[PATCH 2/5] arm: implement vcpu_mark_events_pending

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

Implement vcpu_mark_events_pending using the vgic to inject INT 63, that
we reserve for Xen usage.
In the future the interrupt used for event injection might be dynamic
and could be written into the device tree.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 xen/arch/arm/domain.c |   11 +++++++++++
 xen/arch/arm/dummy.S  |    1 -
 xen/arch/arm/gic.h    |    3 +++
 3 files changed, 14 insertions(+), 1 deletions(-)

diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 1e5cca5..46edcc6 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -272,6 +272,17 @@ void arch_dump_vcpu_info(struct vcpu *v)
 {
 }
 
+void vcpu_mark_events_pending(struct vcpu *v)
+{
+    int already_pending = test_and_set_bit(
+        0, (unsigned long *)&vcpu_info(v, evtchn_upcall_pending));
+
+    if ( already_pending )
+        return;
+
+	vgic_vcpu_inject_irq(v, VGIC_IRQ_EVTCHN_CALLBACK, 1);
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/arch/arm/dummy.S b/xen/arch/arm/dummy.S
index 3f2cc4b..93f6f53 100644
--- a/xen/arch/arm/dummy.S
+++ b/xen/arch/arm/dummy.S
@@ -31,7 +31,6 @@ DUMMY(arch_vcpu_reset);
 DUMMY(free_vcpu_guest_context);
 DUMMY(sync_vcpu_execstate);
 NOP(update_vcpu_system_time);
-DUMMY(vcpu_mark_events_pending);
 DUMMY(vcpu_show_execution_state);
 
 /* Page Reference & Type Maintenance */
diff --git a/xen/arch/arm/gic.h b/xen/arch/arm/gic.h
index 81c388d..36fdea1 100644
--- a/xen/arch/arm/gic.h
+++ b/xen/arch/arm/gic.h
@@ -121,6 +121,9 @@
 #define GICH_LR_CPUID_SHIFT     9
 #define GICH_VTR_NRLRGS         0x3f
 
+/* XXX: write this into the DT */
+#define VGIC_IRQ_EVTCHN_CALLBACK 63
+
 extern int domain_vgic_init(struct domain *d);
 extern int vcpu_vgic_init(struct vcpu *v);
 extern void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int irq,int virtual);
-- 
1.7.2.5