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[linux/fpc-iii.git] / arch / s390 / kernel / time.c
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1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Time of day based timer functions.
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)
11 * Derived from "arch/i386/kernel/time.c"
12 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
15 #define KMSG_COMPONENT "time"
16 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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 <asm/facility.h>
45 #include <asm/delay.h>
46 #include <asm/div64.h>
47 #include <asm/vdso.h>
48 #include <asm/irq.h>
49 #include <asm/irq_regs.h>
50 #include <asm/vtimer.h>
51 #include <asm/stp.h>
52 #include <asm/cio.h>
53 #include "entry.h"
55 unsigned char tod_clock_base[16] __aligned(8) = {
56 /* Force to data section. */
57 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
58 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
60 EXPORT_SYMBOL_GPL(tod_clock_base);
62 u64 clock_comparator_max = -1ULL;
63 EXPORT_SYMBOL_GPL(clock_comparator_max);
65 static DEFINE_PER_CPU(struct clock_event_device, comparators);
67 ATOMIC_NOTIFIER_HEAD(s390_epoch_delta_notifier);
68 EXPORT_SYMBOL(s390_epoch_delta_notifier);
70 unsigned char ptff_function_mask[16];
72 static unsigned long long lpar_offset;
73 static unsigned long long initial_leap_seconds;
74 static unsigned long long tod_steering_end;
75 static long long tod_steering_delta;
78 * Get time offsets with PTFF
80 void __init time_early_init(void)
82 struct ptff_qto qto;
83 struct ptff_qui qui;
85 /* Initialize TOD steering parameters */
86 tod_steering_end = *(unsigned long long *) &tod_clock_base[1];
87 vdso_data->ts_end = tod_steering_end;
89 if (!test_facility(28))
90 return;
92 ptff(&ptff_function_mask, sizeof(ptff_function_mask), PTFF_QAF);
94 /* get LPAR offset */
95 if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0)
96 lpar_offset = qto.tod_epoch_difference;
98 /* get initial leap seconds */
99 if (ptff_query(PTFF_QUI) && ptff(&qui, sizeof(qui), PTFF_QUI) == 0)
100 initial_leap_seconds = (unsigned long long)
101 ((long) qui.old_leap * 4096000000L);
105 * Scheduler clock - returns current time in nanosec units.
107 unsigned long long notrace sched_clock(void)
109 return tod_to_ns(get_tod_clock_monotonic());
111 NOKPROBE_SYMBOL(sched_clock);
113 static void ext_to_timespec64(unsigned char *clk, struct timespec64 *xt)
115 unsigned long long high, low, rem, sec, nsec;
117 /* Split extendnd TOD clock to micro-seconds and sub-micro-seconds */
118 high = (*(unsigned long long *) clk) >> 4;
119 low = (*(unsigned long long *)&clk[7]) << 4;
120 /* Calculate seconds and nano-seconds */
121 sec = high;
122 rem = do_div(sec, 1000000);
123 nsec = (((low >> 32) + (rem << 32)) * 1000) >> 32;
125 xt->tv_sec = sec;
126 xt->tv_nsec = nsec;
129 void clock_comparator_work(void)
131 struct clock_event_device *cd;
133 S390_lowcore.clock_comparator = clock_comparator_max;
134 cd = this_cpu_ptr(&comparators);
135 cd->event_handler(cd);
138 static int s390_next_event(unsigned long delta,
139 struct clock_event_device *evt)
141 S390_lowcore.clock_comparator = get_tod_clock() + delta;
142 set_clock_comparator(S390_lowcore.clock_comparator);
143 return 0;
147 * Set up lowcore and control register of the current cpu to
148 * enable TOD clock and clock comparator interrupts.
150 void init_cpu_timer(void)
152 struct clock_event_device *cd;
153 int cpu;
155 S390_lowcore.clock_comparator = clock_comparator_max;
156 set_clock_comparator(S390_lowcore.clock_comparator);
158 cpu = smp_processor_id();
159 cd = &per_cpu(comparators, cpu);
160 cd->name = "comparator";
161 cd->features = CLOCK_EVT_FEAT_ONESHOT;
162 cd->mult = 16777;
163 cd->shift = 12;
164 cd->min_delta_ns = 1;
165 cd->min_delta_ticks = 1;
166 cd->max_delta_ns = LONG_MAX;
167 cd->max_delta_ticks = ULONG_MAX;
168 cd->rating = 400;
169 cd->cpumask = cpumask_of(cpu);
170 cd->set_next_event = s390_next_event;
172 clockevents_register_device(cd);
174 /* Enable clock comparator timer interrupt. */
175 __ctl_set_bit(0,11);
177 /* Always allow the timing alert external interrupt. */
178 __ctl_set_bit(0, 4);
181 static void clock_comparator_interrupt(struct ext_code ext_code,
182 unsigned int param32,
183 unsigned long param64)
185 inc_irq_stat(IRQEXT_CLK);
186 if (S390_lowcore.clock_comparator == clock_comparator_max)
187 set_clock_comparator(S390_lowcore.clock_comparator);
190 static void stp_timing_alert(struct stp_irq_parm *);
192 static void timing_alert_interrupt(struct ext_code ext_code,
193 unsigned int param32, unsigned long param64)
195 inc_irq_stat(IRQEXT_TLA);
196 if (param32 & 0x00038000)
197 stp_timing_alert((struct stp_irq_parm *) &param32);
200 static void stp_reset(void);
202 void read_persistent_clock64(struct timespec64 *ts)
204 unsigned char clk[STORE_CLOCK_EXT_SIZE];
205 __u64 delta;
207 delta = initial_leap_seconds + TOD_UNIX_EPOCH;
208 get_tod_clock_ext(clk);
209 *(__u64 *) &clk[1] -= delta;
210 if (*(__u64 *) &clk[1] > delta)
211 clk[0]--;
212 ext_to_timespec64(clk, ts);
215 void __init read_persistent_wall_and_boot_offset(struct timespec64 *wall_time,
216 struct timespec64 *boot_offset)
218 unsigned char clk[STORE_CLOCK_EXT_SIZE];
219 struct timespec64 boot_time;
220 __u64 delta;
222 delta = initial_leap_seconds + TOD_UNIX_EPOCH;
223 memcpy(clk, tod_clock_base, STORE_CLOCK_EXT_SIZE);
224 *(__u64 *)&clk[1] -= delta;
225 if (*(__u64 *)&clk[1] > delta)
226 clk[0]--;
227 ext_to_timespec64(clk, &boot_time);
229 read_persistent_clock64(wall_time);
230 *boot_offset = timespec64_sub(*wall_time, boot_time);
233 static u64 read_tod_clock(struct clocksource *cs)
235 unsigned long long now, adj;
237 preempt_disable(); /* protect from changes to steering parameters */
238 now = get_tod_clock();
239 adj = tod_steering_end - now;
240 if (unlikely((s64) adj >= 0))
242 * manually steer by 1 cycle every 2^16 cycles. This
243 * corresponds to shifting the tod delta by 15. 1s is
244 * therefore steered in ~9h. The adjust will decrease
245 * over time, until it finally reaches 0.
247 now += (tod_steering_delta < 0) ? (adj >> 15) : -(adj >> 15);
248 preempt_enable();
249 return now;
252 static struct clocksource clocksource_tod = {
253 .name = "tod",
254 .rating = 400,
255 .read = read_tod_clock,
256 .mask = -1ULL,
257 .mult = 1000,
258 .shift = 12,
259 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
262 struct clocksource * __init clocksource_default_clock(void)
264 return &clocksource_tod;
267 void update_vsyscall(struct timekeeper *tk)
269 u64 nsecps;
271 if (tk->tkr_mono.clock != &clocksource_tod)
272 return;
274 /* Make userspace gettimeofday spin until we're done. */
275 ++vdso_data->tb_update_count;
276 smp_wmb();
277 vdso_data->xtime_tod_stamp = tk->tkr_mono.cycle_last;
278 vdso_data->xtime_clock_sec = tk->xtime_sec;
279 vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec;
280 vdso_data->wtom_clock_sec =
281 tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
282 vdso_data->wtom_clock_nsec = tk->tkr_mono.xtime_nsec +
283 + ((u64) tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift);
284 nsecps = (u64) NSEC_PER_SEC << tk->tkr_mono.shift;
285 while (vdso_data->wtom_clock_nsec >= nsecps) {
286 vdso_data->wtom_clock_nsec -= nsecps;
287 vdso_data->wtom_clock_sec++;
290 vdso_data->xtime_coarse_sec = tk->xtime_sec;
291 vdso_data->xtime_coarse_nsec =
292 (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
293 vdso_data->wtom_coarse_sec =
294 vdso_data->xtime_coarse_sec + tk->wall_to_monotonic.tv_sec;
295 vdso_data->wtom_coarse_nsec =
296 vdso_data->xtime_coarse_nsec + tk->wall_to_monotonic.tv_nsec;
297 while (vdso_data->wtom_coarse_nsec >= NSEC_PER_SEC) {
298 vdso_data->wtom_coarse_nsec -= NSEC_PER_SEC;
299 vdso_data->wtom_coarse_sec++;
302 vdso_data->tk_mult = tk->tkr_mono.mult;
303 vdso_data->tk_shift = tk->tkr_mono.shift;
304 smp_wmb();
305 ++vdso_data->tb_update_count;
308 extern struct timezone sys_tz;
310 void update_vsyscall_tz(void)
312 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
313 vdso_data->tz_dsttime = sys_tz.tz_dsttime;
317 * Initialize the TOD clock and the CPU timer of
318 * the boot cpu.
320 void __init time_init(void)
322 /* Reset time synchronization interfaces. */
323 stp_reset();
325 /* request the clock comparator external interrupt */
326 if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt))
327 panic("Couldn't request external interrupt 0x1004");
329 /* request the timing alert external interrupt */
330 if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt))
331 panic("Couldn't request external interrupt 0x1406");
333 if (__clocksource_register(&clocksource_tod) != 0)
334 panic("Could not register TOD clock source");
336 /* Enable TOD clock interrupts on the boot cpu. */
337 init_cpu_timer();
339 /* Enable cpu timer interrupts on the boot cpu. */
340 vtime_init();
343 static DEFINE_PER_CPU(atomic_t, clock_sync_word);
344 static DEFINE_MUTEX(clock_sync_mutex);
345 static unsigned long clock_sync_flags;
347 #define CLOCK_SYNC_HAS_STP 0
348 #define CLOCK_SYNC_STP 1
351 * The get_clock function for the physical clock. It will get the current
352 * TOD clock, subtract the LPAR offset and write the result to *clock.
353 * The function returns 0 if the clock is in sync with the external time
354 * source. If the clock mode is local it will return -EOPNOTSUPP and
355 * -EAGAIN if the clock is not in sync with the external reference.
357 int get_phys_clock(unsigned long *clock)
359 atomic_t *sw_ptr;
360 unsigned int sw0, sw1;
362 sw_ptr = &get_cpu_var(clock_sync_word);
363 sw0 = atomic_read(sw_ptr);
364 *clock = get_tod_clock() - lpar_offset;
365 sw1 = atomic_read(sw_ptr);
366 put_cpu_var(clock_sync_word);
367 if (sw0 == sw1 && (sw0 & 0x80000000U))
368 /* Success: time is in sync. */
369 return 0;
370 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
371 return -EOPNOTSUPP;
372 if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags))
373 return -EACCES;
374 return -EAGAIN;
376 EXPORT_SYMBOL(get_phys_clock);
379 * Make get_phys_clock() return -EAGAIN.
381 static void disable_sync_clock(void *dummy)
383 atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
385 * Clear the in-sync bit 2^31. All get_phys_clock calls will
386 * fail until the sync bit is turned back on. In addition
387 * increase the "sequence" counter to avoid the race of an
388 * stp event and the complete recovery against get_phys_clock.
390 atomic_andnot(0x80000000, sw_ptr);
391 atomic_inc(sw_ptr);
395 * Make get_phys_clock() return 0 again.
396 * Needs to be called from a context disabled for preemption.
398 static void enable_sync_clock(void)
400 atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
401 atomic_or(0x80000000, sw_ptr);
405 * Function to check if the clock is in sync.
407 static inline int check_sync_clock(void)
409 atomic_t *sw_ptr;
410 int rc;
412 sw_ptr = &get_cpu_var(clock_sync_word);
413 rc = (atomic_read(sw_ptr) & 0x80000000U) != 0;
414 put_cpu_var(clock_sync_word);
415 return rc;
419 * Apply clock delta to the global data structures.
420 * This is called once on the CPU that performed the clock sync.
422 static void clock_sync_global(unsigned long long delta)
424 unsigned long now, adj;
425 struct ptff_qto qto;
427 /* Fixup the monotonic sched clock. */
428 *(unsigned long long *) &tod_clock_base[1] += delta;
429 if (*(unsigned long long *) &tod_clock_base[1] < delta)
430 /* Epoch overflow */
431 tod_clock_base[0]++;
432 /* Adjust TOD steering parameters. */
433 vdso_data->tb_update_count++;
434 now = get_tod_clock();
435 adj = tod_steering_end - now;
436 if (unlikely((s64) adj >= 0))
437 /* Calculate how much of the old adjustment is left. */
438 tod_steering_delta = (tod_steering_delta < 0) ?
439 -(adj >> 15) : (adj >> 15);
440 tod_steering_delta += delta;
441 if ((abs(tod_steering_delta) >> 48) != 0)
442 panic("TOD clock sync offset %lli is too large to drift\n",
443 tod_steering_delta);
444 tod_steering_end = now + (abs(tod_steering_delta) << 15);
445 vdso_data->ts_dir = (tod_steering_delta < 0) ? 0 : 1;
446 vdso_data->ts_end = tod_steering_end;
447 vdso_data->tb_update_count++;
448 /* Update LPAR offset. */
449 if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0)
450 lpar_offset = qto.tod_epoch_difference;
451 /* Call the TOD clock change notifier. */
452 atomic_notifier_call_chain(&s390_epoch_delta_notifier, 0, &delta);
456 * Apply clock delta to the per-CPU data structures of this CPU.
457 * This is called for each online CPU after the call to clock_sync_global.
459 static void clock_sync_local(unsigned long long delta)
461 /* Add the delta to the clock comparator. */
462 if (S390_lowcore.clock_comparator != clock_comparator_max) {
463 S390_lowcore.clock_comparator += delta;
464 set_clock_comparator(S390_lowcore.clock_comparator);
466 /* Adjust the last_update_clock time-stamp. */
467 S390_lowcore.last_update_clock += delta;
470 /* Single threaded workqueue used for stp sync events */
471 static struct workqueue_struct *time_sync_wq;
473 static void __init time_init_wq(void)
475 if (time_sync_wq)
476 return;
477 time_sync_wq = create_singlethread_workqueue("timesync");
480 struct clock_sync_data {
481 atomic_t cpus;
482 int in_sync;
483 unsigned long long clock_delta;
487 * Server Time Protocol (STP) code.
489 static bool stp_online;
490 static struct stp_sstpi stp_info;
491 static void *stp_page;
493 static void stp_work_fn(struct work_struct *work);
494 static DEFINE_MUTEX(stp_work_mutex);
495 static DECLARE_WORK(stp_work, stp_work_fn);
496 static struct timer_list stp_timer;
498 static int __init early_parse_stp(char *p)
500 return kstrtobool(p, &stp_online);
502 early_param("stp", early_parse_stp);
505 * Reset STP attachment.
507 static void __init stp_reset(void)
509 int rc;
511 stp_page = (void *) get_zeroed_page(GFP_ATOMIC);
512 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);
513 if (rc == 0)
514 set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags);
515 else if (stp_online) {
516 pr_warn("The real or virtual hardware system does not provide an STP interface\n");
517 free_page((unsigned long) stp_page);
518 stp_page = NULL;
519 stp_online = false;
523 static void stp_timeout(struct timer_list *unused)
525 queue_work(time_sync_wq, &stp_work);
528 static int __init stp_init(void)
530 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
531 return 0;
532 timer_setup(&stp_timer, stp_timeout, 0);
533 time_init_wq();
534 if (!stp_online)
535 return 0;
536 queue_work(time_sync_wq, &stp_work);
537 return 0;
540 arch_initcall(stp_init);
543 * STP timing alert. There are three causes:
544 * 1) timing status change
545 * 2) link availability change
546 * 3) time control parameter change
547 * In all three cases we are only interested in the clock source state.
548 * If a STP clock source is now available use it.
550 static void stp_timing_alert(struct stp_irq_parm *intparm)
552 if (intparm->tsc || intparm->lac || intparm->tcpc)
553 queue_work(time_sync_wq, &stp_work);
557 * STP sync check machine check. This is called when the timing state
558 * changes from the synchronized state to the unsynchronized state.
559 * After a STP sync check the clock is not in sync. The machine check
560 * is broadcasted to all cpus at the same time.
562 int stp_sync_check(void)
564 disable_sync_clock(NULL);
565 return 1;
569 * STP island condition machine check. This is called when an attached
570 * server attempts to communicate over an STP link and the servers
571 * have matching CTN ids and have a valid stratum-1 configuration
572 * but the configurations do not match.
574 int stp_island_check(void)
576 disable_sync_clock(NULL);
577 return 1;
580 void stp_queue_work(void)
582 queue_work(time_sync_wq, &stp_work);
585 static int stp_sync_clock(void *data)
587 struct clock_sync_data *sync = data;
588 unsigned long long clock_delta;
589 static int first;
590 int rc;
592 enable_sync_clock();
593 if (xchg(&first, 1) == 0) {
594 /* Wait until all other cpus entered the sync function. */
595 while (atomic_read(&sync->cpus) != 0)
596 cpu_relax();
597 rc = 0;
598 if (stp_info.todoff[0] || stp_info.todoff[1] ||
599 stp_info.todoff[2] || stp_info.todoff[3] ||
600 stp_info.tmd != 2) {
601 rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0,
602 &clock_delta);
603 if (rc == 0) {
604 sync->clock_delta = clock_delta;
605 clock_sync_global(clock_delta);
606 rc = chsc_sstpi(stp_page, &stp_info,
607 sizeof(struct stp_sstpi));
608 if (rc == 0 && stp_info.tmd != 2)
609 rc = -EAGAIN;
612 sync->in_sync = rc ? -EAGAIN : 1;
613 xchg(&first, 0);
614 } else {
615 /* Slave */
616 atomic_dec(&sync->cpus);
617 /* Wait for in_sync to be set. */
618 while (READ_ONCE(sync->in_sync) == 0)
619 __udelay(1);
621 if (sync->in_sync != 1)
622 /* Didn't work. Clear per-cpu in sync bit again. */
623 disable_sync_clock(NULL);
624 /* Apply clock delta to per-CPU fields of this CPU. */
625 clock_sync_local(sync->clock_delta);
627 return 0;
631 * STP work. Check for the STP state and take over the clock
632 * synchronization if the STP clock source is usable.
634 static void stp_work_fn(struct work_struct *work)
636 struct clock_sync_data stp_sync;
637 int rc;
639 /* prevent multiple execution. */
640 mutex_lock(&stp_work_mutex);
642 if (!stp_online) {
643 chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);
644 del_timer_sync(&stp_timer);
645 goto out_unlock;
648 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0, NULL);
649 if (rc)
650 goto out_unlock;
652 rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi));
653 if (rc || stp_info.c == 0)
654 goto out_unlock;
656 /* Skip synchronization if the clock is already in sync. */
657 if (check_sync_clock())
658 goto out_unlock;
660 memset(&stp_sync, 0, sizeof(stp_sync));
661 cpus_read_lock();
662 atomic_set(&stp_sync.cpus, num_online_cpus() - 1);
663 stop_machine_cpuslocked(stp_sync_clock, &stp_sync, cpu_online_mask);
664 cpus_read_unlock();
666 if (!check_sync_clock())
668 * There is a usable clock but the synchonization failed.
669 * Retry after a second.
671 mod_timer(&stp_timer, jiffies + HZ);
673 out_unlock:
674 mutex_unlock(&stp_work_mutex);
678 * STP subsys sysfs interface functions
680 static struct bus_type stp_subsys = {
681 .name = "stp",
682 .dev_name = "stp",
685 static ssize_t stp_ctn_id_show(struct device *dev,
686 struct device_attribute *attr,
687 char *buf)
689 if (!stp_online)
690 return -ENODATA;
691 return sprintf(buf, "%016llx\n",
692 *(unsigned long long *) stp_info.ctnid);
695 static DEVICE_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL);
697 static ssize_t stp_ctn_type_show(struct device *dev,
698 struct device_attribute *attr,
699 char *buf)
701 if (!stp_online)
702 return -ENODATA;
703 return sprintf(buf, "%i\n", stp_info.ctn);
706 static DEVICE_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL);
708 static ssize_t stp_dst_offset_show(struct device *dev,
709 struct device_attribute *attr,
710 char *buf)
712 if (!stp_online || !(stp_info.vbits & 0x2000))
713 return -ENODATA;
714 return sprintf(buf, "%i\n", (int)(s16) stp_info.dsto);
717 static DEVICE_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL);
719 static ssize_t stp_leap_seconds_show(struct device *dev,
720 struct device_attribute *attr,
721 char *buf)
723 if (!stp_online || !(stp_info.vbits & 0x8000))
724 return -ENODATA;
725 return sprintf(buf, "%i\n", (int)(s16) stp_info.leaps);
728 static DEVICE_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL);
730 static ssize_t stp_stratum_show(struct device *dev,
731 struct device_attribute *attr,
732 char *buf)
734 if (!stp_online)
735 return -ENODATA;
736 return sprintf(buf, "%i\n", (int)(s16) stp_info.stratum);
739 static DEVICE_ATTR(stratum, 0400, stp_stratum_show, NULL);
741 static ssize_t stp_time_offset_show(struct device *dev,
742 struct device_attribute *attr,
743 char *buf)
745 if (!stp_online || !(stp_info.vbits & 0x0800))
746 return -ENODATA;
747 return sprintf(buf, "%i\n", (int) stp_info.tto);
750 static DEVICE_ATTR(time_offset, 0400, stp_time_offset_show, NULL);
752 static ssize_t stp_time_zone_offset_show(struct device *dev,
753 struct device_attribute *attr,
754 char *buf)
756 if (!stp_online || !(stp_info.vbits & 0x4000))
757 return -ENODATA;
758 return sprintf(buf, "%i\n", (int)(s16) stp_info.tzo);
761 static DEVICE_ATTR(time_zone_offset, 0400,
762 stp_time_zone_offset_show, NULL);
764 static ssize_t stp_timing_mode_show(struct device *dev,
765 struct device_attribute *attr,
766 char *buf)
768 if (!stp_online)
769 return -ENODATA;
770 return sprintf(buf, "%i\n", stp_info.tmd);
773 static DEVICE_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL);
775 static ssize_t stp_timing_state_show(struct device *dev,
776 struct device_attribute *attr,
777 char *buf)
779 if (!stp_online)
780 return -ENODATA;
781 return sprintf(buf, "%i\n", stp_info.tst);
784 static DEVICE_ATTR(timing_state, 0400, stp_timing_state_show, NULL);
786 static ssize_t stp_online_show(struct device *dev,
787 struct device_attribute *attr,
788 char *buf)
790 return sprintf(buf, "%i\n", stp_online);
793 static ssize_t stp_online_store(struct device *dev,
794 struct device_attribute *attr,
795 const char *buf, size_t count)
797 unsigned int value;
799 value = simple_strtoul(buf, NULL, 0);
800 if (value != 0 && value != 1)
801 return -EINVAL;
802 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
803 return -EOPNOTSUPP;
804 mutex_lock(&clock_sync_mutex);
805 stp_online = value;
806 if (stp_online)
807 set_bit(CLOCK_SYNC_STP, &clock_sync_flags);
808 else
809 clear_bit(CLOCK_SYNC_STP, &clock_sync_flags);
810 queue_work(time_sync_wq, &stp_work);
811 mutex_unlock(&clock_sync_mutex);
812 return count;
816 * Can't use DEVICE_ATTR because the attribute should be named
817 * stp/online but dev_attr_online already exists in this file ..
819 static struct device_attribute dev_attr_stp_online = {
820 .attr = { .name = "online", .mode = 0600 },
821 .show = stp_online_show,
822 .store = stp_online_store,
825 static struct device_attribute *stp_attributes[] = {
826 &dev_attr_ctn_id,
827 &dev_attr_ctn_type,
828 &dev_attr_dst_offset,
829 &dev_attr_leap_seconds,
830 &dev_attr_stp_online,
831 &dev_attr_stratum,
832 &dev_attr_time_offset,
833 &dev_attr_time_zone_offset,
834 &dev_attr_timing_mode,
835 &dev_attr_timing_state,
836 NULL
839 static int __init stp_init_sysfs(void)
841 struct device_attribute **attr;
842 int rc;
844 rc = subsys_system_register(&stp_subsys, NULL);
845 if (rc)
846 goto out;
847 for (attr = stp_attributes; *attr; attr++) {
848 rc = device_create_file(stp_subsys.dev_root, *attr);
849 if (rc)
850 goto out_unreg;
852 return 0;
853 out_unreg:
854 for (; attr >= stp_attributes; attr--)
855 device_remove_file(stp_subsys.dev_root, *attr);
856 bus_unregister(&stp_subsys);
857 out:
858 return rc;
861 device_initcall(stp_init_sysfs);