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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Common time routines among all ppc machines.
4 *
5 * Written by Cort Dougan (cort@cs.nmt.edu) to merge
6 * Paul Mackerras' version and mine for PReP and Pmac.
7 * MPC8xx/MBX changes by Dan Malek (dmalek@jlc.net).
8 * Converted for 64-bit by Mike Corrigan (mikejc@us.ibm.com)
9 *
10 * First round of bugfixes by Gabriel Paubert (paubert@iram.es)
11 * to make clock more stable (2.4.0-test5). The only thing
12 * that this code assumes is that the timebases have been synchronized
13 * by firmware on SMP and are never stopped (never do sleep
14 * on SMP then, nap and doze are OK).
15 *
16 * Speeded up do_gettimeofday by getting rid of references to
17 * xtime (which required locks for consistency). (mikejc@us.ibm.com)
18 *
19 * TODO (not necessarily in this file):
20 * - improve precision and reproducibility of timebase frequency
21 * measurement at boot time.
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.
25 *
26 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
27 * "A Kernel Model for Precision Timekeeping" by Dave Mills
28 */
29
30#include <linux/errno.h>
31#include <linux/export.h>
32#include <linux/sched.h>
33#include <linux/sched/clock.h>
34#include <linux/kernel.h>
35#include <linux/param.h>
36#include <linux/string.h>
37#include <linux/mm.h>
38#include <linux/interrupt.h>
39#include <linux/timex.h>
40#include <linux/kernel_stat.h>
41#include <linux/time.h>
42#include <linux/init.h>
43#include <linux/profile.h>
44#include <linux/cpu.h>
45#include <linux/security.h>
46#include <linux/percpu.h>
47#include <linux/rtc.h>
48#include <linux/jiffies.h>
49#include <linux/posix-timers.h>
50#include <linux/irq.h>
51#include <linux/delay.h>
52#include <linux/irq_work.h>
53#include <linux/of_clk.h>
54#include <linux/suspend.h>
55#include <linux/sched/cputime.h>
56#include <linux/processor.h>
57#include <asm/trace.h>
58
59#include <asm/io.h>
60#include <asm/nvram.h>
61#include <asm/cache.h>
62#include <asm/machdep.h>
63#include <linux/uaccess.h>
64#include <asm/time.h>
65#include <asm/prom.h>
66#include <asm/irq.h>
67#include <asm/div64.h>
68#include <asm/smp.h>
69#include <asm/vdso_datapage.h>
70#include <asm/firmware.h>
71#include <asm/asm-prototypes.h>
72
73/* powerpc clocksource/clockevent code */
74
75#include <linux/clockchips.h>
76#include <linux/timekeeper_internal.h>
77
78static u64 rtc_read(struct clocksource *);
79static struct clocksource clocksource_rtc = {
80 .name = "rtc",
81 .rating = 400,
82 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
83 .mask = CLOCKSOURCE_MASK(64),
84 .read = rtc_read,
85};
86
87static u64 timebase_read(struct clocksource *);
88static struct clocksource clocksource_timebase = {
89 .name = "timebase",
90 .rating = 400,
91 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
92 .mask = CLOCKSOURCE_MASK(64),
93 .read = timebase_read,
94};
95
96#define DECREMENTER_DEFAULT_MAX 0x7FFFFFFF
97u64 decrementer_max = DECREMENTER_DEFAULT_MAX;
98
99static int decrementer_set_next_event(unsigned long evt,
100 struct clock_event_device *dev);
101static int decrementer_shutdown(struct clock_event_device *evt);
102
103struct clock_event_device decrementer_clockevent = {
104 .name = "decrementer",
105 .rating = 200,
106 .irq = 0,
107 .set_next_event = decrementer_set_next_event,
108 .set_state_oneshot_stopped = decrementer_shutdown,
109 .set_state_shutdown = decrementer_shutdown,
110 .tick_resume = decrementer_shutdown,
111 .features = CLOCK_EVT_FEAT_ONESHOT |
112 CLOCK_EVT_FEAT_C3STOP,
113};
114EXPORT_SYMBOL(decrementer_clockevent);
115
116DEFINE_PER_CPU(u64, decrementers_next_tb);
117static DEFINE_PER_CPU(struct clock_event_device, decrementers);
118
119#define XSEC_PER_SEC (1024*1024)
120
121#ifdef CONFIG_PPC64
122#define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
123#else
124/* compute ((xsec << 12) * max) >> 32 */
125#define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
126#endif
127
128unsigned long tb_ticks_per_jiffy;
129unsigned long tb_ticks_per_usec = 100; /* sane default */
130EXPORT_SYMBOL(tb_ticks_per_usec);
131unsigned long tb_ticks_per_sec;
132EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */
133
134DEFINE_SPINLOCK(rtc_lock);
135EXPORT_SYMBOL_GPL(rtc_lock);
136
137static u64 tb_to_ns_scale __read_mostly;
138static unsigned tb_to_ns_shift __read_mostly;
139static u64 boot_tb __read_mostly;
140
141extern struct timezone sys_tz;
142static long timezone_offset;
143
144unsigned long ppc_proc_freq;
145EXPORT_SYMBOL_GPL(ppc_proc_freq);
146unsigned long ppc_tb_freq;
147EXPORT_SYMBOL_GPL(ppc_tb_freq);
148
149bool tb_invalid;
150
151#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
152/*
153 * Factor for converting from cputime_t (timebase ticks) to
154 * microseconds. This is stored as 0.64 fixed-point binary fraction.
155 */
156u64 __cputime_usec_factor;
157EXPORT_SYMBOL(__cputime_usec_factor);
158
159#ifdef CONFIG_PPC_SPLPAR
160void (*dtl_consumer)(struct dtl_entry *, u64);
161#endif
162
163static void calc_cputime_factors(void)
164{
165 struct div_result res;
166
167 div128_by_32(1000000, 0, tb_ticks_per_sec, &res);
168 __cputime_usec_factor = res.result_low;
169}
170
171/*
172 * Read the SPURR on systems that have it, otherwise the PURR,
173 * or if that doesn't exist return the timebase value passed in.
174 */
175static inline unsigned long read_spurr(unsigned long tb)
176{
177 if (cpu_has_feature(CPU_FTR_SPURR))
178 return mfspr(SPRN_SPURR);
179 if (cpu_has_feature(CPU_FTR_PURR))
180 return mfspr(SPRN_PURR);
181 return tb;
182}
183
184#ifdef CONFIG_PPC_SPLPAR
185
186#include <asm/dtl.h>
187
188/*
189 * Scan the dispatch trace log and count up the stolen time.
190 * Should be called with interrupts disabled.
191 */
192static u64 scan_dispatch_log(u64 stop_tb)
193{
194 u64 i = local_paca->dtl_ridx;
195 struct dtl_entry *dtl = local_paca->dtl_curr;
196 struct dtl_entry *dtl_end = local_paca->dispatch_log_end;
197 struct lppaca *vpa = local_paca->lppaca_ptr;
198 u64 tb_delta;
199 u64 stolen = 0;
200 u64 dtb;
201
202 if (!dtl)
203 return 0;
204
205 if (i == be64_to_cpu(vpa->dtl_idx))
206 return 0;
207 while (i < be64_to_cpu(vpa->dtl_idx)) {
208 dtb = be64_to_cpu(dtl->timebase);
209 tb_delta = be32_to_cpu(dtl->enqueue_to_dispatch_time) +
210 be32_to_cpu(dtl->ready_to_enqueue_time);
211 barrier();
212 if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) {
213 /* buffer has overflowed */
214 i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG;
215 dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
216 continue;
217 }
218 if (dtb > stop_tb)
219 break;
220 if (dtl_consumer)
221 dtl_consumer(dtl, i);
222 stolen += tb_delta;
223 ++i;
224 ++dtl;
225 if (dtl == dtl_end)
226 dtl = local_paca->dispatch_log;
227 }
228 local_paca->dtl_ridx = i;
229 local_paca->dtl_curr = dtl;
230 return stolen;
231}
232
233/*
234 * Accumulate stolen time by scanning the dispatch trace log.
235 * Called on entry from user mode.
236 */
237void notrace accumulate_stolen_time(void)
238{
239 u64 sst, ust;
240 unsigned long save_irq_soft_mask = irq_soft_mask_return();
241 struct cpu_accounting_data *acct = &local_paca->accounting;
242
243 /* We are called early in the exception entry, before
244 * soft/hard_enabled are sync'ed to the expected state
245 * for the exception. We are hard disabled but the PACA
246 * needs to reflect that so various debug stuff doesn't
247 * complain
248 */
249 irq_soft_mask_set(IRQS_DISABLED);
250
251 sst = scan_dispatch_log(acct->starttime_user);
252 ust = scan_dispatch_log(acct->starttime);
253 acct->stime -= sst;
254 acct->utime -= ust;
255 acct->steal_time += ust + sst;
256
257 irq_soft_mask_set(save_irq_soft_mask);
258}
259
260static inline u64 calculate_stolen_time(u64 stop_tb)
261{
262 if (!firmware_has_feature(FW_FEATURE_SPLPAR))
263 return 0;
264
265 if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx))
266 return scan_dispatch_log(stop_tb);
267
268 return 0;
269}
270
271#else /* CONFIG_PPC_SPLPAR */
272static inline u64 calculate_stolen_time(u64 stop_tb)
273{
274 return 0;
275}
276
277#endif /* CONFIG_PPC_SPLPAR */
278
279/*
280 * Account time for a transition between system, hard irq
281 * or soft irq state.
282 */
283static unsigned long vtime_delta_scaled(struct cpu_accounting_data *acct,
284 unsigned long now, unsigned long stime)
285{
286 unsigned long stime_scaled = 0;
287#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
288 unsigned long nowscaled, deltascaled;
289 unsigned long utime, utime_scaled;
290
291 nowscaled = read_spurr(now);
292 deltascaled = nowscaled - acct->startspurr;
293 acct->startspurr = nowscaled;
294 utime = acct->utime - acct->utime_sspurr;
295 acct->utime_sspurr = acct->utime;
296
297 /*
298 * Because we don't read the SPURR on every kernel entry/exit,
299 * deltascaled includes both user and system SPURR ticks.
300 * Apportion these ticks to system SPURR ticks and user
301 * SPURR ticks in the same ratio as the system time (delta)
302 * and user time (udelta) values obtained from the timebase
303 * over the same interval. The system ticks get accounted here;
304 * the user ticks get saved up in paca->user_time_scaled to be
305 * used by account_process_tick.
306 */
307 stime_scaled = stime;
308 utime_scaled = utime;
309 if (deltascaled != stime + utime) {
310 if (utime) {
311 stime_scaled = deltascaled * stime / (stime + utime);
312 utime_scaled = deltascaled - stime_scaled;
313 } else {
314 stime_scaled = deltascaled;
315 }
316 }
317 acct->utime_scaled += utime_scaled;
318#endif
319
320 return stime_scaled;
321}
322
323static unsigned long vtime_delta(struct task_struct *tsk,
324 unsigned long *stime_scaled,
325 unsigned long *steal_time)
326{
327 unsigned long now, stime;
328 struct cpu_accounting_data *acct = get_accounting(tsk);
329
330 WARN_ON_ONCE(!irqs_disabled());
331
332 now = mftb();
333 stime = now - acct->starttime;
334 acct->starttime = now;
335
336 *stime_scaled = vtime_delta_scaled(acct, now, stime);
337
338 *steal_time = calculate_stolen_time(now);
339
340 return stime;
341}
342
343void vtime_account_kernel(struct task_struct *tsk)
344{
345 unsigned long stime, stime_scaled, steal_time;
346 struct cpu_accounting_data *acct = get_accounting(tsk);
347
348 stime = vtime_delta(tsk, &stime_scaled, &steal_time);
349
350 stime -= min(stime, steal_time);
351 acct->steal_time += steal_time;
352
353 if ((tsk->flags & PF_VCPU) && !irq_count()) {
354 acct->gtime += stime;
355#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
356 acct->utime_scaled += stime_scaled;
357#endif
358 } else {
359 if (hardirq_count())
360 acct->hardirq_time += stime;
361 else if (in_serving_softirq())
362 acct->softirq_time += stime;
363 else
364 acct->stime += stime;
365
366#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
367 acct->stime_scaled += stime_scaled;
368#endif
369 }
370}
371EXPORT_SYMBOL_GPL(vtime_account_kernel);
372
373void vtime_account_idle(struct task_struct *tsk)
374{
375 unsigned long stime, stime_scaled, steal_time;
376 struct cpu_accounting_data *acct = get_accounting(tsk);
377
378 stime = vtime_delta(tsk, &stime_scaled, &steal_time);
379 acct->idle_time += stime + steal_time;
380}
381
382static void vtime_flush_scaled(struct task_struct *tsk,
383 struct cpu_accounting_data *acct)
384{
385#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
386 if (acct->utime_scaled)
387 tsk->utimescaled += cputime_to_nsecs(acct->utime_scaled);
388 if (acct->stime_scaled)
389 tsk->stimescaled += cputime_to_nsecs(acct->stime_scaled);
390
391 acct->utime_scaled = 0;
392 acct->utime_sspurr = 0;
393 acct->stime_scaled = 0;
394#endif
395}
396
397/*
398 * Account the whole cputime accumulated in the paca
399 * Must be called with interrupts disabled.
400 * Assumes that vtime_account_kernel/idle() has been called
401 * recently (i.e. since the last entry from usermode) so that
402 * get_paca()->user_time_scaled is up to date.
403 */
404void vtime_flush(struct task_struct *tsk)
405{
406 struct cpu_accounting_data *acct = get_accounting(tsk);
407
408 if (acct->utime)
409 account_user_time(tsk, cputime_to_nsecs(acct->utime));
410
411 if (acct->gtime)
412 account_guest_time(tsk, cputime_to_nsecs(acct->gtime));
413
414 if (IS_ENABLED(CONFIG_PPC_SPLPAR) && acct->steal_time) {
415 account_steal_time(cputime_to_nsecs(acct->steal_time));
416 acct->steal_time = 0;
417 }
418
419 if (acct->idle_time)
420 account_idle_time(cputime_to_nsecs(acct->idle_time));
421
422 if (acct->stime)
423 account_system_index_time(tsk, cputime_to_nsecs(acct->stime),
424 CPUTIME_SYSTEM);
425
426 if (acct->hardirq_time)
427 account_system_index_time(tsk, cputime_to_nsecs(acct->hardirq_time),
428 CPUTIME_IRQ);
429 if (acct->softirq_time)
430 account_system_index_time(tsk, cputime_to_nsecs(acct->softirq_time),
431 CPUTIME_SOFTIRQ);
432
433 vtime_flush_scaled(tsk, acct);
434
435 acct->utime = 0;
436 acct->gtime = 0;
437 acct->idle_time = 0;
438 acct->stime = 0;
439 acct->hardirq_time = 0;
440 acct->softirq_time = 0;
441}
442
443#else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
444#define calc_cputime_factors()
445#endif
446
447void __delay(unsigned long loops)
448{
449 unsigned long start;
450 int diff;
451
452 spin_begin();
453 if (__USE_RTC()) {
454 start = get_rtcl();
455 do {
456 /* the RTCL register wraps at 1000000000 */
457 diff = get_rtcl() - start;
458 if (diff < 0)
459 diff += 1000000000;
460 spin_cpu_relax();
461 } while (diff < loops);
462 } else if (tb_invalid) {
463 /*
464 * TB is in error state and isn't ticking anymore.
465 * HMI handler was unable to recover from TB error.
466 * Return immediately, so that kernel won't get stuck here.
467 */
468 spin_cpu_relax();
469 } else {
470 start = get_tbl();
471 while (get_tbl() - start < loops)
472 spin_cpu_relax();
473 }
474 spin_end();
475}
476EXPORT_SYMBOL(__delay);
477
478void udelay(unsigned long usecs)
479{
480 __delay(tb_ticks_per_usec * usecs);
481}
482EXPORT_SYMBOL(udelay);
483
484#ifdef CONFIG_SMP
485unsigned long profile_pc(struct pt_regs *regs)
486{
487 unsigned long pc = instruction_pointer(regs);
488
489 if (in_lock_functions(pc))
490 return regs->link;
491
492 return pc;
493}
494EXPORT_SYMBOL(profile_pc);
495#endif
496
497#ifdef CONFIG_IRQ_WORK
498
499/*
500 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
501 */
502#ifdef CONFIG_PPC64
503static inline unsigned long test_irq_work_pending(void)
504{
505 unsigned long x;
506
507 asm volatile("lbz %0,%1(13)"
508 : "=r" (x)
509 : "i" (offsetof(struct paca_struct, irq_work_pending)));
510 return x;
511}
512
513static inline void set_irq_work_pending_flag(void)
514{
515 asm volatile("stb %0,%1(13)" : :
516 "r" (1),
517 "i" (offsetof(struct paca_struct, irq_work_pending)));
518}
519
520static inline void clear_irq_work_pending(void)
521{
522 asm volatile("stb %0,%1(13)" : :
523 "r" (0),
524 "i" (offsetof(struct paca_struct, irq_work_pending)));
525}
526
527#else /* 32-bit */
528
529DEFINE_PER_CPU(u8, irq_work_pending);
530
531#define set_irq_work_pending_flag() __this_cpu_write(irq_work_pending, 1)
532#define test_irq_work_pending() __this_cpu_read(irq_work_pending)
533#define clear_irq_work_pending() __this_cpu_write(irq_work_pending, 0)
534
535#endif /* 32 vs 64 bit */
536
537void arch_irq_work_raise(void)
538{
539 /*
540 * 64-bit code that uses irq soft-mask can just cause an immediate
541 * interrupt here that gets soft masked, if this is called under
542 * local_irq_disable(). It might be possible to prevent that happening
543 * by noticing interrupts are disabled and setting decrementer pending
544 * to be replayed when irqs are enabled. The problem there is that
545 * tracing can call irq_work_raise, including in code that does low
546 * level manipulations of irq soft-mask state (e.g., trace_hardirqs_on)
547 * which could get tangled up if we're messing with the same state
548 * here.
549 */
550 preempt_disable();
551 set_irq_work_pending_flag();
552 set_dec(1);
553 preempt_enable();
554}
555
556#else /* CONFIG_IRQ_WORK */
557
558#define test_irq_work_pending() 0
559#define clear_irq_work_pending()
560
561#endif /* CONFIG_IRQ_WORK */
562
563/*
564 * timer_interrupt - gets called when the decrementer overflows,
565 * with interrupts disabled.
566 */
567void timer_interrupt(struct pt_regs *regs)
568{
569 struct clock_event_device *evt = this_cpu_ptr(&decrementers);
570 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
571 struct pt_regs *old_regs;
572 u64 now;
573
574 /* Some implementations of hotplug will get timer interrupts while
575 * offline, just ignore these and we also need to set
576 * decrementers_next_tb as MAX to make sure __check_irq_replay
577 * don't replay timer interrupt when return, otherwise we'll trap
578 * here infinitely :(
579 */
580 if (unlikely(!cpu_online(smp_processor_id()))) {
581 *next_tb = ~(u64)0;
582 set_dec(decrementer_max);
583 return;
584 }
585
586 /* Ensure a positive value is written to the decrementer, or else
587 * some CPUs will continue to take decrementer exceptions. When the
588 * PPC_WATCHDOG (decrementer based) is configured, keep this at most
589 * 31 bits, which is about 4 seconds on most systems, which gives
590 * the watchdog a chance of catching timer interrupt hard lockups.
591 */
592 if (IS_ENABLED(CONFIG_PPC_WATCHDOG))
593 set_dec(0x7fffffff);
594 else
595 set_dec(decrementer_max);
596
597 /* Conditionally hard-enable interrupts now that the DEC has been
598 * bumped to its maximum value
599 */
600 may_hard_irq_enable();
601
602
603#if defined(CONFIG_PPC32) && defined(CONFIG_PPC_PMAC)
604 if (atomic_read(&ppc_n_lost_interrupts) != 0)
605 do_IRQ(regs);
606#endif
607
608 old_regs = set_irq_regs(regs);
609 irq_enter();
610 trace_timer_interrupt_entry(regs);
611
612 if (test_irq_work_pending()) {
613 clear_irq_work_pending();
614 irq_work_run();
615 }
616
617 now = get_tb_or_rtc();
618 if (now >= *next_tb) {
619 *next_tb = ~(u64)0;
620 if (evt->event_handler)
621 evt->event_handler(evt);
622 __this_cpu_inc(irq_stat.timer_irqs_event);
623 } else {
624 now = *next_tb - now;
625 if (now <= decrementer_max)
626 set_dec(now);
627 /* We may have raced with new irq work */
628 if (test_irq_work_pending())
629 set_dec(1);
630 __this_cpu_inc(irq_stat.timer_irqs_others);
631 }
632
633 trace_timer_interrupt_exit(regs);
634 irq_exit();
635 set_irq_regs(old_regs);
636}
637EXPORT_SYMBOL(timer_interrupt);
638
639#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
640void timer_broadcast_interrupt(void)
641{
642 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
643
644 *next_tb = ~(u64)0;
645 tick_receive_broadcast();
646 __this_cpu_inc(irq_stat.broadcast_irqs_event);
647}
648#endif
649
650#ifdef CONFIG_SUSPEND
651static void generic_suspend_disable_irqs(void)
652{
653 /* Disable the decrementer, so that it doesn't interfere
654 * with suspending.
655 */
656
657 set_dec(decrementer_max);
658 local_irq_disable();
659 set_dec(decrementer_max);
660}
661
662static void generic_suspend_enable_irqs(void)
663{
664 local_irq_enable();
665}
666
667/* Overrides the weak version in kernel/power/main.c */
668void arch_suspend_disable_irqs(void)
669{
670 if (ppc_md.suspend_disable_irqs)
671 ppc_md.suspend_disable_irqs();
672 generic_suspend_disable_irqs();
673}
674
675/* Overrides the weak version in kernel/power/main.c */
676void arch_suspend_enable_irqs(void)
677{
678 generic_suspend_enable_irqs();
679 if (ppc_md.suspend_enable_irqs)
680 ppc_md.suspend_enable_irqs();
681}
682#endif
683
684unsigned long long tb_to_ns(unsigned long long ticks)
685{
686 return mulhdu(ticks, tb_to_ns_scale) << tb_to_ns_shift;
687}
688EXPORT_SYMBOL_GPL(tb_to_ns);
689
690/*
691 * Scheduler clock - returns current time in nanosec units.
692 *
693 * Note: mulhdu(a, b) (multiply high double unsigned) returns
694 * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
695 * are 64-bit unsigned numbers.
696 */
697notrace unsigned long long sched_clock(void)
698{
699 if (__USE_RTC())
700 return get_rtc();
701 return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
702}
703
704
705#ifdef CONFIG_PPC_PSERIES
706
707/*
708 * Running clock - attempts to give a view of time passing for a virtualised
709 * kernels.
710 * Uses the VTB register if available otherwise a next best guess.
711 */
712unsigned long long running_clock(void)
713{
714 /*
715 * Don't read the VTB as a host since KVM does not switch in host
716 * timebase into the VTB when it takes a guest off the CPU, reading the
717 * VTB would result in reading 'last switched out' guest VTB.
718 *
719 * Host kernels are often compiled with CONFIG_PPC_PSERIES checked, it
720 * would be unsafe to rely only on the #ifdef above.
721 */
722 if (firmware_has_feature(FW_FEATURE_LPAR) &&
723 cpu_has_feature(CPU_FTR_ARCH_207S))
724 return mulhdu(get_vtb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
725
726 /*
727 * This is a next best approximation without a VTB.
728 * On a host which is running bare metal there should never be any stolen
729 * time and on a host which doesn't do any virtualisation TB *should* equal
730 * VTB so it makes no difference anyway.
731 */
732 return local_clock() - kcpustat_this_cpu->cpustat[CPUTIME_STEAL];
733}
734#endif
735
736static int __init get_freq(char *name, int cells, unsigned long *val)
737{
738 struct device_node *cpu;
739 const __be32 *fp;
740 int found = 0;
741
742 /* The cpu node should have timebase and clock frequency properties */
743 cpu = of_find_node_by_type(NULL, "cpu");
744
745 if (cpu) {
746 fp = of_get_property(cpu, name, NULL);
747 if (fp) {
748 found = 1;
749 *val = of_read_ulong(fp, cells);
750 }
751
752 of_node_put(cpu);
753 }
754
755 return found;
756}
757
758static void start_cpu_decrementer(void)
759{
760#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
761 unsigned int tcr;
762
763 /* Clear any pending timer interrupts */
764 mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS);
765
766 tcr = mfspr(SPRN_TCR);
767 /*
768 * The watchdog may have already been enabled by u-boot. So leave
769 * TRC[WP] (Watchdog Period) alone.
770 */
771 tcr &= TCR_WP_MASK; /* Clear all bits except for TCR[WP] */
772 tcr |= TCR_DIE; /* Enable decrementer */
773 mtspr(SPRN_TCR, tcr);
774#endif
775}
776
777void __init generic_calibrate_decr(void)
778{
779 ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
780
781 if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&
782 !get_freq("timebase-frequency", 1, &ppc_tb_freq)) {
783
784 printk(KERN_ERR "WARNING: Estimating decrementer frequency "
785 "(not found)\n");
786 }
787
788 ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */
789
790 if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&
791 !get_freq("clock-frequency", 1, &ppc_proc_freq)) {
792
793 printk(KERN_ERR "WARNING: Estimating processor frequency "
794 "(not found)\n");
795 }
796}
797
798int update_persistent_clock64(struct timespec64 now)
799{
800 struct rtc_time tm;
801
802 if (!ppc_md.set_rtc_time)
803 return -ENODEV;
804
805 rtc_time64_to_tm(now.tv_sec + 1 + timezone_offset, &tm);
806
807 return ppc_md.set_rtc_time(&tm);
808}
809
810static void __read_persistent_clock(struct timespec64 *ts)
811{
812 struct rtc_time tm;
813 static int first = 1;
814
815 ts->tv_nsec = 0;
816 /* XXX this is a litle fragile but will work okay in the short term */
817 if (first) {
818 first = 0;
819 if (ppc_md.time_init)
820 timezone_offset = ppc_md.time_init();
821
822 /* get_boot_time() isn't guaranteed to be safe to call late */
823 if (ppc_md.get_boot_time) {
824 ts->tv_sec = ppc_md.get_boot_time() - timezone_offset;
825 return;
826 }
827 }
828 if (!ppc_md.get_rtc_time) {
829 ts->tv_sec = 0;
830 return;
831 }
832 ppc_md.get_rtc_time(&tm);
833
834 ts->tv_sec = rtc_tm_to_time64(&tm);
835}
836
837void read_persistent_clock64(struct timespec64 *ts)
838{
839 __read_persistent_clock(ts);
840
841 /* Sanitize it in case real time clock is set below EPOCH */
842 if (ts->tv_sec < 0) {
843 ts->tv_sec = 0;
844 ts->tv_nsec = 0;
845 }
846
847}
848
849/* clocksource code */
850static notrace u64 rtc_read(struct clocksource *cs)
851{
852 return (u64)get_rtc();
853}
854
855static notrace u64 timebase_read(struct clocksource *cs)
856{
857 return (u64)get_tb();
858}
859
860
861void update_vsyscall(struct timekeeper *tk)
862{
863 struct timespec64 xt;
864 struct clocksource *clock = tk->tkr_mono.clock;
865 u32 mult = tk->tkr_mono.mult;
866 u32 shift = tk->tkr_mono.shift;
867 u64 cycle_last = tk->tkr_mono.cycle_last;
868 u64 new_tb_to_xs, new_stamp_xsec;
869 u64 frac_sec;
870
871 if (clock != &clocksource_timebase)
872 return;
873
874 xt.tv_sec = tk->xtime_sec;
875 xt.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
876
877 /* Make userspace gettimeofday spin until we're done. */
878 ++vdso_data->tb_update_count;
879 smp_mb();
880
881 /*
882 * This computes ((2^20 / 1e9) * mult) >> shift as a
883 * 0.64 fixed-point fraction.
884 * The computation in the else clause below won't overflow
885 * (as long as the timebase frequency is >= 1.049 MHz)
886 * but loses precision because we lose the low bits of the constant
887 * in the shift. Note that 19342813113834067 ~= 2^(20+64) / 1e9.
888 * For a shift of 24 the error is about 0.5e-9, or about 0.5ns
889 * over a second. (Shift values are usually 22, 23 or 24.)
890 * For high frequency clocks such as the 512MHz timebase clock
891 * on POWER[6789], the mult value is small (e.g. 32768000)
892 * and so we can shift the constant by 16 initially
893 * (295147905179 ~= 2^(20+64-16) / 1e9) and then do the
894 * remaining shifts after the multiplication, which gives a
895 * more accurate result (e.g. with mult = 32768000, shift = 24,
896 * the error is only about 1.2e-12, or 0.7ns over 10 minutes).
897 */
898 if (mult <= 62500000 && clock->shift >= 16)
899 new_tb_to_xs = ((u64) mult * 295147905179ULL) >> (clock->shift - 16);
900 else
901 new_tb_to_xs = (u64) mult * (19342813113834067ULL >> clock->shift);
902
903 /*
904 * Compute the fractional second in units of 2^-32 seconds.
905 * The fractional second is tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift
906 * in nanoseconds, so multiplying that by 2^32 / 1e9 gives
907 * it in units of 2^-32 seconds.
908 * We assume shift <= 32 because clocks_calc_mult_shift()
909 * generates shift values in the range 0 - 32.
910 */
911 frac_sec = tk->tkr_mono.xtime_nsec << (32 - shift);
912 do_div(frac_sec, NSEC_PER_SEC);
913
914 /*
915 * Work out new stamp_xsec value for any legacy users of systemcfg.
916 * stamp_xsec is in units of 2^-20 seconds.
917 */
918 new_stamp_xsec = frac_sec >> 12;
919 new_stamp_xsec += tk->xtime_sec * XSEC_PER_SEC;
920
921 /*
922 * tb_update_count is used to allow the userspace gettimeofday code
923 * to assure itself that it sees a consistent view of the tb_to_xs and
924 * stamp_xsec variables. It reads the tb_update_count, then reads
925 * tb_to_xs and stamp_xsec and then reads tb_update_count again. If
926 * the two values of tb_update_count match and are even then the
927 * tb_to_xs and stamp_xsec values are consistent. If not, then it
928 * loops back and reads them again until this criteria is met.
929 */
930 vdso_data->tb_orig_stamp = cycle_last;
931 vdso_data->stamp_xsec = new_stamp_xsec;
932 vdso_data->tb_to_xs = new_tb_to_xs;
933 vdso_data->wtom_clock_sec = tk->wall_to_monotonic.tv_sec;
934 vdso_data->wtom_clock_nsec = tk->wall_to_monotonic.tv_nsec;
935 vdso_data->stamp_xtime_sec = xt.tv_sec;
936 vdso_data->stamp_xtime_nsec = xt.tv_nsec;
937 vdso_data->stamp_sec_fraction = frac_sec;
938 vdso_data->hrtimer_res = hrtimer_resolution;
939 smp_wmb();
940 ++(vdso_data->tb_update_count);
941}
942
943void update_vsyscall_tz(void)
944{
945 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
946 vdso_data->tz_dsttime = sys_tz.tz_dsttime;
947}
948
949static void __init clocksource_init(void)
950{
951 struct clocksource *clock;
952
953 if (__USE_RTC())
954 clock = &clocksource_rtc;
955 else
956 clock = &clocksource_timebase;
957
958 if (clocksource_register_hz(clock, tb_ticks_per_sec)) {
959 printk(KERN_ERR "clocksource: %s is already registered\n",
960 clock->name);
961 return;
962 }
963
964 printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
965 clock->name, clock->mult, clock->shift);
966}
967
968static int decrementer_set_next_event(unsigned long evt,
969 struct clock_event_device *dev)
970{
971 __this_cpu_write(decrementers_next_tb, get_tb_or_rtc() + evt);
972 set_dec(evt);
973
974 /* We may have raced with new irq work */
975 if (test_irq_work_pending())
976 set_dec(1);
977
978 return 0;
979}
980
981static int decrementer_shutdown(struct clock_event_device *dev)
982{
983 decrementer_set_next_event(decrementer_max, dev);
984 return 0;
985}
986
987static void register_decrementer_clockevent(int cpu)
988{
989 struct clock_event_device *dec = &per_cpu(decrementers, cpu);
990
991 *dec = decrementer_clockevent;
992 dec->cpumask = cpumask_of(cpu);
993
994 clockevents_config_and_register(dec, ppc_tb_freq, 2, decrementer_max);
995
996 printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
997 dec->name, dec->mult, dec->shift, cpu);
998
999 /* Set values for KVM, see kvm_emulate_dec() */
1000 decrementer_clockevent.mult = dec->mult;
1001 decrementer_clockevent.shift = dec->shift;
1002}
1003
1004static void enable_large_decrementer(void)
1005{
1006 if (!cpu_has_feature(CPU_FTR_ARCH_300))
1007 return;
1008
1009 if (decrementer_max <= DECREMENTER_DEFAULT_MAX)
1010 return;
1011
1012 /*
1013 * If we're running as the hypervisor we need to enable the LD manually
1014 * otherwise firmware should have done it for us.
1015 */
1016 if (cpu_has_feature(CPU_FTR_HVMODE))
1017 mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_LD);
1018}
1019
1020static void __init set_decrementer_max(void)
1021{
1022 struct device_node *cpu;
1023 u32 bits = 32;
1024
1025 /* Prior to ISAv3 the decrementer is always 32 bit */
1026 if (!cpu_has_feature(CPU_FTR_ARCH_300))
1027 return;
1028
1029 cpu = of_find_node_by_type(NULL, "cpu");
1030
1031 if (of_property_read_u32(cpu, "ibm,dec-bits", &bits) == 0) {
1032 if (bits > 64 || bits < 32) {
1033 pr_warn("time_init: firmware supplied invalid ibm,dec-bits");
1034 bits = 32;
1035 }
1036
1037 /* calculate the signed maximum given this many bits */
1038 decrementer_max = (1ul << (bits - 1)) - 1;
1039 }
1040
1041 of_node_put(cpu);
1042
1043 pr_info("time_init: %u bit decrementer (max: %llx)\n",
1044 bits, decrementer_max);
1045}
1046
1047static void __init init_decrementer_clockevent(void)
1048{
1049 register_decrementer_clockevent(smp_processor_id());
1050}
1051
1052void secondary_cpu_time_init(void)
1053{
1054 /* Enable and test the large decrementer for this cpu */
1055 enable_large_decrementer();
1056
1057 /* Start the decrementer on CPUs that have manual control
1058 * such as BookE
1059 */
1060 start_cpu_decrementer();
1061
1062 /* FIME: Should make unrelatred change to move snapshot_timebase
1063 * call here ! */
1064 register_decrementer_clockevent(smp_processor_id());
1065}
1066
1067/* This function is only called on the boot processor */
1068void __init time_init(void)
1069{
1070 struct div_result res;
1071 u64 scale;
1072 unsigned shift;
1073
1074 if (__USE_RTC()) {
1075 /* 601 processor: dec counts down by 128 every 128ns */
1076 ppc_tb_freq = 1000000000;
1077 } else {
1078 /* Normal PowerPC with timebase register */
1079 ppc_md.calibrate_decr();
1080 printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n",
1081 ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
1082 printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n",
1083 ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
1084 }
1085
1086 tb_ticks_per_jiffy = ppc_tb_freq / HZ;
1087 tb_ticks_per_sec = ppc_tb_freq;
1088 tb_ticks_per_usec = ppc_tb_freq / 1000000;
1089 calc_cputime_factors();
1090
1091 /*
1092 * Compute scale factor for sched_clock.
1093 * The calibrate_decr() function has set tb_ticks_per_sec,
1094 * which is the timebase frequency.
1095 * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
1096 * the 128-bit result as a 64.64 fixed-point number.
1097 * We then shift that number right until it is less than 1.0,
1098 * giving us the scale factor and shift count to use in
1099 * sched_clock().
1100 */
1101 div128_by_32(1000000000, 0, tb_ticks_per_sec, &res);
1102 scale = res.result_low;
1103 for (shift = 0; res.result_high != 0; ++shift) {
1104 scale = (scale >> 1) | (res.result_high << 63);
1105 res.result_high >>= 1;
1106 }
1107 tb_to_ns_scale = scale;
1108 tb_to_ns_shift = shift;
1109 /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
1110 boot_tb = get_tb_or_rtc();
1111
1112 /* If platform provided a timezone (pmac), we correct the time */
1113 if (timezone_offset) {
1114 sys_tz.tz_minuteswest = -timezone_offset / 60;
1115 sys_tz.tz_dsttime = 0;
1116 }
1117
1118 vdso_data->tb_update_count = 0;
1119 vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
1120
1121 /* initialise and enable the large decrementer (if we have one) */
1122 set_decrementer_max();
1123 enable_large_decrementer();
1124
1125 /* Start the decrementer on CPUs that have manual control
1126 * such as BookE
1127 */
1128 start_cpu_decrementer();
1129
1130 /* Register the clocksource */
1131 clocksource_init();
1132
1133 init_decrementer_clockevent();
1134 tick_setup_hrtimer_broadcast();
1135
1136 of_clk_init(NULL);
1137}
1138
1139/*
1140 * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
1141 * result.
1142 */
1143void div128_by_32(u64 dividend_high, u64 dividend_low,
1144 unsigned divisor, struct div_result *dr)
1145{
1146 unsigned long a, b, c, d;
1147 unsigned long w, x, y, z;
1148 u64 ra, rb, rc;
1149
1150 a = dividend_high >> 32;
1151 b = dividend_high & 0xffffffff;
1152 c = dividend_low >> 32;
1153 d = dividend_low & 0xffffffff;
1154
1155 w = a / divisor;
1156 ra = ((u64)(a - (w * divisor)) << 32) + b;
1157
1158 rb = ((u64) do_div(ra, divisor) << 32) + c;
1159 x = ra;
1160
1161 rc = ((u64) do_div(rb, divisor) << 32) + d;
1162 y = rb;
1163
1164 do_div(rc, divisor);
1165 z = rc;
1166
1167 dr->result_high = ((u64)w << 32) + x;
1168 dr->result_low = ((u64)y << 32) + z;
1169
1170}
1171
1172/* We don't need to calibrate delay, we use the CPU timebase for that */
1173void calibrate_delay(void)
1174{
1175 /* Some generic code (such as spinlock debug) use loops_per_jiffy
1176 * as the number of __delay(1) in a jiffy, so make it so
1177 */
1178 loops_per_jiffy = tb_ticks_per_jiffy;
1179}
1180
1181#if IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
1182static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
1183{
1184 ppc_md.get_rtc_time(tm);
1185 return 0;
1186}
1187
1188static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm)
1189{
1190 if (!ppc_md.set_rtc_time)
1191 return -EOPNOTSUPP;
1192
1193 if (ppc_md.set_rtc_time(tm) < 0)
1194 return -EOPNOTSUPP;
1195
1196 return 0;
1197}
1198
1199static const struct rtc_class_ops rtc_generic_ops = {
1200 .read_time = rtc_generic_get_time,
1201 .set_time = rtc_generic_set_time,
1202};
1203
1204static int __init rtc_init(void)
1205{
1206 struct platform_device *pdev;
1207
1208 if (!ppc_md.get_rtc_time)
1209 return -ENODEV;
1210
1211 pdev = platform_device_register_data(NULL, "rtc-generic", -1,
1212 &rtc_generic_ops,
1213 sizeof(rtc_generic_ops));
1214
1215 return PTR_ERR_OR_ZERO(pdev);
1216}
1217
1218device_initcall(rtc_init);
1219#endif
1/*
2 * Common time routines among all ppc machines.
3 *
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)
8 *
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).
14 *
15 * Speeded up do_gettimeofday by getting rid of references to
16 * xtime (which required locks for consistency). (mikejc@us.ibm.com)
17 *
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.
25 *
26 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
27 * "A Kernel Model for Precision Timekeeping" by Dave Mills
28 *
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.
33 */
34
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>
41#include <linux/mm.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>
58
59#include <asm/io.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>
65#include <asm/time.h>
66#include <asm/prom.h>
67#include <asm/irq.h>
68#include <asm/div64.h>
69#include <asm/smp.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>
76#endif
77
78/* powerpc clocksource/clockevent code */
79
80#include <linux/clockchips.h>
81#include <linux/clocksource.h>
82
83static cycle_t rtc_read(struct clocksource *);
84static struct clocksource clocksource_rtc = {
85 .name = "rtc",
86 .rating = 400,
87 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
88 .mask = CLOCKSOURCE_MASK(64),
89 .shift = 22,
90 .mult = 0, /* To be filled in */
91 .read = rtc_read,
92};
93
94static cycle_t timebase_read(struct clocksource *);
95static struct clocksource clocksource_timebase = {
96 .name = "timebase",
97 .rating = 400,
98 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
99 .mask = CLOCKSOURCE_MASK(64),
100 .shift = 22,
101 .mult = 0, /* To be filled in */
102 .read = timebase_read,
103};
104
105#define DECREMENTER_MAX 0x7fffffff
106
107static int decrementer_set_next_event(unsigned long evt,
108 struct clock_event_device *dev);
109static void decrementer_set_mode(enum clock_event_mode mode,
110 struct clock_event_device *dev);
111
112static struct clock_event_device decrementer_clockevent = {
113 .name = "decrementer",
114 .rating = 200,
115 .shift = 0, /* To be filled in */
116 .mult = 0, /* To be filled in */
117 .irq = 0,
118 .set_next_event = decrementer_set_next_event,
119 .set_mode = decrementer_set_mode,
120 .features = CLOCK_EVT_FEAT_ONESHOT,
121};
122
123struct decrementer_clock {
124 struct clock_event_device event;
125 u64 next_tb;
126};
127
128static DEFINE_PER_CPU(struct decrementer_clock, decrementers);
129
130#ifdef CONFIG_PPC_ISERIES
131static unsigned long __initdata iSeries_recal_titan;
132static signed long __initdata iSeries_recal_tb;
133
134/* Forward declaration is only needed for iSereis compiles */
135static void __init clocksource_init(void);
136#endif
137
138#define XSEC_PER_SEC (1024*1024)
139
140#ifdef CONFIG_PPC64
141#define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
142#else
143/* compute ((xsec << 12) * max) >> 32 */
144#define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
145#endif
146
147unsigned long tb_ticks_per_jiffy;
148unsigned long tb_ticks_per_usec = 100; /* sane default */
149EXPORT_SYMBOL(tb_ticks_per_usec);
150unsigned long tb_ticks_per_sec;
151EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */
152
153DEFINE_SPINLOCK(rtc_lock);
154EXPORT_SYMBOL_GPL(rtc_lock);
155
156static u64 tb_to_ns_scale __read_mostly;
157static unsigned tb_to_ns_shift __read_mostly;
158static u64 boot_tb __read_mostly;
159
160extern struct timezone sys_tz;
161static long timezone_offset;
162
163unsigned long ppc_proc_freq;
164EXPORT_SYMBOL_GPL(ppc_proc_freq);
165unsigned long ppc_tb_freq;
166EXPORT_SYMBOL_GPL(ppc_tb_freq);
167
168#ifdef CONFIG_VIRT_CPU_ACCOUNTING
169/*
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.
173 */
174u64 __cputime_jiffies_factor;
175EXPORT_SYMBOL(__cputime_jiffies_factor);
176u64 __cputime_msec_factor;
177EXPORT_SYMBOL(__cputime_msec_factor);
178u64 __cputime_sec_factor;
179EXPORT_SYMBOL(__cputime_sec_factor);
180u64 __cputime_clockt_factor;
181EXPORT_SYMBOL(__cputime_clockt_factor);
182DEFINE_PER_CPU(unsigned long, cputime_last_delta);
183DEFINE_PER_CPU(unsigned long, cputime_scaled_last_delta);
184
185cputime_t cputime_one_jiffy;
186
187void (*dtl_consumer)(struct dtl_entry *, u64);
188
189static void calc_cputime_factors(void)
190{
191 struct div_result res;
192
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;
201}
202
203/*
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.
206 */
207static u64 read_spurr(u64 tb)
208{
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);
213 return tb;
214}
215
216#ifdef CONFIG_PPC_SPLPAR
217
218/*
219 * Scan the dispatch trace log and count up the stolen time.
220 * Should be called with interrupts disabled.
221 */
222static u64 scan_dispatch_log(u64 stop_tb)
223{
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;
228 u64 tb_delta;
229 u64 stolen = 0;
230 u64 dtb;
231
232 if (!dtl)
233 return 0;
234
235 if (i == vpa->dtl_idx)
236 return 0;
237 while (i < vpa->dtl_idx) {
238 if (dtl_consumer)
239 dtl_consumer(dtl, i);
240 dtb = dtl->timebase;
241 tb_delta = dtl->enqueue_to_dispatch_time +
242 dtl->ready_to_enqueue_time;
243 barrier();
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);
248 continue;
249 }
250 if (dtb > stop_tb)
251 break;
252 stolen += tb_delta;
253 ++i;
254 ++dtl;
255 if (dtl == dtl_end)
256 dtl = local_paca->dispatch_log;
257 }
258 local_paca->dtl_ridx = i;
259 local_paca->dtl_curr = dtl;
260 return stolen;
261}
262
263/*
264 * Accumulate stolen time by scanning the dispatch trace log.
265 * Called on entry from user mode.
266 */
267void accumulate_stolen_time(void)
268{
269 u64 sst, ust;
270
271 u8 save_soft_enabled = local_paca->soft_enabled;
272 u8 save_hard_enabled = local_paca->hard_enabled;
273
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
278 * complain
279 */
280 local_paca->soft_enabled = 0;
281 local_paca->hard_enabled = 0;
282
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;
288
289 local_paca->soft_enabled = save_soft_enabled;
290 local_paca->hard_enabled = save_hard_enabled;
291}
292
293static inline u64 calculate_stolen_time(u64 stop_tb)
294{
295 u64 stolen = 0;
296
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;
300 }
301
302 stolen += get_paca()->stolen_time;
303 get_paca()->stolen_time = 0;
304 return stolen;
305}
306
307#else /* CONFIG_PPC_SPLPAR */
308static inline u64 calculate_stolen_time(u64 stop_tb)
309{
310 return 0;
311}
312
313#endif /* CONFIG_PPC_SPLPAR */
314
315/*
316 * Account time for a transition between system, hard irq
317 * or soft irq state.
318 */
319void account_system_vtime(struct task_struct *tsk)
320{
321 u64 now, nowscaled, delta, deltascaled;
322 unsigned long flags;
323 u64 stolen, udelta, sys_scaled, user_scaled;
324
325 local_irq_save(flags);
326 now = mftb();
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;
332
333 stolen = calculate_stolen_time(now);
334
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;
339
340 /*
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.
349 */
350 sys_scaled = delta;
351 user_scaled = udelta;
352 if (deltascaled != delta + udelta) {
353 if (udelta) {
354 sys_scaled = deltascaled * delta / (delta + udelta);
355 user_scaled = deltascaled - sys_scaled;
356 } else {
357 sys_scaled = deltascaled;
358 }
359 }
360 get_paca()->user_time_scaled += user_scaled;
361
362 if (in_interrupt() || idle_task(smp_processor_id()) != tsk) {
363 account_system_time(tsk, 0, delta, sys_scaled);
364 if (stolen)
365 account_steal_time(stolen);
366 } else {
367 account_idle_time(delta + stolen);
368 }
369 local_irq_restore(flags);
370}
371EXPORT_SYMBOL_GPL(account_system_vtime);
372
373/*
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.
381 */
382void account_process_tick(struct task_struct *tsk, int user_tick)
383{
384 cputime_t utime, utimescaled;
385
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);
392}
393
394#else /* ! CONFIG_VIRT_CPU_ACCOUNTING */
395#define calc_cputime_factors()
396#endif
397
398void __delay(unsigned long loops)
399{
400 unsigned long start;
401 int diff;
402
403 if (__USE_RTC()) {
404 start = get_rtcl();
405 do {
406 /* the RTCL register wraps at 1000000000 */
407 diff = get_rtcl() - start;
408 if (diff < 0)
409 diff += 1000000000;
410 } while (diff < loops);
411 } else {
412 start = get_tbl();
413 while (get_tbl() - start < loops)
414 HMT_low();
415 HMT_medium();
416 }
417}
418EXPORT_SYMBOL(__delay);
419
420void udelay(unsigned long usecs)
421{
422 __delay(tb_ticks_per_usec * usecs);
423}
424EXPORT_SYMBOL(udelay);
425
426#ifdef CONFIG_SMP
427unsigned long profile_pc(struct pt_regs *regs)
428{
429 unsigned long pc = instruction_pointer(regs);
430
431 if (in_lock_functions(pc))
432 return regs->link;
433
434 return pc;
435}
436EXPORT_SYMBOL(profile_pc);
437#endif
438
439#ifdef CONFIG_PPC_ISERIES
440
441/*
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.
445 */
446
447static int __init iSeries_tb_recal(void)
448{
449 unsigned long titan, tb;
450
451 /* Make sure we only run on iSeries */
452 if (!firmware_has_feature(FW_FEATURE_ISERIES))
453 return -ENODEV;
454
455 tb = get_tb();
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;
464 char sign = '+';
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;
467
468 if ( tick_diff < 0 ) {
469 tick_diff = -tick_diff;
470 sign = '-';
471 }
472 if ( 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();
481 }
482 else {
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 );
487 }
488 }
489 }
490 iSeries_recal_titan = titan;
491 iSeries_recal_tb = tb;
492
493 /* Called here as now we know accurate values for the timebase */
494 clocksource_init();
495 return 0;
496}
497late_initcall(iSeries_tb_recal);
498
499/* Called from platform early init */
500void __init iSeries_time_init_early(void)
501{
502 iSeries_recal_tb = get_tb();
503 iSeries_recal_titan = HvCallXm_loadTod();
504}
505#endif /* CONFIG_PPC_ISERIES */
506
507#ifdef CONFIG_IRQ_WORK
508
509/*
510 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
511 */
512#ifdef CONFIG_PPC64
513static inline unsigned long test_irq_work_pending(void)
514{
515 unsigned long x;
516
517 asm volatile("lbz %0,%1(13)"
518 : "=r" (x)
519 : "i" (offsetof(struct paca_struct, irq_work_pending)));
520 return x;
521}
522
523static inline void set_irq_work_pending_flag(void)
524{
525 asm volatile("stb %0,%1(13)" : :
526 "r" (1),
527 "i" (offsetof(struct paca_struct, irq_work_pending)));
528}
529
530static inline void clear_irq_work_pending(void)
531{
532 asm volatile("stb %0,%1(13)" : :
533 "r" (0),
534 "i" (offsetof(struct paca_struct, irq_work_pending)));
535}
536
537#else /* 32-bit */
538
539DEFINE_PER_CPU(u8, irq_work_pending);
540
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
544
545#endif /* 32 vs 64 bit */
546
547void arch_irq_work_raise(void)
548{
549 preempt_disable();
550 set_irq_work_pending_flag();
551 set_dec(1);
552 preempt_enable();
553}
554
555#else /* CONFIG_IRQ_WORK */
556
557#define test_irq_work_pending() 0
558#define clear_irq_work_pending()
559
560#endif /* CONFIG_IRQ_WORK */
561
562/*
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)
570 */
571
572/*
573 * timer_interrupt - gets called when the decrementer overflows,
574 * with interrupts disabled.
575 */
576void timer_interrupt(struct pt_regs * regs)
577{
578 struct pt_regs *old_regs;
579 struct decrementer_clock *decrementer = &__get_cpu_var(decrementers);
580 struct clock_event_device *evt = &decrementer->event;
581 u64 now;
582
583 /* Ensure a positive value is written to the decrementer, or else
584 * some CPUs will continue to take decrementer exceptions.
585 */
586 set_dec(DECREMENTER_MAX);
587
588 /* Some implementations of hotplug will get timer interrupts while
589 * offline, just ignore these
590 */
591 if (!cpu_online(smp_processor_id()))
592 return;
593
594 trace_timer_interrupt_entry(regs);
595
596 __get_cpu_var(irq_stat).timer_irqs++;
597
598#if defined(CONFIG_PPC32) && defined(CONFIG_PMAC)
599 if (atomic_read(&ppc_n_lost_interrupts) != 0)
600 do_IRQ(regs);
601#endif
602
603 old_regs = set_irq_regs(regs);
604 irq_enter();
605
606 if (test_irq_work_pending()) {
607 clear_irq_work_pending();
608 irq_work_run();
609 }
610
611#ifdef CONFIG_PPC_ISERIES
612 if (firmware_has_feature(FW_FEATURE_ISERIES))
613 get_lppaca()->int_dword.fields.decr_int = 0;
614#endif
615
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);
621 } else {
622 now = decrementer->next_tb - now;
623 if (now <= DECREMENTER_MAX)
624 set_dec((int)now);
625 }
626
627#ifdef CONFIG_PPC_ISERIES
628 if (firmware_has_feature(FW_FEATURE_ISERIES) && hvlpevent_is_pending())
629 process_hvlpevents();
630#endif
631
632#ifdef CONFIG_PPC64
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);
637 }
638#endif
639
640 irq_exit();
641 set_irq_regs(old_regs);
642
643 trace_timer_interrupt_exit(regs);
644}
645
646#ifdef CONFIG_SUSPEND
647static void generic_suspend_disable_irqs(void)
648{
649 /* Disable the decrementer, so that it doesn't interfere
650 * with suspending.
651 */
652
653 set_dec(0x7fffffff);
654 local_irq_disable();
655 set_dec(0x7fffffff);
656}
657
658static void generic_suspend_enable_irqs(void)
659{
660 local_irq_enable();
661}
662
663/* Overrides the weak version in kernel/power/main.c */
664void arch_suspend_disable_irqs(void)
665{
666 if (ppc_md.suspend_disable_irqs)
667 ppc_md.suspend_disable_irqs();
668 generic_suspend_disable_irqs();
669}
670
671/* Overrides the weak version in kernel/power/main.c */
672void arch_suspend_enable_irqs(void)
673{
674 generic_suspend_enable_irqs();
675 if (ppc_md.suspend_enable_irqs)
676 ppc_md.suspend_enable_irqs();
677}
678#endif
679
680/*
681 * Scheduler clock - returns current time in nanosec units.
682 *
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.
686 */
687unsigned long long sched_clock(void)
688{
689 if (__USE_RTC())
690 return get_rtc();
691 return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
692}
693
694static int __init get_freq(char *name, int cells, unsigned long *val)
695{
696 struct device_node *cpu;
697 const unsigned int *fp;
698 int found = 0;
699
700 /* The cpu node should have timebase and clock frequency properties */
701 cpu = of_find_node_by_type(NULL, "cpu");
702
703 if (cpu) {
704 fp = of_get_property(cpu, name, NULL);
705 if (fp) {
706 found = 1;
707 *val = of_read_ulong(fp, cells);
708 }
709
710 of_node_put(cpu);
711 }
712
713 return found;
714}
715
716/* should become __cpuinit when secondary_cpu_time_init also is */
717void start_cpu_decrementer(void)
718{
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);
722
723 /* Enable decrementer interrupt */
724 mtspr(SPRN_TCR, TCR_DIE);
725#endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */
726}
727
728void __init generic_calibrate_decr(void)
729{
730 ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
731
732 if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&
733 !get_freq("timebase-frequency", 1, &ppc_tb_freq)) {
734
735 printk(KERN_ERR "WARNING: Estimating decrementer frequency "
736 "(not found)\n");
737 }
738
739 ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */
740
741 if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&
742 !get_freq("clock-frequency", 1, &ppc_proc_freq)) {
743
744 printk(KERN_ERR "WARNING: Estimating processor frequency "
745 "(not found)\n");
746 }
747}
748
749int update_persistent_clock(struct timespec now)
750{
751 struct rtc_time tm;
752
753 if (!ppc_md.set_rtc_time)
754 return 0;
755
756 to_tm(now.tv_sec + 1 + timezone_offset, &tm);
757 tm.tm_year -= 1900;
758 tm.tm_mon -= 1;
759
760 return ppc_md.set_rtc_time(&tm);
761}
762
763static void __read_persistent_clock(struct timespec *ts)
764{
765 struct rtc_time tm;
766 static int first = 1;
767
768 ts->tv_nsec = 0;
769 /* XXX this is a litle fragile but will work okay in the short term */
770 if (first) {
771 first = 0;
772 if (ppc_md.time_init)
773 timezone_offset = ppc_md.time_init();
774
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;
778 return;
779 }
780 }
781 if (!ppc_md.get_rtc_time) {
782 ts->tv_sec = 0;
783 return;
784 }
785 ppc_md.get_rtc_time(&tm);
786
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);
789}
790
791void read_persistent_clock(struct timespec *ts)
792{
793 __read_persistent_clock(ts);
794
795 /* Sanitize it in case real time clock is set below EPOCH */
796 if (ts->tv_sec < 0) {
797 ts->tv_sec = 0;
798 ts->tv_nsec = 0;
799 }
800
801}
802
803/* clocksource code */
804static cycle_t rtc_read(struct clocksource *cs)
805{
806 return (cycle_t)get_rtc();
807}
808
809static cycle_t timebase_read(struct clocksource *cs)
810{
811 return (cycle_t)get_tb();
812}
813
814void update_vsyscall(struct timespec *wall_time, struct timespec *wtm,
815 struct clocksource *clock, u32 mult)
816{
817 u64 new_tb_to_xs, new_stamp_xsec;
818 u32 frac_sec;
819
820 if (clock != &clocksource_timebase)
821 return;
822
823 /* Make userspace gettimeofday spin until we're done. */
824 ++vdso_data->tb_update_count;
825 smp_mb();
826
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;
833
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;
837
838 /*
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.
848 */
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;
856 smp_wmb();
857 ++(vdso_data->tb_update_count);
858}
859
860void update_vsyscall_tz(void)
861{
862 /* Make userspace gettimeofday spin until we're done. */
863 ++vdso_data->tb_update_count;
864 smp_mb();
865 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
866 vdso_data->tz_dsttime = sys_tz.tz_dsttime;
867 smp_mb();
868 ++vdso_data->tb_update_count;
869}
870
871static void __init clocksource_init(void)
872{
873 struct clocksource *clock;
874
875 if (__USE_RTC())
876 clock = &clocksource_rtc;
877 else
878 clock = &clocksource_timebase;
879
880 clock->mult = clocksource_hz2mult(tb_ticks_per_sec, clock->shift);
881
882 if (clocksource_register(clock)) {
883 printk(KERN_ERR "clocksource: %s is already registered\n",
884 clock->name);
885 return;
886 }
887
888 printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
889 clock->name, clock->mult, clock->shift);
890}
891
892static int decrementer_set_next_event(unsigned long evt,
893 struct clock_event_device *dev)
894{
895 __get_cpu_var(decrementers).next_tb = get_tb_or_rtc() + evt;
896 set_dec(evt);
897 return 0;
898}
899
900static void decrementer_set_mode(enum clock_event_mode mode,
901 struct clock_event_device *dev)
902{
903 if (mode != CLOCK_EVT_MODE_ONESHOT)
904 decrementer_set_next_event(DECREMENTER_MAX, dev);
905}
906
907static inline uint64_t div_sc64(unsigned long ticks, unsigned long nsec,
908 int shift)
909{
910 uint64_t tmp = ((uint64_t)ticks) << shift;
911
912 do_div(tmp, nsec);
913 return tmp;
914}
915
916static void __init setup_clockevent_multiplier(unsigned long hz)
917{
918 u64 mult, shift = 32;
919
920 while (1) {
921 mult = div_sc64(hz, NSEC_PER_SEC, shift);
922 if (mult && (mult >> 32UL) == 0UL)
923 break;
924
925 shift--;
926 }
927
928 decrementer_clockevent.shift = shift;
929 decrementer_clockevent.mult = mult;
930}
931
932static void register_decrementer_clockevent(int cpu)
933{
934 struct clock_event_device *dec = &per_cpu(decrementers, cpu).event;
935
936 *dec = decrementer_clockevent;
937 dec->cpumask = cpumask_of(cpu);
938
939 printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
940 dec->name, dec->mult, dec->shift, cpu);
941
942 clockevents_register_device(dec);
943}
944
945static void __init init_decrementer_clockevent(void)
946{
947 int cpu = smp_processor_id();
948
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);
954
955 register_decrementer_clockevent(cpu);
956}
957
958void secondary_cpu_time_init(void)
959{
960 /* Start the decrementer on CPUs that have manual control
961 * such as BookE
962 */
963 start_cpu_decrementer();
964
965 /* FIME: Should make unrelatred change to move snapshot_timebase
966 * call here ! */
967 register_decrementer_clockevent(smp_processor_id());
968}
969
970/* This function is only called on the boot processor */
971void __init time_init(void)
972{
973 struct div_result res;
974 u64 scale;
975 unsigned shift;
976
977 if (__USE_RTC()) {
978 /* 601 processor: dec counts down by 128 every 128ns */
979 ppc_tb_freq = 1000000000;
980 } else {
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);
987 }
988
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();
994
995 /*
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
1003 * sched_clock().
1004 */
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;
1010 }
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();
1015
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;
1020 }
1021
1022 vdso_data->tb_update_count = 0;
1023 vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
1024
1025 /* Start the decrementer on CPUs that have manual control
1026 * such as BookE
1027 */
1028 start_cpu_decrementer();
1029
1030 /* Register the clocksource, if we're not running on iSeries */
1031 if (!firmware_has_feature(FW_FEATURE_ISERIES))
1032 clocksource_init();
1033
1034 init_decrementer_clockevent();
1035}
1036
1037
1038#define FEBRUARY 2
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])
1046
1047static int month_days[12] = {
1048 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
1049};
1050
1051/*
1052 * This only works for the Gregorian calendar - i.e. after 1752 (in the UK)
1053 */
1054void GregorianDay(struct rtc_time * tm)
1055{
1056 int leapsToDate;
1057 int lastYear;
1058 int day;
1059 int MonthOffset[] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 };
1060
1061 lastYear = tm->tm_year - 1;
1062
1063 /*
1064 * Number of leap corrections to apply up to end of last year
1065 */
1066 leapsToDate = lastYear / 4 - lastYear / 100 + lastYear / 400;
1067
1068 /*
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
1071 *
1072 * e.g. 1904 was a leap year, 1900 was not, 1996 is, and 2000 was
1073 */
1074 day = tm->tm_mon > 2 && leapyear(tm->tm_year);
1075
1076 day += lastYear*365 + leapsToDate + MonthOffset[tm->tm_mon-1] +
1077 tm->tm_mday;
1078
1079 tm->tm_wday = day % 7;
1080}
1081
1082void to_tm(int tim, struct rtc_time * tm)
1083{
1084 register int i;
1085 register long hms, day;
1086
1087 day = tim / SECDAY;
1088 hms = tim % SECDAY;
1089
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;
1094
1095 /* Number of years in days */
1096 for (i = STARTOFTIME; day >= days_in_year(i); i++)
1097 day -= days_in_year(i);
1098 tm->tm_year = i;
1099
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;
1106 tm->tm_mon = i;
1107
1108 /* Days are what is left over (+1) from all that. */
1109 tm->tm_mday = day + 1;
1110
1111 /*
1112 * Determine the day of week
1113 */
1114 GregorianDay(tm);
1115}
1116
1117/*
1118 * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
1119 * result.
1120 */
1121void div128_by_32(u64 dividend_high, u64 dividend_low,
1122 unsigned divisor, struct div_result *dr)
1123{
1124 unsigned long a, b, c, d;
1125 unsigned long w, x, y, z;
1126 u64 ra, rb, rc;
1127
1128 a = dividend_high >> 32;
1129 b = dividend_high & 0xffffffff;
1130 c = dividend_low >> 32;
1131 d = dividend_low & 0xffffffff;
1132
1133 w = a / divisor;
1134 ra = ((u64)(a - (w * divisor)) << 32) + b;
1135
1136 rb = ((u64) do_div(ra, divisor) << 32) + c;
1137 x = ra;
1138
1139 rc = ((u64) do_div(rb, divisor) << 32) + d;
1140 y = rb;
1141
1142 do_div(rc, divisor);
1143 z = rc;
1144
1145 dr->result_high = ((u64)w << 32) + x;
1146 dr->result_low = ((u64)y << 32) + z;
1147
1148}
1149
1150/* We don't need to calibrate delay, we use the CPU timebase for that */
1151void calibrate_delay(void)
1152{
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
1155 */
1156 loops_per_jiffy = tb_ticks_per_jiffy;
1157}
1158
1159static int __init rtc_init(void)
1160{
1161 struct platform_device *pdev;
1162
1163 if (!ppc_md.get_rtc_time)
1164 return -ENODEV;
1165
1166 pdev = platform_device_register_simple("rtc-generic", -1, NULL, 0);
1167 if (IS_ERR(pdev))
1168 return PTR_ERR(pdev);
1169
1170 return 0;
1171}
1172
1173module_init(rtc_init);