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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Time of day based timer functions.
4 *
5 * S390 version
6 * Copyright IBM Corp. 1999, 2008
7 * Author(s): Hartmut Penner (hp@de.ibm.com),
8 * Martin Schwidefsky (schwidefsky@de.ibm.com),
9 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
10 *
11 * Derived from "arch/i386/kernel/time.c"
12 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
13 */
14
15#define KMSG_COMPONENT "time"
16#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
17
18#include <linux/kernel_stat.h>
19#include <linux/errno.h>
20#include <linux/export.h>
21#include <linux/sched.h>
22#include <linux/sched/clock.h>
23#include <linux/kernel.h>
24#include <linux/param.h>
25#include <linux/string.h>
26#include <linux/mm.h>
27#include <linux/interrupt.h>
28#include <linux/cpu.h>
29#include <linux/stop_machine.h>
30#include <linux/time.h>
31#include <linux/device.h>
32#include <linux/delay.h>
33#include <linux/init.h>
34#include <linux/smp.h>
35#include <linux/types.h>
36#include <linux/profile.h>
37#include <linux/timex.h>
38#include <linux/notifier.h>
39#include <linux/timekeeper_internal.h>
40#include <linux/clockchips.h>
41#include <linux/gfp.h>
42#include <linux/kprobes.h>
43#include <linux/uaccess.h>
44#include <vdso/vsyscall.h>
45#include <vdso/clocksource.h>
46#include <vdso/helpers.h>
47#include <asm/facility.h>
48#include <asm/delay.h>
49#include <asm/div64.h>
50#include <asm/vdso.h>
51#include <asm/irq.h>
52#include <asm/irq_regs.h>
53#include <asm/vtimer.h>
54#include <asm/stp.h>
55#include <asm/cio.h>
56#include "entry.h"
57
58union tod_clock tod_clock_base __section(".data");
59EXPORT_SYMBOL_GPL(tod_clock_base);
60
61u64 clock_comparator_max = -1ULL;
62EXPORT_SYMBOL_GPL(clock_comparator_max);
63
64static DEFINE_PER_CPU(struct clock_event_device, comparators);
65
66ATOMIC_NOTIFIER_HEAD(s390_epoch_delta_notifier);
67EXPORT_SYMBOL(s390_epoch_delta_notifier);
68
69unsigned char ptff_function_mask[16];
70
71static unsigned long lpar_offset;
72static unsigned long initial_leap_seconds;
73static unsigned long tod_steering_end;
74static long tod_steering_delta;
75
76/*
77 * Get time offsets with PTFF
78 */
79void __init time_early_init(void)
80{
81 struct ptff_qto qto;
82 struct ptff_qui qui;
83 int cs;
84
85 /* Initialize TOD steering parameters */
86 tod_steering_end = tod_clock_base.tod;
87 for (cs = 0; cs < CS_BASES; cs++)
88 vdso_data[cs].arch_data.tod_steering_end = tod_steering_end;
89
90 if (!test_facility(28))
91 return;
92
93 ptff(&ptff_function_mask, sizeof(ptff_function_mask), PTFF_QAF);
94
95 /* get LPAR offset */
96 if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0)
97 lpar_offset = qto.tod_epoch_difference;
98
99 /* get initial leap seconds */
100 if (ptff_query(PTFF_QUI) && ptff(&qui, sizeof(qui), PTFF_QUI) == 0)
101 initial_leap_seconds = (unsigned long)
102 ((long) qui.old_leap * 4096000000L);
103}
104
105unsigned long long noinstr sched_clock_noinstr(void)
106{
107 return tod_to_ns(__get_tod_clock_monotonic());
108}
109
110/*
111 * Scheduler clock - returns current time in nanosec units.
112 */
113unsigned long long notrace sched_clock(void)
114{
115 return tod_to_ns(get_tod_clock_monotonic());
116}
117NOKPROBE_SYMBOL(sched_clock);
118
119static void ext_to_timespec64(union tod_clock *clk, struct timespec64 *xt)
120{
121 unsigned long rem, sec, nsec;
122
123 sec = clk->us;
124 rem = do_div(sec, 1000000);
125 nsec = ((clk->sus + (rem << 12)) * 125) >> 9;
126 xt->tv_sec = sec;
127 xt->tv_nsec = nsec;
128}
129
130void clock_comparator_work(void)
131{
132 struct clock_event_device *cd;
133
134 S390_lowcore.clock_comparator = clock_comparator_max;
135 cd = this_cpu_ptr(&comparators);
136 cd->event_handler(cd);
137}
138
139static int s390_next_event(unsigned long delta,
140 struct clock_event_device *evt)
141{
142 S390_lowcore.clock_comparator = get_tod_clock() + delta;
143 set_clock_comparator(S390_lowcore.clock_comparator);
144 return 0;
145}
146
147/*
148 * Set up lowcore and control register of the current cpu to
149 * enable TOD clock and clock comparator interrupts.
150 */
151void init_cpu_timer(void)
152{
153 struct clock_event_device *cd;
154 int cpu;
155
156 S390_lowcore.clock_comparator = clock_comparator_max;
157 set_clock_comparator(S390_lowcore.clock_comparator);
158
159 cpu = smp_processor_id();
160 cd = &per_cpu(comparators, cpu);
161 cd->name = "comparator";
162 cd->features = CLOCK_EVT_FEAT_ONESHOT;
163 cd->mult = 16777;
164 cd->shift = 12;
165 cd->min_delta_ns = 1;
166 cd->min_delta_ticks = 1;
167 cd->max_delta_ns = LONG_MAX;
168 cd->max_delta_ticks = ULONG_MAX;
169 cd->rating = 400;
170 cd->cpumask = cpumask_of(cpu);
171 cd->set_next_event = s390_next_event;
172
173 clockevents_register_device(cd);
174
175 /* Enable clock comparator timer interrupt. */
176 local_ctl_set_bit(0, CR0_CLOCK_COMPARATOR_SUBMASK_BIT);
177
178 /* Always allow the timing alert external interrupt. */
179 local_ctl_set_bit(0, CR0_ETR_SUBMASK_BIT);
180}
181
182static void clock_comparator_interrupt(struct ext_code ext_code,
183 unsigned int param32,
184 unsigned long param64)
185{
186 inc_irq_stat(IRQEXT_CLK);
187 if (S390_lowcore.clock_comparator == clock_comparator_max)
188 set_clock_comparator(S390_lowcore.clock_comparator);
189}
190
191static void stp_timing_alert(struct stp_irq_parm *);
192
193static void timing_alert_interrupt(struct ext_code ext_code,
194 unsigned int param32, unsigned long param64)
195{
196 inc_irq_stat(IRQEXT_TLA);
197 if (param32 & 0x00038000)
198 stp_timing_alert((struct stp_irq_parm *) ¶m32);
199}
200
201static void stp_reset(void);
202
203void read_persistent_clock64(struct timespec64 *ts)
204{
205 union tod_clock clk;
206 u64 delta;
207
208 delta = initial_leap_seconds + TOD_UNIX_EPOCH;
209 store_tod_clock_ext(&clk);
210 clk.eitod -= delta;
211 ext_to_timespec64(&clk, ts);
212}
213
214void __init read_persistent_wall_and_boot_offset(struct timespec64 *wall_time,
215 struct timespec64 *boot_offset)
216{
217 struct timespec64 boot_time;
218 union tod_clock clk;
219 u64 delta;
220
221 delta = initial_leap_seconds + TOD_UNIX_EPOCH;
222 clk = tod_clock_base;
223 clk.eitod -= delta;
224 ext_to_timespec64(&clk, &boot_time);
225
226 read_persistent_clock64(wall_time);
227 *boot_offset = timespec64_sub(*wall_time, boot_time);
228}
229
230static u64 read_tod_clock(struct clocksource *cs)
231{
232 unsigned long now, adj;
233
234 preempt_disable(); /* protect from changes to steering parameters */
235 now = get_tod_clock();
236 adj = tod_steering_end - now;
237 if (unlikely((s64) adj > 0))
238 /*
239 * manually steer by 1 cycle every 2^16 cycles. This
240 * corresponds to shifting the tod delta by 15. 1s is
241 * therefore steered in ~9h. The adjust will decrease
242 * over time, until it finally reaches 0.
243 */
244 now += (tod_steering_delta < 0) ? (adj >> 15) : -(adj >> 15);
245 preempt_enable();
246 return now;
247}
248
249static struct clocksource clocksource_tod = {
250 .name = "tod",
251 .rating = 400,
252 .read = read_tod_clock,
253 .mask = CLOCKSOURCE_MASK(64),
254 .mult = 1000,
255 .shift = 12,
256 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
257 .vdso_clock_mode = VDSO_CLOCKMODE_TOD,
258};
259
260struct clocksource * __init clocksource_default_clock(void)
261{
262 return &clocksource_tod;
263}
264
265/*
266 * Initialize the TOD clock and the CPU timer of
267 * the boot cpu.
268 */
269void __init time_init(void)
270{
271 /* Reset time synchronization interfaces. */
272 stp_reset();
273
274 /* request the clock comparator external interrupt */
275 if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt))
276 panic("Couldn't request external interrupt 0x1004");
277
278 /* request the timing alert external interrupt */
279 if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt))
280 panic("Couldn't request external interrupt 0x1406");
281
282 if (__clocksource_register(&clocksource_tod) != 0)
283 panic("Could not register TOD clock source");
284
285 /* Enable TOD clock interrupts on the boot cpu. */
286 init_cpu_timer();
287
288 /* Enable cpu timer interrupts on the boot cpu. */
289 vtime_init();
290}
291
292static DEFINE_PER_CPU(atomic_t, clock_sync_word);
293static DEFINE_MUTEX(stp_mutex);
294static unsigned long clock_sync_flags;
295
296#define CLOCK_SYNC_HAS_STP 0
297#define CLOCK_SYNC_STP 1
298#define CLOCK_SYNC_STPINFO_VALID 2
299
300/*
301 * The get_clock function for the physical clock. It will get the current
302 * TOD clock, subtract the LPAR offset and write the result to *clock.
303 * The function returns 0 if the clock is in sync with the external time
304 * source. If the clock mode is local it will return -EOPNOTSUPP and
305 * -EAGAIN if the clock is not in sync with the external reference.
306 */
307int get_phys_clock(unsigned long *clock)
308{
309 atomic_t *sw_ptr;
310 unsigned int sw0, sw1;
311
312 sw_ptr = &get_cpu_var(clock_sync_word);
313 sw0 = atomic_read(sw_ptr);
314 *clock = get_tod_clock() - lpar_offset;
315 sw1 = atomic_read(sw_ptr);
316 put_cpu_var(clock_sync_word);
317 if (sw0 == sw1 && (sw0 & 0x80000000U))
318 /* Success: time is in sync. */
319 return 0;
320 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
321 return -EOPNOTSUPP;
322 if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags))
323 return -EACCES;
324 return -EAGAIN;
325}
326EXPORT_SYMBOL(get_phys_clock);
327
328/*
329 * Make get_phys_clock() return -EAGAIN.
330 */
331static void disable_sync_clock(void *dummy)
332{
333 atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
334 /*
335 * Clear the in-sync bit 2^31. All get_phys_clock calls will
336 * fail until the sync bit is turned back on. In addition
337 * increase the "sequence" counter to avoid the race of an
338 * stp event and the complete recovery against get_phys_clock.
339 */
340 atomic_andnot(0x80000000, sw_ptr);
341 atomic_inc(sw_ptr);
342}
343
344/*
345 * Make get_phys_clock() return 0 again.
346 * Needs to be called from a context disabled for preemption.
347 */
348static void enable_sync_clock(void)
349{
350 atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
351 atomic_or(0x80000000, sw_ptr);
352}
353
354/*
355 * Function to check if the clock is in sync.
356 */
357static inline int check_sync_clock(void)
358{
359 atomic_t *sw_ptr;
360 int rc;
361
362 sw_ptr = &get_cpu_var(clock_sync_word);
363 rc = (atomic_read(sw_ptr) & 0x80000000U) != 0;
364 put_cpu_var(clock_sync_word);
365 return rc;
366}
367
368/*
369 * Apply clock delta to the global data structures.
370 * This is called once on the CPU that performed the clock sync.
371 */
372static void clock_sync_global(long delta)
373{
374 unsigned long now, adj;
375 struct ptff_qto qto;
376 int cs;
377
378 /* Fixup the monotonic sched clock. */
379 tod_clock_base.eitod += delta;
380 /* Adjust TOD steering parameters. */
381 now = get_tod_clock();
382 adj = tod_steering_end - now;
383 if (unlikely((s64) adj >= 0))
384 /* Calculate how much of the old adjustment is left. */
385 tod_steering_delta = (tod_steering_delta < 0) ?
386 -(adj >> 15) : (adj >> 15);
387 tod_steering_delta += delta;
388 if ((abs(tod_steering_delta) >> 48) != 0)
389 panic("TOD clock sync offset %li is too large to drift\n",
390 tod_steering_delta);
391 tod_steering_end = now + (abs(tod_steering_delta) << 15);
392 for (cs = 0; cs < CS_BASES; cs++) {
393 vdso_data[cs].arch_data.tod_steering_end = tod_steering_end;
394 vdso_data[cs].arch_data.tod_steering_delta = tod_steering_delta;
395 }
396
397 /* Update LPAR offset. */
398 if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0)
399 lpar_offset = qto.tod_epoch_difference;
400 /* Call the TOD clock change notifier. */
401 atomic_notifier_call_chain(&s390_epoch_delta_notifier, 0, &delta);
402}
403
404/*
405 * Apply clock delta to the per-CPU data structures of this CPU.
406 * This is called for each online CPU after the call to clock_sync_global.
407 */
408static void clock_sync_local(long delta)
409{
410 /* Add the delta to the clock comparator. */
411 if (S390_lowcore.clock_comparator != clock_comparator_max) {
412 S390_lowcore.clock_comparator += delta;
413 set_clock_comparator(S390_lowcore.clock_comparator);
414 }
415 /* Adjust the last_update_clock time-stamp. */
416 S390_lowcore.last_update_clock += delta;
417}
418
419/* Single threaded workqueue used for stp sync events */
420static struct workqueue_struct *time_sync_wq;
421
422static void __init time_init_wq(void)
423{
424 if (time_sync_wq)
425 return;
426 time_sync_wq = create_singlethread_workqueue("timesync");
427}
428
429struct clock_sync_data {
430 atomic_t cpus;
431 int in_sync;
432 long clock_delta;
433};
434
435/*
436 * Server Time Protocol (STP) code.
437 */
438static bool stp_online;
439static struct stp_sstpi stp_info;
440static void *stp_page;
441
442static void stp_work_fn(struct work_struct *work);
443static DECLARE_WORK(stp_work, stp_work_fn);
444static struct timer_list stp_timer;
445
446static int __init early_parse_stp(char *p)
447{
448 return kstrtobool(p, &stp_online);
449}
450early_param("stp", early_parse_stp);
451
452/*
453 * Reset STP attachment.
454 */
455static void __init stp_reset(void)
456{
457 int rc;
458
459 stp_page = (void *) get_zeroed_page(GFP_ATOMIC);
460 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);
461 if (rc == 0)
462 set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags);
463 else if (stp_online) {
464 pr_warn("The real or virtual hardware system does not provide an STP interface\n");
465 free_page((unsigned long) stp_page);
466 stp_page = NULL;
467 stp_online = false;
468 }
469}
470
471static void stp_timeout(struct timer_list *unused)
472{
473 queue_work(time_sync_wq, &stp_work);
474}
475
476static int __init stp_init(void)
477{
478 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
479 return 0;
480 timer_setup(&stp_timer, stp_timeout, 0);
481 time_init_wq();
482 if (!stp_online)
483 return 0;
484 queue_work(time_sync_wq, &stp_work);
485 return 0;
486}
487
488arch_initcall(stp_init);
489
490/*
491 * STP timing alert. There are three causes:
492 * 1) timing status change
493 * 2) link availability change
494 * 3) time control parameter change
495 * In all three cases we are only interested in the clock source state.
496 * If a STP clock source is now available use it.
497 */
498static void stp_timing_alert(struct stp_irq_parm *intparm)
499{
500 if (intparm->tsc || intparm->lac || intparm->tcpc)
501 queue_work(time_sync_wq, &stp_work);
502}
503
504/*
505 * STP sync check machine check. This is called when the timing state
506 * changes from the synchronized state to the unsynchronized state.
507 * After a STP sync check the clock is not in sync. The machine check
508 * is broadcasted to all cpus at the same time.
509 */
510int stp_sync_check(void)
511{
512 disable_sync_clock(NULL);
513 return 1;
514}
515
516/*
517 * STP island condition machine check. This is called when an attached
518 * server attempts to communicate over an STP link and the servers
519 * have matching CTN ids and have a valid stratum-1 configuration
520 * but the configurations do not match.
521 */
522int stp_island_check(void)
523{
524 disable_sync_clock(NULL);
525 return 1;
526}
527
528void stp_queue_work(void)
529{
530 queue_work(time_sync_wq, &stp_work);
531}
532
533static int __store_stpinfo(void)
534{
535 int rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi));
536
537 if (rc)
538 clear_bit(CLOCK_SYNC_STPINFO_VALID, &clock_sync_flags);
539 else
540 set_bit(CLOCK_SYNC_STPINFO_VALID, &clock_sync_flags);
541 return rc;
542}
543
544static int stpinfo_valid(void)
545{
546 return stp_online && test_bit(CLOCK_SYNC_STPINFO_VALID, &clock_sync_flags);
547}
548
549static int stp_sync_clock(void *data)
550{
551 struct clock_sync_data *sync = data;
552 long clock_delta, flags;
553 static int first;
554 int rc;
555
556 enable_sync_clock();
557 if (xchg(&first, 1) == 0) {
558 /* Wait until all other cpus entered the sync function. */
559 while (atomic_read(&sync->cpus) != 0)
560 cpu_relax();
561 rc = 0;
562 if (stp_info.todoff || stp_info.tmd != 2) {
563 flags = vdso_update_begin();
564 rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0,
565 &clock_delta);
566 if (rc == 0) {
567 sync->clock_delta = clock_delta;
568 clock_sync_global(clock_delta);
569 rc = __store_stpinfo();
570 if (rc == 0 && stp_info.tmd != 2)
571 rc = -EAGAIN;
572 }
573 vdso_update_end(flags);
574 }
575 sync->in_sync = rc ? -EAGAIN : 1;
576 xchg(&first, 0);
577 } else {
578 /* Slave */
579 atomic_dec(&sync->cpus);
580 /* Wait for in_sync to be set. */
581 while (READ_ONCE(sync->in_sync) == 0)
582 __udelay(1);
583 }
584 if (sync->in_sync != 1)
585 /* Didn't work. Clear per-cpu in sync bit again. */
586 disable_sync_clock(NULL);
587 /* Apply clock delta to per-CPU fields of this CPU. */
588 clock_sync_local(sync->clock_delta);
589
590 return 0;
591}
592
593static int stp_clear_leap(void)
594{
595 struct __kernel_timex txc;
596 int ret;
597
598 memset(&txc, 0, sizeof(txc));
599
600 ret = do_adjtimex(&txc);
601 if (ret < 0)
602 return ret;
603
604 txc.modes = ADJ_STATUS;
605 txc.status &= ~(STA_INS|STA_DEL);
606 return do_adjtimex(&txc);
607}
608
609static void stp_check_leap(void)
610{
611 struct stp_stzi stzi;
612 struct stp_lsoib *lsoib = &stzi.lsoib;
613 struct __kernel_timex txc;
614 int64_t timediff;
615 int leapdiff, ret;
616
617 if (!stp_info.lu || !check_sync_clock()) {
618 /*
619 * Either a scheduled leap second was removed by the operator,
620 * or STP is out of sync. In both cases, clear the leap second
621 * kernel flags.
622 */
623 if (stp_clear_leap() < 0)
624 pr_err("failed to clear leap second flags\n");
625 return;
626 }
627
628 if (chsc_stzi(stp_page, &stzi, sizeof(stzi))) {
629 pr_err("stzi failed\n");
630 return;
631 }
632
633 timediff = tod_to_ns(lsoib->nlsout - get_tod_clock()) / NSEC_PER_SEC;
634 leapdiff = lsoib->nlso - lsoib->also;
635
636 if (leapdiff != 1 && leapdiff != -1) {
637 pr_err("Cannot schedule %d leap seconds\n", leapdiff);
638 return;
639 }
640
641 if (timediff < 0) {
642 if (stp_clear_leap() < 0)
643 pr_err("failed to clear leap second flags\n");
644 } else if (timediff < 7200) {
645 memset(&txc, 0, sizeof(txc));
646 ret = do_adjtimex(&txc);
647 if (ret < 0)
648 return;
649
650 txc.modes = ADJ_STATUS;
651 if (leapdiff > 0)
652 txc.status |= STA_INS;
653 else
654 txc.status |= STA_DEL;
655 ret = do_adjtimex(&txc);
656 if (ret < 0)
657 pr_err("failed to set leap second flags\n");
658 /* arm Timer to clear leap second flags */
659 mod_timer(&stp_timer, jiffies + msecs_to_jiffies(14400 * MSEC_PER_SEC));
660 } else {
661 /* The day the leap second is scheduled for hasn't been reached. Retry
662 * in one hour.
663 */
664 mod_timer(&stp_timer, jiffies + msecs_to_jiffies(3600 * MSEC_PER_SEC));
665 }
666}
667
668/*
669 * STP work. Check for the STP state and take over the clock
670 * synchronization if the STP clock source is usable.
671 */
672static void stp_work_fn(struct work_struct *work)
673{
674 struct clock_sync_data stp_sync;
675 int rc;
676
677 /* prevent multiple execution. */
678 mutex_lock(&stp_mutex);
679
680 if (!stp_online) {
681 chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);
682 del_timer_sync(&stp_timer);
683 goto out_unlock;
684 }
685
686 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xf0e0, NULL);
687 if (rc)
688 goto out_unlock;
689
690 rc = __store_stpinfo();
691 if (rc || stp_info.c == 0)
692 goto out_unlock;
693
694 /* Skip synchronization if the clock is already in sync. */
695 if (!check_sync_clock()) {
696 memset(&stp_sync, 0, sizeof(stp_sync));
697 cpus_read_lock();
698 atomic_set(&stp_sync.cpus, num_online_cpus() - 1);
699 stop_machine_cpuslocked(stp_sync_clock, &stp_sync, cpu_online_mask);
700 cpus_read_unlock();
701 }
702
703 if (!check_sync_clock())
704 /*
705 * There is a usable clock but the synchronization failed.
706 * Retry after a second.
707 */
708 mod_timer(&stp_timer, jiffies + msecs_to_jiffies(MSEC_PER_SEC));
709 else if (stp_info.lu)
710 stp_check_leap();
711
712out_unlock:
713 mutex_unlock(&stp_mutex);
714}
715
716/*
717 * STP subsys sysfs interface functions
718 */
719static struct bus_type stp_subsys = {
720 .name = "stp",
721 .dev_name = "stp",
722};
723
724static ssize_t ctn_id_show(struct device *dev,
725 struct device_attribute *attr,
726 char *buf)
727{
728 ssize_t ret = -ENODATA;
729
730 mutex_lock(&stp_mutex);
731 if (stpinfo_valid())
732 ret = sprintf(buf, "%016lx\n",
733 *(unsigned long *) stp_info.ctnid);
734 mutex_unlock(&stp_mutex);
735 return ret;
736}
737
738static DEVICE_ATTR_RO(ctn_id);
739
740static ssize_t ctn_type_show(struct device *dev,
741 struct device_attribute *attr,
742 char *buf)
743{
744 ssize_t ret = -ENODATA;
745
746 mutex_lock(&stp_mutex);
747 if (stpinfo_valid())
748 ret = sprintf(buf, "%i\n", stp_info.ctn);
749 mutex_unlock(&stp_mutex);
750 return ret;
751}
752
753static DEVICE_ATTR_RO(ctn_type);
754
755static ssize_t dst_offset_show(struct device *dev,
756 struct device_attribute *attr,
757 char *buf)
758{
759 ssize_t ret = -ENODATA;
760
761 mutex_lock(&stp_mutex);
762 if (stpinfo_valid() && (stp_info.vbits & 0x2000))
763 ret = sprintf(buf, "%i\n", (int)(s16) stp_info.dsto);
764 mutex_unlock(&stp_mutex);
765 return ret;
766}
767
768static DEVICE_ATTR_RO(dst_offset);
769
770static ssize_t leap_seconds_show(struct device *dev,
771 struct device_attribute *attr,
772 char *buf)
773{
774 ssize_t ret = -ENODATA;
775
776 mutex_lock(&stp_mutex);
777 if (stpinfo_valid() && (stp_info.vbits & 0x8000))
778 ret = sprintf(buf, "%i\n", (int)(s16) stp_info.leaps);
779 mutex_unlock(&stp_mutex);
780 return ret;
781}
782
783static DEVICE_ATTR_RO(leap_seconds);
784
785static ssize_t leap_seconds_scheduled_show(struct device *dev,
786 struct device_attribute *attr,
787 char *buf)
788{
789 struct stp_stzi stzi;
790 ssize_t ret;
791
792 mutex_lock(&stp_mutex);
793 if (!stpinfo_valid() || !(stp_info.vbits & 0x8000) || !stp_info.lu) {
794 mutex_unlock(&stp_mutex);
795 return -ENODATA;
796 }
797
798 ret = chsc_stzi(stp_page, &stzi, sizeof(stzi));
799 mutex_unlock(&stp_mutex);
800 if (ret < 0)
801 return ret;
802
803 if (!stzi.lsoib.p)
804 return sprintf(buf, "0,0\n");
805
806 return sprintf(buf, "%lu,%d\n",
807 tod_to_ns(stzi.lsoib.nlsout - TOD_UNIX_EPOCH) / NSEC_PER_SEC,
808 stzi.lsoib.nlso - stzi.lsoib.also);
809}
810
811static DEVICE_ATTR_RO(leap_seconds_scheduled);
812
813static ssize_t stratum_show(struct device *dev,
814 struct device_attribute *attr,
815 char *buf)
816{
817 ssize_t ret = -ENODATA;
818
819 mutex_lock(&stp_mutex);
820 if (stpinfo_valid())
821 ret = sprintf(buf, "%i\n", (int)(s16) stp_info.stratum);
822 mutex_unlock(&stp_mutex);
823 return ret;
824}
825
826static DEVICE_ATTR_RO(stratum);
827
828static ssize_t time_offset_show(struct device *dev,
829 struct device_attribute *attr,
830 char *buf)
831{
832 ssize_t ret = -ENODATA;
833
834 mutex_lock(&stp_mutex);
835 if (stpinfo_valid() && (stp_info.vbits & 0x0800))
836 ret = sprintf(buf, "%i\n", (int) stp_info.tto);
837 mutex_unlock(&stp_mutex);
838 return ret;
839}
840
841static DEVICE_ATTR_RO(time_offset);
842
843static ssize_t time_zone_offset_show(struct device *dev,
844 struct device_attribute *attr,
845 char *buf)
846{
847 ssize_t ret = -ENODATA;
848
849 mutex_lock(&stp_mutex);
850 if (stpinfo_valid() && (stp_info.vbits & 0x4000))
851 ret = sprintf(buf, "%i\n", (int)(s16) stp_info.tzo);
852 mutex_unlock(&stp_mutex);
853 return ret;
854}
855
856static DEVICE_ATTR_RO(time_zone_offset);
857
858static ssize_t timing_mode_show(struct device *dev,
859 struct device_attribute *attr,
860 char *buf)
861{
862 ssize_t ret = -ENODATA;
863
864 mutex_lock(&stp_mutex);
865 if (stpinfo_valid())
866 ret = sprintf(buf, "%i\n", stp_info.tmd);
867 mutex_unlock(&stp_mutex);
868 return ret;
869}
870
871static DEVICE_ATTR_RO(timing_mode);
872
873static ssize_t timing_state_show(struct device *dev,
874 struct device_attribute *attr,
875 char *buf)
876{
877 ssize_t ret = -ENODATA;
878
879 mutex_lock(&stp_mutex);
880 if (stpinfo_valid())
881 ret = sprintf(buf, "%i\n", stp_info.tst);
882 mutex_unlock(&stp_mutex);
883 return ret;
884}
885
886static DEVICE_ATTR_RO(timing_state);
887
888static ssize_t online_show(struct device *dev,
889 struct device_attribute *attr,
890 char *buf)
891{
892 return sprintf(buf, "%i\n", stp_online);
893}
894
895static ssize_t online_store(struct device *dev,
896 struct device_attribute *attr,
897 const char *buf, size_t count)
898{
899 unsigned int value;
900
901 value = simple_strtoul(buf, NULL, 0);
902 if (value != 0 && value != 1)
903 return -EINVAL;
904 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
905 return -EOPNOTSUPP;
906 mutex_lock(&stp_mutex);
907 stp_online = value;
908 if (stp_online)
909 set_bit(CLOCK_SYNC_STP, &clock_sync_flags);
910 else
911 clear_bit(CLOCK_SYNC_STP, &clock_sync_flags);
912 queue_work(time_sync_wq, &stp_work);
913 mutex_unlock(&stp_mutex);
914 return count;
915}
916
917/*
918 * Can't use DEVICE_ATTR because the attribute should be named
919 * stp/online but dev_attr_online already exists in this file ..
920 */
921static DEVICE_ATTR_RW(online);
922
923static struct attribute *stp_dev_attrs[] = {
924 &dev_attr_ctn_id.attr,
925 &dev_attr_ctn_type.attr,
926 &dev_attr_dst_offset.attr,
927 &dev_attr_leap_seconds.attr,
928 &dev_attr_online.attr,
929 &dev_attr_leap_seconds_scheduled.attr,
930 &dev_attr_stratum.attr,
931 &dev_attr_time_offset.attr,
932 &dev_attr_time_zone_offset.attr,
933 &dev_attr_timing_mode.attr,
934 &dev_attr_timing_state.attr,
935 NULL
936};
937ATTRIBUTE_GROUPS(stp_dev);
938
939static int __init stp_init_sysfs(void)
940{
941 return subsys_system_register(&stp_subsys, stp_dev_groups);
942}
943
944device_initcall(stp_init_sysfs);
1/*
2 * arch/s390/kernel/time.c
3 * Time of day based timer functions.
4 *
5 * S390 version
6 * Copyright IBM Corp. 1999, 2008
7 * Author(s): Hartmut Penner (hp@de.ibm.com),
8 * Martin Schwidefsky (schwidefsky@de.ibm.com),
9 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
10 *
11 * Derived from "arch/i386/kernel/time.c"
12 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
13 */
14
15#define KMSG_COMPONENT "time"
16#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
17
18#include <linux/kernel_stat.h>
19#include <linux/errno.h>
20#include <linux/module.h>
21#include <linux/sched.h>
22#include <linux/kernel.h>
23#include <linux/param.h>
24#include <linux/string.h>
25#include <linux/mm.h>
26#include <linux/interrupt.h>
27#include <linux/cpu.h>
28#include <linux/stop_machine.h>
29#include <linux/time.h>
30#include <linux/sysdev.h>
31#include <linux/delay.h>
32#include <linux/init.h>
33#include <linux/smp.h>
34#include <linux/types.h>
35#include <linux/profile.h>
36#include <linux/timex.h>
37#include <linux/notifier.h>
38#include <linux/clocksource.h>
39#include <linux/clockchips.h>
40#include <linux/gfp.h>
41#include <linux/kprobes.h>
42#include <asm/uaccess.h>
43#include <asm/delay.h>
44#include <asm/div64.h>
45#include <asm/vdso.h>
46#include <asm/irq.h>
47#include <asm/irq_regs.h>
48#include <asm/timer.h>
49#include <asm/etr.h>
50#include <asm/cio.h>
51
52/* change this if you have some constant time drift */
53#define USECS_PER_JIFFY ((unsigned long) 1000000/HZ)
54#define CLK_TICKS_PER_JIFFY ((unsigned long) USECS_PER_JIFFY << 12)
55
56u64 sched_clock_base_cc = -1; /* Force to data section. */
57EXPORT_SYMBOL_GPL(sched_clock_base_cc);
58
59static DEFINE_PER_CPU(struct clock_event_device, comparators);
60
61/*
62 * Scheduler clock - returns current time in nanosec units.
63 */
64unsigned long long notrace __kprobes sched_clock(void)
65{
66 return (get_clock_monotonic() * 125) >> 9;
67}
68
69/*
70 * Monotonic_clock - returns # of nanoseconds passed since time_init()
71 */
72unsigned long long monotonic_clock(void)
73{
74 return sched_clock();
75}
76EXPORT_SYMBOL(monotonic_clock);
77
78void tod_to_timeval(__u64 todval, struct timespec *xt)
79{
80 unsigned long long sec;
81
82 sec = todval >> 12;
83 do_div(sec, 1000000);
84 xt->tv_sec = sec;
85 todval -= (sec * 1000000) << 12;
86 xt->tv_nsec = ((todval * 1000) >> 12);
87}
88EXPORT_SYMBOL(tod_to_timeval);
89
90void clock_comparator_work(void)
91{
92 struct clock_event_device *cd;
93
94 S390_lowcore.clock_comparator = -1ULL;
95 set_clock_comparator(S390_lowcore.clock_comparator);
96 cd = &__get_cpu_var(comparators);
97 cd->event_handler(cd);
98}
99
100/*
101 * Fixup the clock comparator.
102 */
103static void fixup_clock_comparator(unsigned long long delta)
104{
105 /* If nobody is waiting there's nothing to fix. */
106 if (S390_lowcore.clock_comparator == -1ULL)
107 return;
108 S390_lowcore.clock_comparator += delta;
109 set_clock_comparator(S390_lowcore.clock_comparator);
110}
111
112static int s390_next_event(unsigned long delta,
113 struct clock_event_device *evt)
114{
115 S390_lowcore.clock_comparator = get_clock() + delta;
116 set_clock_comparator(S390_lowcore.clock_comparator);
117 return 0;
118}
119
120static void s390_set_mode(enum clock_event_mode mode,
121 struct clock_event_device *evt)
122{
123}
124
125/*
126 * Set up lowcore and control register of the current cpu to
127 * enable TOD clock and clock comparator interrupts.
128 */
129void init_cpu_timer(void)
130{
131 struct clock_event_device *cd;
132 int cpu;
133
134 S390_lowcore.clock_comparator = -1ULL;
135 set_clock_comparator(S390_lowcore.clock_comparator);
136
137 cpu = smp_processor_id();
138 cd = &per_cpu(comparators, cpu);
139 cd->name = "comparator";
140 cd->features = CLOCK_EVT_FEAT_ONESHOT;
141 cd->mult = 16777;
142 cd->shift = 12;
143 cd->min_delta_ns = 1;
144 cd->max_delta_ns = LONG_MAX;
145 cd->rating = 400;
146 cd->cpumask = cpumask_of(cpu);
147 cd->set_next_event = s390_next_event;
148 cd->set_mode = s390_set_mode;
149
150 clockevents_register_device(cd);
151
152 /* Enable clock comparator timer interrupt. */
153 __ctl_set_bit(0,11);
154
155 /* Always allow the timing alert external interrupt. */
156 __ctl_set_bit(0, 4);
157}
158
159static void clock_comparator_interrupt(unsigned int ext_int_code,
160 unsigned int param32,
161 unsigned long param64)
162{
163 kstat_cpu(smp_processor_id()).irqs[EXTINT_CLK]++;
164 if (S390_lowcore.clock_comparator == -1ULL)
165 set_clock_comparator(S390_lowcore.clock_comparator);
166}
167
168static void etr_timing_alert(struct etr_irq_parm *);
169static void stp_timing_alert(struct stp_irq_parm *);
170
171static void timing_alert_interrupt(unsigned int ext_int_code,
172 unsigned int param32, unsigned long param64)
173{
174 kstat_cpu(smp_processor_id()).irqs[EXTINT_TLA]++;
175 if (param32 & 0x00c40000)
176 etr_timing_alert((struct etr_irq_parm *) ¶m32);
177 if (param32 & 0x00038000)
178 stp_timing_alert((struct stp_irq_parm *) ¶m32);
179}
180
181static void etr_reset(void);
182static void stp_reset(void);
183
184void read_persistent_clock(struct timespec *ts)
185{
186 tod_to_timeval(get_clock() - TOD_UNIX_EPOCH, ts);
187}
188
189void read_boot_clock(struct timespec *ts)
190{
191 tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, ts);
192}
193
194static cycle_t read_tod_clock(struct clocksource *cs)
195{
196 return get_clock();
197}
198
199static struct clocksource clocksource_tod = {
200 .name = "tod",
201 .rating = 400,
202 .read = read_tod_clock,
203 .mask = -1ULL,
204 .mult = 1000,
205 .shift = 12,
206 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
207};
208
209struct clocksource * __init clocksource_default_clock(void)
210{
211 return &clocksource_tod;
212}
213
214void update_vsyscall(struct timespec *wall_time, struct timespec *wtm,
215 struct clocksource *clock, u32 mult)
216{
217 if (clock != &clocksource_tod)
218 return;
219
220 /* Make userspace gettimeofday spin until we're done. */
221 ++vdso_data->tb_update_count;
222 smp_wmb();
223 vdso_data->xtime_tod_stamp = clock->cycle_last;
224 vdso_data->xtime_clock_sec = wall_time->tv_sec;
225 vdso_data->xtime_clock_nsec = wall_time->tv_nsec;
226 vdso_data->wtom_clock_sec = wtm->tv_sec;
227 vdso_data->wtom_clock_nsec = wtm->tv_nsec;
228 vdso_data->ntp_mult = mult;
229 smp_wmb();
230 ++vdso_data->tb_update_count;
231}
232
233extern struct timezone sys_tz;
234
235void update_vsyscall_tz(void)
236{
237 /* Make userspace gettimeofday spin until we're done. */
238 ++vdso_data->tb_update_count;
239 smp_wmb();
240 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
241 vdso_data->tz_dsttime = sys_tz.tz_dsttime;
242 smp_wmb();
243 ++vdso_data->tb_update_count;
244}
245
246/*
247 * Initialize the TOD clock and the CPU timer of
248 * the boot cpu.
249 */
250void __init time_init(void)
251{
252 /* Reset time synchronization interfaces. */
253 etr_reset();
254 stp_reset();
255
256 /* request the clock comparator external interrupt */
257 if (register_external_interrupt(0x1004, clock_comparator_interrupt))
258 panic("Couldn't request external interrupt 0x1004");
259
260 /* request the timing alert external interrupt */
261 if (register_external_interrupt(0x1406, timing_alert_interrupt))
262 panic("Couldn't request external interrupt 0x1406");
263
264 if (clocksource_register(&clocksource_tod) != 0)
265 panic("Could not register TOD clock source");
266
267 /* Enable TOD clock interrupts on the boot cpu. */
268 init_cpu_timer();
269
270 /* Enable cpu timer interrupts on the boot cpu. */
271 vtime_init();
272}
273
274/*
275 * The time is "clock". old is what we think the time is.
276 * Adjust the value by a multiple of jiffies and add the delta to ntp.
277 * "delay" is an approximation how long the synchronization took. If
278 * the time correction is positive, then "delay" is subtracted from
279 * the time difference and only the remaining part is passed to ntp.
280 */
281static unsigned long long adjust_time(unsigned long long old,
282 unsigned long long clock,
283 unsigned long long delay)
284{
285 unsigned long long delta, ticks;
286 struct timex adjust;
287
288 if (clock > old) {
289 /* It is later than we thought. */
290 delta = ticks = clock - old;
291 delta = ticks = (delta < delay) ? 0 : delta - delay;
292 delta -= do_div(ticks, CLK_TICKS_PER_JIFFY);
293 adjust.offset = ticks * (1000000 / HZ);
294 } else {
295 /* It is earlier than we thought. */
296 delta = ticks = old - clock;
297 delta -= do_div(ticks, CLK_TICKS_PER_JIFFY);
298 delta = -delta;
299 adjust.offset = -ticks * (1000000 / HZ);
300 }
301 sched_clock_base_cc += delta;
302 if (adjust.offset != 0) {
303 pr_notice("The ETR interface has adjusted the clock "
304 "by %li microseconds\n", adjust.offset);
305 adjust.modes = ADJ_OFFSET_SINGLESHOT;
306 do_adjtimex(&adjust);
307 }
308 return delta;
309}
310
311static DEFINE_PER_CPU(atomic_t, clock_sync_word);
312static DEFINE_MUTEX(clock_sync_mutex);
313static unsigned long clock_sync_flags;
314
315#define CLOCK_SYNC_HAS_ETR 0
316#define CLOCK_SYNC_HAS_STP 1
317#define CLOCK_SYNC_ETR 2
318#define CLOCK_SYNC_STP 3
319
320/*
321 * The synchronous get_clock function. It will write the current clock
322 * value to the clock pointer and return 0 if the clock is in sync with
323 * the external time source. If the clock mode is local it will return
324 * -ENOSYS and -EAGAIN if the clock is not in sync with the external
325 * reference.
326 */
327int get_sync_clock(unsigned long long *clock)
328{
329 atomic_t *sw_ptr;
330 unsigned int sw0, sw1;
331
332 sw_ptr = &get_cpu_var(clock_sync_word);
333 sw0 = atomic_read(sw_ptr);
334 *clock = get_clock();
335 sw1 = atomic_read(sw_ptr);
336 put_cpu_var(clock_sync_word);
337 if (sw0 == sw1 && (sw0 & 0x80000000U))
338 /* Success: time is in sync. */
339 return 0;
340 if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags) &&
341 !test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
342 return -ENOSYS;
343 if (!test_bit(CLOCK_SYNC_ETR, &clock_sync_flags) &&
344 !test_bit(CLOCK_SYNC_STP, &clock_sync_flags))
345 return -EACCES;
346 return -EAGAIN;
347}
348EXPORT_SYMBOL(get_sync_clock);
349
350/*
351 * Make get_sync_clock return -EAGAIN.
352 */
353static void disable_sync_clock(void *dummy)
354{
355 atomic_t *sw_ptr = &__get_cpu_var(clock_sync_word);
356 /*
357 * Clear the in-sync bit 2^31. All get_sync_clock calls will
358 * fail until the sync bit is turned back on. In addition
359 * increase the "sequence" counter to avoid the race of an
360 * etr event and the complete recovery against get_sync_clock.
361 */
362 atomic_clear_mask(0x80000000, sw_ptr);
363 atomic_inc(sw_ptr);
364}
365
366/*
367 * Make get_sync_clock return 0 again.
368 * Needs to be called from a context disabled for preemption.
369 */
370static void enable_sync_clock(void)
371{
372 atomic_t *sw_ptr = &__get_cpu_var(clock_sync_word);
373 atomic_set_mask(0x80000000, sw_ptr);
374}
375
376/*
377 * Function to check if the clock is in sync.
378 */
379static inline int check_sync_clock(void)
380{
381 atomic_t *sw_ptr;
382 int rc;
383
384 sw_ptr = &get_cpu_var(clock_sync_word);
385 rc = (atomic_read(sw_ptr) & 0x80000000U) != 0;
386 put_cpu_var(clock_sync_word);
387 return rc;
388}
389
390/* Single threaded workqueue used for etr and stp sync events */
391static struct workqueue_struct *time_sync_wq;
392
393static void __init time_init_wq(void)
394{
395 if (time_sync_wq)
396 return;
397 time_sync_wq = create_singlethread_workqueue("timesync");
398}
399
400/*
401 * External Time Reference (ETR) code.
402 */
403static int etr_port0_online;
404static int etr_port1_online;
405static int etr_steai_available;
406
407static int __init early_parse_etr(char *p)
408{
409 if (strncmp(p, "off", 3) == 0)
410 etr_port0_online = etr_port1_online = 0;
411 else if (strncmp(p, "port0", 5) == 0)
412 etr_port0_online = 1;
413 else if (strncmp(p, "port1", 5) == 0)
414 etr_port1_online = 1;
415 else if (strncmp(p, "on", 2) == 0)
416 etr_port0_online = etr_port1_online = 1;
417 return 0;
418}
419early_param("etr", early_parse_etr);
420
421enum etr_event {
422 ETR_EVENT_PORT0_CHANGE,
423 ETR_EVENT_PORT1_CHANGE,
424 ETR_EVENT_PORT_ALERT,
425 ETR_EVENT_SYNC_CHECK,
426 ETR_EVENT_SWITCH_LOCAL,
427 ETR_EVENT_UPDATE,
428};
429
430/*
431 * Valid bit combinations of the eacr register are (x = don't care):
432 * e0 e1 dp p0 p1 ea es sl
433 * 0 0 x 0 0 0 0 0 initial, disabled state
434 * 0 0 x 0 1 1 0 0 port 1 online
435 * 0 0 x 1 0 1 0 0 port 0 online
436 * 0 0 x 1 1 1 0 0 both ports online
437 * 0 1 x 0 1 1 0 0 port 1 online and usable, ETR or PPS mode
438 * 0 1 x 0 1 1 0 1 port 1 online, usable and ETR mode
439 * 0 1 x 0 1 1 1 0 port 1 online, usable, PPS mode, in-sync
440 * 0 1 x 0 1 1 1 1 port 1 online, usable, ETR mode, in-sync
441 * 0 1 x 1 1 1 0 0 both ports online, port 1 usable
442 * 0 1 x 1 1 1 1 0 both ports online, port 1 usable, PPS mode, in-sync
443 * 0 1 x 1 1 1 1 1 both ports online, port 1 usable, ETR mode, in-sync
444 * 1 0 x 1 0 1 0 0 port 0 online and usable, ETR or PPS mode
445 * 1 0 x 1 0 1 0 1 port 0 online, usable and ETR mode
446 * 1 0 x 1 0 1 1 0 port 0 online, usable, PPS mode, in-sync
447 * 1 0 x 1 0 1 1 1 port 0 online, usable, ETR mode, in-sync
448 * 1 0 x 1 1 1 0 0 both ports online, port 0 usable
449 * 1 0 x 1 1 1 1 0 both ports online, port 0 usable, PPS mode, in-sync
450 * 1 0 x 1 1 1 1 1 both ports online, port 0 usable, ETR mode, in-sync
451 * 1 1 x 1 1 1 1 0 both ports online & usable, ETR, in-sync
452 * 1 1 x 1 1 1 1 1 both ports online & usable, ETR, in-sync
453 */
454static struct etr_eacr etr_eacr;
455static u64 etr_tolec; /* time of last eacr update */
456static struct etr_aib etr_port0;
457static int etr_port0_uptodate;
458static struct etr_aib etr_port1;
459static int etr_port1_uptodate;
460static unsigned long etr_events;
461static struct timer_list etr_timer;
462
463static void etr_timeout(unsigned long dummy);
464static void etr_work_fn(struct work_struct *work);
465static DEFINE_MUTEX(etr_work_mutex);
466static DECLARE_WORK(etr_work, etr_work_fn);
467
468/*
469 * Reset ETR attachment.
470 */
471static void etr_reset(void)
472{
473 etr_eacr = (struct etr_eacr) {
474 .e0 = 0, .e1 = 0, ._pad0 = 4, .dp = 0,
475 .p0 = 0, .p1 = 0, ._pad1 = 0, .ea = 0,
476 .es = 0, .sl = 0 };
477 if (etr_setr(&etr_eacr) == 0) {
478 etr_tolec = get_clock();
479 set_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags);
480 if (etr_port0_online && etr_port1_online)
481 set_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
482 } else if (etr_port0_online || etr_port1_online) {
483 pr_warning("The real or virtual hardware system does "
484 "not provide an ETR interface\n");
485 etr_port0_online = etr_port1_online = 0;
486 }
487}
488
489static int __init etr_init(void)
490{
491 struct etr_aib aib;
492
493 if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags))
494 return 0;
495 time_init_wq();
496 /* Check if this machine has the steai instruction. */
497 if (etr_steai(&aib, ETR_STEAI_STEPPING_PORT) == 0)
498 etr_steai_available = 1;
499 setup_timer(&etr_timer, etr_timeout, 0UL);
500 if (etr_port0_online) {
501 set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
502 queue_work(time_sync_wq, &etr_work);
503 }
504 if (etr_port1_online) {
505 set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
506 queue_work(time_sync_wq, &etr_work);
507 }
508 return 0;
509}
510
511arch_initcall(etr_init);
512
513/*
514 * Two sorts of ETR machine checks. The architecture reads:
515 * "When a machine-check niterruption occurs and if a switch-to-local or
516 * ETR-sync-check interrupt request is pending but disabled, this pending
517 * disabled interruption request is indicated and is cleared".
518 * Which means that we can get etr_switch_to_local events from the machine
519 * check handler although the interruption condition is disabled. Lovely..
520 */
521
522/*
523 * Switch to local machine check. This is called when the last usable
524 * ETR port goes inactive. After switch to local the clock is not in sync.
525 */
526void etr_switch_to_local(void)
527{
528 if (!etr_eacr.sl)
529 return;
530 disable_sync_clock(NULL);
531 if (!test_and_set_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events)) {
532 etr_eacr.es = etr_eacr.sl = 0;
533 etr_setr(&etr_eacr);
534 queue_work(time_sync_wq, &etr_work);
535 }
536}
537
538/*
539 * ETR sync check machine check. This is called when the ETR OTE and the
540 * local clock OTE are farther apart than the ETR sync check tolerance.
541 * After a ETR sync check the clock is not in sync. The machine check
542 * is broadcasted to all cpus at the same time.
543 */
544void etr_sync_check(void)
545{
546 if (!etr_eacr.es)
547 return;
548 disable_sync_clock(NULL);
549 if (!test_and_set_bit(ETR_EVENT_SYNC_CHECK, &etr_events)) {
550 etr_eacr.es = 0;
551 etr_setr(&etr_eacr);
552 queue_work(time_sync_wq, &etr_work);
553 }
554}
555
556/*
557 * ETR timing alert. There are two causes:
558 * 1) port state change, check the usability of the port
559 * 2) port alert, one of the ETR-data-validity bits (v1-v2 bits of the
560 * sldr-status word) or ETR-data word 1 (edf1) or ETR-data word 3 (edf3)
561 * or ETR-data word 4 (edf4) has changed.
562 */
563static void etr_timing_alert(struct etr_irq_parm *intparm)
564{
565 if (intparm->pc0)
566 /* ETR port 0 state change. */
567 set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
568 if (intparm->pc1)
569 /* ETR port 1 state change. */
570 set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
571 if (intparm->eai)
572 /*
573 * ETR port alert on either port 0, 1 or both.
574 * Both ports are not up-to-date now.
575 */
576 set_bit(ETR_EVENT_PORT_ALERT, &etr_events);
577 queue_work(time_sync_wq, &etr_work);
578}
579
580static void etr_timeout(unsigned long dummy)
581{
582 set_bit(ETR_EVENT_UPDATE, &etr_events);
583 queue_work(time_sync_wq, &etr_work);
584}
585
586/*
587 * Check if the etr mode is pss.
588 */
589static inline int etr_mode_is_pps(struct etr_eacr eacr)
590{
591 return eacr.es && !eacr.sl;
592}
593
594/*
595 * Check if the etr mode is etr.
596 */
597static inline int etr_mode_is_etr(struct etr_eacr eacr)
598{
599 return eacr.es && eacr.sl;
600}
601
602/*
603 * Check if the port can be used for TOD synchronization.
604 * For PPS mode the port has to receive OTEs. For ETR mode
605 * the port has to receive OTEs, the ETR stepping bit has to
606 * be zero and the validity bits for data frame 1, 2, and 3
607 * have to be 1.
608 */
609static int etr_port_valid(struct etr_aib *aib, int port)
610{
611 unsigned int psc;
612
613 /* Check that this port is receiving OTEs. */
614 if (aib->tsp == 0)
615 return 0;
616
617 psc = port ? aib->esw.psc1 : aib->esw.psc0;
618 if (psc == etr_lpsc_pps_mode)
619 return 1;
620 if (psc == etr_lpsc_operational_step)
621 return !aib->esw.y && aib->slsw.v1 &&
622 aib->slsw.v2 && aib->slsw.v3;
623 return 0;
624}
625
626/*
627 * Check if two ports are on the same network.
628 */
629static int etr_compare_network(struct etr_aib *aib1, struct etr_aib *aib2)
630{
631 // FIXME: any other fields we have to compare?
632 return aib1->edf1.net_id == aib2->edf1.net_id;
633}
634
635/*
636 * Wrapper for etr_stei that converts physical port states
637 * to logical port states to be consistent with the output
638 * of stetr (see etr_psc vs. etr_lpsc).
639 */
640static void etr_steai_cv(struct etr_aib *aib, unsigned int func)
641{
642 BUG_ON(etr_steai(aib, func) != 0);
643 /* Convert port state to logical port state. */
644 if (aib->esw.psc0 == 1)
645 aib->esw.psc0 = 2;
646 else if (aib->esw.psc0 == 0 && aib->esw.p == 0)
647 aib->esw.psc0 = 1;
648 if (aib->esw.psc1 == 1)
649 aib->esw.psc1 = 2;
650 else if (aib->esw.psc1 == 0 && aib->esw.p == 1)
651 aib->esw.psc1 = 1;
652}
653
654/*
655 * Check if the aib a2 is still connected to the same attachment as
656 * aib a1, the etv values differ by one and a2 is valid.
657 */
658static int etr_aib_follows(struct etr_aib *a1, struct etr_aib *a2, int p)
659{
660 int state_a1, state_a2;
661
662 /* Paranoia check: e0/e1 should better be the same. */
663 if (a1->esw.eacr.e0 != a2->esw.eacr.e0 ||
664 a1->esw.eacr.e1 != a2->esw.eacr.e1)
665 return 0;
666
667 /* Still connected to the same etr ? */
668 state_a1 = p ? a1->esw.psc1 : a1->esw.psc0;
669 state_a2 = p ? a2->esw.psc1 : a2->esw.psc0;
670 if (state_a1 == etr_lpsc_operational_step) {
671 if (state_a2 != etr_lpsc_operational_step ||
672 a1->edf1.net_id != a2->edf1.net_id ||
673 a1->edf1.etr_id != a2->edf1.etr_id ||
674 a1->edf1.etr_pn != a2->edf1.etr_pn)
675 return 0;
676 } else if (state_a2 != etr_lpsc_pps_mode)
677 return 0;
678
679 /* The ETV value of a2 needs to be ETV of a1 + 1. */
680 if (a1->edf2.etv + 1 != a2->edf2.etv)
681 return 0;
682
683 if (!etr_port_valid(a2, p))
684 return 0;
685
686 return 1;
687}
688
689struct clock_sync_data {
690 atomic_t cpus;
691 int in_sync;
692 unsigned long long fixup_cc;
693 int etr_port;
694 struct etr_aib *etr_aib;
695};
696
697static void clock_sync_cpu(struct clock_sync_data *sync)
698{
699 atomic_dec(&sync->cpus);
700 enable_sync_clock();
701 /*
702 * This looks like a busy wait loop but it isn't. etr_sync_cpus
703 * is called on all other cpus while the TOD clocks is stopped.
704 * __udelay will stop the cpu on an enabled wait psw until the
705 * TOD is running again.
706 */
707 while (sync->in_sync == 0) {
708 __udelay(1);
709 /*
710 * A different cpu changes *in_sync. Therefore use
711 * barrier() to force memory access.
712 */
713 barrier();
714 }
715 if (sync->in_sync != 1)
716 /* Didn't work. Clear per-cpu in sync bit again. */
717 disable_sync_clock(NULL);
718 /*
719 * This round of TOD syncing is done. Set the clock comparator
720 * to the next tick and let the processor continue.
721 */
722 fixup_clock_comparator(sync->fixup_cc);
723}
724
725/*
726 * Sync the TOD clock using the port referred to by aibp. This port
727 * has to be enabled and the other port has to be disabled. The
728 * last eacr update has to be more than 1.6 seconds in the past.
729 */
730static int etr_sync_clock(void *data)
731{
732 static int first;
733 unsigned long long clock, old_clock, delay, delta;
734 struct clock_sync_data *etr_sync;
735 struct etr_aib *sync_port, *aib;
736 int port;
737 int rc;
738
739 etr_sync = data;
740
741 if (xchg(&first, 1) == 1) {
742 /* Slave */
743 clock_sync_cpu(etr_sync);
744 return 0;
745 }
746
747 /* Wait until all other cpus entered the sync function. */
748 while (atomic_read(&etr_sync->cpus) != 0)
749 cpu_relax();
750
751 port = etr_sync->etr_port;
752 aib = etr_sync->etr_aib;
753 sync_port = (port == 0) ? &etr_port0 : &etr_port1;
754 enable_sync_clock();
755
756 /* Set clock to next OTE. */
757 __ctl_set_bit(14, 21);
758 __ctl_set_bit(0, 29);
759 clock = ((unsigned long long) (aib->edf2.etv + 1)) << 32;
760 old_clock = get_clock();
761 if (set_clock(clock) == 0) {
762 __udelay(1); /* Wait for the clock to start. */
763 __ctl_clear_bit(0, 29);
764 __ctl_clear_bit(14, 21);
765 etr_stetr(aib);
766 /* Adjust Linux timing variables. */
767 delay = (unsigned long long)
768 (aib->edf2.etv - sync_port->edf2.etv) << 32;
769 delta = adjust_time(old_clock, clock, delay);
770 etr_sync->fixup_cc = delta;
771 fixup_clock_comparator(delta);
772 /* Verify that the clock is properly set. */
773 if (!etr_aib_follows(sync_port, aib, port)) {
774 /* Didn't work. */
775 disable_sync_clock(NULL);
776 etr_sync->in_sync = -EAGAIN;
777 rc = -EAGAIN;
778 } else {
779 etr_sync->in_sync = 1;
780 rc = 0;
781 }
782 } else {
783 /* Could not set the clock ?!? */
784 __ctl_clear_bit(0, 29);
785 __ctl_clear_bit(14, 21);
786 disable_sync_clock(NULL);
787 etr_sync->in_sync = -EAGAIN;
788 rc = -EAGAIN;
789 }
790 xchg(&first, 0);
791 return rc;
792}
793
794static int etr_sync_clock_stop(struct etr_aib *aib, int port)
795{
796 struct clock_sync_data etr_sync;
797 struct etr_aib *sync_port;
798 int follows;
799 int rc;
800
801 /* Check if the current aib is adjacent to the sync port aib. */
802 sync_port = (port == 0) ? &etr_port0 : &etr_port1;
803 follows = etr_aib_follows(sync_port, aib, port);
804 memcpy(sync_port, aib, sizeof(*aib));
805 if (!follows)
806 return -EAGAIN;
807 memset(&etr_sync, 0, sizeof(etr_sync));
808 etr_sync.etr_aib = aib;
809 etr_sync.etr_port = port;
810 get_online_cpus();
811 atomic_set(&etr_sync.cpus, num_online_cpus() - 1);
812 rc = stop_machine(etr_sync_clock, &etr_sync, cpu_online_mask);
813 put_online_cpus();
814 return rc;
815}
816
817/*
818 * Handle the immediate effects of the different events.
819 * The port change event is used for online/offline changes.
820 */
821static struct etr_eacr etr_handle_events(struct etr_eacr eacr)
822{
823 if (test_and_clear_bit(ETR_EVENT_SYNC_CHECK, &etr_events))
824 eacr.es = 0;
825 if (test_and_clear_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events))
826 eacr.es = eacr.sl = 0;
827 if (test_and_clear_bit(ETR_EVENT_PORT_ALERT, &etr_events))
828 etr_port0_uptodate = etr_port1_uptodate = 0;
829
830 if (test_and_clear_bit(ETR_EVENT_PORT0_CHANGE, &etr_events)) {
831 if (eacr.e0)
832 /*
833 * Port change of an enabled port. We have to
834 * assume that this can have caused an stepping
835 * port switch.
836 */
837 etr_tolec = get_clock();
838 eacr.p0 = etr_port0_online;
839 if (!eacr.p0)
840 eacr.e0 = 0;
841 etr_port0_uptodate = 0;
842 }
843 if (test_and_clear_bit(ETR_EVENT_PORT1_CHANGE, &etr_events)) {
844 if (eacr.e1)
845 /*
846 * Port change of an enabled port. We have to
847 * assume that this can have caused an stepping
848 * port switch.
849 */
850 etr_tolec = get_clock();
851 eacr.p1 = etr_port1_online;
852 if (!eacr.p1)
853 eacr.e1 = 0;
854 etr_port1_uptodate = 0;
855 }
856 clear_bit(ETR_EVENT_UPDATE, &etr_events);
857 return eacr;
858}
859
860/*
861 * Set up a timer that expires after the etr_tolec + 1.6 seconds if
862 * one of the ports needs an update.
863 */
864static void etr_set_tolec_timeout(unsigned long long now)
865{
866 unsigned long micros;
867
868 if ((!etr_eacr.p0 || etr_port0_uptodate) &&
869 (!etr_eacr.p1 || etr_port1_uptodate))
870 return;
871 micros = (now > etr_tolec) ? ((now - etr_tolec) >> 12) : 0;
872 micros = (micros > 1600000) ? 0 : 1600000 - micros;
873 mod_timer(&etr_timer, jiffies + (micros * HZ) / 1000000 + 1);
874}
875
876/*
877 * Set up a time that expires after 1/2 second.
878 */
879static void etr_set_sync_timeout(void)
880{
881 mod_timer(&etr_timer, jiffies + HZ/2);
882}
883
884/*
885 * Update the aib information for one or both ports.
886 */
887static struct etr_eacr etr_handle_update(struct etr_aib *aib,
888 struct etr_eacr eacr)
889{
890 /* With both ports disabled the aib information is useless. */
891 if (!eacr.e0 && !eacr.e1)
892 return eacr;
893
894 /* Update port0 or port1 with aib stored in etr_work_fn. */
895 if (aib->esw.q == 0) {
896 /* Information for port 0 stored. */
897 if (eacr.p0 && !etr_port0_uptodate) {
898 etr_port0 = *aib;
899 if (etr_port0_online)
900 etr_port0_uptodate = 1;
901 }
902 } else {
903 /* Information for port 1 stored. */
904 if (eacr.p1 && !etr_port1_uptodate) {
905 etr_port1 = *aib;
906 if (etr_port0_online)
907 etr_port1_uptodate = 1;
908 }
909 }
910
911 /*
912 * Do not try to get the alternate port aib if the clock
913 * is not in sync yet.
914 */
915 if (!eacr.es || !check_sync_clock())
916 return eacr;
917
918 /*
919 * If steai is available we can get the information about
920 * the other port immediately. If only stetr is available the
921 * data-port bit toggle has to be used.
922 */
923 if (etr_steai_available) {
924 if (eacr.p0 && !etr_port0_uptodate) {
925 etr_steai_cv(&etr_port0, ETR_STEAI_PORT_0);
926 etr_port0_uptodate = 1;
927 }
928 if (eacr.p1 && !etr_port1_uptodate) {
929 etr_steai_cv(&etr_port1, ETR_STEAI_PORT_1);
930 etr_port1_uptodate = 1;
931 }
932 } else {
933 /*
934 * One port was updated above, if the other
935 * port is not uptodate toggle dp bit.
936 */
937 if ((eacr.p0 && !etr_port0_uptodate) ||
938 (eacr.p1 && !etr_port1_uptodate))
939 eacr.dp ^= 1;
940 else
941 eacr.dp = 0;
942 }
943 return eacr;
944}
945
946/*
947 * Write new etr control register if it differs from the current one.
948 * Return 1 if etr_tolec has been updated as well.
949 */
950static void etr_update_eacr(struct etr_eacr eacr)
951{
952 int dp_changed;
953
954 if (memcmp(&etr_eacr, &eacr, sizeof(eacr)) == 0)
955 /* No change, return. */
956 return;
957 /*
958 * The disable of an active port of the change of the data port
959 * bit can/will cause a change in the data port.
960 */
961 dp_changed = etr_eacr.e0 > eacr.e0 || etr_eacr.e1 > eacr.e1 ||
962 (etr_eacr.dp ^ eacr.dp) != 0;
963 etr_eacr = eacr;
964 etr_setr(&etr_eacr);
965 if (dp_changed)
966 etr_tolec = get_clock();
967}
968
969/*
970 * ETR work. In this function you'll find the main logic. In
971 * particular this is the only function that calls etr_update_eacr(),
972 * it "controls" the etr control register.
973 */
974static void etr_work_fn(struct work_struct *work)
975{
976 unsigned long long now;
977 struct etr_eacr eacr;
978 struct etr_aib aib;
979 int sync_port;
980
981 /* prevent multiple execution. */
982 mutex_lock(&etr_work_mutex);
983
984 /* Create working copy of etr_eacr. */
985 eacr = etr_eacr;
986
987 /* Check for the different events and their immediate effects. */
988 eacr = etr_handle_events(eacr);
989
990 /* Check if ETR is supposed to be active. */
991 eacr.ea = eacr.p0 || eacr.p1;
992 if (!eacr.ea) {
993 /* Both ports offline. Reset everything. */
994 eacr.dp = eacr.es = eacr.sl = 0;
995 on_each_cpu(disable_sync_clock, NULL, 1);
996 del_timer_sync(&etr_timer);
997 etr_update_eacr(eacr);
998 goto out_unlock;
999 }
1000
1001 /* Store aib to get the current ETR status word. */
1002 BUG_ON(etr_stetr(&aib) != 0);
1003 etr_port0.esw = etr_port1.esw = aib.esw; /* Copy status word. */
1004 now = get_clock();
1005
1006 /*
1007 * Update the port information if the last stepping port change
1008 * or data port change is older than 1.6 seconds.
1009 */
1010 if (now >= etr_tolec + (1600000 << 12))
1011 eacr = etr_handle_update(&aib, eacr);
1012
1013 /*
1014 * Select ports to enable. The preferred synchronization mode is PPS.
1015 * If a port can be enabled depends on a number of things:
1016 * 1) The port needs to be online and uptodate. A port is not
1017 * disabled just because it is not uptodate, but it is only
1018 * enabled if it is uptodate.
1019 * 2) The port needs to have the same mode (pps / etr).
1020 * 3) The port needs to be usable -> etr_port_valid() == 1
1021 * 4) To enable the second port the clock needs to be in sync.
1022 * 5) If both ports are useable and are ETR ports, the network id
1023 * has to be the same.
1024 * The eacr.sl bit is used to indicate etr mode vs. pps mode.
1025 */
1026 if (eacr.p0 && aib.esw.psc0 == etr_lpsc_pps_mode) {
1027 eacr.sl = 0;
1028 eacr.e0 = 1;
1029 if (!etr_mode_is_pps(etr_eacr))
1030 eacr.es = 0;
1031 if (!eacr.es || !eacr.p1 || aib.esw.psc1 != etr_lpsc_pps_mode)
1032 eacr.e1 = 0;
1033 // FIXME: uptodate checks ?
1034 else if (etr_port0_uptodate && etr_port1_uptodate)
1035 eacr.e1 = 1;
1036 sync_port = (etr_port0_uptodate &&
1037 etr_port_valid(&etr_port0, 0)) ? 0 : -1;
1038 } else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_pps_mode) {
1039 eacr.sl = 0;
1040 eacr.e0 = 0;
1041 eacr.e1 = 1;
1042 if (!etr_mode_is_pps(etr_eacr))
1043 eacr.es = 0;
1044 sync_port = (etr_port1_uptodate &&
1045 etr_port_valid(&etr_port1, 1)) ? 1 : -1;
1046 } else if (eacr.p0 && aib.esw.psc0 == etr_lpsc_operational_step) {
1047 eacr.sl = 1;
1048 eacr.e0 = 1;
1049 if (!etr_mode_is_etr(etr_eacr))
1050 eacr.es = 0;
1051 if (!eacr.es || !eacr.p1 ||
1052 aib.esw.psc1 != etr_lpsc_operational_alt)
1053 eacr.e1 = 0;
1054 else if (etr_port0_uptodate && etr_port1_uptodate &&
1055 etr_compare_network(&etr_port0, &etr_port1))
1056 eacr.e1 = 1;
1057 sync_port = (etr_port0_uptodate &&
1058 etr_port_valid(&etr_port0, 0)) ? 0 : -1;
1059 } else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_operational_step) {
1060 eacr.sl = 1;
1061 eacr.e0 = 0;
1062 eacr.e1 = 1;
1063 if (!etr_mode_is_etr(etr_eacr))
1064 eacr.es = 0;
1065 sync_port = (etr_port1_uptodate &&
1066 etr_port_valid(&etr_port1, 1)) ? 1 : -1;
1067 } else {
1068 /* Both ports not usable. */
1069 eacr.es = eacr.sl = 0;
1070 sync_port = -1;
1071 }
1072
1073 /*
1074 * If the clock is in sync just update the eacr and return.
1075 * If there is no valid sync port wait for a port update.
1076 */
1077 if ((eacr.es && check_sync_clock()) || sync_port < 0) {
1078 etr_update_eacr(eacr);
1079 etr_set_tolec_timeout(now);
1080 goto out_unlock;
1081 }
1082
1083 /*
1084 * Prepare control register for clock syncing
1085 * (reset data port bit, set sync check control.
1086 */
1087 eacr.dp = 0;
1088 eacr.es = 1;
1089
1090 /*
1091 * Update eacr and try to synchronize the clock. If the update
1092 * of eacr caused a stepping port switch (or if we have to
1093 * assume that a stepping port switch has occurred) or the
1094 * clock syncing failed, reset the sync check control bit
1095 * and set up a timer to try again after 0.5 seconds
1096 */
1097 etr_update_eacr(eacr);
1098 if (now < etr_tolec + (1600000 << 12) ||
1099 etr_sync_clock_stop(&aib, sync_port) != 0) {
1100 /* Sync failed. Try again in 1/2 second. */
1101 eacr.es = 0;
1102 etr_update_eacr(eacr);
1103 etr_set_sync_timeout();
1104 } else
1105 etr_set_tolec_timeout(now);
1106out_unlock:
1107 mutex_unlock(&etr_work_mutex);
1108}
1109
1110/*
1111 * Sysfs interface functions
1112 */
1113static struct sysdev_class etr_sysclass = {
1114 .name = "etr",
1115};
1116
1117static struct sys_device etr_port0_dev = {
1118 .id = 0,
1119 .cls = &etr_sysclass,
1120};
1121
1122static struct sys_device etr_port1_dev = {
1123 .id = 1,
1124 .cls = &etr_sysclass,
1125};
1126
1127/*
1128 * ETR class attributes
1129 */
1130static ssize_t etr_stepping_port_show(struct sysdev_class *class,
1131 struct sysdev_class_attribute *attr,
1132 char *buf)
1133{
1134 return sprintf(buf, "%i\n", etr_port0.esw.p);
1135}
1136
1137static SYSDEV_CLASS_ATTR(stepping_port, 0400, etr_stepping_port_show, NULL);
1138
1139static ssize_t etr_stepping_mode_show(struct sysdev_class *class,
1140 struct sysdev_class_attribute *attr,
1141 char *buf)
1142{
1143 char *mode_str;
1144
1145 if (etr_mode_is_pps(etr_eacr))
1146 mode_str = "pps";
1147 else if (etr_mode_is_etr(etr_eacr))
1148 mode_str = "etr";
1149 else
1150 mode_str = "local";
1151 return sprintf(buf, "%s\n", mode_str);
1152}
1153
1154static SYSDEV_CLASS_ATTR(stepping_mode, 0400, etr_stepping_mode_show, NULL);
1155
1156/*
1157 * ETR port attributes
1158 */
1159static inline struct etr_aib *etr_aib_from_dev(struct sys_device *dev)
1160{
1161 if (dev == &etr_port0_dev)
1162 return etr_port0_online ? &etr_port0 : NULL;
1163 else
1164 return etr_port1_online ? &etr_port1 : NULL;
1165}
1166
1167static ssize_t etr_online_show(struct sys_device *dev,
1168 struct sysdev_attribute *attr,
1169 char *buf)
1170{
1171 unsigned int online;
1172
1173 online = (dev == &etr_port0_dev) ? etr_port0_online : etr_port1_online;
1174 return sprintf(buf, "%i\n", online);
1175}
1176
1177static ssize_t etr_online_store(struct sys_device *dev,
1178 struct sysdev_attribute *attr,
1179 const char *buf, size_t count)
1180{
1181 unsigned int value;
1182
1183 value = simple_strtoul(buf, NULL, 0);
1184 if (value != 0 && value != 1)
1185 return -EINVAL;
1186 if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags))
1187 return -EOPNOTSUPP;
1188 mutex_lock(&clock_sync_mutex);
1189 if (dev == &etr_port0_dev) {
1190 if (etr_port0_online == value)
1191 goto out; /* Nothing to do. */
1192 etr_port0_online = value;
1193 if (etr_port0_online && etr_port1_online)
1194 set_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
1195 else
1196 clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
1197 set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
1198 queue_work(time_sync_wq, &etr_work);
1199 } else {
1200 if (etr_port1_online == value)
1201 goto out; /* Nothing to do. */
1202 etr_port1_online = value;
1203 if (etr_port0_online && etr_port1_online)
1204 set_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
1205 else
1206 clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
1207 set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
1208 queue_work(time_sync_wq, &etr_work);
1209 }
1210out:
1211 mutex_unlock(&clock_sync_mutex);
1212 return count;
1213}
1214
1215static SYSDEV_ATTR(online, 0600, etr_online_show, etr_online_store);
1216
1217static ssize_t etr_stepping_control_show(struct sys_device *dev,
1218 struct sysdev_attribute *attr,
1219 char *buf)
1220{
1221 return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ?
1222 etr_eacr.e0 : etr_eacr.e1);
1223}
1224
1225static SYSDEV_ATTR(stepping_control, 0400, etr_stepping_control_show, NULL);
1226
1227static ssize_t etr_mode_code_show(struct sys_device *dev,
1228 struct sysdev_attribute *attr, char *buf)
1229{
1230 if (!etr_port0_online && !etr_port1_online)
1231 /* Status word is not uptodate if both ports are offline. */
1232 return -ENODATA;
1233 return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ?
1234 etr_port0.esw.psc0 : etr_port0.esw.psc1);
1235}
1236
1237static SYSDEV_ATTR(state_code, 0400, etr_mode_code_show, NULL);
1238
1239static ssize_t etr_untuned_show(struct sys_device *dev,
1240 struct sysdev_attribute *attr, char *buf)
1241{
1242 struct etr_aib *aib = etr_aib_from_dev(dev);
1243
1244 if (!aib || !aib->slsw.v1)
1245 return -ENODATA;
1246 return sprintf(buf, "%i\n", aib->edf1.u);
1247}
1248
1249static SYSDEV_ATTR(untuned, 0400, etr_untuned_show, NULL);
1250
1251static ssize_t etr_network_id_show(struct sys_device *dev,
1252 struct sysdev_attribute *attr, char *buf)
1253{
1254 struct etr_aib *aib = etr_aib_from_dev(dev);
1255
1256 if (!aib || !aib->slsw.v1)
1257 return -ENODATA;
1258 return sprintf(buf, "%i\n", aib->edf1.net_id);
1259}
1260
1261static SYSDEV_ATTR(network, 0400, etr_network_id_show, NULL);
1262
1263static ssize_t etr_id_show(struct sys_device *dev,
1264 struct sysdev_attribute *attr, char *buf)
1265{
1266 struct etr_aib *aib = etr_aib_from_dev(dev);
1267
1268 if (!aib || !aib->slsw.v1)
1269 return -ENODATA;
1270 return sprintf(buf, "%i\n", aib->edf1.etr_id);
1271}
1272
1273static SYSDEV_ATTR(id, 0400, etr_id_show, NULL);
1274
1275static ssize_t etr_port_number_show(struct sys_device *dev,
1276 struct sysdev_attribute *attr, char *buf)
1277{
1278 struct etr_aib *aib = etr_aib_from_dev(dev);
1279
1280 if (!aib || !aib->slsw.v1)
1281 return -ENODATA;
1282 return sprintf(buf, "%i\n", aib->edf1.etr_pn);
1283}
1284
1285static SYSDEV_ATTR(port, 0400, etr_port_number_show, NULL);
1286
1287static ssize_t etr_coupled_show(struct sys_device *dev,
1288 struct sysdev_attribute *attr, char *buf)
1289{
1290 struct etr_aib *aib = etr_aib_from_dev(dev);
1291
1292 if (!aib || !aib->slsw.v3)
1293 return -ENODATA;
1294 return sprintf(buf, "%i\n", aib->edf3.c);
1295}
1296
1297static SYSDEV_ATTR(coupled, 0400, etr_coupled_show, NULL);
1298
1299static ssize_t etr_local_time_show(struct sys_device *dev,
1300 struct sysdev_attribute *attr, char *buf)
1301{
1302 struct etr_aib *aib = etr_aib_from_dev(dev);
1303
1304 if (!aib || !aib->slsw.v3)
1305 return -ENODATA;
1306 return sprintf(buf, "%i\n", aib->edf3.blto);
1307}
1308
1309static SYSDEV_ATTR(local_time, 0400, etr_local_time_show, NULL);
1310
1311static ssize_t etr_utc_offset_show(struct sys_device *dev,
1312 struct sysdev_attribute *attr, char *buf)
1313{
1314 struct etr_aib *aib = etr_aib_from_dev(dev);
1315
1316 if (!aib || !aib->slsw.v3)
1317 return -ENODATA;
1318 return sprintf(buf, "%i\n", aib->edf3.buo);
1319}
1320
1321static SYSDEV_ATTR(utc_offset, 0400, etr_utc_offset_show, NULL);
1322
1323static struct sysdev_attribute *etr_port_attributes[] = {
1324 &attr_online,
1325 &attr_stepping_control,
1326 &attr_state_code,
1327 &attr_untuned,
1328 &attr_network,
1329 &attr_id,
1330 &attr_port,
1331 &attr_coupled,
1332 &attr_local_time,
1333 &attr_utc_offset,
1334 NULL
1335};
1336
1337static int __init etr_register_port(struct sys_device *dev)
1338{
1339 struct sysdev_attribute **attr;
1340 int rc;
1341
1342 rc = sysdev_register(dev);
1343 if (rc)
1344 goto out;
1345 for (attr = etr_port_attributes; *attr; attr++) {
1346 rc = sysdev_create_file(dev, *attr);
1347 if (rc)
1348 goto out_unreg;
1349 }
1350 return 0;
1351out_unreg:
1352 for (; attr >= etr_port_attributes; attr--)
1353 sysdev_remove_file(dev, *attr);
1354 sysdev_unregister(dev);
1355out:
1356 return rc;
1357}
1358
1359static void __init etr_unregister_port(struct sys_device *dev)
1360{
1361 struct sysdev_attribute **attr;
1362
1363 for (attr = etr_port_attributes; *attr; attr++)
1364 sysdev_remove_file(dev, *attr);
1365 sysdev_unregister(dev);
1366}
1367
1368static int __init etr_init_sysfs(void)
1369{
1370 int rc;
1371
1372 rc = sysdev_class_register(&etr_sysclass);
1373 if (rc)
1374 goto out;
1375 rc = sysdev_class_create_file(&etr_sysclass, &attr_stepping_port);
1376 if (rc)
1377 goto out_unreg_class;
1378 rc = sysdev_class_create_file(&etr_sysclass, &attr_stepping_mode);
1379 if (rc)
1380 goto out_remove_stepping_port;
1381 rc = etr_register_port(&etr_port0_dev);
1382 if (rc)
1383 goto out_remove_stepping_mode;
1384 rc = etr_register_port(&etr_port1_dev);
1385 if (rc)
1386 goto out_remove_port0;
1387 return 0;
1388
1389out_remove_port0:
1390 etr_unregister_port(&etr_port0_dev);
1391out_remove_stepping_mode:
1392 sysdev_class_remove_file(&etr_sysclass, &attr_stepping_mode);
1393out_remove_stepping_port:
1394 sysdev_class_remove_file(&etr_sysclass, &attr_stepping_port);
1395out_unreg_class:
1396 sysdev_class_unregister(&etr_sysclass);
1397out:
1398 return rc;
1399}
1400
1401device_initcall(etr_init_sysfs);
1402
1403/*
1404 * Server Time Protocol (STP) code.
1405 */
1406static int stp_online;
1407static struct stp_sstpi stp_info;
1408static void *stp_page;
1409
1410static void stp_work_fn(struct work_struct *work);
1411static DEFINE_MUTEX(stp_work_mutex);
1412static DECLARE_WORK(stp_work, stp_work_fn);
1413static struct timer_list stp_timer;
1414
1415static int __init early_parse_stp(char *p)
1416{
1417 if (strncmp(p, "off", 3) == 0)
1418 stp_online = 0;
1419 else if (strncmp(p, "on", 2) == 0)
1420 stp_online = 1;
1421 return 0;
1422}
1423early_param("stp", early_parse_stp);
1424
1425/*
1426 * Reset STP attachment.
1427 */
1428static void __init stp_reset(void)
1429{
1430 int rc;
1431
1432 stp_page = (void *) get_zeroed_page(GFP_ATOMIC);
1433 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);
1434 if (rc == 0)
1435 set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags);
1436 else if (stp_online) {
1437 pr_warning("The real or virtual hardware system does "
1438 "not provide an STP interface\n");
1439 free_page((unsigned long) stp_page);
1440 stp_page = NULL;
1441 stp_online = 0;
1442 }
1443}
1444
1445static void stp_timeout(unsigned long dummy)
1446{
1447 queue_work(time_sync_wq, &stp_work);
1448}
1449
1450static int __init stp_init(void)
1451{
1452 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
1453 return 0;
1454 setup_timer(&stp_timer, stp_timeout, 0UL);
1455 time_init_wq();
1456 if (!stp_online)
1457 return 0;
1458 queue_work(time_sync_wq, &stp_work);
1459 return 0;
1460}
1461
1462arch_initcall(stp_init);
1463
1464/*
1465 * STP timing alert. There are three causes:
1466 * 1) timing status change
1467 * 2) link availability change
1468 * 3) time control parameter change
1469 * In all three cases we are only interested in the clock source state.
1470 * If a STP clock source is now available use it.
1471 */
1472static void stp_timing_alert(struct stp_irq_parm *intparm)
1473{
1474 if (intparm->tsc || intparm->lac || intparm->tcpc)
1475 queue_work(time_sync_wq, &stp_work);
1476}
1477
1478/*
1479 * STP sync check machine check. This is called when the timing state
1480 * changes from the synchronized state to the unsynchronized state.
1481 * After a STP sync check the clock is not in sync. The machine check
1482 * is broadcasted to all cpus at the same time.
1483 */
1484void stp_sync_check(void)
1485{
1486 disable_sync_clock(NULL);
1487 queue_work(time_sync_wq, &stp_work);
1488}
1489
1490/*
1491 * STP island condition machine check. This is called when an attached
1492 * server attempts to communicate over an STP link and the servers
1493 * have matching CTN ids and have a valid stratum-1 configuration
1494 * but the configurations do not match.
1495 */
1496void stp_island_check(void)
1497{
1498 disable_sync_clock(NULL);
1499 queue_work(time_sync_wq, &stp_work);
1500}
1501
1502
1503static int stp_sync_clock(void *data)
1504{
1505 static int first;
1506 unsigned long long old_clock, delta;
1507 struct clock_sync_data *stp_sync;
1508 int rc;
1509
1510 stp_sync = data;
1511
1512 if (xchg(&first, 1) == 1) {
1513 /* Slave */
1514 clock_sync_cpu(stp_sync);
1515 return 0;
1516 }
1517
1518 /* Wait until all other cpus entered the sync function. */
1519 while (atomic_read(&stp_sync->cpus) != 0)
1520 cpu_relax();
1521
1522 enable_sync_clock();
1523
1524 rc = 0;
1525 if (stp_info.todoff[0] || stp_info.todoff[1] ||
1526 stp_info.todoff[2] || stp_info.todoff[3] ||
1527 stp_info.tmd != 2) {
1528 old_clock = get_clock();
1529 rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0);
1530 if (rc == 0) {
1531 delta = adjust_time(old_clock, get_clock(), 0);
1532 fixup_clock_comparator(delta);
1533 rc = chsc_sstpi(stp_page, &stp_info,
1534 sizeof(struct stp_sstpi));
1535 if (rc == 0 && stp_info.tmd != 2)
1536 rc = -EAGAIN;
1537 }
1538 }
1539 if (rc) {
1540 disable_sync_clock(NULL);
1541 stp_sync->in_sync = -EAGAIN;
1542 } else
1543 stp_sync->in_sync = 1;
1544 xchg(&first, 0);
1545 return 0;
1546}
1547
1548/*
1549 * STP work. Check for the STP state and take over the clock
1550 * synchronization if the STP clock source is usable.
1551 */
1552static void stp_work_fn(struct work_struct *work)
1553{
1554 struct clock_sync_data stp_sync;
1555 int rc;
1556
1557 /* prevent multiple execution. */
1558 mutex_lock(&stp_work_mutex);
1559
1560 if (!stp_online) {
1561 chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);
1562 del_timer_sync(&stp_timer);
1563 goto out_unlock;
1564 }
1565
1566 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0);
1567 if (rc)
1568 goto out_unlock;
1569
1570 rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi));
1571 if (rc || stp_info.c == 0)
1572 goto out_unlock;
1573
1574 /* Skip synchronization if the clock is already in sync. */
1575 if (check_sync_clock())
1576 goto out_unlock;
1577
1578 memset(&stp_sync, 0, sizeof(stp_sync));
1579 get_online_cpus();
1580 atomic_set(&stp_sync.cpus, num_online_cpus() - 1);
1581 stop_machine(stp_sync_clock, &stp_sync, cpu_online_mask);
1582 put_online_cpus();
1583
1584 if (!check_sync_clock())
1585 /*
1586 * There is a usable clock but the synchonization failed.
1587 * Retry after a second.
1588 */
1589 mod_timer(&stp_timer, jiffies + HZ);
1590
1591out_unlock:
1592 mutex_unlock(&stp_work_mutex);
1593}
1594
1595/*
1596 * STP class sysfs interface functions
1597 */
1598static struct sysdev_class stp_sysclass = {
1599 .name = "stp",
1600};
1601
1602static ssize_t stp_ctn_id_show(struct sysdev_class *class,
1603 struct sysdev_class_attribute *attr,
1604 char *buf)
1605{
1606 if (!stp_online)
1607 return -ENODATA;
1608 return sprintf(buf, "%016llx\n",
1609 *(unsigned long long *) stp_info.ctnid);
1610}
1611
1612static SYSDEV_CLASS_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL);
1613
1614static ssize_t stp_ctn_type_show(struct sysdev_class *class,
1615 struct sysdev_class_attribute *attr,
1616 char *buf)
1617{
1618 if (!stp_online)
1619 return -ENODATA;
1620 return sprintf(buf, "%i\n", stp_info.ctn);
1621}
1622
1623static SYSDEV_CLASS_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL);
1624
1625static ssize_t stp_dst_offset_show(struct sysdev_class *class,
1626 struct sysdev_class_attribute *attr,
1627 char *buf)
1628{
1629 if (!stp_online || !(stp_info.vbits & 0x2000))
1630 return -ENODATA;
1631 return sprintf(buf, "%i\n", (int)(s16) stp_info.dsto);
1632}
1633
1634static SYSDEV_CLASS_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL);
1635
1636static ssize_t stp_leap_seconds_show(struct sysdev_class *class,
1637 struct sysdev_class_attribute *attr,
1638 char *buf)
1639{
1640 if (!stp_online || !(stp_info.vbits & 0x8000))
1641 return -ENODATA;
1642 return sprintf(buf, "%i\n", (int)(s16) stp_info.leaps);
1643}
1644
1645static SYSDEV_CLASS_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL);
1646
1647static ssize_t stp_stratum_show(struct sysdev_class *class,
1648 struct sysdev_class_attribute *attr,
1649 char *buf)
1650{
1651 if (!stp_online)
1652 return -ENODATA;
1653 return sprintf(buf, "%i\n", (int)(s16) stp_info.stratum);
1654}
1655
1656static SYSDEV_CLASS_ATTR(stratum, 0400, stp_stratum_show, NULL);
1657
1658static ssize_t stp_time_offset_show(struct sysdev_class *class,
1659 struct sysdev_class_attribute *attr,
1660 char *buf)
1661{
1662 if (!stp_online || !(stp_info.vbits & 0x0800))
1663 return -ENODATA;
1664 return sprintf(buf, "%i\n", (int) stp_info.tto);
1665}
1666
1667static SYSDEV_CLASS_ATTR(time_offset, 0400, stp_time_offset_show, NULL);
1668
1669static ssize_t stp_time_zone_offset_show(struct sysdev_class *class,
1670 struct sysdev_class_attribute *attr,
1671 char *buf)
1672{
1673 if (!stp_online || !(stp_info.vbits & 0x4000))
1674 return -ENODATA;
1675 return sprintf(buf, "%i\n", (int)(s16) stp_info.tzo);
1676}
1677
1678static SYSDEV_CLASS_ATTR(time_zone_offset, 0400,
1679 stp_time_zone_offset_show, NULL);
1680
1681static ssize_t stp_timing_mode_show(struct sysdev_class *class,
1682 struct sysdev_class_attribute *attr,
1683 char *buf)
1684{
1685 if (!stp_online)
1686 return -ENODATA;
1687 return sprintf(buf, "%i\n", stp_info.tmd);
1688}
1689
1690static SYSDEV_CLASS_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL);
1691
1692static ssize_t stp_timing_state_show(struct sysdev_class *class,
1693 struct sysdev_class_attribute *attr,
1694 char *buf)
1695{
1696 if (!stp_online)
1697 return -ENODATA;
1698 return sprintf(buf, "%i\n", stp_info.tst);
1699}
1700
1701static SYSDEV_CLASS_ATTR(timing_state, 0400, stp_timing_state_show, NULL);
1702
1703static ssize_t stp_online_show(struct sysdev_class *class,
1704 struct sysdev_class_attribute *attr,
1705 char *buf)
1706{
1707 return sprintf(buf, "%i\n", stp_online);
1708}
1709
1710static ssize_t stp_online_store(struct sysdev_class *class,
1711 struct sysdev_class_attribute *attr,
1712 const char *buf, size_t count)
1713{
1714 unsigned int value;
1715
1716 value = simple_strtoul(buf, NULL, 0);
1717 if (value != 0 && value != 1)
1718 return -EINVAL;
1719 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
1720 return -EOPNOTSUPP;
1721 mutex_lock(&clock_sync_mutex);
1722 stp_online = value;
1723 if (stp_online)
1724 set_bit(CLOCK_SYNC_STP, &clock_sync_flags);
1725 else
1726 clear_bit(CLOCK_SYNC_STP, &clock_sync_flags);
1727 queue_work(time_sync_wq, &stp_work);
1728 mutex_unlock(&clock_sync_mutex);
1729 return count;
1730}
1731
1732/*
1733 * Can't use SYSDEV_CLASS_ATTR because the attribute should be named
1734 * stp/online but attr_online already exists in this file ..
1735 */
1736static struct sysdev_class_attribute attr_stp_online = {
1737 .attr = { .name = "online", .mode = 0600 },
1738 .show = stp_online_show,
1739 .store = stp_online_store,
1740};
1741
1742static struct sysdev_class_attribute *stp_attributes[] = {
1743 &attr_ctn_id,
1744 &attr_ctn_type,
1745 &attr_dst_offset,
1746 &attr_leap_seconds,
1747 &attr_stp_online,
1748 &attr_stratum,
1749 &attr_time_offset,
1750 &attr_time_zone_offset,
1751 &attr_timing_mode,
1752 &attr_timing_state,
1753 NULL
1754};
1755
1756static int __init stp_init_sysfs(void)
1757{
1758 struct sysdev_class_attribute **attr;
1759 int rc;
1760
1761 rc = sysdev_class_register(&stp_sysclass);
1762 if (rc)
1763 goto out;
1764 for (attr = stp_attributes; *attr; attr++) {
1765 rc = sysdev_class_create_file(&stp_sysclass, *attr);
1766 if (rc)
1767 goto out_unreg;
1768 }
1769 return 0;
1770out_unreg:
1771 for (; attr >= stp_attributes; attr--)
1772 sysdev_class_remove_file(&stp_sysclass, *attr);
1773 sysdev_class_unregister(&stp_sysclass);
1774out:
1775 return rc;
1776}
1777
1778device_initcall(stp_init_sysfs);