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/module.h>
20 #include <linux/sched.h>
21 #include <linux/kernel.h>
22 #include <linux/param.h>
23 #include <linux/string.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>
46 #include <asm/irq_regs.h>
47 #include <asm/vtimer.h>
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)
56 u64 sched_clock_base_cc
= -1; /* Force to data section. */
57 EXPORT_SYMBOL_GPL(sched_clock_base_cc
);
59 static DEFINE_PER_CPU(struct clock_event_device
, comparators
);
61 ATOMIC_NOTIFIER_HEAD(s390_epoch_delta_notifier
);
62 EXPORT_SYMBOL(s390_epoch_delta_notifier
);
65 * Scheduler clock - returns current time in nanosec units.
67 unsigned long long notrace
sched_clock(void)
69 return tod_to_ns(get_tod_clock_monotonic());
71 NOKPROBE_SYMBOL(sched_clock
);
74 * Monotonic_clock - returns # of nanoseconds passed since time_init()
76 unsigned long long monotonic_clock(void)
80 EXPORT_SYMBOL(monotonic_clock
);
82 void tod_to_timeval(__u64 todval
, struct timespec64
*xt
)
84 unsigned long long sec
;
89 todval
-= (sec
* 1000000) << 12;
90 xt
->tv_nsec
= ((todval
* 1000) >> 12);
92 EXPORT_SYMBOL(tod_to_timeval
);
94 void clock_comparator_work(void)
96 struct clock_event_device
*cd
;
98 S390_lowcore
.clock_comparator
= -1ULL;
99 cd
= this_cpu_ptr(&comparators
);
100 cd
->event_handler(cd
);
104 * Fixup the clock comparator.
106 static void fixup_clock_comparator(unsigned long long delta
)
108 /* If nobody is waiting there's nothing to fix. */
109 if (S390_lowcore
.clock_comparator
== -1ULL)
111 S390_lowcore
.clock_comparator
+= delta
;
112 set_clock_comparator(S390_lowcore
.clock_comparator
);
115 static int s390_next_event(unsigned long delta
,
116 struct clock_event_device
*evt
)
118 S390_lowcore
.clock_comparator
= get_tod_clock() + delta
;
119 set_clock_comparator(S390_lowcore
.clock_comparator
);
124 * Set up lowcore and control register of the current cpu to
125 * enable TOD clock and clock comparator interrupts.
127 void init_cpu_timer(void)
129 struct clock_event_device
*cd
;
132 S390_lowcore
.clock_comparator
= -1ULL;
133 set_clock_comparator(S390_lowcore
.clock_comparator
);
135 cpu
= smp_processor_id();
136 cd
= &per_cpu(comparators
, cpu
);
137 cd
->name
= "comparator";
138 cd
->features
= CLOCK_EVT_FEAT_ONESHOT
;
141 cd
->min_delta_ns
= 1;
142 cd
->max_delta_ns
= LONG_MAX
;
144 cd
->cpumask
= cpumask_of(cpu
);
145 cd
->set_next_event
= s390_next_event
;
147 clockevents_register_device(cd
);
149 /* Enable clock comparator timer interrupt. */
152 /* Always allow the timing alert external interrupt. */
156 static void clock_comparator_interrupt(struct ext_code ext_code
,
157 unsigned int param32
,
158 unsigned long param64
)
160 inc_irq_stat(IRQEXT_CLK
);
161 if (S390_lowcore
.clock_comparator
== -1ULL)
162 set_clock_comparator(S390_lowcore
.clock_comparator
);
165 static void etr_timing_alert(struct etr_irq_parm
*);
166 static void stp_timing_alert(struct stp_irq_parm
*);
168 static void timing_alert_interrupt(struct ext_code ext_code
,
169 unsigned int param32
, unsigned long param64
)
171 inc_irq_stat(IRQEXT_TLA
);
172 if (param32
& 0x00c40000)
173 etr_timing_alert((struct etr_irq_parm
*) ¶m32
);
174 if (param32
& 0x00038000)
175 stp_timing_alert((struct stp_irq_parm
*) ¶m32
);
178 static void etr_reset(void);
179 static void stp_reset(void);
181 void read_persistent_clock64(struct timespec64
*ts
)
183 tod_to_timeval(get_tod_clock() - TOD_UNIX_EPOCH
, ts
);
186 void read_boot_clock64(struct timespec64
*ts
)
188 tod_to_timeval(sched_clock_base_cc
- TOD_UNIX_EPOCH
, ts
);
191 static cycle_t
read_tod_clock(struct clocksource
*cs
)
193 return get_tod_clock();
196 static struct clocksource clocksource_tod
= {
199 .read
= read_tod_clock
,
203 .flags
= CLOCK_SOURCE_IS_CONTINUOUS
,
206 struct clocksource
* __init
clocksource_default_clock(void)
208 return &clocksource_tod
;
211 void update_vsyscall(struct timekeeper
*tk
)
215 if (tk
->tkr_mono
.clock
!= &clocksource_tod
)
218 /* Make userspace gettimeofday spin until we're done. */
219 ++vdso_data
->tb_update_count
;
221 vdso_data
->xtime_tod_stamp
= tk
->tkr_mono
.cycle_last
;
222 vdso_data
->xtime_clock_sec
= tk
->xtime_sec
;
223 vdso_data
->xtime_clock_nsec
= tk
->tkr_mono
.xtime_nsec
;
224 vdso_data
->wtom_clock_sec
=
225 tk
->xtime_sec
+ tk
->wall_to_monotonic
.tv_sec
;
226 vdso_data
->wtom_clock_nsec
= tk
->tkr_mono
.xtime_nsec
+
227 + ((u64
) tk
->wall_to_monotonic
.tv_nsec
<< tk
->tkr_mono
.shift
);
228 nsecps
= (u64
) NSEC_PER_SEC
<< tk
->tkr_mono
.shift
;
229 while (vdso_data
->wtom_clock_nsec
>= nsecps
) {
230 vdso_data
->wtom_clock_nsec
-= nsecps
;
231 vdso_data
->wtom_clock_sec
++;
234 vdso_data
->xtime_coarse_sec
= tk
->xtime_sec
;
235 vdso_data
->xtime_coarse_nsec
=
236 (long)(tk
->tkr_mono
.xtime_nsec
>> tk
->tkr_mono
.shift
);
237 vdso_data
->wtom_coarse_sec
=
238 vdso_data
->xtime_coarse_sec
+ tk
->wall_to_monotonic
.tv_sec
;
239 vdso_data
->wtom_coarse_nsec
=
240 vdso_data
->xtime_coarse_nsec
+ tk
->wall_to_monotonic
.tv_nsec
;
241 while (vdso_data
->wtom_coarse_nsec
>= NSEC_PER_SEC
) {
242 vdso_data
->wtom_coarse_nsec
-= NSEC_PER_SEC
;
243 vdso_data
->wtom_coarse_sec
++;
246 vdso_data
->tk_mult
= tk
->tkr_mono
.mult
;
247 vdso_data
->tk_shift
= tk
->tkr_mono
.shift
;
249 ++vdso_data
->tb_update_count
;
252 extern struct timezone sys_tz
;
254 void update_vsyscall_tz(void)
256 /* Make userspace gettimeofday spin until we're done. */
257 ++vdso_data
->tb_update_count
;
259 vdso_data
->tz_minuteswest
= sys_tz
.tz_minuteswest
;
260 vdso_data
->tz_dsttime
= sys_tz
.tz_dsttime
;
262 ++vdso_data
->tb_update_count
;
266 * Initialize the TOD clock and the CPU timer of
269 void __init
time_init(void)
271 /* Reset time synchronization interfaces. */
275 /* request the clock comparator external interrupt */
276 if (register_external_irq(EXT_IRQ_CLK_COMP
, clock_comparator_interrupt
))
277 panic("Couldn't request external interrupt 0x1004");
279 /* request the timing alert external interrupt */
280 if (register_external_irq(EXT_IRQ_TIMING_ALERT
, timing_alert_interrupt
))
281 panic("Couldn't request external interrupt 0x1406");
283 if (__clocksource_register(&clocksource_tod
) != 0)
284 panic("Could not register TOD clock source");
286 /* Enable TOD clock interrupts on the boot cpu. */
289 /* Enable cpu timer interrupts on the boot cpu. */
294 * The time is "clock". old is what we think the time is.
295 * Adjust the value by a multiple of jiffies and add the delta to ntp.
296 * "delay" is an approximation how long the synchronization took. If
297 * the time correction is positive, then "delay" is subtracted from
298 * the time difference and only the remaining part is passed to ntp.
300 static unsigned long long adjust_time(unsigned long long old
,
301 unsigned long long clock
,
302 unsigned long long delay
)
304 unsigned long long delta
, ticks
;
308 /* It is later than we thought. */
309 delta
= ticks
= clock
- old
;
310 delta
= ticks
= (delta
< delay
) ? 0 : delta
- delay
;
311 delta
-= do_div(ticks
, CLK_TICKS_PER_JIFFY
);
312 adjust
.offset
= ticks
* (1000000 / HZ
);
314 /* It is earlier than we thought. */
315 delta
= ticks
= old
- clock
;
316 delta
-= do_div(ticks
, CLK_TICKS_PER_JIFFY
);
318 adjust
.offset
= -ticks
* (1000000 / HZ
);
320 sched_clock_base_cc
+= delta
;
321 if (adjust
.offset
!= 0) {
322 pr_notice("The ETR interface has adjusted the clock "
323 "by %li microseconds\n", adjust
.offset
);
324 adjust
.modes
= ADJ_OFFSET_SINGLESHOT
;
325 do_adjtimex(&adjust
);
330 static DEFINE_PER_CPU(atomic_t
, clock_sync_word
);
331 static DEFINE_MUTEX(clock_sync_mutex
);
332 static unsigned long clock_sync_flags
;
334 #define CLOCK_SYNC_HAS_ETR 0
335 #define CLOCK_SYNC_HAS_STP 1
336 #define CLOCK_SYNC_ETR 2
337 #define CLOCK_SYNC_STP 3
340 * The synchronous get_clock function. It will write the current clock
341 * value to the clock pointer and return 0 if the clock is in sync with
342 * the external time source. If the clock mode is local it will return
343 * -EOPNOTSUPP and -EAGAIN if the clock is not in sync with the external
346 int get_sync_clock(unsigned long long *clock
)
349 unsigned int sw0
, sw1
;
351 sw_ptr
= &get_cpu_var(clock_sync_word
);
352 sw0
= atomic_read(sw_ptr
);
353 *clock
= get_tod_clock();
354 sw1
= atomic_read(sw_ptr
);
355 put_cpu_var(clock_sync_word
);
356 if (sw0
== sw1
&& (sw0
& 0x80000000U
))
357 /* Success: time is in sync. */
359 if (!test_bit(CLOCK_SYNC_HAS_ETR
, &clock_sync_flags
) &&
360 !test_bit(CLOCK_SYNC_HAS_STP
, &clock_sync_flags
))
362 if (!test_bit(CLOCK_SYNC_ETR
, &clock_sync_flags
) &&
363 !test_bit(CLOCK_SYNC_STP
, &clock_sync_flags
))
367 EXPORT_SYMBOL(get_sync_clock
);
370 * Make get_sync_clock return -EAGAIN.
372 static void disable_sync_clock(void *dummy
)
374 atomic_t
*sw_ptr
= this_cpu_ptr(&clock_sync_word
);
376 * Clear the in-sync bit 2^31. All get_sync_clock calls will
377 * fail until the sync bit is turned back on. In addition
378 * increase the "sequence" counter to avoid the race of an
379 * etr event and the complete recovery against get_sync_clock.
381 atomic_andnot(0x80000000, sw_ptr
);
386 * Make get_sync_clock return 0 again.
387 * Needs to be called from a context disabled for preemption.
389 static void enable_sync_clock(void)
391 atomic_t
*sw_ptr
= this_cpu_ptr(&clock_sync_word
);
392 atomic_or(0x80000000, sw_ptr
);
396 * Function to check if the clock is in sync.
398 static inline int check_sync_clock(void)
403 sw_ptr
= &get_cpu_var(clock_sync_word
);
404 rc
= (atomic_read(sw_ptr
) & 0x80000000U
) != 0;
405 put_cpu_var(clock_sync_word
);
409 /* Single threaded workqueue used for etr and stp sync events */
410 static struct workqueue_struct
*time_sync_wq
;
412 static void __init
time_init_wq(void)
416 time_sync_wq
= create_singlethread_workqueue("timesync");
420 * External Time Reference (ETR) code.
422 static int etr_port0_online
;
423 static int etr_port1_online
;
424 static int etr_steai_available
;
426 static int __init
early_parse_etr(char *p
)
428 if (strncmp(p
, "off", 3) == 0)
429 etr_port0_online
= etr_port1_online
= 0;
430 else if (strncmp(p
, "port0", 5) == 0)
431 etr_port0_online
= 1;
432 else if (strncmp(p
, "port1", 5) == 0)
433 etr_port1_online
= 1;
434 else if (strncmp(p
, "on", 2) == 0)
435 etr_port0_online
= etr_port1_online
= 1;
438 early_param("etr", early_parse_etr
);
441 ETR_EVENT_PORT0_CHANGE
,
442 ETR_EVENT_PORT1_CHANGE
,
443 ETR_EVENT_PORT_ALERT
,
444 ETR_EVENT_SYNC_CHECK
,
445 ETR_EVENT_SWITCH_LOCAL
,
450 * Valid bit combinations of the eacr register are (x = don't care):
451 * e0 e1 dp p0 p1 ea es sl
452 * 0 0 x 0 0 0 0 0 initial, disabled state
453 * 0 0 x 0 1 1 0 0 port 1 online
454 * 0 0 x 1 0 1 0 0 port 0 online
455 * 0 0 x 1 1 1 0 0 both ports online
456 * 0 1 x 0 1 1 0 0 port 1 online and usable, ETR or PPS mode
457 * 0 1 x 0 1 1 0 1 port 1 online, usable and ETR mode
458 * 0 1 x 0 1 1 1 0 port 1 online, usable, PPS mode, in-sync
459 * 0 1 x 0 1 1 1 1 port 1 online, usable, ETR mode, in-sync
460 * 0 1 x 1 1 1 0 0 both ports online, port 1 usable
461 * 0 1 x 1 1 1 1 0 both ports online, port 1 usable, PPS mode, in-sync
462 * 0 1 x 1 1 1 1 1 both ports online, port 1 usable, ETR mode, in-sync
463 * 1 0 x 1 0 1 0 0 port 0 online and usable, ETR or PPS mode
464 * 1 0 x 1 0 1 0 1 port 0 online, usable and ETR mode
465 * 1 0 x 1 0 1 1 0 port 0 online, usable, PPS mode, in-sync
466 * 1 0 x 1 0 1 1 1 port 0 online, usable, ETR mode, in-sync
467 * 1 0 x 1 1 1 0 0 both ports online, port 0 usable
468 * 1 0 x 1 1 1 1 0 both ports online, port 0 usable, PPS mode, in-sync
469 * 1 0 x 1 1 1 1 1 both ports online, port 0 usable, ETR mode, in-sync
470 * 1 1 x 1 1 1 1 0 both ports online & usable, ETR, in-sync
471 * 1 1 x 1 1 1 1 1 both ports online & usable, ETR, in-sync
473 static struct etr_eacr etr_eacr
;
474 static u64 etr_tolec
; /* time of last eacr update */
475 static struct etr_aib etr_port0
;
476 static int etr_port0_uptodate
;
477 static struct etr_aib etr_port1
;
478 static int etr_port1_uptodate
;
479 static unsigned long etr_events
;
480 static struct timer_list etr_timer
;
482 static void etr_timeout(unsigned long dummy
);
483 static void etr_work_fn(struct work_struct
*work
);
484 static DEFINE_MUTEX(etr_work_mutex
);
485 static DECLARE_WORK(etr_work
, etr_work_fn
);
488 * Reset ETR attachment.
490 static void etr_reset(void)
492 etr_eacr
= (struct etr_eacr
) {
493 .e0
= 0, .e1
= 0, ._pad0
= 4, .dp
= 0,
494 .p0
= 0, .p1
= 0, ._pad1
= 0, .ea
= 0,
496 if (etr_setr(&etr_eacr
) == 0) {
497 etr_tolec
= get_tod_clock();
498 set_bit(CLOCK_SYNC_HAS_ETR
, &clock_sync_flags
);
499 if (etr_port0_online
&& etr_port1_online
)
500 set_bit(CLOCK_SYNC_ETR
, &clock_sync_flags
);
501 } else if (etr_port0_online
|| etr_port1_online
) {
502 pr_warn("The real or virtual hardware system does not provide an ETR interface\n");
503 etr_port0_online
= etr_port1_online
= 0;
507 static int __init
etr_init(void)
511 if (!test_bit(CLOCK_SYNC_HAS_ETR
, &clock_sync_flags
))
514 /* Check if this machine has the steai instruction. */
515 if (etr_steai(&aib
, ETR_STEAI_STEPPING_PORT
) == 0)
516 etr_steai_available
= 1;
517 setup_timer(&etr_timer
, etr_timeout
, 0UL);
518 if (etr_port0_online
) {
519 set_bit(ETR_EVENT_PORT0_CHANGE
, &etr_events
);
520 queue_work(time_sync_wq
, &etr_work
);
522 if (etr_port1_online
) {
523 set_bit(ETR_EVENT_PORT1_CHANGE
, &etr_events
);
524 queue_work(time_sync_wq
, &etr_work
);
529 arch_initcall(etr_init
);
532 * Two sorts of ETR machine checks. The architecture reads:
533 * "When a machine-check niterruption occurs and if a switch-to-local or
534 * ETR-sync-check interrupt request is pending but disabled, this pending
535 * disabled interruption request is indicated and is cleared".
536 * Which means that we can get etr_switch_to_local events from the machine
537 * check handler although the interruption condition is disabled. Lovely..
541 * Switch to local machine check. This is called when the last usable
542 * ETR port goes inactive. After switch to local the clock is not in sync.
544 int etr_switch_to_local(void)
548 disable_sync_clock(NULL
);
549 if (!test_and_set_bit(ETR_EVENT_SWITCH_LOCAL
, &etr_events
)) {
550 etr_eacr
.es
= etr_eacr
.sl
= 0;
558 * ETR sync check machine check. This is called when the ETR OTE and the
559 * local clock OTE are farther apart than the ETR sync check tolerance.
560 * After a ETR sync check the clock is not in sync. The machine check
561 * is broadcasted to all cpus at the same time.
563 int etr_sync_check(void)
567 disable_sync_clock(NULL
);
568 if (!test_and_set_bit(ETR_EVENT_SYNC_CHECK
, &etr_events
)) {
576 void etr_queue_work(void)
578 queue_work(time_sync_wq
, &etr_work
);
582 * ETR timing alert. There are two causes:
583 * 1) port state change, check the usability of the port
584 * 2) port alert, one of the ETR-data-validity bits (v1-v2 bits of the
585 * sldr-status word) or ETR-data word 1 (edf1) or ETR-data word 3 (edf3)
586 * or ETR-data word 4 (edf4) has changed.
588 static void etr_timing_alert(struct etr_irq_parm
*intparm
)
591 /* ETR port 0 state change. */
592 set_bit(ETR_EVENT_PORT0_CHANGE
, &etr_events
);
594 /* ETR port 1 state change. */
595 set_bit(ETR_EVENT_PORT1_CHANGE
, &etr_events
);
598 * ETR port alert on either port 0, 1 or both.
599 * Both ports are not up-to-date now.
601 set_bit(ETR_EVENT_PORT_ALERT
, &etr_events
);
602 queue_work(time_sync_wq
, &etr_work
);
605 static void etr_timeout(unsigned long dummy
)
607 set_bit(ETR_EVENT_UPDATE
, &etr_events
);
608 queue_work(time_sync_wq
, &etr_work
);
612 * Check if the etr mode is pss.
614 static inline int etr_mode_is_pps(struct etr_eacr eacr
)
616 return eacr
.es
&& !eacr
.sl
;
620 * Check if the etr mode is etr.
622 static inline int etr_mode_is_etr(struct etr_eacr eacr
)
624 return eacr
.es
&& eacr
.sl
;
628 * Check if the port can be used for TOD synchronization.
629 * For PPS mode the port has to receive OTEs. For ETR mode
630 * the port has to receive OTEs, the ETR stepping bit has to
631 * be zero and the validity bits for data frame 1, 2, and 3
634 static int etr_port_valid(struct etr_aib
*aib
, int port
)
638 /* Check that this port is receiving OTEs. */
642 psc
= port
? aib
->esw
.psc1
: aib
->esw
.psc0
;
643 if (psc
== etr_lpsc_pps_mode
)
645 if (psc
== etr_lpsc_operational_step
)
646 return !aib
->esw
.y
&& aib
->slsw
.v1
&&
647 aib
->slsw
.v2
&& aib
->slsw
.v3
;
652 * Check if two ports are on the same network.
654 static int etr_compare_network(struct etr_aib
*aib1
, struct etr_aib
*aib2
)
656 // FIXME: any other fields we have to compare?
657 return aib1
->edf1
.net_id
== aib2
->edf1
.net_id
;
661 * Wrapper for etr_stei that converts physical port states
662 * to logical port states to be consistent with the output
663 * of stetr (see etr_psc vs. etr_lpsc).
665 static void etr_steai_cv(struct etr_aib
*aib
, unsigned int func
)
667 BUG_ON(etr_steai(aib
, func
) != 0);
668 /* Convert port state to logical port state. */
669 if (aib
->esw
.psc0
== 1)
671 else if (aib
->esw
.psc0
== 0 && aib
->esw
.p
== 0)
673 if (aib
->esw
.psc1
== 1)
675 else if (aib
->esw
.psc1
== 0 && aib
->esw
.p
== 1)
680 * Check if the aib a2 is still connected to the same attachment as
681 * aib a1, the etv values differ by one and a2 is valid.
683 static int etr_aib_follows(struct etr_aib
*a1
, struct etr_aib
*a2
, int p
)
685 int state_a1
, state_a2
;
687 /* Paranoia check: e0/e1 should better be the same. */
688 if (a1
->esw
.eacr
.e0
!= a2
->esw
.eacr
.e0
||
689 a1
->esw
.eacr
.e1
!= a2
->esw
.eacr
.e1
)
692 /* Still connected to the same etr ? */
693 state_a1
= p
? a1
->esw
.psc1
: a1
->esw
.psc0
;
694 state_a2
= p
? a2
->esw
.psc1
: a2
->esw
.psc0
;
695 if (state_a1
== etr_lpsc_operational_step
) {
696 if (state_a2
!= etr_lpsc_operational_step
||
697 a1
->edf1
.net_id
!= a2
->edf1
.net_id
||
698 a1
->edf1
.etr_id
!= a2
->edf1
.etr_id
||
699 a1
->edf1
.etr_pn
!= a2
->edf1
.etr_pn
)
701 } else if (state_a2
!= etr_lpsc_pps_mode
)
704 /* The ETV value of a2 needs to be ETV of a1 + 1. */
705 if (a1
->edf2
.etv
+ 1 != a2
->edf2
.etv
)
708 if (!etr_port_valid(a2
, p
))
714 struct clock_sync_data
{
717 unsigned long long fixup_cc
;
719 struct etr_aib
*etr_aib
;
722 static void clock_sync_cpu(struct clock_sync_data
*sync
)
724 atomic_dec(&sync
->cpus
);
727 * This looks like a busy wait loop but it isn't. etr_sync_cpus
728 * is called on all other cpus while the TOD clocks is stopped.
729 * __udelay will stop the cpu on an enabled wait psw until the
730 * TOD is running again.
732 while (sync
->in_sync
== 0) {
735 * A different cpu changes *in_sync. Therefore use
736 * barrier() to force memory access.
740 if (sync
->in_sync
!= 1)
741 /* Didn't work. Clear per-cpu in sync bit again. */
742 disable_sync_clock(NULL
);
744 * This round of TOD syncing is done. Set the clock comparator
745 * to the next tick and let the processor continue.
747 fixup_clock_comparator(sync
->fixup_cc
);
751 * Sync the TOD clock using the port referred to by aibp. This port
752 * has to be enabled and the other port has to be disabled. The
753 * last eacr update has to be more than 1.6 seconds in the past.
755 static int etr_sync_clock(void *data
)
758 unsigned long long clock
, old_clock
, clock_delta
, delay
, delta
;
759 struct clock_sync_data
*etr_sync
;
760 struct etr_aib
*sync_port
, *aib
;
766 if (xchg(&first
, 1) == 1) {
768 clock_sync_cpu(etr_sync
);
772 /* Wait until all other cpus entered the sync function. */
773 while (atomic_read(&etr_sync
->cpus
) != 0)
776 port
= etr_sync
->etr_port
;
777 aib
= etr_sync
->etr_aib
;
778 sync_port
= (port
== 0) ? &etr_port0
: &etr_port1
;
781 /* Set clock to next OTE. */
782 __ctl_set_bit(14, 21);
783 __ctl_set_bit(0, 29);
784 clock
= ((unsigned long long) (aib
->edf2
.etv
+ 1)) << 32;
785 old_clock
= get_tod_clock();
786 if (set_tod_clock(clock
) == 0) {
787 __udelay(1); /* Wait for the clock to start. */
788 __ctl_clear_bit(0, 29);
789 __ctl_clear_bit(14, 21);
791 /* Adjust Linux timing variables. */
792 delay
= (unsigned long long)
793 (aib
->edf2
.etv
- sync_port
->edf2
.etv
) << 32;
794 delta
= adjust_time(old_clock
, clock
, delay
);
795 clock_delta
= clock
- old_clock
;
796 atomic_notifier_call_chain(&s390_epoch_delta_notifier
, 0,
798 etr_sync
->fixup_cc
= delta
;
799 fixup_clock_comparator(delta
);
800 /* Verify that the clock is properly set. */
801 if (!etr_aib_follows(sync_port
, aib
, port
)) {
803 disable_sync_clock(NULL
);
804 etr_sync
->in_sync
= -EAGAIN
;
807 etr_sync
->in_sync
= 1;
811 /* Could not set the clock ?!? */
812 __ctl_clear_bit(0, 29);
813 __ctl_clear_bit(14, 21);
814 disable_sync_clock(NULL
);
815 etr_sync
->in_sync
= -EAGAIN
;
822 static int etr_sync_clock_stop(struct etr_aib
*aib
, int port
)
824 struct clock_sync_data etr_sync
;
825 struct etr_aib
*sync_port
;
829 /* Check if the current aib is adjacent to the sync port aib. */
830 sync_port
= (port
== 0) ? &etr_port0
: &etr_port1
;
831 follows
= etr_aib_follows(sync_port
, aib
, port
);
832 memcpy(sync_port
, aib
, sizeof(*aib
));
835 memset(&etr_sync
, 0, sizeof(etr_sync
));
836 etr_sync
.etr_aib
= aib
;
837 etr_sync
.etr_port
= port
;
839 atomic_set(&etr_sync
.cpus
, num_online_cpus() - 1);
840 rc
= stop_machine(etr_sync_clock
, &etr_sync
, cpu_online_mask
);
846 * Handle the immediate effects of the different events.
847 * The port change event is used for online/offline changes.
849 static struct etr_eacr
etr_handle_events(struct etr_eacr eacr
)
851 if (test_and_clear_bit(ETR_EVENT_SYNC_CHECK
, &etr_events
))
853 if (test_and_clear_bit(ETR_EVENT_SWITCH_LOCAL
, &etr_events
))
854 eacr
.es
= eacr
.sl
= 0;
855 if (test_and_clear_bit(ETR_EVENT_PORT_ALERT
, &etr_events
))
856 etr_port0_uptodate
= etr_port1_uptodate
= 0;
858 if (test_and_clear_bit(ETR_EVENT_PORT0_CHANGE
, &etr_events
)) {
861 * Port change of an enabled port. We have to
862 * assume that this can have caused an stepping
865 etr_tolec
= get_tod_clock();
866 eacr
.p0
= etr_port0_online
;
869 etr_port0_uptodate
= 0;
871 if (test_and_clear_bit(ETR_EVENT_PORT1_CHANGE
, &etr_events
)) {
874 * Port change of an enabled port. We have to
875 * assume that this can have caused an stepping
878 etr_tolec
= get_tod_clock();
879 eacr
.p1
= etr_port1_online
;
882 etr_port1_uptodate
= 0;
884 clear_bit(ETR_EVENT_UPDATE
, &etr_events
);
889 * Set up a timer that expires after the etr_tolec + 1.6 seconds if
890 * one of the ports needs an update.
892 static void etr_set_tolec_timeout(unsigned long long now
)
894 unsigned long micros
;
896 if ((!etr_eacr
.p0
|| etr_port0_uptodate
) &&
897 (!etr_eacr
.p1
|| etr_port1_uptodate
))
899 micros
= (now
> etr_tolec
) ? ((now
- etr_tolec
) >> 12) : 0;
900 micros
= (micros
> 1600000) ? 0 : 1600000 - micros
;
901 mod_timer(&etr_timer
, jiffies
+ (micros
* HZ
) / 1000000 + 1);
905 * Set up a time that expires after 1/2 second.
907 static void etr_set_sync_timeout(void)
909 mod_timer(&etr_timer
, jiffies
+ HZ
/2);
913 * Update the aib information for one or both ports.
915 static struct etr_eacr
etr_handle_update(struct etr_aib
*aib
,
916 struct etr_eacr eacr
)
918 /* With both ports disabled the aib information is useless. */
919 if (!eacr
.e0
&& !eacr
.e1
)
922 /* Update port0 or port1 with aib stored in etr_work_fn. */
923 if (aib
->esw
.q
== 0) {
924 /* Information for port 0 stored. */
925 if (eacr
.p0
&& !etr_port0_uptodate
) {
927 if (etr_port0_online
)
928 etr_port0_uptodate
= 1;
931 /* Information for port 1 stored. */
932 if (eacr
.p1
&& !etr_port1_uptodate
) {
934 if (etr_port0_online
)
935 etr_port1_uptodate
= 1;
940 * Do not try to get the alternate port aib if the clock
941 * is not in sync yet.
943 if (!eacr
.es
|| !check_sync_clock())
947 * If steai is available we can get the information about
948 * the other port immediately. If only stetr is available the
949 * data-port bit toggle has to be used.
951 if (etr_steai_available
) {
952 if (eacr
.p0
&& !etr_port0_uptodate
) {
953 etr_steai_cv(&etr_port0
, ETR_STEAI_PORT_0
);
954 etr_port0_uptodate
= 1;
956 if (eacr
.p1
&& !etr_port1_uptodate
) {
957 etr_steai_cv(&etr_port1
, ETR_STEAI_PORT_1
);
958 etr_port1_uptodate
= 1;
962 * One port was updated above, if the other
963 * port is not uptodate toggle dp bit.
965 if ((eacr
.p0
&& !etr_port0_uptodate
) ||
966 (eacr
.p1
&& !etr_port1_uptodate
))
975 * Write new etr control register if it differs from the current one.
976 * Return 1 if etr_tolec has been updated as well.
978 static void etr_update_eacr(struct etr_eacr eacr
)
982 if (memcmp(&etr_eacr
, &eacr
, sizeof(eacr
)) == 0)
983 /* No change, return. */
986 * The disable of an active port of the change of the data port
987 * bit can/will cause a change in the data port.
989 dp_changed
= etr_eacr
.e0
> eacr
.e0
|| etr_eacr
.e1
> eacr
.e1
||
990 (etr_eacr
.dp
^ eacr
.dp
) != 0;
994 etr_tolec
= get_tod_clock();
998 * ETR work. In this function you'll find the main logic. In
999 * particular this is the only function that calls etr_update_eacr(),
1000 * it "controls" the etr control register.
1002 static void etr_work_fn(struct work_struct
*work
)
1004 unsigned long long now
;
1005 struct etr_eacr eacr
;
1009 /* prevent multiple execution. */
1010 mutex_lock(&etr_work_mutex
);
1012 /* Create working copy of etr_eacr. */
1015 /* Check for the different events and their immediate effects. */
1016 eacr
= etr_handle_events(eacr
);
1018 /* Check if ETR is supposed to be active. */
1019 eacr
.ea
= eacr
.p0
|| eacr
.p1
;
1021 /* Both ports offline. Reset everything. */
1022 eacr
.dp
= eacr
.es
= eacr
.sl
= 0;
1023 on_each_cpu(disable_sync_clock
, NULL
, 1);
1024 del_timer_sync(&etr_timer
);
1025 etr_update_eacr(eacr
);
1029 /* Store aib to get the current ETR status word. */
1030 BUG_ON(etr_stetr(&aib
) != 0);
1031 etr_port0
.esw
= etr_port1
.esw
= aib
.esw
; /* Copy status word. */
1032 now
= get_tod_clock();
1035 * Update the port information if the last stepping port change
1036 * or data port change is older than 1.6 seconds.
1038 if (now
>= etr_tolec
+ (1600000 << 12))
1039 eacr
= etr_handle_update(&aib
, eacr
);
1042 * Select ports to enable. The preferred synchronization mode is PPS.
1043 * If a port can be enabled depends on a number of things:
1044 * 1) The port needs to be online and uptodate. A port is not
1045 * disabled just because it is not uptodate, but it is only
1046 * enabled if it is uptodate.
1047 * 2) The port needs to have the same mode (pps / etr).
1048 * 3) The port needs to be usable -> etr_port_valid() == 1
1049 * 4) To enable the second port the clock needs to be in sync.
1050 * 5) If both ports are useable and are ETR ports, the network id
1051 * has to be the same.
1052 * The eacr.sl bit is used to indicate etr mode vs. pps mode.
1054 if (eacr
.p0
&& aib
.esw
.psc0
== etr_lpsc_pps_mode
) {
1057 if (!etr_mode_is_pps(etr_eacr
))
1059 if (!eacr
.es
|| !eacr
.p1
|| aib
.esw
.psc1
!= etr_lpsc_pps_mode
)
1061 // FIXME: uptodate checks ?
1062 else if (etr_port0_uptodate
&& etr_port1_uptodate
)
1064 sync_port
= (etr_port0_uptodate
&&
1065 etr_port_valid(&etr_port0
, 0)) ? 0 : -1;
1066 } else if (eacr
.p1
&& aib
.esw
.psc1
== etr_lpsc_pps_mode
) {
1070 if (!etr_mode_is_pps(etr_eacr
))
1072 sync_port
= (etr_port1_uptodate
&&
1073 etr_port_valid(&etr_port1
, 1)) ? 1 : -1;
1074 } else if (eacr
.p0
&& aib
.esw
.psc0
== etr_lpsc_operational_step
) {
1077 if (!etr_mode_is_etr(etr_eacr
))
1079 if (!eacr
.es
|| !eacr
.p1
||
1080 aib
.esw
.psc1
!= etr_lpsc_operational_alt
)
1082 else if (etr_port0_uptodate
&& etr_port1_uptodate
&&
1083 etr_compare_network(&etr_port0
, &etr_port1
))
1085 sync_port
= (etr_port0_uptodate
&&
1086 etr_port_valid(&etr_port0
, 0)) ? 0 : -1;
1087 } else if (eacr
.p1
&& aib
.esw
.psc1
== etr_lpsc_operational_step
) {
1091 if (!etr_mode_is_etr(etr_eacr
))
1093 sync_port
= (etr_port1_uptodate
&&
1094 etr_port_valid(&etr_port1
, 1)) ? 1 : -1;
1096 /* Both ports not usable. */
1097 eacr
.es
= eacr
.sl
= 0;
1102 * If the clock is in sync just update the eacr and return.
1103 * If there is no valid sync port wait for a port update.
1105 if ((eacr
.es
&& check_sync_clock()) || sync_port
< 0) {
1106 etr_update_eacr(eacr
);
1107 etr_set_tolec_timeout(now
);
1112 * Prepare control register for clock syncing
1113 * (reset data port bit, set sync check control.
1119 * Update eacr and try to synchronize the clock. If the update
1120 * of eacr caused a stepping port switch (or if we have to
1121 * assume that a stepping port switch has occurred) or the
1122 * clock syncing failed, reset the sync check control bit
1123 * and set up a timer to try again after 0.5 seconds
1125 etr_update_eacr(eacr
);
1126 if (now
< etr_tolec
+ (1600000 << 12) ||
1127 etr_sync_clock_stop(&aib
, sync_port
) != 0) {
1128 /* Sync failed. Try again in 1/2 second. */
1130 etr_update_eacr(eacr
);
1131 etr_set_sync_timeout();
1133 etr_set_tolec_timeout(now
);
1135 mutex_unlock(&etr_work_mutex
);
1139 * Sysfs interface functions
1141 static struct bus_type etr_subsys
= {
1146 static struct device etr_port0_dev
= {
1151 static struct device etr_port1_dev
= {
1157 * ETR subsys attributes
1159 static ssize_t
etr_stepping_port_show(struct device
*dev
,
1160 struct device_attribute
*attr
,
1163 return sprintf(buf
, "%i\n", etr_port0
.esw
.p
);
1166 static DEVICE_ATTR(stepping_port
, 0400, etr_stepping_port_show
, NULL
);
1168 static ssize_t
etr_stepping_mode_show(struct device
*dev
,
1169 struct device_attribute
*attr
,
1174 if (etr_mode_is_pps(etr_eacr
))
1176 else if (etr_mode_is_etr(etr_eacr
))
1180 return sprintf(buf
, "%s\n", mode_str
);
1183 static DEVICE_ATTR(stepping_mode
, 0400, etr_stepping_mode_show
, NULL
);
1186 * ETR port attributes
1188 static inline struct etr_aib
*etr_aib_from_dev(struct device
*dev
)
1190 if (dev
== &etr_port0_dev
)
1191 return etr_port0_online
? &etr_port0
: NULL
;
1193 return etr_port1_online
? &etr_port1
: NULL
;
1196 static ssize_t
etr_online_show(struct device
*dev
,
1197 struct device_attribute
*attr
,
1200 unsigned int online
;
1202 online
= (dev
== &etr_port0_dev
) ? etr_port0_online
: etr_port1_online
;
1203 return sprintf(buf
, "%i\n", online
);
1206 static ssize_t
etr_online_store(struct device
*dev
,
1207 struct device_attribute
*attr
,
1208 const char *buf
, size_t count
)
1212 value
= simple_strtoul(buf
, NULL
, 0);
1213 if (value
!= 0 && value
!= 1)
1215 if (!test_bit(CLOCK_SYNC_HAS_ETR
, &clock_sync_flags
))
1217 mutex_lock(&clock_sync_mutex
);
1218 if (dev
== &etr_port0_dev
) {
1219 if (etr_port0_online
== value
)
1220 goto out
; /* Nothing to do. */
1221 etr_port0_online
= value
;
1222 if (etr_port0_online
&& etr_port1_online
)
1223 set_bit(CLOCK_SYNC_ETR
, &clock_sync_flags
);
1225 clear_bit(CLOCK_SYNC_ETR
, &clock_sync_flags
);
1226 set_bit(ETR_EVENT_PORT0_CHANGE
, &etr_events
);
1227 queue_work(time_sync_wq
, &etr_work
);
1229 if (etr_port1_online
== value
)
1230 goto out
; /* Nothing to do. */
1231 etr_port1_online
= value
;
1232 if (etr_port0_online
&& etr_port1_online
)
1233 set_bit(CLOCK_SYNC_ETR
, &clock_sync_flags
);
1235 clear_bit(CLOCK_SYNC_ETR
, &clock_sync_flags
);
1236 set_bit(ETR_EVENT_PORT1_CHANGE
, &etr_events
);
1237 queue_work(time_sync_wq
, &etr_work
);
1240 mutex_unlock(&clock_sync_mutex
);
1244 static DEVICE_ATTR(online
, 0600, etr_online_show
, etr_online_store
);
1246 static ssize_t
etr_stepping_control_show(struct device
*dev
,
1247 struct device_attribute
*attr
,
1250 return sprintf(buf
, "%i\n", (dev
== &etr_port0_dev
) ?
1251 etr_eacr
.e0
: etr_eacr
.e1
);
1254 static DEVICE_ATTR(stepping_control
, 0400, etr_stepping_control_show
, NULL
);
1256 static ssize_t
etr_mode_code_show(struct device
*dev
,
1257 struct device_attribute
*attr
, char *buf
)
1259 if (!etr_port0_online
&& !etr_port1_online
)
1260 /* Status word is not uptodate if both ports are offline. */
1262 return sprintf(buf
, "%i\n", (dev
== &etr_port0_dev
) ?
1263 etr_port0
.esw
.psc0
: etr_port0
.esw
.psc1
);
1266 static DEVICE_ATTR(state_code
, 0400, etr_mode_code_show
, NULL
);
1268 static ssize_t
etr_untuned_show(struct device
*dev
,
1269 struct device_attribute
*attr
, char *buf
)
1271 struct etr_aib
*aib
= etr_aib_from_dev(dev
);
1273 if (!aib
|| !aib
->slsw
.v1
)
1275 return sprintf(buf
, "%i\n", aib
->edf1
.u
);
1278 static DEVICE_ATTR(untuned
, 0400, etr_untuned_show
, NULL
);
1280 static ssize_t
etr_network_id_show(struct device
*dev
,
1281 struct device_attribute
*attr
, char *buf
)
1283 struct etr_aib
*aib
= etr_aib_from_dev(dev
);
1285 if (!aib
|| !aib
->slsw
.v1
)
1287 return sprintf(buf
, "%i\n", aib
->edf1
.net_id
);
1290 static DEVICE_ATTR(network
, 0400, etr_network_id_show
, NULL
);
1292 static ssize_t
etr_id_show(struct device
*dev
,
1293 struct device_attribute
*attr
, char *buf
)
1295 struct etr_aib
*aib
= etr_aib_from_dev(dev
);
1297 if (!aib
|| !aib
->slsw
.v1
)
1299 return sprintf(buf
, "%i\n", aib
->edf1
.etr_id
);
1302 static DEVICE_ATTR(id
, 0400, etr_id_show
, NULL
);
1304 static ssize_t
etr_port_number_show(struct device
*dev
,
1305 struct device_attribute
*attr
, char *buf
)
1307 struct etr_aib
*aib
= etr_aib_from_dev(dev
);
1309 if (!aib
|| !aib
->slsw
.v1
)
1311 return sprintf(buf
, "%i\n", aib
->edf1
.etr_pn
);
1314 static DEVICE_ATTR(port
, 0400, etr_port_number_show
, NULL
);
1316 static ssize_t
etr_coupled_show(struct device
*dev
,
1317 struct device_attribute
*attr
, char *buf
)
1319 struct etr_aib
*aib
= etr_aib_from_dev(dev
);
1321 if (!aib
|| !aib
->slsw
.v3
)
1323 return sprintf(buf
, "%i\n", aib
->edf3
.c
);
1326 static DEVICE_ATTR(coupled
, 0400, etr_coupled_show
, NULL
);
1328 static ssize_t
etr_local_time_show(struct device
*dev
,
1329 struct device_attribute
*attr
, char *buf
)
1331 struct etr_aib
*aib
= etr_aib_from_dev(dev
);
1333 if (!aib
|| !aib
->slsw
.v3
)
1335 return sprintf(buf
, "%i\n", aib
->edf3
.blto
);
1338 static DEVICE_ATTR(local_time
, 0400, etr_local_time_show
, NULL
);
1340 static ssize_t
etr_utc_offset_show(struct device
*dev
,
1341 struct device_attribute
*attr
, char *buf
)
1343 struct etr_aib
*aib
= etr_aib_from_dev(dev
);
1345 if (!aib
|| !aib
->slsw
.v3
)
1347 return sprintf(buf
, "%i\n", aib
->edf3
.buo
);
1350 static DEVICE_ATTR(utc_offset
, 0400, etr_utc_offset_show
, NULL
);
1352 static struct device_attribute
*etr_port_attributes
[] = {
1354 &dev_attr_stepping_control
,
1355 &dev_attr_state_code
,
1361 &dev_attr_local_time
,
1362 &dev_attr_utc_offset
,
1366 static int __init
etr_register_port(struct device
*dev
)
1368 struct device_attribute
**attr
;
1371 rc
= device_register(dev
);
1374 for (attr
= etr_port_attributes
; *attr
; attr
++) {
1375 rc
= device_create_file(dev
, *attr
);
1381 for (; attr
>= etr_port_attributes
; attr
--)
1382 device_remove_file(dev
, *attr
);
1383 device_unregister(dev
);
1388 static void __init
etr_unregister_port(struct device
*dev
)
1390 struct device_attribute
**attr
;
1392 for (attr
= etr_port_attributes
; *attr
; attr
++)
1393 device_remove_file(dev
, *attr
);
1394 device_unregister(dev
);
1397 static int __init
etr_init_sysfs(void)
1401 rc
= subsys_system_register(&etr_subsys
, NULL
);
1404 rc
= device_create_file(etr_subsys
.dev_root
, &dev_attr_stepping_port
);
1406 goto out_unreg_subsys
;
1407 rc
= device_create_file(etr_subsys
.dev_root
, &dev_attr_stepping_mode
);
1409 goto out_remove_stepping_port
;
1410 rc
= etr_register_port(&etr_port0_dev
);
1412 goto out_remove_stepping_mode
;
1413 rc
= etr_register_port(&etr_port1_dev
);
1415 goto out_remove_port0
;
1419 etr_unregister_port(&etr_port0_dev
);
1420 out_remove_stepping_mode
:
1421 device_remove_file(etr_subsys
.dev_root
, &dev_attr_stepping_mode
);
1422 out_remove_stepping_port
:
1423 device_remove_file(etr_subsys
.dev_root
, &dev_attr_stepping_port
);
1425 bus_unregister(&etr_subsys
);
1430 device_initcall(etr_init_sysfs
);
1433 * Server Time Protocol (STP) code.
1435 static bool stp_online
;
1436 static struct stp_sstpi stp_info
;
1437 static void *stp_page
;
1439 static void stp_work_fn(struct work_struct
*work
);
1440 static DEFINE_MUTEX(stp_work_mutex
);
1441 static DECLARE_WORK(stp_work
, stp_work_fn
);
1442 static struct timer_list stp_timer
;
1444 static int __init
early_parse_stp(char *p
)
1446 return kstrtobool(p
, &stp_online
);
1448 early_param("stp", early_parse_stp
);
1451 * Reset STP attachment.
1453 static void __init
stp_reset(void)
1457 stp_page
= (void *) get_zeroed_page(GFP_ATOMIC
);
1458 rc
= chsc_sstpc(stp_page
, STP_OP_CTRL
, 0x0000);
1460 set_bit(CLOCK_SYNC_HAS_STP
, &clock_sync_flags
);
1461 else if (stp_online
) {
1462 pr_warn("The real or virtual hardware system does not provide an STP interface\n");
1463 free_page((unsigned long) stp_page
);
1469 static void stp_timeout(unsigned long dummy
)
1471 queue_work(time_sync_wq
, &stp_work
);
1474 static int __init
stp_init(void)
1476 if (!test_bit(CLOCK_SYNC_HAS_STP
, &clock_sync_flags
))
1478 setup_timer(&stp_timer
, stp_timeout
, 0UL);
1482 queue_work(time_sync_wq
, &stp_work
);
1486 arch_initcall(stp_init
);
1489 * STP timing alert. There are three causes:
1490 * 1) timing status change
1491 * 2) link availability change
1492 * 3) time control parameter change
1493 * In all three cases we are only interested in the clock source state.
1494 * If a STP clock source is now available use it.
1496 static void stp_timing_alert(struct stp_irq_parm
*intparm
)
1498 if (intparm
->tsc
|| intparm
->lac
|| intparm
->tcpc
)
1499 queue_work(time_sync_wq
, &stp_work
);
1503 * STP sync check machine check. This is called when the timing state
1504 * changes from the synchronized state to the unsynchronized state.
1505 * After a STP sync check the clock is not in sync. The machine check
1506 * is broadcasted to all cpus at the same time.
1508 int stp_sync_check(void)
1510 disable_sync_clock(NULL
);
1515 * STP island condition machine check. This is called when an attached
1516 * server attempts to communicate over an STP link and the servers
1517 * have matching CTN ids and have a valid stratum-1 configuration
1518 * but the configurations do not match.
1520 int stp_island_check(void)
1522 disable_sync_clock(NULL
);
1526 void stp_queue_work(void)
1528 queue_work(time_sync_wq
, &stp_work
);
1531 static int stp_sync_clock(void *data
)
1534 unsigned long long old_clock
, delta
, new_clock
, clock_delta
;
1535 struct clock_sync_data
*stp_sync
;
1540 if (xchg(&first
, 1) == 1) {
1542 clock_sync_cpu(stp_sync
);
1546 /* Wait until all other cpus entered the sync function. */
1547 while (atomic_read(&stp_sync
->cpus
) != 0)
1550 enable_sync_clock();
1553 if (stp_info
.todoff
[0] || stp_info
.todoff
[1] ||
1554 stp_info
.todoff
[2] || stp_info
.todoff
[3] ||
1555 stp_info
.tmd
!= 2) {
1556 old_clock
= get_tod_clock();
1557 rc
= chsc_sstpc(stp_page
, STP_OP_SYNC
, 0);
1559 new_clock
= get_tod_clock();
1560 delta
= adjust_time(old_clock
, new_clock
, 0);
1561 clock_delta
= new_clock
- old_clock
;
1562 atomic_notifier_call_chain(&s390_epoch_delta_notifier
,
1564 fixup_clock_comparator(delta
);
1565 rc
= chsc_sstpi(stp_page
, &stp_info
,
1566 sizeof(struct stp_sstpi
));
1567 if (rc
== 0 && stp_info
.tmd
!= 2)
1572 disable_sync_clock(NULL
);
1573 stp_sync
->in_sync
= -EAGAIN
;
1575 stp_sync
->in_sync
= 1;
1581 * STP work. Check for the STP state and take over the clock
1582 * synchronization if the STP clock source is usable.
1584 static void stp_work_fn(struct work_struct
*work
)
1586 struct clock_sync_data stp_sync
;
1589 /* prevent multiple execution. */
1590 mutex_lock(&stp_work_mutex
);
1593 chsc_sstpc(stp_page
, STP_OP_CTRL
, 0x0000);
1594 del_timer_sync(&stp_timer
);
1598 rc
= chsc_sstpc(stp_page
, STP_OP_CTRL
, 0xb0e0);
1602 rc
= chsc_sstpi(stp_page
, &stp_info
, sizeof(struct stp_sstpi
));
1603 if (rc
|| stp_info
.c
== 0)
1606 /* Skip synchronization if the clock is already in sync. */
1607 if (check_sync_clock())
1610 memset(&stp_sync
, 0, sizeof(stp_sync
));
1612 atomic_set(&stp_sync
.cpus
, num_online_cpus() - 1);
1613 stop_machine(stp_sync_clock
, &stp_sync
, cpu_online_mask
);
1616 if (!check_sync_clock())
1618 * There is a usable clock but the synchonization failed.
1619 * Retry after a second.
1621 mod_timer(&stp_timer
, jiffies
+ HZ
);
1624 mutex_unlock(&stp_work_mutex
);
1628 * STP subsys sysfs interface functions
1630 static struct bus_type stp_subsys
= {
1635 static ssize_t
stp_ctn_id_show(struct device
*dev
,
1636 struct device_attribute
*attr
,
1641 return sprintf(buf
, "%016llx\n",
1642 *(unsigned long long *) stp_info
.ctnid
);
1645 static DEVICE_ATTR(ctn_id
, 0400, stp_ctn_id_show
, NULL
);
1647 static ssize_t
stp_ctn_type_show(struct device
*dev
,
1648 struct device_attribute
*attr
,
1653 return sprintf(buf
, "%i\n", stp_info
.ctn
);
1656 static DEVICE_ATTR(ctn_type
, 0400, stp_ctn_type_show
, NULL
);
1658 static ssize_t
stp_dst_offset_show(struct device
*dev
,
1659 struct device_attribute
*attr
,
1662 if (!stp_online
|| !(stp_info
.vbits
& 0x2000))
1664 return sprintf(buf
, "%i\n", (int)(s16
) stp_info
.dsto
);
1667 static DEVICE_ATTR(dst_offset
, 0400, stp_dst_offset_show
, NULL
);
1669 static ssize_t
stp_leap_seconds_show(struct device
*dev
,
1670 struct device_attribute
*attr
,
1673 if (!stp_online
|| !(stp_info
.vbits
& 0x8000))
1675 return sprintf(buf
, "%i\n", (int)(s16
) stp_info
.leaps
);
1678 static DEVICE_ATTR(leap_seconds
, 0400, stp_leap_seconds_show
, NULL
);
1680 static ssize_t
stp_stratum_show(struct device
*dev
,
1681 struct device_attribute
*attr
,
1686 return sprintf(buf
, "%i\n", (int)(s16
) stp_info
.stratum
);
1689 static DEVICE_ATTR(stratum
, 0400, stp_stratum_show
, NULL
);
1691 static ssize_t
stp_time_offset_show(struct device
*dev
,
1692 struct device_attribute
*attr
,
1695 if (!stp_online
|| !(stp_info
.vbits
& 0x0800))
1697 return sprintf(buf
, "%i\n", (int) stp_info
.tto
);
1700 static DEVICE_ATTR(time_offset
, 0400, stp_time_offset_show
, NULL
);
1702 static ssize_t
stp_time_zone_offset_show(struct device
*dev
,
1703 struct device_attribute
*attr
,
1706 if (!stp_online
|| !(stp_info
.vbits
& 0x4000))
1708 return sprintf(buf
, "%i\n", (int)(s16
) stp_info
.tzo
);
1711 static DEVICE_ATTR(time_zone_offset
, 0400,
1712 stp_time_zone_offset_show
, NULL
);
1714 static ssize_t
stp_timing_mode_show(struct device
*dev
,
1715 struct device_attribute
*attr
,
1720 return sprintf(buf
, "%i\n", stp_info
.tmd
);
1723 static DEVICE_ATTR(timing_mode
, 0400, stp_timing_mode_show
, NULL
);
1725 static ssize_t
stp_timing_state_show(struct device
*dev
,
1726 struct device_attribute
*attr
,
1731 return sprintf(buf
, "%i\n", stp_info
.tst
);
1734 static DEVICE_ATTR(timing_state
, 0400, stp_timing_state_show
, NULL
);
1736 static ssize_t
stp_online_show(struct device
*dev
,
1737 struct device_attribute
*attr
,
1740 return sprintf(buf
, "%i\n", stp_online
);
1743 static ssize_t
stp_online_store(struct device
*dev
,
1744 struct device_attribute
*attr
,
1745 const char *buf
, size_t count
)
1749 value
= simple_strtoul(buf
, NULL
, 0);
1750 if (value
!= 0 && value
!= 1)
1752 if (!test_bit(CLOCK_SYNC_HAS_STP
, &clock_sync_flags
))
1754 mutex_lock(&clock_sync_mutex
);
1757 set_bit(CLOCK_SYNC_STP
, &clock_sync_flags
);
1759 clear_bit(CLOCK_SYNC_STP
, &clock_sync_flags
);
1760 queue_work(time_sync_wq
, &stp_work
);
1761 mutex_unlock(&clock_sync_mutex
);
1766 * Can't use DEVICE_ATTR because the attribute should be named
1767 * stp/online but dev_attr_online already exists in this file ..
1769 static struct device_attribute dev_attr_stp_online
= {
1770 .attr
= { .name
= "online", .mode
= 0600 },
1771 .show
= stp_online_show
,
1772 .store
= stp_online_store
,
1775 static struct device_attribute
*stp_attributes
[] = {
1778 &dev_attr_dst_offset
,
1779 &dev_attr_leap_seconds
,
1780 &dev_attr_stp_online
,
1782 &dev_attr_time_offset
,
1783 &dev_attr_time_zone_offset
,
1784 &dev_attr_timing_mode
,
1785 &dev_attr_timing_state
,
1789 static int __init
stp_init_sysfs(void)
1791 struct device_attribute
**attr
;
1794 rc
= subsys_system_register(&stp_subsys
, NULL
);
1797 for (attr
= stp_attributes
; *attr
; attr
++) {
1798 rc
= device_create_file(stp_subsys
.dev_root
, *attr
);
1804 for (; attr
>= stp_attributes
; attr
--)
1805 device_remove_file(stp_subsys
.dev_root
, *attr
);
1806 bus_unregister(&stp_subsys
);
1811 device_initcall(stp_init_sysfs
);