1 files changed, 79 insertions, 0 deletions

diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index f9f23fdd96a1..f27c709186c1 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -581,8 +581,87 @@ static struct acpi_scan_handler processor_container_handler = {
 	.attach = acpi_processor_container_attach,
 };
 
+/* The number of the unique processor IDs */
+static int nr_unique_ids __initdata;
+
+/* The number of the duplicate processor IDs */
+static int nr_duplicate_ids __initdata;
+
+/* Used to store the unique processor IDs */
+static int unique_processor_ids[] __initdata = {
+	[0 ... NR_CPUS - 1] = -1,
+};
+
+/* Used to store the duplicate processor IDs */
+static int duplicate_processor_ids[] __initdata = {
+	[0 ... NR_CPUS - 1] = -1,
+};
+
+static void __init processor_validated_ids_update(int proc_id)
+{
+	int i;
+
+	if (nr_unique_ids == NR_CPUS||nr_duplicate_ids == NR_CPUS)
+		return;
+
+	/*
+	 * Firstly, compare the proc_id with duplicate IDs, if the proc_id is
+	 * already in the IDs, do nothing.
+	 */
+	for (i = 0; i < nr_duplicate_ids; i++) {
+		if (duplicate_processor_ids[i] == proc_id)
+			return;
+	}
+
+	/*
+	 * Secondly, compare the proc_id with unique IDs, if the proc_id is in
+	 * the IDs, put it in the duplicate IDs.
+	 */
+	for (i = 0; i < nr_unique_ids; i++) {
+		if (unique_processor_ids[i] == proc_id) {
+			duplicate_processor_ids[nr_duplicate_ids] = proc_id;
+			nr_duplicate_ids++;
+			return;
+		}
+	}
+
+	/*
+	 * Lastly, the proc_id is a unique ID, put it in the unique IDs.
+	 */
+	unique_processor_ids[nr_unique_ids] = proc_id;
+	nr_unique_ids++;
+}
+
+static acpi_status __init acpi_processor_ids_walk(acpi_handle handle,
+						  u32 lvl,
+						  void *context,
+						  void **rv)
+{
+	acpi_status status;
+	union acpi_object object = { 0 };
+	struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
+
+	status = acpi_evaluate_object(handle, NULL, NULL, &buffer);
+	if (ACPI_FAILURE(status))
+		acpi_handle_info(handle, "Not get the processor object\n");
+	else
+		processor_validated_ids_update(object.processor.proc_id);
+
+	return AE_OK;
+}
+
+static void __init acpi_processor_check_duplicates(void)
+{
+	/* Search all processor nodes in ACPI namespace */
+	acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
+						ACPI_UINT32_MAX,
+						acpi_processor_ids_walk,
+						NULL, NULL, NULL);
+}
+
 void __init acpi_processor_init(void)
 {
+	acpi_processor_check_duplicates();
 	acpi_scan_add_handler_with_hotplug(&processor_handler, "processor");
 	acpi_scan_add_handler(&processor_container_handler);
 }