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 | 18 | #include <linux/errno.h> |
3994a52b | 19 | #include <linux/export.h> |
1da177e4 | 20 | #include <linux/sched.h> |
e6017571 | 21 | #include <linux/sched/clock.h> |
1da177e4 LT |
22 | #include <linux/kernel.h> |
23 | #include <linux/param.h> | |
24 | #include <linux/string.h> | |
25 | #include <linux/mm.h> | |
26 | #include <linux/interrupt.h> | |
750887de HC |
27 | #include <linux/cpu.h> |
28 | #include <linux/stop_machine.h> | |
1da177e4 | 29 | #include <linux/time.h> |
3fbacffb | 30 | #include <linux/device.h> |
1da177e4 LT |
31 | #include <linux/delay.h> |
32 | #include <linux/init.h> | |
33 | #include <linux/smp.h> | |
34 | #include <linux/types.h> | |
35 | #include <linux/profile.h> | |
36 | #include <linux/timex.h> | |
37 | #include <linux/notifier.h> | |
189374ae | 38 | #include <linux/timekeeper_internal.h> |
5a62b192 | 39 | #include <linux/clockchips.h> |
5a0e3ad6 | 40 | #include <linux/gfp.h> |
860dba45 | 41 | #include <linux/kprobes.h> |
7c0f6ba6 | 42 | #include <linux/uaccess.h> |
40277891 | 43 | #include <asm/facility.h> |
1da177e4 | 44 | #include <asm/delay.h> |
1da177e4 | 45 | #include <asm/div64.h> |
b020632e | 46 | #include <asm/vdso.h> |
1da177e4 | 47 | #include <asm/irq.h> |
5a489b98 | 48 | #include <asm/irq_regs.h> |
27f6b416 | 49 | #include <asm/vtimer.h> |
fd5ada04 | 50 | #include <asm/stp.h> |
a806170e | 51 | #include <asm/cio.h> |
638ad34a | 52 | #include "entry.h" |
1da177e4 | 53 | |
6e2ef5e4 MS |
54 | unsigned char tod_clock_base[16] __aligned(8) = { |
55 | /* Force to data section. */ | |
56 | 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, | |
57 | 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff | |
58 | }; | |
59 | EXPORT_SYMBOL_GPL(tod_clock_base); | |
60 | ||
61 | u64 clock_comparator_max = -1ULL; | |
62 | EXPORT_SYMBOL_GPL(clock_comparator_max); | |
b6112ccb | 63 | |
5a62b192 | 64 | static DEFINE_PER_CPU(struct clock_event_device, comparators); |
1da177e4 | 65 | |
fdf03650 FZ |
66 | ATOMIC_NOTIFIER_HEAD(s390_epoch_delta_notifier); |
67 | EXPORT_SYMBOL(s390_epoch_delta_notifier); | |
68 | ||
40277891 | 69 | unsigned char ptff_function_mask[16]; |
b1c0854d MS |
70 | |
71 | static unsigned long long lpar_offset; | |
72 | static unsigned long long initial_leap_seconds; | |
75c7b6f3 | 73 | static unsigned long long tod_steering_end; |
191ce9d1 | 74 | static long long tod_steering_delta; |
40277891 MS |
75 | |
76 | /* | |
77 | * Get time offsets with PTFF | |
78 | */ | |
b1c0854d | 79 | void __init time_early_init(void) |
40277891 MS |
80 | { |
81 | struct ptff_qto qto; | |
936cc855 | 82 | struct ptff_qui qui; |
40277891 | 83 | |
75c7b6f3 | 84 | /* Initialize TOD steering parameters */ |
6e2ef5e4 | 85 | tod_steering_end = *(unsigned long long *) &tod_clock_base[1]; |
75c7b6f3 MS |
86 | vdso_data->ts_end = tod_steering_end; |
87 | ||
40277891 MS |
88 | if (!test_facility(28)) |
89 | return; | |
75c7b6f3 | 90 | |
40277891 MS |
91 | ptff(&ptff_function_mask, sizeof(ptff_function_mask), PTFF_QAF); |
92 | ||
93 | /* get LPAR offset */ | |
94 | if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) | |
95 | lpar_offset = qto.tod_epoch_difference; | |
936cc855 MS |
96 | |
97 | /* get initial leap seconds */ | |
98 | if (ptff_query(PTFF_QUI) && ptff(&qui, sizeof(qui), PTFF_QUI) == 0) | |
b1c0854d | 99 | initial_leap_seconds = (unsigned long long) |
936cc855 | 100 | ((long) qui.old_leap * 4096000000L); |
40277891 MS |
101 | } |
102 | ||
1da177e4 LT |
103 | /* |
104 | * Scheduler clock - returns current time in nanosec units. | |
105 | */ | |
7a5388de | 106 | unsigned long long notrace sched_clock(void) |
1da177e4 | 107 | { |
1aae0560 | 108 | return tod_to_ns(get_tod_clock_monotonic()); |
1da177e4 | 109 | } |
7a5388de | 110 | NOKPROBE_SYMBOL(sched_clock); |
1da177e4 | 111 | |
32f65f27 JG |
112 | /* |
113 | * Monotonic_clock - returns # of nanoseconds passed since time_init() | |
114 | */ | |
115 | unsigned long long monotonic_clock(void) | |
116 | { | |
117 | return sched_clock(); | |
118 | } | |
119 | EXPORT_SYMBOL(monotonic_clock); | |
120 | ||
6e2ef5e4 | 121 | static void ext_to_timespec64(unsigned char *clk, struct timespec64 *xt) |
1da177e4 | 122 | { |
6e2ef5e4 MS |
123 | unsigned long long high, low, rem, sec, nsec; |
124 | ||
125 | /* Split extendnd TOD clock to micro-seconds and sub-micro-seconds */ | |
126 | high = (*(unsigned long long *) clk) >> 4; | |
127 | low = (*(unsigned long long *)&clk[7]) << 4; | |
128 | /* Calculate seconds and nano-seconds */ | |
129 | sec = high; | |
130 | rem = do_div(sec, 1000000); | |
131 | nsec = (((low >> 32) + (rem << 32)) * 1000) >> 32; | |
1da177e4 | 132 | |
b1e2ba8d | 133 | xt->tv_sec = sec; |
6e2ef5e4 | 134 | xt->tv_nsec = nsec; |
1da177e4 LT |
135 | } |
136 | ||
5a62b192 | 137 | void clock_comparator_work(void) |
1da177e4 | 138 | { |
5a62b192 | 139 | struct clock_event_device *cd; |
1da177e4 | 140 | |
6e2ef5e4 | 141 | S390_lowcore.clock_comparator = clock_comparator_max; |
eb7e7d76 | 142 | cd = this_cpu_ptr(&comparators); |
5a62b192 | 143 | cd->event_handler(cd); |
1da177e4 LT |
144 | } |
145 | ||
8adbf78e | 146 | static int s390_next_event(unsigned long delta, |
5a62b192 | 147 | struct clock_event_device *evt) |
1da177e4 | 148 | { |
8adbf78e | 149 | S390_lowcore.clock_comparator = get_tod_clock() + delta; |
5a62b192 HC |
150 | set_clock_comparator(S390_lowcore.clock_comparator); |
151 | return 0; | |
1da177e4 LT |
152 | } |
153 | ||
d54853ef MS |
154 | /* |
155 | * Set up lowcore and control register of the current cpu to | |
156 | * enable TOD clock and clock comparator interrupts. | |
1da177e4 LT |
157 | */ |
158 | void init_cpu_timer(void) | |
159 | { | |
5a62b192 HC |
160 | struct clock_event_device *cd; |
161 | int cpu; | |
162 | ||
6e2ef5e4 | 163 | S390_lowcore.clock_comparator = clock_comparator_max; |
5a62b192 HC |
164 | set_clock_comparator(S390_lowcore.clock_comparator); |
165 | ||
166 | cpu = smp_processor_id(); | |
167 | cd = &per_cpu(comparators, cpu); | |
168 | cd->name = "comparator"; | |
8adbf78e | 169 | cd->features = CLOCK_EVT_FEAT_ONESHOT; |
5a62b192 HC |
170 | cd->mult = 16777; |
171 | cd->shift = 12; | |
172 | cd->min_delta_ns = 1; | |
06c54611 | 173 | cd->min_delta_ticks = 1; |
5a62b192 | 174 | cd->max_delta_ns = LONG_MAX; |
06c54611 | 175 | cd->max_delta_ticks = ULONG_MAX; |
5a62b192 | 176 | cd->rating = 400; |
320ab2b0 | 177 | cd->cpumask = cpumask_of(cpu); |
8adbf78e | 178 | cd->set_next_event = s390_next_event; |
5a62b192 HC |
179 | |
180 | clockevents_register_device(cd); | |
d54853ef MS |
181 | |
182 | /* Enable clock comparator timer interrupt. */ | |
183 | __ctl_set_bit(0,11); | |
184 | ||
d2fec595 | 185 | /* Always allow the timing alert external interrupt. */ |
d54853ef MS |
186 | __ctl_set_bit(0, 4); |
187 | } | |
188 | ||
fde15c3a | 189 | static void clock_comparator_interrupt(struct ext_code ext_code, |
f6649a7e MS |
190 | unsigned int param32, |
191 | unsigned long param64) | |
d54853ef | 192 | { |
420f42ec | 193 | inc_irq_stat(IRQEXT_CLK); |
6e2ef5e4 | 194 | if (S390_lowcore.clock_comparator == clock_comparator_max) |
d3d238c7 | 195 | set_clock_comparator(S390_lowcore.clock_comparator); |
d54853ef MS |
196 | } |
197 | ||
d2fec595 MS |
198 | static void stp_timing_alert(struct stp_irq_parm *); |
199 | ||
fde15c3a | 200 | static void timing_alert_interrupt(struct ext_code ext_code, |
f6649a7e | 201 | unsigned int param32, unsigned long param64) |
d2fec595 | 202 | { |
420f42ec | 203 | inc_irq_stat(IRQEXT_TLA); |
f6649a7e MS |
204 | if (param32 & 0x00038000) |
205 | stp_timing_alert((struct stp_irq_parm *) ¶m32); | |
d2fec595 MS |
206 | } |
207 | ||
d2fec595 | 208 | static void stp_reset(void); |
d54853ef | 209 | |
689911c7 | 210 | void read_persistent_clock64(struct timespec64 *ts) |
d54853ef | 211 | { |
6e2ef5e4 MS |
212 | unsigned char clk[STORE_CLOCK_EXT_SIZE]; |
213 | __u64 delta; | |
214 | ||
215 | delta = initial_leap_seconds + TOD_UNIX_EPOCH; | |
216 | get_tod_clock_ext(clk); | |
217 | *(__u64 *) &clk[1] -= delta; | |
218 | if (*(__u64 *) &clk[1] > delta) | |
219 | clk[0]--; | |
220 | ext_to_timespec64(clk, ts); | |
1da177e4 | 221 | } |
d54853ef | 222 | |
689911c7 | 223 | void read_boot_clock64(struct timespec64 *ts) |
23970e38 | 224 | { |
6e2ef5e4 MS |
225 | unsigned char clk[STORE_CLOCK_EXT_SIZE]; |
226 | __u64 delta; | |
227 | ||
228 | delta = initial_leap_seconds + TOD_UNIX_EPOCH; | |
229 | memcpy(clk, tod_clock_base, 16); | |
230 | *(__u64 *) &clk[1] -= delta; | |
231 | if (*(__u64 *) &clk[1] > delta) | |
232 | clk[0]--; | |
233 | ext_to_timespec64(clk, ts); | |
1da177e4 LT |
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; | |
243 | if (unlikely((s64) adj >= 0)) | |
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 MS |
258 | .read = read_tod_clock, |
259 | .mask = -1ULL, | |
260 | .mult = 1000, | |
261 | .shift = 12, | |
cc02d809 | 262 | .flags = CLOCK_SOURCE_IS_CONTINUOUS, |
dc64bef5 MS |
263 | }; |
264 | ||
f1b82746 MS |
265 | struct clocksource * __init clocksource_default_clock(void) |
266 | { | |
267 | return &clocksource_tod; | |
268 | } | |
dc64bef5 | 269 | |
79c74ecb | 270 | void update_vsyscall(struct timekeeper *tk) |
b020632e | 271 | { |
79c74ecb MS |
272 | u64 nsecps; |
273 | ||
876e7881 | 274 | if (tk->tkr_mono.clock != &clocksource_tod) |
b020632e MS |
275 | return; |
276 | ||
277 | /* Make userspace gettimeofday spin until we're done. */ | |
278 | ++vdso_data->tb_update_count; | |
279 | smp_wmb(); | |
876e7881 | 280 | vdso_data->xtime_tod_stamp = tk->tkr_mono.cycle_last; |
79c74ecb | 281 | vdso_data->xtime_clock_sec = tk->xtime_sec; |
876e7881 | 282 | vdso_data->xtime_clock_nsec = tk->tkr_mono.xtime_nsec; |
79c74ecb MS |
283 | vdso_data->wtom_clock_sec = |
284 | tk->xtime_sec + tk->wall_to_monotonic.tv_sec; | |
876e7881 PZ |
285 | vdso_data->wtom_clock_nsec = tk->tkr_mono.xtime_nsec + |
286 | + ((u64) tk->wall_to_monotonic.tv_nsec << tk->tkr_mono.shift); | |
287 | nsecps = (u64) NSEC_PER_SEC << tk->tkr_mono.shift; | |
79c74ecb MS |
288 | while (vdso_data->wtom_clock_nsec >= nsecps) { |
289 | vdso_data->wtom_clock_nsec -= nsecps; | |
290 | vdso_data->wtom_clock_sec++; | |
291 | } | |
b7eacb59 MS |
292 | |
293 | vdso_data->xtime_coarse_sec = tk->xtime_sec; | |
294 | vdso_data->xtime_coarse_nsec = | |
876e7881 | 295 | (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift); |
b7eacb59 MS |
296 | vdso_data->wtom_coarse_sec = |
297 | vdso_data->xtime_coarse_sec + tk->wall_to_monotonic.tv_sec; | |
298 | vdso_data->wtom_coarse_nsec = | |
299 | vdso_data->xtime_coarse_nsec + tk->wall_to_monotonic.tv_nsec; | |
300 | while (vdso_data->wtom_coarse_nsec >= NSEC_PER_SEC) { | |
301 | vdso_data->wtom_coarse_nsec -= NSEC_PER_SEC; | |
302 | vdso_data->wtom_coarse_sec++; | |
303 | } | |
304 | ||
876e7881 PZ |
305 | vdso_data->tk_mult = tk->tkr_mono.mult; |
306 | vdso_data->tk_shift = tk->tkr_mono.shift; | |
b020632e MS |
307 | smp_wmb(); |
308 | ++vdso_data->tb_update_count; | |
309 | } | |
310 | ||
311 | extern struct timezone sys_tz; | |
312 | ||
313 | void update_vsyscall_tz(void) | |
314 | { | |
b020632e MS |
315 | vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; |
316 | vdso_data->tz_dsttime = sys_tz.tz_dsttime; | |
b020632e MS |
317 | } |
318 | ||
1da177e4 LT |
319 | /* |
320 | * Initialize the TOD clock and the CPU timer of | |
321 | * the boot cpu. | |
322 | */ | |
323 | void __init time_init(void) | |
324 | { | |
b6112ccb | 325 | /* Reset time synchronization interfaces. */ |
b6112ccb | 326 | stp_reset(); |
1da177e4 | 327 | |
1da177e4 | 328 | /* request the clock comparator external interrupt */ |
1dad093b TH |
329 | if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt)) |
330 | panic("Couldn't request external interrupt 0x1004"); | |
1da177e4 | 331 | |
d2fec595 | 332 | /* request the timing alert external interrupt */ |
1dad093b | 333 | if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt)) |
d54853ef MS |
334 | panic("Couldn't request external interrupt 0x1406"); |
335 | ||
f8935983 | 336 | if (__clocksource_register(&clocksource_tod) != 0) |
ab96e798 MS |
337 | panic("Could not register TOD clock source"); |
338 | ||
d54853ef MS |
339 | /* Enable TOD clock interrupts on the boot cpu. */ |
340 | init_cpu_timer(); | |
ab96e798 | 341 | |
c185b783 | 342 | /* Enable cpu timer interrupts on the boot cpu. */ |
1da177e4 | 343 | vtime_init(); |
d54853ef MS |
344 | } |
345 | ||
d2fec595 | 346 | static DEFINE_PER_CPU(atomic_t, clock_sync_word); |
8283cb43 | 347 | static DEFINE_MUTEX(clock_sync_mutex); |
d2fec595 MS |
348 | static unsigned long clock_sync_flags; |
349 | ||
ca64f639 DH |
350 | #define CLOCK_SYNC_HAS_STP 0 |
351 | #define CLOCK_SYNC_STP 1 | |
d2fec595 MS |
352 | |
353 | /* | |
40277891 MS |
354 | * The get_clock function for the physical clock. It will get the current |
355 | * TOD clock, subtract the LPAR offset and write the result to *clock. | |
356 | * The function returns 0 if the clock is in sync with the external time | |
357 | * source. If the clock mode is local it will return -EOPNOTSUPP and | |
358 | * -EAGAIN if the clock is not in sync with the external reference. | |
d2fec595 | 359 | */ |
7bf76f01 | 360 | int get_phys_clock(unsigned long *clock) |
d2fec595 MS |
361 | { |
362 | atomic_t *sw_ptr; | |
363 | unsigned int sw0, sw1; | |
364 | ||
365 | sw_ptr = &get_cpu_var(clock_sync_word); | |
366 | sw0 = atomic_read(sw_ptr); | |
40277891 | 367 | *clock = get_tod_clock() - lpar_offset; |
d2fec595 | 368 | sw1 = atomic_read(sw_ptr); |
bd119ee2 | 369 | put_cpu_var(clock_sync_word); |
d2fec595 MS |
370 | if (sw0 == sw1 && (sw0 & 0x80000000U)) |
371 | /* Success: time is in sync. */ | |
372 | return 0; | |
ca64f639 | 373 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) |
a8f6db4d | 374 | return -EOPNOTSUPP; |
ca64f639 | 375 | if (!test_bit(CLOCK_SYNC_STP, &clock_sync_flags)) |
d2fec595 MS |
376 | return -EACCES; |
377 | return -EAGAIN; | |
378 | } | |
40277891 | 379 | EXPORT_SYMBOL(get_phys_clock); |
d2fec595 MS |
380 | |
381 | /* | |
ca64f639 | 382 | * Make get_phys_clock() return -EAGAIN. |
d2fec595 MS |
383 | */ |
384 | static void disable_sync_clock(void *dummy) | |
385 | { | |
eb7e7d76 | 386 | atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); |
d2fec595 | 387 | /* |
ca64f639 | 388 | * Clear the in-sync bit 2^31. All get_phys_clock calls will |
d2fec595 MS |
389 | * fail until the sync bit is turned back on. In addition |
390 | * increase the "sequence" counter to avoid the race of an | |
ca64f639 | 391 | * stp event and the complete recovery against get_phys_clock. |
d2fec595 | 392 | */ |
805de8f4 | 393 | atomic_andnot(0x80000000, sw_ptr); |
d2fec595 MS |
394 | atomic_inc(sw_ptr); |
395 | } | |
396 | ||
397 | /* | |
ca64f639 | 398 | * Make get_phys_clock() return 0 again. |
d2fec595 MS |
399 | * Needs to be called from a context disabled for preemption. |
400 | */ | |
401 | static void enable_sync_clock(void) | |
402 | { | |
eb7e7d76 | 403 | atomic_t *sw_ptr = this_cpu_ptr(&clock_sync_word); |
805de8f4 | 404 | atomic_or(0x80000000, sw_ptr); |
d2fec595 MS |
405 | } |
406 | ||
8283cb43 MS |
407 | /* |
408 | * Function to check if the clock is in sync. | |
409 | */ | |
410 | static inline int check_sync_clock(void) | |
411 | { | |
412 | atomic_t *sw_ptr; | |
413 | int rc; | |
414 | ||
415 | sw_ptr = &get_cpu_var(clock_sync_word); | |
416 | rc = (atomic_read(sw_ptr) & 0x80000000U) != 0; | |
bd119ee2 | 417 | put_cpu_var(clock_sync_word); |
8283cb43 MS |
418 | return rc; |
419 | } | |
420 | ||
b1c0854d MS |
421 | /* |
422 | * Apply clock delta to the global data structures. | |
423 | * This is called once on the CPU that performed the clock sync. | |
424 | */ | |
425 | static void clock_sync_global(unsigned long long delta) | |
426 | { | |
75c7b6f3 | 427 | unsigned long now, adj; |
b1c0854d MS |
428 | struct ptff_qto qto; |
429 | ||
430 | /* Fixup the monotonic sched clock. */ | |
6e2ef5e4 MS |
431 | *(unsigned long long *) &tod_clock_base[1] += delta; |
432 | if (*(unsigned long long *) &tod_clock_base[1] < delta) | |
433 | /* Epoch overflow */ | |
434 | tod_clock_base[0]++; | |
75c7b6f3 MS |
435 | /* Adjust TOD steering parameters. */ |
436 | vdso_data->tb_update_count++; | |
437 | now = get_tod_clock(); | |
438 | adj = tod_steering_end - now; | |
439 | if (unlikely((s64) adj >= 0)) | |
440 | /* Calculate how much of the old adjustment is left. */ | |
191ce9d1 | 441 | tod_steering_delta = (tod_steering_delta < 0) ? |
75c7b6f3 MS |
442 | -(adj >> 15) : (adj >> 15); |
443 | tod_steering_delta += delta; | |
444 | if ((abs(tod_steering_delta) >> 48) != 0) | |
445 | panic("TOD clock sync offset %lli is too large to drift\n", | |
446 | tod_steering_delta); | |
447 | tod_steering_end = now + (abs(tod_steering_delta) << 15); | |
448 | vdso_data->ts_dir = (tod_steering_delta < 0) ? 0 : 1; | |
449 | vdso_data->ts_end = tod_steering_end; | |
450 | vdso_data->tb_update_count++; | |
b1c0854d MS |
451 | /* Update LPAR offset. */ |
452 | if (ptff_query(PTFF_QTO) && ptff(&qto, sizeof(qto), PTFF_QTO) == 0) | |
453 | lpar_offset = qto.tod_epoch_difference; | |
454 | /* Call the TOD clock change notifier. */ | |
455 | atomic_notifier_call_chain(&s390_epoch_delta_notifier, 0, &delta); | |
456 | } | |
457 | ||
458 | /* | |
459 | * Apply clock delta to the per-CPU data structures of this CPU. | |
460 | * This is called for each online CPU after the call to clock_sync_global. | |
461 | */ | |
462 | static void clock_sync_local(unsigned long long delta) | |
463 | { | |
464 | /* Add the delta to the clock comparator. */ | |
6e2ef5e4 | 465 | if (S390_lowcore.clock_comparator != clock_comparator_max) { |
b1c0854d MS |
466 | S390_lowcore.clock_comparator += delta; |
467 | set_clock_comparator(S390_lowcore.clock_comparator); | |
468 | } | |
2ace06ec MS |
469 | /* Adjust the last_update_clock time-stamp. */ |
470 | S390_lowcore.last_update_clock += delta; | |
b1c0854d MS |
471 | } |
472 | ||
ca64f639 | 473 | /* Single threaded workqueue used for stp sync events */ |
750887de HC |
474 | static struct workqueue_struct *time_sync_wq; |
475 | ||
476 | static void __init time_init_wq(void) | |
477 | { | |
179cb81a HC |
478 | if (time_sync_wq) |
479 | return; | |
480 | time_sync_wq = create_singlethread_workqueue("timesync"); | |
750887de HC |
481 | } |
482 | ||
d2fec595 | 483 | struct clock_sync_data { |
750887de | 484 | atomic_t cpus; |
5a62b192 | 485 | int in_sync; |
b1c0854d | 486 | unsigned long long clock_delta; |
d2fec595 | 487 | }; |
5a62b192 | 488 | |
d2fec595 MS |
489 | /* |
490 | * Server Time Protocol (STP) code. | |
491 | */ | |
4cc7ecb7 | 492 | static bool stp_online; |
d2fec595 MS |
493 | static struct stp_sstpi stp_info; |
494 | static void *stp_page; | |
495 | ||
496 | static void stp_work_fn(struct work_struct *work); | |
0b3016b7 | 497 | static DEFINE_MUTEX(stp_work_mutex); |
d2fec595 | 498 | static DECLARE_WORK(stp_work, stp_work_fn); |
04362301 | 499 | static struct timer_list stp_timer; |
d2fec595 MS |
500 | |
501 | static int __init early_parse_stp(char *p) | |
502 | { | |
4cc7ecb7 | 503 | return kstrtobool(p, &stp_online); |
d2fec595 MS |
504 | } |
505 | early_param("stp", early_parse_stp); | |
506 | ||
507 | /* | |
508 | * Reset STP attachment. | |
509 | */ | |
8f847003 | 510 | static void __init stp_reset(void) |
d2fec595 MS |
511 | { |
512 | int rc; | |
513 | ||
d7d1104f | 514 | stp_page = (void *) get_zeroed_page(GFP_ATOMIC); |
2f82f577 | 515 | rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL); |
4a672cfa | 516 | if (rc == 0) |
d2fec595 MS |
517 | set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags); |
518 | else if (stp_online) { | |
baebc70a | 519 | pr_warn("The real or virtual hardware system does not provide an STP interface\n"); |
d7d1104f | 520 | free_page((unsigned long) stp_page); |
d2fec595 | 521 | stp_page = NULL; |
970ba6ac | 522 | stp_online = false; |
d2fec595 MS |
523 | } |
524 | } | |
525 | ||
e99e88a9 | 526 | static void stp_timeout(struct timer_list *unused) |
04362301 MS |
527 | { |
528 | queue_work(time_sync_wq, &stp_work); | |
529 | } | |
530 | ||
d2fec595 MS |
531 | static int __init stp_init(void) |
532 | { | |
750887de HC |
533 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) |
534 | return 0; | |
e99e88a9 | 535 | timer_setup(&stp_timer, stp_timeout, 0); |
750887de HC |
536 | time_init_wq(); |
537 | if (!stp_online) | |
538 | return 0; | |
539 | queue_work(time_sync_wq, &stp_work); | |
d2fec595 MS |
540 | return 0; |
541 | } | |
542 | ||
543 | arch_initcall(stp_init); | |
544 | ||
545 | /* | |
546 | * STP timing alert. There are three causes: | |
547 | * 1) timing status change | |
548 | * 2) link availability change | |
549 | * 3) time control parameter change | |
550 | * In all three cases we are only interested in the clock source state. | |
551 | * If a STP clock source is now available use it. | |
552 | */ | |
553 | static void stp_timing_alert(struct stp_irq_parm *intparm) | |
554 | { | |
555 | if (intparm->tsc || intparm->lac || intparm->tcpc) | |
750887de | 556 | queue_work(time_sync_wq, &stp_work); |
d2fec595 MS |
557 | } |
558 | ||
559 | /* | |
560 | * STP sync check machine check. This is called when the timing state | |
561 | * changes from the synchronized state to the unsynchronized state. | |
562 | * After a STP sync check the clock is not in sync. The machine check | |
563 | * is broadcasted to all cpus at the same time. | |
564 | */ | |
29b0a825 | 565 | int stp_sync_check(void) |
d2fec595 | 566 | { |
d2fec595 | 567 | disable_sync_clock(NULL); |
29b0a825 | 568 | return 1; |
d2fec595 MS |
569 | } |
570 | ||
571 | /* | |
572 | * STP island condition machine check. This is called when an attached | |
573 | * server attempts to communicate over an STP link and the servers | |
574 | * have matching CTN ids and have a valid stratum-1 configuration | |
575 | * but the configurations do not match. | |
576 | */ | |
29b0a825 | 577 | int stp_island_check(void) |
d2fec595 | 578 | { |
d2fec595 | 579 | disable_sync_clock(NULL); |
29b0a825 | 580 | return 1; |
d2fec595 MS |
581 | } |
582 | ||
29b0a825 HC |
583 | void stp_queue_work(void) |
584 | { | |
585 | queue_work(time_sync_wq, &stp_work); | |
586 | } | |
750887de HC |
587 | |
588 | static int stp_sync_clock(void *data) | |
d2fec595 | 589 | { |
b1c0854d | 590 | struct clock_sync_data *sync = data; |
41ad0220 | 591 | unsigned long long clock_delta; |
b1c0854d | 592 | static int first; |
d2fec595 MS |
593 | int rc; |
594 | ||
d2fec595 | 595 | enable_sync_clock(); |
b1c0854d MS |
596 | if (xchg(&first, 1) == 0) { |
597 | /* Wait until all other cpus entered the sync function. */ | |
598 | while (atomic_read(&sync->cpus) != 0) | |
599 | cpu_relax(); | |
600 | rc = 0; | |
601 | if (stp_info.todoff[0] || stp_info.todoff[1] || | |
602 | stp_info.todoff[2] || stp_info.todoff[3] || | |
603 | stp_info.tmd != 2) { | |
604 | rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0, | |
605 | &clock_delta); | |
606 | if (rc == 0) { | |
607 | sync->clock_delta = clock_delta; | |
608 | clock_sync_global(clock_delta); | |
609 | rc = chsc_sstpi(stp_page, &stp_info, | |
610 | sizeof(struct stp_sstpi)); | |
611 | if (rc == 0 && stp_info.tmd != 2) | |
612 | rc = -EAGAIN; | |
613 | } | |
d2fec595 | 614 | } |
b1c0854d MS |
615 | sync->in_sync = rc ? -EAGAIN : 1; |
616 | xchg(&first, 0); | |
617 | } else { | |
618 | /* Slave */ | |
619 | atomic_dec(&sync->cpus); | |
620 | /* Wait for in_sync to be set. */ | |
621 | while (READ_ONCE(sync->in_sync) == 0) | |
622 | __udelay(1); | |
d2fec595 | 623 | } |
b1c0854d MS |
624 | if (sync->in_sync != 1) |
625 | /* Didn't work. Clear per-cpu in sync bit again. */ | |
d2fec595 | 626 | disable_sync_clock(NULL); |
b1c0854d MS |
627 | /* Apply clock delta to per-CPU fields of this CPU. */ |
628 | clock_sync_local(sync->clock_delta); | |
629 | ||
750887de HC |
630 | return 0; |
631 | } | |
d2fec595 | 632 | |
750887de HC |
633 | /* |
634 | * STP work. Check for the STP state and take over the clock | |
635 | * synchronization if the STP clock source is usable. | |
636 | */ | |
637 | static void stp_work_fn(struct work_struct *work) | |
638 | { | |
639 | struct clock_sync_data stp_sync; | |
640 | int rc; | |
641 | ||
0b3016b7 MS |
642 | /* prevent multiple execution. */ |
643 | mutex_lock(&stp_work_mutex); | |
644 | ||
750887de | 645 | if (!stp_online) { |
2f82f577 | 646 | chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000, NULL); |
04362301 | 647 | del_timer_sync(&stp_timer); |
0b3016b7 | 648 | goto out_unlock; |
750887de HC |
649 | } |
650 | ||
2f82f577 | 651 | rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0, NULL); |
750887de | 652 | if (rc) |
0b3016b7 | 653 | goto out_unlock; |
750887de HC |
654 | |
655 | rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi)); | |
656 | if (rc || stp_info.c == 0) | |
0b3016b7 | 657 | goto out_unlock; |
750887de | 658 | |
8283cb43 MS |
659 | /* Skip synchronization if the clock is already in sync. */ |
660 | if (check_sync_clock()) | |
661 | goto out_unlock; | |
662 | ||
750887de | 663 | memset(&stp_sync, 0, sizeof(stp_sync)); |
2337e879 | 664 | cpus_read_lock(); |
750887de | 665 | atomic_set(&stp_sync.cpus, num_online_cpus() - 1); |
2337e879 SAS |
666 | stop_machine_cpuslocked(stp_sync_clock, &stp_sync, cpu_online_mask); |
667 | cpus_read_unlock(); | |
0b3016b7 | 668 | |
04362301 MS |
669 | if (!check_sync_clock()) |
670 | /* | |
671 | * There is a usable clock but the synchonization failed. | |
672 | * Retry after a second. | |
673 | */ | |
674 | mod_timer(&stp_timer, jiffies + HZ); | |
675 | ||
0b3016b7 MS |
676 | out_unlock: |
677 | mutex_unlock(&stp_work_mutex); | |
d2fec595 MS |
678 | } |
679 | ||
680 | /* | |
3fbacffb | 681 | * STP subsys sysfs interface functions |
d2fec595 | 682 | */ |
3fbacffb KS |
683 | static struct bus_type stp_subsys = { |
684 | .name = "stp", | |
685 | .dev_name = "stp", | |
d2fec595 MS |
686 | }; |
687 | ||
3fbacffb KS |
688 | static ssize_t stp_ctn_id_show(struct device *dev, |
689 | struct device_attribute *attr, | |
c9be0a36 | 690 | char *buf) |
d2fec595 MS |
691 | { |
692 | if (!stp_online) | |
693 | return -ENODATA; | |
694 | return sprintf(buf, "%016llx\n", | |
695 | *(unsigned long long *) stp_info.ctnid); | |
696 | } | |
697 | ||
3fbacffb | 698 | static DEVICE_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL); |
d2fec595 | 699 | |
3fbacffb KS |
700 | static ssize_t stp_ctn_type_show(struct device *dev, |
701 | struct device_attribute *attr, | |
c9be0a36 | 702 | char *buf) |
d2fec595 MS |
703 | { |
704 | if (!stp_online) | |
705 | return -ENODATA; | |
706 | return sprintf(buf, "%i\n", stp_info.ctn); | |
707 | } | |
708 | ||
3fbacffb | 709 | static DEVICE_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL); |
d2fec595 | 710 | |
3fbacffb KS |
711 | static ssize_t stp_dst_offset_show(struct device *dev, |
712 | struct device_attribute *attr, | |
c9be0a36 | 713 | char *buf) |
d2fec595 MS |
714 | { |
715 | if (!stp_online || !(stp_info.vbits & 0x2000)) | |
716 | return -ENODATA; | |
717 | return sprintf(buf, "%i\n", (int)(s16) stp_info.dsto); | |
718 | } | |
719 | ||
3fbacffb | 720 | static DEVICE_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL); |
d2fec595 | 721 | |
3fbacffb KS |
722 | static ssize_t stp_leap_seconds_show(struct device *dev, |
723 | struct device_attribute *attr, | |
c9be0a36 | 724 | char *buf) |
d2fec595 MS |
725 | { |
726 | if (!stp_online || !(stp_info.vbits & 0x8000)) | |
727 | return -ENODATA; | |
728 | return sprintf(buf, "%i\n", (int)(s16) stp_info.leaps); | |
729 | } | |
730 | ||
3fbacffb | 731 | static DEVICE_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL); |
d2fec595 | 732 | |
3fbacffb KS |
733 | static ssize_t stp_stratum_show(struct device *dev, |
734 | struct device_attribute *attr, | |
c9be0a36 | 735 | char *buf) |
d2fec595 MS |
736 | { |
737 | if (!stp_online) | |
738 | return -ENODATA; | |
739 | return sprintf(buf, "%i\n", (int)(s16) stp_info.stratum); | |
740 | } | |
741 | ||
3fbacffb | 742 | static DEVICE_ATTR(stratum, 0400, stp_stratum_show, NULL); |
d2fec595 | 743 | |
3fbacffb KS |
744 | static ssize_t stp_time_offset_show(struct device *dev, |
745 | struct device_attribute *attr, | |
c9be0a36 | 746 | char *buf) |
d2fec595 MS |
747 | { |
748 | if (!stp_online || !(stp_info.vbits & 0x0800)) | |
749 | return -ENODATA; | |
750 | return sprintf(buf, "%i\n", (int) stp_info.tto); | |
751 | } | |
752 | ||
3fbacffb | 753 | static DEVICE_ATTR(time_offset, 0400, stp_time_offset_show, NULL); |
d2fec595 | 754 | |
3fbacffb KS |
755 | static ssize_t stp_time_zone_offset_show(struct device *dev, |
756 | struct device_attribute *attr, | |
c9be0a36 | 757 | char *buf) |
d2fec595 MS |
758 | { |
759 | if (!stp_online || !(stp_info.vbits & 0x4000)) | |
760 | return -ENODATA; | |
761 | return sprintf(buf, "%i\n", (int)(s16) stp_info.tzo); | |
762 | } | |
763 | ||
3fbacffb | 764 | static DEVICE_ATTR(time_zone_offset, 0400, |
d2fec595 MS |
765 | stp_time_zone_offset_show, NULL); |
766 | ||
3fbacffb KS |
767 | static ssize_t stp_timing_mode_show(struct device *dev, |
768 | struct device_attribute *attr, | |
c9be0a36 | 769 | char *buf) |
d2fec595 MS |
770 | { |
771 | if (!stp_online) | |
772 | return -ENODATA; | |
773 | return sprintf(buf, "%i\n", stp_info.tmd); | |
774 | } | |
775 | ||
3fbacffb | 776 | static DEVICE_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL); |
d2fec595 | 777 | |
3fbacffb KS |
778 | static ssize_t stp_timing_state_show(struct device *dev, |
779 | struct device_attribute *attr, | |
c9be0a36 | 780 | char *buf) |
d2fec595 MS |
781 | { |
782 | if (!stp_online) | |
783 | return -ENODATA; | |
784 | return sprintf(buf, "%i\n", stp_info.tst); | |
785 | } | |
786 | ||
3fbacffb | 787 | static DEVICE_ATTR(timing_state, 0400, stp_timing_state_show, NULL); |
d2fec595 | 788 | |
3fbacffb KS |
789 | static ssize_t stp_online_show(struct device *dev, |
790 | struct device_attribute *attr, | |
c9be0a36 | 791 | char *buf) |
d2fec595 MS |
792 | { |
793 | return sprintf(buf, "%i\n", stp_online); | |
794 | } | |
795 | ||
3fbacffb KS |
796 | static ssize_t stp_online_store(struct device *dev, |
797 | struct device_attribute *attr, | |
d2fec595 MS |
798 | const char *buf, size_t count) |
799 | { | |
800 | unsigned int value; | |
801 | ||
802 | value = simple_strtoul(buf, NULL, 0); | |
803 | if (value != 0 && value != 1) | |
804 | return -EINVAL; | |
805 | if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) | |
806 | return -EOPNOTSUPP; | |
8283cb43 | 807 | mutex_lock(&clock_sync_mutex); |
d2fec595 | 808 | stp_online = value; |
8283cb43 MS |
809 | if (stp_online) |
810 | set_bit(CLOCK_SYNC_STP, &clock_sync_flags); | |
811 | else | |
812 | clear_bit(CLOCK_SYNC_STP, &clock_sync_flags); | |
750887de | 813 | queue_work(time_sync_wq, &stp_work); |
8283cb43 | 814 | mutex_unlock(&clock_sync_mutex); |
d2fec595 MS |
815 | return count; |
816 | } | |
817 | ||
818 | /* | |
3fbacffb KS |
819 | * Can't use DEVICE_ATTR because the attribute should be named |
820 | * stp/online but dev_attr_online already exists in this file .. | |
d2fec595 | 821 | */ |
3fbacffb | 822 | static struct device_attribute dev_attr_stp_online = { |
d2fec595 MS |
823 | .attr = { .name = "online", .mode = 0600 }, |
824 | .show = stp_online_show, | |
825 | .store = stp_online_store, | |
826 | }; | |
827 | ||
3fbacffb KS |
828 | static struct device_attribute *stp_attributes[] = { |
829 | &dev_attr_ctn_id, | |
830 | &dev_attr_ctn_type, | |
831 | &dev_attr_dst_offset, | |
832 | &dev_attr_leap_seconds, | |
833 | &dev_attr_stp_online, | |
834 | &dev_attr_stratum, | |
835 | &dev_attr_time_offset, | |
836 | &dev_attr_time_zone_offset, | |
837 | &dev_attr_timing_mode, | |
838 | &dev_attr_timing_state, | |
d2fec595 MS |
839 | NULL |
840 | }; | |
841 | ||
842 | static int __init stp_init_sysfs(void) | |
843 | { | |
3fbacffb | 844 | struct device_attribute **attr; |
d2fec595 MS |
845 | int rc; |
846 | ||
3fbacffb | 847 | rc = subsys_system_register(&stp_subsys, NULL); |
d2fec595 MS |
848 | if (rc) |
849 | goto out; | |
850 | for (attr = stp_attributes; *attr; attr++) { | |
3fbacffb | 851 | rc = device_create_file(stp_subsys.dev_root, *attr); |
d2fec595 MS |
852 | if (rc) |
853 | goto out_unreg; | |
854 | } | |
855 | return 0; | |
856 | out_unreg: | |
857 | for (; attr >= stp_attributes; attr--) | |
3fbacffb KS |
858 | device_remove_file(stp_subsys.dev_root, *attr); |
859 | bus_unregister(&stp_subsys); | |
d2fec595 MS |
860 | out: |
861 | return rc; | |
862 | } | |
863 | ||
864 | device_initcall(stp_init_sysfs); |