diff --git a/Documentation/acpi/apei/einj.txt b/Documentation/acpi/apei/einj.txt
index 838b7f0..dfab718 100644
--- a/Documentation/acpi/apei/einj.txt
+++ b/Documentation/acpi/apei/einj.txt
@@ -45,5 +45,15 @@
   injection. Before this, please specify all necessary error
   parameters.
 
+- param1
+  This file is used to set the first error parameter value. Effect of
+  parameter depends on error_type specified. For memory error, this is
+  physical memory address.
+
+- param2
+  This file is used to set the second error parameter value. Effect of
+  parameter depends on error_type specified. For memory error, this is
+  physical memory address mask.
+
 For more information about EINJ, please refer to ACPI specification
 version 4.0, section 17.5.