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KVM: PIT: remove usage of count_load_time for channel 0

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We can infer elapsed time from hrtimer_expires_remaining.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Marcelo Tosatti 2009-02-23 10:57:40 -03:00 committed by Avi Kivity
parent 5a05d54554
commit fd66842370
1 changed files with 31 additions and 6 deletions
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37
arch/x86/kvm/i8254.c
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@ -98,6 +98,32 @@ 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;
remaining = hrtimer_expires_remaining(&ps->pit_timer.timer);
if (ktime_to_ns(remaining) < 0)
remaining = ktime_set(0, 0);
elapsed = ps->pit_timer.period;
if (ktime_to_ns(remaining) <= ps->pit_timer.period)
elapsed = ps->pit_timer.period - ktime_to_ns(remaining);
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 +133,7 @@ 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 +163,7 @@ 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) {
@ -208,8 +234,6 @@ static int __pit_timer_fn(struct kvm_kpit_state *ps)
wake_up_interruptible(&vcpu0->wq);
hrtimer_add_expires_ns(&pt->timer, pt->period);
if (pt->period)
ps->channels[0].count_load_time = ktime_get();
return (pt->period == 0 ? 0 : 1);
}
@ -305,11 +329,12 @@ static void pit_load_count(struct kvm *kvm, int channel, u32 val)
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 */