ACPICA: Add subsystem option to force copy of DSDT to local memory

Optionally copy the entire DSDT to local memory (instead of
simply mapping it.) There are some BIOSs that corrupt or replace
the original DSDT, creating the need for this option. Default is
FALSE, do not copy the DSDT.

https://bugzilla.kernel.org/show_bug.cgi?id=14679

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

drivers/acpi/acpica/tbxface.c

@@ -531,6 +531,16 @@ static acpi_status acpi_tb_load_namespace(void)
 		goto unlock_and_exit;
 	}
 
+	/*
+	 * Optionally copy the entire DSDT to local memory (instead of simply
+	 * mapping it.) There are some BIOSs that corrupt or replace the original
+	 * DSDT, creating the need for this option. Default is FALSE, do not copy
+	 * the DSDT.
+	 */
+	if (acpi_gbl_copy_dsdt_locally) {
+		acpi_tb_copy_dsdt(acpi_gbl_DSDT);
+	}
+
 	/*
 	 * Save the original DSDT header for detection of table corruption
 	 * and/or replacement of the DSDT from outside the OS.