1 /* 2 * Time of day based timer functions. 3 * 4 * S390 version 5 * Copyright IBM Corp. 1999, 2008 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 14 #define KMSG_COMPONENT "time" 15 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 16 17 #include <linux/kernel_stat.h> 18 #include <linux/errno.h> 19 #include <linux/module.h> 20 #include <linux/sched.h> 21 #include <linux/kernel.h> 22 #include <linux/param.h> 23 #include <linux/string.h> 24 #include <linux/mm.h> 25 #include <linux/interrupt.h> 26 #include <linux/cpu.h> 27 #include <linux/stop_machine.h> 28 #include <linux/time.h> 29 #include <linux/device.h> 30 #include <linux/delay.h> 31 #include <linux/init.h> 32 #include <linux/smp.h> 33 #include <linux/types.h> 34 #include <linux/profile.h> 35 #include <linux/timex.h> 36 #include <linux/notifier.h> 37 #include <linux/timekeeper_internal.h> 38 #include <linux/clockchips.h> 39 #include <linux/gfp.h> 40 #include <linux/kprobes.h> 41 #include <asm/uaccess.h> 42 #include <asm/delay.h> 43 #include <asm/div64.h> 44 #include <asm/vdso.h> 45 #include <asm/irq.h> 46 #include <asm/irq_regs.h> 47 #include <asm/vtimer.h> 48 #include <asm/etr.h> 49 #include <asm/cio.h> 50 #include "entry.h" 51 52 /* change this if you have some constant time drift */ 53 #define USECS_PER_JIFFY ((unsigned long) 1000000/HZ) 54 #define CLK_TICKS_PER_JIFFY ((unsigned long) USECS_PER_JIFFY << 12) 55 56 u64 sched_clock_base_cc = -1; /* Force to data section. */ 57 EXPORT_SYMBOL_GPL(sched_clock_base_cc); 58 59 static DEFINE_PER_CPU(struct clock_event_device, comparators); 60 61 /* 62 * Scheduler clock - returns current time in nanosec units. 63 */ 64 unsigned long long notrace __kprobes sched_clock(void) 65 { 66 return tod_to_ns(get_tod_clock_monotonic()); 67 } 68 69 /* 70 * Monotonic_clock - returns # of nanoseconds passed since time_init() 71 */ 72 unsigned long long monotonic_clock(void) 73 { 74 return sched_clock(); 75 } 76 EXPORT_SYMBOL(monotonic_clock); 77 78 void tod_to_timeval(__u64 todval, struct timespec *xt) 79 { 80 unsigned long long sec; 81 82 sec = todval >> 12; 83 do_div(sec, 1000000); 84 xt->tv_sec = sec; 85 todval -= (sec * 1000000) << 12; 86 xt->tv_nsec = ((todval * 1000) >> 12); 87 } 88 EXPORT_SYMBOL(tod_to_timeval); 89 90 void clock_comparator_work(void) 91 { 92 struct clock_event_device *cd; 93 94 S390_lowcore.clock_comparator = -1ULL; 95 cd = &__get_cpu_var(comparators); 96 cd->event_handler(cd); 97 } 98 99 /* 100 * Fixup the clock comparator. 101 */ 102 static void fixup_clock_comparator(unsigned long long delta) 103 { 104 /* If nobody is waiting there's nothing to fix. */ 105 if (S390_lowcore.clock_comparator == -1ULL) 106 return; 107 S390_lowcore.clock_comparator += delta; 108 set_clock_comparator(S390_lowcore.clock_comparator); 109 } 110 111 static int s390_next_event(unsigned long delta, 112 struct clock_event_device *evt) 113 { 114 S390_lowcore.clock_comparator = get_tod_clock() + delta; 115 set_clock_comparator(S390_lowcore.clock_comparator); 116 return 0; 117 } 118 119 static void s390_set_mode(enum clock_event_mode mode, 120 struct clock_event_device *evt) 121 { 122 } 123 124 /* 125 * Set up lowcore and control register of the current cpu to 126 * enable TOD clock and clock comparator interrupts. 127 */ 128 void init_cpu_timer(void) 129 { 130 struct clock_event_device *cd; 131 int cpu; 132 133 S390_lowcore.clock_comparator = -1ULL; 134 set_clock_comparator(S390_lowcore.clock_comparator); 135 136 cpu = smp_processor_id(); 137 cd = &per_cpu(comparators, cpu); 138 cd->name = "comparator"; 139 cd->features = CLOCK_EVT_FEAT_ONESHOT; 140 cd->mult = 16777; 141 cd->shift = 12; 142 cd->min_delta_ns = 1; 143 cd->max_delta_ns = LONG_MAX; 144 cd->rating = 400; 145 cd->cpumask = cpumask_of(cpu); 146 cd->set_next_event = s390_next_event; 147 cd->set_mode = s390_set_mode; 148 149 clockevents_register_device(cd); 150 151 /* Enable clock comparator timer interrupt. */ 152 __ctl_set_bit(0,11); 153 154 /* Always allow the timing alert external interrupt. */ 155 __ctl_set_bit(0, 4); 156 } 157 158 static void clock_comparator_interrupt(struct ext_code ext_code, 159 unsigned int param32, 160 unsigned long param64) 161 { 162 inc_irq_stat(IRQEXT_CLK); 163 if (S390_lowcore.clock_comparator == -1ULL) 164 set_clock_comparator(S390_lowcore.clock_comparator); 165 } 166 167 static void etr_timing_alert(struct etr_irq_parm *); 168 static void stp_timing_alert(struct stp_irq_parm *); 169 170 static void timing_alert_interrupt(struct ext_code ext_code, 171 unsigned int param32, unsigned long param64) 172 { 173 inc_irq_stat(IRQEXT_TLA); 174 if (param32 & 0x00c40000) 175 etr_timing_alert((struct etr_irq_parm *) ¶m32); 176 if (param32 & 0x00038000) 177 stp_timing_alert((struct stp_irq_parm *) ¶m32); 178 } 179 180 static void etr_reset(void); 181 static void stp_reset(void); 182 183 void read_persistent_clock(struct timespec *ts) 184 { 185 tod_to_timeval(get_tod_clock() - TOD_UNIX_EPOCH, ts); 186 } 187 188 void read_boot_clock(struct timespec *ts) 189 { 190 tod_to_timeval(sched_clock_base_cc - TOD_UNIX_EPOCH, ts); 191 } 192 193 static cycle_t read_tod_clock(struct clocksource *cs) 194 { 195 return get_tod_clock(); 196 } 197 198 static struct clocksource clocksource_tod = { 199 .name = "tod", 200 .rating = 400, 201 .read = read_tod_clock, 202 .mask = -1ULL, 203 .mult = 1000, 204 .shift = 12, 205 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 206 }; 207 208 struct clocksource * __init clocksource_default_clock(void) 209 { 210 return &clocksource_tod; 211 } 212 213 void update_vsyscall(struct timekeeper *tk) 214 { 215 u64 nsecps; 216 217 if (tk->clock != &clocksource_tod) 218 return; 219 220 /* Make userspace gettimeofday spin until we're done. */ 221 ++vdso_data->tb_update_count; 222 smp_wmb(); 223 vdso_data->xtime_tod_stamp = tk->clock->cycle_last; 224 vdso_data->xtime_clock_sec = tk->xtime_sec; 225 vdso_data->xtime_clock_nsec = tk->xtime_nsec; 226 vdso_data->wtom_clock_sec = 227 tk->xtime_sec + tk->wall_to_monotonic.tv_sec; 228 vdso_data->wtom_clock_nsec = tk->xtime_nsec + 229 + (tk->wall_to_monotonic.tv_nsec << tk->shift); 230 nsecps = (u64) NSEC_PER_SEC << tk->shift; 231 while (vdso_data->wtom_clock_nsec >= nsecps) { 232 vdso_data->wtom_clock_nsec -= nsecps; 233 vdso_data->wtom_clock_sec++; 234 } 235 vdso_data->tk_mult = tk->mult; 236 vdso_data->tk_shift = tk->shift; 237 smp_wmb(); 238 ++vdso_data->tb_update_count; 239 } 240 241 extern struct timezone sys_tz; 242 243 void update_vsyscall_tz(void) 244 { 245 /* Make userspace gettimeofday spin until we're done. */ 246 ++vdso_data->tb_update_count; 247 smp_wmb(); 248 vdso_data->tz_minuteswest = sys_tz.tz_minuteswest; 249 vdso_data->tz_dsttime = sys_tz.tz_dsttime; 250 smp_wmb(); 251 ++vdso_data->tb_update_count; 252 } 253 254 /* 255 * Initialize the TOD clock and the CPU timer of 256 * the boot cpu. 257 */ 258 void __init time_init(void) 259 { 260 /* Reset time synchronization interfaces. */ 261 etr_reset(); 262 stp_reset(); 263 264 /* request the clock comparator external interrupt */ 265 if (register_external_irq(EXT_IRQ_CLK_COMP, clock_comparator_interrupt)) 266 panic("Couldn't request external interrupt 0x1004"); 267 268 /* request the timing alert external interrupt */ 269 if (register_external_irq(EXT_IRQ_TIMING_ALERT, timing_alert_interrupt)) 270 panic("Couldn't request external interrupt 0x1406"); 271 272 if (clocksource_register(&clocksource_tod) != 0) 273 panic("Could not register TOD clock source"); 274 275 /* Enable TOD clock interrupts on the boot cpu. */ 276 init_cpu_timer(); 277 278 /* Enable cpu timer interrupts on the boot cpu. */ 279 vtime_init(); 280 } 281 282 /* 283 * The time is "clock". old is what we think the time is. 284 * Adjust the value by a multiple of jiffies and add the delta to ntp. 285 * "delay" is an approximation how long the synchronization took. If 286 * the time correction is positive, then "delay" is subtracted from 287 * the time difference and only the remaining part is passed to ntp. 288 */ 289 static unsigned long long adjust_time(unsigned long long old, 290 unsigned long long clock, 291 unsigned long long delay) 292 { 293 unsigned long long delta, ticks; 294 struct timex adjust; 295 296 if (clock > old) { 297 /* It is later than we thought. */ 298 delta = ticks = clock - old; 299 delta = ticks = (delta < delay) ? 0 : delta - delay; 300 delta -= do_div(ticks, CLK_TICKS_PER_JIFFY); 301 adjust.offset = ticks * (1000000 / HZ); 302 } else { 303 /* It is earlier than we thought. */ 304 delta = ticks = old - clock; 305 delta -= do_div(ticks, CLK_TICKS_PER_JIFFY); 306 delta = -delta; 307 adjust.offset = -ticks * (1000000 / HZ); 308 } 309 sched_clock_base_cc += delta; 310 if (adjust.offset != 0) { 311 pr_notice("The ETR interface has adjusted the clock " 312 "by %li microseconds\n", adjust.offset); 313 adjust.modes = ADJ_OFFSET_SINGLESHOT; 314 do_adjtimex(&adjust); 315 } 316 return delta; 317 } 318 319 static DEFINE_PER_CPU(atomic_t, clock_sync_word); 320 static DEFINE_MUTEX(clock_sync_mutex); 321 static unsigned long clock_sync_flags; 322 323 #define CLOCK_SYNC_HAS_ETR 0 324 #define CLOCK_SYNC_HAS_STP 1 325 #define CLOCK_SYNC_ETR 2 326 #define CLOCK_SYNC_STP 3 327 328 /* 329 * The synchronous get_clock function. It will write the current clock 330 * value to the clock pointer and return 0 if the clock is in sync with 331 * the external time source. If the clock mode is local it will return 332 * -EOPNOTSUPP and -EAGAIN if the clock is not in sync with the external 333 * reference. 334 */ 335 int get_sync_clock(unsigned long long *clock) 336 { 337 atomic_t *sw_ptr; 338 unsigned int sw0, sw1; 339 340 sw_ptr = &get_cpu_var(clock_sync_word); 341 sw0 = atomic_read(sw_ptr); 342 *clock = get_tod_clock(); 343 sw1 = atomic_read(sw_ptr); 344 put_cpu_var(clock_sync_word); 345 if (sw0 == sw1 && (sw0 & 0x80000000U)) 346 /* Success: time is in sync. */ 347 return 0; 348 if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags) && 349 !test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) 350 return -EOPNOTSUPP; 351 if (!test_bit(CLOCK_SYNC_ETR, &clock_sync_flags) && 352 !test_bit(CLOCK_SYNC_STP, &clock_sync_flags)) 353 return -EACCES; 354 return -EAGAIN; 355 } 356 EXPORT_SYMBOL(get_sync_clock); 357 358 /* 359 * Make get_sync_clock return -EAGAIN. 360 */ 361 static void disable_sync_clock(void *dummy) 362 { 363 atomic_t *sw_ptr = &__get_cpu_var(clock_sync_word); 364 /* 365 * Clear the in-sync bit 2^31. All get_sync_clock calls will 366 * fail until the sync bit is turned back on. In addition 367 * increase the "sequence" counter to avoid the race of an 368 * etr event and the complete recovery against get_sync_clock. 369 */ 370 atomic_clear_mask(0x80000000, sw_ptr); 371 atomic_inc(sw_ptr); 372 } 373 374 /* 375 * Make get_sync_clock return 0 again. 376 * Needs to be called from a context disabled for preemption. 377 */ 378 static void enable_sync_clock(void) 379 { 380 atomic_t *sw_ptr = &__get_cpu_var(clock_sync_word); 381 atomic_set_mask(0x80000000, sw_ptr); 382 } 383 384 /* 385 * Function to check if the clock is in sync. 386 */ 387 static inline int check_sync_clock(void) 388 { 389 atomic_t *sw_ptr; 390 int rc; 391 392 sw_ptr = &get_cpu_var(clock_sync_word); 393 rc = (atomic_read(sw_ptr) & 0x80000000U) != 0; 394 put_cpu_var(clock_sync_word); 395 return rc; 396 } 397 398 /* Single threaded workqueue used for etr and stp sync events */ 399 static struct workqueue_struct *time_sync_wq; 400 401 static void __init time_init_wq(void) 402 { 403 if (time_sync_wq) 404 return; 405 time_sync_wq = create_singlethread_workqueue("timesync"); 406 } 407 408 /* 409 * External Time Reference (ETR) code. 410 */ 411 static int etr_port0_online; 412 static int etr_port1_online; 413 static int etr_steai_available; 414 415 static int __init early_parse_etr(char *p) 416 { 417 if (strncmp(p, "off", 3) == 0) 418 etr_port0_online = etr_port1_online = 0; 419 else if (strncmp(p, "port0", 5) == 0) 420 etr_port0_online = 1; 421 else if (strncmp(p, "port1", 5) == 0) 422 etr_port1_online = 1; 423 else if (strncmp(p, "on", 2) == 0) 424 etr_port0_online = etr_port1_online = 1; 425 return 0; 426 } 427 early_param("etr", early_parse_etr); 428 429 enum etr_event { 430 ETR_EVENT_PORT0_CHANGE, 431 ETR_EVENT_PORT1_CHANGE, 432 ETR_EVENT_PORT_ALERT, 433 ETR_EVENT_SYNC_CHECK, 434 ETR_EVENT_SWITCH_LOCAL, 435 ETR_EVENT_UPDATE, 436 }; 437 438 /* 439 * Valid bit combinations of the eacr register are (x = don't care): 440 * e0 e1 dp p0 p1 ea es sl 441 * 0 0 x 0 0 0 0 0 initial, disabled state 442 * 0 0 x 0 1 1 0 0 port 1 online 443 * 0 0 x 1 0 1 0 0 port 0 online 444 * 0 0 x 1 1 1 0 0 both ports online 445 * 0 1 x 0 1 1 0 0 port 1 online and usable, ETR or PPS mode 446 * 0 1 x 0 1 1 0 1 port 1 online, usable and ETR mode 447 * 0 1 x 0 1 1 1 0 port 1 online, usable, PPS mode, in-sync 448 * 0 1 x 0 1 1 1 1 port 1 online, usable, ETR mode, in-sync 449 * 0 1 x 1 1 1 0 0 both ports online, port 1 usable 450 * 0 1 x 1 1 1 1 0 both ports online, port 1 usable, PPS mode, in-sync 451 * 0 1 x 1 1 1 1 1 both ports online, port 1 usable, ETR mode, in-sync 452 * 1 0 x 1 0 1 0 0 port 0 online and usable, ETR or PPS mode 453 * 1 0 x 1 0 1 0 1 port 0 online, usable and ETR mode 454 * 1 0 x 1 0 1 1 0 port 0 online, usable, PPS mode, in-sync 455 * 1 0 x 1 0 1 1 1 port 0 online, usable, ETR mode, in-sync 456 * 1 0 x 1 1 1 0 0 both ports online, port 0 usable 457 * 1 0 x 1 1 1 1 0 both ports online, port 0 usable, PPS mode, in-sync 458 * 1 0 x 1 1 1 1 1 both ports online, port 0 usable, ETR mode, in-sync 459 * 1 1 x 1 1 1 1 0 both ports online & usable, ETR, in-sync 460 * 1 1 x 1 1 1 1 1 both ports online & usable, ETR, in-sync 461 */ 462 static struct etr_eacr etr_eacr; 463 static u64 etr_tolec; /* time of last eacr update */ 464 static struct etr_aib etr_port0; 465 static int etr_port0_uptodate; 466 static struct etr_aib etr_port1; 467 static int etr_port1_uptodate; 468 static unsigned long etr_events; 469 static struct timer_list etr_timer; 470 471 static void etr_timeout(unsigned long dummy); 472 static void etr_work_fn(struct work_struct *work); 473 static DEFINE_MUTEX(etr_work_mutex); 474 static DECLARE_WORK(etr_work, etr_work_fn); 475 476 /* 477 * Reset ETR attachment. 478 */ 479 static void etr_reset(void) 480 { 481 etr_eacr = (struct etr_eacr) { 482 .e0 = 0, .e1 = 0, ._pad0 = 4, .dp = 0, 483 .p0 = 0, .p1 = 0, ._pad1 = 0, .ea = 0, 484 .es = 0, .sl = 0 }; 485 if (etr_setr(&etr_eacr) == 0) { 486 etr_tolec = get_tod_clock(); 487 set_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags); 488 if (etr_port0_online && etr_port1_online) 489 set_bit(CLOCK_SYNC_ETR, &clock_sync_flags); 490 } else if (etr_port0_online || etr_port1_online) { 491 pr_warning("The real or virtual hardware system does " 492 "not provide an ETR interface\n"); 493 etr_port0_online = etr_port1_online = 0; 494 } 495 } 496 497 static int __init etr_init(void) 498 { 499 struct etr_aib aib; 500 501 if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags)) 502 return 0; 503 time_init_wq(); 504 /* Check if this machine has the steai instruction. */ 505 if (etr_steai(&aib, ETR_STEAI_STEPPING_PORT) == 0) 506 etr_steai_available = 1; 507 setup_timer(&etr_timer, etr_timeout, 0UL); 508 if (etr_port0_online) { 509 set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events); 510 queue_work(time_sync_wq, &etr_work); 511 } 512 if (etr_port1_online) { 513 set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events); 514 queue_work(time_sync_wq, &etr_work); 515 } 516 return 0; 517 } 518 519 arch_initcall(etr_init); 520 521 /* 522 * Two sorts of ETR machine checks. The architecture reads: 523 * "When a machine-check niterruption occurs and if a switch-to-local or 524 * ETR-sync-check interrupt request is pending but disabled, this pending 525 * disabled interruption request is indicated and is cleared". 526 * Which means that we can get etr_switch_to_local events from the machine 527 * check handler although the interruption condition is disabled. Lovely.. 528 */ 529 530 /* 531 * Switch to local machine check. This is called when the last usable 532 * ETR port goes inactive. After switch to local the clock is not in sync. 533 */ 534 void etr_switch_to_local(void) 535 { 536 if (!etr_eacr.sl) 537 return; 538 disable_sync_clock(NULL); 539 if (!test_and_set_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events)) { 540 etr_eacr.es = etr_eacr.sl = 0; 541 etr_setr(&etr_eacr); 542 queue_work(time_sync_wq, &etr_work); 543 } 544 } 545 546 /* 547 * ETR sync check machine check. This is called when the ETR OTE and the 548 * local clock OTE are farther apart than the ETR sync check tolerance. 549 * After a ETR sync check the clock is not in sync. The machine check 550 * is broadcasted to all cpus at the same time. 551 */ 552 void etr_sync_check(void) 553 { 554 if (!etr_eacr.es) 555 return; 556 disable_sync_clock(NULL); 557 if (!test_and_set_bit(ETR_EVENT_SYNC_CHECK, &etr_events)) { 558 etr_eacr.es = 0; 559 etr_setr(&etr_eacr); 560 queue_work(time_sync_wq, &etr_work); 561 } 562 } 563 564 /* 565 * ETR timing alert. There are two causes: 566 * 1) port state change, check the usability of the port 567 * 2) port alert, one of the ETR-data-validity bits (v1-v2 bits of the 568 * sldr-status word) or ETR-data word 1 (edf1) or ETR-data word 3 (edf3) 569 * or ETR-data word 4 (edf4) has changed. 570 */ 571 static void etr_timing_alert(struct etr_irq_parm *intparm) 572 { 573 if (intparm->pc0) 574 /* ETR port 0 state change. */ 575 set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events); 576 if (intparm->pc1) 577 /* ETR port 1 state change. */ 578 set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events); 579 if (intparm->eai) 580 /* 581 * ETR port alert on either port 0, 1 or both. 582 * Both ports are not up-to-date now. 583 */ 584 set_bit(ETR_EVENT_PORT_ALERT, &etr_events); 585 queue_work(time_sync_wq, &etr_work); 586 } 587 588 static void etr_timeout(unsigned long dummy) 589 { 590 set_bit(ETR_EVENT_UPDATE, &etr_events); 591 queue_work(time_sync_wq, &etr_work); 592 } 593 594 /* 595 * Check if the etr mode is pss. 596 */ 597 static inline int etr_mode_is_pps(struct etr_eacr eacr) 598 { 599 return eacr.es && !eacr.sl; 600 } 601 602 /* 603 * Check if the etr mode is etr. 604 */ 605 static inline int etr_mode_is_etr(struct etr_eacr eacr) 606 { 607 return eacr.es && eacr.sl; 608 } 609 610 /* 611 * Check if the port can be used for TOD synchronization. 612 * For PPS mode the port has to receive OTEs. For ETR mode 613 * the port has to receive OTEs, the ETR stepping bit has to 614 * be zero and the validity bits for data frame 1, 2, and 3 615 * have to be 1. 616 */ 617 static int etr_port_valid(struct etr_aib *aib, int port) 618 { 619 unsigned int psc; 620 621 /* Check that this port is receiving OTEs. */ 622 if (aib->tsp == 0) 623 return 0; 624 625 psc = port ? aib->esw.psc1 : aib->esw.psc0; 626 if (psc == etr_lpsc_pps_mode) 627 return 1; 628 if (psc == etr_lpsc_operational_step) 629 return !aib->esw.y && aib->slsw.v1 && 630 aib->slsw.v2 && aib->slsw.v3; 631 return 0; 632 } 633 634 /* 635 * Check if two ports are on the same network. 636 */ 637 static int etr_compare_network(struct etr_aib *aib1, struct etr_aib *aib2) 638 { 639 // FIXME: any other fields we have to compare? 640 return aib1->edf1.net_id == aib2->edf1.net_id; 641 } 642 643 /* 644 * Wrapper for etr_stei that converts physical port states 645 * to logical port states to be consistent with the output 646 * of stetr (see etr_psc vs. etr_lpsc). 647 */ 648 static void etr_steai_cv(struct etr_aib *aib, unsigned int func) 649 { 650 BUG_ON(etr_steai(aib, func) != 0); 651 /* Convert port state to logical port state. */ 652 if (aib->esw.psc0 == 1) 653 aib->esw.psc0 = 2; 654 else if (aib->esw.psc0 == 0 && aib->esw.p == 0) 655 aib->esw.psc0 = 1; 656 if (aib->esw.psc1 == 1) 657 aib->esw.psc1 = 2; 658 else if (aib->esw.psc1 == 0 && aib->esw.p == 1) 659 aib->esw.psc1 = 1; 660 } 661 662 /* 663 * Check if the aib a2 is still connected to the same attachment as 664 * aib a1, the etv values differ by one and a2 is valid. 665 */ 666 static int etr_aib_follows(struct etr_aib *a1, struct etr_aib *a2, int p) 667 { 668 int state_a1, state_a2; 669 670 /* Paranoia check: e0/e1 should better be the same. */ 671 if (a1->esw.eacr.e0 != a2->esw.eacr.e0 || 672 a1->esw.eacr.e1 != a2->esw.eacr.e1) 673 return 0; 674 675 /* Still connected to the same etr ? */ 676 state_a1 = p ? a1->esw.psc1 : a1->esw.psc0; 677 state_a2 = p ? a2->esw.psc1 : a2->esw.psc0; 678 if (state_a1 == etr_lpsc_operational_step) { 679 if (state_a2 != etr_lpsc_operational_step || 680 a1->edf1.net_id != a2->edf1.net_id || 681 a1->edf1.etr_id != a2->edf1.etr_id || 682 a1->edf1.etr_pn != a2->edf1.etr_pn) 683 return 0; 684 } else if (state_a2 != etr_lpsc_pps_mode) 685 return 0; 686 687 /* The ETV value of a2 needs to be ETV of a1 + 1. */ 688 if (a1->edf2.etv + 1 != a2->edf2.etv) 689 return 0; 690 691 if (!etr_port_valid(a2, p)) 692 return 0; 693 694 return 1; 695 } 696 697 struct clock_sync_data { 698 atomic_t cpus; 699 int in_sync; 700 unsigned long long fixup_cc; 701 int etr_port; 702 struct etr_aib *etr_aib; 703 }; 704 705 static void clock_sync_cpu(struct clock_sync_data *sync) 706 { 707 atomic_dec(&sync->cpus); 708 enable_sync_clock(); 709 /* 710 * This looks like a busy wait loop but it isn't. etr_sync_cpus 711 * is called on all other cpus while the TOD clocks is stopped. 712 * __udelay will stop the cpu on an enabled wait psw until the 713 * TOD is running again. 714 */ 715 while (sync->in_sync == 0) { 716 __udelay(1); 717 /* 718 * A different cpu changes *in_sync. Therefore use 719 * barrier() to force memory access. 720 */ 721 barrier(); 722 } 723 if (sync->in_sync != 1) 724 /* Didn't work. Clear per-cpu in sync bit again. */ 725 disable_sync_clock(NULL); 726 /* 727 * This round of TOD syncing is done. Set the clock comparator 728 * to the next tick and let the processor continue. 729 */ 730 fixup_clock_comparator(sync->fixup_cc); 731 } 732 733 /* 734 * Sync the TOD clock using the port referred to by aibp. This port 735 * has to be enabled and the other port has to be disabled. The 736 * last eacr update has to be more than 1.6 seconds in the past. 737 */ 738 static int etr_sync_clock(void *data) 739 { 740 static int first; 741 unsigned long long clock, old_clock, delay, delta; 742 struct clock_sync_data *etr_sync; 743 struct etr_aib *sync_port, *aib; 744 int port; 745 int rc; 746 747 etr_sync = data; 748 749 if (xchg(&first, 1) == 1) { 750 /* Slave */ 751 clock_sync_cpu(etr_sync); 752 return 0; 753 } 754 755 /* Wait until all other cpus entered the sync function. */ 756 while (atomic_read(&etr_sync->cpus) != 0) 757 cpu_relax(); 758 759 port = etr_sync->etr_port; 760 aib = etr_sync->etr_aib; 761 sync_port = (port == 0) ? &etr_port0 : &etr_port1; 762 enable_sync_clock(); 763 764 /* Set clock to next OTE. */ 765 __ctl_set_bit(14, 21); 766 __ctl_set_bit(0, 29); 767 clock = ((unsigned long long) (aib->edf2.etv + 1)) << 32; 768 old_clock = get_tod_clock(); 769 if (set_tod_clock(clock) == 0) { 770 __udelay(1); /* Wait for the clock to start. */ 771 __ctl_clear_bit(0, 29); 772 __ctl_clear_bit(14, 21); 773 etr_stetr(aib); 774 /* Adjust Linux timing variables. */ 775 delay = (unsigned long long) 776 (aib->edf2.etv - sync_port->edf2.etv) << 32; 777 delta = adjust_time(old_clock, clock, delay); 778 etr_sync->fixup_cc = delta; 779 fixup_clock_comparator(delta); 780 /* Verify that the clock is properly set. */ 781 if (!etr_aib_follows(sync_port, aib, port)) { 782 /* Didn't work. */ 783 disable_sync_clock(NULL); 784 etr_sync->in_sync = -EAGAIN; 785 rc = -EAGAIN; 786 } else { 787 etr_sync->in_sync = 1; 788 rc = 0; 789 } 790 } else { 791 /* Could not set the clock ?!? */ 792 __ctl_clear_bit(0, 29); 793 __ctl_clear_bit(14, 21); 794 disable_sync_clock(NULL); 795 etr_sync->in_sync = -EAGAIN; 796 rc = -EAGAIN; 797 } 798 xchg(&first, 0); 799 return rc; 800 } 801 802 static int etr_sync_clock_stop(struct etr_aib *aib, int port) 803 { 804 struct clock_sync_data etr_sync; 805 struct etr_aib *sync_port; 806 int follows; 807 int rc; 808 809 /* Check if the current aib is adjacent to the sync port aib. */ 810 sync_port = (port == 0) ? &etr_port0 : &etr_port1; 811 follows = etr_aib_follows(sync_port, aib, port); 812 memcpy(sync_port, aib, sizeof(*aib)); 813 if (!follows) 814 return -EAGAIN; 815 memset(&etr_sync, 0, sizeof(etr_sync)); 816 etr_sync.etr_aib = aib; 817 etr_sync.etr_port = port; 818 get_online_cpus(); 819 atomic_set(&etr_sync.cpus, num_online_cpus() - 1); 820 rc = stop_machine(etr_sync_clock, &etr_sync, cpu_online_mask); 821 put_online_cpus(); 822 return rc; 823 } 824 825 /* 826 * Handle the immediate effects of the different events. 827 * The port change event is used for online/offline changes. 828 */ 829 static struct etr_eacr etr_handle_events(struct etr_eacr eacr) 830 { 831 if (test_and_clear_bit(ETR_EVENT_SYNC_CHECK, &etr_events)) 832 eacr.es = 0; 833 if (test_and_clear_bit(ETR_EVENT_SWITCH_LOCAL, &etr_events)) 834 eacr.es = eacr.sl = 0; 835 if (test_and_clear_bit(ETR_EVENT_PORT_ALERT, &etr_events)) 836 etr_port0_uptodate = etr_port1_uptodate = 0; 837 838 if (test_and_clear_bit(ETR_EVENT_PORT0_CHANGE, &etr_events)) { 839 if (eacr.e0) 840 /* 841 * Port change of an enabled port. We have to 842 * assume that this can have caused an stepping 843 * port switch. 844 */ 845 etr_tolec = get_tod_clock(); 846 eacr.p0 = etr_port0_online; 847 if (!eacr.p0) 848 eacr.e0 = 0; 849 etr_port0_uptodate = 0; 850 } 851 if (test_and_clear_bit(ETR_EVENT_PORT1_CHANGE, &etr_events)) { 852 if (eacr.e1) 853 /* 854 * Port change of an enabled port. We have to 855 * assume that this can have caused an stepping 856 * port switch. 857 */ 858 etr_tolec = get_tod_clock(); 859 eacr.p1 = etr_port1_online; 860 if (!eacr.p1) 861 eacr.e1 = 0; 862 etr_port1_uptodate = 0; 863 } 864 clear_bit(ETR_EVENT_UPDATE, &etr_events); 865 return eacr; 866 } 867 868 /* 869 * Set up a timer that expires after the etr_tolec + 1.6 seconds if 870 * one of the ports needs an update. 871 */ 872 static void etr_set_tolec_timeout(unsigned long long now) 873 { 874 unsigned long micros; 875 876 if ((!etr_eacr.p0 || etr_port0_uptodate) && 877 (!etr_eacr.p1 || etr_port1_uptodate)) 878 return; 879 micros = (now > etr_tolec) ? ((now - etr_tolec) >> 12) : 0; 880 micros = (micros > 1600000) ? 0 : 1600000 - micros; 881 mod_timer(&etr_timer, jiffies + (micros * HZ) / 1000000 + 1); 882 } 883 884 /* 885 * Set up a time that expires after 1/2 second. 886 */ 887 static void etr_set_sync_timeout(void) 888 { 889 mod_timer(&etr_timer, jiffies + HZ/2); 890 } 891 892 /* 893 * Update the aib information for one or both ports. 894 */ 895 static struct etr_eacr etr_handle_update(struct etr_aib *aib, 896 struct etr_eacr eacr) 897 { 898 /* With both ports disabled the aib information is useless. */ 899 if (!eacr.e0 && !eacr.e1) 900 return eacr; 901 902 /* Update port0 or port1 with aib stored in etr_work_fn. */ 903 if (aib->esw.q == 0) { 904 /* Information for port 0 stored. */ 905 if (eacr.p0 && !etr_port0_uptodate) { 906 etr_port0 = *aib; 907 if (etr_port0_online) 908 etr_port0_uptodate = 1; 909 } 910 } else { 911 /* Information for port 1 stored. */ 912 if (eacr.p1 && !etr_port1_uptodate) { 913 etr_port1 = *aib; 914 if (etr_port0_online) 915 etr_port1_uptodate = 1; 916 } 917 } 918 919 /* 920 * Do not try to get the alternate port aib if the clock 921 * is not in sync yet. 922 */ 923 if (!eacr.es || !check_sync_clock()) 924 return eacr; 925 926 /* 927 * If steai is available we can get the information about 928 * the other port immediately. If only stetr is available the 929 * data-port bit toggle has to be used. 930 */ 931 if (etr_steai_available) { 932 if (eacr.p0 && !etr_port0_uptodate) { 933 etr_steai_cv(&etr_port0, ETR_STEAI_PORT_0); 934 etr_port0_uptodate = 1; 935 } 936 if (eacr.p1 && !etr_port1_uptodate) { 937 etr_steai_cv(&etr_port1, ETR_STEAI_PORT_1); 938 etr_port1_uptodate = 1; 939 } 940 } else { 941 /* 942 * One port was updated above, if the other 943 * port is not uptodate toggle dp bit. 944 */ 945 if ((eacr.p0 && !etr_port0_uptodate) || 946 (eacr.p1 && !etr_port1_uptodate)) 947 eacr.dp ^= 1; 948 else 949 eacr.dp = 0; 950 } 951 return eacr; 952 } 953 954 /* 955 * Write new etr control register if it differs from the current one. 956 * Return 1 if etr_tolec has been updated as well. 957 */ 958 static void etr_update_eacr(struct etr_eacr eacr) 959 { 960 int dp_changed; 961 962 if (memcmp(&etr_eacr, &eacr, sizeof(eacr)) == 0) 963 /* No change, return. */ 964 return; 965 /* 966 * The disable of an active port of the change of the data port 967 * bit can/will cause a change in the data port. 968 */ 969 dp_changed = etr_eacr.e0 > eacr.e0 || etr_eacr.e1 > eacr.e1 || 970 (etr_eacr.dp ^ eacr.dp) != 0; 971 etr_eacr = eacr; 972 etr_setr(&etr_eacr); 973 if (dp_changed) 974 etr_tolec = get_tod_clock(); 975 } 976 977 /* 978 * ETR work. In this function you'll find the main logic. In 979 * particular this is the only function that calls etr_update_eacr(), 980 * it "controls" the etr control register. 981 */ 982 static void etr_work_fn(struct work_struct *work) 983 { 984 unsigned long long now; 985 struct etr_eacr eacr; 986 struct etr_aib aib; 987 int sync_port; 988 989 /* prevent multiple execution. */ 990 mutex_lock(&etr_work_mutex); 991 992 /* Create working copy of etr_eacr. */ 993 eacr = etr_eacr; 994 995 /* Check for the different events and their immediate effects. */ 996 eacr = etr_handle_events(eacr); 997 998 /* Check if ETR is supposed to be active. */ 999 eacr.ea = eacr.p0 || eacr.p1; 1000 if (!eacr.ea) { 1001 /* Both ports offline. Reset everything. */ 1002 eacr.dp = eacr.es = eacr.sl = 0; 1003 on_each_cpu(disable_sync_clock, NULL, 1); 1004 del_timer_sync(&etr_timer); 1005 etr_update_eacr(eacr); 1006 goto out_unlock; 1007 } 1008 1009 /* Store aib to get the current ETR status word. */ 1010 BUG_ON(etr_stetr(&aib) != 0); 1011 etr_port0.esw = etr_port1.esw = aib.esw; /* Copy status word. */ 1012 now = get_tod_clock(); 1013 1014 /* 1015 * Update the port information if the last stepping port change 1016 * or data port change is older than 1.6 seconds. 1017 */ 1018 if (now >= etr_tolec + (1600000 << 12)) 1019 eacr = etr_handle_update(&aib, eacr); 1020 1021 /* 1022 * Select ports to enable. The preferred synchronization mode is PPS. 1023 * If a port can be enabled depends on a number of things: 1024 * 1) The port needs to be online and uptodate. A port is not 1025 * disabled just because it is not uptodate, but it is only 1026 * enabled if it is uptodate. 1027 * 2) The port needs to have the same mode (pps / etr). 1028 * 3) The port needs to be usable -> etr_port_valid() == 1 1029 * 4) To enable the second port the clock needs to be in sync. 1030 * 5) If both ports are useable and are ETR ports, the network id 1031 * has to be the same. 1032 * The eacr.sl bit is used to indicate etr mode vs. pps mode. 1033 */ 1034 if (eacr.p0 && aib.esw.psc0 == etr_lpsc_pps_mode) { 1035 eacr.sl = 0; 1036 eacr.e0 = 1; 1037 if (!etr_mode_is_pps(etr_eacr)) 1038 eacr.es = 0; 1039 if (!eacr.es || !eacr.p1 || aib.esw.psc1 != etr_lpsc_pps_mode) 1040 eacr.e1 = 0; 1041 // FIXME: uptodate checks ? 1042 else if (etr_port0_uptodate && etr_port1_uptodate) 1043 eacr.e1 = 1; 1044 sync_port = (etr_port0_uptodate && 1045 etr_port_valid(&etr_port0, 0)) ? 0 : -1; 1046 } else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_pps_mode) { 1047 eacr.sl = 0; 1048 eacr.e0 = 0; 1049 eacr.e1 = 1; 1050 if (!etr_mode_is_pps(etr_eacr)) 1051 eacr.es = 0; 1052 sync_port = (etr_port1_uptodate && 1053 etr_port_valid(&etr_port1, 1)) ? 1 : -1; 1054 } else if (eacr.p0 && aib.esw.psc0 == etr_lpsc_operational_step) { 1055 eacr.sl = 1; 1056 eacr.e0 = 1; 1057 if (!etr_mode_is_etr(etr_eacr)) 1058 eacr.es = 0; 1059 if (!eacr.es || !eacr.p1 || 1060 aib.esw.psc1 != etr_lpsc_operational_alt) 1061 eacr.e1 = 0; 1062 else if (etr_port0_uptodate && etr_port1_uptodate && 1063 etr_compare_network(&etr_port0, &etr_port1)) 1064 eacr.e1 = 1; 1065 sync_port = (etr_port0_uptodate && 1066 etr_port_valid(&etr_port0, 0)) ? 0 : -1; 1067 } else if (eacr.p1 && aib.esw.psc1 == etr_lpsc_operational_step) { 1068 eacr.sl = 1; 1069 eacr.e0 = 0; 1070 eacr.e1 = 1; 1071 if (!etr_mode_is_etr(etr_eacr)) 1072 eacr.es = 0; 1073 sync_port = (etr_port1_uptodate && 1074 etr_port_valid(&etr_port1, 1)) ? 1 : -1; 1075 } else { 1076 /* Both ports not usable. */ 1077 eacr.es = eacr.sl = 0; 1078 sync_port = -1; 1079 } 1080 1081 /* 1082 * If the clock is in sync just update the eacr and return. 1083 * If there is no valid sync port wait for a port update. 1084 */ 1085 if ((eacr.es && check_sync_clock()) || sync_port < 0) { 1086 etr_update_eacr(eacr); 1087 etr_set_tolec_timeout(now); 1088 goto out_unlock; 1089 } 1090 1091 /* 1092 * Prepare control register for clock syncing 1093 * (reset data port bit, set sync check control. 1094 */ 1095 eacr.dp = 0; 1096 eacr.es = 1; 1097 1098 /* 1099 * Update eacr and try to synchronize the clock. If the update 1100 * of eacr caused a stepping port switch (or if we have to 1101 * assume that a stepping port switch has occurred) or the 1102 * clock syncing failed, reset the sync check control bit 1103 * and set up a timer to try again after 0.5 seconds 1104 */ 1105 etr_update_eacr(eacr); 1106 if (now < etr_tolec + (1600000 << 12) || 1107 etr_sync_clock_stop(&aib, sync_port) != 0) { 1108 /* Sync failed. Try again in 1/2 second. */ 1109 eacr.es = 0; 1110 etr_update_eacr(eacr); 1111 etr_set_sync_timeout(); 1112 } else 1113 etr_set_tolec_timeout(now); 1114 out_unlock: 1115 mutex_unlock(&etr_work_mutex); 1116 } 1117 1118 /* 1119 * Sysfs interface functions 1120 */ 1121 static struct bus_type etr_subsys = { 1122 .name = "etr", 1123 .dev_name = "etr", 1124 }; 1125 1126 static struct device etr_port0_dev = { 1127 .id = 0, 1128 .bus = &etr_subsys, 1129 }; 1130 1131 static struct device etr_port1_dev = { 1132 .id = 1, 1133 .bus = &etr_subsys, 1134 }; 1135 1136 /* 1137 * ETR subsys attributes 1138 */ 1139 static ssize_t etr_stepping_port_show(struct device *dev, 1140 struct device_attribute *attr, 1141 char *buf) 1142 { 1143 return sprintf(buf, "%i\n", etr_port0.esw.p); 1144 } 1145 1146 static DEVICE_ATTR(stepping_port, 0400, etr_stepping_port_show, NULL); 1147 1148 static ssize_t etr_stepping_mode_show(struct device *dev, 1149 struct device_attribute *attr, 1150 char *buf) 1151 { 1152 char *mode_str; 1153 1154 if (etr_mode_is_pps(etr_eacr)) 1155 mode_str = "pps"; 1156 else if (etr_mode_is_etr(etr_eacr)) 1157 mode_str = "etr"; 1158 else 1159 mode_str = "local"; 1160 return sprintf(buf, "%s\n", mode_str); 1161 } 1162 1163 static DEVICE_ATTR(stepping_mode, 0400, etr_stepping_mode_show, NULL); 1164 1165 /* 1166 * ETR port attributes 1167 */ 1168 static inline struct etr_aib *etr_aib_from_dev(struct device *dev) 1169 { 1170 if (dev == &etr_port0_dev) 1171 return etr_port0_online ? &etr_port0 : NULL; 1172 else 1173 return etr_port1_online ? &etr_port1 : NULL; 1174 } 1175 1176 static ssize_t etr_online_show(struct device *dev, 1177 struct device_attribute *attr, 1178 char *buf) 1179 { 1180 unsigned int online; 1181 1182 online = (dev == &etr_port0_dev) ? etr_port0_online : etr_port1_online; 1183 return sprintf(buf, "%i\n", online); 1184 } 1185 1186 static ssize_t etr_online_store(struct device *dev, 1187 struct device_attribute *attr, 1188 const char *buf, size_t count) 1189 { 1190 unsigned int value; 1191 1192 value = simple_strtoul(buf, NULL, 0); 1193 if (value != 0 && value != 1) 1194 return -EINVAL; 1195 if (!test_bit(CLOCK_SYNC_HAS_ETR, &clock_sync_flags)) 1196 return -EOPNOTSUPP; 1197 mutex_lock(&clock_sync_mutex); 1198 if (dev == &etr_port0_dev) { 1199 if (etr_port0_online == value) 1200 goto out; /* Nothing to do. */ 1201 etr_port0_online = value; 1202 if (etr_port0_online && etr_port1_online) 1203 set_bit(CLOCK_SYNC_ETR, &clock_sync_flags); 1204 else 1205 clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags); 1206 set_bit(ETR_EVENT_PORT0_CHANGE, &etr_events); 1207 queue_work(time_sync_wq, &etr_work); 1208 } else { 1209 if (etr_port1_online == value) 1210 goto out; /* Nothing to do. */ 1211 etr_port1_online = value; 1212 if (etr_port0_online && etr_port1_online) 1213 set_bit(CLOCK_SYNC_ETR, &clock_sync_flags); 1214 else 1215 clear_bit(CLOCK_SYNC_ETR, &clock_sync_flags); 1216 set_bit(ETR_EVENT_PORT1_CHANGE, &etr_events); 1217 queue_work(time_sync_wq, &etr_work); 1218 } 1219 out: 1220 mutex_unlock(&clock_sync_mutex); 1221 return count; 1222 } 1223 1224 static DEVICE_ATTR(online, 0600, etr_online_show, etr_online_store); 1225 1226 static ssize_t etr_stepping_control_show(struct device *dev, 1227 struct device_attribute *attr, 1228 char *buf) 1229 { 1230 return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ? 1231 etr_eacr.e0 : etr_eacr.e1); 1232 } 1233 1234 static DEVICE_ATTR(stepping_control, 0400, etr_stepping_control_show, NULL); 1235 1236 static ssize_t etr_mode_code_show(struct device *dev, 1237 struct device_attribute *attr, char *buf) 1238 { 1239 if (!etr_port0_online && !etr_port1_online) 1240 /* Status word is not uptodate if both ports are offline. */ 1241 return -ENODATA; 1242 return sprintf(buf, "%i\n", (dev == &etr_port0_dev) ? 1243 etr_port0.esw.psc0 : etr_port0.esw.psc1); 1244 } 1245 1246 static DEVICE_ATTR(state_code, 0400, etr_mode_code_show, NULL); 1247 1248 static ssize_t etr_untuned_show(struct device *dev, 1249 struct device_attribute *attr, char *buf) 1250 { 1251 struct etr_aib *aib = etr_aib_from_dev(dev); 1252 1253 if (!aib || !aib->slsw.v1) 1254 return -ENODATA; 1255 return sprintf(buf, "%i\n", aib->edf1.u); 1256 } 1257 1258 static DEVICE_ATTR(untuned, 0400, etr_untuned_show, NULL); 1259 1260 static ssize_t etr_network_id_show(struct device *dev, 1261 struct device_attribute *attr, char *buf) 1262 { 1263 struct etr_aib *aib = etr_aib_from_dev(dev); 1264 1265 if (!aib || !aib->slsw.v1) 1266 return -ENODATA; 1267 return sprintf(buf, "%i\n", aib->edf1.net_id); 1268 } 1269 1270 static DEVICE_ATTR(network, 0400, etr_network_id_show, NULL); 1271 1272 static ssize_t etr_id_show(struct device *dev, 1273 struct device_attribute *attr, char *buf) 1274 { 1275 struct etr_aib *aib = etr_aib_from_dev(dev); 1276 1277 if (!aib || !aib->slsw.v1) 1278 return -ENODATA; 1279 return sprintf(buf, "%i\n", aib->edf1.etr_id); 1280 } 1281 1282 static DEVICE_ATTR(id, 0400, etr_id_show, NULL); 1283 1284 static ssize_t etr_port_number_show(struct device *dev, 1285 struct device_attribute *attr, char *buf) 1286 { 1287 struct etr_aib *aib = etr_aib_from_dev(dev); 1288 1289 if (!aib || !aib->slsw.v1) 1290 return -ENODATA; 1291 return sprintf(buf, "%i\n", aib->edf1.etr_pn); 1292 } 1293 1294 static DEVICE_ATTR(port, 0400, etr_port_number_show, NULL); 1295 1296 static ssize_t etr_coupled_show(struct device *dev, 1297 struct device_attribute *attr, char *buf) 1298 { 1299 struct etr_aib *aib = etr_aib_from_dev(dev); 1300 1301 if (!aib || !aib->slsw.v3) 1302 return -ENODATA; 1303 return sprintf(buf, "%i\n", aib->edf3.c); 1304 } 1305 1306 static DEVICE_ATTR(coupled, 0400, etr_coupled_show, NULL); 1307 1308 static ssize_t etr_local_time_show(struct device *dev, 1309 struct device_attribute *attr, char *buf) 1310 { 1311 struct etr_aib *aib = etr_aib_from_dev(dev); 1312 1313 if (!aib || !aib->slsw.v3) 1314 return -ENODATA; 1315 return sprintf(buf, "%i\n", aib->edf3.blto); 1316 } 1317 1318 static DEVICE_ATTR(local_time, 0400, etr_local_time_show, NULL); 1319 1320 static ssize_t etr_utc_offset_show(struct device *dev, 1321 struct device_attribute *attr, char *buf) 1322 { 1323 struct etr_aib *aib = etr_aib_from_dev(dev); 1324 1325 if (!aib || !aib->slsw.v3) 1326 return -ENODATA; 1327 return sprintf(buf, "%i\n", aib->edf3.buo); 1328 } 1329 1330 static DEVICE_ATTR(utc_offset, 0400, etr_utc_offset_show, NULL); 1331 1332 static struct device_attribute *etr_port_attributes[] = { 1333 &dev_attr_online, 1334 &dev_attr_stepping_control, 1335 &dev_attr_state_code, 1336 &dev_attr_untuned, 1337 &dev_attr_network, 1338 &dev_attr_id, 1339 &dev_attr_port, 1340 &dev_attr_coupled, 1341 &dev_attr_local_time, 1342 &dev_attr_utc_offset, 1343 NULL 1344 }; 1345 1346 static int __init etr_register_port(struct device *dev) 1347 { 1348 struct device_attribute **attr; 1349 int rc; 1350 1351 rc = device_register(dev); 1352 if (rc) 1353 goto out; 1354 for (attr = etr_port_attributes; *attr; attr++) { 1355 rc = device_create_file(dev, *attr); 1356 if (rc) 1357 goto out_unreg; 1358 } 1359 return 0; 1360 out_unreg: 1361 for (; attr >= etr_port_attributes; attr--) 1362 device_remove_file(dev, *attr); 1363 device_unregister(dev); 1364 out: 1365 return rc; 1366 } 1367 1368 static void __init etr_unregister_port(struct device *dev) 1369 { 1370 struct device_attribute **attr; 1371 1372 for (attr = etr_port_attributes; *attr; attr++) 1373 device_remove_file(dev, *attr); 1374 device_unregister(dev); 1375 } 1376 1377 static int __init etr_init_sysfs(void) 1378 { 1379 int rc; 1380 1381 rc = subsys_system_register(&etr_subsys, NULL); 1382 if (rc) 1383 goto out; 1384 rc = device_create_file(etr_subsys.dev_root, &dev_attr_stepping_port); 1385 if (rc) 1386 goto out_unreg_subsys; 1387 rc = device_create_file(etr_subsys.dev_root, &dev_attr_stepping_mode); 1388 if (rc) 1389 goto out_remove_stepping_port; 1390 rc = etr_register_port(&etr_port0_dev); 1391 if (rc) 1392 goto out_remove_stepping_mode; 1393 rc = etr_register_port(&etr_port1_dev); 1394 if (rc) 1395 goto out_remove_port0; 1396 return 0; 1397 1398 out_remove_port0: 1399 etr_unregister_port(&etr_port0_dev); 1400 out_remove_stepping_mode: 1401 device_remove_file(etr_subsys.dev_root, &dev_attr_stepping_mode); 1402 out_remove_stepping_port: 1403 device_remove_file(etr_subsys.dev_root, &dev_attr_stepping_port); 1404 out_unreg_subsys: 1405 bus_unregister(&etr_subsys); 1406 out: 1407 return rc; 1408 } 1409 1410 device_initcall(etr_init_sysfs); 1411 1412 /* 1413 * Server Time Protocol (STP) code. 1414 */ 1415 static int stp_online; 1416 static struct stp_sstpi stp_info; 1417 static void *stp_page; 1418 1419 static void stp_work_fn(struct work_struct *work); 1420 static DEFINE_MUTEX(stp_work_mutex); 1421 static DECLARE_WORK(stp_work, stp_work_fn); 1422 static struct timer_list stp_timer; 1423 1424 static int __init early_parse_stp(char *p) 1425 { 1426 if (strncmp(p, "off", 3) == 0) 1427 stp_online = 0; 1428 else if (strncmp(p, "on", 2) == 0) 1429 stp_online = 1; 1430 return 0; 1431 } 1432 early_param("stp", early_parse_stp); 1433 1434 /* 1435 * Reset STP attachment. 1436 */ 1437 static void __init stp_reset(void) 1438 { 1439 int rc; 1440 1441 stp_page = (void *) get_zeroed_page(GFP_ATOMIC); 1442 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000); 1443 if (rc == 0) 1444 set_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags); 1445 else if (stp_online) { 1446 pr_warning("The real or virtual hardware system does " 1447 "not provide an STP interface\n"); 1448 free_page((unsigned long) stp_page); 1449 stp_page = NULL; 1450 stp_online = 0; 1451 } 1452 } 1453 1454 static void stp_timeout(unsigned long dummy) 1455 { 1456 queue_work(time_sync_wq, &stp_work); 1457 } 1458 1459 static int __init stp_init(void) 1460 { 1461 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) 1462 return 0; 1463 setup_timer(&stp_timer, stp_timeout, 0UL); 1464 time_init_wq(); 1465 if (!stp_online) 1466 return 0; 1467 queue_work(time_sync_wq, &stp_work); 1468 return 0; 1469 } 1470 1471 arch_initcall(stp_init); 1472 1473 /* 1474 * STP timing alert. There are three causes: 1475 * 1) timing status change 1476 * 2) link availability change 1477 * 3) time control parameter change 1478 * In all three cases we are only interested in the clock source state. 1479 * If a STP clock source is now available use it. 1480 */ 1481 static void stp_timing_alert(struct stp_irq_parm *intparm) 1482 { 1483 if (intparm->tsc || intparm->lac || intparm->tcpc) 1484 queue_work(time_sync_wq, &stp_work); 1485 } 1486 1487 /* 1488 * STP sync check machine check. This is called when the timing state 1489 * changes from the synchronized state to the unsynchronized state. 1490 * After a STP sync check the clock is not in sync. The machine check 1491 * is broadcasted to all cpus at the same time. 1492 */ 1493 void stp_sync_check(void) 1494 { 1495 disable_sync_clock(NULL); 1496 queue_work(time_sync_wq, &stp_work); 1497 } 1498 1499 /* 1500 * STP island condition machine check. This is called when an attached 1501 * server attempts to communicate over an STP link and the servers 1502 * have matching CTN ids and have a valid stratum-1 configuration 1503 * but the configurations do not match. 1504 */ 1505 void stp_island_check(void) 1506 { 1507 disable_sync_clock(NULL); 1508 queue_work(time_sync_wq, &stp_work); 1509 } 1510 1511 1512 static int stp_sync_clock(void *data) 1513 { 1514 static int first; 1515 unsigned long long old_clock, delta; 1516 struct clock_sync_data *stp_sync; 1517 int rc; 1518 1519 stp_sync = data; 1520 1521 if (xchg(&first, 1) == 1) { 1522 /* Slave */ 1523 clock_sync_cpu(stp_sync); 1524 return 0; 1525 } 1526 1527 /* Wait until all other cpus entered the sync function. */ 1528 while (atomic_read(&stp_sync->cpus) != 0) 1529 cpu_relax(); 1530 1531 enable_sync_clock(); 1532 1533 rc = 0; 1534 if (stp_info.todoff[0] || stp_info.todoff[1] || 1535 stp_info.todoff[2] || stp_info.todoff[3] || 1536 stp_info.tmd != 2) { 1537 old_clock = get_tod_clock(); 1538 rc = chsc_sstpc(stp_page, STP_OP_SYNC, 0); 1539 if (rc == 0) { 1540 delta = adjust_time(old_clock, get_tod_clock(), 0); 1541 fixup_clock_comparator(delta); 1542 rc = chsc_sstpi(stp_page, &stp_info, 1543 sizeof(struct stp_sstpi)); 1544 if (rc == 0 && stp_info.tmd != 2) 1545 rc = -EAGAIN; 1546 } 1547 } 1548 if (rc) { 1549 disable_sync_clock(NULL); 1550 stp_sync->in_sync = -EAGAIN; 1551 } else 1552 stp_sync->in_sync = 1; 1553 xchg(&first, 0); 1554 return 0; 1555 } 1556 1557 /* 1558 * STP work. Check for the STP state and take over the clock 1559 * synchronization if the STP clock source is usable. 1560 */ 1561 static void stp_work_fn(struct work_struct *work) 1562 { 1563 struct clock_sync_data stp_sync; 1564 int rc; 1565 1566 /* prevent multiple execution. */ 1567 mutex_lock(&stp_work_mutex); 1568 1569 if (!stp_online) { 1570 chsc_sstpc(stp_page, STP_OP_CTRL, 0x0000); 1571 del_timer_sync(&stp_timer); 1572 goto out_unlock; 1573 } 1574 1575 rc = chsc_sstpc(stp_page, STP_OP_CTRL, 0xb0e0); 1576 if (rc) 1577 goto out_unlock; 1578 1579 rc = chsc_sstpi(stp_page, &stp_info, sizeof(struct stp_sstpi)); 1580 if (rc || stp_info.c == 0) 1581 goto out_unlock; 1582 1583 /* Skip synchronization if the clock is already in sync. */ 1584 if (check_sync_clock()) 1585 goto out_unlock; 1586 1587 memset(&stp_sync, 0, sizeof(stp_sync)); 1588 get_online_cpus(); 1589 atomic_set(&stp_sync.cpus, num_online_cpus() - 1); 1590 stop_machine(stp_sync_clock, &stp_sync, cpu_online_mask); 1591 put_online_cpus(); 1592 1593 if (!check_sync_clock()) 1594 /* 1595 * There is a usable clock but the synchonization failed. 1596 * Retry after a second. 1597 */ 1598 mod_timer(&stp_timer, jiffies + HZ); 1599 1600 out_unlock: 1601 mutex_unlock(&stp_work_mutex); 1602 } 1603 1604 /* 1605 * STP subsys sysfs interface functions 1606 */ 1607 static struct bus_type stp_subsys = { 1608 .name = "stp", 1609 .dev_name = "stp", 1610 }; 1611 1612 static ssize_t stp_ctn_id_show(struct device *dev, 1613 struct device_attribute *attr, 1614 char *buf) 1615 { 1616 if (!stp_online) 1617 return -ENODATA; 1618 return sprintf(buf, "%016llx\n", 1619 *(unsigned long long *) stp_info.ctnid); 1620 } 1621 1622 static DEVICE_ATTR(ctn_id, 0400, stp_ctn_id_show, NULL); 1623 1624 static ssize_t stp_ctn_type_show(struct device *dev, 1625 struct device_attribute *attr, 1626 char *buf) 1627 { 1628 if (!stp_online) 1629 return -ENODATA; 1630 return sprintf(buf, "%i\n", stp_info.ctn); 1631 } 1632 1633 static DEVICE_ATTR(ctn_type, 0400, stp_ctn_type_show, NULL); 1634 1635 static ssize_t stp_dst_offset_show(struct device *dev, 1636 struct device_attribute *attr, 1637 char *buf) 1638 { 1639 if (!stp_online || !(stp_info.vbits & 0x2000)) 1640 return -ENODATA; 1641 return sprintf(buf, "%i\n", (int)(s16) stp_info.dsto); 1642 } 1643 1644 static DEVICE_ATTR(dst_offset, 0400, stp_dst_offset_show, NULL); 1645 1646 static ssize_t stp_leap_seconds_show(struct device *dev, 1647 struct device_attribute *attr, 1648 char *buf) 1649 { 1650 if (!stp_online || !(stp_info.vbits & 0x8000)) 1651 return -ENODATA; 1652 return sprintf(buf, "%i\n", (int)(s16) stp_info.leaps); 1653 } 1654 1655 static DEVICE_ATTR(leap_seconds, 0400, stp_leap_seconds_show, NULL); 1656 1657 static ssize_t stp_stratum_show(struct device *dev, 1658 struct device_attribute *attr, 1659 char *buf) 1660 { 1661 if (!stp_online) 1662 return -ENODATA; 1663 return sprintf(buf, "%i\n", (int)(s16) stp_info.stratum); 1664 } 1665 1666 static DEVICE_ATTR(stratum, 0400, stp_stratum_show, NULL); 1667 1668 static ssize_t stp_time_offset_show(struct device *dev, 1669 struct device_attribute *attr, 1670 char *buf) 1671 { 1672 if (!stp_online || !(stp_info.vbits & 0x0800)) 1673 return -ENODATA; 1674 return sprintf(buf, "%i\n", (int) stp_info.tto); 1675 } 1676 1677 static DEVICE_ATTR(time_offset, 0400, stp_time_offset_show, NULL); 1678 1679 static ssize_t stp_time_zone_offset_show(struct device *dev, 1680 struct device_attribute *attr, 1681 char *buf) 1682 { 1683 if (!stp_online || !(stp_info.vbits & 0x4000)) 1684 return -ENODATA; 1685 return sprintf(buf, "%i\n", (int)(s16) stp_info.tzo); 1686 } 1687 1688 static DEVICE_ATTR(time_zone_offset, 0400, 1689 stp_time_zone_offset_show, NULL); 1690 1691 static ssize_t stp_timing_mode_show(struct device *dev, 1692 struct device_attribute *attr, 1693 char *buf) 1694 { 1695 if (!stp_online) 1696 return -ENODATA; 1697 return sprintf(buf, "%i\n", stp_info.tmd); 1698 } 1699 1700 static DEVICE_ATTR(timing_mode, 0400, stp_timing_mode_show, NULL); 1701 1702 static ssize_t stp_timing_state_show(struct device *dev, 1703 struct device_attribute *attr, 1704 char *buf) 1705 { 1706 if (!stp_online) 1707 return -ENODATA; 1708 return sprintf(buf, "%i\n", stp_info.tst); 1709 } 1710 1711 static DEVICE_ATTR(timing_state, 0400, stp_timing_state_show, NULL); 1712 1713 static ssize_t stp_online_show(struct device *dev, 1714 struct device_attribute *attr, 1715 char *buf) 1716 { 1717 return sprintf(buf, "%i\n", stp_online); 1718 } 1719 1720 static ssize_t stp_online_store(struct device *dev, 1721 struct device_attribute *attr, 1722 const char *buf, size_t count) 1723 { 1724 unsigned int value; 1725 1726 value = simple_strtoul(buf, NULL, 0); 1727 if (value != 0 && value != 1) 1728 return -EINVAL; 1729 if (!test_bit(CLOCK_SYNC_HAS_STP, &clock_sync_flags)) 1730 return -EOPNOTSUPP; 1731 mutex_lock(&clock_sync_mutex); 1732 stp_online = value; 1733 if (stp_online) 1734 set_bit(CLOCK_SYNC_STP, &clock_sync_flags); 1735 else 1736 clear_bit(CLOCK_SYNC_STP, &clock_sync_flags); 1737 queue_work(time_sync_wq, &stp_work); 1738 mutex_unlock(&clock_sync_mutex); 1739 return count; 1740 } 1741 1742 /* 1743 * Can't use DEVICE_ATTR because the attribute should be named 1744 * stp/online but dev_attr_online already exists in this file .. 1745 */ 1746 static struct device_attribute dev_attr_stp_online = { 1747 .attr = { .name = "online", .mode = 0600 }, 1748 .show = stp_online_show, 1749 .store = stp_online_store, 1750 }; 1751 1752 static struct device_attribute *stp_attributes[] = { 1753 &dev_attr_ctn_id, 1754 &dev_attr_ctn_type, 1755 &dev_attr_dst_offset, 1756 &dev_attr_leap_seconds, 1757 &dev_attr_stp_online, 1758 &dev_attr_stratum, 1759 &dev_attr_time_offset, 1760 &dev_attr_time_zone_offset, 1761 &dev_attr_timing_mode, 1762 &dev_attr_timing_state, 1763 NULL 1764 }; 1765 1766 static int __init stp_init_sysfs(void) 1767 { 1768 struct device_attribute **attr; 1769 int rc; 1770 1771 rc = subsys_system_register(&stp_subsys, NULL); 1772 if (rc) 1773 goto out; 1774 for (attr = stp_attributes; *attr; attr++) { 1775 rc = device_create_file(stp_subsys.dev_root, *attr); 1776 if (rc) 1777 goto out_unreg; 1778 } 1779 return 0; 1780 out_unreg: 1781 for (; attr >= stp_attributes; attr--) 1782 device_remove_file(stp_subsys.dev_root, *attr); 1783 bus_unregister(&stp_subsys); 1784 out: 1785 return rc; 1786 } 1787 1788 device_initcall(stp_init_sysfs); 1789