diff options
Diffstat (limited to 'src/hw/timer/mc146818rtc.c')
| -rw-r--r-- | src/hw/timer/mc146818rtc.c | 965 |
1 files changed, 965 insertions, 0 deletions
diff --git a/src/hw/timer/mc146818rtc.c b/src/hw/timer/mc146818rtc.c new file mode 100644 index 0000000..a9f0efd --- /dev/null +++ b/src/hw/timer/mc146818rtc.c @@ -0,0 +1,965 @@ +/* + * QEMU MC146818 RTC emulation + * + * Copyright (c) 2003-2004 Fabrice Bellard + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ +#include "hw/hw.h" +#include "qemu/timer.h" +#include "sysemu/sysemu.h" +#include "hw/timer/mc146818rtc.h" +#include "qapi/visitor.h" +#include "qapi-event.h" +#include "qmp-commands.h" + +#ifdef TARGET_I386 +#include "hw/i386/apic.h" +#endif + +//#define DEBUG_CMOS +//#define DEBUG_COALESCED + +#ifdef DEBUG_CMOS +# define CMOS_DPRINTF(format, ...) printf(format, ## __VA_ARGS__) +#else +# define CMOS_DPRINTF(format, ...) do { } while (0) +#endif + +#ifdef DEBUG_COALESCED +# define DPRINTF_C(format, ...) printf(format, ## __VA_ARGS__) +#else +# define DPRINTF_C(format, ...) do { } while (0) +#endif + +#define SEC_PER_MIN 60 +#define MIN_PER_HOUR 60 +#define SEC_PER_HOUR 3600 +#define HOUR_PER_DAY 24 +#define SEC_PER_DAY 86400 + +#define RTC_REINJECT_ON_ACK_COUNT 20 +#define RTC_CLOCK_RATE 32768 +#define UIP_HOLD_LENGTH (8 * NANOSECONDS_PER_SECOND / 32768) + +#define MC146818_RTC(obj) OBJECT_CHECK(RTCState, (obj), TYPE_MC146818_RTC) + +typedef struct RTCState { + ISADevice parent_obj; + + MemoryRegion io; + uint8_t cmos_data[128]; + uint8_t cmos_index; + int32_t base_year; + uint64_t base_rtc; + uint64_t last_update; + int64_t offset; + qemu_irq irq; + int it_shift; + /* periodic timer */ + QEMUTimer *periodic_timer; + int64_t next_periodic_time; + /* update-ended timer */ + QEMUTimer *update_timer; + uint64_t next_alarm_time; + uint16_t irq_reinject_on_ack_count; + uint32_t irq_coalesced; + uint32_t period; + QEMUTimer *coalesced_timer; + Notifier clock_reset_notifier; + LostTickPolicy lost_tick_policy; + Notifier suspend_notifier; + QLIST_ENTRY(RTCState) link; +} RTCState; + +static void rtc_set_time(RTCState *s); +static void rtc_update_time(RTCState *s); +static void rtc_set_cmos(RTCState *s, const struct tm *tm); +static inline int rtc_from_bcd(RTCState *s, int a); +static uint64_t get_next_alarm(RTCState *s); + +static inline bool rtc_running(RTCState *s) +{ + return (!(s->cmos_data[RTC_REG_B] & REG_B_SET) && + (s->cmos_data[RTC_REG_A] & 0x70) <= 0x20); +} + +static uint64_t get_guest_rtc_ns(RTCState *s) +{ + uint64_t guest_rtc; + uint64_t guest_clock = qemu_clock_get_ns(rtc_clock); + + guest_rtc = s->base_rtc * NANOSECONDS_PER_SECOND + + guest_clock - s->last_update + s->offset; + return guest_rtc; +} + +#ifdef TARGET_I386 +static void rtc_coalesced_timer_update(RTCState *s) +{ + if (s->irq_coalesced == 0) { + timer_del(s->coalesced_timer); + } else { + /* divide each RTC interval to 2 - 8 smaller intervals */ + int c = MIN(s->irq_coalesced, 7) + 1; + int64_t next_clock = qemu_clock_get_ns(rtc_clock) + + muldiv64(s->period / c, get_ticks_per_sec(), RTC_CLOCK_RATE); + timer_mod(s->coalesced_timer, next_clock); + } +} + +static void rtc_coalesced_timer(void *opaque) +{ + RTCState *s = opaque; + + if (s->irq_coalesced != 0) { + apic_reset_irq_delivered(); + s->cmos_data[RTC_REG_C] |= 0xc0; + DPRINTF_C("cmos: injecting from timer\n"); + qemu_irq_raise(s->irq); + if (apic_get_irq_delivered()) { + s->irq_coalesced--; + DPRINTF_C("cmos: coalesced irqs decreased to %d\n", + s->irq_coalesced); + } + } + + rtc_coalesced_timer_update(s); +} +#endif + +/* handle periodic timer */ +static void periodic_timer_update(RTCState *s, int64_t current_time) +{ + int period_code, period; + int64_t cur_clock, next_irq_clock; + + period_code = s->cmos_data[RTC_REG_A] & 0x0f; + if (period_code != 0 + && (s->cmos_data[RTC_REG_B] & REG_B_PIE)) { + if (period_code <= 2) + period_code += 7; + /* period in 32 Khz cycles */ + period = 1 << (period_code - 1); +#ifdef TARGET_I386 + if (period != s->period) { + s->irq_coalesced = (s->irq_coalesced * s->period) / period; + DPRINTF_C("cmos: coalesced irqs scaled to %d\n", s->irq_coalesced); + } + s->period = period; +#endif + /* compute 32 khz clock */ + cur_clock = muldiv64(current_time, RTC_CLOCK_RATE, get_ticks_per_sec()); + next_irq_clock = (cur_clock & ~(period - 1)) + period; + s->next_periodic_time = + muldiv64(next_irq_clock, get_ticks_per_sec(), RTC_CLOCK_RATE) + 1; + timer_mod(s->periodic_timer, s->next_periodic_time); + } else { +#ifdef TARGET_I386 + s->irq_coalesced = 0; +#endif + timer_del(s->periodic_timer); + } +} + +static void rtc_periodic_timer(void *opaque) +{ + RTCState *s = opaque; + + periodic_timer_update(s, s->next_periodic_time); + s->cmos_data[RTC_REG_C] |= REG_C_PF; + if (s->cmos_data[RTC_REG_B] & REG_B_PIE) { + s->cmos_data[RTC_REG_C] |= REG_C_IRQF; +#ifdef TARGET_I386 + if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) { + if (s->irq_reinject_on_ack_count >= RTC_REINJECT_ON_ACK_COUNT) + s->irq_reinject_on_ack_count = 0; + apic_reset_irq_delivered(); + qemu_irq_raise(s->irq); + if (!apic_get_irq_delivered()) { + s->irq_coalesced++; + rtc_coalesced_timer_update(s); + DPRINTF_C("cmos: coalesced irqs increased to %d\n", + s->irq_coalesced); + } + } else +#endif + qemu_irq_raise(s->irq); + } +} + +/* handle update-ended timer */ +static void check_update_timer(RTCState *s) +{ + uint64_t next_update_time; + uint64_t guest_nsec; + int next_alarm_sec; + + /* From the data sheet: "Holding the dividers in reset prevents + * interrupts from operating, while setting the SET bit allows" + * them to occur. However, it will prevent an alarm interrupt + * from occurring, because the time of day is not updated. + */ + if ((s->cmos_data[RTC_REG_A] & 0x60) == 0x60) { + timer_del(s->update_timer); + return; + } + if ((s->cmos_data[RTC_REG_C] & REG_C_UF) && + (s->cmos_data[RTC_REG_B] & REG_B_SET)) { + timer_del(s->update_timer); + return; + } + if ((s->cmos_data[RTC_REG_C] & REG_C_UF) && + (s->cmos_data[RTC_REG_C] & REG_C_AF)) { + timer_del(s->update_timer); + return; + } + + guest_nsec = get_guest_rtc_ns(s) % NANOSECONDS_PER_SECOND; + /* if UF is clear, reprogram to next second */ + next_update_time = qemu_clock_get_ns(rtc_clock) + + NANOSECONDS_PER_SECOND - guest_nsec; + + /* Compute time of next alarm. One second is already accounted + * for in next_update_time. + */ + next_alarm_sec = get_next_alarm(s); + s->next_alarm_time = next_update_time + + (next_alarm_sec - 1) * NANOSECONDS_PER_SECOND; + + if (s->cmos_data[RTC_REG_C] & REG_C_UF) { + /* UF is set, but AF is clear. Program the timer to target + * the alarm time. */ + next_update_time = s->next_alarm_time; + } + if (next_update_time != timer_expire_time_ns(s->update_timer)) { + timer_mod(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 uint64_t get_next_alarm(RTCState *s) +{ + int32_t alarm_sec, alarm_min, alarm_hour, cur_hour, cur_min, cur_sec; + int32_t hour, min, sec; + + rtc_update_time(s); + + 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 = alarm_hour == -1 ? -1 : 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 (alarm_hour == -1) { + alarm_hour = cur_hour; + if (alarm_min == -1) { + alarm_min = cur_min; + if (alarm_sec == -1) { + alarm_sec = cur_sec + 1; + } else if (cur_sec > alarm_sec) { + alarm_min++; + } + } else if (cur_min == alarm_min) { + if (alarm_sec == -1) { + alarm_sec = cur_sec + 1; + } else { + if (cur_sec > alarm_sec) { + alarm_hour++; + } + } + if (alarm_sec == SEC_PER_MIN) { + /* wrap to next hour, minutes is not in don't care mode */ + alarm_sec = 0; + alarm_hour++; + } + } else if (cur_min > alarm_min) { + alarm_hour++; + } + } else if (cur_hour == alarm_hour) { + if (alarm_min == -1) { + alarm_min = cur_min; + if (alarm_sec == -1) { + alarm_sec = cur_sec + 1; + } else if (cur_sec > alarm_sec) { + alarm_min++; + } + + if (alarm_sec == SEC_PER_MIN) { + alarm_sec = 0; + alarm_min++; + } + /* wrap to next day, hour is not in don't care mode */ + alarm_min %= MIN_PER_HOUR; + } else if (cur_min == alarm_min) { + if (alarm_sec == -1) { + alarm_sec = cur_sec + 1; + } + /* wrap to next day, hours+minutes not in don't care mode */ + alarm_sec %= SEC_PER_MIN; + } + } + + /* values that are still don't care fire at the next min/sec */ + if (alarm_min == -1) { + alarm_min = 0; + } + if (alarm_sec == -1) { + alarm_sec = 0; + } + + /* keep values in range */ + if (alarm_sec == SEC_PER_MIN) { + alarm_sec = 0; + alarm_min++; + } + if (alarm_min == MIN_PER_HOUR) { + alarm_min = 0; + alarm_hour++; + } + alarm_hour %= HOUR_PER_DAY; + + hour = alarm_hour - cur_hour; + min = hour * MIN_PER_HOUR + alarm_min - cur_min; + sec = min * SEC_PER_MIN + alarm_sec - cur_sec; + return sec <= 0 ? sec + SEC_PER_DAY : sec; +} + +static void rtc_update_timer(void *opaque) +{ + RTCState *s = opaque; + int32_t irqs = REG_C_UF; + int32_t new_irqs; + + assert((s->cmos_data[RTC_REG_A] & 0x60) != 0x60); + + /* UIP might have been latched, update time and clear it. */ + rtc_update_time(s); + s->cmos_data[RTC_REG_A] &= ~REG_A_UIP; + + if (qemu_clock_get_ns(rtc_clock) >= s->next_alarm_time) { + 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, hwaddr addr, + uint64_t data, unsigned size) +{ + RTCState *s = opaque; + + if ((addr & 1) == 0) { + s->cmos_index = data & 0x7f; + } else { + CMOS_DPRINTF("cmos: write index=0x%02x val=0x%02" PRIx64 "\n", + s->cmos_index, data); + switch(s->cmos_index) { + case RTC_SECONDS_ALARM: + case RTC_MINUTES_ALARM: + case RTC_HOURS_ALARM: + s->cmos_data[s->cmos_index] = data; + check_update_timer(s); + break; + case RTC_IBM_PS2_CENTURY_BYTE: + s->cmos_index = RTC_CENTURY; + /* fall through */ + case RTC_CENTURY: + case RTC_SECONDS: + case RTC_MINUTES: + case RTC_HOURS: + case RTC_DAY_OF_WEEK: + case RTC_DAY_OF_MONTH: + case RTC_MONTH: + case RTC_YEAR: + s->cmos_data[s->cmos_index] = data; + /* if in set mode, do not update the time */ + if (rtc_running(s)) { + rtc_set_time(s); + check_update_timer(s); + } + break; + case RTC_REG_A: + if ((data & 0x60) == 0x60) { + if (rtc_running(s)) { + rtc_update_time(s); + } + /* What happens to UIP when divider reset is enabled is + * unclear from the datasheet. Shouldn't matter much + * though. + */ + s->cmos_data[RTC_REG_A] &= ~REG_A_UIP; + } else if (((s->cmos_data[RTC_REG_A] & 0x60) == 0x60) && + (data & 0x70) <= 0x20) { + /* when the divider reset is removed, the first update cycle + * begins one-half second later*/ + if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) { + s->offset = 500000000; + rtc_set_time(s); + } + s->cmos_data[RTC_REG_A] &= ~REG_A_UIP; + } + /* UIP bit is read only */ + s->cmos_data[RTC_REG_A] = (data & ~REG_A_UIP) | + (s->cmos_data[RTC_REG_A] & REG_A_UIP); + periodic_timer_update(s, qemu_clock_get_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 (rtc_running(s)) { + 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->cmos_data[RTC_REG_A] & 0x70) <= 0x20) { + s->offset = get_guest_rtc_ns(s) % NANOSECONDS_PER_SECOND; + rtc_set_time(s); + } + } + /* if an interrupt flag is already set when the interrupt + * becomes enabled, raise an interrupt immediately. */ + if (data & s->cmos_data[RTC_REG_C] & REG_C_MASK) { + s->cmos_data[RTC_REG_C] |= REG_C_IRQF; + qemu_irq_raise(s->irq); + } else { + s->cmos_data[RTC_REG_C] &= ~REG_C_IRQF; + qemu_irq_lower(s->irq); + } + s->cmos_data[RTC_REG_B] = data; + periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + check_update_timer(s); + break; + case RTC_REG_C: + case RTC_REG_D: + /* cannot write to them */ + break; + default: + s->cmos_data[s->cmos_index] = data; + break; + } + } +} + +static inline int rtc_to_bcd(RTCState *s, int a) +{ + if (s->cmos_data[RTC_REG_B] & REG_B_DM) { + return a; + } else { + return ((a / 10) << 4) | (a % 10); + } +} + +static inline int rtc_from_bcd(RTCState *s, int a) +{ + if ((a & 0xc0) == 0xc0) { + return -1; + } + if (s->cmos_data[RTC_REG_B] & REG_B_DM) { + return a; + } else { + return ((a >> 4) * 10) + (a & 0x0f); + } +} + +static void rtc_get_time(RTCState *s, struct tm *tm) +{ + tm->tm_sec = rtc_from_bcd(s, s->cmos_data[RTC_SECONDS]); + tm->tm_min = rtc_from_bcd(s, s->cmos_data[RTC_MINUTES]); + tm->tm_hour = rtc_from_bcd(s, s->cmos_data[RTC_HOURS] & 0x7f); + if (!(s->cmos_data[RTC_REG_B] & REG_B_24H)) { + tm->tm_hour %= 12; + if (s->cmos_data[RTC_HOURS] & 0x80) { + tm->tm_hour += 12; + } + } + tm->tm_wday = rtc_from_bcd(s, s->cmos_data[RTC_DAY_OF_WEEK]) - 1; + tm->tm_mday = rtc_from_bcd(s, s->cmos_data[RTC_DAY_OF_MONTH]); + 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 + + rtc_from_bcd(s, s->cmos_data[RTC_CENTURY]) * 100 - 1900; +} + +static QLIST_HEAD(, RTCState) rtc_devices = + QLIST_HEAD_INITIALIZER(rtc_devices); + +#ifdef TARGET_I386 +void qmp_rtc_reset_reinjection(Error **errp) +{ + RTCState *s; + + QLIST_FOREACH(s, &rtc_devices, link) { + s->irq_coalesced = 0; + } +} +#endif + +static void rtc_set_time(RTCState *s) +{ + struct tm tm; + + rtc_get_time(s, &tm); + s->base_rtc = mktimegm(&tm); + s->last_update = qemu_clock_get_ns(rtc_clock); + + qapi_event_send_rtc_change(qemu_timedate_diff(&tm), &error_abort); +} + +static void rtc_set_cmos(RTCState *s, const struct tm *tm) +{ + int year; + + s->cmos_data[RTC_SECONDS] = rtc_to_bcd(s, tm->tm_sec); + s->cmos_data[RTC_MINUTES] = rtc_to_bcd(s, tm->tm_min); + if (s->cmos_data[RTC_REG_B] & REG_B_24H) { + /* 24 hour format */ + s->cmos_data[RTC_HOURS] = rtc_to_bcd(s, tm->tm_hour); + } else { + /* 12 hour format */ + int h = (tm->tm_hour % 12) ? tm->tm_hour % 12 : 12; + s->cmos_data[RTC_HOURS] = rtc_to_bcd(s, h); + if (tm->tm_hour >= 12) + s->cmos_data[RTC_HOURS] |= 0x80; + } + s->cmos_data[RTC_DAY_OF_WEEK] = rtc_to_bcd(s, tm->tm_wday + 1); + s->cmos_data[RTC_DAY_OF_MONTH] = rtc_to_bcd(s, tm->tm_mday); + s->cmos_data[RTC_MONTH] = rtc_to_bcd(s, tm->tm_mon + 1); + year = tm->tm_year + 1900 - s->base_year; + s->cmos_data[RTC_YEAR] = rtc_to_bcd(s, year % 100); + s->cmos_data[RTC_CENTURY] = rtc_to_bcd(s, year / 100); +} + +static void rtc_update_time(RTCState *s) +{ + struct tm ret; + time_t guest_sec; + int64_t guest_nsec; + + guest_nsec = get_guest_rtc_ns(s); + guest_sec = guest_nsec / NANOSECONDS_PER_SECOND; + gmtime_r(&guest_sec, &ret); + + /* Is SET flag of Register B disabled? */ + if ((s->cmos_data[RTC_REG_B] & REG_B_SET) == 0) { + rtc_set_cmos(s, &ret); + } +} + +static int update_in_progress(RTCState *s) +{ + int64_t guest_nsec; + + if (!rtc_running(s)) { + return 0; + } + if (timer_pending(s->update_timer)) { + int64_t next_update_time = timer_expire_time_ns(s->update_timer); + /* Latch UIP until the timer expires. */ + if (qemu_clock_get_ns(rtc_clock) >= + (next_update_time - UIP_HOLD_LENGTH)) { + s->cmos_data[RTC_REG_A] |= REG_A_UIP; + return 1; + } + } + + guest_nsec = get_guest_rtc_ns(s); + /* UIP bit will be set at last 244us of every second. */ + if ((guest_nsec % NANOSECONDS_PER_SECOND) >= + (NANOSECONDS_PER_SECOND - UIP_HOLD_LENGTH)) { + return 1; + } + return 0; +} + +static uint64_t cmos_ioport_read(void *opaque, hwaddr addr, + unsigned size) +{ + RTCState *s = opaque; + int ret; + if ((addr & 1) == 0) { + return 0xff; + } else { + switch(s->cmos_index) { + case RTC_IBM_PS2_CENTURY_BYTE: + s->cmos_index = RTC_CENTURY; + /* fall through */ + case RTC_CENTURY: + case RTC_SECONDS: + case RTC_MINUTES: + case RTC_HOURS: + case RTC_DAY_OF_WEEK: + case RTC_DAY_OF_MONTH: + case RTC_MONTH: + case RTC_YEAR: + /* if not in set mode, calibrate cmos before + * reading*/ + if (rtc_running(s)) { + 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) && + s->irq_reinject_on_ack_count < RTC_REINJECT_ON_ACK_COUNT) { + s->irq_reinject_on_ack_count++; + s->cmos_data[RTC_REG_C] |= REG_C_IRQF | REG_C_PF; + apic_reset_irq_delivered(); + DPRINTF_C("cmos: injecting on ack\n"); + qemu_irq_raise(s->irq); + if (apic_get_irq_delivered()) { + s->irq_coalesced--; + DPRINTF_C("cmos: coalesced irqs decreased to %d\n", + s->irq_coalesced); + } + } +#endif + break; + default: + ret = s->cmos_data[s->cmos_index]; + break; + } + CMOS_DPRINTF("cmos: read index=0x%02x val=0x%02x\n", + s->cmos_index, ret); + return ret; + } +} + +void rtc_set_memory(ISADevice *dev, int addr, int val) +{ + RTCState *s = MC146818_RTC(dev); + if (addr >= 0 && addr <= 127) + s->cmos_data[addr] = val; +} + +int rtc_get_memory(ISADevice *dev, int addr) +{ + RTCState *s = MC146818_RTC(dev); + assert(addr >= 0 && addr <= 127); + return s->cmos_data[addr]; +} + +static void rtc_set_date_from_host(ISADevice *dev) +{ + RTCState *s = MC146818_RTC(dev); + struct tm tm; + + qemu_get_timedate(&tm, 0); + + s->base_rtc = mktimegm(&tm); + s->last_update = qemu_clock_get_ns(rtc_clock); + s->offset = 0; + + /* set the CMOS date */ + rtc_set_cmos(s, &tm); +} + +static int rtc_post_load(void *opaque, int version_id) +{ + RTCState *s = opaque; + + if (version_id <= 2) { + rtc_set_time(s); + s->offset = 0; + check_update_timer(s); + } + + uint64_t now = qemu_clock_get_ns(rtc_clock); + if (now < s->next_periodic_time || + now > (s->next_periodic_time + get_max_clock_jump())) { + periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + } + +#ifdef TARGET_I386 + if (version_id >= 2) { + if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) { + rtc_coalesced_timer_update(s); + } + } +#endif + return 0; +} + +static bool rtc_irq_reinject_on_ack_count_needed(void *opaque) +{ + RTCState *s = (RTCState *)opaque; + return s->irq_reinject_on_ack_count != 0; +} + +static const VMStateDescription vmstate_rtc_irq_reinject_on_ack_count = { + .name = "mc146818rtc/irq_reinject_on_ack_count", + .version_id = 1, + .minimum_version_id = 1, + .needed = rtc_irq_reinject_on_ack_count_needed, + .fields = (VMStateField[]) { + VMSTATE_UINT16(irq_reinject_on_ack_count, RTCState), + VMSTATE_END_OF_LIST() + } +}; + +static const VMStateDescription vmstate_rtc = { + .name = "mc146818rtc", + .version_id = 3, + .minimum_version_id = 1, + .post_load = rtc_post_load, + .fields = (VMStateField[]) { + VMSTATE_BUFFER(cmos_data, RTCState), + VMSTATE_UINT8(cmos_index, RTCState), + VMSTATE_UNUSED(7*4), + VMSTATE_TIMER_PTR(periodic_timer, RTCState), + VMSTATE_INT64(next_periodic_time, 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_PTR_V(update_timer, RTCState, 3), + VMSTATE_UINT64_V(next_alarm_time, RTCState, 3), + VMSTATE_END_OF_LIST() + }, + .subsections = (const VMStateDescription*[]) { + &vmstate_rtc_irq_reinject_on_ack_count, + NULL + } +}; + +static void rtc_notify_clock_reset(Notifier *notifier, void *data) +{ + RTCState *s = container_of(notifier, RTCState, clock_reset_notifier); + int64_t now = *(int64_t *)data; + + rtc_set_date_from_host(ISA_DEVICE(s)); + periodic_timer_update(s, now); + check_update_timer(s); +#ifdef TARGET_I386 + if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) { + rtc_coalesced_timer_update(s); + } +#endif +} + +/* set CMOS shutdown status register (index 0xF) as S3_resume(0xFE) + BIOS will read it and start S3 resume at POST Entry */ +static void rtc_notify_suspend(Notifier *notifier, void *data) +{ + RTCState *s = container_of(notifier, RTCState, suspend_notifier); + rtc_set_memory(ISA_DEVICE(s), 0xF, 0xFE); +} + +static void rtc_reset(void *opaque) +{ + RTCState *s = 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); + +#ifdef TARGET_I386 + if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) { + s->irq_coalesced = 0; + s->irq_reinject_on_ack_count = 0; + } +#endif +} + +static const MemoryRegionOps cmos_ops = { + .read = cmos_ioport_read, + .write = cmos_ioport_write, + .impl = { + .min_access_size = 1, + .max_access_size = 1, + }, + .endianness = DEVICE_LITTLE_ENDIAN, +}; + +static void rtc_get_date(Object *obj, struct tm *current_tm, Error **errp) +{ + RTCState *s = MC146818_RTC(obj); + + rtc_update_time(s); + rtc_get_time(s, current_tm); +} + +static void rtc_realizefn(DeviceState *dev, Error **errp) +{ + ISADevice *isadev = ISA_DEVICE(dev); + RTCState *s = MC146818_RTC(dev); + int base = 0x70; + + s->cmos_data[RTC_REG_A] = 0x26; + s->cmos_data[RTC_REG_B] = 0x02; + s->cmos_data[RTC_REG_C] = 0x00; + s->cmos_data[RTC_REG_D] = 0x80; + + /* This is for historical reasons. The default base year qdev property + * was set to 2000 for most machine types before the century byte was + * implemented. + * + * This if statement means that the century byte will be always 0 + * (at least until 2079...) for base_year = 1980, but will be set + * correctly for base_year = 2000. + */ + if (s->base_year == 2000) { + s->base_year = 0; + } + + rtc_set_date_from_host(isadev); + +#ifdef TARGET_I386 + switch (s->lost_tick_policy) { + case LOST_TICK_POLICY_SLEW: + s->coalesced_timer = + timer_new_ns(rtc_clock, rtc_coalesced_timer, s); + break; + case LOST_TICK_POLICY_DISCARD: + break; + default: + error_setg(errp, "Invalid lost tick policy."); + return; + } +#endif + + s->periodic_timer = timer_new_ns(rtc_clock, rtc_periodic_timer, s); + s->update_timer = timer_new_ns(rtc_clock, rtc_update_timer, s); + check_update_timer(s); + + s->clock_reset_notifier.notify = rtc_notify_clock_reset; + qemu_clock_register_reset_notifier(rtc_clock, + &s->clock_reset_notifier); + + s->suspend_notifier.notify = rtc_notify_suspend; + qemu_register_suspend_notifier(&s->suspend_notifier); + + memory_region_init_io(&s->io, OBJECT(s), &cmos_ops, s, "rtc", 2); + isa_register_ioport(isadev, &s->io, base); + + qdev_set_legacy_instance_id(dev, base, 3); + qemu_register_reset(rtc_reset, s); + + object_property_add_tm(OBJECT(s), "date", rtc_get_date, NULL); + + object_property_add_alias(qdev_get_machine(), "rtc-time", + OBJECT(s), "date", NULL); +} + +ISADevice *rtc_init(ISABus *bus, int base_year, qemu_irq intercept_irq) +{ + DeviceState *dev; + ISADevice *isadev; + RTCState *s; + + isadev = isa_create(bus, TYPE_MC146818_RTC); + dev = DEVICE(isadev); + s = MC146818_RTC(isadev); + qdev_prop_set_int32(dev, "base_year", base_year); + qdev_init_nofail(dev); + if (intercept_irq) { + s->irq = intercept_irq; + } else { + isa_init_irq(isadev, &s->irq, RTC_ISA_IRQ); + } + QLIST_INSERT_HEAD(&rtc_devices, s, link); + + return isadev; +} + +static Property mc146818rtc_properties[] = { + DEFINE_PROP_INT32("base_year", RTCState, base_year, 1980), + DEFINE_PROP_LOSTTICKPOLICY("lost_tick_policy", RTCState, + lost_tick_policy, LOST_TICK_POLICY_DISCARD), + DEFINE_PROP_END_OF_LIST(), +}; + +static void rtc_class_initfn(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = rtc_realizefn; + dc->vmsd = &vmstate_rtc; + dc->props = mc146818rtc_properties; + /* Reason: needs to be wired up by rtc_init() */ + dc->cannot_instantiate_with_device_add_yet = true; +} + +static void rtc_finalize(Object *obj) +{ + object_property_del(qdev_get_machine(), "rtc", NULL); +} + +static const TypeInfo mc146818rtc_info = { + .name = TYPE_MC146818_RTC, + .parent = TYPE_ISA_DEVICE, + .instance_size = sizeof(RTCState), + .class_init = rtc_class_initfn, + .instance_finalize = rtc_finalize, +}; + +static void mc146818rtc_register_types(void) +{ + type_register_static(&mc146818rtc_info); +} + +type_init(mc146818rtc_register_types) |
