diff options
Diffstat (limited to 'hw/timer')
| -rw-r--r-- | hw/timer/mc146818rtc.c | 203 |
1 files changed, 137 insertions, 66 deletions
diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c index 93de3e1cc5..1b8d3d7d4c 100644 --- a/hw/timer/mc146818rtc.c +++ b/hw/timer/mc146818rtc.c @@ -112,7 +112,6 @@ static uint64_t get_guest_rtc_ns(RTCState *s) guest_clock - s->last_update + s->offset; } -#ifdef TARGET_I386 static void rtc_coalesced_timer_update(RTCState *s) { if (s->irq_coalesced == 0) { @@ -121,21 +120,39 @@ static void rtc_coalesced_timer_update(RTCState *s) /* 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, NANOSECONDS_PER_SECOND, RTC_CLOCK_RATE); + periodic_clock_to_ns(s->period / c); timer_mod(s->coalesced_timer, next_clock); } } +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; + } +} + +static bool rtc_policy_slew_deliver_irq(RTCState *s) +{ + apic_reset_irq_delivered(); + qemu_irq_raise(s->irq); + return apic_get_irq_delivered(); +} + 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()) { + if (rtc_policy_slew_deliver_irq(s)) { s->irq_coalesced--; DPRINTF_C("cmos: coalesced irqs decreased to %d\n", s->irq_coalesced); @@ -144,40 +161,101 @@ static void rtc_coalesced_timer(void *opaque) rtc_coalesced_timer_update(s); } +#else +static bool rtc_policy_slew_deliver_irq(RTCState *s) +{ + assert(0); + return false; +} #endif -/* handle periodic timer */ -static void periodic_timer_update(RTCState *s, int64_t current_time) +static uint32_t rtc_periodic_clock_ticks(RTCState *s) { - int period_code, period; - int64_t cur_clock, next_irq_clock; + int period_code; + + if (!(s->cmos_data[RTC_REG_B] & REG_B_PIE)) { + return 0; + } 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 + + return periodic_period_to_clock(period_code); +} + +/* + * handle periodic timer. @old_period indicates the periodic timer update + * is just due to period adjustment. + */ +static void +periodic_timer_update(RTCState *s, int64_t current_time, uint32_t old_period) +{ + uint32_t period; + int64_t cur_clock, next_irq_clock, lost_clock = 0; + + period = rtc_periodic_clock_ticks(s); + + if (period) { /* compute 32 khz clock */ cur_clock = muldiv64(current_time, RTC_CLOCK_RATE, NANOSECONDS_PER_SECOND); - next_irq_clock = (cur_clock & ~(period - 1)) + period; - s->next_periodic_time = muldiv64(next_irq_clock, NANOSECONDS_PER_SECOND, - RTC_CLOCK_RATE) + 1; + /* + * if the periodic timer's update is due to period re-configuration, + * we should count the clock since last interrupt. + */ + if (old_period) { + int64_t last_periodic_clock, next_periodic_clock; + + next_periodic_clock = muldiv64(s->next_periodic_time, + RTC_CLOCK_RATE, NANOSECONDS_PER_SECOND); + last_periodic_clock = next_periodic_clock - old_period; + lost_clock = cur_clock - last_periodic_clock; + assert(lost_clock >= 0); + } + + /* + * s->irq_coalesced can change for two reasons: + * + * a) if one or more periodic timer interrupts have been lost, + * lost_clock will be more that a period. + * + * b) when the period may be reconfigured, we expect the OS to + * treat delayed tick as the new period. So, when switching + * from a shorter to a longer period, scale down the missing, + * because the OS will treat past delayed ticks as longer + * (leftovers are put back into lost_clock). When switching + * to a shorter period, scale up the missing ticks since the + * OS handler will treat past delayed ticks as shorter. + */ + if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) { + uint32_t old_irq_coalesced = s->irq_coalesced; + + s->period = period; + lost_clock += old_irq_coalesced * old_period; + s->irq_coalesced = lost_clock / s->period; + lost_clock %= s->period; + if (old_irq_coalesced != s->irq_coalesced || + old_period != s->period) { + DPRINTF_C("cmos: coalesced irqs scaled from %d to %d, " + "period scaled from %d to %d\n", old_irq_coalesced, + s->irq_coalesced, old_period, s->period); + rtc_coalesced_timer_update(s); + } + } else { + /* + * no way to compensate the interrupt if LOST_TICK_POLICY_SLEW + * is not used, we should make the time progress anyway. + */ + lost_clock = MIN(lost_clock, period); + } + + assert(lost_clock >= 0 && lost_clock <= period); + + next_irq_clock = cur_clock + period - lost_clock; + s->next_periodic_time = periodic_clock_to_ns(next_irq_clock) + 1; timer_mod(s->periodic_timer, s->next_periodic_time); } else { -#ifdef TARGET_I386 s->irq_coalesced = 0; -#endif timer_del(s->periodic_timer); } } @@ -186,25 +264,21 @@ static void rtc_periodic_timer(void *opaque) { RTCState *s = opaque; - periodic_timer_update(s, s->next_periodic_time); + periodic_timer_update(s, s->next_periodic_time, 0); 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_reinject_on_ack_count = 0; + if (!rtc_policy_slew_deliver_irq(s)) { 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); + qemu_irq_raise(s->irq); } } @@ -391,6 +465,8 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, uint64_t data, unsigned size) { RTCState *s = opaque; + uint32_t old_period; + bool update_periodic_timer; if ((addr & 1) == 0) { s->cmos_index = data & 0x7f; @@ -423,6 +499,9 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, } break; case RTC_REG_A: + update_periodic_timer = (s->cmos_data[RTC_REG_A] ^ data) & 0x0f; + old_period = rtc_periodic_clock_ticks(s); + if ((data & 0x60) == 0x60) { if (rtc_running(s)) { rtc_update_time(s); @@ -445,10 +524,19 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, /* 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)); + + if (update_periodic_timer) { + periodic_timer_update(s, qemu_clock_get_ns(rtc_clock), + old_period); + } + check_update_timer(s); break; case RTC_REG_B: + update_periodic_timer = (s->cmos_data[RTC_REG_B] ^ data) + & REG_B_PIE; + old_period = rtc_periodic_clock_ticks(s); + if (data & REG_B_SET) { /* update cmos to when the rtc was stopping */ if (rtc_running(s)) { @@ -475,7 +563,12 @@ static void cmos_ioport_write(void *opaque, hwaddr addr, qemu_irq_lower(s->irq); } s->cmos_data[RTC_REG_B] = data; - periodic_timer_update(s, qemu_clock_get_ns(rtc_clock)); + + if (update_periodic_timer) { + periodic_timer_update(s, qemu_clock_get_ns(rtc_clock), + old_period); + } + check_update_timer(s); break; case RTC_REG_C: @@ -529,20 +622,6 @@ static void rtc_get_time(RTCState *s, struct tm *tm) 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; @@ -662,22 +741,19 @@ static uint64_t cmos_ioport_read(void *opaque, hwaddr addr, 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()) { + if (rtc_policy_slew_deliver_irq(s)) { 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]; @@ -743,17 +819,15 @@ static int rtc_post_load(void *opaque, int version_id) 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)); + periodic_timer_update(s, qemu_clock_get_ns(rtc_clock), 0); } } -#ifdef TARGET_I386 if (version_id >= 2) { if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) { rtc_coalesced_timer_update(s); } } -#endif return 0; } @@ -808,13 +882,12 @@ static void rtc_notify_clock_reset(Notifier *notifier, void *data) int64_t now = *(int64_t *)data; rtc_set_date_from_host(ISA_DEVICE(s)); - periodic_timer_update(s, now); + periodic_timer_update(s, now, 0); 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) @@ -835,12 +908,10 @@ static void rtc_reset(void *opaque) 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 = { @@ -886,19 +957,19 @@ static void rtc_realizefn(DeviceState *dev, Error **errp) rtc_set_date_from_host(isadev); -#ifdef TARGET_I386 switch (s->lost_tick_policy) { +#ifdef TARGET_I386 case LOST_TICK_POLICY_SLEW: s->coalesced_timer = timer_new_ns(rtc_clock, rtc_coalesced_timer, s); break; +#endif 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); |