Documentation/acpi/apei/einj.txt

   1                         APEI Error INJection
   2                         ~~~~~~~~~~~~~~~~~~~~
   3
   4 EINJ provides a hardware error injection mechanism
   5 It is very useful for debugging and testing of other APEI and RAS features.
   6
   7 To use EINJ, make sure the following are enabled in your kernel
   8 configuration:
   9
  10 CONFIG_DEBUG_FS
  11 CONFIG_ACPI_APEI
  12 CONFIG_ACPI_APEI_EINJ
  13
  14 The user interface of EINJ is debug file system, under the
  15 directory apei/einj. The following files are provided.
  16
  17 - available_error_type
  18   Reading this file returns the error injection capability of the
  19   platform, that is, which error types are supported. The error type
  20   definition is as follow, the left field is the error type value, the
  21   right field is error description.
  22
  23     0x00000001  Processor Correctable
  24     0x00000002  Processor Uncorrectable non-fatal
  25     0x00000004  Processor Uncorrectable fatal
  26     0x00000008  Memory Correctable
  27     0x00000010  Memory Uncorrectable non-fatal
  28     0x00000020  Memory Uncorrectable fatal
  29     0x00000040  PCI Express Correctable
  30     0x00000080  PCI Express Uncorrectable fatal
  31     0x00000100  PCI Express Uncorrectable non-fatal
  32     0x00000200  Platform Correctable
  33     0x00000400  Platform Uncorrectable non-fatal
  34     0x00000800  Platform Uncorrectable fatal
  35
  36   The format of file contents are as above, except there are only the
  37   available error type lines.
  38
  39 - error_type
  40   This file is used to set the error type value. The error type value
  41   is defined in "available_error_type" description.
  42
  43 - error_inject
  44   Write any integer to this file to trigger the error
  45   injection. Before this, please specify all necessary error
  46   parameters.
  47
  48 - param1
  49   This file is used to set the first error parameter value. Effect of
  50   parameter depends on error_type specified.
  51
  52 - param2
  53   This file is used to set the second error parameter value. Effect of
  54   parameter depends on error_type specified.
  55
  56 BIOS versions based in the ACPI 4.0 specification have limited options
  57 to control where the errors are injected.  Your BIOS may support an
  58 extension (enabled with the param_extension=1 module parameter, or
  59 boot command line einj.param_extension=1). This allows the address
  60 and mask for memory injections to be specified by the param1 and
  61 param2 files in apei/einj.
  62
  63 BIOS versions using the ACPI 5.0 specification have more control over
  64 the target of the injection. For processor related errors (type 0x1,
  65 0x2 and 0x4) the APICID of the target should be provided using the
  66 param1 file in apei/einj. For memory errors (type 0x8, 0x10 and 0x20)
  67 the address is set using param1 with a mask in param2 (0x0 is equivalent
  68 to all ones). For PCI express errors (type 0x40, 0x80 and 0x100) the
  69 segment, bus, device and function are specified using param1:
  70
  71          31     24 23    16 15    11 10      8  7        0
  72         +-------------------------------------------------+
  73         | segment |   bus  | device | function | reserved |
  74         +-------------------------------------------------+
  75
  76 An ACPI 5.0 BIOS may also allow vendor specific errors to be injected.
  77 In this case a file named vendor will contain identifying information
  78 from the BIOS that hopefully will allow an application wishing to use
  79 the vendor specific extension to tell that they are running on a BIOS
  80 that supports it. All vendor extensions have the 0x80000000 bit set in
  81 error_type. A file vendor_flags controls the interpretation of param1
  82 and param2 (1 = PROCESSOR, 2 = MEMORY, 4 = PCI). See your BIOS vendor
  83 documentation for details (and expect changes to this API if vendors
  84 creativity in using this feature expands beyond our expectations).
  85
  86 Example:
  87 # cd /sys/kernel/debug/apei/einj
  88 # cat available_error_type              # See which errors can be injected
  89 0x00000002      Processor Uncorrectable non-fatal
  90 0x00000008      Memory Correctable
  91 0x00000010      Memory Uncorrectable non-fatal
  92 # echo 0x12345000 > param1              # Set memory address for injection
  93 # echo 0xfffffffffffff000 > param2      # Mask - anywhere in this page
  94 # echo 0x8 > error_type                 # Choose correctable memory error
  95 # echo 1 > error_inject                 # Inject now
  96
  97
  98 For more information about EINJ, please refer to ACPI specification
  99 version 4.0, section 17.5 and ACPI 5.0, section 18.6.