summaryrefslogtreecommitdiffstats
path: root/arch/x86/kvm/i8254.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kvm/i8254.c')
-rw-r--r--arch/x86/kvm/i8254.c109
1 files changed, 60 insertions, 49 deletions
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index c13bb92..4d6f0d2 100644
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -98,6 +98,37 @@ static int pit_get_gate(struct kvm *kvm, int channel)
return kvm->arch.vpit->pit_state.channels[channel].gate;
}
+static s64 __kpit_elapsed(struct kvm *kvm)
+{
+ s64 elapsed;
+ ktime_t remaining;
+ struct kvm_kpit_state *ps = &kvm->arch.vpit->pit_state;
+
+ /*
+ * The Counter does not stop when it reaches zero. In
+ * Modes 0, 1, 4, and 5 the Counter ``wraps around'' to
+ * the highest count, either FFFF hex for binary counting
+ * or 9999 for BCD counting, and continues counting.
+ * Modes 2 and 3 are periodic; the Counter reloads
+ * itself with the initial count and continues counting
+ * from there.
+ */
+ remaining = hrtimer_expires_remaining(&ps->pit_timer.timer);
+ elapsed = ps->pit_timer.period - ktime_to_ns(remaining);
+ elapsed = mod_64(elapsed, ps->pit_timer.period);
+
+ return elapsed;
+}
+
+static s64 kpit_elapsed(struct kvm *kvm, struct kvm_kpit_channel_state *c,
+ int channel)
+{
+ if (channel == 0)
+ return __kpit_elapsed(kvm);
+
+ return ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time));
+}
+
static int pit_get_count(struct kvm *kvm, int channel)
{
struct kvm_kpit_channel_state *c =
@@ -107,7 +138,7 @@ static int pit_get_count(struct kvm *kvm, int channel)
WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
- t = ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time));
+ t = kpit_elapsed(kvm, c, channel);
d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
switch (c->mode) {
@@ -137,7 +168,7 @@ static int pit_get_out(struct kvm *kvm, int channel)
WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
- t = ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time));
+ t = kpit_elapsed(kvm, c, channel);
d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
switch (c->mode) {
@@ -193,28 +224,6 @@ static void pit_latch_status(struct kvm *kvm, int channel)
}
}
-static int __pit_timer_fn(struct kvm_kpit_state *ps)
-{
- struct kvm_vcpu *vcpu0 = ps->pit->kvm->vcpus[0];
- struct kvm_kpit_timer *pt = &ps->pit_timer;
-
- if (!atomic_inc_and_test(&pt->pending))
- set_bit(KVM_REQ_PENDING_TIMER, &vcpu0->requests);
-
- if (!pt->reinject)
- atomic_set(&pt->pending, 1);
-
- if (vcpu0 && waitqueue_active(&vcpu0->wq))
- wake_up_interruptible(&vcpu0->wq);
-
- hrtimer_add_expires_ns(&pt->timer, pt->period);
- pt->scheduled = hrtimer_get_expires_ns(&pt->timer);
- if (pt->period)
- ps->channels[0].count_load_time = ktime_get();
-
- return (pt->period == 0 ? 0 : 1);
-}
-
int pit_has_pending_timer(struct kvm_vcpu *vcpu)
{
struct kvm_pit *pit = vcpu->kvm->arch.vpit;
@@ -235,21 +244,6 @@ static void kvm_pit_ack_irq(struct kvm_irq_ack_notifier *kian)
spin_unlock(&ps->inject_lock);
}
-static enum hrtimer_restart pit_timer_fn(struct hrtimer *data)
-{
- struct kvm_kpit_state *ps;
- int restart_timer = 0;
-
- ps = container_of(data, struct kvm_kpit_state, pit_timer.timer);
-
- restart_timer = __pit_timer_fn(ps);
-
- if (restart_timer)
- return HRTIMER_RESTART;
- else
- return HRTIMER_NORESTART;
-}
-
void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu)
{
struct kvm_pit *pit = vcpu->kvm->arch.vpit;
@@ -263,15 +257,26 @@ void __kvm_migrate_pit_timer(struct kvm_vcpu *vcpu)
hrtimer_start_expires(timer, HRTIMER_MODE_ABS);
}
-static void destroy_pit_timer(struct kvm_kpit_timer *pt)
+static void destroy_pit_timer(struct kvm_timer *pt)
{
pr_debug("pit: execute del timer!\n");
hrtimer_cancel(&pt->timer);
}
+static bool kpit_is_periodic(struct kvm_timer *ktimer)
+{
+ struct kvm_kpit_state *ps = container_of(ktimer, struct kvm_kpit_state,
+ pit_timer);
+ return ps->is_periodic;
+}
+
+static struct kvm_timer_ops kpit_ops = {
+ .is_periodic = kpit_is_periodic,
+};
+
static void create_pit_timer(struct kvm_kpit_state *ps, u32 val, int is_period)
{
- struct kvm_kpit_timer *pt = &ps->pit_timer;
+ struct kvm_timer *pt = &ps->pit_timer;
s64 interval;
interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ);
@@ -280,8 +285,14 @@ static void create_pit_timer(struct kvm_kpit_state *ps, u32 val, int is_period)
/* TODO The new value only affected after the retriggered */
hrtimer_cancel(&pt->timer);
- pt->period = (is_period == 0) ? 0 : interval;
- pt->timer.function = pit_timer_fn;
+ pt->period = interval;
+ ps->is_periodic = is_period;
+
+ pt->timer.function = kvm_timer_fn;
+ pt->t_ops = &kpit_ops;
+ pt->kvm = ps->pit->kvm;
+ pt->vcpu_id = 0;
+
atomic_set(&pt->pending, 0);
ps->irq_ack = 1;
@@ -298,23 +309,23 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val)
pr_debug("pit: load_count val is %d, channel is %d\n", val, channel);
/*
- * Though spec said the state of 8254 is undefined after power-up,
- * seems some tricky OS like Windows XP depends on IRQ0 interrupt
- * when booting up.
- * So here setting initialize rate for it, and not a specific number
+ * The largest possible initial count is 0; this is equivalent
+ * to 216 for binary counting and 104 for BCD counting.
*/
if (val == 0)
val = 0x10000;
- ps->channels[channel].count_load_time = ktime_get();
ps->channels[channel].count = val;
- if (channel != 0)
+ if (channel != 0) {
+ ps->channels[channel].count_load_time = ktime_get();
return;
+ }
/* Two types of timer
* mode 1 is one shot, mode 2 is period, otherwise del timer */
switch (ps->channels[0].mode) {
+ case 0:
case 1:
/* FIXME: enhance mode 4 precision */
case 4:
OpenPOWER on IntegriCloud