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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.
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.
24 *
25 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
26 * "A Kernel Model for Precision Timekeeping" by Dave Mills
27 *
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.
32 */
33
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>
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/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 <linux/processor.h>
63#include <asm/trace.h>
64
65#include <asm/io.h>
66#include <asm/nvram.h>
67#include <asm/cache.h>
68#include <asm/machdep.h>
69#include <linux/uaccess.h>
70#include <asm/time.h>
71#include <asm/prom.h>
72#include <asm/irq.h>
73#include <asm/div64.h>
74#include <asm/smp.h>
75#include <asm/vdso_datapage.h>
76#include <asm/firmware.h>
77#include <asm/asm-prototypes.h>
78
79/* powerpc clocksource/clockevent code */
80
81#include <linux/clockchips.h>
82#include <linux/timekeeper_internal.h>
83
84static u64 rtc_read(struct clocksource *);
85static struct clocksource clocksource_rtc = {
86 .name = "rtc",
87 .rating = 400,
88 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
89 .mask = CLOCKSOURCE_MASK(64),
90 .read = rtc_read,
91};
92
93static u64 timebase_read(struct clocksource *);
94static struct clocksource clocksource_timebase = {
95 .name = "timebase",
96 .rating = 400,
97 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
98 .mask = CLOCKSOURCE_MASK(64),
99 .read = timebase_read,
100};
101
102#define DECREMENTER_DEFAULT_MAX 0x7FFFFFFF
103u64 decrementer_max = DECREMENTER_DEFAULT_MAX;
104
105static int decrementer_set_next_event(unsigned long evt,
106 struct clock_event_device *dev);
107static int decrementer_shutdown(struct clock_event_device *evt);
108
109struct clock_event_device decrementer_clockevent = {
110 .name = "decrementer",
111 .rating = 200,
112 .irq = 0,
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,
118};
119EXPORT_SYMBOL(decrementer_clockevent);
120
121DEFINE_PER_CPU(u64, decrementers_next_tb);
122static DEFINE_PER_CPU(struct clock_event_device, decrementers);
123
124#define XSEC_PER_SEC (1024*1024)
125
126#ifdef CONFIG_PPC64
127#define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
128#else
129/* compute ((xsec << 12) * max) >> 32 */
130#define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
131#endif
132
133unsigned long tb_ticks_per_jiffy;
134unsigned long tb_ticks_per_usec = 100; /* sane default */
135EXPORT_SYMBOL(tb_ticks_per_usec);
136unsigned long tb_ticks_per_sec;
137EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */
138
139DEFINE_SPINLOCK(rtc_lock);
140EXPORT_SYMBOL_GPL(rtc_lock);
141
142static u64 tb_to_ns_scale __read_mostly;
143static unsigned tb_to_ns_shift __read_mostly;
144static u64 boot_tb __read_mostly;
145
146extern struct timezone sys_tz;
147static long timezone_offset;
148
149unsigned long ppc_proc_freq;
150EXPORT_SYMBOL_GPL(ppc_proc_freq);
151unsigned long ppc_tb_freq;
152EXPORT_SYMBOL_GPL(ppc_tb_freq);
153
154#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
155/*
156 * Factor for converting from cputime_t (timebase ticks) to
157 * microseconds. This is stored as 0.64 fixed-point binary fraction.
158 */
159u64 __cputime_usec_factor;
160EXPORT_SYMBOL(__cputime_usec_factor);
161
162#ifdef CONFIG_PPC_SPLPAR
163void (*dtl_consumer)(struct dtl_entry *, u64);
164#endif
165
166#ifdef CONFIG_PPC64
167#define get_accounting(tsk) (&get_paca()->accounting)
168#else
169#define get_accounting(tsk) (&task_thread_info(tsk)->accounting)
170#endif
171
172static void calc_cputime_factors(void)
173{
174 struct div_result res;
175
176 div128_by_32(1000000, 0, tb_ticks_per_sec, &res);
177 __cputime_usec_factor = res.result_low;
178}
179
180/*
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.
183 */
184static unsigned long read_spurr(unsigned long tb)
185{
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);
190 return tb;
191}
192
193#ifdef CONFIG_PPC_SPLPAR
194
195/*
196 * Scan the dispatch trace log and count up the stolen time.
197 * Should be called with interrupts disabled.
198 */
199static u64 scan_dispatch_log(u64 stop_tb)
200{
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;
205 u64 tb_delta;
206 u64 stolen = 0;
207 u64 dtb;
208
209 if (!dtl)
210 return 0;
211
212 if (i == be64_to_cpu(vpa->dtl_idx))
213 return 0;
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);
218 barrier();
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);
223 continue;
224 }
225 if (dtb > stop_tb)
226 break;
227 if (dtl_consumer)
228 dtl_consumer(dtl, i);
229 stolen += tb_delta;
230 ++i;
231 ++dtl;
232 if (dtl == dtl_end)
233 dtl = local_paca->dispatch_log;
234 }
235 local_paca->dtl_ridx = i;
236 local_paca->dtl_curr = dtl;
237 return stolen;
238}
239
240/*
241 * Accumulate stolen time by scanning the dispatch trace log.
242 * Called on entry from user mode.
243 */
244void accumulate_stolen_time(void)
245{
246 u64 sst, ust;
247 unsigned long save_irq_soft_mask = irq_soft_mask_return();
248 struct cpu_accounting_data *acct = &local_paca->accounting;
249
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
254 * complain
255 */
256 irq_soft_mask_set(IRQS_DISABLED);
257
258 sst = scan_dispatch_log(acct->starttime_user);
259 ust = scan_dispatch_log(acct->starttime);
260 acct->stime -= sst;
261 acct->utime -= ust;
262 acct->steal_time += ust + sst;
263
264 irq_soft_mask_set(save_irq_soft_mask);
265}
266
267static inline u64 calculate_stolen_time(u64 stop_tb)
268{
269 if (!firmware_has_feature(FW_FEATURE_SPLPAR))
270 return 0;
271
272 if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx))
273 return scan_dispatch_log(stop_tb);
274
275 return 0;
276}
277
278#else /* CONFIG_PPC_SPLPAR */
279static inline u64 calculate_stolen_time(u64 stop_tb)
280{
281 return 0;
282}
283
284#endif /* CONFIG_PPC_SPLPAR */
285
286/*
287 * Account time for a transition between system, hard irq
288 * or soft irq state.
289 */
290static unsigned long vtime_delta(struct task_struct *tsk,
291 unsigned long *stime_scaled,
292 unsigned long *steal_time)
293{
294 unsigned long now, nowscaled, deltascaled;
295 unsigned long stime;
296 unsigned long utime, utime_scaled;
297 struct cpu_accounting_data *acct = get_accounting(tsk);
298
299 WARN_ON_ONCE(!irqs_disabled());
300
301 now = mftb();
302 nowscaled = read_spurr(now);
303 stime = now - acct->starttime;
304 acct->starttime = now;
305 deltascaled = nowscaled - acct->startspurr;
306 acct->startspurr = nowscaled;
307
308 *steal_time = calculate_stolen_time(now);
309
310 utime = acct->utime - acct->utime_sspurr;
311 acct->utime_sspurr = acct->utime;
312
313 /*
314 * Because we don't read the SPURR on every kernel entry/exit,
315 * deltascaled includes both user and system SPURR ticks.
316 * Apportion these ticks to system SPURR ticks and user
317 * SPURR ticks in the same ratio as the system time (delta)
318 * and user time (udelta) values obtained from the timebase
319 * over the same interval. The system ticks get accounted here;
320 * the user ticks get saved up in paca->user_time_scaled to be
321 * used by account_process_tick.
322 */
323 *stime_scaled = stime;
324 utime_scaled = utime;
325 if (deltascaled != stime + utime) {
326 if (utime) {
327 *stime_scaled = deltascaled * stime / (stime + utime);
328 utime_scaled = deltascaled - *stime_scaled;
329 } else {
330 *stime_scaled = deltascaled;
331 }
332 }
333 acct->utime_scaled += utime_scaled;
334
335 return stime;
336}
337
338void vtime_account_system(struct task_struct *tsk)
339{
340 unsigned long stime, stime_scaled, steal_time;
341 struct cpu_accounting_data *acct = get_accounting(tsk);
342
343 stime = vtime_delta(tsk, &stime_scaled, &steal_time);
344
345 stime -= min(stime, steal_time);
346 acct->steal_time += steal_time;
347
348 if ((tsk->flags & PF_VCPU) && !irq_count()) {
349 acct->gtime += stime;
350 acct->utime_scaled += stime_scaled;
351 } else {
352 if (hardirq_count())
353 acct->hardirq_time += stime;
354 else if (in_serving_softirq())
355 acct->softirq_time += stime;
356 else
357 acct->stime += stime;
358
359 acct->stime_scaled += stime_scaled;
360 }
361}
362EXPORT_SYMBOL_GPL(vtime_account_system);
363
364void vtime_account_idle(struct task_struct *tsk)
365{
366 unsigned long stime, stime_scaled, steal_time;
367 struct cpu_accounting_data *acct = get_accounting(tsk);
368
369 stime = vtime_delta(tsk, &stime_scaled, &steal_time);
370 acct->idle_time += stime + steal_time;
371}
372
373/*
374 * Account the whole cputime accumulated in the paca
375 * Must be called with interrupts disabled.
376 * Assumes that vtime_account_system/idle() has been called
377 * recently (i.e. since the last entry from usermode) so that
378 * get_paca()->user_time_scaled is up to date.
379 */
380void vtime_flush(struct task_struct *tsk)
381{
382 struct cpu_accounting_data *acct = get_accounting(tsk);
383
384 if (acct->utime)
385 account_user_time(tsk, cputime_to_nsecs(acct->utime));
386
387 if (acct->utime_scaled)
388 tsk->utimescaled += cputime_to_nsecs(acct->utime_scaled);
389
390 if (acct->gtime)
391 account_guest_time(tsk, cputime_to_nsecs(acct->gtime));
392
393 if (acct->steal_time)
394 account_steal_time(cputime_to_nsecs(acct->steal_time));
395
396 if (acct->idle_time)
397 account_idle_time(cputime_to_nsecs(acct->idle_time));
398
399 if (acct->stime)
400 account_system_index_time(tsk, cputime_to_nsecs(acct->stime),
401 CPUTIME_SYSTEM);
402 if (acct->stime_scaled)
403 tsk->stimescaled += cputime_to_nsecs(acct->stime_scaled);
404
405 if (acct->hardirq_time)
406 account_system_index_time(tsk, cputime_to_nsecs(acct->hardirq_time),
407 CPUTIME_IRQ);
408 if (acct->softirq_time)
409 account_system_index_time(tsk, cputime_to_nsecs(acct->softirq_time),
410 CPUTIME_SOFTIRQ);
411
412 acct->utime = 0;
413 acct->utime_scaled = 0;
414 acct->utime_sspurr = 0;
415 acct->gtime = 0;
416 acct->steal_time = 0;
417 acct->idle_time = 0;
418 acct->stime = 0;
419 acct->stime_scaled = 0;
420 acct->hardirq_time = 0;
421 acct->softirq_time = 0;
422}
423
424#ifdef CONFIG_PPC32
425/*
426 * Called from the context switch with interrupts disabled, to charge all
427 * accumulated times to the current process, and to prepare accounting on
428 * the next process.
429 */
430void arch_vtime_task_switch(struct task_struct *prev)
431{
432 struct cpu_accounting_data *acct = get_accounting(current);
433
434 acct->starttime = get_accounting(prev)->starttime;
435 acct->startspurr = get_accounting(prev)->startspurr;
436}
437#endif /* CONFIG_PPC32 */
438
439#else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
440#define calc_cputime_factors()
441#endif
442
443void __delay(unsigned long loops)
444{
445 unsigned long start;
446 int diff;
447
448 spin_begin();
449 if (__USE_RTC()) {
450 start = get_rtcl();
451 do {
452 /* the RTCL register wraps at 1000000000 */
453 diff = get_rtcl() - start;
454 if (diff < 0)
455 diff += 1000000000;
456 spin_cpu_relax();
457 } while (diff < loops);
458 } else {
459 start = get_tbl();
460 while (get_tbl() - start < loops)
461 spin_cpu_relax();
462 }
463 spin_end();
464}
465EXPORT_SYMBOL(__delay);
466
467void udelay(unsigned long usecs)
468{
469 __delay(tb_ticks_per_usec * usecs);
470}
471EXPORT_SYMBOL(udelay);
472
473#ifdef CONFIG_SMP
474unsigned long profile_pc(struct pt_regs *regs)
475{
476 unsigned long pc = instruction_pointer(regs);
477
478 if (in_lock_functions(pc))
479 return regs->link;
480
481 return pc;
482}
483EXPORT_SYMBOL(profile_pc);
484#endif
485
486#ifdef CONFIG_IRQ_WORK
487
488/*
489 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
490 */
491#ifdef CONFIG_PPC64
492static inline unsigned long test_irq_work_pending(void)
493{
494 unsigned long x;
495
496 asm volatile("lbz %0,%1(13)"
497 : "=r" (x)
498 : "i" (offsetof(struct paca_struct, irq_work_pending)));
499 return x;
500}
501
502static inline void set_irq_work_pending_flag(void)
503{
504 asm volatile("stb %0,%1(13)" : :
505 "r" (1),
506 "i" (offsetof(struct paca_struct, irq_work_pending)));
507}
508
509static inline void clear_irq_work_pending(void)
510{
511 asm volatile("stb %0,%1(13)" : :
512 "r" (0),
513 "i" (offsetof(struct paca_struct, irq_work_pending)));
514}
515
516#else /* 32-bit */
517
518DEFINE_PER_CPU(u8, irq_work_pending);
519
520#define set_irq_work_pending_flag() __this_cpu_write(irq_work_pending, 1)
521#define test_irq_work_pending() __this_cpu_read(irq_work_pending)
522#define clear_irq_work_pending() __this_cpu_write(irq_work_pending, 0)
523
524#endif /* 32 vs 64 bit */
525
526void arch_irq_work_raise(void)
527{
528 preempt_disable();
529 set_irq_work_pending_flag();
530 set_dec(1);
531 preempt_enable();
532}
533
534#else /* CONFIG_IRQ_WORK */
535
536#define test_irq_work_pending() 0
537#define clear_irq_work_pending()
538
539#endif /* CONFIG_IRQ_WORK */
540
541static void __timer_interrupt(void)
542{
543 struct pt_regs *regs = get_irq_regs();
544 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
545 struct clock_event_device *evt = this_cpu_ptr(&decrementers);
546 u64 now;
547
548 trace_timer_interrupt_entry(regs);
549
550 if (test_irq_work_pending()) {
551 clear_irq_work_pending();
552 irq_work_run();
553 }
554
555 now = get_tb_or_rtc();
556 if (now >= *next_tb) {
557 *next_tb = ~(u64)0;
558 if (evt->event_handler)
559 evt->event_handler(evt);
560 __this_cpu_inc(irq_stat.timer_irqs_event);
561 } else {
562 now = *next_tb - now;
563 if (now <= decrementer_max)
564 set_dec(now);
565 /* We may have raced with new irq work */
566 if (test_irq_work_pending())
567 set_dec(1);
568 __this_cpu_inc(irq_stat.timer_irqs_others);
569 }
570
571#ifdef CONFIG_PPC64
572 /* collect purr register values often, for accurate calculations */
573 if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
574 struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
575 cu->current_tb = mfspr(SPRN_PURR);
576 }
577#endif
578
579 trace_timer_interrupt_exit(regs);
580}
581
582/*
583 * timer_interrupt - gets called when the decrementer overflows,
584 * with interrupts disabled.
585 */
586void timer_interrupt(struct pt_regs * regs)
587{
588 struct pt_regs *old_regs;
589 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
590
591 /* Ensure a positive value is written to the decrementer, or else
592 * some CPUs will continue to take decrementer exceptions.
593 */
594 set_dec(decrementer_max);
595
596 /* Some implementations of hotplug will get timer interrupts while
597 * offline, just ignore these and we also need to set
598 * decrementers_next_tb as MAX to make sure __check_irq_replay
599 * don't replay timer interrupt when return, otherwise we'll trap
600 * here infinitely :(
601 */
602 if (!cpu_online(smp_processor_id())) {
603 *next_tb = ~(u64)0;
604 return;
605 }
606
607 /* Conditionally hard-enable interrupts now that the DEC has been
608 * bumped to its maximum value
609 */
610 may_hard_irq_enable();
611
612
613#if defined(CONFIG_PPC32) && defined(CONFIG_PPC_PMAC)
614 if (atomic_read(&ppc_n_lost_interrupts) != 0)
615 do_IRQ(regs);
616#endif
617
618 old_regs = set_irq_regs(regs);
619 irq_enter();
620
621 __timer_interrupt();
622 irq_exit();
623 set_irq_regs(old_regs);
624}
625EXPORT_SYMBOL(timer_interrupt);
626
627/*
628 * Hypervisor decrementer interrupts shouldn't occur but are sometimes
629 * left pending on exit from a KVM guest. We don't need to do anything
630 * to clear them, as they are edge-triggered.
631 */
632void hdec_interrupt(struct pt_regs *regs)
633{
634}
635
636#ifdef CONFIG_SUSPEND
637static void generic_suspend_disable_irqs(void)
638{
639 /* Disable the decrementer, so that it doesn't interfere
640 * with suspending.
641 */
642
643 set_dec(decrementer_max);
644 local_irq_disable();
645 set_dec(decrementer_max);
646}
647
648static void generic_suspend_enable_irqs(void)
649{
650 local_irq_enable();
651}
652
653/* Overrides the weak version in kernel/power/main.c */
654void arch_suspend_disable_irqs(void)
655{
656 if (ppc_md.suspend_disable_irqs)
657 ppc_md.suspend_disable_irqs();
658 generic_suspend_disable_irqs();
659}
660
661/* Overrides the weak version in kernel/power/main.c */
662void arch_suspend_enable_irqs(void)
663{
664 generic_suspend_enable_irqs();
665 if (ppc_md.suspend_enable_irqs)
666 ppc_md.suspend_enable_irqs();
667}
668#endif
669
670unsigned long long tb_to_ns(unsigned long long ticks)
671{
672 return mulhdu(ticks, tb_to_ns_scale) << tb_to_ns_shift;
673}
674EXPORT_SYMBOL_GPL(tb_to_ns);
675
676/*
677 * Scheduler clock - returns current time in nanosec units.
678 *
679 * Note: mulhdu(a, b) (multiply high double unsigned) returns
680 * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
681 * are 64-bit unsigned numbers.
682 */
683notrace unsigned long long sched_clock(void)
684{
685 if (__USE_RTC())
686 return get_rtc();
687 return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
688}
689
690
691#ifdef CONFIG_PPC_PSERIES
692
693/*
694 * Running clock - attempts to give a view of time passing for a virtualised
695 * kernels.
696 * Uses the VTB register if available otherwise a next best guess.
697 */
698unsigned long long running_clock(void)
699{
700 /*
701 * Don't read the VTB as a host since KVM does not switch in host
702 * timebase into the VTB when it takes a guest off the CPU, reading the
703 * VTB would result in reading 'last switched out' guest VTB.
704 *
705 * Host kernels are often compiled with CONFIG_PPC_PSERIES checked, it
706 * would be unsafe to rely only on the #ifdef above.
707 */
708 if (firmware_has_feature(FW_FEATURE_LPAR) &&
709 cpu_has_feature(CPU_FTR_ARCH_207S))
710 return mulhdu(get_vtb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
711
712 /*
713 * This is a next best approximation without a VTB.
714 * On a host which is running bare metal there should never be any stolen
715 * time and on a host which doesn't do any virtualisation TB *should* equal
716 * VTB so it makes no difference anyway.
717 */
718 return local_clock() - kcpustat_this_cpu->cpustat[CPUTIME_STEAL];
719}
720#endif
721
722static int __init get_freq(char *name, int cells, unsigned long *val)
723{
724 struct device_node *cpu;
725 const __be32 *fp;
726 int found = 0;
727
728 /* The cpu node should have timebase and clock frequency properties */
729 cpu = of_find_node_by_type(NULL, "cpu");
730
731 if (cpu) {
732 fp = of_get_property(cpu, name, NULL);
733 if (fp) {
734 found = 1;
735 *val = of_read_ulong(fp, cells);
736 }
737
738 of_node_put(cpu);
739 }
740
741 return found;
742}
743
744static void start_cpu_decrementer(void)
745{
746#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
747 unsigned int tcr;
748
749 /* Clear any pending timer interrupts */
750 mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS);
751
752 tcr = mfspr(SPRN_TCR);
753 /*
754 * The watchdog may have already been enabled by u-boot. So leave
755 * TRC[WP] (Watchdog Period) alone.
756 */
757 tcr &= TCR_WP_MASK; /* Clear all bits except for TCR[WP] */
758 tcr |= TCR_DIE; /* Enable decrementer */
759 mtspr(SPRN_TCR, tcr);
760#endif
761}
762
763void __init generic_calibrate_decr(void)
764{
765 ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
766
767 if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&
768 !get_freq("timebase-frequency", 1, &ppc_tb_freq)) {
769
770 printk(KERN_ERR "WARNING: Estimating decrementer frequency "
771 "(not found)\n");
772 }
773
774 ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */
775
776 if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&
777 !get_freq("clock-frequency", 1, &ppc_proc_freq)) {
778
779 printk(KERN_ERR "WARNING: Estimating processor frequency "
780 "(not found)\n");
781 }
782}
783
784int update_persistent_clock(struct timespec now)
785{
786 struct rtc_time tm;
787
788 if (!ppc_md.set_rtc_time)
789 return -ENODEV;
790
791 to_tm(now.tv_sec + 1 + timezone_offset, &tm);
792 tm.tm_year -= 1900;
793 tm.tm_mon -= 1;
794
795 return ppc_md.set_rtc_time(&tm);
796}
797
798static void __read_persistent_clock(struct timespec *ts)
799{
800 struct rtc_time tm;
801 static int first = 1;
802
803 ts->tv_nsec = 0;
804 /* XXX this is a litle fragile but will work okay in the short term */
805 if (first) {
806 first = 0;
807 if (ppc_md.time_init)
808 timezone_offset = ppc_md.time_init();
809
810 /* get_boot_time() isn't guaranteed to be safe to call late */
811 if (ppc_md.get_boot_time) {
812 ts->tv_sec = ppc_md.get_boot_time() - timezone_offset;
813 return;
814 }
815 }
816 if (!ppc_md.get_rtc_time) {
817 ts->tv_sec = 0;
818 return;
819 }
820 ppc_md.get_rtc_time(&tm);
821
822 ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
823 tm.tm_hour, tm.tm_min, tm.tm_sec);
824}
825
826void read_persistent_clock(struct timespec *ts)
827{
828 __read_persistent_clock(ts);
829
830 /* Sanitize it in case real time clock is set below EPOCH */
831 if (ts->tv_sec < 0) {
832 ts->tv_sec = 0;
833 ts->tv_nsec = 0;
834 }
835
836}
837
838/* clocksource code */
839static notrace u64 rtc_read(struct clocksource *cs)
840{
841 return (u64)get_rtc();
842}
843
844static notrace u64 timebase_read(struct clocksource *cs)
845{
846 return (u64)get_tb();
847}
848
849
850void update_vsyscall(struct timekeeper *tk)
851{
852 struct timespec xt;
853 struct clocksource *clock = tk->tkr_mono.clock;
854 u32 mult = tk->tkr_mono.mult;
855 u32 shift = tk->tkr_mono.shift;
856 u64 cycle_last = tk->tkr_mono.cycle_last;
857 u64 new_tb_to_xs, new_stamp_xsec;
858 u64 frac_sec;
859
860 if (clock != &clocksource_timebase)
861 return;
862
863 xt.tv_sec = tk->xtime_sec;
864 xt.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
865
866 /* Make userspace gettimeofday spin until we're done. */
867 ++vdso_data->tb_update_count;
868 smp_mb();
869
870 /*
871 * This computes ((2^20 / 1e9) * mult) >> shift as a
872 * 0.64 fixed-point fraction.
873 * The computation in the else clause below won't overflow
874 * (as long as the timebase frequency is >= 1.049 MHz)
875 * but loses precision because we lose the low bits of the constant
876 * in the shift. Note that 19342813113834067 ~= 2^(20+64) / 1e9.
877 * For a shift of 24 the error is about 0.5e-9, or about 0.5ns
878 * over a second. (Shift values are usually 22, 23 or 24.)
879 * For high frequency clocks such as the 512MHz timebase clock
880 * on POWER[6789], the mult value is small (e.g. 32768000)
881 * and so we can shift the constant by 16 initially
882 * (295147905179 ~= 2^(20+64-16) / 1e9) and then do the
883 * remaining shifts after the multiplication, which gives a
884 * more accurate result (e.g. with mult = 32768000, shift = 24,
885 * the error is only about 1.2e-12, or 0.7ns over 10 minutes).
886 */
887 if (mult <= 62500000 && clock->shift >= 16)
888 new_tb_to_xs = ((u64) mult * 295147905179ULL) >> (clock->shift - 16);
889 else
890 new_tb_to_xs = (u64) mult * (19342813113834067ULL >> clock->shift);
891
892 /*
893 * Compute the fractional second in units of 2^-32 seconds.
894 * The fractional second is tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift
895 * in nanoseconds, so multiplying that by 2^32 / 1e9 gives
896 * it in units of 2^-32 seconds.
897 * We assume shift <= 32 because clocks_calc_mult_shift()
898 * generates shift values in the range 0 - 32.
899 */
900 frac_sec = tk->tkr_mono.xtime_nsec << (32 - shift);
901 do_div(frac_sec, NSEC_PER_SEC);
902
903 /*
904 * Work out new stamp_xsec value for any legacy users of systemcfg.
905 * stamp_xsec is in units of 2^-20 seconds.
906 */
907 new_stamp_xsec = frac_sec >> 12;
908 new_stamp_xsec += tk->xtime_sec * XSEC_PER_SEC;
909
910 /*
911 * tb_update_count is used to allow the userspace gettimeofday code
912 * to assure itself that it sees a consistent view of the tb_to_xs and
913 * stamp_xsec variables. It reads the tb_update_count, then reads
914 * tb_to_xs and stamp_xsec and then reads tb_update_count again. If
915 * the two values of tb_update_count match and are even then the
916 * tb_to_xs and stamp_xsec values are consistent. If not, then it
917 * loops back and reads them again until this criteria is met.
918 */
919 vdso_data->tb_orig_stamp = cycle_last;
920 vdso_data->stamp_xsec = new_stamp_xsec;
921 vdso_data->tb_to_xs = new_tb_to_xs;
922 vdso_data->wtom_clock_sec = tk->wall_to_monotonic.tv_sec;
923 vdso_data->wtom_clock_nsec = tk->wall_to_monotonic.tv_nsec;
924 vdso_data->stamp_xtime = xt;
925 vdso_data->stamp_sec_fraction = frac_sec;
926 smp_wmb();
927 ++(vdso_data->tb_update_count);
928}
929
930void update_vsyscall_tz(void)
931{
932 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
933 vdso_data->tz_dsttime = sys_tz.tz_dsttime;
934}
935
936static void __init clocksource_init(void)
937{
938 struct clocksource *clock;
939
940 if (__USE_RTC())
941 clock = &clocksource_rtc;
942 else
943 clock = &clocksource_timebase;
944
945 if (clocksource_register_hz(clock, tb_ticks_per_sec)) {
946 printk(KERN_ERR "clocksource: %s is already registered\n",
947 clock->name);
948 return;
949 }
950
951 printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
952 clock->name, clock->mult, clock->shift);
953}
954
955static int decrementer_set_next_event(unsigned long evt,
956 struct clock_event_device *dev)
957{
958 __this_cpu_write(decrementers_next_tb, get_tb_or_rtc() + evt);
959 set_dec(evt);
960
961 /* We may have raced with new irq work */
962 if (test_irq_work_pending())
963 set_dec(1);
964
965 return 0;
966}
967
968static int decrementer_shutdown(struct clock_event_device *dev)
969{
970 decrementer_set_next_event(decrementer_max, dev);
971 return 0;
972}
973
974/* Interrupt handler for the timer broadcast IPI */
975void tick_broadcast_ipi_handler(void)
976{
977 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
978
979 *next_tb = get_tb_or_rtc();
980 __timer_interrupt();
981}
982
983static void register_decrementer_clockevent(int cpu)
984{
985 struct clock_event_device *dec = &per_cpu(decrementers, cpu);
986
987 *dec = decrementer_clockevent;
988 dec->cpumask = cpumask_of(cpu);
989
990 printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
991 dec->name, dec->mult, dec->shift, cpu);
992
993 clockevents_register_device(dec);
994}
995
996static void enable_large_decrementer(void)
997{
998 if (!cpu_has_feature(CPU_FTR_ARCH_300))
999 return;
1000
1001 if (decrementer_max <= DECREMENTER_DEFAULT_MAX)
1002 return;
1003
1004 /*
1005 * If we're running as the hypervisor we need to enable the LD manually
1006 * otherwise firmware should have done it for us.
1007 */
1008 if (cpu_has_feature(CPU_FTR_HVMODE))
1009 mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_LD);
1010}
1011
1012static void __init set_decrementer_max(void)
1013{
1014 struct device_node *cpu;
1015 u32 bits = 32;
1016
1017 /* Prior to ISAv3 the decrementer is always 32 bit */
1018 if (!cpu_has_feature(CPU_FTR_ARCH_300))
1019 return;
1020
1021 cpu = of_find_node_by_type(NULL, "cpu");
1022
1023 if (of_property_read_u32(cpu, "ibm,dec-bits", &bits) == 0) {
1024 if (bits > 64 || bits < 32) {
1025 pr_warn("time_init: firmware supplied invalid ibm,dec-bits");
1026 bits = 32;
1027 }
1028
1029 /* calculate the signed maximum given this many bits */
1030 decrementer_max = (1ul << (bits - 1)) - 1;
1031 }
1032
1033 of_node_put(cpu);
1034
1035 pr_info("time_init: %u bit decrementer (max: %llx)\n",
1036 bits, decrementer_max);
1037}
1038
1039static void __init init_decrementer_clockevent(void)
1040{
1041 int cpu = smp_processor_id();
1042
1043 clockevents_calc_mult_shift(&decrementer_clockevent, ppc_tb_freq, 4);
1044
1045 decrementer_clockevent.max_delta_ns =
1046 clockevent_delta2ns(decrementer_max, &decrementer_clockevent);
1047 decrementer_clockevent.max_delta_ticks = decrementer_max;
1048 decrementer_clockevent.min_delta_ns =
1049 clockevent_delta2ns(2, &decrementer_clockevent);
1050 decrementer_clockevent.min_delta_ticks = 2;
1051
1052 register_decrementer_clockevent(cpu);
1053}
1054
1055void secondary_cpu_time_init(void)
1056{
1057 /* Enable and test the large decrementer for this cpu */
1058 enable_large_decrementer();
1059
1060 /* Start the decrementer on CPUs that have manual control
1061 * such as BookE
1062 */
1063 start_cpu_decrementer();
1064
1065 /* FIME: Should make unrelatred change to move snapshot_timebase
1066 * call here ! */
1067 register_decrementer_clockevent(smp_processor_id());
1068}
1069
1070/* This function is only called on the boot processor */
1071void __init time_init(void)
1072{
1073 struct div_result res;
1074 u64 scale;
1075 unsigned shift;
1076
1077 if (__USE_RTC()) {
1078 /* 601 processor: dec counts down by 128 every 128ns */
1079 ppc_tb_freq = 1000000000;
1080 } else {
1081 /* Normal PowerPC with timebase register */
1082 ppc_md.calibrate_decr();
1083 printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n",
1084 ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
1085 printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n",
1086 ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
1087 }
1088
1089 tb_ticks_per_jiffy = ppc_tb_freq / HZ;
1090 tb_ticks_per_sec = ppc_tb_freq;
1091 tb_ticks_per_usec = ppc_tb_freq / 1000000;
1092 calc_cputime_factors();
1093
1094 /*
1095 * Compute scale factor for sched_clock.
1096 * The calibrate_decr() function has set tb_ticks_per_sec,
1097 * which is the timebase frequency.
1098 * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
1099 * the 128-bit result as a 64.64 fixed-point number.
1100 * We then shift that number right until it is less than 1.0,
1101 * giving us the scale factor and shift count to use in
1102 * sched_clock().
1103 */
1104 div128_by_32(1000000000, 0, tb_ticks_per_sec, &res);
1105 scale = res.result_low;
1106 for (shift = 0; res.result_high != 0; ++shift) {
1107 scale = (scale >> 1) | (res.result_high << 63);
1108 res.result_high >>= 1;
1109 }
1110 tb_to_ns_scale = scale;
1111 tb_to_ns_shift = shift;
1112 /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
1113 boot_tb = get_tb_or_rtc();
1114
1115 /* If platform provided a timezone (pmac), we correct the time */
1116 if (timezone_offset) {
1117 sys_tz.tz_minuteswest = -timezone_offset / 60;
1118 sys_tz.tz_dsttime = 0;
1119 }
1120
1121 vdso_data->tb_update_count = 0;
1122 vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
1123
1124 /* initialise and enable the large decrementer (if we have one) */
1125 set_decrementer_max();
1126 enable_large_decrementer();
1127
1128 /* Start the decrementer on CPUs that have manual control
1129 * such as BookE
1130 */
1131 start_cpu_decrementer();
1132
1133 /* Register the clocksource */
1134 clocksource_init();
1135
1136 init_decrementer_clockevent();
1137 tick_setup_hrtimer_broadcast();
1138
1139#ifdef CONFIG_COMMON_CLK
1140 of_clk_init(NULL);
1141#endif
1142}
1143
1144
1145#define FEBRUARY 2
1146#define STARTOFTIME 1970
1147#define SECDAY 86400L
1148#define SECYR (SECDAY * 365)
1149#define leapyear(year) ((year) % 4 == 0 && \
1150 ((year) % 100 != 0 || (year) % 400 == 0))
1151#define days_in_year(a) (leapyear(a) ? 366 : 365)
1152#define days_in_month(a) (month_days[(a) - 1])
1153
1154static int month_days[12] = {
1155 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
1156};
1157
1158void to_tm(int tim, struct rtc_time * tm)
1159{
1160 register int i;
1161 register long hms, day;
1162
1163 day = tim / SECDAY;
1164 hms = tim % SECDAY;
1165
1166 /* Hours, minutes, seconds are easy */
1167 tm->tm_hour = hms / 3600;
1168 tm->tm_min = (hms % 3600) / 60;
1169 tm->tm_sec = (hms % 3600) % 60;
1170
1171 /* Number of years in days */
1172 for (i = STARTOFTIME; day >= days_in_year(i); i++)
1173 day -= days_in_year(i);
1174 tm->tm_year = i;
1175
1176 /* Number of months in days left */
1177 if (leapyear(tm->tm_year))
1178 days_in_month(FEBRUARY) = 29;
1179 for (i = 1; day >= days_in_month(i); i++)
1180 day -= days_in_month(i);
1181 days_in_month(FEBRUARY) = 28;
1182 tm->tm_mon = i;
1183
1184 /* Days are what is left over (+1) from all that. */
1185 tm->tm_mday = day + 1;
1186
1187 /*
1188 * No-one uses the day of the week.
1189 */
1190 tm->tm_wday = -1;
1191}
1192EXPORT_SYMBOL(to_tm);
1193
1194/*
1195 * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
1196 * result.
1197 */
1198void div128_by_32(u64 dividend_high, u64 dividend_low,
1199 unsigned divisor, struct div_result *dr)
1200{
1201 unsigned long a, b, c, d;
1202 unsigned long w, x, y, z;
1203 u64 ra, rb, rc;
1204
1205 a = dividend_high >> 32;
1206 b = dividend_high & 0xffffffff;
1207 c = dividend_low >> 32;
1208 d = dividend_low & 0xffffffff;
1209
1210 w = a / divisor;
1211 ra = ((u64)(a - (w * divisor)) << 32) + b;
1212
1213 rb = ((u64) do_div(ra, divisor) << 32) + c;
1214 x = ra;
1215
1216 rc = ((u64) do_div(rb, divisor) << 32) + d;
1217 y = rb;
1218
1219 do_div(rc, divisor);
1220 z = rc;
1221
1222 dr->result_high = ((u64)w << 32) + x;
1223 dr->result_low = ((u64)y << 32) + z;
1224
1225}
1226
1227/* We don't need to calibrate delay, we use the CPU timebase for that */
1228void calibrate_delay(void)
1229{
1230 /* Some generic code (such as spinlock debug) use loops_per_jiffy
1231 * as the number of __delay(1) in a jiffy, so make it so
1232 */
1233 loops_per_jiffy = tb_ticks_per_jiffy;
1234}
1235
1236#if IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
1237static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
1238{
1239 ppc_md.get_rtc_time(tm);
1240 return 0;
1241}
1242
1243static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm)
1244{
1245 if (!ppc_md.set_rtc_time)
1246 return -EOPNOTSUPP;
1247
1248 if (ppc_md.set_rtc_time(tm) < 0)
1249 return -EOPNOTSUPP;
1250
1251 return 0;
1252}
1253
1254static const struct rtc_class_ops rtc_generic_ops = {
1255 .read_time = rtc_generic_get_time,
1256 .set_time = rtc_generic_set_time,
1257};
1258
1259static int __init rtc_init(void)
1260{
1261 struct platform_device *pdev;
1262
1263 if (!ppc_md.get_rtc_time)
1264 return -ENODEV;
1265
1266 pdev = platform_device_register_data(NULL, "rtc-generic", -1,
1267 &rtc_generic_ops,
1268 sizeof(rtc_generic_ops));
1269
1270 return PTR_ERR_OR_ZERO(pdev);
1271}
1272
1273device_initcall(rtc_init);
1274#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.
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.
24 *
25 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
26 * "A Kernel Model for Precision Timekeeping" by Dave Mills
27 *
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.
32 */
33
34#include <linux/errno.h>
35#include <linux/export.h>
36#include <linux/sched.h>
37#include <linux/kernel.h>
38#include <linux/param.h>
39#include <linux/string.h>
40#include <linux/mm.h>
41#include <linux/interrupt.h>
42#include <linux/timex.h>
43#include <linux/kernel_stat.h>
44#include <linux/time.h>
45#include <linux/clockchips.h>
46#include <linux/init.h>
47#include <linux/profile.h>
48#include <linux/cpu.h>
49#include <linux/security.h>
50#include <linux/percpu.h>
51#include <linux/rtc.h>
52#include <linux/jiffies.h>
53#include <linux/posix-timers.h>
54#include <linux/irq.h>
55#include <linux/delay.h>
56#include <linux/irq_work.h>
57#include <linux/clk-provider.h>
58#include <linux/suspend.h>
59#include <linux/rtc.h>
60#include <asm/trace.h>
61
62#include <asm/io.h>
63#include <asm/processor.h>
64#include <asm/nvram.h>
65#include <asm/cache.h>
66#include <asm/machdep.h>
67#include <linux/uaccess.h>
68#include <asm/time.h>
69#include <asm/prom.h>
70#include <asm/irq.h>
71#include <asm/div64.h>
72#include <asm/smp.h>
73#include <asm/vdso_datapage.h>
74#include <asm/firmware.h>
75#include <asm/cputime.h>
76#include <asm/asm-prototypes.h>
77
78/* powerpc clocksource/clockevent code */
79
80#include <linux/clockchips.h>
81#include <linux/timekeeper_internal.h>
82
83static u64 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 .read = rtc_read,
90};
91
92static u64 timebase_read(struct clocksource *);
93static struct clocksource clocksource_timebase = {
94 .name = "timebase",
95 .rating = 400,
96 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
97 .mask = CLOCKSOURCE_MASK(64),
98 .read = timebase_read,
99};
100
101#define DECREMENTER_DEFAULT_MAX 0x7FFFFFFF
102u64 decrementer_max = DECREMENTER_DEFAULT_MAX;
103
104static int decrementer_set_next_event(unsigned long evt,
105 struct clock_event_device *dev);
106static int decrementer_shutdown(struct clock_event_device *evt);
107
108struct clock_event_device decrementer_clockevent = {
109 .name = "decrementer",
110 .rating = 200,
111 .irq = 0,
112 .set_next_event = decrementer_set_next_event,
113 .set_state_shutdown = decrementer_shutdown,
114 .tick_resume = decrementer_shutdown,
115 .features = CLOCK_EVT_FEAT_ONESHOT |
116 CLOCK_EVT_FEAT_C3STOP,
117};
118EXPORT_SYMBOL(decrementer_clockevent);
119
120DEFINE_PER_CPU(u64, decrementers_next_tb);
121static DEFINE_PER_CPU(struct clock_event_device, decrementers);
122
123#define XSEC_PER_SEC (1024*1024)
124
125#ifdef CONFIG_PPC64
126#define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
127#else
128/* compute ((xsec << 12) * max) >> 32 */
129#define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
130#endif
131
132unsigned long tb_ticks_per_jiffy;
133unsigned long tb_ticks_per_usec = 100; /* sane default */
134EXPORT_SYMBOL(tb_ticks_per_usec);
135unsigned long tb_ticks_per_sec;
136EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */
137
138DEFINE_SPINLOCK(rtc_lock);
139EXPORT_SYMBOL_GPL(rtc_lock);
140
141static u64 tb_to_ns_scale __read_mostly;
142static unsigned tb_to_ns_shift __read_mostly;
143static u64 boot_tb __read_mostly;
144
145extern struct timezone sys_tz;
146static long timezone_offset;
147
148unsigned long ppc_proc_freq;
149EXPORT_SYMBOL_GPL(ppc_proc_freq);
150unsigned long ppc_tb_freq;
151EXPORT_SYMBOL_GPL(ppc_tb_freq);
152
153#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
154/*
155 * Factors for converting from cputime_t (timebase ticks) to
156 * jiffies, microseconds, seconds, and clock_t (1/USER_HZ seconds).
157 * These are all stored as 0.64 fixed-point binary fractions.
158 */
159u64 __cputime_jiffies_factor;
160EXPORT_SYMBOL(__cputime_jiffies_factor);
161u64 __cputime_usec_factor;
162EXPORT_SYMBOL(__cputime_usec_factor);
163u64 __cputime_sec_factor;
164EXPORT_SYMBOL(__cputime_sec_factor);
165u64 __cputime_clockt_factor;
166EXPORT_SYMBOL(__cputime_clockt_factor);
167
168cputime_t cputime_one_jiffy;
169
170#ifdef CONFIG_PPC_SPLPAR
171void (*dtl_consumer)(struct dtl_entry *, u64);
172#endif
173
174#ifdef CONFIG_PPC64
175#define get_accounting(tsk) (&get_paca()->accounting)
176#else
177#define get_accounting(tsk) (&task_thread_info(tsk)->accounting)
178#endif
179
180static void calc_cputime_factors(void)
181{
182 struct div_result res;
183
184 div128_by_32(HZ, 0, tb_ticks_per_sec, &res);
185 __cputime_jiffies_factor = res.result_low;
186 div128_by_32(1000000, 0, tb_ticks_per_sec, &res);
187 __cputime_usec_factor = res.result_low;
188 div128_by_32(1, 0, tb_ticks_per_sec, &res);
189 __cputime_sec_factor = res.result_low;
190 div128_by_32(USER_HZ, 0, tb_ticks_per_sec, &res);
191 __cputime_clockt_factor = res.result_low;
192}
193
194/*
195 * Read the SPURR on systems that have it, otherwise the PURR,
196 * or if that doesn't exist return the timebase value passed in.
197 */
198static unsigned long read_spurr(unsigned long tb)
199{
200 if (cpu_has_feature(CPU_FTR_SPURR))
201 return mfspr(SPRN_SPURR);
202 if (cpu_has_feature(CPU_FTR_PURR))
203 return mfspr(SPRN_PURR);
204 return tb;
205}
206
207#ifdef CONFIG_PPC_SPLPAR
208
209/*
210 * Scan the dispatch trace log and count up the stolen time.
211 * Should be called with interrupts disabled.
212 */
213static u64 scan_dispatch_log(u64 stop_tb)
214{
215 u64 i = local_paca->dtl_ridx;
216 struct dtl_entry *dtl = local_paca->dtl_curr;
217 struct dtl_entry *dtl_end = local_paca->dispatch_log_end;
218 struct lppaca *vpa = local_paca->lppaca_ptr;
219 u64 tb_delta;
220 u64 stolen = 0;
221 u64 dtb;
222
223 if (!dtl)
224 return 0;
225
226 if (i == be64_to_cpu(vpa->dtl_idx))
227 return 0;
228 while (i < be64_to_cpu(vpa->dtl_idx)) {
229 dtb = be64_to_cpu(dtl->timebase);
230 tb_delta = be32_to_cpu(dtl->enqueue_to_dispatch_time) +
231 be32_to_cpu(dtl->ready_to_enqueue_time);
232 barrier();
233 if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) {
234 /* buffer has overflowed */
235 i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG;
236 dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
237 continue;
238 }
239 if (dtb > stop_tb)
240 break;
241 if (dtl_consumer)
242 dtl_consumer(dtl, i);
243 stolen += tb_delta;
244 ++i;
245 ++dtl;
246 if (dtl == dtl_end)
247 dtl = local_paca->dispatch_log;
248 }
249 local_paca->dtl_ridx = i;
250 local_paca->dtl_curr = dtl;
251 return stolen;
252}
253
254/*
255 * Accumulate stolen time by scanning the dispatch trace log.
256 * Called on entry from user mode.
257 */
258void accumulate_stolen_time(void)
259{
260 u64 sst, ust;
261 u8 save_soft_enabled = local_paca->soft_enabled;
262 struct cpu_accounting_data *acct = &local_paca->accounting;
263
264 /* We are called early in the exception entry, before
265 * soft/hard_enabled are sync'ed to the expected state
266 * for the exception. We are hard disabled but the PACA
267 * needs to reflect that so various debug stuff doesn't
268 * complain
269 */
270 local_paca->soft_enabled = 0;
271
272 sst = scan_dispatch_log(acct->starttime_user);
273 ust = scan_dispatch_log(acct->starttime);
274 acct->system_time -= sst;
275 acct->user_time -= ust;
276 local_paca->stolen_time += ust + sst;
277
278 local_paca->soft_enabled = save_soft_enabled;
279}
280
281static inline u64 calculate_stolen_time(u64 stop_tb)
282{
283 u64 stolen = 0;
284
285 if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx)) {
286 stolen = scan_dispatch_log(stop_tb);
287 get_paca()->accounting.system_time -= stolen;
288 }
289
290 stolen += get_paca()->stolen_time;
291 get_paca()->stolen_time = 0;
292 return stolen;
293}
294
295#else /* CONFIG_PPC_SPLPAR */
296static inline u64 calculate_stolen_time(u64 stop_tb)
297{
298 return 0;
299}
300
301#endif /* CONFIG_PPC_SPLPAR */
302
303/*
304 * Account time for a transition between system, hard irq
305 * or soft irq state.
306 */
307static unsigned long vtime_delta(struct task_struct *tsk,
308 unsigned long *sys_scaled,
309 unsigned long *stolen)
310{
311 unsigned long now, nowscaled, deltascaled;
312 unsigned long udelta, delta, user_scaled;
313 struct cpu_accounting_data *acct = get_accounting(tsk);
314
315 WARN_ON_ONCE(!irqs_disabled());
316
317 now = mftb();
318 nowscaled = read_spurr(now);
319 acct->system_time += now - acct->starttime;
320 acct->starttime = now;
321 deltascaled = nowscaled - acct->startspurr;
322 acct->startspurr = nowscaled;
323
324 *stolen = calculate_stolen_time(now);
325
326 delta = acct->system_time;
327 acct->system_time = 0;
328 udelta = acct->user_time - acct->utime_sspurr;
329 acct->utime_sspurr = acct->user_time;
330
331 /*
332 * Because we don't read the SPURR on every kernel entry/exit,
333 * deltascaled includes both user and system SPURR ticks.
334 * Apportion these ticks to system SPURR ticks and user
335 * SPURR ticks in the same ratio as the system time (delta)
336 * and user time (udelta) values obtained from the timebase
337 * over the same interval. The system ticks get accounted here;
338 * the user ticks get saved up in paca->user_time_scaled to be
339 * used by account_process_tick.
340 */
341 *sys_scaled = delta;
342 user_scaled = udelta;
343 if (deltascaled != delta + udelta) {
344 if (udelta) {
345 *sys_scaled = deltascaled * delta / (delta + udelta);
346 user_scaled = deltascaled - *sys_scaled;
347 } else {
348 *sys_scaled = deltascaled;
349 }
350 }
351 acct->user_time_scaled += user_scaled;
352
353 return delta;
354}
355
356void vtime_account_system(struct task_struct *tsk)
357{
358 unsigned long delta, sys_scaled, stolen;
359
360 delta = vtime_delta(tsk, &sys_scaled, &stolen);
361 account_system_time(tsk, 0, delta);
362 tsk->stimescaled += sys_scaled;
363 if (stolen)
364 account_steal_time(stolen);
365}
366EXPORT_SYMBOL_GPL(vtime_account_system);
367
368void vtime_account_idle(struct task_struct *tsk)
369{
370 unsigned long delta, sys_scaled, stolen;
371
372 delta = vtime_delta(tsk, &sys_scaled, &stolen);
373 account_idle_time(delta + stolen);
374}
375
376/*
377 * Transfer the user time accumulated in the paca
378 * by the exception entry and exit code to the generic
379 * process user time records.
380 * Must be called with interrupts disabled.
381 * Assumes that vtime_account_system/idle() has been called
382 * recently (i.e. since the last entry from usermode) so that
383 * get_paca()->user_time_scaled is up to date.
384 */
385void vtime_account_user(struct task_struct *tsk)
386{
387 cputime_t utime, utimescaled;
388 struct cpu_accounting_data *acct = get_accounting(tsk);
389
390 utime = acct->user_time;
391 utimescaled = acct->user_time_scaled;
392 acct->user_time = 0;
393 acct->user_time_scaled = 0;
394 acct->utime_sspurr = 0;
395 account_user_time(tsk, utime);
396 tsk->utimescaled += utimescaled;
397}
398
399#ifdef CONFIG_PPC32
400/*
401 * Called from the context switch with interrupts disabled, to charge all
402 * accumulated times to the current process, and to prepare accounting on
403 * the next process.
404 */
405void arch_vtime_task_switch(struct task_struct *prev)
406{
407 struct cpu_accounting_data *acct = get_accounting(current);
408
409 acct->starttime = get_accounting(prev)->starttime;
410 acct->system_time = 0;
411 acct->user_time = 0;
412}
413#endif /* CONFIG_PPC32 */
414
415#else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
416#define calc_cputime_factors()
417#endif
418
419void __delay(unsigned long loops)
420{
421 unsigned long start;
422 int diff;
423
424 if (__USE_RTC()) {
425 start = get_rtcl();
426 do {
427 /* the RTCL register wraps at 1000000000 */
428 diff = get_rtcl() - start;
429 if (diff < 0)
430 diff += 1000000000;
431 } while (diff < loops);
432 } else {
433 start = get_tbl();
434 while (get_tbl() - start < loops)
435 HMT_low();
436 HMT_medium();
437 }
438}
439EXPORT_SYMBOL(__delay);
440
441void udelay(unsigned long usecs)
442{
443 __delay(tb_ticks_per_usec * usecs);
444}
445EXPORT_SYMBOL(udelay);
446
447#ifdef CONFIG_SMP
448unsigned long profile_pc(struct pt_regs *regs)
449{
450 unsigned long pc = instruction_pointer(regs);
451
452 if (in_lock_functions(pc))
453 return regs->link;
454
455 return pc;
456}
457EXPORT_SYMBOL(profile_pc);
458#endif
459
460#ifdef CONFIG_IRQ_WORK
461
462/*
463 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
464 */
465#ifdef CONFIG_PPC64
466static inline unsigned long test_irq_work_pending(void)
467{
468 unsigned long x;
469
470 asm volatile("lbz %0,%1(13)"
471 : "=r" (x)
472 : "i" (offsetof(struct paca_struct, irq_work_pending)));
473 return x;
474}
475
476static inline void set_irq_work_pending_flag(void)
477{
478 asm volatile("stb %0,%1(13)" : :
479 "r" (1),
480 "i" (offsetof(struct paca_struct, irq_work_pending)));
481}
482
483static inline void clear_irq_work_pending(void)
484{
485 asm volatile("stb %0,%1(13)" : :
486 "r" (0),
487 "i" (offsetof(struct paca_struct, irq_work_pending)));
488}
489
490#else /* 32-bit */
491
492DEFINE_PER_CPU(u8, irq_work_pending);
493
494#define set_irq_work_pending_flag() __this_cpu_write(irq_work_pending, 1)
495#define test_irq_work_pending() __this_cpu_read(irq_work_pending)
496#define clear_irq_work_pending() __this_cpu_write(irq_work_pending, 0)
497
498#endif /* 32 vs 64 bit */
499
500void arch_irq_work_raise(void)
501{
502 preempt_disable();
503 set_irq_work_pending_flag();
504 set_dec(1);
505 preempt_enable();
506}
507
508#else /* CONFIG_IRQ_WORK */
509
510#define test_irq_work_pending() 0
511#define clear_irq_work_pending()
512
513#endif /* CONFIG_IRQ_WORK */
514
515static void __timer_interrupt(void)
516{
517 struct pt_regs *regs = get_irq_regs();
518 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
519 struct clock_event_device *evt = this_cpu_ptr(&decrementers);
520 u64 now;
521
522 trace_timer_interrupt_entry(regs);
523
524 if (test_irq_work_pending()) {
525 clear_irq_work_pending();
526 irq_work_run();
527 }
528
529 now = get_tb_or_rtc();
530 if (now >= *next_tb) {
531 *next_tb = ~(u64)0;
532 if (evt->event_handler)
533 evt->event_handler(evt);
534 __this_cpu_inc(irq_stat.timer_irqs_event);
535 } else {
536 now = *next_tb - now;
537 if (now <= decrementer_max)
538 set_dec(now);
539 /* We may have raced with new irq work */
540 if (test_irq_work_pending())
541 set_dec(1);
542 __this_cpu_inc(irq_stat.timer_irqs_others);
543 }
544
545#ifdef CONFIG_PPC64
546 /* collect purr register values often, for accurate calculations */
547 if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
548 struct cpu_usage *cu = this_cpu_ptr(&cpu_usage_array);
549 cu->current_tb = mfspr(SPRN_PURR);
550 }
551#endif
552
553 trace_timer_interrupt_exit(regs);
554}
555
556/*
557 * timer_interrupt - gets called when the decrementer overflows,
558 * with interrupts disabled.
559 */
560void timer_interrupt(struct pt_regs * regs)
561{
562 struct pt_regs *old_regs;
563 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
564
565 /* Ensure a positive value is written to the decrementer, or else
566 * some CPUs will continue to take decrementer exceptions.
567 */
568 set_dec(decrementer_max);
569
570 /* Some implementations of hotplug will get timer interrupts while
571 * offline, just ignore these and we also need to set
572 * decrementers_next_tb as MAX to make sure __check_irq_replay
573 * don't replay timer interrupt when return, otherwise we'll trap
574 * here infinitely :(
575 */
576 if (!cpu_online(smp_processor_id())) {
577 *next_tb = ~(u64)0;
578 return;
579 }
580
581 /* Conditionally hard-enable interrupts now that the DEC has been
582 * bumped to its maximum value
583 */
584 may_hard_irq_enable();
585
586
587#if defined(CONFIG_PPC32) && defined(CONFIG_PPC_PMAC)
588 if (atomic_read(&ppc_n_lost_interrupts) != 0)
589 do_IRQ(regs);
590#endif
591
592 old_regs = set_irq_regs(regs);
593 irq_enter();
594
595 __timer_interrupt();
596 irq_exit();
597 set_irq_regs(old_regs);
598}
599EXPORT_SYMBOL(timer_interrupt);
600
601/*
602 * Hypervisor decrementer interrupts shouldn't occur but are sometimes
603 * left pending on exit from a KVM guest. We don't need to do anything
604 * to clear them, as they are edge-triggered.
605 */
606void hdec_interrupt(struct pt_regs *regs)
607{
608}
609
610#ifdef CONFIG_SUSPEND
611static void generic_suspend_disable_irqs(void)
612{
613 /* Disable the decrementer, so that it doesn't interfere
614 * with suspending.
615 */
616
617 set_dec(decrementer_max);
618 local_irq_disable();
619 set_dec(decrementer_max);
620}
621
622static void generic_suspend_enable_irqs(void)
623{
624 local_irq_enable();
625}
626
627/* Overrides the weak version in kernel/power/main.c */
628void arch_suspend_disable_irqs(void)
629{
630 if (ppc_md.suspend_disable_irqs)
631 ppc_md.suspend_disable_irqs();
632 generic_suspend_disable_irqs();
633}
634
635/* Overrides the weak version in kernel/power/main.c */
636void arch_suspend_enable_irqs(void)
637{
638 generic_suspend_enable_irqs();
639 if (ppc_md.suspend_enable_irqs)
640 ppc_md.suspend_enable_irqs();
641}
642#endif
643
644unsigned long long tb_to_ns(unsigned long long ticks)
645{
646 return mulhdu(ticks, tb_to_ns_scale) << tb_to_ns_shift;
647}
648EXPORT_SYMBOL_GPL(tb_to_ns);
649
650/*
651 * Scheduler clock - returns current time in nanosec units.
652 *
653 * Note: mulhdu(a, b) (multiply high double unsigned) returns
654 * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
655 * are 64-bit unsigned numbers.
656 */
657unsigned long long sched_clock(void)
658{
659 if (__USE_RTC())
660 return get_rtc();
661 return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
662}
663
664
665#ifdef CONFIG_PPC_PSERIES
666
667/*
668 * Running clock - attempts to give a view of time passing for a virtualised
669 * kernels.
670 * Uses the VTB register if available otherwise a next best guess.
671 */
672unsigned long long running_clock(void)
673{
674 /*
675 * Don't read the VTB as a host since KVM does not switch in host
676 * timebase into the VTB when it takes a guest off the CPU, reading the
677 * VTB would result in reading 'last switched out' guest VTB.
678 *
679 * Host kernels are often compiled with CONFIG_PPC_PSERIES checked, it
680 * would be unsafe to rely only on the #ifdef above.
681 */
682 if (firmware_has_feature(FW_FEATURE_LPAR) &&
683 cpu_has_feature(CPU_FTR_ARCH_207S))
684 return mulhdu(get_vtb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
685
686 /*
687 * This is a next best approximation without a VTB.
688 * On a host which is running bare metal there should never be any stolen
689 * time and on a host which doesn't do any virtualisation TB *should* equal
690 * VTB so it makes no difference anyway.
691 */
692 return local_clock() - cputime_to_nsecs(kcpustat_this_cpu->cpustat[CPUTIME_STEAL]);
693}
694#endif
695
696static int __init get_freq(char *name, int cells, unsigned long *val)
697{
698 struct device_node *cpu;
699 const __be32 *fp;
700 int found = 0;
701
702 /* The cpu node should have timebase and clock frequency properties */
703 cpu = of_find_node_by_type(NULL, "cpu");
704
705 if (cpu) {
706 fp = of_get_property(cpu, name, NULL);
707 if (fp) {
708 found = 1;
709 *val = of_read_ulong(fp, cells);
710 }
711
712 of_node_put(cpu);
713 }
714
715 return found;
716}
717
718static void start_cpu_decrementer(void)
719{
720#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
721 /* Clear any pending timer interrupts */
722 mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS);
723
724 /* Enable decrementer interrupt */
725 mtspr(SPRN_TCR, TCR_DIE);
726#endif /* defined(CONFIG_BOOKE) || defined(CONFIG_40x) */
727}
728
729void __init generic_calibrate_decr(void)
730{
731 ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
732
733 if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&
734 !get_freq("timebase-frequency", 1, &ppc_tb_freq)) {
735
736 printk(KERN_ERR "WARNING: Estimating decrementer frequency "
737 "(not found)\n");
738 }
739
740 ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */
741
742 if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&
743 !get_freq("clock-frequency", 1, &ppc_proc_freq)) {
744
745 printk(KERN_ERR "WARNING: Estimating processor frequency "
746 "(not found)\n");
747 }
748}
749
750int update_persistent_clock(struct timespec now)
751{
752 struct rtc_time tm;
753
754 if (!ppc_md.set_rtc_time)
755 return -ENODEV;
756
757 to_tm(now.tv_sec + 1 + timezone_offset, &tm);
758 tm.tm_year -= 1900;
759 tm.tm_mon -= 1;
760
761 return ppc_md.set_rtc_time(&tm);
762}
763
764static void __read_persistent_clock(struct timespec *ts)
765{
766 struct rtc_time tm;
767 static int first = 1;
768
769 ts->tv_nsec = 0;
770 /* XXX this is a litle fragile but will work okay in the short term */
771 if (first) {
772 first = 0;
773 if (ppc_md.time_init)
774 timezone_offset = ppc_md.time_init();
775
776 /* get_boot_time() isn't guaranteed to be safe to call late */
777 if (ppc_md.get_boot_time) {
778 ts->tv_sec = ppc_md.get_boot_time() - timezone_offset;
779 return;
780 }
781 }
782 if (!ppc_md.get_rtc_time) {
783 ts->tv_sec = 0;
784 return;
785 }
786 ppc_md.get_rtc_time(&tm);
787
788 ts->tv_sec = mktime(tm.tm_year+1900, tm.tm_mon+1, tm.tm_mday,
789 tm.tm_hour, tm.tm_min, tm.tm_sec);
790}
791
792void read_persistent_clock(struct timespec *ts)
793{
794 __read_persistent_clock(ts);
795
796 /* Sanitize it in case real time clock is set below EPOCH */
797 if (ts->tv_sec < 0) {
798 ts->tv_sec = 0;
799 ts->tv_nsec = 0;
800 }
801
802}
803
804/* clocksource code */
805static u64 rtc_read(struct clocksource *cs)
806{
807 return (u64)get_rtc();
808}
809
810static u64 timebase_read(struct clocksource *cs)
811{
812 return (u64)get_tb();
813}
814
815void update_vsyscall_old(struct timespec *wall_time, struct timespec *wtm,
816 struct clocksource *clock, u32 mult, u64 cycle_last)
817{
818 u64 new_tb_to_xs, new_stamp_xsec;
819 u32 frac_sec;
820
821 if (clock != &clocksource_timebase)
822 return;
823
824 /* Make userspace gettimeofday spin until we're done. */
825 ++vdso_data->tb_update_count;
826 smp_mb();
827
828 /* 19342813113834067 ~= 2^(20+64) / 1e9 */
829 new_tb_to_xs = (u64) mult * (19342813113834067ULL >> clock->shift);
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 = 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 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
863 vdso_data->tz_dsttime = sys_tz.tz_dsttime;
864}
865
866static void __init clocksource_init(void)
867{
868 struct clocksource *clock;
869
870 if (__USE_RTC())
871 clock = &clocksource_rtc;
872 else
873 clock = &clocksource_timebase;
874
875 if (clocksource_register_hz(clock, tb_ticks_per_sec)) {
876 printk(KERN_ERR "clocksource: %s is already registered\n",
877 clock->name);
878 return;
879 }
880
881 printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
882 clock->name, clock->mult, clock->shift);
883}
884
885static int decrementer_set_next_event(unsigned long evt,
886 struct clock_event_device *dev)
887{
888 __this_cpu_write(decrementers_next_tb, get_tb_or_rtc() + evt);
889 set_dec(evt);
890
891 /* We may have raced with new irq work */
892 if (test_irq_work_pending())
893 set_dec(1);
894
895 return 0;
896}
897
898static int decrementer_shutdown(struct clock_event_device *dev)
899{
900 decrementer_set_next_event(decrementer_max, dev);
901 return 0;
902}
903
904/* Interrupt handler for the timer broadcast IPI */
905void tick_broadcast_ipi_handler(void)
906{
907 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
908
909 *next_tb = get_tb_or_rtc();
910 __timer_interrupt();
911}
912
913static void register_decrementer_clockevent(int cpu)
914{
915 struct clock_event_device *dec = &per_cpu(decrementers, cpu);
916
917 *dec = decrementer_clockevent;
918 dec->cpumask = cpumask_of(cpu);
919
920 printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
921 dec->name, dec->mult, dec->shift, cpu);
922
923 clockevents_register_device(dec);
924}
925
926static void enable_large_decrementer(void)
927{
928 if (!cpu_has_feature(CPU_FTR_ARCH_300))
929 return;
930
931 if (decrementer_max <= DECREMENTER_DEFAULT_MAX)
932 return;
933
934 /*
935 * If we're running as the hypervisor we need to enable the LD manually
936 * otherwise firmware should have done it for us.
937 */
938 if (cpu_has_feature(CPU_FTR_HVMODE))
939 mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_LD);
940}
941
942static void __init set_decrementer_max(void)
943{
944 struct device_node *cpu;
945 u32 bits = 32;
946
947 /* Prior to ISAv3 the decrementer is always 32 bit */
948 if (!cpu_has_feature(CPU_FTR_ARCH_300))
949 return;
950
951 cpu = of_find_node_by_type(NULL, "cpu");
952
953 if (of_property_read_u32(cpu, "ibm,dec-bits", &bits) == 0) {
954 if (bits > 64 || bits < 32) {
955 pr_warn("time_init: firmware supplied invalid ibm,dec-bits");
956 bits = 32;
957 }
958
959 /* calculate the signed maximum given this many bits */
960 decrementer_max = (1ul << (bits - 1)) - 1;
961 }
962
963 of_node_put(cpu);
964
965 pr_info("time_init: %u bit decrementer (max: %llx)\n",
966 bits, decrementer_max);
967}
968
969static void __init init_decrementer_clockevent(void)
970{
971 int cpu = smp_processor_id();
972
973 clockevents_calc_mult_shift(&decrementer_clockevent, ppc_tb_freq, 4);
974
975 decrementer_clockevent.max_delta_ns =
976 clockevent_delta2ns(decrementer_max, &decrementer_clockevent);
977 decrementer_clockevent.min_delta_ns =
978 clockevent_delta2ns(2, &decrementer_clockevent);
979
980 register_decrementer_clockevent(cpu);
981}
982
983void secondary_cpu_time_init(void)
984{
985 /* Enable and test the large decrementer for this cpu */
986 enable_large_decrementer();
987
988 /* Start the decrementer on CPUs that have manual control
989 * such as BookE
990 */
991 start_cpu_decrementer();
992
993 /* FIME: Should make unrelatred change to move snapshot_timebase
994 * call here ! */
995 register_decrementer_clockevent(smp_processor_id());
996}
997
998/* This function is only called on the boot processor */
999void __init time_init(void)
1000{
1001 struct div_result res;
1002 u64 scale;
1003 unsigned shift;
1004
1005 if (__USE_RTC()) {
1006 /* 601 processor: dec counts down by 128 every 128ns */
1007 ppc_tb_freq = 1000000000;
1008 } else {
1009 /* Normal PowerPC with timebase register */
1010 ppc_md.calibrate_decr();
1011 printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n",
1012 ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
1013 printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n",
1014 ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
1015 }
1016
1017 tb_ticks_per_jiffy = ppc_tb_freq / HZ;
1018 tb_ticks_per_sec = ppc_tb_freq;
1019 tb_ticks_per_usec = ppc_tb_freq / 1000000;
1020 calc_cputime_factors();
1021 setup_cputime_one_jiffy();
1022
1023 /*
1024 * Compute scale factor for sched_clock.
1025 * The calibrate_decr() function has set tb_ticks_per_sec,
1026 * which is the timebase frequency.
1027 * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
1028 * the 128-bit result as a 64.64 fixed-point number.
1029 * We then shift that number right until it is less than 1.0,
1030 * giving us the scale factor and shift count to use in
1031 * sched_clock().
1032 */
1033 div128_by_32(1000000000, 0, tb_ticks_per_sec, &res);
1034 scale = res.result_low;
1035 for (shift = 0; res.result_high != 0; ++shift) {
1036 scale = (scale >> 1) | (res.result_high << 63);
1037 res.result_high >>= 1;
1038 }
1039 tb_to_ns_scale = scale;
1040 tb_to_ns_shift = shift;
1041 /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
1042 boot_tb = get_tb_or_rtc();
1043
1044 /* If platform provided a timezone (pmac), we correct the time */
1045 if (timezone_offset) {
1046 sys_tz.tz_minuteswest = -timezone_offset / 60;
1047 sys_tz.tz_dsttime = 0;
1048 }
1049
1050 vdso_data->tb_update_count = 0;
1051 vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
1052
1053 /* initialise and enable the large decrementer (if we have one) */
1054 set_decrementer_max();
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 /* Register the clocksource */
1063 clocksource_init();
1064
1065 init_decrementer_clockevent();
1066 tick_setup_hrtimer_broadcast();
1067
1068#ifdef CONFIG_COMMON_CLK
1069 of_clk_init(NULL);
1070#endif
1071}
1072
1073
1074#define FEBRUARY 2
1075#define STARTOFTIME 1970
1076#define SECDAY 86400L
1077#define SECYR (SECDAY * 365)
1078#define leapyear(year) ((year) % 4 == 0 && \
1079 ((year) % 100 != 0 || (year) % 400 == 0))
1080#define days_in_year(a) (leapyear(a) ? 366 : 365)
1081#define days_in_month(a) (month_days[(a) - 1])
1082
1083static int month_days[12] = {
1084 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
1085};
1086
1087void to_tm(int tim, struct rtc_time * tm)
1088{
1089 register int i;
1090 register long hms, day;
1091
1092 day = tim / SECDAY;
1093 hms = tim % SECDAY;
1094
1095 /* Hours, minutes, seconds are easy */
1096 tm->tm_hour = hms / 3600;
1097 tm->tm_min = (hms % 3600) / 60;
1098 tm->tm_sec = (hms % 3600) % 60;
1099
1100 /* Number of years in days */
1101 for (i = STARTOFTIME; day >= days_in_year(i); i++)
1102 day -= days_in_year(i);
1103 tm->tm_year = i;
1104
1105 /* Number of months in days left */
1106 if (leapyear(tm->tm_year))
1107 days_in_month(FEBRUARY) = 29;
1108 for (i = 1; day >= days_in_month(i); i++)
1109 day -= days_in_month(i);
1110 days_in_month(FEBRUARY) = 28;
1111 tm->tm_mon = i;
1112
1113 /* Days are what is left over (+1) from all that. */
1114 tm->tm_mday = day + 1;
1115
1116 /*
1117 * No-one uses the day of the week.
1118 */
1119 tm->tm_wday = -1;
1120}
1121EXPORT_SYMBOL(to_tm);
1122
1123/*
1124 * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
1125 * result.
1126 */
1127void div128_by_32(u64 dividend_high, u64 dividend_low,
1128 unsigned divisor, struct div_result *dr)
1129{
1130 unsigned long a, b, c, d;
1131 unsigned long w, x, y, z;
1132 u64 ra, rb, rc;
1133
1134 a = dividend_high >> 32;
1135 b = dividend_high & 0xffffffff;
1136 c = dividend_low >> 32;
1137 d = dividend_low & 0xffffffff;
1138
1139 w = a / divisor;
1140 ra = ((u64)(a - (w * divisor)) << 32) + b;
1141
1142 rb = ((u64) do_div(ra, divisor) << 32) + c;
1143 x = ra;
1144
1145 rc = ((u64) do_div(rb, divisor) << 32) + d;
1146 y = rb;
1147
1148 do_div(rc, divisor);
1149 z = rc;
1150
1151 dr->result_high = ((u64)w << 32) + x;
1152 dr->result_low = ((u64)y << 32) + z;
1153
1154}
1155
1156/* We don't need to calibrate delay, we use the CPU timebase for that */
1157void calibrate_delay(void)
1158{
1159 /* Some generic code (such as spinlock debug) use loops_per_jiffy
1160 * as the number of __delay(1) in a jiffy, so make it so
1161 */
1162 loops_per_jiffy = tb_ticks_per_jiffy;
1163}
1164
1165#if IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
1166static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
1167{
1168 ppc_md.get_rtc_time(tm);
1169 return rtc_valid_tm(tm);
1170}
1171
1172static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm)
1173{
1174 if (!ppc_md.set_rtc_time)
1175 return -EOPNOTSUPP;
1176
1177 if (ppc_md.set_rtc_time(tm) < 0)
1178 return -EOPNOTSUPP;
1179
1180 return 0;
1181}
1182
1183static const struct rtc_class_ops rtc_generic_ops = {
1184 .read_time = rtc_generic_get_time,
1185 .set_time = rtc_generic_set_time,
1186};
1187
1188static int __init rtc_init(void)
1189{
1190 struct platform_device *pdev;
1191
1192 if (!ppc_md.get_rtc_time)
1193 return -ENODEV;
1194
1195 pdev = platform_device_register_data(NULL, "rtc-generic", -1,
1196 &rtc_generic_ops,
1197 sizeof(rtc_generic_ops));
1198
1199 return PTR_ERR_OR_ZERO(pdev);
1200}
1201
1202device_initcall(rtc_init);
1203#endif