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-rw-r--r--hw/timer/mc146818rtc.c203
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);
generated by cgit v1.2.3 (git 2.26.2) at 2025-03-19 23:18:47 +0000