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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> |
40277891 | 44 | #include <asm/facility.h> |
1da177e4 | 45 | #include <asm/delay.h> |
1da177e4 | 46 | #include <asm/div64.h> |
b020632e | 47 | #include <asm/vdso.h> |
1da177e4 | 48 | #include <asm/irq.h> |
5a489b98 | 49 | #include <asm/irq_regs.h> |
27f6b416 | 50 | #include <asm/vtimer.h> |
fd5ada04 | 51 | #include <asm/stp.h> |
a806170e | 52 | #include <asm/cio.h> |
638ad34a | 53 | #include "entry.h" |
1da177e4 | 54 | |
6e2ef5e4 MS |
55 | unsigned char tod_clock_base[16] __aligned(8) = { |
56 | /* Force to data section. */ | |
57 | 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, | |
58 | 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff | |
59 | }; | |
60 | EXPORT_SYMBOL_GPL(tod_clock_base); | |
61 | ||
62 | u64 clock_comparator_max = -1ULL; | |
63 | EXPORT_SYMBOL_GPL(clock_comparator_max); | |
b6112ccb | 64 | |
5a62b192 | 65 | static DEFINE_PER_CPU(struct clock_event_device, comparators); |
1da177e4 | 66 | |
fdf03650 FZ |
67 | ATOMIC_NOTIFIER_HEAD(s390_epoch_delta_notifier); |
68 | EXPORT_SYMBOL(s390_epoch_delta_notifier); | |
69 | ||
40277891 | 70 | unsigned char ptff_function_mask[16]; |
b1c0854d MS |
71 | |
72 | static unsigned long long lpar_offset; | |
73 | static unsigned long long initial_leap_seconds; | |
75c7b6f3 | 74 | static unsigned long long tod_steering_end; |
191ce9d1 | 75 | static long long tod_steering_delta; |
40277891 MS |
76 | |
77 | /* | |
78 | * Get time offsets with PTFF | |
79 | */ | |
b1c0854d | 80 | void __init time_early_init(void) |
40277891 MS |
81 | { |
82 | struct ptff_qto qto; | |
936cc855 | 83 | struct ptff_qui qui; |
40277891 | 84 | |
75c7b6f3 | 85 | /* Initialize TOD steering parameters */ |
6e2ef5e4 | 86 | tod_steering_end = *(unsigned long long *) &tod_clock_base[1]; |
75c7b6f3 MS |
87 | vdso_data->ts_end = tod_steering_end; |
88 | ||
40277891 MS |
89 | if (!test_facility(28)) |
90 | return; | |
75c7b6f3 | 91 | |
40277891 MS |
92 | ptff(&ptff_function_mask, sizeof(ptff_function_mask), PTFF_QAF); |
93 | ||
94 | /* get LPAR offset */ | |
95 | if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) | |
96 | lpar_offset = qto.tod_epoch_difference; | |
936cc855 MS |
97 | |
98 | /* get initial leap seconds */ | |
99 | if (ptff_query(PTFF_QUI) && ptff(&qui, sizeof(qui), PTFF_QUI) == 0) | |
b1c0854d | 100 | initial_leap_seconds = (unsigned long long) |
936cc855 | 101 | ((long) qui.old_leap * 4096000000L); |
40277891 MS |
102 | } |
103 | ||
1da177e4 LT |
104 | /* |
105 | * Scheduler clock - returns current time in nanosec units. | |
106 | */ | |
7a5388de | 107 | unsigned long long notrace sched_clock(void) |
1da177e4 | 108 | { |
1aae0560 | 109 | return tod_to_ns(get_tod_clock_monotonic()); |
1da177e4 | 110 | } |
7a5388de | 111 | NOKPROBE_SYMBOL(sched_clock); |
1da177e4 | 112 | |
32f65f27 JG |
113 | /* |
114 | * Monotonic_clock - returns # of nanoseconds passed since time_init() | |
115 | */ | |
116 | unsigned long long monotonic_clock(void) | |
117 | { | |
118 | return sched_clock(); | |
119 | } | |
120 | EXPORT_SYMBOL(monotonic_clock); | |
121 | ||
6e2ef5e4 | 122 | static void ext_to_timespec64(unsigned char *clk, struct timespec64 *xt) |
1da177e4 | 123 | { |
6e2ef5e4 MS |
124 | unsigned long long high, low, rem, sec, nsec; |
125 | ||
126 | /* Split extendnd TOD clock to micro-seconds and sub-micro-seconds */ | |
127 | high = (*(unsigned long long *) clk) >> 4; | |
128 | low = (*(unsigned long long *)&clk[7]) << 4; | |
129 | /* Calculate seconds and nano-seconds */ | |
130 | sec = high; | |
131 | rem = do_div(sec, 1000000); | |
132 | nsec = (((low >> 32) + (rem << 32)) * 1000) >> 32; | |
1da177e4 | 133 | |
b1e2ba8d | 134 | xt->tv_sec = sec; |
6e2ef5e4 | 135 | xt->tv_nsec = nsec; |
1da177e4 LT |
136 | } |
137 | ||
5a62b192 | 138 | void clock_comparator_work(void) |
1da177e4 | 139 | { |
5a62b192 | 140 | struct clock_event_device *cd; |
1da177e4 | 141 | |
6e2ef5e4 | 142 | S390_lowcore.clock_comparator = clock_comparator_max; |
eb7e7d76 | 143 | cd = this_cpu_ptr(&comparators); |
5a62b192 | 144 | cd->event_handler(cd); |
1da177e4 LT |
145 | } |
146 | ||
8adbf78e | 147 | static int s390_next_event(unsigned long delta, |
5a62b192 | 148 | struct clock_event_device *evt) |
1da177e4 | 149 | { |
8adbf78e | 150 | S390_lowcore.clock_comparator = get_tod_clock() + delta; |
5a62b192 HC |
151 | set_clock_comparator(S390_lowcore.clock_comparator); |
152 | return 0; | |
1da177e4 LT |
153 | } |
154 | ||
d54853ef MS |
155 | /* |
156 | * Set up lowcore and control register of the current cpu to | |
157 | * enable TOD clock and clock comparator interrupts. | |
1da177e4 LT |
158 | */ |
159 | void init_cpu_timer(void) | |
160 | { | |
5a62b192 HC |
161 | struct clock_event_device *cd; |
162 | int cpu; | |
163 | ||
6e2ef5e4 | 164 | S390_lowcore.clock_comparator = clock_comparator_max; |
5a62b192 HC |
165 | set_clock_comparator(S390_lowcore.clock_comparator); |
166 | ||
167 | cpu = smp_processor_id(); | |
168 | cd = &per_cpu(comparators, cpu); | |
169 | cd->name = "comparator"; | |
8adbf78e | 170 | cd->features = CLOCK_EVT_FEAT_ONESHOT; |
5a62b192 HC |
171 | cd->mult = 16777; |
172 | cd->shift = 12; | |
173 | cd->min_delta_ns = 1; | |
06c54611 | 174 | cd->min_delta_ticks = 1; |
5a62b192 | 175 | cd->max_delta_ns = LONG_MAX; |
06c54611 | 176 | cd->max_delta_ticks = ULONG_MAX; |
5a62b192 | 177 | cd->rating = 400; |
320ab2b0 | 178 | cd->cpumask = cpumask_of(cpu); |
8adbf78e | 179 | cd->set_next_event = s390_next_event; |
5a62b192 HC |
180 | |
181 | clockevents_register_device(cd); | |
d54853ef MS |
182 | |
183 | /* Enable clock comparator timer interrupt. */ | |
184 | __ctl_set_bit(0,11); | |
185 | ||
d2fec595 | 186 | /* Always allow the timing alert external interrupt. */ |
d54853ef MS |
187 | __ctl_set_bit(0, 4); |
188 | } | |
189 | ||
fde15c3a | 190 | static void clock_comparator_interrupt(struct ext_code ext_code, |
f6649a7e MS |
191 | unsigned int param32, |
192 | unsigned long param64) | |
d54853ef | 193 | { |
420f42ec | 194 | inc_irq_stat(IRQEXT_CLK); |
6e2ef5e4 | 195 | if (S390_lowcore.clock_comparator == clock_comparator_max) |
d3d238c7 | 196 | set_clock_comparator(S390_lowcore.clock_comparator); |
d54853ef MS |
197 | } |
198 | ||
d2fec595 MS |
199 | static void stp_timing_alert(struct stp_irq_parm *); |
200 | ||
fde15c3a | 201 | static void timing_alert_interrupt(struct ext_code ext_code, |
f6649a7e | 202 | unsigned int param32, unsigned long param64) |
d2fec595 | 203 | { |
420f42ec | 204 | inc_irq_stat(IRQEXT_TLA); |
f6649a7e MS |
205 | if (param32 & 0x00038000) |
206 | stp_timing_alert((struct stp_irq_parm *) ¶m32); | |
d2fec595 MS |
207 | } |
208 | ||
d2fec595 | 209 | static void stp_reset(void); |
d54853ef | 210 | |
689911c7 | 211 | void read_persistent_clock64(struct timespec64 *ts) |
d54853ef | 212 | { |
6e2ef5e4 MS |
213 | unsigned char clk[STORE_CLOCK_EXT_SIZE]; |
214 | __u64 delta; | |
215 | ||
216 | delta = initial_leap_seconds + TOD_UNIX_EPOCH; | |
217 | get_tod_clock_ext(clk); | |
218 | *(__u64 *) &clk[1] -= delta; | |
219 | if (*(__u64 *) &clk[1] > delta) | |
220 | clk[0]--; | |
221 | ext_to_timespec64(clk, ts); | |
1da177e4 | 222 | } |
d54853ef | 223 | |
be2e0e42 PT |
224 | void __init read_persistent_wall_and_boot_offset(struct timespec64 *wall_time, |
225 | struct timespec64 *boot_offset) | |
226 | { | |
227 | unsigned char clk[STORE_CLOCK_EXT_SIZE]; | |
228 | struct timespec64 boot_time; | |
229 | __u64 delta; | |
230 | ||
231 | delta = initial_leap_seconds + TOD_UNIX_EPOCH; | |
232 | memcpy(clk, tod_clock_base, STORE_CLOCK_EXT_SIZE); | |
233 | *(__u64 *)&clk[1] -= delta; | |
234 | if (*(__u64 *)&clk[1] > delta) | |
235 | clk[0]--; | |
236 | ext_to_timespec64(clk, &boot_time); | |
237 | ||
238 | read_persistent_clock64(wall_time); | |
239 | *boot_offset = timespec64_sub(*wall_time, boot_time); | |
240 | } | |
241 | ||
a5a1d1c2 | 242 | static u64 read_tod_clock(struct clocksource *cs) |
dc64bef5 | 243 | { |
75c7b6f3 MS |
244 | unsigned long long now, adj; |
245 | ||
246 | preempt_disable(); /* protect from changes to steering parameters */ | |
247 | now = get_tod_clock(); | |
248 | adj = tod_steering_end - now; | |
249 | if (unlikely((s64) adj >= 0)) | |
250 | /* | |
251 | * manually steer by 1 cycle every 2^16 cycles. This | |
252 | * corresponds to shifting the tod delta by 15. 1s is | |
253 | * therefore steered in ~9h. The adjust will decrease | |
254 | * over time, until it finally reaches 0. | |
255 | */ | |
191ce9d1 | 256 | now += (tod_steering_delta < 0) ? (adj >> 15) : -(adj >> 15); |
75c7b6f3 MS |
257 | preempt_enable(); |
258 | return now; | |
dc64bef5 MS |
259 | } |
260 | ||
261 | static struct clocksource clocksource_tod = { | |
262 | .name = "tod", | |
d2cb0e6e | 263 | .rating = 400, |
dc64bef5 MS |
264 | .read = read_tod_clock, |
265 | .mask = -1ULL, | |
266 | .mult = 1000, | |
267 | .shift = 12, | |
cc02d809 | 268 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
dc64bef5 MS |
269 | }; |
270 | ||
f1b82746 MS |
271 | struct clocksource * __init clocksource_default_clock(void) |
272 | { | |
273 | return &clocksource_tod; | |
274 | } | |
dc64bef5 | 275 | |
79c74ecb | 276 | void update_vsyscall(struct timekeeper *tk) |
b020632e | 277 | { |
79c74ecb MS |
278 | u64 nsecps; |
279 | ||
876e7881 | 280 | if (tk->tkr_mono.clock != &clocksource_tod) |
b020632e MS |
281 | return; |
282 | ||
283 | /* Make userspace gettimeofday spin until we're done. */ | |
284 | ++vdso_data->tb_update_count; | |
285 | smp_wmb(); | |
876e7881 | 286 | vdso_data->xtime_tod_stamp = tk->tkr_mono.cycle_last; |
79c74ecb | 287 | vdso_data->xtime_clock_sec = tk->xtime_sec; |
876e7881 | 288 | vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec; |
79c74ecb MS |
289 | vdso_data->wtom_clock_sec = |
290 | tk->xtime_sec + tk->wall_to_monotonic.tv_sec; | |
876e7881 PZ |
291 | vdso_data->wtom_clock_nsec = tk->tkr_mono.xtime_nsec + |
292 | + ((u64) tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift); | |
293 | nsecps = (u64) NSEC_PER_SEC << tk->tkr_mono.shift; | |
79c74ecb MS |
294 | while (vdso_data->wtom_clock_nsec >= nsecps) { |
295 | vdso_data->wtom_clock_nsec -= nsecps; | |
296 | vdso_data->wtom_clock_sec++; | |
297 | } | |
b7eacb59 MS |
298 | |
299 | vdso_data->xtime_coarse_sec = tk->xtime_sec; | |
300 | vdso_data->xtime_coarse_nsec = | |
876e7881 | 301 | (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
b7eacb59 MS |
302 | vdso_data->wtom_coarse_sec = |
303 | vdso_data->xtime_coarse_sec + tk->wall_to_monotonic.tv_sec; | |
304 | vdso_data->wtom_coarse_nsec = | |
305 | vdso_data->xtime_coarse_nsec + tk->wall_to_monotonic.tv_nsec; | |
306 | while (vdso_data->wtom_coarse_nsec >= NSEC_PER_SEC) { | |
307 | vdso_data->wtom_coarse_nsec -= NSEC_PER_SEC; | |
308 | vdso_data->wtom_coarse_sec++; | |
309 | } | |
310 | ||
876e7881 PZ |
311 | vdso_data->tk_mult = tk->tkr_mono.mult; |
312 | vdso_data->tk_shift = tk->tkr_mono.shift; | |
b020632e MS |
313 | smp_wmb(); |
314 | ++vdso_data->tb_update_count; | |
315 | } | |
316 | ||
317 | extern struct timezone sys_tz; | |
318 | ||
319 | void update_vsyscall_tz(void) | |
320 | { | |
b020632e MS |
321 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; |
322 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
b020632e MS |
323 | } |
324 | ||
1da177e4 LT |
325 | /* |
326 | * Initialize the TOD clock and the CPU timer of | |
327 | * the boot cpu. | |
328 | */ | |
329 | void __init time_init(void) | |
330 | { | |
b6112ccb | 331 | /* Reset time synchronization interfaces. */ |
b6112ccb | 332 | stp_reset(); |
1da177e4 | 333 | |
1da177e4 | 334 | /* request the clock comparator external interrupt */ |
1dad093b TH |
335 | if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt)) |
336 | panic("Couldn't request external interrupt 0x1004"); | |
1da177e4 | 337 | |
d2fec595 | 338 | /* request the timing alert external interrupt */ |
1dad093b | 339 | if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt)) |
d54853ef MS |
340 | panic("Couldn't request external interrupt 0x1406"); |
341 | ||
f8935983 | 342 | if (__clocksource_register(&clocksource_tod) != 0) |
ab96e798 MS |
343 | panic("Could not register TOD clock source"); |
344 | ||
d54853ef MS |
345 | /* Enable TOD clock interrupts on the boot cpu. */ |
346 | init_cpu_timer(); | |
ab96e798 | 347 | |
c185b783 | 348 | /* Enable cpu timer interrupts on the boot cpu. */ |
1da177e4 | 349 | vtime_init(); |
d54853ef MS |
350 | } |
351 | ||
d2fec595 | 352 | static DEFINE_PER_CPU(atomic_t, clock_sync_word); |
8283cb43 | 353 | static DEFINE_MUTEX(clock_sync_mutex); |
d2fec595 MS |
354 | static unsigned long clock_sync_flags; |
355 | ||
ca64f639 DH |
356 | #define CLOCK_SYNC_HAS_STP 0 |
357 | #define CLOCK_SYNC_STP 1 | |
d2fec595 MS |
358 | |
359 | /* | |
40277891 MS |
360 | * The get_clock function for the physical clock. It will get the current |
361 | * TOD clock, subtract the LPAR offset and write the result to *clock. | |
362 | * The function returns 0 if the clock is in sync with the external time | |
363 | * source. If the clock mode is local it will return -EOPNOTSUPP and | |
364 | * -EAGAIN if the clock is not in sync with the external reference. | |
d2fec595 | 365 | */ |
7bf76f01 | 366 | int get_phys_clock(unsigned long *clock) |
d2fec595 MS |
367 | { |
368 | atomic_t *sw_ptr; | |
369 | unsigned int sw0, sw1; | |
370 | ||
371 | sw_ptr = &get_cpu_var(clock_sync_word); | |
372 | sw0 = atomic_read(sw_ptr); | |
40277891 | 373 | *clock = get_tod_clock() - lpar_offset; |
d2fec595 | 374 | sw1 = atomic_read(sw_ptr); |
bd119ee2 | 375 | put_cpu_var(clock_sync_word); |
d2fec595 MS |
376 | if (sw0 == sw1 && (sw0 & 0x80000000U)) |
377 | /* Success: time is in sync. */ | |
378 | return 0; | |
ca64f639 | 379 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) |
a8f6db4d | 380 | return -EOPNOTSUPP; |
ca64f639 | 381 | if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags)) |
d2fec595 MS |
382 | return -EACCES; |
383 | return -EAGAIN; | |
384 | } | |
40277891 | 385 | EXPORT_SYMBOL(get_phys_clock); |
d2fec595 MS |
386 | |
387 | /* | |
ca64f639 | 388 | * Make get_phys_clock() return -EAGAIN. |
d2fec595 MS |
389 | */ |
390 | static void disable_sync_clock(void *dummy) | |
391 | { | |
eb7e7d76 | 392 | atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); |
d2fec595 | 393 | /* |
ca64f639 | 394 | * Clear the in-sync bit 2^31. All get_phys_clock calls will |
d2fec595 MS |
395 | * fail until the sync bit is turned back on. In addition |
396 | * increase the "sequence" counter to avoid the race of an | |
ca64f639 | 397 | * stp event and the complete recovery against get_phys_clock. |
d2fec595 | 398 | */ |
805de8f4 | 399 | atomic_andnot(0x80000000, sw_ptr); |
d2fec595 MS |
400 | atomic_inc(sw_ptr); |
401 | } | |
402 | ||
403 | /* | |
ca64f639 | 404 | * Make get_phys_clock() return 0 again. |
d2fec595 MS |
405 | * Needs to be called from a context disabled for preemption. |
406 | */ | |
407 | static void enable_sync_clock(void) | |
408 | { | |
eb7e7d76 | 409 | atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); |
805de8f4 | 410 | atomic_or(0x80000000, sw_ptr); |
d2fec595 MS |
411 | } |
412 | ||
8283cb43 MS |
413 | /* |
414 | * Function to check if the clock is in sync. | |
415 | */ | |
416 | static inline int check_sync_clock(void) | |
417 | { | |
418 | atomic_t *sw_ptr; | |
419 | int rc; | |
420 | ||
421 | sw_ptr = &get_cpu_var(clock_sync_word); | |
422 | rc = (atomic_read(sw_ptr) & 0x80000000U) != 0; | |
bd119ee2 | 423 | put_cpu_var(clock_sync_word); |
8283cb43 MS |
424 | return rc; |
425 | } | |
426 | ||
b1c0854d MS |
427 | /* |
428 | * Apply clock delta to the global data structures. | |
429 | * This is called once on the CPU that performed the clock sync. | |
430 | */ | |
431 | static void clock_sync_global(unsigned long long delta) | |
432 | { | |
75c7b6f3 | 433 | unsigned long now, adj; |
b1c0854d MS |
434 | struct ptff_qto qto; |
435 | ||
436 | /* Fixup the monotonic sched clock. */ | |
6e2ef5e4 MS |
437 | *(unsigned long long *) &tod_clock_base[1] += delta; |
438 | if (*(unsigned long long *) &tod_clock_base[1] < delta) | |
439 | /* Epoch overflow */ | |
440 | tod_clock_base[0]++; | |
75c7b6f3 MS |
441 | /* Adjust TOD steering parameters. */ |
442 | vdso_data->tb_update_count++; | |
443 | now = get_tod_clock(); | |
444 | adj = tod_steering_end - now; | |
445 | if (unlikely((s64) adj >= 0)) | |
446 | /* Calculate how much of the old adjustment is left. */ | |
191ce9d1 | 447 | tod_steering_delta = (tod_steering_delta < 0) ? |
75c7b6f3 MS |
448 | -(adj >> 15) : (adj >> 15); |
449 | tod_steering_delta += delta; | |
450 | if ((abs(tod_steering_delta) >> 48) != 0) | |
451 | panic("TOD clock sync offset %lli is too large to drift\n", | |
452 | tod_steering_delta); | |
453 | tod_steering_end = now + (abs(tod_steering_delta) << 15); | |
454 | vdso_data->ts_dir = (tod_steering_delta < 0) ? 0 : 1; | |
455 | vdso_data->ts_end = tod_steering_end; | |
456 | vdso_data->tb_update_count++; | |
b1c0854d MS |
457 | /* Update LPAR offset. */ |
458 | if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) | |
459 | lpar_offset = qto.tod_epoch_difference; | |
460 | /* Call the TOD clock change notifier. */ | |
461 | atomic_notifier_call_chain(&s390_epoch_delta_notifier, 0, &delta); | |
462 | } | |
463 | ||
464 | /* | |
465 | * Apply clock delta to the per-CPU data structures of this CPU. | |
466 | * This is called for each online CPU after the call to clock_sync_global. | |
467 | */ | |
468 | static void clock_sync_local(unsigned long long delta) | |
469 | { | |
470 | /* Add the delta to the clock comparator. */ | |
6e2ef5e4 | 471 | if (S390_lowcore.clock_comparator != clock_comparator_max) { |
b1c0854d MS |
472 | S390_lowcore.clock_comparator += delta; |
473 | set_clock_comparator(S390_lowcore.clock_comparator); | |
474 | } | |
2ace06ec MS |
475 | /* Adjust the last_update_clock time-stamp. */ |
476 | S390_lowcore.last_update_clock += delta; | |
b1c0854d MS |
477 | } |
478 | ||
ca64f639 | 479 | /* Single threaded workqueue used for stp sync events */ |
750887de HC |
480 | static struct workqueue_struct *time_sync_wq; |
481 | ||
482 | static void __init time_init_wq(void) | |
483 | { | |
179cb81a HC |
484 | if (time_sync_wq) |
485 | return; | |
486 | time_sync_wq = create_singlethread_workqueue("timesync"); | |
750887de HC |
487 | } |
488 | ||
d2fec595 | 489 | struct clock_sync_data { |
750887de | 490 | atomic_t cpus; |
5a62b192 | 491 | int in_sync; |
b1c0854d | 492 | unsigned long long clock_delta; |
d2fec595 | 493 | }; |
5a62b192 | 494 | |
d2fec595 MS |
495 | /* |
496 | * Server Time Protocol (STP) code. | |
497 | */ | |
4cc7ecb7 | 498 | static bool stp_online; |
d2fec595 MS |
499 | static struct stp_sstpi stp_info; |
500 | static void *stp_page; | |
501 | ||
502 | static void stp_work_fn(struct work_struct *work); | |
0b3016b7 | 503 | static DEFINE_MUTEX(stp_work_mutex); |
d2fec595 | 504 | static DECLARE_WORK(stp_work, stp_work_fn); |
04362301 | 505 | static struct timer_list stp_timer; |
d2fec595 MS |
506 | |
507 | static int __init early_parse_stp(char *p) | |
508 | { | |
4cc7ecb7 | 509 | return kstrtobool(p, &stp_online); |
d2fec595 MS |
510 | } |
511 | early_param("stp", early_parse_stp); | |
512 | ||
513 | /* | |
514 | * Reset STP attachment. | |
515 | */ | |
8f847003 | 516 | static void __init stp_reset(void) |
d2fec595 MS |
517 | { |
518 | int rc; | |
519 | ||
d7d1104f | 520 | stp_page = (void *) get_zeroed_page(GFP_ATOMIC); |
2f82f577 | 521 | rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL); |
4a672cfa | 522 | if (rc == 0) |
d2fec595 MS |
523 | set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags); |
524 | else if (stp_online) { | |
baebc70a | 525 | pr_warn("The real or virtual hardware system does not provide an STP interface\n"); |
d7d1104f | 526 | free_page((unsigned long) stp_page); |
d2fec595 | 527 | stp_page = NULL; |
970ba6ac | 528 | stp_online = false; |
d2fec595 MS |
529 | } |
530 | } | |
531 | ||
e99e88a9 | 532 | static void stp_timeout(struct timer_list *unused) |
04362301 MS |
533 | { |
534 | queue_work(time_sync_wq, &stp_work); | |
535 | } | |
536 | ||
d2fec595 MS |
537 | static int __init stp_init(void) |
538 | { | |
750887de HC |
539 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) |
540 | return 0; | |
e99e88a9 | 541 | timer_setup(&stp_timer, stp_timeout, 0); |
750887de HC |
542 | time_init_wq(); |
543 | if (!stp_online) | |
544 | return 0; | |
545 | queue_work(time_sync_wq, &stp_work); | |
d2fec595 MS |
546 | return 0; |
547 | } | |
548 | ||
549 | arch_initcall(stp_init); | |
550 | ||
551 | /* | |
552 | * STP timing alert. There are three causes: | |
553 | * 1) timing status change | |
554 | * 2) link availability change | |
555 | * 3) time control parameter change | |
556 | * In all three cases we are only interested in the clock source state. | |
557 | * If a STP clock source is now available use it. | |
558 | */ | |
559 | static void stp_timing_alert(struct stp_irq_parm *intparm) | |
560 | { | |
561 | if (intparm->tsc || intparm->lac || intparm->tcpc) | |
750887de | 562 | queue_work(time_sync_wq, &stp_work); |
d2fec595 MS |
563 | } |
564 | ||
565 | /* | |
566 | * STP sync check machine check. This is called when the timing state | |
567 | * changes from the synchronized state to the unsynchronized state. | |
568 | * After a STP sync check the clock is not in sync. The machine check | |
569 | * is broadcasted to all cpus at the same time. | |
570 | */ | |
29b0a825 | 571 | int stp_sync_check(void) |
d2fec595 | 572 | { |
d2fec595 | 573 | disable_sync_clock(NULL); |
29b0a825 | 574 | return 1; |
d2fec595 MS |
575 | } |
576 | ||
577 | /* | |
578 | * STP island condition machine check. This is called when an attached | |
579 | * server attempts to communicate over an STP link and the servers | |
580 | * have matching CTN ids and have a valid stratum-1 configuration | |
581 | * but the configurations do not match. | |
582 | */ | |
29b0a825 | 583 | int stp_island_check(void) |
d2fec595 | 584 | { |
d2fec595 | 585 | disable_sync_clock(NULL); |
29b0a825 | 586 | return 1; |
d2fec595 MS |
587 | } |
588 | ||
29b0a825 HC |
589 | void stp_queue_work(void) |
590 | { | |
591 | queue_work(time_sync_wq, &stp_work); | |
592 | } | |
750887de HC |
593 | |
594 | static int stp_sync_clock(void *data) | |
d2fec595 | 595 | { |
b1c0854d | 596 | struct clock_sync_data *sync = data; |
41ad0220 | 597 | unsigned long long clock_delta; |
b1c0854d | 598 | static int first; |
d2fec595 MS |
599 | int rc; |
600 | ||
d2fec595 | 601 | enable_sync_clock(); |
b1c0854d MS |
602 | if (xchg(&first, 1) == 0) { |
603 | /* Wait until all other cpus entered the sync function. */ | |
604 | while (atomic_read(&sync->cpus) != 0) | |
605 | cpu_relax(); | |
606 | rc = 0; | |
607 | if (stp_info.todoff[0] || stp_info.todoff[1] || | |
608 | stp_info.todoff[2] || stp_info.todoff[3] || | |
609 | stp_info.tmd != 2) { | |
610 | rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0, | |
611 | &clock_delta); | |
612 | if (rc == 0) { | |
613 | sync->clock_delta = clock_delta; | |
614 | clock_sync_global(clock_delta); | |
615 | rc = chsc_sstpi(stp_page, &stp_info, | |
616 | sizeof(struct stp_sstpi)); | |
617 | if (rc == 0 && stp_info.tmd != 2) | |
618 | rc = -EAGAIN; | |
619 | } | |
d2fec595 | 620 | } |
b1c0854d MS |
621 | sync->in_sync = rc ? -EAGAIN : 1; |
622 | xchg(&first, 0); | |
623 | } else { | |
624 | /* Slave */ | |
625 | atomic_dec(&sync->cpus); | |
626 | /* Wait for in_sync to be set. */ | |
627 | while (READ_ONCE(sync->in_sync) == 0) | |
628 | __udelay(1); | |
d2fec595 | 629 | } |
b1c0854d MS |
630 | if (sync->in_sync != 1) |
631 | /* Didn't work. Clear per-cpu in sync bit again. */ | |
d2fec595 | 632 | disable_sync_clock(NULL); |
b1c0854d MS |
633 | /* Apply clock delta to per-CPU fields of this CPU. */ |
634 | clock_sync_local(sync->clock_delta); | |
635 | ||
750887de HC |
636 | return 0; |
637 | } | |
d2fec595 | 638 | |
750887de HC |
639 | /* |
640 | * STP work. Check for the STP state and take over the clock | |
641 | * synchronization if the STP clock source is usable. | |
642 | */ | |
643 | static void stp_work_fn(struct work_struct *work) | |
644 | { | |
645 | struct clock_sync_data stp_sync; | |
646 | int rc; | |
647 | ||
0b3016b7 MS |
648 | /* prevent multiple execution. */ |
649 | mutex_lock(&stp_work_mutex); | |
650 | ||
750887de | 651 | if (!stp_online) { |
2f82f577 | 652 | chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL); |
04362301 | 653 | del_timer_sync(&stp_timer); |
0b3016b7 | 654 | goto out_unlock; |
750887de HC |
655 | } |
656 | ||
2f82f577 | 657 | rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0, NULL); |
750887de | 658 | if (rc) |
0b3016b7 | 659 | goto out_unlock; |
750887de HC |
660 | |
661 | rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi)); | |
662 | if (rc || stp_info.c == 0) | |
0b3016b7 | 663 | goto out_unlock; |
750887de | 664 | |
8283cb43 MS |
665 | /* Skip synchronization if the clock is already in sync. */ |
666 | if (check_sync_clock()) | |
667 | goto out_unlock; | |
668 | ||
750887de | 669 | memset(&stp_sync, 0, sizeof(stp_sync)); |
2337e879 | 670 | cpus_read_lock(); |
750887de | 671 | atomic_set(&stp_sync.cpus, num_online_cpus() - 1); |
2337e879 SAS |
672 | stop_machine_cpuslocked(stp_sync_clock, &stp_sync, cpu_online_mask); |
673 | cpus_read_unlock(); | |
0b3016b7 | 674 | |
04362301 MS |
675 | if (!check_sync_clock()) |
676 | /* | |
677 | * There is a usable clock but the synchonization failed. | |
678 | * Retry after a second. | |
679 | */ | |
680 | mod_timer(&stp_timer, jiffies + HZ); | |
681 | ||
0b3016b7 MS |
682 | out_unlock: |
683 | mutex_unlock(&stp_work_mutex); | |
d2fec595 MS |
684 | } |
685 | ||
686 | /* | |
3fbacffb | 687 | * STP subsys sysfs interface functions |
d2fec595 | 688 | */ |
3fbacffb KS |
689 | static struct bus_type stp_subsys = { |
690 | .name = "stp", | |
691 | .dev_name = "stp", | |
d2fec595 MS |
692 | }; |
693 | ||
3fbacffb KS |
694 | static ssize_t stp_ctn_id_show(struct device *dev, |
695 | struct device_attribute *attr, | |
c9be0a36 | 696 | char *buf) |
d2fec595 MS |
697 | { |
698 | if (!stp_online) | |
699 | return -ENODATA; | |
700 | return sprintf(buf, "%016llx\n", | |
701 | *(unsigned long long *) stp_info.ctnid); | |
702 | } | |
703 | ||
3fbacffb | 704 | static DEVICE_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL); |
d2fec595 | 705 | |
3fbacffb KS |
706 | static ssize_t stp_ctn_type_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", stp_info.ctn); | |
713 | } | |
714 | ||
3fbacffb | 715 | static DEVICE_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL); |
d2fec595 | 716 | |
3fbacffb KS |
717 | static ssize_t stp_dst_offset_show(struct device *dev, |
718 | struct device_attribute *attr, | |
c9be0a36 | 719 | char *buf) |
d2fec595 MS |
720 | { |
721 | if (!stp_online || !(stp_info.vbits & 0x2000)) | |
722 | return -ENODATA; | |
723 | return sprintf(buf, "%i\n", (int)(s16) stp_info.dsto); | |
724 | } | |
725 | ||
3fbacffb | 726 | static DEVICE_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL); |
d2fec595 | 727 | |
3fbacffb KS |
728 | static ssize_t stp_leap_seconds_show(struct device *dev, |
729 | struct device_attribute *attr, | |
c9be0a36 | 730 | char *buf) |
d2fec595 MS |
731 | { |
732 | if (!stp_online || !(stp_info.vbits & 0x8000)) | |
733 | return -ENODATA; | |
734 | return sprintf(buf, "%i\n", (int)(s16) stp_info.leaps); | |
735 | } | |
736 | ||
3fbacffb | 737 | static DEVICE_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL); |
d2fec595 | 738 | |
3fbacffb KS |
739 | static ssize_t stp_stratum_show(struct device *dev, |
740 | struct device_attribute *attr, | |
c9be0a36 | 741 | char *buf) |
d2fec595 MS |
742 | { |
743 | if (!stp_online) | |
744 | return -ENODATA; | |
745 | return sprintf(buf, "%i\n", (int)(s16) stp_info.stratum); | |
746 | } | |
747 | ||
3fbacffb | 748 | static DEVICE_ATTR(stratum, 0400, stp_stratum_show, NULL); |
d2fec595 | 749 | |
3fbacffb KS |
750 | static ssize_t stp_time_offset_show(struct device *dev, |
751 | struct device_attribute *attr, | |
c9be0a36 | 752 | char *buf) |
d2fec595 MS |
753 | { |
754 | if (!stp_online || !(stp_info.vbits & 0x0800)) | |
755 | return -ENODATA; | |
756 | return sprintf(buf, "%i\n", (int) stp_info.tto); | |
757 | } | |
758 | ||
3fbacffb | 759 | static DEVICE_ATTR(time_offset, 0400, stp_time_offset_show, NULL); |
d2fec595 | 760 | |
3fbacffb KS |
761 | static ssize_t stp_time_zone_offset_show(struct device *dev, |
762 | struct device_attribute *attr, | |
c9be0a36 | 763 | char *buf) |
d2fec595 MS |
764 | { |
765 | if (!stp_online || !(stp_info.vbits & 0x4000)) | |
766 | return -ENODATA; | |
767 | return sprintf(buf, "%i\n", (int)(s16) stp_info.tzo); | |
768 | } | |
769 | ||
3fbacffb | 770 | static DEVICE_ATTR(time_zone_offset, 0400, |
d2fec595 MS |
771 | stp_time_zone_offset_show, NULL); |
772 | ||
3fbacffb KS |
773 | static ssize_t stp_timing_mode_show(struct device *dev, |
774 | struct device_attribute *attr, | |
c9be0a36 | 775 | char *buf) |
d2fec595 MS |
776 | { |
777 | if (!stp_online) | |
778 | return -ENODATA; | |
779 | return sprintf(buf, "%i\n", stp_info.tmd); | |
780 | } | |
781 | ||
3fbacffb | 782 | static DEVICE_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL); |
d2fec595 | 783 | |
3fbacffb KS |
784 | static ssize_t stp_timing_state_show(struct device *dev, |
785 | struct device_attribute *attr, | |
c9be0a36 | 786 | char *buf) |
d2fec595 MS |
787 | { |
788 | if (!stp_online) | |
789 | return -ENODATA; | |
790 | return sprintf(buf, "%i\n", stp_info.tst); | |
791 | } | |
792 | ||
3fbacffb | 793 | static DEVICE_ATTR(timing_state, 0400, stp_timing_state_show, NULL); |
d2fec595 | 794 | |
3fbacffb KS |
795 | static ssize_t stp_online_show(struct device *dev, |
796 | struct device_attribute *attr, | |
c9be0a36 | 797 | char *buf) |
d2fec595 MS |
798 | { |
799 | return sprintf(buf, "%i\n", stp_online); | |
800 | } | |
801 | ||
3fbacffb KS |
802 | static ssize_t stp_online_store(struct device *dev, |
803 | struct device_attribute *attr, | |
d2fec595 MS |
804 | const char *buf, size_t count) |
805 | { | |
806 | unsigned int value; | |
807 | ||
808 | value = simple_strtoul(buf, NULL, 0); | |
809 | if (value != 0 && value != 1) | |
810 | return -EINVAL; | |
811 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) | |
812 | return -EOPNOTSUPP; | |
8283cb43 | 813 | mutex_lock(&clock_sync_mutex); |
d2fec595 | 814 | stp_online = value; |
8283cb43 MS |
815 | if (stp_online) |
816 | set_bit(CLOCK_SYNC_STP, &clock_sync_flags); | |
817 | else | |
818 | clear_bit(CLOCK_SYNC_STP, &clock_sync_flags); | |
750887de | 819 | queue_work(time_sync_wq, &stp_work); |
8283cb43 | 820 | mutex_unlock(&clock_sync_mutex); |
d2fec595 MS |
821 | return count; |
822 | } | |
823 | ||
824 | /* | |
3fbacffb KS |
825 | * Can't use DEVICE_ATTR because the attribute should be named |
826 | * stp/online but dev_attr_online already exists in this file .. | |
d2fec595 | 827 | */ |
3fbacffb | 828 | static struct device_attribute dev_attr_stp_online = { |
d2fec595 MS |
829 | .attr = { .name = "online", .mode = 0600 }, |
830 | .show = stp_online_show, | |
831 | .store = stp_online_store, | |
832 | }; | |
833 | ||
3fbacffb KS |
834 | static struct device_attribute *stp_attributes[] = { |
835 | &dev_attr_ctn_id, | |
836 | &dev_attr_ctn_type, | |
837 | &dev_attr_dst_offset, | |
838 | &dev_attr_leap_seconds, | |
839 | &dev_attr_stp_online, | |
840 | &dev_attr_stratum, | |
841 | &dev_attr_time_offset, | |
842 | &dev_attr_time_zone_offset, | |
843 | &dev_attr_timing_mode, | |
844 | &dev_attr_timing_state, | |
d2fec595 MS |
845 | NULL |
846 | }; | |
847 | ||
848 | static int __init stp_init_sysfs(void) | |
849 | { | |
3fbacffb | 850 | struct device_attribute **attr; |
d2fec595 MS |
851 | int rc; |
852 | ||
3fbacffb | 853 | rc = subsys_system_register(&stp_subsys, NULL); |
d2fec595 MS |
854 | if (rc) |
855 | goto out; | |
856 | for (attr = stp_attributes; *attr; attr++) { | |
3fbacffb | 857 | rc = device_create_file(stp_subsys.dev_root, *attr); |
d2fec595 MS |
858 | if (rc) |
859 | goto out_unreg; | |
860 | } | |
861 | return 0; | |
862 | out_unreg: | |
863 | for (; attr >= stp_attributes; attr--) | |
3fbacffb KS |
864 | device_remove_file(stp_subsys.dev_root, *attr); |
865 | bus_unregister(&stp_subsys); | |
d2fec595 MS |
866 | out: |
867 | return rc; | |
868 | } | |
869 | ||
870 | device_initcall(stp_init_sysfs); |