xen: remap GSIs as pirqs when running as initial domain

Implement xen_register_gsi to setup the correct triggering and polarity
properties of a gsi.
Implement xen_register_pirq to register a particular gsi as pirq and
receive interrupts as events.
Call xen_setup_pirqs to register all the legacy ISA irqs as pirqs.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/arch/x86/include/asm/xen/pci.h b/arch/x86/include/asm/xen/pci.h
index f89a42aff284..2329b3eaf8d3 100644
--- a/arch/x86/include/asm/xen/pci.h
+++ b/arch/x86/include/asm/xen/pci.h
@@ -13,6 +13,13 @@ static inline int pci_xen_hvm_init(void)
         return -1;
 }
 #endif
+#if defined(CONFIG_XEN_DOM0)
+void __init xen_setup_pirqs(void);
+#else
+static inline void __init xen_setup_pirqs(void)
+{
+}
+#endif
 
 #if defined(CONFIG_PCI_MSI)
 #if defined(CONFIG_PCI_XEN)