Commit | Line | Data |
---|---|---|
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> |
7c0f6ba6 | 41 | #include <linux/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 | 65 | static unsigned long long tod_steering_end; |
191ce9d1 | 66 | static 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 | */ | |
191ce9d1 | 226 | now += (tod_steering_delta < 0) ? (adj >> 15) : -(adj >> 15); |
75c7b6f3 MS |
227 | preempt_enable(); |
228 | return now; | |
dc64bef5 MS |
229 | } |
230 | ||
231 | static struct clocksource clocksource_tod = { | |
232 | .name = "tod", | |
d2cb0e6e | 233 | .rating = 400, |
dc64bef5 MS |
234 | .read = read_tod_clock, |
235 | .mask = -1ULL, | |
236 | .mult = 1000, | |
237 | .shift = 12, | |
cc02d809 | 238 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
dc64bef5 MS |
239 | }; |
240 | ||
f1b82746 MS |
241 | struct clocksource * __init clocksource_default_clock(void) |
242 | { | |
243 | return &clocksource_tod; | |
244 | } | |
dc64bef5 | 245 | |
79c74ecb | 246 | void update_vsyscall(struct timekeeper *tk) |
b020632e | 247 | { |
79c74ecb MS |
248 | u64 nsecps; |
249 | ||
876e7881 | 250 | if (tk->tkr_mono.clock != &clocksource_tod) |
b020632e MS |
251 | return; |
252 | ||
253 | /* Make userspace gettimeofday spin until we're done. */ | |
254 | ++vdso_data->tb_update_count; | |
255 | smp_wmb(); | |
876e7881 | 256 | vdso_data->xtime_tod_stamp = tk->tkr_mono.cycle_last; |
79c74ecb | 257 | vdso_data->xtime_clock_sec = tk->xtime_sec; |
876e7881 | 258 | vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec; |
79c74ecb MS |
259 | vdso_data->wtom_clock_sec = |
260 | tk->xtime_sec + tk->wall_to_monotonic.tv_sec; | |
876e7881 PZ |
261 | vdso_data->wtom_clock_nsec = tk->tkr_mono.xtime_nsec + |
262 | + ((u64) tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift); | |
263 | nsecps = (u64) NSEC_PER_SEC << tk->tkr_mono.shift; | |
79c74ecb MS |
264 | while (vdso_data->wtom_clock_nsec >= nsecps) { |
265 | vdso_data->wtom_clock_nsec -= nsecps; | |
266 | vdso_data->wtom_clock_sec++; | |
267 | } | |
b7eacb59 MS |
268 | |
269 | vdso_data->xtime_coarse_sec = tk->xtime_sec; | |
270 | vdso_data->xtime_coarse_nsec = | |
876e7881 | 271 | (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
b7eacb59 MS |
272 | vdso_data->wtom_coarse_sec = |
273 | vdso_data->xtime_coarse_sec + tk->wall_to_monotonic.tv_sec; | |
274 | vdso_data->wtom_coarse_nsec = | |
275 | vdso_data->xtime_coarse_nsec + tk->wall_to_monotonic.tv_nsec; | |
276 | while (vdso_data->wtom_coarse_nsec >= NSEC_PER_SEC) { | |
277 | vdso_data->wtom_coarse_nsec -= NSEC_PER_SEC; | |
278 | vdso_data->wtom_coarse_sec++; | |
279 | } | |
280 | ||
876e7881 PZ |
281 | vdso_data->tk_mult = tk->tkr_mono.mult; |
282 | vdso_data->tk_shift = tk->tkr_mono.shift; | |
b020632e MS |
283 | smp_wmb(); |
284 | ++vdso_data->tb_update_count; | |
285 | } | |
286 | ||
287 | extern struct timezone sys_tz; | |
288 | ||
289 | void update_vsyscall_tz(void) | |
290 | { | |
b020632e MS |
291 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; |
292 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
b020632e MS |
293 | } |
294 | ||
1da177e4 LT |
295 | /* |
296 | * Initialize the TOD clock and the CPU timer of | |
297 | * the boot cpu. | |
298 | */ | |
299 | void __init time_init(void) | |
300 | { | |
b6112ccb | 301 | /* Reset time synchronization interfaces. */ |
b6112ccb | 302 | stp_reset(); |
1da177e4 | 303 | |
1da177e4 | 304 | /* request the clock comparator external interrupt */ |
1dad093b TH |
305 | if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt)) |
306 | panic("Couldn't request external interrupt 0x1004"); | |
1da177e4 | 307 | |
d2fec595 | 308 | /* request the timing alert external interrupt */ |
1dad093b | 309 | if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt)) |
d54853ef MS |
310 | panic("Couldn't request external interrupt 0x1406"); |
311 | ||
f8935983 | 312 | if (__clocksource_register(&clocksource_tod) != 0) |
ab96e798 MS |
313 | panic("Could not register TOD clock source"); |
314 | ||
d54853ef MS |
315 | /* Enable TOD clock interrupts on the boot cpu. */ |
316 | init_cpu_timer(); | |
ab96e798 | 317 | |
c185b783 | 318 | /* Enable cpu timer interrupts on the boot cpu. */ |
1da177e4 | 319 | vtime_init(); |
d54853ef MS |
320 | } |
321 | ||
d2fec595 | 322 | static DEFINE_PER_CPU(atomic_t, clock_sync_word); |
8283cb43 | 323 | static DEFINE_MUTEX(clock_sync_mutex); |
d2fec595 MS |
324 | static unsigned long clock_sync_flags; |
325 | ||
ca64f639 DH |
326 | #define CLOCK_SYNC_HAS_STP 0 |
327 | #define CLOCK_SYNC_STP 1 | |
d2fec595 MS |
328 | |
329 | /* | |
40277891 MS |
330 | * The get_clock function for the physical clock. It will get the current |
331 | * TOD clock, subtract the LPAR offset and write the result to *clock. | |
332 | * The function returns 0 if the clock is in sync with the external time | |
333 | * source. If the clock mode is local it will return -EOPNOTSUPP and | |
334 | * -EAGAIN if the clock is not in sync with the external reference. | |
d2fec595 | 335 | */ |
40277891 | 336 | int get_phys_clock(unsigned long long *clock) |
d2fec595 MS |
337 | { |
338 | atomic_t *sw_ptr; | |
339 | unsigned int sw0, sw1; | |
340 | ||
341 | sw_ptr = &get_cpu_var(clock_sync_word); | |
342 | sw0 = atomic_read(sw_ptr); | |
40277891 | 343 | *clock = get_tod_clock() - lpar_offset; |
d2fec595 | 344 | sw1 = atomic_read(sw_ptr); |
bd119ee2 | 345 | put_cpu_var(clock_sync_word); |
d2fec595 MS |
346 | if (sw0 == sw1 && (sw0 & 0x80000000U)) |
347 | /* Success: time is in sync. */ | |
348 | return 0; | |
ca64f639 | 349 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) |
a8f6db4d | 350 | return -EOPNOTSUPP; |
ca64f639 | 351 | if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags)) |
d2fec595 MS |
352 | return -EACCES; |
353 | return -EAGAIN; | |
354 | } | |
40277891 | 355 | EXPORT_SYMBOL(get_phys_clock); |
d2fec595 MS |
356 | |
357 | /* | |
ca64f639 | 358 | * Make get_phys_clock() return -EAGAIN. |
d2fec595 MS |
359 | */ |
360 | static void disable_sync_clock(void *dummy) | |
361 | { | |
eb7e7d76 | 362 | atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); |
d2fec595 | 363 | /* |
ca64f639 | 364 | * Clear the in-sync bit 2^31. All get_phys_clock calls will |
d2fec595 MS |
365 | * fail until the sync bit is turned back on. In addition |
366 | * increase the "sequence" counter to avoid the race of an | |
ca64f639 | 367 | * stp event and the complete recovery against get_phys_clock. |
d2fec595 | 368 | */ |
805de8f4 | 369 | atomic_andnot(0x80000000, sw_ptr); |
d2fec595 MS |
370 | atomic_inc(sw_ptr); |
371 | } | |
372 | ||
373 | /* | |
ca64f639 | 374 | * Make get_phys_clock() return 0 again. |
d2fec595 MS |
375 | * Needs to be called from a context disabled for preemption. |
376 | */ | |
377 | static void enable_sync_clock(void) | |
378 | { | |
eb7e7d76 | 379 | atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); |
805de8f4 | 380 | atomic_or(0x80000000, sw_ptr); |
d2fec595 MS |
381 | } |
382 | ||
8283cb43 MS |
383 | /* |
384 | * Function to check if the clock is in sync. | |
385 | */ | |
386 | static inline int check_sync_clock(void) | |
387 | { | |
388 | atomic_t *sw_ptr; | |
389 | int rc; | |
390 | ||
391 | sw_ptr = &get_cpu_var(clock_sync_word); | |
392 | rc = (atomic_read(sw_ptr) & 0x80000000U) != 0; | |
bd119ee2 | 393 | put_cpu_var(clock_sync_word); |
8283cb43 MS |
394 | return rc; |
395 | } | |
396 | ||
b1c0854d MS |
397 | /* |
398 | * Apply clock delta to the global data structures. | |
399 | * This is called once on the CPU that performed the clock sync. | |
400 | */ | |
401 | static void clock_sync_global(unsigned long long delta) | |
402 | { | |
75c7b6f3 | 403 | unsigned long now, adj; |
b1c0854d MS |
404 | struct ptff_qto qto; |
405 | ||
406 | /* Fixup the monotonic sched clock. */ | |
407 | sched_clock_base_cc += delta; | |
75c7b6f3 MS |
408 | /* Adjust TOD steering parameters. */ |
409 | vdso_data->tb_update_count++; | |
410 | now = get_tod_clock(); | |
411 | adj = tod_steering_end - now; | |
412 | if (unlikely((s64) adj >= 0)) | |
413 | /* Calculate how much of the old adjustment is left. */ | |
191ce9d1 | 414 | tod_steering_delta = (tod_steering_delta < 0) ? |
75c7b6f3 MS |
415 | -(adj >> 15) : (adj >> 15); |
416 | tod_steering_delta += delta; | |
417 | if ((abs(tod_steering_delta) >> 48) != 0) | |
418 | panic("TOD clock sync offset %lli is too large to drift\n", | |
419 | tod_steering_delta); | |
420 | tod_steering_end = now + (abs(tod_steering_delta) << 15); | |
421 | vdso_data->ts_dir = (tod_steering_delta < 0) ? 0 : 1; | |
422 | vdso_data->ts_end = tod_steering_end; | |
423 | vdso_data->tb_update_count++; | |
b1c0854d MS |
424 | /* Update LPAR offset. */ |
425 | if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) | |
426 | lpar_offset = qto.tod_epoch_difference; | |
427 | /* Call the TOD clock change notifier. */ | |
428 | atomic_notifier_call_chain(&s390_epoch_delta_notifier, 0, &delta); | |
429 | } | |
430 | ||
431 | /* | |
432 | * Apply clock delta to the per-CPU data structures of this CPU. | |
433 | * This is called for each online CPU after the call to clock_sync_global. | |
434 | */ | |
435 | static void clock_sync_local(unsigned long long delta) | |
436 | { | |
437 | /* Add the delta to the clock comparator. */ | |
438 | if (S390_lowcore.clock_comparator != -1ULL) { | |
439 | S390_lowcore.clock_comparator += delta; | |
440 | set_clock_comparator(S390_lowcore.clock_comparator); | |
441 | } | |
2ace06ec MS |
442 | /* Adjust the last_update_clock time-stamp. */ |
443 | S390_lowcore.last_update_clock += delta; | |
b1c0854d MS |
444 | } |
445 | ||
ca64f639 | 446 | /* Single threaded workqueue used for stp sync events */ |
750887de HC |
447 | static struct workqueue_struct *time_sync_wq; |
448 | ||
449 | static void __init time_init_wq(void) | |
450 | { | |
179cb81a HC |
451 | if (time_sync_wq) |
452 | return; | |
453 | time_sync_wq = create_singlethread_workqueue("timesync"); | |
750887de HC |
454 | } |
455 | ||
d2fec595 | 456 | struct clock_sync_data { |
750887de | 457 | atomic_t cpus; |
5a62b192 | 458 | int in_sync; |
b1c0854d | 459 | unsigned long long clock_delta; |
d2fec595 | 460 | }; |
5a62b192 | 461 | |
d2fec595 MS |
462 | /* |
463 | * Server Time Protocol (STP) code. | |
464 | */ | |
4cc7ecb7 | 465 | static bool stp_online; |
d2fec595 MS |
466 | static struct stp_sstpi stp_info; |
467 | static void *stp_page; | |
468 | ||
469 | static void stp_work_fn(struct work_struct *work); | |
0b3016b7 | 470 | static DEFINE_MUTEX(stp_work_mutex); |
d2fec595 | 471 | static DECLARE_WORK(stp_work, stp_work_fn); |
04362301 | 472 | static struct timer_list stp_timer; |
d2fec595 MS |
473 | |
474 | static int __init early_parse_stp(char *p) | |
475 | { | |
4cc7ecb7 | 476 | return kstrtobool(p, &stp_online); |
d2fec595 MS |
477 | } |
478 | early_param("stp", early_parse_stp); | |
479 | ||
480 | /* | |
481 | * Reset STP attachment. | |
482 | */ | |
8f847003 | 483 | static void __init stp_reset(void) |
d2fec595 MS |
484 | { |
485 | int rc; | |
486 | ||
d7d1104f | 487 | stp_page = (void *) get_zeroed_page(GFP_ATOMIC); |
2f82f577 | 488 | rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL); |
4a672cfa | 489 | if (rc == 0) |
d2fec595 MS |
490 | set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags); |
491 | else if (stp_online) { | |
baebc70a | 492 | pr_warn("The real or virtual hardware system does not provide an STP interface\n"); |
d7d1104f | 493 | free_page((unsigned long) stp_page); |
d2fec595 MS |
494 | stp_page = NULL; |
495 | stp_online = 0; | |
496 | } | |
497 | } | |
498 | ||
04362301 MS |
499 | static void stp_timeout(unsigned long dummy) |
500 | { | |
501 | queue_work(time_sync_wq, &stp_work); | |
502 | } | |
503 | ||
d2fec595 MS |
504 | static int __init stp_init(void) |
505 | { | |
750887de HC |
506 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) |
507 | return 0; | |
04362301 | 508 | setup_timer(&stp_timer, stp_timeout, 0UL); |
750887de HC |
509 | time_init_wq(); |
510 | if (!stp_online) | |
511 | return 0; | |
512 | queue_work(time_sync_wq, &stp_work); | |
d2fec595 MS |
513 | return 0; |
514 | } | |
515 | ||
516 | arch_initcall(stp_init); | |
517 | ||
518 | /* | |
519 | * STP timing alert. There are three causes: | |
520 | * 1) timing status change | |
521 | * 2) link availability change | |
522 | * 3) time control parameter change | |
523 | * In all three cases we are only interested in the clock source state. | |
524 | * If a STP clock source is now available use it. | |
525 | */ | |
526 | static void stp_timing_alert(struct stp_irq_parm *intparm) | |
527 | { | |
528 | if (intparm->tsc || intparm->lac || intparm->tcpc) | |
750887de | 529 | queue_work(time_sync_wq, &stp_work); |
d2fec595 MS |
530 | } |
531 | ||
532 | /* | |
533 | * STP sync check machine check. This is called when the timing state | |
534 | * changes from the synchronized state to the unsynchronized state. | |
535 | * After a STP sync check the clock is not in sync. The machine check | |
536 | * is broadcasted to all cpus at the same time. | |
537 | */ | |
29b0a825 | 538 | int stp_sync_check(void) |
d2fec595 | 539 | { |
d2fec595 | 540 | disable_sync_clock(NULL); |
29b0a825 | 541 | return 1; |
d2fec595 MS |
542 | } |
543 | ||
544 | /* | |
545 | * STP island condition machine check. This is called when an attached | |
546 | * server attempts to communicate over an STP link and the servers | |
547 | * have matching CTN ids and have a valid stratum-1 configuration | |
548 | * but the configurations do not match. | |
549 | */ | |
29b0a825 | 550 | int stp_island_check(void) |
d2fec595 | 551 | { |
d2fec595 | 552 | disable_sync_clock(NULL); |
29b0a825 | 553 | return 1; |
d2fec595 MS |
554 | } |
555 | ||
29b0a825 HC |
556 | void stp_queue_work(void) |
557 | { | |
558 | queue_work(time_sync_wq, &stp_work); | |
559 | } | |
750887de HC |
560 | |
561 | static int stp_sync_clock(void *data) | |
d2fec595 | 562 | { |
b1c0854d | 563 | struct clock_sync_data *sync = data; |
41ad0220 | 564 | unsigned long long clock_delta; |
b1c0854d | 565 | static int first; |
d2fec595 MS |
566 | int rc; |
567 | ||
d2fec595 | 568 | enable_sync_clock(); |
b1c0854d MS |
569 | if (xchg(&first, 1) == 0) { |
570 | /* Wait until all other cpus entered the sync function. */ | |
571 | while (atomic_read(&sync->cpus) != 0) | |
572 | cpu_relax(); | |
573 | rc = 0; | |
574 | if (stp_info.todoff[0] || stp_info.todoff[1] || | |
575 | stp_info.todoff[2] || stp_info.todoff[3] || | |
576 | stp_info.tmd != 2) { | |
577 | rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0, | |
578 | &clock_delta); | |
579 | if (rc == 0) { | |
580 | sync->clock_delta = clock_delta; | |
581 | clock_sync_global(clock_delta); | |
582 | rc = chsc_sstpi(stp_page, &stp_info, | |
583 | sizeof(struct stp_sstpi)); | |
584 | if (rc == 0 && stp_info.tmd != 2) | |
585 | rc = -EAGAIN; | |
586 | } | |
d2fec595 | 587 | } |
b1c0854d MS |
588 | sync->in_sync = rc ? -EAGAIN : 1; |
589 | xchg(&first, 0); | |
590 | } else { | |
591 | /* Slave */ | |
592 | atomic_dec(&sync->cpus); | |
593 | /* Wait for in_sync to be set. */ | |
594 | while (READ_ONCE(sync->in_sync) == 0) | |
595 | __udelay(1); | |
d2fec595 | 596 | } |
b1c0854d MS |
597 | if (sync->in_sync != 1) |
598 | /* Didn't work. Clear per-cpu in sync bit again. */ | |
d2fec595 | 599 | disable_sync_clock(NULL); |
b1c0854d MS |
600 | /* Apply clock delta to per-CPU fields of this CPU. */ |
601 | clock_sync_local(sync->clock_delta); | |
602 | ||
750887de HC |
603 | return 0; |
604 | } | |
d2fec595 | 605 | |
750887de HC |
606 | /* |
607 | * STP work. Check for the STP state and take over the clock | |
608 | * synchronization if the STP clock source is usable. | |
609 | */ | |
610 | static void stp_work_fn(struct work_struct *work) | |
611 | { | |
612 | struct clock_sync_data stp_sync; | |
613 | int rc; | |
614 | ||
0b3016b7 MS |
615 | /* prevent multiple execution. */ |
616 | mutex_lock(&stp_work_mutex); | |
617 | ||
750887de | 618 | if (!stp_online) { |
2f82f577 | 619 | chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL); |
04362301 | 620 | del_timer_sync(&stp_timer); |
0b3016b7 | 621 | goto out_unlock; |
750887de HC |
622 | } |
623 | ||
2f82f577 | 624 | rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0, NULL); |
750887de | 625 | if (rc) |
0b3016b7 | 626 | goto out_unlock; |
750887de HC |
627 | |
628 | rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi)); | |
629 | if (rc || stp_info.c == 0) | |
0b3016b7 | 630 | goto out_unlock; |
750887de | 631 | |
8283cb43 MS |
632 | /* Skip synchronization if the clock is already in sync. */ |
633 | if (check_sync_clock()) | |
634 | goto out_unlock; | |
635 | ||
750887de HC |
636 | memset(&stp_sync, 0, sizeof(stp_sync)); |
637 | get_online_cpus(); | |
638 | atomic_set(&stp_sync.cpus, num_online_cpus() - 1); | |
0f1959f5 | 639 | stop_machine(stp_sync_clock, &stp_sync, cpu_online_mask); |
750887de | 640 | put_online_cpus(); |
0b3016b7 | 641 | |
04362301 MS |
642 | if (!check_sync_clock()) |
643 | /* | |
644 | * There is a usable clock but the synchonization failed. | |
645 | * Retry after a second. | |
646 | */ | |
647 | mod_timer(&stp_timer, jiffies + HZ); | |
648 | ||
0b3016b7 MS |
649 | out_unlock: |
650 | mutex_unlock(&stp_work_mutex); | |
d2fec595 MS |
651 | } |
652 | ||
653 | /* | |
3fbacffb | 654 | * STP subsys sysfs interface functions |
d2fec595 | 655 | */ |
3fbacffb KS |
656 | static struct bus_type stp_subsys = { |
657 | .name = "stp", | |
658 | .dev_name = "stp", | |
d2fec595 MS |
659 | }; |
660 | ||
3fbacffb KS |
661 | static ssize_t stp_ctn_id_show(struct device *dev, |
662 | struct device_attribute *attr, | |
c9be0a36 | 663 | char *buf) |
d2fec595 MS |
664 | { |
665 | if (!stp_online) | |
666 | return -ENODATA; | |
667 | return sprintf(buf, "%016llx\n", | |
668 | *(unsigned long long *) stp_info.ctnid); | |
669 | } | |
670 | ||
3fbacffb | 671 | static DEVICE_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL); |
d2fec595 | 672 | |
3fbacffb KS |
673 | static ssize_t stp_ctn_type_show(struct device *dev, |
674 | struct device_attribute *attr, | |
c9be0a36 | 675 | char *buf) |
d2fec595 MS |
676 | { |
677 | if (!stp_online) | |
678 | return -ENODATA; | |
679 | return sprintf(buf, "%i\n", stp_info.ctn); | |
680 | } | |
681 | ||
3fbacffb | 682 | static DEVICE_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL); |
d2fec595 | 683 | |
3fbacffb KS |
684 | static ssize_t stp_dst_offset_show(struct device *dev, |
685 | struct device_attribute *attr, | |
c9be0a36 | 686 | char *buf) |
d2fec595 MS |
687 | { |
688 | if (!stp_online || !(stp_info.vbits & 0x2000)) | |
689 | return -ENODATA; | |
690 | return sprintf(buf, "%i\n", (int)(s16) stp_info.dsto); | |
691 | } | |
692 | ||
3fbacffb | 693 | static DEVICE_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL); |
d2fec595 | 694 | |
3fbacffb KS |
695 | static ssize_t stp_leap_seconds_show(struct device *dev, |
696 | struct device_attribute *attr, | |
c9be0a36 | 697 | char *buf) |
d2fec595 MS |
698 | { |
699 | if (!stp_online || !(stp_info.vbits & 0x8000)) | |
700 | return -ENODATA; | |
701 | return sprintf(buf, "%i\n", (int)(s16) stp_info.leaps); | |
702 | } | |
703 | ||
3fbacffb | 704 | static DEVICE_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL); |
d2fec595 | 705 | |
3fbacffb KS |
706 | static ssize_t stp_stratum_show(struct device *dev, |
707 | struct device_attribute *attr, | |
c9be0a36 | 708 | char *buf) |
d2fec595 MS |
709 | { |
710 | if (!stp_online) | |
711 | return -ENODATA; | |
712 | return sprintf(buf, "%i\n", (int)(s16) stp_info.stratum); | |
713 | } | |
714 | ||
3fbacffb | 715 | static DEVICE_ATTR(stratum, 0400, stp_stratum_show, NULL); |
d2fec595 | 716 | |
3fbacffb KS |
717 | static ssize_t stp_time_offset_show(struct device *dev, |
718 | struct device_attribute *attr, | |
c9be0a36 | 719 | char *buf) |
d2fec595 MS |
720 | { |
721 | if (!stp_online || !(stp_info.vbits & 0x0800)) | |
722 | return -ENODATA; | |
723 | return sprintf(buf, "%i\n", (int) stp_info.tto); | |
724 | } | |
725 | ||
3fbacffb | 726 | static DEVICE_ATTR(time_offset, 0400, stp_time_offset_show, NULL); |
d2fec595 | 727 | |
3fbacffb KS |
728 | static ssize_t stp_time_zone_offset_show(struct device *dev, |
729 | struct device_attribute *attr, | |
c9be0a36 | 730 | char *buf) |
d2fec595 MS |
731 | { |
732 | if (!stp_online || !(stp_info.vbits & 0x4000)) | |
733 | return -ENODATA; | |
734 | return sprintf(buf, "%i\n", (int)(s16) stp_info.tzo); | |
735 | } | |
736 | ||
3fbacffb | 737 | static DEVICE_ATTR(time_zone_offset, 0400, |
d2fec595 MS |
738 | stp_time_zone_offset_show, NULL); |
739 | ||
3fbacffb KS |
740 | static ssize_t stp_timing_mode_show(struct device *dev, |
741 | struct device_attribute *attr, | |
c9be0a36 | 742 | char *buf) |
d2fec595 MS |
743 | { |
744 | if (!stp_online) | |
745 | return -ENODATA; | |
746 | return sprintf(buf, "%i\n", stp_info.tmd); | |
747 | } | |
748 | ||
3fbacffb | 749 | static DEVICE_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL); |
d2fec595 | 750 | |
3fbacffb KS |
751 | static ssize_t stp_timing_state_show(struct device *dev, |
752 | struct device_attribute *attr, | |
c9be0a36 | 753 | char *buf) |
d2fec595 MS |
754 | { |
755 | if (!stp_online) | |
756 | return -ENODATA; | |
757 | return sprintf(buf, "%i\n", stp_info.tst); | |
758 | } | |
759 | ||
3fbacffb | 760 | static DEVICE_ATTR(timing_state, 0400, stp_timing_state_show, NULL); |
d2fec595 | 761 | |
3fbacffb KS |
762 | static ssize_t stp_online_show(struct device *dev, |
763 | struct device_attribute *attr, | |
c9be0a36 | 764 | char *buf) |
d2fec595 MS |
765 | { |
766 | return sprintf(buf, "%i\n", stp_online); | |
767 | } | |
768 | ||
3fbacffb KS |
769 | static ssize_t stp_online_store(struct device *dev, |
770 | struct device_attribute *attr, | |
d2fec595 MS |
771 | const char *buf, size_t count) |
772 | { | |
773 | unsigned int value; | |
774 | ||
775 | value = simple_strtoul(buf, NULL, 0); | |
776 | if (value != 0 && value != 1) | |
777 | return -EINVAL; | |
778 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) | |
779 | return -EOPNOTSUPP; | |
8283cb43 | 780 | mutex_lock(&clock_sync_mutex); |
d2fec595 | 781 | stp_online = value; |
8283cb43 MS |
782 | if (stp_online) |
783 | set_bit(CLOCK_SYNC_STP, &clock_sync_flags); | |
784 | else | |
785 | clear_bit(CLOCK_SYNC_STP, &clock_sync_flags); | |
750887de | 786 | queue_work(time_sync_wq, &stp_work); |
8283cb43 | 787 | mutex_unlock(&clock_sync_mutex); |
d2fec595 MS |
788 | return count; |
789 | } | |
790 | ||
791 | /* | |
3fbacffb KS |
792 | * Can't use DEVICE_ATTR because the attribute should be named |
793 | * stp/online but dev_attr_online already exists in this file .. | |
d2fec595 | 794 | */ |
3fbacffb | 795 | static struct device_attribute dev_attr_stp_online = { |
d2fec595 MS |
796 | .attr = { .name = "online", .mode = 0600 }, |
797 | .show = stp_online_show, | |
798 | .store = stp_online_store, | |
799 | }; | |
800 | ||
3fbacffb KS |
801 | static struct device_attribute *stp_attributes[] = { |
802 | &dev_attr_ctn_id, | |
803 | &dev_attr_ctn_type, | |
804 | &dev_attr_dst_offset, | |
805 | &dev_attr_leap_seconds, | |
806 | &dev_attr_stp_online, | |
807 | &dev_attr_stratum, | |
808 | &dev_attr_time_offset, | |
809 | &dev_attr_time_zone_offset, | |
810 | &dev_attr_timing_mode, | |
811 | &dev_attr_timing_state, | |
d2fec595 MS |
812 | NULL |
813 | }; | |
814 | ||
815 | static int __init stp_init_sysfs(void) | |
816 | { | |
3fbacffb | 817 | struct device_attribute **attr; |
d2fec595 MS |
818 | int rc; |
819 | ||
3fbacffb | 820 | rc = subsys_system_register(&stp_subsys, NULL); |
d2fec595 MS |
821 | if (rc) |
822 | goto out; | |
823 | for (attr = stp_attributes; *attr; attr++) { | |
3fbacffb | 824 | rc = device_create_file(stp_subsys.dev_root, *attr); |
d2fec595 MS |
825 | if (rc) |
826 | goto out_unreg; | |
827 | } | |
828 | return 0; | |
829 | out_unreg: | |
830 | for (; attr >= stp_attributes; attr--) | |
3fbacffb KS |
831 | device_remove_file(stp_subsys.dev_root, *attr); |
832 | bus_unregister(&stp_subsys); | |
d2fec595 MS |
833 | out: |
834 | return rc; | |
835 | } | |
836 | ||
837 | device_initcall(stp_init_sysfs); |