| Message ID | 20180305160415.16760-48-andre.przywara@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | New VGIC(-v2) implementation | expand |
Hi Andre, On 05/03/18 16:04, Andre Przywara wrote: > To find an unused virtual IRQ number Xen uses a scheme to track used > virtual IRQs. > Implement this interface in the new VGIC to make the Xen core/arch code > happy. > This is actually somewhat VGIC agnostic, so is mostly a copy of the code > from the old VGIC. But it has to live in the VGIC files, so we can't > easily reuse the existing implementation. > > Signed-off-by: Andre Przywara <andre.przywara@linaro.org> Acked-by: Julien Grall <julien.grall@arm.com> Cheers, > --- > Changelog RFC ... v1: > - no changes > > xen/arch/arm/vgic/vgic.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 44 insertions(+) > > diff --git a/xen/arch/arm/vgic/vgic.c b/xen/arch/arm/vgic/vgic.c > index 0bf257c865..e9ef992e1e 100644 > --- a/xen/arch/arm/vgic/vgic.c > +++ b/xen/arch/arm/vgic/vgic.c > @@ -721,6 +721,50 @@ bool vgic_evtchn_irq_pending(struct vcpu *v) > return pending; > } > > +bool vgic_reserve_virq(struct domain *d, unsigned int virq) > +{ > + if ( virq >= vgic_num_irqs(d) ) > + return false; > + > + return !test_and_set_bit(virq, d->arch.vgic.allocated_irqs); > +} > + > +int vgic_allocate_virq(struct domain *d, bool spi) > +{ > + int first, end; > + unsigned int virq; > + > + if ( !spi ) > + { > + /* We only allocate PPIs. SGIs are all reserved */ > + first = 16; > + end = 32; > + } > + else > + { > + first = 32; > + end = vgic_num_irqs(d); > + } > + > + /* > + * There is no spinlock to protect allocated_irqs, therefore > + * test_and_set_bit may fail. If so retry it. > + */ > + do > + { > + virq = find_next_zero_bit(d->arch.vgic.allocated_irqs, end, first); > + if ( virq >= end ) > + return -1; > + } while ( test_and_set_bit(virq, d->arch.vgic.allocated_irqs) ); > + > + return virq; > +} > + > +void vgic_free_virq(struct domain *d, unsigned int virq) > +{ > + clear_bit(virq, d->arch.vgic.allocated_irqs); > +} > + > struct irq_desc *vgic_get_hw_irq_desc(struct domain *d, struct vcpu *v, > unsigned int virq) > { >
diff --git a/xen/arch/arm/vgic/vgic.c b/xen/arch/arm/vgic/vgic.c index 0bf257c865..e9ef992e1e 100644 --- a/xen/arch/arm/vgic/vgic.c +++ b/xen/arch/arm/vgic/vgic.c @@ -721,6 +721,50 @@ bool vgic_evtchn_irq_pending(struct vcpu *v) return pending; } +bool vgic_reserve_virq(struct domain *d, unsigned int virq) +{ + if ( virq >= vgic_num_irqs(d) ) + return false; + + return !test_and_set_bit(virq, d->arch.vgic.allocated_irqs); +} + +int vgic_allocate_virq(struct domain *d, bool spi) +{ + int first, end; + unsigned int virq; + + if ( !spi ) + { + /* We only allocate PPIs. SGIs are all reserved */ + first = 16; + end = 32; + } + else + { + first = 32; + end = vgic_num_irqs(d); + } + + /* + * There is no spinlock to protect allocated_irqs, therefore + * test_and_set_bit may fail. If so retry it. + */ + do + { + virq = find_next_zero_bit(d->arch.vgic.allocated_irqs, end, first); + if ( virq >= end ) + return -1; + } while ( test_and_set_bit(virq, d->arch.vgic.allocated_irqs) ); + + return virq; +} + +void vgic_free_virq(struct domain *d, unsigned int virq) +{ + clear_bit(virq, d->arch.vgic.allocated_irqs); +} + struct irq_desc *vgic_get_hw_irq_desc(struct domain *d, struct vcpu *v, unsigned int virq) {
To find an unused virtual IRQ number Xen uses a scheme to track used virtual IRQs. Implement this interface in the new VGIC to make the Xen core/arch code happy. This is actually somewhat VGIC agnostic, so is mostly a copy of the code from the old VGIC. But it has to live in the VGIC files, so we can't easily reuse the existing implementation. Signed-off-by: Andre Przywara <andre.przywara@linaro.org> --- Changelog RFC ... v1: - no changes xen/arch/arm/vgic/vgic.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+)