diff --git a/arch/ia64/kernel/topology.c b/arch/ia64/kernel/topology.c
index a2484fc1a06c43482e575888ca1991d45faf43e7..abb17a613b172f2feac86f38981c255d226864ac 100644
--- a/arch/ia64/kernel/topology.c
+++ b/arch/ia64/kernel/topology.c
@@ -27,6 +27,15 @@
 
 static struct ia64_cpu *sysfs_cpus;
 
+void arch_fix_phys_package_id(int num, u32 slot)
+{
+#ifdef CONFIG_SMP
+	if (cpu_data(num)->socket_id == -1)
+		cpu_data(num)->socket_id = slot;
+#endif
+}
+EXPORT_SYMBOL_GPL(arch_fix_phys_package_id);
+
 int arch_register_cpu(int num)
 {
 #if defined (CONFIG_ACPI) && defined (CONFIG_HOTPLUG_CPU)
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index dd28c912e84f7a0927f7b3148dee47f3c8404e72..5241e3ff50803f6048e5084f6c3135678f7465b2 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -603,6 +603,15 @@ static int acpi_processor_get_info(struct acpi_processor *pr, unsigned has_uid)
 		request_region(pr->throttling.address, 6, "ACPI CPU throttle");
 	}
 
+	/*
+	 * If ACPI describes a slot number for this CPU, we can use it
+	 * ensure we get the right value in the "physical id" field
+	 * of /proc/cpuinfo
+	 */
+	status = acpi_evaluate_object(pr->handle, "_SUN", NULL, &buffer);
+	if (ACPI_SUCCESS(status))
+		arch_fix_phys_package_id(pr->id, object.integer.value);
+
 	return 0;
 }
 
diff --git a/include/asm-ia64/topology.h b/include/asm-ia64/topology.h
index f2f72ef2a8974cc3496dc0fd92435626f708a7e8..32863b3bb1d3e9bdd8cba30a5eb3356b3cbbb467 100644
--- a/include/asm-ia64/topology.h
+++ b/include/asm-ia64/topology.h
@@ -116,6 +116,8 @@ void build_cpu_to_node_map(void);
 #define smt_capable() 				(smp_num_siblings > 1)
 #endif
 
+extern void arch_fix_phys_package_id(int num, u32 slot);
+
 #define pcibus_to_cpumask(bus)	(pcibus_to_node(bus) == -1 ? \
 					CPU_MASK_ALL : \
 					node_to_cpumask(pcibus_to_node(bus)) \
diff --git a/include/asm-x86/topology.h b/include/asm-x86/topology.h
index 0e6d6b03affe13071ab3f6da6b5ffa7b369a0766..4f35a0fb4f22ac5ba6d459a45f4eb8971eb50cac 100644
--- a/include/asm-x86/topology.h
+++ b/include/asm-x86/topology.h
@@ -193,6 +193,10 @@ extern cpumask_t cpu_coregroup_map(int cpu);
 #define topology_thread_siblings(cpu)		(per_cpu(cpu_sibling_map, cpu))
 #endif
 
+static inline void arch_fix_phys_package_id(int num, u32 slot)
+{
+}
+
 struct pci_bus;
 void set_pci_bus_resources_arch_default(struct pci_bus *b);