diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 42a93621f5b0..951f093a96fe 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1407,9 +1407,21 @@ __init void prefill_possible_map(void)
 {
 	int i, possible;
 
-	/* no processor from mptable or madt */
-	if (!num_processors)
-		num_processors = 1;
+	/* No boot processor was found in mptable or ACPI MADT */
+	if (!num_processors) {
+		int apicid = boot_cpu_physical_apicid;
+		int cpu = hard_smp_processor_id();
+
+		pr_warn("Boot CPU (id %d) not listed by BIOS\n", cpu);
+
+		/* Make sure boot cpu is enumerated */
+		if (apic->cpu_present_to_apicid(0) == BAD_APICID &&
+		    apic->apic_id_valid(apicid))
+			generic_processor_info(apicid, boot_cpu_apic_version);
+
+		if (!num_processors)
+			num_processors = 1;
+	}
 
 	i = setup_max_cpus ?: 1;
 	if (setup_possible_cpus == -1) {