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/init.h>
46 #include <linux/profile.h>
47 #include <linux/cpu.h>
48 #include <linux/security.h>
49 #include <linux/percpu.h>
50 #include <linux/rtc.h>
51 #include <linux/jiffies.h>
52 #include <linux/posix-timers.h>
53 #include <linux/irq.h>
54 #include <linux/delay.h>
55 #include <linux/irq_work.h>
56 #include <asm/trace.h>
59 #include <asm/processor.h>
60 #include <asm/nvram.h>
61 #include <asm/cache.h>
62 #include <asm/machdep.h>
63 #include <asm/uaccess.h>
67 #include <asm/div64.h>
69 #include <asm/vdso_datapage.h>
70 #include <asm/firmware.h>
71 #include <asm/cputime.h>
73 /* powerpc clocksource/clockevent code */
75 #include <linux/clockchips.h>
76 #include <linux/timekeeper_internal.h>
78 static cycle_t
rtc_read(struct clocksource
*);
79 static struct clocksource clocksource_rtc
= {
82 .flags
= CLOCK_SOURCE_IS_CONTINUOUS
,
83 .mask
= CLOCKSOURCE_MASK(64),
87 static cycle_t
timebase_read(struct clocksource
*);
88 static struct clocksource clocksource_timebase
= {
91 .flags
= CLOCK_SOURCE_IS_CONTINUOUS
,
92 .mask
= CLOCKSOURCE_MASK(64),
93 .read
= timebase_read
,
96 #define DECREMENTER_MAX 0x7fffffff
98 static int decrementer_set_next_event(unsigned long evt
,
99 struct clock_event_device
*dev
);
100 static void decrementer_set_mode(enum clock_event_mode mode
,
101 struct clock_event_device
*dev
);
103 struct clock_event_device decrementer_clockevent
= {
104 .name
= "decrementer",
107 .set_next_event
= decrementer_set_next_event
,
108 .set_mode
= decrementer_set_mode
,
109 .features
= CLOCK_EVT_FEAT_ONESHOT
,
111 EXPORT_SYMBOL(decrementer_clockevent
);
113 DEFINE_PER_CPU(u64
, decrementers_next_tb
);
114 static DEFINE_PER_CPU(struct clock_event_device
, decrementers
);
116 #define XSEC_PER_SEC (1024*1024)
119 #define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
121 /* compute ((xsec << 12) * max) >> 32 */
122 #define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
125 unsigned long tb_ticks_per_jiffy
;
126 unsigned long tb_ticks_per_usec
= 100; /* sane default */
127 EXPORT_SYMBOL(tb_ticks_per_usec
);
128 unsigned long tb_ticks_per_sec
;
129 EXPORT_SYMBOL(tb_ticks_per_sec
); /* for cputime_t conversions */
131 DEFINE_SPINLOCK(rtc_lock
);
132 EXPORT_SYMBOL_GPL(rtc_lock
);
134 static u64 tb_to_ns_scale __read_mostly
;
135 static unsigned tb_to_ns_shift __read_mostly
;
136 static u64 boot_tb __read_mostly
;
138 extern struct timezone sys_tz
;
139 static long timezone_offset
;
141 unsigned long ppc_proc_freq
;
142 EXPORT_SYMBOL_GPL(ppc_proc_freq
);
143 unsigned long ppc_tb_freq
;
144 EXPORT_SYMBOL_GPL(ppc_tb_freq
);
146 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
148 * Factors for converting from cputime_t (timebase ticks) to
149 * jiffies, microseconds, seconds, and clock_t (1/USER_HZ seconds).
150 * These are all stored as 0.64 fixed-point binary fractions.
152 u64 __cputime_jiffies_factor
;
153 EXPORT_SYMBOL(__cputime_jiffies_factor
);
154 u64 __cputime_usec_factor
;
155 EXPORT_SYMBOL(__cputime_usec_factor
);
156 u64 __cputime_sec_factor
;
157 EXPORT_SYMBOL(__cputime_sec_factor
);
158 u64 __cputime_clockt_factor
;
159 EXPORT_SYMBOL(__cputime_clockt_factor
);
160 DEFINE_PER_CPU(unsigned long, cputime_last_delta
);
161 DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta
);
163 cputime_t cputime_one_jiffy
;
165 void (*dtl_consumer
)(struct dtl_entry
*, u64
);
167 static void calc_cputime_factors(void)
169 struct div_result res
;
171 div128_by_32(HZ
, 0, tb_ticks_per_sec
, &res
);
172 __cputime_jiffies_factor
= res
.result_low
;
173 div128_by_32(1000000, 0, tb_ticks_per_sec
, &res
);
174 __cputime_usec_factor
= res
.result_low
;
175 div128_by_32(1, 0, tb_ticks_per_sec
, &res
);
176 __cputime_sec_factor
= res
.result_low
;
177 div128_by_32(USER_HZ
, 0, tb_ticks_per_sec
, &res
);
178 __cputime_clockt_factor
= res
.result_low
;
182 * Read the SPURR on systems that have it, otherwise the PURR,
183 * or if that doesn't exist return the timebase value passed in.
185 static u64
read_spurr(u64 tb
)
187 if (cpu_has_feature(CPU_FTR_SPURR
))
188 return mfspr(SPRN_SPURR
);
189 if (cpu_has_feature(CPU_FTR_PURR
))
190 return mfspr(SPRN_PURR
);
194 #ifdef CONFIG_PPC_SPLPAR
197 * Scan the dispatch trace log and count up the stolen time.
198 * Should be called with interrupts disabled.
200 static u64
scan_dispatch_log(u64 stop_tb
)
202 u64 i
= local_paca
->dtl_ridx
;
203 struct dtl_entry
*dtl
= local_paca
->dtl_curr
;
204 struct dtl_entry
*dtl_end
= local_paca
->dispatch_log_end
;
205 struct lppaca
*vpa
= local_paca
->lppaca_ptr
;
213 if (i
== vpa
->dtl_idx
)
215 while (i
< vpa
->dtl_idx
) {
217 dtl_consumer(dtl
, i
);
219 tb_delta
= dtl
->enqueue_to_dispatch_time
+
220 dtl
->ready_to_enqueue_time
;
222 if (i
+ N_DISPATCH_LOG
< vpa
->dtl_idx
) {
223 /* buffer has overflowed */
224 i
= vpa
->dtl_idx
- N_DISPATCH_LOG
;
225 dtl
= local_paca
->dispatch_log
+ (i
% N_DISPATCH_LOG
);
234 dtl
= local_paca
->dispatch_log
;
236 local_paca
->dtl_ridx
= i
;
237 local_paca
->dtl_curr
= dtl
;
242 * Accumulate stolen time by scanning the dispatch trace log.
243 * Called on entry from user mode.
245 void accumulate_stolen_time(void)
249 u8 save_soft_enabled
= local_paca
->soft_enabled
;
251 /* We are called early in the exception entry, before
252 * soft/hard_enabled are sync'ed to the expected state
253 * for the exception. We are hard disabled but the PACA
254 * needs to reflect that so various debug stuff doesn't
257 local_paca
->soft_enabled
= 0;
259 sst
= scan_dispatch_log(local_paca
->starttime_user
);
260 ust
= scan_dispatch_log(local_paca
->starttime
);
261 local_paca
->system_time
-= sst
;
262 local_paca
->user_time
-= ust
;
263 local_paca
->stolen_time
+= ust
+ sst
;
265 local_paca
->soft_enabled
= save_soft_enabled
;
268 static inline u64
calculate_stolen_time(u64 stop_tb
)
272 if (get_paca()->dtl_ridx
!= get_paca()->lppaca_ptr
->dtl_idx
) {
273 stolen
= scan_dispatch_log(stop_tb
);
274 get_paca()->system_time
-= stolen
;
277 stolen
+= get_paca()->stolen_time
;
278 get_paca()->stolen_time
= 0;
282 #else /* CONFIG_PPC_SPLPAR */
283 static inline u64
calculate_stolen_time(u64 stop_tb
)
288 #endif /* CONFIG_PPC_SPLPAR */
291 * Account time for a transition between system, hard irq
294 static u64
vtime_delta(struct task_struct
*tsk
,
295 u64
*sys_scaled
, u64
*stolen
)
297 u64 now
, nowscaled
, deltascaled
;
298 u64 udelta
, delta
, user_scaled
;
301 nowscaled
= read_spurr(now
);
302 get_paca()->system_time
+= now
- get_paca()->starttime
;
303 get_paca()->starttime
= now
;
304 deltascaled
= nowscaled
- get_paca()->startspurr
;
305 get_paca()->startspurr
= nowscaled
;
307 *stolen
= calculate_stolen_time(now
);
309 delta
= get_paca()->system_time
;
310 get_paca()->system_time
= 0;
311 udelta
= get_paca()->user_time
- get_paca()->utime_sspurr
;
312 get_paca()->utime_sspurr
= get_paca()->user_time
;
315 * Because we don't read the SPURR on every kernel entry/exit,
316 * deltascaled includes both user and system SPURR ticks.
317 * Apportion these ticks to system SPURR ticks and user
318 * SPURR ticks in the same ratio as the system time (delta)
319 * and user time (udelta) values obtained from the timebase
320 * over the same interval. The system ticks get accounted here;
321 * the user ticks get saved up in paca->user_time_scaled to be
322 * used by account_process_tick.
325 user_scaled
= udelta
;
326 if (deltascaled
!= delta
+ udelta
) {
328 *sys_scaled
= deltascaled
* delta
/ (delta
+ udelta
);
329 user_scaled
= deltascaled
- *sys_scaled
;
331 *sys_scaled
= deltascaled
;
334 get_paca()->user_time_scaled
+= user_scaled
;
339 void __vtime_account_system(struct task_struct
*tsk
)
341 u64 delta
, sys_scaled
, stolen
;
343 delta
= vtime_delta(tsk
, &sys_scaled
, &stolen
);
344 account_system_time(tsk
, 0, delta
, sys_scaled
);
346 account_steal_time(stolen
);
349 void __vtime_account_idle(struct task_struct
*tsk
)
351 u64 delta
, sys_scaled
, stolen
;
353 delta
= vtime_delta(tsk
, &sys_scaled
, &stolen
);
354 account_idle_time(delta
+ stolen
);
358 * Transfer the user and system times accumulated in the paca
359 * by the exception entry and exit code to the generic process
360 * user and system time records.
361 * Must be called with interrupts disabled.
362 * Assumes that vtime_account() has been called recently
363 * (i.e. since the last entry from usermode) so that
364 * get_paca()->user_time_scaled is up to date.
366 void account_process_tick(struct task_struct
*tsk
, int user_tick
)
368 cputime_t utime
, utimescaled
;
370 utime
= get_paca()->user_time
;
371 utimescaled
= get_paca()->user_time_scaled
;
372 get_paca()->user_time
= 0;
373 get_paca()->user_time_scaled
= 0;
374 get_paca()->utime_sspurr
= 0;
375 account_user_time(tsk
, utime
, utimescaled
);
378 void vtime_task_switch(struct task_struct
*prev
)
381 account_process_tick(prev
, 0);
384 #else /* ! CONFIG_VIRT_CPU_ACCOUNTING */
385 #define calc_cputime_factors()
388 void __delay(unsigned long loops
)
396 /* the RTCL register wraps at 1000000000 */
397 diff
= get_rtcl() - start
;
400 } while (diff
< loops
);
403 while (get_tbl() - start
< loops
)
408 EXPORT_SYMBOL(__delay
);
410 void udelay(unsigned long usecs
)
412 __delay(tb_ticks_per_usec
* usecs
);
414 EXPORT_SYMBOL(udelay
);
417 unsigned long profile_pc(struct pt_regs
*regs
)
419 unsigned long pc
= instruction_pointer(regs
);
421 if (in_lock_functions(pc
))
426 EXPORT_SYMBOL(profile_pc
);
429 #ifdef CONFIG_IRQ_WORK
432 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
435 static inline unsigned long test_irq_work_pending(void)
439 asm volatile("lbz %0,%1(13)"
441 : "i" (offsetof(struct paca_struct
, irq_work_pending
)));
445 static inline void set_irq_work_pending_flag(void)
447 asm volatile("stb %0,%1(13)" : :
449 "i" (offsetof(struct paca_struct
, irq_work_pending
)));
452 static inline void clear_irq_work_pending(void)
454 asm volatile("stb %0,%1(13)" : :
456 "i" (offsetof(struct paca_struct
, irq_work_pending
)));
461 DEFINE_PER_CPU(u8
, irq_work_pending
);
463 #define set_irq_work_pending_flag() __get_cpu_var(irq_work_pending) = 1
464 #define test_irq_work_pending() __get_cpu_var(irq_work_pending)
465 #define clear_irq_work_pending() __get_cpu_var(irq_work_pending) = 0
467 #endif /* 32 vs 64 bit */
469 void arch_irq_work_raise(void)
472 set_irq_work_pending_flag();
477 #else /* CONFIG_IRQ_WORK */
479 #define test_irq_work_pending() 0
480 #define clear_irq_work_pending()
482 #endif /* CONFIG_IRQ_WORK */
485 * timer_interrupt - gets called when the decrementer overflows,
486 * with interrupts disabled.
488 void timer_interrupt(struct pt_regs
* regs
)
490 struct pt_regs
*old_regs
;
491 u64
*next_tb
= &__get_cpu_var(decrementers_next_tb
);
492 struct clock_event_device
*evt
= &__get_cpu_var(decrementers
);
495 /* Ensure a positive value is written to the decrementer, or else
496 * some CPUs will continue to take decrementer exceptions.
498 set_dec(DECREMENTER_MAX
);
500 /* Some implementations of hotplug will get timer interrupts while
501 * offline, just ignore these
503 if (!cpu_online(smp_processor_id()))
506 /* Conditionally hard-enable interrupts now that the DEC has been
507 * bumped to its maximum value
509 may_hard_irq_enable();
511 __get_cpu_var(irq_stat
).timer_irqs
++;
513 #if defined(CONFIG_PPC32) && defined(CONFIG_PMAC)
514 if (atomic_read(&ppc_n_lost_interrupts
) != 0)
518 old_regs
= set_irq_regs(regs
);
521 trace_timer_interrupt_entry(regs
);
523 if (test_irq_work_pending()) {
524 clear_irq_work_pending();
528 now
= get_tb_or_rtc();
529 if (now
>= *next_tb
) {
531 if (evt
->event_handler
)
532 evt
->event_handler(evt
);
534 now
= *next_tb
- now
;
535 if (now
<= DECREMENTER_MAX
)
540 /* collect purr register values often, for accurate calculations */
541 if (firmware_has_feature(FW_FEATURE_SPLPAR
)) {
542 struct cpu_usage
*cu
= &__get_cpu_var(cpu_usage_array
);
543 cu
->current_tb
= mfspr(SPRN_PURR
);
547 trace_timer_interrupt_exit(regs
);
550 set_irq_regs(old_regs
);
554 * Hypervisor decrementer interrupts shouldn't occur but are sometimes
555 * left pending on exit from a KVM guest. We don't need to do anything
556 * to clear them, as they are edge-triggered.
558 void hdec_interrupt(struct pt_regs
*regs
)
562 #ifdef CONFIG_SUSPEND
563 static void generic_suspend_disable_irqs(void)
565 /* Disable the decrementer, so that it doesn't interfere
569 set_dec(DECREMENTER_MAX
);
571 set_dec(DECREMENTER_MAX
);
574 static void generic_suspend_enable_irqs(void)
579 /* Overrides the weak version in kernel/power/main.c */
580 void arch_suspend_disable_irqs(void)
582 if (ppc_md
.suspend_disable_irqs
)
583 ppc_md
.suspend_disable_irqs();
584 generic_suspend_disable_irqs();
587 /* Overrides the weak version in kernel/power/main.c */
588 void arch_suspend_enable_irqs(void)
590 generic_suspend_enable_irqs();
591 if (ppc_md
.suspend_enable_irqs
)
592 ppc_md
.suspend_enable_irqs();
597 * Scheduler clock - returns current time in nanosec units.
599 * Note: mulhdu(a, b) (multiply high double unsigned) returns
600 * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
601 * are 64-bit unsigned numbers.
603 unsigned long long sched_clock(void)
607 return mulhdu(get_tb() - boot_tb
, tb_to_ns_scale
) << tb_to_ns_shift
;
610 static int __init
get_freq(char *name
, int cells
, unsigned long *val
)
612 struct device_node
*cpu
;
613 const unsigned int *fp
;
616 /* The cpu node should have timebase and clock frequency properties */
617 cpu
= of_find_node_by_type(NULL
, "cpu");
620 fp
= of_get_property(cpu
, name
, NULL
);
623 *val
= of_read_ulong(fp
, cells
);
632 /* should become __cpuinit when secondary_cpu_time_init also is */
633 void start_cpu_decrementer(void)
635 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
636 /* Clear any pending timer interrupts */
637 mtspr(SPRN_TSR
, TSR_ENW
| TSR_WIS
| TSR_DIS
| TSR_FIS
);
639 /* Enable decrementer interrupt */
640 mtspr(SPRN_TCR
, TCR_DIE
);
641 #endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */
644 void __init
generic_calibrate_decr(void)
646 ppc_tb_freq
= DEFAULT_TB_FREQ
; /* hardcoded default */
648 if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq
) &&
649 !get_freq("timebase-frequency", 1, &ppc_tb_freq
)) {
651 printk(KERN_ERR
"WARNING: Estimating decrementer frequency "
655 ppc_proc_freq
= DEFAULT_PROC_FREQ
; /* hardcoded default */
657 if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq
) &&
658 !get_freq("clock-frequency", 1, &ppc_proc_freq
)) {
660 printk(KERN_ERR
"WARNING: Estimating processor frequency "
665 int update_persistent_clock(struct timespec now
)
669 if (!ppc_md
.set_rtc_time
)
672 to_tm(now
.tv_sec
+ 1 + timezone_offset
, &tm
);
676 return ppc_md
.set_rtc_time(&tm
);
679 static void __read_persistent_clock(struct timespec
*ts
)
682 static int first
= 1;
685 /* XXX this is a litle fragile but will work okay in the short term */
688 if (ppc_md
.time_init
)
689 timezone_offset
= ppc_md
.time_init();
691 /* get_boot_time() isn't guaranteed to be safe to call late */
692 if (ppc_md
.get_boot_time
) {
693 ts
->tv_sec
= ppc_md
.get_boot_time() - timezone_offset
;
697 if (!ppc_md
.get_rtc_time
) {
701 ppc_md
.get_rtc_time(&tm
);
703 ts
->tv_sec
= mktime(tm
.tm_year
+1900, tm
.tm_mon
+1, tm
.tm_mday
,
704 tm
.tm_hour
, tm
.tm_min
, tm
.tm_sec
);
707 void read_persistent_clock(struct timespec
*ts
)
709 __read_persistent_clock(ts
);
711 /* Sanitize it in case real time clock is set below EPOCH */
712 if (ts
->tv_sec
< 0) {
719 /* clocksource code */
720 static cycle_t
rtc_read(struct clocksource
*cs
)
722 return (cycle_t
)get_rtc();
725 static cycle_t
timebase_read(struct clocksource
*cs
)
727 return (cycle_t
)get_tb();
730 void update_vsyscall_old(struct timespec
*wall_time
, struct timespec
*wtm
,
731 struct clocksource
*clock
, u32 mult
)
733 u64 new_tb_to_xs
, new_stamp_xsec
;
736 if (clock
!= &clocksource_timebase
)
739 /* Make userspace gettimeofday spin until we're done. */
740 ++vdso_data
->tb_update_count
;
743 /* 19342813113834067 ~= 2^(20+64) / 1e9 */
744 new_tb_to_xs
= (u64
) mult
* (19342813113834067ULL >> clock
->shift
);
745 new_stamp_xsec
= (u64
) wall_time
->tv_nsec
* XSEC_PER_SEC
;
746 do_div(new_stamp_xsec
, 1000000000);
747 new_stamp_xsec
+= (u64
) wall_time
->tv_sec
* XSEC_PER_SEC
;
749 BUG_ON(wall_time
->tv_nsec
>= NSEC_PER_SEC
);
750 /* this is tv_nsec / 1e9 as a 0.32 fraction */
751 frac_sec
= ((u64
) wall_time
->tv_nsec
* 18446744073ULL) >> 32;
754 * tb_update_count is used to allow the userspace gettimeofday code
755 * to assure itself that it sees a consistent view of the tb_to_xs and
756 * stamp_xsec variables. It reads the tb_update_count, then reads
757 * tb_to_xs and stamp_xsec and then reads tb_update_count again. If
758 * the two values of tb_update_count match and are even then the
759 * tb_to_xs and stamp_xsec values are consistent. If not, then it
760 * loops back and reads them again until this criteria is met.
761 * We expect the caller to have done the first increment of
762 * vdso_data->tb_update_count already.
764 vdso_data
->tb_orig_stamp
= clock
->cycle_last
;
765 vdso_data
->stamp_xsec
= new_stamp_xsec
;
766 vdso_data
->tb_to_xs
= new_tb_to_xs
;
767 vdso_data
->wtom_clock_sec
= wtm
->tv_sec
;
768 vdso_data
->wtom_clock_nsec
= wtm
->tv_nsec
;
769 vdso_data
->stamp_xtime
= *wall_time
;
770 vdso_data
->stamp_sec_fraction
= frac_sec
;
772 ++(vdso_data
->tb_update_count
);
775 void update_vsyscall_tz(void)
777 /* Make userspace gettimeofday spin until we're done. */
778 ++vdso_data
->tb_update_count
;
780 vdso_data
->tz_minuteswest
= sys_tz
.tz_minuteswest
;
781 vdso_data
->tz_dsttime
= sys_tz
.tz_dsttime
;
783 ++vdso_data
->tb_update_count
;
786 static void __init
clocksource_init(void)
788 struct clocksource
*clock
;
791 clock
= &clocksource_rtc
;
793 clock
= &clocksource_timebase
;
795 if (clocksource_register_hz(clock
, tb_ticks_per_sec
)) {
796 printk(KERN_ERR
"clocksource: %s is already registered\n",
801 printk(KERN_INFO
"clocksource: %s mult[%x] shift[%d] registered\n",
802 clock
->name
, clock
->mult
, clock
->shift
);
805 static int decrementer_set_next_event(unsigned long evt
,
806 struct clock_event_device
*dev
)
808 __get_cpu_var(decrementers_next_tb
) = get_tb_or_rtc() + evt
;
813 static void decrementer_set_mode(enum clock_event_mode mode
,
814 struct clock_event_device
*dev
)
816 if (mode
!= CLOCK_EVT_MODE_ONESHOT
)
817 decrementer_set_next_event(DECREMENTER_MAX
, dev
);
820 static void register_decrementer_clockevent(int cpu
)
822 struct clock_event_device
*dec
= &per_cpu(decrementers
, cpu
);
824 *dec
= decrementer_clockevent
;
825 dec
->cpumask
= cpumask_of(cpu
);
827 printk_once(KERN_DEBUG
"clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
828 dec
->name
, dec
->mult
, dec
->shift
, cpu
);
830 clockevents_register_device(dec
);
833 static void __init
init_decrementer_clockevent(void)
835 int cpu
= smp_processor_id();
837 clockevents_calc_mult_shift(&decrementer_clockevent
, ppc_tb_freq
, 4);
839 decrementer_clockevent
.max_delta_ns
=
840 clockevent_delta2ns(DECREMENTER_MAX
, &decrementer_clockevent
);
841 decrementer_clockevent
.min_delta_ns
=
842 clockevent_delta2ns(2, &decrementer_clockevent
);
844 register_decrementer_clockevent(cpu
);
847 void secondary_cpu_time_init(void)
849 /* Start the decrementer on CPUs that have manual control
852 start_cpu_decrementer();
854 /* FIME: Should make unrelatred change to move snapshot_timebase
856 register_decrementer_clockevent(smp_processor_id());
859 /* This function is only called on the boot processor */
860 void __init
time_init(void)
862 struct div_result res
;
867 /* 601 processor: dec counts down by 128 every 128ns */
868 ppc_tb_freq
= 1000000000;
870 /* Normal PowerPC with timebase register */
871 ppc_md
.calibrate_decr();
872 printk(KERN_DEBUG
"time_init: decrementer frequency = %lu.%.6lu MHz\n",
873 ppc_tb_freq
/ 1000000, ppc_tb_freq
% 1000000);
874 printk(KERN_DEBUG
"time_init: processor frequency = %lu.%.6lu MHz\n",
875 ppc_proc_freq
/ 1000000, ppc_proc_freq
% 1000000);
878 tb_ticks_per_jiffy
= ppc_tb_freq
/ HZ
;
879 tb_ticks_per_sec
= ppc_tb_freq
;
880 tb_ticks_per_usec
= ppc_tb_freq
/ 1000000;
881 calc_cputime_factors();
882 setup_cputime_one_jiffy();
885 * Compute scale factor for sched_clock.
886 * The calibrate_decr() function has set tb_ticks_per_sec,
887 * which is the timebase frequency.
888 * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
889 * the 128-bit result as a 64.64 fixed-point number.
890 * We then shift that number right until it is less than 1.0,
891 * giving us the scale factor and shift count to use in
894 div128_by_32(1000000000, 0, tb_ticks_per_sec
, &res
);
895 scale
= res
.result_low
;
896 for (shift
= 0; res
.result_high
!= 0; ++shift
) {
897 scale
= (scale
>> 1) | (res
.result_high
<< 63);
898 res
.result_high
>>= 1;
900 tb_to_ns_scale
= scale
;
901 tb_to_ns_shift
= shift
;
902 /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
903 boot_tb
= get_tb_or_rtc();
905 /* If platform provided a timezone (pmac), we correct the time */
906 if (timezone_offset
) {
907 sys_tz
.tz_minuteswest
= -timezone_offset
/ 60;
908 sys_tz
.tz_dsttime
= 0;
911 vdso_data
->tb_update_count
= 0;
912 vdso_data
->tb_ticks_per_sec
= tb_ticks_per_sec
;
914 /* Start the decrementer on CPUs that have manual control
917 start_cpu_decrementer();
919 /* Register the clocksource */
922 init_decrementer_clockevent();
927 #define STARTOFTIME 1970
928 #define SECDAY 86400L
929 #define SECYR (SECDAY * 365)
930 #define leapyear(year) ((year) % 4 == 0 && \
931 ((year) % 100 != 0 || (year) % 400 == 0))
932 #define days_in_year(a) (leapyear(a) ? 366 : 365)
933 #define days_in_month(a) (month_days[(a) - 1])
935 static int month_days
[12] = {
936 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
940 * This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
942 void GregorianDay(struct rtc_time
* tm
)
947 int MonthOffset
[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
949 lastYear
= tm
->tm_year
- 1;
952 * Number of leap corrections to apply up to end of last year
954 leapsToDate
= lastYear
/ 4 - lastYear
/ 100 + lastYear
/ 400;
957 * This year is a leap year if it is divisible by 4 except when it is
958 * divisible by 100 unless it is divisible by 400
960 * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
962 day
= tm
->tm_mon
> 2 && leapyear(tm
->tm_year
);
964 day
+= lastYear
*365 + leapsToDate
+ MonthOffset
[tm
->tm_mon
-1] +
967 tm
->tm_wday
= day
% 7;
970 void to_tm(int tim
, struct rtc_time
* tm
)
973 register long hms
, day
;
978 /* Hours, minutes, seconds are easy */
979 tm
->tm_hour
= hms
/ 3600;
980 tm
->tm_min
= (hms
% 3600) / 60;
981 tm
->tm_sec
= (hms
% 3600) % 60;
983 /* Number of years in days */
984 for (i
= STARTOFTIME
; day
>= days_in_year(i
); i
++)
985 day
-= days_in_year(i
);
988 /* Number of months in days left */
989 if (leapyear(tm
->tm_year
))
990 days_in_month(FEBRUARY
) = 29;
991 for (i
= 1; day
>= days_in_month(i
); i
++)
992 day
-= days_in_month(i
);
993 days_in_month(FEBRUARY
) = 28;
996 /* Days are what is left over (+1) from all that. */
997 tm
->tm_mday
= day
+ 1;
1000 * Determine the day of week
1006 * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
1009 void div128_by_32(u64 dividend_high
, u64 dividend_low
,
1010 unsigned divisor
, struct div_result
*dr
)
1012 unsigned long a
, b
, c
, d
;
1013 unsigned long w
, x
, y
, z
;
1016 a
= dividend_high
>> 32;
1017 b
= dividend_high
& 0xffffffff;
1018 c
= dividend_low
>> 32;
1019 d
= dividend_low
& 0xffffffff;
1022 ra
= ((u64
)(a
- (w
* divisor
)) << 32) + b
;
1024 rb
= ((u64
) do_div(ra
, divisor
) << 32) + c
;
1027 rc
= ((u64
) do_div(rb
, divisor
) << 32) + d
;
1030 do_div(rc
, divisor
);
1033 dr
->result_high
= ((u64
)w
<< 32) + x
;
1034 dr
->result_low
= ((u64
)y
<< 32) + z
;
1038 /* We don't need to calibrate delay, we use the CPU timebase for that */
1039 void calibrate_delay(void)
1041 /* Some generic code (such as spinlock debug) use loops_per_jiffy
1042 * as the number of __delay(1) in a jiffy, so make it so
1044 loops_per_jiffy
= tb_ticks_per_jiffy
;
1047 static int __init
rtc_init(void)
1049 struct platform_device
*pdev
;
1051 if (!ppc_md
.get_rtc_time
)
1054 pdev
= platform_device_register_simple("rtc-generic", -1, NULL
, 0);
1056 return PTR_ERR(pdev
);
1061 module_init(rtc_init
);