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 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)
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))
91 ptff(&ptff_function_mask
, sizeof(ptff_function_mask
), PTFF_QAF
);
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 */
130 rem
= do_div(sec
, 1000000);
131 nsec
= (((low
>> 32) + (rem
<< 32)) * 1000) >> 32;
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
);
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
;
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
;
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
;
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. */
185 /* Always allow the timing alert external interrupt. */
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
*) ¶m32
);
208 static void stp_reset(void);
210 void read_persistent_clock64(struct timespec64
*ts
)
212 unsigned char clk
[STORE_CLOCK_EXT_SIZE
];
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
)
220 ext_to_timespec64(clk
, ts
);
223 void read_boot_clock64(struct timespec64
*ts
)
225 unsigned char clk
[STORE_CLOCK_EXT_SIZE
];
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
)
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);
255 static struct clocksource clocksource_tod
= {
258 .read
= read_tod_clock
,
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
)
274 if (tk
->tkr_mono
.clock
!= &clocksource_tod
)
277 /* Make userspace gettimeofday spin until we're done. */
278 ++vdso_data
->tb_update_count
;
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
;
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
323 void __init
time_init(void)
325 /* Reset time synchronization interfaces. */
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. */
342 /* Enable cpu timer interrupts on the boot cpu. */
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
)
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. */
373 if (!test_bit(CLOCK_SYNC_HAS_STP
, &clock_sync_flags
))
375 if (!test_bit(CLOCK_SYNC_STP
, &clock_sync_flags
))
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
);
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)
415 sw_ptr
= &get_cpu_var(clock_sync_word
);
416 rc
= (atomic_read(sw_ptr
) & 0x80000000U
) != 0;
417 put_cpu_var(clock_sync_word
);
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
;
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
)
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",
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)
480 time_sync_wq
= create_singlethread_workqueue("timesync");
483 struct clock_sync_data
{
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)
514 stp_page
= (void *) get_zeroed_page(GFP_ATOMIC
);
515 rc
= chsc_sstpc(stp_page
, STP_OP_CTRL
, 0x0000, NULL
);
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
);
526 static void stp_timeout(struct timer_list
*unused
)
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
))
535 timer_setup(&stp_timer
, stp_timeout
, 0);
539 queue_work(time_sync_wq
, &stp_work
);
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
);
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
);
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
;
596 if (xchg(&first
, 1) == 0) {
597 /* Wait until all other cpus entered the sync function. */
598 while (atomic_read(&sync
->cpus
) != 0)
601 if (stp_info
.todoff
[0] || stp_info
.todoff
[1] ||
602 stp_info
.todoff
[2] || stp_info
.todoff
[3] ||
604 rc
= chsc_sstpc(stp_page
, STP_OP_SYNC
, 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)
615 sync
->in_sync
= rc
? -EAGAIN
: 1;
619 atomic_dec(&sync
->cpus
);
620 /* Wait for in_sync to be set. */
621 while (READ_ONCE(sync
->in_sync
) == 0)
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
);
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
;
642 /* prevent multiple execution. */
643 mutex_lock(&stp_work_mutex
);
646 chsc_sstpc(stp_page
, STP_OP_CTRL
, 0x0000, NULL
);
647 del_timer_sync(&stp_timer
);
651 rc
= chsc_sstpc(stp_page
, STP_OP_CTRL
, 0xb0e0, NULL
);
655 rc
= chsc_sstpi(stp_page
, &stp_info
, sizeof(struct stp_sstpi
));
656 if (rc
|| stp_info
.c
== 0)
659 /* Skip synchronization if the clock is already in sync. */
660 if (check_sync_clock())
663 memset(&stp_sync
, 0, sizeof(stp_sync
));
665 atomic_set(&stp_sync
.cpus
, num_online_cpus() - 1);
666 stop_machine_cpuslocked(stp_sync_clock
, &stp_sync
, cpu_online_mask
);
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
);
677 mutex_unlock(&stp_work_mutex
);
681 * STP subsys sysfs interface functions
683 static struct bus_type stp_subsys
= {
688 static ssize_t
stp_ctn_id_show(struct device
*dev
,
689 struct device_attribute
*attr
,
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
,
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
,
715 if (!stp_online
|| !(stp_info
.vbits
& 0x2000))
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
,
726 if (!stp_online
|| !(stp_info
.vbits
& 0x8000))
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
,
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
,
748 if (!stp_online
|| !(stp_info
.vbits
& 0x0800))
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
,
759 if (!stp_online
|| !(stp_info
.vbits
& 0x4000))
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
,
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
,
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
,
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
)
802 value
= simple_strtoul(buf
, NULL
, 0);
803 if (value
!= 0 && value
!= 1)
805 if (!test_bit(CLOCK_SYNC_HAS_STP
, &clock_sync_flags
))
807 mutex_lock(&clock_sync_mutex
);
810 set_bit(CLOCK_SYNC_STP
, &clock_sync_flags
);
812 clear_bit(CLOCK_SYNC_STP
, &clock_sync_flags
);
813 queue_work(time_sync_wq
, &stp_work
);
814 mutex_unlock(&clock_sync_mutex
);
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
[] = {
831 &dev_attr_dst_offset
,
832 &dev_attr_leap_seconds
,
833 &dev_attr_stp_online
,
835 &dev_attr_time_offset
,
836 &dev_attr_time_zone_offset
,
837 &dev_attr_timing_mode
,
838 &dev_attr_timing_state
,
842 static int __init
stp_init_sysfs(void)
844 struct device_attribute
**attr
;
847 rc
= subsys_system_register(&stp_subsys
, NULL
);
850 for (attr
= stp_attributes
; *attr
; attr
++) {
851 rc
= device_create_file(stp_subsys
.dev_root
, *attr
);
857 for (; attr
>= stp_attributes
; attr
--)
858 device_remove_file(stp_subsys
.dev_root
, *attr
);
859 bus_unregister(&stp_subsys
);
864 device_initcall(stp_init_sysfs
);