2 * Time of day based timer functions.
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>
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>
48 #include <asm/irq_regs.h>
49 #include <asm/vtimer.h>
54 u64 sched_clock_base_cc
= -1; /* Force to data section. */
55 EXPORT_SYMBOL_GPL(sched_clock_base_cc
);
57 static DEFINE_PER_CPU(struct clock_event_device
, comparators
);
59 ATOMIC_NOTIFIER_HEAD(s390_epoch_delta_notifier
);
60 EXPORT_SYMBOL(s390_epoch_delta_notifier
);
62 unsigned char ptff_function_mask
[16];
64 static unsigned long long lpar_offset
;
65 static unsigned long long initial_leap_seconds
;
66 static unsigned long long tod_steering_end
;
67 static long long tod_steering_delta
;
70 * Get time offsets with PTFF
72 void __init
time_early_init(void)
77 /* Initialize TOD steering parameters */
78 tod_steering_end
= sched_clock_base_cc
;
79 vdso_data
->ts_end
= tod_steering_end
;
81 if (!test_facility(28))
84 ptff(&ptff_function_mask
, sizeof(ptff_function_mask
), PTFF_QAF
);
87 if (ptff_query(PTFF_QTO
) && ptff(&qto
, sizeof(qto
), PTFF_QTO
) == 0)
88 lpar_offset
= qto
.tod_epoch_difference
;
90 /* get initial leap seconds */
91 if (ptff_query(PTFF_QUI
) && ptff(&qui
, sizeof(qui
), PTFF_QUI
) == 0)
92 initial_leap_seconds
= (unsigned long long)
93 ((long) qui
.old_leap
* 4096000000L);
97 * Scheduler clock - returns current time in nanosec units.
99 unsigned long long notrace
sched_clock(void)
101 return tod_to_ns(get_tod_clock_monotonic());
103 NOKPROBE_SYMBOL(sched_clock
);
106 * Monotonic_clock - returns # of nanoseconds passed since time_init()
108 unsigned long long monotonic_clock(void)
110 return sched_clock();
112 EXPORT_SYMBOL(monotonic_clock
);
114 static void tod_to_timeval(__u64 todval
, struct timespec64
*xt
)
116 unsigned long long sec
;
119 do_div(sec
, 1000000);
121 todval
-= (sec
* 1000000) << 12;
122 xt
->tv_nsec
= ((todval
* 1000) >> 12);
125 void clock_comparator_work(void)
127 struct clock_event_device
*cd
;
129 S390_lowcore
.clock_comparator
= -1ULL;
130 cd
= this_cpu_ptr(&comparators
);
131 cd
->event_handler(cd
);
134 static int s390_next_event(unsigned long delta
,
135 struct clock_event_device
*evt
)
137 S390_lowcore
.clock_comparator
= get_tod_clock() + delta
;
138 set_clock_comparator(S390_lowcore
.clock_comparator
);
143 * Set up lowcore and control register of the current cpu to
144 * enable TOD clock and clock comparator interrupts.
146 void init_cpu_timer(void)
148 struct clock_event_device
*cd
;
151 S390_lowcore
.clock_comparator
= -1ULL;
152 set_clock_comparator(S390_lowcore
.clock_comparator
);
154 cpu
= smp_processor_id();
155 cd
= &per_cpu(comparators
, cpu
);
156 cd
->name
= "comparator";
157 cd
->features
= CLOCK_EVT_FEAT_ONESHOT
;
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
;
165 cd
->cpumask
= cpumask_of(cpu
);
166 cd
->set_next_event
= s390_next_event
;
168 clockevents_register_device(cd
);
170 /* Enable clock comparator timer interrupt. */
173 /* Always allow the timing alert external interrupt. */
177 static void clock_comparator_interrupt(struct ext_code ext_code
,
178 unsigned int param32
,
179 unsigned long param64
)
181 inc_irq_stat(IRQEXT_CLK
);
182 if (S390_lowcore
.clock_comparator
== -1ULL)
183 set_clock_comparator(S390_lowcore
.clock_comparator
);
186 static void stp_timing_alert(struct stp_irq_parm
*);
188 static void timing_alert_interrupt(struct ext_code ext_code
,
189 unsigned int param32
, unsigned long param64
)
191 inc_irq_stat(IRQEXT_TLA
);
192 if (param32
& 0x00038000)
193 stp_timing_alert((struct stp_irq_parm
*) ¶m32
);
196 static void stp_reset(void);
198 void read_persistent_clock64(struct timespec64
*ts
)
202 clock
= get_tod_clock() - initial_leap_seconds
;
203 tod_to_timeval(clock
- TOD_UNIX_EPOCH
, ts
);
206 void read_boot_clock64(struct timespec64
*ts
)
210 clock
= sched_clock_base_cc
- initial_leap_seconds
;
211 tod_to_timeval(clock
- TOD_UNIX_EPOCH
, ts
);
214 static u64
read_tod_clock(struct clocksource
*cs
)
216 unsigned long long now
, adj
;
218 preempt_disable(); /* protect from changes to steering parameters */
219 now
= get_tod_clock();
220 adj
= tod_steering_end
- now
;
221 if (unlikely((s64
) adj
>= 0))
223 * manually steer by 1 cycle every 2^16 cycles. This
224 * corresponds to shifting the tod delta by 15. 1s is
225 * therefore steered in ~9h. The adjust will decrease
226 * over time, until it finally reaches 0.
228 now
+= (tod_steering_delta
< 0) ? (adj
>> 15) : -(adj
>> 15);
233 static struct clocksource clocksource_tod
= {
236 .read
= read_tod_clock
,
240 .flags
= CLOCK_SOURCE_IS_CONTINUOUS
,
243 struct clocksource
* __init
clocksource_default_clock(void)
245 return &clocksource_tod
;
248 void update_vsyscall(struct timekeeper
*tk
)
252 if (tk
->tkr_mono
.clock
!= &clocksource_tod
)
255 /* Make userspace gettimeofday spin until we're done. */
256 ++vdso_data
->tb_update_count
;
258 vdso_data
->xtime_tod_stamp
= tk
->tkr_mono
.cycle_last
;
259 vdso_data
->xtime_clock_sec
= tk
->xtime_sec
;
260 vdso_data
->xtime_clock_nsec
= tk
->tkr_mono
.xtime_nsec
;
261 vdso_data
->wtom_clock_sec
=
262 tk
->xtime_sec
+ tk
->wall_to_monotonic
.tv_sec
;
263 vdso_data
->wtom_clock_nsec
= tk
->tkr_mono
.xtime_nsec
+
264 + ((u64
) tk
->wall_to_monotonic
.tv_nsec
<< tk
->tkr_mono
.shift
);
265 nsecps
= (u64
) NSEC_PER_SEC
<< tk
->tkr_mono
.shift
;
266 while (vdso_data
->wtom_clock_nsec
>= nsecps
) {
267 vdso_data
->wtom_clock_nsec
-= nsecps
;
268 vdso_data
->wtom_clock_sec
++;
271 vdso_data
->xtime_coarse_sec
= tk
->xtime_sec
;
272 vdso_data
->xtime_coarse_nsec
=
273 (long)(tk
->tkr_mono
.xtime_nsec
>> tk
->tkr_mono
.shift
);
274 vdso_data
->wtom_coarse_sec
=
275 vdso_data
->xtime_coarse_sec
+ tk
->wall_to_monotonic
.tv_sec
;
276 vdso_data
->wtom_coarse_nsec
=
277 vdso_data
->xtime_coarse_nsec
+ tk
->wall_to_monotonic
.tv_nsec
;
278 while (vdso_data
->wtom_coarse_nsec
>= NSEC_PER_SEC
) {
279 vdso_data
->wtom_coarse_nsec
-= NSEC_PER_SEC
;
280 vdso_data
->wtom_coarse_sec
++;
283 vdso_data
->tk_mult
= tk
->tkr_mono
.mult
;
284 vdso_data
->tk_shift
= tk
->tkr_mono
.shift
;
286 ++vdso_data
->tb_update_count
;
289 extern struct timezone sys_tz
;
291 void update_vsyscall_tz(void)
293 vdso_data
->tz_minuteswest
= sys_tz
.tz_minuteswest
;
294 vdso_data
->tz_dsttime
= sys_tz
.tz_dsttime
;
298 * Initialize the TOD clock and the CPU timer of
301 void __init
time_init(void)
303 /* Reset time synchronization interfaces. */
306 /* request the clock comparator external interrupt */
307 if (register_external_irq(EXT_IRQ_CLK_COMP
, clock_comparator_interrupt
))
308 panic("Couldn't request external interrupt 0x1004");
310 /* request the timing alert external interrupt */
311 if (register_external_irq(EXT_IRQ_TIMING_ALERT
, timing_alert_interrupt
))
312 panic("Couldn't request external interrupt 0x1406");
314 if (__clocksource_register(&clocksource_tod
) != 0)
315 panic("Could not register TOD clock source");
317 /* Enable TOD clock interrupts on the boot cpu. */
320 /* Enable cpu timer interrupts on the boot cpu. */
324 static DEFINE_PER_CPU(atomic_t
, clock_sync_word
);
325 static DEFINE_MUTEX(clock_sync_mutex
);
326 static unsigned long clock_sync_flags
;
328 #define CLOCK_SYNC_HAS_STP 0
329 #define CLOCK_SYNC_STP 1
332 * The get_clock function for the physical clock. It will get the current
333 * TOD clock, subtract the LPAR offset and write the result to *clock.
334 * The function returns 0 if the clock is in sync with the external time
335 * source. If the clock mode is local it will return -EOPNOTSUPP and
336 * -EAGAIN if the clock is not in sync with the external reference.
338 int get_phys_clock(unsigned long long *clock
)
341 unsigned int sw0
, sw1
;
343 sw_ptr
= &get_cpu_var(clock_sync_word
);
344 sw0
= atomic_read(sw_ptr
);
345 *clock
= get_tod_clock() - lpar_offset
;
346 sw1
= atomic_read(sw_ptr
);
347 put_cpu_var(clock_sync_word
);
348 if (sw0
== sw1
&& (sw0
& 0x80000000U
))
349 /* Success: time is in sync. */
351 if (!test_bit(CLOCK_SYNC_HAS_STP
, &clock_sync_flags
))
353 if (!test_bit(CLOCK_SYNC_STP
, &clock_sync_flags
))
357 EXPORT_SYMBOL(get_phys_clock
);
360 * Make get_phys_clock() return -EAGAIN.
362 static void disable_sync_clock(void *dummy
)
364 atomic_t
*sw_ptr
= this_cpu_ptr(&clock_sync_word
);
366 * Clear the in-sync bit 2^31. All get_phys_clock calls will
367 * fail until the sync bit is turned back on. In addition
368 * increase the "sequence" counter to avoid the race of an
369 * stp event and the complete recovery against get_phys_clock.
371 atomic_andnot(0x80000000, sw_ptr
);
376 * Make get_phys_clock() return 0 again.
377 * Needs to be called from a context disabled for preemption.
379 static void enable_sync_clock(void)
381 atomic_t
*sw_ptr
= this_cpu_ptr(&clock_sync_word
);
382 atomic_or(0x80000000, sw_ptr
);
386 * Function to check if the clock is in sync.
388 static inline int check_sync_clock(void)
393 sw_ptr
= &get_cpu_var(clock_sync_word
);
394 rc
= (atomic_read(sw_ptr
) & 0x80000000U
) != 0;
395 put_cpu_var(clock_sync_word
);
400 * Apply clock delta to the global data structures.
401 * This is called once on the CPU that performed the clock sync.
403 static void clock_sync_global(unsigned long long delta
)
405 unsigned long now
, adj
;
408 /* Fixup the monotonic sched clock. */
409 sched_clock_base_cc
+= delta
;
410 /* Adjust TOD steering parameters. */
411 vdso_data
->tb_update_count
++;
412 now
= get_tod_clock();
413 adj
= tod_steering_end
- now
;
414 if (unlikely((s64
) adj
>= 0))
415 /* Calculate how much of the old adjustment is left. */
416 tod_steering_delta
= (tod_steering_delta
< 0) ?
417 -(adj
>> 15) : (adj
>> 15);
418 tod_steering_delta
+= delta
;
419 if ((abs(tod_steering_delta
) >> 48) != 0)
420 panic("TOD clock sync offset %lli is too large to drift\n",
422 tod_steering_end
= now
+ (abs(tod_steering_delta
) << 15);
423 vdso_data
->ts_dir
= (tod_steering_delta
< 0) ? 0 : 1;
424 vdso_data
->ts_end
= tod_steering_end
;
425 vdso_data
->tb_update_count
++;
426 /* Update LPAR offset. */
427 if (ptff_query(PTFF_QTO
) && ptff(&qto
, sizeof(qto
), PTFF_QTO
) == 0)
428 lpar_offset
= qto
.tod_epoch_difference
;
429 /* Call the TOD clock change notifier. */
430 atomic_notifier_call_chain(&s390_epoch_delta_notifier
, 0, &delta
);
434 * Apply clock delta to the per-CPU data structures of this CPU.
435 * This is called for each online CPU after the call to clock_sync_global.
437 static void clock_sync_local(unsigned long long delta
)
439 /* Add the delta to the clock comparator. */
440 if (S390_lowcore
.clock_comparator
!= -1ULL) {
441 S390_lowcore
.clock_comparator
+= delta
;
442 set_clock_comparator(S390_lowcore
.clock_comparator
);
444 /* Adjust the last_update_clock time-stamp. */
445 S390_lowcore
.last_update_clock
+= delta
;
448 /* Single threaded workqueue used for stp sync events */
449 static struct workqueue_struct
*time_sync_wq
;
451 static void __init
time_init_wq(void)
455 time_sync_wq
= create_singlethread_workqueue("timesync");
458 struct clock_sync_data
{
461 unsigned long long clock_delta
;
465 * Server Time Protocol (STP) code.
467 static bool stp_online
;
468 static struct stp_sstpi stp_info
;
469 static void *stp_page
;
471 static void stp_work_fn(struct work_struct
*work
);
472 static DEFINE_MUTEX(stp_work_mutex
);
473 static DECLARE_WORK(stp_work
, stp_work_fn
);
474 static struct timer_list stp_timer
;
476 static int __init
early_parse_stp(char *p
)
478 return kstrtobool(p
, &stp_online
);
480 early_param("stp", early_parse_stp
);
483 * Reset STP attachment.
485 static void __init
stp_reset(void)
489 stp_page
= (void *) get_zeroed_page(GFP_ATOMIC
);
490 rc
= chsc_sstpc(stp_page
, STP_OP_CTRL
, 0x0000, NULL
);
492 set_bit(CLOCK_SYNC_HAS_STP
, &clock_sync_flags
);
493 else if (stp_online
) {
494 pr_warn("The real or virtual hardware system does not provide an STP interface\n");
495 free_page((unsigned long) stp_page
);
501 static void stp_timeout(unsigned long dummy
)
503 queue_work(time_sync_wq
, &stp_work
);
506 static int __init
stp_init(void)
508 if (!test_bit(CLOCK_SYNC_HAS_STP
, &clock_sync_flags
))
510 setup_timer(&stp_timer
, stp_timeout
, 0UL);
514 queue_work(time_sync_wq
, &stp_work
);
518 arch_initcall(stp_init
);
521 * STP timing alert. There are three causes:
522 * 1) timing status change
523 * 2) link availability change
524 * 3) time control parameter change
525 * In all three cases we are only interested in the clock source state.
526 * If a STP clock source is now available use it.
528 static void stp_timing_alert(struct stp_irq_parm
*intparm
)
530 if (intparm
->tsc
|| intparm
->lac
|| intparm
->tcpc
)
531 queue_work(time_sync_wq
, &stp_work
);
535 * STP sync check machine check. This is called when the timing state
536 * changes from the synchronized state to the unsynchronized state.
537 * After a STP sync check the clock is not in sync. The machine check
538 * is broadcasted to all cpus at the same time.
540 int stp_sync_check(void)
542 disable_sync_clock(NULL
);
547 * STP island condition machine check. This is called when an attached
548 * server attempts to communicate over an STP link and the servers
549 * have matching CTN ids and have a valid stratum-1 configuration
550 * but the configurations do not match.
552 int stp_island_check(void)
554 disable_sync_clock(NULL
);
558 void stp_queue_work(void)
560 queue_work(time_sync_wq
, &stp_work
);
563 static int stp_sync_clock(void *data
)
565 struct clock_sync_data
*sync
= data
;
566 unsigned long long clock_delta
;
571 if (xchg(&first
, 1) == 0) {
572 /* Wait until all other cpus entered the sync function. */
573 while (atomic_read(&sync
->cpus
) != 0)
576 if (stp_info
.todoff
[0] || stp_info
.todoff
[1] ||
577 stp_info
.todoff
[2] || stp_info
.todoff
[3] ||
579 rc
= chsc_sstpc(stp_page
, STP_OP_SYNC
, 0,
582 sync
->clock_delta
= clock_delta
;
583 clock_sync_global(clock_delta
);
584 rc
= chsc_sstpi(stp_page
, &stp_info
,
585 sizeof(struct stp_sstpi
));
586 if (rc
== 0 && stp_info
.tmd
!= 2)
590 sync
->in_sync
= rc
? -EAGAIN
: 1;
594 atomic_dec(&sync
->cpus
);
595 /* Wait for in_sync to be set. */
596 while (READ_ONCE(sync
->in_sync
) == 0)
599 if (sync
->in_sync
!= 1)
600 /* Didn't work. Clear per-cpu in sync bit again. */
601 disable_sync_clock(NULL
);
602 /* Apply clock delta to per-CPU fields of this CPU. */
603 clock_sync_local(sync
->clock_delta
);
609 * STP work. Check for the STP state and take over the clock
610 * synchronization if the STP clock source is usable.
612 static void stp_work_fn(struct work_struct
*work
)
614 struct clock_sync_data stp_sync
;
617 /* prevent multiple execution. */
618 mutex_lock(&stp_work_mutex
);
621 chsc_sstpc(stp_page
, STP_OP_CTRL
, 0x0000, NULL
);
622 del_timer_sync(&stp_timer
);
626 rc
= chsc_sstpc(stp_page
, STP_OP_CTRL
, 0xb0e0, NULL
);
630 rc
= chsc_sstpi(stp_page
, &stp_info
, sizeof(struct stp_sstpi
));
631 if (rc
|| stp_info
.c
== 0)
634 /* Skip synchronization if the clock is already in sync. */
635 if (check_sync_clock())
638 memset(&stp_sync
, 0, sizeof(stp_sync
));
640 atomic_set(&stp_sync
.cpus
, num_online_cpus() - 1);
641 stop_machine_cpuslocked(stp_sync_clock
, &stp_sync
, cpu_online_mask
);
644 if (!check_sync_clock())
646 * There is a usable clock but the synchonization failed.
647 * Retry after a second.
649 mod_timer(&stp_timer
, jiffies
+ HZ
);
652 mutex_unlock(&stp_work_mutex
);
656 * STP subsys sysfs interface functions
658 static struct bus_type stp_subsys
= {
663 static ssize_t
stp_ctn_id_show(struct device
*dev
,
664 struct device_attribute
*attr
,
669 return sprintf(buf
, "%016llx\n",
670 *(unsigned long long *) stp_info
.ctnid
);
673 static DEVICE_ATTR(ctn_id
, 0400, stp_ctn_id_show
, NULL
);
675 static ssize_t
stp_ctn_type_show(struct device
*dev
,
676 struct device_attribute
*attr
,
681 return sprintf(buf
, "%i\n", stp_info
.ctn
);
684 static DEVICE_ATTR(ctn_type
, 0400, stp_ctn_type_show
, NULL
);
686 static ssize_t
stp_dst_offset_show(struct device
*dev
,
687 struct device_attribute
*attr
,
690 if (!stp_online
|| !(stp_info
.vbits
& 0x2000))
692 return sprintf(buf
, "%i\n", (int)(s16
) stp_info
.dsto
);
695 static DEVICE_ATTR(dst_offset
, 0400, stp_dst_offset_show
, NULL
);
697 static ssize_t
stp_leap_seconds_show(struct device
*dev
,
698 struct device_attribute
*attr
,
701 if (!stp_online
|| !(stp_info
.vbits
& 0x8000))
703 return sprintf(buf
, "%i\n", (int)(s16
) stp_info
.leaps
);
706 static DEVICE_ATTR(leap_seconds
, 0400, stp_leap_seconds_show
, NULL
);
708 static ssize_t
stp_stratum_show(struct device
*dev
,
709 struct device_attribute
*attr
,
714 return sprintf(buf
, "%i\n", (int)(s16
) stp_info
.stratum
);
717 static DEVICE_ATTR(stratum
, 0400, stp_stratum_show
, NULL
);
719 static ssize_t
stp_time_offset_show(struct device
*dev
,
720 struct device_attribute
*attr
,
723 if (!stp_online
|| !(stp_info
.vbits
& 0x0800))
725 return sprintf(buf
, "%i\n", (int) stp_info
.tto
);
728 static DEVICE_ATTR(time_offset
, 0400, stp_time_offset_show
, NULL
);
730 static ssize_t
stp_time_zone_offset_show(struct device
*dev
,
731 struct device_attribute
*attr
,
734 if (!stp_online
|| !(stp_info
.vbits
& 0x4000))
736 return sprintf(buf
, "%i\n", (int)(s16
) stp_info
.tzo
);
739 static DEVICE_ATTR(time_zone_offset
, 0400,
740 stp_time_zone_offset_show
, NULL
);
742 static ssize_t
stp_timing_mode_show(struct device
*dev
,
743 struct device_attribute
*attr
,
748 return sprintf(buf
, "%i\n", stp_info
.tmd
);
751 static DEVICE_ATTR(timing_mode
, 0400, stp_timing_mode_show
, NULL
);
753 static ssize_t
stp_timing_state_show(struct device
*dev
,
754 struct device_attribute
*attr
,
759 return sprintf(buf
, "%i\n", stp_info
.tst
);
762 static DEVICE_ATTR(timing_state
, 0400, stp_timing_state_show
, NULL
);
764 static ssize_t
stp_online_show(struct device
*dev
,
765 struct device_attribute
*attr
,
768 return sprintf(buf
, "%i\n", stp_online
);
771 static ssize_t
stp_online_store(struct device
*dev
,
772 struct device_attribute
*attr
,
773 const char *buf
, size_t count
)
777 value
= simple_strtoul(buf
, NULL
, 0);
778 if (value
!= 0 && value
!= 1)
780 if (!test_bit(CLOCK_SYNC_HAS_STP
, &clock_sync_flags
))
782 mutex_lock(&clock_sync_mutex
);
785 set_bit(CLOCK_SYNC_STP
, &clock_sync_flags
);
787 clear_bit(CLOCK_SYNC_STP
, &clock_sync_flags
);
788 queue_work(time_sync_wq
, &stp_work
);
789 mutex_unlock(&clock_sync_mutex
);
794 * Can't use DEVICE_ATTR because the attribute should be named
795 * stp/online but dev_attr_online already exists in this file ..
797 static struct device_attribute dev_attr_stp_online
= {
798 .attr
= { .name
= "online", .mode
= 0600 },
799 .show
= stp_online_show
,
800 .store
= stp_online_store
,
803 static struct device_attribute
*stp_attributes
[] = {
806 &dev_attr_dst_offset
,
807 &dev_attr_leap_seconds
,
808 &dev_attr_stp_online
,
810 &dev_attr_time_offset
,
811 &dev_attr_time_zone_offset
,
812 &dev_attr_timing_mode
,
813 &dev_attr_timing_state
,
817 static int __init
stp_init_sysfs(void)
819 struct device_attribute
**attr
;
822 rc
= subsys_system_register(&stp_subsys
, NULL
);
825 for (attr
= stp_attributes
; *attr
; attr
++) {
826 rc
= device_create_file(stp_subsys
.dev_root
, *attr
);
832 for (; attr
>= stp_attributes
; attr
--)
833 device_remove_file(stp_subsys
.dev_root
, *attr
);
834 bus_unregister(&stp_subsys
);
839 device_initcall(stp_init_sysfs
);