[PATCH-4.5 v2 02/10] xen/arm: support HW interrupts in gic_set_lr

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

If the irq to be injected is an hardware irq (p->desc != NULL), set
GICH_LR_HW.

Remove the code to EOI a physical interrupt on behalf of the guest
because it has become unnecessary.

Also add a struct vcpu* parameter to gic_set_lr.

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

---

Changes in v2:
- remove the EOI code, now unnecessary;
- do not assume physical IRQ == virtual IRQ;
- refactor gic_set_lr.
---
 xen/arch/arm/gic.c |   52 +++++++++++++++++-----------------------------------
 1 file changed, 17 insertions(+), 35 deletions(-)

diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c
index acf7195..64c8aa7 100644
--- a/xen/arch/arm/gic.c
+++ b/xen/arch/arm/gic.c
@@ -618,20 +618,24 @@ int __init setup_dt_irq(const struct dt_irq *irq, struct irqaction *new)
     return rc;
 }
 
-static inline void gic_set_lr(int lr, unsigned int virtual_irq,
+static inline void gic_set_lr(struct vcpu *v, int lr, unsigned int irq,
         unsigned int state, unsigned int priority)
 {
-    int maintenance_int = GICH_LR_MAINTENANCE_IRQ;
-    struct pending_irq *p = irq_to_pending(current, virtual_irq);
+    struct pending_irq *p = irq_to_pending(v, irq);
+    uint32_t lr_reg;
 
     BUG_ON(lr >= nr_lrs);
     BUG_ON(lr < 0);
     BUG_ON(state & ~(GICH_LR_STATE_MASK<<GICH_LR_STATE_SHIFT));
 
-    GICH[GICH_LR + lr] = state |
-        maintenance_int |
+    lr_reg = state | GICH_LR_MAINTENANCE_IRQ |
         ((priority >> 3) << GICH_LR_PRIORITY_SHIFT) |
-        ((virtual_irq & GICH_LR_VIRTUAL_MASK) << GICH_LR_VIRTUAL_SHIFT);
+        ((irq & GICH_LR_VIRTUAL_MASK) << GICH_LR_VIRTUAL_SHIFT);
+    if ( p->desc != NULL )
+        lr_reg |= GICH_LR_HW |
+            ((p->desc->irq & GICH_LR_PHYSICAL_MASK) << GICH_LR_PHYSICAL_SHIFT);
+
+    GICH[GICH_LR + lr] = lr_reg;
 
     set_bit(GIC_IRQ_GUEST_VISIBLE, &p->status);
     clear_bit(GIC_IRQ_GUEST_PENDING, &p->status);
@@ -666,7 +670,7 @@ void gic_remove_from_queues(struct vcpu *v, unsigned int virtual_irq)
     spin_unlock(&gic.lock);
 }
 
-void gic_set_guest_irq(struct vcpu *v, unsigned int virtual_irq,
+void gic_set_guest_irq(struct vcpu *v, unsigned int irq,
         unsigned int state, unsigned int priority)
 {
     int i;
@@ -679,12 +683,12 @@ void gic_set_guest_irq(struct vcpu *v, unsigned int virtual_irq,
         i = find_first_zero_bit(&this_cpu(lr_mask), nr_lrs);
         if (i < nr_lrs) {
             set_bit(i, &this_cpu(lr_mask));
-            gic_set_lr(i, virtual_irq, state, priority);
+            gic_set_lr(v, i, irq, state, priority);
             goto out;
         }
     }
 
-    gic_add_to_lr_pending(v, virtual_irq, priority);
+    gic_add_to_lr_pending(v, irq, priority);
 
 out:
     spin_unlock_irqrestore(&gic.lock, flags);
@@ -703,7 +707,7 @@ static void gic_restore_pending_irqs(struct vcpu *v)
         if ( i >= nr_lrs ) return;
 
         spin_lock_irqsave(&gic.lock, flags);
-        gic_set_lr(i, p->irq, GICH_LR_PENDING, p->priority);
+        gic_set_lr(v, i, p->irq, GICH_LR_PENDING, p->priority);
         list_del_init(&p->lr_queue);
         set_bit(i, &this_cpu(lr_mask));
         spin_unlock_irqrestore(&gic.lock, flags);
@@ -904,15 +908,9 @@ int gicv_setup(struct domain *d)
 
 }
 
-static void gic_irq_eoi(void *info)
-{
-    int virq = (uintptr_t) info;
-    GICC[GICC_DIR] = virq;
-}
-
 static void maintenance_interrupt(int irq, void *dev_id, struct cpu_user_regs *regs)
 {
-    int i = 0, virq, pirq = -1;
+    int i = 0, virq;
     uint32_t lr;
     struct vcpu *v = current;
     uint64_t eisr = GICH[GICH_EISR0] | (((uint64_t) GICH[GICH_EISR1]) << 32);
@@ -920,10 +918,8 @@ static void maintenance_interrupt(int irq, void *dev_id, struct cpu_user_regs *r
     while ((i = find_next_bit((const long unsigned int *) &eisr,
                               64, i)) < 64) {
         struct pending_irq *p, *p2;
-        int cpu;
         bool_t inflight;
 
-        cpu = -1;
         inflight = 0;
 
         spin_lock_irq(&gic.lock);
@@ -933,12 +929,8 @@ static void maintenance_interrupt(int irq, void *dev_id, struct cpu_user_regs *r
         clear_bit(i, &this_cpu(lr_mask));
 
         p = irq_to_pending(v, virq);
-        if ( p->desc != NULL ) {
+        if ( p->desc != NULL )
             p->desc->status &= ~IRQ_INPROGRESS;
-            /* Assume only one pcpu needs to EOI the irq */
-            cpu = p->desc->arch.eoi_cpu;
-            pirq = p->desc->irq;
-        }
         if ( test_bit(GIC_IRQ_GUEST_PENDING, &p->status) &&
              test_bit(GIC_IRQ_GUEST_ENABLED, &p->status))
         {
@@ -950,7 +942,7 @@ static void maintenance_interrupt(int irq, void *dev_id, struct cpu_user_regs *r
 
         if ( !list_empty(&v->arch.vgic.lr_pending) ) {
             p2 = list_entry(v->arch.vgic.lr_pending.next, typeof(*p2), lr_queue);
-            gic_set_lr(i, p2->irq, GICH_LR_PENDING, p2->priority);
+            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));
         }
@@ -963,16 +955,6 @@ static void maintenance_interrupt(int irq, void *dev_id, struct cpu_user_regs *r
             spin_unlock_irq(&v->arch.vgic.lock);
         }
 
-        if ( p->desc != NULL ) {
-            /* this is not racy because we can't receive another irq of the
-             * same type until we EOI it.  */
-            if ( cpu == smp_processor_id() )
-                gic_irq_eoi((void*)(uintptr_t)pirq);
-            else
-                on_selected_cpus(cpumask_of(cpu),
-                                 gic_irq_eoi, (void*)(uintptr_t)pirq, 0);
-        }
-
         i++;
     }
 }
-- 
1.7.10.4