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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v5 10/10] xen/arm: gic_events_need_delivery and irq priorities
gic_events_need_delivery should only return positive if an outstanding
pending irq has an higher priority than the currently active irq and the
priority mask.
Rewrite the function by going through the priority ordered inflight and
lr_queue lists.
In gic_restore_pending_irqs replace lower priority pending (and not
active) irqs in GICH_LRs with higher priority irqs if no more GICH_LRs
are available.
Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
---
Changes in v5:
- improve in code comments;
- use list_for_each_entry_reverse instead of writing my own list walker.
Changes in v4:
- in gic_events_need_delivery go through inflight_irqs and only consider
enabled irqs.
---
xen/arch/arm/gic.c | 77 ++++++++++++++++++++++++++++++++++++++----
xen/include/asm-arm/domain.h | 5 +--
xen/include/asm-arm/gic.h | 3 ++
3 files changed, 76 insertions(+), 9 deletions(-)
diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index 5450c8a..6442d44 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -723,6 +723,7 @@ static void gic_clear_one_lr(struct vcpu *v, int i)
p = irq_to_pending(v, irq);
if ( lr & GICH_LR_ACTIVE )
{
+ set_bit(GIC_IRQ_GUEST_ACTIVE, &p->status);
/* HW interrupts cannot be ACTIVE and PENDING */
if ( p->desc == NULL &&
test_bit(GIC_IRQ_GUEST_ENABLED, &p->status) &&
@@ -737,6 +738,7 @@ static void gic_clear_one_lr(struct vcpu *v, int i)
if ( p->desc != NULL )
p->desc->status &= ~IRQ_INPROGRESS;
clear_bit(GIC_IRQ_GUEST_VISIBLE, &p->status);
+ clear_bit(GIC_IRQ_GUEST_ACTIVE, &p->status);
p->lr = GIC_INVALID_LR;
if ( test_bit(GIC_IRQ_GUEST_PENDING, &p->status) &&
test_bit(GIC_IRQ_GUEST_ENABLED, &p->status))
@@ -765,22 +767,51 @@ void gic_clear_lrs(struct vcpu *v)
static void gic_restore_pending_irqs(struct vcpu *v)
{
- int i;
- struct pending_irq *p, *t;
+ int i = 0, lrs = nr_lrs;
+ struct pending_irq *p, *t, *p_r;
unsigned long flags;
+ if ( list_empty(&v->arch.vgic.lr_pending) )
+ return;
+
+ spin_lock_irqsave(&v->arch.vgic.lock, flags);
+
list_for_each_entry_safe ( p, t, &v->arch.vgic.lr_pending, lr_queue )
{
i = find_first_zero_bit(&this_cpu(lr_mask), nr_lrs);
- if ( i >= nr_lrs ) return;
+ if ( i >= nr_lrs )
+ {
+ list_for_each_entry_reverse( p_r,
+ &v->arch.vgic.inflight_irqs,
+ inflight )
+ {
+ if ( test_bit(GIC_IRQ_GUEST_VISIBLE, &p_r->status) &&
+ !test_bit(GIC_IRQ_GUEST_ACTIVE, &p_r->status) )
+ goto found;
+ if ( &p_r->inflight == p->inflight.next )
+ goto out;
+ }
+ goto out;
+
+found:
+ i = p_r->lr;
+ p_r->lr = GIC_INVALID_LR;
+ set_bit(GIC_IRQ_GUEST_PENDING, &p_r->status);
+ clear_bit(GIC_IRQ_GUEST_VISIBLE, &p_r->status);
+ gic_add_to_lr_pending(v, p_r);
+ }
- spin_lock_irqsave(&v->arch.vgic.lock, flags);
gic_set_lr(i, p, GICH_LR_PENDING);
list_del_init(&p->lr_queue);
set_bit(i, &this_cpu(lr_mask));
- spin_unlock_irqrestore(&v->arch.vgic.lock, flags);
+
+ lrs--;
+ if ( lrs == 0 )
+ break;
}
+out:
+ spin_unlock_irqrestore(&v->arch.vgic.lock, flags);
}
void gic_clear_pending_irqs(struct vcpu *v)
@@ -796,8 +827,40 @@ void gic_clear_pending_irqs(struct vcpu *v)
int gic_events_need_delivery(void)
{
- return (!list_empty(¤t->arch.vgic.lr_pending) ||
- this_cpu(lr_mask));
+ int mask_priority, lrs = nr_lrs;
+ int max_priority = 0xff, active_priority = 0xff;
+ struct vcpu *v = current;
+ struct pending_irq *p;
+ unsigned long flags;
+
+ mask_priority = (GICH[GICH_VMCR] >> GICH_VMCR_PRIORITY_SHIFT) &
GICH_VMCR_PRIORITY_MASK;
+
+ spin_lock_irqsave(&v->arch.vgic.lock, flags);
+
+ /* TODO: We order the guest irqs by priority, but we don't change
+ * the priority of host irqs. */
+ list_for_each_entry( p, &v->arch.vgic.inflight_irqs, inflight )
+ {
+ if ( test_bit(GIC_IRQ_GUEST_ACTIVE, &p->status) )
+ {
+ if ( p->priority < active_priority )
+ active_priority = p->priority;
+ } else if ( test_bit(GIC_IRQ_GUEST_ENABLED, &p->status) ) {
+ if ( p->priority < max_priority )
+ max_priority = p->priority;
+ }
+ lrs--;
+ if ( lrs == 0 )
+ break;
+ }
+
+ spin_unlock_irqrestore(&v->arch.vgic.lock, flags);
+
+ if ( max_priority < active_priority &&
+ (max_priority >> 3) < mask_priority )
+ return 1;
+ else
+ return 0;
}
void gic_inject(void)
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index dcbeba1..696f36c 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -55,8 +55,9 @@ struct pending_irq
*
*/
#define GIC_IRQ_GUEST_PENDING 0
-#define GIC_IRQ_GUEST_VISIBLE 1
-#define GIC_IRQ_GUEST_ENABLED 2
+#define GIC_IRQ_GUEST_ACTIVE 1
+#define GIC_IRQ_GUEST_VISIBLE 2
+#define GIC_IRQ_GUEST_ENABLED 3
unsigned long status;
struct irq_desc *desc; /* only set it the irq corresponds to a physical
irq */
int irq;
diff --git a/xen/include/asm-arm/gic.h b/xen/include/asm-arm/gic.h
index 5a9dc77..5d8f7f1 100644
--- a/xen/include/asm-arm/gic.h
+++ b/xen/include/asm-arm/gic.h
@@ -129,6 +129,9 @@
#define GICH_LR_CPUID_SHIFT 9
#define GICH_VTR_NRLRGS 0x3f
+#define GICH_VMCR_PRIORITY_MASK 0x1f
+#define GICH_VMCR_PRIORITY_SHIFT 27
+
/*
* The minimum GICC_BPR is required to be in the range 0-3. We set
* GICC_BPR to 0 but we must expect that it might be 3. This means we
--
1.7.10.4
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