diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 5eb71d22c3d5..59d52e3aef12 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -882,40 +882,10 @@ __init void prefill_possible_map(void)
 		set_cpu_possible(i, true);
 }
 
-static int _acpi_map_lsapic(acpi_handle handle, int *pcpu)
+static int _acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
 {
-	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *obj;
-	struct acpi_madt_local_sapic *lsapic;
 	cpumask_t tmp_map;
-	int cpu, physid;
-
-	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
-		return -EINVAL;
-
-	if (!buffer.length || !buffer.pointer)
-		return -EINVAL;
-
-	obj = buffer.pointer;
-	if (obj->type != ACPI_TYPE_BUFFER)
-	{
-		kfree(buffer.pointer);
-		return -EINVAL;
-	}
-
-	lsapic = (struct acpi_madt_local_sapic *)obj->buffer.pointer;
-
-	if ((lsapic->header.type != ACPI_MADT_TYPE_LOCAL_SAPIC) ||
-	    (!(lsapic->lapic_flags & ACPI_MADT_ENABLED))) {
-		kfree(buffer.pointer);
-		return -EINVAL;
-	}
-
-	physid = ((lsapic->id << 8) | (lsapic->eid));
-
-	kfree(buffer.pointer);
-	buffer.length = ACPI_ALLOCATE_BUFFER;
-	buffer.pointer = NULL;
+	int cpu;
 
 	cpumask_complement(&tmp_map, cpu_present_mask);
 	cpu = cpumask_first(&tmp_map);
@@ -934,9 +904,9 @@ static int _acpi_map_lsapic(acpi_handle handle, int *pcpu)
 }
 
 /* wrapper to silence section mismatch warning */
-int __ref acpi_map_lsapic(acpi_handle handle, int *pcpu)
+int __ref acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
 {
-	return _acpi_map_lsapic(handle, pcpu);
+	return _acpi_map_lsapic(handle, physid, pcpu);
 }
 EXPORT_SYMBOL(acpi_map_lsapic);
 
diff --git a/arch/x86/include/asm/mpspec.h b/arch/x86/include/asm/mpspec.h
index 626cf70082d7..3142a94c7b4b 100644
--- a/arch/x86/include/asm/mpspec.h
+++ b/arch/x86/include/asm/mpspec.h
@@ -94,7 +94,7 @@ static inline void early_reserve_e820_mpc_new(void) { }
 #define default_get_smp_config x86_init_uint_noop
 #endif
 
-void generic_processor_info(int apicid, int version);
+int generic_processor_info(int apicid, int version);
 #ifdef CONFIG_ACPI
 extern void mp_register_ioapic(int id, u32 address, u32 gsi_base);
 extern void mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger,
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 40c76604199f..1f7c0746611f 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -189,24 +189,31 @@ static int __init acpi_parse_madt(struct acpi_table_header *table)
 	return 0;
 }
 
-static void acpi_register_lapic(int id, u8 enabled)
+/**
+ * acpi_register_lapic - register a local apic and generates a logic cpu number
+ * @id: local apic id to register
+ * @enabled: this cpu is enabled or not
+ *
+ * Returns the logic cpu number which maps to the local apic
+ */
+static int acpi_register_lapic(int id, u8 enabled)
 {
 	unsigned int ver = 0;
 
 	if (id >= MAX_LOCAL_APIC) {
 		printk(KERN_INFO PREFIX "skipped apicid that is too big\n");
-		return;
+		return -EINVAL;
 	}
 
 	if (!enabled) {
 		++disabled_cpus;
-		return;
+		return -EINVAL;
 	}
 
 	if (boot_cpu_physical_apicid != -1U)
 		ver = apic_version[boot_cpu_physical_apicid];
 
-	generic_processor_info(id, ver);
+	return generic_processor_info(id, ver);
 }
 
 static int __init
@@ -614,84 +621,27 @@ static void acpi_map_cpu2node(acpi_handle handle, int cpu, int physid)
 #endif
 }
 
-static int _acpi_map_lsapic(acpi_handle handle, int *pcpu)
+static int _acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
 {
-	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
-	union acpi_object *obj;
-	struct acpi_madt_local_apic *lapic;
-	cpumask_var_t tmp_map, new_map;
-	u8 physid;
 	int cpu;
-	int retval = -ENOMEM;
 
-	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
-		return -EINVAL;
-
-	if (!buffer.length || !buffer.pointer)
-		return -EINVAL;
-
-	obj = buffer.pointer;
-	if (obj->type != ACPI_TYPE_BUFFER ||
-	    obj->buffer.length < sizeof(*lapic)) {
-		kfree(buffer.pointer);
-		return -EINVAL;
-	}
-
-	lapic = (struct acpi_madt_local_apic *)obj->buffer.pointer;
-
-	if (lapic->header.type != ACPI_MADT_TYPE_LOCAL_APIC ||
-	    !(lapic->lapic_flags & ACPI_MADT_ENABLED)) {
-		kfree(buffer.pointer);
-		return -EINVAL;
-	}
-
-	physid = lapic->id;
-
-	kfree(buffer.pointer);
-	buffer.length = ACPI_ALLOCATE_BUFFER;
-	buffer.pointer = NULL;
-	lapic = NULL;
-
-	if (!alloc_cpumask_var(&tmp_map, GFP_KERNEL))
-		goto out;
-
-	if (!alloc_cpumask_var(&new_map, GFP_KERNEL))
-		goto free_tmp_map;
-
-	cpumask_copy(tmp_map, cpu_present_mask);
-	acpi_register_lapic(physid, ACPI_MADT_ENABLED);
-
-	/*
-	 * If acpi_register_lapic successfully generates a new logical cpu
-	 * number, then the following will get us exactly what was mapped
-	 */
-	cpumask_andnot(new_map, cpu_present_mask, tmp_map);
-	if (cpumask_empty(new_map)) {
-		printk ("Unable to map lapic to logical cpu number\n");
-		retval = -EINVAL;
-		goto free_new_map;
+	cpu = acpi_register_lapic(physid, ACPI_MADT_ENABLED);
+	if (cpu < 0) {
+		pr_info(PREFIX "Unable to map lapic to logical cpu number\n");
+		return cpu;
 	}
 
 	acpi_processor_set_pdc(handle);
-
-	cpu = cpumask_first(new_map);
 	acpi_map_cpu2node(handle, cpu, physid);
 
 	*pcpu = cpu;
-	retval = 0;
-
-free_new_map:
-	free_cpumask_var(new_map);
-free_tmp_map:
-	free_cpumask_var(tmp_map);
-out:
-	return retval;
+	return 0;
 }
 
 /* wrapper to silence section mismatch warning */
-int __ref acpi_map_lsapic(acpi_handle handle, int *pcpu)
+int __ref acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
 {
-	return _acpi_map_lsapic(handle, pcpu);
+	return _acpi_map_lsapic(handle, physid, pcpu);
 }
 EXPORT_SYMBOL(acpi_map_lsapic);
 
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index a7eb82d9b012..ed165d657380 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -2107,7 +2107,7 @@ void disconnect_bsp_APIC(int virt_wire_setup)
 	apic_write(APIC_LVT1, value);
 }
 
-void generic_processor_info(int apicid, int version)
+int generic_processor_info(int apicid, int version)
 {
 	int cpu, max = nr_cpu_ids;
 	bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid,
@@ -2127,7 +2127,7 @@ void generic_processor_info(int apicid, int version)
 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
 
 		disabled_cpus++;
-		return;
+		return -ENODEV;
 	}
 
 	if (num_processors >= nr_cpu_ids) {
@@ -2138,7 +2138,7 @@ void generic_processor_info(int apicid, int version)
 			"  Processor %d/0x%x ignored.\n", max, thiscpu, apicid);
 
 		disabled_cpus++;
-		return;
+		return -EINVAL;
 	}
 
 	num_processors++;
@@ -2183,6 +2183,8 @@ void generic_processor_info(int apicid, int version)
 #endif
 	set_cpu_possible(cpu, true);
 	set_cpu_present(cpu, true);
+
+	return cpu;
 }
 
 int hard_smp_processor_id(void)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 357abdc1406a..3c1d6b0c09a4 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -140,15 +140,11 @@ static int acpi_processor_errata_piix4(struct pci_dev *dev)
 	return 0;
 }
 
-static int acpi_processor_errata(struct acpi_processor *pr)
+static int acpi_processor_errata(void)
 {
 	int result = 0;
 	struct pci_dev *dev = NULL;
 
-
-	if (!pr)
-		return -EINVAL;
-
 	/*
 	 * PIIX4
 	 */
@@ -181,7 +177,7 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 	cpu_maps_update_begin();
 	cpu_hotplug_begin();
 
-	ret = acpi_map_lsapic(pr->handle, &pr->id);
+	ret = acpi_map_lsapic(pr->handle, pr->apic_id, &pr->id);
 	if (ret)
 		goto out;
 
@@ -221,10 +217,7 @@ static int acpi_processor_get_info(struct acpi_device *device)
 	static int cpu0_initialized;
 	unsigned long long value;
 
-	if (num_online_cpus() > 1)
-		errata.smp = TRUE;
-
-	acpi_processor_errata(pr);
+	acpi_processor_errata();
 
 	/*
 	 * Check to see if we have bus mastering arbitration control.  This
@@ -248,11 +241,6 @@ static int acpi_processor_get_info(struct acpi_device *device)
 			return -ENODEV;
 		}
 
-		/*
-		 * TBD: Synch processor ID (via LAPIC/LSAPIC structures) on SMP.
-		 *      >>> 'acpi_get_processor_id(acpi_id, &id)' in
-		 *      arch/xxx/acpi.c
-		 */
 		pr->acpi_id = object.processor.proc_id;
 	} else {
 		/*
@@ -270,7 +258,9 @@ static int acpi_processor_get_info(struct acpi_device *device)
 		device_declaration = 1;
 		pr->acpi_id = value;
 	}
-	cpu_index = acpi_get_cpuid(pr->handle, device_declaration, pr->acpi_id);
+	pr->apic_id = acpi_get_apicid(pr->handle, device_declaration,
+					pr->acpi_id);
+	cpu_index = acpi_map_cpuid(pr->apic_id, pr->acpi_id);
 
 	/* Handle UP system running SMP kernel, with no LAPIC in MADT */
 	if (!cpu0_initialized && (cpu_index == -1) &&
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index cf34d903f4fb..b3171f30b319 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -162,16 +162,23 @@ exit:
 	return apic_id;
 }
 
-int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
+int acpi_get_apicid(acpi_handle handle, int type, u32 acpi_id)
 {
-#ifdef CONFIG_SMP
-	int i;
-#endif
-	int apic_id = -1;
+	int apic_id;
 
 	apic_id = map_mat_entry(handle, type, acpi_id);
 	if (apic_id == -1)
 		apic_id = map_madt_entry(type, acpi_id);
+
+	return apic_id;
+}
+
+int acpi_map_cpuid(int apic_id, u32 acpi_id)
+{
+#ifdef CONFIG_SMP
+	int i;
+#endif
+
 	if (apic_id == -1) {
 		/*
 		 * On UP processor, there is no _MAT or MADT table.
@@ -211,6 +218,15 @@ int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
 #endif
 	return -1;
 }
+
+int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
+{
+	int apic_id;
+
+	apic_id = acpi_get_apicid(handle, type, acpi_id);
+
+	return acpi_map_cpuid(apic_id, acpi_id);
+}
 EXPORT_SYMBOL_GPL(acpi_get_cpuid);
 
 static bool __init processor_physically_present(acpi_handle handle)
diff --git a/drivers/acpi/processor_driver.c b/drivers/acpi/processor_driver.c
index e534ba66d5b8..40fc773ab6e0 100644
--- a/drivers/acpi/processor_driver.c
+++ b/drivers/acpi/processor_driver.c
@@ -153,8 +153,7 @@ static int acpi_cpu_soft_notify(struct notifier_block *nfb,
 	return NOTIFY_OK;
 }
 
-static struct notifier_block __refdata acpi_cpu_notifier =
-{
+static struct notifier_block __refdata acpi_cpu_notifier = {
 	    .notifier_call = acpi_cpu_soft_notify,
 };
 
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index 66096d06925e..7816e45f5d5a 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -199,6 +199,7 @@ struct acpi_processor_flags {
 struct acpi_processor {
 	acpi_handle handle;
 	u32 acpi_id;
+	u32 apic_id;
 	u32 id;
 	u32 pblk;
 	int performance_platform_limit;
@@ -314,6 +315,8 @@ static inline int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
 
 /* in processor_core.c */
 void acpi_processor_set_pdc(acpi_handle handle);
+int acpi_get_apicid(acpi_handle, int type, u32 acpi_id);
+int acpi_map_cpuid(int apic_id, u32 acpi_id);
 int acpi_get_cpuid(acpi_handle, int type, u32 acpi_id);
 
 /* in processor_throttling.c */
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index a5db4aeefa36..3bc74141453f 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -116,7 +116,7 @@ void acpi_numa_arch_fixup(void);
 
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 /* Arch dependent functions for cpu hotplug support */
-int acpi_map_lsapic(acpi_handle handle, int *pcpu);
+int acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu);
 int acpi_unmap_lsapic(int cpu);
 #endif /* CONFIG_ACPI_HOTPLUG_CPU */