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