Documentation / acpi / apei / einj.txt
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Based on kernel version 3.9. Page generated on 2013-05-02 22:54 EST.
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 - notrigger 57 The EINJ mechanism is a two step process. First inject the error, then 58 perform some actions to trigger it. Setting "notrigger" to 1 skips the 59 trigger phase, which *may* allow the user to cause the error in some other 60 context by a simple access to the cpu, memory location, or device that is 61 the target of the error injection. Whether this actually works depends 62 on what operations the BIOS actually includes in the trigger phase. 63 64 BIOS versions based in the ACPI 4.0 specification have limited options 65 to control where the errors are injected. Your BIOS may support an 66 extension (enabled with the param_extension=1 module parameter, or 67 boot command line einj.param_extension=1). This allows the address 68 and mask for memory injections to be specified by the param1 and 69 param2 files in apei/einj. 70 71 BIOS versions using the ACPI 5.0 specification have more control over 72 the target of the injection. For processor related errors (type 0x1, 73 0x2 and 0x4) the APICID of the target should be provided using the 74 param1 file in apei/einj. For memory errors (type 0x8, 0x10 and 0x20) 75 the address is set using param1 with a mask in param2 (0x0 is equivalent 76 to all ones). For PCI express errors (type 0x40, 0x80 and 0x100) the 77 segment, bus, device and function are specified using param1: 78 79 31 24 23 16 15 11 10 8 7 0 80 +-------------------------------------------------+ 81 | segment | bus | device | function | reserved | 82 +-------------------------------------------------+ 83 84 An ACPI 5.0 BIOS may also allow vendor specific errors to be injected. 85 In this case a file named vendor will contain identifying information 86 from the BIOS that hopefully will allow an application wishing to use 87 the vendor specific extension to tell that they are running on a BIOS 88 that supports it. All vendor extensions have the 0x80000000 bit set in 89 error_type. A file vendor_flags controls the interpretation of param1 90 and param2 (1 = PROCESSOR, 2 = MEMORY, 4 = PCI). See your BIOS vendor 91 documentation for details (and expect changes to this API if vendors 92 creativity in using this feature expands beyond our expectations). 93 94 Example: 95 # cd /sys/kernel/debug/apei/einj 96 # cat available_error_type # See which errors can be injected 97 0x00000002 Processor Uncorrectable non-fatal 98 0x00000008 Memory Correctable 99 0x00000010 Memory Uncorrectable non-fatal 100 # echo 0x12345000 > param1 # Set memory address for injection 101 # echo 0xfffffffffffff000 > param2 # Mask - anywhere in this page 102 # echo 0x8 > error_type # Choose correctable memory error 103 # echo 1 > error_inject # Inject now 104 105 106 For more information about EINJ, please refer to ACPI specification 107 version 4.0, section 17.5 and ACPI 5.0, section 18.6.
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