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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
105/*
106 * Scheduler clock - returns current time in nanosec units.
107 */
108unsigned long long notrace sched_clock(void)
109{
110 return tod_to_ns(get_tod_clock_monotonic());
111}
112NOKPROBE_SYMBOL(sched_clock);
113
114static void ext_to_timespec64(union tod_clock *clk, struct timespec64 *xt)
115{
116 unsigned long rem, sec, nsec;
117
118 sec = clk->us;
119 rem = do_div(sec, 1000000);
120 nsec = ((clk->sus + (rem << 12)) * 125) >> 9;
121 xt->tv_sec = sec;
122 xt->tv_nsec = nsec;
123}
124
125void clock_comparator_work(void)
126{
127 struct clock_event_device *cd;
128
129 S390_lowcore.clock_comparator = clock_comparator_max;
130 cd = this_cpu_ptr(&comparators);
131 cd->event_handler(cd);
132}
133
134static int s390_next_event(unsigned long delta,
135 struct clock_event_device *evt)
136{
137 S390_lowcore.clock_comparator = get_tod_clock() + delta;
138 set_clock_comparator(S390_lowcore.clock_comparator);
139 return 0;
140}
141
142/*
143 * Set up lowcore and control register of the current cpu to
144 * enable TOD clock and clock comparator interrupts.
145 */
146void init_cpu_timer(void)
147{
148 struct clock_event_device *cd;
149 int cpu;
150
151 S390_lowcore.clock_comparator = clock_comparator_max;
152 set_clock_comparator(S390_lowcore.clock_comparator);
153
154 cpu = smp_processor_id();
155 cd = &per_cpu(comparators, cpu);
156 cd->name = "comparator";
157 cd->features = CLOCK_EVT_FEAT_ONESHOT;
158 cd->mult = 16777;
159 cd->shift = 12;
160 cd->min_delta_ns = 1;
161 cd->min_delta_ticks = 1;
162 cd->max_delta_ns = LONG_MAX;
163 cd->max_delta_ticks = ULONG_MAX;
164 cd->rating = 400;
165 cd->cpumask = cpumask_of(cpu);
166 cd->set_next_event = s390_next_event;
167
168 clockevents_register_device(cd);
169
170 /* Enable clock comparator timer interrupt. */
171 __ctl_set_bit(0,11);
172
173 /* Always allow the timing alert external interrupt. */
174 __ctl_set_bit(0, 4);
175}
176
177static void clock_comparator_interrupt(struct ext_code ext_code,
178 unsigned int param32,
179 unsigned long param64)
180{
181 inc_irq_stat(IRQEXT_CLK);
182 if (S390_lowcore.clock_comparator == clock_comparator_max)
183 set_clock_comparator(S390_lowcore.clock_comparator);
184}
185
186static void stp_timing_alert(struct stp_irq_parm *);
187
188static void timing_alert_interrupt(struct ext_code ext_code,
189 unsigned int param32, unsigned long param64)
190{
191 inc_irq_stat(IRQEXT_TLA);
192 if (param32 & 0x00038000)
193 stp_timing_alert((struct stp_irq_parm *) ¶m32);
194}
195
196static void stp_reset(void);
197
198void read_persistent_clock64(struct timespec64 *ts)
199{
200 union tod_clock clk;
201 u64 delta;
202
203 delta = initial_leap_seconds + TOD_UNIX_EPOCH;
204 store_tod_clock_ext(&clk);
205 clk.eitod -= delta;
206 ext_to_timespec64(&clk, ts);
207}
208
209void __init read_persistent_wall_and_boot_offset(struct timespec64 *wall_time,
210 struct timespec64 *boot_offset)
211{
212 struct timespec64 boot_time;
213 union tod_clock clk;
214 u64 delta;
215
216 delta = initial_leap_seconds + TOD_UNIX_EPOCH;
217 clk = tod_clock_base;
218 clk.eitod -= delta;
219 ext_to_timespec64(&clk, &boot_time);
220
221 read_persistent_clock64(wall_time);
222 *boot_offset = timespec64_sub(*wall_time, boot_time);
223}
224
225static u64 read_tod_clock(struct clocksource *cs)
226{
227 unsigned long now, adj;
228
229 preempt_disable(); /* protect from changes to steering parameters */
230 now = get_tod_clock();
231 adj = tod_steering_end - now;
232 if (unlikely((s64) adj > 0))
233 /*
234 * manually steer by 1 cycle every 2^16 cycles. This
235 * corresponds to shifting the tod delta by 15. 1s is
236 * therefore steered in ~9h. The adjust will decrease
237 * over time, until it finally reaches 0.
238 */
239 now += (tod_steering_delta < 0) ? (adj >> 15) : -(adj >> 15);
240 preempt_enable();
241 return now;
242}
243
244static struct clocksource clocksource_tod = {
245 .name = "tod",
246 .rating = 400,
247 .read = read_tod_clock,
248 .mask = CLOCKSOURCE_MASK(64),
249 .mult = 1000,
250 .shift = 12,
251 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
252 .vdso_clock_mode = VDSO_CLOCKMODE_TOD,
253};
254
255struct clocksource * __init clocksource_default_clock(void)
256{
257 return &clocksource_tod;
258}
259
260/*
261 * Initialize the TOD clock and the CPU timer of
262 * the boot cpu.
263 */
264void __init time_init(void)
265{
266 /* Reset time synchronization interfaces. */
267 stp_reset();
268
269 /* request the clock comparator external interrupt */
270 if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt))
271 panic("Couldn't request external interrupt 0x1004");
272
273 /* request the timing alert external interrupt */
274 if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt))
275 panic("Couldn't request external interrupt 0x1406");
276
277 if (__clocksource_register(&clocksource_tod) != 0)
278 panic("Could not register TOD clock source");
279
280 /* Enable TOD clock interrupts on the boot cpu. */
281 init_cpu_timer();
282
283 /* Enable cpu timer interrupts on the boot cpu. */
284 vtime_init();
285}
286
287static DEFINE_PER_CPU(atomic_t, clock_sync_word);
288static DEFINE_MUTEX(stp_mutex);
289static unsigned long clock_sync_flags;
290
291#define CLOCK_SYNC_HAS_STP 0
292#define CLOCK_SYNC_STP 1
293#define CLOCK_SYNC_STPINFO_VALID 2
294
295/*
296 * The get_clock function for the physical clock. It will get the current
297 * TOD clock, subtract the LPAR offset and write the result to *clock.
298 * The function returns 0 if the clock is in sync with the external time
299 * source. If the clock mode is local it will return -EOPNOTSUPP and
300 * -EAGAIN if the clock is not in sync with the external reference.
301 */
302int get_phys_clock(unsigned long *clock)
303{
304 atomic_t *sw_ptr;
305 unsigned int sw0, sw1;
306
307 sw_ptr = &get_cpu_var(clock_sync_word);
308 sw0 = atomic_read(sw_ptr);
309 *clock = get_tod_clock() - lpar_offset;
310 sw1 = atomic_read(sw_ptr);
311 put_cpu_var(clock_sync_word);
312 if (sw0 == sw1 && (sw0 & 0x80000000U))
313 /* Success: time is in sync. */
314 return 0;
315 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
316 return -EOPNOTSUPP;
317 if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags))
318 return -EACCES;
319 return -EAGAIN;
320}
321EXPORT_SYMBOL(get_phys_clock);
322
323/*
324 * Make get_phys_clock() return -EAGAIN.
325 */
326static void disable_sync_clock(void *dummy)
327{
328 atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
329 /*
330 * Clear the in-sync bit 2^31. All get_phys_clock calls will
331 * fail until the sync bit is turned back on. In addition
332 * increase the "sequence" counter to avoid the race of an
333 * stp event and the complete recovery against get_phys_clock.
334 */
335 atomic_andnot(0x80000000, sw_ptr);
336 atomic_inc(sw_ptr);
337}
338
339/*
340 * Make get_phys_clock() return 0 again.
341 * Needs to be called from a context disabled for preemption.
342 */
343static void enable_sync_clock(void)
344{
345 atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
346 atomic_or(0x80000000, sw_ptr);
347}
348
349/*
350 * Function to check if the clock is in sync.
351 */
352static inline int check_sync_clock(void)
353{
354 atomic_t *sw_ptr;
355 int rc;
356
357 sw_ptr = &get_cpu_var(clock_sync_word);
358 rc = (atomic_read(sw_ptr) & 0x80000000U) != 0;
359 put_cpu_var(clock_sync_word);
360 return rc;
361}
362
363/*
364 * Apply clock delta to the global data structures.
365 * This is called once on the CPU that performed the clock sync.
366 */
367static void clock_sync_global(long delta)
368{
369 unsigned long now, adj;
370 struct ptff_qto qto;
371 int cs;
372
373 /* Fixup the monotonic sched clock. */
374 tod_clock_base.eitod += delta;
375 /* Adjust TOD steering parameters. */
376 now = get_tod_clock();
377 adj = tod_steering_end - now;
378 if (unlikely((s64) adj >= 0))
379 /* Calculate how much of the old adjustment is left. */
380 tod_steering_delta = (tod_steering_delta < 0) ?
381 -(adj >> 15) : (adj >> 15);
382 tod_steering_delta += delta;
383 if ((abs(tod_steering_delta) >> 48) != 0)
384 panic("TOD clock sync offset %li is too large to drift\n",
385 tod_steering_delta);
386 tod_steering_end = now + (abs(tod_steering_delta) << 15);
387 for (cs = 0; cs < CS_BASES; cs++) {
388 vdso_data[cs].arch_data.tod_steering_end = tod_steering_end;
389 vdso_data[cs].arch_data.tod_steering_delta = tod_steering_delta;
390 }
391
392 /* Update LPAR offset. */
393 if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0)
394 lpar_offset = qto.tod_epoch_difference;
395 /* Call the TOD clock change notifier. */
396 atomic_notifier_call_chain(&s390_epoch_delta_notifier, 0, &delta);
397}
398
399/*
400 * Apply clock delta to the per-CPU data structures of this CPU.
401 * This is called for each online CPU after the call to clock_sync_global.
402 */
403static void clock_sync_local(long delta)
404{
405 /* Add the delta to the clock comparator. */
406 if (S390_lowcore.clock_comparator != clock_comparator_max) {
407 S390_lowcore.clock_comparator += delta;
408 set_clock_comparator(S390_lowcore.clock_comparator);
409 }
410 /* Adjust the last_update_clock time-stamp. */
411 S390_lowcore.last_update_clock += delta;
412}
413
414/* Single threaded workqueue used for stp sync events */
415static struct workqueue_struct *time_sync_wq;
416
417static void __init time_init_wq(void)
418{
419 if (time_sync_wq)
420 return;
421 time_sync_wq = create_singlethread_workqueue("timesync");
422}
423
424struct clock_sync_data {
425 atomic_t cpus;
426 int in_sync;
427 long clock_delta;
428};
429
430/*
431 * Server Time Protocol (STP) code.
432 */
433static bool stp_online;
434static struct stp_sstpi stp_info;
435static void *stp_page;
436
437static void stp_work_fn(struct work_struct *work);
438static DECLARE_WORK(stp_work, stp_work_fn);
439static struct timer_list stp_timer;
440
441static int __init early_parse_stp(char *p)
442{
443 return kstrtobool(p, &stp_online);
444}
445early_param("stp", early_parse_stp);
446
447/*
448 * Reset STP attachment.
449 */
450static void __init stp_reset(void)
451{
452 int rc;
453
454 stp_page = (void *) get_zeroed_page(GFP_ATOMIC);
455 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);
456 if (rc == 0)
457 set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags);
458 else if (stp_online) {
459 pr_warn("The real or virtual hardware system does not provide an STP interface\n");
460 free_page((unsigned long) stp_page);
461 stp_page = NULL;
462 stp_online = false;
463 }
464}
465
466static void stp_timeout(struct timer_list *unused)
467{
468 queue_work(time_sync_wq, &stp_work);
469}
470
471static int __init stp_init(void)
472{
473 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
474 return 0;
475 timer_setup(&stp_timer, stp_timeout, 0);
476 time_init_wq();
477 if (!stp_online)
478 return 0;
479 queue_work(time_sync_wq, &stp_work);
480 return 0;
481}
482
483arch_initcall(stp_init);
484
485/*
486 * STP timing alert. There are three causes:
487 * 1) timing status change
488 * 2) link availability change
489 * 3) time control parameter change
490 * In all three cases we are only interested in the clock source state.
491 * If a STP clock source is now available use it.
492 */
493static void stp_timing_alert(struct stp_irq_parm *intparm)
494{
495 if (intparm->tsc || intparm->lac || intparm->tcpc)
496 queue_work(time_sync_wq, &stp_work);
497}
498
499/*
500 * STP sync check machine check. This is called when the timing state
501 * changes from the synchronized state to the unsynchronized state.
502 * After a STP sync check the clock is not in sync. The machine check
503 * is broadcasted to all cpus at the same time.
504 */
505int stp_sync_check(void)
506{
507 disable_sync_clock(NULL);
508 return 1;
509}
510
511/*
512 * STP island condition machine check. This is called when an attached
513 * server attempts to communicate over an STP link and the servers
514 * have matching CTN ids and have a valid stratum-1 configuration
515 * but the configurations do not match.
516 */
517int stp_island_check(void)
518{
519 disable_sync_clock(NULL);
520 return 1;
521}
522
523void stp_queue_work(void)
524{
525 queue_work(time_sync_wq, &stp_work);
526}
527
528static int __store_stpinfo(void)
529{
530 int rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi));
531
532 if (rc)
533 clear_bit(CLOCK_SYNC_STPINFO_VALID, &clock_sync_flags);
534 else
535 set_bit(CLOCK_SYNC_STPINFO_VALID, &clock_sync_flags);
536 return rc;
537}
538
539static int stpinfo_valid(void)
540{
541 return stp_online && test_bit(CLOCK_SYNC_STPINFO_VALID, &clock_sync_flags);
542}
543
544static int stp_sync_clock(void *data)
545{
546 struct clock_sync_data *sync = data;
547 long clock_delta, flags;
548 static int first;
549 int rc;
550
551 enable_sync_clock();
552 if (xchg(&first, 1) == 0) {
553 /* Wait until all other cpus entered the sync function. */
554 while (atomic_read(&sync->cpus) != 0)
555 cpu_relax();
556 rc = 0;
557 if (stp_info.todoff || stp_info.tmd != 2) {
558 flags = vdso_update_begin();
559 rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0,
560 &clock_delta);
561 if (rc == 0) {
562 sync->clock_delta = clock_delta;
563 clock_sync_global(clock_delta);
564 rc = __store_stpinfo();
565 if (rc == 0 && stp_info.tmd != 2)
566 rc = -EAGAIN;
567 }
568 vdso_update_end(flags);
569 }
570 sync->in_sync = rc ? -EAGAIN : 1;
571 xchg(&first, 0);
572 } else {
573 /* Slave */
574 atomic_dec(&sync->cpus);
575 /* Wait for in_sync to be set. */
576 while (READ_ONCE(sync->in_sync) == 0)
577 __udelay(1);
578 }
579 if (sync->in_sync != 1)
580 /* Didn't work. Clear per-cpu in sync bit again. */
581 disable_sync_clock(NULL);
582 /* Apply clock delta to per-CPU fields of this CPU. */
583 clock_sync_local(sync->clock_delta);
584
585 return 0;
586}
587
588static int stp_clear_leap(void)
589{
590 struct __kernel_timex txc;
591 int ret;
592
593 memset(&txc, 0, sizeof(txc));
594
595 ret = do_adjtimex(&txc);
596 if (ret < 0)
597 return ret;
598
599 txc.modes = ADJ_STATUS;
600 txc.status &= ~(STA_INS|STA_DEL);
601 return do_adjtimex(&txc);
602}
603
604static void stp_check_leap(void)
605{
606 struct stp_stzi stzi;
607 struct stp_lsoib *lsoib = &stzi.lsoib;
608 struct __kernel_timex txc;
609 int64_t timediff;
610 int leapdiff, ret;
611
612 if (!stp_info.lu || !check_sync_clock()) {
613 /*
614 * Either a scheduled leap second was removed by the operator,
615 * or STP is out of sync. In both cases, clear the leap second
616 * kernel flags.
617 */
618 if (stp_clear_leap() < 0)
619 pr_err("failed to clear leap second flags\n");
620 return;
621 }
622
623 if (chsc_stzi(stp_page, &stzi, sizeof(stzi))) {
624 pr_err("stzi failed\n");
625 return;
626 }
627
628 timediff = tod_to_ns(lsoib->nlsout - get_tod_clock()) / NSEC_PER_SEC;
629 leapdiff = lsoib->nlso - lsoib->also;
630
631 if (leapdiff != 1 && leapdiff != -1) {
632 pr_err("Cannot schedule %d leap seconds\n", leapdiff);
633 return;
634 }
635
636 if (timediff < 0) {
637 if (stp_clear_leap() < 0)
638 pr_err("failed to clear leap second flags\n");
639 } else if (timediff < 7200) {
640 memset(&txc, 0, sizeof(txc));
641 ret = do_adjtimex(&txc);
642 if (ret < 0)
643 return;
644
645 txc.modes = ADJ_STATUS;
646 if (leapdiff > 0)
647 txc.status |= STA_INS;
648 else
649 txc.status |= STA_DEL;
650 ret = do_adjtimex(&txc);
651 if (ret < 0)
652 pr_err("failed to set leap second flags\n");
653 /* arm Timer to clear leap second flags */
654 mod_timer(&stp_timer, jiffies + msecs_to_jiffies(14400 * MSEC_PER_SEC));
655 } else {
656 /* The day the leap second is scheduled for hasn't been reached. Retry
657 * in one hour.
658 */
659 mod_timer(&stp_timer, jiffies + msecs_to_jiffies(3600 * MSEC_PER_SEC));
660 }
661}
662
663/*
664 * STP work. Check for the STP state and take over the clock
665 * synchronization if the STP clock source is usable.
666 */
667static void stp_work_fn(struct work_struct *work)
668{
669 struct clock_sync_data stp_sync;
670 int rc;
671
672 /* prevent multiple execution. */
673 mutex_lock(&stp_mutex);
674
675 if (!stp_online) {
676 chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);
677 del_timer_sync(&stp_timer);
678 goto out_unlock;
679 }
680
681 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xf0e0, NULL);
682 if (rc)
683 goto out_unlock;
684
685 rc = __store_stpinfo();
686 if (rc || stp_info.c == 0)
687 goto out_unlock;
688
689 /* Skip synchronization if the clock is already in sync. */
690 if (!check_sync_clock()) {
691 memset(&stp_sync, 0, sizeof(stp_sync));
692 cpus_read_lock();
693 atomic_set(&stp_sync.cpus, num_online_cpus() - 1);
694 stop_machine_cpuslocked(stp_sync_clock, &stp_sync, cpu_online_mask);
695 cpus_read_unlock();
696 }
697
698 if (!check_sync_clock())
699 /*
700 * There is a usable clock but the synchonization failed.
701 * Retry after a second.
702 */
703 mod_timer(&stp_timer, jiffies + msecs_to_jiffies(MSEC_PER_SEC));
704 else if (stp_info.lu)
705 stp_check_leap();
706
707out_unlock:
708 mutex_unlock(&stp_mutex);
709}
710
711/*
712 * STP subsys sysfs interface functions
713 */
714static struct bus_type stp_subsys = {
715 .name = "stp",
716 .dev_name = "stp",
717};
718
719static ssize_t ctn_id_show(struct device *dev,
720 struct device_attribute *attr,
721 char *buf)
722{
723 ssize_t ret = -ENODATA;
724
725 mutex_lock(&stp_mutex);
726 if (stpinfo_valid())
727 ret = sprintf(buf, "%016lx\n",
728 *(unsigned long *) stp_info.ctnid);
729 mutex_unlock(&stp_mutex);
730 return ret;
731}
732
733static DEVICE_ATTR_RO(ctn_id);
734
735static ssize_t ctn_type_show(struct device *dev,
736 struct device_attribute *attr,
737 char *buf)
738{
739 ssize_t ret = -ENODATA;
740
741 mutex_lock(&stp_mutex);
742 if (stpinfo_valid())
743 ret = sprintf(buf, "%i\n", stp_info.ctn);
744 mutex_unlock(&stp_mutex);
745 return ret;
746}
747
748static DEVICE_ATTR_RO(ctn_type);
749
750static ssize_t dst_offset_show(struct device *dev,
751 struct device_attribute *attr,
752 char *buf)
753{
754 ssize_t ret = -ENODATA;
755
756 mutex_lock(&stp_mutex);
757 if (stpinfo_valid() && (stp_info.vbits & 0x2000))
758 ret = sprintf(buf, "%i\n", (int)(s16) stp_info.dsto);
759 mutex_unlock(&stp_mutex);
760 return ret;
761}
762
763static DEVICE_ATTR_RO(dst_offset);
764
765static ssize_t leap_seconds_show(struct device *dev,
766 struct device_attribute *attr,
767 char *buf)
768{
769 ssize_t ret = -ENODATA;
770
771 mutex_lock(&stp_mutex);
772 if (stpinfo_valid() && (stp_info.vbits & 0x8000))
773 ret = sprintf(buf, "%i\n", (int)(s16) stp_info.leaps);
774 mutex_unlock(&stp_mutex);
775 return ret;
776}
777
778static DEVICE_ATTR_RO(leap_seconds);
779
780static ssize_t leap_seconds_scheduled_show(struct device *dev,
781 struct device_attribute *attr,
782 char *buf)
783{
784 struct stp_stzi stzi;
785 ssize_t ret;
786
787 mutex_lock(&stp_mutex);
788 if (!stpinfo_valid() || !(stp_info.vbits & 0x8000) || !stp_info.lu) {
789 mutex_unlock(&stp_mutex);
790 return -ENODATA;
791 }
792
793 ret = chsc_stzi(stp_page, &stzi, sizeof(stzi));
794 mutex_unlock(&stp_mutex);
795 if (ret < 0)
796 return ret;
797
798 if (!stzi.lsoib.p)
799 return sprintf(buf, "0,0\n");
800
801 return sprintf(buf, "%lu,%d\n",
802 tod_to_ns(stzi.lsoib.nlsout - TOD_UNIX_EPOCH) / NSEC_PER_SEC,
803 stzi.lsoib.nlso - stzi.lsoib.also);
804}
805
806static DEVICE_ATTR_RO(leap_seconds_scheduled);
807
808static ssize_t stratum_show(struct device *dev,
809 struct device_attribute *attr,
810 char *buf)
811{
812 ssize_t ret = -ENODATA;
813
814 mutex_lock(&stp_mutex);
815 if (stpinfo_valid())
816 ret = sprintf(buf, "%i\n", (int)(s16) stp_info.stratum);
817 mutex_unlock(&stp_mutex);
818 return ret;
819}
820
821static DEVICE_ATTR_RO(stratum);
822
823static ssize_t time_offset_show(struct device *dev,
824 struct device_attribute *attr,
825 char *buf)
826{
827 ssize_t ret = -ENODATA;
828
829 mutex_lock(&stp_mutex);
830 if (stpinfo_valid() && (stp_info.vbits & 0x0800))
831 ret = sprintf(buf, "%i\n", (int) stp_info.tto);
832 mutex_unlock(&stp_mutex);
833 return ret;
834}
835
836static DEVICE_ATTR_RO(time_offset);
837
838static ssize_t time_zone_offset_show(struct device *dev,
839 struct device_attribute *attr,
840 char *buf)
841{
842 ssize_t ret = -ENODATA;
843
844 mutex_lock(&stp_mutex);
845 if (stpinfo_valid() && (stp_info.vbits & 0x4000))
846 ret = sprintf(buf, "%i\n", (int)(s16) stp_info.tzo);
847 mutex_unlock(&stp_mutex);
848 return ret;
849}
850
851static DEVICE_ATTR_RO(time_zone_offset);
852
853static ssize_t timing_mode_show(struct device *dev,
854 struct device_attribute *attr,
855 char *buf)
856{
857 ssize_t ret = -ENODATA;
858
859 mutex_lock(&stp_mutex);
860 if (stpinfo_valid())
861 ret = sprintf(buf, "%i\n", stp_info.tmd);
862 mutex_unlock(&stp_mutex);
863 return ret;
864}
865
866static DEVICE_ATTR_RO(timing_mode);
867
868static ssize_t timing_state_show(struct device *dev,
869 struct device_attribute *attr,
870 char *buf)
871{
872 ssize_t ret = -ENODATA;
873
874 mutex_lock(&stp_mutex);
875 if (stpinfo_valid())
876 ret = sprintf(buf, "%i\n", stp_info.tst);
877 mutex_unlock(&stp_mutex);
878 return ret;
879}
880
881static DEVICE_ATTR_RO(timing_state);
882
883static ssize_t online_show(struct device *dev,
884 struct device_attribute *attr,
885 char *buf)
886{
887 return sprintf(buf, "%i\n", stp_online);
888}
889
890static ssize_t online_store(struct device *dev,
891 struct device_attribute *attr,
892 const char *buf, size_t count)
893{
894 unsigned int value;
895
896 value = simple_strtoul(buf, NULL, 0);
897 if (value != 0 && value != 1)
898 return -EINVAL;
899 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
900 return -EOPNOTSUPP;
901 mutex_lock(&stp_mutex);
902 stp_online = value;
903 if (stp_online)
904 set_bit(CLOCK_SYNC_STP, &clock_sync_flags);
905 else
906 clear_bit(CLOCK_SYNC_STP, &clock_sync_flags);
907 queue_work(time_sync_wq, &stp_work);
908 mutex_unlock(&stp_mutex);
909 return count;
910}
911
912/*
913 * Can't use DEVICE_ATTR because the attribute should be named
914 * stp/online but dev_attr_online already exists in this file ..
915 */
916static DEVICE_ATTR_RW(online);
917
918static struct attribute *stp_dev_attrs[] = {
919 &dev_attr_ctn_id.attr,
920 &dev_attr_ctn_type.attr,
921 &dev_attr_dst_offset.attr,
922 &dev_attr_leap_seconds.attr,
923 &dev_attr_online.attr,
924 &dev_attr_leap_seconds_scheduled.attr,
925 &dev_attr_stratum.attr,
926 &dev_attr_time_offset.attr,
927 &dev_attr_time_zone_offset.attr,
928 &dev_attr_timing_mode.attr,
929 &dev_attr_timing_state.attr,
930 NULL
931};
932ATTRIBUTE_GROUPS(stp_dev);
933
934static int __init stp_init_sysfs(void)
935{
936 return subsys_system_register(&stp_subsys, stp_dev_groups);
937}
938
939device_initcall(stp_init_sysfs);
1/*
2 * Time of day based timer functions.
3 *
4 * S390 version
5 * Copyright IBM Corp. 1999, 2008
6 * Author(s): Hartmut Penner (hp@de.ibm.com),
7 * Martin Schwidefsky (schwidefsky@de.ibm.com),
8 * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
9 *
10 * Derived from "arch/i386/kernel/time.c"
11 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
12 */
13
14#define KMSG_COMPONENT "time"
15#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
16
17#include <linux/kernel_stat.h>
18#include <linux/errno.h>
19#include <linux/module.h>
20#include <linux/sched.h>
21#include <linux/kernel.h>
22#include <linux/param.h>
23#include <linux/string.h>
24#include <linux/mm.h>
25#include <linux/interrupt.h>
26#include <linux/cpu.h>
27#include <linux/stop_machine.h>
28#include <linux/time.h>
29#include <linux/device.h>
30#include <linux/delay.h>
31#include <linux/init.h>
32#include <linux/smp.h>
33#include <linux/types.h>
34#include <linux/profile.h>
35#include <linux/timex.h>
36#include <linux/notifier.h>
37#include <linux/timekeeper_internal.h>
38#include <linux/clockchips.h>
39#include <linux/gfp.h>
40#include <linux/kprobes.h>
41#include <asm/uaccess.h>
42#include <asm/delay.h>
43#include <asm/div64.h>
44#include <asm/vdso.h>
45#include <asm/irq.h>
46#include <asm/irq_regs.h>
47#include <asm/vtimer.h>
48#include <asm/etr.h>
49#include <asm/cio.h>
50#include "entry.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 tod_to_ns(get_tod_clock_monotonic());
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 cd = &__get_cpu_var(comparators);
96 cd->event_handler(cd);
97}
98
99/*
100 * Fixup the clock comparator.
101 */
102static void fixup_clock_comparator(unsigned long long delta)
103{
104 /* If nobody is waiting there's nothing to fix. */
105 if (S390_lowcore.clock_comparator == -1ULL)
106 return;
107 S390_lowcore.clock_comparator += delta;
108 set_clock_comparator(S390_lowcore.clock_comparator);
109}
110
111static int s390_next_event(unsigned long delta,
112 struct clock_event_device *evt)
113{
114 S390_lowcore.clock_comparator = get_tod_clock() + delta;
115 set_clock_comparator(S390_lowcore.clock_comparator);
116 return 0;
117}
118
119static void s390_set_mode(enum clock_event_mode mode,
120 struct clock_event_device *evt)
121{
122}
123
124/*
125 * Set up lowcore and control register of the current cpu to
126 * enable TOD clock and clock comparator interrupts.
127 */
128void init_cpu_timer(void)
129{
130 struct clock_event_device *cd;
131 int cpu;
132
133 S390_lowcore.clock_comparator = -1ULL;
134 set_clock_comparator(S390_lowcore.clock_comparator);
135
136 cpu = smp_processor_id();
137 cd = &per_cpu(comparators, cpu);
138 cd->name = "comparator";
139 cd->features = CLOCK_EVT_FEAT_ONESHOT;
140 cd->mult = 16777;
141 cd->shift = 12;
142 cd->min_delta_ns = 1;
143 cd->max_delta_ns = LONG_MAX;
144 cd->rating = 400;
145 cd->cpumask = cpumask_of(cpu);
146 cd->set_next_event = s390_next_event;
147 cd->set_mode = s390_set_mode;
148
149 clockevents_register_device(cd);
150
151 /* Enable clock comparator timer interrupt. */
152 __ctl_set_bit(0,11);
153
154 /* Always allow the timing alert external interrupt. */
155 __ctl_set_bit(0, 4);
156}
157
158static void clock_comparator_interrupt(struct ext_code ext_code,
159 unsigned int param32,
160 unsigned long param64)
161{
162 inc_irq_stat(IRQEXT_CLK);
163 if (S390_lowcore.clock_comparator == -1ULL)
164 set_clock_comparator(S390_lowcore.clock_comparator);
165}
166
167static void etr_timing_alert(struct etr_irq_parm *);
168static void stp_timing_alert(struct stp_irq_parm *);
169
170static void timing_alert_interrupt(struct ext_code ext_code,
171 unsigned int param32, unsigned long param64)
172{
173 inc_irq_stat(IRQEXT_TLA);
174 if (param32 & 0x00c40000)
175 etr_timing_alert((struct etr_irq_parm *) ¶m32);
176 if (param32 & 0x00038000)
177 stp_timing_alert((struct stp_irq_parm *) ¶m32);
178}
179
180static void etr_reset(void);
181static void stp_reset(void);
182
183void read_persistent_clock(struct timespec *ts)
184{
185 tod_to_timeval(get_tod_clock() - TOD_UNIX_EPOCH, ts);
186}
187
188void read_boot_clock(struct timespec *ts)
189{
190 tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, ts);
191}
192
193static cycle_t read_tod_clock(struct clocksource *cs)
194{
195 return get_tod_clock();
196}
197
198static struct clocksource clocksource_tod = {
199 .name = "tod",
200 .rating = 400,
201 .read = read_tod_clock,
202 .mask = -1ULL,
203 .mult = 1000,
204 .shift = 12,
205 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
206};
207
208struct clocksource * __init clocksource_default_clock(void)
209{
210 return &clocksource_tod;
211}
212
213void update_vsyscall(struct timekeeper *tk)
214{
215 u64 nsecps;
216
217 if (tk->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 = tk->clock->cycle_last;
224 vdso_data->xtime_clock_sec = tk->xtime_sec;
225 vdso_data->xtime_clock_nsec = tk->xtime_nsec;
226 vdso_data->wtom_clock_sec =
227 tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
228 vdso_data->wtom_clock_nsec = tk->xtime_nsec +
229 + (tk->wall_to_monotonic.tv_nsec << tk->shift);
230 nsecps = (u64) NSEC_PER_SEC << tk->shift;
231 while (vdso_data->wtom_clock_nsec >= nsecps) {
232 vdso_data->wtom_clock_nsec -= nsecps;
233 vdso_data->wtom_clock_sec++;
234 }
235 vdso_data->tk_mult = tk->mult;
236 vdso_data->tk_shift = tk->shift;
237 smp_wmb();
238 ++vdso_data->tb_update_count;
239}
240
241extern struct timezone sys_tz;
242
243void update_vsyscall_tz(void)
244{
245 /* Make userspace gettimeofday spin until we're done. */
246 ++vdso_data->tb_update_count;
247 smp_wmb();
248 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
249 vdso_data->tz_dsttime = sys_tz.tz_dsttime;
250 smp_wmb();
251 ++vdso_data->tb_update_count;
252}
253
254/*
255 * Initialize the TOD clock and the CPU timer of
256 * the boot cpu.
257 */
258void __init time_init(void)
259{
260 /* Reset time synchronization interfaces. */
261 etr_reset();
262 stp_reset();
263
264 /* request the clock comparator external interrupt */
265 if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt))
266 panic("Couldn't request external interrupt 0x1004");
267
268 /* request the timing alert external interrupt */
269 if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt))
270 panic("Couldn't request external interrupt 0x1406");
271
272 if (clocksource_register(&clocksource_tod) != 0)
273 panic("Could not register TOD clock source");
274
275 /* Enable TOD clock interrupts on the boot cpu. */
276 init_cpu_timer();
277
278 /* Enable cpu timer interrupts on the boot cpu. */
279 vtime_init();
280}
281
282/*
283 * The time is "clock". old is what we think the time is.
284 * Adjust the value by a multiple of jiffies and add the delta to ntp.
285 * "delay" is an approximation how long the synchronization took. If
286 * the time correction is positive, then "delay" is subtracted from
287 * the time difference and only the remaining part is passed to ntp.
288 */
289static unsigned long long adjust_time(unsigned long long old,
290 unsigned long long clock,
291 unsigned long long delay)
292{
293 unsigned long long delta, ticks;
294 struct timex adjust;
295
296 if (clock > old) {
297 /* It is later than we thought. */
298 delta = ticks = clock - old;
299 delta = ticks = (delta < delay) ? 0 : delta - delay;
300 delta -= do_div(ticks, CLK_TICKS_PER_JIFFY);
301 adjust.offset = ticks * (1000000 / HZ);
302 } else {
303 /* It is earlier than we thought. */
304 delta = ticks = old - clock;
305 delta -= do_div(ticks, CLK_TICKS_PER_JIFFY);
306 delta = -delta;
307 adjust.offset = -ticks * (1000000 / HZ);
308 }
309 sched_clock_base_cc += delta;
310 if (adjust.offset != 0) {
311 pr_notice("The ETR interface has adjusted the clock "
312 "by %li microseconds\n", adjust.offset);
313 adjust.modes = ADJ_OFFSET_SINGLESHOT;
314 do_adjtimex(&adjust);
315 }
316 return delta;
317}
318
319static DEFINE_PER_CPU(atomic_t, clock_sync_word);
320static DEFINE_MUTEX(clock_sync_mutex);
321static unsigned long clock_sync_flags;
322
323#define CLOCK_SYNC_HAS_ETR 0
324#define CLOCK_SYNC_HAS_STP 1
325#define CLOCK_SYNC_ETR 2
326#define CLOCK_SYNC_STP 3
327
328/*
329 * The synchronous get_clock function. It will write the current clock
330 * value to the clock pointer and return 0 if the clock is in sync with
331 * the external time source. If the clock mode is local it will return
332 * -EOPNOTSUPP and -EAGAIN if the clock is not in sync with the external
333 * reference.
334 */
335int get_sync_clock(unsigned long long *clock)
336{
337 atomic_t *sw_ptr;
338 unsigned int sw0, sw1;
339
340 sw_ptr = &get_cpu_var(clock_sync_word);
341 sw0 = atomic_read(sw_ptr);
342 *clock = get_tod_clock();
343 sw1 = atomic_read(sw_ptr);
344 put_cpu_var(clock_sync_word);
345 if (sw0 == sw1 && (sw0 & 0x80000000U))
346 /* Success: time is in sync. */
347 return 0;
348 if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags) &&
349 !test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
350 return -EOPNOTSUPP;
351 if (!test_bit(CLOCK_SYNC_ETR, &clock_sync_flags) &&
352 !test_bit(CLOCK_SYNC_STP, &clock_sync_flags))
353 return -EACCES;
354 return -EAGAIN;
355}
356EXPORT_SYMBOL(get_sync_clock);
357
358/*
359 * Make get_sync_clock return -EAGAIN.
360 */
361static void disable_sync_clock(void *dummy)
362{
363 atomic_t *sw_ptr = &__get_cpu_var(clock_sync_word);
364 /*
365 * Clear the in-sync bit 2^31. All get_sync_clock calls will
366 * fail until the sync bit is turned back on. In addition
367 * increase the "sequence" counter to avoid the race of an
368 * etr event and the complete recovery against get_sync_clock.
369 */
370 atomic_clear_mask(0x80000000, sw_ptr);
371 atomic_inc(sw_ptr);
372}
373
374/*
375 * Make get_sync_clock return 0 again.
376 * Needs to be called from a context disabled for preemption.
377 */
378static void enable_sync_clock(void)
379{
380 atomic_t *sw_ptr = &__get_cpu_var(clock_sync_word);
381 atomic_set_mask(0x80000000, sw_ptr);
382}
383
384/*
385 * Function to check if the clock is in sync.
386 */
387static inline int check_sync_clock(void)
388{
389 atomic_t *sw_ptr;
390 int rc;
391
392 sw_ptr = &get_cpu_var(clock_sync_word);
393 rc = (atomic_read(sw_ptr) & 0x80000000U) != 0;
394 put_cpu_var(clock_sync_word);
395 return rc;
396}
397
398/* Single threaded workqueue used for etr and stp sync events */
399static struct workqueue_struct *time_sync_wq;
400
401static void __init time_init_wq(void)
402{
403 if (time_sync_wq)
404 return;
405 time_sync_wq = create_singlethread_workqueue("timesync");
406}
407
408/*
409 * External Time Reference (ETR) code.
410 */
411static int etr_port0_online;
412static int etr_port1_online;
413static int etr_steai_available;
414
415static int __init early_parse_etr(char *p)
416{
417 if (strncmp(p, "off", 3) == 0)
418 etr_port0_online = etr_port1_online = 0;
419 else if (strncmp(p, "port0", 5) == 0)
420 etr_port0_online = 1;
421 else if (strncmp(p, "port1", 5) == 0)
422 etr_port1_online = 1;
423 else if (strncmp(p, "on", 2) == 0)
424 etr_port0_online = etr_port1_online = 1;
425 return 0;
426}
427early_param("etr", early_parse_etr);
428
429enum etr_event {
430 ETR_EVENT_PORT0_CHANGE,
431 ETR_EVENT_PORT1_CHANGE,
432 ETR_EVENT_PORT_ALERT,
433 ETR_EVENT_SYNC_CHECK,
434 ETR_EVENT_SWITCH_LOCAL,
435 ETR_EVENT_UPDATE,
436};
437
438/*
439 * Valid bit combinations of the eacr register are (x = don't care):
440 * e0 e1 dp p0 p1 ea es sl
441 * 0 0 x 0 0 0 0 0 initial, disabled state
442 * 0 0 x 0 1 1 0 0 port 1 online
443 * 0 0 x 1 0 1 0 0 port 0 online
444 * 0 0 x 1 1 1 0 0 both ports online
445 * 0 1 x 0 1 1 0 0 port 1 online and usable, ETR or PPS mode
446 * 0 1 x 0 1 1 0 1 port 1 online, usable and ETR mode
447 * 0 1 x 0 1 1 1 0 port 1 online, usable, PPS mode, in-sync
448 * 0 1 x 0 1 1 1 1 port 1 online, usable, ETR mode, in-sync
449 * 0 1 x 1 1 1 0 0 both ports online, port 1 usable
450 * 0 1 x 1 1 1 1 0 both ports online, port 1 usable, PPS mode, in-sync
451 * 0 1 x 1 1 1 1 1 both ports online, port 1 usable, ETR mode, in-sync
452 * 1 0 x 1 0 1 0 0 port 0 online and usable, ETR or PPS mode
453 * 1 0 x 1 0 1 0 1 port 0 online, usable and ETR mode
454 * 1 0 x 1 0 1 1 0 port 0 online, usable, PPS mode, in-sync
455 * 1 0 x 1 0 1 1 1 port 0 online, usable, ETR mode, in-sync
456 * 1 0 x 1 1 1 0 0 both ports online, port 0 usable
457 * 1 0 x 1 1 1 1 0 both ports online, port 0 usable, PPS mode, in-sync
458 * 1 0 x 1 1 1 1 1 both ports online, port 0 usable, ETR mode, in-sync
459 * 1 1 x 1 1 1 1 0 both ports online & usable, ETR, in-sync
460 * 1 1 x 1 1 1 1 1 both ports online & usable, ETR, in-sync
461 */
462static struct etr_eacr etr_eacr;
463static u64 etr_tolec; /* time of last eacr update */
464static struct etr_aib etr_port0;
465static int etr_port0_uptodate;
466static struct etr_aib etr_port1;
467static int etr_port1_uptodate;
468static unsigned long etr_events;
469static struct timer_list etr_timer;
470
471static void etr_timeout(unsigned long dummy);
472static void etr_work_fn(struct work_struct *work);
473static DEFINE_MUTEX(etr_work_mutex);
474static DECLARE_WORK(etr_work, etr_work_fn);
475
476/*
477 * Reset ETR attachment.
478 */
479static void etr_reset(void)
480{
481 etr_eacr = (struct etr_eacr) {
482 .e0 = 0, .e1 = 0, ._pad0 = 4, .dp = 0,
483 .p0 = 0, .p1 = 0, ._pad1 = 0, .ea = 0,
484 .es = 0, .sl = 0 };
485 if (etr_setr(&etr_eacr) == 0) {
486 etr_tolec = get_tod_clock();
487 set_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags);
488 if (etr_port0_online && etr_port1_online)
489 set_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
490 } else if (etr_port0_online || etr_port1_online) {
491 pr_warning("The real or virtual hardware system does "
492 "not provide an ETR interface\n");
493 etr_port0_online = etr_port1_online = 0;
494 }
495}
496
497static int __init etr_init(void)
498{
499 struct etr_aib aib;
500
501 if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags))
502 return 0;
503 time_init_wq();
504 /* Check if this machine has the steai instruction. */
505 if (etr_steai(&aib, ETR_STEAI_STEPPING_PORT) == 0)
506 etr_steai_available = 1;
507 setup_timer(&etr_timer, etr_timeout, 0UL);
508 if (etr_port0_online) {
509 set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
510 queue_work(time_sync_wq, &etr_work);
511 }
512 if (etr_port1_online) {
513 set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
514 queue_work(time_sync_wq, &etr_work);
515 }
516 return 0;
517}
518
519arch_initcall(etr_init);
520
521/*
522 * Two sorts of ETR machine checks. The architecture reads:
523 * "When a machine-check niterruption occurs and if a switch-to-local or
524 * ETR-sync-check interrupt request is pending but disabled, this pending
525 * disabled interruption request is indicated and is cleared".
526 * Which means that we can get etr_switch_to_local events from the machine
527 * check handler although the interruption condition is disabled. Lovely..
528 */
529
530/*
531 * Switch to local machine check. This is called when the last usable
532 * ETR port goes inactive. After switch to local the clock is not in sync.
533 */
534void etr_switch_to_local(void)
535{
536 if (!etr_eacr.sl)
537 return;
538 disable_sync_clock(NULL);
539 if (!test_and_set_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events)) {
540 etr_eacr.es = etr_eacr.sl = 0;
541 etr_setr(&etr_eacr);
542 queue_work(time_sync_wq, &etr_work);
543 }
544}
545
546/*
547 * ETR sync check machine check. This is called when the ETR OTE and the
548 * local clock OTE are farther apart than the ETR sync check tolerance.
549 * After a ETR sync check the clock is not in sync. The machine check
550 * is broadcasted to all cpus at the same time.
551 */
552void etr_sync_check(void)
553{
554 if (!etr_eacr.es)
555 return;
556 disable_sync_clock(NULL);
557 if (!test_and_set_bit(ETR_EVENT_SYNC_CHECK, &etr_events)) {
558 etr_eacr.es = 0;
559 etr_setr(&etr_eacr);
560 queue_work(time_sync_wq, &etr_work);
561 }
562}
563
564/*
565 * ETR timing alert. There are two causes:
566 * 1) port state change, check the usability of the port
567 * 2) port alert, one of the ETR-data-validity bits (v1-v2 bits of the
568 * sldr-status word) or ETR-data word 1 (edf1) or ETR-data word 3 (edf3)
569 * or ETR-data word 4 (edf4) has changed.
570 */
571static void etr_timing_alert(struct etr_irq_parm *intparm)
572{
573 if (intparm->pc0)
574 /* ETR port 0 state change. */
575 set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
576 if (intparm->pc1)
577 /* ETR port 1 state change. */
578 set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
579 if (intparm->eai)
580 /*
581 * ETR port alert on either port 0, 1 or both.
582 * Both ports are not up-to-date now.
583 */
584 set_bit(ETR_EVENT_PORT_ALERT, &etr_events);
585 queue_work(time_sync_wq, &etr_work);
586}
587
588static void etr_timeout(unsigned long dummy)
589{
590 set_bit(ETR_EVENT_UPDATE, &etr_events);
591 queue_work(time_sync_wq, &etr_work);
592}
593
594/*
595 * Check if the etr mode is pss.
596 */
597static inline int etr_mode_is_pps(struct etr_eacr eacr)
598{
599 return eacr.es && !eacr.sl;
600}
601
602/*
603 * Check if the etr mode is etr.
604 */
605static inline int etr_mode_is_etr(struct etr_eacr eacr)
606{
607 return eacr.es && eacr.sl;
608}
609
610/*
611 * Check if the port can be used for TOD synchronization.
612 * For PPS mode the port has to receive OTEs. For ETR mode
613 * the port has to receive OTEs, the ETR stepping bit has to
614 * be zero and the validity bits for data frame 1, 2, and 3
615 * have to be 1.
616 */
617static int etr_port_valid(struct etr_aib *aib, int port)
618{
619 unsigned int psc;
620
621 /* Check that this port is receiving OTEs. */
622 if (aib->tsp == 0)
623 return 0;
624
625 psc = port ? aib->esw.psc1 : aib->esw.psc0;
626 if (psc == etr_lpsc_pps_mode)
627 return 1;
628 if (psc == etr_lpsc_operational_step)
629 return !aib->esw.y && aib->slsw.v1 &&
630 aib->slsw.v2 && aib->slsw.v3;
631 return 0;
632}
633
634/*
635 * Check if two ports are on the same network.
636 */
637static int etr_compare_network(struct etr_aib *aib1, struct etr_aib *aib2)
638{
639 // FIXME: any other fields we have to compare?
640 return aib1->edf1.net_id == aib2->edf1.net_id;
641}
642
643/*
644 * Wrapper for etr_stei that converts physical port states
645 * to logical port states to be consistent with the output
646 * of stetr (see etr_psc vs. etr_lpsc).
647 */
648static void etr_steai_cv(struct etr_aib *aib, unsigned int func)
649{
650 BUG_ON(etr_steai(aib, func) != 0);
651 /* Convert port state to logical port state. */
652 if (aib->esw.psc0 == 1)
653 aib->esw.psc0 = 2;
654 else if (aib->esw.psc0 == 0 && aib->esw.p == 0)
655 aib->esw.psc0 = 1;
656 if (aib->esw.psc1 == 1)
657 aib->esw.psc1 = 2;
658 else if (aib->esw.psc1 == 0 && aib->esw.p == 1)
659 aib->esw.psc1 = 1;
660}
661
662/*
663 * Check if the aib a2 is still connected to the same attachment as
664 * aib a1, the etv values differ by one and a2 is valid.
665 */
666static int etr_aib_follows(struct etr_aib *a1, struct etr_aib *a2, int p)
667{
668 int state_a1, state_a2;
669
670 /* Paranoia check: e0/e1 should better be the same. */
671 if (a1->esw.eacr.e0 != a2->esw.eacr.e0 ||
672 a1->esw.eacr.e1 != a2->esw.eacr.e1)
673 return 0;
674
675 /* Still connected to the same etr ? */
676 state_a1 = p ? a1->esw.psc1 : a1->esw.psc0;
677 state_a2 = p ? a2->esw.psc1 : a2->esw.psc0;
678 if (state_a1 == etr_lpsc_operational_step) {
679 if (state_a2 != etr_lpsc_operational_step ||
680 a1->edf1.net_id != a2->edf1.net_id ||
681 a1->edf1.etr_id != a2->edf1.etr_id ||
682 a1->edf1.etr_pn != a2->edf1.etr_pn)
683 return 0;
684 } else if (state_a2 != etr_lpsc_pps_mode)
685 return 0;
686
687 /* The ETV value of a2 needs to be ETV of a1 + 1. */
688 if (a1->edf2.etv + 1 != a2->edf2.etv)
689 return 0;
690
691 if (!etr_port_valid(a2, p))
692 return 0;
693
694 return 1;
695}
696
697struct clock_sync_data {
698 atomic_t cpus;
699 int in_sync;
700 unsigned long long fixup_cc;
701 int etr_port;
702 struct etr_aib *etr_aib;
703};
704
705static void clock_sync_cpu(struct clock_sync_data *sync)
706{
707 atomic_dec(&sync->cpus);
708 enable_sync_clock();
709 /*
710 * This looks like a busy wait loop but it isn't. etr_sync_cpus
711 * is called on all other cpus while the TOD clocks is stopped.
712 * __udelay will stop the cpu on an enabled wait psw until the
713 * TOD is running again.
714 */
715 while (sync->in_sync == 0) {
716 __udelay(1);
717 /*
718 * A different cpu changes *in_sync. Therefore use
719 * barrier() to force memory access.
720 */
721 barrier();
722 }
723 if (sync->in_sync != 1)
724 /* Didn't work. Clear per-cpu in sync bit again. */
725 disable_sync_clock(NULL);
726 /*
727 * This round of TOD syncing is done. Set the clock comparator
728 * to the next tick and let the processor continue.
729 */
730 fixup_clock_comparator(sync->fixup_cc);
731}
732
733/*
734 * Sync the TOD clock using the port referred to by aibp. This port
735 * has to be enabled and the other port has to be disabled. The
736 * last eacr update has to be more than 1.6 seconds in the past.
737 */
738static int etr_sync_clock(void *data)
739{
740 static int first;
741 unsigned long long clock, old_clock, delay, delta;
742 struct clock_sync_data *etr_sync;
743 struct etr_aib *sync_port, *aib;
744 int port;
745 int rc;
746
747 etr_sync = data;
748
749 if (xchg(&first, 1) == 1) {
750 /* Slave */
751 clock_sync_cpu(etr_sync);
752 return 0;
753 }
754
755 /* Wait until all other cpus entered the sync function. */
756 while (atomic_read(&etr_sync->cpus) != 0)
757 cpu_relax();
758
759 port = etr_sync->etr_port;
760 aib = etr_sync->etr_aib;
761 sync_port = (port == 0) ? &etr_port0 : &etr_port1;
762 enable_sync_clock();
763
764 /* Set clock to next OTE. */
765 __ctl_set_bit(14, 21);
766 __ctl_set_bit(0, 29);
767 clock = ((unsigned long long) (aib->edf2.etv + 1)) << 32;
768 old_clock = get_tod_clock();
769 if (set_tod_clock(clock) == 0) {
770 __udelay(1); /* Wait for the clock to start. */
771 __ctl_clear_bit(0, 29);
772 __ctl_clear_bit(14, 21);
773 etr_stetr(aib);
774 /* Adjust Linux timing variables. */
775 delay = (unsigned long long)
776 (aib->edf2.etv - sync_port->edf2.etv) << 32;
777 delta = adjust_time(old_clock, clock, delay);
778 etr_sync->fixup_cc = delta;
779 fixup_clock_comparator(delta);
780 /* Verify that the clock is properly set. */
781 if (!etr_aib_follows(sync_port, aib, port)) {
782 /* Didn't work. */
783 disable_sync_clock(NULL);
784 etr_sync->in_sync = -EAGAIN;
785 rc = -EAGAIN;
786 } else {
787 etr_sync->in_sync = 1;
788 rc = 0;
789 }
790 } else {
791 /* Could not set the clock ?!? */
792 __ctl_clear_bit(0, 29);
793 __ctl_clear_bit(14, 21);
794 disable_sync_clock(NULL);
795 etr_sync->in_sync = -EAGAIN;
796 rc = -EAGAIN;
797 }
798 xchg(&first, 0);
799 return rc;
800}
801
802static int etr_sync_clock_stop(struct etr_aib *aib, int port)
803{
804 struct clock_sync_data etr_sync;
805 struct etr_aib *sync_port;
806 int follows;
807 int rc;
808
809 /* Check if the current aib is adjacent to the sync port aib. */
810 sync_port = (port == 0) ? &etr_port0 : &etr_port1;
811 follows = etr_aib_follows(sync_port, aib, port);
812 memcpy(sync_port, aib, sizeof(*aib));
813 if (!follows)
814 return -EAGAIN;
815 memset(&etr_sync, 0, sizeof(etr_sync));
816 etr_sync.etr_aib = aib;
817 etr_sync.etr_port = port;
818 get_online_cpus();
819 atomic_set(&etr_sync.cpus, num_online_cpus() - 1);
820 rc = stop_machine(etr_sync_clock, &etr_sync, cpu_online_mask);
821 put_online_cpus();
822 return rc;
823}
824
825/*
826 * Handle the immediate effects of the different events.
827 * The port change event is used for online/offline changes.
828 */
829static struct etr_eacr etr_handle_events(struct etr_eacr eacr)
830{
831 if (test_and_clear_bit(ETR_EVENT_SYNC_CHECK, &etr_events))
832 eacr.es = 0;
833 if (test_and_clear_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events))
834 eacr.es = eacr.sl = 0;
835 if (test_and_clear_bit(ETR_EVENT_PORT_ALERT, &etr_events))
836 etr_port0_uptodate = etr_port1_uptodate = 0;
837
838 if (test_and_clear_bit(ETR_EVENT_PORT0_CHANGE, &etr_events)) {
839 if (eacr.e0)
840 /*
841 * Port change of an enabled port. We have to
842 * assume that this can have caused an stepping
843 * port switch.
844 */
845 etr_tolec = get_tod_clock();
846 eacr.p0 = etr_port0_online;
847 if (!eacr.p0)
848 eacr.e0 = 0;
849 etr_port0_uptodate = 0;
850 }
851 if (test_and_clear_bit(ETR_EVENT_PORT1_CHANGE, &etr_events)) {
852 if (eacr.e1)
853 /*
854 * Port change of an enabled port. We have to
855 * assume that this can have caused an stepping
856 * port switch.
857 */
858 etr_tolec = get_tod_clock();
859 eacr.p1 = etr_port1_online;
860 if (!eacr.p1)
861 eacr.e1 = 0;
862 etr_port1_uptodate = 0;
863 }
864 clear_bit(ETR_EVENT_UPDATE, &etr_events);
865 return eacr;
866}
867
868/*
869 * Set up a timer that expires after the etr_tolec + 1.6 seconds if
870 * one of the ports needs an update.
871 */
872static void etr_set_tolec_timeout(unsigned long long now)
873{
874 unsigned long micros;
875
876 if ((!etr_eacr.p0 || etr_port0_uptodate) &&
877 (!etr_eacr.p1 || etr_port1_uptodate))
878 return;
879 micros = (now > etr_tolec) ? ((now - etr_tolec) >> 12) : 0;
880 micros = (micros > 1600000) ? 0 : 1600000 - micros;
881 mod_timer(&etr_timer, jiffies + (micros * HZ) / 1000000 + 1);
882}
883
884/*
885 * Set up a time that expires after 1/2 second.
886 */
887static void etr_set_sync_timeout(void)
888{
889 mod_timer(&etr_timer, jiffies + HZ/2);
890}
891
892/*
893 * Update the aib information for one or both ports.
894 */
895static struct etr_eacr etr_handle_update(struct etr_aib *aib,
896 struct etr_eacr eacr)
897{
898 /* With both ports disabled the aib information is useless. */
899 if (!eacr.e0 && !eacr.e1)
900 return eacr;
901
902 /* Update port0 or port1 with aib stored in etr_work_fn. */
903 if (aib->esw.q == 0) {
904 /* Information for port 0 stored. */
905 if (eacr.p0 && !etr_port0_uptodate) {
906 etr_port0 = *aib;
907 if (etr_port0_online)
908 etr_port0_uptodate = 1;
909 }
910 } else {
911 /* Information for port 1 stored. */
912 if (eacr.p1 && !etr_port1_uptodate) {
913 etr_port1 = *aib;
914 if (etr_port0_online)
915 etr_port1_uptodate = 1;
916 }
917 }
918
919 /*
920 * Do not try to get the alternate port aib if the clock
921 * is not in sync yet.
922 */
923 if (!eacr.es || !check_sync_clock())
924 return eacr;
925
926 /*
927 * If steai is available we can get the information about
928 * the other port immediately. If only stetr is available the
929 * data-port bit toggle has to be used.
930 */
931 if (etr_steai_available) {
932 if (eacr.p0 && !etr_port0_uptodate) {
933 etr_steai_cv(&etr_port0, ETR_STEAI_PORT_0);
934 etr_port0_uptodate = 1;
935 }
936 if (eacr.p1 && !etr_port1_uptodate) {
937 etr_steai_cv(&etr_port1, ETR_STEAI_PORT_1);
938 etr_port1_uptodate = 1;
939 }
940 } else {
941 /*
942 * One port was updated above, if the other
943 * port is not uptodate toggle dp bit.
944 */
945 if ((eacr.p0 && !etr_port0_uptodate) ||
946 (eacr.p1 && !etr_port1_uptodate))
947 eacr.dp ^= 1;
948 else
949 eacr.dp = 0;
950 }
951 return eacr;
952}
953
954/*
955 * Write new etr control register if it differs from the current one.
956 * Return 1 if etr_tolec has been updated as well.
957 */
958static void etr_update_eacr(struct etr_eacr eacr)
959{
960 int dp_changed;
961
962 if (memcmp(&etr_eacr, &eacr, sizeof(eacr)) == 0)
963 /* No change, return. */
964 return;
965 /*
966 * The disable of an active port of the change of the data port
967 * bit can/will cause a change in the data port.
968 */
969 dp_changed = etr_eacr.e0 > eacr.e0 || etr_eacr.e1 > eacr.e1 ||
970 (etr_eacr.dp ^ eacr.dp) != 0;
971 etr_eacr = eacr;
972 etr_setr(&etr_eacr);
973 if (dp_changed)
974 etr_tolec = get_tod_clock();
975}
976
977/*
978 * ETR work. In this function you'll find the main logic. In
979 * particular this is the only function that calls etr_update_eacr(),
980 * it "controls" the etr control register.
981 */
982static void etr_work_fn(struct work_struct *work)
983{
984 unsigned long long now;
985 struct etr_eacr eacr;
986 struct etr_aib aib;
987 int sync_port;
988
989 /* prevent multiple execution. */
990 mutex_lock(&etr_work_mutex);
991
992 /* Create working copy of etr_eacr. */
993 eacr = etr_eacr;
994
995 /* Check for the different events and their immediate effects. */
996 eacr = etr_handle_events(eacr);
997
998 /* Check if ETR is supposed to be active. */
999 eacr.ea = eacr.p0 || eacr.p1;
1000 if (!eacr.ea) {
1001 /* Both ports offline. Reset everything. */
1002 eacr.dp = eacr.es = eacr.sl = 0;
1003 on_each_cpu(disable_sync_clock, NULL, 1);
1004 del_timer_sync(&etr_timer);
1005 etr_update_eacr(eacr);
1006 goto out_unlock;
1007 }
1008
1009 /* Store aib to get the current ETR status word. */
1010 BUG_ON(etr_stetr(&aib) != 0);
1011 etr_port0.esw = etr_port1.esw = aib.esw; /* Copy status word. */
1012 now = get_tod_clock();
1013
1014 /*
1015 * Update the port information if the last stepping port change
1016 * or data port change is older than 1.6 seconds.
1017 */
1018 if (now >= etr_tolec + (1600000 << 12))
1019 eacr = etr_handle_update(&aib, eacr);
1020
1021 /*
1022 * Select ports to enable. The preferred synchronization mode is PPS.
1023 * If a port can be enabled depends on a number of things:
1024 * 1) The port needs to be online and uptodate. A port is not
1025 * disabled just because it is not uptodate, but it is only
1026 * enabled if it is uptodate.
1027 * 2) The port needs to have the same mode (pps / etr).
1028 * 3) The port needs to be usable -> etr_port_valid() == 1
1029 * 4) To enable the second port the clock needs to be in sync.
1030 * 5) If both ports are useable and are ETR ports, the network id
1031 * has to be the same.
1032 * The eacr.sl bit is used to indicate etr mode vs. pps mode.
1033 */
1034 if (eacr.p0 && aib.esw.psc0 == etr_lpsc_pps_mode) {
1035 eacr.sl = 0;
1036 eacr.e0 = 1;
1037 if (!etr_mode_is_pps(etr_eacr))
1038 eacr.es = 0;
1039 if (!eacr.es || !eacr.p1 || aib.esw.psc1 != etr_lpsc_pps_mode)
1040 eacr.e1 = 0;
1041 // FIXME: uptodate checks ?
1042 else if (etr_port0_uptodate && etr_port1_uptodate)
1043 eacr.e1 = 1;
1044 sync_port = (etr_port0_uptodate &&
1045 etr_port_valid(&etr_port0, 0)) ? 0 : -1;
1046 } else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_pps_mode) {
1047 eacr.sl = 0;
1048 eacr.e0 = 0;
1049 eacr.e1 = 1;
1050 if (!etr_mode_is_pps(etr_eacr))
1051 eacr.es = 0;
1052 sync_port = (etr_port1_uptodate &&
1053 etr_port_valid(&etr_port1, 1)) ? 1 : -1;
1054 } else if (eacr.p0 && aib.esw.psc0 == etr_lpsc_operational_step) {
1055 eacr.sl = 1;
1056 eacr.e0 = 1;
1057 if (!etr_mode_is_etr(etr_eacr))
1058 eacr.es = 0;
1059 if (!eacr.es || !eacr.p1 ||
1060 aib.esw.psc1 != etr_lpsc_operational_alt)
1061 eacr.e1 = 0;
1062 else if (etr_port0_uptodate && etr_port1_uptodate &&
1063 etr_compare_network(&etr_port0, &etr_port1))
1064 eacr.e1 = 1;
1065 sync_port = (etr_port0_uptodate &&
1066 etr_port_valid(&etr_port0, 0)) ? 0 : -1;
1067 } else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_operational_step) {
1068 eacr.sl = 1;
1069 eacr.e0 = 0;
1070 eacr.e1 = 1;
1071 if (!etr_mode_is_etr(etr_eacr))
1072 eacr.es = 0;
1073 sync_port = (etr_port1_uptodate &&
1074 etr_port_valid(&etr_port1, 1)) ? 1 : -1;
1075 } else {
1076 /* Both ports not usable. */
1077 eacr.es = eacr.sl = 0;
1078 sync_port = -1;
1079 }
1080
1081 /*
1082 * If the clock is in sync just update the eacr and return.
1083 * If there is no valid sync port wait for a port update.
1084 */
1085 if ((eacr.es && check_sync_clock()) || sync_port < 0) {
1086 etr_update_eacr(eacr);
1087 etr_set_tolec_timeout(now);
1088 goto out_unlock;
1089 }
1090
1091 /*
1092 * Prepare control register for clock syncing
1093 * (reset data port bit, set sync check control.
1094 */
1095 eacr.dp = 0;
1096 eacr.es = 1;
1097
1098 /*
1099 * Update eacr and try to synchronize the clock. If the update
1100 * of eacr caused a stepping port switch (or if we have to
1101 * assume that a stepping port switch has occurred) or the
1102 * clock syncing failed, reset the sync check control bit
1103 * and set up a timer to try again after 0.5 seconds
1104 */
1105 etr_update_eacr(eacr);
1106 if (now < etr_tolec + (1600000 << 12) ||
1107 etr_sync_clock_stop(&aib, sync_port) != 0) {
1108 /* Sync failed. Try again in 1/2 second. */
1109 eacr.es = 0;
1110 etr_update_eacr(eacr);
1111 etr_set_sync_timeout();
1112 } else
1113 etr_set_tolec_timeout(now);
1114out_unlock:
1115 mutex_unlock(&etr_work_mutex);
1116}
1117
1118/*
1119 * Sysfs interface functions
1120 */
1121static struct bus_type etr_subsys = {
1122 .name = "etr",
1123 .dev_name = "etr",
1124};
1125
1126static struct device etr_port0_dev = {
1127 .id = 0,
1128 .bus = &etr_subsys,
1129};
1130
1131static struct device etr_port1_dev = {
1132 .id = 1,
1133 .bus = &etr_subsys,
1134};
1135
1136/*
1137 * ETR subsys attributes
1138 */
1139static ssize_t etr_stepping_port_show(struct device *dev,
1140 struct device_attribute *attr,
1141 char *buf)
1142{
1143 return sprintf(buf, "%i\n", etr_port0.esw.p);
1144}
1145
1146static DEVICE_ATTR(stepping_port, 0400, etr_stepping_port_show, NULL);
1147
1148static ssize_t etr_stepping_mode_show(struct device *dev,
1149 struct device_attribute *attr,
1150 char *buf)
1151{
1152 char *mode_str;
1153
1154 if (etr_mode_is_pps(etr_eacr))
1155 mode_str = "pps";
1156 else if (etr_mode_is_etr(etr_eacr))
1157 mode_str = "etr";
1158 else
1159 mode_str = "local";
1160 return sprintf(buf, "%s\n", mode_str);
1161}
1162
1163static DEVICE_ATTR(stepping_mode, 0400, etr_stepping_mode_show, NULL);
1164
1165/*
1166 * ETR port attributes
1167 */
1168static inline struct etr_aib *etr_aib_from_dev(struct device *dev)
1169{
1170 if (dev == &etr_port0_dev)
1171 return etr_port0_online ? &etr_port0 : NULL;
1172 else
1173 return etr_port1_online ? &etr_port1 : NULL;
1174}
1175
1176static ssize_t etr_online_show(struct device *dev,
1177 struct device_attribute *attr,
1178 char *buf)
1179{
1180 unsigned int online;
1181
1182 online = (dev == &etr_port0_dev) ? etr_port0_online : etr_port1_online;
1183 return sprintf(buf, "%i\n", online);
1184}
1185
1186static ssize_t etr_online_store(struct device *dev,
1187 struct device_attribute *attr,
1188 const char *buf, size_t count)
1189{
1190 unsigned int value;
1191
1192 value = simple_strtoul(buf, NULL, 0);
1193 if (value != 0 && value != 1)
1194 return -EINVAL;
1195 if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags))
1196 return -EOPNOTSUPP;
1197 mutex_lock(&clock_sync_mutex);
1198 if (dev == &etr_port0_dev) {
1199 if (etr_port0_online == value)
1200 goto out; /* Nothing to do. */
1201 etr_port0_online = value;
1202 if (etr_port0_online && etr_port1_online)
1203 set_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
1204 else
1205 clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
1206 set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events);
1207 queue_work(time_sync_wq, &etr_work);
1208 } else {
1209 if (etr_port1_online == value)
1210 goto out; /* Nothing to do. */
1211 etr_port1_online = value;
1212 if (etr_port0_online && etr_port1_online)
1213 set_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
1214 else
1215 clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags);
1216 set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events);
1217 queue_work(time_sync_wq, &etr_work);
1218 }
1219out:
1220 mutex_unlock(&clock_sync_mutex);
1221 return count;
1222}
1223
1224static DEVICE_ATTR(online, 0600, etr_online_show, etr_online_store);
1225
1226static ssize_t etr_stepping_control_show(struct device *dev,
1227 struct device_attribute *attr,
1228 char *buf)
1229{
1230 return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ?
1231 etr_eacr.e0 : etr_eacr.e1);
1232}
1233
1234static DEVICE_ATTR(stepping_control, 0400, etr_stepping_control_show, NULL);
1235
1236static ssize_t etr_mode_code_show(struct device *dev,
1237 struct device_attribute *attr, char *buf)
1238{
1239 if (!etr_port0_online && !etr_port1_online)
1240 /* Status word is not uptodate if both ports are offline. */
1241 return -ENODATA;
1242 return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ?
1243 etr_port0.esw.psc0 : etr_port0.esw.psc1);
1244}
1245
1246static DEVICE_ATTR(state_code, 0400, etr_mode_code_show, NULL);
1247
1248static ssize_t etr_untuned_show(struct device *dev,
1249 struct device_attribute *attr, char *buf)
1250{
1251 struct etr_aib *aib = etr_aib_from_dev(dev);
1252
1253 if (!aib || !aib->slsw.v1)
1254 return -ENODATA;
1255 return sprintf(buf, "%i\n", aib->edf1.u);
1256}
1257
1258static DEVICE_ATTR(untuned, 0400, etr_untuned_show, NULL);
1259
1260static ssize_t etr_network_id_show(struct device *dev,
1261 struct device_attribute *attr, char *buf)
1262{
1263 struct etr_aib *aib = etr_aib_from_dev(dev);
1264
1265 if (!aib || !aib->slsw.v1)
1266 return -ENODATA;
1267 return sprintf(buf, "%i\n", aib->edf1.net_id);
1268}
1269
1270static DEVICE_ATTR(network, 0400, etr_network_id_show, NULL);
1271
1272static ssize_t etr_id_show(struct device *dev,
1273 struct device_attribute *attr, char *buf)
1274{
1275 struct etr_aib *aib = etr_aib_from_dev(dev);
1276
1277 if (!aib || !aib->slsw.v1)
1278 return -ENODATA;
1279 return sprintf(buf, "%i\n", aib->edf1.etr_id);
1280}
1281
1282static DEVICE_ATTR(id, 0400, etr_id_show, NULL);
1283
1284static ssize_t etr_port_number_show(struct device *dev,
1285 struct device_attribute *attr, char *buf)
1286{
1287 struct etr_aib *aib = etr_aib_from_dev(dev);
1288
1289 if (!aib || !aib->slsw.v1)
1290 return -ENODATA;
1291 return sprintf(buf, "%i\n", aib->edf1.etr_pn);
1292}
1293
1294static DEVICE_ATTR(port, 0400, etr_port_number_show, NULL);
1295
1296static ssize_t etr_coupled_show(struct device *dev,
1297 struct device_attribute *attr, char *buf)
1298{
1299 struct etr_aib *aib = etr_aib_from_dev(dev);
1300
1301 if (!aib || !aib->slsw.v3)
1302 return -ENODATA;
1303 return sprintf(buf, "%i\n", aib->edf3.c);
1304}
1305
1306static DEVICE_ATTR(coupled, 0400, etr_coupled_show, NULL);
1307
1308static ssize_t etr_local_time_show(struct device *dev,
1309 struct device_attribute *attr, char *buf)
1310{
1311 struct etr_aib *aib = etr_aib_from_dev(dev);
1312
1313 if (!aib || !aib->slsw.v3)
1314 return -ENODATA;
1315 return sprintf(buf, "%i\n", aib->edf3.blto);
1316}
1317
1318static DEVICE_ATTR(local_time, 0400, etr_local_time_show, NULL);
1319
1320static ssize_t etr_utc_offset_show(struct device *dev,
1321 struct device_attribute *attr, char *buf)
1322{
1323 struct etr_aib *aib = etr_aib_from_dev(dev);
1324
1325 if (!aib || !aib->slsw.v3)
1326 return -ENODATA;
1327 return sprintf(buf, "%i\n", aib->edf3.buo);
1328}
1329
1330static DEVICE_ATTR(utc_offset, 0400, etr_utc_offset_show, NULL);
1331
1332static struct device_attribute *etr_port_attributes[] = {
1333 &dev_attr_online,
1334 &dev_attr_stepping_control,
1335 &dev_attr_state_code,
1336 &dev_attr_untuned,
1337 &dev_attr_network,
1338 &dev_attr_id,
1339 &dev_attr_port,
1340 &dev_attr_coupled,
1341 &dev_attr_local_time,
1342 &dev_attr_utc_offset,
1343 NULL
1344};
1345
1346static int __init etr_register_port(struct device *dev)
1347{
1348 struct device_attribute **attr;
1349 int rc;
1350
1351 rc = device_register(dev);
1352 if (rc)
1353 goto out;
1354 for (attr = etr_port_attributes; *attr; attr++) {
1355 rc = device_create_file(dev, *attr);
1356 if (rc)
1357 goto out_unreg;
1358 }
1359 return 0;
1360out_unreg:
1361 for (; attr >= etr_port_attributes; attr--)
1362 device_remove_file(dev, *attr);
1363 device_unregister(dev);
1364out:
1365 return rc;
1366}
1367
1368static void __init etr_unregister_port(struct device *dev)
1369{
1370 struct device_attribute **attr;
1371
1372 for (attr = etr_port_attributes; *attr; attr++)
1373 device_remove_file(dev, *attr);
1374 device_unregister(dev);
1375}
1376
1377static int __init etr_init_sysfs(void)
1378{
1379 int rc;
1380
1381 rc = subsys_system_register(&etr_subsys, NULL);
1382 if (rc)
1383 goto out;
1384 rc = device_create_file(etr_subsys.dev_root, &dev_attr_stepping_port);
1385 if (rc)
1386 goto out_unreg_subsys;
1387 rc = device_create_file(etr_subsys.dev_root, &dev_attr_stepping_mode);
1388 if (rc)
1389 goto out_remove_stepping_port;
1390 rc = etr_register_port(&etr_port0_dev);
1391 if (rc)
1392 goto out_remove_stepping_mode;
1393 rc = etr_register_port(&etr_port1_dev);
1394 if (rc)
1395 goto out_remove_port0;
1396 return 0;
1397
1398out_remove_port0:
1399 etr_unregister_port(&etr_port0_dev);
1400out_remove_stepping_mode:
1401 device_remove_file(etr_subsys.dev_root, &dev_attr_stepping_mode);
1402out_remove_stepping_port:
1403 device_remove_file(etr_subsys.dev_root, &dev_attr_stepping_port);
1404out_unreg_subsys:
1405 bus_unregister(&etr_subsys);
1406out:
1407 return rc;
1408}
1409
1410device_initcall(etr_init_sysfs);
1411
1412/*
1413 * Server Time Protocol (STP) code.
1414 */
1415static int stp_online;
1416static struct stp_sstpi stp_info;
1417static void *stp_page;
1418
1419static void stp_work_fn(struct work_struct *work);
1420static DEFINE_MUTEX(stp_work_mutex);
1421static DECLARE_WORK(stp_work, stp_work_fn);
1422static struct timer_list stp_timer;
1423
1424static int __init early_parse_stp(char *p)
1425{
1426 if (strncmp(p, "off", 3) == 0)
1427 stp_online = 0;
1428 else if (strncmp(p, "on", 2) == 0)
1429 stp_online = 1;
1430 return 0;
1431}
1432early_param("stp", early_parse_stp);
1433
1434/*
1435 * Reset STP attachment.
1436 */
1437static void __init stp_reset(void)
1438{
1439 int rc;
1440
1441 stp_page = (void *) get_zeroed_page(GFP_ATOMIC);
1442 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);
1443 if (rc == 0)
1444 set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags);
1445 else if (stp_online) {
1446 pr_warning("The real or virtual hardware system does "
1447 "not provide an STP interface\n");
1448 free_page((unsigned long) stp_page);
1449 stp_page = NULL;
1450 stp_online = 0;
1451 }
1452}
1453
1454static void stp_timeout(unsigned long dummy)
1455{
1456 queue_work(time_sync_wq, &stp_work);
1457}
1458
1459static int __init stp_init(void)
1460{
1461 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
1462 return 0;
1463 setup_timer(&stp_timer, stp_timeout, 0UL);
1464 time_init_wq();
1465 if (!stp_online)
1466 return 0;
1467 queue_work(time_sync_wq, &stp_work);
1468 return 0;
1469}
1470
1471arch_initcall(stp_init);
1472
1473/*
1474 * STP timing alert. There are three causes:
1475 * 1) timing status change
1476 * 2) link availability change
1477 * 3) time control parameter change
1478 * In all three cases we are only interested in the clock source state.
1479 * If a STP clock source is now available use it.
1480 */
1481static void stp_timing_alert(struct stp_irq_parm *intparm)
1482{
1483 if (intparm->tsc || intparm->lac || intparm->tcpc)
1484 queue_work(time_sync_wq, &stp_work);
1485}
1486
1487/*
1488 * STP sync check machine check. This is called when the timing state
1489 * changes from the synchronized state to the unsynchronized state.
1490 * After a STP sync check the clock is not in sync. The machine check
1491 * is broadcasted to all cpus at the same time.
1492 */
1493void stp_sync_check(void)
1494{
1495 disable_sync_clock(NULL);
1496 queue_work(time_sync_wq, &stp_work);
1497}
1498
1499/*
1500 * STP island condition machine check. This is called when an attached
1501 * server attempts to communicate over an STP link and the servers
1502 * have matching CTN ids and have a valid stratum-1 configuration
1503 * but the configurations do not match.
1504 */
1505void stp_island_check(void)
1506{
1507 disable_sync_clock(NULL);
1508 queue_work(time_sync_wq, &stp_work);
1509}
1510
1511
1512static int stp_sync_clock(void *data)
1513{
1514 static int first;
1515 unsigned long long old_clock, delta;
1516 struct clock_sync_data *stp_sync;
1517 int rc;
1518
1519 stp_sync = data;
1520
1521 if (xchg(&first, 1) == 1) {
1522 /* Slave */
1523 clock_sync_cpu(stp_sync);
1524 return 0;
1525 }
1526
1527 /* Wait until all other cpus entered the sync function. */
1528 while (atomic_read(&stp_sync->cpus) != 0)
1529 cpu_relax();
1530
1531 enable_sync_clock();
1532
1533 rc = 0;
1534 if (stp_info.todoff[0] || stp_info.todoff[1] ||
1535 stp_info.todoff[2] || stp_info.todoff[3] ||
1536 stp_info.tmd != 2) {
1537 old_clock = get_tod_clock();
1538 rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0);
1539 if (rc == 0) {
1540 delta = adjust_time(old_clock, get_tod_clock(), 0);
1541 fixup_clock_comparator(delta);
1542 rc = chsc_sstpi(stp_page, &stp_info,
1543 sizeof(struct stp_sstpi));
1544 if (rc == 0 && stp_info.tmd != 2)
1545 rc = -EAGAIN;
1546 }
1547 }
1548 if (rc) {
1549 disable_sync_clock(NULL);
1550 stp_sync->in_sync = -EAGAIN;
1551 } else
1552 stp_sync->in_sync = 1;
1553 xchg(&first, 0);
1554 return 0;
1555}
1556
1557/*
1558 * STP work. Check for the STP state and take over the clock
1559 * synchronization if the STP clock source is usable.
1560 */
1561static void stp_work_fn(struct work_struct *work)
1562{
1563 struct clock_sync_data stp_sync;
1564 int rc;
1565
1566 /* prevent multiple execution. */
1567 mutex_lock(&stp_work_mutex);
1568
1569 if (!stp_online) {
1570 chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000);
1571 del_timer_sync(&stp_timer);
1572 goto out_unlock;
1573 }
1574
1575 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0);
1576 if (rc)
1577 goto out_unlock;
1578
1579 rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi));
1580 if (rc || stp_info.c == 0)
1581 goto out_unlock;
1582
1583 /* Skip synchronization if the clock is already in sync. */
1584 if (check_sync_clock())
1585 goto out_unlock;
1586
1587 memset(&stp_sync, 0, sizeof(stp_sync));
1588 get_online_cpus();
1589 atomic_set(&stp_sync.cpus, num_online_cpus() - 1);
1590 stop_machine(stp_sync_clock, &stp_sync, cpu_online_mask);
1591 put_online_cpus();
1592
1593 if (!check_sync_clock())
1594 /*
1595 * There is a usable clock but the synchonization failed.
1596 * Retry after a second.
1597 */
1598 mod_timer(&stp_timer, jiffies + HZ);
1599
1600out_unlock:
1601 mutex_unlock(&stp_work_mutex);
1602}
1603
1604/*
1605 * STP subsys sysfs interface functions
1606 */
1607static struct bus_type stp_subsys = {
1608 .name = "stp",
1609 .dev_name = "stp",
1610};
1611
1612static ssize_t stp_ctn_id_show(struct device *dev,
1613 struct device_attribute *attr,
1614 char *buf)
1615{
1616 if (!stp_online)
1617 return -ENODATA;
1618 return sprintf(buf, "%016llx\n",
1619 *(unsigned long long *) stp_info.ctnid);
1620}
1621
1622static DEVICE_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL);
1623
1624static ssize_t stp_ctn_type_show(struct device *dev,
1625 struct device_attribute *attr,
1626 char *buf)
1627{
1628 if (!stp_online)
1629 return -ENODATA;
1630 return sprintf(buf, "%i\n", stp_info.ctn);
1631}
1632
1633static DEVICE_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL);
1634
1635static ssize_t stp_dst_offset_show(struct device *dev,
1636 struct device_attribute *attr,
1637 char *buf)
1638{
1639 if (!stp_online || !(stp_info.vbits & 0x2000))
1640 return -ENODATA;
1641 return sprintf(buf, "%i\n", (int)(s16) stp_info.dsto);
1642}
1643
1644static DEVICE_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL);
1645
1646static ssize_t stp_leap_seconds_show(struct device *dev,
1647 struct device_attribute *attr,
1648 char *buf)
1649{
1650 if (!stp_online || !(stp_info.vbits & 0x8000))
1651 return -ENODATA;
1652 return sprintf(buf, "%i\n", (int)(s16) stp_info.leaps);
1653}
1654
1655static DEVICE_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL);
1656
1657static ssize_t stp_stratum_show(struct device *dev,
1658 struct device_attribute *attr,
1659 char *buf)
1660{
1661 if (!stp_online)
1662 return -ENODATA;
1663 return sprintf(buf, "%i\n", (int)(s16) stp_info.stratum);
1664}
1665
1666static DEVICE_ATTR(stratum, 0400, stp_stratum_show, NULL);
1667
1668static ssize_t stp_time_offset_show(struct device *dev,
1669 struct device_attribute *attr,
1670 char *buf)
1671{
1672 if (!stp_online || !(stp_info.vbits & 0x0800))
1673 return -ENODATA;
1674 return sprintf(buf, "%i\n", (int) stp_info.tto);
1675}
1676
1677static DEVICE_ATTR(time_offset, 0400, stp_time_offset_show, NULL);
1678
1679static ssize_t stp_time_zone_offset_show(struct device *dev,
1680 struct device_attribute *attr,
1681 char *buf)
1682{
1683 if (!stp_online || !(stp_info.vbits & 0x4000))
1684 return -ENODATA;
1685 return sprintf(buf, "%i\n", (int)(s16) stp_info.tzo);
1686}
1687
1688static DEVICE_ATTR(time_zone_offset, 0400,
1689 stp_time_zone_offset_show, NULL);
1690
1691static ssize_t stp_timing_mode_show(struct device *dev,
1692 struct device_attribute *attr,
1693 char *buf)
1694{
1695 if (!stp_online)
1696 return -ENODATA;
1697 return sprintf(buf, "%i\n", stp_info.tmd);
1698}
1699
1700static DEVICE_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL);
1701
1702static ssize_t stp_timing_state_show(struct device *dev,
1703 struct device_attribute *attr,
1704 char *buf)
1705{
1706 if (!stp_online)
1707 return -ENODATA;
1708 return sprintf(buf, "%i\n", stp_info.tst);
1709}
1710
1711static DEVICE_ATTR(timing_state, 0400, stp_timing_state_show, NULL);
1712
1713static ssize_t stp_online_show(struct device *dev,
1714 struct device_attribute *attr,
1715 char *buf)
1716{
1717 return sprintf(buf, "%i\n", stp_online);
1718}
1719
1720static ssize_t stp_online_store(struct device *dev,
1721 struct device_attribute *attr,
1722 const char *buf, size_t count)
1723{
1724 unsigned int value;
1725
1726 value = simple_strtoul(buf, NULL, 0);
1727 if (value != 0 && value != 1)
1728 return -EINVAL;
1729 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
1730 return -EOPNOTSUPP;
1731 mutex_lock(&clock_sync_mutex);
1732 stp_online = value;
1733 if (stp_online)
1734 set_bit(CLOCK_SYNC_STP, &clock_sync_flags);
1735 else
1736 clear_bit(CLOCK_SYNC_STP, &clock_sync_flags);
1737 queue_work(time_sync_wq, &stp_work);
1738 mutex_unlock(&clock_sync_mutex);
1739 return count;
1740}
1741
1742/*
1743 * Can't use DEVICE_ATTR because the attribute should be named
1744 * stp/online but dev_attr_online already exists in this file ..
1745 */
1746static struct device_attribute dev_attr_stp_online = {
1747 .attr = { .name = "online", .mode = 0600 },
1748 .show = stp_online_show,
1749 .store = stp_online_store,
1750};
1751
1752static struct device_attribute *stp_attributes[] = {
1753 &dev_attr_ctn_id,
1754 &dev_attr_ctn_type,
1755 &dev_attr_dst_offset,
1756 &dev_attr_leap_seconds,
1757 &dev_attr_stp_online,
1758 &dev_attr_stratum,
1759 &dev_attr_time_offset,
1760 &dev_attr_time_zone_offset,
1761 &dev_attr_timing_mode,
1762 &dev_attr_timing_state,
1763 NULL
1764};
1765
1766static int __init stp_init_sysfs(void)
1767{
1768 struct device_attribute **attr;
1769 int rc;
1770
1771 rc = subsys_system_register(&stp_subsys, NULL);
1772 if (rc)
1773 goto out;
1774 for (attr = stp_attributes; *attr; attr++) {
1775 rc = device_create_file(stp_subsys.dev_root, *attr);
1776 if (rc)
1777 goto out_unreg;
1778 }
1779 return 0;
1780out_unreg:
1781 for (; attr >= stp_attributes; attr--)
1782 device_remove_file(stp_subsys.dev_root, *attr);
1783 bus_unregister(&stp_subsys);
1784out:
1785 return rc;
1786}
1787
1788device_initcall(stp_init_sysfs);