diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 2c44989..067ef44 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -887,7 +887,7 @@ static int _acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
 }
 
 /* wrapper to silence section mismatch warning */
-int __ref acpi_map_cpu(acpi_handle handle, int physid, int *pcpu)
+int __ref acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, int *pcpu)
 {
 	return _acpi_map_lsapic(handle, physid, pcpu);
 }
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 3d525c6..e4f8582 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -757,7 +757,7 @@ static int _acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
 }
 
 /* wrapper to silence section mismatch warning */
-int __ref acpi_map_cpu(acpi_handle handle, int physid, int *pcpu)
+int __ref acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, int *pcpu)
 {
 	return _acpi_map_lsapic(handle, physid, pcpu);
 }
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 1020b1b..58f335c 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -170,7 +170,7 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr)
 	acpi_status status;
 	int ret;
 
-	if (pr->phys_id == -1)
+	if (pr->phys_id == PHYS_CPUID_INVALID)
 		return -ENODEV;
 
 	status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
@@ -215,7 +215,8 @@ static int acpi_processor_get_info(struct acpi_device *device)
 	union acpi_object object = { 0 };
 	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
 	struct acpi_processor *pr = acpi_driver_data(device);
-	int phys_id, cpu_index, device_declaration = 0;
+	phys_cpuid_t phys_id;
+	int cpu_index, device_declaration = 0;
 	acpi_status status = AE_OK;
 	static int cpu0_initialized;
 	unsigned long long value;
@@ -263,7 +264,7 @@ static int acpi_processor_get_info(struct acpi_device *device)
 	}
 
 	phys_id = acpi_get_phys_id(pr->handle, device_declaration, pr->acpi_id);
-	if (phys_id < 0)
+	if (phys_id == PHYS_CPUID_INVALID)
 		acpi_handle_debug(pr->handle, "failed to get CPU physical ID.\n");
 	pr->phys_id = phys_id;
 
diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
index 7962651..51cc299 100644
--- a/drivers/acpi/processor_core.c
+++ b/drivers/acpi/processor_core.c
@@ -32,7 +32,7 @@ static struct acpi_table_madt *get_madt_table(void)
 }
 
 static int map_lapic_id(struct acpi_subtable_header *entry,
-		 u32 acpi_id, int *apic_id)
+		 u32 acpi_id, phys_cpuid_t *apic_id)
 {
 	struct acpi_madt_local_apic *lapic =
 		container_of(entry, struct acpi_madt_local_apic, header);
@@ -48,7 +48,7 @@ static int map_lapic_id(struct acpi_subtable_header *entry,
 }
 
 static int map_x2apic_id(struct acpi_subtable_header *entry,
-			 int device_declaration, u32 acpi_id, int *apic_id)
+		int device_declaration, u32 acpi_id, phys_cpuid_t *apic_id)
 {
 	struct acpi_madt_local_x2apic *apic =
 		container_of(entry, struct acpi_madt_local_x2apic, header);
@@ -65,7 +65,7 @@ static int map_x2apic_id(struct acpi_subtable_header *entry,
 }
 
 static int map_lsapic_id(struct acpi_subtable_header *entry,
-		int device_declaration, u32 acpi_id, int *apic_id)
+		int device_declaration, u32 acpi_id, phys_cpuid_t *apic_id)
 {
 	struct acpi_madt_local_sapic *lsapic =
 		container_of(entry, struct acpi_madt_local_sapic, header);
@@ -83,10 +83,10 @@ static int map_lsapic_id(struct acpi_subtable_header *entry,
 	return 0;
 }
 
-static int map_madt_entry(int type, u32 acpi_id)
+static phys_cpuid_t map_madt_entry(int type, u32 acpi_id)
 {
 	unsigned long madt_end, entry;
-	int phys_id = -1;	/* CPU hardware ID */
+	phys_cpuid_t phys_id = PHYS_CPUID_INVALID;	/* CPU hardware ID */
 	struct acpi_table_madt *madt;
 
 	madt = get_madt_table();
@@ -117,12 +117,12 @@ static int map_madt_entry(int type, u32 acpi_id)
 	return phys_id;
 }
 
-static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
+static phys_cpuid_t map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
 {
 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 	union acpi_object *obj;
 	struct acpi_subtable_header *header;
-	int phys_id = -1;
+	phys_cpuid_t phys_id = PHYS_CPUID_INVALID;
 
 	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
 		goto exit;
@@ -149,27 +149,27 @@ exit:
 	return phys_id;
 }
 
-int acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id)
+phys_cpuid_t acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id)
 {
-	int phys_id;
+	phys_cpuid_t phys_id;
 
 	phys_id = map_mat_entry(handle, type, acpi_id);
-	if (phys_id == -1)
+	if (phys_id == PHYS_CPUID_INVALID)
 		phys_id = map_madt_entry(type, acpi_id);
 
 	return phys_id;
 }
 
-int acpi_map_cpuid(int phys_id, u32 acpi_id)
+int acpi_map_cpuid(phys_cpuid_t phys_id, u32 acpi_id)
 {
 #ifdef CONFIG_SMP
 	int i;
 #endif
 
-	if (phys_id == -1) {
+	if (phys_id == PHYS_CPUID_INVALID) {
 		/*
 		 * On UP processor, there is no _MAT or MADT table.
-		 * So above phys_id is always set to -1.
+		 * So above phys_id is always set to PHYS_CPUID_INVALID.
 		 *
 		 * BIOS may define multiple CPU handles even for UP processor.
 		 * For example,
@@ -190,7 +190,7 @@ int acpi_map_cpuid(int phys_id, u32 acpi_id)
 		if (nr_cpu_ids <= 1 && acpi_id == 0)
 			return acpi_id;
 		else
-			return phys_id;
+			return -1;
 	}
 
 #ifdef CONFIG_SMP
@@ -208,7 +208,7 @@ int acpi_map_cpuid(int phys_id, u32 acpi_id)
 
 int acpi_get_cpuid(acpi_handle handle, int type, u32 acpi_id)
 {
-	int phys_id;
+	phys_cpuid_t phys_id;
 
 	phys_id = acpi_get_phys_id(handle, type, acpi_id);
 
diff --git a/include/acpi/processor.h b/include/acpi/processor.h
index b95dc32..4188a4d 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -196,7 +196,7 @@ struct acpi_processor_flags {
 struct acpi_processor {
 	acpi_handle handle;
 	u32 acpi_id;
-	u32 phys_id;	/* CPU hardware ID such as APIC ID for x86 */
+	phys_cpuid_t phys_id;	/* CPU hardware ID such as APIC ID for x86 */
 	u32 id;		/* CPU logical ID allocated by OS */
 	u32 pblk;
 	int performance_platform_limit;
@@ -310,8 +310,8 @@ static inline int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
 #endif				/* CONFIG_CPU_FREQ */
 
 /* in processor_core.c */
-int acpi_get_phys_id(acpi_handle, int type, u32 acpi_id);
-int acpi_map_cpuid(int phys_id, u32 acpi_id);
+phys_cpuid_t acpi_get_phys_id(acpi_handle, int type, u32 acpi_id);
+int acpi_map_cpuid(phys_cpuid_t phys_id, u32 acpi_id);
 int acpi_get_cpuid(acpi_handle, int type, u32 acpi_id);
 
 /* in processor_pdc.c */
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 24c7aa8..6ec33c5 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -146,9 +146,14 @@ void acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa);
 int acpi_numa_memory_affinity_init (struct acpi_srat_mem_affinity *ma);
 void acpi_numa_arch_fixup(void);
 
+#ifndef PHYS_CPUID_INVALID
+typedef u32 phys_cpuid_t;
+#define PHYS_CPUID_INVALID (phys_cpuid_t)(-1)
+#endif
+
 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 /* Arch dependent functions for cpu hotplug support */
-int acpi_map_cpu(acpi_handle handle, int physid, int *pcpu);
+int acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, int *pcpu);
 int acpi_unmap_cpu(int cpu);
 #endif /* CONFIG_ACPI_HOTPLUG_CPU */
 
