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Commit | Line | Data |
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a17ae4c3 | 1 | // SPDX-License-Identifier: GPL-2.0 |
1da177e4 | 2 | /* |
1da177e4 LT |
3 | * Time of day based timer functions. |
4 | * | |
5 | * S390 version | |
d2fec595 | 6 | * Copyright IBM Corp. 1999, 2008 |
1da177e4 LT |
7 | * Author(s): Hartmut Penner (hp@de.ibm.com), |
8 | * Martin Schwidefsky (schwidefsky@de.ibm.com), | |
9 | * Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com) | |
10 | * | |
11 | * Derived from "arch/i386/kernel/time.c" | |
12 | * Copyright (C) 1991, 1992, 1995 Linus Torvalds | |
13 | */ | |
14 | ||
feab6501 MS |
15 | #define KMSG_COMPONENT "time" |
16 | #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt | |
17 | ||
052ff461 | 18 | #include <linux/kernel_stat.h> |
1da177e4 | 19 | #include <linux/errno.h> |
3994a52b | 20 | #include <linux/export.h> |
1da177e4 | 21 | #include <linux/sched.h> |
e6017571 | 22 | #include <linux/sched/clock.h> |
1da177e4 LT |
23 | #include <linux/kernel.h> |
24 | #include <linux/param.h> | |
25 | #include <linux/string.h> | |
26 | #include <linux/mm.h> | |
27 | #include <linux/interrupt.h> | |
750887de HC |
28 | #include <linux/cpu.h> |
29 | #include <linux/stop_machine.h> | |
1da177e4 | 30 | #include <linux/time.h> |
3fbacffb | 31 | #include <linux/device.h> |
1da177e4 LT |
32 | #include <linux/delay.h> |
33 | #include <linux/init.h> | |
34 | #include <linux/smp.h> | |
35 | #include <linux/types.h> | |
36 | #include <linux/profile.h> | |
37 | #include <linux/timex.h> | |
38 | #include <linux/notifier.h> | |
189374ae | 39 | #include <linux/timekeeper_internal.h> |
5a62b192 | 40 | #include <linux/clockchips.h> |
5a0e3ad6 | 41 | #include <linux/gfp.h> |
860dba45 | 42 | #include <linux/kprobes.h> |
7c0f6ba6 | 43 | #include <linux/uaccess.h> |
4bff8cb5 SS |
44 | #include <vdso/vsyscall.h> |
45 | #include <vdso/clocksource.h> | |
46 | #include <vdso/helpers.h> | |
40277891 | 47 | #include <asm/facility.h> |
1da177e4 | 48 | #include <asm/delay.h> |
1da177e4 | 49 | #include <asm/div64.h> |
b020632e | 50 | #include <asm/vdso.h> |
1da177e4 | 51 | #include <asm/irq.h> |
5a489b98 | 52 | #include <asm/irq_regs.h> |
27f6b416 | 53 | #include <asm/vtimer.h> |
fd5ada04 | 54 | #include <asm/stp.h> |
a806170e | 55 | #include <asm/cio.h> |
638ad34a | 56 | #include "entry.h" |
1da177e4 | 57 | |
6e2ef5e4 MS |
58 | unsigned char tod_clock_base[16] __aligned(8) = { |
59 | /* Force to data section. */ | |
60 | 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, | |
61 | 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff | |
62 | }; | |
63 | EXPORT_SYMBOL_GPL(tod_clock_base); | |
64 | ||
65 | u64 clock_comparator_max = -1ULL; | |
66 | EXPORT_SYMBOL_GPL(clock_comparator_max); | |
b6112ccb | 67 | |
5a62b192 | 68 | static DEFINE_PER_CPU(struct clock_event_device, comparators); |
1da177e4 | 69 | |
fdf03650 FZ |
70 | ATOMIC_NOTIFIER_HEAD(s390_epoch_delta_notifier); |
71 | EXPORT_SYMBOL(s390_epoch_delta_notifier); | |
72 | ||
40277891 | 73 | unsigned char ptff_function_mask[16]; |
b1c0854d MS |
74 | |
75 | static unsigned long long lpar_offset; | |
76 | static unsigned long long initial_leap_seconds; | |
75c7b6f3 | 77 | static unsigned long long tod_steering_end; |
191ce9d1 | 78 | static long long tod_steering_delta; |
40277891 MS |
79 | |
80 | /* | |
81 | * Get time offsets with PTFF | |
82 | */ | |
b1c0854d | 83 | void __init time_early_init(void) |
40277891 MS |
84 | { |
85 | struct ptff_qto qto; | |
936cc855 | 86 | struct ptff_qui qui; |
40277891 | 87 | |
75c7b6f3 | 88 | /* Initialize TOD steering parameters */ |
6e2ef5e4 | 89 | tod_steering_end = *(unsigned long long *) &tod_clock_base[1]; |
4bff8cb5 | 90 | vdso_data->arch_data.tod_steering_end = tod_steering_end; |
75c7b6f3 | 91 | |
40277891 MS |
92 | if (!test_facility(28)) |
93 | return; | |
75c7b6f3 | 94 | |
40277891 MS |
95 | ptff(&ptff_function_mask, sizeof(ptff_function_mask), PTFF_QAF); |
96 | ||
97 | /* get LPAR offset */ | |
98 | if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) | |
99 | lpar_offset = qto.tod_epoch_difference; | |
936cc855 MS |
100 | |
101 | /* get initial leap seconds */ | |
102 | if (ptff_query(PTFF_QUI) && ptff(&qui, sizeof(qui), PTFF_QUI) == 0) | |
b1c0854d | 103 | initial_leap_seconds = (unsigned long long) |
936cc855 | 104 | ((long) qui.old_leap * 4096000000L); |
40277891 MS |
105 | } |
106 | ||
1da177e4 LT |
107 | /* |
108 | * Scheduler clock - returns current time in nanosec units. | |
109 | */ | |
7a5388de | 110 | unsigned long long notrace sched_clock(void) |
1da177e4 | 111 | { |
1aae0560 | 112 | return tod_to_ns(get_tod_clock_monotonic()); |
1da177e4 | 113 | } |
7a5388de | 114 | NOKPROBE_SYMBOL(sched_clock); |
1da177e4 | 115 | |
6e2ef5e4 | 116 | static void ext_to_timespec64(unsigned char *clk, struct timespec64 *xt) |
1da177e4 | 117 | { |
6e2ef5e4 MS |
118 | unsigned long long high, low, rem, sec, nsec; |
119 | ||
120 | /* Split extendnd TOD clock to micro-seconds and sub-micro-seconds */ | |
121 | high = (*(unsigned long long *) clk) >> 4; | |
122 | low = (*(unsigned long long *)&clk[7]) << 4; | |
123 | /* Calculate seconds and nano-seconds */ | |
124 | sec = high; | |
125 | rem = do_div(sec, 1000000); | |
126 | nsec = (((low >> 32) + (rem << 32)) * 1000) >> 32; | |
1da177e4 | 127 | |
b1e2ba8d | 128 | xt->tv_sec = sec; |
6e2ef5e4 | 129 | xt->tv_nsec = nsec; |
1da177e4 LT |
130 | } |
131 | ||
5a62b192 | 132 | void clock_comparator_work(void) |
1da177e4 | 133 | { |
5a62b192 | 134 | struct clock_event_device *cd; |
1da177e4 | 135 | |
6e2ef5e4 | 136 | S390_lowcore.clock_comparator = clock_comparator_max; |
eb7e7d76 | 137 | cd = this_cpu_ptr(&comparators); |
5a62b192 | 138 | cd->event_handler(cd); |
1da177e4 LT |
139 | } |
140 | ||
8adbf78e | 141 | static int s390_next_event(unsigned long delta, |
5a62b192 | 142 | struct clock_event_device *evt) |
1da177e4 | 143 | { |
8adbf78e | 144 | S390_lowcore.clock_comparator = get_tod_clock() + delta; |
5a62b192 HC |
145 | set_clock_comparator(S390_lowcore.clock_comparator); |
146 | return 0; | |
1da177e4 LT |
147 | } |
148 | ||
d54853ef MS |
149 | /* |
150 | * Set up lowcore and control register of the current cpu to | |
151 | * enable TOD clock and clock comparator interrupts. | |
1da177e4 LT |
152 | */ |
153 | void init_cpu_timer(void) | |
154 | { | |
5a62b192 HC |
155 | struct clock_event_device *cd; |
156 | int cpu; | |
157 | ||
6e2ef5e4 | 158 | S390_lowcore.clock_comparator = clock_comparator_max; |
5a62b192 HC |
159 | set_clock_comparator(S390_lowcore.clock_comparator); |
160 | ||
161 | cpu = smp_processor_id(); | |
162 | cd = &per_cpu(comparators, cpu); | |
163 | cd->name = "comparator"; | |
8adbf78e | 164 | cd->features = CLOCK_EVT_FEAT_ONESHOT; |
5a62b192 HC |
165 | cd->mult = 16777; |
166 | cd->shift = 12; | |
167 | cd->min_delta_ns = 1; | |
06c54611 | 168 | cd->min_delta_ticks = 1; |
5a62b192 | 169 | cd->max_delta_ns = LONG_MAX; |
06c54611 | 170 | cd->max_delta_ticks = ULONG_MAX; |
5a62b192 | 171 | cd->rating = 400; |
320ab2b0 | 172 | cd->cpumask = cpumask_of(cpu); |
8adbf78e | 173 | cd->set_next_event = s390_next_event; |
5a62b192 HC |
174 | |
175 | clockevents_register_device(cd); | |
d54853ef MS |
176 | |
177 | /* Enable clock comparator timer interrupt. */ | |
178 | __ctl_set_bit(0,11); | |
179 | ||
d2fec595 | 180 | /* Always allow the timing alert external interrupt. */ |
d54853ef MS |
181 | __ctl_set_bit(0, 4); |
182 | } | |
183 | ||
fde15c3a | 184 | static void clock_comparator_interrupt(struct ext_code ext_code, |
f6649a7e MS |
185 | unsigned int param32, |
186 | unsigned long param64) | |
d54853ef | 187 | { |
420f42ec | 188 | inc_irq_stat(IRQEXT_CLK); |
6e2ef5e4 | 189 | if (S390_lowcore.clock_comparator == clock_comparator_max) |
d3d238c7 | 190 | set_clock_comparator(S390_lowcore.clock_comparator); |
d54853ef MS |
191 | } |
192 | ||
d2fec595 MS |
193 | static void stp_timing_alert(struct stp_irq_parm *); |
194 | ||
fde15c3a | 195 | static void timing_alert_interrupt(struct ext_code ext_code, |
f6649a7e | 196 | unsigned int param32, unsigned long param64) |
d2fec595 | 197 | { |
420f42ec | 198 | inc_irq_stat(IRQEXT_TLA); |
f6649a7e MS |
199 | if (param32 & 0x00038000) |
200 | stp_timing_alert((struct stp_irq_parm *) ¶m32); | |
d2fec595 MS |
201 | } |
202 | ||
d2fec595 | 203 | static void stp_reset(void); |
d54853ef | 204 | |
689911c7 | 205 | void read_persistent_clock64(struct timespec64 *ts) |
d54853ef | 206 | { |
6e2ef5e4 MS |
207 | unsigned char clk[STORE_CLOCK_EXT_SIZE]; |
208 | __u64 delta; | |
209 | ||
210 | delta = initial_leap_seconds + TOD_UNIX_EPOCH; | |
211 | get_tod_clock_ext(clk); | |
212 | *(__u64 *) &clk[1] -= delta; | |
213 | if (*(__u64 *) &clk[1] > delta) | |
214 | clk[0]--; | |
215 | ext_to_timespec64(clk, ts); | |
1da177e4 | 216 | } |
d54853ef | 217 | |
be2e0e42 PT |
218 | void __init read_persistent_wall_and_boot_offset(struct timespec64 *wall_time, |
219 | struct timespec64 *boot_offset) | |
220 | { | |
221 | unsigned char clk[STORE_CLOCK_EXT_SIZE]; | |
222 | struct timespec64 boot_time; | |
223 | __u64 delta; | |
224 | ||
225 | delta = initial_leap_seconds + TOD_UNIX_EPOCH; | |
226 | memcpy(clk, tod_clock_base, STORE_CLOCK_EXT_SIZE); | |
227 | *(__u64 *)&clk[1] -= delta; | |
228 | if (*(__u64 *)&clk[1] > delta) | |
229 | clk[0]--; | |
230 | ext_to_timespec64(clk, &boot_time); | |
231 | ||
232 | read_persistent_clock64(wall_time); | |
233 | *boot_offset = timespec64_sub(*wall_time, boot_time); | |
234 | } | |
235 | ||
a5a1d1c2 | 236 | static u64 read_tod_clock(struct clocksource *cs) |
dc64bef5 | 237 | { |
75c7b6f3 MS |
238 | unsigned long long now, adj; |
239 | ||
240 | preempt_disable(); /* protect from changes to steering parameters */ | |
241 | now = get_tod_clock(); | |
242 | adj = tod_steering_end - now; | |
41115582 | 243 | if (unlikely((s64) adj > 0)) |
75c7b6f3 MS |
244 | /* |
245 | * manually steer by 1 cycle every 2^16 cycles. This | |
246 | * corresponds to shifting the tod delta by 15. 1s is | |
247 | * therefore steered in ~9h. The adjust will decrease | |
248 | * over time, until it finally reaches 0. | |
249 | */ | |
191ce9d1 | 250 | now += (tod_steering_delta < 0) ? (adj >> 15) : -(adj >> 15); |
75c7b6f3 MS |
251 | preempt_enable(); |
252 | return now; | |
dc64bef5 MS |
253 | } |
254 | ||
255 | static struct clocksource clocksource_tod = { | |
256 | .name = "tod", | |
d2cb0e6e | 257 | .rating = 400, |
dc64bef5 | 258 | .read = read_tod_clock, |
58e15716 | 259 | .mask = CLOCKSOURCE_MASK(64), |
dc64bef5 MS |
260 | .mult = 1000, |
261 | .shift = 12, | |
cc02d809 | 262 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
4bff8cb5 | 263 | .vdso_clock_mode = VDSO_CLOCKMODE_TOD, |
dc64bef5 MS |
264 | }; |
265 | ||
f1b82746 MS |
266 | struct clocksource * __init clocksource_default_clock(void) |
267 | { | |
268 | return &clocksource_tod; | |
269 | } | |
dc64bef5 | 270 | |
1da177e4 LT |
271 | /* |
272 | * Initialize the TOD clock and the CPU timer of | |
273 | * the boot cpu. | |
274 | */ | |
275 | void __init time_init(void) | |
276 | { | |
b6112ccb | 277 | /* Reset time synchronization interfaces. */ |
b6112ccb | 278 | stp_reset(); |
1da177e4 | 279 | |
1da177e4 | 280 | /* request the clock comparator external interrupt */ |
1dad093b TH |
281 | if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt)) |
282 | panic("Couldn't request external interrupt 0x1004"); | |
1da177e4 | 283 | |
d2fec595 | 284 | /* request the timing alert external interrupt */ |
1dad093b | 285 | if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt)) |
d54853ef MS |
286 | panic("Couldn't request external interrupt 0x1406"); |
287 | ||
f8935983 | 288 | if (__clocksource_register(&clocksource_tod) != 0) |
ab96e798 MS |
289 | panic("Could not register TOD clock source"); |
290 | ||
d54853ef MS |
291 | /* Enable TOD clock interrupts on the boot cpu. */ |
292 | init_cpu_timer(); | |
ab96e798 | 293 | |
c185b783 | 294 | /* Enable cpu timer interrupts on the boot cpu. */ |
1da177e4 | 295 | vtime_init(); |
d54853ef MS |
296 | } |
297 | ||
d2fec595 | 298 | static DEFINE_PER_CPU(atomic_t, clock_sync_word); |
ad5ceb33 | 299 | static DEFINE_MUTEX(stp_mutex); |
d2fec595 MS |
300 | static unsigned long clock_sync_flags; |
301 | ||
b3bd0249 SS |
302 | #define CLOCK_SYNC_HAS_STP 0 |
303 | #define CLOCK_SYNC_STP 1 | |
304 | #define CLOCK_SYNC_STPINFO_VALID 2 | |
d2fec595 MS |
305 | |
306 | /* | |
40277891 MS |
307 | * The get_clock function for the physical clock. It will get the current |
308 | * TOD clock, subtract the LPAR offset and write the result to *clock. | |
309 | * The function returns 0 if the clock is in sync with the external time | |
310 | * source. If the clock mode is local it will return -EOPNOTSUPP and | |
311 | * -EAGAIN if the clock is not in sync with the external reference. | |
d2fec595 | 312 | */ |
7bf76f01 | 313 | int get_phys_clock(unsigned long *clock) |
d2fec595 MS |
314 | { |
315 | atomic_t *sw_ptr; | |
316 | unsigned int sw0, sw1; | |
317 | ||
318 | sw_ptr = &get_cpu_var(clock_sync_word); | |
319 | sw0 = atomic_read(sw_ptr); | |
40277891 | 320 | *clock = get_tod_clock() - lpar_offset; |
d2fec595 | 321 | sw1 = atomic_read(sw_ptr); |
bd119ee2 | 322 | put_cpu_var(clock_sync_word); |
d2fec595 MS |
323 | if (sw0 == sw1 && (sw0 & 0x80000000U)) |
324 | /* Success: time is in sync. */ | |
325 | return 0; | |
ca64f639 | 326 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) |
a8f6db4d | 327 | return -EOPNOTSUPP; |
ca64f639 | 328 | if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags)) |
d2fec595 MS |
329 | return -EACCES; |
330 | return -EAGAIN; | |
331 | } | |
40277891 | 332 | EXPORT_SYMBOL(get_phys_clock); |
d2fec595 MS |
333 | |
334 | /* | |
ca64f639 | 335 | * Make get_phys_clock() return -EAGAIN. |
d2fec595 MS |
336 | */ |
337 | static void disable_sync_clock(void *dummy) | |
338 | { | |
eb7e7d76 | 339 | atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); |
d2fec595 | 340 | /* |
ca64f639 | 341 | * Clear the in-sync bit 2^31. All get_phys_clock calls will |
d2fec595 MS |
342 | * fail until the sync bit is turned back on. In addition |
343 | * increase the "sequence" counter to avoid the race of an | |
ca64f639 | 344 | * stp event and the complete recovery against get_phys_clock. |
d2fec595 | 345 | */ |
805de8f4 | 346 | atomic_andnot(0x80000000, sw_ptr); |
d2fec595 MS |
347 | atomic_inc(sw_ptr); |
348 | } | |
349 | ||
350 | /* | |
ca64f639 | 351 | * Make get_phys_clock() return 0 again. |
d2fec595 MS |
352 | * Needs to be called from a context disabled for preemption. |
353 | */ | |
354 | static void enable_sync_clock(void) | |
355 | { | |
eb7e7d76 | 356 | atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); |
805de8f4 | 357 | atomic_or(0x80000000, sw_ptr); |
d2fec595 MS |
358 | } |
359 | ||
8283cb43 MS |
360 | /* |
361 | * Function to check if the clock is in sync. | |
362 | */ | |
363 | static inline int check_sync_clock(void) | |
364 | { | |
365 | atomic_t *sw_ptr; | |
366 | int rc; | |
367 | ||
368 | sw_ptr = &get_cpu_var(clock_sync_word); | |
369 | rc = (atomic_read(sw_ptr) & 0x80000000U) != 0; | |
bd119ee2 | 370 | put_cpu_var(clock_sync_word); |
8283cb43 MS |
371 | return rc; |
372 | } | |
373 | ||
b1c0854d MS |
374 | /* |
375 | * Apply clock delta to the global data structures. | |
376 | * This is called once on the CPU that performed the clock sync. | |
377 | */ | |
378 | static void clock_sync_global(unsigned long long delta) | |
379 | { | |
75c7b6f3 | 380 | unsigned long now, adj; |
b1c0854d MS |
381 | struct ptff_qto qto; |
382 | ||
383 | /* Fixup the monotonic sched clock. */ | |
6e2ef5e4 MS |
384 | *(unsigned long long *) &tod_clock_base[1] += delta; |
385 | if (*(unsigned long long *) &tod_clock_base[1] < delta) | |
386 | /* Epoch overflow */ | |
387 | tod_clock_base[0]++; | |
75c7b6f3 | 388 | /* Adjust TOD steering parameters. */ |
75c7b6f3 MS |
389 | now = get_tod_clock(); |
390 | adj = tod_steering_end - now; | |
391 | if (unlikely((s64) adj >= 0)) | |
392 | /* Calculate how much of the old adjustment is left. */ | |
191ce9d1 | 393 | tod_steering_delta = (tod_steering_delta < 0) ? |
75c7b6f3 MS |
394 | -(adj >> 15) : (adj >> 15); |
395 | tod_steering_delta += delta; | |
396 | if ((abs(tod_steering_delta) >> 48) != 0) | |
397 | panic("TOD clock sync offset %lli is too large to drift\n", | |
398 | tod_steering_delta); | |
399 | tod_steering_end = now + (abs(tod_steering_delta) << 15); | |
4bff8cb5 | 400 | vdso_data->arch_data.tod_steering_end = tod_steering_end; |
d7a6e830 | 401 | vdso_data->arch_data.tod_steering_delta = tod_steering_delta; |
4bff8cb5 | 402 | |
b1c0854d MS |
403 | /* Update LPAR offset. */ |
404 | if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) | |
405 | lpar_offset = qto.tod_epoch_difference; | |
406 | /* Call the TOD clock change notifier. */ | |
407 | atomic_notifier_call_chain(&s390_epoch_delta_notifier, 0, &delta); | |
408 | } | |
409 | ||
410 | /* | |
411 | * Apply clock delta to the per-CPU data structures of this CPU. | |
412 | * This is called for each online CPU after the call to clock_sync_global. | |
413 | */ | |
414 | static void clock_sync_local(unsigned long long delta) | |
415 | { | |
416 | /* Add the delta to the clock comparator. */ | |
6e2ef5e4 | 417 | if (S390_lowcore.clock_comparator != clock_comparator_max) { |
b1c0854d MS |
418 | S390_lowcore.clock_comparator += delta; |
419 | set_clock_comparator(S390_lowcore.clock_comparator); | |
420 | } | |
2ace06ec MS |
421 | /* Adjust the last_update_clock time-stamp. */ |
422 | S390_lowcore.last_update_clock += delta; | |
b1c0854d MS |
423 | } |
424 | ||
ca64f639 | 425 | /* Single threaded workqueue used for stp sync events */ |
750887de HC |
426 | static struct workqueue_struct *time_sync_wq; |
427 | ||
428 | static void __init time_init_wq(void) | |
429 | { | |
179cb81a HC |
430 | if (time_sync_wq) |
431 | return; | |
432 | time_sync_wq = create_singlethread_workqueue("timesync"); | |
750887de HC |
433 | } |
434 | ||
d2fec595 | 435 | struct clock_sync_data { |
750887de | 436 | atomic_t cpus; |
5a62b192 | 437 | int in_sync; |
b1c0854d | 438 | unsigned long long clock_delta; |
d2fec595 | 439 | }; |
5a62b192 | 440 | |
d2fec595 MS |
441 | /* |
442 | * Server Time Protocol (STP) code. | |
443 | */ | |
4cc7ecb7 | 444 | static bool stp_online; |
d2fec595 MS |
445 | static struct stp_sstpi stp_info; |
446 | static void *stp_page; | |
447 | ||
448 | static void stp_work_fn(struct work_struct *work); | |
449 | static DECLARE_WORK(stp_work, stp_work_fn); | |
04362301 | 450 | static struct timer_list stp_timer; |
d2fec595 MS |
451 | |
452 | static int __init early_parse_stp(char *p) | |
453 | { | |
4cc7ecb7 | 454 | return kstrtobool(p, &stp_online); |
d2fec595 MS |
455 | } |
456 | early_param("stp", early_parse_stp); | |
457 | ||
458 | /* | |
459 | * Reset STP attachment. | |
460 | */ | |
8f847003 | 461 | static void __init stp_reset(void) |
d2fec595 MS |
462 | { |
463 | int rc; | |
464 | ||
d7d1104f | 465 | stp_page = (void *) get_zeroed_page(GFP_ATOMIC); |
2f82f577 | 466 | rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL); |
4a672cfa | 467 | if (rc == 0) |
d2fec595 MS |
468 | set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags); |
469 | else if (stp_online) { | |
baebc70a | 470 | pr_warn("The real or virtual hardware system does not provide an STP interface\n"); |
d7d1104f | 471 | free_page((unsigned long) stp_page); |
d2fec595 | 472 | stp_page = NULL; |
970ba6ac | 473 | stp_online = false; |
d2fec595 MS |
474 | } |
475 | } | |
476 | ||
e99e88a9 | 477 | static void stp_timeout(struct timer_list *unused) |
04362301 MS |
478 | { |
479 | queue_work(time_sync_wq, &stp_work); | |
480 | } | |
481 | ||
d2fec595 MS |
482 | static int __init stp_init(void) |
483 | { | |
750887de HC |
484 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) |
485 | return 0; | |
e99e88a9 | 486 | timer_setup(&stp_timer, stp_timeout, 0); |
750887de HC |
487 | time_init_wq(); |
488 | if (!stp_online) | |
489 | return 0; | |
490 | queue_work(time_sync_wq, &stp_work); | |
d2fec595 MS |
491 | return 0; |
492 | } | |
493 | ||
494 | arch_initcall(stp_init); | |
495 | ||
496 | /* | |
497 | * STP timing alert. There are three causes: | |
498 | * 1) timing status change | |
499 | * 2) link availability change | |
500 | * 3) time control parameter change | |
501 | * In all three cases we are only interested in the clock source state. | |
502 | * If a STP clock source is now available use it. | |
503 | */ | |
504 | static void stp_timing_alert(struct stp_irq_parm *intparm) | |
505 | { | |
506 | if (intparm->tsc || intparm->lac || intparm->tcpc) | |
750887de | 507 | queue_work(time_sync_wq, &stp_work); |
d2fec595 MS |
508 | } |
509 | ||
510 | /* | |
511 | * STP sync check machine check. This is called when the timing state | |
512 | * changes from the synchronized state to the unsynchronized state. | |
513 | * After a STP sync check the clock is not in sync. The machine check | |
514 | * is broadcasted to all cpus at the same time. | |
515 | */ | |
29b0a825 | 516 | int stp_sync_check(void) |
d2fec595 | 517 | { |
d2fec595 | 518 | disable_sync_clock(NULL); |
29b0a825 | 519 | return 1; |
d2fec595 MS |
520 | } |
521 | ||
522 | /* | |
523 | * STP island condition machine check. This is called when an attached | |
524 | * server attempts to communicate over an STP link and the servers | |
525 | * have matching CTN ids and have a valid stratum-1 configuration | |
526 | * but the configurations do not match. | |
527 | */ | |
29b0a825 | 528 | int stp_island_check(void) |
d2fec595 | 529 | { |
d2fec595 | 530 | disable_sync_clock(NULL); |
29b0a825 | 531 | return 1; |
d2fec595 MS |
532 | } |
533 | ||
29b0a825 HC |
534 | void stp_queue_work(void) |
535 | { | |
536 | queue_work(time_sync_wq, &stp_work); | |
537 | } | |
750887de | 538 | |
b3bd0249 SS |
539 | static int __store_stpinfo(void) |
540 | { | |
541 | int rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi)); | |
542 | ||
543 | if (rc) | |
544 | clear_bit(CLOCK_SYNC_STPINFO_VALID, &clock_sync_flags); | |
545 | else | |
546 | set_bit(CLOCK_SYNC_STPINFO_VALID, &clock_sync_flags); | |
547 | return rc; | |
548 | } | |
549 | ||
550 | static int stpinfo_valid(void) | |
551 | { | |
552 | return stp_online && test_bit(CLOCK_SYNC_STPINFO_VALID, &clock_sync_flags); | |
553 | } | |
554 | ||
750887de | 555 | static int stp_sync_clock(void *data) |
d2fec595 | 556 | { |
b1c0854d | 557 | struct clock_sync_data *sync = data; |
4bff8cb5 | 558 | unsigned long long clock_delta, flags; |
b1c0854d | 559 | static int first; |
d2fec595 MS |
560 | int rc; |
561 | ||
d2fec595 | 562 | enable_sync_clock(); |
b1c0854d MS |
563 | if (xchg(&first, 1) == 0) { |
564 | /* Wait until all other cpus entered the sync function. */ | |
565 | while (atomic_read(&sync->cpus) != 0) | |
566 | cpu_relax(); | |
567 | rc = 0; | |
568 | if (stp_info.todoff[0] || stp_info.todoff[1] || | |
569 | stp_info.todoff[2] || stp_info.todoff[3] || | |
570 | stp_info.tmd != 2) { | |
4bff8cb5 | 571 | flags = vdso_update_begin(); |
b1c0854d MS |
572 | rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0, |
573 | &clock_delta); | |
574 | if (rc == 0) { | |
575 | sync->clock_delta = clock_delta; | |
576 | clock_sync_global(clock_delta); | |
b3bd0249 | 577 | rc = __store_stpinfo(); |
b1c0854d MS |
578 | if (rc == 0 && stp_info.tmd != 2) |
579 | rc = -EAGAIN; | |
580 | } | |
4bff8cb5 | 581 | vdso_update_end(flags); |
d2fec595 | 582 | } |
b1c0854d MS |
583 | sync->in_sync = rc ? -EAGAIN : 1; |
584 | xchg(&first, 0); | |
585 | } else { | |
586 | /* Slave */ | |
587 | atomic_dec(&sync->cpus); | |
588 | /* Wait for in_sync to be set. */ | |
589 | while (READ_ONCE(sync->in_sync) == 0) | |
590 | __udelay(1); | |
d2fec595 | 591 | } |
b1c0854d MS |
592 | if (sync->in_sync != 1) |
593 | /* Didn't work. Clear per-cpu in sync bit again. */ | |
d2fec595 | 594 | disable_sync_clock(NULL); |
b1c0854d MS |
595 | /* Apply clock delta to per-CPU fields of this CPU. */ |
596 | clock_sync_local(sync->clock_delta); | |
597 | ||
750887de HC |
598 | return 0; |
599 | } | |
d2fec595 | 600 | |
b2539aa0 SS |
601 | static int stp_clear_leap(void) |
602 | { | |
603 | struct __kernel_timex txc; | |
604 | int ret; | |
605 | ||
606 | memset(&txc, 0, sizeof(txc)); | |
607 | ||
608 | ret = do_adjtimex(&txc); | |
609 | if (ret < 0) | |
610 | return ret; | |
611 | ||
612 | txc.modes = ADJ_STATUS; | |
613 | txc.status &= ~(STA_INS|STA_DEL); | |
614 | return do_adjtimex(&txc); | |
615 | } | |
616 | ||
617 | static void stp_check_leap(void) | |
618 | { | |
619 | struct stp_stzi stzi; | |
620 | struct stp_lsoib *lsoib = &stzi.lsoib; | |
621 | struct __kernel_timex txc; | |
622 | int64_t timediff; | |
623 | int leapdiff, ret; | |
624 | ||
625 | if (!stp_info.lu || !check_sync_clock()) { | |
626 | /* | |
627 | * Either a scheduled leap second was removed by the operator, | |
628 | * or STP is out of sync. In both cases, clear the leap second | |
629 | * kernel flags. | |
630 | */ | |
631 | if (stp_clear_leap() < 0) | |
632 | pr_err("failed to clear leap second flags\n"); | |
633 | return; | |
634 | } | |
635 | ||
636 | if (chsc_stzi(stp_page, &stzi, sizeof(stzi))) { | |
637 | pr_err("stzi failed\n"); | |
638 | return; | |
639 | } | |
640 | ||
641 | timediff = tod_to_ns(lsoib->nlsout - get_tod_clock()) / NSEC_PER_SEC; | |
642 | leapdiff = lsoib->nlso - lsoib->also; | |
643 | ||
644 | if (leapdiff != 1 && leapdiff != -1) { | |
645 | pr_err("Cannot schedule %d leap seconds\n", leapdiff); | |
646 | return; | |
647 | } | |
648 | ||
649 | if (timediff < 0) { | |
650 | if (stp_clear_leap() < 0) | |
651 | pr_err("failed to clear leap second flags\n"); | |
652 | } else if (timediff < 7200) { | |
653 | memset(&txc, 0, sizeof(txc)); | |
654 | ret = do_adjtimex(&txc); | |
655 | if (ret < 0) | |
656 | return; | |
657 | ||
658 | txc.modes = ADJ_STATUS; | |
659 | if (leapdiff > 0) | |
660 | txc.status |= STA_INS; | |
661 | else | |
662 | txc.status |= STA_DEL; | |
663 | ret = do_adjtimex(&txc); | |
664 | if (ret < 0) | |
665 | pr_err("failed to set leap second flags\n"); | |
666 | /* arm Timer to clear leap second flags */ | |
667 | mod_timer(&stp_timer, jiffies + msecs_to_jiffies(14400 * MSEC_PER_SEC)); | |
668 | } else { | |
669 | /* The day the leap second is scheduled for hasn't been reached. Retry | |
670 | * in one hour. | |
671 | */ | |
672 | mod_timer(&stp_timer, jiffies + msecs_to_jiffies(3600 * MSEC_PER_SEC)); | |
673 | } | |
674 | } | |
675 | ||
750887de HC |
676 | /* |
677 | * STP work. Check for the STP state and take over the clock | |
678 | * synchronization if the STP clock source is usable. | |
679 | */ | |
680 | static void stp_work_fn(struct work_struct *work) | |
681 | { | |
682 | struct clock_sync_data stp_sync; | |
683 | int rc; | |
684 | ||
0b3016b7 | 685 | /* prevent multiple execution. */ |
ad5ceb33 | 686 | mutex_lock(&stp_mutex); |
0b3016b7 | 687 | |
750887de | 688 | if (!stp_online) { |
2f82f577 | 689 | chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL); |
04362301 | 690 | del_timer_sync(&stp_timer); |
0b3016b7 | 691 | goto out_unlock; |
750887de HC |
692 | } |
693 | ||
b2539aa0 | 694 | rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xf0e0, NULL); |
750887de | 695 | if (rc) |
0b3016b7 | 696 | goto out_unlock; |
750887de | 697 | |
b3bd0249 | 698 | rc = __store_stpinfo(); |
750887de | 699 | if (rc || stp_info.c == 0) |
0b3016b7 | 700 | goto out_unlock; |
750887de | 701 | |
8283cb43 | 702 | /* Skip synchronization if the clock is already in sync. */ |
b2539aa0 SS |
703 | if (!check_sync_clock()) { |
704 | memset(&stp_sync, 0, sizeof(stp_sync)); | |
705 | cpus_read_lock(); | |
706 | atomic_set(&stp_sync.cpus, num_online_cpus() - 1); | |
707 | stop_machine_cpuslocked(stp_sync_clock, &stp_sync, cpu_online_mask); | |
708 | cpus_read_unlock(); | |
709 | } | |
0b3016b7 | 710 | |
04362301 MS |
711 | if (!check_sync_clock()) |
712 | /* | |
713 | * There is a usable clock but the synchonization failed. | |
714 | * Retry after a second. | |
715 | */ | |
0188d08a | 716 | mod_timer(&stp_timer, jiffies + msecs_to_jiffies(MSEC_PER_SEC)); |
b2539aa0 SS |
717 | else if (stp_info.lu) |
718 | stp_check_leap(); | |
04362301 | 719 | |
0b3016b7 | 720 | out_unlock: |
ad5ceb33 | 721 | mutex_unlock(&stp_mutex); |
d2fec595 MS |
722 | } |
723 | ||
724 | /* | |
3fbacffb | 725 | * STP subsys sysfs interface functions |
d2fec595 | 726 | */ |
3fbacffb KS |
727 | static struct bus_type stp_subsys = { |
728 | .name = "stp", | |
729 | .dev_name = "stp", | |
d2fec595 MS |
730 | }; |
731 | ||
66a049b7 | 732 | static ssize_t ctn_id_show(struct device *dev, |
3fbacffb | 733 | struct device_attribute *attr, |
c9be0a36 | 734 | char *buf) |
d2fec595 | 735 | { |
b3bd0249 SS |
736 | ssize_t ret = -ENODATA; |
737 | ||
ad5ceb33 | 738 | mutex_lock(&stp_mutex); |
b3bd0249 SS |
739 | if (stpinfo_valid()) |
740 | ret = sprintf(buf, "%016llx\n", | |
741 | *(unsigned long long *) stp_info.ctnid); | |
ad5ceb33 | 742 | mutex_unlock(&stp_mutex); |
b3bd0249 | 743 | return ret; |
d2fec595 MS |
744 | } |
745 | ||
66a049b7 | 746 | static DEVICE_ATTR_RO(ctn_id); |
d2fec595 | 747 | |
66a049b7 | 748 | static ssize_t ctn_type_show(struct device *dev, |
3fbacffb | 749 | struct device_attribute *attr, |
c9be0a36 | 750 | char *buf) |
d2fec595 | 751 | { |
b3bd0249 SS |
752 | ssize_t ret = -ENODATA; |
753 | ||
ad5ceb33 | 754 | mutex_lock(&stp_mutex); |
b3bd0249 SS |
755 | if (stpinfo_valid()) |
756 | ret = sprintf(buf, "%i\n", stp_info.ctn); | |
ad5ceb33 | 757 | mutex_unlock(&stp_mutex); |
b3bd0249 | 758 | return ret; |
d2fec595 MS |
759 | } |
760 | ||
66a049b7 | 761 | static DEVICE_ATTR_RO(ctn_type); |
d2fec595 | 762 | |
66a049b7 | 763 | static ssize_t dst_offset_show(struct device *dev, |
3fbacffb | 764 | struct device_attribute *attr, |
c9be0a36 | 765 | char *buf) |
d2fec595 | 766 | { |
b3bd0249 SS |
767 | ssize_t ret = -ENODATA; |
768 | ||
ad5ceb33 | 769 | mutex_lock(&stp_mutex); |
b3bd0249 SS |
770 | if (stpinfo_valid() && (stp_info.vbits & 0x2000)) |
771 | ret = sprintf(buf, "%i\n", (int)(s16) stp_info.dsto); | |
ad5ceb33 | 772 | mutex_unlock(&stp_mutex); |
b3bd0249 | 773 | return ret; |
d2fec595 MS |
774 | } |
775 | ||
66a049b7 | 776 | static DEVICE_ATTR_RO(dst_offset); |
d2fec595 | 777 | |
66a049b7 | 778 | static ssize_t leap_seconds_show(struct device *dev, |
3fbacffb | 779 | struct device_attribute *attr, |
c9be0a36 | 780 | char *buf) |
d2fec595 | 781 | { |
b3bd0249 SS |
782 | ssize_t ret = -ENODATA; |
783 | ||
ad5ceb33 | 784 | mutex_lock(&stp_mutex); |
b3bd0249 SS |
785 | if (stpinfo_valid() && (stp_info.vbits & 0x8000)) |
786 | ret = sprintf(buf, "%i\n", (int)(s16) stp_info.leaps); | |
ad5ceb33 | 787 | mutex_unlock(&stp_mutex); |
b3bd0249 | 788 | return ret; |
d2fec595 MS |
789 | } |
790 | ||
66a049b7 | 791 | static DEVICE_ATTR_RO(leap_seconds); |
d2fec595 | 792 | |
4fb53dde SS |
793 | static ssize_t leap_seconds_scheduled_show(struct device *dev, |
794 | struct device_attribute *attr, | |
795 | char *buf) | |
796 | { | |
797 | struct stp_stzi stzi; | |
798 | ssize_t ret; | |
799 | ||
ad5ceb33 | 800 | mutex_lock(&stp_mutex); |
4fb53dde | 801 | if (!stpinfo_valid() || !(stp_info.vbits & 0x8000) || !stp_info.lu) { |
ad5ceb33 | 802 | mutex_unlock(&stp_mutex); |
4fb53dde SS |
803 | return -ENODATA; |
804 | } | |
805 | ||
806 | ret = chsc_stzi(stp_page, &stzi, sizeof(stzi)); | |
ad5ceb33 | 807 | mutex_unlock(&stp_mutex); |
4fb53dde SS |
808 | if (ret < 0) |
809 | return ret; | |
810 | ||
811 | if (!stzi.lsoib.p) | |
812 | return sprintf(buf, "0,0\n"); | |
813 | ||
814 | return sprintf(buf, "%llu,%d\n", | |
815 | tod_to_ns(stzi.lsoib.nlsout - TOD_UNIX_EPOCH) / NSEC_PER_SEC, | |
816 | stzi.lsoib.nlso - stzi.lsoib.also); | |
817 | } | |
818 | ||
819 | static DEVICE_ATTR_RO(leap_seconds_scheduled); | |
820 | ||
66a049b7 | 821 | static ssize_t stratum_show(struct device *dev, |
3fbacffb | 822 | struct device_attribute *attr, |
c9be0a36 | 823 | char *buf) |
d2fec595 | 824 | { |
b3bd0249 SS |
825 | ssize_t ret = -ENODATA; |
826 | ||
ad5ceb33 | 827 | mutex_lock(&stp_mutex); |
b3bd0249 SS |
828 | if (stpinfo_valid()) |
829 | ret = sprintf(buf, "%i\n", (int)(s16) stp_info.stratum); | |
ad5ceb33 | 830 | mutex_unlock(&stp_mutex); |
b3bd0249 | 831 | return ret; |
d2fec595 MS |
832 | } |
833 | ||
66a049b7 | 834 | static DEVICE_ATTR_RO(stratum); |
d2fec595 | 835 | |
66a049b7 | 836 | static ssize_t time_offset_show(struct device *dev, |
3fbacffb | 837 | struct device_attribute *attr, |
c9be0a36 | 838 | char *buf) |
d2fec595 | 839 | { |
b3bd0249 SS |
840 | ssize_t ret = -ENODATA; |
841 | ||
ad5ceb33 | 842 | mutex_lock(&stp_mutex); |
b3bd0249 SS |
843 | if (stpinfo_valid() && (stp_info.vbits & 0x0800)) |
844 | ret = sprintf(buf, "%i\n", (int) stp_info.tto); | |
ad5ceb33 | 845 | mutex_unlock(&stp_mutex); |
b3bd0249 | 846 | return ret; |
d2fec595 MS |
847 | } |
848 | ||
66a049b7 | 849 | static DEVICE_ATTR_RO(time_offset); |
d2fec595 | 850 | |
66a049b7 | 851 | static ssize_t time_zone_offset_show(struct device *dev, |
3fbacffb | 852 | struct device_attribute *attr, |
c9be0a36 | 853 | char *buf) |
d2fec595 | 854 | { |
b3bd0249 SS |
855 | ssize_t ret = -ENODATA; |
856 | ||
ad5ceb33 | 857 | mutex_lock(&stp_mutex); |
b3bd0249 SS |
858 | if (stpinfo_valid() && (stp_info.vbits & 0x4000)) |
859 | ret = sprintf(buf, "%i\n", (int)(s16) stp_info.tzo); | |
ad5ceb33 | 860 | mutex_unlock(&stp_mutex); |
b3bd0249 | 861 | return ret; |
d2fec595 MS |
862 | } |
863 | ||
66a049b7 | 864 | static DEVICE_ATTR_RO(time_zone_offset); |
d2fec595 | 865 | |
66a049b7 | 866 | static ssize_t timing_mode_show(struct device *dev, |
3fbacffb | 867 | struct device_attribute *attr, |
c9be0a36 | 868 | char *buf) |
d2fec595 | 869 | { |
b3bd0249 SS |
870 | ssize_t ret = -ENODATA; |
871 | ||
ad5ceb33 | 872 | mutex_lock(&stp_mutex); |
b3bd0249 SS |
873 | if (stpinfo_valid()) |
874 | ret = sprintf(buf, "%i\n", stp_info.tmd); | |
ad5ceb33 | 875 | mutex_unlock(&stp_mutex); |
b3bd0249 | 876 | return ret; |
d2fec595 MS |
877 | } |
878 | ||
66a049b7 | 879 | static DEVICE_ATTR_RO(timing_mode); |
d2fec595 | 880 | |
66a049b7 | 881 | static ssize_t timing_state_show(struct device *dev, |
3fbacffb | 882 | struct device_attribute *attr, |
c9be0a36 | 883 | char *buf) |
d2fec595 | 884 | { |
b3bd0249 SS |
885 | ssize_t ret = -ENODATA; |
886 | ||
ad5ceb33 | 887 | mutex_lock(&stp_mutex); |
b3bd0249 SS |
888 | if (stpinfo_valid()) |
889 | ret = sprintf(buf, "%i\n", stp_info.tst); | |
ad5ceb33 | 890 | mutex_unlock(&stp_mutex); |
b3bd0249 | 891 | return ret; |
d2fec595 MS |
892 | } |
893 | ||
66a049b7 | 894 | static DEVICE_ATTR_RO(timing_state); |
d2fec595 | 895 | |
66a049b7 | 896 | static ssize_t online_show(struct device *dev, |
3fbacffb | 897 | struct device_attribute *attr, |
c9be0a36 | 898 | char *buf) |
d2fec595 MS |
899 | { |
900 | return sprintf(buf, "%i\n", stp_online); | |
901 | } | |
902 | ||
66a049b7 | 903 | static ssize_t online_store(struct device *dev, |
3fbacffb | 904 | struct device_attribute *attr, |
d2fec595 MS |
905 | const char *buf, size_t count) |
906 | { | |
907 | unsigned int value; | |
908 | ||
909 | value = simple_strtoul(buf, NULL, 0); | |
910 | if (value != 0 && value != 1) | |
911 | return -EINVAL; | |
912 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) | |
913 | return -EOPNOTSUPP; | |
ad5ceb33 | 914 | mutex_lock(&stp_mutex); |
d2fec595 | 915 | stp_online = value; |
8283cb43 MS |
916 | if (stp_online) |
917 | set_bit(CLOCK_SYNC_STP, &clock_sync_flags); | |
918 | else | |
919 | clear_bit(CLOCK_SYNC_STP, &clock_sync_flags); | |
750887de | 920 | queue_work(time_sync_wq, &stp_work); |
ad5ceb33 | 921 | mutex_unlock(&stp_mutex); |
d2fec595 MS |
922 | return count; |
923 | } | |
924 | ||
925 | /* | |
3fbacffb KS |
926 | * Can't use DEVICE_ATTR because the attribute should be named |
927 | * stp/online but dev_attr_online already exists in this file .. | |
d2fec595 | 928 | */ |
66a049b7 | 929 | static DEVICE_ATTR_RW(online); |
d2fec595 | 930 | |
074ff04e JW |
931 | static struct attribute *stp_dev_attrs[] = { |
932 | &dev_attr_ctn_id.attr, | |
933 | &dev_attr_ctn_type.attr, | |
934 | &dev_attr_dst_offset.attr, | |
935 | &dev_attr_leap_seconds.attr, | |
936 | &dev_attr_online.attr, | |
937 | &dev_attr_leap_seconds_scheduled.attr, | |
938 | &dev_attr_stratum.attr, | |
939 | &dev_attr_time_offset.attr, | |
940 | &dev_attr_time_zone_offset.attr, | |
941 | &dev_attr_timing_mode.attr, | |
942 | &dev_attr_timing_state.attr, | |
d2fec595 MS |
943 | NULL |
944 | }; | |
074ff04e | 945 | ATTRIBUTE_GROUPS(stp_dev); |
d2fec595 MS |
946 | |
947 | static int __init stp_init_sysfs(void) | |
948 | { | |
074ff04e | 949 | return subsys_system_register(&stp_subsys, stp_dev_groups); |
d2fec595 MS |
950 | } |
951 | ||
952 | device_initcall(stp_init_sysfs); |