			APEI Error INJection
			~~~~~~~~~~~~~~~~~~~~

EINJ provides a hardware error injection mechanism
It is very useful for debugging and testing of other APEI and RAS features.

To use EINJ, make sure the following are enabled in your kernel
configuration:

CONFIG_DEBUG_FS
CONFIG_ACPI_APEI
CONFIG_ACPI_APEI_EINJ

The user interface of EINJ is debug file system, under the
directory apei/einj. The following files are provided.

- available_error_type
  Reading this file returns the error injection capability of the
  platform, that is, which error types are supported. The error type
  definition is as follow, the left field is the error type value, the
  right field is error description.

    0x00000001	Processor Correctable
    0x00000002	Processor Uncorrectable non-fatal
    0x00000004	Processor Uncorrectable fatal
    0x00000008  Memory Correctable
    0x00000010  Memory Uncorrectable non-fatal
    0x00000020  Memory Uncorrectable fatal
    0x00000040	PCI Express Correctable
    0x00000080	PCI Express Uncorrectable fatal
    0x00000100	PCI Express Uncorrectable non-fatal
    0x00000200	Platform Correctable
    0x00000400	Platform Uncorrectable non-fatal
    0x00000800	Platform Uncorrectable fatal

  The format of file contents are as above, except there are only the
  available error type lines.

- error_type
  This file is used to set the error type value. The error type value
  is defined in "available_error_type" description.

- error_inject
  Write any integer to this file to trigger the error
  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.  Only available if param_extension module
  parameter is specified.

- 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.  Only available if param_extension
  module parameter is specified.

Injecting parameter support is a BIOS version specific extension, that
is, it only works on some BIOS version.  If you want to use it, please
make sure your BIOS version has the proper support and specify
"param_extension=y" in module parameter.

For more information about EINJ, please refer to ACPI specification
version 4.0, section 17.5.