1 files changed, 43 insertions, 0 deletions
diff --git a/arch/x86/kernel/apic/apic_common.c b/arch/x86/kernel/apic/apic_common.c
new file mode 100644
index 000000000000..2ed3b5c88c7f
--- /dev/null
+++ b/arch/x86/kernel/apic/apic_common.c
@@ -0,0 +1,43 @@
+/*
+ * Common functions shared between the various APIC flavours
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+#include <linux/irq.h>
+#include <linux/kvm_types.h>
+#include <asm/apic.h>
+
+#include "local.h"
+
+u32 apic_default_calc_apicid(unsigned int cpu)
+{
+	return per_cpu(x86_cpu_to_apicid, cpu);
+}
+
+u32 apic_flat_calc_apicid(unsigned int cpu)
+{
+	return 1U << cpu;
+}
+
+u32 default_cpu_present_to_apicid(int mps_cpu)
+{
+	if (mps_cpu < nr_cpu_ids && cpu_present(mps_cpu))
+		return (int)per_cpu(x86_cpu_to_apicid, mps_cpu);
+	else
+		return BAD_APICID;
+}
+EXPORT_SYMBOL_FOR_KVM(default_cpu_present_to_apicid);
+
+/*
+ * Set up the logical destination ID when the APIC operates in logical
+ * destination mode.
+ */
+void default_init_apic_ldr(void)
+{
+	unsigned long val;
+
+	apic_write(APIC_DFR, APIC_DFR_FLAT);
+	val = apic_read(APIC_LDR) & ~APIC_LDR_MASK;
+	val |= SET_APIC_LOGICAL_ID(1UL << smp_processor_id());
+	apic_write(APIC_LDR, val);
+}