| Message ID | 1462531568-9799-17-git-send-email-andre.przywara@arm.com |
|---|---|
| State | Superseded |
| Headers | show |
On 05/06/2016 12:45 PM, Andre Przywara wrote: > From: Christoffer Dall <christoffer.dall@linaro.org> > > Adds the sorting function to cover the case where you have more IRQs > to consider than you have LRs. We now consider priorities. > > Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> > Signed-off-by: Andre Przywara <andre.przywara@arm.com> > --- > virt/kvm/arm/vgic/vgic.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 57 insertions(+) > > diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c > index 92b78a0..4fb20fd 100644 > --- a/virt/kvm/arm/vgic/vgic.c > +++ b/virt/kvm/arm/vgic/vgic.c > @@ -16,6 +16,7 @@ > > #include <linux/kvm.h> > #include <linux/kvm_host.h> > +#include <linux/list_sort.h> > > #include "vgic.h" > > @@ -96,6 +97,62 @@ static struct kvm_vcpu *vgic_target_oracle(struct vgic_irq *irq) > } > > /* > + * The order of items in the ap_lists defines how we'll pack things in LRs as > + * well, the first items in the list being the first things populated in the > + * LRs. > + * > + * A hard rule is that active interrupts can never be pushed out of the LRs > + * (and therefore take priority) since we cannot reliably trap on deactivation > + * of IRQs and therefore they have to be present in the LRs. > + * > + * Otherwise things should be sorted by the priority field and the GIC > + * hardware support will take care of preemption of priority groups etc. > + * > + * Return negative if "a" sorts before "b", 0 to preserve order, and positive > + * to sort "b" before "a". > + */ > +static int vgic_irq_cmp(void *priv, struct list_head *a, struct list_head *b) > +{ > + struct vgic_irq *irqa = container_of(a, struct vgic_irq, ap_list); > + struct vgic_irq *irqb = container_of(b, struct vgic_irq, ap_list); > + bool penda, pendb; > + int ret; > + > + spin_lock(&irqa->irq_lock); > + spin_lock(&irqb->irq_lock); > + > + if (irqa->active || irqb->active) { > + ret = (int)irqb->active - (int)irqa->active; > + goto out; > + } > + > + penda = irqa->enabled && irqa->pending; > + pendb = irqb->enabled && irqb->pending; > + > + if (!penda || !pendb) { > + ret = (int)pendb - (int)penda; > + goto out; > + } > + > + /* Both pending and enabled, sort by priority */ > + ret = irqa->priority - irqb->priority; > +out: > + spin_unlock(&irqb->irq_lock); > + spin_unlock(&irqa->irq_lock); > + return ret; > +} > + > +/* Must be called with the ap_list_lock held */ > +static void vgic_sort_ap_list(struct kvm_vcpu *vcpu) > +{ > + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; > + > + DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock)); > + > + list_sort(NULL, &vgic_cpu->ap_list_head, vgic_irq_cmp); > +} > + > +/* > * Only valid injection if changing level for level-triggered IRQs or for a > * rising edge. > */ > Reviewed-by: Eric Auger <eric.auger@linaro.org> Eric _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c index 92b78a0..4fb20fd 100644 --- a/virt/kvm/arm/vgic/vgic.c +++ b/virt/kvm/arm/vgic/vgic.c @@ -16,6 +16,7 @@ #include <linux/kvm.h> #include <linux/kvm_host.h> +#include <linux/list_sort.h> #include "vgic.h" @@ -96,6 +97,62 @@ static struct kvm_vcpu *vgic_target_oracle(struct vgic_irq *irq) } /* + * The order of items in the ap_lists defines how we'll pack things in LRs as + * well, the first items in the list being the first things populated in the + * LRs. + * + * A hard rule is that active interrupts can never be pushed out of the LRs + * (and therefore take priority) since we cannot reliably trap on deactivation + * of IRQs and therefore they have to be present in the LRs. + * + * Otherwise things should be sorted by the priority field and the GIC + * hardware support will take care of preemption of priority groups etc. + * + * Return negative if "a" sorts before "b", 0 to preserve order, and positive + * to sort "b" before "a". + */ +static int vgic_irq_cmp(void *priv, struct list_head *a, struct list_head *b) +{ + struct vgic_irq *irqa = container_of(a, struct vgic_irq, ap_list); + struct vgic_irq *irqb = container_of(b, struct vgic_irq, ap_list); + bool penda, pendb; + int ret; + + spin_lock(&irqa->irq_lock); + spin_lock(&irqb->irq_lock); + + if (irqa->active || irqb->active) { + ret = (int)irqb->active - (int)irqa->active; + goto out; + } + + penda = irqa->enabled && irqa->pending; + pendb = irqb->enabled && irqb->pending; + + if (!penda || !pendb) { + ret = (int)pendb - (int)penda; + goto out; + } + + /* Both pending and enabled, sort by priority */ + ret = irqa->priority - irqb->priority; +out: + spin_unlock(&irqb->irq_lock); + spin_unlock(&irqa->irq_lock); + return ret; +} + +/* Must be called with the ap_list_lock held */ +static void vgic_sort_ap_list(struct kvm_vcpu *vcpu) +{ + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu; + + DEBUG_SPINLOCK_BUG_ON(!spin_is_locked(&vgic_cpu->ap_list_lock)); + + list_sort(NULL, &vgic_cpu->ap_list_head, vgic_irq_cmp); +} + +/* * Only valid injection if changing level for level-triggered IRQs or for a * rising edge. */