+acpi_status acpi_tb_is_table_installed(struct acpi_table_desc *new_table_desc)
+{
+ struct acpi_table_desc *table_desc;
+
+ ACPI_FUNCTION_TRACE("tb_is_table_installed");
+
+ /* Get the list descriptor and first table descriptor */
+
+ table_desc = acpi_gbl_table_lists[new_table_desc->type].next;
+
+ /* Examine all installed tables of this type */
+
+ while (table_desc) {
+ /*
+ * If the table lengths match, perform a full bytewise compare. This
+ * means that we will allow tables with duplicate oem_table_id(s), as
+ * long as the tables are different in some way.
+ *
+ * Checking if the table has been loaded into the namespace means that
+ * we don't check for duplicate tables during the initial installation
+ * of tables within the RSDT/XSDT.
+ */
+ if ((table_desc->loaded_into_namespace) &&
+ (table_desc->pointer->length ==
+ new_table_desc->pointer->length)
+ &&
+ (!ACPI_MEMCMP
+ (table_desc->pointer, new_table_desc->pointer,
+ new_table_desc->pointer->length))) {
+ /* Match: this table is already installed */
+
+ ACPI_DEBUG_PRINT((ACPI_DB_TABLES,
+ "Table [%4.4s] already installed: Rev %X oem_table_id [%8.8s]\n",
+ new_table_desc->pointer->signature,
+ new_table_desc->pointer->revision,
+ new_table_desc->pointer->
+ oem_table_id));
+
+ new_table_desc->owner_id = table_desc->owner_id;
+ new_table_desc->installed_desc = table_desc;
+
+ return_ACPI_STATUS(AE_ALREADY_EXISTS);
+ }