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Diffstat (limited to 'arch/x86/xen/apic.c')
-rw-r--r--arch/x86/xen/apic.c33
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/x86/xen/apic.c b/arch/x86/xen/apic.c
new file mode 100644
index 000000000000..ec57bd3818a4
--- /dev/null
+++ b/arch/x86/xen/apic.c
@@ -0,0 +1,33 @@
+#include <linux/init.h>
+
+#include <asm/x86_init.h>
+#include <asm/apic.h>
+#include <asm/xen/hypercall.h>
+
+#include <xen/xen.h>
+#include <xen/interface/physdev.h>
+
+unsigned int xen_io_apic_read(unsigned apic, unsigned reg)
+{
+ struct physdev_apic apic_op;
+ int ret;
+
+ apic_op.apic_physbase = mpc_ioapic_addr(apic);
+ apic_op.reg = reg;
+ ret = HYPERVISOR_physdev_op(PHYSDEVOP_apic_read, &apic_op);
+ if (!ret)
+ return apic_op.value;
+
+ /* fallback to return an emulated IO_APIC values */
+ if (reg == 0x1)
+ return 0x00170020;
+ else if (reg == 0x0)
+ return apic << 24;
+
+ return 0xfd;
+}
+
+void __init xen_init_apic(void)
+{
+ x86_io_apic_ops.read = xen_io_apic_read;
+}