[Xen-changelog] [xen master] ARM: new VGIC: Handle virtual IRQ allocation/reservation

[patchbot@xxxxxxx]

commit fac8124ec1cb2ae433c2fc8d1a9b8ee326e3bea6
Author:     Andre Przywara <andre.przywara@xxxxxxxxxx>
AuthorDate: Wed Feb 7 13:57:39 2018 +0000
Commit:     Stefano Stabellini <sstabellini@xxxxxxxxxx>
CommitDate: Wed Mar 28 11:21:03 2018 -0700

    ARM: new VGIC: Handle virtual IRQ allocation/reservation
    
    To find an unused virtual IRQ number Xen uses a scheme to track used
    virtual IRQs.
    Implement this interface in the new VGIC to make the Xen core/arch code
    happy.
    This is actually somewhat VGIC agnostic, so is mostly a copy of the code
    from the old VGIC. But it has to live in the VGIC files, so we can't
    easily reuse the existing implementation.
    
    Signed-off-by: Andre Przywara <andre.przywara@xxxxxxxxxx>
    Acked-by: Julien Grall <julien.grall@xxxxxxx>
    Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 xen/arch/arm/vgic/vgic.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/xen/arch/arm/vgic/vgic.c b/xen/arch/arm/vgic/vgic.c
index 689faaecaa..0228db0971 100644
--- a/xen/arch/arm/vgic/vgic.c
+++ b/xen/arch/arm/vgic/vgic.c
@@ -715,6 +715,50 @@ bool vgic_evtchn_irq_pending(struct vcpu *v)
     return pending;
 }
 
+bool vgic_reserve_virq(struct domain *d, unsigned int virq)
+{
+    if ( virq >= vgic_num_irqs(d) )
+        return false;
+
+    return !test_and_set_bit(virq, d->arch.vgic.allocated_irqs);
+}
+
+int vgic_allocate_virq(struct domain *d, bool spi)
+{
+    int first, end;
+    unsigned int virq;
+
+    if ( !spi )
+    {
+        /* We only allocate PPIs. SGIs are all reserved */
+        first = 16;
+        end = 32;
+    }
+    else
+    {
+        first = 32;
+        end = vgic_num_irqs(d);
+    }
+
+    /*
+     * There is no spinlock to protect allocated_irqs, therefore
+     * test_and_set_bit may fail. If so retry it.
+     */
+    do
+    {
+        virq = find_next_zero_bit(d->arch.vgic.allocated_irqs, end, first);
+        if ( virq >= end )
+            return -1;
+    } while ( test_and_set_bit(virq, d->arch.vgic.allocated_irqs) );
+
+    return virq;
+}
+
+void vgic_free_virq(struct domain *d, unsigned int virq)
+{
+    clear_bit(virq, d->arch.vgic.allocated_irqs);
+}
+
 struct irq_desc *vgic_get_hw_irq_desc(struct domain *d, struct vcpu *v,
                                       unsigned int virq)
 {
--
generated by git-patchbot for /home/xen/git/xen.git#master

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