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/sched/clock.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/clockchips.h>
47 #include <linux/init.h>
48 #include <linux/profile.h>
49 #include <linux/cpu.h>
50 #include <linux/security.h>
51 #include <linux/percpu.h>
52 #include <linux/rtc.h>
53 #include <linux/jiffies.h>
54 #include <linux/posix-timers.h>
55 #include <linux/irq.h>
56 #include <linux/delay.h>
57 #include <linux/irq_work.h>
58 #include <linux/clk-provider.h>
59 #include <linux/suspend.h>
60 #include <linux/rtc.h>
61 #include <linux/sched/cputime.h>
62 #include <asm/trace.h>
65 #include <asm/processor.h>
66 #include <asm/nvram.h>
67 #include <asm/cache.h>
68 #include <asm/machdep.h>
69 #include <linux/uaccess.h>
73 #include <asm/div64.h>
75 #include <asm/vdso_datapage.h>
76 #include <asm/firmware.h>
77 #include <asm/asm-prototypes.h>
79 /* powerpc clocksource/clockevent code */
81 #include <linux/clockchips.h>
82 #include <linux/timekeeper_internal.h>
84 static u64
rtc_read(struct clocksource
*);
85 static struct clocksource clocksource_rtc
= {
88 .flags
= CLOCK_SOURCE_IS_CONTINUOUS
,
89 .mask
= CLOCKSOURCE_MASK(64),
93 static u64
timebase_read(struct clocksource
*);
94 static struct clocksource clocksource_timebase
= {
97 .flags
= CLOCK_SOURCE_IS_CONTINUOUS
,
98 .mask
= CLOCKSOURCE_MASK(64),
99 .read
= timebase_read
,
102 #define DECREMENTER_DEFAULT_MAX 0x7FFFFFFF
103 u64 decrementer_max
= DECREMENTER_DEFAULT_MAX
;
105 static int decrementer_set_next_event(unsigned long evt
,
106 struct clock_event_device
*dev
);
107 static int decrementer_shutdown(struct clock_event_device
*evt
);
109 struct clock_event_device decrementer_clockevent
= {
110 .name
= "decrementer",
113 .set_next_event
= decrementer_set_next_event
,
114 .set_state_shutdown
= decrementer_shutdown
,
115 .tick_resume
= decrementer_shutdown
,
116 .features
= CLOCK_EVT_FEAT_ONESHOT
|
117 CLOCK_EVT_FEAT_C3STOP
,
119 EXPORT_SYMBOL(decrementer_clockevent
);
121 DEFINE_PER_CPU(u64
, decrementers_next_tb
);
122 static DEFINE_PER_CPU(struct clock_event_device
, decrementers
);
124 #define XSEC_PER_SEC (1024*1024)
127 #define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
129 /* compute ((xsec << 12) * max) >> 32 */
130 #define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
133 unsigned long tb_ticks_per_jiffy
;
134 unsigned long tb_ticks_per_usec
= 100; /* sane default */
135 EXPORT_SYMBOL(tb_ticks_per_usec
);
136 unsigned long tb_ticks_per_sec
;
137 EXPORT_SYMBOL(tb_ticks_per_sec
); /* for cputime_t conversions */
139 DEFINE_SPINLOCK(rtc_lock
);
140 EXPORT_SYMBOL_GPL(rtc_lock
);
142 static u64 tb_to_ns_scale __read_mostly
;
143 static unsigned tb_to_ns_shift __read_mostly
;
144 static u64 boot_tb __read_mostly
;
146 extern struct timezone sys_tz
;
147 static long timezone_offset
;
149 unsigned long ppc_proc_freq
;
150 EXPORT_SYMBOL_GPL(ppc_proc_freq
);
151 unsigned long ppc_tb_freq
;
152 EXPORT_SYMBOL_GPL(ppc_tb_freq
);
154 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
156 * Factor for converting from cputime_t (timebase ticks) to
157 * microseconds. This is stored as 0.64 fixed-point binary fraction.
159 u64 __cputime_usec_factor
;
160 EXPORT_SYMBOL(__cputime_usec_factor
);
162 #ifdef CONFIG_PPC_SPLPAR
163 void (*dtl_consumer
)(struct dtl_entry
*, u64
);
167 #define get_accounting(tsk) (&get_paca()->accounting)
169 #define get_accounting(tsk) (&task_thread_info(tsk)->accounting)
172 static void calc_cputime_factors(void)
174 struct div_result res
;
176 div128_by_32(1000000, 0, tb_ticks_per_sec
, &res
);
177 __cputime_usec_factor
= res
.result_low
;
181 * Read the SPURR on systems that have it, otherwise the PURR,
182 * or if that doesn't exist return the timebase value passed in.
184 static unsigned long read_spurr(unsigned long tb
)
186 if (cpu_has_feature(CPU_FTR_SPURR
))
187 return mfspr(SPRN_SPURR
);
188 if (cpu_has_feature(CPU_FTR_PURR
))
189 return mfspr(SPRN_PURR
);
193 #ifdef CONFIG_PPC_SPLPAR
196 * Scan the dispatch trace log and count up the stolen time.
197 * Should be called with interrupts disabled.
199 static u64
scan_dispatch_log(u64 stop_tb
)
201 u64 i
= local_paca
->dtl_ridx
;
202 struct dtl_entry
*dtl
= local_paca
->dtl_curr
;
203 struct dtl_entry
*dtl_end
= local_paca
->dispatch_log_end
;
204 struct lppaca
*vpa
= local_paca
->lppaca_ptr
;
212 if (i
== be64_to_cpu(vpa
->dtl_idx
))
214 while (i
< be64_to_cpu(vpa
->dtl_idx
)) {
215 dtb
= be64_to_cpu(dtl
->timebase
);
216 tb_delta
= be32_to_cpu(dtl
->enqueue_to_dispatch_time
) +
217 be32_to_cpu(dtl
->ready_to_enqueue_time
);
219 if (i
+ N_DISPATCH_LOG
< be64_to_cpu(vpa
->dtl_idx
)) {
220 /* buffer has overflowed */
221 i
= be64_to_cpu(vpa
->dtl_idx
) - N_DISPATCH_LOG
;
222 dtl
= local_paca
->dispatch_log
+ (i
% N_DISPATCH_LOG
);
228 dtl_consumer(dtl
, i
);
233 dtl
= local_paca
->dispatch_log
;
235 local_paca
->dtl_ridx
= i
;
236 local_paca
->dtl_curr
= dtl
;
241 * Accumulate stolen time by scanning the dispatch trace log.
242 * Called on entry from user mode.
244 void accumulate_stolen_time(void)
247 u8 save_soft_enabled
= local_paca
->soft_enabled
;
248 struct cpu_accounting_data
*acct
= &local_paca
->accounting
;
250 /* We are called early in the exception entry, before
251 * soft/hard_enabled are sync'ed to the expected state
252 * for the exception. We are hard disabled but the PACA
253 * needs to reflect that so various debug stuff doesn't
256 local_paca
->soft_enabled
= 0;
258 sst
= scan_dispatch_log(acct
->starttime_user
);
259 ust
= scan_dispatch_log(acct
->starttime
);
262 acct
->steal_time
+= ust
+ sst
;
264 local_paca
->soft_enabled
= save_soft_enabled
;
267 static inline u64
calculate_stolen_time(u64 stop_tb
)
269 if (get_paca()->dtl_ridx
!= be64_to_cpu(get_lppaca()->dtl_idx
))
270 return scan_dispatch_log(stop_tb
);
275 #else /* CONFIG_PPC_SPLPAR */
276 static inline u64
calculate_stolen_time(u64 stop_tb
)
281 #endif /* CONFIG_PPC_SPLPAR */
284 * Account time for a transition between system, hard irq
287 static unsigned long vtime_delta(struct task_struct
*tsk
,
288 unsigned long *stime_scaled
,
289 unsigned long *steal_time
)
291 unsigned long now
, nowscaled
, deltascaled
;
293 unsigned long utime
, utime_scaled
;
294 struct cpu_accounting_data
*acct
= get_accounting(tsk
);
296 WARN_ON_ONCE(!irqs_disabled());
299 nowscaled
= read_spurr(now
);
300 stime
= now
- acct
->starttime
;
301 acct
->starttime
= now
;
302 deltascaled
= nowscaled
- acct
->startspurr
;
303 acct
->startspurr
= nowscaled
;
305 *steal_time
= calculate_stolen_time(now
);
307 utime
= acct
->utime
- acct
->utime_sspurr
;
308 acct
->utime_sspurr
= acct
->utime
;
311 * Because we don't read the SPURR on every kernel entry/exit,
312 * deltascaled includes both user and system SPURR ticks.
313 * Apportion these ticks to system SPURR ticks and user
314 * SPURR ticks in the same ratio as the system time (delta)
315 * and user time (udelta) values obtained from the timebase
316 * over the same interval. The system ticks get accounted here;
317 * the user ticks get saved up in paca->user_time_scaled to be
318 * used by account_process_tick.
320 *stime_scaled
= stime
;
321 utime_scaled
= utime
;
322 if (deltascaled
!= stime
+ utime
) {
324 *stime_scaled
= deltascaled
* stime
/ (stime
+ utime
);
325 utime_scaled
= deltascaled
- *stime_scaled
;
327 *stime_scaled
= deltascaled
;
330 acct
->utime_scaled
+= utime_scaled
;
335 void vtime_account_system(struct task_struct
*tsk
)
337 unsigned long stime
, stime_scaled
, steal_time
;
338 struct cpu_accounting_data
*acct
= get_accounting(tsk
);
340 stime
= vtime_delta(tsk
, &stime_scaled
, &steal_time
);
342 stime
-= min(stime
, steal_time
);
343 acct
->steal_time
+= steal_time
;
345 if ((tsk
->flags
& PF_VCPU
) && !irq_count()) {
346 acct
->gtime
+= stime
;
347 acct
->utime_scaled
+= stime_scaled
;
350 acct
->hardirq_time
+= stime
;
351 else if (in_serving_softirq())
352 acct
->softirq_time
+= stime
;
354 acct
->stime
+= stime
;
356 acct
->stime_scaled
+= stime_scaled
;
359 EXPORT_SYMBOL_GPL(vtime_account_system
);
361 void vtime_account_idle(struct task_struct
*tsk
)
363 unsigned long stime
, stime_scaled
, steal_time
;
364 struct cpu_accounting_data
*acct
= get_accounting(tsk
);
366 stime
= vtime_delta(tsk
, &stime_scaled
, &steal_time
);
367 acct
->idle_time
+= stime
+ steal_time
;
371 * Account the whole cputime accumulated in the paca
372 * Must be called with interrupts disabled.
373 * Assumes that vtime_account_system/idle() has been called
374 * recently (i.e. since the last entry from usermode) so that
375 * get_paca()->user_time_scaled is up to date.
377 void vtime_flush(struct task_struct
*tsk
)
379 struct cpu_accounting_data
*acct
= get_accounting(tsk
);
382 account_user_time(tsk
, cputime_to_nsecs(acct
->utime
));
384 if (acct
->utime_scaled
)
385 tsk
->utimescaled
+= cputime_to_nsecs(acct
->utime_scaled
);
388 account_guest_time(tsk
, cputime_to_nsecs(acct
->gtime
));
390 if (acct
->steal_time
)
391 account_steal_time(cputime_to_nsecs(acct
->steal_time
));
394 account_idle_time(cputime_to_nsecs(acct
->idle_time
));
397 account_system_index_time(tsk
, cputime_to_nsecs(acct
->stime
),
399 if (acct
->stime_scaled
)
400 tsk
->stimescaled
+= cputime_to_nsecs(acct
->stime_scaled
);
402 if (acct
->hardirq_time
)
403 account_system_index_time(tsk
, cputime_to_nsecs(acct
->hardirq_time
),
405 if (acct
->softirq_time
)
406 account_system_index_time(tsk
, cputime_to_nsecs(acct
->softirq_time
),
410 acct
->utime_scaled
= 0;
411 acct
->utime_sspurr
= 0;
413 acct
->steal_time
= 0;
416 acct
->stime_scaled
= 0;
417 acct
->hardirq_time
= 0;
418 acct
->softirq_time
= 0;
423 * Called from the context switch with interrupts disabled, to charge all
424 * accumulated times to the current process, and to prepare accounting on
427 void arch_vtime_task_switch(struct task_struct
*prev
)
429 struct cpu_accounting_data
*acct
= get_accounting(current
);
431 acct
->starttime
= get_accounting(prev
)->starttime
;
432 acct
->startspurr
= get_accounting(prev
)->startspurr
;
434 #endif /* CONFIG_PPC32 */
436 #else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
437 #define calc_cputime_factors()
440 void __delay(unsigned long loops
)
448 /* the RTCL register wraps at 1000000000 */
449 diff
= get_rtcl() - start
;
452 } while (diff
< loops
);
455 while (get_tbl() - start
< loops
)
460 EXPORT_SYMBOL(__delay
);
462 void udelay(unsigned long usecs
)
464 __delay(tb_ticks_per_usec
* usecs
);
466 EXPORT_SYMBOL(udelay
);
469 unsigned long profile_pc(struct pt_regs
*regs
)
471 unsigned long pc
= instruction_pointer(regs
);
473 if (in_lock_functions(pc
))
478 EXPORT_SYMBOL(profile_pc
);
481 #ifdef CONFIG_IRQ_WORK
484 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
487 static inline unsigned long test_irq_work_pending(void)
491 asm volatile("lbz %0,%1(13)"
493 : "i" (offsetof(struct paca_struct
, irq_work_pending
)));
497 static inline void set_irq_work_pending_flag(void)
499 asm volatile("stb %0,%1(13)" : :
501 "i" (offsetof(struct paca_struct
, irq_work_pending
)));
504 static inline void clear_irq_work_pending(void)
506 asm volatile("stb %0,%1(13)" : :
508 "i" (offsetof(struct paca_struct
, irq_work_pending
)));
513 DEFINE_PER_CPU(u8
, irq_work_pending
);
515 #define set_irq_work_pending_flag() __this_cpu_write(irq_work_pending, 1)
516 #define test_irq_work_pending() __this_cpu_read(irq_work_pending)
517 #define clear_irq_work_pending() __this_cpu_write(irq_work_pending, 0)
519 #endif /* 32 vs 64 bit */
521 void arch_irq_work_raise(void)
524 set_irq_work_pending_flag();
529 #else /* CONFIG_IRQ_WORK */
531 #define test_irq_work_pending() 0
532 #define clear_irq_work_pending()
534 #endif /* CONFIG_IRQ_WORK */
536 static void __timer_interrupt(void)
538 struct pt_regs
*regs
= get_irq_regs();
539 u64
*next_tb
= this_cpu_ptr(&decrementers_next_tb
);
540 struct clock_event_device
*evt
= this_cpu_ptr(&decrementers
);
543 trace_timer_interrupt_entry(regs
);
545 if (test_irq_work_pending()) {
546 clear_irq_work_pending();
550 now
= get_tb_or_rtc();
551 if (now
>= *next_tb
) {
553 if (evt
->event_handler
)
554 evt
->event_handler(evt
);
555 __this_cpu_inc(irq_stat
.timer_irqs_event
);
557 now
= *next_tb
- now
;
558 if (now
<= decrementer_max
)
560 /* We may have raced with new irq work */
561 if (test_irq_work_pending())
563 __this_cpu_inc(irq_stat
.timer_irqs_others
);
567 /* collect purr register values often, for accurate calculations */
568 if (firmware_has_feature(FW_FEATURE_SPLPAR
)) {
569 struct cpu_usage
*cu
= this_cpu_ptr(&cpu_usage_array
);
570 cu
->current_tb
= mfspr(SPRN_PURR
);
574 trace_timer_interrupt_exit(regs
);
578 * timer_interrupt - gets called when the decrementer overflows,
579 * with interrupts disabled.
581 void timer_interrupt(struct pt_regs
* regs
)
583 struct pt_regs
*old_regs
;
584 u64
*next_tb
= this_cpu_ptr(&decrementers_next_tb
);
586 /* Ensure a positive value is written to the decrementer, or else
587 * some CPUs will continue to take decrementer exceptions.
589 set_dec(decrementer_max
);
591 /* Some implementations of hotplug will get timer interrupts while
592 * offline, just ignore these and we also need to set
593 * decrementers_next_tb as MAX to make sure __check_irq_replay
594 * don't replay timer interrupt when return, otherwise we'll trap
597 if (!cpu_online(smp_processor_id())) {
602 /* Conditionally hard-enable interrupts now that the DEC has been
603 * bumped to its maximum value
605 may_hard_irq_enable();
608 #if defined(CONFIG_PPC32) && defined(CONFIG_PPC_PMAC)
609 if (atomic_read(&ppc_n_lost_interrupts
) != 0)
613 old_regs
= set_irq_regs(regs
);
618 set_irq_regs(old_regs
);
620 EXPORT_SYMBOL(timer_interrupt
);
623 * Hypervisor decrementer interrupts shouldn't occur but are sometimes
624 * left pending on exit from a KVM guest. We don't need to do anything
625 * to clear them, as they are edge-triggered.
627 void hdec_interrupt(struct pt_regs
*regs
)
631 #ifdef CONFIG_SUSPEND
632 static void generic_suspend_disable_irqs(void)
634 /* Disable the decrementer, so that it doesn't interfere
638 set_dec(decrementer_max
);
640 set_dec(decrementer_max
);
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();
665 unsigned long long tb_to_ns(unsigned long long ticks
)
667 return mulhdu(ticks
, tb_to_ns_scale
) << tb_to_ns_shift
;
669 EXPORT_SYMBOL_GPL(tb_to_ns
);
672 * Scheduler clock - returns current time in nanosec units.
674 * Note: mulhdu(a, b) (multiply high double unsigned) returns
675 * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
676 * are 64-bit unsigned numbers.
678 unsigned long long sched_clock(void)
682 return mulhdu(get_tb() - boot_tb
, tb_to_ns_scale
) << tb_to_ns_shift
;
686 #ifdef CONFIG_PPC_PSERIES
689 * Running clock - attempts to give a view of time passing for a virtualised
691 * Uses the VTB register if available otherwise a next best guess.
693 unsigned long long running_clock(void)
696 * Don't read the VTB as a host since KVM does not switch in host
697 * timebase into the VTB when it takes a guest off the CPU, reading the
698 * VTB would result in reading 'last switched out' guest VTB.
700 * Host kernels are often compiled with CONFIG_PPC_PSERIES checked, it
701 * would be unsafe to rely only on the #ifdef above.
703 if (firmware_has_feature(FW_FEATURE_LPAR
) &&
704 cpu_has_feature(CPU_FTR_ARCH_207S
))
705 return mulhdu(get_vtb() - boot_tb
, tb_to_ns_scale
) << tb_to_ns_shift
;
708 * This is a next best approximation without a VTB.
709 * On a host which is running bare metal there should never be any stolen
710 * time and on a host which doesn't do any virtualisation TB *should* equal
711 * VTB so it makes no difference anyway.
713 return local_clock() - kcpustat_this_cpu
->cpustat
[CPUTIME_STEAL
];
717 static int __init
get_freq(char *name
, int cells
, unsigned long *val
)
719 struct device_node
*cpu
;
723 /* The cpu node should have timebase and clock frequency properties */
724 cpu
= of_find_node_by_type(NULL
, "cpu");
727 fp
= of_get_property(cpu
, name
, NULL
);
730 *val
= of_read_ulong(fp
, cells
);
739 static void start_cpu_decrementer(void)
741 #if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
742 /* Clear any pending timer interrupts */
743 mtspr(SPRN_TSR
, TSR_ENW
| TSR_WIS
| TSR_DIS
| TSR_FIS
);
745 /* Enable decrementer interrupt */
746 mtspr(SPRN_TCR
, TCR_DIE
);
747 #endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */
750 void __init
generic_calibrate_decr(void)
752 ppc_tb_freq
= DEFAULT_TB_FREQ
; /* hardcoded default */
754 if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq
) &&
755 !get_freq("timebase-frequency", 1, &ppc_tb_freq
)) {
757 printk(KERN_ERR
"WARNING: Estimating decrementer frequency "
761 ppc_proc_freq
= DEFAULT_PROC_FREQ
; /* hardcoded default */
763 if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq
) &&
764 !get_freq("clock-frequency", 1, &ppc_proc_freq
)) {
766 printk(KERN_ERR
"WARNING: Estimating processor frequency "
771 int update_persistent_clock(struct timespec now
)
775 if (!ppc_md
.set_rtc_time
)
778 to_tm(now
.tv_sec
+ 1 + timezone_offset
, &tm
);
782 return ppc_md
.set_rtc_time(&tm
);
785 static void __read_persistent_clock(struct timespec
*ts
)
788 static int first
= 1;
791 /* XXX this is a litle fragile but will work okay in the short term */
794 if (ppc_md
.time_init
)
795 timezone_offset
= ppc_md
.time_init();
797 /* get_boot_time() isn't guaranteed to be safe to call late */
798 if (ppc_md
.get_boot_time
) {
799 ts
->tv_sec
= ppc_md
.get_boot_time() - timezone_offset
;
803 if (!ppc_md
.get_rtc_time
) {
807 ppc_md
.get_rtc_time(&tm
);
809 ts
->tv_sec
= mktime(tm
.tm_year
+1900, tm
.tm_mon
+1, tm
.tm_mday
,
810 tm
.tm_hour
, tm
.tm_min
, tm
.tm_sec
);
813 void read_persistent_clock(struct timespec
*ts
)
815 __read_persistent_clock(ts
);
817 /* Sanitize it in case real time clock is set below EPOCH */
818 if (ts
->tv_sec
< 0) {
825 /* clocksource code */
826 static u64
rtc_read(struct clocksource
*cs
)
828 return (u64
)get_rtc();
831 static u64
timebase_read(struct clocksource
*cs
)
833 return (u64
)get_tb();
836 void update_vsyscall_old(struct timespec
*wall_time
, struct timespec
*wtm
,
837 struct clocksource
*clock
, u32 mult
, u64 cycle_last
)
839 u64 new_tb_to_xs
, new_stamp_xsec
;
842 if (clock
!= &clocksource_timebase
)
845 /* Make userspace gettimeofday spin until we're done. */
846 ++vdso_data
->tb_update_count
;
849 /* 19342813113834067 ~= 2^(20+64) / 1e9 */
850 new_tb_to_xs
= (u64
) mult
* (19342813113834067ULL >> clock
->shift
);
851 new_stamp_xsec
= (u64
) wall_time
->tv_nsec
* XSEC_PER_SEC
;
852 do_div(new_stamp_xsec
, 1000000000);
853 new_stamp_xsec
+= (u64
) wall_time
->tv_sec
* XSEC_PER_SEC
;
855 BUG_ON(wall_time
->tv_nsec
>= NSEC_PER_SEC
);
856 /* this is tv_nsec / 1e9 as a 0.32 fraction */
857 frac_sec
= ((u64
) wall_time
->tv_nsec
* 18446744073ULL) >> 32;
860 * tb_update_count is used to allow the userspace gettimeofday code
861 * to assure itself that it sees a consistent view of the tb_to_xs and
862 * stamp_xsec variables. It reads the tb_update_count, then reads
863 * tb_to_xs and stamp_xsec and then reads tb_update_count again. If
864 * the two values of tb_update_count match and are even then the
865 * tb_to_xs and stamp_xsec values are consistent. If not, then it
866 * loops back and reads them again until this criteria is met.
867 * We expect the caller to have done the first increment of
868 * vdso_data->tb_update_count already.
870 vdso_data
->tb_orig_stamp
= cycle_last
;
871 vdso_data
->stamp_xsec
= new_stamp_xsec
;
872 vdso_data
->tb_to_xs
= new_tb_to_xs
;
873 vdso_data
->wtom_clock_sec
= wtm
->tv_sec
;
874 vdso_data
->wtom_clock_nsec
= wtm
->tv_nsec
;
875 vdso_data
->stamp_xtime
= *wall_time
;
876 vdso_data
->stamp_sec_fraction
= frac_sec
;
878 ++(vdso_data
->tb_update_count
);
881 void update_vsyscall_tz(void)
883 vdso_data
->tz_minuteswest
= sys_tz
.tz_minuteswest
;
884 vdso_data
->tz_dsttime
= sys_tz
.tz_dsttime
;
887 static void __init
clocksource_init(void)
889 struct clocksource
*clock
;
892 clock
= &clocksource_rtc
;
894 clock
= &clocksource_timebase
;
896 if (clocksource_register_hz(clock
, tb_ticks_per_sec
)) {
897 printk(KERN_ERR
"clocksource: %s is already registered\n",
902 printk(KERN_INFO
"clocksource: %s mult[%x] shift[%d] registered\n",
903 clock
->name
, clock
->mult
, clock
->shift
);
906 static int decrementer_set_next_event(unsigned long evt
,
907 struct clock_event_device
*dev
)
909 __this_cpu_write(decrementers_next_tb
, get_tb_or_rtc() + evt
);
912 /* We may have raced with new irq work */
913 if (test_irq_work_pending())
919 static int decrementer_shutdown(struct clock_event_device
*dev
)
921 decrementer_set_next_event(decrementer_max
, dev
);
925 /* Interrupt handler for the timer broadcast IPI */
926 void tick_broadcast_ipi_handler(void)
928 u64
*next_tb
= this_cpu_ptr(&decrementers_next_tb
);
930 *next_tb
= get_tb_or_rtc();
934 static void register_decrementer_clockevent(int cpu
)
936 struct clock_event_device
*dec
= &per_cpu(decrementers
, cpu
);
938 *dec
= decrementer_clockevent
;
939 dec
->cpumask
= cpumask_of(cpu
);
941 printk_once(KERN_DEBUG
"clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
942 dec
->name
, dec
->mult
, dec
->shift
, cpu
);
944 clockevents_register_device(dec
);
947 static void enable_large_decrementer(void)
949 if (!cpu_has_feature(CPU_FTR_ARCH_300
))
952 if (decrementer_max
<= DECREMENTER_DEFAULT_MAX
)
956 * If we're running as the hypervisor we need to enable the LD manually
957 * otherwise firmware should have done it for us.
959 if (cpu_has_feature(CPU_FTR_HVMODE
))
960 mtspr(SPRN_LPCR
, mfspr(SPRN_LPCR
) | LPCR_LD
);
963 static void __init
set_decrementer_max(void)
965 struct device_node
*cpu
;
968 /* Prior to ISAv3 the decrementer is always 32 bit */
969 if (!cpu_has_feature(CPU_FTR_ARCH_300
))
972 cpu
= of_find_node_by_type(NULL
, "cpu");
974 if (of_property_read_u32(cpu
, "ibm,dec-bits", &bits
) == 0) {
975 if (bits
> 64 || bits
< 32) {
976 pr_warn("time_init: firmware supplied invalid ibm,dec-bits");
980 /* calculate the signed maximum given this many bits */
981 decrementer_max
= (1ul << (bits
- 1)) - 1;
986 pr_info("time_init: %u bit decrementer (max: %llx)\n",
987 bits
, decrementer_max
);
990 static void __init
init_decrementer_clockevent(void)
992 int cpu
= smp_processor_id();
994 clockevents_calc_mult_shift(&decrementer_clockevent
, ppc_tb_freq
, 4);
996 decrementer_clockevent
.max_delta_ns
=
997 clockevent_delta2ns(decrementer_max
, &decrementer_clockevent
);
998 decrementer_clockevent
.min_delta_ns
=
999 clockevent_delta2ns(2, &decrementer_clockevent
);
1001 register_decrementer_clockevent(cpu
);
1004 void secondary_cpu_time_init(void)
1006 /* Enable and test the large decrementer for this cpu */
1007 enable_large_decrementer();
1009 /* Start the decrementer on CPUs that have manual control
1012 start_cpu_decrementer();
1014 /* FIME: Should make unrelatred change to move snapshot_timebase
1016 register_decrementer_clockevent(smp_processor_id());
1019 /* This function is only called on the boot processor */
1020 void __init
time_init(void)
1022 struct div_result res
;
1027 /* 601 processor: dec counts down by 128 every 128ns */
1028 ppc_tb_freq
= 1000000000;
1030 /* Normal PowerPC with timebase register */
1031 ppc_md
.calibrate_decr();
1032 printk(KERN_DEBUG
"time_init: decrementer frequency = %lu.%.6lu MHz\n",
1033 ppc_tb_freq
/ 1000000, ppc_tb_freq
% 1000000);
1034 printk(KERN_DEBUG
"time_init: processor frequency = %lu.%.6lu MHz\n",
1035 ppc_proc_freq
/ 1000000, ppc_proc_freq
% 1000000);
1038 tb_ticks_per_jiffy
= ppc_tb_freq
/ HZ
;
1039 tb_ticks_per_sec
= ppc_tb_freq
;
1040 tb_ticks_per_usec
= ppc_tb_freq
/ 1000000;
1041 calc_cputime_factors();
1044 * Compute scale factor for sched_clock.
1045 * The calibrate_decr() function has set tb_ticks_per_sec,
1046 * which is the timebase frequency.
1047 * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
1048 * the 128-bit result as a 64.64 fixed-point number.
1049 * We then shift that number right until it is less than 1.0,
1050 * giving us the scale factor and shift count to use in
1053 div128_by_32(1000000000, 0, tb_ticks_per_sec
, &res
);
1054 scale
= res
.result_low
;
1055 for (shift
= 0; res
.result_high
!= 0; ++shift
) {
1056 scale
= (scale
>> 1) | (res
.result_high
<< 63);
1057 res
.result_high
>>= 1;
1059 tb_to_ns_scale
= scale
;
1060 tb_to_ns_shift
= shift
;
1061 /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
1062 boot_tb
= get_tb_or_rtc();
1064 /* If platform provided a timezone (pmac), we correct the time */
1065 if (timezone_offset
) {
1066 sys_tz
.tz_minuteswest
= -timezone_offset
/ 60;
1067 sys_tz
.tz_dsttime
= 0;
1070 vdso_data
->tb_update_count
= 0;
1071 vdso_data
->tb_ticks_per_sec
= tb_ticks_per_sec
;
1073 /* initialise and enable the large decrementer (if we have one) */
1074 set_decrementer_max();
1075 enable_large_decrementer();
1077 /* Start the decrementer on CPUs that have manual control
1080 start_cpu_decrementer();
1082 /* Register the clocksource */
1085 init_decrementer_clockevent();
1086 tick_setup_hrtimer_broadcast();
1088 #ifdef CONFIG_COMMON_CLK
1095 #define STARTOFTIME 1970
1096 #define SECDAY 86400L
1097 #define SECYR (SECDAY * 365)
1098 #define leapyear(year) ((year) % 4 == 0 && \
1099 ((year) % 100 != 0 || (year) % 400 == 0))
1100 #define days_in_year(a) (leapyear(a) ? 366 : 365)
1101 #define days_in_month(a) (month_days[(a) - 1])
1103 static int month_days
[12] = {
1104 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
1107 void to_tm(int tim
, struct rtc_time
* tm
)
1110 register long hms
, day
;
1115 /* Hours, minutes, seconds are easy */
1116 tm
->tm_hour
= hms
/ 3600;
1117 tm
->tm_min
= (hms
% 3600) / 60;
1118 tm
->tm_sec
= (hms
% 3600) % 60;
1120 /* Number of years in days */
1121 for (i
= STARTOFTIME
; day
>= days_in_year(i
); i
++)
1122 day
-= days_in_year(i
);
1125 /* Number of months in days left */
1126 if (leapyear(tm
->tm_year
))
1127 days_in_month(FEBRUARY
) = 29;
1128 for (i
= 1; day
>= days_in_month(i
); i
++)
1129 day
-= days_in_month(i
);
1130 days_in_month(FEBRUARY
) = 28;
1133 /* Days are what is left over (+1) from all that. */
1134 tm
->tm_mday
= day
+ 1;
1137 * No-one uses the day of the week.
1141 EXPORT_SYMBOL(to_tm
);
1144 * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
1147 void div128_by_32(u64 dividend_high
, u64 dividend_low
,
1148 unsigned divisor
, struct div_result
*dr
)
1150 unsigned long a
, b
, c
, d
;
1151 unsigned long w
, x
, y
, z
;
1154 a
= dividend_high
>> 32;
1155 b
= dividend_high
& 0xffffffff;
1156 c
= dividend_low
>> 32;
1157 d
= dividend_low
& 0xffffffff;
1160 ra
= ((u64
)(a
- (w
* divisor
)) << 32) + b
;
1162 rb
= ((u64
) do_div(ra
, divisor
) << 32) + c
;
1165 rc
= ((u64
) do_div(rb
, divisor
) << 32) + d
;
1168 do_div(rc
, divisor
);
1171 dr
->result_high
= ((u64
)w
<< 32) + x
;
1172 dr
->result_low
= ((u64
)y
<< 32) + z
;
1176 /* We don't need to calibrate delay, we use the CPU timebase for that */
1177 void calibrate_delay(void)
1179 /* Some generic code (such as spinlock debug) use loops_per_jiffy
1180 * as the number of __delay(1) in a jiffy, so make it so
1182 loops_per_jiffy
= tb_ticks_per_jiffy
;
1185 #if IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
1186 static int rtc_generic_get_time(struct device
*dev
, struct rtc_time
*tm
)
1188 ppc_md
.get_rtc_time(tm
);
1189 return rtc_valid_tm(tm
);
1192 static int rtc_generic_set_time(struct device
*dev
, struct rtc_time
*tm
)
1194 if (!ppc_md
.set_rtc_time
)
1197 if (ppc_md
.set_rtc_time(tm
) < 0)
1203 static const struct rtc_class_ops rtc_generic_ops
= {
1204 .read_time
= rtc_generic_get_time
,
1205 .set_time
= rtc_generic_set_time
,
1208 static int __init
rtc_init(void)
1210 struct platform_device
*pdev
;
1212 if (!ppc_md
.get_rtc_time
)
1215 pdev
= platform_device_register_data(NULL
, "rtc-generic", -1,
1217 sizeof(rtc_generic_ops
));
1219 return PTR_ERR_OR_ZERO(pdev
);
1222 device_initcall(rtc_init
);