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