[Xen-devel,PATCH-4.5,v3,05/12] xen/arm: set GICH_HCR_UIE if all the LRs are in use

Message ID 1393439997-26936-5-git-send-email-stefano.stabellini@eu.citrix.com
State New
Headers show

Commit Message

Stefano Stabellini Feb. 26, 2014, 6:39 p.m.
On return to guest, if there are no free LRs and we still have more
interrupt to inject, set GICH_HCR_UIE so that we are going to receive a
maintenance interrupt when no pending interrupts are present in the LR
registers.
The maintenance interrupt handler won't do anything anymore, but
receiving the interrupt is going to cause gic_inject to be called on
return to guest that is going to clear the old LRs and inject new
interrupts.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

---

Changes in v2:
- disable/enable the GICH_HCR_UIE bit in GICH_HCR;
- only enable GICH_HCR_UIE if this_cpu(lr_mask) == ((1 << nr_lrs) - 1).
---
 xen/arch/arm/gic.c |    6 ++++++
 1 file changed, 6 insertions(+)

Patch

diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index 15e5f91..371ebd8 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -789,6 +789,12 @@  void gic_inject(void)
         vgic_vcpu_inject_irq(current, current->domain->arch.evtchn_irq);
 
     gic_restore_pending_irqs(current);
+
+    if ( !list_empty(&current->arch.vgic.lr_pending) &&
+         this_cpu(lr_mask) == ((1 << nr_lrs) - 1) )
+        GICH[GICH_HCR] |= GICH_HCR_UIE;
+    else
+        GICH[GICH_HCR] &= ~GICH_HCR_UIE;
 }
 
 int gic_route_irq_to_guest(struct domain *d, const struct dt_irq *irq,