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);