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Commit | Line | Data |
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1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Time of day based timer functions. |
3 | * | |
4 | * S390 version | |
d2fec595 | 5 | * Copyright IBM Corp. 1999, 2008 |
1da177e4 LT |
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) | |
9 | * | |
10 | * Derived from "arch/i386/kernel/time.c" | |
11 | * Copyright (C) 1991, 1992, 1995 Linus Torvalds | |
12 | */ | |
13 | ||
feab6501 MS |
14 | #define KMSG_COMPONENT "time" |
15 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
16 | ||
052ff461 | 17 | #include <linux/kernel_stat.h> |
1da177e4 LT |
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> | |
24 | #include <linux/mm.h> | |
25 | #include <linux/interrupt.h> | |
750887de HC |
26 | #include <linux/cpu.h> |
27 | #include <linux/stop_machine.h> | |
1da177e4 | 28 | #include <linux/time.h> |
3fbacffb | 29 | #include <linux/device.h> |
1da177e4 LT |
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> | |
189374ae | 37 | #include <linux/timekeeper_internal.h> |
5a62b192 | 38 | #include <linux/clockchips.h> |
5a0e3ad6 | 39 | #include <linux/gfp.h> |
860dba45 | 40 | #include <linux/kprobes.h> |
1da177e4 | 41 | #include <asm/uaccess.h> |
40277891 | 42 | #include <asm/facility.h> |
1da177e4 | 43 | #include <asm/delay.h> |
1da177e4 | 44 | #include <asm/div64.h> |
b020632e | 45 | #include <asm/vdso.h> |
1da177e4 | 46 | #include <asm/irq.h> |
5a489b98 | 47 | #include <asm/irq_regs.h> |
27f6b416 | 48 | #include <asm/vtimer.h> |
fd5ada04 | 49 | #include <asm/stp.h> |
a806170e | 50 | #include <asm/cio.h> |
638ad34a | 51 | #include "entry.h" |
1da177e4 LT |
52 | |
53 | /* change this if you have some constant time drift */ | |
54 | #define USECS_PER_JIFFY ((unsigned long) 1000000/HZ) | |
55 | #define CLK_TICKS_PER_JIFFY ((unsigned long) USECS_PER_JIFFY << 12) | |
56 | ||
b6112ccb | 57 | u64 sched_clock_base_cc = -1; /* Force to data section. */ |
05e7ff7d | 58 | EXPORT_SYMBOL_GPL(sched_clock_base_cc); |
b6112ccb | 59 | |
5a62b192 | 60 | static DEFINE_PER_CPU(struct clock_event_device, comparators); |
1da177e4 | 61 | |
fdf03650 FZ |
62 | ATOMIC_NOTIFIER_HEAD(s390_epoch_delta_notifier); |
63 | EXPORT_SYMBOL(s390_epoch_delta_notifier); | |
64 | ||
40277891 MS |
65 | unsigned char ptff_function_mask[16]; |
66 | unsigned long lpar_offset; | |
936cc855 | 67 | unsigned long initial_leap_seconds; |
40277891 MS |
68 | |
69 | /* | |
70 | * Get time offsets with PTFF | |
71 | */ | |
72 | void __init ptff_init(void) | |
73 | { | |
74 | struct ptff_qto qto; | |
936cc855 | 75 | struct ptff_qui qui; |
40277891 MS |
76 | |
77 | if (!test_facility(28)) | |
78 | return; | |
79 | ptff(&ptff_function_mask, sizeof(ptff_function_mask), PTFF_QAF); | |
80 | ||
81 | /* get LPAR offset */ | |
82 | if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) | |
83 | lpar_offset = qto.tod_epoch_difference; | |
936cc855 MS |
84 | |
85 | /* get initial leap seconds */ | |
86 | if (ptff_query(PTFF_QUI) && ptff(&qui, sizeof(qui), PTFF_QUI) == 0) | |
87 | initial_leap_seconds = (unsigned long) | |
88 | ((long) qui.old_leap * 4096000000L); | |
40277891 MS |
89 | } |
90 | ||
1da177e4 LT |
91 | /* |
92 | * Scheduler clock - returns current time in nanosec units. | |
93 | */ | |
7a5388de | 94 | unsigned long long notrace sched_clock(void) |
1da177e4 | 95 | { |
1aae0560 | 96 | return tod_to_ns(get_tod_clock_monotonic()); |
1da177e4 | 97 | } |
7a5388de | 98 | NOKPROBE_SYMBOL(sched_clock); |
1da177e4 | 99 | |
32f65f27 JG |
100 | /* |
101 | * Monotonic_clock - returns # of nanoseconds passed since time_init() | |
102 | */ | |
103 | unsigned long long monotonic_clock(void) | |
104 | { | |
105 | return sched_clock(); | |
106 | } | |
107 | EXPORT_SYMBOL(monotonic_clock); | |
108 | ||
689911c7 | 109 | void tod_to_timeval(__u64 todval, struct timespec64 *xt) |
1da177e4 LT |
110 | { |
111 | unsigned long long sec; | |
112 | ||
113 | sec = todval >> 12; | |
114 | do_div(sec, 1000000); | |
b1e2ba8d | 115 | xt->tv_sec = sec; |
1da177e4 | 116 | todval -= (sec * 1000000) << 12; |
b1e2ba8d | 117 | xt->tv_nsec = ((todval * 1000) >> 12); |
1da177e4 | 118 | } |
b592e89a | 119 | EXPORT_SYMBOL(tod_to_timeval); |
1da177e4 | 120 | |
5a62b192 | 121 | void clock_comparator_work(void) |
1da177e4 | 122 | { |
5a62b192 | 123 | struct clock_event_device *cd; |
1da177e4 | 124 | |
5a62b192 | 125 | S390_lowcore.clock_comparator = -1ULL; |
eb7e7d76 | 126 | cd = this_cpu_ptr(&comparators); |
5a62b192 | 127 | cd->event_handler(cd); |
1da177e4 LT |
128 | } |
129 | ||
1da177e4 | 130 | /* |
5a62b192 | 131 | * Fixup the clock comparator. |
1da177e4 | 132 | */ |
5a62b192 | 133 | static void fixup_clock_comparator(unsigned long long delta) |
1da177e4 | 134 | { |
5a62b192 HC |
135 | /* If nobody is waiting there's nothing to fix. */ |
136 | if (S390_lowcore.clock_comparator == -1ULL) | |
1da177e4 | 137 | return; |
5a62b192 HC |
138 | S390_lowcore.clock_comparator += delta; |
139 | set_clock_comparator(S390_lowcore.clock_comparator); | |
1da177e4 LT |
140 | } |
141 | ||
8adbf78e | 142 | static int s390_next_event(unsigned long delta, |
5a62b192 | 143 | struct clock_event_device *evt) |
1da177e4 | 144 | { |
8adbf78e | 145 | S390_lowcore.clock_comparator = get_tod_clock() + delta; |
5a62b192 HC |
146 | set_clock_comparator(S390_lowcore.clock_comparator); |
147 | return 0; | |
1da177e4 LT |
148 | } |
149 | ||
d54853ef MS |
150 | /* |
151 | * Set up lowcore and control register of the current cpu to | |
152 | * enable TOD clock and clock comparator interrupts. | |
1da177e4 LT |
153 | */ |
154 | void init_cpu_timer(void) | |
155 | { | |
5a62b192 HC |
156 | struct clock_event_device *cd; |
157 | int cpu; | |
158 | ||
159 | S390_lowcore.clock_comparator = -1ULL; | |
160 | set_clock_comparator(S390_lowcore.clock_comparator); | |
161 | ||
162 | cpu = smp_processor_id(); | |
163 | cd = &per_cpu(comparators, cpu); | |
164 | cd->name = "comparator"; | |
8adbf78e | 165 | cd->features = CLOCK_EVT_FEAT_ONESHOT; |
5a62b192 HC |
166 | cd->mult = 16777; |
167 | cd->shift = 12; | |
168 | cd->min_delta_ns = 1; | |
169 | cd->max_delta_ns = LONG_MAX; | |
170 | cd->rating = 400; | |
320ab2b0 | 171 | cd->cpumask = cpumask_of(cpu); |
8adbf78e | 172 | cd->set_next_event = s390_next_event; |
5a62b192 HC |
173 | |
174 | clockevents_register_device(cd); | |
d54853ef MS |
175 | |
176 | /* Enable clock comparator timer interrupt. */ | |
177 | __ctl_set_bit(0,11); | |
178 | ||
d2fec595 | 179 | /* Always allow the timing alert external interrupt. */ |
d54853ef MS |
180 | __ctl_set_bit(0, 4); |
181 | } | |
182 | ||
fde15c3a | 183 | static void clock_comparator_interrupt(struct ext_code ext_code, |
f6649a7e MS |
184 | unsigned int param32, |
185 | unsigned long param64) | |
d54853ef | 186 | { |
420f42ec | 187 | inc_irq_stat(IRQEXT_CLK); |
d3d238c7 HC |
188 | if (S390_lowcore.clock_comparator == -1ULL) |
189 | set_clock_comparator(S390_lowcore.clock_comparator); | |
d54853ef MS |
190 | } |
191 | ||
d2fec595 MS |
192 | static void stp_timing_alert(struct stp_irq_parm *); |
193 | ||
fde15c3a | 194 | static void timing_alert_interrupt(struct ext_code ext_code, |
f6649a7e | 195 | unsigned int param32, unsigned long param64) |
d2fec595 | 196 | { |
420f42ec | 197 | inc_irq_stat(IRQEXT_TLA); |
f6649a7e MS |
198 | if (param32 & 0x00038000) |
199 | stp_timing_alert((struct stp_irq_parm *) ¶m32); | |
d2fec595 MS |
200 | } |
201 | ||
d2fec595 | 202 | static void stp_reset(void); |
d54853ef | 203 | |
689911c7 | 204 | void read_persistent_clock64(struct timespec64 *ts) |
d54853ef | 205 | { |
936cc855 MS |
206 | __u64 clock; |
207 | ||
208 | clock = get_tod_clock() - initial_leap_seconds; | |
209 | tod_to_timeval(clock - TOD_UNIX_EPOCH, ts); | |
1da177e4 | 210 | } |
d54853ef | 211 | |
689911c7 | 212 | void read_boot_clock64(struct timespec64 *ts) |
23970e38 | 213 | { |
936cc855 MS |
214 | __u64 clock; |
215 | ||
216 | clock = sched_clock_base_cc - initial_leap_seconds; | |
217 | tod_to_timeval(clock - TOD_UNIX_EPOCH, ts); | |
1da177e4 LT |
218 | } |
219 | ||
8e19608e | 220 | static cycle_t read_tod_clock(struct clocksource *cs) |
dc64bef5 | 221 | { |
1aae0560 | 222 | return get_tod_clock(); |
dc64bef5 MS |
223 | } |
224 | ||
225 | static struct clocksource clocksource_tod = { | |
226 | .name = "tod", | |
d2cb0e6e | 227 | .rating = 400, |
dc64bef5 MS |
228 | .read = read_tod_clock, |
229 | .mask = -1ULL, | |
230 | .mult = 1000, | |
231 | .shift = 12, | |
cc02d809 | 232 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
dc64bef5 MS |
233 | }; |
234 | ||
f1b82746 MS |
235 | struct clocksource * __init clocksource_default_clock(void) |
236 | { | |
237 | return &clocksource_tod; | |
238 | } | |
dc64bef5 | 239 | |
79c74ecb | 240 | void update_vsyscall(struct timekeeper *tk) |
b020632e | 241 | { |
79c74ecb MS |
242 | u64 nsecps; |
243 | ||
876e7881 | 244 | if (tk->tkr_mono.clock != &clocksource_tod) |
b020632e MS |
245 | return; |
246 | ||
247 | /* Make userspace gettimeofday spin until we're done. */ | |
248 | ++vdso_data->tb_update_count; | |
249 | smp_wmb(); | |
876e7881 | 250 | vdso_data->xtime_tod_stamp = tk->tkr_mono.cycle_last; |
79c74ecb | 251 | vdso_data->xtime_clock_sec = tk->xtime_sec; |
876e7881 | 252 | vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec; |
79c74ecb MS |
253 | vdso_data->wtom_clock_sec = |
254 | tk->xtime_sec + tk->wall_to_monotonic.tv_sec; | |
876e7881 PZ |
255 | vdso_data->wtom_clock_nsec = tk->tkr_mono.xtime_nsec + |
256 | + ((u64) tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift); | |
257 | nsecps = (u64) NSEC_PER_SEC << tk->tkr_mono.shift; | |
79c74ecb MS |
258 | while (vdso_data->wtom_clock_nsec >= nsecps) { |
259 | vdso_data->wtom_clock_nsec -= nsecps; | |
260 | vdso_data->wtom_clock_sec++; | |
261 | } | |
b7eacb59 MS |
262 | |
263 | vdso_data->xtime_coarse_sec = tk->xtime_sec; | |
264 | vdso_data->xtime_coarse_nsec = | |
876e7881 | 265 | (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
b7eacb59 MS |
266 | vdso_data->wtom_coarse_sec = |
267 | vdso_data->xtime_coarse_sec + tk->wall_to_monotonic.tv_sec; | |
268 | vdso_data->wtom_coarse_nsec = | |
269 | vdso_data->xtime_coarse_nsec + tk->wall_to_monotonic.tv_nsec; | |
270 | while (vdso_data->wtom_coarse_nsec >= NSEC_PER_SEC) { | |
271 | vdso_data->wtom_coarse_nsec -= NSEC_PER_SEC; | |
272 | vdso_data->wtom_coarse_sec++; | |
273 | } | |
274 | ||
876e7881 PZ |
275 | vdso_data->tk_mult = tk->tkr_mono.mult; |
276 | vdso_data->tk_shift = tk->tkr_mono.shift; | |
b020632e MS |
277 | smp_wmb(); |
278 | ++vdso_data->tb_update_count; | |
279 | } | |
280 | ||
281 | extern struct timezone sys_tz; | |
282 | ||
283 | void update_vsyscall_tz(void) | |
284 | { | |
285 | /* Make userspace gettimeofday spin until we're done. */ | |
286 | ++vdso_data->tb_update_count; | |
287 | smp_wmb(); | |
288 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; | |
289 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
290 | smp_wmb(); | |
291 | ++vdso_data->tb_update_count; | |
292 | } | |
293 | ||
1da177e4 LT |
294 | /* |
295 | * Initialize the TOD clock and the CPU timer of | |
296 | * the boot cpu. | |
297 | */ | |
298 | void __init time_init(void) | |
299 | { | |
b6112ccb | 300 | /* Reset time synchronization interfaces. */ |
b6112ccb | 301 | stp_reset(); |
1da177e4 | 302 | |
1da177e4 | 303 | /* request the clock comparator external interrupt */ |
1dad093b TH |
304 | if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt)) |
305 | panic("Couldn't request external interrupt 0x1004"); | |
1da177e4 | 306 | |
d2fec595 | 307 | /* request the timing alert external interrupt */ |
1dad093b | 308 | if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt)) |
d54853ef MS |
309 | panic("Couldn't request external interrupt 0x1406"); |
310 | ||
f8935983 | 311 | if (__clocksource_register(&clocksource_tod) != 0) |
ab96e798 MS |
312 | panic("Could not register TOD clock source"); |
313 | ||
d54853ef MS |
314 | /* Enable TOD clock interrupts on the boot cpu. */ |
315 | init_cpu_timer(); | |
ab96e798 | 316 | |
c185b783 | 317 | /* Enable cpu timer interrupts on the boot cpu. */ |
1da177e4 | 318 | vtime_init(); |
d54853ef MS |
319 | } |
320 | ||
d2fec595 MS |
321 | /* |
322 | * The time is "clock". old is what we think the time is. | |
323 | * Adjust the value by a multiple of jiffies and add the delta to ntp. | |
324 | * "delay" is an approximation how long the synchronization took. If | |
325 | * the time correction is positive, then "delay" is subtracted from | |
326 | * the time difference and only the remaining part is passed to ntp. | |
327 | */ | |
328 | static unsigned long long adjust_time(unsigned long long old, | |
329 | unsigned long long clock, | |
330 | unsigned long long delay) | |
331 | { | |
332 | unsigned long long delta, ticks; | |
333 | struct timex adjust; | |
334 | ||
335 | if (clock > old) { | |
336 | /* It is later than we thought. */ | |
337 | delta = ticks = clock - old; | |
338 | delta = ticks = (delta < delay) ? 0 : delta - delay; | |
339 | delta -= do_div(ticks, CLK_TICKS_PER_JIFFY); | |
340 | adjust.offset = ticks * (1000000 / HZ); | |
341 | } else { | |
342 | /* It is earlier than we thought. */ | |
343 | delta = ticks = old - clock; | |
344 | delta -= do_div(ticks, CLK_TICKS_PER_JIFFY); | |
345 | delta = -delta; | |
346 | adjust.offset = -ticks * (1000000 / HZ); | |
347 | } | |
8107d829 | 348 | sched_clock_base_cc += delta; |
d2fec595 | 349 | if (adjust.offset != 0) { |
feab6501 MS |
350 | pr_notice("The ETR interface has adjusted the clock " |
351 | "by %li microseconds\n", adjust.offset); | |
d2fec595 MS |
352 | adjust.modes = ADJ_OFFSET_SINGLESHOT; |
353 | do_adjtimex(&adjust); | |
354 | } | |
355 | return delta; | |
356 | } | |
357 | ||
358 | static DEFINE_PER_CPU(atomic_t, clock_sync_word); | |
8283cb43 | 359 | static DEFINE_MUTEX(clock_sync_mutex); |
d2fec595 MS |
360 | static unsigned long clock_sync_flags; |
361 | ||
362 | #define CLOCK_SYNC_HAS_ETR 0 | |
363 | #define CLOCK_SYNC_HAS_STP 1 | |
364 | #define CLOCK_SYNC_ETR 2 | |
365 | #define CLOCK_SYNC_STP 3 | |
366 | ||
367 | /* | |
40277891 MS |
368 | * The get_clock function for the physical clock. It will get the current |
369 | * TOD clock, subtract the LPAR offset and write the result to *clock. | |
370 | * The function returns 0 if the clock is in sync with the external time | |
371 | * source. If the clock mode is local it will return -EOPNOTSUPP and | |
372 | * -EAGAIN if the clock is not in sync with the external reference. | |
d2fec595 | 373 | */ |
40277891 | 374 | int get_phys_clock(unsigned long long *clock) |
d2fec595 MS |
375 | { |
376 | atomic_t *sw_ptr; | |
377 | unsigned int sw0, sw1; | |
378 | ||
379 | sw_ptr = &get_cpu_var(clock_sync_word); | |
380 | sw0 = atomic_read(sw_ptr); | |
40277891 | 381 | *clock = get_tod_clock() - lpar_offset; |
d2fec595 | 382 | sw1 = atomic_read(sw_ptr); |
bd119ee2 | 383 | put_cpu_var(clock_sync_word); |
d2fec595 MS |
384 | if (sw0 == sw1 && (sw0 & 0x80000000U)) |
385 | /* Success: time is in sync. */ | |
386 | return 0; | |
387 | if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags) && | |
388 | !test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) | |
a8f6db4d | 389 | return -EOPNOTSUPP; |
d2fec595 MS |
390 | if (!test_bit(CLOCK_SYNC_ETR, &clock_sync_flags) && |
391 | !test_bit(CLOCK_SYNC_STP, &clock_sync_flags)) | |
392 | return -EACCES; | |
393 | return -EAGAIN; | |
394 | } | |
40277891 | 395 | EXPORT_SYMBOL(get_phys_clock); |
d2fec595 MS |
396 | |
397 | /* | |
398 | * Make get_sync_clock return -EAGAIN. | |
399 | */ | |
400 | static void disable_sync_clock(void *dummy) | |
401 | { | |
eb7e7d76 | 402 | atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); |
d2fec595 MS |
403 | /* |
404 | * Clear the in-sync bit 2^31. All get_sync_clock calls will | |
405 | * fail until the sync bit is turned back on. In addition | |
406 | * increase the "sequence" counter to avoid the race of an | |
407 | * etr event and the complete recovery against get_sync_clock. | |
408 | */ | |
805de8f4 | 409 | atomic_andnot(0x80000000, sw_ptr); |
d2fec595 MS |
410 | atomic_inc(sw_ptr); |
411 | } | |
412 | ||
413 | /* | |
414 | * Make get_sync_clock return 0 again. | |
415 | * Needs to be called from a context disabled for preemption. | |
416 | */ | |
417 | static void enable_sync_clock(void) | |
418 | { | |
eb7e7d76 | 419 | atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); |
805de8f4 | 420 | atomic_or(0x80000000, sw_ptr); |
d2fec595 MS |
421 | } |
422 | ||
8283cb43 MS |
423 | /* |
424 | * Function to check if the clock is in sync. | |
425 | */ | |
426 | static inline int check_sync_clock(void) | |
427 | { | |
428 | atomic_t *sw_ptr; | |
429 | int rc; | |
430 | ||
431 | sw_ptr = &get_cpu_var(clock_sync_word); | |
432 | rc = (atomic_read(sw_ptr) & 0x80000000U) != 0; | |
bd119ee2 | 433 | put_cpu_var(clock_sync_word); |
8283cb43 MS |
434 | return rc; |
435 | } | |
436 | ||
750887de HC |
437 | /* Single threaded workqueue used for etr and stp sync events */ |
438 | static struct workqueue_struct *time_sync_wq; | |
439 | ||
440 | static void __init time_init_wq(void) | |
441 | { | |
179cb81a HC |
442 | if (time_sync_wq) |
443 | return; | |
444 | time_sync_wq = create_singlethread_workqueue("timesync"); | |
750887de HC |
445 | } |
446 | ||
d2fec595 | 447 | struct clock_sync_data { |
750887de | 448 | atomic_t cpus; |
5a62b192 HC |
449 | int in_sync; |
450 | unsigned long long fixup_cc; | |
750887de HC |
451 | int etr_port; |
452 | struct etr_aib *etr_aib; | |
d2fec595 | 453 | }; |
5a62b192 | 454 | |
750887de | 455 | static void clock_sync_cpu(struct clock_sync_data *sync) |
d54853ef | 456 | { |
750887de | 457 | atomic_dec(&sync->cpus); |
d2fec595 | 458 | enable_sync_clock(); |
d54853ef MS |
459 | /* |
460 | * This looks like a busy wait loop but it isn't. etr_sync_cpus | |
461 | * is called on all other cpus while the TOD clocks is stopped. | |
462 | * __udelay will stop the cpu on an enabled wait psw until the | |
463 | * TOD is running again. | |
464 | */ | |
d2fec595 | 465 | while (sync->in_sync == 0) { |
d54853ef | 466 | __udelay(1); |
6c732de2 HC |
467 | /* |
468 | * A different cpu changes *in_sync. Therefore use | |
469 | * barrier() to force memory access. | |
470 | */ | |
471 | barrier(); | |
472 | } | |
d2fec595 | 473 | if (sync->in_sync != 1) |
d54853ef | 474 | /* Didn't work. Clear per-cpu in sync bit again. */ |
d2fec595 | 475 | disable_sync_clock(NULL); |
d54853ef MS |
476 | /* |
477 | * This round of TOD syncing is done. Set the clock comparator | |
478 | * to the next tick and let the processor continue. | |
479 | */ | |
d2fec595 | 480 | fixup_clock_comparator(sync->fixup_cc); |
d54853ef MS |
481 | } |
482 | ||
d2fec595 MS |
483 | /* |
484 | * Server Time Protocol (STP) code. | |
485 | */ | |
4cc7ecb7 | 486 | static bool stp_online; |
d2fec595 MS |
487 | static struct stp_sstpi stp_info; |
488 | static void *stp_page; | |
489 | ||
490 | static void stp_work_fn(struct work_struct *work); | |
0b3016b7 | 491 | static DEFINE_MUTEX(stp_work_mutex); |
d2fec595 | 492 | static DECLARE_WORK(stp_work, stp_work_fn); |
04362301 | 493 | static struct timer_list stp_timer; |
d2fec595 MS |
494 | |
495 | static int __init early_parse_stp(char *p) | |
496 | { | |
4cc7ecb7 | 497 | return kstrtobool(p, &stp_online); |
d2fec595 MS |
498 | } |
499 | early_param("stp", early_parse_stp); | |
500 | ||
501 | /* | |
502 | * Reset STP attachment. | |
503 | */ | |
8f847003 | 504 | static void __init stp_reset(void) |
d2fec595 MS |
505 | { |
506 | int rc; | |
507 | ||
d7d1104f | 508 | stp_page = (void *) get_zeroed_page(GFP_ATOMIC); |
2f82f577 | 509 | rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL); |
4a672cfa | 510 | if (rc == 0) |
d2fec595 MS |
511 | set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags); |
512 | else if (stp_online) { | |
baebc70a | 513 | pr_warn("The real or virtual hardware system does not provide an STP interface\n"); |
d7d1104f | 514 | free_page((unsigned long) stp_page); |
d2fec595 MS |
515 | stp_page = NULL; |
516 | stp_online = 0; | |
517 | } | |
518 | } | |
519 | ||
04362301 MS |
520 | static void stp_timeout(unsigned long dummy) |
521 | { | |
522 | queue_work(time_sync_wq, &stp_work); | |
523 | } | |
524 | ||
d2fec595 MS |
525 | static int __init stp_init(void) |
526 | { | |
750887de HC |
527 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) |
528 | return 0; | |
04362301 | 529 | setup_timer(&stp_timer, stp_timeout, 0UL); |
750887de HC |
530 | time_init_wq(); |
531 | if (!stp_online) | |
532 | return 0; | |
533 | queue_work(time_sync_wq, &stp_work); | |
d2fec595 MS |
534 | return 0; |
535 | } | |
536 | ||
537 | arch_initcall(stp_init); | |
538 | ||
539 | /* | |
540 | * STP timing alert. There are three causes: | |
541 | * 1) timing status change | |
542 | * 2) link availability change | |
543 | * 3) time control parameter change | |
544 | * In all three cases we are only interested in the clock source state. | |
545 | * If a STP clock source is now available use it. | |
546 | */ | |
547 | static void stp_timing_alert(struct stp_irq_parm *intparm) | |
548 | { | |
549 | if (intparm->tsc || intparm->lac || intparm->tcpc) | |
750887de | 550 | queue_work(time_sync_wq, &stp_work); |
d2fec595 MS |
551 | } |
552 | ||
553 | /* | |
554 | * STP sync check machine check. This is called when the timing state | |
555 | * changes from the synchronized state to the unsynchronized state. | |
556 | * After a STP sync check the clock is not in sync. The machine check | |
557 | * is broadcasted to all cpus at the same time. | |
558 | */ | |
29b0a825 | 559 | int stp_sync_check(void) |
d2fec595 | 560 | { |
d2fec595 | 561 | disable_sync_clock(NULL); |
29b0a825 | 562 | return 1; |
d2fec595 MS |
563 | } |
564 | ||
565 | /* | |
566 | * STP island condition machine check. This is called when an attached | |
567 | * server attempts to communicate over an STP link and the servers | |
568 | * have matching CTN ids and have a valid stratum-1 configuration | |
569 | * but the configurations do not match. | |
570 | */ | |
29b0a825 | 571 | int stp_island_check(void) |
d2fec595 | 572 | { |
d2fec595 | 573 | disable_sync_clock(NULL); |
29b0a825 | 574 | return 1; |
d2fec595 MS |
575 | } |
576 | ||
29b0a825 HC |
577 | void stp_queue_work(void) |
578 | { | |
579 | queue_work(time_sync_wq, &stp_work); | |
580 | } | |
750887de HC |
581 | |
582 | static int stp_sync_clock(void *data) | |
d2fec595 | 583 | { |
750887de | 584 | static int first; |
fdf03650 | 585 | unsigned long long old_clock, delta, new_clock, clock_delta; |
750887de | 586 | struct clock_sync_data *stp_sync; |
40277891 | 587 | struct ptff_qto qto; |
d2fec595 MS |
588 | int rc; |
589 | ||
750887de | 590 | stp_sync = data; |
d2fec595 | 591 | |
750887de HC |
592 | if (xchg(&first, 1) == 1) { |
593 | /* Slave */ | |
594 | clock_sync_cpu(stp_sync); | |
595 | return 0; | |
596 | } | |
d2fec595 | 597 | |
750887de HC |
598 | /* Wait until all other cpus entered the sync function. */ |
599 | while (atomic_read(&stp_sync->cpus) != 0) | |
600 | cpu_relax(); | |
d2fec595 | 601 | |
d2fec595 MS |
602 | enable_sync_clock(); |
603 | ||
d2fec595 MS |
604 | rc = 0; |
605 | if (stp_info.todoff[0] || stp_info.todoff[1] || | |
606 | stp_info.todoff[2] || stp_info.todoff[3] || | |
607 | stp_info.tmd != 2) { | |
1aae0560 | 608 | old_clock = get_tod_clock(); |
2f82f577 | 609 | rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0, &clock_delta); |
d2fec595 | 610 | if (rc == 0) { |
2f82f577 | 611 | new_clock = old_clock + clock_delta; |
fdf03650 | 612 | delta = adjust_time(old_clock, new_clock, 0); |
40277891 MS |
613 | if (ptff_query(PTFF_QTO) && |
614 | ptff(&qto, sizeof(qto), PTFF_QTO) == 0) | |
615 | /* Update LPAR offset */ | |
616 | lpar_offset = qto.tod_epoch_difference; | |
fdf03650 FZ |
617 | atomic_notifier_call_chain(&s390_epoch_delta_notifier, |
618 | 0, &clock_delta); | |
d2fec595 MS |
619 | fixup_clock_comparator(delta); |
620 | rc = chsc_sstpi(stp_page, &stp_info, | |
621 | sizeof(struct stp_sstpi)); | |
622 | if (rc == 0 && stp_info.tmd != 2) | |
623 | rc = -EAGAIN; | |
624 | } | |
625 | } | |
626 | if (rc) { | |
627 | disable_sync_clock(NULL); | |
750887de | 628 | stp_sync->in_sync = -EAGAIN; |
d2fec595 | 629 | } else |
750887de HC |
630 | stp_sync->in_sync = 1; |
631 | xchg(&first, 0); | |
632 | return 0; | |
633 | } | |
d2fec595 | 634 | |
750887de HC |
635 | /* |
636 | * STP work. Check for the STP state and take over the clock | |
637 | * synchronization if the STP clock source is usable. | |
638 | */ | |
639 | static void stp_work_fn(struct work_struct *work) | |
640 | { | |
641 | struct clock_sync_data stp_sync; | |
642 | int rc; | |
643 | ||
0b3016b7 MS |
644 | /* prevent multiple execution. */ |
645 | mutex_lock(&stp_work_mutex); | |
646 | ||
750887de | 647 | if (!stp_online) { |
2f82f577 | 648 | chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL); |
04362301 | 649 | del_timer_sync(&stp_timer); |
0b3016b7 | 650 | goto out_unlock; |
750887de HC |
651 | } |
652 | ||
2f82f577 | 653 | rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0, NULL); |
750887de | 654 | if (rc) |
0b3016b7 | 655 | goto out_unlock; |
750887de HC |
656 | |
657 | rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi)); | |
658 | if (rc || stp_info.c == 0) | |
0b3016b7 | 659 | goto out_unlock; |
750887de | 660 | |
8283cb43 MS |
661 | /* Skip synchronization if the clock is already in sync. */ |
662 | if (check_sync_clock()) | |
663 | goto out_unlock; | |
664 | ||
750887de HC |
665 | memset(&stp_sync, 0, sizeof(stp_sync)); |
666 | get_online_cpus(); | |
667 | atomic_set(&stp_sync.cpus, num_online_cpus() - 1); | |
0f1959f5 | 668 | stop_machine(stp_sync_clock, &stp_sync, cpu_online_mask); |
750887de | 669 | put_online_cpus(); |
0b3016b7 | 670 | |
04362301 MS |
671 | if (!check_sync_clock()) |
672 | /* | |
673 | * There is a usable clock but the synchonization failed. | |
674 | * Retry after a second. | |
675 | */ | |
676 | mod_timer(&stp_timer, jiffies + HZ); | |
677 | ||
0b3016b7 MS |
678 | out_unlock: |
679 | mutex_unlock(&stp_work_mutex); | |
d2fec595 MS |
680 | } |
681 | ||
682 | /* | |
3fbacffb | 683 | * STP subsys sysfs interface functions |
d2fec595 | 684 | */ |
3fbacffb KS |
685 | static struct bus_type stp_subsys = { |
686 | .name = "stp", | |
687 | .dev_name = "stp", | |
d2fec595 MS |
688 | }; |
689 | ||
3fbacffb KS |
690 | static ssize_t stp_ctn_id_show(struct device *dev, |
691 | struct device_attribute *attr, | |
c9be0a36 | 692 | char *buf) |
d2fec595 MS |
693 | { |
694 | if (!stp_online) | |
695 | return -ENODATA; | |
696 | return sprintf(buf, "%016llx\n", | |
697 | *(unsigned long long *) stp_info.ctnid); | |
698 | } | |
699 | ||
3fbacffb | 700 | static DEVICE_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL); |
d2fec595 | 701 | |
3fbacffb KS |
702 | static ssize_t stp_ctn_type_show(struct device *dev, |
703 | struct device_attribute *attr, | |
c9be0a36 | 704 | char *buf) |
d2fec595 MS |
705 | { |
706 | if (!stp_online) | |
707 | return -ENODATA; | |
708 | return sprintf(buf, "%i\n", stp_info.ctn); | |
709 | } | |
710 | ||
3fbacffb | 711 | static DEVICE_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL); |
d2fec595 | 712 | |
3fbacffb KS |
713 | static ssize_t stp_dst_offset_show(struct device *dev, |
714 | struct device_attribute *attr, | |
c9be0a36 | 715 | char *buf) |
d2fec595 MS |
716 | { |
717 | if (!stp_online || !(stp_info.vbits & 0x2000)) | |
718 | return -ENODATA; | |
719 | return sprintf(buf, "%i\n", (int)(s16) stp_info.dsto); | |
720 | } | |
721 | ||
3fbacffb | 722 | static DEVICE_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL); |
d2fec595 | 723 | |
3fbacffb KS |
724 | static ssize_t stp_leap_seconds_show(struct device *dev, |
725 | struct device_attribute *attr, | |
c9be0a36 | 726 | char *buf) |
d2fec595 MS |
727 | { |
728 | if (!stp_online || !(stp_info.vbits & 0x8000)) | |
729 | return -ENODATA; | |
730 | return sprintf(buf, "%i\n", (int)(s16) stp_info.leaps); | |
731 | } | |
732 | ||
3fbacffb | 733 | static DEVICE_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL); |
d2fec595 | 734 | |
3fbacffb KS |
735 | static ssize_t stp_stratum_show(struct device *dev, |
736 | struct device_attribute *attr, | |
c9be0a36 | 737 | char *buf) |
d2fec595 MS |
738 | { |
739 | if (!stp_online) | |
740 | return -ENODATA; | |
741 | return sprintf(buf, "%i\n", (int)(s16) stp_info.stratum); | |
742 | } | |
743 | ||
3fbacffb | 744 | static DEVICE_ATTR(stratum, 0400, stp_stratum_show, NULL); |
d2fec595 | 745 | |
3fbacffb KS |
746 | static ssize_t stp_time_offset_show(struct device *dev, |
747 | struct device_attribute *attr, | |
c9be0a36 | 748 | char *buf) |
d2fec595 MS |
749 | { |
750 | if (!stp_online || !(stp_info.vbits & 0x0800)) | |
751 | return -ENODATA; | |
752 | return sprintf(buf, "%i\n", (int) stp_info.tto); | |
753 | } | |
754 | ||
3fbacffb | 755 | static DEVICE_ATTR(time_offset, 0400, stp_time_offset_show, NULL); |
d2fec595 | 756 | |
3fbacffb KS |
757 | static ssize_t stp_time_zone_offset_show(struct device *dev, |
758 | struct device_attribute *attr, | |
c9be0a36 | 759 | char *buf) |
d2fec595 MS |
760 | { |
761 | if (!stp_online || !(stp_info.vbits & 0x4000)) | |
762 | return -ENODATA; | |
763 | return sprintf(buf, "%i\n", (int)(s16) stp_info.tzo); | |
764 | } | |
765 | ||
3fbacffb | 766 | static DEVICE_ATTR(time_zone_offset, 0400, |
d2fec595 MS |
767 | stp_time_zone_offset_show, NULL); |
768 | ||
3fbacffb KS |
769 | static ssize_t stp_timing_mode_show(struct device *dev, |
770 | struct device_attribute *attr, | |
c9be0a36 | 771 | char *buf) |
d2fec595 MS |
772 | { |
773 | if (!stp_online) | |
774 | return -ENODATA; | |
775 | return sprintf(buf, "%i\n", stp_info.tmd); | |
776 | } | |
777 | ||
3fbacffb | 778 | static DEVICE_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL); |
d2fec595 | 779 | |
3fbacffb KS |
780 | static ssize_t stp_timing_state_show(struct device *dev, |
781 | struct device_attribute *attr, | |
c9be0a36 | 782 | char *buf) |
d2fec595 MS |
783 | { |
784 | if (!stp_online) | |
785 | return -ENODATA; | |
786 | return sprintf(buf, "%i\n", stp_info.tst); | |
787 | } | |
788 | ||
3fbacffb | 789 | static DEVICE_ATTR(timing_state, 0400, stp_timing_state_show, NULL); |
d2fec595 | 790 | |
3fbacffb KS |
791 | static ssize_t stp_online_show(struct device *dev, |
792 | struct device_attribute *attr, | |
c9be0a36 | 793 | char *buf) |
d2fec595 MS |
794 | { |
795 | return sprintf(buf, "%i\n", stp_online); | |
796 | } | |
797 | ||
3fbacffb KS |
798 | static ssize_t stp_online_store(struct device *dev, |
799 | struct device_attribute *attr, | |
d2fec595 MS |
800 | const char *buf, size_t count) |
801 | { | |
802 | unsigned int value; | |
803 | ||
804 | value = simple_strtoul(buf, NULL, 0); | |
805 | if (value != 0 && value != 1) | |
806 | return -EINVAL; | |
807 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) | |
808 | return -EOPNOTSUPP; | |
8283cb43 | 809 | mutex_lock(&clock_sync_mutex); |
d2fec595 | 810 | stp_online = value; |
8283cb43 MS |
811 | if (stp_online) |
812 | set_bit(CLOCK_SYNC_STP, &clock_sync_flags); | |
813 | else | |
814 | clear_bit(CLOCK_SYNC_STP, &clock_sync_flags); | |
750887de | 815 | queue_work(time_sync_wq, &stp_work); |
8283cb43 | 816 | mutex_unlock(&clock_sync_mutex); |
d2fec595 MS |
817 | return count; |
818 | } | |
819 | ||
820 | /* | |
3fbacffb KS |
821 | * Can't use DEVICE_ATTR because the attribute should be named |
822 | * stp/online but dev_attr_online already exists in this file .. | |
d2fec595 | 823 | */ |
3fbacffb | 824 | static struct device_attribute dev_attr_stp_online = { |
d2fec595 MS |
825 | .attr = { .name = "online", .mode = 0600 }, |
826 | .show = stp_online_show, | |
827 | .store = stp_online_store, | |
828 | }; | |
829 | ||
3fbacffb KS |
830 | static struct device_attribute *stp_attributes[] = { |
831 | &dev_attr_ctn_id, | |
832 | &dev_attr_ctn_type, | |
833 | &dev_attr_dst_offset, | |
834 | &dev_attr_leap_seconds, | |
835 | &dev_attr_stp_online, | |
836 | &dev_attr_stratum, | |
837 | &dev_attr_time_offset, | |
838 | &dev_attr_time_zone_offset, | |
839 | &dev_attr_timing_mode, | |
840 | &dev_attr_timing_state, | |
d2fec595 MS |
841 | NULL |
842 | }; | |
843 | ||
844 | static int __init stp_init_sysfs(void) | |
845 | { | |
3fbacffb | 846 | struct device_attribute **attr; |
d2fec595 MS |
847 | int rc; |
848 | ||
3fbacffb | 849 | rc = subsys_system_register(&stp_subsys, NULL); |
d2fec595 MS |
850 | if (rc) |
851 | goto out; | |
852 | for (attr = stp_attributes; *attr; attr++) { | |
3fbacffb | 853 | rc = device_create_file(stp_subsys.dev_root, *attr); |
d2fec595 MS |
854 | if (rc) |
855 | goto out_unreg; | |
856 | } | |
857 | return 0; | |
858 | out_unreg: | |
859 | for (; attr >= stp_attributes; attr--) | |
3fbacffb KS |
860 | device_remove_file(stp_subsys.dev_root, *attr); |
861 | bus_unregister(&stp_subsys); | |
d2fec595 MS |
862 | out: |
863 | return rc; | |
864 | } | |
865 | ||
866 | device_initcall(stp_init_sysfs); |