diff options
| -rw-r--r-- | hw/mc146818rtc.c | 329 |
1 files changed, 194 insertions, 135 deletions
diff --git a/hw/mc146818rtc.c b/hw/mc146818rtc.c index b41eb4b944..54c98a53d3 100644 --- a/hw/mc146818rtc.c +++ b/hw/mc146818rtc.c @@ -45,8 +45,11 @@ # define DPRINTF_C(format, ...) do { } while (0) #endif +#define NSEC_PER_SEC 1000000000LL + #define RTC_REINJECT_ON_ACK_COUNT 20 #define RTC_CLOCK_RATE 32768 +#define UIP_HOLD_LENGTH (8 * NSEC_PER_SEC / 32768) typedef struct RTCState { ISADevice dev; @@ -55,27 +58,40 @@ typedef struct RTCState { uint8_t cmos_index; struct tm current_tm; int32_t base_year; + uint64_t base_rtc; + uint64_t last_update; + int64_t offset; qemu_irq irq; qemu_irq sqw_irq; int it_shift; /* periodic timer */ QEMUTimer *periodic_timer; int64_t next_periodic_time; - /* second update */ - int64_t next_second_time; + /* update-ended timer */ + QEMUTimer *update_timer; uint16_t irq_reinject_on_ack_count; uint32_t irq_coalesced; uint32_t period; QEMUTimer *coalesced_timer; - QEMUTimer *second_timer; - QEMUTimer *second_timer2; Notifier clock_reset_notifier; LostTickPolicy lost_tick_policy; Notifier suspend_notifier; } RTCState; static void rtc_set_time(RTCState *s); -static void rtc_copy_date(RTCState *s); +static void rtc_update_time(RTCState *s); +static void rtc_set_cmos(RTCState *s); +static inline int rtc_from_bcd(RTCState *s, int a); + +static uint64_t get_guest_rtc_ns(RTCState *s) +{ + uint64_t guest_rtc; + uint64_t guest_clock = qemu_get_clock_ns(rtc_clock); + + guest_rtc = s->base_rtc * NSEC_PER_SEC + + guest_clock - s->last_update + s->offset; + return guest_rtc; +} #ifdef TARGET_I386 static void rtc_coalesced_timer_update(RTCState *s) @@ -111,6 +127,7 @@ static void rtc_coalesced_timer(void *opaque) } #endif +/* handle periodic timer */ static void periodic_timer_update(RTCState *s, int64_t current_time) { int period_code, period; @@ -176,6 +193,100 @@ static void rtc_periodic_timer(void *opaque) } } +/* handle update-ended timer */ +static void check_update_timer(RTCState *s) +{ + uint64_t next_update_time; + uint64_t guest_nsec; + + /* From the data sheet: setting the SET bit does not prevent + * interrupts from occurring! However, it will prevent an + * alarm interrupt from occurring, because the time of day is + * not updated. + */ + if ((s->cmos_data[RTC_REG_C] & REG_C_UF) && + (s->cmos_data[RTC_REG_B] & REG_B_SET)) { + qemu_del_timer(s->update_timer); + return; + } + if ((s->cmos_data[RTC_REG_C] & REG_C_UF) && + (s->cmos_data[RTC_REG_C] & REG_C_AF)) { + qemu_del_timer(s->update_timer); + return; + } + + guest_nsec = get_guest_rtc_ns(s) % NSEC_PER_SEC; + /* reprogram to next second */ + next_update_time = qemu_get_clock_ns(rtc_clock) + + NSEC_PER_SEC - guest_nsec; + if (next_update_time != qemu_timer_expire_time_ns(s->update_timer)) { + qemu_mod_timer(s->update_timer, next_update_time); + } +} + +static inline uint8_t convert_hour(RTCState *s, uint8_t hour) +{ + if (!(s->cmos_data[RTC_REG_B] & REG_B_24H)) { + hour %= 12; + if (s->cmos_data[RTC_HOURS] & 0x80) { + hour += 12; + } + } + return hour; +} + +static uint32_t check_alarm(RTCState *s) +{ + uint8_t alarm_hour, alarm_min, alarm_sec; + uint8_t cur_hour, cur_min, cur_sec; + + alarm_sec = rtc_from_bcd(s, s->cmos_data[RTC_SECONDS_ALARM]); + alarm_min = rtc_from_bcd(s, s->cmos_data[RTC_MINUTES_ALARM]); + alarm_hour = rtc_from_bcd(s, s->cmos_data[RTC_HOURS_ALARM]); + alarm_hour = convert_hour(s, alarm_hour); + + cur_sec = rtc_from_bcd(s, s->cmos_data[RTC_SECONDS]); + cur_min = rtc_from_bcd(s, s->cmos_data[RTC_MINUTES]); + cur_hour = rtc_from_bcd(s, s->cmos_data[RTC_HOURS]); + cur_hour = convert_hour(s, cur_hour); + + if (((s->cmos_data[RTC_SECONDS_ALARM] & 0xc0) == 0xc0 + || alarm_sec == cur_sec) && + ((s->cmos_data[RTC_MINUTES_ALARM] & 0xc0) == 0xc0 + || alarm_min == cur_min) && + ((s->cmos_data[RTC_HOURS_ALARM] & 0xc0) == 0xc0 + || alarm_hour == cur_hour)) { + return 1; + } + return 0; + +} + +static void rtc_update_timer(void *opaque) +{ + RTCState *s = opaque; + int32_t irqs = REG_C_UF; + int32_t new_irqs; + + /* UIP might have been latched, update time and clear it. */ + rtc_update_time(s); + s->cmos_data[RTC_REG_A] &= ~REG_A_UIP; + + if (check_alarm(s)) { + irqs |= REG_C_AF; + if (s->cmos_data[RTC_REG_B] & REG_B_AIE) { + qemu_system_wakeup_request(QEMU_WAKEUP_REASON_RTC); + } + } + new_irqs = irqs & ~s->cmos_data[RTC_REG_C]; + s->cmos_data[RTC_REG_C] |= irqs; + if ((new_irqs & s->cmos_data[RTC_REG_B]) != 0) { + s->cmos_data[RTC_REG_C] |= REG_C_IRQF; + qemu_irq_raise(s->irq); + } + check_update_timer(s); +} + static void cmos_ioport_write(void *opaque, uint32_t addr, uint32_t data) { RTCState *s = opaque; @@ -190,6 +301,7 @@ static void cmos_ioport_write(void *opaque, uint32_t addr, uint32_t data) case RTC_MINUTES_ALARM: case RTC_HOURS_ALARM: s->cmos_data[s->cmos_index] = data; + check_update_timer(s); break; case RTC_SECONDS: case RTC_MINUTES: @@ -202,6 +314,7 @@ static void cmos_ioport_write(void *opaque, uint32_t addr, uint32_t data) /* if in set mode, do not update the time */ if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) { rtc_set_time(s); + check_update_timer(s); } break; case RTC_REG_A: @@ -209,15 +322,21 @@ static void cmos_ioport_write(void *opaque, uint32_t addr, uint32_t data) s->cmos_data[RTC_REG_A] = (data & ~REG_A_UIP) | (s->cmos_data[RTC_REG_A] & REG_A_UIP); periodic_timer_update(s, qemu_get_clock_ns(rtc_clock)); + check_update_timer(s); break; case RTC_REG_B: if (data & REG_B_SET) { + /* update cmos to when the rtc was stopping */ + if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) { + rtc_update_time(s); + } /* set mode: reset UIP mode */ s->cmos_data[RTC_REG_A] &= ~REG_A_UIP; data &= ~REG_B_UIE; } else { /* if disabling set mode, update the time */ if (s->cmos_data[RTC_REG_B] & REG_B_SET) { + s->offset = get_guest_rtc_ns(s) % NSEC_PER_SEC; rtc_set_time(s); } } @@ -232,6 +351,7 @@ static void cmos_ioport_write(void *opaque, uint32_t addr, uint32_t data) } s->cmos_data[RTC_REG_B] = data; periodic_timer_update(s, qemu_get_clock_ns(rtc_clock)); + check_update_timer(s); break; case RTC_REG_C: case RTC_REG_D: @@ -280,10 +400,13 @@ static void rtc_set_time(RTCState *s) tm->tm_mon = rtc_from_bcd(s, s->cmos_data[RTC_MONTH]) - 1; tm->tm_year = rtc_from_bcd(s, s->cmos_data[RTC_YEAR]) + s->base_year - 1900; + s->base_rtc = mktimegm(tm); + s->last_update = qemu_get_clock_ns(rtc_clock); + rtc_change_mon_event(tm); } -static void rtc_copy_date(RTCState *s) +static void rtc_set_cmos(RTCState *s) { const struct tm *tm = &s->current_tm; int year; @@ -309,122 +432,41 @@ static void rtc_copy_date(RTCState *s) s->cmos_data[RTC_YEAR] = rtc_to_bcd(s, year); } -/* month is between 0 and 11. */ -static int get_days_in_month(int month, int year) +static void rtc_update_time(RTCState *s) { - static const int days_tab[12] = { - 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 - }; - int d; - if ((unsigned )month >= 12) - return 31; - d = days_tab[month]; - if (month == 1) { - if ((year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0)) - d++; - } - return d; + struct tm ret; + time_t guest_sec; + int64_t guest_nsec; + + guest_nsec = get_guest_rtc_ns(s); + guest_sec = guest_nsec / NSEC_PER_SEC; + gmtime_r(&guest_sec, &ret); + s->current_tm = ret; + rtc_set_cmos(s); } -/* update 'tm' to the next second */ -static void rtc_next_second(struct tm *tm) +static int update_in_progress(RTCState *s) { - int days_in_month; - - tm->tm_sec++; - if ((unsigned)tm->tm_sec >= 60) { - tm->tm_sec = 0; - tm->tm_min++; - if ((unsigned)tm->tm_min >= 60) { - tm->tm_min = 0; - tm->tm_hour++; - if ((unsigned)tm->tm_hour >= 24) { - tm->tm_hour = 0; - /* next day */ - tm->tm_wday++; - if ((unsigned)tm->tm_wday >= 7) - tm->tm_wday = 0; - days_in_month = get_days_in_month(tm->tm_mon, - tm->tm_year + 1900); - tm->tm_mday++; - if (tm->tm_mday < 1) { - tm->tm_mday = 1; - } else if (tm->tm_mday > days_in_month) { - tm->tm_mday = 1; - tm->tm_mon++; - if (tm->tm_mon >= 12) { - tm->tm_mon = 0; - tm->tm_year++; - } - } - } - } - } -} - - -static void rtc_update_second(void *opaque) -{ - RTCState *s = opaque; - int64_t delay; - - /* if the oscillator is not in normal operation, we do not update */ - if ((s->cmos_data[RTC_REG_A] & 0x70) != 0x20) { - s->next_second_time += get_ticks_per_sec(); - qemu_mod_timer(s->second_timer, s->next_second_time); - } else { - rtc_next_second(&s->current_tm); + int64_t guest_nsec; - if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) { - /* update in progress bit */ - s->cmos_data[RTC_REG_A] |= REG_A_UIP; - } - /* should be 244 us = 8 / RTC_CLOCK_RATE seconds, but currently the - timers do not have the necessary resolution. */ - delay = (get_ticks_per_sec() * 1) / 100; - if (delay < 1) - delay = 1; - qemu_mod_timer(s->second_timer2, - s->next_second_time + delay); + if (s->cmos_data[RTC_REG_B] & REG_B_SET) { + return 0; } -} - -static void rtc_update_second2(void *opaque) -{ - RTCState *s = opaque; - - if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) { - rtc_copy_date(s); - } - - /* check alarm */ - if (((s->cmos_data[RTC_SECONDS_ALARM] & 0xc0) == 0xc0 || - rtc_from_bcd(s, s->cmos_data[RTC_SECONDS_ALARM]) == s->current_tm.tm_sec) && - ((s->cmos_data[RTC_MINUTES_ALARM] & 0xc0) == 0xc0 || - rtc_from_bcd(s, s->cmos_data[RTC_MINUTES_ALARM]) == s->current_tm.tm_min) && - ((s->cmos_data[RTC_HOURS_ALARM] & 0xc0) == 0xc0 || - rtc_from_bcd(s, s->cmos_data[RTC_HOURS_ALARM]) == s->current_tm.tm_hour)) { - - s->cmos_data[RTC_REG_C] |= REG_C_AF; - if (s->cmos_data[RTC_REG_B] & REG_B_AIE) { - qemu_system_wakeup_request(QEMU_WAKEUP_REASON_RTC); - qemu_irq_raise(s->irq); - s->cmos_data[RTC_REG_C] |= REG_C_IRQF; + if (qemu_timer_pending(s->update_timer)) { + int64_t next_update_time = qemu_timer_expire_time_ns(s->update_timer); + /* Latch UIP until the timer expires. */ + if (qemu_get_clock_ns(rtc_clock) >= (next_update_time - UIP_HOLD_LENGTH)) { + s->cmos_data[RTC_REG_A] |= REG_A_UIP; + return 1; } } - /* update ended interrupt */ - s->cmos_data[RTC_REG_C] |= REG_C_UF; - if (s->cmos_data[RTC_REG_B] & REG_B_UIE) { - s->cmos_data[RTC_REG_C] |= REG_C_IRQF; - qemu_irq_raise(s->irq); + guest_nsec = get_guest_rtc_ns(s); + /* UIP bit will be set at last 244us of every second. */ + if ((guest_nsec % NSEC_PER_SEC) >= (NSEC_PER_SEC - UIP_HOLD_LENGTH)) { + return 1; } - - /* clear update in progress bit */ - s->cmos_data[RTC_REG_A] &= ~REG_A_UIP; - - s->next_second_time += get_ticks_per_sec(); - qemu_mod_timer(s->second_timer, s->next_second_time); + return 0; } static uint32_t cmos_ioport_read(void *opaque, uint32_t addr) @@ -442,15 +484,28 @@ static uint32_t cmos_ioport_read(void *opaque, uint32_t addr) case RTC_DAY_OF_MONTH: case RTC_MONTH: case RTC_YEAR: + /* if not in set mode, calibrate cmos before + * reading*/ + if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) { + rtc_update_time(s); + } ret = s->cmos_data[s->cmos_index]; break; case RTC_REG_A: + if (update_in_progress(s)) { + s->cmos_data[s->cmos_index] |= REG_A_UIP; + } else { + s->cmos_data[s->cmos_index] &= ~REG_A_UIP; + } ret = s->cmos_data[s->cmos_index]; break; case RTC_REG_C: ret = s->cmos_data[s->cmos_index]; qemu_irq_lower(s->irq); s->cmos_data[RTC_REG_C] = 0x00; + if (ret & (REG_C_UF | REG_C_AF)) { + check_update_timer(s); + } #ifdef TARGET_I386 if(s->irq_coalesced && (s->cmos_data[RTC_REG_B] & REG_B_PIE) && @@ -485,13 +540,6 @@ void rtc_set_memory(ISADevice *dev, int addr, int val) s->cmos_data[addr] = val; } -void rtc_set_date(ISADevice *dev, const struct tm *tm) -{ - RTCState *s = DO_UPCAST(RTCState, dev, dev); - s->current_tm = *tm; - rtc_copy_date(s); -} - /* PC cmos mappings */ #define REG_IBM_CENTURY_BYTE 0x32 #define REG_IBM_PS2_CENTURY_BYTE 0x37 @@ -502,9 +550,15 @@ static void rtc_set_date_from_host(ISADevice *dev) struct tm tm; int val; - /* set the CMOS date */ qemu_get_timedate(&tm, 0); - rtc_set_date(dev, &tm); + + s->base_rtc = mktimegm(&tm); + s->last_update = qemu_get_clock_ns(rtc_clock); + s->offset = 0; + + /* set the CMOS date */ + s->current_tm = tm; + rtc_set_cmos(s); val = rtc_to_bcd(s, (tm.tm_year / 100) + 19); rtc_set_memory(dev, REG_IBM_CENTURY_BYTE, val); @@ -513,9 +567,15 @@ static void rtc_set_date_from_host(ISADevice *dev) static int rtc_post_load(void *opaque, int version_id) { -#ifdef TARGET_I386 RTCState *s = opaque; + if (version_id <= 2) { + rtc_set_time(s); + s->offset = 0; + check_update_timer(s); + } + +#ifdef TARGET_I386 if (version_id >= 2) { if (s->lost_tick_policy == LOST_TICK_SLEW) { rtc_coalesced_timer_update(s); @@ -527,7 +587,7 @@ static int rtc_post_load(void *opaque, int version_id) static const VMStateDescription vmstate_rtc = { .name = "mc146818rtc", - .version_id = 2, + .version_id = 3, .minimum_version_id = 1, .minimum_version_id_old = 1, .post_load = rtc_post_load, @@ -543,11 +603,13 @@ static const VMStateDescription vmstate_rtc = { VMSTATE_INT32(current_tm.tm_year, RTCState), VMSTATE_TIMER(periodic_timer, RTCState), VMSTATE_INT64(next_periodic_time, RTCState), - VMSTATE_INT64(next_second_time, RTCState), - VMSTATE_TIMER(second_timer, RTCState), - VMSTATE_TIMER(second_timer2, RTCState), + VMSTATE_UNUSED(3*8), VMSTATE_UINT32_V(irq_coalesced, RTCState, 2), VMSTATE_UINT32_V(period, RTCState, 2), + VMSTATE_UINT64_V(base_rtc, RTCState, 3), + VMSTATE_UINT64_V(last_update, RTCState, 3), + VMSTATE_INT64_V(offset, RTCState, 3), + VMSTATE_TIMER_V(update_timer, RTCState, 3), VMSTATE_END_OF_LIST() } }; @@ -558,9 +620,8 @@ static void rtc_notify_clock_reset(Notifier *notifier, void *data) int64_t now = *(int64_t *)data; rtc_set_date_from_host(&s->dev); - s->next_second_time = now + (get_ticks_per_sec() * 99) / 100; - qemu_mod_timer(s->second_timer2, s->next_second_time); periodic_timer_update(s, now); + check_update_timer(s); #ifdef TARGET_I386 if (s->lost_tick_policy == LOST_TICK_SLEW) { rtc_coalesced_timer_update(s); @@ -582,6 +643,7 @@ static void rtc_reset(void *opaque) s->cmos_data[RTC_REG_B] &= ~(REG_B_PIE | REG_B_AIE | REG_B_SQWE); s->cmos_data[RTC_REG_C] &= ~(REG_C_UF | REG_C_IRQF | REG_C_PF | REG_C_AF); + check_update_timer(s); qemu_irq_lower(s->irq); @@ -607,6 +669,7 @@ static void rtc_get_date(Object *obj, Visitor *v, void *opaque, ISADevice *isa = ISA_DEVICE(obj); RTCState *s = DO_UPCAST(RTCState, dev, isa); + rtc_update_time(s); visit_start_struct(v, NULL, "struct tm", name, 0, errp); visit_type_int32(v, &s->current_tm.tm_year, "tm_year", errp); visit_type_int32(v, &s->current_tm.tm_mon, "tm_mon", errp); @@ -643,8 +706,8 @@ static int rtc_initfn(ISADevice *dev) #endif s->periodic_timer = qemu_new_timer_ns(rtc_clock, rtc_periodic_timer, s); - s->second_timer = qemu_new_timer_ns(rtc_clock, rtc_update_second, s); - s->second_timer2 = qemu_new_timer_ns(rtc_clock, rtc_update_second2, s); + s->update_timer = qemu_new_timer_ns(rtc_clock, rtc_update_timer, s); + check_update_timer(s); s->clock_reset_notifier.notify = rtc_notify_clock_reset; qemu_register_clock_reset_notifier(rtc_clock, &s->clock_reset_notifier); @@ -652,14 +715,10 @@ static int rtc_initfn(ISADevice *dev) s->suspend_notifier.notify = rtc_notify_suspend; qemu_register_suspend_notifier(&s->suspend_notifier); - s->next_second_time = - qemu_get_clock_ns(rtc_clock) + (get_ticks_per_sec() * 99) / 100; - qemu_mod_timer(s->second_timer2, s->next_second_time); - memory_region_init_io(&s->io, &cmos_ops, s, "rtc", 2); isa_register_ioport(dev, &s->io, base); - qdev_set_legacy_instance_id(&dev->qdev, base, 2); + qdev_set_legacy_instance_id(&dev->qdev, base, 3); qemu_register_reset(rtc_reset, s); object_property_add(OBJECT(s), "date", "struct tm", |