[PATCH-4.5 v2 03/10] xen/arm: do not request maintenance_interrupts

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

Do not set GICH_LR_MAINTENANCE_IRQ for every interrupt with set in the
GICH_LR registers.

Introduce a new function, gic_clear_lrs, that goes over the GICH_LR
registers, clear the invalid ones and free the corresponding interrupts
from the inflight queue if appropriate. Add the interrupt to lr_pending
if the GIC_IRQ_GUEST_PENDING is still set.

Call gic_clear_lrs from gic_restore_state and on return to guest
(gic_inject).

Remove the now unused code in maintenance_interrupts and gic_irq_eoi.

In vgic_vcpu_inject_irq, if the target is a vcpu running on another cpu,
send and SGI to it to interrupt it and force it to clear the old LRs.

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

---

Changes in v2:
- simplify gic_clear_lrs.
---
 xen/arch/arm/gic.c  |   99 ++++++++++++++++++++++++++-------------------------
 xen/arch/arm/vgic.c |    3 +-
 2 files changed, 51 insertions(+), 51 deletions(-)

diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index 64c8aa7..ee383bc 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -67,6 +67,8 @@ static DEFINE_PER_CPU(u8, gic_cpu_id);
 /* Maximum cpu interface per GIC */
 #define NR_GIC_CPU_IF 8
 
+static void gic_clear_lrs(struct vcpu *v);
+
 static unsigned int gic_cpu_mask(const cpumask_t *cpumask)
 {
     unsigned int cpu;
@@ -126,6 +128,7 @@ void gic_restore_state(struct vcpu *v)
     GICH[GICH_HCR] = GICH_HCR_EN;
     isb();
 
+    gic_clear_lrs(v);
     gic_restore_pending_irqs(v);
 }
 
@@ -628,8 +631,7 @@ static inline void gic_set_lr(struct vcpu *v, int lr, unsigned int irq,
     BUG_ON(lr < 0);
     BUG_ON(state & ~(GICH_LR_STATE_MASK<<GICH_LR_STATE_SHIFT));
 
-    lr_reg = state | GICH_LR_MAINTENANCE_IRQ |
-        ((priority >> 3) << GICH_LR_PRIORITY_SHIFT) |
+    lr_reg = state | ((priority >> 3) << GICH_LR_PRIORITY_SHIFT) |
         ((irq & GICH_LR_VIRTUAL_MASK) << GICH_LR_VIRTUAL_SHIFT);
     if ( p->desc != NULL )
         lr_reg |= GICH_LR_HW |
@@ -695,6 +697,50 @@ out:
     return;
 }
 
+static void gic_clear_lrs(struct vcpu *v)
+{
+    struct pending_irq *p;
+    int i = 0, irq;
+    uint32_t lr;
+    bool_t inflight;
+
+    ASSERT(!local_irq_is_enabled());
+
+    while ((i = find_next_bit((const long unsigned int *) &this_cpu(lr_mask),
+                              nr_lrs, i)) < nr_lrs) {
+        lr = GICH[GICH_LR + i];
+        if ( !(lr & (GICH_LR_PENDING|GICH_LR_ACTIVE)) )
+        {
+            inflight = 0;
+            GICH[GICH_LR + i] = 0;
+            clear_bit(i, &this_cpu(lr_mask));
+
+            irq = (lr >> GICH_LR_VIRTUAL_SHIFT) & GICH_LR_VIRTUAL_MASK;
+            spin_lock(&gic.lock);
+            p = irq_to_pending(v, irq);
+            if ( p->desc != NULL )
+                p->desc->status &= ~IRQ_INPROGRESS;
+            clear_bit(GIC_IRQ_GUEST_VISIBLE, &p->status);
+            if ( test_bit(GIC_IRQ_GUEST_PENDING, &p->status) &&
+                    test_bit(GIC_IRQ_GUEST_ENABLED, &p->status))
+            {
+                inflight = 1;
+                gic_add_to_lr_pending(v, irq, p->priority);
+            }
+            spin_unlock(&gic.lock);
+            if ( !inflight )
+            {
+                spin_lock(&v->arch.vgic.lock);
+                list_del_init(&p->inflight);
+                spin_unlock(&v->arch.vgic.lock);
+            }
+
+        }
+
+        i++;
+    }
+}
+
 static void gic_restore_pending_irqs(struct vcpu *v)
 {
     int i;
@@ -751,6 +797,8 @@ int gic_events_need_delivery(void)
 
 void gic_inject(void)
 {
+    gic_clear_lrs(current);
+
     if ( vcpu_info(current, evtchn_upcall_pending) )
         vgic_vcpu_inject_irq(current, current->domain->arch.evtchn_irq);
 
@@ -910,53 +958,6 @@ int gicv_setup(struct domain *d)
 
 static void maintenance_interrupt(int irq, void *dev_id, struct cpu_user_regs *regs)
 {
-    int i = 0, virq;
-    uint32_t lr;
-    struct vcpu *v = current;
-    uint64_t eisr = GICH[GICH_EISR0] | (((uint64_t) GICH[GICH_EISR1]) << 32);
-
-    while ((i = find_next_bit((const long unsigned int *) &eisr,
-                              64, i)) < 64) {
-        struct pending_irq *p, *p2;
-        bool_t inflight;
-
-        inflight = 0;
-
-        spin_lock_irq(&gic.lock);
-        lr = GICH[GICH_LR + i];
-        virq = lr & GICH_LR_VIRTUAL_MASK;
-        GICH[GICH_LR + i] = 0;
-        clear_bit(i, &this_cpu(lr_mask));
-
-        p = irq_to_pending(v, virq);
-        if ( p->desc != NULL )
-            p->desc->status &= ~IRQ_INPROGRESS;
-        if ( test_bit(GIC_IRQ_GUEST_PENDING, &p->status) &&
-             test_bit(GIC_IRQ_GUEST_ENABLED, &p->status))
-        {
-            inflight = 1;
-            gic_add_to_lr_pending(v, virq, p->priority);
-        }
-
-        clear_bit(GIC_IRQ_GUEST_VISIBLE, &p->status);
-
-        if ( !list_empty(&v->arch.vgic.lr_pending) ) {
-            p2 = list_entry(v->arch.vgic.lr_pending.next, typeof(*p2), lr_queue);
-            gic_set_lr(v, i, p2->irq, GICH_LR_PENDING, p2->priority);
-            list_del_init(&p2->lr_queue);
-            set_bit(i, &this_cpu(lr_mask));
-        }
-        spin_unlock_irq(&gic.lock);
-
-        if ( !inflight )
-        {
-            spin_lock_irq(&v->arch.vgic.lock);
-            list_del_init(&p->inflight);
-            spin_unlock_irq(&v->arch.vgic.lock);
-        }
-
-        i++;
-    }
 }
 
 void gic_dump_info(struct vcpu *v)
diff --git a/xen/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index 7d10227..da15f4d 100644
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -699,8 +699,7 @@ void vgic_vcpu_inject_irq(struct vcpu *v, unsigned int irq)
         if ( (irq != current->domain->arch.evtchn_irq) ||
              (!test_bit(GIC_IRQ_GUEST_VISIBLE, &n->status)) )
             set_bit(GIC_IRQ_GUEST_PENDING, &n->status);
-        spin_unlock_irqrestore(&v->arch.vgic.lock, flags);
-        return;
+        goto out;
     }
 
     /* vcpu offline */
-- 
1.7.10.4