x86/speculation/mds: Fix documentation typo
[linux/fpc-iii.git] / arch / s390 / kernel / time.c
blob5cbd52169348faf9c09bc258c2cd0072e0089ee0
1 /*
2 * Time of day based timer functions.
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)
10 * Derived from "arch/i386/kernel/time.c"
11 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
14 #define KMSG_COMPONENT "time"
15 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
17 #include <linux/kernel_stat.h>
18 #include <linux/errno.h>
19 #include <linux/export.h>
20 #include <linux/sched.h>
21 #include <linux/sched/clock.h>
22 #include <linux/kernel.h>
23 #include <linux/param.h>
24 #include <linux/string.h>
25 #include <linux/mm.h>
26 #include <linux/interrupt.h>
27 #include <linux/cpu.h>
28 #include <linux/stop_machine.h>
29 #include <linux/time.h>
30 #include <linux/device.h>
31 #include <linux/delay.h>
32 #include <linux/init.h>
33 #include <linux/smp.h>
34 #include <linux/types.h>
35 #include <linux/profile.h>
36 #include <linux/timex.h>
37 #include <linux/notifier.h>
38 #include <linux/timekeeper_internal.h>
39 #include <linux/clockchips.h>
40 #include <linux/gfp.h>
41 #include <linux/kprobes.h>
42 #include <linux/uaccess.h>
43 #include <asm/facility.h>
44 #include <asm/delay.h>
45 #include <asm/div64.h>
46 #include <asm/vdso.h>
47 #include <asm/irq.h>
48 #include <asm/irq_regs.h>
49 #include <asm/vtimer.h>
50 #include <asm/stp.h>
51 #include <asm/cio.h>
52 #include "entry.h"
54 unsigned char tod_clock_base[16] __aligned(8) = {
55 /* Force to data section. */
56 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
57 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
59 EXPORT_SYMBOL_GPL(tod_clock_base);
61 u64 clock_comparator_max = -1ULL;
62 EXPORT_SYMBOL_GPL(clock_comparator_max);
64 static DEFINE_PER_CPU(struct clock_event_device, comparators);
66 ATOMIC_NOTIFIER_HEAD(s390_epoch_delta_notifier);
67 EXPORT_SYMBOL(s390_epoch_delta_notifier);
69 unsigned char ptff_function_mask[16];
71 static unsigned long long lpar_offset;
72 static unsigned long long initial_leap_seconds;
73 static unsigned long long tod_steering_end;
74 static long long tod_steering_delta;
77 * Get time offsets with PTFF
79 void __init time_early_init(void)
81 struct ptff_qto qto;
82 struct ptff_qui qui;
84 /* Initialize TOD steering parameters */
85 tod_steering_end = *(unsigned long long *) &tod_clock_base[1];
86 vdso_data->ts_end = tod_steering_end;
88 if (!test_facility(28))
89 return;
91 ptff(&ptff_function_mask, sizeof(ptff_function_mask), PTFF_QAF);
93 /* get LPAR offset */
94 if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0)
95 lpar_offset = qto.tod_epoch_difference;
97 /* get initial leap seconds */
98 if (ptff_query(PTFF_QUI) && ptff(&qui, sizeof(qui), PTFF_QUI) == 0)
99 initial_leap_seconds = (unsigned long long)
100 ((long) qui.old_leap * 4096000000L);
104 * Scheduler clock - returns current time in nanosec units.
106 unsigned long long notrace sched_clock(void)
108 return tod_to_ns(get_tod_clock_monotonic());
110 NOKPROBE_SYMBOL(sched_clock);
113 * Monotonic_clock - returns # of nanoseconds passed since time_init()
115 unsigned long long monotonic_clock(void)
117 return sched_clock();
119 EXPORT_SYMBOL(monotonic_clock);
121 static void ext_to_timespec64(unsigned char *clk, struct timespec64 *xt)
123 unsigned long long high, low, rem, sec, nsec;
125 /* Split extendnd TOD clock to micro-seconds and sub-micro-seconds */
126 high = (*(unsigned long long *) clk) >> 4;
127 low = (*(unsigned long long *)&clk[7]) << 4;
128 /* Calculate seconds and nano-seconds */
129 sec = high;
130 rem = do_div(sec, 1000000);
131 nsec = (((low >> 32) + (rem << 32)) * 1000) >> 32;
133 xt->tv_sec = sec;
134 xt->tv_nsec = nsec;
137 void clock_comparator_work(void)
139 struct clock_event_device *cd;
141 S390_lowcore.clock_comparator = clock_comparator_max;
142 cd = this_cpu_ptr(&comparators);
143 cd->event_handler(cd);
146 static int s390_next_event(unsigned long delta,
147 struct clock_event_device *evt)
149 S390_lowcore.clock_comparator = get_tod_clock() + delta;
150 set_clock_comparator(S390_lowcore.clock_comparator);
151 return 0;
155 * Set up lowcore and control register of the current cpu to
156 * enable TOD clock and clock comparator interrupts.
158 void init_cpu_timer(void)
160 struct clock_event_device *cd;
161 int cpu;
163 S390_lowcore.clock_comparator = clock_comparator_max;
164 set_clock_comparator(S390_lowcore.clock_comparator);
166 cpu = smp_processor_id();
167 cd = &per_cpu(comparators, cpu);
168 cd->name = "comparator";
169 cd->features = CLOCK_EVT_FEAT_ONESHOT;
170 cd->mult = 16777;
171 cd->shift = 12;
172 cd->min_delta_ns = 1;
173 cd->min_delta_ticks = 1;
174 cd->max_delta_ns = LONG_MAX;
175 cd->max_delta_ticks = ULONG_MAX;
176 cd->rating = 400;
177 cd->cpumask = cpumask_of(cpu);
178 cd->set_next_event = s390_next_event;
180 clockevents_register_device(cd);
182 /* Enable clock comparator timer interrupt. */
183 __ctl_set_bit(0,11);
185 /* Always allow the timing alert external interrupt. */
186 __ctl_set_bit(0, 4);
189 static void clock_comparator_interrupt(struct ext_code ext_code,
190 unsigned int param32,
191 unsigned long param64)
193 inc_irq_stat(IRQEXT_CLK);
194 if (S390_lowcore.clock_comparator == clock_comparator_max)
195 set_clock_comparator(S390_lowcore.clock_comparator);
198 static void stp_timing_alert(struct stp_irq_parm *);
200 static void timing_alert_interrupt(struct ext_code ext_code,
201 unsigned int param32, unsigned long param64)
203 inc_irq_stat(IRQEXT_TLA);
204 if (param32 & 0x00038000)
205 stp_timing_alert((struct stp_irq_parm *) &param32);
208 static void stp_reset(void);
210 void read_persistent_clock64(struct timespec64 *ts)
212 unsigned char clk[STORE_CLOCK_EXT_SIZE];
213 __u64 delta;
215 delta = initial_leap_seconds + TOD_UNIX_EPOCH;
216 get_tod_clock_ext(clk);
217 *(__u64 *) &clk[1] -= delta;
218 if (*(__u64 *) &clk[1] > delta)
219 clk[0]--;
220 ext_to_timespec64(clk, ts);
223 void read_boot_clock64(struct timespec64 *ts)
225 unsigned char clk[STORE_CLOCK_EXT_SIZE];
226 __u64 delta;
228 delta = initial_leap_seconds + TOD_UNIX_EPOCH;
229 memcpy(clk, tod_clock_base, 16);
230 *(__u64 *) &clk[1] -= delta;
231 if (*(__u64 *) &clk[1] > delta)
232 clk[0]--;
233 ext_to_timespec64(clk, ts);
236 static u64 read_tod_clock(struct clocksource *cs)
238 unsigned long long now, adj;
240 preempt_disable(); /* protect from changes to steering parameters */
241 now = get_tod_clock();
242 adj = tod_steering_end - now;
243 if (unlikely((s64) adj >= 0))
245 * manually steer by 1 cycle every 2^16 cycles. This
246 * corresponds to shifting the tod delta by 15. 1s is
247 * therefore steered in ~9h. The adjust will decrease
248 * over time, until it finally reaches 0.
250 now += (tod_steering_delta < 0) ? (adj >> 15) : -(adj >> 15);
251 preempt_enable();
252 return now;
255 static struct clocksource clocksource_tod = {
256 .name = "tod",
257 .rating = 400,
258 .read = read_tod_clock,
259 .mask = -1ULL,
260 .mult = 1000,
261 .shift = 12,
262 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
265 struct clocksource * __init clocksource_default_clock(void)
267 return &clocksource_tod;
270 void update_vsyscall(struct timekeeper *tk)
272 u64 nsecps;
274 if (tk->tkr_mono.clock != &clocksource_tod)
275 return;
277 /* Make userspace gettimeofday spin until we're done. */
278 ++vdso_data->tb_update_count;
279 smp_wmb();
280 vdso_data->xtime_tod_stamp = tk->tkr_mono.cycle_last;
281 vdso_data->xtime_clock_sec = tk->xtime_sec;
282 vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec;
283 vdso_data->wtom_clock_sec =
284 tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
285 vdso_data->wtom_clock_nsec = tk->tkr_mono.xtime_nsec +
286 + ((u64) tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift);
287 nsecps = (u64) NSEC_PER_SEC << tk->tkr_mono.shift;
288 while (vdso_data->wtom_clock_nsec >= nsecps) {
289 vdso_data->wtom_clock_nsec -= nsecps;
290 vdso_data->wtom_clock_sec++;
293 vdso_data->xtime_coarse_sec = tk->xtime_sec;
294 vdso_data->xtime_coarse_nsec =
295 (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
296 vdso_data->wtom_coarse_sec =
297 vdso_data->xtime_coarse_sec + tk->wall_to_monotonic.tv_sec;
298 vdso_data->wtom_coarse_nsec =
299 vdso_data->xtime_coarse_nsec + tk->wall_to_monotonic.tv_nsec;
300 while (vdso_data->wtom_coarse_nsec >= NSEC_PER_SEC) {
301 vdso_data->wtom_coarse_nsec -= NSEC_PER_SEC;
302 vdso_data->wtom_coarse_sec++;
305 vdso_data->tk_mult = tk->tkr_mono.mult;
306 vdso_data->tk_shift = tk->tkr_mono.shift;
307 smp_wmb();
308 ++vdso_data->tb_update_count;
311 extern struct timezone sys_tz;
313 void update_vsyscall_tz(void)
315 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
316 vdso_data->tz_dsttime = sys_tz.tz_dsttime;
320 * Initialize the TOD clock and the CPU timer of
321 * the boot cpu.
323 void __init time_init(void)
325 /* Reset time synchronization interfaces. */
326 stp_reset();
328 /* request the clock comparator external interrupt */
329 if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt))
330 panic("Couldn't request external interrupt 0x1004");
332 /* request the timing alert external interrupt */
333 if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt))
334 panic("Couldn't request external interrupt 0x1406");
336 if (__clocksource_register(&clocksource_tod) != 0)
337 panic("Could not register TOD clock source");
339 /* Enable TOD clock interrupts on the boot cpu. */
340 init_cpu_timer();
342 /* Enable cpu timer interrupts on the boot cpu. */
343 vtime_init();
346 static DEFINE_PER_CPU(atomic_t, clock_sync_word);
347 static DEFINE_MUTEX(clock_sync_mutex);
348 static unsigned long clock_sync_flags;
350 #define CLOCK_SYNC_HAS_STP 0
351 #define CLOCK_SYNC_STP 1
354 * The get_clock function for the physical clock. It will get the current
355 * TOD clock, subtract the LPAR offset and write the result to *clock.
356 * The function returns 0 if the clock is in sync with the external time
357 * source. If the clock mode is local it will return -EOPNOTSUPP and
358 * -EAGAIN if the clock is not in sync with the external reference.
360 int get_phys_clock(unsigned long *clock)
362 atomic_t *sw_ptr;
363 unsigned int sw0, sw1;
365 sw_ptr = &get_cpu_var(clock_sync_word);
366 sw0 = atomic_read(sw_ptr);
367 *clock = get_tod_clock() - lpar_offset;
368 sw1 = atomic_read(sw_ptr);
369 put_cpu_var(clock_sync_word);
370 if (sw0 == sw1 && (sw0 & 0x80000000U))
371 /* Success: time is in sync. */
372 return 0;
373 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
374 return -EOPNOTSUPP;
375 if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags))
376 return -EACCES;
377 return -EAGAIN;
379 EXPORT_SYMBOL(get_phys_clock);
382 * Make get_phys_clock() return -EAGAIN.
384 static void disable_sync_clock(void *dummy)
386 atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
388 * Clear the in-sync bit 2^31. All get_phys_clock calls will
389 * fail until the sync bit is turned back on. In addition
390 * increase the "sequence" counter to avoid the race of an
391 * stp event and the complete recovery against get_phys_clock.
393 atomic_andnot(0x80000000, sw_ptr);
394 atomic_inc(sw_ptr);
398 * Make get_phys_clock() return 0 again.
399 * Needs to be called from a context disabled for preemption.
401 static void enable_sync_clock(void)
403 atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word);
404 atomic_or(0x80000000, sw_ptr);
408 * Function to check if the clock is in sync.
410 static inline int check_sync_clock(void)
412 atomic_t *sw_ptr;
413 int rc;
415 sw_ptr = &get_cpu_var(clock_sync_word);
416 rc = (atomic_read(sw_ptr) & 0x80000000U) != 0;
417 put_cpu_var(clock_sync_word);
418 return rc;
422 * Apply clock delta to the global data structures.
423 * This is called once on the CPU that performed the clock sync.
425 static void clock_sync_global(unsigned long long delta)
427 unsigned long now, adj;
428 struct ptff_qto qto;
430 /* Fixup the monotonic sched clock. */
431 *(unsigned long long *) &tod_clock_base[1] += delta;
432 if (*(unsigned long long *) &tod_clock_base[1] < delta)
433 /* Epoch overflow */
434 tod_clock_base[0]++;
435 /* Adjust TOD steering parameters. */
436 vdso_data->tb_update_count++;
437 now = get_tod_clock();
438 adj = tod_steering_end - now;
439 if (unlikely((s64) adj >= 0))
440 /* Calculate how much of the old adjustment is left. */
441 tod_steering_delta = (tod_steering_delta < 0) ?
442 -(adj >> 15) : (adj >> 15);
443 tod_steering_delta += delta;
444 if ((abs(tod_steering_delta) >> 48) != 0)
445 panic("TOD clock sync offset %lli is too large to drift\n",
446 tod_steering_delta);
447 tod_steering_end = now + (abs(tod_steering_delta) << 15);
448 vdso_data->ts_dir = (tod_steering_delta < 0) ? 0 : 1;
449 vdso_data->ts_end = tod_steering_end;
450 vdso_data->tb_update_count++;
451 /* Update LPAR offset. */
452 if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0)
453 lpar_offset = qto.tod_epoch_difference;
454 /* Call the TOD clock change notifier. */
455 atomic_notifier_call_chain(&s390_epoch_delta_notifier, 0, &delta);
459 * Apply clock delta to the per-CPU data structures of this CPU.
460 * This is called for each online CPU after the call to clock_sync_global.
462 static void clock_sync_local(unsigned long long delta)
464 /* Add the delta to the clock comparator. */
465 if (S390_lowcore.clock_comparator != clock_comparator_max) {
466 S390_lowcore.clock_comparator += delta;
467 set_clock_comparator(S390_lowcore.clock_comparator);
469 /* Adjust the last_update_clock time-stamp. */
470 S390_lowcore.last_update_clock += delta;
473 /* Single threaded workqueue used for stp sync events */
474 static struct workqueue_struct *time_sync_wq;
476 static void __init time_init_wq(void)
478 if (time_sync_wq)
479 return;
480 time_sync_wq = create_singlethread_workqueue("timesync");
483 struct clock_sync_data {
484 atomic_t cpus;
485 int in_sync;
486 unsigned long long clock_delta;
490 * Server Time Protocol (STP) code.
492 static bool stp_online;
493 static struct stp_sstpi stp_info;
494 static void *stp_page;
496 static void stp_work_fn(struct work_struct *work);
497 static DEFINE_MUTEX(stp_work_mutex);
498 static DECLARE_WORK(stp_work, stp_work_fn);
499 static struct timer_list stp_timer;
501 static int __init early_parse_stp(char *p)
503 return kstrtobool(p, &stp_online);
505 early_param("stp", early_parse_stp);
508 * Reset STP attachment.
510 static void __init stp_reset(void)
512 int rc;
514 stp_page = (void *) get_zeroed_page(GFP_ATOMIC);
515 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);
516 if (rc == 0)
517 set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags);
518 else if (stp_online) {
519 pr_warn("The real or virtual hardware system does not provide an STP interface\n");
520 free_page((unsigned long) stp_page);
521 stp_page = NULL;
522 stp_online = false;
526 static void stp_timeout(unsigned long dummy)
528 queue_work(time_sync_wq, &stp_work);
531 static int __init stp_init(void)
533 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
534 return 0;
535 setup_timer(&stp_timer, stp_timeout, 0UL);
536 time_init_wq();
537 if (!stp_online)
538 return 0;
539 queue_work(time_sync_wq, &stp_work);
540 return 0;
543 arch_initcall(stp_init);
546 * STP timing alert. There are three causes:
547 * 1) timing status change
548 * 2) link availability change
549 * 3) time control parameter change
550 * In all three cases we are only interested in the clock source state.
551 * If a STP clock source is now available use it.
553 static void stp_timing_alert(struct stp_irq_parm *intparm)
555 if (intparm->tsc || intparm->lac || intparm->tcpc)
556 queue_work(time_sync_wq, &stp_work);
560 * STP sync check machine check. This is called when the timing state
561 * changes from the synchronized state to the unsynchronized state.
562 * After a STP sync check the clock is not in sync. The machine check
563 * is broadcasted to all cpus at the same time.
565 int stp_sync_check(void)
567 disable_sync_clock(NULL);
568 return 1;
572 * STP island condition machine check. This is called when an attached
573 * server attempts to communicate over an STP link and the servers
574 * have matching CTN ids and have a valid stratum-1 configuration
575 * but the configurations do not match.
577 int stp_island_check(void)
579 disable_sync_clock(NULL);
580 return 1;
583 void stp_queue_work(void)
585 queue_work(time_sync_wq, &stp_work);
588 static int stp_sync_clock(void *data)
590 struct clock_sync_data *sync = data;
591 unsigned long long clock_delta;
592 static int first;
593 int rc;
595 enable_sync_clock();
596 if (xchg(&first, 1) == 0) {
597 /* Wait until all other cpus entered the sync function. */
598 while (atomic_read(&sync->cpus) != 0)
599 cpu_relax();
600 rc = 0;
601 if (stp_info.todoff[0] || stp_info.todoff[1] ||
602 stp_info.todoff[2] || stp_info.todoff[3] ||
603 stp_info.tmd != 2) {
604 rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0,
605 &clock_delta);
606 if (rc == 0) {
607 sync->clock_delta = clock_delta;
608 clock_sync_global(clock_delta);
609 rc = chsc_sstpi(stp_page, &stp_info,
610 sizeof(struct stp_sstpi));
611 if (rc == 0 && stp_info.tmd != 2)
612 rc = -EAGAIN;
615 sync->in_sync = rc ? -EAGAIN : 1;
616 xchg(&first, 0);
617 } else {
618 /* Slave */
619 atomic_dec(&sync->cpus);
620 /* Wait for in_sync to be set. */
621 while (READ_ONCE(sync->in_sync) == 0)
622 __udelay(1);
624 if (sync->in_sync != 1)
625 /* Didn't work. Clear per-cpu in sync bit again. */
626 disable_sync_clock(NULL);
627 /* Apply clock delta to per-CPU fields of this CPU. */
628 clock_sync_local(sync->clock_delta);
630 return 0;
634 * STP work. Check for the STP state and take over the clock
635 * synchronization if the STP clock source is usable.
637 static void stp_work_fn(struct work_struct *work)
639 struct clock_sync_data stp_sync;
640 int rc;
642 /* prevent multiple execution. */
643 mutex_lock(&stp_work_mutex);
645 if (!stp_online) {
646 chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL);
647 del_timer_sync(&stp_timer);
648 goto out_unlock;
651 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0, NULL);
652 if (rc)
653 goto out_unlock;
655 rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi));
656 if (rc || stp_info.c == 0)
657 goto out_unlock;
659 /* Skip synchronization if the clock is already in sync. */
660 if (check_sync_clock())
661 goto out_unlock;
663 memset(&stp_sync, 0, sizeof(stp_sync));
664 cpus_read_lock();
665 atomic_set(&stp_sync.cpus, num_online_cpus() - 1);
666 stop_machine_cpuslocked(stp_sync_clock, &stp_sync, cpu_online_mask);
667 cpus_read_unlock();
669 if (!check_sync_clock())
671 * There is a usable clock but the synchonization failed.
672 * Retry after a second.
674 mod_timer(&stp_timer, jiffies + HZ);
676 out_unlock:
677 mutex_unlock(&stp_work_mutex);
681 * STP subsys sysfs interface functions
683 static struct bus_type stp_subsys = {
684 .name = "stp",
685 .dev_name = "stp",
688 static ssize_t stp_ctn_id_show(struct device *dev,
689 struct device_attribute *attr,
690 char *buf)
692 if (!stp_online)
693 return -ENODATA;
694 return sprintf(buf, "%016llx\n",
695 *(unsigned long long *) stp_info.ctnid);
698 static DEVICE_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL);
700 static ssize_t stp_ctn_type_show(struct device *dev,
701 struct device_attribute *attr,
702 char *buf)
704 if (!stp_online)
705 return -ENODATA;
706 return sprintf(buf, "%i\n", stp_info.ctn);
709 static DEVICE_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL);
711 static ssize_t stp_dst_offset_show(struct device *dev,
712 struct device_attribute *attr,
713 char *buf)
715 if (!stp_online || !(stp_info.vbits & 0x2000))
716 return -ENODATA;
717 return sprintf(buf, "%i\n", (int)(s16) stp_info.dsto);
720 static DEVICE_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL);
722 static ssize_t stp_leap_seconds_show(struct device *dev,
723 struct device_attribute *attr,
724 char *buf)
726 if (!stp_online || !(stp_info.vbits & 0x8000))
727 return -ENODATA;
728 return sprintf(buf, "%i\n", (int)(s16) stp_info.leaps);
731 static DEVICE_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL);
733 static ssize_t stp_stratum_show(struct device *dev,
734 struct device_attribute *attr,
735 char *buf)
737 if (!stp_online)
738 return -ENODATA;
739 return sprintf(buf, "%i\n", (int)(s16) stp_info.stratum);
742 static DEVICE_ATTR(stratum, 0400, stp_stratum_show, NULL);
744 static ssize_t stp_time_offset_show(struct device *dev,
745 struct device_attribute *attr,
746 char *buf)
748 if (!stp_online || !(stp_info.vbits & 0x0800))
749 return -ENODATA;
750 return sprintf(buf, "%i\n", (int) stp_info.tto);
753 static DEVICE_ATTR(time_offset, 0400, stp_time_offset_show, NULL);
755 static ssize_t stp_time_zone_offset_show(struct device *dev,
756 struct device_attribute *attr,
757 char *buf)
759 if (!stp_online || !(stp_info.vbits & 0x4000))
760 return -ENODATA;
761 return sprintf(buf, "%i\n", (int)(s16) stp_info.tzo);
764 static DEVICE_ATTR(time_zone_offset, 0400,
765 stp_time_zone_offset_show, NULL);
767 static ssize_t stp_timing_mode_show(struct device *dev,
768 struct device_attribute *attr,
769 char *buf)
771 if (!stp_online)
772 return -ENODATA;
773 return sprintf(buf, "%i\n", stp_info.tmd);
776 static DEVICE_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL);
778 static ssize_t stp_timing_state_show(struct device *dev,
779 struct device_attribute *attr,
780 char *buf)
782 if (!stp_online)
783 return -ENODATA;
784 return sprintf(buf, "%i\n", stp_info.tst);
787 static DEVICE_ATTR(timing_state, 0400, stp_timing_state_show, NULL);
789 static ssize_t stp_online_show(struct device *dev,
790 struct device_attribute *attr,
791 char *buf)
793 return sprintf(buf, "%i\n", stp_online);
796 static ssize_t stp_online_store(struct device *dev,
797 struct device_attribute *attr,
798 const char *buf, size_t count)
800 unsigned int value;
802 value = simple_strtoul(buf, NULL, 0);
803 if (value != 0 && value != 1)
804 return -EINVAL;
805 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags))
806 return -EOPNOTSUPP;
807 mutex_lock(&clock_sync_mutex);
808 stp_online = value;
809 if (stp_online)
810 set_bit(CLOCK_SYNC_STP, &clock_sync_flags);
811 else
812 clear_bit(CLOCK_SYNC_STP, &clock_sync_flags);
813 queue_work(time_sync_wq, &stp_work);
814 mutex_unlock(&clock_sync_mutex);
815 return count;
819 * Can't use DEVICE_ATTR because the attribute should be named
820 * stp/online but dev_attr_online already exists in this file ..
822 static struct device_attribute dev_attr_stp_online = {
823 .attr = { .name = "online", .mode = 0600 },
824 .show = stp_online_show,
825 .store = stp_online_store,
828 static struct device_attribute *stp_attributes[] = {
829 &dev_attr_ctn_id,
830 &dev_attr_ctn_type,
831 &dev_attr_dst_offset,
832 &dev_attr_leap_seconds,
833 &dev_attr_stp_online,
834 &dev_attr_stratum,
835 &dev_attr_time_offset,
836 &dev_attr_time_zone_offset,
837 &dev_attr_timing_mode,
838 &dev_attr_timing_state,
839 NULL
842 static int __init stp_init_sysfs(void)
844 struct device_attribute **attr;
845 int rc;
847 rc = subsys_system_register(&stp_subsys, NULL);
848 if (rc)
849 goto out;
850 for (attr = stp_attributes; *attr; attr++) {
851 rc = device_create_file(stp_subsys.dev_root, *attr);
852 if (rc)
853 goto out_unreg;
855 return 0;
856 out_unreg:
857 for (; attr >= stp_attributes; attr--)
858 device_remove_file(stp_subsys.dev_root, *attr);
859 bus_unregister(&stp_subsys);
860 out:
861 return rc;
864 device_initcall(stp_init_sysfs);