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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/sched/cputime.h>
35#include <linux/kernel.h>
36#include <linux/param.h>
37#include <linux/string.h>
38#include <linux/mm.h>
39#include <linux/interrupt.h>
40#include <linux/timex.h>
41#include <linux/kernel_stat.h>
42#include <linux/time.h>
43#include <linux/init.h>
44#include <linux/profile.h>
45#include <linux/cpu.h>
46#include <linux/security.h>
47#include <linux/percpu.h>
48#include <linux/rtc.h>
49#include <linux/jiffies.h>
50#include <linux/posix-timers.h>
51#include <linux/irq.h>
52#include <linux/delay.h>
53#include <linux/irq_work.h>
54#include <linux/of_clk.h>
55#include <linux/suspend.h>
56#include <linux/processor.h>
57#include <linux/mc146818rtc.h>
58#include <linux/platform_device.h>
59
60#include <asm/trace.h>
61#include <asm/interrupt.h>
62#include <asm/io.h>
63#include <asm/nvram.h>
64#include <asm/cache.h>
65#include <asm/machdep.h>
66#include <linux/uaccess.h>
67#include <asm/time.h>
68#include <asm/irq.h>
69#include <asm/div64.h>
70#include <asm/smp.h>
71#include <asm/vdso_datapage.h>
72#include <asm/firmware.h>
73#include <asm/mce.h>
74
75/* powerpc clocksource/clockevent code */
76
77#include <linux/clockchips.h>
78#include <linux/timekeeper_internal.h>
79
80static u64 timebase_read(struct clocksource *);
81static struct clocksource clocksource_timebase = {
82 .name = "timebase",
83 .rating = 400,
84 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
85 .mask = CLOCKSOURCE_MASK(64),
86 .read = timebase_read,
87 .vdso_clock_mode = VDSO_CLOCKMODE_ARCHTIMER,
88};
89
90#define DECREMENTER_DEFAULT_MAX 0x7FFFFFFF
91u64 decrementer_max = DECREMENTER_DEFAULT_MAX;
92EXPORT_SYMBOL_GPL(decrementer_max); /* for KVM HDEC */
93
94static int decrementer_set_next_event(unsigned long evt,
95 struct clock_event_device *dev);
96static int decrementer_shutdown(struct clock_event_device *evt);
97
98struct clock_event_device decrementer_clockevent = {
99 .name = "decrementer",
100 .rating = 200,
101 .irq = 0,
102 .set_next_event = decrementer_set_next_event,
103 .set_state_oneshot_stopped = decrementer_shutdown,
104 .set_state_shutdown = decrementer_shutdown,
105 .tick_resume = decrementer_shutdown,
106 .features = CLOCK_EVT_FEAT_ONESHOT |
107 CLOCK_EVT_FEAT_C3STOP,
108};
109EXPORT_SYMBOL(decrementer_clockevent);
110
111/*
112 * This always puts next_tb beyond now, so the clock event will never fire
113 * with the usual comparison, no need for a separate test for stopped.
114 */
115#define DEC_CLOCKEVENT_STOPPED ~0ULL
116DEFINE_PER_CPU(u64, decrementers_next_tb) = DEC_CLOCKEVENT_STOPPED;
117EXPORT_SYMBOL_GPL(decrementers_next_tb);
118static DEFINE_PER_CPU(struct clock_event_device, decrementers);
119
120#define XSEC_PER_SEC (1024*1024)
121
122#ifdef CONFIG_PPC64
123#define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
124#else
125/* compute ((xsec << 12) * max) >> 32 */
126#define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
127#endif
128
129unsigned long tb_ticks_per_jiffy;
130unsigned long tb_ticks_per_usec = 100; /* sane default */
131EXPORT_SYMBOL(tb_ticks_per_usec);
132unsigned long tb_ticks_per_sec;
133EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime conversions */
134
135DEFINE_SPINLOCK(rtc_lock);
136EXPORT_SYMBOL_GPL(rtc_lock);
137
138static u64 tb_to_ns_scale __read_mostly;
139static unsigned tb_to_ns_shift __read_mostly;
140static u64 boot_tb __read_mostly;
141
142extern struct timezone sys_tz;
143static long timezone_offset;
144
145unsigned long ppc_proc_freq;
146EXPORT_SYMBOL_GPL(ppc_proc_freq);
147unsigned long ppc_tb_freq;
148EXPORT_SYMBOL_GPL(ppc_tb_freq);
149
150bool tb_invalid;
151
152#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
153/*
154 * Read the SPURR on systems that have it, otherwise the PURR,
155 * or if that doesn't exist return the timebase value passed in.
156 */
157static inline unsigned long read_spurr(unsigned long tb)
158{
159 if (cpu_has_feature(CPU_FTR_SPURR))
160 return mfspr(SPRN_SPURR);
161 if (cpu_has_feature(CPU_FTR_PURR))
162 return mfspr(SPRN_PURR);
163 return tb;
164}
165
166/*
167 * Account time for a transition between system, hard irq
168 * or soft irq state.
169 */
170static unsigned long vtime_delta_scaled(struct cpu_accounting_data *acct,
171 unsigned long now, unsigned long stime)
172{
173 unsigned long stime_scaled = 0;
174#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
175 unsigned long nowscaled, deltascaled;
176 unsigned long utime, utime_scaled;
177
178 nowscaled = read_spurr(now);
179 deltascaled = nowscaled - acct->startspurr;
180 acct->startspurr = nowscaled;
181 utime = acct->utime - acct->utime_sspurr;
182 acct->utime_sspurr = acct->utime;
183
184 /*
185 * Because we don't read the SPURR on every kernel entry/exit,
186 * deltascaled includes both user and system SPURR ticks.
187 * Apportion these ticks to system SPURR ticks and user
188 * SPURR ticks in the same ratio as the system time (delta)
189 * and user time (udelta) values obtained from the timebase
190 * over the same interval. The system ticks get accounted here;
191 * the user ticks get saved up in paca->user_time_scaled to be
192 * used by account_process_tick.
193 */
194 stime_scaled = stime;
195 utime_scaled = utime;
196 if (deltascaled != stime + utime) {
197 if (utime) {
198 stime_scaled = deltascaled * stime / (stime + utime);
199 utime_scaled = deltascaled - stime_scaled;
200 } else {
201 stime_scaled = deltascaled;
202 }
203 }
204 acct->utime_scaled += utime_scaled;
205#endif
206
207 return stime_scaled;
208}
209
210static unsigned long vtime_delta(struct cpu_accounting_data *acct,
211 unsigned long *stime_scaled,
212 unsigned long *steal_time)
213{
214 unsigned long now, stime;
215
216 WARN_ON_ONCE(!irqs_disabled());
217
218 now = mftb();
219 stime = now - acct->starttime;
220 acct->starttime = now;
221
222 *stime_scaled = vtime_delta_scaled(acct, now, stime);
223
224 if (IS_ENABLED(CONFIG_PPC_SPLPAR) &&
225 firmware_has_feature(FW_FEATURE_SPLPAR))
226 *steal_time = pseries_calculate_stolen_time(now);
227 else
228 *steal_time = 0;
229
230 return stime;
231}
232
233static void vtime_delta_kernel(struct cpu_accounting_data *acct,
234 unsigned long *stime, unsigned long *stime_scaled)
235{
236 unsigned long steal_time;
237
238 *stime = vtime_delta(acct, stime_scaled, &steal_time);
239 *stime -= min(*stime, steal_time);
240 acct->steal_time += steal_time;
241}
242
243void vtime_account_kernel(struct task_struct *tsk)
244{
245 struct cpu_accounting_data *acct = get_accounting(tsk);
246 unsigned long stime, stime_scaled;
247
248 vtime_delta_kernel(acct, &stime, &stime_scaled);
249
250 if (tsk->flags & PF_VCPU) {
251 acct->gtime += stime;
252#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
253 acct->utime_scaled += stime_scaled;
254#endif
255 } else {
256 acct->stime += stime;
257#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
258 acct->stime_scaled += stime_scaled;
259#endif
260 }
261}
262EXPORT_SYMBOL_GPL(vtime_account_kernel);
263
264void vtime_account_idle(struct task_struct *tsk)
265{
266 unsigned long stime, stime_scaled, steal_time;
267 struct cpu_accounting_data *acct = get_accounting(tsk);
268
269 stime = vtime_delta(acct, &stime_scaled, &steal_time);
270 acct->idle_time += stime + steal_time;
271}
272
273static void vtime_account_irq_field(struct cpu_accounting_data *acct,
274 unsigned long *field)
275{
276 unsigned long stime, stime_scaled;
277
278 vtime_delta_kernel(acct, &stime, &stime_scaled);
279 *field += stime;
280#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
281 acct->stime_scaled += stime_scaled;
282#endif
283}
284
285void vtime_account_softirq(struct task_struct *tsk)
286{
287 struct cpu_accounting_data *acct = get_accounting(tsk);
288 vtime_account_irq_field(acct, &acct->softirq_time);
289}
290
291void vtime_account_hardirq(struct task_struct *tsk)
292{
293 struct cpu_accounting_data *acct = get_accounting(tsk);
294 vtime_account_irq_field(acct, &acct->hardirq_time);
295}
296
297static void vtime_flush_scaled(struct task_struct *tsk,
298 struct cpu_accounting_data *acct)
299{
300#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
301 if (acct->utime_scaled)
302 tsk->utimescaled += cputime_to_nsecs(acct->utime_scaled);
303 if (acct->stime_scaled)
304 tsk->stimescaled += cputime_to_nsecs(acct->stime_scaled);
305
306 acct->utime_scaled = 0;
307 acct->utime_sspurr = 0;
308 acct->stime_scaled = 0;
309#endif
310}
311
312/*
313 * Account the whole cputime accumulated in the paca
314 * Must be called with interrupts disabled.
315 * Assumes that vtime_account_kernel/idle() has been called
316 * recently (i.e. since the last entry from usermode) so that
317 * get_paca()->user_time_scaled is up to date.
318 */
319void vtime_flush(struct task_struct *tsk)
320{
321 struct cpu_accounting_data *acct = get_accounting(tsk);
322
323 if (acct->utime)
324 account_user_time(tsk, cputime_to_nsecs(acct->utime));
325
326 if (acct->gtime)
327 account_guest_time(tsk, cputime_to_nsecs(acct->gtime));
328
329 if (IS_ENABLED(CONFIG_PPC_SPLPAR) && acct->steal_time) {
330 account_steal_time(cputime_to_nsecs(acct->steal_time));
331 acct->steal_time = 0;
332 }
333
334 if (acct->idle_time)
335 account_idle_time(cputime_to_nsecs(acct->idle_time));
336
337 if (acct->stime)
338 account_system_index_time(tsk, cputime_to_nsecs(acct->stime),
339 CPUTIME_SYSTEM);
340
341 if (acct->hardirq_time)
342 account_system_index_time(tsk, cputime_to_nsecs(acct->hardirq_time),
343 CPUTIME_IRQ);
344 if (acct->softirq_time)
345 account_system_index_time(tsk, cputime_to_nsecs(acct->softirq_time),
346 CPUTIME_SOFTIRQ);
347
348 vtime_flush_scaled(tsk, acct);
349
350 acct->utime = 0;
351 acct->gtime = 0;
352 acct->idle_time = 0;
353 acct->stime = 0;
354 acct->hardirq_time = 0;
355 acct->softirq_time = 0;
356}
357#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
358
359void __delay(unsigned long loops)
360{
361 unsigned long start;
362
363 spin_begin();
364 if (tb_invalid) {
365 /*
366 * TB is in error state and isn't ticking anymore.
367 * HMI handler was unable to recover from TB error.
368 * Return immediately, so that kernel won't get stuck here.
369 */
370 spin_cpu_relax();
371 } else {
372 start = mftb();
373 while (mftb() - start < loops)
374 spin_cpu_relax();
375 }
376 spin_end();
377}
378EXPORT_SYMBOL(__delay);
379
380void udelay(unsigned long usecs)
381{
382 __delay(tb_ticks_per_usec * usecs);
383}
384EXPORT_SYMBOL(udelay);
385
386#ifdef CONFIG_SMP
387unsigned long profile_pc(struct pt_regs *regs)
388{
389 unsigned long pc = instruction_pointer(regs);
390
391 if (in_lock_functions(pc))
392 return regs->link;
393
394 return pc;
395}
396EXPORT_SYMBOL(profile_pc);
397#endif
398
399#ifdef CONFIG_IRQ_WORK
400
401/*
402 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
403 */
404#ifdef CONFIG_PPC64
405static inline unsigned long test_irq_work_pending(void)
406{
407 unsigned long x;
408
409 asm volatile("lbz %0,%1(13)"
410 : "=r" (x)
411 : "i" (offsetof(struct paca_struct, irq_work_pending)));
412 return x;
413}
414
415static inline void set_irq_work_pending_flag(void)
416{
417 asm volatile("stb %0,%1(13)" : :
418 "r" (1),
419 "i" (offsetof(struct paca_struct, irq_work_pending)));
420}
421
422static inline void clear_irq_work_pending(void)
423{
424 asm volatile("stb %0,%1(13)" : :
425 "r" (0),
426 "i" (offsetof(struct paca_struct, irq_work_pending)));
427}
428
429#else /* 32-bit */
430
431DEFINE_PER_CPU(u8, irq_work_pending);
432
433#define set_irq_work_pending_flag() __this_cpu_write(irq_work_pending, 1)
434#define test_irq_work_pending() __this_cpu_read(irq_work_pending)
435#define clear_irq_work_pending() __this_cpu_write(irq_work_pending, 0)
436
437#endif /* 32 vs 64 bit */
438
439void arch_irq_work_raise(void)
440{
441 /*
442 * 64-bit code that uses irq soft-mask can just cause an immediate
443 * interrupt here that gets soft masked, if this is called under
444 * local_irq_disable(). It might be possible to prevent that happening
445 * by noticing interrupts are disabled and setting decrementer pending
446 * to be replayed when irqs are enabled. The problem there is that
447 * tracing can call irq_work_raise, including in code that does low
448 * level manipulations of irq soft-mask state (e.g., trace_hardirqs_on)
449 * which could get tangled up if we're messing with the same state
450 * here.
451 */
452 preempt_disable();
453 set_irq_work_pending_flag();
454 set_dec(1);
455 preempt_enable();
456}
457
458static void set_dec_or_work(u64 val)
459{
460 set_dec(val);
461 /* We may have raced with new irq work */
462 if (unlikely(test_irq_work_pending()))
463 set_dec(1);
464}
465
466#else /* CONFIG_IRQ_WORK */
467
468#define test_irq_work_pending() 0
469#define clear_irq_work_pending()
470
471static void set_dec_or_work(u64 val)
472{
473 set_dec(val);
474}
475#endif /* CONFIG_IRQ_WORK */
476
477#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
478void timer_rearm_host_dec(u64 now)
479{
480 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
481
482 WARN_ON_ONCE(!arch_irqs_disabled());
483 WARN_ON_ONCE(mfmsr() & MSR_EE);
484
485 if (now >= *next_tb) {
486 local_paca->irq_happened |= PACA_IRQ_DEC;
487 } else {
488 now = *next_tb - now;
489 if (now > decrementer_max)
490 now = decrementer_max;
491 set_dec_or_work(now);
492 }
493}
494EXPORT_SYMBOL_GPL(timer_rearm_host_dec);
495#endif
496
497/*
498 * timer_interrupt - gets called when the decrementer overflows,
499 * with interrupts disabled.
500 */
501DEFINE_INTERRUPT_HANDLER_ASYNC(timer_interrupt)
502{
503 struct clock_event_device *evt = this_cpu_ptr(&decrementers);
504 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
505 struct pt_regs *old_regs;
506 u64 now;
507
508 /*
509 * Some implementations of hotplug will get timer interrupts while
510 * offline, just ignore these.
511 */
512 if (unlikely(!cpu_online(smp_processor_id()))) {
513 set_dec(decrementer_max);
514 return;
515 }
516
517 /* Conditionally hard-enable interrupts. */
518 if (should_hard_irq_enable(regs)) {
519 /*
520 * Ensure a positive value is written to the decrementer, or
521 * else some CPUs will continue to take decrementer exceptions.
522 * When the PPC_WATCHDOG (decrementer based) is configured,
523 * keep this at most 31 bits, which is about 4 seconds on most
524 * systems, which gives the watchdog a chance of catching timer
525 * interrupt hard lockups.
526 */
527 if (IS_ENABLED(CONFIG_PPC_WATCHDOG))
528 set_dec(0x7fffffff);
529 else
530 set_dec(decrementer_max);
531
532 do_hard_irq_enable();
533 }
534
535#if defined(CONFIG_PPC32) && defined(CONFIG_PPC_PMAC)
536 if (atomic_read(&ppc_n_lost_interrupts) != 0)
537 __do_IRQ(regs);
538#endif
539
540 old_regs = set_irq_regs(regs);
541
542 trace_timer_interrupt_entry(regs);
543
544 if (test_irq_work_pending()) {
545 clear_irq_work_pending();
546 mce_run_irq_context_handlers();
547 irq_work_run();
548 }
549
550 now = get_tb();
551 if (now >= *next_tb) {
552 evt->event_handler(evt);
553 __this_cpu_inc(irq_stat.timer_irqs_event);
554 } else {
555 now = *next_tb - now;
556 if (now > decrementer_max)
557 now = decrementer_max;
558 set_dec_or_work(now);
559 __this_cpu_inc(irq_stat.timer_irqs_others);
560 }
561
562 trace_timer_interrupt_exit(regs);
563
564 set_irq_regs(old_regs);
565}
566EXPORT_SYMBOL(timer_interrupt);
567
568#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
569void timer_broadcast_interrupt(void)
570{
571 tick_receive_broadcast();
572 __this_cpu_inc(irq_stat.broadcast_irqs_event);
573}
574#endif
575
576#ifdef CONFIG_SUSPEND
577/* Overrides the weak version in kernel/power/main.c */
578void arch_suspend_disable_irqs(void)
579{
580 if (ppc_md.suspend_disable_irqs)
581 ppc_md.suspend_disable_irqs();
582
583 /* Disable the decrementer, so that it doesn't interfere
584 * with suspending.
585 */
586
587 set_dec(decrementer_max);
588 local_irq_disable();
589 set_dec(decrementer_max);
590}
591
592/* Overrides the weak version in kernel/power/main.c */
593void arch_suspend_enable_irqs(void)
594{
595 local_irq_enable();
596
597 if (ppc_md.suspend_enable_irqs)
598 ppc_md.suspend_enable_irqs();
599}
600#endif
601
602unsigned long long tb_to_ns(unsigned long long ticks)
603{
604 return mulhdu(ticks, tb_to_ns_scale) << tb_to_ns_shift;
605}
606EXPORT_SYMBOL_GPL(tb_to_ns);
607
608/*
609 * Scheduler clock - returns current time in nanosec units.
610 *
611 * Note: mulhdu(a, b) (multiply high double unsigned) returns
612 * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
613 * are 64-bit unsigned numbers.
614 */
615notrace unsigned long long sched_clock(void)
616{
617 return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
618}
619
620
621#ifdef CONFIG_PPC_PSERIES
622
623/*
624 * Running clock - attempts to give a view of time passing for a virtualised
625 * kernels.
626 * Uses the VTB register if available otherwise a next best guess.
627 */
628unsigned long long running_clock(void)
629{
630 /*
631 * Don't read the VTB as a host since KVM does not switch in host
632 * timebase into the VTB when it takes a guest off the CPU, reading the
633 * VTB would result in reading 'last switched out' guest VTB.
634 *
635 * Host kernels are often compiled with CONFIG_PPC_PSERIES checked, it
636 * would be unsafe to rely only on the #ifdef above.
637 */
638 if (firmware_has_feature(FW_FEATURE_LPAR) &&
639 cpu_has_feature(CPU_FTR_ARCH_207S))
640 return mulhdu(get_vtb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
641
642 /*
643 * This is a next best approximation without a VTB.
644 * On a host which is running bare metal there should never be any stolen
645 * time and on a host which doesn't do any virtualisation TB *should* equal
646 * VTB so it makes no difference anyway.
647 */
648 return local_clock() - kcpustat_this_cpu->cpustat[CPUTIME_STEAL];
649}
650#endif
651
652static int __init get_freq(char *name, int cells, unsigned long *val)
653{
654 struct device_node *cpu;
655 const __be32 *fp;
656 int found = 0;
657
658 /* The cpu node should have timebase and clock frequency properties */
659 cpu = of_find_node_by_type(NULL, "cpu");
660
661 if (cpu) {
662 fp = of_get_property(cpu, name, NULL);
663 if (fp) {
664 found = 1;
665 *val = of_read_ulong(fp, cells);
666 }
667
668 of_node_put(cpu);
669 }
670
671 return found;
672}
673
674static void start_cpu_decrementer(void)
675{
676#ifdef CONFIG_BOOKE_OR_40x
677 unsigned int tcr;
678
679 /* Clear any pending timer interrupts */
680 mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS);
681
682 tcr = mfspr(SPRN_TCR);
683 /*
684 * The watchdog may have already been enabled by u-boot. So leave
685 * TRC[WP] (Watchdog Period) alone.
686 */
687 tcr &= TCR_WP_MASK; /* Clear all bits except for TCR[WP] */
688 tcr |= TCR_DIE; /* Enable decrementer */
689 mtspr(SPRN_TCR, tcr);
690#endif
691}
692
693void __init generic_calibrate_decr(void)
694{
695 ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
696
697 if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&
698 !get_freq("timebase-frequency", 1, &ppc_tb_freq)) {
699
700 printk(KERN_ERR "WARNING: Estimating decrementer frequency "
701 "(not found)\n");
702 }
703
704 ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */
705
706 if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&
707 !get_freq("clock-frequency", 1, &ppc_proc_freq)) {
708
709 printk(KERN_ERR "WARNING: Estimating processor frequency "
710 "(not found)\n");
711 }
712}
713
714int update_persistent_clock64(struct timespec64 now)
715{
716 struct rtc_time tm;
717
718 if (!ppc_md.set_rtc_time)
719 return -ENODEV;
720
721 rtc_time64_to_tm(now.tv_sec + 1 + timezone_offset, &tm);
722
723 return ppc_md.set_rtc_time(&tm);
724}
725
726static void __read_persistent_clock(struct timespec64 *ts)
727{
728 struct rtc_time tm;
729 static int first = 1;
730
731 ts->tv_nsec = 0;
732 /* XXX this is a little fragile but will work okay in the short term */
733 if (first) {
734 first = 0;
735 if (ppc_md.time_init)
736 timezone_offset = ppc_md.time_init();
737
738 /* get_boot_time() isn't guaranteed to be safe to call late */
739 if (ppc_md.get_boot_time) {
740 ts->tv_sec = ppc_md.get_boot_time() - timezone_offset;
741 return;
742 }
743 }
744 if (!ppc_md.get_rtc_time) {
745 ts->tv_sec = 0;
746 return;
747 }
748 ppc_md.get_rtc_time(&tm);
749
750 ts->tv_sec = rtc_tm_to_time64(&tm);
751}
752
753void read_persistent_clock64(struct timespec64 *ts)
754{
755 __read_persistent_clock(ts);
756
757 /* Sanitize it in case real time clock is set below EPOCH */
758 if (ts->tv_sec < 0) {
759 ts->tv_sec = 0;
760 ts->tv_nsec = 0;
761 }
762
763}
764
765/* clocksource code */
766static notrace u64 timebase_read(struct clocksource *cs)
767{
768 return (u64)get_tb();
769}
770
771static void __init clocksource_init(void)
772{
773 struct clocksource *clock = &clocksource_timebase;
774
775 if (clocksource_register_hz(clock, tb_ticks_per_sec)) {
776 printk(KERN_ERR "clocksource: %s is already registered\n",
777 clock->name);
778 return;
779 }
780
781 printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
782 clock->name, clock->mult, clock->shift);
783}
784
785static int decrementer_set_next_event(unsigned long evt,
786 struct clock_event_device *dev)
787{
788 __this_cpu_write(decrementers_next_tb, get_tb() + evt);
789 set_dec_or_work(evt);
790
791 return 0;
792}
793
794static int decrementer_shutdown(struct clock_event_device *dev)
795{
796 __this_cpu_write(decrementers_next_tb, DEC_CLOCKEVENT_STOPPED);
797 set_dec_or_work(decrementer_max);
798
799 return 0;
800}
801
802static void register_decrementer_clockevent(int cpu)
803{
804 struct clock_event_device *dec = &per_cpu(decrementers, cpu);
805
806 *dec = decrementer_clockevent;
807 dec->cpumask = cpumask_of(cpu);
808
809 clockevents_config_and_register(dec, ppc_tb_freq, 2, decrementer_max);
810
811 printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
812 dec->name, dec->mult, dec->shift, cpu);
813
814 /* Set values for KVM, see kvm_emulate_dec() */
815 decrementer_clockevent.mult = dec->mult;
816 decrementer_clockevent.shift = dec->shift;
817}
818
819static void enable_large_decrementer(void)
820{
821 if (!cpu_has_feature(CPU_FTR_ARCH_300))
822 return;
823
824 if (decrementer_max <= DECREMENTER_DEFAULT_MAX)
825 return;
826
827 /*
828 * If we're running as the hypervisor we need to enable the LD manually
829 * otherwise firmware should have done it for us.
830 */
831 if (cpu_has_feature(CPU_FTR_HVMODE))
832 mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_LD);
833}
834
835static void __init set_decrementer_max(void)
836{
837 struct device_node *cpu;
838 u32 bits = 32;
839
840 /* Prior to ISAv3 the decrementer is always 32 bit */
841 if (!cpu_has_feature(CPU_FTR_ARCH_300))
842 return;
843
844 cpu = of_find_node_by_type(NULL, "cpu");
845
846 if (of_property_read_u32(cpu, "ibm,dec-bits", &bits) == 0) {
847 if (bits > 64 || bits < 32) {
848 pr_warn("time_init: firmware supplied invalid ibm,dec-bits");
849 bits = 32;
850 }
851
852 /* calculate the signed maximum given this many bits */
853 decrementer_max = (1ul << (bits - 1)) - 1;
854 }
855
856 of_node_put(cpu);
857
858 pr_info("time_init: %u bit decrementer (max: %llx)\n",
859 bits, decrementer_max);
860}
861
862static void __init init_decrementer_clockevent(void)
863{
864 register_decrementer_clockevent(smp_processor_id());
865}
866
867void secondary_cpu_time_init(void)
868{
869 /* Enable and test the large decrementer for this cpu */
870 enable_large_decrementer();
871
872 /* Start the decrementer on CPUs that have manual control
873 * such as BookE
874 */
875 start_cpu_decrementer();
876
877 /* FIME: Should make unrelated change to move snapshot_timebase
878 * call here ! */
879 register_decrementer_clockevent(smp_processor_id());
880}
881
882/* This function is only called on the boot processor */
883void __init time_init(void)
884{
885 struct div_result res;
886 u64 scale;
887 unsigned shift;
888
889 /* Normal PowerPC with timebase register */
890 ppc_md.calibrate_decr();
891 printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n",
892 ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
893 printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n",
894 ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
895
896 tb_ticks_per_jiffy = ppc_tb_freq / HZ;
897 tb_ticks_per_sec = ppc_tb_freq;
898 tb_ticks_per_usec = ppc_tb_freq / 1000000;
899
900 /*
901 * Compute scale factor for sched_clock.
902 * The calibrate_decr() function has set tb_ticks_per_sec,
903 * which is the timebase frequency.
904 * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
905 * the 128-bit result as a 64.64 fixed-point number.
906 * We then shift that number right until it is less than 1.0,
907 * giving us the scale factor and shift count to use in
908 * sched_clock().
909 */
910 div128_by_32(1000000000, 0, tb_ticks_per_sec, &res);
911 scale = res.result_low;
912 for (shift = 0; res.result_high != 0; ++shift) {
913 scale = (scale >> 1) | (res.result_high << 63);
914 res.result_high >>= 1;
915 }
916 tb_to_ns_scale = scale;
917 tb_to_ns_shift = shift;
918 /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
919 boot_tb = get_tb();
920
921 /* If platform provided a timezone (pmac), we correct the time */
922 if (timezone_offset) {
923 sys_tz.tz_minuteswest = -timezone_offset / 60;
924 sys_tz.tz_dsttime = 0;
925 }
926
927 vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
928
929 /* initialise and enable the large decrementer (if we have one) */
930 set_decrementer_max();
931 enable_large_decrementer();
932
933 /* Start the decrementer on CPUs that have manual control
934 * such as BookE
935 */
936 start_cpu_decrementer();
937
938 /* Register the clocksource */
939 clocksource_init();
940
941 init_decrementer_clockevent();
942 tick_setup_hrtimer_broadcast();
943
944 of_clk_init(NULL);
945 enable_sched_clock_irqtime();
946}
947
948/*
949 * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
950 * result.
951 */
952void div128_by_32(u64 dividend_high, u64 dividend_low,
953 unsigned divisor, struct div_result *dr)
954{
955 unsigned long a, b, c, d;
956 unsigned long w, x, y, z;
957 u64 ra, rb, rc;
958
959 a = dividend_high >> 32;
960 b = dividend_high & 0xffffffff;
961 c = dividend_low >> 32;
962 d = dividend_low & 0xffffffff;
963
964 w = a / divisor;
965 ra = ((u64)(a - (w * divisor)) << 32) + b;
966
967 rb = ((u64) do_div(ra, divisor) << 32) + c;
968 x = ra;
969
970 rc = ((u64) do_div(rb, divisor) << 32) + d;
971 y = rb;
972
973 do_div(rc, divisor);
974 z = rc;
975
976 dr->result_high = ((u64)w << 32) + x;
977 dr->result_low = ((u64)y << 32) + z;
978
979}
980
981/* We don't need to calibrate delay, we use the CPU timebase for that */
982void calibrate_delay(void)
983{
984 /* Some generic code (such as spinlock debug) use loops_per_jiffy
985 * as the number of __delay(1) in a jiffy, so make it so
986 */
987 loops_per_jiffy = tb_ticks_per_jiffy;
988}
989
990#if IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
991static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
992{
993 ppc_md.get_rtc_time(tm);
994 return 0;
995}
996
997static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm)
998{
999 if (!ppc_md.set_rtc_time)
1000 return -EOPNOTSUPP;
1001
1002 if (ppc_md.set_rtc_time(tm) < 0)
1003 return -EOPNOTSUPP;
1004
1005 return 0;
1006}
1007
1008static const struct rtc_class_ops rtc_generic_ops = {
1009 .read_time = rtc_generic_get_time,
1010 .set_time = rtc_generic_set_time,
1011};
1012
1013static int __init rtc_init(void)
1014{
1015 struct platform_device *pdev;
1016
1017 if (!ppc_md.get_rtc_time)
1018 return -ENODEV;
1019
1020 pdev = platform_device_register_data(NULL, "rtc-generic", -1,
1021 &rtc_generic_ops,
1022 sizeof(rtc_generic_ops));
1023
1024 return PTR_ERR_OR_ZERO(pdev);
1025}
1026
1027device_initcall(rtc_init);
1028#endif
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/clk-provider.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/*
187 * Scan the dispatch trace log and count up the stolen time.
188 * Should be called with interrupts disabled.
189 */
190static u64 scan_dispatch_log(u64 stop_tb)
191{
192 u64 i = local_paca->dtl_ridx;
193 struct dtl_entry *dtl = local_paca->dtl_curr;
194 struct dtl_entry *dtl_end = local_paca->dispatch_log_end;
195 struct lppaca *vpa = local_paca->lppaca_ptr;
196 u64 tb_delta;
197 u64 stolen = 0;
198 u64 dtb;
199
200 if (!dtl)
201 return 0;
202
203 if (i == be64_to_cpu(vpa->dtl_idx))
204 return 0;
205 while (i < be64_to_cpu(vpa->dtl_idx)) {
206 dtb = be64_to_cpu(dtl->timebase);
207 tb_delta = be32_to_cpu(dtl->enqueue_to_dispatch_time) +
208 be32_to_cpu(dtl->ready_to_enqueue_time);
209 barrier();
210 if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) {
211 /* buffer has overflowed */
212 i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG;
213 dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
214 continue;
215 }
216 if (dtb > stop_tb)
217 break;
218 if (dtl_consumer)
219 dtl_consumer(dtl, i);
220 stolen += tb_delta;
221 ++i;
222 ++dtl;
223 if (dtl == dtl_end)
224 dtl = local_paca->dispatch_log;
225 }
226 local_paca->dtl_ridx = i;
227 local_paca->dtl_curr = dtl;
228 return stolen;
229}
230
231/*
232 * Accumulate stolen time by scanning the dispatch trace log.
233 * Called on entry from user mode.
234 */
235void accumulate_stolen_time(void)
236{
237 u64 sst, ust;
238 unsigned long save_irq_soft_mask = irq_soft_mask_return();
239 struct cpu_accounting_data *acct = &local_paca->accounting;
240
241 /* We are called early in the exception entry, before
242 * soft/hard_enabled are sync'ed to the expected state
243 * for the exception. We are hard disabled but the PACA
244 * needs to reflect that so various debug stuff doesn't
245 * complain
246 */
247 irq_soft_mask_set(IRQS_DISABLED);
248
249 sst = scan_dispatch_log(acct->starttime_user);
250 ust = scan_dispatch_log(acct->starttime);
251 acct->stime -= sst;
252 acct->utime -= ust;
253 acct->steal_time += ust + sst;
254
255 irq_soft_mask_set(save_irq_soft_mask);
256}
257
258static inline u64 calculate_stolen_time(u64 stop_tb)
259{
260 if (!firmware_has_feature(FW_FEATURE_SPLPAR))
261 return 0;
262
263 if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx))
264 return scan_dispatch_log(stop_tb);
265
266 return 0;
267}
268
269#else /* CONFIG_PPC_SPLPAR */
270static inline u64 calculate_stolen_time(u64 stop_tb)
271{
272 return 0;
273}
274
275#endif /* CONFIG_PPC_SPLPAR */
276
277/*
278 * Account time for a transition between system, hard irq
279 * or soft irq state.
280 */
281static unsigned long vtime_delta_scaled(struct cpu_accounting_data *acct,
282 unsigned long now, unsigned long stime)
283{
284 unsigned long stime_scaled = 0;
285#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
286 unsigned long nowscaled, deltascaled;
287 unsigned long utime, utime_scaled;
288
289 nowscaled = read_spurr(now);
290 deltascaled = nowscaled - acct->startspurr;
291 acct->startspurr = nowscaled;
292 utime = acct->utime - acct->utime_sspurr;
293 acct->utime_sspurr = acct->utime;
294
295 /*
296 * Because we don't read the SPURR on every kernel entry/exit,
297 * deltascaled includes both user and system SPURR ticks.
298 * Apportion these ticks to system SPURR ticks and user
299 * SPURR ticks in the same ratio as the system time (delta)
300 * and user time (udelta) values obtained from the timebase
301 * over the same interval. The system ticks get accounted here;
302 * the user ticks get saved up in paca->user_time_scaled to be
303 * used by account_process_tick.
304 */
305 stime_scaled = stime;
306 utime_scaled = utime;
307 if (deltascaled != stime + utime) {
308 if (utime) {
309 stime_scaled = deltascaled * stime / (stime + utime);
310 utime_scaled = deltascaled - stime_scaled;
311 } else {
312 stime_scaled = deltascaled;
313 }
314 }
315 acct->utime_scaled += utime_scaled;
316#endif
317
318 return stime_scaled;
319}
320
321static unsigned long vtime_delta(struct task_struct *tsk,
322 unsigned long *stime_scaled,
323 unsigned long *steal_time)
324{
325 unsigned long now, stime;
326 struct cpu_accounting_data *acct = get_accounting(tsk);
327
328 WARN_ON_ONCE(!irqs_disabled());
329
330 now = mftb();
331 stime = now - acct->starttime;
332 acct->starttime = now;
333
334 *stime_scaled = vtime_delta_scaled(acct, now, stime);
335
336 *steal_time = calculate_stolen_time(now);
337
338 return stime;
339}
340
341void vtime_account_system(struct task_struct *tsk)
342{
343 unsigned long stime, stime_scaled, steal_time;
344 struct cpu_accounting_data *acct = get_accounting(tsk);
345
346 stime = vtime_delta(tsk, &stime_scaled, &steal_time);
347
348 stime -= min(stime, steal_time);
349 acct->steal_time += steal_time;
350
351 if ((tsk->flags & PF_VCPU) && !irq_count()) {
352 acct->gtime += stime;
353#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
354 acct->utime_scaled += stime_scaled;
355#endif
356 } else {
357 if (hardirq_count())
358 acct->hardirq_time += stime;
359 else if (in_serving_softirq())
360 acct->softirq_time += stime;
361 else
362 acct->stime += stime;
363
364#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
365 acct->stime_scaled += stime_scaled;
366#endif
367 }
368}
369EXPORT_SYMBOL_GPL(vtime_account_system);
370
371void vtime_account_idle(struct task_struct *tsk)
372{
373 unsigned long stime, stime_scaled, steal_time;
374 struct cpu_accounting_data *acct = get_accounting(tsk);
375
376 stime = vtime_delta(tsk, &stime_scaled, &steal_time);
377 acct->idle_time += stime + steal_time;
378}
379
380static void vtime_flush_scaled(struct task_struct *tsk,
381 struct cpu_accounting_data *acct)
382{
383#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
384 if (acct->utime_scaled)
385 tsk->utimescaled += cputime_to_nsecs(acct->utime_scaled);
386 if (acct->stime_scaled)
387 tsk->stimescaled += cputime_to_nsecs(acct->stime_scaled);
388
389 acct->utime_scaled = 0;
390 acct->utime_sspurr = 0;
391 acct->stime_scaled = 0;
392#endif
393}
394
395/*
396 * Account the whole cputime accumulated in the paca
397 * Must be called with interrupts disabled.
398 * Assumes that vtime_account_system/idle() has been called
399 * recently (i.e. since the last entry from usermode) so that
400 * get_paca()->user_time_scaled is up to date.
401 */
402void vtime_flush(struct task_struct *tsk)
403{
404 struct cpu_accounting_data *acct = get_accounting(tsk);
405
406 if (acct->utime)
407 account_user_time(tsk, cputime_to_nsecs(acct->utime));
408
409 if (acct->gtime)
410 account_guest_time(tsk, cputime_to_nsecs(acct->gtime));
411
412 if (IS_ENABLED(CONFIG_PPC_SPLPAR) && acct->steal_time) {
413 account_steal_time(cputime_to_nsecs(acct->steal_time));
414 acct->steal_time = 0;
415 }
416
417 if (acct->idle_time)
418 account_idle_time(cputime_to_nsecs(acct->idle_time));
419
420 if (acct->stime)
421 account_system_index_time(tsk, cputime_to_nsecs(acct->stime),
422 CPUTIME_SYSTEM);
423
424 if (acct->hardirq_time)
425 account_system_index_time(tsk, cputime_to_nsecs(acct->hardirq_time),
426 CPUTIME_IRQ);
427 if (acct->softirq_time)
428 account_system_index_time(tsk, cputime_to_nsecs(acct->softirq_time),
429 CPUTIME_SOFTIRQ);
430
431 vtime_flush_scaled(tsk, acct);
432
433 acct->utime = 0;
434 acct->gtime = 0;
435 acct->idle_time = 0;
436 acct->stime = 0;
437 acct->hardirq_time = 0;
438 acct->softirq_time = 0;
439}
440
441#else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
442#define calc_cputime_factors()
443#endif
444
445void __delay(unsigned long loops)
446{
447 unsigned long start;
448 int diff;
449
450 spin_begin();
451 if (__USE_RTC()) {
452 start = get_rtcl();
453 do {
454 /* the RTCL register wraps at 1000000000 */
455 diff = get_rtcl() - start;
456 if (diff < 0)
457 diff += 1000000000;
458 spin_cpu_relax();
459 } while (diff < loops);
460 } else if (tb_invalid) {
461 /*
462 * TB is in error state and isn't ticking anymore.
463 * HMI handler was unable to recover from TB error.
464 * Return immediately, so that kernel won't get stuck here.
465 */
466 spin_cpu_relax();
467 } else {
468 start = get_tbl();
469 while (get_tbl() - start < loops)
470 spin_cpu_relax();
471 }
472 spin_end();
473}
474EXPORT_SYMBOL(__delay);
475
476void udelay(unsigned long usecs)
477{
478 __delay(tb_ticks_per_usec * usecs);
479}
480EXPORT_SYMBOL(udelay);
481
482#ifdef CONFIG_SMP
483unsigned long profile_pc(struct pt_regs *regs)
484{
485 unsigned long pc = instruction_pointer(regs);
486
487 if (in_lock_functions(pc))
488 return regs->link;
489
490 return pc;
491}
492EXPORT_SYMBOL(profile_pc);
493#endif
494
495#ifdef CONFIG_IRQ_WORK
496
497/*
498 * 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
499 */
500#ifdef CONFIG_PPC64
501static inline unsigned long test_irq_work_pending(void)
502{
503 unsigned long x;
504
505 asm volatile("lbz %0,%1(13)"
506 : "=r" (x)
507 : "i" (offsetof(struct paca_struct, irq_work_pending)));
508 return x;
509}
510
511static inline void set_irq_work_pending_flag(void)
512{
513 asm volatile("stb %0,%1(13)" : :
514 "r" (1),
515 "i" (offsetof(struct paca_struct, irq_work_pending)));
516}
517
518static inline void clear_irq_work_pending(void)
519{
520 asm volatile("stb %0,%1(13)" : :
521 "r" (0),
522 "i" (offsetof(struct paca_struct, irq_work_pending)));
523}
524
525void arch_irq_work_raise(void)
526{
527 preempt_disable();
528 set_irq_work_pending_flag();
529 /*
530 * Non-nmi code running with interrupts disabled will replay
531 * irq_happened before it re-enables interrupts, so setthe
532 * decrementer there instead of causing a hardware exception
533 * which would immediately hit the masked interrupt handler
534 * and have the net effect of setting the decrementer in
535 * irq_happened.
536 *
537 * NMI interrupts can not check this when they return, so the
538 * decrementer hardware exception is raised, which will fire
539 * when interrupts are next enabled.
540 *
541 * BookE does not support this yet, it must audit all NMI
542 * interrupt handlers to ensure they call nmi_enter() so this
543 * check would be correct.
544 */
545 if (IS_ENABLED(CONFIG_BOOKE) || !irqs_disabled() || in_nmi()) {
546 set_dec(1);
547 } else {
548 hard_irq_disable();
549 local_paca->irq_happened |= PACA_IRQ_DEC;
550 }
551 preempt_enable();
552}
553
554#else /* 32-bit */
555
556DEFINE_PER_CPU(u8, irq_work_pending);
557
558#define set_irq_work_pending_flag() __this_cpu_write(irq_work_pending, 1)
559#define test_irq_work_pending() __this_cpu_read(irq_work_pending)
560#define clear_irq_work_pending() __this_cpu_write(irq_work_pending, 0)
561
562void arch_irq_work_raise(void)
563{
564 preempt_disable();
565 set_irq_work_pending_flag();
566 set_dec(1);
567 preempt_enable();
568}
569
570#endif /* 32 vs 64 bit */
571
572#else /* CONFIG_IRQ_WORK */
573
574#define test_irq_work_pending() 0
575#define clear_irq_work_pending()
576
577#endif /* CONFIG_IRQ_WORK */
578
579/*
580 * timer_interrupt - gets called when the decrementer overflows,
581 * with interrupts disabled.
582 */
583void timer_interrupt(struct pt_regs *regs)
584{
585 struct clock_event_device *evt = this_cpu_ptr(&decrementers);
586 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
587 struct pt_regs *old_regs;
588 u64 now;
589
590 /* Some implementations of hotplug will get timer interrupts while
591 * offline, just ignore these and we also need to set
592 * decrementers_next_tb as MAX to make sure __check_irq_replay
593 * don't replay timer interrupt when return, otherwise we'll trap
594 * here infinitely :(
595 */
596 if (unlikely(!cpu_online(smp_processor_id()))) {
597 *next_tb = ~(u64)0;
598 set_dec(decrementer_max);
599 return;
600 }
601
602 /* Ensure a positive value is written to the decrementer, or else
603 * some CPUs will continue to take decrementer exceptions. When the
604 * PPC_WATCHDOG (decrementer based) is configured, keep this at most
605 * 31 bits, which is about 4 seconds on most systems, which gives
606 * the watchdog a chance of catching timer interrupt hard lockups.
607 */
608 if (IS_ENABLED(CONFIG_PPC_WATCHDOG))
609 set_dec(0x7fffffff);
610 else
611 set_dec(decrementer_max);
612
613 /* Conditionally hard-enable interrupts now that the DEC has been
614 * bumped to its maximum value
615 */
616 may_hard_irq_enable();
617
618
619#if defined(CONFIG_PPC32) && defined(CONFIG_PPC_PMAC)
620 if (atomic_read(&ppc_n_lost_interrupts) != 0)
621 do_IRQ(regs);
622#endif
623
624 old_regs = set_irq_regs(regs);
625 irq_enter();
626 trace_timer_interrupt_entry(regs);
627
628 if (test_irq_work_pending()) {
629 clear_irq_work_pending();
630 irq_work_run();
631 }
632
633 now = get_tb_or_rtc();
634 if (now >= *next_tb) {
635 *next_tb = ~(u64)0;
636 if (evt->event_handler)
637 evt->event_handler(evt);
638 __this_cpu_inc(irq_stat.timer_irqs_event);
639 } else {
640 now = *next_tb - now;
641 if (now <= decrementer_max)
642 set_dec(now);
643 /* We may have raced with new irq work */
644 if (test_irq_work_pending())
645 set_dec(1);
646 __this_cpu_inc(irq_stat.timer_irqs_others);
647 }
648
649 trace_timer_interrupt_exit(regs);
650 irq_exit();
651 set_irq_regs(old_regs);
652}
653EXPORT_SYMBOL(timer_interrupt);
654
655#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
656void timer_broadcast_interrupt(void)
657{
658 u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
659
660 *next_tb = ~(u64)0;
661 tick_receive_broadcast();
662 __this_cpu_inc(irq_stat.broadcast_irqs_event);
663}
664#endif
665
666/*
667 * Hypervisor decrementer interrupts shouldn't occur but are sometimes
668 * left pending on exit from a KVM guest. We don't need to do anything
669 * to clear them, as they are edge-triggered.
670 */
671void hdec_interrupt(struct pt_regs *regs)
672{
673}
674
675#ifdef CONFIG_SUSPEND
676static void generic_suspend_disable_irqs(void)
677{
678 /* Disable the decrementer, so that it doesn't interfere
679 * with suspending.
680 */
681
682 set_dec(decrementer_max);
683 local_irq_disable();
684 set_dec(decrementer_max);
685}
686
687static void generic_suspend_enable_irqs(void)
688{
689 local_irq_enable();
690}
691
692/* Overrides the weak version in kernel/power/main.c */
693void arch_suspend_disable_irqs(void)
694{
695 if (ppc_md.suspend_disable_irqs)
696 ppc_md.suspend_disable_irqs();
697 generic_suspend_disable_irqs();
698}
699
700/* Overrides the weak version in kernel/power/main.c */
701void arch_suspend_enable_irqs(void)
702{
703 generic_suspend_enable_irqs();
704 if (ppc_md.suspend_enable_irqs)
705 ppc_md.suspend_enable_irqs();
706}
707#endif
708
709unsigned long long tb_to_ns(unsigned long long ticks)
710{
711 return mulhdu(ticks, tb_to_ns_scale) << tb_to_ns_shift;
712}
713EXPORT_SYMBOL_GPL(tb_to_ns);
714
715/*
716 * Scheduler clock - returns current time in nanosec units.
717 *
718 * Note: mulhdu(a, b) (multiply high double unsigned) returns
719 * the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
720 * are 64-bit unsigned numbers.
721 */
722notrace unsigned long long sched_clock(void)
723{
724 if (__USE_RTC())
725 return get_rtc();
726 return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
727}
728
729
730#ifdef CONFIG_PPC_PSERIES
731
732/*
733 * Running clock - attempts to give a view of time passing for a virtualised
734 * kernels.
735 * Uses the VTB register if available otherwise a next best guess.
736 */
737unsigned long long running_clock(void)
738{
739 /*
740 * Don't read the VTB as a host since KVM does not switch in host
741 * timebase into the VTB when it takes a guest off the CPU, reading the
742 * VTB would result in reading 'last switched out' guest VTB.
743 *
744 * Host kernels are often compiled with CONFIG_PPC_PSERIES checked, it
745 * would be unsafe to rely only on the #ifdef above.
746 */
747 if (firmware_has_feature(FW_FEATURE_LPAR) &&
748 cpu_has_feature(CPU_FTR_ARCH_207S))
749 return mulhdu(get_vtb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
750
751 /*
752 * This is a next best approximation without a VTB.
753 * On a host which is running bare metal there should never be any stolen
754 * time and on a host which doesn't do any virtualisation TB *should* equal
755 * VTB so it makes no difference anyway.
756 */
757 return local_clock() - kcpustat_this_cpu->cpustat[CPUTIME_STEAL];
758}
759#endif
760
761static int __init get_freq(char *name, int cells, unsigned long *val)
762{
763 struct device_node *cpu;
764 const __be32 *fp;
765 int found = 0;
766
767 /* The cpu node should have timebase and clock frequency properties */
768 cpu = of_find_node_by_type(NULL, "cpu");
769
770 if (cpu) {
771 fp = of_get_property(cpu, name, NULL);
772 if (fp) {
773 found = 1;
774 *val = of_read_ulong(fp, cells);
775 }
776
777 of_node_put(cpu);
778 }
779
780 return found;
781}
782
783static void start_cpu_decrementer(void)
784{
785#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
786 unsigned int tcr;
787
788 /* Clear any pending timer interrupts */
789 mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS);
790
791 tcr = mfspr(SPRN_TCR);
792 /*
793 * The watchdog may have already been enabled by u-boot. So leave
794 * TRC[WP] (Watchdog Period) alone.
795 */
796 tcr &= TCR_WP_MASK; /* Clear all bits except for TCR[WP] */
797 tcr |= TCR_DIE; /* Enable decrementer */
798 mtspr(SPRN_TCR, tcr);
799#endif
800}
801
802void __init generic_calibrate_decr(void)
803{
804 ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
805
806 if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&
807 !get_freq("timebase-frequency", 1, &ppc_tb_freq)) {
808
809 printk(KERN_ERR "WARNING: Estimating decrementer frequency "
810 "(not found)\n");
811 }
812
813 ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */
814
815 if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&
816 !get_freq("clock-frequency", 1, &ppc_proc_freq)) {
817
818 printk(KERN_ERR "WARNING: Estimating processor frequency "
819 "(not found)\n");
820 }
821}
822
823int update_persistent_clock64(struct timespec64 now)
824{
825 struct rtc_time tm;
826
827 if (!ppc_md.set_rtc_time)
828 return -ENODEV;
829
830 rtc_time64_to_tm(now.tv_sec + 1 + timezone_offset, &tm);
831
832 return ppc_md.set_rtc_time(&tm);
833}
834
835static void __read_persistent_clock(struct timespec64 *ts)
836{
837 struct rtc_time tm;
838 static int first = 1;
839
840 ts->tv_nsec = 0;
841 /* XXX this is a litle fragile but will work okay in the short term */
842 if (first) {
843 first = 0;
844 if (ppc_md.time_init)
845 timezone_offset = ppc_md.time_init();
846
847 /* get_boot_time() isn't guaranteed to be safe to call late */
848 if (ppc_md.get_boot_time) {
849 ts->tv_sec = ppc_md.get_boot_time() - timezone_offset;
850 return;
851 }
852 }
853 if (!ppc_md.get_rtc_time) {
854 ts->tv_sec = 0;
855 return;
856 }
857 ppc_md.get_rtc_time(&tm);
858
859 ts->tv_sec = rtc_tm_to_time64(&tm);
860}
861
862void read_persistent_clock64(struct timespec64 *ts)
863{
864 __read_persistent_clock(ts);
865
866 /* Sanitize it in case real time clock is set below EPOCH */
867 if (ts->tv_sec < 0) {
868 ts->tv_sec = 0;
869 ts->tv_nsec = 0;
870 }
871
872}
873
874/* clocksource code */
875static notrace u64 rtc_read(struct clocksource *cs)
876{
877 return (u64)get_rtc();
878}
879
880static notrace u64 timebase_read(struct clocksource *cs)
881{
882 return (u64)get_tb();
883}
884
885
886void update_vsyscall(struct timekeeper *tk)
887{
888 struct timespec xt;
889 struct clocksource *clock = tk->tkr_mono.clock;
890 u32 mult = tk->tkr_mono.mult;
891 u32 shift = tk->tkr_mono.shift;
892 u64 cycle_last = tk->tkr_mono.cycle_last;
893 u64 new_tb_to_xs, new_stamp_xsec;
894 u64 frac_sec;
895
896 if (clock != &clocksource_timebase)
897 return;
898
899 xt.tv_sec = tk->xtime_sec;
900 xt.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
901
902 /* Make userspace gettimeofday spin until we're done. */
903 ++vdso_data->tb_update_count;
904 smp_mb();
905
906 /*
907 * This computes ((2^20 / 1e9) * mult) >> shift as a
908 * 0.64 fixed-point fraction.
909 * The computation in the else clause below won't overflow
910 * (as long as the timebase frequency is >= 1.049 MHz)
911 * but loses precision because we lose the low bits of the constant
912 * in the shift. Note that 19342813113834067 ~= 2^(20+64) / 1e9.
913 * For a shift of 24 the error is about 0.5e-9, or about 0.5ns
914 * over a second. (Shift values are usually 22, 23 or 24.)
915 * For high frequency clocks such as the 512MHz timebase clock
916 * on POWER[6789], the mult value is small (e.g. 32768000)
917 * and so we can shift the constant by 16 initially
918 * (295147905179 ~= 2^(20+64-16) / 1e9) and then do the
919 * remaining shifts after the multiplication, which gives a
920 * more accurate result (e.g. with mult = 32768000, shift = 24,
921 * the error is only about 1.2e-12, or 0.7ns over 10 minutes).
922 */
923 if (mult <= 62500000 && clock->shift >= 16)
924 new_tb_to_xs = ((u64) mult * 295147905179ULL) >> (clock->shift - 16);
925 else
926 new_tb_to_xs = (u64) mult * (19342813113834067ULL >> clock->shift);
927
928 /*
929 * Compute the fractional second in units of 2^-32 seconds.
930 * The fractional second is tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift
931 * in nanoseconds, so multiplying that by 2^32 / 1e9 gives
932 * it in units of 2^-32 seconds.
933 * We assume shift <= 32 because clocks_calc_mult_shift()
934 * generates shift values in the range 0 - 32.
935 */
936 frac_sec = tk->tkr_mono.xtime_nsec << (32 - shift);
937 do_div(frac_sec, NSEC_PER_SEC);
938
939 /*
940 * Work out new stamp_xsec value for any legacy users of systemcfg.
941 * stamp_xsec is in units of 2^-20 seconds.
942 */
943 new_stamp_xsec = frac_sec >> 12;
944 new_stamp_xsec += tk->xtime_sec * XSEC_PER_SEC;
945
946 /*
947 * tb_update_count is used to allow the userspace gettimeofday code
948 * to assure itself that it sees a consistent view of the tb_to_xs and
949 * stamp_xsec variables. It reads the tb_update_count, then reads
950 * tb_to_xs and stamp_xsec and then reads tb_update_count again. If
951 * the two values of tb_update_count match and are even then the
952 * tb_to_xs and stamp_xsec values are consistent. If not, then it
953 * loops back and reads them again until this criteria is met.
954 */
955 vdso_data->tb_orig_stamp = cycle_last;
956 vdso_data->stamp_xsec = new_stamp_xsec;
957 vdso_data->tb_to_xs = new_tb_to_xs;
958 vdso_data->wtom_clock_sec = tk->wall_to_monotonic.tv_sec;
959 vdso_data->wtom_clock_nsec = tk->wall_to_monotonic.tv_nsec;
960 vdso_data->stamp_xtime = xt;
961 vdso_data->stamp_sec_fraction = frac_sec;
962 smp_wmb();
963 ++(vdso_data->tb_update_count);
964}
965
966void update_vsyscall_tz(void)
967{
968 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
969 vdso_data->tz_dsttime = sys_tz.tz_dsttime;
970}
971
972static void __init clocksource_init(void)
973{
974 struct clocksource *clock;
975
976 if (__USE_RTC())
977 clock = &clocksource_rtc;
978 else
979 clock = &clocksource_timebase;
980
981 if (clocksource_register_hz(clock, tb_ticks_per_sec)) {
982 printk(KERN_ERR "clocksource: %s is already registered\n",
983 clock->name);
984 return;
985 }
986
987 printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
988 clock->name, clock->mult, clock->shift);
989}
990
991static int decrementer_set_next_event(unsigned long evt,
992 struct clock_event_device *dev)
993{
994 __this_cpu_write(decrementers_next_tb, get_tb_or_rtc() + evt);
995 set_dec(evt);
996
997 /* We may have raced with new irq work */
998 if (test_irq_work_pending())
999 set_dec(1);
1000
1001 return 0;
1002}
1003
1004static int decrementer_shutdown(struct clock_event_device *dev)
1005{
1006 decrementer_set_next_event(decrementer_max, dev);
1007 return 0;
1008}
1009
1010static void register_decrementer_clockevent(int cpu)
1011{
1012 struct clock_event_device *dec = &per_cpu(decrementers, cpu);
1013
1014 *dec = decrementer_clockevent;
1015 dec->cpumask = cpumask_of(cpu);
1016
1017 clockevents_config_and_register(dec, ppc_tb_freq, 2, decrementer_max);
1018
1019 printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
1020 dec->name, dec->mult, dec->shift, cpu);
1021
1022 /* Set values for KVM, see kvm_emulate_dec() */
1023 decrementer_clockevent.mult = dec->mult;
1024 decrementer_clockevent.shift = dec->shift;
1025}
1026
1027static void enable_large_decrementer(void)
1028{
1029 if (!cpu_has_feature(CPU_FTR_ARCH_300))
1030 return;
1031
1032 if (decrementer_max <= DECREMENTER_DEFAULT_MAX)
1033 return;
1034
1035 /*
1036 * If we're running as the hypervisor we need to enable the LD manually
1037 * otherwise firmware should have done it for us.
1038 */
1039 if (cpu_has_feature(CPU_FTR_HVMODE))
1040 mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_LD);
1041}
1042
1043static void __init set_decrementer_max(void)
1044{
1045 struct device_node *cpu;
1046 u32 bits = 32;
1047
1048 /* Prior to ISAv3 the decrementer is always 32 bit */
1049 if (!cpu_has_feature(CPU_FTR_ARCH_300))
1050 return;
1051
1052 cpu = of_find_node_by_type(NULL, "cpu");
1053
1054 if (of_property_read_u32(cpu, "ibm,dec-bits", &bits) == 0) {
1055 if (bits > 64 || bits < 32) {
1056 pr_warn("time_init: firmware supplied invalid ibm,dec-bits");
1057 bits = 32;
1058 }
1059
1060 /* calculate the signed maximum given this many bits */
1061 decrementer_max = (1ul << (bits - 1)) - 1;
1062 }
1063
1064 of_node_put(cpu);
1065
1066 pr_info("time_init: %u bit decrementer (max: %llx)\n",
1067 bits, decrementer_max);
1068}
1069
1070static void __init init_decrementer_clockevent(void)
1071{
1072 register_decrementer_clockevent(smp_processor_id());
1073}
1074
1075void secondary_cpu_time_init(void)
1076{
1077 /* Enable and test the large decrementer for this cpu */
1078 enable_large_decrementer();
1079
1080 /* Start the decrementer on CPUs that have manual control
1081 * such as BookE
1082 */
1083 start_cpu_decrementer();
1084
1085 /* FIME: Should make unrelatred change to move snapshot_timebase
1086 * call here ! */
1087 register_decrementer_clockevent(smp_processor_id());
1088}
1089
1090/* This function is only called on the boot processor */
1091void __init time_init(void)
1092{
1093 struct div_result res;
1094 u64 scale;
1095 unsigned shift;
1096
1097 if (__USE_RTC()) {
1098 /* 601 processor: dec counts down by 128 every 128ns */
1099 ppc_tb_freq = 1000000000;
1100 } else {
1101 /* Normal PowerPC with timebase register */
1102 ppc_md.calibrate_decr();
1103 printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n",
1104 ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
1105 printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n",
1106 ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
1107 }
1108
1109 tb_ticks_per_jiffy = ppc_tb_freq / HZ;
1110 tb_ticks_per_sec = ppc_tb_freq;
1111 tb_ticks_per_usec = ppc_tb_freq / 1000000;
1112 calc_cputime_factors();
1113
1114 /*
1115 * Compute scale factor for sched_clock.
1116 * The calibrate_decr() function has set tb_ticks_per_sec,
1117 * which is the timebase frequency.
1118 * We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
1119 * the 128-bit result as a 64.64 fixed-point number.
1120 * We then shift that number right until it is less than 1.0,
1121 * giving us the scale factor and shift count to use in
1122 * sched_clock().
1123 */
1124 div128_by_32(1000000000, 0, tb_ticks_per_sec, &res);
1125 scale = res.result_low;
1126 for (shift = 0; res.result_high != 0; ++shift) {
1127 scale = (scale >> 1) | (res.result_high << 63);
1128 res.result_high >>= 1;
1129 }
1130 tb_to_ns_scale = scale;
1131 tb_to_ns_shift = shift;
1132 /* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
1133 boot_tb = get_tb_or_rtc();
1134
1135 /* If platform provided a timezone (pmac), we correct the time */
1136 if (timezone_offset) {
1137 sys_tz.tz_minuteswest = -timezone_offset / 60;
1138 sys_tz.tz_dsttime = 0;
1139 }
1140
1141 vdso_data->tb_update_count = 0;
1142 vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
1143
1144 /* initialise and enable the large decrementer (if we have one) */
1145 set_decrementer_max();
1146 enable_large_decrementer();
1147
1148 /* Start the decrementer on CPUs that have manual control
1149 * such as BookE
1150 */
1151 start_cpu_decrementer();
1152
1153 /* Register the clocksource */
1154 clocksource_init();
1155
1156 init_decrementer_clockevent();
1157 tick_setup_hrtimer_broadcast();
1158
1159#ifdef CONFIG_COMMON_CLK
1160 of_clk_init(NULL);
1161#endif
1162}
1163
1164/*
1165 * Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
1166 * result.
1167 */
1168void div128_by_32(u64 dividend_high, u64 dividend_low,
1169 unsigned divisor, struct div_result *dr)
1170{
1171 unsigned long a, b, c, d;
1172 unsigned long w, x, y, z;
1173 u64 ra, rb, rc;
1174
1175 a = dividend_high >> 32;
1176 b = dividend_high & 0xffffffff;
1177 c = dividend_low >> 32;
1178 d = dividend_low & 0xffffffff;
1179
1180 w = a / divisor;
1181 ra = ((u64)(a - (w * divisor)) << 32) + b;
1182
1183 rb = ((u64) do_div(ra, divisor) << 32) + c;
1184 x = ra;
1185
1186 rc = ((u64) do_div(rb, divisor) << 32) + d;
1187 y = rb;
1188
1189 do_div(rc, divisor);
1190 z = rc;
1191
1192 dr->result_high = ((u64)w << 32) + x;
1193 dr->result_low = ((u64)y << 32) + z;
1194
1195}
1196
1197/* We don't need to calibrate delay, we use the CPU timebase for that */
1198void calibrate_delay(void)
1199{
1200 /* Some generic code (such as spinlock debug) use loops_per_jiffy
1201 * as the number of __delay(1) in a jiffy, so make it so
1202 */
1203 loops_per_jiffy = tb_ticks_per_jiffy;
1204}
1205
1206#if IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
1207static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
1208{
1209 ppc_md.get_rtc_time(tm);
1210 return 0;
1211}
1212
1213static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm)
1214{
1215 if (!ppc_md.set_rtc_time)
1216 return -EOPNOTSUPP;
1217
1218 if (ppc_md.set_rtc_time(tm) < 0)
1219 return -EOPNOTSUPP;
1220
1221 return 0;
1222}
1223
1224static const struct rtc_class_ops rtc_generic_ops = {
1225 .read_time = rtc_generic_get_time,
1226 .set_time = rtc_generic_set_time,
1227};
1228
1229static int __init rtc_init(void)
1230{
1231 struct platform_device *pdev;
1232
1233 if (!ppc_md.get_rtc_time)
1234 return -ENODEV;
1235
1236 pdev = platform_device_register_data(NULL, "rtc-generic", -1,
1237 &rtc_generic_ops,
1238 sizeof(rtc_generic_ops));
1239
1240 return PTR_ERR_OR_ZERO(pdev);
1241}
1242
1243device_initcall(rtc_init);
1244#endif