1 /* 2 * QEMU MC146818 RTC emulation 3 * 4 * Copyright (c) 2003-2004 Fabrice Bellard 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining a copy 7 * of this software and associated documentation files (the "Software"), to deal 8 * in the Software without restriction, including without limitation the rights 9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 10 * copies of the Software, and to permit persons to whom the Software is 11 * furnished to do so, subject to the following conditions: 12 * 13 * The above copyright notice and this permission notice shall be included in 14 * all copies or substantial portions of the Software. 15 * 16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 22 * THE SOFTWARE. 23 */ 24 25 #include "qemu/osdep.h" 26 #include "qemu-common.h" 27 #include "qemu/cutils.h" 28 #include "qemu/module.h" 29 #include "qemu/bcd.h" 30 #include "hw/irq.h" 31 #include "hw/qdev-properties.h" 32 #include "qemu/timer.h" 33 #include "sysemu/sysemu.h" 34 #include "sysemu/replay.h" 35 #include "sysemu/reset.h" 36 #include "sysemu/runstate.h" 37 #include "hw/rtc/mc146818rtc.h" 38 #include "hw/rtc/mc146818rtc_regs.h" 39 #include "migration/vmstate.h" 40 #include "qapi/error.h" 41 #include "qapi/qapi-events-misc-target.h" 42 #include "qapi/visitor.h" 43 #include "exec/address-spaces.h" 44 #include "hw/rtc/mc146818rtc_regs.h" 45 46 #ifdef TARGET_I386 47 #include "qapi/qapi-commands-misc-target.h" 48 #include "hw/i386/apic.h" 49 #endif 50 51 //#define DEBUG_CMOS 52 //#define DEBUG_COALESCED 53 54 #ifdef DEBUG_CMOS 55 # define CMOS_DPRINTF(format, ...) printf(format, ## __VA_ARGS__) 56 #else 57 # define CMOS_DPRINTF(format, ...) do { } while (0) 58 #endif 59 60 #ifdef DEBUG_COALESCED 61 # define DPRINTF_C(format, ...) printf(format, ## __VA_ARGS__) 62 #else 63 # define DPRINTF_C(format, ...) do { } while (0) 64 #endif 65 66 #define SEC_PER_MIN 60 67 #define MIN_PER_HOUR 60 68 #define SEC_PER_HOUR 3600 69 #define HOUR_PER_DAY 24 70 #define SEC_PER_DAY 86400 71 72 #define RTC_REINJECT_ON_ACK_COUNT 20 73 #define RTC_CLOCK_RATE 32768 74 #define UIP_HOLD_LENGTH (8 * NANOSECONDS_PER_SECOND / 32768) 75 76 static void rtc_set_time(RTCState *s); 77 static void rtc_update_time(RTCState *s); 78 static void rtc_set_cmos(RTCState *s, const struct tm *tm); 79 static inline int rtc_from_bcd(RTCState *s, int a); 80 static uint64_t get_next_alarm(RTCState *s); 81 82 static inline bool rtc_running(RTCState *s) 83 { 84 return (!(s->cmos_data[RTC_REG_B] & REG_B_SET) && 85 (s->cmos_data[RTC_REG_A] & 0x70) <= 0x20); 86 } 87 88 static uint64_t get_guest_rtc_ns(RTCState *s) 89 { 90 uint64_t guest_clock = qemu_clock_get_ns(rtc_clock); 91 92 return s->base_rtc * NANOSECONDS_PER_SECOND + 93 guest_clock - s->last_update + s->offset; 94 } 95 96 static void rtc_coalesced_timer_update(RTCState *s) 97 { 98 if (s->irq_coalesced == 0) { 99 timer_del(s->coalesced_timer); 100 } else { 101 /* divide each RTC interval to 2 - 8 smaller intervals */ 102 int c = MIN(s->irq_coalesced, 7) + 1; 103 int64_t next_clock = qemu_clock_get_ns(rtc_clock) + 104 periodic_clock_to_ns(s->period / c); 105 timer_mod(s->coalesced_timer, next_clock); 106 } 107 } 108 109 static QLIST_HEAD(, RTCState) rtc_devices = 110 QLIST_HEAD_INITIALIZER(rtc_devices); 111 112 #ifdef TARGET_I386 113 void qmp_rtc_reset_reinjection(Error **errp) 114 { 115 RTCState *s; 116 117 QLIST_FOREACH(s, &rtc_devices, link) { 118 s->irq_coalesced = 0; 119 } 120 } 121 122 static bool rtc_policy_slew_deliver_irq(RTCState *s) 123 { 124 apic_reset_irq_delivered(); 125 qemu_irq_raise(s->irq); 126 return apic_get_irq_delivered(); 127 } 128 129 static void rtc_coalesced_timer(void *opaque) 130 { 131 RTCState *s = opaque; 132 133 if (s->irq_coalesced != 0) { 134 s->cmos_data[RTC_REG_C] |= 0xc0; 135 DPRINTF_C("cmos: injecting from timer\n"); 136 if (rtc_policy_slew_deliver_irq(s)) { 137 s->irq_coalesced--; 138 DPRINTF_C("cmos: coalesced irqs decreased to %d\n", 139 s->irq_coalesced); 140 } 141 } 142 143 rtc_coalesced_timer_update(s); 144 } 145 #else 146 static bool rtc_policy_slew_deliver_irq(RTCState *s) 147 { 148 assert(0); 149 return false; 150 } 151 #endif 152 153 static uint32_t rtc_periodic_clock_ticks(RTCState *s) 154 { 155 int period_code; 156 157 if (!(s->cmos_data[RTC_REG_B] & REG_B_PIE)) { 158 return 0; 159 } 160 161 period_code = s->cmos_data[RTC_REG_A] & 0x0f; 162 163 return periodic_period_to_clock(period_code); 164 } 165 166 /* 167 * handle periodic timer. @old_period indicates the periodic timer update 168 * is just due to period adjustment. 169 */ 170 static void 171 periodic_timer_update(RTCState *s, int64_t current_time, uint32_t old_period) 172 { 173 uint32_t period; 174 int64_t cur_clock, next_irq_clock, lost_clock = 0; 175 176 period = rtc_periodic_clock_ticks(s); 177 178 if (!period) { 179 s->irq_coalesced = 0; 180 timer_del(s->periodic_timer); 181 return; 182 } 183 184 /* compute 32 khz clock */ 185 cur_clock = 186 muldiv64(current_time, RTC_CLOCK_RATE, NANOSECONDS_PER_SECOND); 187 188 /* 189 * if the periodic timer's update is due to period re-configuration, 190 * we should count the clock since last interrupt. 191 */ 192 if (old_period) { 193 int64_t last_periodic_clock, next_periodic_clock; 194 195 next_periodic_clock = muldiv64(s->next_periodic_time, 196 RTC_CLOCK_RATE, NANOSECONDS_PER_SECOND); 197 last_periodic_clock = next_periodic_clock - old_period; 198 lost_clock = cur_clock - last_periodic_clock; 199 assert(lost_clock >= 0); 200 201 /* 202 * s->irq_coalesced can change for two reasons: 203 * 204 * a) if one or more periodic timer interrupts have been lost, 205 * lost_clock will be more that a period. 206 * 207 * b) when the period may be reconfigured, we expect the OS to 208 * treat delayed tick as the new period. So, when switching 209 * from a shorter to a longer period, scale down the missing, 210 * because the OS will treat past delayed ticks as longer 211 * (leftovers are put back into lost_clock). When switching 212 * to a shorter period, scale up the missing ticks since the 213 * OS handler will treat past delayed ticks as shorter. 214 */ 215 if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) { 216 uint32_t old_irq_coalesced = s->irq_coalesced; 217 218 s->period = period; 219 lost_clock += old_irq_coalesced * old_period; 220 s->irq_coalesced = lost_clock / s->period; 221 lost_clock %= s->period; 222 if (old_irq_coalesced != s->irq_coalesced || 223 old_period != s->period) { 224 DPRINTF_C("cmos: coalesced irqs scaled from %d to %d, " 225 "period scaled from %d to %d\n", old_irq_coalesced, 226 s->irq_coalesced, old_period, s->period); 227 rtc_coalesced_timer_update(s); 228 } 229 } else { 230 /* 231 * no way to compensate the interrupt if LOST_TICK_POLICY_SLEW 232 * is not used, we should make the time progress anyway. 233 */ 234 lost_clock = MIN(lost_clock, period); 235 } 236 } 237 238 assert(lost_clock >= 0 && lost_clock <= period); 239 240 next_irq_clock = cur_clock + period - lost_clock; 241 s->next_periodic_time = periodic_clock_to_ns(next_irq_clock) + 1; 242 timer_mod(s->periodic_timer, s->next_periodic_time); 243 } 244 245 static void rtc_periodic_timer(void *opaque) 246 { 247 RTCState *s = opaque; 248 249 periodic_timer_update(s, s->next_periodic_time, 0); 250 s->cmos_data[RTC_REG_C] |= REG_C_PF; 251 if (s->cmos_data[RTC_REG_B] & REG_B_PIE) { 252 s->cmos_data[RTC_REG_C] |= REG_C_IRQF; 253 if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) { 254 if (s->irq_reinject_on_ack_count >= RTC_REINJECT_ON_ACK_COUNT) 255 s->irq_reinject_on_ack_count = 0; 256 if (!rtc_policy_slew_deliver_irq(s)) { 257 s->irq_coalesced++; 258 rtc_coalesced_timer_update(s); 259 DPRINTF_C("cmos: coalesced irqs increased to %d\n", 260 s->irq_coalesced); 261 } 262 } else 263 qemu_irq_raise(s->irq); 264 } 265 } 266 267 /* handle update-ended timer */ 268 static void check_update_timer(RTCState *s) 269 { 270 uint64_t next_update_time; 271 uint64_t guest_nsec; 272 int next_alarm_sec; 273 274 /* From the data sheet: "Holding the dividers in reset prevents 275 * interrupts from operating, while setting the SET bit allows" 276 * them to occur. 277 */ 278 if ((s->cmos_data[RTC_REG_A] & 0x60) == 0x60) { 279 assert((s->cmos_data[RTC_REG_A] & REG_A_UIP) == 0); 280 timer_del(s->update_timer); 281 return; 282 } 283 284 guest_nsec = get_guest_rtc_ns(s) % NANOSECONDS_PER_SECOND; 285 next_update_time = qemu_clock_get_ns(rtc_clock) 286 + NANOSECONDS_PER_SECOND - guest_nsec; 287 288 /* Compute time of next alarm. One second is already accounted 289 * for in next_update_time. 290 */ 291 next_alarm_sec = get_next_alarm(s); 292 s->next_alarm_time = next_update_time + 293 (next_alarm_sec - 1) * NANOSECONDS_PER_SECOND; 294 295 /* If update_in_progress latched the UIP bit, we must keep the timer 296 * programmed to the next second, so that UIP is cleared. Otherwise, 297 * if UF is already set, we might be able to optimize. 298 */ 299 if (!(s->cmos_data[RTC_REG_A] & REG_A_UIP) && 300 (s->cmos_data[RTC_REG_C] & REG_C_UF)) { 301 /* If AF cannot change (i.e. either it is set already, or 302 * SET=1 and then the time is not updated), nothing to do. 303 */ 304 if ((s->cmos_data[RTC_REG_B] & REG_B_SET) || 305 (s->cmos_data[RTC_REG_C] & REG_C_AF)) { 306 timer_del(s->update_timer); 307 return; 308 } 309 310 /* UF is set, but AF is clear. Program the timer to target 311 * the alarm time. */ 312 next_update_time = s->next_alarm_time; 313 } 314 if (next_update_time != timer_expire_time_ns(s->update_timer)) { 315 timer_mod(s->update_timer, next_update_time); 316 } 317 } 318 319 static inline uint8_t convert_hour(RTCState *s, uint8_t hour) 320 { 321 if (!(s->cmos_data[RTC_REG_B] & REG_B_24H)) { 322 hour %= 12; 323 if (s->cmos_data[RTC_HOURS] & 0x80) { 324 hour += 12; 325 } 326 } 327 return hour; 328 } 329 330 static uint64_t get_next_alarm(RTCState *s) 331 { 332 int32_t alarm_sec, alarm_min, alarm_hour, cur_hour, cur_min, cur_sec; 333 int32_t hour, min, sec; 334 335 rtc_update_time(s); 336 337 alarm_sec = rtc_from_bcd(s, s->cmos_data[RTC_SECONDS_ALARM]); 338 alarm_min = rtc_from_bcd(s, s->cmos_data[RTC_MINUTES_ALARM]); 339 alarm_hour = rtc_from_bcd(s, s->cmos_data[RTC_HOURS_ALARM]); 340 alarm_hour = alarm_hour == -1 ? -1 : convert_hour(s, alarm_hour); 341 342 cur_sec = rtc_from_bcd(s, s->cmos_data[RTC_SECONDS]); 343 cur_min = rtc_from_bcd(s, s->cmos_data[RTC_MINUTES]); 344 cur_hour = rtc_from_bcd(s, s->cmos_data[RTC_HOURS]); 345 cur_hour = convert_hour(s, cur_hour); 346 347 if (alarm_hour == -1) { 348 alarm_hour = cur_hour; 349 if (alarm_min == -1) { 350 alarm_min = cur_min; 351 if (alarm_sec == -1) { 352 alarm_sec = cur_sec + 1; 353 } else if (cur_sec > alarm_sec) { 354 alarm_min++; 355 } 356 } else if (cur_min == alarm_min) { 357 if (alarm_sec == -1) { 358 alarm_sec = cur_sec + 1; 359 } else { 360 if (cur_sec > alarm_sec) { 361 alarm_hour++; 362 } 363 } 364 if (alarm_sec == SEC_PER_MIN) { 365 /* wrap to next hour, minutes is not in don't care mode */ 366 alarm_sec = 0; 367 alarm_hour++; 368 } 369 } else if (cur_min > alarm_min) { 370 alarm_hour++; 371 } 372 } else if (cur_hour == alarm_hour) { 373 if (alarm_min == -1) { 374 alarm_min = cur_min; 375 if (alarm_sec == -1) { 376 alarm_sec = cur_sec + 1; 377 } else if (cur_sec > alarm_sec) { 378 alarm_min++; 379 } 380 381 if (alarm_sec == SEC_PER_MIN) { 382 alarm_sec = 0; 383 alarm_min++; 384 } 385 /* wrap to next day, hour is not in don't care mode */ 386 alarm_min %= MIN_PER_HOUR; 387 } else if (cur_min == alarm_min) { 388 if (alarm_sec == -1) { 389 alarm_sec = cur_sec + 1; 390 } 391 /* wrap to next day, hours+minutes not in don't care mode */ 392 alarm_sec %= SEC_PER_MIN; 393 } 394 } 395 396 /* values that are still don't care fire at the next min/sec */ 397 if (alarm_min == -1) { 398 alarm_min = 0; 399 } 400 if (alarm_sec == -1) { 401 alarm_sec = 0; 402 } 403 404 /* keep values in range */ 405 if (alarm_sec == SEC_PER_MIN) { 406 alarm_sec = 0; 407 alarm_min++; 408 } 409 if (alarm_min == MIN_PER_HOUR) { 410 alarm_min = 0; 411 alarm_hour++; 412 } 413 alarm_hour %= HOUR_PER_DAY; 414 415 hour = alarm_hour - cur_hour; 416 min = hour * MIN_PER_HOUR + alarm_min - cur_min; 417 sec = min * SEC_PER_MIN + alarm_sec - cur_sec; 418 return sec <= 0 ? sec + SEC_PER_DAY : sec; 419 } 420 421 static void rtc_update_timer(void *opaque) 422 { 423 RTCState *s = opaque; 424 int32_t irqs = REG_C_UF; 425 int32_t new_irqs; 426 427 assert((s->cmos_data[RTC_REG_A] & 0x60) != 0x60); 428 429 /* UIP might have been latched, update time and clear it. */ 430 rtc_update_time(s); 431 s->cmos_data[RTC_REG_A] &= ~REG_A_UIP; 432 433 if (qemu_clock_get_ns(rtc_clock) >= s->next_alarm_time) { 434 irqs |= REG_C_AF; 435 if (s->cmos_data[RTC_REG_B] & REG_B_AIE) { 436 qemu_system_wakeup_request(QEMU_WAKEUP_REASON_RTC, NULL); 437 } 438 } 439 440 new_irqs = irqs & ~s->cmos_data[RTC_REG_C]; 441 s->cmos_data[RTC_REG_C] |= irqs; 442 if ((new_irqs & s->cmos_data[RTC_REG_B]) != 0) { 443 s->cmos_data[RTC_REG_C] |= REG_C_IRQF; 444 qemu_irq_raise(s->irq); 445 } 446 check_update_timer(s); 447 } 448 449 static void cmos_ioport_write(void *opaque, hwaddr addr, 450 uint64_t data, unsigned size) 451 { 452 RTCState *s = opaque; 453 uint32_t old_period; 454 bool update_periodic_timer; 455 456 if ((addr & 1) == 0) { 457 s->cmos_index = data & 0x7f; 458 } else { 459 CMOS_DPRINTF("cmos: write index=0x%02x val=0x%02" PRIx64 "\n", 460 s->cmos_index, data); 461 switch(s->cmos_index) { 462 case RTC_SECONDS_ALARM: 463 case RTC_MINUTES_ALARM: 464 case RTC_HOURS_ALARM: 465 s->cmos_data[s->cmos_index] = data; 466 check_update_timer(s); 467 break; 468 case RTC_IBM_PS2_CENTURY_BYTE: 469 s->cmos_index = RTC_CENTURY; 470 /* fall through */ 471 case RTC_CENTURY: 472 case RTC_SECONDS: 473 case RTC_MINUTES: 474 case RTC_HOURS: 475 case RTC_DAY_OF_WEEK: 476 case RTC_DAY_OF_MONTH: 477 case RTC_MONTH: 478 case RTC_YEAR: 479 s->cmos_data[s->cmos_index] = data; 480 /* if in set mode, do not update the time */ 481 if (rtc_running(s)) { 482 rtc_set_time(s); 483 check_update_timer(s); 484 } 485 break; 486 case RTC_REG_A: 487 update_periodic_timer = (s->cmos_data[RTC_REG_A] ^ data) & 0x0f; 488 old_period = rtc_periodic_clock_ticks(s); 489 490 if ((data & 0x60) == 0x60) { 491 if (rtc_running(s)) { 492 rtc_update_time(s); 493 } 494 /* What happens to UIP when divider reset is enabled is 495 * unclear from the datasheet. Shouldn't matter much 496 * though. 497 */ 498 s->cmos_data[RTC_REG_A] &= ~REG_A_UIP; 499 } else if (((s->cmos_data[RTC_REG_A] & 0x60) == 0x60) && 500 (data & 0x70) <= 0x20) { 501 /* when the divider reset is removed, the first update cycle 502 * begins one-half second later*/ 503 if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) { 504 s->offset = 500000000; 505 rtc_set_time(s); 506 } 507 s->cmos_data[RTC_REG_A] &= ~REG_A_UIP; 508 } 509 /* UIP bit is read only */ 510 s->cmos_data[RTC_REG_A] = (data & ~REG_A_UIP) | 511 (s->cmos_data[RTC_REG_A] & REG_A_UIP); 512 513 if (update_periodic_timer) { 514 periodic_timer_update(s, qemu_clock_get_ns(rtc_clock), 515 old_period); 516 } 517 518 check_update_timer(s); 519 break; 520 case RTC_REG_B: 521 update_periodic_timer = (s->cmos_data[RTC_REG_B] ^ data) 522 & REG_B_PIE; 523 old_period = rtc_periodic_clock_ticks(s); 524 525 if (data & REG_B_SET) { 526 /* update cmos to when the rtc was stopping */ 527 if (rtc_running(s)) { 528 rtc_update_time(s); 529 } 530 /* set mode: reset UIP mode */ 531 s->cmos_data[RTC_REG_A] &= ~REG_A_UIP; 532 data &= ~REG_B_UIE; 533 } else { 534 /* if disabling set mode, update the time */ 535 if ((s->cmos_data[RTC_REG_B] & REG_B_SET) && 536 (s->cmos_data[RTC_REG_A] & 0x70) <= 0x20) { 537 s->offset = get_guest_rtc_ns(s) % NANOSECONDS_PER_SECOND; 538 rtc_set_time(s); 539 } 540 } 541 /* if an interrupt flag is already set when the interrupt 542 * becomes enabled, raise an interrupt immediately. */ 543 if (data & s->cmos_data[RTC_REG_C] & REG_C_MASK) { 544 s->cmos_data[RTC_REG_C] |= REG_C_IRQF; 545 qemu_irq_raise(s->irq); 546 } else { 547 s->cmos_data[RTC_REG_C] &= ~REG_C_IRQF; 548 qemu_irq_lower(s->irq); 549 } 550 s->cmos_data[RTC_REG_B] = data; 551 552 if (update_periodic_timer) { 553 periodic_timer_update(s, qemu_clock_get_ns(rtc_clock), 554 old_period); 555 } 556 557 check_update_timer(s); 558 break; 559 case RTC_REG_C: 560 case RTC_REG_D: 561 /* cannot write to them */ 562 break; 563 default: 564 s->cmos_data[s->cmos_index] = data; 565 break; 566 } 567 } 568 } 569 570 static inline int rtc_to_bcd(RTCState *s, int a) 571 { 572 if (s->cmos_data[RTC_REG_B] & REG_B_DM) { 573 return a; 574 } else { 575 return ((a / 10) << 4) | (a % 10); 576 } 577 } 578 579 static inline int rtc_from_bcd(RTCState *s, int a) 580 { 581 if ((a & 0xc0) == 0xc0) { 582 return -1; 583 } 584 if (s->cmos_data[RTC_REG_B] & REG_B_DM) { 585 return a; 586 } else { 587 return ((a >> 4) * 10) + (a & 0x0f); 588 } 589 } 590 591 static void rtc_get_time(RTCState *s, struct tm *tm) 592 { 593 tm->tm_sec = rtc_from_bcd(s, s->cmos_data[RTC_SECONDS]); 594 tm->tm_min = rtc_from_bcd(s, s->cmos_data[RTC_MINUTES]); 595 tm->tm_hour = rtc_from_bcd(s, s->cmos_data[RTC_HOURS] & 0x7f); 596 if (!(s->cmos_data[RTC_REG_B] & REG_B_24H)) { 597 tm->tm_hour %= 12; 598 if (s->cmos_data[RTC_HOURS] & 0x80) { 599 tm->tm_hour += 12; 600 } 601 } 602 tm->tm_wday = rtc_from_bcd(s, s->cmos_data[RTC_DAY_OF_WEEK]) - 1; 603 tm->tm_mday = rtc_from_bcd(s, s->cmos_data[RTC_DAY_OF_MONTH]); 604 tm->tm_mon = rtc_from_bcd(s, s->cmos_data[RTC_MONTH]) - 1; 605 tm->tm_year = 606 rtc_from_bcd(s, s->cmos_data[RTC_YEAR]) + s->base_year + 607 rtc_from_bcd(s, s->cmos_data[RTC_CENTURY]) * 100 - 1900; 608 } 609 610 static void rtc_set_time(RTCState *s) 611 { 612 struct tm tm; 613 614 rtc_get_time(s, &tm); 615 s->base_rtc = mktimegm(&tm); 616 s->last_update = qemu_clock_get_ns(rtc_clock); 617 618 qapi_event_send_rtc_change(qemu_timedate_diff(&tm)); 619 } 620 621 static void rtc_set_cmos(RTCState *s, const struct tm *tm) 622 { 623 int year; 624 625 s->cmos_data[RTC_SECONDS] = rtc_to_bcd(s, tm->tm_sec); 626 s->cmos_data[RTC_MINUTES] = rtc_to_bcd(s, tm->tm_min); 627 if (s->cmos_data[RTC_REG_B] & REG_B_24H) { 628 /* 24 hour format */ 629 s->cmos_data[RTC_HOURS] = rtc_to_bcd(s, tm->tm_hour); 630 } else { 631 /* 12 hour format */ 632 int h = (tm->tm_hour % 12) ? tm->tm_hour % 12 : 12; 633 s->cmos_data[RTC_HOURS] = rtc_to_bcd(s, h); 634 if (tm->tm_hour >= 12) 635 s->cmos_data[RTC_HOURS] |= 0x80; 636 } 637 s->cmos_data[RTC_DAY_OF_WEEK] = rtc_to_bcd(s, tm->tm_wday + 1); 638 s->cmos_data[RTC_DAY_OF_MONTH] = rtc_to_bcd(s, tm->tm_mday); 639 s->cmos_data[RTC_MONTH] = rtc_to_bcd(s, tm->tm_mon + 1); 640 year = tm->tm_year + 1900 - s->base_year; 641 s->cmos_data[RTC_YEAR] = rtc_to_bcd(s, year % 100); 642 s->cmos_data[RTC_CENTURY] = rtc_to_bcd(s, year / 100); 643 } 644 645 static void rtc_update_time(RTCState *s) 646 { 647 struct tm ret; 648 time_t guest_sec; 649 int64_t guest_nsec; 650 651 guest_nsec = get_guest_rtc_ns(s); 652 guest_sec = guest_nsec / NANOSECONDS_PER_SECOND; 653 gmtime_r(&guest_sec, &ret); 654 655 /* Is SET flag of Register B disabled? */ 656 if ((s->cmos_data[RTC_REG_B] & REG_B_SET) == 0) { 657 rtc_set_cmos(s, &ret); 658 } 659 } 660 661 static int update_in_progress(RTCState *s) 662 { 663 int64_t guest_nsec; 664 665 if (!rtc_running(s)) { 666 return 0; 667 } 668 if (timer_pending(s->update_timer)) { 669 int64_t next_update_time = timer_expire_time_ns(s->update_timer); 670 /* Latch UIP until the timer expires. */ 671 if (qemu_clock_get_ns(rtc_clock) >= 672 (next_update_time - UIP_HOLD_LENGTH)) { 673 s->cmos_data[RTC_REG_A] |= REG_A_UIP; 674 return 1; 675 } 676 } 677 678 guest_nsec = get_guest_rtc_ns(s); 679 /* UIP bit will be set at last 244us of every second. */ 680 if ((guest_nsec % NANOSECONDS_PER_SECOND) >= 681 (NANOSECONDS_PER_SECOND - UIP_HOLD_LENGTH)) { 682 return 1; 683 } 684 return 0; 685 } 686 687 static uint64_t cmos_ioport_read(void *opaque, hwaddr addr, 688 unsigned size) 689 { 690 RTCState *s = opaque; 691 int ret; 692 if ((addr & 1) == 0) { 693 return 0xff; 694 } else { 695 switch(s->cmos_index) { 696 case RTC_IBM_PS2_CENTURY_BYTE: 697 s->cmos_index = RTC_CENTURY; 698 /* fall through */ 699 case RTC_CENTURY: 700 case RTC_SECONDS: 701 case RTC_MINUTES: 702 case RTC_HOURS: 703 case RTC_DAY_OF_WEEK: 704 case RTC_DAY_OF_MONTH: 705 case RTC_MONTH: 706 case RTC_YEAR: 707 /* if not in set mode, calibrate cmos before 708 * reading*/ 709 if (rtc_running(s)) { 710 rtc_update_time(s); 711 } 712 ret = s->cmos_data[s->cmos_index]; 713 break; 714 case RTC_REG_A: 715 ret = s->cmos_data[s->cmos_index]; 716 if (update_in_progress(s)) { 717 ret |= REG_A_UIP; 718 } 719 break; 720 case RTC_REG_C: 721 ret = s->cmos_data[s->cmos_index]; 722 qemu_irq_lower(s->irq); 723 s->cmos_data[RTC_REG_C] = 0x00; 724 if (ret & (REG_C_UF | REG_C_AF)) { 725 check_update_timer(s); 726 } 727 728 if(s->irq_coalesced && 729 (s->cmos_data[RTC_REG_B] & REG_B_PIE) && 730 s->irq_reinject_on_ack_count < RTC_REINJECT_ON_ACK_COUNT) { 731 s->irq_reinject_on_ack_count++; 732 s->cmos_data[RTC_REG_C] |= REG_C_IRQF | REG_C_PF; 733 DPRINTF_C("cmos: injecting on ack\n"); 734 if (rtc_policy_slew_deliver_irq(s)) { 735 s->irq_coalesced--; 736 DPRINTF_C("cmos: coalesced irqs decreased to %d\n", 737 s->irq_coalesced); 738 } 739 } 740 break; 741 default: 742 ret = s->cmos_data[s->cmos_index]; 743 break; 744 } 745 CMOS_DPRINTF("cmos: read index=0x%02x val=0x%02x\n", 746 s->cmos_index, ret); 747 return ret; 748 } 749 } 750 751 void rtc_set_memory(ISADevice *dev, int addr, int val) 752 { 753 RTCState *s = MC146818_RTC(dev); 754 if (addr >= 0 && addr <= 127) 755 s->cmos_data[addr] = val; 756 } 757 758 int rtc_get_memory(ISADevice *dev, int addr) 759 { 760 RTCState *s = MC146818_RTC(dev); 761 assert(addr >= 0 && addr <= 127); 762 return s->cmos_data[addr]; 763 } 764 765 static void rtc_set_date_from_host(ISADevice *dev) 766 { 767 RTCState *s = MC146818_RTC(dev); 768 struct tm tm; 769 770 qemu_get_timedate(&tm, 0); 771 772 s->base_rtc = mktimegm(&tm); 773 s->last_update = qemu_clock_get_ns(rtc_clock); 774 s->offset = 0; 775 776 /* set the CMOS date */ 777 rtc_set_cmos(s, &tm); 778 } 779 780 static int rtc_pre_save(void *opaque) 781 { 782 RTCState *s = opaque; 783 784 rtc_update_time(s); 785 786 return 0; 787 } 788 789 static int rtc_post_load(void *opaque, int version_id) 790 { 791 RTCState *s = opaque; 792 793 if (version_id <= 2 || rtc_clock == QEMU_CLOCK_REALTIME) { 794 rtc_set_time(s); 795 s->offset = 0; 796 check_update_timer(s); 797 } 798 799 /* The periodic timer is deterministic in record/replay mode, 800 * so there is no need to update it after loading the vmstate. 801 * Reading RTC here would misalign record and replay. 802 */ 803 if (replay_mode == REPLAY_MODE_NONE) { 804 uint64_t now = qemu_clock_get_ns(rtc_clock); 805 if (now < s->next_periodic_time || 806 now > (s->next_periodic_time + get_max_clock_jump())) { 807 periodic_timer_update(s, qemu_clock_get_ns(rtc_clock), 0); 808 } 809 } 810 811 if (version_id >= 2) { 812 if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) { 813 rtc_coalesced_timer_update(s); 814 } 815 } 816 return 0; 817 } 818 819 static bool rtc_irq_reinject_on_ack_count_needed(void *opaque) 820 { 821 RTCState *s = (RTCState *)opaque; 822 return s->irq_reinject_on_ack_count != 0; 823 } 824 825 static const VMStateDescription vmstate_rtc_irq_reinject_on_ack_count = { 826 .name = "mc146818rtc/irq_reinject_on_ack_count", 827 .version_id = 1, 828 .minimum_version_id = 1, 829 .needed = rtc_irq_reinject_on_ack_count_needed, 830 .fields = (VMStateField[]) { 831 VMSTATE_UINT16(irq_reinject_on_ack_count, RTCState), 832 VMSTATE_END_OF_LIST() 833 } 834 }; 835 836 static const VMStateDescription vmstate_rtc = { 837 .name = "mc146818rtc", 838 .version_id = 3, 839 .minimum_version_id = 1, 840 .pre_save = rtc_pre_save, 841 .post_load = rtc_post_load, 842 .fields = (VMStateField[]) { 843 VMSTATE_BUFFER(cmos_data, RTCState), 844 VMSTATE_UINT8(cmos_index, RTCState), 845 VMSTATE_UNUSED(7*4), 846 VMSTATE_TIMER_PTR(periodic_timer, RTCState), 847 VMSTATE_INT64(next_periodic_time, RTCState), 848 VMSTATE_UNUSED(3*8), 849 VMSTATE_UINT32_V(irq_coalesced, RTCState, 2), 850 VMSTATE_UINT32_V(period, RTCState, 2), 851 VMSTATE_UINT64_V(base_rtc, RTCState, 3), 852 VMSTATE_UINT64_V(last_update, RTCState, 3), 853 VMSTATE_INT64_V(offset, RTCState, 3), 854 VMSTATE_TIMER_PTR_V(update_timer, RTCState, 3), 855 VMSTATE_UINT64_V(next_alarm_time, RTCState, 3), 856 VMSTATE_END_OF_LIST() 857 }, 858 .subsections = (const VMStateDescription*[]) { 859 &vmstate_rtc_irq_reinject_on_ack_count, 860 NULL 861 } 862 }; 863 864 /* set CMOS shutdown status register (index 0xF) as S3_resume(0xFE) 865 BIOS will read it and start S3 resume at POST Entry */ 866 static void rtc_notify_suspend(Notifier *notifier, void *data) 867 { 868 RTCState *s = container_of(notifier, RTCState, suspend_notifier); 869 rtc_set_memory(ISA_DEVICE(s), 0xF, 0xFE); 870 } 871 872 static void rtc_reset(void *opaque) 873 { 874 RTCState *s = opaque; 875 876 s->cmos_data[RTC_REG_B] &= ~(REG_B_PIE | REG_B_AIE | REG_B_SQWE); 877 s->cmos_data[RTC_REG_C] &= ~(REG_C_UF | REG_C_IRQF | REG_C_PF | REG_C_AF); 878 check_update_timer(s); 879 880 qemu_irq_lower(s->irq); 881 882 if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) { 883 s->irq_coalesced = 0; 884 s->irq_reinject_on_ack_count = 0; 885 } 886 } 887 888 static const MemoryRegionOps cmos_ops = { 889 .read = cmos_ioport_read, 890 .write = cmos_ioport_write, 891 .impl = { 892 .min_access_size = 1, 893 .max_access_size = 1, 894 }, 895 .endianness = DEVICE_LITTLE_ENDIAN, 896 }; 897 898 static void rtc_get_date(Object *obj, struct tm *current_tm, Error **errp) 899 { 900 RTCState *s = MC146818_RTC(obj); 901 902 rtc_update_time(s); 903 rtc_get_time(s, current_tm); 904 } 905 906 static void rtc_realizefn(DeviceState *dev, Error **errp) 907 { 908 ISADevice *isadev = ISA_DEVICE(dev); 909 RTCState *s = MC146818_RTC(dev); 910 int base = 0x70; 911 912 s->cmos_data[RTC_REG_A] = 0x26; 913 s->cmos_data[RTC_REG_B] = 0x02; 914 s->cmos_data[RTC_REG_C] = 0x00; 915 s->cmos_data[RTC_REG_D] = 0x80; 916 917 /* This is for historical reasons. The default base year qdev property 918 * was set to 2000 for most machine types before the century byte was 919 * implemented. 920 * 921 * This if statement means that the century byte will be always 0 922 * (at least until 2079...) for base_year = 1980, but will be set 923 * correctly for base_year = 2000. 924 */ 925 if (s->base_year == 2000) { 926 s->base_year = 0; 927 } 928 929 rtc_set_date_from_host(isadev); 930 931 switch (s->lost_tick_policy) { 932 #ifdef TARGET_I386 933 case LOST_TICK_POLICY_SLEW: 934 s->coalesced_timer = 935 timer_new_ns(rtc_clock, rtc_coalesced_timer, s); 936 break; 937 #endif 938 case LOST_TICK_POLICY_DISCARD: 939 break; 940 default: 941 error_setg(errp, "Invalid lost tick policy."); 942 return; 943 } 944 945 s->periodic_timer = timer_new_ns(rtc_clock, rtc_periodic_timer, s); 946 s->update_timer = timer_new_ns(rtc_clock, rtc_update_timer, s); 947 check_update_timer(s); 948 949 s->suspend_notifier.notify = rtc_notify_suspend; 950 qemu_register_suspend_notifier(&s->suspend_notifier); 951 952 memory_region_init_io(&s->io, OBJECT(s), &cmos_ops, s, "rtc", 2); 953 isa_register_ioport(isadev, &s->io, base); 954 955 /* register rtc 0x70 port for coalesced_pio */ 956 memory_region_set_flush_coalesced(&s->io); 957 memory_region_init_io(&s->coalesced_io, OBJECT(s), &cmos_ops, 958 s, "rtc-index", 1); 959 memory_region_add_subregion(&s->io, 0, &s->coalesced_io); 960 memory_region_add_coalescing(&s->coalesced_io, 0, 1); 961 962 qdev_set_legacy_instance_id(dev, base, 3); 963 qemu_register_reset(rtc_reset, s); 964 965 object_property_add_tm(OBJECT(s), "date", rtc_get_date, NULL); 966 967 qdev_init_gpio_out(dev, &s->irq, 1); 968 QLIST_INSERT_HEAD(&rtc_devices, s, link); 969 } 970 971 ISADevice *mc146818_rtc_init(ISABus *bus, int base_year, qemu_irq intercept_irq) 972 { 973 DeviceState *dev; 974 ISADevice *isadev; 975 976 isadev = isa_create(bus, TYPE_MC146818_RTC); 977 dev = DEVICE(isadev); 978 qdev_prop_set_int32(dev, "base_year", base_year); 979 qdev_init_nofail(dev); 980 if (intercept_irq) { 981 qdev_connect_gpio_out(dev, 0, intercept_irq); 982 } else { 983 isa_connect_gpio_out(isadev, 0, RTC_ISA_IRQ); 984 } 985 986 object_property_add_alias(qdev_get_machine(), "rtc-time", OBJECT(isadev), 987 "date", NULL); 988 989 return isadev; 990 } 991 992 static Property mc146818rtc_properties[] = { 993 DEFINE_PROP_INT32("base_year", RTCState, base_year, 1980), 994 DEFINE_PROP_LOSTTICKPOLICY("lost_tick_policy", RTCState, 995 lost_tick_policy, LOST_TICK_POLICY_DISCARD), 996 DEFINE_PROP_END_OF_LIST(), 997 }; 998 999 static void rtc_resetdev(DeviceState *d) 1000 { 1001 RTCState *s = MC146818_RTC(d); 1002 1003 /* Reason: VM do suspend self will set 0xfe 1004 * Reset any values other than 0xfe(Guest suspend case) */ 1005 if (s->cmos_data[0x0f] != 0xfe) { 1006 s->cmos_data[0x0f] = 0x00; 1007 } 1008 } 1009 1010 static void rtc_class_initfn(ObjectClass *klass, void *data) 1011 { 1012 DeviceClass *dc = DEVICE_CLASS(klass); 1013 1014 dc->realize = rtc_realizefn; 1015 dc->reset = rtc_resetdev; 1016 dc->vmsd = &vmstate_rtc; 1017 dc->props = mc146818rtc_properties; 1018 } 1019 1020 static const TypeInfo mc146818rtc_info = { 1021 .name = TYPE_MC146818_RTC, 1022 .parent = TYPE_ISA_DEVICE, 1023 .instance_size = sizeof(RTCState), 1024 .class_init = rtc_class_initfn, 1025 }; 1026 1027 static void mc146818rtc_register_types(void) 1028 { 1029 type_register_static(&mc146818rtc_info); 1030 } 1031 1032 type_init(mc146818rtc_register_types) 1033