec
*ts
)
695 static int first
= 1;
698 /* XXX this is a litle fragile but will work okay in the short term */
701 if (ppc_md
.time_init
)
702 timezone_offset
= ppc_md
.time_init();
704 /* get_boot_time() isn't guaranteed to be safe to call late */
705 if (ppc_md
.get_boot_time
) {
706 ts
->tv_sec
= ppc_md
.get_boot_time() - timezone_offset
;
710 if (!ppc_md
.get_rtc_time
) {
714 ppc_md
.get_rtc_time(&tm
);
716 ts
->tv_sec
= mktime(tm
.tm_year
+1900, tm
.tm_mon
+1, tm
.tm_mday
,
717 tm
.tm_hour
, tm
.tm_min
, tm
.tm_sec
);
720 void read_persistent_clock(struct timespec
*ts
)
722 __read_persistent_clock(ts
);
724 /* Sanitize it in case real time clock is set below EPOCH */
725 if (ts
->tv_sec
< 0) {
732 /* clocksource code */
733 static cycle_t
rtc_read(struct clocksource
*cs
)
735 return (cycle_t
)get_rtc();
738 static cycle_t
timebase_read(struct clocksource
*cs
)
740 return (cycle_t
)get_tb();
743 void update_vsyscall_old(struct timespec
*wall_time
, struct timespec
*wtm
,
744 struct clocksource
*clock
, u32 mult
, cycle_t cycle_last
)
746 u64 new_tb_to_xs
, new_stamp_xsec
;
749 if (clock
!= &clocksource_timebase
)
752 /* Make userspace gettimeofday spin until we're done. */
753 ++vdso_data
->tb_update_count
;
756 /* 19342813113834067 ~= 2^(20+64) / 1e9 */
757 new_tb_to_xs
= (u64
) mult
* (19342813113834067ULL >> clock
->shift
);
758 new_stamp_xsec
= (u64
) wall_time
->tv_nsec
* XSEC_PER_SEC
;
759 do_div(new_stamp_xsec
, 1000000000);
760 new_stamp_xsec
+= (u64
) wall_time
->tv_sec
* XSEC_PER_SEC
;
762 BUG_ON(wall_time
->tv_nsec
>= NSEC_PER_SEC
);
763 /* this is tv_nsec / 1e9 as a 0.32 fraction */
764 frac_sec
= ((u64
) wall_time
->tv_nsec
* 18446744073ULL) >> 32;
767 * tb_update_count is used to allow the userspace gettimeofday code
768 * to assure itself that it sees a consistent view of the tb_to_xs and
769 * stamp_xsec variables. It reads the tb_update_count, then reads
770 * tb_to_xs and stamp_xsec and then reads tb_update_count again. If
771 * the two values of tb_update_count match and are even then the
772 * tb_to_xs and stamp_xsec values are consistent. If not, then it
773 * loops back and reads them again until this criteria is met.
774 * We expect the caller to have done the first increment of
775 * vdso_data->tb_update_count already.
777 vdso_data
->tb_orig_stamp
= cycle_last
;
778 vdso_data
->stamp_xsec
= new_stamp_xsec
;
779 vdso_data
->tb_to_xs
= new_tb_to_xs
;
780 vdso_data
->wtom_clock_sec
= wtm
->tv_sec
;
781 vdso_data
->wtom_clock_nsec
= wtm
->tv_nsec
;
782 vdso_data
->stamp_xtime
= *wall_time
;
783 vdso_data
->stamp_sec_fraction
= frac_sec
;
785 ++(vdso_data
->tb_update_count
);
788 void update_vsyscall_tz(void)
790 vdso_data
->tz_minuteswest
= sys_tz
.tz_minuteswest
;
791 vdso_data
->tz_dsttime
= sys_tz
.tz_dsttime
;
794 static void __init
clocksource_init(void)
796 struct clocksource
*clock
;
799 clock
= &clocksource_rtc
;
801 clock
= &clocksource_timebase
;
803 if (clocksource_register_hz(clock
, tb_ticks_per_sec
)) {
804 printk(KERN_ERR
"clocksource: %s is already registered\n",
809 printk(KERN_INFO
"clocksource: %s mult[%x] shift[%d] registered\n",
810 clock
->name
, clock
->mult
, clock
->shift
);
813 static int decrementer_set_next_event(unsigned long evt
,
814 struct clock_event_device
*dev
)
816 __get_cpu_var(decrementers_next_tb
) = get_tb_or_rtc() + evt
;
819 /* We may have raced with new irq work */
820 if (test_irq_work_pending())
826 static void decrementer_set_mode(enum clock_event_mode mode
,
827 struct clock_event_device
*dev
)
829 if (mode
!= CLOCK_EVT_MODE_ONESHOT
)
830 decrementer_set_next_event(DECREMENTER_MAX
, dev
);
833 /* Interrupt handler for the timer broadcast IPI */
834 void tick_broadcast_ipi_handler(void)
836 u64
*next_tb
= &__get_cpu_var(decrementers_next_tb
);
838 *next_tb
= get_tb_or_rtc();
842 static void register_decrementer_clockevent(int cpu
)
844 struct clock_event_device
*dec
= &per_cpu(decrementers
, cpu
);
846 *dec
= decrementer_clockevent
;
847 dec
->cpumask
= cpumask_of(cpu
);
849 printk_once(KERN_DEBUG
"clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
850 dec
->name
, dec
->mult
, dec
->shift
, cpu
);
852 clockevents_register_device(dec
);
855 static void __init
init_decrementer_clockevent(void)
857 int cpu
= smp_processor_id();
859 clockevents_calc_mult_shift(&decrementer_clockevent
, ppc_tb_freq
, 4);
861 decrementer_clockevent
.max_delta_ns
=
862 clockevent_delta2ns(DECREMENTER_MAX
, &decrementer_clockevent
);
863 decrementer_clockevent
.min_delta_ns
=
864 clockevent_delta2ns(2, &decrementer_clockevent
);
866 register_decrementer_clockevent(cpu
);
869 void secondary_cpu_time_init(void)
871 /* Start the decrementer on CPUs that have manual control
874 start_cpu_decrementer();
876 /* FIME: Should make unrelatred change to move snapshot_timebase
878 register_decrementer_clockevent(smp_processor_id());
881 /* This function is only called on the boot processor */
882 void __init
time_init(void)
884 struct div_result res
;
889 /* 601 processor: dec counts down by 128 every 128ns */
890 ppc_tb_freq
= 1000000000;
892 /* Normal PowerPC with timebase register */
893 ppc_md
.calibrate_decr();
894 printk(KERN_DEBUG
"time_init: decrementer frequency = %lu.%.6lu MHz\n",
895 ppc_tb_freq
/ 1000000, ppc_tb_freq
% 1000000);
896 printk(KERN_DEBUG
"time_init: processor frequency = %lu.%.6lu MHz\n",
897 ppc_proc_freq
/ 1000000, ppc_proc_freq
% 1000000);
900 tb_ticks_per_jiffy
= ppc_tb_freq
/ HZ
;
901 tb_ticks_per_sec
= ppc_tb_freq
;
902 tb_ticks_per_usec
= ppc_tb_freq
/ 1000000;
903 calc_cputime_factors();
904 setup_cputime_one_jiffy();
907 * Compute scale factor for sched_clock.
908 * The calibrate_decr() function has set tb_ticks_per_sec,
909 * which is the timebase frequency.
910 * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
911 * the 128-bit result as a 64.64 fixed-point number.
912 * We then shift that number right until it is less than 1.0,
913 * giving us the scale factor and shift count to use in
916 div128_by_32(1000000000, 0, tb_ticks_per_sec
, &res
);
917 scale
= res
.result_low
;
918 for (shift
= 0; res
.result_high
!= 0; ++shift
) {
919 scale
= (scale
>> 1) | (res
.result_high
<< 63);
920 res
.result_high
>>= 1;
922 tb_to_ns_scale
= scale
;
923 tb_to_ns_shift
= shift
;
924 /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
925 boot_tb
= get_tb_or_rtc();
927 /* If platform provided a timezone (pmac), we correct the time */
928 if (timezone_offset
) {
929 sys_tz
.tz_minuteswest
= -timezone_offset
/ 60;
930 sys_tz
.tz_dsttime
= 0;
933 vdso_data
->tb_update_count
= 0;
934 vdso_data
->tb_ticks_per_sec
= tb_ticks_per_sec
;
936 /* Start the decrementer on CPUs that have manual control
939 start_cpu_decrementer();
941 /* Register the clocksource */
944 init_decrementer_clockevent();
945 tick_setup_hrtimer_broadcast();
950 #define STARTOFTIME 1970
951 #define SECDAY 86400L
952 #define SECYR (SECDAY * 365)
953 #define leapyear(year) ((year) % 4 == 0 && \
954 ((year) % 100 != 0 || (year) % 400 == 0))
955 #define days_in_year(a) (leapyear(a) ? 366 : 365)
956 #define days_in_month(a) (month_days[(a) - 1])
958 static int month_days
[12] = {
959 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
963 * This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
965 void GregorianDay(struct rtc_time
* tm
)
970 int MonthOffset
[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
972 lastYear
= tm
->tm_year
- 1;
975 * Number of leap corrections to apply up to end of last year
977 leapsToDate
= lastYear
/ 4 - lastYear
/ 100 + lastYear
/ 400;
980 * This year is a leap year if it is divisible by 4 except when it is
981 * divisible by 100 unless it is divisible by 400
983 * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
985 day
= tm
->tm_mon
> 2 && leapyear(tm
->tm_year
);
987 day
+= lastYear
*365 + leapsToDate
+ MonthOffset
[tm
->tm_mon
-1] +
990 tm
->tm_wday
= day
% 7;
993 void to_tm(int tim
, struct rtc_time
* tm
)
996 register long hms
, day
;
1001 /* Hours, minutes, seconds are easy */
1002 tm
->tm_hour
= hms
/ 3600;
1003 tm
->tm_min
= (hms
% 3600) / 60;
1004 tm
->tm_sec
= (hms
% 3600) % 60;
1006 /* Number of years in days */
1007 for (i
= STARTOFTIME
; day
>= days_in_year(i
); i
++)
1008 day
-= days_in_year(i
);
1011 /* Number of months in days left */
1012 if (leapyear(tm
->tm_year
))
1013 days_in_month(FEBRUARY
) = 29;
1014 for (i
= 1; day
>= days_in_month(i
); i
++)
1015 day
-= days_in_month(i
);
1016 days_in_month(FEBRUARY
) = 28;
1019 /* Days are what is left over (+1) from all that. */
1020 tm
->tm_mday
= day
+ 1;
1023 * Determine the day of week
1029 * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
1032 void div128_by_32(u64 dividend_high
, u64 dividend_low
,
1033 unsigned divisor
, struct div_result
*dr
)
1035 unsigned long a
, b
, c
, d
;
1036 unsigned long w
, x
, y
, z
;
1039 a
= dividend_high
>> 32;
1040 b
= dividend_high
& 0xffffffff;
1041 c
= dividend_low
>> 32;
1042 d
= dividend_low
& 0xffffffff;
1045 ra
= ((u64
)(a
- (w
* divisor
)) << 32) + b
;
1047 rb
= ((u64
) do_div(ra
, divisor
) << 32) + c
;
1050 rc
= ((u64
) do_div(rb
, divisor
) << 32) + d
;
1053 do_div(rc
, divisor
);
1056 dr
->result_high
= ((u64
)w
<< 32) + x
;
1057 dr
->result_low
= ((u64
)y
<< 32) + z
;
1061 /* We don't need to calibrate delay, we use the CPU timebase for that */
1062 void calibrate_delay(void)
1064 /* Some generic code (such as spinlock debug) use loops_per_jiffy
1065 * as the number of __delay(1) in a jiffy, so make it so
1067 loops_per_jiffy
= tb_ticks_per_jiffy
;
1070 static int __init
rtc_init(void)
1072 struct platform_device
*pdev
;
1074 if (!ppc_md
.get_rtc_time
)
1077 pdev
= platform_device_register_simple("rtc-generic", -1, NULL
, 0);
1079 return PTR_ERR_OR_ZERO(pdev
);
1082 module_init(rtc_init
);