[RFC PATCH v2 06/19] KVM: arm/arm64: Make timer_arm and timer_disarm helpers more generic

Christoffer Dall
2017-07-17T14:26:46Z

We are about to add an additional soft timer to the arch timer state for
a VCPU and would like to be able to reuse the functions to program and
cancel a timer, so we make them slightly more generic and rename to make
it more clear that these functions work on soft timers and not the
hardware resource that this code is managing.

Signed-off-by: Christoffer Dall <cdall@linaro.org>
---
virt/kvm/arm/arch_timer.c | 33 ++++++++++++++++-----------------
1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 8e89d63..871d8ae 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -56,26 +56,22 @@ u64 kvm_phys_timer_read(void)
return timecounter->cc->read(timecounter->cc);
}

-static bool timer_is_armed(struct arch_timer_cpu *timer)
+static bool soft_timer_is_armed(struct arch_timer_cpu *timer)
{
return timer->armed;
}

-/* timer_arm: as in "arm the timer", not as in ARM the company */
-static void timer_arm(struct arch_timer_cpu *timer, u64 ns)
+static void soft_timer_start(struct hrtimer *hrt, u64 ns)
{
- timer->armed = true;
- hrtimer_start(&timer->timer, ktime_add_ns(ktime_get(), ns),
+ hrtimer_start(hrt, ktime_add_ns(ktime_get(), ns),
HRTIMER_MODE_ABS);
}

-static void timer_disarm(struct arch_timer_cpu *timer)
+static void soft_timer_cancel(struct hrtimer *hrt, struct work_struct *work)
{
- if (timer_is_armed(timer)) {
- hrtimer_cancel(&timer->timer);
- cancel_work_sync(&timer->expired);
- timer->armed = false;
- }
+ hrtimer_cancel(hrt);
+ if (work)
+ cancel_work_sync(work);
}

static irqreturn_t kvm_arch_timer_handler(int irq, void *dev_id)
@@ -271,7 +267,7 @@ static void kvm_timer_emulate(struct kvm_vcpu *vcpu,
return;

/* The timer has not yet expired, schedule a background timer */
- timer_arm(timer, kvm_timer_compute_delta(timer_ctx));
+ soft_timer_start(&timer->timer, kvm_timer_compute_delta(timer_ctx));
}

/*
@@ -285,7 +281,7 @@ void kvm_timer_schedule(struct kvm_vcpu *vcpu)
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);
struct arch_timer_context *ptimer = vcpu_ptimer(vcpu);

- BUG_ON(timer_is_armed(timer));
+ BUG_ON(soft_timer_is_armed(timer));

/*
* No need to schedule a background timer if any guest timer has
@@ -306,13 +302,16 @@ void kvm_timer_schedule(struct kvm_vcpu *vcpu)
* The guest timers have not yet expired, schedule a background timer.
* Set the earliest expiration time among the guest timers.
*/
- timer_arm(timer, kvm_timer_earliest_exp(vcpu));
+ timer->armed = true;
+ soft_timer_start(&timer->timer, kvm_timer_earliest_exp(vcpu));
}

void kvm_timer_unschedule(struct kvm_vcpu *vcpu)
{
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
- timer_disarm(timer);
+
+ soft_timer_cancel(&timer->timer, &timer->expired);
+ timer->armed = false;
}

static void kvm_timer_flush_hwstate_vgic(struct kvm_vcpu *vcpu)
@@ -448,7 +447,7 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu)
* This is to cancel the background timer for the physical timer
* emulation if it is set.
*/
- timer_disarm(timer);
+ soft_timer_cancel(&timer->timer, &timer->expired);

/*
* The guest could have modified the timer registers or the timer
@@ -615,7 +614,7 @@ void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu)
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
struct arch_timer_context *vtimer = vcpu_vtimer(vcpu);

- timer_disarm(timer);
+ soft_timer_cancel(&timer->timer, &timer->expired);
kvm_vgic_unmap_phys_irq(vcpu, vtimer->irq.irq);
}

--
2.9.0