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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 | 52 | |
b6112ccb | 53 | u64 sched_clock_base_cc = -1; /* Force to data section. */ |
05e7ff7d | 54 | EXPORT_SYMBOL_GPL(sched_clock_base_cc); |
b6112ccb | 55 | |
5a62b192 | 56 | static DEFINE_PER_CPU(struct clock_event_device, comparators); |
1da177e4 | 57 | |
fdf03650 FZ |
58 | ATOMIC_NOTIFIER_HEAD(s390_epoch_delta_notifier); |
59 | EXPORT_SYMBOL(s390_epoch_delta_notifier); | |
60 | ||
40277891 | 61 | unsigned char ptff_function_mask[16]; |
b1c0854d MS |
62 | |
63 | static unsigned long long lpar_offset; | |
64 | static unsigned long long initial_leap_seconds; | |
75c7b6f3 MS |
65 | static unsigned long long tod_steering_end; |
66 | static unsigned long long tod_steering_delta; | |
40277891 MS |
67 | |
68 | /* | |
69 | * Get time offsets with PTFF | |
70 | */ | |
b1c0854d | 71 | void __init time_early_init(void) |
40277891 MS |
72 | { |
73 | struct ptff_qto qto; | |
936cc855 | 74 | struct ptff_qui qui; |
40277891 | 75 | |
75c7b6f3 MS |
76 | /* Initialize TOD steering parameters */ |
77 | tod_steering_end = sched_clock_base_cc; | |
78 | vdso_data->ts_end = tod_steering_end; | |
79 | ||
40277891 MS |
80 | if (!test_facility(28)) |
81 | return; | |
75c7b6f3 | 82 | |
40277891 MS |
83 | ptff(&ptff_function_mask, sizeof(ptff_function_mask), PTFF_QAF); |
84 | ||
85 | /* get LPAR offset */ | |
86 | if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) | |
87 | lpar_offset = qto.tod_epoch_difference; | |
936cc855 MS |
88 | |
89 | /* get initial leap seconds */ | |
90 | if (ptff_query(PTFF_QUI) && ptff(&qui, sizeof(qui), PTFF_QUI) == 0) | |
b1c0854d | 91 | initial_leap_seconds = (unsigned long long) |
936cc855 | 92 | ((long) qui.old_leap * 4096000000L); |
40277891 MS |
93 | } |
94 | ||
1da177e4 LT |
95 | /* |
96 | * Scheduler clock - returns current time in nanosec units. | |
97 | */ | |
7a5388de | 98 | unsigned long long notrace sched_clock(void) |
1da177e4 | 99 | { |
1aae0560 | 100 | return tod_to_ns(get_tod_clock_monotonic()); |
1da177e4 | 101 | } |
7a5388de | 102 | NOKPROBE_SYMBOL(sched_clock); |
1da177e4 | 103 | |
32f65f27 JG |
104 | /* |
105 | * Monotonic_clock - returns # of nanoseconds passed since time_init() | |
106 | */ | |
107 | unsigned long long monotonic_clock(void) | |
108 | { | |
109 | return sched_clock(); | |
110 | } | |
111 | EXPORT_SYMBOL(monotonic_clock); | |
112 | ||
689911c7 | 113 | void tod_to_timeval(__u64 todval, struct timespec64 *xt) |
1da177e4 LT |
114 | { |
115 | unsigned long long sec; | |
116 | ||
117 | sec = todval >> 12; | |
118 | do_div(sec, 1000000); | |
b1e2ba8d | 119 | xt->tv_sec = sec; |
1da177e4 | 120 | todval -= (sec * 1000000) << 12; |
b1e2ba8d | 121 | xt->tv_nsec = ((todval * 1000) >> 12); |
1da177e4 | 122 | } |
b592e89a | 123 | EXPORT_SYMBOL(tod_to_timeval); |
1da177e4 | 124 | |
5a62b192 | 125 | void clock_comparator_work(void) |
1da177e4 | 126 | { |
5a62b192 | 127 | struct clock_event_device *cd; |
1da177e4 | 128 | |
5a62b192 | 129 | S390_lowcore.clock_comparator = -1ULL; |
eb7e7d76 | 130 | cd = this_cpu_ptr(&comparators); |
5a62b192 | 131 | cd->event_handler(cd); |
1da177e4 LT |
132 | } |
133 | ||
8adbf78e | 134 | static int s390_next_event(unsigned long delta, |
5a62b192 | 135 | struct clock_event_device *evt) |
1da177e4 | 136 | { |
8adbf78e | 137 | S390_lowcore.clock_comparator = get_tod_clock() + delta; |
5a62b192 HC |
138 | set_clock_comparator(S390_lowcore.clock_comparator); |
139 | return 0; | |
1da177e4 LT |
140 | } |
141 | ||
d54853ef MS |
142 | /* |
143 | * Set up lowcore and control register of the current cpu to | |
144 | * enable TOD clock and clock comparator interrupts. | |
1da177e4 LT |
145 | */ |
146 | void init_cpu_timer(void) | |
147 | { | |
5a62b192 HC |
148 | struct clock_event_device *cd; |
149 | int cpu; | |
150 | ||
151 | S390_lowcore.clock_comparator = -1ULL; | |
152 | set_clock_comparator(S390_lowcore.clock_comparator); | |
153 | ||
154 | cpu = smp_processor_id(); | |
155 | cd = &per_cpu(comparators, cpu); | |
156 | cd->name = "comparator"; | |
8adbf78e | 157 | cd->features = CLOCK_EVT_FEAT_ONESHOT; |
5a62b192 HC |
158 | cd->mult = 16777; |
159 | cd->shift = 12; | |
160 | cd->min_delta_ns = 1; | |
161 | cd->max_delta_ns = LONG_MAX; | |
162 | cd->rating = 400; | |
320ab2b0 | 163 | cd->cpumask = cpumask_of(cpu); |
8adbf78e | 164 | cd->set_next_event = s390_next_event; |
5a62b192 HC |
165 | |
166 | clockevents_register_device(cd); | |
d54853ef MS |
167 | |
168 | /* Enable clock comparator timer interrupt. */ | |
169 | __ctl_set_bit(0,11); | |
170 | ||
d2fec595 | 171 | /* Always allow the timing alert external interrupt. */ |
d54853ef MS |
172 | __ctl_set_bit(0, 4); |
173 | } | |
174 | ||
fde15c3a | 175 | static void clock_comparator_interrupt(struct ext_code ext_code, |
f6649a7e MS |
176 | unsigned int param32, |
177 | unsigned long param64) | |
d54853ef | 178 | { |
420f42ec | 179 | inc_irq_stat(IRQEXT_CLK); |
d3d238c7 HC |
180 | if (S390_lowcore.clock_comparator == -1ULL) |
181 | set_clock_comparator(S390_lowcore.clock_comparator); | |
d54853ef MS |
182 | } |
183 | ||
d2fec595 MS |
184 | static void stp_timing_alert(struct stp_irq_parm *); |
185 | ||
fde15c3a | 186 | static void timing_alert_interrupt(struct ext_code ext_code, |
f6649a7e | 187 | unsigned int param32, unsigned long param64) |
d2fec595 | 188 | { |
420f42ec | 189 | inc_irq_stat(IRQEXT_TLA); |
f6649a7e MS |
190 | if (param32 & 0x00038000) |
191 | stp_timing_alert((struct stp_irq_parm *) ¶m32); | |
d2fec595 MS |
192 | } |
193 | ||
d2fec595 | 194 | static void stp_reset(void); |
d54853ef | 195 | |
689911c7 | 196 | void read_persistent_clock64(struct timespec64 *ts) |
d54853ef | 197 | { |
936cc855 MS |
198 | __u64 clock; |
199 | ||
200 | clock = get_tod_clock() - initial_leap_seconds; | |
201 | tod_to_timeval(clock - TOD_UNIX_EPOCH, ts); | |
1da177e4 | 202 | } |
d54853ef | 203 | |
689911c7 | 204 | void read_boot_clock64(struct timespec64 *ts) |
23970e38 | 205 | { |
936cc855 MS |
206 | __u64 clock; |
207 | ||
208 | clock = sched_clock_base_cc - initial_leap_seconds; | |
209 | tod_to_timeval(clock - TOD_UNIX_EPOCH, ts); | |
1da177e4 LT |
210 | } |
211 | ||
8e19608e | 212 | static cycle_t read_tod_clock(struct clocksource *cs) |
dc64bef5 | 213 | { |
75c7b6f3 MS |
214 | unsigned long long now, adj; |
215 | ||
216 | preempt_disable(); /* protect from changes to steering parameters */ | |
217 | now = get_tod_clock(); | |
218 | adj = tod_steering_end - now; | |
219 | if (unlikely((s64) adj >= 0)) | |
220 | /* | |
221 | * manually steer by 1 cycle every 2^16 cycles. This | |
222 | * corresponds to shifting the tod delta by 15. 1s is | |
223 | * therefore steered in ~9h. The adjust will decrease | |
224 | * over time, until it finally reaches 0. | |
225 | */ | |
226 | now += ((s64) tod_steering_delta < 0) ? | |
227 | (adj >> 15) : -(adj >> 15); | |
228 | preempt_enable(); | |
229 | return now; | |
dc64bef5 MS |
230 | } |
231 | ||
232 | static struct clocksource clocksource_tod = { | |
233 | .name = "tod", | |
d2cb0e6e | 234 | .rating = 400, |
dc64bef5 MS |
235 | .read = read_tod_clock, |
236 | .mask = -1ULL, | |
237 | .mult = 1000, | |
238 | .shift = 12, | |
cc02d809 | 239 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
dc64bef5 MS |
240 | }; |
241 | ||
f1b82746 MS |
242 | struct clocksource * __init clocksource_default_clock(void) |
243 | { | |
244 | return &clocksource_tod; | |
245 | } | |
dc64bef5 | 246 | |
79c74ecb | 247 | void update_vsyscall(struct timekeeper *tk) |
b020632e | 248 | { |
79c74ecb MS |
249 | u64 nsecps; |
250 | ||
876e7881 | 251 | if (tk->tkr_mono.clock != &clocksource_tod) |
b020632e MS |
252 | return; |
253 | ||
254 | /* Make userspace gettimeofday spin until we're done. */ | |
255 | ++vdso_data->tb_update_count; | |
256 | smp_wmb(); | |
876e7881 | 257 | vdso_data->xtime_tod_stamp = tk->tkr_mono.cycle_last; |
79c74ecb | 258 | vdso_data->xtime_clock_sec = tk->xtime_sec; |
876e7881 | 259 | vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec; |
79c74ecb MS |
260 | vdso_data->wtom_clock_sec = |
261 | tk->xtime_sec + tk->wall_to_monotonic.tv_sec; | |
876e7881 PZ |
262 | vdso_data->wtom_clock_nsec = tk->tkr_mono.xtime_nsec + |
263 | + ((u64) tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift); | |
264 | nsecps = (u64) NSEC_PER_SEC << tk->tkr_mono.shift; | |
79c74ecb MS |
265 | while (vdso_data->wtom_clock_nsec >= nsecps) { |
266 | vdso_data->wtom_clock_nsec -= nsecps; | |
267 | vdso_data->wtom_clock_sec++; | |
268 | } | |
b7eacb59 MS |
269 | |
270 | vdso_data->xtime_coarse_sec = tk->xtime_sec; | |
271 | vdso_data->xtime_coarse_nsec = | |
876e7881 | 272 | (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
b7eacb59 MS |
273 | vdso_data->wtom_coarse_sec = |
274 | vdso_data->xtime_coarse_sec + tk->wall_to_monotonic.tv_sec; | |
275 | vdso_data->wtom_coarse_nsec = | |
276 | vdso_data->xtime_coarse_nsec + tk->wall_to_monotonic.tv_nsec; | |
277 | while (vdso_data->wtom_coarse_nsec >= NSEC_PER_SEC) { | |
278 | vdso_data->wtom_coarse_nsec -= NSEC_PER_SEC; | |
279 | vdso_data->wtom_coarse_sec++; | |
280 | } | |
281 | ||
876e7881 PZ |
282 | vdso_data->tk_mult = tk->tkr_mono.mult; |
283 | vdso_data->tk_shift = tk->tkr_mono.shift; | |
b020632e MS |
284 | smp_wmb(); |
285 | ++vdso_data->tb_update_count; | |
286 | } | |
287 | ||
288 | extern struct timezone sys_tz; | |
289 | ||
290 | void update_vsyscall_tz(void) | |
291 | { | |
b020632e MS |
292 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; |
293 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
b020632e MS |
294 | } |
295 | ||
1da177e4 LT |
296 | /* |
297 | * Initialize the TOD clock and the CPU timer of | |
298 | * the boot cpu. | |
299 | */ | |
300 | void __init time_init(void) | |
301 | { | |
b6112ccb | 302 | /* Reset time synchronization interfaces. */ |
b6112ccb | 303 | stp_reset(); |
1da177e4 | 304 | |
1da177e4 | 305 | /* request the clock comparator external interrupt */ |
1dad093b TH |
306 | if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt)) |
307 | panic("Couldn't request external interrupt 0x1004"); | |
1da177e4 | 308 | |
d2fec595 | 309 | /* request the timing alert external interrupt */ |
1dad093b | 310 | if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt)) |
d54853ef MS |
311 | panic("Couldn't request external interrupt 0x1406"); |
312 | ||
f8935983 | 313 | if (__clocksource_register(&clocksource_tod) != 0) |
ab96e798 MS |
314 | panic("Could not register TOD clock source"); |
315 | ||
d54853ef MS |
316 | /* Enable TOD clock interrupts on the boot cpu. */ |
317 | init_cpu_timer(); | |
ab96e798 | 318 | |
c185b783 | 319 | /* Enable cpu timer interrupts on the boot cpu. */ |
1da177e4 | 320 | vtime_init(); |
d54853ef MS |
321 | } |
322 | ||
d2fec595 | 323 | static DEFINE_PER_CPU(atomic_t, clock_sync_word); |
8283cb43 | 324 | static DEFINE_MUTEX(clock_sync_mutex); |
d2fec595 MS |
325 | static unsigned long clock_sync_flags; |
326 | ||
ca64f639 DH |
327 | #define CLOCK_SYNC_HAS_STP 0 |
328 | #define CLOCK_SYNC_STP 1 | |
d2fec595 MS |
329 | |
330 | /* | |
40277891 MS |
331 | * The get_clock function for the physical clock. It will get the current |
332 | * TOD clock, subtract the LPAR offset and write the result to *clock. | |
333 | * The function returns 0 if the clock is in sync with the external time | |
334 | * source. If the clock mode is local it will return -EOPNOTSUPP and | |
335 | * -EAGAIN if the clock is not in sync with the external reference. | |
d2fec595 | 336 | */ |
40277891 | 337 | int get_phys_clock(unsigned long long *clock) |
d2fec595 MS |
338 | { |
339 | atomic_t *sw_ptr; | |
340 | unsigned int sw0, sw1; | |
341 | ||
342 | sw_ptr = &get_cpu_var(clock_sync_word); | |
343 | sw0 = atomic_read(sw_ptr); | |
40277891 | 344 | *clock = get_tod_clock() - lpar_offset; |
d2fec595 | 345 | sw1 = atomic_read(sw_ptr); |
bd119ee2 | 346 | put_cpu_var(clock_sync_word); |
d2fec595 MS |
347 | if (sw0 == sw1 && (sw0 & 0x80000000U)) |
348 | /* Success: time is in sync. */ | |
349 | return 0; | |
ca64f639 | 350 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) |
a8f6db4d | 351 | return -EOPNOTSUPP; |
ca64f639 | 352 | if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags)) |
d2fec595 MS |
353 | return -EACCES; |
354 | return -EAGAIN; | |
355 | } | |
40277891 | 356 | EXPORT_SYMBOL(get_phys_clock); |
d2fec595 MS |
357 | |
358 | /* | |
ca64f639 | 359 | * Make get_phys_clock() return -EAGAIN. |
d2fec595 MS |
360 | */ |
361 | static void disable_sync_clock(void *dummy) | |
362 | { | |
eb7e7d76 | 363 | atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); |
d2fec595 | 364 | /* |
ca64f639 | 365 | * Clear the in-sync bit 2^31. All get_phys_clock calls will |
d2fec595 MS |
366 | * fail until the sync bit is turned back on. In addition |
367 | * increase the "sequence" counter to avoid the race of an | |
ca64f639 | 368 | * stp event and the complete recovery against get_phys_clock. |
d2fec595 | 369 | */ |
805de8f4 | 370 | atomic_andnot(0x80000000, sw_ptr); |
d2fec595 MS |
371 | atomic_inc(sw_ptr); |
372 | } | |
373 | ||
374 | /* | |
ca64f639 | 375 | * Make get_phys_clock() return 0 again. |
d2fec595 MS |
376 | * Needs to be called from a context disabled for preemption. |
377 | */ | |
378 | static void enable_sync_clock(void) | |
379 | { | |
eb7e7d76 | 380 | atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); |
805de8f4 | 381 | atomic_or(0x80000000, sw_ptr); |
d2fec595 MS |
382 | } |
383 | ||
8283cb43 MS |
384 | /* |
385 | * Function to check if the clock is in sync. | |
386 | */ | |
387 | static inline int check_sync_clock(void) | |
388 | { | |
389 | atomic_t *sw_ptr; | |
390 | int rc; | |
391 | ||
392 | sw_ptr = &get_cpu_var(clock_sync_word); | |
393 | rc = (atomic_read(sw_ptr) & 0x80000000U) != 0; | |
bd119ee2 | 394 | put_cpu_var(clock_sync_word); |
8283cb43 MS |
395 | return rc; |
396 | } | |
397 | ||
b1c0854d MS |
398 | /* |
399 | * Apply clock delta to the global data structures. | |
400 | * This is called once on the CPU that performed the clock sync. | |
401 | */ | |
402 | static void clock_sync_global(unsigned long long delta) | |
403 | { | |
75c7b6f3 | 404 | unsigned long now, adj; |
b1c0854d MS |
405 | struct ptff_qto qto; |
406 | ||
407 | /* Fixup the monotonic sched clock. */ | |
408 | sched_clock_base_cc += delta; | |
75c7b6f3 MS |
409 | /* Adjust TOD steering parameters. */ |
410 | vdso_data->tb_update_count++; | |
411 | now = get_tod_clock(); | |
412 | adj = tod_steering_end - now; | |
413 | if (unlikely((s64) adj >= 0)) | |
414 | /* Calculate how much of the old adjustment is left. */ | |
415 | tod_steering_delta = ((s64) tod_steering_delta < 0) ? | |
416 | -(adj >> 15) : (adj >> 15); | |
417 | tod_steering_delta += delta; | |
418 | if ((abs(tod_steering_delta) >> 48) != 0) | |
419 | panic("TOD clock sync offset %lli is too large to drift\n", | |
420 | tod_steering_delta); | |
421 | tod_steering_end = now + (abs(tod_steering_delta) << 15); | |
422 | vdso_data->ts_dir = (tod_steering_delta < 0) ? 0 : 1; | |
423 | vdso_data->ts_end = tod_steering_end; | |
424 | vdso_data->tb_update_count++; | |
b1c0854d MS |
425 | /* Update LPAR offset. */ |
426 | if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) | |
427 | lpar_offset = qto.tod_epoch_difference; | |
428 | /* Call the TOD clock change notifier. */ | |
429 | atomic_notifier_call_chain(&s390_epoch_delta_notifier, 0, &delta); | |
430 | } | |
431 | ||
432 | /* | |
433 | * Apply clock delta to the per-CPU data structures of this CPU. | |
434 | * This is called for each online CPU after the call to clock_sync_global. | |
435 | */ | |
436 | static void clock_sync_local(unsigned long long delta) | |
437 | { | |
438 | /* Add the delta to the clock comparator. */ | |
439 | if (S390_lowcore.clock_comparator != -1ULL) { | |
440 | S390_lowcore.clock_comparator += delta; | |
441 | set_clock_comparator(S390_lowcore.clock_comparator); | |
442 | } | |
2ace06ec MS |
443 | /* Adjust the last_update_clock time-stamp. */ |
444 | S390_lowcore.last_update_clock += delta; | |
b1c0854d MS |
445 | } |
446 | ||
ca64f639 | 447 | /* Single threaded workqueue used for stp sync events */ |
750887de HC |
448 | static struct workqueue_struct *time_sync_wq; |
449 | ||
450 | static void __init time_init_wq(void) | |
451 | { | |
179cb81a HC |
452 | if (time_sync_wq) |
453 | return; | |
454 | time_sync_wq = create_singlethread_workqueue("timesync"); | |
750887de HC |
455 | } |
456 | ||
d2fec595 | 457 | struct clock_sync_data { |
750887de | 458 | atomic_t cpus; |
5a62b192 | 459 | int in_sync; |
b1c0854d | 460 | unsigned long long clock_delta; |
d2fec595 | 461 | }; |
5a62b192 | 462 | |
d2fec595 MS |
463 | /* |
464 | * Server Time Protocol (STP) code. | |
465 | */ | |
4cc7ecb7 | 466 | static bool stp_online; |
d2fec595 MS |
467 | static struct stp_sstpi stp_info; |
468 | static void *stp_page; | |
469 | ||
470 | static void stp_work_fn(struct work_struct *work); | |
0b3016b7 | 471 | static DEFINE_MUTEX(stp_work_mutex); |
d2fec595 | 472 | static DECLARE_WORK(stp_work, stp_work_fn); |
04362301 | 473 | static struct timer_list stp_timer; |
d2fec595 MS |
474 | |
475 | static int __init early_parse_stp(char *p) | |
476 | { | |
4cc7ecb7 | 477 | return kstrtobool(p, &stp_online); |
d2fec595 MS |
478 | } |
479 | early_param("stp", early_parse_stp); | |
480 | ||
481 | /* | |
482 | * Reset STP attachment. | |
483 | */ | |
8f847003 | 484 | static void __init stp_reset(void) |
d2fec595 MS |
485 | { |
486 | int rc; | |
487 | ||
d7d1104f | 488 | stp_page = (void *) get_zeroed_page(GFP_ATOMIC); |
2f82f577 | 489 | rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL); |
4a672cfa | 490 | if (rc == 0) |
d2fec595 MS |
491 | set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags); |
492 | else if (stp_online) { | |
baebc70a | 493 | pr_warn("The real or virtual hardware system does not provide an STP interface\n"); |
d7d1104f | 494 | free_page((unsigned long) stp_page); |
d2fec595 MS |
495 | stp_page = NULL; |
496 | stp_online = 0; | |
497 | } | |
498 | } | |
499 | ||
04362301 MS |
500 | static void stp_timeout(unsigned long dummy) |
501 | { | |
502 | queue_work(time_sync_wq, &stp_work); | |
503 | } | |
504 | ||
d2fec595 MS |
505 | static int __init stp_init(void) |
506 | { | |
750887de HC |
507 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) |
508 | return 0; | |
04362301 | 509 | setup_timer(&stp_timer, stp_timeout, 0UL); |
750887de HC |
510 | time_init_wq(); |
511 | if (!stp_online) | |
512 | return 0; | |
513 | queue_work(time_sync_wq, &stp_work); | |
d2fec595 MS |
514 | return 0; |
515 | } | |
516 | ||
517 | arch_initcall(stp_init); | |
518 | ||
519 | /* | |
520 | * STP timing alert. There are three causes: | |
521 | * 1) timing status change | |
522 | * 2) link availability change | |
523 | * 3) time control parameter change | |
524 | * In all three cases we are only interested in the clock source state. | |
525 | * If a STP clock source is now available use it. | |
526 | */ | |
527 | static void stp_timing_alert(struct stp_irq_parm *intparm) | |
528 | { | |
529 | if (intparm->tsc || intparm->lac || intparm->tcpc) | |
750887de | 530 | queue_work(time_sync_wq, &stp_work); |
d2fec595 MS |
531 | } |
532 | ||
533 | /* | |
534 | * STP sync check machine check. This is called when the timing state | |
535 | * changes from the synchronized state to the unsynchronized state. | |
536 | * After a STP sync check the clock is not in sync. The machine check | |
537 | * is broadcasted to all cpus at the same time. | |
538 | */ | |
29b0a825 | 539 | int stp_sync_check(void) |
d2fec595 | 540 | { |
d2fec595 | 541 | disable_sync_clock(NULL); |
29b0a825 | 542 | return 1; |
d2fec595 MS |
543 | } |
544 | ||
545 | /* | |
546 | * STP island condition machine check. This is called when an attached | |
547 | * server attempts to communicate over an STP link and the servers | |
548 | * have matching CTN ids and have a valid stratum-1 configuration | |
549 | * but the configurations do not match. | |
550 | */ | |
29b0a825 | 551 | int stp_island_check(void) |
d2fec595 | 552 | { |
d2fec595 | 553 | disable_sync_clock(NULL); |
29b0a825 | 554 | return 1; |
d2fec595 MS |
555 | } |
556 | ||
29b0a825 HC |
557 | void stp_queue_work(void) |
558 | { | |
559 | queue_work(time_sync_wq, &stp_work); | |
560 | } | |
750887de HC |
561 | |
562 | static int stp_sync_clock(void *data) | |
d2fec595 | 563 | { |
b1c0854d | 564 | struct clock_sync_data *sync = data; |
41ad0220 | 565 | unsigned long long clock_delta; |
b1c0854d | 566 | static int first; |
d2fec595 MS |
567 | int rc; |
568 | ||
d2fec595 | 569 | enable_sync_clock(); |
b1c0854d MS |
570 | if (xchg(&first, 1) == 0) { |
571 | /* Wait until all other cpus entered the sync function. */ | |
572 | while (atomic_read(&sync->cpus) != 0) | |
573 | cpu_relax(); | |
574 | rc = 0; | |
575 | if (stp_info.todoff[0] || stp_info.todoff[1] || | |
576 | stp_info.todoff[2] || stp_info.todoff[3] || | |
577 | stp_info.tmd != 2) { | |
578 | rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0, | |
579 | &clock_delta); | |
580 | if (rc == 0) { | |
581 | sync->clock_delta = clock_delta; | |
582 | clock_sync_global(clock_delta); | |
583 | rc = chsc_sstpi(stp_page, &stp_info, | |
584 | sizeof(struct stp_sstpi)); | |
585 | if (rc == 0 && stp_info.tmd != 2) | |
586 | rc = -EAGAIN; | |
587 | } | |
d2fec595 | 588 | } |
b1c0854d MS |
589 | sync->in_sync = rc ? -EAGAIN : 1; |
590 | xchg(&first, 0); | |
591 | } else { | |
592 | /* Slave */ | |
593 | atomic_dec(&sync->cpus); | |
594 | /* Wait for in_sync to be set. */ | |
595 | while (READ_ONCE(sync->in_sync) == 0) | |
596 | __udelay(1); | |
d2fec595 | 597 | } |
b1c0854d MS |
598 | if (sync->in_sync != 1) |
599 | /* Didn't work. Clear per-cpu in sync bit again. */ | |
d2fec595 | 600 | disable_sync_clock(NULL); |
b1c0854d MS |
601 | /* Apply clock delta to per-CPU fields of this CPU. */ |
602 | clock_sync_local(sync->clock_delta); | |
603 | ||
750887de HC |
604 | return 0; |
605 | } | |
d2fec595 | 606 | |
750887de HC |
607 | /* |
608 | * STP work. Check for the STP state and take over the clock | |
609 | * synchronization if the STP clock source is usable. | |
610 | */ | |
611 | static void stp_work_fn(struct work_struct *work) | |
612 | { | |
613 | struct clock_sync_data stp_sync; | |
614 | int rc; | |
615 | ||
0b3016b7 MS |
616 | /* prevent multiple execution. */ |
617 | mutex_lock(&stp_work_mutex); | |
618 | ||
750887de | 619 | if (!stp_online) { |
2f82f577 | 620 | chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL); |
04362301 | 621 | del_timer_sync(&stp_timer); |
0b3016b7 | 622 | goto out_unlock; |
750887de HC |
623 | } |
624 | ||
2f82f577 | 625 | rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0, NULL); |
750887de | 626 | if (rc) |
0b3016b7 | 627 | goto out_unlock; |
750887de HC |
628 | |
629 | rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi)); | |
630 | if (rc || stp_info.c == 0) | |
0b3016b7 | 631 | goto out_unlock; |
750887de | 632 | |
8283cb43 MS |
633 | /* Skip synchronization if the clock is already in sync. */ |
634 | if (check_sync_clock()) | |
635 | goto out_unlock; | |
636 | ||
750887de HC |
637 | memset(&stp_sync, 0, sizeof(stp_sync)); |
638 | get_online_cpus(); | |
639 | atomic_set(&stp_sync.cpus, num_online_cpus() - 1); | |
0f1959f5 | 640 | stop_machine(stp_sync_clock, &stp_sync, cpu_online_mask); |
750887de | 641 | put_online_cpus(); |
0b3016b7 | 642 | |
04362301 MS |
643 | if (!check_sync_clock()) |
644 | /* | |
645 | * There is a usable clock but the synchonization failed. | |
646 | * Retry after a second. | |
647 | */ | |
648 | mod_timer(&stp_timer, jiffies + HZ); | |
649 | ||
0b3016b7 MS |
650 | out_unlock: |
651 | mutex_unlock(&stp_work_mutex); | |
d2fec595 MS |
652 | } |
653 | ||
654 | /* | |
3fbacffb | 655 | * STP subsys sysfs interface functions |
d2fec595 | 656 | */ |
3fbacffb KS |
657 | static struct bus_type stp_subsys = { |
658 | .name = "stp", | |
659 | .dev_name = "stp", | |
d2fec595 MS |
660 | }; |
661 | ||
3fbacffb KS |
662 | static ssize_t stp_ctn_id_show(struct device *dev, |
663 | struct device_attribute *attr, | |
c9be0a36 | 664 | char *buf) |
d2fec595 MS |
665 | { |
666 | if (!stp_online) | |
667 | return -ENODATA; | |
668 | return sprintf(buf, "%016llx\n", | |
669 | *(unsigned long long *) stp_info.ctnid); | |
670 | } | |
671 | ||
3fbacffb | 672 | static DEVICE_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL); |
d2fec595 | 673 | |
3fbacffb KS |
674 | static ssize_t stp_ctn_type_show(struct device *dev, |
675 | struct device_attribute *attr, | |
c9be0a36 | 676 | char *buf) |
d2fec595 MS |
677 | { |
678 | if (!stp_online) | |
679 | return -ENODATA; | |
680 | return sprintf(buf, "%i\n", stp_info.ctn); | |
681 | } | |
682 | ||
3fbacffb | 683 | static DEVICE_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL); |
d2fec595 | 684 | |
3fbacffb KS |
685 | static ssize_t stp_dst_offset_show(struct device *dev, |
686 | struct device_attribute *attr, | |
c9be0a36 | 687 | char *buf) |
d2fec595 MS |
688 | { |
689 | if (!stp_online || !(stp_info.vbits & 0x2000)) | |
690 | return -ENODATA; | |
691 | return sprintf(buf, "%i\n", (int)(s16) stp_info.dsto); | |
692 | } | |
693 | ||
3fbacffb | 694 | static DEVICE_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL); |
d2fec595 | 695 | |
3fbacffb KS |
696 | static ssize_t stp_leap_seconds_show(struct device *dev, |
697 | struct device_attribute *attr, | |
c9be0a36 | 698 | char *buf) |
d2fec595 MS |
699 | { |
700 | if (!stp_online || !(stp_info.vbits & 0x8000)) | |
701 | return -ENODATA; | |
702 | return sprintf(buf, "%i\n", (int)(s16) stp_info.leaps); | |
703 | } | |
704 | ||
3fbacffb | 705 | static DEVICE_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL); |
d2fec595 | 706 | |
3fbacffb KS |
707 | static ssize_t stp_stratum_show(struct device *dev, |
708 | struct device_attribute *attr, | |
c9be0a36 | 709 | char *buf) |
d2fec595 MS |
710 | { |
711 | if (!stp_online) | |
712 | return -ENODATA; | |
713 | return sprintf(buf, "%i\n", (int)(s16) stp_info.stratum); | |
714 | } | |
715 | ||
3fbacffb | 716 | static DEVICE_ATTR(stratum, 0400, stp_stratum_show, NULL); |
d2fec595 | 717 | |
3fbacffb KS |
718 | static ssize_t stp_time_offset_show(struct device *dev, |
719 | struct device_attribute *attr, | |
c9be0a36 | 720 | char *buf) |
d2fec595 MS |
721 | { |
722 | if (!stp_online || !(stp_info.vbits & 0x0800)) | |
723 | return -ENODATA; | |
724 | return sprintf(buf, "%i\n", (int) stp_info.tto); | |
725 | } | |
726 | ||
3fbacffb | 727 | static DEVICE_ATTR(time_offset, 0400, stp_time_offset_show, NULL); |
d2fec595 | 728 | |
3fbacffb KS |
729 | static ssize_t stp_time_zone_offset_show(struct device *dev, |
730 | struct device_attribute *attr, | |
c9be0a36 | 731 | char *buf) |
d2fec595 MS |
732 | { |
733 | if (!stp_online || !(stp_info.vbits & 0x4000)) | |
734 | return -ENODATA; | |
735 | return sprintf(buf, "%i\n", (int)(s16) stp_info.tzo); | |
736 | } | |
737 | ||
3fbacffb | 738 | static DEVICE_ATTR(time_zone_offset, 0400, |
d2fec595 MS |
739 | stp_time_zone_offset_show, NULL); |
740 | ||
3fbacffb KS |
741 | static ssize_t stp_timing_mode_show(struct device *dev, |
742 | struct device_attribute *attr, | |
c9be0a36 | 743 | char *buf) |
d2fec595 MS |
744 | { |
745 | if (!stp_online) | |
746 | return -ENODATA; | |
747 | return sprintf(buf, "%i\n", stp_info.tmd); | |
748 | } | |
749 | ||
3fbacffb | 750 | static DEVICE_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL); |
d2fec595 | 751 | |
3fbacffb KS |
752 | static ssize_t stp_timing_state_show(struct device *dev, |
753 | struct device_attribute *attr, | |
c9be0a36 | 754 | char *buf) |
d2fec595 MS |
755 | { |
756 | if (!stp_online) | |
757 | return -ENODATA; | |
758 | return sprintf(buf, "%i\n", stp_info.tst); | |
759 | } | |
760 | ||
3fbacffb | 761 | static DEVICE_ATTR(timing_state, 0400, stp_timing_state_show, NULL); |
d2fec595 | 762 | |
3fbacffb KS |
763 | static ssize_t stp_online_show(struct device *dev, |
764 | struct device_attribute *attr, | |
c9be0a36 | 765 | char *buf) |
d2fec595 MS |
766 | { |
767 | return sprintf(buf, "%i\n", stp_online); | |
768 | } | |
769 | ||
3fbacffb KS |
770 | static ssize_t stp_online_store(struct device *dev, |
771 | struct device_attribute *attr, | |
d2fec595 MS |
772 | const char *buf, size_t count) |
773 | { | |
774 | unsigned int value; | |
775 | ||
776 | value = simple_strtoul(buf, NULL, 0); | |
777 | if (value != 0 && value != 1) | |
778 | return -EINVAL; | |
779 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) | |
780 | return -EOPNOTSUPP; | |
8283cb43 | 781 | mutex_lock(&clock_sync_mutex); |
d2fec595 | 782 | stp_online = value; |
8283cb43 MS |
783 | if (stp_online) |
784 | set_bit(CLOCK_SYNC_STP, &clock_sync_flags); | |
785 | else | |
786 | clear_bit(CLOCK_SYNC_STP, &clock_sync_flags); | |
750887de | 787 | queue_work(time_sync_wq, &stp_work); |
8283cb43 | 788 | mutex_unlock(&clock_sync_mutex); |
d2fec595 MS |
789 | return count; |
790 | } | |
791 | ||
792 | /* | |
3fbacffb KS |
793 | * Can't use DEVICE_ATTR because the attribute should be named |
794 | * stp/online but dev_attr_online already exists in this file .. | |
d2fec595 | 795 | */ |
3fbacffb | 796 | static struct device_attribute dev_attr_stp_online = { |
d2fec595 MS |
797 | .attr = { .name = "online", .mode = 0600 }, |
798 | .show = stp_online_show, | |
799 | .store = stp_online_store, | |
800 | }; | |
801 | ||
3fbacffb KS |
802 | static struct device_attribute *stp_attributes[] = { |
803 | &dev_attr_ctn_id, | |
804 | &dev_attr_ctn_type, | |
805 | &dev_attr_dst_offset, | |
806 | &dev_attr_leap_seconds, | |
807 | &dev_attr_stp_online, | |
808 | &dev_attr_stratum, | |
809 | &dev_attr_time_offset, | |
810 | &dev_attr_time_zone_offset, | |
811 | &dev_attr_timing_mode, | |
812 | &dev_attr_timing_state, | |
d2fec595 MS |
813 | NULL |
814 | }; | |
815 | ||
816 | static int __init stp_init_sysfs(void) | |
817 | { | |
3fbacffb | 818 | struct device_attribute **attr; |
d2fec595 MS |
819 | int rc; |
820 | ||
3fbacffb | 821 | rc = subsys_system_register(&stp_subsys, NULL); |
d2fec595 MS |
822 | if (rc) |
823 | goto out; | |
824 | for (attr = stp_attributes; *attr; attr++) { | |
3fbacffb | 825 | rc = device_create_file(stp_subsys.dev_root, *attr); |
d2fec595 MS |
826 | if (rc) |
827 | goto out_unreg; | |
828 | } | |
829 | return 0; | |
830 | out_unreg: | |
831 | for (; attr >= stp_attributes; attr--) | |
3fbacffb KS |
832 | device_remove_file(stp_subsys.dev_root, *attr); |
833 | bus_unregister(&stp_subsys); | |
d2fec595 MS |
834 | out: |
835 | return rc; | |
836 | } | |
837 | ||
838 | device_initcall(stp_init_sysfs); |